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Antibiotics, Volume 9, Issue 8 (August 2020) – 94 articles

Cover Story (view full-size image): The Earth’s immense oceans are home to a great diversity of biological resources, including copious microorganisms like bacteria that are, still, very much underexplored. In this work, we discuss how some of the greatest health challenges faced by humans, such as the rise of antibiotic resistance in bacteria, pathogenic fungi and parasites, cancer incidence, and viral infection outbreaks, can be tackled by studying the bacteria found in oceans. Moreover, we give an overview of the research pipeline of novel molecules, from the identification of bioactive bacterial crude extracts to the isolation and chemical characterization of the molecules within the framework of the One Health approach. This work demonstrates the current relevance of marine bacteria for the discovery of novel bioactive natural products. View this paper.
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Article
Amoxicillin-Clavulanic Acid Empirical Oral Therapy for the Management of Children with Acute Haematogenous Osteomyelitis
Antibiotics 2020, 9(8), 525; https://doi.org/10.3390/antibiotics9080525 - 18 Aug 2020
Viewed by 1071
Abstract
According to the Guidelines of the European Society of Pediatric Infectious Diseases (ESPID), in low methicillin-resistant Staphylococcus aureus (MRSA) prevalence settings, short intravenous therapy is recommended in uncomplicated cases of acute haematogenous osteomyelitis (AHOM), followed by empirical oral therapy, preferentially with first/second-generation cephalosporin [...] Read more.
According to the Guidelines of the European Society of Pediatric Infectious Diseases (ESPID), in low methicillin-resistant Staphylococcus aureus (MRSA) prevalence settings, short intravenous therapy is recommended in uncomplicated cases of acute haematogenous osteomyelitis (AHOM), followed by empirical oral therapy, preferentially with first/second-generation cephalosporin or dicloxacillin or flucloxacillin. However, several practical issues may arise using some of the first-line antibiotics such as poor palatability or adherence problems. Clinical, laboratory and therapeutic data from children with AHOM hospitalized in one Italian Paediatric Hospital between 2010 and 2019 were retrospectively collected and analyzed. The aim of the study was to highlight the extent of the use and the possible role of amoxicillin-clavulanic acid in the oral treatment of children with AHOM. Two hundred and ten children were included. S.aureus was identified in 42/58 children (72.4% of identified bacteria); 2/42 S.aureus isolates were MRSA (4.8%). No Kingella kingae was identified. Amoxicillin-clavulanic acid was the most commonly used oral drug (60.1%; n = 107/178) and it was associated with clinical cure in all treated children. Overall, four children developed sequelae. One (0.9%) sequela occurred among the 107 children treated with amoxicillin-clavulanic acid. Our results suggest that amoxicillin-clavulanic acid might be an option for oral antibiotic therapy in children with AHOM. Full article
Review
The Pathogenic Role of Actinomyces spp. and Related Organisms in Genitourinary Infections: Discoveries in the New, Modern Diagnostic Era
Antibiotics 2020, 9(8), 524; https://doi.org/10.3390/antibiotics9080524 - 17 Aug 2020
Cited by 4 | Viewed by 1449
Abstract
Actinomycosis is a chronic, suppurative, granulomatous infectious disease, caused by different species of Actinomyces bacteria. To date, 26 validly published Actinomyces species have been described as part of a normal human microbiota or from human clinical specimens. Due to the rapid spread of [...] Read more.
Actinomycosis is a chronic, suppurative, granulomatous infectious disease, caused by different species of Actinomyces bacteria. To date, 26 validly published Actinomyces species have been described as part of a normal human microbiota or from human clinical specimens. Due to the rapid spread of new, modern diagnostic procedures, 13 of 26 of these species have been described in this century and the Actinomycetaceae family has undergone several taxonomic revisions, including the introduction of many novel species termed Actinomyces-like organisms (ALOs). There is scarce data available on the role of these novel bacterial species in various infectious processes in human medicine. The aim of this review is to provide a comprehensive overview of Actinomyces and closely related organisms involved in human diseases—with a special focus on newly described species—in particular their role in genitourinary tract infections in females and males. Full article
(This article belongs to the Special Issue Microbiological and Clinical Aspects of Actinomyces Infections)
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Article
Rapid Antibacterial Activity of Cannabichromenic Acid against Methicillin-Resistant Staphylococcus aureus
Antibiotics 2020, 9(8), 523; https://doi.org/10.3390/antibiotics9080523 - 16 Aug 2020
Cited by 1 | Viewed by 2463
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) has proven to be an imminent threat to public health, intensifying the need for novel therapeutics. Previous evidence suggests that cannabinoids harbour potent antibacterial activity. In this study, a group of previously inaccessible phytocannabinoids and synthetic analogues were examined [...] Read more.
Methicillin-resistant Staphylococcus aureus (MRSA) has proven to be an imminent threat to public health, intensifying the need for novel therapeutics. Previous evidence suggests that cannabinoids harbour potent antibacterial activity. In this study, a group of previously inaccessible phytocannabinoids and synthetic analogues were examined for potential antibacterial activity. The minimum inhibitory concentrations and dynamics of bacterial inhibition, determined through resazurin reduction and time-kill assays, revealed the potent antibacterial activity of the phytocannabinoids against gram-positive antibiotic-resistant bacterial species, including MRSA. One phytocannabinoid, cannabichromenic acid (CBCA), demonstrated faster and more potent bactericidal activity than vancomycin, the currently recommended antibiotic for the treatment of MRSA infections. Such bactericidal activity was sustained against low-and high-dose inoculums as well as exponential- and stationary-phase MRSA cells. Further, mammalian cell viability was maintained in the presence of CBCA. Finally, microscopic evaluation suggests that CBCA may function through the degradation of the bacterial lipid membrane and alteration of the bacterial nucleoid. The results of the current study provide encouraging evidence that cannabinoids may serve as a previously unrecognised resource for the generation of novel antibiotics active against MRSA. Full article
(This article belongs to the Special Issue Methicillin-Resistant Staphylococci)
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Review
Lactoferrin Functionalized Biomaterials: Tools for Prevention of Implant-Associated Infections
Antibiotics 2020, 9(8), 522; https://doi.org/10.3390/antibiotics9080522 - 15 Aug 2020
Cited by 2 | Viewed by 1182
Abstract
Tissue engineering is one of the most important biotechnologies in the biomedical field. It requires the application of the principles of scientific engineering in order to design and build natural or synthetic biomaterials feasible for the maintenance of tissues and organs. Depending on [...] Read more.
Tissue engineering is one of the most important biotechnologies in the biomedical field. It requires the application of the principles of scientific engineering in order to design and build natural or synthetic biomaterials feasible for the maintenance of tissues and organs. Depending on the specific applications, the selection of the proper material remains a significant clinical concern. Implant-associated infection is one of the most severe complications in orthopedic implant surgeries. The treatment of these infections is difficult because the surface of the implant serves not only as a substrate for the formation of the biofilm, but also for the selection of multidrug-resistant bacterial strains. Therefore, a promising new approach for prevention of implant-related infection involves development of new implantable, non-antibiotic-based biomaterials. This review provides a brief overview of antimicrobial peptide-based biomaterials—especially those coated with lactoferrin. Full article
(This article belongs to the Special Issue Antimicrobial Action of Biomaterials)
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Article
Effectiveness of Electronic Guidelines (GERH®) to Improve the Clinical Use of Antibiotics in An Intensive Care Unit
Antibiotics 2020, 9(8), 521; https://doi.org/10.3390/antibiotics9080521 - 15 Aug 2020
Viewed by 1038
Abstract
The objective of the study was to evaluate the capacity of GERH®-derived local resistance maps (LRMs) to predict antibiotic susceptibility profiles and recommend the appropriate empirical treatment for ICU patients with nosocomial infection. Data gathered between 2007 and 2016 were retrospectively [...] Read more.
