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Antimicrobial resistance (AMR) poses a severe global health threat, yet the transmission pathways of AMR within communal public environments, where humans and animals interact, remain poorly explored. This study investigated AMR risk pathways, prevalence, and seasonality of extended-spectrum β-lactamase (ESBL) producing E. coli and K. pneumoniae, and observed practices contributing to environmental contamination within urban, peri-urban, and rural Malawi. Using the SaniPath tool, in August 2020, transect walks across three Malawian study sites identified potential AMR exposure pathways, including drains, standing water, soil, and areas of communal hand contact. Subsequently, from September-2020 to August-2021, 1440 environmental samples were collected at critical points along exposure routes (n = 40/month from each site). These underwent microbiological analysis using chromogenic agar techniques to detect the presence of ESBL E. coli and ESBL K. pneumoniae. Results showed the highest ESBL prevalence in urban environments (68.1 %, 95%CI = 0.64-0.72, p < 0.001) with a higher ESBL presence seen in drains (58.8 %, 95%CI = 055-0.62, p < 0.001) and soil (54.1 %, 95%CI = 0.46-0.62, p < 0.001) compared to other pathways. Environmental contamination was attributed to unavailability and poor condition of sanitation and hygiene infrastructure based on key informant interviews with community leaders (n = 9) and confirmed by independent observation. ESBL prevalence varied between seasons (χ 2 (2,N = 1440) = 10.89, p = 0.004), with the highest in the hot-dry period (55.8 % (n = 201)). Prevalence also increased with increased rainfall (for ESBL E.coli). We highlight that community environments are likely to be a crucial component in AMR transmission, evident in the abundance of ESBL bacteria in identified exposure pathways. Additionally, poor sanitation infrastructure and practices coupled with seasonal dynamics further affect the presence of ESBLs in communal environments. Therefore, a context appropriate whole system approach that tackles infrastructure and behavioural factors, supported by effective surveillance is required to impact AMR and a range of aligned development challenges in these settings., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background and Aims: The emergence of Pseudomonas aeruginosa ( P. aeruginosa ) antibiotic resistance is an important public health problem worldwide that can negatively affect infection control. Therefore, obtaining knowledge about antibiotic resistance mechanisms is necessary for infection control policies. This study aimed to determine the frequency of class C and D β-lactamases in P. aeruginosa strains isolated from patients referred to Ardabil hospitals using phenotypic and genotypic tests., Methods: Phenotypic detection of β-lactamases including AmpC cephalosporinase, oxacillinase (OXA)-type extended-spectrum β-lactamases (ESBLs), and OXA-type carbapenemases were performed using the disk diffusion-based methods. Amplification of genes encoding classes C ( ampC and FOX genes) and D ( OXA-1 , OXA-2 , OXA-10 , OXA-23 , and OXA-48 genes) β-lactamases was performed using the polymerase chain reaction (PCR) method. A quantitative reverse transcription PCR (qRT-PCR) method was used to determine the expression level of the ampC gene among multiple drug-resistant and imipenem-resistant P. aeruginosa strains., Results: In phenotypic tests, the prevalence of AmpC cephalosporinase, OXA-type ESBLs, and OXA-type carbapenemases were 52.5%, 7.2%, and 95.8%, respectively. In genotypic tests, the prevalence of ampC , FOX , OXA-1 , OXA-2 , OXA-10 , OXA-23 , and OXA-48 genes were 100%, 0%, 4.3%, 60.8%, 42%, 29.7%, and 2.9%, respectively. In addition, the ampC gene overexpression was seen in 16 (33.3%) drug-resistant P. aeruginosa clinical isolates., Conclusion: Given the presence of class C and D β-lactamases in clinical isolates of P. aeruginosa in Ardabil hospitals, early detection of these strains can help prevent the spread of resistant strains in hospital environments and subsequent treatment failure., Competing Interests: The authors declare that there is no conflict of interest., (© 2024 The Author(s). Health Science Reports published by Wiley Periodicals LLC.)

Plasmid-mediated quinolone resistance (PMQR) in extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae ( K. pneumoniae ) contributes to treatment failures, extended hospital stays, and increased mortality percentages. We aimed to determine the prevalence of PMQR genes in ESBL-producing K. pneumoniae isolates from clinical samples in Babol, North of Iran region. This is the first study in this region to investigate this specific association. A total of 95  K. pneumoniae isolates were obtained from hospitalized patients with various clinical infections during March 2022 to February 2023. Disk diffusion and Combination disk method were performed to identification of antimicrobial resistance profiles and ESBL-producing strains. The presence of ESBL and PMQR genes among K. pneumoniae isolates was assessed using polymerase chain reaction (PCR) method. Of the isolates, 68 (71.57 %) were considered as ESBL-producers. The bla TEM , bla SHV and bla CTX-M genes were detected in 74.73 %, 57.89 %, and 41.05 % of K. pneumoniae isolates, respectively. Among the PMQR encoding genes, the highest and lowest frequency was associated to qepA (67.3 %) and qnrA (4.2 %), respectively. The frequency of qnrA , qnrB, qnrS , acc ( 6' )- Ib - cr , qepA , oqxA , and oqxB genes in 26 MDR-Kp isolates was 11.53 % (n; 3), 69.23 % (n; 18), 65.38 % (n; 17), 73.07 % (n; 19), 80.76 % (n; 21), 84.61 % (n; 22), and 76.92 % (n; 20), respectively. Our result revealed of the 68 ESBL gene-positive isolates, 60 (88.23 %) were positive for the PMQR gene. The co-occurrence of these genes within resistant isolates suggests potential linkage on mobile genetic elements such as plasmids. These findings highlight the significant burden of PMQR determinants in ESBL-producing K. pneumoniae and underscore the urgent need for effective control measures. Implementing robust antimicrobial stewardship programs and strengthening drug-resistance surveillance and control protocols are crucial to prevent the spread of resistant isolates., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Background: The global burden associated with antimicrobial resistance is of increasing concern., Aim: To evaluate risk factors associated with multidrug-resistant (MDR) infection and its clinical impact in a cohort of patients with healthcare-associated bacteraemic urinary tract infections (BUTIs)., Methods: This was a prospective, multicentre, post-hoc analysis of patients with healthcare-associated-BUTI (ITUBRAS-2). The primary outcome was MDR profile. Secondary outcomes were clinical response (at 48-72 h and at hospital discharge) and length of hospital stay from onset of BUTI. Logistic regression was used to evaluate variables associated with MDR profile and clinical response. Length of hospital stay was evaluated using multivariate median regression., Findings: In all, 443 episodes were included, of which 271 (61.17%) were classified as expressing an MDR profile. In univariate analysis, MDR profile was associated with E. coli episodes (odds ratio (OR): 3.13; 95% confidence interval (CI): 2.11-4.69, P < 0.001) and the extensively drug-resistant (XDR) pattern with P. aeruginosa aetiology (7.84; 2.37-25.95; P = 0.001). MDR was independently associated with prior use of fluoroquinolones (adjusted OR: 2.43; 95% CI: 1.25-4.69), cephalosporins (2.14; 1.35-3.41), and imipenem or meropenem (2.08; 1.03-4.20) but not with prior ertapenem. In terms of outcomes, MDR profile was not associated with lower frequency of clinical cure, but was associated with longer hospital stay., Conclusion: MDR profile was independently associated with prior use of fluoroquinolones, cephalosporins, imipenem, and meropenem, but not with prior ertapenem. MDR-BUTI episodes were not associated with worse clinical cure, although they were independently associated with longer duration of hospital stay., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

ESBL-producing Escherichia coli strains threaten public health and obligate the use of last-resort antibiotics. This study identified 15 E. coli isolates through 16S rRNA and gyrB genes, specific to E. coli, in 120 egg samples (12.5%). Antibiotic resistance was detected according to the EUCAST and CLSI in E. coli isolates. 2 isolates were susceptible to all antibiotics, one isolate was resistant to one antibiotic, one isolate was resistant to 2 antibiotics, and 11 E. coli isolates (73.3%) had multidrug resistance. Most frequent antibiotic resistances were detected against ampicillin (80%), tetracycline (66.6%), and chloramphenicol (66.6%). A double-disc confirmation test was used to detect ESBL production, and blaTEM, blaSHV, blaCTX-M and blaOXA genes were searched by PCR. The blaTEM (100%) gene was found in all resistant E. coli isolates, and the blaCTX-M gene was detected in only 3 (20%) E. coli isolates. None of the E. coli isolates contained the genes responsible for carbapenem and colistin resistance. Our results show that multi-drug antibiotic resistance and the blaTEM gene are frequent in E. coli from table eggs in Istanbul. This is the first preliminary study on ESBL-producing E. coli isolates in table eggs in Türkiye.

Background: Pulmonary abscesses resulting from epididymitis caused by extended spectrum β-lactamase-producing hypervirulent Klebsiella pneumoniae (ESBL-hvKp) in a nondiabetic patient are extremely uncommon. The infection caused by this disseminated drug-resistant bacteria, which is generally considered an intractable case, poses a potential challenge in clinical practice., Case Presentation: In this case report, we present the clinical course of a 71-year-old male patient with epididymitis, who subsequently developed cough and dyspnea following anti-infection treatment. Imaging examinations revealed severe pneumonia and pulmonary abscess. The infection of ESBL-hvKp in the epididymis led to bacteremia and subsequent lung lesions. Due to poor response to anti-infection therapy, the patient required an extended duration of anti-infection treatment and ultimately chosed to discontinue treatment., Conclusions: Acute epididymitis caused by ESBL-hvKP infection can result in the spread of the infection through the bloodstream, leading to severe pneumonia and lung abscess. Given the critical condition of the patient, even with active anti-infection treatment, there is a risk of treatment failure or potentially fatal outcomes., (© 2024. The Author(s).)

