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Extended‐spectrum β‐lactamase (ESBL)–producing Gram‐negative bacteria pose a severe therapeutic challenge globally. Streptomyces remain one of the most prolific natural sources of antibacterial and antioxidant secondary metabolites, yet their activity against ESBL‐producing pathogens remains under‐explored. Soil‐derived Streptomyces isolates were screened for bioactivity, and the most potent strain (SM7) was identified by 16S rRNA sequencing. Secondary metabolites were extracted using ethyl‐acetate and evaluated for antibacterial activity against ESBL‐producing Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae using agar diffusion, MIC, and MBC assays. Antioxidant activity was assessed using DPPH and ABTS assays, while GC–MS and molecular docking were employed to identify and characterize bioactive compounds. Streptomyces sp. SM7 exhibited strong antibacterial activity, producing inhibition zones of 21.4 ± 0.6 mm, 19.2 ± 0.4 mm, and 17.6 ± 0.5 mm against ESBL‐producing E. coli, K. pneumoniae, and E. cloacae, respectively. MIC values ranged from 62.5 to 250 µg/mL, with bactericidal MBC/MIC ratios of 2. The extract showed potent antioxidant activity with DPPH and ABTS IC₅₀ values of 48.9 µg/mL and 61.4 µg/mL, respectively. GC–MS identified 18 bioactive compounds, with 2,4‐di‐tert‐butylphenol (18.6%) as the major constituent, which exhibited a docking affinity of −7.1 kcal/mol against bacterial DHFR. Streptomyces sp. SM7 produces phenolic‐ and fatty‐acid‐rich metabolites with potent bactericidal and antioxidant activities against ESBL‐producing pathogens, highlighting its promise as a natural source of next‐generation antimicrobial agents. These findings support Streptomyces sp. SM7 as a promising lead for downstream purification, mechanism‐guided optimization, and future drug‐development efforts targeting difficult‐to‐treat ESBL‐producing Enterobacterales. soil‐derived Streptomyces sp. SM7 with bactericidal and antioxidant activities

Antibiotic-resistant bacteria (ARBs) can now be detected not only in clinical institutions but also in wastewater treatment plants (WWTPs), extending the range of emergence to residential areas. In this study, we investigated the change of antibiotic-resistant Escherichia coli ( E. coli ) and other coliforms in each treatment process at WWTPs. Throughout the treatment process, the numbers of E. coli and other coliforms were significantly reduced to less than 5.7 ± 0.5 CFU/100 ml and 2.4 ± 0.0×10 2 CFU/100 ml, respectively. However, ESBL-producing E. coli and other coliforms were detected in each treatment process (even after chlorination) at 5.6% and 4.8%, compared to the total E. coli and other coliforms counts. Then, ESBL-producing-related genes were identified via PCR analyses, and the most predominant gene was CTX-M-9 in both E. coli (47.2%) and other coliforms (47.3%). Although actual WWTPs greatly reduced the number of bacteria, the relative prevalence of ESBL-producing bacteria was increased, suggesting that ESBL-producing bacteria remain in the effluent at minimal concentrations and could be diffusing to water bodies.

Pyelonephritis is a serious condition that is rarely described in horses. In contrast, urinary tract infections are common in humans and small animals, and multi‐drug‐resistant urinary infections are an emerging threat. In this report, we describe a horse with unilateral pyelonephritis caused by extended‐spectrum beta‐lactamase‐producing bacteria belonging to the Enterobacter cloacae complex. [Correction added on 9 August 2023, after first online publication: The preceding sentence was corrected.] An 11‐year‐old Swedish warmblood gelding was diagnosed with a cystolith and a cystotomy through an open left para‐inguinal approach was performed. Seven days after surgery the horse presented with pyrexia, dullness and colic. Diagnostic testing and renal transabdominal ultrasonography confirmed the presence of a right‐sided pyelonephritis. Culture and antimicrobial susceptibility testing revealed a pure growth of extended‐spectrum beta‐lactamases‐producing E. cloacae complex bacteria with resistance against beta‐lactams, aminoglycoside and trimethoprim–sulphonamide classes. Treatment included prolonged oral antimicrobials according to susceptibility testing results (enrofloxacin), judicious use of non‐steroidal anti‐inflammatory drugs, fluid therapy and gastric ulcer prophylaxis. The horse recovered successfully and is currently in good health (follow‐up of 5 years). Once the infection resolved, unilateral renal scarring occurred. Multidrug‐resistant upper‐urinary infections occur in horses and should be considered in a post‐surgical patient that develops fever. Early diagnosis, urine bacterial culturing and antimicrobial susceptibility testing were crucial in this case to successful management.

