ESBL-producing Escherichia Coli Research Articles

Extended-spectrum beta-lactamase- and carbapenemase-producing Escherichia coli isolates causing hospital- and community-acquired infections in Tunisia (2001-2019): expansion of CTX-M-15-C2 and CTX-M-27-C1 ST131 subclades.

We aimed to investigate the microbiological features of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBL-EC) and carbapenemase-producing E. coli (CP-EC) causing hospital- and community-acquired infections in Tunisia over the last two decades. The study captured the emergence and expansion of the CTX-M-15-C2 ST131 subclade and successively the CTX-M-27-C1 ST131 subclade, which were responsible for the steady increase in the prevalence of ESBL-EC. However, the incidence of CP-EC remained stable over the study period with a highly diverse content in carbapenemase genes dominated by blaOXA-48-like. This is the first study to provide comprehensive data on the epidemiology of ESBL-EC and CP-EC in a North African country.

Klebsiella pneumoniae, a human-dog shuttle organism for the genes of CTX-M ESBL.

Antimicrobials reserved for human medicines are permitted for companion animals and it is important to understand multidrug-resistant pathogens recovered from companion animals in terms of epidemiological correlation with human pathogens and possibility of transmission to human-beings. Seventeen of each CTX-M-type extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) and Klebsiella pneumoniae (ESBL-KP) canine isolates were assessed. Entire genomes of the 34 isolates were sequenced. Plasmid transfer and relative growth rates were assessed at differed temperature conditions indicating the body temperature of dogs, that of human-beings, and environment. ESBL-ECs were clonally diverse, while ESBL-KPs were not. The ESBL-ECs carried the blaCTX-M-15 gene in plasmids and the blaCTX-M-14-like gene either in chromosomes or in plasmids. The ESBL-KPs possessed the blaCTX-M-15 gene in plasmids (n = 15). One of the isolates carried another blaCTX-M-15 gene in a chromosome simultaneously and the other isolate had an additional blaCTX-M-9 gene-harbouring plasmid, together. Two ESBL-KP isolates carried the blaCTX-M-14 gene in plasmids. Plasmid transfer ESBL-EC to K. pneumoniae was efficient and the differed biological costs by temperature was much more in ESBL-EC than in ESBL-KP. Intersectoral dissemination of ESBL-ECs occurred mainly by horizontal gene transfer, while that of ESBL-KPs occurred by clonal dissemination.

Human Faecal Carriage Of Antibiotic Resistance And Molecular Characterization Of ESBL Producing Escherichia Coli In The Community.

Human Faecal Carriage Of Antibiotic Resistance And Molecular Characterization Of ESBL Producing Escherichia Coli In The Community.

Carriage and antimicrobial susceptibility patterns of rectal ESBL E. coli in surgical patients at the University Teaching Hospitals in Lusaka, Zambia.

Surgical site infections (SSIs) are on the rise and are a global concern as they complicate the recovery of patients postoperatively. Bacterial colonization of the patient's skin and alimentary tract are known to be major contributing sources to SSIs. However, Zambia lacks data relating to carriage rates of antibiotic-resistant rectal Escherichia coli among surgical patients. This was a cross-sectional study aimed at determining the preoperative (preop) and postoperative (postop) carriage and antimicrobial susceptibility patterns of rectal ESBL-producing E. coli (ESBL-Ec) in elective surgery patients at the highest tertiary hospital in Lusaka, Zambia. Phenotypic methods were used in the identification of E. coli. Antibiotic susceptibility patterns and identification of ESBL-Ec was determined by Kirby-Bauer disc diffusion. A total of 120 study participants were recruited, of which 75 were followed up at least 72 h after surgery. From 195 rectal swabs cultured, 177 (90.8%) were positive for E. coli, of which 53 (29.9%) were ESBL-Ec, with a significantly (P < 0.0001) higher proportion in postop (47.9%) than preop (17.3%) participants. Overall, ESBL-Ec isolates showed higher resistance in postop than preop to cefotaxime (100% versus 88.9%, respectively), ampicillin (100% versus 94.4%), ciprofloxacin (88.3% versus 83.3%), amoxicillin/clavulanic acid (80% versus 66.7%) and cefepime (80% versus 77.8%). MDR ESBL-Ec strains were more frequent in postop than in preop participants (91.4% versus 88.9%). The study showed a significantly higher rate of antimicrobial-resistant rectal E. coli in postop than preop participants. There is a need to ascertain the source of the resistance and to institute robust infection control measures, preop screening of surgical patients for ESBL-Ec, and to raise awareness on prudent use of antibiotics.

