Search Results (120)

Proteus mirabilis is a zoonotic pathogen that poses a growing threat to both animal and human health due to rising antimicrobial resistance (AMR). It is widely found in animals, including China’s nationally protected captive giant and red pandas. This study isolated Proteus mirabilis from panda feces to assess AMR and virulence traits, and used whole-genome sequencing (WGS) to evaluate the spread of resistance genes (ARGs) and virulence genes (VAGs). In this study, 37 isolates were obtained, 20 from red pandas and 17 from giant pandas. Multidrug-resistant (MDR) strains were present in both hosts. Giant panda isolates showed the highest resistance to ampicillin and cefazolin (58.8%), while red panda isolates were most resistant to trimethoprim/sulfamethoxazole (65%) and imipenem (55%). Giant panda-derived strains also exhibited stronger biofilm formation and swarming motility. WGS identified 31 ARGs and 73 VAGs, many linked to mobile genetic elements (MGEs) such as plasmids, integrons, and ICEs. In addition, we found frequent co-localization of drug resistance genes/VAGs with MGEs, indicating a high possibility of horizontal gene transfer (HGT). This study provides crucial insights into AMR and virulence risks in P. mirabilis from captive pandas, supporting targeted surveillance and control strategies. Full article

Feline urinary tract infections (UTIs) present a common challenge in veterinary practice, underscoring the importance of understanding local bacterial pathogens and antimicrobial resistance (AMR). This study determined bacterial prevalence and antimicrobial susceptibility in cats at Kasetsart University’s Veterinary Teaching Hospital in Bangkok, Thailand. Of the 543 cystocentesis urine samples collected from 428 cats, 115 (21.2%) tested positive for bacterial cultures, leading to a diagnosis of UTIs in 95 cats (22.2%). The most prevalent isolates included Escherichia coli (24.8%), Staphylococcus species (19.2%), Proteus mirabilis (13.6%), Pseudomonas aeruginosa (12.0%), and Enterococcus species (12.0%). Staphylococcus felis (8.8%) and Staphylococcus pseudintermedius (5.6%) were the predominant Staphylococcus species. Rare pathogens such as Corynebacterium urealyticum and Lactococcus garvieae were also identified. Antimicrobial testing revealed alarming resistance, with 69.2% of isolates exhibiting multidrug resistance (MDR). Escherichia coli and Proteus mirabilis showed high resistance to amoxicillin/clavulanic acid (AMC) (45.2–70.6%) and sulfamethoxazole/trimethoprim (SXT) (51.6–52.9%). Enterococcus faecium exhibited 85.7% resistance to AMC. Methicillin resistance was identified in 41.7% of Staphylococcus isolates, particularly high in Staphylococcus epidermidis (75.0%) and Staphylococcus pseudintermedius (71.4%). High fluoroquinolone resistance among MDR isolates further exacerbates AMR concerns. These results indicate that MDR Gram-negative, Staphylococcus, and Enterococcus species complicate the empirical treatment of feline UTIs, highlighting significant implications for AMR in veterinary practice. Full article

Background: During the COVID-19 pandemic, the emergence of multidrug-resistant (MDR) pathogens, driven by heightened antibiotic usage and device-associated infections, has posed significant challenges to healthcare. This study reports an outbreak of Proteus mirabilis producing NDM-5 and CTX-M-15 β-lactamases in a hospital in Buenos Aires, Argentina, from October 2020 to April 2021. To our knowledge, this represents the first documented outbreak of NDM-5-producing P. mirabilis in the country. Methods: A total of 82 isolates were recovered from 40 patients, with 41.5% from blood cultures and 18.3% from respiratory and urinary samples, among others. Antimicrobial susceptibility testing, PCR-based methods, and MALDI-TOF MS cluster analysis were conducted. Whole genome sequencing (WGS) was performed to characterize the MLST, resistome and plasmid content. Biofilm formation assays and in vitro rifampicin susceptibility tests were also conducted. Result: Most isolates exhibited resistance to carbapenems, cephalosporins, aminoglycosides, and fluoroquinolones, while retaining susceptibility to aztreonam. Genetic analysis confirmed the co-presence of the bla_NDM-5 and bla_CTX-M-15 genes. Clonal relationships was supported by PCR-based typing and MALDI-TOF MS cluster analysis. WGS revealed a resistome comprising 25 resistance genes, including rmtB and both β-lactamases, as well as the presence of an incomplete IncQ1 replicon associated with multiple resistance determinants. MLST classified this clone as belonging to ST135. Despite the biofilm-forming capacity observed across strains, rifampicin demonstrated potential for disrupting established biofilms at concentrations ≥32 µg/mL in vitro. The MDR profile of the outbreak strain significantly limited therapeutic options. Conclusions: This study highlights the growing threat of NDM-producing P. mirabilis in Argentina. The absence of surveillance cultures from the index case limits insights into the outbreak’s origin. These findings underscore the importance of integrating genomic surveillance into infection control protocols to mitigate the spread of MDR pathogens. Full article

