Search Results (823)

Black cumin (Nigella sativa L.) oil has been traditionally used to manage infectious diseases. The scientific validation of its antibacterial potential remains of significant pharmacological interest. This study evaluated the in vitro antibacterial activity of cold-pressed black cumin oil against selected bacterial strains and compared its efficacy with that of common β-lactam antibiotics, supplemented by mechanistic insight through molecular docking. Pure oil was obtained via cold-press extraction from seeds. Antibacterial activity was evaluated using the disk diffusion and broth microdilution methods against Staphylococcus aureus NCTC10788, Bacillus cereus NCTC7464, Listeria monocytogenes ATCC11994, Escherichia coli NCTC2001, and Salmonella typhimurium NCTC11994. Commercial antibiotic disks containing cloxacillin (5 µg), cefoperazone (75 µg), penicillin (40 µg), and amoxicillin (25 µg) served as a reference. Potential molecular interactions were explored by the density functional theory (DFT) optimization of thymoquinone at the B3LYP/6-31+G(d,p) level, followed by molecular docking against bacterial targets. Inhibition zone diameters ranged from 13.5 ± 0.7 mm to 34 ± 2.1 mm, and minimum inhibitory concentration (MIC) values varied between 6.7 ± 2.3 and 64 ± 0.0 µg/mL depending on the bacterial strain tested. Black cumin oil demonstrated a stronger inhibitory effect on B. cereus and L. monocytogenes than the other bacteria tested, and exhibited a significantly higher inhibitory effect than some of the antibiotics tested (p < 0.05). In contrast, no statistically significant differences were observed among treatments against E. coli (p > 0.05). Overall, Gram-positive bacteria showed greater susceptibility to black cumin oil than Gram-negative bacteria. The computational analyses demonstrated stable binding interactions supporting the experimental results. These integrative in vitro and in silico findings provide mechanistic evidence for the traditional use of black cumin oil in treating infections. The results suggest that black cumin oil could be a promising natural antibacterial candidate; however, further toxicological and pharmacokinetic evaluations are required prior to clinical use. Full article

The Ili River is a transboundary water body in Central Asia and a key region along the Belt and Road Initiative, yet antibiotic pollution in this river remains unexplored. This study investigated the occurrence, distribution, and ecological risks of 14 antibiotics in the Yining section of the Ili River and the effluent of the Huocheng Wastewater Treatment Plant (HWTP). We optimized and validated an analytical method using solid-phase extraction coupled with high-performance liquid chromatography-tandem–mass spectrometry (SPE-HPLC-MS/MS). The method achieved low detection limits (0.05–1.0 ng·L⁻¹) and good recoveries (70.0–108.3%). Results showed that HWTP removed 9.8–98.3% of detected antibiotics, with negative removal observed for several compounds due to desorption or metabolite reconversion. In the Yining river section, tetracyclines dominated (55.9% of total antibiotics), followed by fluoroquinolones (33.8%), macrolides (9.7%), and β-lactams (0.6%). Ecological risk assessment using the risk quotient method revealed that the combined risk (RQ_s) in the Yining section ranged from 1.54 to 2.74, indicating a high-risk level. Chlortetracycline exhibited the highest individual risk (RQ 0.92–0.97) and is proposed as a priority pollutant. This study provides the first baseline data on antibiotic pollution in a Central Asian transboundary river and underscores the need for international cooperation in water quality management within the Belt and Road framework. Full article