Extended-spectrum β-lactamase-producing Escherichia coli from poultry: A review

Extended-spectrum β-lactamases (ESBLs) are β-lactamase enzymes produced by Gram-negative bacterial pathogens that harbor the ESBL genes. In addition, most ESBL genes are plasmid-mediated and usually encode a broader spectrum of antimicrobial resistance, especially to penicillins, first-generation, second-generation, and third-generation cephalosporins, as well as monobactam, such as aztreonam. Escherichia coli has become an opportunistic pathogen, especially in poultry, and has been implicated in zoonotic diseases that can be transmitted to humans, resulting in public health problems. Poultry can act as carriers of ESBL-producing E. coli (ESBL-EC) bacteria to humans through poultry meat that is contaminated by waste products, feces, and excretions. The ESBL gene CTX-M type was identified as the main cause of infection in humans and was detected in poultry as a cause of infection accompanied by clinical symptoms. Several studies have also shown a link between E. coli and ESBL gene transfer from birds to humans. Controlling the spread of ESBL-EC involves maintaining the cleanliness of poultry products, especially meat, and eliminating contaminant sources from poultry. Likewise, maintaining the environmental cleanliness of poultry slaughterhouses and poultry farms must be taken as a precautionary measure to curtail the increasing spread of ESBL-EC into the environment. This review aimed to explain the spread of ESBL-producing E. coli in poultry. Keywords: Escherichia coli, extended-spectrum β-lactamase, poultry, public health, zoonosis.

Resistance to aztreonam-avibactam among clinical isolates of Escherichia coli is primarily mediated by altered penicillin-binding protein 3 and impermeability

This study was conducted to investigate decreased susceptibility (minimum inhibitory concentrations [MICs] 0.25–4 mg/L) and resistance (MICs > 4 mg/L) to aztreonam-avibactam (ATM-AVI). Contemporary non-replicate clinical isolates of carbapenemase-producing Escherichia coli (CP-EC) (n=90) and ESBL-producing E. coli (EP-EC) (n=12) were used. CP-EC belonged to 25 distinct sequence types (STs) and all EP-EC belonged to ST405. All strains were isolated from 2019 to 2022 at the Karolinska University Laboratory, Stockholm, Sweden. ATM-AVI MICs were determined using broth microdilution. The EUCAST epidemiological cut-off value of 0.125 mg/L was used to define the wild type (WT). Whole-genome sequences (Illumina) were analysed for detecting resistance determinants among WT vs. non-WT isolates. Among 102 isolates, 40 (39%) and 62 (61%) were WT and non-WT, respectively. Among non-WT isolates, resistance was noted for 20 and decreased susceptibility for 42. Resistance was observed among 14/47 New Delhi metallo-β-lactamase (NDM)-producers, 5/43 OXA-48 group producers, and 1/12 EP-EC. Decreased susceptibility was observed among 29/47 NDM, 13/43 OXA-48 group, and 3/12 EP-EC. Resistant isolates predominantly belonged to ST405, followed by STs 410, 361, 167, 617, and 1284. Penicillin-binding protein 3 (PBP3) inserts (YRIK/YRIN) were observed in 20/20 and CMY-42 in 5/20 resistant isolates. Several mutations in the ftsI (encoding PBP3) and regulatory genes of outer membrane proteins (OmpC and OmpF) and efflux pumps (AcrAB-TolC) were detected. A ≥ 2-fold reduction in MICs was observed among 20/20 vs. 7/20 isolates tested in the presence of the membrane permeabiliser, polymyxin B nanopeptide (PMBN) and efflux inhibitor, phenylalanine arginine β-naphthylamide (PAβN), respectively. In conclusion, resistance to ATM-AVI is a result of interplay of various determinants, including target alterations, deactivating enzymes, and decreased permeability.

Exploring the presence, genomic traits, and pathogenic potential of extended-spectrum β-lactamase Escherichia coli in freshwater, wastewater, and hospital effluents.

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. 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. ESBL-EC are widely distributed in the aquatic environment in Belgium and contain a variety of ESBL and CP genes.

