Presence Of Extended-spectrum Beta-lactamase Genes Research Articles

ANTIBIOTIC SUSCEPTIBILITY AND DETECTION OF EXTENDED-SPECTRUM B-LACTAMASE GENES IN GRAM-NEGATIVE BACTERIA ISOLATED FROM AUTOMATED TELLER MACHINES

Antibiotic-resistant (AR) bacteria especially from commonly shared surfaces in the environment, pose a serious threat to global public health. The increasing demand for electronic banking and the associated risk of the spread of pathogenic bacteria makes it crucial to assess the antibiotic susceptibility and the presence of extended-spectrum beta-lactamase genes in bacteria isolated from automated teller machines (ATMs). Following standard procedures, a total of 22 samples were collected randomly from different ATMs using sterile cotton swabs soaked in physiologic saline and cultured on selective media. Isolates were characterized biochemically. Antibiotics susceptibility test was carried out on isolates using the Kirby-Bauer disc diffusion method. All Gram-negative isolates were subjected to polymerase chain reaction (PCR) to evaluate the common extended-spectrum beta-lactamase –encoding (ESBL) genes. Bacterial isolates were characterized as Klebsiella pneumoniae (33.33%), Pseudomonas aeruginosa (19.61%), Escherichia coli (15.69%), Staphylococcus aureus (9.80%), Acinetobacter spp. (7.84%), Enterobacter spp. and Bacillus subtilis (5.88%), and Enterococcus faecalis (1.96%). The highest antibiotic resistance pattern was displayed against ceftazidime (45.1%), followed by tetracycline (43.1%), cefixime (41.2%), ciprofloxacin and chloramphenicol (29.4%) and meropenem (9.8%). The TEM gene (54.8%) was recovered most, followed by CTX-M (28.6%) and SHV (19.0%). This study reveals that ATMs could harbour pathogenic bacteria with antibiotic resistance (AR) genes especially ESBL genes (blaTEM) which could be responsible for the widespread resistance to antibiotics. Therefore, adequate personal hygiene by users, proper cleaning regimen to sanitize these facilities regularly and public enlightenment are recommended to reduce the accompanying risks of spreading AR genes within the environment

Frequency of Fecal Carriage of ESBL Resistance Genes in Multidrug-Resistant Pseudomonas aeruginosa Isolates from Cancer Patients at Laquintinie Hospital, Douala, Littoral Region, Cameroon.

Background. Opportunistic infections are the second cause of death among cancer patients. This study aimed at determining the antimicrobial profile and the prevalence of extended-spectrum beta-lactamase (ESBL)-gene carriage of Pseudomonas aeruginosa isolates among cancer patients at the Douala Laquintinie Hospital, Littoral Region of Cameroon. Between October 2021 and March 2023, 507 study participants were recruited among whom 307 (60.55%) were cancer patients, compared to 200 (39.45%) noncancer patients. Fifty-eight P. aeruginosa isolates were isolated from fecal samples of forty-five cancer patients and thirteen noncancer patients using Cetrimide agar. The antimicrobial resistance profile of the isolates was determined using the Kirby-Bauer disk diffusion method. The polymerase chain reaction was used to detect the presence of extended-spectrum beta-lactamase genes among P. aeruginosa isolates. P. aeruginosa showed significant resistance rates in cancer patients compared to noncancer patients to imipenem, cefotaxime, and ceftazidime, piperacillin-tazobactam, ticarcillin-clavulanic acid, and ciprofloxacin. The multidrug resistance (MDR) rate was significantly (p < 0.05) higher in cancer patients than in noncancer patients. The frequency of beta-lactamase genes in the 58 ESBL-producing P. aeruginosa isolates was determined as 72.41% for bla TEM, 37.93% for bla OXA, 74.14% for blaCTX-M, and 44.83% for bla SHV genes. The study revealed an alarmingly high prevalence of fecal carriage of ESBL-producing P. aeruginosa with a high rate of MDR among cancer patients. It indicates that regular monitoring and surveillance of ESBL-producing P. aeruginosa among cancer patients are needed to improve the management of patients.

Characterization of integrons, extended spectrum beta lactamases and genetic diversity among uropathogenic Escherichia coli isolates from Kerman, south east of Iran.