Background/Objectives: Length of hospital stay (LOS) is a critical measure of healthcare efficiency. This study investigated factors contributing to prolonged LOS in adult patients with urinary tract infections (UTIs) in Lebanon and assessed microbial susceptibility patterns of causative pathogens. Methods: A retrospective cohort study was conducted across five Lebanese university hospitals (March 2022–December 2023), analyzing 401 patients. Data on microbiological findings and the LOS were extracted from medical records. Statistical analyses, including descriptive statistics, bivariate tests (t-tests, ANOVA, and Pearson’s correlation), and multiple linear regression (significance: p ≤ 0.05), were performed using IBM SPSS^® 27. Results: The mean LOS was 5.85 ± 2.41 days. Prolonged hospitalization was associated with patient-related factors (age, comorbidities, UTI type, specific symptoms, and multidrug-resistant infections) and treatment-related factors. Empirical use of carbapenems (β = 0.783, p = 0.004) and fluoroquinolones (β = 1.360, p = 0.014), along with inappropriate antibiotic prescriptions (β = 0.609, p = 0.022), significantly extended the LOS. Conversely, antibiotic de-escalation based on culture results reduced the LOS (β = −0.567, p = 0.029). Escherichia coli (61.8%) was the predominant pathogen, followed by Klebsiella pneumoniae (11.9%), Proteus mirabilis (7.8%), and Pseudomonas aeruginosa (7.5%). Notably, susceptibility to antibiotics showed a concerning decline. Conclusions: Inappropriate antibiotic prescriptions were linked to a prolonged LOS, emphasizing the need for judicious antimicrobial use. The positive impact of de-escalation supports culture-guided therapy. Declining antibiotic susceptibility highlights the urgency for robust antimicrobial stewardship programs (ASPs) and a national microbial resistance database to combat antimicrobial resistance (AMR) in Lebanon. Full article

Background: Antimicrobial resistance is a problem that threatens the entire world population. Blue light irradiation (BLI) is a novel technology with a bactericidal effect. However, it has only been employed in experimental and preclinical trials. Methods: We employed BLI on four kinds of bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, and Escherichia coli) and six kinds of artificial implants utilizing a BioLight LED lamp and MEDILIGHT at a 453 nm wavelength. Results: The results showed that the antibacterial effect of BLI enhanced with time and dosage. Irradiation of 165.6 J/cm² corresponding to 120 min of constant mode irradiation, resulted in a significant reduction in the CFU for all four strains. Moreover, the cycling mode (30 s on/30 s off) of the MEDILIGHT prototype showed a more effective microbial effect compared to the constant mode using the BioLight LED lamp. Pseudomonas aeruginosa was the most sensitive strain to BLI, and Staphylococcus aureus showed relatively greater resistance to BLI. BLI showed different antibacterial effects on various types of implants, indicating that different physical properties of artificial implants were more likely to influence the bactericidal effect of BLI. Decreased ATP highlighted energy deprivation after BLI. Genechip analysis of Escherichia coli under constant mode and cycling mode of BLI revealed the downregulation of metabolism-related pathways, and most genes involved in the TCA cycle were downregulated. Conclusions: Our results showed that cycling mode BLI has great potential for use in future disinfection applications. We also proposed a new viewpoint that energy deprivation might be another possible mechanism underlying the antibacterial effect of BLI. Full article

