Phenotypic and genotypic characterizations of extended-spectrum beta-lactamase-producing Escherichia coli in Thailand

The resistance patterns and molecular characteristics of ESBL/AmpC-producing Escherichia coli from captive panda ecosystem in China

Escherichia coli (E. coli) plays an important ecological role, and is a useful bioindicator to recognize the evolution of resistance in human, animal and environment. Recently, extended-spectrum β-lactamases (ESBL) producing E.coli has posed a threat to public health. Generally, captive healthy giant pandas are not exposed to antibiotics; however, they still acquire antimicrobial resistant bacteria. In order to understand whether there is an exchange of resistance genes within the ecosystems of captive giant pandas, this study explored resistance characteristics of 330 commensal E. coli isolates from feces of giant pandas, the surroundings, and breeders. Isolates from different sources showed similar resistance phenotype, and ESBL/AmpC-producing isolates showed more profound resistance to antibiotics than non-ESBL/AmpC-producing isolates (P<0.05). Furthermore, the occurrence of broad-spectrum β-lactamase related resistance genes and colistin resistance genes was detected, and isolates phylogenetic typing and multilocus sequence typing (MLST) were applied in this study. Seven different β-lactamase resistance genes (blaCTX-M-55, blaCTX-M-15, blaCTX-M-27, blaCTX-M-65, blaTEM-1, blaOXA-1 and blaCMY) and mcr-1 were found in 68 ESBL/AmpC-producing isolates. blaCTX-M-55 (48.53 %) was found the most predominant resistance genes, followed by blaTEM-1 (19.12 %) and blaCTX-M-27 (16.18 %). Nonetheless, blaCTX-M-55 was commonly detected in the isolates from giant pandas (63.16 %), the surroundings (43.48 %), and breeders (33.33 %). However, there were no carbapenemase genes detected in this study. mcr-1 was harbored in only one isolate from giant panda. Forty-five tansconjugants were successfully obtained in the conjugation experiments. The presence of antimicrobial resistance and related resistance genes tested were observed in the transconjugants. The results indicated that 52.63 % of the isolates from giant panda 73.91 % of the isolates from surroundings, and 100 % of the isolates from breeders were phylogroup A. Total of 27 sequence types (ST) were recognized from the isolate by MLST and found that ST48 (19/68; 27.94 %) was the predominant ST type, especially in the isolates from giant pandas and the surroundings. In conclusion, commensal ESBL/AmpC-producing E. coli becomes a reservoir of ESBL resistance genes, which is a potential threaten to health of giant pandas. The interaction between giant pandas, surroundings and breeders contribute to development of resistant phenotypes and genotypes which might transfer across species or the surroundings easily; hence, strict monitoring based on a "One Health" approach is recommended.

Extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae: insights from a tertiary hospital in Southern Thailand

Broad-spectrum ampicillin-resistant and third-generation cephalosporin-resistant Enterobacteriaceae, particularly Escherichia coli and Klebsiella pneumoniae that have pathological features in humans, have become a global concern. This study aimed to investigate the prevalence, antimicrobial susceptibility, and molecular genetic features of extended-spectrum beta-lactamase (ESBL)-producing E. coli and K. pneumoniae isolates in Southern Thailand. Between January and August 2021, samples (n = 199) were collected from a tertiary care hospital in Southern Thailand. ESBL and AmpC-lactamase genes were identified using multiplex polymerase chain reaction (PCR). The genetic relationship between ESBL-producing E. coli and K. pneumoniae was determined using the enterobacterial repetitive intergenic consensus (ERIC) polymerase chain reaction. ESBL-producing E. coli and K. pneumoniae isolates were mostly collected from catheter urine samples of infected female patients. The ESBL production prevalence was highest in the medical wards (n = 75, 37.7%), followed by that in surgical wards (n = 64, 32.2%) and operating rooms (n = 19, 9.5%). Antimicrobial susceptibility analysis revealed that all isolates were resistant to ampicillin, cefotaxime, ceftazidime, ceftriaxone, and cefuroxime; 79.4% were resistant to ciprofloxacin; and 64.3% were resistant to trimethoprim-sulfamethoxazole. In ESBL-producing K. pneumoniae and E. coli, blaTEM (n = 57, 72.2%) and blaCTX-M (n = 61, 50.8%) genes were prominent; however, no blaVEB, blaGES, or blaPER were found in any of these isolates. Furthermore, only ESBL-producing K. pneumoniae had co-harbored blaTEM and blaSHV genes at 11.6%. The ERIC-PCR pattern of multidrug-resistant ESBL-producing strains demonstrated that the isolates were clonally related (95%). Notably, the presence of multidrug-resistant and extremely resistant ESBL producers was 83.4% and 16.6%, respectively. This study highlights the presence of blaTEM, blaCTX-M, and co-harbored genes in ESBL-producing bacterial isolates from hospitalized patients, which are associated with considerable resistance to beta-lactamase and third-generation cephalosporins.

IMPORTANCE

We advocate for evidence-based guidelines and antimicrobial stewardship programs to encourage rational and appropriate antibiotic use, ultimately reducing the selection pressure for drug-resistant bacteria and lowering the likelihood of ESBL-producing bacterial infections.