The study aimed to investigate the distribution of genes encoding integrons, extended spectrum beta-lactamase (ESBL) in E. coli isolated from UTIs, as well as the genetic diversity among the isolates. E. coli isolates were recovered from the patients with UTI in Kerman Iran. Antibiotic susceptibility was done according to CLSI guidelines. The presence of ESBL genes and integrons was evaluated using PCR. PCR and sequencing were applied for the evaluation of cassette content of integrons. Genotyping of the isolates was performed by multiple-locus variable-number tandem repeat analysis (MLVA). Imipenem was the most effective antibiotic, while the highest resistance was observed to streptomycin. In total 40.2% of isolates were ESBL producers. Of 69 integron-positive isolates, 59 only had class I integrons, 4 only had class II integrons and 6 had both types. The most common gene cassette found within class I integrons was dfrA17-aadA5 (n=27). The E. coli isolates were divided into 16 MLVA clusters. The current study demonstrated the simultaneous presence of class I integrons and ESBLs involved in the resistance of UPEC isolates to antibacterial agents. Our finding also revealed that the E. coli isolates belonged to diverse clones.

Detection of extended-spectrum beta-lactamase genes among Escherichia coli isolates from urinary tract infection in Mashhad

Urinary tract infections (UTIs) are known as one of the most important infections around the world, and Escherichia coli is the most important cause of UTI. Also, the empiric treatment and misusing of antimicrobial agents has led to increasing multi-drug resistance around the world which is a worldwide concern. Extended-spectrum beta-lactamase (ESBLs) is an enzyme group that is produced by the Enterobacteriaceae family. The three main ESBLs enzyme are as follow: bla CTX-M , bla TEM , and bla SHV , additionally, there are several types of each of them by the same mechanism. This study was conducted to evaluate the prevalence of ESBL genes among E. coli isolated from UTI patients. A total of 105 isolates were collected from UTI patients at two hospitals in Mashhad from 2017 to 2019. Bacterial identification was performed by standard microbiologic methods. The assessment of antimicrobial susceptibility was accomplished by the disk diffusion method. The presence of ESBL genes was investigated by multiplex-PCR. The prevalence of UTI, among females, was identified more than males. Furthermore, the bla TEM and bla CTX-M genes were detected in all isolates, but only six isolates (5.7%) were harboring bla SHV . The considerable role of E. coli in UTI infection, as well as the presence of ESBL genes in E. coli strains, emphasize the need for surveillance of antimicrobial therapy to prevent the extension of resistance among clinical strains.

Detection of extended-spectrum beta-lactamase (ESBL) genes and plasmid replicons in Enterobacteriaceae using PlasmidSPAdes assembly of short-read sequence data.

Knowledge of the epidemiology of plasmids is essential for understanding the evolution and spread of antimicrobial resistance. PlasmidSPAdes attempts to reconstruct plasmids using short-read sequence data. Accurate detection of extended-spectrum beta-lactamase (ESBL) genes and plasmid replicon genes is a prerequisite for the use of plasmid assembly tools to investigate the role of plasmids in the spread and evolution of ESBL production in Enterobacteriaceae . This study evaluated the performance of PlasmidSPAdes plasmid assembly for Enterobacteriaceae in terms of detection of ESBL-encoding genes, plasmid replicons and chromosomal wgMLST genes, and assessed the effect of k-mer size. Short-read sequence data for 59 ESBL-producing Enterobacteriaceae were assembled with PlasmidSPAdes using different k-mer sizes (21, 33, 55, 77, 99 and 127). For every k-mer size, the presence of ESBL genes, plasmid replicons and a selection of chromosomal wgMLST genes in the plasmid assembly was determined. Out of 241 plasmid replicons and 66 ESBL genes detected by whole-genome assembly, 213 plasmid replicons [88 %; 95 % confidence interval (CI): 83.9–91.9] and 43 ESBL genes (65 %; 95 % CI: 53.1–75.6) were detected in the plasmid assemblies obtained by PlasmidSPAdes. For most ESBL genes (83.3 %) and plasmid replicons (72.0 %), detection results did not differ between the k-mer sizes used in the plasmid assembly. No optimal k-mer size could be defined for the number of ESBL genes and plasmid replicons detected. For most isolates, the number of chromosomal wgMLST genes detected in the plasmid assemblies decreased with increasing k-mer size. Based on our findings, PlasmidSPAdes is not a suitable plasmid assembly tool for short-read sequence data for ESBL-encoding plasmids of Enterobacteriaceae .