Background/Objectives: Klebsiella (K.) pneumoniae is a significant pathogen in both humans and animals. However, data on its occurrence in animals in Germany remain limited. This study aimed to investigate the antimicrobial resistance (AMR) phenotypes, AMR genes, and virulence traits of animal-derived K. pneumoniae isolates from Germany. Methods: A total of 59 K. pneumoniae isolates obtained in 2023 from dogs, cats, horses, cattle, and chickens across 11 German federal states were analysed. Phenotypic antimicrobial susceptibility testing (AST) was performed, and whole-genome sequencing (WGS) was used for genomic characterisation, including detection of AMR genes, virulence-associated genes, sequence types (STs), and plasmid replicons. Results: Most isolates (78%) were susceptible to all tested antibiotics, while three isolates were classified as multidrug-resistant (MDR). Resistance was most frequently observed for piperacillin (n = 8) and trimethoprim/sulfamethoxazole (n = 4). Carbapenem resistance was detected in two isolates (one from a dog and one from a cat), and phenotypic colistin resistance in one dog isolate. WGS identified 96 AMR genes across isolates, with 20–42 AMR determinants per isolate, conferring resistance to β-lactams, aminoglycosides, fluoroquinolones, sulfonamides, tetracyclines, trimethoprim, and fosfomycin. Ten extended-spectrum β-lactamase (ESBL)-producing isolates carried genes including bla_CTX-M-15, bla_SHV-2, bla_SHV-27, bla_SHV-42, bla_SHV-106, and bla_TEM-158. Although fosA was detected in all isolates, only three exhibited phenotypic resistance to fosfomycin. A total of 52 STs were identified, including high-risk clones. One hypervirulent isolate (ST60) carrying hypervirulence-associated genes rmpA and iroB was detected. Plasmid replicons were present in 70% of isolates, while plasmid-associated AMR genes were identified in nine isolates. Conclusions: This study demonstrates the genomic diversity of K. pneumoniae identified in companion animals and highlights the presence of AMR and virulence determinants relevant to a One Health context. Full article

Background: Staphylococcus aureus acquires methicillin resistance genes through the SCCmec element. Although spontaneous SCCmec excision has been observed, its frequency, type-specific variation, and responsiveness to environmental conditions remain undefined. Here, we systematically quantified SCCmec excision across diverse prototypic types/subtypes and evaluated the factors that contribute to excision variability. Methods: Twenty five prototypic MRSA strains (SCCmec types I–VIII, XI–XIII and defined subtypes) were examined under standard growth temperature (37 °C), elevated temperature (42 °C), desiccation, prolonged continuous culture (30 days), and sub-lethal oxacillin pressure. Excision frequencies were quantified using qPCR, normalized to the gyrB housekeeping gene using the formula: 10^{−((Ct,orfX−Ct,gyrB)/3.32)}. Statistical analyses included one-way ANOVA, t-tests, and OLS regression for time-dependent trends. Results: At 37 °C, excision frequencies ranged from 2.40 × 10⁻⁶ to 1.32 × 10⁻³ and varied among representative SCCmec types/subtypes but were unrelated to SCCmec size (R² = 0.027, p = 0.44). Type I showed no detectable excision due to a truncated ccrB gene. At 42 °C, excision increased in 14 of 24 types (median +11.2%; eight significant) and decreased in 10 (median −7.4%; four significant). Desiccation produced similar effects, with nine types increasing (median +7.1%; four significant), 14 decreasing (median −8.2%; five significant), and one unchanged. Continuous culture exhibited progressive increases in excision across multiple types (R² = 0.3–0.94), whereas sub-lethal oxacillin uniformly maintained low detectable excision frequencies across all SCCmec types. Conclusions: Excision varied among representative SCCmec types and was influenced heterogeneously by distinct stress conditions. Continuous culture promoted excision, whereas oxacillin exposure maintained low detectable excision. This work quantitatively confirms spontaneous SCCmec excision and provides new insights into MRSA genome plasticity. Full article