Background: Infections resulting from multidrug-resistant Enterobacterales (MDR-E) pose a growing global threat, presenting challenges in treatment and contributing significantly to morbidity and mortality rates. The main objective of this study was to characterize phenotypically and genetically extended-spectrum β-lactamase- and carbapenemase- producing Enterobacterales (ESBLE and CPE respectively) isolated from clinical samples in the West Bank, Palestine., Methods: A cross sectional study was conducted in October 2023 on clinical bacterial isolates collected from five governmental hospitals in the West Bank, Palestine. The isolates obtained from the microbiology laboratories of the participating hospitals, underwent identification and antibiotic susceptibility testing (AST) using the VITEK ® 2 Compact system. ESBL production was determined by the Vitek2 Compact system. A modified carbapenem inactivation method (mCIM) was employed to identify carbapenemase-producing Enterobacterales (CPE). Resistance genes were detected by real-time PCR., Results: Out of the total 1380 collected isolates, we randomly selected 600 isolates for analysis. Our analysis indicated that 287 (47.83%) were extended-spectrum beta-lactamase producers (ESBLE), and 102 (17%) as carbapenem-resistant Enterobacterales (CRE) isolates. A total of 424 isolates (70.67%) were identified as multidrug-resistant Enterobacterales (MDRE). The most prevalent ESBL species were K. pneumoniae (n = 124; 43.2%), E. coli (n = 119; 41.5%) and E. cloacae (n = 31; 10.8%). Among the CRE isolates, 85 (83.33%) were carbapenemase-producing Enterobacterales (CPE). The most frequent CRE species were K. pneumoniae (n = 63; 61.7%), E. coli (n = 25; 24.5%) and E. cloacae (n = 13; 12.8%). Additionally, 47 (7.83%) isolates exhibited resistance to colistin (CT), with 38 (37.62%) being CT-resistant CRE and 9 (3.14%) being CT-resistant ESBLE while sensitive to carbapenems. We noticed that 11 isolates (6 Klebsiella pneumoniae and 5 Enterobacter cloacae complex) demonstrated sensitivity to carbapenems by phenotype but carried silent CPE genes (1 blaOXA48, and 6 blaNDM, 4 blaOXA48, blaNDM). ESBL-producing Enterobacterales strains exhibited varied resistance patterns across different antibiotic classes. E. coli isolates showed notable 48% resistance to trimethoprim/sulfamethoxazole. K. pneumoniae isolates displayed a significant resistance to trimethoprim/sulfamethoxazole, nitrofurantoin, and fosfomycin (54%, 90%, and 70% respectively). E. cloacae isolates showed complete resistance to nitrofurantoin and fosfomycin. P. mirabilis isolates exhibited high resistance against fluoroquinolones (83%), and complete resistance to trimethoprim/sulfamethoxazole, nitrofurantoin and fosfomycin., Conclusion: This study showed the high burden of the ESBLE and CRE among the samples collected from the participating hospitals. The most common species were K. pneumoniae and E. coli. There was a high prevalence of blaCTXm. Adopting both conventional and molecular techniques is essential for better surveillance of the emergence and spread of antimicrobial-resistant Enterobacterales infections in Palestine., (© 2024. The Author(s).)

Background Diabetic foot ulcers (DFUs) are prevalent complications of diabetes mellitus, often leading to severe infections and adverse clinical outcomes. Klebsiella pneumoniae , a gram-negative bacterium, has emerged as a significant causative agent in DFU infections, raising concerns due to its increasing antibiotic resistance, particularly in extended-spectrum β-lactamase (ESBL) and metallo-β-lactamase (MBL) production. Aim This study aimed to comprehensively assess the prevalence, antibiotic resistance profiles, and clinical correlates of ESBL- and MBL-producing K. pneumoniae isolates specifically derived from DFUs. Methods A cross-sectional observational study was conducted at Krishna Vishwa Vidyapeeth from January 2023 to June 2023, involving 126 patients diagnosed with DFUs. Clinical and demographic data were collected, and wound swabs underwent microbiological analysis. Phenotypic detection methods were employed to identify ESBL and MBL production, followed by standardized antibiotic susceptibility testing. Results Among the 126 isolates tested, 36 (28.6%) were identified as ESBL-producing and 21 (16.7%) as MBL-producing strains. ESBL-producing isolates exhibited high resistance rates to antibiotics such as ampicillin (92.3%), amoxicillin-acid (84.6%), and cephalosporins, including ceftriaxone (76.9%), and cefepime (73.8%). MBL-producing isolates demonstrated even broader resistance profiles, including resistance to fluoroquinolones (ciprofloxacin, 60.0%; levofloxacin, 57.1%), aminoglycosides (gentamicin, 42.9%), and carbapenems (meropenem, 38.1%; imipenem, 35.7%). Conclusion This study identifies a significant prevalence of ESBL- and MBL-producing K. pneumoniae in DFUs, showcasing high antibiotic resistance rates. Comorbidities correlate significantly with the presence of resistant isolates, necessitating treatment strategies for effective management., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Krishna Vishwa Vidyapeeth issued approval KVV/IEC/07/2023. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Patil et al.)

The extended-spectrum β-lactamases (ESβLs) are bacterial enzymes capable of hydrolyzing penicillins, cephalosporins, and aztreonam. The prevalence of ESβL is increasing among clinically significant microorganisms worldwide, drastically reducing the therapeutic management of infectious diseases. The study aimed to determine the drug susceptibility of ESβL-positive clinical isolates acquired from patients hospitalized in Lodz, central Poland, and analyze the prevalence of specific genes, determining acquired resistance in these bacteria. The samples of ESβL-positive clinical isolates were gathered in 2022 from medical microbiological laboratories in the city of Lodz, central Poland. The strains were subjected to biochemical identification and antimicrobial susceptibility testing following EUCAST guidelines. The presence of studied genes (bla CTX-M , bla SHV , bla TEM , bla PER , bla VEB ) was confirmed by PCR. Over 50% of studied isolates were resistant to gentamicin, cefepime, ceftazidime and ciprofloxacin. The most common ESβL gene was bla CTX-M . In most isolates, the resistance genes occurred simultaneously. The bla PER was not detected in any of the tested strains. ESβL-producing strains are largely susceptible to the currently available antibiotics. The observation of the coexistence of different genes in most clinical isolates is alarming.

Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBL-EC) is regarded as one of the most important priority pathogens within the One Health interface. However, few studies have investigated the occurrence of ESBL-EC in giant pandas, along with their antibiotic-resistant characteristics and horizontal gene transfer abilities. In this study, we successfully identified 12 ESBL-EC strains (8.33%, 12/144) out of 144 E. coli strains which isolated from giant pandas. We further detected antibiotic resistance genes (ARGs), virulence-associated genes (VAGs) and mobile genetic elements (MGEs) among the 12 ESBL-EC strains, and the results showed that 13 ARGs and 11 VAGs were detected, of which bla CTX-M (100.00%, 12/12, with 5 variants observed) and papA (83.33%, 10/12) were the most prevalent, respectively. And ISEcp1 (66.67%, 8/12) and IS26 (66.67%, 8/12) were the predominant MGEs. Furthermore, horizontal gene transfer ability analysis of the 12 ESBL-EC showed that all bla CTX-M genes could be transferred by conjugative plasmids, indicating high horizontal gene transfer ability. In addition, ARGs of rmtB and sul2 , VAGs of papA , fimC and ompT , MGEs of ISEcp1 and IS26 were all found to be co-transferred with bla CTX-M . Phylogenetic analysis clustered these ESBL-EC strains into group B2 (75.00%, 9/12), D (16.67%, 2/12), and B1 (8.33%, 1/12), and 10 sequence types (STs) were identified among 12 ESBL-EC (including ST48, ST127, ST206, ST354, ST648, ST1706, and four new STs). Our present study showed that ESBL-EC strains from captive giant pandas are reservoirs of ARGs, VAGs and MGEs that can co-transfer with bla CTX-M via plasmids. Transmissible ESBL-EC strains with high diversity of resistance and virulence elements are a potential threat to humans, animals and surrounding environment., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Liu, Fan, Zhang, Yuan, Zhong, Wang, Wang, Zhou, Zhang, Geng, Peng, Wang, Zhang, Yan, Luo, Shi and Zhong.)

Aims: The purpose of this work was to study extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBL-EC) in freshwaters, hospital effluents, and wastewaters during two sampling campaigns in 2021., Methods and Results: Water sampling was performed at 24 stations in the Ourthe watershed in Belgium. A total of 644 ESBL (n = 642) and AmpC (n = 2) E. coli strains were isolated. Disk-diffusion assays were performed following the EUCAST's recommendations. All strains were tested for the presence of blaCTX-M-1, blaCTX-M-2, and blaCTX-M-9 gene groups by PCR. Genes belonging to blaCTX-M-1 and blaCTX-M-9 groups were detected, respectively, in 73.6% and 14.9% of the strains. No blaCTX-M-2 group's gene was found. A subset of strains (n = 40) was selected for whole genome sequencing. Escherichia coli serotype O18: H7 ST 1463 was predominant (n = 14) in the sequenced strains and showed pathogenicity in the Galleria mellonella larvae model. β-lactamase genes identified were blaCTX-M (n = 21), with blaCTX-M-15 mostly represented (n = 15), as well as blaTEM (n = 11), blaOXA (n = 7), blaSHV (n = 9), and carbapenemase (CP) genes were observed in several strains-blaKPC-3 (n = 19), blaNDM-1 (n = 1), blaVIM-1 (n = 2), and blaOXA-244 (n = 2)-even from freshwaters., Conclusions: ESBL-EC are widely distributed in the aquatic environment in Belgium and contain a variety of ESBL and CP genes., (© The Author(s) 2024. Published by Oxford University Press on behalf of Applied Microbiology International.)