Background: The close relationship between humans and petsraises health concerns due to the potential transmission of antimicrobial-resistant (AMR) bacteria and genes. Bacterial otitis is an emerging health problem in dogs, given its widespread prevalence and impact on animal welfare. Early detection of resistance is vital in veterinary medicine to anticipate future treatment challenges. Objective: This study aimed to determine the prevalence of AMR bacteria involved in 12,498 cases of otitis in dogs from the Iberian Peninsula and the evolution of AMR patterns over an 11-year period. Methods: Data was provided by the Veterinary Medicine Department of a large private diagnostic laboratory in Barcelona. Antimicrobial susceptibility testing was performed using the standard disk diffusion method and minimum inhibitory concentration (MIC) testing. Results: The frequency of the principal bacterial agents was 35% Staphylococcus spp. (principally S. pseudointermedius), 20% Pseudomonas spp. (P. aeruginosa), 13% Streptococcus spp. (S. canis), and 11% Enterobacterales (Escherichia coli and Proteus mirabilis). Antimicrobial susceptibility testing revealed P. aeruginosa (among Gram-negatives) and Enterococcus faecalis (among Gram-positives) as the species with the highest AMR to multiple antimicrobial classes throughout the years. According to the frequency and time evolution of multidrug resistance (MDR), Gram-negative bacteria like P. mirabilis (33%) and E. coli (25%) presented higher MDR rates compared to Gram-positive strains like Corynebacterium (7%) and Enterococcus (5%). The AMR evolution also showed an increase in resistance patterns in Proteus spp. to doxycycline and Streptococcus spp. to amikacin. Conclusions: This information can be useful for clinicians, particularly in this region, to make rational antimicrobial use decisions, especially when empirical treatment is common in companion animal veterinary medicine. In summary, improving treatment guidelines is a key strategy for safeguarding both animal and human health, reinforcing the One Health approach. Full article

Proteus mirabilis (P. mirabilis) is an opportunistic pathogen involved in urinary tract infections as well as various nosocomial infections. Emerging resistances to beta-lactams in this species complicates potential treatment since it is intrinsically resistant to colistin. Eleven isolates of carbapenem-non-susceptible P. mirabilis were identified in Sousse Hospital, Tunisia, from January 2018 to December 2022. MICs were determined and isolates were sequenced to determine their resistomes, sequence types, virulence factors, and their clonal relationships. Susceptibility testing showed that all isolates were resistant to carbapenems, aminoglycosides, fluoroquinolones, chloramphenicol, and the trimethoprim/sulfamethoxazole combination. They remained susceptible to the aztreonam/avibactam combination. All isolates produced NDM-1 carbapenemase and ArmA 16S rRNA methylase. In addition, one isolate co-produced the bla_VEB-6 gene. All isolates belonged to ST135, and phylogenetic analysis revealed that they were closely related. This study described the first outbreak of NDM-1-producing P. mirabilis in Tunisia. Full article

Proteus mirabilis is a significant foodborne opportunistic pathogen associated with various nosocomial infections. Chicken farms may serve as an important reservoir for P. mirabilis. However, research on antibiotic resistance and genomic features of P. mirabilis in China’s poultry industry is limited. This study isolates P. mirabilis from a breeder farm in China and investigates the dissemination of P. mirabilis and clinically significant antibiotic resistance genes (ARGs), including bla_NDM and bla_CTX-M. From 510 samples, 69 isolates were obtained, classified into 11 sequence types (STs), with ST135 and ST175 predominating. A total of 39 ARGs were detected, including fosA3, floR, bla_CTX-M-3, bla_CTX-M-65, and bla_NDM-1. Genetic analysis revealed that bla_NDM-1 was exclusively located on Salmonella genomic island 1 (SGI1), while bla_CTX-M was found in various mobile genetic elements (MGEs), including Tn7, SXT/R391 integrative conjugative elements (ICEs), Proteus mirabilis genomic resistance island 1 (PmGRI1), and SGI1. Notably, many isolates carried multiple MGEs, suggesting frequent horizontal transfer of ARGs in P. mirabilis. These findings underscore the role of P. mirabilis in carrying and spreading antibiotic resistance, posing significant risks to the poultry industry and public health. Full article

