Extended-spectrum Beta-lactamase Phenotype Research Articles

Multidrug-resistant phenotypes of genetically diverse Escherichia coli isolates from healthy domestic cats.

Β-lactamases-producing Escherichia coli are a widely distributed source of antimicrobial resistance (AMR), for animals and humans. Little is known about the sensitivity profile and genetic characteristics of E. coli strains isolated from domestic cats. We report a cross-sectional study that evaluated E. coli strains isolated from domestic cats in Panama. For this study the following antibiotics were analyzed: ampicillin, amoxicillin-clavulanate cefepime, cefotaxime, cefoxitin, ceftazidime, aztreonam, imipenem, gentamicin, kanamycin, streptomycin, tetracycline, ciprofloxacin, nalidixic acid, trimethoprim-sulfamethoxazole, and chloramphenicol. The data obtained were classified as resistant, intermediate, or sensitive. MDR strains were established when the strain presented resistance to at least one antibiotic from three or more antimicrobial classes. Forty-eight E. coli isolates were obtained, of which 80% presented resistance to at least one of the antibiotics analyzed, while only 20% were sensitive to all (p = 0.0001). The most common resistance was to gentamicin (58%). Twenty-nine percent were identified as multidrug-resistant isolates and 4% with extended spectrum beta-lactamase phenotype. The genes blaTEM (39%), blaMOX(16%), blaACC (16%) and blaEBC (8%) were detected. Plasmid-mediated resistance qnrB (25%) and qnrA (13%) are reported. The most frequent sequence types (STs) being ST399 and we reported 5 new STs. Our results suggest that in intestinal strains of E. coli isolated from domestic cats there is a high frequency of AMR.

Molecular characterization of carbapenemase and extended spectrum beta-lactamase producing Acinetobacter baumannii isolates causing surgical site infections in Ethiopia

BackgroundAcinetobacter baumannii is an opportunistic pathogen that can cause a variety of nosocomial infections in humans. This study aimed to molecularly characterize extended-spectrum beta-lactamase (ESBL) producing and carbapenem-resistant Acinetobacter species isolated from surgical site infections (SSI).MethodsA multicentre cross-sectional study was performed among SSI patients at four hospitals located in Northern, Southern, Southwest, and Central parts of Ethiopia. The isolates were identified by microbiological methods and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Antibiotic susceptibility was determined using disk diffusion. The presence of phenotypic ESBL and carbapenemase production was detected by employing standard microbiological tests, including combined disk diffusion (CDT). ESBL and carbapenem resistance determinants genes were studied by polymerase chain reaction (PCR) and sequencing.ResultsA total of 8.7% Acinetobacter species were identified from 493 culture-positive isolates out of 752 SSI wounds. The species identified by MALDI-TOF MS were 88.4% A. baumannii, 4.7% Acinetobacter pittii, 4.7% Acinetobacter soli, and 2.3% Acinetobacter lactucae. Of all isolates 93% were positive for ESBL enzymes according to the CDT. Using whole genome sequencing 62.8% of the A. baumannii harbored one or more beta-lactamase genes, and 46.5% harbored one or more carbapenemase producing genes. The distribution of beta-lactamases among Acinetobacter species by hospitals was 53.8%, 64.3%, 75%, and 75% at JUSH, TASH, DTCSH, and HUCSH respectively. Among ESBL genes, blaCTX−M alleles were detected in 21.4% of isolates; of these 83.3% were blaCTX−M−15. The predominant carbapenemase gene of blaOXA type was detected in 24 carbapenem-resistant A. baumannii followed by blaNDM alleles carried in 12 A. baumannii with blaNDM−1 as the most common.ConclusionsThe frequency of Acinetobacter species that produce metallobetalactamases (MBLs) and ESBLs that were found in this study is extremely scary and calls for strict infection prevention and control procedures in health facilities helps to set effective antibiotics stewardship.