The objective of the study was to evaluate the capacity of GERH®-derived local resistance maps (LRMs) to predict antibiotic susceptibility profiles and recommend the appropriate empirical treatment for ICU patients with nosocomial infection. Data gathered between 2007 and 2016 were retrospectively studied to compare susceptibility information from antibiograms of microorganisms isolated in blood cultures, lower respiratory tract samples, and urine samples from all ICU patients meeting clinical criteria for infection with the susceptibility mapped by LRMs for these bacterial species. Susceptibility described by LRMs was concordant with in vitro study results in 73.9% of cases. The LRM-predicted outcome agreed with the antibiogram result in >90% of cases infected with the bacteria for which GERH® offers data on susceptibility to daptomycin, vancomycin, teicoplanin, linezolid, and rifampicin. Full adherence to LRM recommendations would have improved the percentage adequacy of empirical prescriptions by 2.2% for lower respiratory tract infections (p = 0.018), 3.1% for bacteremia (p = 0.07), and 5.3% for urinary tract infections (p = 0.142). LRMs may moderately improve the adequacy of empirical antibiotic therapy, especially for lower respiratory tract infections. LRMs recommend appropriate prescriptions in approximately 50% of cases but are less useful in patients with bacteremia or urinary tract infection. Full article
(This article belongs to the Special Issue Surveillance of Antimicrobial Use on Different Levels)
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Article
Strain-Specific Adaptations of Streptococcus mitis-oralis to Serial In Vitro Passage in Daptomycin (DAP): Genotypic and Phenotypic Characteristics
Antibiotics 2020, 9(8), 520; https://doi.org/10.3390/antibiotics9080520 - 15 Aug 2020
Cited by 1 | Viewed by 1128
Abstract
Viridans group streptococci (VGS), especially the Streptococcus mitis-oralis subgroup, are pivotal pathogens in a variety of invasive endovascular infections, including “toxic shock” in neutropenic cancer patients and infective endocarditis (IE). Previously, we showed that the serial in vitro passage of S. mitis-oralis strains [...] Read more.
Viridans group streptococci (VGS), especially the Streptococcus mitis-oralis subgroup, are pivotal pathogens in a variety of invasive endovascular infections, including “toxic shock” in neutropenic cancer patients and infective endocarditis (IE). Previously, we showed that the serial in vitro passage of S. mitis-oralis strains in sublethal daptomycin (DAP) resulted in rapid, high-level and stable DAP-resistance (DAP-R), which is accompanied by distinct changes in several genotypic and phenotypic signatures: (1) the disappearance of two key membrane phospholipids, phosphatidylglycerol (PG) and cardiolipin (CL); (2) increased membrane fluidity; (3) increased positive surface charge; (4) single nucleotide polymorphisms (SNPs) in two loci involved in CL biosynthesis (pgsA; cdsA); and (5) DAP hyperaccumulation. The current study examined these same metrics following in vitro serial DAP passages of a separate well-characterized S. mitis-oralis bloodstream isolate (SF100). Although some metrics seen in prior DAP post-passage strains were recapitulated with SF100 (e.g., pgsA SNPs, enhanced membrane fluidity), we observed the following major differences (comparing the parental versus post-passage variant): (1) no change in PG content; (2) reduced, but not absent, CL, with enhancement in phosphatidic acid (PA) content; (3) an unusual pattern of CL localization; (4) significantly decreased positive surface charge; (5) no difference in DAP accumulation; and (6) no cdsA SNPs. Thus, S. mitis-oralis strains are not “pre-programmed” phenotypically and/or genotypically to adapt in an identical manner during the evolution of the DAP-R. Full article
(This article belongs to the Section Mechanisms of Antibiotic Action)
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Article
Enzybiotics LYSSTAPH-S and LYSDERM-S as Potential Therapeutic Agents for Chronic MRSA Wound Infections
Antibiotics 2020, 9(8), 519; https://doi.org/10.3390/antibiotics9080519 - 15 Aug 2020
Cited by 1 | Viewed by 1209
Abstract
Antibacterial antibiotic therapy has played an important role in the treatment of bacterial infections for almost a century. The increasing resistance of pathogenic bacteria to antibiotics leads to an attempt to use previously neglected antibacterial therapies. Here we provide information on the two [...] Read more.
Antibacterial antibiotic therapy has played an important role in the treatment of bacterial infections for almost a century. The increasing resistance of pathogenic bacteria to antibiotics leads to an attempt to use previously neglected antibacterial therapies. Here we provide information on the two recombinantly modified antistaphylococcal enzymes derived from lysostaphin (LYSSTAPH-S) and endolysin (LYSDERM-S) derived from kayvirus 812F1 whose target sites reside in the bacterial cell wall. LYSSTAPH-S showed a stable antimicrobial effect over 24-h testing, even in concentrations lower than 1 µg/mL across a wide variety of epidemiologically important sequence types (STs) of methicillin-resistant Staphylococcus aureus (MRSA), especially in the stationary phase of growth (status comparable to chronic infections). LYSDERM-S showed a less potent antimicrobial effect that lasted only a few hours at concentrations of 15 μg/mL and higher. Our data indicate that these antimicrobial enzymes could be of substantial help in the treatment of chronic MRSA wound infections. Full article
(This article belongs to the Special Issue Phage Therapy, Lysin Therapy, and Antibiotics, a Trio Due to Come)
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Article
Chemical Profiling and Discrimination of Essential Oils from Six Ferula Species Using GC Analyses Coupled with Chemometrics and Evaluation of Their Antioxidant and Enzyme Inhibitory Potential
Antibiotics 2020, 9(8), 518; https://doi.org/10.3390/antibiotics9080518 - 14 Aug 2020
Cited by 6 | Viewed by 1182
Abstract
The differences in the composition of essential oils obtained from the aerial parts of six Ferula species viz., F. caratavica (Fc), F. kuchistanica (Fk), F. pseudoreoselinum (Fp), F. samarcandica (Fs), F. tenuisecta (Ft) [...] Read more.