River waters in Greece: A reservoir for clinically relevant extended-spectrum-β-lactamases-producing Escherichia coli

In the current study, the genotypic characteristics such as antimicrobial resistance and virulence genes, and plasmid replicons and phenotypic characteristics such as biofilm formation and antimicrobial resistance of 87 extended-spectrum beta-lactamase (ESBL)-producing E. coli (ESBL-Ec) isolated from 7 water bodies in northern Greece were investigated. Our data show a high prevalence (60.0 %) of ESBL-Ec in surface waters that exhibit high genetic diversity, suggesting multiple sources of their transmission into the aquatic environment. When evaluating the antimicrobial resistance of isolates, wide variation in their resistance profiles has been detected, with all isolates being multi-drug resistant (MDR). Regarding biofilm formation capacity and phylogenetic groups, the majority (54.0 %, 47/87) of ESBL-Ec were classified as no biofilm producers mainly assigned to phylogroup A (35.6 %; 31/87), followed by B2 (26.5 %; 23/87). PCR screening showed that a high proportion of the isolates tested positive for the blaCTX-M-1 group genes (69 %, 60/87), followed by blaTEM (55.2 %, 48/87), blaOXA (25.3 %, 22/87) and blaCTX-M-9 (17.2 %, 15/87). A subset of 28 ESBL-Ec strains was further investigated by applying whole genome sequencing (WGS), and among them, certain clinically significant sequence types were identified, such as ST131 and ST10. The corresponding in silico analysis predicted all these isolates as human pathogens, while a significant proportion of WGS-ESBL-Ec were assigned to extraintestinal pathogenic E. coli (ExPEC; 32.1 %), and urinary pathogenic E. coli (UPEC; 28.6 %) pathotypes. Comparative phylogenetic analysis, showed that the genomes of the ST131-O25:H4-H30 isolates are genetically linked to the human clinical strains. Here, we report for the first time the detection of a plasmid-mediated mobile colistin resistance gene in ESBL-Ec in Greece isolated from an environmental source. Overall, this study underlines the role of surface waters as a reservoir for antibiotic resistance genes and for presumptive pathogenic ESBL-Ec.

Surveillance and Resistance of Community-Onset Extended-Spectrum β-Lactamase-Producing Escherichia coli and Klebsiella pneumonia in Oral and Maxillofacial Surgery Site Infections.

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.

Characterization of Extended-Spectrum β-Lactamase-Producing Escherichia coli in Animal Farms in Hunan Province, China.

Multi-drug resistance of bacteria producing extended-spectrum β-lactamase (ESBL) is a public health challenge. Thus, this study aimed to investigate the antimicrobial susceptibility of ESBL-producing Escherichia coli (ESBL-EC) in Hunan Province, China. A total of 1366 fecal samples were collected from pig, chicken, and cattle farms over a six-year period, which were assessed using strain isolation, 16S rRNA identification, polymerase chain reaction, drug sensitivity testing, whole-genome sequencing, and bioinformatics analysis. The results showed an overall prevalence of 6.66% for ESBL-EC strains, with ESBL positivity extents for pigs, chickens, and cattle isolates at 6.77%, 6.54%, and 12.5%, respectively. Most ESBL-EC isolates were resistant to cefotaxime, tetracycline, and trimethoprim-sulfamethoxazole; however, all the isolates were susceptible to meropenem, with relatively low resistance to amikacin and tigecycline. Various multi-locus sequence types with different origins and similar affinities were identified, with ST155 (n = 16) being the most common subtype. Several types of resistance genes were identified among the 91 positive strains, with beta-lactamase blaCTX-M-55 being the most common ESBL genotype. IncFIB was the predominant plasmid type. Widespread use of antibiotics in animal farming may increase antibiotic resistance, posing a serious threat to the health of farmed animals and, thus, to human food security and health.

Presence of Extended Spectrum Beta-lactamase-producing Escherichia coli from Meat Handler and Poultry Cecal Samples

Antimicrobial resistance is a global health issue that affects humans, animals, and agriculture. This study assessed the prevalence and antimicrobial susceptibility of extended-spectrum beta- lactamase-producing Escherichia coli (ESBL-EC) in poultry and hand swabs of meat handlers working in a dressing plant in the Philippines. Fourteen (14) hand swabs from poultry handlers and 89 poultry cecal samples were collected and screened for ESBL production using MacConkey agar supplemented with cefotaxime and eosin methylene blue agar. Identification of E. coli through biochemical testing and antimicrobial susceptibility testing was then performed using the VITEK 2 System. Results showed that 7.14% (1/14) of the hand swabs and 23.60% (21/89) of the poultry cecal samples were positive for ESBL-EC. Identified isolates were further evaluated for their antimicrobial susceptibility using 33 antibiotics from various groups. Results showed 100% (22/22) resistance to the following antimicrobial drugs: ampicillin, ticarcillin, cefalotin, cefuroxime, cefuroxime axetil, cefixime, cefotaxime, nalidixic acid, ciprofloxacin, levofloxacin, moxifloxacin, ofloxacin, tetracycline, trimethoprim, and trimethoprim/ sulfamethoxazole. Resistance of select ESBL-EC isolates against other drugs under the beta-lactam, tetracycline, chloramphenicol, and aminoglycoside groups were also observed. Antimicrobial-resistant bacteria may be found in both human and animal sources, which highlights the need for ensuring safety practices to prevent their spread in the community. Gene sequencing and phylogenetic analysis may be used to further evaluate this relationship. Continuous surveillance and review of standards and protocols are also needed to monitor antimicrobial resistance, as underlined by the strategies of the One Health approach.

