Extended-spectrum Beta-lactamase Phenotype Research Articles

Risk factors for extended-spectrum beta-lactamase (ESBL)-producing E. coli carriage among children in a food animal-producing region of Ecuador: A repeated measures observational study.

The spread of antibiotic-resistant bacteria may be driven by human-animal-environment interactions, especially in regions with limited restrictions on antibiotic use, widespread food animal production, and free-roaming domestic animals. In this study, we aimed to identify risk factors related to commercial food animal production, small-scale or "backyard" food animal production, domestic animal ownership, and practices related to animal handling, waste disposal, and antibiotic use in Ecuadorian communities. We conducted a repeated measures study from 2018 to 2021 in 7 semirural parishes of Quito, Ecuador to identify determinants of third-generation cephalosporin-resistant E. coli (3GCR-EC) and extended-spectrum beta-lactamase E. coli (ESBL-EC) in children. We collected 1,699 fecal samples from 600 children and 1,871 domestic animal fecal samples from 376 of the same households at up to 5 time points per household over the 3-year study period. We used multivariable log-binomial regression models to estimate relative risks (RR) of 3GCR-EC and ESBL-EC carriage, adjusting for child sex and age, caregiver education, household wealth, and recent child antibiotic use. Risk factors for 3GCR-EC included living within 5 km of more than 5 commercial food animal operations (RR: 1.26; 95% confidence interval (CI): 1.10, 1.45; p-value: 0.001), household pig ownership (RR: 1.23; 95% CI: 1.02, 1.48; p-value: 0.030) and child pet contact (RR: 1.23; 95% CI: 1.09, 1.39; p-value: 0.001). Risk factors for ESBL-EC were dog ownership (RR: 1.35; 95% CI: 1.00, 1.83; p-value: 0.053), child pet contact (RR: 1.54; 95% CI: 1.10, 2.16; p-value: 0.012), and placing animal feces on household land/crops (RR: 1.63; 95% CI: 1.09, 2.46; p-value: 0.019). The primary limitations of this study are the use of proxy and self-reported exposure measures and the use of a single beta-lactamase drug (ceftazidime with clavulanic acid) in combination disk diffusion tests for ESBL confirmation, potentially underestimating phenotypic ESBL production among cephalosporin-resistant E. coli isolates. To improve ESBL determination, it is recommended to use 2 combination disk diffusion tests (ceftazidime with clavulanic acid and cefotaxime with clavulanic acid) for ESBL confirmatory testing. Future studies should also characterize transmission pathways by assessing antibiotic resistance in commercial food animals and environmental reservoirs. In this study, we observed an increase in enteric colonization of antibiotic-resistant bacteria among children with exposures to domestic animals and their waste in the household environment and children living in areas with a higher density of commercial food animal production operations.

Molecular characterization of highly prevalent Escherichia coli and Escherichia marmotae resistant to extended-spectrum cephalosporins in European starlings (Sturnus vulgaris) in Tunisia.

European starlings are widespread migratory birds that have already been described as carrying bacteria resistant to extended-spectrum cephalosporins (ESC-R). These birds are well known in Tunisia because they spend the wintertime in this country and are hunted for human consumption. The goal of our study was to estimate the proportion of ESC-R in these birds and to characterize the collected isolates using whole-genome sequencing. Results showed that 21.5% (42/200) of the birds carried either an extended-spectrum beta-lactamase (ESBL) or an acquired AmpC gene. Diverse bla CTX-M genes were responsible for the ESBL phenotype, bla CTX-M-14 being the most prevalent, while only bla CMY-2 and one bla CMY-62 were found in AmpC-positive isolates. Likewise, different genetic determinants carried these resistance genes, including IncHI2, and IncF plasmids for bla CTX-M genes and IncI1 plasmids for bla CMY-2 genes. Three chromosomally encoded bla CTX-M-15 genes were also identified. Surprisingly, species identification revealed a large proportion (32.7%) of Escherichia marmotae isolates. This species is phenotypically indistinguishable from Escherichia coli and has obviously the same capacity to acquire ESC-R genes. Our data also strongly suggest that at least the IncHI2/pST3 plasmid can spread equally between E. coli and E. marmotae. Given the potential transmission routes between humans and animals, either by direct contact with dejections or through meat preparation, it is important to closely monitor antimicrobial resistance in European starlings in Tunisia and to set up further studies to identify the sources of contamination of these birds. IMPORTANCE The One Health concept highlighted knowledge gaps in the understanding of the transmission routes of resistant bacteria. A major interest was shown in wild migratory birds since they might spread resistant bacteria over long distances. Our study brings further evidence that wild birds, even though they are not directly submitted to antibiotic treatments, can be heavily contaminated by resistant bacteria. Our results identified numerous combinations of resistance genes, genetic supports, and bacterial clones that can spread vertically or horizontally and maintain a high level of resistance in the bird population. Some of these determinants are widespread in humans or animals (IncHI2/pST3 plasmids and pandemic clones), while some others are less frequent (atypical IncI1 plasmid and minor clones). Consequently, it is essential to be aware of the risks of transmission and to take all necessary measures to prevent the proportions of resistant isolates from increasing uncontrollably.

