Search Results (206)

The widespread emergence of resistant pathogenic microorganisms are diminishing the effectiveness of existing antimicrobial drugs, posing an enormous threat to global public health. This phenomenon, known as antimicrobial resistance (AMR), is primarily driven by the misuse and overuse of antimicrobial drugs. Natural product researchers around the globe, in response to antibiotics resistance, are searching for new antimicrobial lead compounds from unexplored or underexplored ecological niches such as the marine environment. In order to isolate new antimicrobial lead compounds, two Streptomyces spp. were isolated from marine sediment samples by a serial dilution technique and subsequently cultured in modified Bennett’s broth medium. Repeated chromatographic steps of ethyl acetate (EtOAc) extracts obtained from the culture broth led to the isolation of a new compound with an unusual chemical skeleton, streptopiperithiazol (1), and a synthetically known (2) compound. These compounds were characterized by the extensive analysis of 1D and 2D spectroscopic as well as HRMS data. The absolute configuration of 1 was unresolved due to limited yield and lack of proper facilities for taking CD and ECD spectra. In vitro activity study of compounds 1 and 2 revealed that these compounds had better activity against Gram-positive bacteria than Gram-negative bacteria and yeast. Full article

Background/Objectives: European hedgehogs (Erinaceus europaeus) are present in areas where there is human activity; therefore, they can be a source of pathogens for other animals and humans. Methods: Eighteen hedgehog carcasses were collected and analyzed for Staphylococcus spp. Isolated strains were typed and analyzed for exfoliative toxins genes and the phenotypic and genotypic characteristics of antimicrobial resistance. Results: A total of 54 strains were isolated and typed as S. aureus, S. xylosus, S. sciuri, S. pseudintermedius, S. simulans, S. chromogenes, S. epidermidis, S. hyicus, and S. lentus. No strains had the eta and etb genes coding for exfoliative toxins. Overall, 39/54 (72.20%) isolates showed phenotypic resistance to at least one antimicrobial and 21/54 (38.80%) showed more than one resistance. The lowest efficacy was observed for erythromycin, with 40/54 (74.08%) strains classified as intermediate and 6/54 (11.11%) classified as resistant. Among the 29 isolates shown to be penicillin-resistant, 11 (37.93%) were oxacillin-resistant, with a minimum inhibitory concentration (MIC). Among the 54 staphylococcal strains, 2 (3.70%) were resistant to vancomycin, both with an MIC value equal to the maximum concentration of the antibiotic tested (256 μg/mL) and 2 (3.70%) had an intermediate resistance profile with an 8 μg/mL MIC value. No strains had the genes vanA and vanB. Two of the 29 (6.90%) penicillin-resistant strains had the blaZ gene; 8 (27.13%) strains had the mecA gene. Overall, 2/54 (3.70%) isolates were classified as extensively drug-resistant (XDR) and 9/54 (16.66%) were classified as multidrug-resistant (MDR). Conclusions: Hedgehogs can harbor antimicrobial-resistant staphylococci and can be sources of these bacteria for other animals and humans. They can also serve as bioindicators of the pathogens and antimicrobial-resistant bacteria circulating in a given habitat. Full article

The excessive use of antimicrobials drives the emergence of multidrug resistance (MDR) in bacterial strains, which harbor resistance genes to survive under diverse drug pressures. Such resistance can result in life-threatening infections. The predominance of MDR Pseudomonas spp. poses significant challenges to public health and environmental sustainability, particularly in ecosystems affected by human activities. Characterizing MDR Pseudomonas spp. is crucial for developing effective diagnostic tools and biosecurity protocols, with broader implications for managing other pathogenic bacteria. Strains were diagnosed through 16S rRNA PCR and sequencing, complemented by phylogenetic analysis to evaluate local and global evolutionary connections. Antibiotic susceptibility tests revealed extensive resistance across multiple classes, with MIC values surpassing clinical breakpoints. This study examined the genetic diversity, resistance potential, and phylogenetic relationships among Pseudomonas aeruginosa strain DG2 and Pseudomonas fluorescens strain FM3, which were isolated from solid waste dump sites (n = 30) and dairy farms (n = 22) in West Bengal, India. Phylogenetic analysis reveals distinct clusters that highlight significant geographic linkages and genetic variability among the strains. Significant biofilm production under antibiotic exposure markedly increased resistance levels. RAPD-PCR profiling revealed substantial genetic diversity among the isolates, indicating variations in their genetic makeup. In contrast, SDS-PAGE analysis provided insights into the protein expression patterns that are activated by stress, which are closely linked to MDR. This dual approach offers a clearer perspective on their adaptive responses to environmental stressors. This study underscores the need for vigilant monitoring of MDR Pseudomonas spp. in anthropogenically impacted environments to mitigate risks to human and animal health. Surveillance strategies combining phenotypic and molecular approaches are essential to assess the risks posed by resilient pathogens. Solid waste and dairy farm ecosystems emerge as critical reservoirs for the evolution and dissemination of MDR Pseudomonas spp. Full article