Escherichia coli sequence type 410 with carbapenemases: a paradigm shift within E. coli toward multidrug resistance

Escherichia coli sequence type ST410 is an emerging carbapenemase-producing multidrug-resistant (MDR) high-risk One-Health clone with the potential to significantly increase carbapenem resistance among E. coli. ST410 belongs to two clades (ST410-A and ST410-B) and three subclades (ST410-B1, ST410-B2, and ST410-B3). After a fimH switch between clades ST410-A and ST410-B1, ST410-B2 and ST410-B3 subclades showed a stepwise progression toward developing MDR. (i) ST410-B2 initially acquired fluoroquinolone resistance (via homologous recombination) in the 1980s. (ii) ST410-B2 then obtained CMY-2, CTX-M-15, and OXA-181 genes on different plasmid platforms during the 1990s. (iii) This was followed by the chromosomal integration of blaCMY-2, fstl YRIN insertion, and ompC/ompF mutations during the 2000s to create the ST410-B3 subclade. (iv) An IncF plasmid "replacement" scenario happened when ST410-B2 transformed into ST410-B3: F36:31:A4:B1 plasmids were replaced by F1:A1:B49 plasmids (both containing blaCTX-M-15) followed by blaNDM-5 incorporation during the 2010s. User-friendly cost-effective methods for the rapid identification of ST410 isolates and clades are needed because limited data are available about the frequencies and global distribution of ST410 clades. Basic mechanistic, evolutionary, surveillance, and clinical studies are urgently required to investigate the success of ST410 (including the ability to acquire successive MDR determinants). Such information will aid with management and prevention strategies to curb the spread of carbapenem-resistant E. coli. The medical community can ill afford to ignore the spread of a global E. coli clone with the potential to end the carbapenem era.

Phenotypic and genotypic characterization of extended spectrum beta-lactamase producing E. coli harboring carbapenem and colistin-resistant genes from poultry farms in Egypt

Background

eEscherichia coli (E. coli) bacteria that produce extended spectrum beta-lactamase (ESBL) is associated with a high prevalence of human illnesses worldwide. The emergence of resistance to carbapenem and colistin compounds poses further challenges to the treatment options for these illnesses. This study aimed to evaluate the phenotypic and genotypic pattern of resistance to carbapenem and colistin in ESBL-producing E. coli. Escherichia coli isolates collected from the respiratory tract of chickens in El-Sharkia government, Egypt.

Methods

A total of 250 lung samples were collected from 50 poultry farms. These samples were then subjected to isolation, identification, and serotyping of E. coli. The presence of antimicrobial resistance was identified by disc diffusion testing. The occurrence of ESBL phenotypes was also assessed using the double disc synergy method. PCR/sequencing techniques were employed to examine the presence of ESBL (β-lactamase (bla)-TEM, blaSHV, and blaCTX-M), colistin (mcr-1), and carbapenem (blaNDM, blaVIM, and blaKPC) resistance genes.

Results

The findings revealed that 140 out of 250 (56%) were identified as E. coli. All E. coli isolates had a high level of multi-antimicrobial resistance (MAR) with an index value greater than 0.2, and 65.7% of them were confirmed to produce ESBL. Out of the 92 ESBL phenotypes, 55 (59.7%), 32 (34.7%), 18 (19.6%), and 37 (40.2%) isolates harbor b laTEM-3, b laSHV-4, b laCTX-M-1, a nd blaCTX-M-14 genes, respectively. The blaNDM-1 gene was identified in all 40 phenotypes that exhibited resistance to carbapenem, accounting for 28.5% of all strains of E. coli and 43.4% of ESBL isolates. The VIM and KPC genes were not detected in any of the samples. Furthermore, there was a significant prevalence of the mobilized colistin resistance (mcr)-1 gene, with 64 (69.5%) of the ESBL isolates exhibiting this gene.

Conclusion

The prevalence of ESBL-producing E. coli, particularly those resistant to carbapenem and colistin, poses a significant public health risk in society.

Occurrence of multidrug resistance associated with extended-spectrum β‑lactamase and the biofilm forming ability of Escherichia coli in environmental swine husbandry

Extended-spectrum beta-lactamase (ESBL) production and biofilm formation are mechanisms employed by Escherichia coli to resist beta-lactam antibiotics. Thus, we aimed to examine antibiotic resistance associated with ESBL production and biofilm formation in E. coli isolates from swine farms in Southern Thailand. In total, 159 E. coli isolates were obtained, with 44 isolates identified as ESBL producers, originating from feces (18.87 %) and wastewater (8.80 %) samples. All ESBL-producing strains exhibited resistance to ampicillin (100 %), followed by the cephalosporin group (97.73 %) and tetracycline (84.09 %). Multidrug resistance was observed in 17 isolates (38.63 %). Among the isolates from feces samples, the blaGES gene was the most prevalent, detected in 90 % of the samples, followed by blaCTX-M9 (86.67 %) and blaCTX-M1 (66.67 %), respectively. In the bacteria isolated from wastewater, both blaGES and blaCTX-M9 genes were the predominant resistance genes, detected in 100 % of the isolates, followed by blaCTX-M1 (64.29 %) and blaTEM (50 %), respectively. Strong biofilm formation was observed in 11 isolates (36.67 %) from feces and 4 isolates (25.57 %) from wastewater samples. Notably, nearly 100 % of ESBL-producing strains isolated from feces tested positive for both pgaA and pgaC genes, which play a role in intracellular adhesion and biofilm production. These findings contribute to the understanding and potential control of ESBL-producing E. coli, and the dissemination of antibiotic resistance and biofilm-related genes in swine farms.