The differences in the composition of essential oils obtained from the aerial parts of six Ferula species viz., F. caratavica (Fc), F. kuchistanica (Fk), F. pseudoreoselinum (Fp), F. samarcandica (Fs), F. tenuisecta (Ft) and F. varia (Fv) were detected both qualitatively and semi-quantitatively using GC-MS and GC-FID analyses. One hundred and six metabolites were identified that account for 92.1, 96.43, 87.43, 95.95, 92.90 and 89.48% of Fc, Fk, Fp, Fs, Ft and Fv whole essential oils, respectively. The data from the GC-MS analyses were subjected to unsupervised pattern recognition chemometric analysis utilizing principal component analysis (PCA) to improve the visualization of such differences among the six species. Fk and Ft are very closely related to each other and were gathered together in one cluster. The antioxidant potential was assessed in vitro using different assays including 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), cupric reducing antioxidant capacity (CUPRAC), ferric reducing power (FRAP) and phosphomolybdenum (PM) assays. Ft and Fp exhibited the most notable antioxidant properties as evidenced by their pronounced activities in most of the antioxidant assays performed, followed by Fc. Fk showed the most effective tyrosinase inhibitory potential, which was estimated as 119.67 mgKAE/g oil, while Fp exhibited the most potent α-amylase inhibitory potential, which was equivalent to 2.61 mmol ACAE/g oil. Thus, it was concluded that Ferula species could serve as a promising natural antioxidant drug that could be included in different products and spices to alleviate hyperglycemia and used as a natural ingredient in pharmaceutical cosmetics to counteract hyperpigmentation. Full article
(This article belongs to the Special Issue Chemical Composition and Biological Activities of Essential Oils)
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Article
Melittin from Apis florea Venom as a Promising Therapeutic Agent for Skin Cancer Treatment
Antibiotics 2020, 9(8), 517; https://doi.org/10.3390/antibiotics9080517 - 14 Aug 2020
Cited by 3 | Viewed by 1491
Abstract
Melittin, a major component found in bee venom, is produced by the Apis species of the honey bee. In this study, the effect of melittin derived from Apis florea (Mel-AF), which is a wild honey bee species that is indigenous to Thailand, was [...] Read more.
Melittin, a major component found in bee venom, is produced by the Apis species of the honey bee. In this study, the effect of melittin derived from Apis florea (Mel-AF), which is a wild honey bee species that is indigenous to Thailand, was investigated against human malignant melanoma (A375) cells. In this study, Mel-AF exhibited considerable potential in the anti-proliferative action of A375 cells. Subsequently, the cellular mechanism of Mel-AF that induced cell death was investigated in terms of apoptosis. As a result, gene and protein expression levels, which indicated the activation of cytochrome-c release and caspase-9 expression, eventually triggered the release of the caspase-3 executioner upon Mel-AF. We then determined that apoptosis-mediated cell death was carried out through the intrinsic mitochondrial pathway. Moreover, advanced abilities, including cell motility and invasion, were significantly suppressed. Mel-AF manipulated the actin arrangement via the trapping of stress fibers that were found underneath the membrane, which resulted in the defective actin cytoskeleton organization. Consequently, the expression of EGFR, a binding protein to F-actin, was also found to be suppressed. This outcome strongly supports the effects of Mel-AF in the inhibition of progressive malignant activity through the disruption of actin cytoskeleton-EGFR interaction and the EGFR signaling system. Thus, the findings of our current study indicate the potential usefulness of Mel-AF in cancer treatments as an apoptosis inducer and a potential actin-targeting agent. Full article
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Article
In Vitro Activities of Colistin and Sitafloxacin Combinations against Multidrug-, Carbapenem-, and Colistin-Resistant Acinetobacter baumannii Using the Broth Microdilution Checkerboard and Time-Kill Methods
Antibiotics 2020, 9(8), 516; https://doi.org/10.3390/antibiotics9080516 - 14 Aug 2020
Viewed by 1173
Abstract
Drug-resistant Acinetobacter baumannii (A. baumannii) infections are a critical global problem, with limited treatment choices. This study aims to determine the in vitro activities of colistin–sitafloxacin combinations against multidrug-, carbapenem- and colistin-resistant A. baumannii (MDR-AB, CRAB, CoR-AB, respectively) clinical isolates from tertiary [...] Read more.
Drug-resistant Acinetobacter baumannii (A. baumannii) infections are a critical global problem, with limited treatment choices. This study aims to determine the in vitro activities of colistin–sitafloxacin combinations against multidrug-, carbapenem- and colistin-resistant A. baumannii (MDR-AB, CRAB, CoR-AB, respectively) clinical isolates from tertiary care hospitals. We used the broth microdilution checkerboard and time-kill methods in this study. Synergy was found using both methods. The colistin–sitafloxacin combination showed synergy in MDR-AB, CRAB, and CoR-AB isolates (3.4%, 3.1%, and 20.9%, respectively). No antagonism was found in any type of drug-resistant isolate. The majority of CoR-AB isolates became susceptible to colistin (95.4%). The time-kill method also showed that this combination could suppress regrowth back to the initial inocula of all representative isolates. Our results demonstrated that the colistin–sitafloxacin combination might be an interesting option for the treatment of drug-resistant A. baumannii. However, further in vivo and clinical studies are required. Full article
(This article belongs to the Special Issue Antibacterial Resistance and Novel Therapeutic Strategies)
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Article
A Trypsin Inhibitor from Moringa oleifera Flowers Modulates the Immune Response In Vitro of Trypanosoma cruzi-Infected Human Cells
Antibiotics 2020, 9(8), 515; https://doi.org/10.3390/antibiotics9080515 - 14 Aug 2020
Cited by 1 | Viewed by 1090
Abstract
Trypanosoma cruzi causes the lethal Chagas disease, which is endemic in Latin America. Flowers of Moringa oleifera (Moringaceae) express a trypsin inhibitor (MoFTI) whose toxicity to T. cruzi trypomastigotes was previously reported. Here, we studied the effects of MoFTI on the viability of [...] Read more.
Trypanosoma cruzi causes the lethal Chagas disease, which is endemic in Latin America. Flowers of Moringa oleifera (Moringaceae) express a trypsin inhibitor (MoFTI) whose toxicity to T. cruzi trypomastigotes was previously reported. Here, we studied the effects of MoFTI on the viability of human peripheral blood mononuclear cells (PBMCs) as well as on the production of cytokines and nitric oxide (NO) by T. cruzi-infected PBMCs. Incubation with MoFTI (trypsin inhibitory activity: 62 U/mg) led to lysis of trypomastigotes (LC50 of 43.5 µg/mL) but did not affect the viability of PBMCs when tested at concentrations up to 500 µg/mL. A selectivity index > 11.48 was determined. When T. cruzi-infected PBMCs were treated with MoFTI (43.5 or 87.0 µg/mL), the release of the pro-inflammatory cytokine TNF-α and INF-γ, as well as of NO, was stimulated. The release of the anti-inflammatory cytokine IL-10 also increased. In conclusion, the toxicity to T. cruzi and the production of IL-10 by infected PBMCs treated with MoFTI suggest that this molecule may be able to control parasitemia while regulating the inflammation, preventing the progress of Chagas disease. The data reported here stimulate future investigations concerning the in vivo effects of MoFTI on immune response in Chagas disease. Full article
(This article belongs to the Special Issue Natural Compounds as Antimicrobial Agents, 2nd Volume)
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Article
Clinical and Economic Burden of Carbapenem-Resistant Infection or Colonization Caused by Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii: A Multicenter Study in China
Antibiotics 2020, 9(8), 514; https://doi.org/10.3390/antibiotics9080514 - 13 Aug 2020
Cited by 4 | Viewed by 1369
Abstract
Background: Carbapenem resistant Klebsiella pneumoniae (CRKP), Pseudomonas aeruginosa (CRPA), and Acinetobacter baumannii (CRAB) pose significant threats to public health. However, the clinical and economic impacts of CRKP, CRPA, and CRAB remain largely uninvestigated in China. This study aimed to examine the clinical and [...] Read more.