Urogenital infections contribute greatly to both hospital- and community-acquired infections. In Ghana, the prevalence of resistance to commonly used antibiotics is relatively high. This study sought to evaluate the antibiotic sensitivity of bacterial urogenital pathogens from patient samples in a regional and district hospital in the Volta Region of Ghana. A retrospective cross-sectional study was conducted using data obtained between January and December 2023 from Volta Regional Hospital and Margret Marquart Catholic Hospital. Bacteria were isolated from urine, urethral swabs, and vaginal swabs from 204 patients. Data on culture and sensitivity assays performed using the Kirby–Bauer disc diffusion method were extracted and analyzed using WHONET. The most prevalent organisms isolated from the samples from both facilities were Escherichia coli (24.9%), Staphylococcus aureus (21.5%), and Klebsiella oxytoca (8.8%). The isolates were mostly resistant to amoxicillin/clavulanic acid (n = 75, 95% CI [91.8–99.9]), meropenem (n = 61, 95% CI [87.6–99.4]), cefuroxime (n = 54, 95% CI [78.9–96.5]), ampicillin (n = 124, 95% CI [61.2–77.9]), and piperacillin (n = 43, 95% CI [82.9–99.2]). Multidrug-resistant (MDR, 70 (34.1%)), extensively drug-resistant (XDR, 63 (30.7%)), and pandrug-resistant (PDR, 9 (4.3%)) strains of S. aureus, E. coli, and Pseudomonas aeruginosa were identified from the patient samples. The study highlights the presence of high-priority resistant urogenital pathogens of public health significance to varied antibiotic groups. Full article

The war between humans and bacteria started centuries ago. With the advent of antibiotics, there was a temporary ceasefire in this war, but the scenario soon started becoming worse with the emergence of drug-resistant strains within years of the deployment of antibiotics in the market. With the surge in the misuse of antibiotics, there was a drastic increase in the number of multidrug-resistant (MDR) and extensively drug-resistant bacterial strains, even to antibiotics like Methicillin and vancomycin, aggravating the healthcare scenario. The threat of MDR ESKAPE pathogens is particularly high in nosocomial infections, where biofilms formed by bacteria create a protective barrier that makes them highly resistant to antibiotics, complicating the treatment efforts. Scientists are looking at natural and sustainable solutions, as several studies have projected deaths contributed by drug-resistant bacteria to go beyond 50 million by 2050. Many plant-derived metabolites have shown excellent antibacterial and antibiofilm properties that can be tapped for combating superbugs. The present review explores the current status of various studies on antibacterial plant metabolites like alkaloids and flavonoids and their mechanisms in disrupting biofilms and killing bacteria by way of inhibiting key survival strategies of bacteria like motility, quorum-sensing, reactive oxygen species production, and adhesion. These mechanisms were found to be varied in Gram-positive, Gram-negative, and acid-fast bacteria like Mycobacterium tuberculosis, which will be discussed in detail. The successful tapping of the benefits of such plant-derived chemicals in combination with evolving techniques of nanotechnology and targeted drug delivery can go a long way in achieving the goal of One Health, which advocates the unity of multiple practices for the optimal health of people, animals, and the environment. Full article