A randomized, controlled trial of prulifloxacin as conversion therapy after intravenous carbapenem in the treatment of acute pyelonephritis caused by third generation cephalosporin resistant pathogens: A pilot study

The efficacy of converting to oral fluoroquinolones after initial intravenous antibiotics for the treatment of acute pyelonephritis (APN) caused by the third-generation cephalosporin resistant Enterobacteriaceae (3-GCrEC) needs to be investigated. The objective was to compare the clinical and bacteriological outcome of oral prulifloxacin with intravenous ertapenem for the treatment of APN caused by 3-GCrEC. A pilot, randomized controlled trial of patients with APN caused by 3-GCrEC was conducted at two hospitals from August 2015 to December 2020. Any intravenous antimicrobial drug was initially permitted for empirical therapy. On day 4, adult patients (aged >18 years) with either non-bacteremic or bacteremic APN were eligible for the study if their infection was caused by 3-GCrEC susceptible to the study drugs. The patients were randomly assigned to receive either oral prulifloxacin or intravenous ertapenem. The total duration of antimicrobial therapy was 14 days. Of the 21 enrolled patients, 11 were treated with prulifloxacin, and 10 were treated with ertapenem. At the test of cure visit, there was no statistically significant difference between the patients with overall clinical success who were treated with prulifloxacin (90.9%) and those treated with ertapenem (100%, p = 0.999). In addition, there was no statistically significant difference in microbiological eradication between the prulifloxacin and ertapenem groups (100% vs. 100%, p = 0.999). The converting to oral prulifloxacin after intravenous antibiotics therapy appears to be an alternative option for treatment of APN caused by 3-GCrEC. A further large randomized controlled trial should be investigated.

Phylogenomic analysis of a global collection of Escherichia coli ST38: evidence of interspecies and environmental transmission?

IMPORTANCE

Extraintestinal pathogenic Escherichia coli (ExPEC) sequence type (ST) 38 is one of the top 10 human pandemic lineages. Although a major cause of urinary tract and blood stream infections, ST38 has been poorly characterized from a global phylogenomic perspective. A comprehensive genome-scale analysis of 925 ST38 isolate genomes identified two broad ancestral clades and linkage of discrete ST38 clusters with specific bla CTX-M variants. In addition, the clades and clusters carry important virulence genes, with diverse but poorly characterized plasmids. Numerous putative interhost and environment transmission events were identified here by the presence of ST38 clones (defined as isolates with ≤35 SNPs) within humans, companion animals, food sources, urban birds, wildlife, and the environment. A small cluster of international ST38 clones from diverse sources, likely representing progenitors of a hospital outbreak that occurred in Brisbane, Australia, in 2017, was also identified. Our study emphasizes the importance of characterizing isolate genomes derived from nonhuman sources and geographical locations, without any selection bias.

Detection of Extended-spectrum β-lactamase-producing Escherichia coli isolates by isothermal amplification and association of their virulence genes and phylogroups with extraintestinal infection

Extraintestinal pathogenic Escherichia coli (ExPEC) producing extended-spectrum β-lactamases (ESBL) cause serious human infections due to their virulence and multidrug resistance (MDR) profiles. We characterized 144 ExPEC strains (collected from a tertiary cancer institute) in terms of antimicrobial susceptibility spectrum, ESBL variants, virulence factors (VF) patterns, and Clermont's phylogroup classification. The developed multiplex recombinase polymerase amplification and thermophilic helicase-dependent amplification (tHDA) assays for bla_CTX-M, bla_OXA, bla_SHV, and bla_TEM detection, respectively, were validated using PCR-sequencing results. All ESBL-ExPEC isolates carried bla_CTX-M genes with following prevalence frequency of variants: bla_CTX-M-15 (50.5%) > bla_CTX-M-55 (17.9%) > bla_CTX-M-27 (16.8%) > bla_CTX-M-14 (14.7%). The multiplex recombinase polymerase amplification assay had 100% sensitivity, and specificity for bla_CTX-M, bla_OXA, bla_SHV, while tHDA had 86.89% sensitivity, and 100% specificity for bla_TEM. The VF genes showed the following prevalence frequency: traT (67.4%) > ompT (52.6%) > iutA (50.5%) > fimH (47.4%) > iha (33.7%) > hlyA (26.3%) > papC (12.6%) > cvaC (3.2%), in ESBL-ExPEC isolates which belonged to phylogroups A (28.4%), B2 (28.4%), and F (22.1%). The distribution of traT, ompT, and hlyA and phylogroup B2 were significantly different (P < 0.05) between ESBL-ExPEC and non-ESBL-ExPEC isolates. Thus, these equipment-free isothermal resistance gene amplification assays contribute to effective treatment and control of virulent ExPEC, especially antimicrobial resistance strains.

Epidemiology of extended-spectrum beta-lactamase-producing Escherichia coli at the human-animal-environment interface in a farming community of central Uganda

BACKGROUND

Extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-Ec) represents a significant global public health concern. The epidemiology of ESBL-Ec in Uganda is not well understood although it is harbored by humans, animals, and the environment. This study explains the epidemiology of ESBL-Ec using a one health approach in selected farming households in Wakiso district, Uganda.