Background: Scant data are available on the link between armed conflicts and the development and spread of antimicrobial resistance., Objectives: We performed a systematic review with the aim to summarize the available data on the prevalence and features of antibiotic resistance and the causes of antibiotic resistance development during armed conflicts in the 21st century., Methods: Data sources: PubMed and SCOPUS databases were searched from 1 January 2000 to 30 November 2023., Study Eligibility Criteria: Original articles reporting data on armed conflicts and antimicrobial resistance were included in this systematic review. No attempt was made to obtain information from unpublished studies. No language restriction was applied. Methods of data synthesis: Both quantitative and qualitative information were summarized by means of textual descriptions., Participants: Patients or soldiers deployed in armed conflict zones., Tests: culture-dependent antibiotic sensitivity testing or molecular detection of the genetic determinants of antibiotic resistance after a confirmed diagnosis of bacterial infection. Assessment of risk of bias: To evaluate the quality of the included studies, we adapted the tool recommended by the Joanna Briggs Institute., Results: Thirty-four studies were identified, published between November 2004 and November 2023. The quality of included studies was high and medium in 47% and 53% of the studies, respectively. The included studies reported high infection and colonization rates of multidrug-resistant bacteria. Studies performed during the Eastern Ukraine conflict reported high rates of New Delhi metallo-β-lactamase producers., Discussion: Our findings confirm that wars lead to a large pool of multidrug-resistant infections that could potentially spread. Infection control in healthcare facilities in conflict zones and proper antimicrobial stewardship are crucial., (Copyright © 2024 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Introduction: The emergence of multidrug-resistant Gram-negative bacilli and the development of new antibiotics have complicated the selection of optimal regimens. International guidelines are valuable tools, but are limited by the scarcity of high-quality randomized trials in many situations., Methods: A panel of experts from the French and Italian Societies of Infectious Diseases aimed to address unresolved issues in clinical practice based on their experience, an updated literature review and open discussions., Results: The panel reached consensus for the following 'first choices': (i) cefepime for ventilator-acquired pneumonia due to AmpC β-lactamase-producing Enterobacterales; (ii) the β-lactam/β-lactamase inhibitor combination most active in vitro, or cefiderocol combined with fosfomycin, and aerosolized colistin or aminoglycosides, for severe pneumonia due to Pseudomonas aeruginosa resistant to ceftolozane-tazobactam; (iii) high-dose piperacillin-tazobactam (including loading dose and continuous infusion) for complicated urinary tract infections (cUTIs) caused by extended-spectrum β-lactamase-producing Enterobacterales with piperacillin-tazobactam minimum inhibitory concentration (MIC) ≤8 mg/L; (iv) high-dose cefepime for cUTIs due to AmpC β-lactamase-producing Enterobacterales other than Enterobacter spp. if cefepime MIC ≤2 mg/L; (v) ceftolozane-tazobactam or ceftazidime-avibactam plus metronidazole for intra-abdominal infections (IAIs) due to third-generation cephalosporin-resistant Enterobacterales; (vi) ceftazidime-avibactam plus aztreonam plus metronidazole for IAIs due to metallo-β-lactamase-producing Enterobacterales; (vii) ampicillin-sulbactam plus colistin for bloodstream infections (BSIs) caused by carbapenem-resistant Acinetobacter baumannii; (viii) meropenem-vaborbactam for BSIs caused by Klebsiella pneumoniae carbapenemase-producing Enterobacterales; and (ix) ceftazidime-avibactam plus fosfomycin for neurological infections caused by carbapenem-resistant P. aeruginosa., Conclusions: These expert choices were based on the necessary balance between antimicrobial stewardship principles and the need to provide optimal treatment for individual patients in each situation., (Copyright © 2024 Elsevier Ltd and International Society of Antimicrobial Chemotherapy. All rights reserved.)

The widespread prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli limits treatment options and is a worldwide problem. The aim of this study was to investigate the antimicrobial susceptibility and ESBL-type of 204 strains of CTX-M-type ESBLs-producing E. coli isolated from 2011 to 2017 in the Chubu region of Japan. Minimal inhibitory concentrations were determined in accordance with the guidelines of the Clinical and Laboratory Standards Institute. Genes encoding CTX-M group β-lactamases were detected by PCR amplification. The CTX-M subtypes were determined using sequence analysis. The CTX-M-9 group was the most frequently detected ESBL group, and CTX-M-27 was the most frequently detected ESBL gene. CTX-M-15-producing strains showed significantly lower rates of susceptibility to tazobactam/piperacillin (TAZ/PIPC) than those by CTX-M-14 and -27-producing strains. Additional analysis of secondary β-lactamases revealed that most of the OXA-1-positive strains were CTX-M-15-producing strains (94.7%). These strains displayed significantly lower susceptibility rates to TAZ/PIPC (47.4%), sulbactam/ampicillin (SBT/ABPC) (0.0%), and amikacin (AMK) (73.7%) than those by OXA-1-negative strains, suggesting that the high non-susceptibility rate of the CTX-M-15-producing strain was due to the co-carriage of OXA-1. The CTX-M-15-producing strains showed reduced susceptibility to TAZ/PIPC, SBT/ABPC, and AMK, presumably due to the co-carriage of OXA-1.

A 21-year-old previously healthy Japanese woman visited an outpatient clinic because of abdominal pain, watery diarrhea, vomiting, and mild fever that had started on the previous day. She traveled to rural and urban areas of Rwanda and returned to Japan 3 days before. Stool culture yielded the Plesiomonas shigelloides strain TMCH301018, against which minimum inhibitory concentrations of cefotaxime and cefotaxime-clavulanate were 128 and ≤0.12/4 μg/mL, respectively. The strain had the bla CTX-M-27 gene and an IncA/C replicon-type plasmid. Moreover, a transformant produced by introduction of an IncA/C plasmid extracted from TMCH301018 into Escherichia coli DH5α was positive for the bla CTX-M-27 gene and fulfilled the criteria of extended-spectrum β-lactamase (ESBL) production described by the Clinical and Laboratory Standards Institute, indicating that TMCH301018 produced ESBL of CTX-M-27 and the ESBL-encoding gene was located on an IncA/C plasmid. Pathogenicity of TMCH301018 for the patient's complaints was uncertain because a molecular assay detected other enteropathogens in the stool specimen and the symptoms improved within 2 days with administration of oral ciprofloxacin, to which TMCH301018 was not susceptible. To our knowledge, this is the first report describing the isolation of ESBL-producing P. shigelloides., Competing Interests: Declaration of competing interest The authors have stated explicitly that there are no conflicts of interest in connection with this article., (Copyright © 2024 Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Infection Prevention and Control. Published by Elsevier Ltd. All rights reserved.)

Klebsiella pneumoniae is one of the most prevalent bacteria causing urinary tract infections (UTIs). Its increasing resistance to a wide array of antibiotics limits available treatment options. This study investigated the characteristics and trends of antimicrobial resistance in K. pneumoniae isolated from UTIs in Crete, Greece, during 2017 and 2022. Among the 11,946 Enterobacteriaceae isolated from urine specimens, a total of 1,771 K. pneumoniae isolates were identified (14.8%), with an isolation frequency secondary to Escherichia coli (66.3%). K. pneumoniae isolates increased over the years, with a peak in the year 2022. Higher resistance rates were detected in ciprofloxacin (41%), trimethoprim/sulfamethoxazole (TMP/SMX) (38.1%) and nitrofurantoin (33.9%). Resistance to ciprofloxacin, amoxicillin/clavulanic acid, tigecycline, and TMP/SMX significantly increased from 33.7%, 24%, 6%, and 33.1%, respectively, over the years 2017-2019, to 47.8%, 34.2%, 14.3% and 42.8%, respectively, over the period 2020-2022. ESBL production and carbapenem resistance were decreased by 2.2% and 3.7%, respectively, over the two three-year periods (2017-2019 and 2020-2022). Among the 278 carbapenem-resistant K. pneumoniae (CRKP) isolates, 164 (59%), 66 (23.7%), 18 (6.5%) and 16 (5.8%) were positive for KPC, NDM, VIM and OXA-48 enzymes, respectively. Only 14 (5%) isolates harboured two carbapenemase genes, namely 10 (3.6%) both blaNDM and blaVIM, and 4 (1.4%) both blaKPC and blaNDM. Females, inpatients and the elderly were more frequently affected by CRKP. The frequency of multidrug-resistant (MDR) and extensively drug-resistant (XDR) isolates were 32.6% and 7.7%, respectively. Continuous surveillance of local microbial prevalence and monitoring of antimicrobial resistance patterns provide critical information to guide the empiric therapy for UTIs and control the spread of MDR bacteria.

Objective: This research aimed to analyze the clinical characteristics, prognosis, and antimicrobial treatment of bloodstream infections (BSI) caused by Enterobacter cloacae complex (ECC)., Methods: The clinical data of patients with bloodstream infections caused by Enterobacter cloacae complex from April 2017 to June 2023 were collected retrospectively. These data were then analyzed in subgroups based on the detection results of extended-spectrum β-lactamase (ESBL), 30-day mortality, and the type of antimicrobial agent used (β-lactam/β-lactamase inhibitor combinations (BLICs) or carbapenems)., Results: The proportion of ESBL-producing Enterobacter cloacae complex was 32.5% (37/114). Meanwhile, ICU admission, receiving surgical treatment within 3 months, and biliary tract infection were identified as risk factors for ESBL-producing ECC-BSI. Additionally, immunocompromised status and Sequential Organ Failure Assessment (SOFA) score ≥ 6.0 were identified as independent risk factors of 30-day mortality in patients with ECC-BSI (n = 108). Further analysis in BSI patients caused by non-ESBL-producing ECC revealed that patients treated with BLICs (n = 45) had lower SOFA scores and lower incidence of hypoproteinemia and sepsis compared with patients treated with carbapenems (n = 20). Moreover, in non-ESBL-producing ECC-BSI patients, the univariate Cox regression analysis indicated a significantly lower 30-day mortality rate in patients treated with BLICs compared to those treated with carbapenems (hazard ratios (HR) [95% CI] 0.190 [0.055-0.662], P = 0.009; adjusted HR [95% CI] 0.106 [0.013-0.863], P = 0.036)., Conclusion: This study investigated the factors influencing the susceptibility to infection by ESBL-producing strains and risk factors for 30-day mortality in ECC-BSI patients. The results revealed that ESBL-negative ECC-BSI patients treated with BLICs exhibited significantly lower 30-day mortality compared to those treated with carbapenems. BLICs were found to be more effective in ECC-BSI patients with milder disease (ESBL-negative and SOFA ≤6.0)., Competing Interests: The authors report no conflicts of interest in this work., (© 2024 Liu et al.)