Introduction: Urinary tract infections (UTIs) represent a growing concern in both clinical practice and public health, affecting hospitalized and outpatient populations across all ages and genders. This study aims to evaluate the prevalence of uropathogens and their antimicrobial resistance profiles in male and female patients comparatively at a tertiary urological center. Materials and Methods: A retrospective descriptive analysis was conducted, covering three identical 6-month periods—September 1 to February 28—in three consecutive years from 2023 to 2025. The study included 2270 male patients (2270. 57.06%) and 1708 female patients (1708. 42.94%), all with at least one positive urine culture (>10⁵ CFU/mL). Data on age, gender, bacterial species, and antimicrobial agents were collected and analyzed. Results: A higher prevalence of Gram-negative bacteria was observed compared to Gram-positive bacteria in both male (1752; 77.18% vs. 518; 22.82%) and female (1369; 80.15% vs. 339; 19.85%) groups. The most common microorganisms were Escherichia coli, followed by Klebsiella and Enterococcus. Klebsiella showed high rates of antimicrobial resistance, especially in males, across various antibiotic classes such as amoxicillin-clavulanic acid (60.6% vs. 43.25%), levofloxacin (40.18% vs. 27.91%), aztreonam (37.4% vs. 27.27%), and ceftazidime (36.23% vs. 24.03%). High resistance levels, although not statistically significant, were also noted for trimethoprim/sulfamethoxazole (43.64%) and nitrofurantoin (65.69%). In males, E. coli exhibited higher resistance rates to trimethoprim/sulfamethoxazole (44.65% vs. 32.89%), levofloxacin (43.27% vs. 30.78%), and amoxicillin-clavulanic acid (40.18% vs. 27.19%). Carbapenems remained highly susceptible in both groups. Enterococcus showed similar resistance patterns in both cohorts, primarily resistant to penicillin and levofloxacin. Conclusion: This study highlights higher resistance rates among Gram-negative bacteria in males to commonly used antibiotics such as fluoroquinolones, trimethoprim/sulfamethoxazole, and β-lactams. Resistance patterns in Gram-positive bacteria remained stable across both populations, with high susceptibility to fosfomycin, nitrofurantoin, linezolid, and carbapenems. Differences between sexes emphasize the need for more detailed analysis of local and sex-specific resistance patterns. Full article

Background: Community-acquired pneumonia (CAP) is a major cause of morbidity and mortality globally, with serious implications in Lebanon. Both international and local guidelines advocate for empirical antibiotic treatments by illness severity, yet the extent to which these are followed in Lebanese hospitals is unclear. This research examined the adherence to CAP treatment guidelines and its association with clinical outcomes. Methods: We retrospectively studied adults admitted to two Lebanese referral hospitals (Mount Lebanon University Medical Center and Ain Wazein Medical Village) from April 2011 to March 2025 with CAP. Adherence to empirical antibiotic regimens was determined based on the guidelines from the Lebanese Society of Infectious Diseases and Clinical Microbiology, American Thoracic Society/Infectious Diseases Society of America, and British Thoracic Society/National Institute for Health and Care Excellence. The outcomes assessed were in-hospital mortality, Intensive Care Unit (ICU) admission, and length of hospital stay (LOS). We used logistic and linear regression analyses, adjusting for demographic and clinical variables. Results: A total of 337 patients were included with an average age of 61 years; 53.7% were male, 51.6% were admitted to the ICU, and the in-hospital mortality rate was 27%. In general, 65.6% of the treatment regimens adhered to at least one guideline. The combination of β-lactam and macrolide was the most common, used in 87.8% of cases, while monotherapy was administered in 31.8% of cases and included β-lactam, macrolide, fluoroquinolone, and other antibiotics; most monotherapies were non-adherent to guidelines, except for selected fluoroquinolone monotherapy cases that may be considered guideline-concordant under ATS/IDSA recommendations depending on clinical context. Adherence to guidelines did not significantly affect mortality rates (25.8% vs. 29.3%), ICU admissions (52.5% vs. 50.0%), or length of stay (11.4 vs. 9.3 days). Multivariate analysis revealed that older age (OR 1.025, 95% CI 1.008–1.042) and ICU admission (OR 1.024, 95% CI 1.012–1.039) were independent predictors of adverse outcomes, whereas guideline adherence, comorbidities, and inflammatory markers were not independently linked. Surprisingly, mortality was higher among younger patients (average age 58 vs. 67 years, p < 0.001). Conclusions: Although guideline-concordant empirical therapy was prevalent in this two-center Lebanese retrospective population, it did not independently correlate with length of stay following adjustment, ICU admission, or in-hospital mortality. Patient-related and clinical factors, such as the severity of the illness, may have an impact on observed differences in outcomes, which should be taken as relationships. Full article