Clinical, phenotypic, and genotypic characteristics of ESBL-producing Salmonella enterica bloodstream infections from Qatar

BackgroundResistant Salmonella infections are a major global public health challenge particularly for multidrug-resistant (MDR) isolates manifesting as bloodstream infections (BSIs). ObjectivesTo evaluate clinical, phenotypic, and genotypic characteristics of extended-spectrum beta-lactamase (ESBL) producing Salmonella enterica BSIs from Qatar. MethodsPhenotypic ESBL Salmonella enterica from adult patients presenting with positive BSIs were collected between January 2019 to May 2020. Microbiological identification and characterization were performed using standard methods while genetic characteristics were examined through whole genome sequencing studies. ResultsOf 151 episodes of Salmonella enterica BSI, 15 (10%) phenotypic ESBL isolates were collected. Recent travel was recorded in most cases (80%) with recent exposure to antimicrobials (27%). High-level resistance to quinolines, aminoglycosides, and cephalosporins was recorded (80-100%) while meropenem, tigecycline and colistin demonstrated universal susceptibility. Genomic evaluation demonstrated dominance of serotype Salmonella Typhi sequence type 1 (93%) while antimicrobial resistance genes revealed dominance of aminoglycoside resistance (100%), qnrS1 quinolones resistance (80%), blaCTX-M-15 ESBLs (86.7%), and paucity of AmpC resistance genes (6.7%). ConclusionsInvasive MDR Salmonella enterica is mainly imported, connected to patients from high prevalent regions with recent travel and antimicrobial use caused by specific resistant clones. In suspected cases of multidrug resistance, carbapenem therapy is recommended.

Connectivity at the human-wildlife interface: starling movements relate to carriage of E. coli

Synanthropic bird species in human, poultry or livestock environments can increase the spread of pathogens and antibiotic-resistant bacteria between wild and domestic animals. We present the first telemetry-based spatial networks for a small songbird. We quantified landscape connectivity exerted by spotless starling movements, and aimed to determine if connectivity patterns were related to carriage of potential pathogens. We captured 28 starlings on a partridge farm in 2020 and tested them for Avian influenza virus, West Nile virus WNV, Avian orthoavulavirus 1, Coronavirus, Salmonella spp. and Escherichia coli. We did not detect any viruses or Salmonella, but one individual had antibodies against WNV or cross-reacting Flaviviruses. We found E. coli in 61 % (17 of 28) of starlings, 76 % (13 of 17) of which were resistant to gentamicin, 12 % (2 of 17) to cefotaxime/enrofloxacin and 6 % (1 of 17) were phenotypic extended spectrum beta-lactamase (ESBL) carriers. We GPS-tracked 17 starlings and constructed spatial networks showing how their movements (i.e. links) connect different farms with nearby urban and natural habitats (i.e. nodes with different attributes). Using E. coli carriage as a proxy for acquisition/dispersal of bacteria, we found differences across spatial networks constructed for E. coli positive (n = 7) and E. coli negative (n = 9) starlings. We used Exponential Random Graph Models to reveal significant differences between networks. In particular, an urban roost was more connected to other sites by movements of E. coli positive than by movements of E. coli negative starlings. Furthermore, an open pine forest used mainly for roosting was more connected to other sites by movements of E. coli negative than by movements of E. coli positive starlings. Using E. coli as a proxy for a potential pathogen carried by starlings, we reveal the pathways of spread that starlings could provide between farms, urban and natural habitats.

Antibiotic resistance among Aerobic Gram-Negative Bacilli isolated from patients with oral inflammatory dysbiotic conditions—a retrospective study

IntroductionAerobic Gram-Negative Bacilli (AGNB) are not part of the resident oral microflora but are occasionally found in high abundance under inflammatory dysbiotic conditions at various oral niches. The aim of the present study was to investigate the identity and antibiotic susceptibility of AGNB isolated from patients in Sweden with mucosal lesions, periodontitis, and peri-implantitis, with special attention to antibiotic resistance and on the presence of phenotypic Extended Spectrum Beta-Lactamase (ESBL) isolates.Materials and methodsMicrobiolgical samples were harvested from 211 patients in total, experiencing mucosal lesions (N = 113), periodontitis (N = 62), or peri-implantitis (N = 36). The growth of AGNB's was semiquantified by selective and non-selective culture and the strains were isolated, identified, and tested for antibiotic susceptibility. A total of 251 AGNB strains, occurring in moderate to heavy growth (>100 CFU/ml sample), indicating a dysbiotic microbiota, were identified. The disc diffusion method was used for screening of the antibiotic susceptibility of the isolates. Phenotypic identification of ESBL isolates was based on resistance to ceftazidime and/or cefotaxime.ResultsThe most commonly detected AGNB isolates in oral inflammatory dysbiotic conditions were fermentative species belonging to Enterobacteriaceae e.g. Citrobacter spp., Enterobacter spp., Escherichia coli, Klebsiella spp, and the non-fermentative environmental Burkholderia cepacia, Pseudomonas spp., and Stenotrophomonas maltophilia. No clear trends were seen in frequency of the various species in samples from mucosal lesions, severe periodontitis, and peri-implantitis cases. The 138 Enterobacteriaceae isolates and 113 environmental AGNB isolated showed a high antibiotic resistance in general against antibiotics commonly used in dentistry (Amoxicillin, Amoxicillin + Clavulanic acid, Ampicillin, Clindamycin, Doxycycline, Erythromycin, Oxacillin, PenicillinV, and Tetracycline). The majority of these isolates were susceptible to ciprofloxacin. Ten isolates (4.1%) were phenotypically classified as ESBL positive. The ESBL isolates were predominantly found among isolates of S. maltophilia, while only one ESBL positive isolate was found among Enterobacteriaceae.ConclusionsPhenotypically identified ESBL isolates can occasionally be present among oral AGNB strains isolated in abundance from the dysbiotic microbiota occurring in cases with oral mucosal lesions, severe periodontitis, or peri-implantitis.