Introduction: Extended-spectrum β-lactamase (ESBL) production among Enterobacteriaceae, such as E. coli, has been increasing worldwide, which causes treatment failure for urinary tract infections. Therefore, this study aimed to determine the prevalence and risk factors for the production of ESBL in E. coli from patients with urinary tract infections (UTI) in Zanzibar., Methods: a prospective cross-sectional study was conducted from January 2018 to December 2021 in Zanzibar. Data were retrieved from a routine bacteriological laboratory culture report from urine samples of 4306 patients at the Lancet Laboratory. In addition, the patient's social demographics and clinical data were retrieved by examining the medical records in the respective hospitals. All inpatients older than fifteen years diagnosed with urinary tract infections (UTI) and requested urine culture and sensitivity were included. The Chi-square and Fischer's exact tests were used to compare antibiotic resistance. In addition, a binary logistic regression analysis was used to predict ESBL production risk factors., Results: the prevalence of E. coli-producing ESBL was 13.4% (578/4030). Infection of ESBL. E. coli was prevalent in females 52.6% (n=304) compared to male patients, 47.4% (n=274), and the majority 38.8% (n=224), were people of young age, between 16-30 years. The average age of patients was 31.5±10.2 years, with minimum age of 16 years and a maximum age of 72 years. In multivariate analysis, results shown that previously hospitalised patients aOR: 6.35, 95% Cl 3.37-11.92; p=0.001, long hospital stays aOR: 10.34, 95% Cl 3.03-22.29; p <0.001, prior use of penicillin aOR: 7.78, 95% Cl 2.99-29.11; p < 0.001, and prior use of cephalosporin drugs aOR: 4.64, 95% Cl 2.99-9.96; p=0.001, were strongly associated with the emergence of ESBL-producing E. coli in urinary tract infection patients. ESBL E. coli showed high resistance to amoxicillin 99.5% (n=575), ampicillin 97.8.% (n=570), cotrimazaxole 86.2% (n=344), ceftriaxone 73.7% (n=344), ciprofloxacin 73.2% (n=423), and ceftaxime 59.5% (n=426). There was a less resistance to ampicillin -cloxacillin 44.3% (n=256), gentamicin 22.5% (n=22.5), and norfloxacin 18.9% (n=109) respectively. Isolates were shown to be more susceptible to meropenem at 1.6% (n=9)., Conclusion: the overall prevalence of ESBL-producing E. coli is 13.4%. The risk of emergence ESBL was higher in patients with previous history of hospitalisation, long hospital stay, prior use of penicillin and cephalosporin drugs. High level of antimicrobial resistance observed against most commonly used antibiotics in treatment of urinary tract infections. The clinicians should rely on microbiological diagnosis in treatment of UTIs to reduce risk of treatment failure. Further study should be carried out to assess the prevalence and resistance pattern of other uropathogens and other risk factors., Competing Interests: The authors declare no competing interests., (Copyright: Muhiddin Hamada Omar et al.)

Background: There is a lack of data on the characteristics of overlap between acquired antimicrobial resistance and virulence factors in Klebsiella pneumoniae in high-risk settings, especially with the inclusion of surveillance isolates along with the clinical. We investigated K. pneumoniae isolates, from a neonatal intensive care unit (NICU) in Nepal, for the presence of both accessory virulence factors and acquired antimicrobial resistance., Methods: Thirty-eight clinical and nineteen surveillance K. pneumoniae isolates obtained between January 2017 and August 2022 in the NICU of Siddhi Memorial Hospital, Bhaktapur, Nepal were investigated with antimicrobial susceptibility testing, PCR-based detection of β-lactamases and virulence factors, and genetic similarity by ERIC-PCR., Results: K. pneumoniae was found positive in 37/85 (43.5%) blood culture-positive neonatal bloodstream infections, 34/954 (3.6%) patient surveillance cultures, and 15/451 (3.3%) environmental surveillance samples. Among 57 isolates analyzed in this study, we detected multidrug resistance in 37/57 (64.9%), which was combined with at least one accessory virulence factor in 21/37 (56.8%). This overlap was mostly among β-lactamase producing isolates with accessory mechanisms of iron acquisition. These isolates displayed heterogenous ERIC-PCR patterns suggesting genetic diversity., Conclusions: The clinical significance of this overlap between acquired antimicrobial resistance and accessory virulence genes in K. pneumoniae needs further investigation. Better resource allocation is necessary to strengthen infection prevention and control interventions in resource-limited settings., (© 2024. The Author(s).)

The global rise of zoonotic bacteria resistant to multiple antimicrobial classes and the growing occurrence of infections caused by Aeromonas spp. resistant to β-lactam antibiotics pose a severe threat to animal and human health. However, the contribution of natural environments, particularly aquatic ecosystems, as ideal settings for the development and spread of antimicrobial resistance (AMR) is a key concern. Investigating the phenotypic antibiotic resistance and detection of β-lactamase producing Aeromonas spp. in Lamellidens marginalis , which inhabit all freshwater ecosystems of the Indian subcontinent, is essential for implications in monitoring food safety and drug resistance. In the present investigation, 92 isolates of Aeromonas spp. were recovered from 105 bivalves and screened for their antimicrobial resistance patterns. In vitro antibiotic resistance profiling showed a higher Multiple Antibiotic Resistance (MAR) index of 0.8 with the highest resistance against ampicillin/sulbactam (82%), while 58, 44, 39 and 38% of the isolates were resistant to cephalothin, erythromycin, cefoxitin and imipenem, respectively. PCR results revealed that these isolates carried the bla TEM gene (94%), which was followed by the bla CTX-M gene (51%) and the bla SHV gene (45%). A combination of bla SHV , bla CTX-M , and bla TEM genes was found in 17% of the isolates, indicating the presence of all three resistance genes. This is the first investigation which highlights the importance of multidrug-resistant Aeromonas spp. in L. marginalis . The identification of extended-spectrum-β-lactamases (ESBLs) genes demand the necessity of continuous surveillance and systematic monitoring, considering its potential health risks for both animals and human beings.

Background: The prevalence of community-onset infections of extended spectrum β-lactamase (ESBL)-producing strains has increased globally, yet surveillance and resistance in patients with oral and maxillofacial surgery site infections is less investigated. Patients and Methods: A retrospective cohort study was performed to investigate risk factors and resistance of ESBL-producing Escherichia coli (ESBL-EC) and ESBL-producing Klebsiella pneumonia (ESBL-KP) among community-onset patients with oral and maxillofacial surgery during January 2010 to December 2016. Demographic features, predisposing factors, clinical outcomes, and antibiotic agent costs were analyzed. Antimicrobial susceptibility testing of nine antimicrobial agents against ESBL-KP and ESBL-EC were measured. Results: Among 2,183 cultures from infection sites in patients with oral and maxillofacial surgery site (45 cases [2.06%]) were confirmed with community-onset ESBL-KP (24; 1.10%) or ESBL-EC (21; 0.96%) infection. Multivariable analysis showed the independent risk factors for ESBL-producing bacterial infection were prior history of hospitalization (adjusted odds ratio [aOR], 10.984; 95% confidence interval [CI], 5.965-59.879; p = 0.025) and malignant condition (aOR, 3.373; 95% CI 2.947-7.634; p = 0.024). Based on antimicrobial susceptibility testing, 57.8% ESBL-KP and ESBL-EC were found receiving inappropriate antimicrobial therapy, and antibiotic agent costs were higher than non-ESBL-producing bacterial infections ($493.8 ± $367.3 vs. $304.1 ± $334.7; p = 0.031). Conclusions: Infections caused by ESBL-KP and ESBL-EC among patients in sites with oral and maxillofacial surgery are associated with prior history of hospitalization and malignant conditions. Prompt detection and appropriate antibiotic administration for community-onset infections of ESBLs are necessary for such populations.

Objective: In this study, we sought to determine the types and prevalence of antimicrobial resistance determinants (ARDs) in Burkholderia spp. strains using the Antimicrobial Resistance Determinant Microarray (ARDM)., Results: Whole genome amplicons from 22 B. mallei (BM) and 37 B. pseudomallei (BP) isolates were tested for > 500 ARDs using ARDM v.3.1. ARDM detected the following Burkholderia spp.-derived genes, aac(6), bla BP/MBL-3 , blaA BPS , penA-BP, and qacE, in both BM and BP while bla BP/MBL-1 , macB, bla OXA-42/43  and penA-BC were observed in BP only. The method of denaturing template for whole genome amplification greatly affected the numbers and types of genes detected by the ARDM. Bla TEM was detected in nearly a third of BM and BP amplicons derived from thermally, but not chemically denatured templates. Bla TEM results were confirmed by PCR, with 81% concordance between methods. Sequences from 414-nt PCR amplicons (13 preparations) were 100% identical to the Klebsiella pneumoniae reference gene. Although bla TEM sequences have been observed in B. glumae, B. cepacia, and other undefined Burkholderia strains, this is the first report of such sequences in BM/BP/B. thailandensis (BT) clade. These results highlight the importance of sample preparation in achieving adequate genome coverage in methods requiring untargeted amplification before analysis., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Background: The accelerating prevalence of extended-spectrum β-lactamase (ESBL)-producing and multidrug-resistance (MDR) Escherichia coli(E. coli) become a public health challenge worldwide. This study aimed to discuss the prevalence of drug-resistant E. coli colonization and analyze its risk factors and clinical characteristics among young infants in Southern Taiwan., Methods: Stool samples were collected from young infants, aged less than three months, within three days of their hospitalization from September to December 2019 in a tertiary hospital. A questionnaire was designed for parents to complete. E. coli colonies were selected and analyzed for antimicrobial susceptibility. PCR-based multilocus sequence typing was to detect the presence of sequence type ST131 and bla CTX-M genes., Results: Among 100 enrolled infants, 36% had fecal carriage of E. coli isolates, of which twenty nine (80.5%) were MDR, thirteen (36.1%) were ESBL-producing isolates and five (13.8%) and ten (27.7%) were ST131 and strains carrying CTX-M-14 gene, respectively. Compared to non-ST131 and non-CTX-M-14 gene carrier, isolates of ST131 and CTX-M-14 gene carrier showed a significantly higher resistance rate to cefixime, ceftriaxone, and gentamycin, with p value all <0.05., Conclusion: The prevalence of ESBL-producing and MDR E. coli fecal carriage were both high in young infants. The most common sequence type is ST131, of which all are strains carrying CTX-M-14. Further surveillance and investigation to control for the high prevalence of antimicrobial-resistant E. coli fecal carriage among infants in Taiwan are warranted., Competing Interests: Conflict of interest The authors declare that they have no potential conflicts of interest., (Copyright © 2023 Taiwan Pediatric Association. Published by Elsevier B.V. All rights reserved.)