Fecal carriage of extended spectrum beta-lactamase and fluoroquinolone resistant gene in non-typhoidal Salmonella enterica isolates from food-producing animals and humans

This study seeks to determine the feacal carriage of extended spectrum beta-lactamase and fluoroquinolone resistant non-typhoidal Salmonella enterica isolates from food-producing animals and humans. A total of three hundred (300) fecal samples were collected using sterile universal containers from food-producing animals namely (Chicken [100], Pig [100] and humans (100) from Onicha Local Government Area of Ebonyi State and analyzed for the presence of non-typhoidal Salmonella enterica using standard microbiological techniques. Phenotypic detection of extended-spectrum beta-lactamase (ESBL) were done by disc diffusion and Double Disk Synergy Test. Molecular characterization for ESBL and fluoroquinolone-resistant genes were done by PCR with specific primers. The result shows that non-typhoidal Salmonella species (NTS) accounted for 25 % and 17 % in poultry and pig fecal sample respectively while 60 % and 40% were phenotypic ESBL producers respectively. When compared statistically there is significant difference among isolates confirmed ESBL-positive (P˂ 0.05). Also, none of the 16 (58 %) NTS isolated from humans harbored ESBL phenotype. PCR analysis with β-lactam specific primer detected the presence of blaOXA 50 % and 50 %, blaSHV 36 %, and 64 %, blaTEM 43 % and 57 %, blaCTX-M 36 % and 64 % in poultry and pig respectively. Fluoroquinolone resistant gene QnrA was present in 0 and 100 % of poultry and pig respectively. QnrB was 40 % and 60 % in poultry and pig isolates respectively. QnrS was present in 64 % isolates of poultry and 13 % isolates in pig. The high prevalence of genes encoding beta-lactamases and fluoroquinolone resistance (TEM, SHV, CTX-M and OXA, (qnrA, qnrB and qnrS) were present more in poultry and pig than in humans and demonstrate a significant public health threat from consumption of food-producing animal harboring such pathogenic resistant genotype if not properly controlled.
 Keywords: Extended spectrum beta-lactamase, Fluoroquinolone, non-typhoidal Salmonella enterica, feacal carriage

Distribution and Antibiotic Resistance Profile of Extended Spectrum Beta-Lactamase Producing Escherichia coli from Fish Farms within Abakaliki Metropolis

Background and Objectives: The emergence of antibiotic resistant determinant in fish farms and its spread is on the increase and has evolved into strains that are resistant to many classes of antibiotics. Thus, it is critical to identify the distribution and antibiotic resistance profile of Extended Spectrum Beta-lactamase (ESBL) producing Escherichia coli from fish farms within Abakaliki Metropolis.
 Methodology: Aseptically, fifty (50) milliliters of fishpond water was collected from twenty locations in fifteen (15) fish farms and were analyze using standard microbiological culture and identification of Escherichia coli. Detection of phenotypic extended spectrum β-lactamases production was performed using Double-Disk Synergy Test (DDST). Antibiotic susceptibility studies of extended spectrum β-lactamases producing Escherichia coli was determined using the Kirby–Bauer disk diffusion method and the results were construed using the Clinical Laboratory Standard Institute (CLSI) zone diameter breakpoints.
 Results: Extended spectrum beta-lactamase producing Escherichia coli distribution from fishpond water revealed overall occurrence rate of 34(11.3 %). The proportion of ESBL producing Escherichia coli was 5(25.0 %) from fish farm L followed by Farm A, Farm E, Farm G, which both accounted for 20.0 % respectively while the least occurrence of 1(5.0 %) was recorded against Farm I. ESBL-producing E. coli were resistant to cephalosporin particularly Ceftriaxone (88.2%), Ceftazidime (91.2 %), Cefotaxime (94.1) and Cefepime (85.3 %). This was followed by Amoxicillin-Clavulanate (91. 2 %), Azetronam (97.1 %). In all, Ciprofloxacin (82.4 %), Imipenem (97.1 %), and Meropenem (100 %) were the most effective antibiotic against ESBL-producing E. coli isolate.
 Conclusion: This study reveals the prevalence of the ESBL phenotype in fish farms. The increasing prevalence of resistance to routinely used antibiotics in medical and veterinary therapies among the study isolates from aquaculture products poses a significant challenge to the treatment of human and animal diseases. As a result, adequate antibiotic intervention is essential to ensure the continued efficacy of antibiotics for aquaculture and human health, as well as the industry's viability.