The management of infectious diseases has proven to be a daunting task for clinicians worldwide, and the rapid development of antibiotic resistance among Gram-negative bacteria is making it even more challenging. The first-line therapy is empirical, and it most often comprises β-lactam antibiotics. Among Gram-negative bacteria, Proteus mirabilis, an important community and hospital pathogen associated primarily with urinary tract and wound infection, holds a special place. This review’s aim was to collate and examine recent studies investigating β-lactam resistance phenotypes and mechanisms of Proteus species and the global significance of its β-lactam resistance evolution. Moreover, the genetic background of resistance traits and the role of mobile genetic elements in the dissemination of resistance genes were evaluated. P. mirabilis as the dominant pathogen develops resistance to expanded-spectrum cephalosporins (ESC) by producing extended-spectrum β-lactamases (ESBL) and plasmid-mediated AmpC β-lactamases (p-AmpC). β-lactamase-mediated resistance to carbapenems in Enterobacterales, including Proteus spp., is mostly due to expression of carbapenemases of class A (KPC); class B (metallo-β-lactamases or MBLs of IMP, VIM, or NDM series); or class D or carbapenem-hydrolyzing oxacillinases (CHDL). Previously, a dominant ESBL type in P. mirabilis was TEM-52; yet, lately, it has been replaced by CTX-M variants, particularly CTX-M-14. ESC resistance can also be mediated by p-AmpC, with CMY-16 as the dominant variant. Carbapenem resistance in Proteus spp. is a challenge due to its intrinsic resistance to colistin and tigecyclin. The first carbapenemases reported belonged to class B, most frequently VIM-1 and NDM-5. In Europe, predominantly France and Belgium, a clonal lineage positive for OXA-23 CHDL spreads rapidly undetected, due to its low-level resistance to carbapenems. The amazing capacity of Proteus spp. to accumulate a plethora of various resistance traits is leading to multidrug or extensively drug-resistant phenotypes. Full article

The etiology and resistance pattern of bacterial conjunctivitis varies depending on the patient’s care setting and age. A retrospective, observational study was conducted in a tertiary care teaching hospital. A total of 126 patients—76 adults and 50 children—diagnosed with conjunctival infection during inpatient or ambulatory care were analyzed. In the samples of adult patients, isolates were represented by Gram-positive cocci (57.7%; Staphylococcus spp., S. pneumoniae) followed by Enterobacterales (17.97%; P. mirabilis, E. coli, Klebsiella spp.), and non-fermenters (7.69%; Pseudomonas spp., A. baumannii). Multidrug-resistant (52.17%) and extensively drug-resistant (21.73%) pathogens (predominantly Gram-negative bacilli) were identified in conjunctival swabs of hospitalized adult patients. The main isolates (55.77%) identified in children’s conjunctival swabs belonged to S. aureus, H. influenzae, and S. pneumoniae, followed by Enterobacterales (19.22%; E. coli, P. mirabilis, M. morganii) and fungi (3.48%). Methicillin-resistant S. aureus (35.71%) and extended-spectrum beta-lactamase-producing K. pneumoniae (8.7%) were identified in the pediatric subgroup of patients. In critically ill adult patients assisted in the intensive care or burn functional units, bacterial conjunctivitis followed the pattern of infections and antimicrobial resistance specific to these categories of patients. In the case of hospitalized children, conjunctivitis was an integral part of the age-related pathology. Full article