Introduction: Carbapenems and piperacillin/tazobactam (PIPC/TAZ) are commonly used as the initial therapy to treat extended-spectrum β-lactamase (ESBL)-producing Enterobacterales in acute cholangitis. However, the overuse of these antibiotics contributes to the spread of antimicrobial resistance. Cefmetazole (CMZ) is stable to hydrolysis by ESBLs, so it may be an alternative to carbapenems and PIPC/TAZ. However, the effectiveness of CMZ compared with that of carbapenems and PIPC/TAZ as the initial therapy for acute cholangitis is unknown., Methods: We conducted a retrospective cohort study at a university hospital between April 1, 2014, and December 31, 2022. Patients with bacteremic acute cholangitis who received CMZ, carbapenems, or PIPC/TAZ as the initial therapy were included. The patients were divided into a CMZ group and a carbapenems or PIPC/TAZ (CP) group to compare patient outcomes., Results: A total of 99 patients (54 in the CMZ group and 45 in the CP group) were analyzed. The baseline characteristics of the patients were similar and 30-day mortality did not differ between groups (4% vs. 7%, P = 0.66). However, the CMZ group had a shorter length of stay (LOS) (8 days vs. 15 days, P < 0.001) and lower mean antibiotic cost (98.92 USD vs. 269.49 USD, P < 0.001) than the CP group., Conclusions: In bacteremic acute cholangitis, initial therapy with CMZ may contribute to a shorter LOS and lower antibiotic costs than treatment with carbapenems and PIPC/TAZ, without worsening patient outcomes., Competing Interests: Declarations of competing interest All authors have no conflicts of interest to declare., (Copyright © 2023 Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Infection Prevention and Control. Published by Elsevier Ltd. All rights reserved.)

Background: Antibiotic resistance is one of the most serious global health problems and threatens the effective treatment of bacterial infections. Of greatest concern are infections caused by extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC). The aim of our study was to evaluate the prevalence and molecular characteristics of ESBL-EC isolated over an 18-year pre-COVID period from lower respiratory tract (LRT) samples collected from selected Slovenian hospitals., Objectives and Methods: All isolates were identified by MALDI-TOF and phenotypically confirmed as ESBLs by a disk diffusion assay. Using a PCR approach, 487 non-repetitive isolates were assigned to phylogroups, sequence type groups, and clonal groups. Isolates were also screened for virulence-associated genes (VAGs) and antimicrobial resistance genes., Results: The prevalence of ESBL-EC isolates from LRT in a large university hospital was low (1.4%) in 2005 and increased to 10.8% by 2019. The resistance profile of 487 non-repetitive isolates included in the study showed a high frequency of group 1 bla CTX-M (77.4%; n = 377), bla TEM (54.4%; n = 265) and aac(6')-Ib-cr (52%; n = 253) genes and a low proportion of bla SHV and qnr genes. Isolates were predominantly assigned to phylogroup B2 (73.1%; n = 356), which was significantly associated with clonal group ST131. The ST131 group accounted for 67.6% (n = 329) of all isolates and had a higher number of virulence factor genes than the non-ST131 group. The virulence gene profile of ST131 was consistent with that of other extraintestinal pathogenic E. coli (ExPEC) strains and was significantly associated with ten of sixteen virulence factor genes tested. Using ERIC-PCR fingerprinting, isolates with the same ERIC-profile in samples from different patients, and at different locations and sampling dates were confirmed, indicating the presence of "hospital-adapted" strains., Conclusion: Our results suggest that the ESBL-EC isolates from LRT do not represent a specific pathotype, but rather resemble other ExPEC isolates, and may be adapted to the hospital environment. To our knowledge, this is the first study of ESBL-EC isolated from LRT samples collected over a long period of time., (© 2024. The Author(s).)

Background: The present study aimed to investigate the prevalence and molecular characterization of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) isolated from dairy cattle with endometritis in China. The prevalence of ESBL-producing E. coli in sample was detected using ChromID ESBL agar, and genotyping of the ESBL producers was performed by PCR and DNA sequencing., Results: The results revealed that the proportion of positive pathogens tested was 69.76% (180/258) in samples obtained from cows diagnosed with clinical endometritis, with E. coli accounting for 170 out of the 180 positive samples. The infection rate of isolated E. coli was 39.14% (101/258), and co-infections with other pathogens were prevalent. Furthermore, among the 158 E. coli isolates, 50 strains were identified as ESBL producers, with TEM and CTX-M prevalence rates at 78.00% and 32.00%, respectively. Drug sensitivity experiments indicated that 50 isolates of ESBL- producing E. coli were multidrug resistance (MDR), with 48.0% of them exhibiting positive results for both the class 1 integron gene and five gene cassettes associated with resistance to trimethoprim (dfr1 and dfrA17) and aminoglycosides (aadA1, aadA5, and dfrA1), respectively., Conclusion: This investigation demonstrated a substantial prevalence and heightened level of antimicrobial resistance among ESBL-producing E. coli isolates derived from dairy cattle infected with endometritis in China., (© 2024. The Author(s).)

Introduction: This study compares the clinical and microbiological efficacy of ceftolozane/tazobactam (CTLZ/TAZ) and piperacillin/tazobactam (PIPC/TAZ) for treating complicated cystitis or acute pyelonephritis., Methods: Patients who had been treated with empiric antibiotics, CTLZ/TAZ (52 cases) or PIPC/TAZ (47 cases), due to urinary tract infections (UTIs) were eligible for this study. Patients' demographic backgrounds, types of UTIs, and causative microorganisms isolated from urine or blood bacterial cultures were collected. Short-term clinical efficacy at the end of the initial empiric therapy, long-term clinical efficacy including sequential antibiotic treatments (nonrecurrence rate within 1 month after the initial empiric therapy), and microbiological efficacy were retrospectively compared in both CTLZ/TAZ and PIPC/TAZ groups., Results: Complicated UTIs were present in most eligible patients, and no significant difference in the patients' background was observed between the two groups. Escherichia coli and Enterococcus faecalis were the most common microorganisms isolated from urine culture in both groups. The short-term clinical effective rate of CTLZ/TAZ and PIPC/TAZ was 80.8% and 87.2%, respectively. For long-term clinical efficacy, the nonrecurrence rate of UTIs was present in 95.1% and 89.7% of patients with CTLZ/TAZ and PIPC/TAZ, respectively. No significant difference was observed in the short- and long-term effects between the two groups. The microbiological efficacy of the CTLZ/TAZ and PIPC/TAZ groups was 72.7% and 86.0%, respectively. No significant difference in microbiological effects was also observed between the two groups., Conclusions: This study demonstrated the noninferiority of CTLZ/TAZ to PIPC/TAZ, suggesting that CTLZ/TAZ is an alternative antibiotic used as empiric therapy for UTIs., Competing Interests: Declaration of competing interest None., (Copyright © 2023 Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Infection Prevention and Control. Published by Elsevier Ltd. All rights reserved.)

Carbapenems are antimicrobial agents commonly used to treat extended-spectrum β-lactamase (ESBL)-producing bacteria. Although cefmetazole (CMZ) is considered effective for ESBL-producing Escherichia coli (ESBL-EC) bacteremia, previous studies showed its limitations, including the influence of the initial antimicrobial agent. Here, we examined the effects of different approaches to antimicrobial therapy with CMZ and meropenem (MEPM) on the time to defervescence in ESBL-EC bacteremia. Notably, the influence of previous antimicrobial agents was excluded. Inpatients with ESBL-EC detected in blood cultures between April 2018 and March 2023 were included and assigned to CMZ ( n = 14), MEPM ( n = 8), de-escalation to CMZ (dCMZ; n = 9), or escalation to MEPM (eMEPM; n = 11) groups. The median time to defervescence was 3.5, 1.0, 2.0, and 4.0 days in the CMZ, MEPM, dCMZ, and eMEPM groups, respectively, with no significant differences. Cox proportional hazards analysis showed a significant difference in the hazard ratio (95% confidence interval) of 0.378 (0.145-0.984) for the time to defervescence with CMZ versus MEPM ( p = 0.046). The extent of a delayed time to defervescence is greater with early CMZ administration than with MEPM administration in patients with non-severe ESBL-EC bacteremia.

Background: The rising prevalence of extended-spectrum beta-lactamase and carbapenemase-producing Enterobacteriaceae (ESβL-PE) in street foods poses a significant risk to human health due to its epidemiological significance. Thus, the aim of this study was to determine the magnitude of foodborne Enterobacteriaceae that produce carbapenemase and ESβL, as well as their patterns of antibiotic resistance, in the studied area., Methods: A community-based cross-sectional study was carried out from January 1st, 2023, to February 30th, 2023. One hundred randomly chosen street-vended food items (one hundred grams of each food item) were aseptically collected, and aliquots of 0.1 ml from the homogenized (25 g of samples into 225 ml of buffered peptone water (BPW)) were inoculated on MacConkey agar and Xylose Lysine Deoxycholate Agar (XLD). Enterobacteriaceae isolates were identified using various biochemical tests. ESβL and carbapenemase were first screened by indicator cephalosporins and carbapenem antibiotics, respectively. ESβL and carbapenemase were confirmed by a double-disc synergy test and modified carbapenem inactivation methods, respectively. Kirby-Bauer disc diffusion method was used for the antimicrobial-resistant test., Results: A total of 112 Enterobacteriaceae belonging to six different genera were isolated. E. coli was attributed 39 (34.8%), followed by Citrobacter spp. 22 (19.6%) and K. pneumoniae 18 (16.1%), with only 8 (7.1%) isolated Salmonella spp. About 15.2% (n = 17) and 8.9% (n = 10) of Enterobacteriaceae were phenotypically confirmed to be extended-spectrum beta-lactamase (ESβL) and carbapenemase producers, respectively. The highest percentage of ESβL-producing isolates was attributed to K. pneumoniae (n = 5), E. coli (n = 4), and Enterobacter spp. (n = 3). Proteus spp. and Salmonella spp. isolates were carbapenemase-negative. All carbapenemase-positive isolates were found to be ESβL-producers. 70.6% (12/17) of ESβL-producing Enterobacteriaceae were found to be multidrug-resistant (MDR)., Conclusion: A considerable number of multidrug-resistant ESβL and carbapenemase-producing Enterobacteriaceae were identified, suggesting that street foods may be a potential source of MDR foodborne infections. Consequently, it is important to conduct routine examinations of street food items and track trends in medication resistance., (© 2023. The Author(s).)