Occurrence of ESBL- and AmpC-Producing E. coli in French Griffon Vultures Feeding on Extensive Livestock Carcasses.

Despite the fact that the selective pressure of antibiotics on wild birds is supposed to be very weak, they are considered potential vectors of antimicrobial resistance (AMR). Obligate scavengers such as vultures can present high proportions of resistance to extended-spectrum cephalosporins (ESC) and multi-drug-resistant (MDR) bacteria, partially due to feeding stations that are provisioned with livestock carcasses from intensive farming. Here we investigated whether griffon vultures (Gyps fulvus) from two populations located in the French Alps, which feed on livestock carcasses from extensive farms, may carry such resistant bacteria. Phenotypic and genotypic characterization showed an 11.8% proportion of ESC-resistant bacteria, including five extended-spectrum beta-lactamase (ESBL)-producing and one AmpC-producing E. coli. The five ESBL-positive E. coli were clonal and all came from the same vulture population, proving their spread between animals. The ESBL phenotype was due to a blaCTX-M-15 gene located on the chromosome. Both ESBL- and AmpC-positive E. coli belonged to minor STs (ST212 and ST3274, respectively); interestingly, ST212 has already been identified in wild birds around the world, including vultures. These results suggest that actions are needed to mitigate the spread of MDR bacteria through wild birds, particularly in commensal species.

Extended-Spectrum Beta-lactamase and Metallo-beta-lactamase Production among Escherichia coli and Klebsiella pneumoniae Strains from Urine of Pregnant Women in Afikpo, Ebonyi State, Nigeria

Aim: The aim of this study was to determine the occurrence of Extended-spectrum beta-lactamase (ESBL) and Metallo-beta-lactamase (MBL) among Escherichia coli and Klebsiella pneumoniae strains from pregnant women attending Mater Misericordia Hospital Afikpo, Ebonyi state, Nigeria.
 Study Design: This is a laboratory based prospective study carried out on pregnant women suspected of having urinary tract infection and was requested to undergo diagnosis at microbiology laboratory of the hospital.
 Place and Duration of Study: The study was conducted in the Department of Science Laboratory Technology, Akanu Ibiam Federal Polytechnic, Unwana, Afikpo, Ebonyi State, Nigeria from October, 2022 to January, 2023.
 Methodology: Clean-catch midstream urine samples were collected from 206 pregnant women suspected of having urinary tract infection and were requested to undergo medical diagnosis at microbiology laboratory of the hospital. The urine samples were processed following standard microbiological procedure. Antimicrobial susceptibility testing was determined using the disc diffusion method, while ESBL phenotypes were determine by the Double-Disc Synergy Test (DDST). Disc potentiation test was performed to check for MBL production.
 Results: Out of the 206 urine samples processed, 24 (11.7 %) E. coli and 12 (5.8 %) K. pneumoniae were isolated. The antimicrobial susceptibility of the isolates recorded a 100 % resistance with Amoxicillin/Clavulanic acid and Cotrimoxazole. The Gram-negative isolates showed a high sensitivity of 100 % to Netilmicin, Meropenem and Ofloxacin. Overall, 35 (97.2 %) multidrug resistance (MDR) was observed of the bacteria isolates. A total of 9 (37.5 %) E. coli and 4 (33.3 %) K. pneumoniae was found positive for ESBL production whereas, 5 (20.8 %) E. coli and 2 (16.7 %) K. pneumoniae were MBL positive.
 Conclusion: The level of drug resistance in this study underscores the need for regular surveillance for effective management of urinary tract infection in pregnancy.

Investigation of Delafloxacin Resistance in Multidrug-Resistant Escherichia coli Strains and the Detection of E. coli ST43 International High-Risk Clone.

Delafloxacin is a novel fluoroquinolone agent that is approved for clinical application. In this study, we analyzed the antibacterial efficacy of delafloxacin in a collection of 47 Escherichia coli strains. Antimicrobial susceptibility testing was performed by the broth microdilution method and minimum inhibitory concentration (MIC) values were determined for delafloxacin, ciprofloxacin, levofloxacin, moxifloxacin, ceftazidime, cefotaxime, and imipenem. Two multidrug-resistant E. coli strains, which exhibited delafloxacin and ciprofloxacin resistance as well as extended-spectrum beta-lactamase (ESBL) phenotype, were selected for whole-genome sequencing (WGS). In our study, delafloxacin and ciprofloxacin resistance rates were 47% (22/47) and 51% (24/47), respectively. In the strain collection, 46 E. coli were associated with ESBL production. The MIC50 value for delafloxacin was 0.125 mg/L, while all other fluoroquinolones had an MIC50 value of 0.25 mg/L in our collection. Delafloxacin susceptibility was detected in 20 ESBL positive and ciprofloxacin resistant E. coli strains; by contrast, E. coli strains that exhibited a ciprofloxacin MIC value above 1 mg/L were delafloxacin-resistant. WGS analysis on the two selected E. coli strains (920/1 and 951/2) demonstrated that delafloxacin resistance is mediated by multiple chromosomal mutations, namely, five mutations in E. coli 920/1 (gyrA S83L, D87N, parC S80I, E84V, and parE I529L) and four mutations in E. coli 951/2 (gyrA S83L, D87N, parC S80I, and E84V). Both strains carried an ESBL gene, blaCTX-M-1 in E. coli 920/1 and blaCTX-M-15 in E. coli 951/2. Based on multilocus sequence typing, both strains belong to the E. coli sequence type 43 (ST43). In this paper, we report a remarkable high rate (47%) of delafloxacin resistance among multidrug-resistant E. coli as well as the E. coli ST43 international high-risk clone in Hungary.