The objective of this study was to determine the epidemiological, clinical, and laboratory characteristics of newborns with sepsis in northwestern Mexico, identify the microorganisms causing early- and late-onset sepsis, and assess antimicrobial resistance. Additionally, it sought to associate neonatal characteristics with antimicrobial resistance or mortality. A retrospective study was conducted from August 2021 to April 2023, during which 8382 neonatal clinical records were analyzed to collect epidemiological, clinical, and laboratory characteristics, as well as microorganisms isolated from neonates and their antimicrobial resistance profiles. Of these, 314 neonates with sepsis were included. The incidence of neonatal sepsis was 4% (314/8382), and the mortality was 12.7% (40/314); late-onset sepsis (65.3%) was more frequent than early-onset sepsis (34.7%). Staphylococcus epidermidis was the most frequently isolated bacterium in neonates with sepsis (both early- and late-onset). Gram-positive bacteria, such as Staphylococcus hominis and Enterococcus faecium, were associated with early-onset sepsis, whereas fungi, particularly Candida albicans, were associated with late-onset sepsis. Of the microorganisms, 52.6% were multidrug resistant (MDR), 10.8% were extensively drug resistant (XDR), and 5.5% were pan-drug resistant (PDR). Low birth weight, prematurity, cesarean section, mechanical ventilation, tachycardia, and low hemoglobin and platelet levels, among others, were associated with XDR or MDR microorganisms. In contrast, low birth weight, mechanical ventilation, stroke, unexpected delivery, respiratory distress, tachycardia, convulsive crisis, high procalcitonin, urea, and AST/TGO levels, among others, were associated with mortality. The incidence, types of sepsis, antimicrobial resistance, and associations identified in this study will aid in diagnosing neonatal sepsis earlier and may reduce mortality in our region. Full article

Background/Objectives: The main objective of this research work was to identify and determine the antibiotic resistance of the false-positive isolates on chromogenic agar when analyzing Salmonella in chicken meat. Methods: A total of 234 samples of chicken meat (carcasses, cuts and preparations) were studied using buffered peptone water for primary enrichment, Rappaport–Vassiliadis soy broth for secondary enrichment and Salmonella Chromogen Agar Set as a selective solid medium. Colonies with a morphology characteristic of Salmonella (one isolate per sample) were identified by matrix-assisted laser desorption ionization and time-of-flight mass spectrometry (MALDI-TOF). Results: Colonies with a characteristic morphology of Salmonella were detected in 71 samples. Only five isolates (7.0% of the total) corresponded to the genus Salmonella. Other genera detected were Hafnia (three isolates; 4.2% of the total), Escherichia (22; 31.0%), Klebsiella (19; 26.8%), Proteus (6; 8.5%) and Pseudomonas (16; 22.5%). The 66 isolates of these last five genera were tested for susceptibility to a panel of 42 antibiotics of clinical importance by disc diffusion. All isolates presented multiple resistances, to between 4 and 29 antibiotics, all of them having a multi drug-resistant (MDR) phenotype except for one Pseudomonas strain, with an extensively drug-resistant (XDR) phenotype. Conclusions: These results highlight the low selectivity of this method, with the specific culture media under test, for the detection of Salmonella in poultry meat. The considerable prevalence of antibiotic resistance observed suggests a need to improve control measures throughout the poultry meat production chain to prevent this food from becoming a reservoir of bacteria with resistance to multiple antibiotics. Full article