METHODOLOGY

Environmental, human, and animal samples were collected from 104 households. Additional data were obtained using observation checklists and through interviews with household members using a semi-structured questionnaire. Surface swabs, soil, water, human and animal fecal samples were introduced onto ESBL chromogenic agar. The isolates were identified using biochemical tests and double-disk synergy tests. To assess associations, prevalence ratios (PRs) were computed using a generalized linear model (GLM) analysis with modified Poisson and a log link with robust standard errors in R software.

RESULTS

Approximately 83% (86/104) households had at least one positive ESBL-Ec isolate. The overall prevalence of ESBL-Ec at the human-animal-environment interface was approximately 25.0% (95% CI: 22.7-28.3). Specifically, humans, animals and the environment had an ESBL-Ec prevalence of 35.4%, 55.4%, and 9.2% respectively. Having visitors (adj PR = 1.19, 95% CI: 1.04-1.36), utilizing veterinary services (adj PR = 1.39, 95% CI: 1.20-1.61) and using animal waste for gardening (adj PR = 1.29, 95% CI: 1.05-1.60) were positively associated with household ESBL-Ec contamination. Covering the drinking water container with a lid (adj PR = 0.84 95% CI: 0.73-0.96) was associated with absence of ESBL-Ec in a household.

CONCLUSION

There is wider dissemination of ESBL-Ec in the environment, humans, and animals, indicating poor infection prevention and control (IPC) measures in the area. Improved collaborative one health mitigation strategies such as safe water chain, farm biosecurity, household and facility-based IPC measures are recommended to reduce the burden of antimicrobial resistance at community level.

Extended-spectrum beta-lactamase-producing Escherichia coli from pork in Muang district, Chiang Mai Province, Thailand

Background and Aim

Contaminated pork is one of the transmission routes for pathogens. Extended-spectrum beta-lactamases (ESBL)-producing Escherichia coli is one of the critical threats to global public health. This study aimed to examine pork from different types of markets in Muang district, Chiangmai Province, Thailand, for a proportion of ESBL-producing E. coli, antibiotic resistance of ESBL-producing E. coli and ESBL-producing E. coli genotypes.

Materials and Methods

Samples were collected from different market types; fresh markets, pork stores, and supermarkets, enriched and inoculated on selective media. Extended-spectrum beta-lactamases-producing E. coli was identified using double-disk diffusion method according to Clinical and Laboratory Standards Institute 2016. Antibiotic susceptibility test was performed through VITEK^® System and ESBL-encoding genes were detected using a multiplex polymerase chain reaction.

Results

About 69% of the samples were positive to ESBL-producing E. coli and showed high rates of resistance for ampicillin (100%), piperacillin (100%), cefalexin (100%), cefpodoxime (100%), cefovecin (100%) and ceftiofur (100%), gentamycin (89.86%), and tetracycline (TE) (84.06%). All isolates were multiple drug resistant; resistance patterns of beta-lactams, aminoglycosides, TEs, nitrobenzene derivatives, and sulfonamide groups were observed. The ESBL-producing E. coli-positive isolates carried blaCTX-M groups (100%), blaTEM (98.55%), and blaSHV (1.45%). None of blaOXA was found in this study.

Conclusion

Extended-spectrum beta-lactamases-producing E. coli was found in various types of markets; all isolates were detected as multidrug-resistant. The dissemination of such strains can conceivably cause concerning public health, implying that supervised antimicrobial use in pork production and sanitary food preparation is recommended.

Multidrug-Resistant and Genetic Characterization of Extended-Spectrum Beta-Lactamase-Producing E. coli Recovered from Chickens and Humans in Egypt

Simple Summary

Feeding food chain animals with sub-therapeutic doses for prophylaxis or for growth-promoting purposes has led to the emergence of resistant bugs such as ESBL-E. coli. Infections caused by these superbugs are tremendously associated with treatment failures and high morbidity/mortality rates. Scarce information is currently available on the relation between the incidence of ESBL-E. coli in human and food chain animals in Egypt. The current study analyzed chicken and human fecal samples for isolation and characterization of ESBL-producing E. coli followed by sequencing the isolates. Significant similarities were detected between human and chicken isolates, indicating the possibility of zoonotic transmission. In conclusion, the study encouraged managing the use of antibiotics in veterinary field, to reduce the selection and spread of life-threating bugs to humans.

Abstract

Colonization of food chain animals such as chickens with extended-spectrum β-lactamases (ESBL) poses a major health threat to human. The current study aimed to determine the phenotypic and genotypic relationship between ESBL-producing E. coli from diseased human and chickens in Egypt. A total of 56 out of 120 chicken farms (46.7%) and 9 human samples (100%) were phenotypically and genotypically identified with at least one ESBL-phenotype/gene. Chicken isolates showed a high proportion of beta lactamase from CTX-M group 9 > TEM > PER families, followed by CTX-M group 1 > SHV > GES > OXA group10 > VEB > OXA group2 families, while human isolates only contained the CTX-M family. A high incidence of ESBL genes from the CTX-M family was recognized in both human and chicken isolates. Furthermore, nucleotide identity showed high similarity between chicken and human isolates. In conclusion, the current study traced phenotypes and genotypes of ESBL-producing E. coli from chickens and human samples in Egypt, reporting degrees of similarity that suggest potential zoonotic transmission. Our data highlighted the significant importance of chicken as a major food source not only in Egypt but all over the world in the spreading of ESBL-producing E. coli to human.