Macrococcus is a genus of Gram-positive cocci in the Staphylococcaceae family and a close phylogenetic relative of Staphylococcus. It is not a significant human pathogen but is known to widely colonize different environments, including animal skin and food products. Phylogenetically, Macrococcus is distinct from yet closely related to Staphylococcus, particularly the sciuri group. The species is effectively identified through such molecular markers as hsp60 and 16S rDNA. A key biochemical feature is an identified FAD-dependent oleate hydratase in Macrococcus equipercicus (M. equipercicus). Critically, Macrococcus carries various mobile antibiotic-resistance genes, especially against β-lactams (e.g., mecB, mecD) and macrolides (e.g., mef(F), msr(G)); these genes are located on plasmids, SCCmec-like elements, or resistance islands (e.g., McRI_mecD), which facilitates their horizontal transfer. Surveillance confirms the widespread presence of methicillin-resistant Macrococcus, often with a multidrug-resistant phenotype, in food animals and their products. Although its own pathogenicity is low, Macrococcus acts as a reservoir and transmission platform for resistance genes: through horizontal gene transfer, it can potentially confer resistance to pathogenic Staphylococcus, thereby posing a threat to animal and public health. This review summarizes the basic biological characteristics and drug resistance-related research progress of the genus Macrococcus; it aims to provide a reference for subsequent studies as well as to establish technical support and a theoretical basis for the epidemiological investigation, drug-resistant strain identification, and clinical drug-resistance risk prevention and control of Macrococcus. Full article

Background/Objectives: The thermal stability and degradation kinetics of β-lactam antibiotics are critical for understanding their behavior under processing and storage conditions. This study investigates the thermal decomposition of meropenem, ceftriaxone sodium, and cefazolin sodium in order to evaluate their kinetic parameters, assess the presence of the compensation effect, and determine isokinetic temperatures. Methods: Thermal analysis was performed using simultaneous TG/DTG/DSC measurements. Non-isothermal degradation experiments were conducted at four different heating rates. Kinetic parameters were evaluated using two isoconversional methods (Friedman and Flynn–Wall–Ozawa) and ASTM E698-based approach to obtain average activation energies. To determine the pre-exponential factor (A), the Coats–Redfern method was applied using multiple kinetic models. The resulting lnA—E_a pairs obtained from different models were used to construct lnA = f(E_a) correlations, enabling the evaluation of the compensation effect and calculation of isokinetic temperatures (T_iso). Results: All three β-lactam antibiotics exhibited consistent kinetic behavior across the applied models, with the F3 reaction model providing the best fit based on R² values. A clear linear relationship between lnA and E_a was observed, confirming the presence of an enthalpy–entropy compensation effect. However, significant differences in isokinetic temperatures were obtained indicating variability in kinetic compensation behavior among the studied compounds. Conclusions: The thermal degradation of the investigated β-lactam antibiotics follows a consistent kinetic framework, supported by isoconversional and model-fitting approaches. Nevertheless, the absence of a unique isokinetic temperature suggests differences in transition-state stabilization and enthalpy–entropy balance, likely driven by structural variations among the compounds. Full article