Proteus mirabilis has been identified as the third most frequent reason for catheter-associated urinary tract infections. The production of urease significantly enhances the force of catheter blockage caused by biofilm formation. Because biofilms are important virulence factors that make antibiotics less potent, it is becoming increasingly important to develop novel alternative antibiotics. In addition to the unique properties they possess, nanoparticles made from metal oxide are currently attracting considerable attention as possible antibacterials. This research aims to explore the potential anti-biofilm properties of green manufactured ZnO-CuO nanoparticles generated by P. mirabilis. By synthesizing reductive enzymes, bacterial cells can participate in the biosynthesis process. This study explores whether green synthesized ZnO-CuO nanoparticles can work as an anti-biofilm agent formed by P. mirabilis. These nanoparticles were generated using Bacteriocins to determine their effectiveness against bacteria, which were partially purified and showed antimicrobial activity against Gram-negative bacteria of P. mirabilis. AFM, TEM, FESEM, XRD, and ultraviolet (UV)–visible spectroscopy were used to analyze the biosynthesized nanoparticles to ascertain their chemical and physical characteristics. XRD verified the hexagonal structure, TEM demonstrated a size range of 96.00 nm, and FESEM verified the surface morphology. The dispersion and roughness of the nanoparticles are shown through AFM examination. The produced nanoparticles’ UV-visible spectra displayed a maximum peak at 287 and 232 nm. When applied to strains (wild-type) of Proteus mirabilis (multidrug-resistant), copper and zinc nanoparticles had notable biofilm inhibitory effects. Weak biofilm production has been demonstrated by bacteria that effectively generate biofilms, following incubation with 128 μg/mL subminimum inhibitory concentrations (MICs) of CuO nanoparticles for 24 and 48 h at 37 °C. Following treatment with the ZnO-CuO nanocomposite of these strains, downregulation alterations in LuxS expression were detected by utilizing a real-time PCR process. After this, isolates were treated with the nanocomposite, and downregulated shifts in LuxS expression were found by utilizing the real-time PCR technique in contrast with the isolates that were not treated. Zinc oxide (ZnO) nanoparticles can be utilized as antibacterial agents in a concentration-dependent manner, aligning with all observed findings. The present research demonstrates that green synthesized copper oxide–zinc oxide nanocomposites are effective anti-biofilm agents against P. mirabilis. Their noteworthy downregulation of LuxS gene expression successfully prevents biofilm formation and swarming motility. Full article

Two significant clinical issues associated with the use of urinary catheters are catheter-associated urinary tract infection and encrustation. This study describes the design of novel hydrogels based on fatty acid-containing p(hydroxyethylmethacrylate, HEMA) and their resistance to both microbial adherence and encrustation. Incorporation of fatty acids increased the contact angle (surface hydrophobicity), decreased the ultimate tensile strength only after storage at pH 9 in artificial urine (AU) but not at lower pH values, decreased the Young’s modulus and % elongation at break (both stored in deionised water, AU pH 6 and AU pH 9) and decreased equilibrium swelling (only when stored in deionised water or AU pH 6 but not AU pH 9). Moderate reductions in adherence of Escherichia coli, Proteus mirabilis and Staphylococcus epidermidis to certain fatty acid containing (primarily decanoic acid and myristic acid) hydrogels were observed. No relationship was observed between hydrogel contact angle and resistance to microbial attachment. Most fatty acid-containing hydrogels exhibited significant, concentration-dependent resistance to encrustation, postulated to be due both to a greasy film resultant from the formation of the calcium/magnesium fatty acid salts at the surface and the role of Tween^® 80 in facilitating the removal of the fatty acid salts from the surface of the hydrogel. The observed enhanced resistance of the hydrogels to encrustation offers opportunities for the use of such systems as platforms for coatings of urinary catheters. Full article

The aim of this paper is to evaluate, from a chemical and antibacterial point of view, sprouts from species of Fabaceae and Brassicaceae families, to establish a correlation between analyzed parameters and to test the possibility of using these functional compounds in the flour food industry. The material used was lentil sprouts (LS), pea sprouts (PS), bean sprouts (BS), and radish sprouts (RS), which were chemically analyzed by determining the content of total and individual polyphenols and macro- and microelements. The antimicrobial potential of the sprout extracts obtained was tested using the disk diffusion method on five bacterial strains: Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Enterococcus faecalis, and Staphylococcus aureus. In order to capitalize on the flour food industry, the sprouts were introduced in the recipes for the manufacture of some cookies, and sensory analysis was performed. The results obtained indicated that LS are the sprouts with the highest content of TPC (524.130 mg/100 g) and highest content for Ni, Cu, Zn, Fe, Mn, and Mg, while the highest values for Ca were recorded in the case of PS (256.575 ± 2.23 mg/kg), and for K in the case of the BS sample (4819.450 ± 1.1 mg/kg). The RS extract has been shown to be effective against E. faecalis (MIC-70 µL/mL), S. aureus (MIC 50 µL/mL), and PS against S. aureus (MIC 70 µL/mL). Regarding the sensory analysis of cookies, the panelists participating in the study preferred products based on BS and PS in a percentage of 2.5%. Full article