Extended-spectrum beta-lactamases in poultry in Africa: a systematic review

Extended-spectrum beta-lactamase (ESBL)-producing bacteria present a unique problem because of their ability to cause infections that are difficult to treat in animals and humans. The presence of ESBL-Escherichia coli (E. coli) in poultry raises a major public health concern due to the risk of zoonotic transfer via the food chain and direct contact with birds and the environment. This review aimed to determine the frequency of ESBL-producing E. coli and associated ESBL genes in poultry in Africa. Three databases (PubMed, ScienceDirect, and Web of Science) and predetermined websites were searched to identify scientific and grey literature. Studies (1582) were screened at title, abstract, and full-text levels. This review was registered with PROSPERO (CRD42021259872). Thirty-three studies were deemed eligible for this review. Phenotypic ESBL expression was confirmed in 22 studies (66.7%) with a wide range of colonization noted in sampled poultry (1 – 100%). The blaCTX-Mgene was the most commonly isolated with the variants blaCTX-M-1and blaCTX-M-15being the most predominant in North and West Africa respectively. ESBL-producing E. coli isolates are frequently detected in poultry in farms and slaughterhouses across Africa thereby posing a potential health risk to humans. The paucity of data however does not allow for inferences to be made about the true extent of ESBLs in poultry in Africa.

Prevalence of multidrug-resistant and extended-spectrum β-lactamase-producing Escherichia coli from chicken farms in Egypt.

Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli strains exhibit antibiotic resistance and are known to infect humans worldwide. This study assessed the phenotypic and genotypic prevalence of ESBL-resistant E. coli isolates recovered from the respiratory tracts of chickens in El-Sharkia Governorate, Egypt. We obtained 250 lung samples (one lung/bird) from 50 chicken farms (5 chickens/farm) to isolate, identify, and serotype E. coli. Antimicrobial resistance susceptibility was determined using the disk diffusion method, while the ESBL phenotype was identified using double disk synergy. We detected the β-lactamase genes, blaTEM, and blaSHV, using a polymerase chain reaction. The results showed that 140/250 (56%) were infected with E. coli. All the serogroups of isolated E. coli exhibited high multi-antimicrobial resistance index values (>0.2), and 65.7% were confirmed to have ESBL. Among the isolates with the ESBL phenotypes, 55 (60%) and 32 (35%) contained the blaTEM and blaSHV genes, respectively. The widespread distribution of multidrug-resistant and ESBL-producing E. coli among poultry farms is a significant human health hazard. These results will help the Egyptian authorities to implement a national one-health approach to combat the antimicrobial resistance problem.

Prevalence of Extended-Spectrum β-Lactamases in Multidrug-Resistant Klebsiella pneumoniae Isolates in Jordanian Hospitals

The increase in the prevalence of infections caused by certain bacteria, such as Klebsiella pneumonia (K. pneumoniae), is a global health concern. Bacterial production of an enzyme called extended-spectrum beta-lactamase (ESBL) can generate resistance to antimicrobial therapeutics. Therefore, between 2012 and 2013, we investigated K. pneumoniae that produce ESBLs with the prevalence of individual genes including blaSHV, blaCTX-M, blaTEM, and blaOXA isolated from clinical samples. A total of 99 variable diagnostic samples including blood from hematological malignancies (n = 14) or other clinical sources including sputum, pus, urine, and wound (n = 85) were analyzed. All samples' bacterial type was confirmed and their susceptibility to antimicrobial agents was established. Polymerase chain reaction (PCR) amplification was carried out to ascertain presence of specific genes that included blaSHV, blaCTX-M, blaTEM, and blaOXA. Plasmid DNA profiles were determined to assess significance between resistance to antimicrobial agents and plasmid number. It was found that among non-hematologic malignancy isolates, the highest rate of resistance was 87.9% to imipenem, with lowest rate being 2% to ampicillin. However, in hematologic malignancy isolates, the highest microbial resistance was 92.9% to ampicillin with the lowest rate of resistance at 28.6% to imipenem. Among collected isolates, 45% were ESBL-producers with 50% occurrence in hematologic malignancy individuals that were ESBL-producers. Within ESBL-producing isolates from hematologic malignancy individuals, blaSHV was detected in 100%, blaCTX-M in 85.7%, and blaTEM and blaOXA-1 at 57.1% and 27.1%, respectively. In addition, blaSHV,blaCTX-M, and blaOXA were found in all non-hematological malignancy individuals with blaTEM detected in 55.5% of samples. Our findings indicate that ESBLs expressing blaSHV and blaCTX-M genes are significantly prevalent in K. pneumoniae isolates from hematologic malignancy individuals. Plasmid analysis indicated plasmids in isolates collected from hematological malignancy individuals. Furthermore, there was a correlation between resistance to antimicrobial agents and plasmids within two groups analyzed. This study indicates an increase in incidence of K. pneumoniae infections displaying ESBL phenotypes in Jordan.