Background/Objectives: Residues of β-lactam antibiotics in foods of animal origin are important for official residue control and public-health risk assessment. Sample storage conditions may affect the measured concentrations of these analytes, whereas cooking may influence consumer exposure. This study evaluated the stability of six β-lactam antibiotics—amoxicillin, ampicillin, phenoxymethylpenicillin, benzylpenicillin, cefazolin, and cefotaxime—and clavulanic acid, a β-lactamase inhibitor, in chicken meat during storage and thermal processing. Methods: Incurred chicken meat samples were obtained after in vivo administration of the studied compounds. Stability was assessed during storage at +4 °C, −20 °C, and −86 °C for up to 165 days, during repeated freeze–thaw handling, and during heating at 100 °C for up to 30 min. The target compounds were quantified by HPLC–MS/MS after acetonitrile extraction and hexane clean-up. Results: The studied compounds were unstable at +4 °C, with concentrations decreasing below the detection limit within 3–27 days depending on the compound. Storage at −20 °C was insufficient for long-term preservation of most penicillins, whereas −86 °C improved stability. Cefazolin was the most stable compound under the tested storage conditions, while cefotaxime was the least stable. Heating at 100 °C for 30 min caused substantial reduction in parent-compound concentrations, ranging from 63.8 ± 4.0% for cefazolin to complete disappearance below the detection limit for cefotaxime. Conclusions: For reliable official residue analysis, chicken meat samples intended for β-lactam testing should be stored at −86 °C whenever long-term storage is required. Repeated thawing should be avoided. Cooking substantially reduces the concentrations of the parent compounds but cannot be considered a reliable safety measure, because degradation may be incomplete and degradation products were not assessed in this study. Full article

Background/Objectives: Patients in long-term care hospitals (LTCHs) are at increased risk of harboring antimicrobial-resistant organisms due to frequent healthcare exposure and multiple comorbidities. This retrospective observational study aimed to compare the antimicrobial susceptibility of bacterial isolates from LTCH-onset infections (LTCHIs) with those from community-acquired infections (CAIs) in elderly patients. Methods: This study was conducted at a 700-bed urban tertiary university hospital and included patients aged ≥65 years with positive cultures for bacteremia, lower respiratory tract infections (LRTIs), or urinary tract infections (UTIs) within 48 h of admission. Medical records, including antimicrobial susceptibility test results, were reviewed for a total of 1780 patients and their isolates. Antimicrobial susceptibility patterns were compared between LTCHI and CAI patients. Results: Patients with LTCHI exhibited significantly higher antimicrobial non-susceptibility than those with CAIs across multiple pathogens and antimicrobial classes (p < 0.05). In bacteremia, Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae from LTCHI cases showed increased non-susceptibility to β-lactams and fluoroquinolones. In LRTIs, Pseudomonas aeruginosa and Acinetobacter baumannii demonstrated high non-susceptibility to carbapenems (52.9% and 90%, respectively) and aminoglycosides. In UTIs, LTCHI isolates exhibited broader resistance among Enterobacterales and P. aeruginosa. Notably, the proportion of multidrug-resistant organisms, including carbapenem-resistant Enterobacterales (15.4–50.0%) and carbapenem-resistant Acinetobacter baumannii (90.5%), was substantially higher in the LTCHI group across all infection sites. Conclusions: Elderly patients with LTCHI are more likely to harbor antimicrobial-resistant pathogens than those with CAIs. Careful consideration of LTCHI origin is therefore essential for empirical antibiotic selection and for strategies aimed at limiting further resistance. Full article

Klebsiella pneumoniae is an opportunistic pathogen associated with both community-acquired and nosocomial infections. Multidrug-resistant (MDR) strains are increasingly implicated in urinary tract infections (UTIs), traveller’s diarrhoea, bacteraemia, and sepsis. β-lactam antibiotics are commonly used for treatment; however, antimicrobial resistance has emerged largely due to the production of extended-spectrum β-lactamases (ESBLs), which confer resistance mainly to penicillins, oxyimino-cephalosporins, and monobactams, while cephamycins and carbapenems usually remain stable to ESBL-mediated hydrolysis and compromise therapeutic efficacy. ESBL-producing strains represent a major cause of severe Gram-negative infections. This study aimed to determine the prevalence of ESBL-producing K. pneumoniae among UTI patients in Jordanian hospitals (Al Mafraq, Ma’an, and Islamic Hospitals), evaluate their antimicrobial susceptibility patterns, and detect antimicrobial resistance genes at the molecular level. A total of 450 urine isolates of K. pneumoniae were collected from UTI patients between November 2023 and May 2024. Isolates were identified in hospital laboratories using standard microbiological methods. Antimicrobial susceptibility testing was performed, and molecular characterisation of ESBL-associated genes was conducted using polymerase chain reaction (PCR). Out of 450 K. pneumoniae isolates collected from UTI patients across three Jordanian regions, 72 (16%) were confirmed as ESBL producers. Among the 72 ESBL-positive K. pneumoniae isolates, 34 (47.2%) were recovered from the Central region, 20 (27.8%) from the North, and 18 (25.0%) from the South. Molecular analysis revealed that 41.7% of ESBL-producing isolates carried the blaCTX-M gene, while 33.3% harboured the blaOXA gene. All ESBL-producing isolates demonstrated antimicrobial resistance to third-generation cephalosporins. A significantly higher proportion of ESBL-producing isolates was identified in female patients (84.7%) compared with males (15.3%). A significant association was observed between blaOXA gene distribution and geographic region (p = 0.016), whereas blaCTX-M gene distribution showed no significant regional association. ESBL-producing K. pneumoniae accounted for a substantial proportion of UTI isolates in Jordan, with blaCTX-M identified as the predominant resistance gene. The higher burden observed in the Central region and among female patients highlights notable distribution patterns in this cohort. These findings emphasise the necessity for sustained molecular surveillance and strengthened antimicrobial stewardship strategies to limit the dissemination of ESBL-producing strains in Jordanian healthcare settings. Full article