Prevalence, antibiotic sensitivity pattern and genetic analysis of extended spectrum beta lactamase producing Escherichia coli and Klebsiella spp among patients with community acquired urinary tract infection in Galle district, Sri Lanka

Community acquired urinary tract infections (CA-UTI) are commonly caused by Escherichia coli and Klebsiella spp which are known extended spectrum beta lactamase (ESBL) producers. To determine, the prevalence and characteristics of ESBL producing of E. coli and Klebsiella spp in the community, and the association of risk factors with ESBL CA-UTI. Descriptive cross-sectional study with urine cultures performed from clinically suspected CA-UTI patients by CLSI standards. Conventional multiplex PCR was performed for gene analysis. Cultures were positive in 178 (38%) patients from 465. Majority were females (103, 58%). Most frequently isolated was E. coli (149, 84%) with 68(46%) ESBL producers followed by 16(9%) Klebsiella pneumoniae with 4 (25%) ESBL producers. Majority of patients with ESBL CA-UTI were >50 yrs (35/72, 49%) and 13 (18%) children <10 years were present. ABST of ESBL producers revealed high resistance rates for quinolones (41%) and >80% sensitivity for nitrofurantoin, fosfomycin, mecillinam, aminoglycosides and carbapenems. Presence of ESBL genes were 83% CTX –M, 71% OXA, 24% TEM and 9% SHV with one organism often producing more than one gene in 29 isolates (71%). Haematuria and structural abnormalities of urinary tract were significantly associated with increased ESBL CA-UTI (p<0.01). ESBL prevalence of this community was 40% in CA-UTI with E.coli predominance among female majority. >80% ESBL organisms show high sensitivity for aminoglycosides, carbapenems, nitrofurantoin, mecillinam and fosfomycin. Frequently isolated ESBL gene was CTX-M. Haematuria and structural abnormalities of urinary tract were significantly associated with ESBL CA-UTI

Correction to: Antimicrobial resistance and the presence of extended-spectrum beta-lactamase genes in Escherichia coli isolated from the environment of horse riding centers.

The original publication of this paper contains a mistake.

Antimicrobial resistance and the presence of extended-spectrum beta-lactamase genes in Escherichia coli isolated from the environment of horse riding centers

The aim of the study was to determine the antimicrobial resistance profile and the occurrence of extended-spectrum beta-lactamase genes and to analyze the genetic diversity of Escherichia coli strains isolated from the environment of horse riding centers. The study was conducted using E. coli strains isolated from the air, manure, and horse nostril swabs in three horse riding centers differing in the system of horse keeping—stable (OJK Pegaz and KJK Szary) and free-range (SKH Nielepice). Resistance to antibiotics was determined using the disk-diffusion method, and the PCR technique was employed to detect the extended-spectrum β-lactamase (ESBL) genes, while the genetic diversity of strains was assessed by rep-PCR. A total of 200 strains were collected during the 2-year study, with the majority isolated from KJK Szary, while the smallest number was obtained from SKH Nielepice. The strains were mostly resistant to ampicillin, aztreonam, and ticarcillin. The tested strains were most frequently resistant to one or two antibiotics, with a maximum of ten antimicrobials at the same time. Two multidrug-resistant (MDR) strains were detected in OJK Pegaz while in KJK Szary there were two MDR and one extensively drug-resistant (XDR) strain. The ESBL mechanism was most frequently observed in OJK Pegaz (20.31% of strains) followed by KJK Szary (15.53% of strains) and SKH Nielepice (15.15% of strains). Among the ESBL-determining genes, only blaTEM and blaCTXM-9 were detected—blaTEM was mostly found in KJK Szary (53.40% of strains), while the second detected gene—blaCTXM-9—was most frequent in SKH Nielepice (6.06% of strains). The rep-PCR genotyping showed high variation among the analyzed strains, whereas its degree differed between the studied facilities, indicating that the type of horse keeping (stable vs. free-range) affects the genetic diversity of the E. coli strains. Having regard to the fact that the tested strains of E. coli were derived from non-hospitalized horses that were not treated pharmacologically, we can assume that the observed antimicrobial resistance may be of both—natural origin, i.e., not the result of the selection pressure, and acquired, the source of which could be people present in the horse riding facilities, the remaining horses which were not included in the study, and air, as well as water, fodder, and litter of the animals. Therefore, it can be concluded that the studied horses are the source of resistant E. coli and it is reasonable to continue monitoring the changes in antimicrobial resistance in those bacteria.

Molecular epidemiology of extended-spectrum beta-lactamase (ESBL)-positive Klebsiella pneumoniae from bloodstream infections and risk factors for mortality.