High prevalence of extensively drug resistant and extended spectrum beta lactamases (ESBLs) producing uropathogenic Escherichia coli isolated from Faisalabad, Pakistan.

Urinary tract infections (UTIs) are predominantly caused by uropathogenic Escherichia coli (E. coli). There is rapid increase in antimicrobial resistance in UTIs, also declared as a serious health threat by World Health Organization (WHO). Present study was designed to investigate the antimicrobial resistance status with specific focus on ESBLs and carbapenemases in local uropathogenic E. coli (UPEC) isolates. E. coli isolates were characterized from patients of all ages visiting diagnostic laboratories for urine examination. Demographic data was also recorded for each patient. Antibiograms were developed to observe antibiotic resistance in UPEC using Kirby Bauer disc diffusion technique. Double Disc Synergy test (DDST) was used for phenotypic ESBL test. ESBLs and carbapenemases genes were detected in UPEC using PCR. The PCR results were confirmed by sequencing. The UPEC isolates under study exhibited 78%, 77%, 74%, 72% and 55% resistance against cefotaxime, amoxicillin, erythromycin, ceftriaxone and cefixime, respectively. Resistance against colistin and meropenem was observed in 64% and 34% isolates, respectively. Phenotypic DDST identified 48% isolates as ESBLs producers. Genotypic characterization identified 70%, 74.4% and 49% prevalence of CTXM-1, TEM-1 and CTXM-15 genes respectively. One isolate was observed exhibiting co-existence of all ESBL genes. TEM-1 + CTXM-1 and TEM-1 + CTXM-1 + CTXM-15 + OXA-1 gene patterns were dominant among ESBLs. For carbapenem-resistance, 14% isolates indicated the presence of KPC whereas GES and VIM was detected in 7% and 3.4% isolates, respectively. In conclusion, our results present a high prevalence of extensively drug resistant UPEC isolates with a considerable percentage of ESBL producers. These findings propose the need of continuous surveillance for antimicrobial resistance and targeted antimicrobial therapy.

Characterisation of ESBL/AmpC-Producing Enterobacteriaceae isolated from poultry farms in Peninsular Malaysia.

Extended-spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases (AmpCs)-producing Enterobacteriaceae have been increasingly reported and imposing significant threat to public. Livestock production industry might be the important source for clinically important ESBL-producing Enterobacteriaceae. This study aims to investigate the resistance profile, phenotypic ESBL production, beta-lactamase genes, virulence factors, and plasmid replicon types among 59 Enterobacteriaceae strains isolated from poultry faecal samples in Malaysia's commercial poultry farm. There were 38.7% and 32.3% of Escherichia coli resistant to cefotaxime and cefoxitin, respectively, while Klebsiellaspp. demonstrated resistance rate of 52.6% to both mentioned antimicrobials. Majority of the E. coli isolates carried blaTEM and blaCMY-2 group. blaSHV was the most prevalent gene detected in Klebsiellaspp., followed by blaDHA and blaTEM. Resistance to extended spectrum cephalosporin in our isolates was primarily mediated by plasmid mediated AmpC beta-lactamase such as CMY-2 group and DHA enzyme. The CTX-M genes were found in two ESBL-producing E. coli. IncF, IncI1, and IncN plasmids were most frequently detected in E. coli and Klebsiellaspp. The virulence factor, including EAST1 and pAA were identified at low frequency. This study highlights the poultry as a reservoir of resistance and virulence determinants and prevalence of plasmids in Enterobacteriaceae might drive their dissemination.

High Resistance to Antibiotics Recommended in Standard Treatment Guidelines in Ghana: A Cross-Sectional Study of Antimicrobial Resistance Patterns in Patients with Urinary Tract Infections between 2017-2021.