The emergence of CTX-M-55 in ESBL-producing Escherichia coli from vegetables sold in local markets of northern Thailand

Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli are spreading worldwide and pose a public health issue. An assessment of their presence in the environment and in food chain products would clarify the pathway of this foodborne transmission. Here, we investigated the prevalence of ESBL-producing E. coli in fresh vegetables purchased from fresh markets in Chiang Rai, Thailand. Overall, 8.8% of the samples collected contained ESBL-producing E. coli, of which 81.3% were multidrug-resistant. All isolates carried the bla_CTX-M-55 gene, and 10 isolates contained the ISEcp1 gene. One E. coli strain carried bla_CTX-M-55 coexisting with bla_TEM-1. Thirteen different sequence types (ST48, ST101, ST155, ST165, ST398, ST414, ST457, ST515, ST542, ST1081, ST3045, ST7538 and ST10651) were identified. One strain belonged to ST101, which is one of the most prevalent STs among human isolates. Our study thus demonstrated the spread of CTX-M-55 on non-ST131 vegetable isolates that are not global pandemic strains and suggests that they may be a source of antibiotic resistance gene transfer from agricultural foods to humans. Further studies are needed to investigate the possibility that these ESBL producers could transfer resistance genes to commensal E. coli and cause severe disease.

Multiple and High-Risk Clones of Extended-Spectrum Cephalosporin-Resistant and blaNDM-5-Harbouring Uropathogenic Escherichia coli from Cats and Dogs in Thailand

Resistance to extended-spectrum cephalosporins (ESC) and carbapenems in Escherichia coli (E. coli), increasingly identified in small animals, indicates a crisis of an antimicrobial resistance situation in veterinary medicine and public health. This study aimed to characterise the genetic features of ESC-resistant E. coli isolated from cats and dogs with urinary tract infections in Thailand. Of 72 ESC-resistant E. coli isolated from diagnostic samples (2016–2018), bla_CTX-M including group 1 (CTX-M-55, -15 and -173) and group 9 (CTX-M-14, -27, -65 and -90) variants were detected in 47 isolates (65.28%) using PCR and DNA sequencing. Additional antimicrobial resistance genes, including plasmid-mediated AmpC (CIT and DHA), bla_NDM-5, mcr-3, mph(A) and aac(6′)-Ib-cr, were detected in these isolates. Using a broth microdilution assay, all the strains exhibited multidrug-resistant phenotypes. The phylogroups were F (36.11%), A (20.83%), B1 (19.44%), B2 (19.44%) and D (4.17%), with several virulence genes, plasmid replicons and an integrase gene. The DNA fingerprinting using a repetitive extragenic palindromic sequence-PCR presented clonal relationships within phylogroups. Multiple human-associated, high-risk ExPEC clones associated with multidrug resistance, including sequence type (ST) 38, ST131, ST224, ST167, ST354, ST410, ST617 and ST648, were identified, suggesting clonal dissemination. Dogs and cats are a potential reservoir of ESC-resistant E. coli and significant antimicrobial resistance genes.

Prevalence of non-extended spectrum β-lactamases SHV-1 and TEM-1 or -2 types in multidrug-resistant Enterobacteriaceae in northern Iran

The present study aimed to evaluate TEM-1 or -2 and SHV-1 β-lactamases frequency in multidrug-resistant (MDR) Enterobacteriaceae isolated from patients' urine in northern Iran. The resistance pattern to 20 antibiotics and ESBL production in 200 MDR Enterobacteriaceae was detected using the disk diffusion test and double-disk synergy test (DDST), respectively. Multiplex PCR was applied to detect bla_{TEM-1 or -2} and bla_SHV genes in isolates. DDST findings were inconsistent with multiplex PCR results. The distribution of each of bla_{TEM-1 or -2} and bla_SHV genes, either alone or in combination, in the ESBL-producing isolates was higher than the non-ESBL-producing isolates. There was a significant effect of the presence of bla_{TEM-1 or -2} gene on resistance to cephalotin at the p < 0.01 level and cefepime, tetracycline, and streptomycin at the P < 0.05 level, and the presence of bla_SHV-1 gene on resistance to fosfomycin at the P < 0.05 level as well as the presence both bla_{TEM-1 or -2} and bla_SHV-1 genes on resistance to cephalotin and fosfomycin at the P < 0.01 level. In all isolates, ESBL production, except for cephalotin resistance, did not improve resistance to other antibiotics used and even non-ESBL-producing isolates showed higher resistance to antibiotics compared to ESBL-producing isolates. It seems that mechanisms other than production of ESBL to be involved as part of the resistance mechanisms of the studied isolates against the used antibiotics. For epidemiological studies, both phenotypic and molecular tests must be included to identify the bla_{TEM-1 or -2} and bla_SHV-1 genotypes to ensure infection prevention and control.

Prevalence and characterization of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolated from raw vegetables retailed in Southern Thailand

Background

The increasing prevalence of broad-spectrum ampicillin-resistant and third-generation cephalosporin-resistant Enterobacteriaceae, particularly Escherichia coli and Klebsiella pneumoniae, has become a global concern, with its clinical impacts on both human and veterinary medicine. This study examined the prevalence, antimicrobial susceptibility, and molecular genetic features of extended-spectrum β-lactamase (ESBL)-producing E. coli and K. pneumoniae isolates from 10 types of raw vegetables.