The environmental contamination plays a significant role in the emergence of antimicrobial resistance. In this study, we report a genomic analysis of an extensively drug-resistant and bla NDM-1 -producing Klebsiella pneumoniae (EW807) strain recovered from a surface water sample. Strain EW807 belonged to sequence type (ST) 340 and serotype O4:KL15, a high-risk clone of the clonal group 258. This strain carried a broad resistome, including bla NDM-1 and bla CTX-M-15 . The core genome multilocus sequence typing phylogenetic analysis revealed that the EW807 strain was most related to strains from Brazil and the USA. An IncX3 plasmid was identified harboring the bla NDM-1 gene, while an IncFIB(K) plasmid was detected carrying the bla CTX-M-15 in addition to multidrug resistance and multimetal tolerance regions. IncX3 and IncFIB(K) plasmids shared high similarity with plasmids from a human in China and a dog in Brazil, respectively. The regions harboring the bla NDM-1 and bla CTX-M-15 genes contained sequences from the Tn3 family. These findings suggest that IncX3 plasmid could play a role in the spread of NDM-1 in a post-pandemic scenario. To the best of our knowledge, this is the first report of bla NDM-1 -producing K. pneumoniae ST340 O4:KL15 strain in the environment. Therefore, the presence of high-risk clones of K. pneumoniae carrying carbapenemases in the environment requires strict surveillance., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Aims: The main objective of this study was to compare extended-spectrum β-lactamase (ESBL) Escherichia coli fecal titers during 12 days between two groups: mice who received proton pump inhibitors (PPIs) and those that did not., Methods and Results: We tested three different in vivo models: model 1, high inoculum (106 CFU ml-1); model 2, low inoculum (102 CFU ml-1); and model 3, low inoculum and 2-day amoxicillin wash-out. There was no significant difference between the two groups in fecal ESBL E. coli titers in models 1 and 2. The fecal titers of ESBL E. coli were probably too high to show differences in colonization related to PPI treatment. By introducing a 2-day wash-out period after stopping amoxicillin (model 3), the fecal ESBL E. coli titers were higher in the PPI-treated mice during 12 days (3 log versus 11 log day CFU g-1; P < 0.05). This result highlighted that PPIs promote stable ESBL E. coli digestive carriage in mice. Fecal quantitative PCR showed that mice with low ESBL E. coli fecal titers had a much higher concentration of equol-producing bacteria, Muribaculum sp., and Adlercreutzia caecimuris., Conclusions: Pantoprazole treatment promotes sustained digestive carriage of ESBL E. coli in amoxicillin-treated mice., (© The Author(s) 2023. Published by Oxford University Press on behalf of Applied Microbiology International.)

Introduction: The spread of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) is a serious concern in companion animal medicine owing to their ability to develop multidrug resistance. Cefmetazole (CMZ) is a candidate drug for treating ESBL-E infections; however, its regimen in dogs has not been established. In this study, we investigated the pharmacokinetic (PK) indices of CMZ in dogs and performed PK-pharmacodynamic (PD) analyses using Monte Carlo Simulation (MCS)., Methods: In total, six healthy dogs received an intravenous bolus dose of CMZ (40 mg/kg body weight). Serum CMZ concentrations were evaluated using liquid chromatography-mass spectrometry, and PK indices were determined based on non-compartmental analysis. The PK-PD cut-off (COPD) values were calculated as the highest minimum inhibitory concentration (MIC) that achieved ≥90% probability of target attainment for a target value of unbounded drug concentration exceeding 40% of the dosing interval. The cumulative fraction of response (CFR) was calculated based on the MIC distribution of wild-type ESBL-E from companion animals., Results: The area under the concentration-time curve and elimination half-time were 103.36 ± 7.49 mg·h/L and 0.84 ± 0.07 h, respectively. MCS analysis revealed that COPD values for regimens of 40 mg/kg q12, q8h, and q6h were ≤ 0.5, ≤2, and ≤ 4 μg/mL, respectively. A regimen of 40 mg/kg q6h was estimated to achieve a CFR of 80-90% for Escherichia coli and Klebsiella pneumoniae . By contrast, all regimens exhibited a CFR of ≤70% for Proteus mirabilis and Enterobacter cloacae., Discussion: We conclude that CMZ at 40 mg/kg q6h could be a viable treatment regimen for dogs infected with ESBL-producing Escherichia coli and Klebsiella pneumoniae ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2023 Kusumoto, Motegi, Uno, Yokono and Harada.)

Background: Several pieces of evidence suggest that certain pathobionts belonging to Enterobacterales are associated with the development and progression of inflammatory bowel diseases (IBD). Extended-spectrum β-lactamases (ESBLs) ESBLs are frequently found in the Enterobacterales members, particularly in Escherichia coli and Klebsiella spp., and might trigger antibiotic-induced perturbations of the intestinal microbiota and led to more severe disease activity in IBD. Therefore, the severity of IBD could be influenced by ESBL-producing Enterobacterales, and hence, this study aimed to investigate the presence of ESBLs and carbapenemases among mucosa-associated E. coli and Klebsiella pneumoniae isolated from colonic biopsies of Iranian patients with IBD., Methods: In this cross-sectional study, E. coli and K. pneumoniae were isolated from inflamed ileum and/or colon tissue of patients with IBD, including Ulcerative colitis (UC) and Crohn's disease (CD), during colonoscopy. Demographic data and clinical characteristics were recorded, and UC and CD disease activity and extent were evaluated according to the full Mayo score and Crohn's disease activity index (CDAI), respectively. Phenotypic and molecular detection of ESBL- and carbapenemase-producing E. coli and Klebsiella pneumoniae were carried out. Disease activity and other clinical and microbial features were compared in patients with and without gut colonization with ESBL producers., Results: A total of 83 IBD patients, including 67 UC and 16 CD, were enrolled in the initial analysis. Intestinal colonization with ESBL-producing E. coli and/or Klebsiella pneumoniae was found in 37 (55.2%) of UC and 9 (56.2%) of DC patients - mostly harbored E. coli containing the bla CTX-M and bla TEM genes. UC patients with intestinal colonization with ESBL-producers had more severe disease compared with patients without colonization. Moreover, 10.2% of tested E. coli and 34.8% of K. pneumoniea were recognized as potential carbapenemase producers., Conclusion: Intestinal colonization with ESBL producers could arise disease activity in IBD patients. Further large-scale case-control studies should be performed to investigate the possible confounding factors that could contribute to this outcome., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Escherichia coli significantly causes nosocomial infections and rampant spread of antimicrobial resistance (AMR). There is limited data on genomic characterization of extended-spectrum β-lactamase (ESBL)-producing E. coli from African clinical settings. This hospital-based longitudinal study unraveled the genetic resistance elements in ESBL E. coli isolates from Uganda and Tanzania using whole-genome sequencing (WGS). A total of 142 ESBL multi-drug resistant E. coli bacterial isolates from both Tanzania and Uganda were sequenced and out of these, 36/57 (63.1%) and 67/85 (78.8%) originated from Uganda and Tanzania respectively. Mutations in RarD, yaaA and ybgl conferring resistances to chloramphenicol, peroxidase and quinolones were observed from Ugandan and Tanzanian isolates. We reported very high frequencies for bla CTX-M-15 with 11/18(61.1%), and bla CTX-M-27 with 12/23 (52.1%), bla TEM-1B with 13/23 (56.5%) of isolates originating from Uganda and Tanzania respectively all conferring resistance to Beta-lactam-penicillin inhibitors. We observed chloramphenicol resistance-conferring gene mdfA in 21/23 (91.3%) of Tanzanian isolates. Extraintestinal E. coli sequence type (ST) 131 accounted for 5/59 (8.4%) of Tanzanian isolates while enterotoxigenic E. coli ST656 was reported in 9/34 (26.4%) of Ugandan isolates. Virulence factors originating from Shigella dysenteriae Sd197 (gspC, gspD, gspE, gspF, gspG, gspF, gspH, gspI), Yersinia pestis CO92 (irp1, ybtU, ybtX, iucA), Salmonella enterica subsp. enterica serovar Typhimurium str. LT2 (csgF and csgG), and Pseudomonas aeruginosa PAO1 (flhA, fliG, fliM) were identified in these isolates. Overall, this study highlights a concerning prevalence and diversity of AMR-conferring elements shaping the genomic structure of multi-drug resistant E. coli in clinical settings in East Africa. It underscores the urgent need to strengthen infection-prevention controls and advocate for the routine use of WGS in national AMR surveillance and monitoring programs.Availability of WGS analysis pipeline: the rMAP source codes, installation, and implementation manual can free be accessed via https://github.com/GunzIvan28/rMAP ., (© 2023. BioMed Central Ltd., part of Springer Nature.)

The extended-spectrum β-lactamase (ESBL)-producing Enterobacterales (ESBL-EB) encompass several important human pathogens and are found on the World Health Organization (WHO) priority pathogens list of antibiotic-resistant bacteria. They are a group of organisms which demonstrate resistance to third-generation cephalosporins (3GC) and their presence has been documented worldwide, including in aquaculture and the aquatic environment. This risk profile was developed following the Codex Guidelines for Risk Analysis of Foodborne Antimicrobial Resistance with the objectives of describing the current state of knowledge of ESBL-EB in relation to retail shrimp and salmon available to consumers in Canada, the primary aquacultured species consumed in Canada. The risk profile found that Enterobacterales and ESBL-EB have been found in multiple aquatic environments, as well as multiple host species and production levels. Although the information available did not permit the conclusion as to whether there is a human health risk related to ESBLs in Enterobacterales in salmon and shrimp available for consumption by Canadians, ESBL-EB in imported seafood available at the retail level in Canada have been found. Surveillance activities to detect ESBL-EB in seafood are needed; salmon and shrimp could be used in initial surveillance activities, representing domestic and imported products.