Management of urinary tract infections is challenged by increasing antimicrobial resistance (AMR) worldwide. In this study, we describe the trends in antimicrobial resistance of uropathogens isolated from the largest private sector laboratory in Ghana over a five-year period. We reviewed positive urine cultures at the MDS Lancet Laboratories from 2017 to 2021. The proportions of uropathogens with antimicrobial resistance to oral and parenteral antimicrobials recommended by the Ghana standard treatment guidelines were determined. The proportion of multi-drug resistant isolates, ESBL and carbapenemase-producing phenotypes were determined. Of 94,134 urine specimens submitted for culture, 20,010 (22.1%) were culture positive. Enterobacterales was the most common group of organisms, E. coli (70.6%) being the most common isolate and Enterococcus spp. the most common gram-positive (1.3%) organisms. Among oral antimicrobials, the highest resistance was observed to ciprofloxacin (62.3%) and cefuroxime (60.2%) and the least resistance to fosfomycin (1.9%). The least resistance among parenteral antimicrobials was to meropenem (0.3%). The highest multi-drug resistance levels were observed among Klebsiella spp. (68.6%) and E. coli (64.0%). Extended-spectrum beta-lactamase (ESBL) positivity was highest in Klebsiella spp. (58.6%) and E. coli (50.0%). There may be a need to review the Ghana standard treatment guidelines to reflect increased resistance among uropathogens to recommended antimicrobials.

Antibiotic susceptibility profiles and detection of genes mediating extended-spectrum β-lactamase (Esbl) production in escherichia coli isolates from National Hospital, Abuja.

Extended-spectrum beta-lactamases (ESBL) are the most widespread of the new beta-lactamases and are a significant threat to patient care in the hospital and the community. Aim: The study assessed the prevalence, antibiotic susceptibility profile, and major ESBL encoding genes among Escherichia coli isolated from clinical specimens of patients in the National Hospital, Abuja (NHA). E. coli isolated from diverse clinical specimens obtained from clinically proven cases of infection managed at the NHA were included in the study. The antimicrobial susceptibility was performed by the Kirby-Bauer method and E-test was used to confirm the ESBL phenotype. Multiplex polymerase chain reaction (PCR) was used to detect the genes mediating ESBL production. Meropenem, fosfomycin, and tigecycline demonstrated excellent activities against all isolates: of the 400 isolates, 392 (98%), 386 (96.5%), and 362 (90.5%) were susceptible, respectively. Similarly, 358 (89.5%) were susceptible to amikacin, 323 (80.3%) nitrofurantoin, 281 (70.3%) ceftazidime, and 279 (69.8%) cefotaxime. A total of 271 (67.8%), 219 (54.8%), and 208 (52.0%) were resistant to amoxicillin-clavulanate, ciprofloxacillin, and gentamicin, respectively. However, all the isolates were resistant to ampicillin. There was a significantly higher proportion of multidrug resistance among ESBL-producing isolates compared to non-ESBL-producing isolates (P = 0.0001). Of the 121 phenotypically detected ESBL isolates, 119 (98.3%) harbored genes mediating the production of Cefotaximase- Munich (CTX-M), Temoniera (TEM) or Sulfhydryl Variable (SHV) enzymes. The prevalence of ESBLs among E. coli was relatively high, at 30.2%. About 81% of all blood isolates were ESBL-producers. blaCTX-M is the predominant type of ESBL gene among E. coli. A high proportion of the ESBL-producing isolates expressed a combination of two or three genes together.

Molecular Detection of Extended Spectrum Beta-Lactamases in Clinical Isolates of Pseudomonas aeruginosa

Pseudomonas aeruginosa producing extended spectrum beta lactamases (ESBL) is a major concern in the hospital settings. It is usually reported in Enterobacteriaceae and is less frequently observed in P. aeruginosa. There is no recommended test for ESBL detection in P.aeruginosa. Therefore, we determined the occurrence of ESBL in clinical isolates of P.aeruginosa by both phenotypic and genotypic methods. Antimicrobial susceptibility tests were done on two hundred and thirteen isolates of P. aeruginosa. Phenotypic detection of ESBL was performed using combined disk method and ESBL encoding genes such as blaVEB, blaPER, blaPSE, blaGES, blaTEM, blaSHV, blaCTX-M, blaBEL, blaOXA1, blaOXA10, blaOXA2 were studied by simplex PCR. Of the 213 isolates, 85 were identified as resistant to ceftazidime and 27/85 isolates were confirmed to be ESBL producers by phenotypic method. The presence of genes encoding ESBLs comprising of blaTEM (n=44), blaOXA-10 (n=19) isolates, blaOXA-1 (n=5), blaOXA-2 (n=3) were found. All OXA gene positive isolates exhibited the ESBL phenotype. The blaGES gene were identified in 4/85 (5%) isolates. This study shows the prevalence of ESBL among clinical isolates of P.aeruginosa and in particular, the presence of GES β lactamases.