Background: Carbapenem resistant Klebsiella pneumoniae (CRKP), Pseudomonas aeruginosa (CRPA), and Acinetobacter baumannii (CRAB) pose significant threats to public health. However, the clinical and economic impacts of CRKP, CRPA, and CRAB remain largely uninvestigated in China. This study aimed to examine the clinical and economic burden of CRKP, CRPA, and CRAB compared with carbapenem susceptible cases in China. Method: We conducted a retrospective and multicenter study among inpatients hospitalized at four tertiary hospitals between 2013 and 2015 who had K. pneumoniae, P. aeruginosa, and A. baumannii positive clinical samples. Propensity score matching (PSM) was used to balance the impact of potential confounding variables, including age, sex, insurance, number of diagnosis, comorbidities (disease diagnosis, and Charlson comorbidity index), admission to intensive care unit, and surgeries. The main indicators included economic costs, length of stay (LOS), and mortality rate. Results: We included 12,022 inpatients infected or colonized with K. pneumoniae, P. aeruginosa, and A. baumannii between 2013 and 2015, including 831 with CRKP and 4328 with carbapenem susceptible K. pneumoniae (CSKP), 1244 with CRPA and 2674 with carbapenem susceptible P. aeruginosa (CSPA), 1665 with CRAB and 1280 with carbapenem susceptible A. baumannii (CSAB). After PSM, 822 pairs, 1155 pairs, and 682 pairs, respectively were generated. Compared with carbapenem-susceptible cases, those with CRKP, CRPA, and CRAB were associated with statistically significantly increased total hospital cost ($14,252, p < 0.0001; $4605, p < 0.0001; $7277, p < 0.0001) and excess LOS (13.2 days, p < 0.0001; 5.4 days, p = 0.0003; 15.8 days, p = 0.0004). In addition, there were statistically significantly differences in hospital mortality rate between CRKP and CSKP, and CRAB and CSAB group (2.94%, p = 0.024; 4.03%, p = 0.03); however, the difference between CRPA and CSPA group was marginal significant (2.03%, p = 0.052). Conclusion: It highlights the clinical and economic impact of CRKP, CRPA, and CRAB to justify more resources for implementing antibiotic stewardship practices to improve clinical outcomes and to reduce economic costs. Full article
(This article belongs to the Special Issue Antibiotics Use and Antimicrobial Resistance in Hospital)
Article
Evaluation of Antioxidant, Antimicrobial and Tyrosinase Inhibitory Activities of Extracts from Tricholosporum goniospermum, an Edible Wild Mushroom
Antibiotics 2020, 9(8), 513; https://doi.org/10.3390/antibiotics9080513 - 13 Aug 2020
Cited by 14 | Viewed by 1719
Abstract
Tricholosporum goniospermum (Bres.) Guzmán ex T.J. Baroni is an excellent edible mushroom whose compounds and biological properties are still unknown. In this study, n-hexane, ethyl acetate and methanol extracts from fruiting bodies and liquid-cultured mycelia were compared for the analysis of phenolic compounds, [...] Read more.
Tricholosporum goniospermum (Bres.) Guzmán ex T.J. Baroni is an excellent edible mushroom whose compounds and biological properties are still unknown. In this study, n-hexane, ethyl acetate and methanol extracts from fruiting bodies and liquid-cultured mycelia were compared for the analysis of phenolic compounds, the evaluation of scavenger (DPPH, ABTS) and reducing (CUPRAC, FRAP) activities, and the enzyme inhibition of α-amylase, acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and tyrosinase. Additionally, T. goniospermum extracts were evaluated for antibacterial and antimycotic activities against Gram+ and Gram− bacteria, and clinical yeast and fungal dermatophytes. Finally, based on the extract content in phenolic compounds, in silico studies, including the docking approach, were conducted to predict the putative targets (namely tyrosinase, lanosterol-14-α-demethylase, the multidrug efflux system transporters of E. coli (mdtK) and P. aeruginosa (pmpM), and S. aureus β-lactamase (ORF259)) underlying the observed bio-pharmacological and microbiological effects. The methanolic extract from mycelia was the richest in gallic acid, whereas the ethyl acetate extract from fruiting bodies was the sole extract to show levels of catechin. Specifically, docking runs demonstrated an affinity of catechin towards all docked proteins, in the micromolar range. These in silico data are consistent, at least in part, with the highest activity of ethyl acetate extract as an antimicrobial and anti-tyrosinase (554.30 mg KAE/g for fruiting bodies and 412.81 mg KAE/g for mycelia) agent. The ethyl acetate extracts were also noted as being the most active (2.97 mmol ACAE/g for fruiting bodies and 2.25 mmol ACAE/g for mycelia) on α-amylase. BChE inhibitory activities varied from 2.61 to 26.78 mg GALAE/g, while the tested extracts were not active on AChE. In conclusion, all mushroom extracts tested in this study had potent antimicrobial activities. Particularly, among the tested extracts, the ethyl acetate extract showed the highest efficacy as both an antimicrobial and anti-tyrosinase agent. This could be related, albeit partially, to its content of catechin. In this regard, the bioinformatics analyses showed interactions of catechin with tyrosinase and specific microbial proteins involved in the resistance to chemotherapeutic drugs, thus suggesting innovative pharmacological applications of T. goniospermum extracts. Full article
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Article
Content and Mechanism of Action of National Antimicrobial Stewardship Interventions on Management of Respiratory Tract Infections in Primary and Community Care
Antibiotics 2020, 9(8), 512; https://doi.org/10.3390/antibiotics9080512 - 13 Aug 2020
Cited by 4 | Viewed by 1427
Abstract
A major modifiable factor contributing to antimicrobial resistance (AMR) is inappropriate use and overuse of antimicrobials, such as antibiotics. This study aimed to describe the content and mechanism of action of antimicrobial stewardship (AMS) interventions to improve appropriate antibiotic use for respiratory tract [...] Read more.
A major modifiable factor contributing to antimicrobial resistance (AMR) is inappropriate use and overuse of antimicrobials, such as antibiotics. This study aimed to describe the content and mechanism of action of antimicrobial stewardship (AMS) interventions to improve appropriate antibiotic use for respiratory tract infections (RTI) in primary and community care. This study also aimed to describe who these interventions were aimed at and the specific behaviors targeted for change. Evidence-based guidelines, peer-review publications, and infection experts were consulted to identify behaviors relevant to AMS for RTI in primary care and interventions to target these behaviors. Behavior change tools were used to describe the content of interventions. Theoretical frameworks were used to describe mechanisms of action. A total of 32 behaviors targeting six different groups were identified (patients; prescribers; community pharmacists; providers; commissioners; providers and commissioners). Thirty-nine interventions targeting the behaviors were identified (patients = 15, prescribers = 22, community pharmacy staff = 8, providers = 18, and commissioners = 18). Interventions targeted a mean of 5.8 behaviors (range 1–27). Influences on behavior most frequently targeted by interventions were psychological capability (knowledge and skills); reflective motivation (beliefs about consequences, intentions, social/professional role and identity); and physical opportunity (environmental context and resources). Interventions were most commonly characterized as achieving change by training, enabling, or educating and were delivered mainly through guidelines, service provision, and communications & marketing. Interventions included a mean of four Behavior Change Techniques (BCTs) (range 1–14). We identified little intervention content targeting automatic motivation and social opportunity influences on behavior. The majority of interventions focussed on education and training, which target knowledge and skills though the provision of instructions on how to perform a behavior and information about health consequences. Interventions could be refined with the inclusion of relevant BCTs, such as goal-setting and action planning (identified in only a few interventions), to translate instruction on how to perform a behavior into action. This study provides a platform to refine content and plan evaluation of antimicrobial stewardship interventions. Full article
(This article belongs to the Special Issue Antimicrobial Stewardship in Primary Care)
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Article
Effective Treatment for Uncomplicated Urinary Tract Infections with Oral Fosfomycin, Single Center Four Year Retrospective Study
Antibiotics 2020, 9(8), 511; https://doi.org/10.3390/antibiotics9080511 - 13 Aug 2020
Cited by 1 | Viewed by 1094
Abstract
Fosfomycin represents a relatively old antibiotic, but it is experiencing a comeback in recent years. According to some studies, the increasing therapeutic use of this drug led to a rapid increase in the levels of resistance in bacteria causing urinary tract infection. In [...] Read more.