Background and Aim: Escherichia coli causes a bacterial illness that frequently affects cats. Diseases caused by E. coli are treated using antibiotics. Because of their proximity to humans, cats possess an extremely high risk of contracting antibiotic resistance genes when their owners touch cat feces containing E. coli that harbor resistance genes. This study was conducted to identify multidrug-resistant E. coli and extended-spectrum β-lactamase (ESBL)-producing genes from cat rectal swabs collected at Surabaya City Veterinary Hospital to determine antibiotic sensitivity., Materials and Methods: Samples of cat rectal swabs were cultured in Brilliant Green Bile Lactose Broth medium and then streaked on eosin methylene blue agar medium for bacterial isolation, whereas Gram-staining and IMViC tests were conducted to confirm the identification results. The Kirby-Bauer diffusion test was used to determine antibiotic sensitivity, and the double-disk synergy test was used to determine ESBL-producing bacteria. Molecular detection of the genes TEM and CTX-M was performed using a polymerase chain reaction., Results: Based on morphological culture, Gram-staining, and biochemical testing, the results of sample inspection showed that of the 100 cat rectal swab samples isolated, 71 (71%) were positive for E. coli . Furthermore, 23 E. coli isolates (32.39%) demonstrated the highest resistance to ampicillin. Four isolates were confirmed to be multidurg-resistant and ESBL-producing strains. Molecular examination revealed that three E. coli isolates harbored TEM and CTX-M ., Conclusion: In conclusion, pet owners must be educated on the use of antibiotics to improve their knowledge about the risks of antibiotic resistance., Competing Interests: The authors declare that they have no competing interests., (Copyright: © Farizqi, et al.)

Wildlife in urban areas have the potential to disseminate antimicrobial-resistant bacteria (ARB) across a wider environment. Using antimicrobial-supplemented agar plates, we isolated extended-spectrum β-lactamase-producing Escherichia coli (EEC) and quinolone-resistant E. coli (QREC) from 144, 23, and 30 deer feces from Nara Park (NP), rural area neighboring NP (RA), and Mt. Odaigahara (MO), respectively. In NP and RA, the prevalence of EEC was 24.3 and 4.3%, respectively; that of QREC was 11.1 and 17.4%, respectively. Neither EEC nor QREC were detected in MO. The pulsotypes of EEC and QREC isolates differed between NP and RA. Our study suggests that deer of the Nara Prefecture are potential carriers of ARB, but long-distance dissemination is unlikely due to limited deer movement.

The global prevalence of infections caused by extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) is increasing, and for Escherichia coli , observations indicate that this is partly driven by community-onset cases. The ESBL-E population structure in the community is scarcely described, and data on risk factors for carriage are conflicting. Here, we report the prevalence and population structure of fecal ESBL-producing E. coli and Klebsiella pneumoniae (ESBL-Ec/Kp) in a general adult population, examine risk factors, and compare carriage isolates with contemporary clinical isolates. Fecal samples obtained from 4,999 participants (54% women) ≥40 years in the seventh survey of the population-based Tromsø Study, Norway (2015, 2016), were screened for ESBL-Ec/Kp. In addition, we included 118 ESBL-Ec clinical isolates from the Norwegian surveillance program in 2014. All isolates were whole-genome sequenced. Risk factors associated with carriage were analyzed using multivariable logistic regression. ESBL-Ec gastrointestinal carriage prevalence was 3.3% [95% confidence interval (CI) 2.8%-3.9%, no sex difference] and 0.08% (0.02%-0.20%) for ESBL-Kp. For ESBL-Ec, travel to Asia was the only independent risk factor (adjusted odds ratio 3.46, 95% CI 2.18-5.49). E. coli ST131 was most prevalent in both collections. However, the ST131 proportion was significantly lower in carriage (24%) versus clinical isolates (58%, P < 0.001). Carriage isolates were genetically more diverse with a higher proportion of phylogroup A (26%) than clinical isolates (5%, P < 0.001), indicating that ESBL gene acquisition occurs in a variety of E. coli lineages colonizing the gut. STs commonly related to extraintestinal infections were more frequent in clinical isolates also carrying a higher prevalence of antimicrobial resistance, which could indicate clone-associated pathogenicity.IMPORTANCEESBL-Ec and ESBL-Kp are major pathogens in the global burden of antimicrobial resistance. However, there is a gap in knowledge concerning the bacterial population structure of human ESBL-Ec/Kp carriage isolates in the community. We have examined ESBL-Ec/Kp isolates from a population-based study and compared these to contemporary clinical isolates. The large genetic diversity of carriage isolates indicates frequent ESBL gene acquisition, while those causing invasive infections are more clone dependent and associated with a higher prevalence of antibiotic resistance. The knowledge of factors associated with ESBL carriage helps to identify patients at risk to combat the spread of resistant bacteria within the healthcare system. Particularly, previous travel to Asia stands out as a major risk factor for carriage and should be considered in selecting empirical antibiotic treatment in critically ill patients., Competing Interests: The authors declare no conflict of interest.

Urinary tract infection (UTI) and bloodstream infection (BSI) caused by extended-spectrum β-lactamase (ESBL)-producing bacteria are important healthcare problems. Appropriate infection management requires the direct detection of organisms in clinical specimens. We assessed the capability of the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry-based MBT STAR-Cepha kit to detect ESBL producers in clinical urine and blood samples. Over a 1-year period, 90 urine samples and 55 positive monomicrobial (Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, or Proteus mirabilis) blood cultures were collected from patients with UTI or BSI at Hamamatsu University Hospital. β-lactamase activity in these samples was directly detected using the MBT STAR-Cepha kit, and the results were compared with those of antimicrobial susceptibility testing and polymerase chain reaction detection assay for the isolates. In receiver operating characteristic curve analysis, the kit assay showed low accuracy in detecting ESBL producers in urine samples (area under the curve [AUC], 0.69). Meanwhile, the AUC for detecting all ESBL-producing bacteria in positive blood cultures was 0.81. The kit assay detected cefotaxime (CTX) resistance (mainly in CTX-M-type ESBL producers) with high accuracy in positive blood cultures; however, it did not accurately detect ESBL producers in urine samples and CTX-susceptible isolates with other ESBL-associated genes (e.g., TEM and SHV types) in positive blood cultures. MBT STAR-Cepha testing can accurately discriminate CTX-resistant ESBL producers in BSI cases and thus can contribute to effective infection management. The results suggest that different sample types, antibiotic resistance profiles, and resistance genes can affect the kit performance., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: This study was funded by Bruker Japan K. K., (Copyright © 2023 Elsevier B.V. All rights reserved.)

A CTX-M-65‒producing Salmonella enterica serovar Infantis clone, probably originating in Latin America and initially reported in the United States, has emerged in Taiwan. Chicken meat is the most likely primary carrier. Four of the 9 drug resistance genes have integrated into the chromosome: bla CTX-M-65 , tet(A), sul1, and aadA1.

Dogs have been reported as potential carriers of antimicrobial-resistant bacteria, but the role of cats has been poorly studied. The aim of this study was to investigate the presence and the risk factors associated with the fecal carriage of extended-spectrum β-lactamase and AmpC (ESBL/AmpC)-producing Escherichia coli ( E. coli ) in pet and stray cats. Fecal samples were collected between 2020 and 2022 from healthy and unhealthy cats and screened for ESBL/AmpC-producing E. coli using selective media. The presence of ESBL/AmpC-producing E. coli was confirmed by phenotypic and molecular methods. The evaluation of minimum inhibitory concentrations (MICs) was performed on positive isolates. Host and hospitalization data were analyzed to identify risk factors. A total of 97 cats' samples were collected, and ESBL/AmpC-producing E. coli were detected in 6/97 (6.2%), supported by the detection of bla CTX-M (100%), bla TEM (83.3%), and bla SHV (16.7%) genes and the overexpression of chromosomal ampC (1%). All E. coli isolates were categorized as multidrug-resistant. Unhealthy status and previous antibiotic therapy were significantly associated with ESBL/AmpC-producing E. coli fecal carriage. Our results suggest that cats may be carriers of ESBL/AmpC-producing E. coli , highlighting the need for antimicrobial stewardship in veterinary medicine and an antimicrobial-resistance surveillance program focusing on companion animals, including stray cats.

Objectives: A previous study showed higher prevalence of Escherichia coli (E. coli) expressing extended-spectrum β-lactamases (ESBL-Ec) among men who have sex with men (MSM) in Amsterdam, the Netherlands, compared with the general Dutch population. This study genetically characterised the ESBL-Ec isolates and investigated whether the increased prevalence could be explained by transmission between participants., Methods: Whole-genome sequences were obtained from 93 unique ESBL-Ec isolates that were cultured from rectal swabs of 79 participants. Isolates were typed according to the Achtman MLST scheme and ESBL and virulence genes were identified. Pairwise SNP distances were determined between isolates. Isolate pairs with ≤ 25 SNPs were considered part of a putative transmission event, and events between multiple participants formed putative transmission clusters. To investigate whether putatively transmitted isolates belonged to globally expanded lineages, the level of hierarchical clustering with international isolates was assessed using core genome MLST (cgMLST) implemented on the Enterobase platform., Results: The most frequently detected E. coli types were ST131:bla CTX-M-15 (16 of 117, 13.5%), ST131:bla CTX-M-27 , ST3075:bla CTX-M-15 and ST14:bla SHV-12 (all six of 117, 6.5%). Fourteen putative transmission events were identified, forming four putative transmission clusters. The largest putative transmission cluster contained ST131 isolates, which clustered with multiple international isolates in SNP and cgMLST analysis. One other transmission cluster (ST14:bla SHV-12 ) and two transmission events (ST14:bla SHV-12 and ST394:bla CTX-M-15 ) contained very rarely reported strains., Conclusions: The identification of unique ESBL-Ec strains involved in putative transmission and carried by multiple participants demonstrated a high probability of ESBL-Ec transmission between MSM in Amsterdam; therefore, ESBL-Ec infection should be considered in cases of sexually active MSM having associated symptoms., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

This study aimed to investigate the drug resistance, molecular characteristics, and genetic relationship of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolated from food and human stool samples in northern Xinjiang. From 2015 to 2016, a total of 431 samples (meats and vegetables) were collected from retail markets and supermarkets located in the regions of Urumqi, Shihezi, and Kuitun in Xinjiang, China, and 20 human stool samples from the Shihezi Hospital. The PCR method was used to detect E. coli , and the presence of ESBL-producing E. coli was confirmed using the K-B disk diffusion confirmatory method. The susceptibility to ESBL-producing E. coli was tested by the microdilution broth method, and the minimum inhibitory concentration was determined. PCR was used to detect the resistance and virulence genes of ESBL-producing E. coli , and phylogenetics, plasmid replicon typing, screening of three integrons, and multilocus sequence typing (MLST) were performed. The results showed that 127 E. coli strains (15 human stool and 112 food samples) were isolated. Out of the 127 E. coli strains, 38 strains (6 human stool and 32 food 34 samples) of ESBL-producing E. coli were identified through screening. These 38 strains showed resistance to cefotaxime (94.74%) and cefepime (94.74%), and were sensitive to meropenem (0.00%). The most detected resistance genes were bla TEM (47.37%), and the most detected virulence genes were fimH (97.73%), ompA (97.73%), hlyE (97.73%), and crl (97.37%). The isolates belonged to phylogroups B 1 (42.11%), C (23.68%), and A (21.05%). Among the plasmid replicon subtypes, IncFIB was the main type (42.11%). The integrons detected were of the first type (47.37%) and the third type (26.32%). The 38 E. coli strains had 19 different sequence-type (ST) strains. These 38 strains of ESBL-producing E. coli were analyzed using MLST and STs are varied.