Effects of breastfeeding on children’s gut colonization with multidrug-resistant Enterobacterales in peri-urban Lima, Peru

ABSTRACT Children living in low-resource settings are frequently gut-colonized with multidrug-resistant bacteria. We explored whether breastfeeding may protect against children’s incident gut colonization with extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-Ec) and Klebsiella, Enterobacter, or Citrobacter spp. (ESBL-KEC). We screened 937 monthly stool samples collected from 112 children aged 1–16 months during a 2016–19 prospective cohort study of enteric infections in peri-urban Lima. We used 52,816 daily surveys to examine how exposures to breastfeeding in the 30 days prior to a stool sample were associated with children’s risks of incident gut-colonization, controlling for antibiotic use and other covariates. We sequenced 78 ESBL-Ec from 47 children to explore their diversity. Gut-colonization with ESBL-Ec was increasingly prevalent as children aged, approaching 75% by 16 months, while ESBL-KEC prevalence fluctuated between 18% and 36%. Through 6 months of age, exclusively providing human milk in the 30 days prior to a stool sample did not reduce children’s risk of incident gut-colonization with ESBL-Ec or ESBL-KEC. From 6 to 16 months of age, every 3 additional days of breastfeeding in the prior 30 days was associated with 6% lower risk of incident ESBL-Ec gut-colonization (95% CI: 0.90, 0.98, p = .003). No effects were observed on incident ESBL-KEC colonization. We detected highly diverse ESBL-Ec among children and few differences between children who were predominantly breastfed (mean age: 4.1 months) versus older children (10.8 months). Continued breastfeeding after 6 months conferred protection against children’s incident gut colonization with ESBL-Ec in this setting. Policies supporting continued breastfeeding should be considered in efforts to combat antibiotic resistance.

Gut colonization and subsequent infection of neonates caused by extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae.

The gut microbiota harbors diverse bacteria considered reservoirs for antimicrobial resistance genes. The global emergence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales (ESBL-PE) significantly contributes to healthcare-associated infections (HAIs). We investigated the presence of ESBL-producing Escherichia coli (ESBL-PEco) and ESBL-producing Klebsiella pneumoniae (ESBL-PKpn) in neonatal patients' guts. Furthermore, we identified the factors contributing to the transition towards ESBL-PEco and ESBL-PKpn-associated healthcare-associated infections (HAIs). The study was conducted from August 2019 to February 2020, in a Neonatal Intensive Care Unit of the Hospital Infantil de México Federico Gómez. Rectal samples were obtained upon admission, on a weekly basis for a month, and then biweekly until discharge from the neonatology ward. Clinical data, culture results, and infection information were gathered. We conducted antimicrobial tests, multiplex PCR assay, and pulsed-field gel electrophoresis (PFGE) to determine the antimicrobial resistance profile and genetic relationships. A comparison between the group's controls and cases was performed using the Wilcoxon and Student t-tests. Of the 61 patients enrolled, 47 were included, and 203 rectal samples were collected, identifying 242 isolates. In 41/47 (87%) patients, colonization was due to ESBL-PEco or ESBL-PKpn. And nine of them developed HAIs (22%, 9/41). ESBL-PEco resistance to cephalosporins ranged from 25.4% to 100%, while ESBL-PKpn resistance varied from 3% to 99%, and both bacteria were susceptible to carbapenems, tigecillin, and colistin. The prevalent bla CTX-M-group-1 gene accounted for 77.2% in ESBL-PEco and 82.2% in ESBL-PKpn, followed by bla TEM 50% and bla OXA-1 43.8% in ESBL-PEco and bla TEM 80.2% and bla SHV 76.2% in ESBL-PKpn. Analysis of clonality revealed identical colonizing and infection isolates in only seven patients. Significant risk factors included hospital stay duration, duration of antibiotic treatment, and invasive device usage. Our findings suggest high ESBL-PEco and ESBL-PKpn rates of colonization often lead to infection in neonates. Attention should be paid to patients with ESBL-PE.