Molecular Characterization of Carbapenem-Resistant Acinetobacter baumannii Isolated from Intensive Care Unit Patients in Jordanian Hospitals.

Acinetobacter baumannii is a common cause of healthcare-associated infections (HAI) worldwide, mostly occurring in intensive care units (ICUs). Extended-spectrum beta lactamases (ESBL)-positive A. baumannii strains have emerged as highly resistant to most currently used antimicrobial agents, including carbapenems. The most common mechanism for carbapenem resistance in this species is β-lactamase-mediated resistance. Carbapenem-hydrolyzing class D oxacillinases are widespread among multidrug-resistant (MDR) A. baumannii strains. The present study was conducted to determine the presence and distribution of blaOXA genes among multidrug-resistant A. baumannii isolated from ICU patients and genes encoding insertion sequence (IS-1) in these isolates. Additionally, the plasmid DNA profiles of these isolates were determined. A total of 120 clinical isolates of A. baumannii from various ICU clinical specimens of four main Jordanian hospitals were collected. Bacterial isolate identification was confirmed by biochemical testing and antibiotic sensitivity was then assessed. PCR amplification and automated sequencing were carried out to detect the presence of blaOXA-51, blaOXA-23, blaOXA-24, and blaOXA-58 genes, and ISAba1 insertion sequence. Out of the 120 A. baumannii isolates, 95% of the isolates were resistant to three or more classes of the antibiotics tested and were identified as MDR. The most frequent resistance of the isolates was against piperacillin (96.7%), cephalosporins (97.5%), and β-lactam/β-lactamase inhibitor combinations antibiotics (95.8%). There were 24 (20%) ESBL-producing isolates. A co-existence of blaOXA-51 gene and ISAba1 in all the 24 ESBL-producing isolates was determined. In addition, in the 24 ESBL-producing isolates, 21 (87.5%) carried blaOXA-51 and blaOXA-23 genes, 1 (4.2%) carried blaOXA-51 and blaOXA-24, but all were negative for the blaOXA-58 gene. Plasmid DNA profile A and profile B were the most common (29%) in ESBL-positive MDR A. baumannii isolates while plasmid DNA profile A was the most common in the ESBL-negative isolates. In conclusion, there was an increase in prevalence of MDR-A. baumannii in ICU wards in Jordanian hospitals, especially those having an ESBL phenotype. Thus, identification of ESBL genes is necessary for the surveillance of their transmission in hospitals.

Detection of extended spectrum beta-lactamase (ESBL)–production in Salmonella Typhimurium isolated from poultry birds in Nasarawa State, Nigeria

Salmonella Typhimurium is an important zoonotic food borne pathogen and the second most widely studied pathogen in relation to antimicrobial resistance studies in Nigeria. Its resistance to β-lactam antibiotics is on the rise globally due to persistent exposure and production of Extended Spectrum Beta-lactamase enzymes (ESBLs) which is barely reported to occur among food producing animals in Nigeria. This poses a threat to the successful therapy of salmonellosis infections and raises concern on food safety. Further complicating these challenges is the lack of strict laws mitigating antibiotic usage in Nigeria. The study was conducted in the Microbiology laboratory of Nasarawa State University, Keffi, Nigeria. A total of 300 samples each of poultry droppings, flesh, feeds, human hand swabs and stool were randomly collected following ethical approval and screened for ESBL- producing S. Typhimurium using standard Microbiological methods of isolation and identification. Antibiotic susceptibility testing, phenotypic ESBL detection and interpretation were carried out as described by the Clinical Laboratory and Standard Institute (CLSI) guideline. The bla genes were identified using polymerase chain reaction (PCR) method. A total of 106 S.Typhimurium were isolated with the following resistance profile; Ampicillin 99(93.4%), Augmentin 104(98.1%), Ceftriaxone 74(69.8%), Ceftazidime 50(47.2%), Imipenem 1(1.0%). The antibiotic resistance of S. Typhimurium in the study is significant (P = 0.01). The Multiple Antibiotic Resistance (MAR) Index was > 0.2. Out of 106 isolates, 32 distinct antimicrobial resistant phenotypes were observed and 62 (81.6%) were confirmed ESBL producers having 19 distinct phenotypes. The bla genes were identified among 38.7% (24/62) isolates; 100% blaSHV (24/24), 87.5 %(21/24)blaTEM with 54.2% (13/24) co-carriage of blaTEM-SHV. The blaCTX-M was not detected. Poultry is therefore an important reservoir and source of transmission of ESBL- producing S.Typhimurium, which is a major public health concern. The high MAR index suggests frequent antibiotic usage within our study area, thus calls for antibiotic stewardship in animal production in Nigeria.