The rapid increase in drug resistance in recent years has become a significant global public health concern. Escherichia coli are ubiquitous bacteria, widely distributed in various environments. This study isolated a bacterial strain (HD-593) from diseased Chinese soft-shelled turtles (Pelodiscus sinensis). The bacterium was identified based on morphology, biochemical tests, and 16S rRNA sequencing, confirming it as E. coli. Drug susceptibility tests revealed that the HD-593 strain was highly resistant to ceftriaxone, enrofloxacin, doxycycline, sulfadiazine, gentamicin, neomycin, florfenicol, carbenicillin, cefradine, erythromycin, penicillin, ampicillin, midecamycin, and streptomycin. Resistance gene analysis confirmed the presence of quinolone resistance genes (oqxA and oqxB), aminoglycoside resistance genes (aac(3)-II and aphA1), a β-lactam resistance gene (blaTEM), and an acylaminol resistance gene (floR) in HD-593. The median lethal dose (LD50) of HD-593 for P. sinensis was 6.53 × 10⁵ CFU/g. Biochemical analysis of serum revealed that HD-593 infection caused a significant reduction in total protein, albumin, and globulin levels, while markedly increasing the levels of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase. Histopathological analysis revealed severe intestinal damage characterized by villi detachment and muscle cell necrosis. Additionally, extensive splenocyte necrosis with nuclear marginalization, glomerular swelling, and pronounced hepatic steatosis accompanied by distended sinusoids were observed. This study identified a multidrug-resistant E. coli strain from deceased P. sinensis, suggesting that drug resistance genes may circulate in aquaculture ecosystems, posing potential risks to aquaculture. Full article

Extensive use of classical antibiotics has led to the growing emergence of many resistant strains of pathogenic bacteria. To combat this challenge, researchers have turned to the antimicrobial peptides (AMPs). Aurein 1.2 (GLFDIIKKIAESF-NH2) was demonstrated to have broad spectrum bi-functionality against bacterial and cancer cells. The Solid Phase Peptide Synthesis (Fmoc-strategy) was used for the synthesis of new analogs of aurein 1.2. The purity of all compounds was monitored by HPLC, and their structures were proven using mass spectrometry. Cytotoxicity and antiproliferative effects were studied using 3T3 NRU and MTT tests, respectively. The antibacterial activity was estimated against Gram-positive and Gram-negative bacteria using broth microdilution method in concentrations from 0 to 320 µg/mL to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). The antiproliferative activity test shows that the peptide analog EH [Orn]⁸ has the highest activity (IC₅₀ = 44 ± 38 μM) for the three cell lines studied (MCF-12F, MCF-7, and MDA-MB-231). The same compound exhibited good antimicrobial activity. The obtained results reveal that replacement of Lys with non-proteinogenic amino acids can increase both the potency and activity spectra of natural template peptides, making them suitable candidates for new drug development. Full article

tet(X4)-positive IncHI1 plasmids are widely prevalent in various bacteria. To understand their transmission characteristics, we analyzed two extensively drug-resistant (XDR) Escherichia coli strains isolated from pet dog feces in Henan Province, China. Strain T28R harbored tet(X4)-positive IncHI1, IncF18:A-:B-, and mcr-1-positive IncI2 plasmids, while T16R carried tet(X4)-positive IncHI1, F16:A-:B-, and mcr-1-positive IncX4 plasmids. Four representative fusion plasmids, pT28R-F1, pT28R-F2, pT28R-F3, and pT16R-F1, in transconjugants were analyzed using WGS and PCR mapping. The results showed that IS26 from the IncF18:A-:B--plasmid attacked the conjugative transfer-associated genes trhc and rsp on the IncHI1 plasmid, generating pT28R-F1 and pT28R-F2. pT28R-F3 was generated through ISCro1- and ISCR2-mediated homologous recombination, deleting the Tra1 region of the IncHI1 plasmid. T16R-F1 emerged from ISCR2- and IS1B-mediated homologous recombination, losing transfer regions of parental plasmids. Notably, fusion plasmids lost the temperature sensitivity of the IncHI1 plasmid, with conjugation frequencies between 1.57 × 10⁻⁴ and 3.84 × 10⁻⁵ at 28 °C and 37 °C. The findings suggest that tet(X4)-positive IncHI1 plasmids could be mobilized with the assistance of conjugative helper plasmids and that fusion events enhance the adaptability of these plasmids, thus facilitating the spread of antibiotic resistance, posing a growing public health threat. Full article