Methods

In total, 305 samples were collected from 9 markets in Nakhon Si Thammarat, Thailand, in 2020.

Results

ESBL-producing E. coli and K. pneumoniae isolates were found in 14 of the 305 samples obtained from 7 out of 10 types of vegetables (4.6% of the total). Further, 14 ESBL-producing E. coli (n = 5/14) and K. pneumoniae isolates (n = 9/14) (1.6% and 3.0%, respectively) were highly sensitive to β-lactam/carbapenem antibiotics (imipenem, 100%). ESBL-producing E. coli (n = 4) and K. pneumoniae isolates (n = 8) were also sensitive to non-β-lactam aminoglycosides (amikacin, 80.00% and 88.89%, respectively). ESBL producers were most resistant to β-lactam antibiotics, including ampicillin (85.71%) and the cephalosporins cefotaxime and ceftazidime (64.29%). The most frequently detected gene in ESBL-producing E. coli and K. pneumoniae was bla_SHV . However, two ESBL-producing E. coli isolates also carried three other ESBL-encoding variants, bla_TEM , bla_CTX-M1 , bla_GES and bla_TEM, bla_SHV, bla_CTX-M9 , which may be due to their association with food chains and humans.

Discussion

Indeed, our results suggest that raw vegetables are an important source of ESBL-resistant E. coli and K. pneumoniae, which are potentially transmittable to humans via raw vegetable intake.

Detection of carbapenemase-producing, hypervirulent Klebsiella spp. in wastewater and their potential transmission to river water and WWTP employees

Wastewater treatment plants (WWTPs) release drug-resistant microorganisms to water bodies (with effluents), and WWTP employees are exposed to bioaerosol emissions from the processed wastewater. Bacteria of the genus Klebsiella, in particular carbapenemase-producing (CP), hyper-virulent (Hvr) strains of Klebsiella pneumoniae, play a special role in this process. Klebsiella spp. strains isolated from wastewater, river water and the upper respiratory tract of WWTP employees were analyzed in this study. The isolated strains were identified as K. pneumoniae (K. pn) or K. non-pneumoniae (K. npn). The prevalence of nine types of genes encoding resistance to beta-lactams, nine genes encoding virulence factors and K1/K2 capsular serotypes, three genes encoding multi drug effluent pump systems, and the class 1 integron-integrase gene was determined by PCR. A total of 284 Klebsiella spp. isolates were obtained in the study: 270 environmental strains and 14 strains from the upper respiratory tract. Among environmental isolates 90.7% (245/270) harbored beta-lactam resistance genes, 17.4% (47/270) were classified as CP strains, 11.1% (30/270) were classified as Hvr strains, and 1.9% (5/270) were classified as CP-Hvr strains. CP-Hvr strains were also isolated from WWTP employees. Genes encoding β-lactamases (including carbapenemases), complete efflux pump systems and the K1 serotype were identified more frequently in K. pn strains. In turn, K. npn strains were characterized by a higher prevalence of bla_SHV and intI1 genes and K2 serotype gene. The strains isolated from wastewater and river water also differed in the abundance of drug resistance and virulence genes. The results of the study indicate that CP-Hvr K. pn strains are possibly transmitted from wastewater via bioareosol to the upper respiratory tract of WWTP employees. bla_GES-type carbapenemases significantly contributed to the spread of drug resistance in the environment.

Comparative Study of ESBL Production Among Uropathogenic Escherichia coli Clinical Isolates from Pre- and Post-menopausal Women in Egypt

Urinary tract infection (UTI) is regarded one of the most frequent bacterial infections in women. Accordingly, the aim of the current study was to determine the prevalence of extended-spectrum beta-lactamase (ESBL), as well as the degree of antimicrobial resistance among premenopausal (n = 44) and postmenopausal (n = 49) women suffering from uncomplicated UTI. Urinary samples (n = 93) collected from women with UTI were tested for their antimicrobial sensitivity and assessed for ESBL production by both phenotypic and genotypic methods. Phenotypically, the presence of ESBL was observed in 64 isolates, while polymerase chain reaction detected ESBL-encoding genes in 57 isolates. The CTX-M gene was the most predominant (51.6%), followed by TEM (46.2%), and the SHV gene (17.2%). Surprisingly, all ESBL-producing Escherichia coli isolates were multidrug-resistant (MDR). To the best of our knowledge, this is the first study conducted in Egypt showing significant correlation between ESBL production, multidrug resistance and menopausal state in women. The results demonstrate alarming signal for the dissemination of ESBL genes among uropathogenic E. coli that are MDR in Egypt.

Prevalence and antimicrobial susceptibility of extended-spectrum beta lactamases-producing Escherichia coli and Klebsiella pneumoniae isolated in selected hospitals of Anyigba, Nigeria

BACKGROUND

Escherichia coli and Klebsiella pneumoniae are commonly implicated in urinary tract infections accounting for majority of the antimicrobial resistance encountered in hospitals.

OBJECTIVES

To determine the prevalence and antimicrobial susceptibility of extended-spectrum beta-lactamases (ESBLs) producing E. coli and K. pneumoniae among patients in Anyigba, Nigeria.

METHODS

This hospital-based cross-sectional study was conducted using urine samples from 200 patients of Grimmard Catholic hospital and Maria Goretti hospital. Urine samples were processed to identify ESBL-producing E. coli and K. pneumoniae using standard microbiological techniques. Isolates were then tested against antimicrobial agents.