Antibiotic-resistant characteristics and horizontal gene transfer ability analysis of extended-spectrum β-lactamase-producing Escherichia coli isolated from giant pandas.

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.

Removal of antibiotic resistant bacteria in wastewater treatment plants

Antibiotic Resistant Bacteria (ARB) emergence is an increasing threat to public health globally. Wastewater Treatment Plants (WWTPs) play a crucial role in the dissemination of ARB in the environment due to limitations in ARB removal. This study investigated the presence and characteristics of ARB, specifically Extended-Spectrum Beta-Lactamase producing Escherichia coli (ESBL-Ec) and Vancomycin Resistant Enterococci (VRE) , in two WWTPs treating wastewater from hospital and domestic source. The study employed phenotypic and genotypic tests to confirm the presence of ESBL-Ec and VRE, and evaluated their resistance to antibiotics. The results indicated the presence of ESBL-Ec and VRE in both WWTP influent up to (6.0 ± 0.25) x 105 and (1.38 ± 0.25) × 104 CFU/100 mL, respectively, suggesting the potential dissemination of ARB to environment. Although the WWTPs demonstrated relatively high removal efficiencies for ESBL-Ec and VRE up to 4.1 and 5.0 log reduction, respectively, the presence of resistant genes suggested the need for further optimization of treatment processes to mitigate the spread of ARB. The findings highlighted the significance of improved disinfection methods, monitoring antibiotic usage, and implementing robust antimicrobial resistance surveillance systems in WWTPs to minimize the environmental impact associated with ARB dissemination.

Occurrence of extended-spectrum beta-lactamase producing escherichia coli in groundwater

Groundwater is a vital source of clean water globally. The presence of E.coli, specifically ESBL-producing E.coli (ESBL-Ec), in groundwater can pose a significant risk to human health. This study aimed to analyze the concentrations of E.coli and ESBL-Ec in five groundwater samples (A1-A5) near the Cipayung landfill, as well as one groundwater (A6) from a residential area. Morevorer, one septic tank sample located near A6 was also collected (ST). Characterization of the the blaCTX-M gene associated with cefotaxime resistance were conducted. Phenotypic analysis involved the Double Disk Sinergy Test to confirm ESBL enzyme activity against antibiotics, while genotypic analysis utilized the Multiplex PCR to characterize the blaCTX-M gene. Results indicated that the E. coli concentrations in groundwater ranged from (4.0 ± 2.0) × 10-1 CFU/100 mL to (4.0 ± 0.3) × 103 CFU/100 mL. ESBL-Ec was consistently detected at A1, A2, A4, and ST with average concentrations of (6.5 ± 3.0) × 100 CFU/100 mL, (1.3 ± 0.5) × 100 CFU/100 mL, (1.1 ± 0.1) × 101 CFU/100 mL, and (7.2 ± 1.1) × 103 CFU/100 mL, respectively. Multiplex PCR revealed the presence of blaCTX-M group 1 and group 2 genes at samples A1, A2, A4, and ST. This study highlighted the need for preventive measures to minimize ESBL-Ec spread in groundwater.

Genomic characterization of extended-spectrum β-lactamase-producing Enterobacterales isolated from abdominal surgical patients.

Rectal swabs of 104 patients who underwent abdominal surgery were screened for ESBL producers. Sequence types (STs) and resistance genes were identified by whole-genome sequencing of 46 isolates from 17 patients. All but seven isolates were assigned to recognized STs. While 18 ESBL-producing E. coli (EPEC) strains were of unique STs, ESBL-producing K. pneumoniae (EPKP) strains were mainly ST14 or ST15. Eight patients harboured strains of the same ST before and after abdominal surgery. The most prevalent resistant genes in E. coli were blaEC (69.57%), blaCTX-M (65.22%), and blaTEM (36.95%), while blaSHV was present in only K. pneumoniae (41.30%). Overall, genes encoding β-lactamases of classes A (blaCTX-M, blaTEM, blaZ), C (blaSHV, blaMIR, and blaDHA), and D (blaOXA) were identified, the most prevalent variants being blaCTX-M-15, blaTEM-1B, blaSHV-28, and blaOXA-1. Interestingly, blaCMY-2, the most common pAmpC β-lactamase genes reported worldwide, and mobile colistin resistance genes, mcr-10-1, were also identified. The presence of blaCMY-2 and mcr-10-1 is concerning as they may constitute a potentially high risk of pan-resistant post-surgical infections. It is imperative that healthcare professionals monitor intra-abdominal surgical site infections rigorously to prevent transmission of faecal ESBL carriage in high-risk patients.