Background This study focuses on the AMR profiles in E. coli isolated from captive mammals at EcoZoo San Martín, Baños de Agua Santa, Ecuador, highlighting the role of wildlife as reservoirs of resistant bacteria. Aims The aim of this research is to investigate the antimicrobial resistance profiles of E. coli strains isolated from various species of captive mammals, emphasizing the potential zoonotic risks and the necessity for integrated AMR management strategies. Materials & Methods A total of 189 fecal samples were collected from 70 mammals across 27 species. These samples were screened for E. coli, resulting in 90 identified strains. The resistance profiles of these strains to 16 antibiotics, including 10 β‐lactams and 6 non‐β‐lactams, were determined using the disk diffusion method. Additionally, the presence of Extended‐Spectrum Beta‐Lactamase (ESBL) genes and other resistance genes was analyzed using PCR. Results Significant resistance was observed, with 52.22% of isolates resistant to ampicillin, 42.22% to ceftriaxone and cefuroxime, and 27.78% identified as ESBL‐producing E. coli. Multiresistance (resistance to more than three antibiotic groups) was found in 35.56% of isolates. Carnivorous and omnivorous animals, particularly those with prior antibiotic treatments, were more likely to harbor resistant strains. Discussion These findings underscore the role of captive mammals as indicators of environmental AMR. The high prevalence of resistant E. coli in these animals suggests that zoos could be significant reservoirs for the spread of antibiotic‐resistant bacteria. The results align with other studies showing that diet and antibiotic treatment history influence resistance profiles. Conclusion The study highlights the need for an integrated approach involving veterinary care, habitat management, and public awareness to prevent captive wildlife from becoming reservoirs of antibiotic‐resistant bacteria. Improved waste management practices and responsible antibiotic use are crucial to mitigate the risks of AMR in zoo environments and reduce zoonotic threats. Among 90 E. coli isolates from 70 mammals, significant resistance was found to ampicillin (52.22%), ceftriaxone (42.22%) and cefuroxime (42.22%), with 27.78% being ESBL‐producing. Notably, 66.67% of isolates showed resistance to at least one antibiotic, and 35.56% exhibited multiresistant phenotypes. These findings highlight the need for integrated veterinary care, habitat management and public awareness to prevent AMR spread in zoo environments.

Domestic environment, in particular, kitchen setting is a well-established source of microbial contamination. Kitchen sponges represent an important vehicle of microbial transmission and maintenance of spoilage bacteria and pathogenic strains responsible for food borne diseases. The aim of this study was to evaluate the microbial communities of 100 ‘in-use’ kitchen sponges, improving the knowledge on their role in cross-contamination in domestic environment and transmission of ESBLproducing strains. Sponges were processed for: aerobic mesophilic bacteria (AMB), Enterobacteriaceae (EB), yeasts and molds (YM), coagulase-positive staphylococci (CPS), micrococci (MCC), anaerobic sulfite reducing bacteria (ASR), and for the detection of Listeria monocytogenes, Salmonella spp. and Yersinia enterocolitica. A total of 309 enterobacteria strains were identified and then processed for ESBL (Extended Spectrum Beta Lactamase) phenotypical expression. A high contamination level of kitchen sponges was observed (mean value AMB 8.25±1.1; EB 5.89±1.2; YM 5.57±1.1; MCC 4.82±0.1 log CFU/g). Identified enterobacteria strains revealed several opportunistic and pathogenic agents such as Enterobacter cloacae (28%), Citrobacter freundii (23.3%), Cronobacter sakazakii (14.6%) and other strains in lower percentage. Listeria monocytogenes was found in only one sponge (1%). A total of 69 (22.3%) enterobacteria resulted ESBL+, with the following prevalence: P. rettgeri (50%), L. adenocarboxilata (30%), K. pneumoniae (25%), K. oxytoca (25%), C. sakazakii (20%), E. cloacae (20.7%), C. freundii (20.1%). Results confirm the potential role of kitchen sponges as vehicle for food-borne pathogens such as, C. sakazakii for the first time, infectious agents and spoilage microorganisms. The observed high contamination level and the presence of several ESBLs opportunistic pathogens, stresses the necessity to improve a proper education of the consumers on the effective treatment to reduce their microbial loads.

The increasing prevalence of broad-spectrum ampicillin-resistant and third-generation cephalosporin-resistant , particularly and , has become a global concern, with its clinical impacts on both human and veterinary medicine. This study examined the prevalence, antimicrobial susceptibility, and molecular genetic features of extended-spectrum β-lactamase (ESBL)-producing and isolates from 10 types of raw vegetables. In total, 305 samples were collected from 9 markets in Nakhon Si Thammarat, Thailand, in 2020. ESBL-producing and isolates were found in 14 of the 305 samples obtained from 7 out of 10 types of vegetables (4.6% of the total). Further, 14 ESBL-producing (  = 5/14) and isolates (  = 9/14) (1.6% and 3.0%, respectively) were highly sensitive to β-lactam/carbapenem antibiotics (imipenem, 100%). ESBL-producing (  = 4) and isolates (  = 8) were also sensitive to non-β-lactam aminoglycosides (amikacin, 80.00% and 88.89%, respectively). ESBL producers were most resistant to β-lactam antibiotics, including ampicillin (85.71%) and the cephalosporins cefotaxime and ceftazidime (64.29%). The most frequently detected gene in ESBL-producing and was . However, two ESBL-producing isolates also carried three other ESBL-encoding variants, , , , which may be due to their association with food chains and humans. Indeed, our results suggest that raw vegetables are an important source of ESBL-resistant and , which are potentially transmittable to humans via raw vegetable intake.