Due to the involvement of biofilms in the pathogenesis of bone and joint infections (BJI), the treatment of these infections is often challenging, especially when multidrug- or extensively drug-resistant (MDR/XDR) pathogens are involved. Intravenous fosfomycin (FOS) is a phosphoenolpyruvate analogue with a unique mode of action and broad-spectrum activity against both Gram-positive (GP) and Gram-negative (GN) pathogens. It is used in various severe and deep-seated infections, including BJIs. This review article focuses on preclinical and clinical data surrounding the use of FOS for biofilm-related BJIs. Data from several in vitro and animal models of infection demonstrated that FOS, especially in combination with other antibiotics, is effective against biofilms of (methicillin-resistant) Staphylococcus spp., (vancomycin-resistant) Enterococcus spp., carbapenem-resistant and extended-spectrum beta-lactamase-producing Enterobacterales, and MDR Pseudomonas aeruginosa. Data from clinical studies, mostly retrospective observational studies and case reports/case series, revealed that FOS was typically used in combination with other antibiotics for the treatment of various BJI, including acute and chronic osteomyelitis, prosthetic joint infections, and fracture-related infections, in adult and pediatric patients. Success rates often exceeded 80%. FOS exhibits good and fast penetration into bone tissue and is generally well tolerated, with only a few adverse drug reactions, such as gastrointestinal disorders and electrolyte imbalances. Collectively, the data indicate that FOS is a valuable option as part of combination regimens for the treatment of BJIs caused by both GP and GN bacteria. Full article

Antibiotic resistance to Klebsiella pneumoniae poses a major public health threat, particularly in intensive care unit (ICU) settings. The emergence of extensively drug-resistant (XDR) strains complicates treatment options, requiring a deeper understanding of their genetic makeup and potential therapeutic targets. This research delineated an extensively drug-resistant (XDR) Klebsiella pneumoniae strain obtained from an ICU patient and telomeric temperate phage derived from hospital effluent. The bacteria showed strong resistance to multiple antibiotics, including penicillin (≥16 μg/mL), ceftriaxone (≥32 μg/mL), and meropenem (≥8 μg/mL), which was caused by SHV-11 beta-lactamase, NDM-1 carbapenemase, and porin mutations (OmpK37, MdtQ). The strain was categorized as K46 and O2a types and carried virulence genes involved in iron acquisition, adhesion, and immune evasion, as well as plasmids (IncHI1B_1_pNDM-MAR, IncFIB) and eleven prophage regions, reflecting its genetic adaptability and resistance dissemination. The 172,025 bp linear genome and 46.3% GC content of the N-15-like phage showed strong genomic similarities to phages of the Sugarlandvirus genus, especially those that infect K. pneumoniae. There were structural proteins (11.8%), DNA replication and repair enzymes (9.3%), and a toxin–antitoxin system (0.4%) encoded by the phage genome. A protelomerase and ParA/B partitioning proteins indicate that the phage is replicating and maintaining itself in a manner similar to the N15 phage, which is renowned for maintaining a linear plasmid prophage throughout lysogeny. Understanding the dynamics of antibiotic resistance and pathogen development requires knowledge of phages like this one, which are known for their temperate nature and their function in altering bacterial virulence and resistance profiles. The regulatory and structural proteins of the phage also provide a model for research into the biology of temperate phages and their effects on microbial communities. The importance of temperate phages in bacterial genomes and their function in the larger framework of microbial ecology and evolution is emphasized in this research. Full article

Tuberculosis (TB) is an infectious disease caused by bacteria that primarily target the lungs. The transmission of this disease occurs through the air in the form of droplet nuclei. Unfortunately, there has been an emergence of resistance to strains of such infections, such as multidrug- as well as extensively drug-resistant strains. Healthcare workers (HCWs) are particularly vulnerable to contracting TB due to their direct contact with patients. This study aims to evaluate the knowledge, attitude, and practices among Lebanese healthcare workers towards TB and its resistant forms, particularly multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB). This study is a cross-sectional, descriptive, questionnaire-based research study that was conducted on HCWs in Lebanon. A total of 517 HCWs were included in this study. The findings displayed that 48.52% of HCWs had good knowledge of TB and MDR-TB/XDR-TB, 49.52% had average knowledge, and 2.13% had bad knowledge. Moreover, only 16.25% had a good attitude, 71.92% had an average attitude, and 11.8% had a bad attitude. Furthermore, only 14.7% had good practices, 54.74% had average practices, and 30.56% had bad practices. Having a history of testing for TB was found to be related to increased attitude. Also, the history of having TB-infected family members was found to be linked to both increased attitude and practice scores. Moreover, this study highlights the idea that high knowledge scores do not mean high attitude or high practices scores. On the same note, acceptable attitude scores do not inflict acceptable practice scores. The findings of this study showed that there is an overall good knowledge regarding TB, MDR-TB, and XDR-TB, average attitude, and average-to-bad practices. Gaps are seen in all sectors, even knowledge, especially with matters related to the diagnosis of MDR-TB/XDR-TB and its treatment duration. Also, the attitude section revealed a gap in the understanding of the modes of transmission of such an infection. Full article