The global spread of multidrug-resistant (MDR) Gram-negative pathogens has significantly narrowed therapeutic options for serious infections. MDR organisms frequently harbor multiple resistance mechanisms, such as β-lactamases and non-β-lactam determinants, which limit the activity of many β-lactam/β-lactamase inhibitor combinations and complicate the clinical utility of newer agents such as cefiderocol and aztreonam–avibactam. These challenges highlight the need for mechanistically distinct, non-β-lactam therapies capable of maintaining activity in MDR settings. Eravacycline is a fully synthetic fluorocycline antibiotic that inhibits bacterial protein synthesis through high-affinity binding to the 30S ribosomal subunit, a mechanism unaffected by β-lactamase-mediated resistance. Structural modifications at key positions confer stability against common tetracycline resistance mechanisms, including efflux pumps and ribosomal protection proteins. In vitro surveillance studies consistently demonstrate potent activity against a broad range of MDR Gram-negative pathogens, notably carbapenem-resistant Enterobacterales and isolates harboring metallo-β-lactamases. The clinical efficacy and safety of eravacycline have been established in pivotal Phase 3 trials for complicated intra-abdominal infections. Although highly resistant phenotypes were underrepresented in these trials, emerging real-world data describe off-label use in MDR Gram-negative infections, often as salvage or step-down therapy. These experiences suggest acceptable clinical outcomes and favorable tolerability in complex, high-risk patients. This review synthesizes mechanistic, microbiologic, pharmacologic, and clinical evidence supporting eravacycline’s potential role in the management of MDR Gram-negative infections. Full article

Background/Objectives: Antimicrobial conjugates have attracted considerable interest in addressing the threat of antimicrobial resistance by minimising the likelihood of resistance onset. Antimicrobial peptide mimic–antibiotic conjugates offer a unique strategy to revitalise current clinical agents through increased membrane permeabilisation, prolonging the longevity of traditional antibiotics while broadening the spectrum of activity of the AMP mimic. Methods: This study explored non-cleavable, enzyme-cleavable, and pH-cleavable linked conjugates between an anthranilamide-based peptide mimic and current clinically available antibiotics to assess the viability of conjugation in enhancing antimicrobial activity as measured through MIC assays. Cleavage studies were conducted to assess the stimulus susceptibility of relevant compounds. Results: Four amide-linked non-cleavable conjugates were synthesised. Of these, a primary amide-linked conjugate between ciprofloxacin and the peptidomimetic had the most significant activity with an MIC of 15.6 µM towards Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa, and an MIC of 7.8 µM towards Gram-negative Escherichia coli. A hydrazone-based pH-sensitive linker system was synthesised and had an MIC of 15.6 µM towards Gram-negative E. coli. Finally, an enzyme-cleavable cephalosporin conjugate system was investigated, which offered a unique method for the specific treatment of resistant bacterial strains. Cleavage studies of this conjugate suggested rapid degradation of the β-lactam ring and release of the subunit. Conclusions: This work presents conjugate systems between peptide mimics and antibiotics as a new, promising strategy to broaden the antimicrobial spectrum of novel antimicrobial agents. Full article