Fosfomycin represents a relatively old antibiotic, but it is experiencing a comeback in recent years. According to some studies, the increasing therapeutic use of this drug led to a rapid increase in the levels of resistance in bacteria causing urinary tract infection. In the presented study, levels of resistance to fosfomycin in more than 3500 bacterial isolates before and after fosfomycin introduction into therapeutic use in the Czech Republic and the clinical efficacy of treatment in 300 patients using this drug were assessed. The results show that the resistance levels to fosfomycin in Escherichia coli isolates before and after the drug registration were not significantly different (3.4% and 4.4%, respectively). In some other Gram-negative rods, such as otherwise susceptible Enterobacter, resistance to fosfomycin increased significantly from 45.6% to 76.6%. Fosfomycin treatment of urinary tract infections showed an excellent seven-day clinical efficacy (79.7%). However, when used to treat recurrent or complicated urinary tract infections, fosfomycin treatment was associated with high levels of infection relapse, leading to relapse in a total of 20.4% of patients during the first two months. This indicates that fosfomycin exhibits good efficacy only for the treatment of uncomplicated urinary tract infections Full article
(This article belongs to the Special Issue Antimicrobial Prescribing and Stewardship, 1st Volume)
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Review
The Ascidian-Derived Metabolites with Antimicrobial Properties
Antibiotics 2020, 9(8), 510; https://doi.org/10.3390/antibiotics9080510 - 13 Aug 2020
Cited by 11 | Viewed by 1569
Abstract
Among the sub-phylum of Tunicate, ascidians represent the most abundant class of marine invertebrates, with 3000 species by heterogeneous habitat, that is, from shallow water to deep sea, already reported. The chemistry of these sessile filter-feeding organisms is an attractive reservoir of varied [...] Read more.
Among the sub-phylum of Tunicate, ascidians represent the most abundant class of marine invertebrates, with 3000 species by heterogeneous habitat, that is, from shallow water to deep sea, already reported. The chemistry of these sessile filter-feeding organisms is an attractive reservoir of varied and peculiar bioactive compounds. Most secondary metabolites isolated from ascidians stand out for their potential as putative therapeutic agents in the treatment of several illnesses like microbial infections. In this review, we present and discuss the antibacterial activity shown by the main groups of ascidian-derived products, such as sulfur-containing compounds, meroterpenes, alkaloids, peptides, furanones, and their derivatives. Moreover, the direct evidence of a symbiotic association between marine ascidians and microorganisms shed light on the real producers of many extremely potent marine natural compounds. Hence, we also report the antibacterial potential, joined to antifungal and antiviral activity, of metabolites isolated from ascidian-associate microorganisms by culture-dependent methods. Full article
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Article
The Bristol Sponge Microbiome Collection: A Unique Repository of Deep-Sea Microorganisms and Associated Natural Products
Antibiotics 2020, 9(8), 509; https://doi.org/10.3390/antibiotics9080509 - 13 Aug 2020
Cited by 1 | Viewed by 1819
Abstract
The deep ocean is the largest habitat for life on Earth, though the microorganisms that occupy this unique environmental niche remain largely unexplored. Due to the significant logistical and operational challenges associated with accessing the deep ocean, bioprospecting programmes that seek to generate [...] Read more.
The deep ocean is the largest habitat for life on Earth, though the microorganisms that occupy this unique environmental niche remain largely unexplored. Due to the significant logistical and operational challenges associated with accessing the deep ocean, bioprospecting programmes that seek to generate novel products from marine organisms have, to date, focused predominantly on samples recovered from shallow seas. For this reason, the deep ocean remains a largely untapped resource of novel microbiological life and associated natural products. Here we report the establishment of the Bristol Sponge Microbiome Collection (BISECT), a unique repository of deep-sea microorganisms and associated metabolites isolated from the microbiota of marine sponges, recovered from previously unsurveyed regions of the mid Atlantic Ocean, at depths of 0.3–3 km. An integrated biodiscovery pipeline comprising molecular, genetic, bioinformatic and analytical tools is also described, which is being applied to interrogate this collection. The potential of this approach is illustrated using data reporting our initial efforts to identify antimicrobial natural product lead compounds. Prospects for the use of BISECT to address allied pharmaceutical needs, along with mechanisms of access to the collection are also discussed Full article
(This article belongs to the Special Issue Novel Antibiotics from Actinomycetes)
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Article
A Quantitative Survey of Bacterial Persistence in the Presence of Antibiotics: Towards Antipersister Antimicrobial Discovery
Antibiotics 2020, 9(8), 508; https://doi.org/10.3390/antibiotics9080508 - 13 Aug 2020
Cited by 3 | Viewed by 2006
Abstract
Background: Bacterial persistence to antibiotics relates to the phenotypic ability to survive lethal concentrations of otherwise bactericidal antibiotics. The quantitative nature of the time–kill assay, which is the sector’s standard for the study of antibiotic bacterial persistence, is an invaluable asset for [...] Read more.
Background: Bacterial persistence to antibiotics relates to the phenotypic ability to survive lethal concentrations of otherwise bactericidal antibiotics. The quantitative nature of the time–kill assay, which is the sector’s standard for the study of antibiotic bacterial persistence, is an invaluable asset for global, unbiased, and cross-species analyses. Methods: We compiled the results of antibiotic persistence from antibiotic-sensitive bacteria during planktonic growth. The data were extracted from a sample of 187 publications over the last 50 years. The antibiotics used in this compilation were also compared in terms of structural similarity to fluorescent molecules known to accumulate in Escherichia coli. Results: We reviewed in detail data from 54 antibiotics and 36 bacterial species. Persistence varies widely as a function of the type of antibiotic (membrane-active antibiotics admit the fewest), the nature of the growth phase and medium (persistence is less common in exponential phase and rich media), and the Gram staining of the target organism (persistence is more common in Gram positives). Some antibiotics bear strong structural similarity to fluorophores known to be taken up by E. coli, potentially allowing competitive assays. Some antibiotics also, paradoxically, seem to allow more persisters at higher antibiotic concentrations. Conclusions: We consolidated an actionable knowledge base to support a rational development of antipersister antimicrobials. Persistence is seen as a step on the pathway to antimicrobial resistance, and we found no organisms that failed to exhibit it. Novel antibiotics need to have antipersister activity. Discovery strategies should include persister-specific approaches that could find antibiotics that preferably target the membrane structure and permeability of slow-growing cells. Full article
(This article belongs to the Section Mechanism and Evolution of Antibiotic Resistance)
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Article
Implementation of the WHO Approved “Tailoring Antimicrobial Resistance Programs (TAP)” Reduces Patients’ Request for Antibiotics
Antibiotics 2020, 9(8), 507; https://doi.org/10.3390/antibiotics9080507 - 12 Aug 2020
Cited by 1 | Viewed by 1307
Abstract
The misuse of antibiotics is a worldwide public health concern. Behavioral Intervention programs that aim to reduce patients’ own request for antibiotics during their visit to primary care clinics is an attractive strategy to combat this problem. We tested the effectiveness of a [...] Read more.