Farms are a major source of antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB), and previous research mainly focuses on polluted soils and breeding environments. However, slaughtering is an important link in the transmission of ARGs and ARB from farmland to dining table. In this study, we aim to reveal the pollution of ARGs and ARB in the slaughter process of broilers. First, by qualitative and quantitative analysis of ARGs in samples collected from the broiler slaughtering and processing production chain, the contamination level of ARGs was reflected; secondly, potential hosts for ARGs and microbial community were analyzed to reflect the possible transmission rules; thirdly, through the antibiotic susceptibility spectrum analysis of four typical food-borne pathogens, the distribution of ARB was revealed. The results showed that 24 types of ARGs were detected positive on the broiler slaughter production line, and tetracycline-resistance genes (20.45%) were the most frequently detected. The types of ARGs vary with sampling process, and all sampling links contain high levels of sul2 and intI1. The most abundant ARGs were detected in chicken surface in the scalding stage and entrails surface in the evisceration stage. There was a significant correlation between intI1 and tetM, suggesting that tetM might be able to enter the human food chain through class-1 integrons. The host range of the oqxB gene is the most extensive, including Sphingobacterium, Bacteroidia unclassified, Rothia, Microbacterium, Algoriella, etc. In the relevant links of the slaughter production line, the microbial community structure is similar. Removing viscera may cause diffusion of ARGs carried by intestinal microorganisms and contaminate chicken and following processing production. The four food-borne pathogens we tested are widely present in all aspects of the slaughter process, and most of them have multi-drug resistance and even have a high degree of resistance to some veterinary drugs banned by the Ministry of Agriculture. Our study preliminarily revealed the pollution of ARGs and ARB in the slaughter process of broilers, and these results are helpful to carry out food safety risk assessment and formulate corresponding control measures. Full article

Background/Objectives: Urinary tract infections (UTI) represent a global problem with implications for mortality and morbidity. Published data present different bacterial incidences and different antibiotic resistance. The objective of our study is to evaluate the bacteria distribution in positive urine cultures in a mixed adult population and evaluate the differences in antibiotic resistance in in- and outpatients. Methods: We analyzed 1186 positive urine cultures in 2021 from the Emergency County Hospital “Pius Brinzeu” from Timisoara, Romania. We evaluated the bacteria distribution and antibiotic resistance stratified by in and outpatients from a mixed adult population. Results: The median age was 67, with 65.7% females and 28.5% were outpatients. In inpatients, the most commonly identified bacteria was E. coli, followed by Enterococcus spp., and Klebsiella spp., while in outpatients, E. coli, Enterococcus spp., and Klebsiella spp. were the leading ones. Overall, E. coli presented the highest resistance rate to ampicillin, Enterococcus spp. to ciprofloxacin, Klebsiella spp. to cephalosporins, and Proteus spp. to trimethoprim/sulfamethoxazole. Inpatients presented higher resistance rates for E. coli to ceftazidime, cefuroxime, gentamycin, ciprofloxacin, and trimethoprim/sulfamethoxazole, Klebsiella spp. to most cephalosporin, gentamycin and levofloxacin, Proteus spp. to gentamycin and Enterococcus spp. to gentamycin and quinolones when compared to outpatients. The highest incidence of extensively drug-resistant (XDR) bacteria was among Acinetobacter baumanii, followed by Pseudomonas spp., and Serratia spp. Conclusions: susceptibility. Bacteria identified in inpatients’ positive urine cultures present higher resistance rates to several antibiotics. Our study could be a foundation for a local or even national guideline for the antibiotic treatment of urinary tract infections. Full article