The global rise in temperatures due to climate change has made it difficult even for specialised desert-adapted plant species to survive on sandy desert soils. Two of Namibia’s iconic desert-adapted plant species, Welwitschia mirabilis and the quiver tree Aloidendron dichotomum, have recently been shown to be under threat because of climate change. In the current study, three ecologically important Namibian Euphorbia milk bushes were evaluated for their climate change response. By comparing good-quality aerial photographs from the 1960s and recent 2020s high-resolution satellite images, it was determined by QGIS remote sensing techniques that very high percentages of the large succulents E. damarana, E. gummifera, and E. gregaria have died during the last 50 years in arid areas of Namibia. Areas like Brandberg (northern Namibia), Klein Karas (south-east), and Garub (south-west), with a high sandy-textured ground cover, have seen the loss of around 90% of E. damarana and E. gregaria and about 61% of E. gummifera in this period. This is alarming, as it could threaten the survival of several animal species adapted to feed on them, especially during droughts. This study focused on large succulent euphorbias, distinguishable in satellite images and historical photographs. It was observed that many other plant species are also severely stressed in arid sandy areas. The obtained results were ground-truthed and species identification was confirmed by the chemical analysis of remaining dead twigs using GC-MS and metabolomics. The ERA5 satellite’s 2 m above-ground temperature data show a 2 °C rise in annual average noon temperatures since 1950 at the three locations analysed. Annual daily temperatures increased by 1.3 °C since 1950, exceeding the global average rise of about 1.0 °C since 1900. This suggests that euphorbias and other plants on low-water-capacity sandy soils in Namibia face greater climate change pressure than plants globally. Full article

Background/Objectives: Chronic wounds, including hidradenitis suppurativa (HS) and venous ulcers (VU), are commonly associated with complex microbial communities that may influence wound healing and treatment outcomes. Understanding microbial diversity and antibiotic resistance patterns is essential in order to optimize therapeutic strategies. This study aimed to investigate the microbial populations and antibiotic resistance profiles in HS and VU patients, comparing the prevalence of common pathogens and their antimicrobial resistance profiles. Methods: We conducted a cross-sectional analysis that included a total of 112 individuals (24 with the diagnosis of hidradenitis suppurativa and 88 diagnosed with venous ulcer). Wound swabs were cultured to identify bacterial species, and antibiotic resistance was assessed using a standard panel of antibiotics. Prevalence rates of key pathogens, such as Staphylococcus aureus, Pseudomonas aeruginosa, and Enterococcus faecalis, were compared between the two groups. Resistance patterns were analyzed using statistical methods to identify significant differences. Results: Staphylococcus aureus was the most common pathogen in both groups (45.8% in HS; 38.6% in VU), with a notable prevalence of methicillin-resistant S. aureus (MRSA). Pseudomonas aeruginosa was exclusively identified in VU patients (27.3%), while beta-hemolytic Streptococcus and Corynebacterium amycolatum were identified in HS cases only. Antibiotic resistance was moderate, notably in S. aureus and Proteus mirabilis, while one case of multidrug-resistant Pseudomonas aeruginosa was identified. Conclusions: This study highlights the distinctive microbial profiles and antibiotic resistance patterns in HS and VU chronic wounds. The predominance of S. aureus in both groups underscores the need for targeted therapies, while the absence of P. aeruginosa in HS wounds and the higher prevalence of other species emphasizes wound-specific microbial variations. These findings underscore the importance of personalized treatment strategies and continuous surveillance of antimicrobial resistance. Full article