The misuse of antibiotics is a worldwide public health concern. Behavioral Intervention programs that aim to reduce patients’ own request for antibiotics during their visit to primary care clinics is an attractive strategy to combat this problem. We tested the effectiveness of a behavioral modification method known as the Tailoring Antimicrobial resistance Programs (TAP) in reducing the request for antibiotics by patients visiting primary care clinics for mild upper respiratory tract infections (URTIs). A stratified cluster randomized design with two groups pre-post, comparing intervention with the control, was conducted in six health centers. TAP was implemented for eight weeks. Request for antibiotics was assessed before (period 1) and after introducing TAP (period 2). The percentage of patients or their escorts who requested antibiotics in period 1 was 59.7% in the control group and 60.2% in the intervention group. The percentage of patients who requested antibiotics did not significantly change between period 1 and 2 in the control group, who continued to receive the standard of care. The above percentage significantly decreased in the intervention group from 60.2% to 38.5% (p < 0.05). We conclude that behavioral change programs including TAP are a viable alternative strategy to address antibiotic misuse in Jordan. Full article
(This article belongs to the Special Issue Antimicrobial Prescribing and Stewardship, 1st Volume)
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Article
Copper Kills Escherichia coli Persister Cells
Antibiotics 2020, 9(8), 506; https://doi.org/10.3390/antibiotics9080506 - 12 Aug 2020
Cited by 5 | Viewed by 1343
Abstract
Due to their reduced metabolism, persister cells can survive most antimicrobial treatments, which usually rely on corrupting active biochemical pathways. Therefore, molecules that kill bacterial persisters should function in a metabolism-independent manner. Some anti-persister compounds have been found previously, such as the DNA-crosslinkers [...] Read more.
Due to their reduced metabolism, persister cells can survive most antimicrobial treatments, which usually rely on corrupting active biochemical pathways. Therefore, molecules that kill bacterial persisters should function in a metabolism-independent manner. Some anti-persister compounds have been found previously, such as the DNA-crosslinkers mitomycin C and cisplatin, but more effective and lower cost alternatives are needed. Copper alloys have been used since ancient times due to their antimicrobial properties, and they are still used in agriculture to control plant bacterial diseases. By stopping transcription with rifampicin and by treating with ampicillin to remove non-persister cells, we created a population that consists solely of Escherichia coli persister cells. Using this population of persister cells, we demonstrate that cupric compounds kill E. coli persister cells. Hence, copper ions may be used in controlling the spread of important bacterial strains that withstand treatment with conventional antimicrobials by forming persister cells. Full article
(This article belongs to the Special Issue Antimicrobial Resistance of Dormant Bacterial Cells)
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Review
E-Health Tools to Improve Antibiotic Use and Resistances: A Systematic Review
Antibiotics 2020, 9(8), 505; https://doi.org/10.3390/antibiotics9080505 - 12 Aug 2020
Cited by 2 | Viewed by 1808
Abstract
(1) Background: e-Health tools, especially in the form of clinical decision support systems (CDSSs), have been emerging more quickly than ever before. The main objective of this systematic review is to assess the influence of these tools on antibiotic use for respiratory tract [...] Read more.
(1) Background: e-Health tools, especially in the form of clinical decision support systems (CDSSs), have been emerging more quickly than ever before. The main objective of this systematic review is to assess the influence of these tools on antibiotic use for respiratory tract infections. (2) Methods: The scientific databases, MEDLINE-PubMed and EMBASE, were searched. The search was conducted by two independent researchers. The search strategy was mainly designed to identify relevant studies on the effectiveness of CDSSs in improving antibiotic use, as a primary outcome, and on the acceptability and usability of CDSSs, as a secondary outcome. (3) Results: After the selection, 22 articles were included. The outcomes were grouped either into antibiotics prescription practices or adherence to guidelines concerning antibiotics prescription. Overall, 15 out of the 22 studies had statistically significant outcomes related to the interventions. (4) Conclusions: Overall, the results show a positive impact on the prescription and conscientious use of antibiotics for respiratory tract infections, both with respect to patients and prescribing healthcare professionals. CDSSs have been shown to have great potential as powerful tools for improving both clinical care and patient outcomes. Full article
(This article belongs to the Special Issue Interventions to Improve Antibiotic Use)
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Review
Aminoglycosides: From Antibiotics to Building Blocks for the Synthesis and Development of Gene Delivery Vehicles
Antibiotics 2020, 9(8), 504; https://doi.org/10.3390/antibiotics9080504 - 11 Aug 2020
Cited by 5 | Viewed by 1413
Abstract
Aminoglycosides are a class of naturally occurring and semi synthetic antibiotics that have been used for a long time in fighting bacterial infections. Due to acquired antibiotic resistance and inherent toxicity, aminoglycosides have experienced a decrease in interest over time. However, in the [...] Read more.
Aminoglycosides are a class of naturally occurring and semi synthetic antibiotics that have been used for a long time in fighting bacterial infections. Due to acquired antibiotic resistance and inherent toxicity, aminoglycosides have experienced a decrease in interest over time. However, in the last decade, we are seeing a renaissance of aminoglycosides thanks to a better understanding of their chemistry and mode of action, which had led to new trends of application. The purpose of this comprehensive review is to highlight one of these new fields of application: the use of aminoglycosides as building blocks for the development of liposomal and polymeric vectors for gene delivery. The design, synthetic strategies, ability to condensate the genetic material, the efficiency in transfection, and cytotoxicity as well as when available, the antibacterial activity of aminoglycoside-based cationic lipids and polymers are covered and critically analyzed. Full article
(This article belongs to the Section Antibiotics Use and Antimicrobial Stewardship)
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Article
Development of an NGS-Based Workflow for Improved Monitoring of Circulating Plasmids in Support of Risk Assessment of Antimicrobial Resistance Gene Dissemination
Antibiotics 2020, 9(8), 503; https://doi.org/10.3390/antibiotics9080503 - 11 Aug 2020
Cited by 2 | Viewed by 1747
Abstract
Antimicrobial resistance (AMR) is one of the most prominent public health threats. AMR genes localized on plasmids can be easily transferred between bacterial isolates by horizontal gene transfer, thereby contributing to the spread of AMR. Next-generation sequencing (NGS) technologies are ideal for the [...] Read more.