Introduction: Urinary tract infections (UTIs) in male patients are a topic that has received less attention in the medical literature. Current management strategies recommended by most guidelines are largely based on research involving female populations, which limits their applicability to men, in whom UTIs are often considered complicated. While the COVID-19 pandemic has brought about many changes in antibiotic treatment, this study aims to compare antimicrobial resistance patterns of uropathogens in male patients between the COVID-19 pandemic and post-pandemic periods. Materials and Methods: A retrospective descriptive study including urine-culture positive cases in male patients was conducted at a tertiary-level university urology center in Bucharest, Romania. To assess temporal trends, the analysis used four selected six-month intervals during the COVID-19 pandemic (2020–2022) and the post-pandemic period (2023–2025). Inclusion was limited to adult male patients aged at least 18 years who had a single identified pathogen and significant bacteriuria (at least 10⁵ CFU/mL). Duplicate and polymicrobial samples were excluded. In accordance with CLSI guidelines, bacteria were identified and antimicrobial susceptibility was assessed using standard microbiological methods. Statistical analysis was made using Python 3.11.3. Results: A total of 3158 urine positive urine cultures from male patients were included. Gram-negative isolates were the most frequent, with E. coli being the most common urinary pathogen, followed by Klebsiella. The most common Gram-positive isolate was Enterococcus. Antimicrobial resistance in Gram-negative pathogens were higher in the post-pandemic period compared to the pandemic period, particularly to amoxicillin-clavulanic acid, and levofloxacin, with carbapenem resistance exceeding 20%. E. coli showed increased resistance rates to levofloxacin, and amoxicillin-clavulanic acid, and ceftazidime. Resistance of Klebsiella spp. exceeded 30% for imipenem and meropenem. Resistance to amoxicillin-clavulanic, ceftazidime, and imipenem acid increased in Proteus spp. Even though Pseudomonas spp.demonstrated higher resistance rates to several antibiotics, no statistical differences were observed. Enterococcus spp. showed a stable profile, demonstrating resistance to levofloxacin, penicillin, and ampicillin. Conclusion: Among male patients, uropathogens’ antimicrobial resistance was higher in the post-pandemic period compared to the COVID-19 period, particularly among Gram-negative bacteria. Regarding empirical therapy, there are significant concerns regarding the rise in resistance to antibiotics such as fluoroquinolones and β-lactams, as well as the emergence of resistance to carbapenems. Full article

Wastewater treatment plants (WWTPs) are identified as contributors to faecal pollution and the spread of antimicrobial resistance (AMR) in water ecosystems. This research examined the prevalence, profiles of antimicrobial resistance, and pathogenic types of Escherichia coli in effluent from WWTPs and nearby river systems in the Vhembe District. Between May and June 2025, 28 water samples were collected from two WWTP discharge points as well as upstream and downstream locations along the Mvudi, Luvuvhu, and Madadzhe Rivers. The enumeration of E. coli was conducted using Colilert Quanti-Tray method, with isolates obtained via membrane filtration and confirmed using API 20E and VITEK^®2 systems. Antimicrobial susceptibility was assessed using VITEK^®2, while pathotypes were detected through multiplex PCR. E. coli was found at all sampling locations; however, differences in concentrations across sampling sites and sampling periods were not statistically significant (p > 0.05). Out of 26 confirmed isolates, a significant resistance to β-lactam antibiotics was noted, especially ampicillin (100%). Pathotype analysis revealed strains such as ETEC, EAEC, and EPEC. These results underline extensive contamination by antimicrobial-resistant E. coli in rivers affected by WWTP discharge, which poses potential public health concerns and underscores the necessity for enhanced monitoring efforts. Additional research is needed to validate these findings. Full article