RESULTS

A total of 156 bacterial isolates were recovered consisting 128 of E. coli and 28 of K. pneumoniae. Extended spectrum beta-lactamases production was observed in 69% of E. coli and 31% of K. pneumoniae. These pathogens were resistant to 3 or more antibiotics. Of the antimicrobials tested, cefotaxime demonstrated the highest rates of resistance (100%) for both ESBL-producing E. coli and K. pneumoniae. Fifty-four isolates of ESBL-producing E. coli showed a high level of resistance to amoxicillin clavulanic acid (83.3%), ciprofloxacin (83.3%), and ceftazidime (79.6%). ESBL-positive K. pneumoniae isolates were highly resistant to ciprofloxacin (75%), and amoxicillin clavulanic acid (83.3%). Cefoxitin (62.5%) and gentamicin (66.7%) showed substantially higher rates of resistance against these isolates while all 24 strains were resistant to imipenem.

CONCLUSION

This study indicated the prevalence of ESBL-positive Gram-negative pathogens in these study sites and also demonstrated their resistance to a few antibiotics. This highlights the need for new antimicrobials that are potent and improved policy on use of antibiotics.

Virulence gene transcription, phylogroups, and antibiotic resistance of cervico-vaginal pathogenic E. coli in Mexico

The pathogenicity of Escherichia coli strains that cause cervico-vaginal infections (CVI) is due to the presence of several virulence genes. The objective of this study was to define the variability regarding the genotype of antibiotic resistance, the transcription profiles of virulence genes after in vitro infection of the vaginal cell line A431 and the phylogroup composition of a group of cervico-vaginal E. coli strains (CVEC). A total of 200 E. coli strains isolated from Mexican women with CVI from two medical units of the Mexican Institute of Social Security were analysed. E. coli strains and antibiotic resistance genes were identified using conventional polymerase chain reaction (PCR), and phylogroups were identified using multiplex PCR. Virulence gene transcription was measured through reverse-transcriptase real-time PCR after infection of the vaginal cell line A431. The most common antibiotic resistance genes among the CVEC strains were aac(3)II, TEM, dfrA1, sul1, and qnrA. The predominant phylogroup was B2. The genes most frequently transcribed in these strains were fimH, papC, irp2, iroN, kpsMTII, cnf1, and ompT, mainly in CVEC strains isolated from chronic and occasional vaginal infections. The strains showed a large diversity of transcription of the virulence genes phenotype and antibiotic resistance genotype, especially in the strains of phylogroups, B2, A, and D. The strains formed 2 large clusters, which contained several subclusters. The genetic diversity of CVEC strains was high. These strains have a large number of transcription patterns of virulence genes, and one-third of them carry three to seven antibiotic resistance genes.

Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae: Update on Molecular Epidemiology and Treatment Options

Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae are a major global public health concern. Presently, Escherichia coli with CTX-Ms are the most common species associated with global ESBLs; CTX-M-15 is the most frequent CTX-M worldwide and is followed by CTX-M-14, which is often found in South-East Asia. Recent surveillance studies showed that CTX-M-27 is emerging in certain parts of the world especially in Japan and Europe. The population structure of ESBL-producing E. coli is dominated globally by an high-risk clone named ST131. Escherichia coli ST131 belongs to three clades (A, B, and C) and three different subclades (C1, C1-M27, and C2). Clade C1-M27 is associated with bla_CTX-M-27, and C2 with bla_CTX-M-15. Recent whole genome sequencing studies have shown that clade C has evolved from clade B in a stepwise fashion, resulting in one of the most influential global antimicrobial resistance clones that has emerged during the 2000's. Other important E. coli clones that have been detected among ESBL producers include ST405, ST38, ST648, ST410, and ST1193. The INCREMENT project has shown that ertapenem is as effective as other carbapenems for treating serious infections due to ESBL-producing Enterobacteriaceae. The results of the MERINO open-label randomized controlled study has provided clear evidence that piperacillin-tazobactam should be avoided for targeted therapy of blood-stream infections due to ESBL-producing E. coli and K. pneumoniae, regardless of the patient population, source of infection, bacterial species, and susceptibility result of piperacillin-tazobactam. Research is still warranted to define the optimal therapy of less severe infections due to ESBL-producing Enterobactericeae.

Multilocus sequence typing and bla ESBL characterization of extended-spectrum beta-lactamase-producing Escherichia coli isolated from healthy humans and swine in Northern Thailand

Purpose

Here, we investigated the genetic relationships and characteristics of extended- spectrum beta-lactamase-producing Escherichia coli (ESBL-E. coli) isolates from healthy hosts, humans in the community and swine among the livestock of Amphor Mueang, Lamphun Province, Thailand.

Patients and methods

Four hundred and nine rectal swabs were collected from healthy people and swine. A total of 212 ESBL-E. coli was isolated and phenotypically confirmed by a combination disk method. Putative ESBL-encoding genes, including bla_CTX-M, bla_TEM, and bla_SHV, were examined by multiplex-PCR. Randomly selected 42 ESBL-E. coli isolates were whole genome sequenced to characterize the ESBL-encoding genes and identify additional antimicrobial resistance genes. The genetic relatedness of 212 ESBL-E. coli was investigated by multilocus sequence typing.