Antimicrobial resistance (AMR) is one of the most prominent public health threats. AMR genes localized on plasmids can be easily transferred between bacterial isolates by horizontal gene transfer, thereby contributing to the spread of AMR. Next-generation sequencing (NGS) technologies are ideal for the detection of AMR genes; however, reliable reconstruction of plasmids is still a challenge due to large repetitive regions. This study proposes a workflow to reconstruct plasmids with NGS data in view of AMR gene localization, i.e., chromosomal or on a plasmid. Whole-genome and plasmid DNA extraction methods were compared, as were assemblies consisting of short reads (Illumina MiSeq), long reads (Oxford Nanopore Technologies) and a combination of both (hybrid). Furthermore, the added value of conjugation of a plasmid to a known host was evaluated. As a case study, an isolate harboring a large, low-copy mcr-1-carrying plasmid (>200 kb) was used. Hybrid assemblies of NGS data obtained from whole-genome DNA extractions of the original isolates resulted in the most complete reconstruction of plasmids. The optimal workflow was successfully applied to multidrug-resistant Salmonella Kentucky isolates, where the transfer of an ESBL-gene-containing fragment from a plasmid to the chromosome was detected. This study highlights a strategy including wet and dry lab parameters that allows accurate plasmid reconstruction, which will contribute to an improved monitoring of circulating plasmids and the assessment of their risk of transfer. Full article
(This article belongs to the Special Issue Microbial Drug Resistance Genes)
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Article
Efficacy and Gut Dysbiosis of Gentamicin-Intercalated Smectite as a New Therapeutic Agent against Helicobacter pylori in a Mouse Model
Antibiotics 2020, 9(8), 502; https://doi.org/10.3390/antibiotics9080502 - 10 Aug 2020
Cited by 1 | Viewed by 1024
Abstract
Helicobacter pylori eradication rate with conventional standard therapy is decreasing owing to antibiotic resistance, necessitating novel antibacterial strategies against H. pylori. We evaluated the efficacy of a gentamicin-intercalated smectite hybrid (S-GM)-based treatment and analyzed fecal microbiome composition in H. pylori-infected mice. [...] Read more.
Helicobacter pylori eradication rate with conventional standard therapy is decreasing owing to antibiotic resistance, necessitating novel antibacterial strategies against H. pylori. We evaluated the efficacy of a gentamicin-intercalated smectite hybrid (S-GM)-based treatment and analyzed fecal microbiome composition in H. pylori-infected mice. To evaluate anti-H. pylori efficacy, mice were divided into eight groups, and H. pylori eradication was assessed by a Campylobacter-like organism (CLO) test and PCR assay of H. pylori in gastric mucosa. One week after H. pylori eradication, pro-inflammatory cytokine levels and atrophic changes in gastric mucosa were examined. Stool specimens were collected and analyzed for microbiome changes. The S-GM-based triple regimen decreased bacterial burden in vivo, compared with that in untreated mice or mice treated with other regimens. The therapeutic reactions in the CLO test from gastric mucosa were both 90% in the standard triple therapy and S-GM therapy group, respectively. Those of H. pylori PCR in mouse gastric mucosa were significantly lower in standard triple therapy and S-GM therapy groups than in the non-treatment group. Toxicity test results showed that S-GM therapy reduced IL-8 level and atrophic changes in gastric mucosa. Stool microbiome analysis revealed that compared with mice treated with the standard triple therapy, mice treated with the S-GM therapy showed microbiome diversity and abundant microorganisms at the phylum level. Our results suggested that S-GM is a promising and effective therapeutic agent against H. pylori infection. Full article
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Article
Trends in Antimicrobial Susceptibility of Escherichia coli Isolates in a Taiwanese Child Cohort with Urinary Tract Infections between 2004 and 2018
Antibiotics 2020, 9(8), 501; https://doi.org/10.3390/antibiotics9080501 - 10 Aug 2020
Viewed by 1172
Abstract
The aim of this study was to investigate the annual incidence of Escherichia coli isolates in urinary tract infections (UTIs) and the antimicrobial resistance of the third-generation cephalosporin (3GCs) to E. coli, including the factors associated with the resistance in hospitalized children [...] Read more.
The aim of this study was to investigate the annual incidence of Escherichia coli isolates in urinary tract infections (UTIs) and the antimicrobial resistance of the third-generation cephalosporin (3GCs) to E. coli, including the factors associated with the resistance in hospitalized children in Taiwan. A large electronic database of medical records combining hospital admission and microbiological data during 2004–2018 was used to study childhood UTIs in Taiwan. Annual incidence rate ratios (IRR) of E. coli in children with UTIs and its resistant rate to the 3GCs and other antibiotics were estimated by linear Poisson regression. Factors associated with E. coli resistance to 3GCs were assessed through multivariable logistic regression analysis. E. coli UTIs occurred in 10,756 unique individuals among 41,879 hospitalized children, with 92.58% being community associated based on urine culture results reported within four days after the hospitalization. The overall IRR E. coli UTI was 1.01 (95% confidence interval (CI) 0.99–1.02) in community-associated (CA) and 0.96 (0.90–1.02) in healthcare-associated infections. The trend in 3GCs against E. coli increased (IRR 1.18, 95% CI 1.13–1.24) over time in CA-UTIs. Complex chronic disease (adjusted odds ratio (aOR), 2.04; 95% CI, 1.47–2.83) and antibiotics therapy ≤ 3 months prior (aOR, 1.49; 95% CI, 1.15–1.94) were associated with increased risk of 3GCs resistance to E. coli. The study results suggested little or no change in the trend of E. coli UTIs in Taiwanese youths over the past 15 years. Nevertheless, the increase in 3GCs-resistant E. coli was substantial. Interventions for children with complex chronic comorbidities and prior antibiotic treatment could be effective in reducing the incidence of 3GCs-resistant E. coli in CA-UTIs in this region and more generally. Full article
(This article belongs to the Section Antibiotics Use and Antimicrobial Stewardship)
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Review
Fosfomycin as Partner Drug for Systemic Infection Management. A Systematic Review of Its Synergistic Properties from In Vitro and In Vivo Studies
Antibiotics 2020, 9(8), 500; https://doi.org/10.3390/antibiotics9080500 - 10 Aug 2020
Cited by 8 | Viewed by 1763
Abstract
Fosfomycin is being increasingly prescribed for multidrug-resistant bacterial infections. In patients with systemic involvement, intravenous fosfomycin is usually administered as a partner drug, as part of an antibiotic regimen. Hence, the knowledge of fosfomycin pharmacodynamic interactions (synergistic, additive, indifferent and antagonistic effect) is [...] Read more.
Fosfomycin is being increasingly prescribed for multidrug-resistant bacterial infections. In patients with systemic involvement, intravenous fosfomycin is usually administered as a partner drug, as part of an antibiotic regimen. Hence, the knowledge of fosfomycin pharmacodynamic interactions (synergistic, additive, indifferent and antagonistic effect) is fundamental for a proper clinical management of severe bacterial infections. We performed a systematic review to point out fosfomycin’s synergistic properties, when administered with other antibiotics, in order to help clinicians to maximize drug efficacy optimizing its use in clinical practice. Interactions were more frequently additive or indifferent (65.4%). Synergism accounted for 33.7% of total interactions, while antagonism occurred sporadically (0.9%). Clinically significant synergistic interactions were mostly distributed in combination with penicillins (51%), carbapenems (43%), chloramphenicol (39%) and cephalosporins (33%) in Enterobactaerales; with linezolid (74%), tetracyclines (72%) and daptomycin (56%) in Staphylococcus aureus; with chloramphenicol (53%), aminoglycosides (43%) and cephalosporins (36%) against Pseudomonas aeruginosa; with daptomycin (97%) in Enterococcus spp. and with sulbactam (75%) and penicillins (60%) and in Acinetobacter spp. fosfomycin-based antibiotic associations benefit from increase in the bactericidal effect and prevention of antimicrobial resistances. Taken together, the presence of synergistic interactions and the nearly total absence of antagonisms, make fosfomycin a good partner drug in clinical practice. Full article
(This article belongs to the Special Issue Antibacterial Drug Discovery)
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Communication
Characterizing Antimicrobial Resistance in Chicken Pathogens: A Step towards Improved Antimicrobial Stewardship in Poultry Production in Vietnam
Antibiotics 2020, 9(8), 499; https://doi.org/10.3390/antibiotics9080499 - 10 Aug 2020
Cited by 1 | Viewed by 1455
Abstract
In the Mekong Delta of Vietnam, farmers use large quantities of antimicrobials to raise small-scale chicken flocks, often including active ingredients regarded of “critical importance’” by the World Health Organization. Due to limitations in laboratory capacity, the choice of antimicrobials normally does not [...] Read more.