The escalating challenge of antimicrobial resistance necessitates the development of novel antibacterial agents. In this study, a series of five vanillin Schiff bases (SB-1 to SB-5) were synthesized from vanillin and various aromatic amines. The chemical structures of these compounds were characterized using Thin Layer Chromatography (TLC), Fourier Transform Infrared Spectroscopy (FT-IR), proton nuclear magnetic resonance ( 1 H -NMR), carbon-13 NMR ( 13 C -NMR), and mass spectrometry techniques. Antibacterial efficacy was evaluated against strains of bacteria producing extended-spectrum beta-lactamases (ESBL), including Escherichia coli , Pseudomonas aeruginosa , and Klebsiella pneumoniae using the disc diffusion method. Cytotoxic effects were assessed through haemocompatibility and brine shrimp lethality assays. The Schiff bases demonstrated notable antibacterial activities, with SB-1, SB-2, SB-4, and SB-5 exhibiting zones of inhibition up to 16.0, 16.5, 16.6, and 15.5 mm against ESBL E. coli , respectively. SB-3 showed a maximum inhibition zone of 15.0 mm against ESBL K. pneumoniae . In cytotoxicity assays, the compounds exhibited IC 50 values against red blood cells (RBCs) greater than 200 μg/mL and ranging from 45.7 to 50.5 μg/mL for the brine shrimp assay. While demonstrating potent antibacterial properties, the toxicity towards human RBCs suggests that further toxicity evaluations and structural modifications are essential for developing safer therapeutic agents based on vanillin Schiff bases.

Antimicrobial resistance (AMR) is a major global concern in both human and veterinary medicine. Among antimicrobial resistance (AMR) bacteria, Extended-Spectrum Beta-Lactamases (ESBLs) pose a serious health risk because infections can be difficult to treat. These Gram-negative bacteria can be frequently found in poultry and in Italy, where such protein production is established. ESBL-producing Escherichia coli, Salmonella and Klebsiella in chicken and turkey may pose a significant public health risk due to potential transmission between poultry and humans. This review aims to assess the prevalence of ESBL-producing E. coli, Salmonella and Klebsiella phenotypically and genotypically in Italian poultry, identifying the most common genes, detection methods and potential information gaps. An initial pool of 1462 studies found in scientific databases (Web of Sciences, PubMed, etc.) was screened and 29 were identified as eligible for our review. Of these studies, 79.3% investigated both phenotypic and genotypic ESBL expression while blaCTX−M, blaTEM and blaSHV were considered as targeted gene families. Large differences in prevalence were reported (0–100%). The blaCTX−M−1 and blaTEM−1 genes were the most prevalent in Italian territory. ESBL-producing E. coli, Salmonella and Klebsiella were frequently detected in farms and slaughterhouses, posing a potential threat to humans through contact (direct and indirect) with birds through handling, inhalation of infected dust, drinking contaminated water, ingestion of meat and meat products and the environment. Considering the frequent occurrence of ESBL-producing bacteria in Italian poultry, it is advisable to further improve biosecurity and to introduce more systematic surveillance. Additionally, the focus should be on the wild birds as they are ESBL carriers.

ESBL-producing Enterobacteriaceae spp., which are acquired in both community and hospital settings, are widespread globally (7). The study encompassed individuals with community-acquired UTIs who were admitted to the hospital between June 2021 and March 2024. Data collected from the medical records database encompassed demographics (age, sex), past medical history (UTI episodes, hospitalizations), prior antibiotic use (prophylaxis and within one month of admission), diagnostic tests [blood culture, laboratory results like complete blood count, urinalysis, C-reactive protein (CRP), abdominal ultrasound, voiding cystourethrogram (VCUG)], and initial and defnitive antimicrobial therapy and duration of therapy. MALDI-TOF MS is an advanced method that uses laser energy to ionize bacterial proteins, allowing rapid and precise identifcation by analyzing their mass-to-charge ratios.

In this study, risk factors were investigated in children with community-acquired urinary tract infections (UTI) caused by extended-spectrum beta-lactamases (ESBL)-producing E. coli or Klebsiella spp. One hundred and fifty-five patients were diagnosed with ESBL-positive UTI (case group) in the outpatient clinics of Hacettepe University Children’s Hospital between 1 January 2004 and 31 December 2006. A control group, 155 out of 4,105 children, was matched by age and sex among children with ESBL-negative UTI. A total of 310 patients’ files were evaluated retrospectively. As regards the symptoms of UTI, no statistical differences were seen between the two groups. Although the most frequently isolated microorganism was E. coli in both groups, Klebsiella spp. was found to be more frequent in those diagnosed with ESBL(+) UTI ( p  < 0.001). Having an underlying disease and hospitalization, infections, and use of antibiotics within the last 3 months were found to be potential risk factors ( p  < 0.001). With conditional logistic regression analysis, having an underlying disease and hospitalization within the last 3 months were identified as independent risk factors for ESBL(+) UTI. In conclusion, the recognition of risk factors for UTI, caused by ESBL(+) bacteria in children, may aid in the identification of high-risk cases and may enable proper management of these patients.