Results

Overall, bla_CTX-M was the dominant ESBL-encoding gene found in 95.75% of the isolates, followed by bla_TEM (60.85%) and bla_SHV (2.40%). While bla_CTX-M-55 was the most common bla_ESBL subgroup found in this study. Whole genome sequencing showed a total of 15 different antimicrobial resistance genes other than bla_ESBL, including sul, qnr, aph(3ʹ)-Ia, among the selected 42 ESBL-E. coli isolates. Over half of the ESBL-E. coli (56.60%) carried bla_CTX-M co-existing with bla_TEM. The most common sequence types (STs) identified from human isolates were ST131, ST101, and ST70 while those isolated from swine were ST10, ST48, and ST131. ST131 strains carrying bla_CTX-M were the major isolated ESBL-E. coli strains, supporting a previous study that considered this strain truly pathogenic. Noticeably, 66.51% of ESBL-E. coli strains shared 19 identical STs, including a host-restricted ST131 between humans and swine, suggesting that transmission between these two hosts might be possible.

Conclusion

Proof of a direct transfer of ESBL-E. coli from animals to humans, or vice versa, is required for further elucidation. The ESBL-E. coli isolated from both types of healthy hosts may serve as a reservoir for community-acquired antimicrobial resistance.

Risk Factors for Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae Carriage in Patients Admitted to Intensive Care Unit in a Tertiary Care Hospital in Thailand

Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) are important causes of serious infections in intensive care unit (ICU). This study aimed to investigate the risk factors for intestinal carriage of ESBL-PE among patients admitted to ICU, subsequent ESBL-PE infections, and outcomes of these patients. This study prospectively collected rectal swabs from 215 ICU patients in Northern Thailand and ESBL-PE were isolated. A high prevalence of ESBL-PE carriage (134/215, 62.3%) at ICU admission was observed, with Escherichia coli representing the predominant organism (67.5%) followed by Klebsiella pneumoniae (19.4%). Multivariate logistic regression analysis identified chronic renal disease as the independent risk factor for ESBL-PE carriage (p = 0.009; adjusted odds ratio = 4.369; 95% confidence interval = 1.455-13.119). Among colonized patients, 2.2% (3/134) developed ESBL-PE infections during ICU stay. Phylogenetic analysis of E. coli (n = 108) showed that the predominant group was group A (38.0%), followed by groups B1 (17.6%), D (15.7%), B2 (14.8%), C (7.4%), and F (6.5%). Multilocus sequence typing analysis of the pathogenic groups B2, D, and F revealed 11 different sequence types (STs), with ST131 (n = 13) as the most prevalent, followed by ST648 (n = 5), ST38 (n = 4), ST393 (n = 3), and ST1193 (n = 3). These results are of concern since ESBL-PE may be a prerequisite for endogenous infections and potentially disseminate within the hospital. This is the first study describing ESBL-PE carriage among patients at ICU admission and subsequent ESBL-PE infections in Thailand.

Phenotypic and genotypic characterization of multi-drug-resistant Escherichia coli isolates harboring blaCTX-M group extended-spectrum β-lactamases recovered from pediatric patients in Shenzhen, southern China

Aims and Objectives: The emergence and spread of extended-spectrum β-lactamases (ESBLs) particularly CTX-M producing multi-drug-resistant (MDR) Escherichia coli (E. coli) is one of the greatest challenges for community health globally. The study investigated the phenotypic and genotypic characteristics of ESBLs-producing E. coli recovered from pediatric patients from Shenzhen Children’s Hospital, China.

Materials and methods: Present study, a total of 2,670 isolates of E. coli were collected from Shenzhen Children’s Hospital, China of which 950 were ESBLs producer. ESBLs production was confirmed by using the combination disc diffusion method, and antimicrobial susceptibility test was detected. In addition, β-lactamase-producing genes and co-existence of carbapenem/colistin resistance genes were determined by PCR assay and sequencing. The diversity and phylogenetic relationship were determined by multi-locus sequence typing method.

Results: Thirty-five percent (n=950) prevalence of ESBLs-producing E. coli we reported in Shenzhen, China of which 50 ESBLs producing E. coli were randomly selected for a further characterization. All 50 ESBLs- producing E. coli isolates revealed MDR phenotype and 100% were resistant to Ampicillin/sulbactam, Ampicillin, Cefazolin, and Ceftriaxone. All 50 ESBLs producers harbored at least one type of β-lactamase gene particular bla_CTX-M. The PCR and sequencing revealed the most common CTX-M subtype was bla_CTX-M-15 (n=18), followed by bla_CTX-M-14 (n=16), bla_CTX-M-90 (n=9), bla_CTX-M-55 (n=3), bla_CTX-M-27, bla_CTX-M-101, and bla_CTX-M-211 each (n=1). Co-existence of bla_CTX-M with bla_TEM, bla_SHV, bla_GES, and bla_VEB was detected in few isolates. Among identified sequence types, ST131 (12%) was more dominant in ESBLs-producing E. coli. Phylogenetic group A was the most prominent group among the ESBLs-producing E. coli based on multiplex PCR.

Conclusion: Our study shows the prevalence of bla_CTX-M gene in ESBLs-producing E. coli in pediatric patients in Shenzhen, China. We highlight the importance to monitor the emergence and trends of ESBLs-producing isolates in a pediatric healthcare setting.