In the Mekong Delta of Vietnam, farmers use large quantities of antimicrobials to raise small-scale chicken flocks, often including active ingredients regarded of “critical importance’” by the World Health Organization. Due to limitations in laboratory capacity, the choice of antimicrobials normally does not follow any empirical criteria of effectiveness. The aim of this study was to highlight non-critically important antimicrobials against which chicken pathogens are likely to be susceptible as a basis for treatment guidelines. Microtiter broth dilution method was performed to determine the minimal inhibitory concentration (MIC) of 12 commonly used antimicrobials for 58 isolates, including Ornithobacterium rhinotracheale (ORT) (n = 22), Gallibacterium anatis (n = 19), and Avibacterium endocarditidis (n = 17). Unfortunately, internationally accepted breakpoints for resistance in these organisms do not exist. We drew tentative epidemiological cut-offs (TECOFFs) for those antimicrobial-pathogen combinations where MIC distributions suggested the presence of a distinct non-wild-type population. Based on the observed results, doxycycline would be the drug of choice for A.endocarditidis (11.8% presumptive non-wild type) and G. anatis infections (5.3% presumptive non-wild type). A total of 13.6% ORT isolates were non-wild type with regards to oxytetracycline, making it the drug of choice against this pathogen. This study illustrates the challenges in interpreting susceptibility testing results and the need to establish internationally accepted breakpoints for veterinary pathogens. Full article
(This article belongs to the Special Issue Antimicrobial Resistance in Pathogens Isolated from Animals)
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Review
Antimicrobial Stewardship in General Practice: A Scoping Review of the Component Parts
Antibiotics 2020, 9(8), 498; https://doi.org/10.3390/antibiotics9080498 - 09 Aug 2020
Cited by 5 | Viewed by 2144
Abstract
There is no published health-system-wide framework to guide antimicrobial stewardship (AMS) in general practice. The aim of this scoping review was to identify the component parts necessary to inform a framework to guide AMS in general practice. Six databases and nine websites were [...] Read more.
There is no published health-system-wide framework to guide antimicrobial stewardship (AMS) in general practice. The aim of this scoping review was to identify the component parts necessary to inform a framework to guide AMS in general practice. Six databases and nine websites were searched. The sixteen papers included were those that reported on AMS in general practice in a country where antibiotics were available by prescription from a registered provider. Six multidimensional components were identified: 1. Governance, including a national action plan with accountability, prescriber accreditation, and practice level policies. 2. Education of general practitioners (GPs) and the public about AMS and antimicrobial resistance (AMR). 3. Consultation support, including decision support with patient information resources and prescribing guidelines. 4. Pharmacist and nurse involvement. 5. Monitoring of antibiotic prescribing and AMR with feedback to GPs. 6. Research into gaps in AMS and AMR evidence with translation into practice. This framework for AMS in general practice identifies health-system-wide components to support GPs to improve the quality of antibiotic prescribing. It may assist in the development and evaluation of AMS interventions in general practice. It also provides a guide to components for inclusion in reports on AMS interventions. Full article
(This article belongs to the Special Issue Antimicrobial Stewardship in Primary Care)
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Review
Antibiotic Use in Low and Middle-Income Countries and the Challenges of Antimicrobial Resistance in Surgery
Antibiotics 2020, 9(8), 497; https://doi.org/10.3390/antibiotics9080497 - 09 Aug 2020
Cited by 6 | Viewed by 1955
Abstract
Antimicrobial resistance (AMR) is a phenomenon resulting from the natural evolution of microbes. Nonetheless, human activities accelerate the pace at which microorganisms develop and spread resistance. AMR is a complex and multidimensional problem, threatening not only human and animal health, but also regional, [...] Read more.
Antimicrobial resistance (AMR) is a phenomenon resulting from the natural evolution of microbes. Nonetheless, human activities accelerate the pace at which microorganisms develop and spread resistance. AMR is a complex and multidimensional problem, threatening not only human and animal health, but also regional, national, and global security, and the economy. Inappropriate use of antibiotics, and poor infection prevention and control strategies are contributing to the emergence and dissemination of AMR. All healthcare providers play an important role in preventing the occurrence and spread of AMR. The organization of healthcare systems, availability of diagnostic testing and appropriate antibiotics, infection prevention and control practices, along with prescribing practices (such as over-the-counter availability of antibiotics) differs markedly between high-income countries and low and middle-income countries (LMICs). These differences may affect the implementation of antibiotic prescribing practices in these settings. The strategy to reduce the global burden of AMR includes, among other aspects, an in-depth modification of the use of existing and future antibiotics in all aspects of medical practice. The Global Alliance for Infections in Surgery has instituted an interdisciplinary working group including healthcare professionals from different countries with different backgrounds to assess the need for implementing education and increasing awareness about correct antibiotic prescribing practices across the surgical pathways. This article discusses aspects specific to LMICs, where pre-existing factors make surgeons’ compliance with best practices even more important. Full article
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Article
Synergy of Linezolid with Several Antimicrobial Agents against Linezolid-Methicillin-Resistant Staphylococcal Strains
Antibiotics 2020, 9(8), 496; https://doi.org/10.3390/antibiotics9080496 - 09 Aug 2020
Cited by 4 | Viewed by 1057
Abstract
Linezolid is a synthetic oxazolydinone active against multi-resistant Gram-positive cocci that inhibits proteins synthesis by interacting with the 50S ribosomal subunit. Although linezolid-resistant strains are infrequent, several outbreaks have been recently described, associated with prolonged treatment with the antibiotic. As an alternative to [...] Read more.
Linezolid is a synthetic oxazolydinone active against multi-resistant Gram-positive cocci that inhibits proteins synthesis by interacting with the 50S ribosomal subunit. Although linezolid-resistant strains are infrequent, several outbreaks have been recently described, associated with prolonged treatment with the antibiotic. As an alternative to monotherapy, the combination of different antibiotics is a commonly used option to prevent the selection of resistant strains. In this work, we evaluated combinations of linezolid with classic and new aminoglycosides (amikacin, gentamicin and plazomicin), carbapenems (doripenem, imipenem and meropenem) and fosfomycin on several linezolid- and methicillin-resistant strains of Staphylococcus aureus and S. epidermidis, isolated in a hospital intensive care unit in Madrid, Spain. Using checkerboard and time-kill assays, interesting synergistic effects were encountered for the combination of linezolid with imipenem in all the staphylococcal strains, and for linezolid–doripenem in S.epidermidis isolates. The combination of plazomicin seemed to also have a good synergistic or partially synergistic activity against most of the isolates. None of the combinations assayed showed an antagonistic effect. Full article
(This article belongs to the Special Issue Methicillin-Resistant Staphylococci)
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