The susceptibility of 218 extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae isolates from companion animals to three cephamycins (cefmetazole, flomoxef, and latamoxef) was investigated. Phenotypic testing found 8 of 120 Klebsiella pneumoniae (KP) and 15 of 69 Enterobacter cloacae (EC) isolates were ESBL and AmpC β-lactamase (ABL) co-producers. Isolates of KP, Proteus mirabilis, and EC that only produced ESBL exhibited susceptibility rates to cefmetazole (95.5%, 82.7%, and 9.3%), flomoxef (99.1%, 96.6%, and 74.0%), and latamoxef (99.1%, 100%, and 100%), respectively. Notably, isolates of KP and EC co-producing ESBL and ABL had significantly lower susceptibility rates to the studied drugs when compared with only ESBL producers. This implies that the in vitro activity of cephamycins against ESBL-producing bacteria can differ depending on ABL production and bacterial species.

The increasing incidence of extended-spectrum β-lactamase (ESBL)-producing Escherichia ( E .) coli in backyard chicken farming in Pakistan is of serious concern. This study aimed to assess the prevalence, antimicrobial resistance patterns and risk factors associated with ESBL avian pathogenic E. coli (APEC) isolated from backyard chickens in the Jhang district, Punjab, Pakistan. In total, 320 cloacal swabs were collected from four breeds of backyard chicken (Aseel, Golden, Misri and Necked Neck). ESBL E. coli were phenotypically identified using double disc synergy test (DDST) and corresponding genes were confirmed by multiplex polymerase chain reaction (mPCR). Out of the 320 samples, 164 (51.3%) were confirmed as E. coli, while 74 (45.1%) were characterized as ESBL E. coli . The frequency of isolation of ESBL E. coli was highest in Aseel chickens (35.1%). Of the 164 confirmed E. coli , 95.1%, 78.6%, 76.8%, 71.3%, 70.1%, 68.9%, 60.4% and 57.3% were resistant against tylosin, doxycycline, cefotaxime, enrofloxacin, colistin, trimethoprim/sulfamethoxazole, chloramphenicol and gentamicin, respectively. The ESBL gene types detected and their corresponding proportions were bla CTX-M (54.1 %, 40/74), bla TEM , (12.2%, 9/74) and co-existence ( bla CTX-M and bla TEM ) were shown in 33.8% (25/74). The bla CTX-M gene sequence showed homology to bla CTX-M-15 from clinical isolates. The mean multiple antibiotic resistance index (MARI) was found to be higher among ESBL E. coli (0.25) when compared to non-ESBL E. coli (0.17). Both free-range husbandry management system ( p = 0.02, OR: 30.00, 95% CI = 1.47-611.79) and high antimicrobial usage in the last 6 months ( p = 0.01, OR: 25.17, 95% CI = 1.81-348.71) were found significantly associated with isolation of ESBL-producing E. coli in the tested samples using binary logistic regression analysis. This study confirmed the potential of backyard chickens as a reservoir for ESBL E. coli in the Jhang district, Punjab, Pakistan.

Extended spectrum β-lactamase (ESBL)-producing Enterobacterales has spread rapidly around the world, reaching remote areas. In this regard, wild birds that acquire ESBL producers from anthropogenically impacted areas can become reservoirs, contributing to further dissemination of antimicrobial-resistant bacteria categorized as critical priority pathogens to remote environments, during migration seasons. We have conducted a microbiological and genomic investigation on the occurrence and features of ESBL-producing Enterobacterales in wild birds from the remote Acuy Island, in the Gulf of Corcovado, at Chilean Patagonia. Strikingly, five ESBL-producing Escherichia coli were isolated from migratory and resident gulls. Whole-genome sequencing (WGS) analysis revealed the presence of two E. coli clones belonging to international sequence types (STs) ST295 and ST388, producing CTX-M-55 and CTX-M-1 ESBLs, respectively. Moreover, E. coli carried a wide resistome and virulome associated with human and animal infections. Phylogenomic analysis of global and publicly genomes of E. coli ST388 (n = 51) and ST295 (n = 85) clustered gulls isolates along to E. coli strains isolated from the environment, companion animal and livestock in the United States of America, within or close to the migratory route of Franklin's gull, suggesting a possible trans hemispheric movement of international clones of WHO critical priority ESBL producing pathogens., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The increase in multidrug-resistant microorganisms that produce extended-spectrum β-lactamases (ESBLs) and carbapenemases is a serious problem worldwide. Recently, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) has been used for the rapid detection of antibiotic-resistant bacteria. The objective of this study was to establish a method to detect ESBL-producing Escherichia coli by monitoring the hydrolyzation of cefotaxime (CTX) using MALDI-TOF MS. According to the ratio of the peak intensity of CTX and hydrolyzed-CTX-related compounds, the ESBL-producing strains could be clearly distinguished after 15 min of incubation. Moreover, the minimum inhibitory concentration (MIC) values for E. coli were 8 μg/mL and lower than 4 μg/mL, which could be distinguished after 30 min and 60 min of incubation, respectively. The enzymatic activity was determined using the difference in the signal intensity of the hydrolyzed CTX at 370 Da for the ESBL-producing strains incubated with or without clavulanate. The ESBL-producing strains with low enzymatic activity or bla CTX-M genes could be detected by monitoring the hydrolyzed CTX. These results show that this method can rapidly detect high-sensitivity ESBL-producing E. coli .

Background: Extended-spectrum beta-lactamase-producing Enterobacterales (eESBL) have high prevalence in hospitals, but real-time monitoring of nosocomial acquisition through conventional typing methods is challenging. Moreover, patient-to-patient transmission varies between the main species, namely Escherichia coli and Klebsiella pneumoniae, which draws into question the relevance of applying identical preventive measures., Aim: To detect eESBL cross-transmission events (CTEs) using the quantitative antibiogram (QA) method in combination with epidemiological data (combined QA method), and to determine the effectiveness of standard or contact precautions for eESBL species., Methods: First, a validation set was used to compare the relevance of the combined QA method with a combination of pulsed-field gel electrophoresis and epidemiological data (combined PFGE method). Next, a 4-year retrospective analysis was conducted to detect eESBL CTEs in hospitalized patients. Two species were screened - ESBL E. coli (ESBL-Ec) and ESBL K. pneumoniae (ESBL-Kp). During the study, standard precautions alone were applied to patients with ESBL-Ec, whereas contact precautions were applied for patients with ESBL-Kp., Findings: As a proof of concept, use of the combined QA method and the combined PFGE method for the detection of CTEs gave identical results for E. coli, and similar results for at least 75% of K. pneumoniae. Overall, 722 patients with ESBL-Ec isolates and 280 patients with ESBL-Kp isolates were included in the retrospective analysis. Nine and 23 CTEs were identified for E. coli and K. pneumoniae, respectively, involving 20 (2.7%) and 36 (12.8%) patients, respectively., Conclusion: The combined QA method constitutes a rapid tool for epidemiological surveillance to detect CTEs. In the study hospital, standard precautions are sufficient to prevent acquisition of ESBL-Ec, whereas contact precautions must be implemented to prevent acquisition of ESBL-Kp., (Copyright © 2023 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

The global spread of antimicrobial resistance (AMR) is alarming. Escherichia coli is a Gram-negative bacterium that causes healthcare-associated infections and is a major threat to public health. Currently, no comprehensive antimicrobial surveillance of multidrug-resistant E. coli of diverse phylogroups along the meat value chain has been implemented in Higashihiroshima, Japan. Therefore, by employing the One Health approach, 1183 bacterial isolates, including 303 recovered from meat samples in 2009, were screened for the presence of antimicrobial resistance determinants using multiplex PCR and DNA sequencing techniques. Seventy-seven non-duplicate E. coli isolates that harbored AMR genes were subjected to antimicrobial susceptibility testing and the detection of integrons. Phylogenetic characterization, which has not been previously investigated, was used to assign E. coli to one of the eight phylogroups. Twenty-six out of 33 (78.8%) and 34 out of 44 (77.3%) E. coli isolates from 2009 and 2021 exhibited multidrug resistance (MDR) phenotypes, respectively. The most common clinical resistance was observed against ampicillin, tetracycline, kanamycin, sulfamethoxazole/trimethoprim, cefotaxime, and chloramphenicol. Overall, 22.1% (17/77) of the E. coli isolates carried extended-spectrum β-lactamase (ESBL)-encoding genes and showed the ESBL-resistant phenotypes. For the two isolation years, AmpC/ESBL prevalence decreased from 42.4% in 2009 to 20.5% in 2021. The identified AMR genes included bla CTX-M-1 , bla CTX-M-2 , bla CTX-M-14 , bla CTX-M-15 , and bla SHV-12 (ESBL-types); bla SHV-1 , bla TEM-1 , bla TEM-135 , and bla TEM-176 (narrow-spectrum types); bla CMY-4 , bla ADC-32 , bla ADC-216 , bla ACT-48 , and bla ACT-51 (AmpC types); and integrons. All E. coli isolates were negative for carbapenemase-encoding genes, whereas one isolate from 2009 carried mcr-5.1 allele. Approximately 52% of E. coli isolates identified in 2009 were assigned to phylogroup A compared to the 20.5% in 2021. Notably, the highest proportions of E. coli phylogroups exhibiting MDR were groups A, B1, and F, suggesting that members of these groups are mostly associated with drug resistance. This study highlights the role of meat as a significant reservoir of MDR E. coli and potential source for transmission of AMR genes. Our findings emphasize the importance of continuous monitoring to track the changes in the spread of antimicrobial resistance in the food chain., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Tadashi Shimamoto reports financial support and administrative support were provided by Hiroshima University., (Copyright © 2023 Elsevier B.V. All rights reserved.)