Study of Plasmid-Mediated Quinolone Resistance in Klebsiella pneumoniae: Relation to Extended-Spectrum Beta-Lactamases

Klebsiella pneumoniae (K. pneumoniae) is an important pathogen associated with various infections. The emergence of antibiotic resistances, such as quinolone resistance and those due to extended-spectrum beta-lactamases (ESBL), reduces the available choices for treatment. The objectives of the current study include the evaluation of the prevalence of the plasmid-mediated quinolone resistance genes qepA, acrA, acrB, and aac(6’)-Ib-cr by polymerase chain reaction (PCR) in K. pneumoniae and the determination of the mechanism relating these genes to the ESBL phenotype and resistance to other groups of antibiotics. In total, 300 clinical isolates of K. pneumoniae were included in the study. Isolates were subjected to antibiotic sensitivity tests using the disc diffusion method. Quinolone resistance by the minimum inhibitory concentration method and detection of ESBL resistance by the double disc diffusion method were also determined. PCR analyses revealed the prevalence of acrA, aac(6’)-Ib-cr, acrB, and qepA in 74.3%, 73.7%, 71%, and 6.7% of the isolates, respectively. Quinolone-resistant isolates positive for plasmid-encoded genes represented 82.7% of K. pneumoniae isolates positive for ESBL activity. The results also showed that the isolates of K. pneumoniae carrying plasmid-encoded quinolone resistance genes had significantly increased resistance to amikacin, amoxicillin/clavulanate, gentamicin, and cefoxitin than those isolates without quinolone resistance genes. Therefore, there was a high prevalence of acrA, acrB, and aac(6’)-Ib-cr among K. pneumoniae and the prevalence of quinolone resistance was significantly associated with the ESBL resistance phenotype. Moreover, the presence of quinolone resistance genes was associated with resistance to aminoglycosides, namely amikacin and gentamicin.

Increased rates of extended-spectrum beta-lactamase isolates in patients hospitalized with culture-positive urinary Enterobacterales in the United States: 2011 – 2020

Antimicrobial resistance in Enterobacterales has made empiric therapy for hospitalized patients with urinary tract infections (UTIs) more challenging. We analyzed the antibiotic susceptibility of nonduplicate Enterobacterales isolates from urine cultures tested at US hospitals in the BD Insights Research Database (2011–2020). Multivariable generalized estimating equation models were used to assess resistance trends over time. A total of 322 US hospitals provided data on 876,507 urinary Enterobacterales isolates (62.4% Escherichia coli). Enterobacterales antibiotic resistance rates were 64.6%, 29.3%, 27.6%, and 26.3% for beta-lactams, fluoroquinolones, nitrofurantoin, and trimethoprim/sulfamethoxazole, respectively, and 12.4% had an extended-spectrum beta-lactamase (ESBL) phenotype. In multivariable models, rates of ESBL isolates and isolates resistant to ≥3 drug classes increased significantly between 2011 and 2020, while other categories of resistance generally decreased. We conclude that antimicrobial resistance is common in urinary Enterobacterales isolates. Management of UTIs should be guided by urine culture data and may benefit from new therapies.

Zoonotic bacteria in clinically healthy goats in petting zoo settings of zoological gardens in Germany.

Goats and other small ruminants are frequently used as contact animals in petting zoo settings of zoological gardens. However, they are capable to carry a broad spectrum of zoonotic pathogens without clinical signs. In this study, we analysed the presence of different zoonotic pathogens in 300 clinically healthy goats from 14 zoological gardens in Germany. Rectal and nasal swabs were investigated with a series of cultural and molecular techniques. In addition, vaginal swabs of the 230 female goats were investigated for the presence of Coxiella burnetii by real-time PCR. Antibodies against C.burnetii were tested in milk and serum by ELISA. Campylobacter spp. were found in 22.7%, Shiga-toxigenic Escherichia coli in 20.0% and Arcobacter spp. were found in 1.7% of the tested 300 goats after culture from rectal swabs and subsequent PCR. One sample contained an Escherichia fergusonii isolate with a blaCTX-M-1 -encoded extended-spectrum beta-lactamase phenotype. Neither Yersinia spp. nor Salmonella spp. were found. Nasal swabs of 20.7% of the goats yielded Staphylococcus aureus including one mecC-positive methicillin-resistant isolate. Neither Yersinia spp. nor Salmonella spp. were found, and none of the 230 vaginal swabs was positive for C.burnetii. Attempts to detect dermatophytes failed. In conclusion, a possible risk of transmission of zoonotic bacteria from goats in petting zoos to visitors should be considered. Appropriate information and facilities for hand washing and disinfection should be provided in all zoological gardens using goats as contact animals due to the regular presence of zoonotic bacteria in the collection.