Effect of Different Approaches to Antimicrobial Therapy with Cefmetazole and Meropenem on the Time to Defervescence in Non-Severe Extended-Spectrum β-Lactamase-Producing Escherichia coli Bacteremia.

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.

Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Feces and Wastewater Treatment System in Swine Farms, Thailand

The antimicrobial resistance (AMR) problem is one that demands urgent interventions to minimize the rapid spread in humans, animals and the environment. Extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-Ec) could spread from livestock farms to environment or circulate in farms via wastewater. This study aimed to quantify and characterize ESBL-Ec in swine feces and wastewater samples collected from 2 conventional swine farms with wastewater treatment systems. Microbiological analysis was performed on fecal and wastewater samples, and the concentration of cefotaxime (CTX)-resistant bacteria, indicative of ESBL-Ec, was determined across different stages of wastewater treatment. Additionally, ESBL-Ec was isolated and identified from fresh feces, swine house wastewater, and treated wastewater from covered lagoons and photosynthetic ponds. Results indicated a higher concentration of CTX-resistant bacteria in the wastewater in the early process of wastewater treatment. However, CTX-resistant bacteria were not detected in the final photosynthetic pond in one of the 2 farms. ESBL-Ec was identified in fresh feces from swine houses and wastewater treatment plants in both farms. Further antimicrobial susceptibility testing revealed diverse resistance patterns among the ESBL-Ec isolates, with tetracycline and gentamicin demonstrated the highest resistance rates. The ESBL genes identified belonged to the CTX-M-14, CTX-M-17 and CTX-M-55. This study demonstrated the presence of ESBL-Ec in swine feces and wastewater, emphasizing the importance of effective wastewater treatment before discharging to limit the spread of AMR bacteria. HIGHLIGHTS ESBL producers was isolated from fecal and wastewater samples from swine farms The wastewater treatment system could reduce cefotaxime-resistant bacteria CTX-M-14, CTX-M-17 and CTX-M-55 genes were detected in swine farms, Thailand GRAPHICAL ABSTRACT

Gut microbiome dynamics in index patients colonized with extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales after hospital discharge and their household contacts.

This study investigated the gut microbiome dynamics of index patients colonized with extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-Ec) (n = 5) or extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-Kp) (n = 3) and their household contacts (n = 9) up to 4 months after hospital discharge of the index patient using 16S rRNA amplicon gene sequencing. Samples were collected at the day of hospital discharge of the index patient, 1 week and 2 and 4 months after discharge. Compared to household contacts, we observed a significant lower alpha diversity (P < 0.001) among index patients and significant (P < 0.05) separation between the two groups for beta diversity. Principal component analysis of the samples from each household (i.e., index patient and respective household contact) showed a clear shift in microbiome composition, in 4/8 index patients, from dissimilar to more similar to the household contact group. This suggests recovery of the microbiome to a healthier status, which was also reflected by de novo colonization of (health-associated) taxa. In contrast, the four time-point samples of the household contacts clustered together indicating a stable microbiome composition over time irrespective of low-level ESBL-Ec (n = 3) or ESBL-Kp (n = 2) colonization. In conclusion, here we show that, at the day of hospital discharge, the microbiome composition of index patients is dissimilar from that of household contacts. Over time, signals of microbiome recovery were observed in half of the index patients. The stable microbiome composition in household contacts irrespective of low-level ESBL-Ec or ESBL-Kp colonization suggests that the gut microbiome in these healthy people provided colonization resistance against ESBL-PE outgrowth. IMPORTANCE Colonization with extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-PE) often precedes infections and is therefore considered as a great threat for public health. Here, we studied the gut microbiome dynamics in eight index patients colonized with ESBL-PE after hospital discharge and the impact of exposure to this index patient on the gut microbiome dynamics of their household contacts. We showed that the microbiome composition from index patients is different from their household contacts upon hospital discharge and that, in some of the index patients, their microbiome composition over time shifted toward the composition of their household contacts. In contrast, household contacts showed a stable microbiome composition over time irrespective of low-level extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-Ec) or extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-Kp) gut colonization, suggesting that, in healthy microbiomes, colonization resistance is able to prevent ESBL-PE expansion.