The prevalence of extended-spectrum beta-lactamase (ESBL)-positive Klebsiella pneumoniae is growing worldwide. Infections with these bacteria are suspected to be related to increased mortality. We aimed to estimate the distribution of ESBL genotypes and to assess the impact on mortality associated with ESBL positivity in cases of bloodstream infection (BSI) due to K. pneumoniae. We performed a cohort study on patients with K. pneumoniae BSI between 2008 and 2011. Presence of ESBL genes was analyzed by PCR and sequencing. Risk factors for mortality were analyzed by Cox-proportional hazard regression. We identified 286 ESBL-negative (81%) and 66 (19%) ESBL-positive cases. 97% (n = 64) of the ESBL-positive isolates were susceptible for meropenem. The most common ESBL genotypes were CTX-M-15 (60%), SHV-5 (27%) and CTX-M-3 (5%). Significant risk factors for mortality were chronic pulmonary disease (HR 1.747) and moderate/severe renal disease (HR 2.572). ESBL positivity was not associated with increased mortality.

First description of Escherichia coli producing CTX-M-15- extended spectrum beta lactamase (ESBL) in out-patients from south eastern Nigeria

We studied the presence of extended spectrum beta lactamases (ESBLs) in 44 clinical isolates of Escherichia coli collected from out-patients in two university teaching hospitals in South-Eastern Nigeria. Species identification was performed by standard microbiology methods and re-confirmed by MALDI-TOF technology. Phenotypic characterization of ESBL enzymes was done by double disc synergy test and presence of ESBL genes was determined by specific PCR followed by sequencing. Transfer of plasmid DNA was carried out by transformation using E. coli DH5 as recipient strain. Phenotypic characterization identified all isolates to be ESBL positive. 77% of strains were from urine, 13.6% from vaginal swabs and 9.0% from wound swabs. 63.6% were from female patients, 68% were from outpatients and 95.5% from patients younger than 30 years. All ESBL producers were positive in a PCR for blaCTX-M-1 cluster, in exemplary strains blaCTX-M-15 was found by sequencing. In all strains ISEcp1 was found upstream and ORF477 downstream of blaCTX-M. PCR for blaTEM and blaOXA-1 was positive in 93.1% of strains, whereas blaSHV was not detected, aac(6′)-Ib-cr was found in 97.7% of strains. RAPD analysis revealed seven different clonal groups named A through G with the majority of the strains (65.9%) belonging to clone A. Transfer of an ESBL plasmid with co-resistance to gentamicin, kanamycin, tobramycin, doxycycline and trimethropim-sulfamethoxazole was successful in 19 (43.2%) strains. This study showed a high rate of CTX-M-1 cluster - ESBLs in South-Eastern Nigeria and further confirms the worldwide spread of CTX-M ESBL in clinical isolates.

Strains of &lt;i&gt;Klebsiella Pneumoniae&lt;/i&gt; from Intensive Care Unit Producing CTX-M-15 Extended Spectrum Beta Lactamases

Problem statement: Resistance to third generation cephalosporins due to acquisition and expression of Extended Spectrum β-Lactamase (ESBL) among Gram-negative bacteria is on the increase. Infections involving extended spectrum beta lactamase bacteria are associated with significant morbidity and mortality. Therefore, infections due to ESBL isolates continue to pose a serious challenge to infection management worldwide. Since screening for ESBL is not a common practice in hospitals in Enugu state, this study was undertaken to characterize ESBL genes in K. pneumoniae strains from intensive care unit of the University of Nigeria Teaching Hospital (UNTH) Enugu. Approach: Over a period of 29 months, 57 patients out of 140 receiving treatment in the intensive care unit of the University of Nigeria Teaching Hospitals Enugu were found to be infected with extended-spectrum β-lactamase-producing strains of K. pneumoniae. Species identification of K. pneumoniae strains was performed by Standard Microbiology methods and re-confirmed by MALDI-TOF technology. Phenotypic characterization of Extended Spectrum Beta Lactamase (ESBL) was determined by double disc synergy test and presence of ESBL genes was determined by specific PCR. Results: All ESBL producers were positive in a PCR for blaCTX-M-1 cluster and on sequencing, blaCTXM-15 were found to be present. Genotypic characterization of extended spectrum beta-lactamase producing K. pneumoniae showed that all isolates carried CTX-M-15and SHV genes, 41(71.9%) carried aac (6’)-Ib-cr and blaOXA-1, 19(33%) carried blaTEM. ISEcp1 was found upstream and ORF 477 downstream of blaCTX-M. in all strains. Random amplified polymorphic DNA analysis grouped the strains into two clonal groups- A and B and majority of the strains belong to clonal group A (n = 42). Conclusion: This study shows for the first time the presence of ESBL genes in K. pneumoniae from the ICU of UNTH Enugu and therefore strongly butresses the need for regular screening for ESBL-producing bacteria in clinical specimen in ICU and other wards in Nigerian hospitals.