Phenotypic characterization of ESBL-producing urinary isolates of E. coli and Klebsiella spp. in a tertiary care children's hospital in Nepal

BackgroundThe production of extended-spectrum beta-lactamases (ESBLs) among uropathogens, particularly E. coli and Klebsiella spp., poses a severe public health concern. This study explored the epidemiology of ESBL-producing E. coli and Klebsiella spp. isolated from urine samples obtained at a tertiary care children's hospital in Nepal.MethodsA cross-sectional study was conducted from August 2016 to February 2017. A total of 745 clean catch urine samples were obtained from pediatric patients under the age of 13 and subjected to semiquantitative culture. E. coli and Klebsiella spp. were identified using standard laboratory protocols. Antibiotic susceptibility testing was performed using the Kirby-Bauer disc diffusion method, and ESBL producers were phenotypically identified using the combined disk method.ResultsAmong the bacterial isolates, E. coli predominated, accounting for 139 (81.8%) positive cases. Notably, E. coli showed high susceptibility to nitrofurantoin, with 117 (84.2%) isolates being susceptible. Meanwhile, K. pneumoniae showed high susceptibility to gentamicin, with 21 (91.3%) isolates being susceptible. Of the 163 isolates of E. coli and Klebsiella spp., 62 (38.0%) were identified as multidrug-resistant (MDR), with 42 (25.8%) confirmed as phenotypic ESBL producers. Remarkably, all 41 (100%) ESBL-producing E. coli isolates were susceptible to imipenem.ConclusionsThe prevalence of ESBL producers among E. coli and K. pneumoniae isolates from pediatric patients underscores the importance of antimicrobial stewardship. Nitrofurantoin and gentamicin emerge as effective empirical treatment choices against these pathogens in children. However, the high rates of multidrug resistance and ESBL production highlight the necessity for routine surveillance, and early detection strategies to manage such infections effectively.

Prevalence of extended-spectrum beta-lactamase and molecular detection of blaTEM, blaSHV, and blaCTX-M genotypes among gram-negative Bacilli isolates from hospital acquired infections in pediatrics, one institutional study

BackgroundGram-negative bacilli represents an important pathogen in hospital-acquired infections (HAIs) worldwide. The emergence of antibiotic resistance in these pathogens warrants attention for the proper management of infections. Extended-spectrum beta-lactamase (ESBL) resistance represents a major therapeutic problem in infections due to Gram-negative bacilli.The present study aimed to study the extended-spectrum beta-lactamase genes blaTEM, blaSHV, and blaCTX-M by multiplex polymerase reaction in isolated Gram-negative bacilli from HAIs in pediatric patients.MethodsThe study included one hundred-five isolates of Gram-negative bacilli from pediatric patients with different types of HAIs. The isolates were subjected to full microbiological identification, antibiotics susceptibility by disc diffusion method, the phenotypic study of ESBL, and the genetic study of ESBL genes by multiplex PCR.ResultsFifty isolates of Gram-Negative bacilli showed ESBL activity by a phenotypic study by double disc diffusion method (50/105). All ESBL producers’ isolates were positive by PCR for ESBL genes. The most frequent gene was blaTEM (64%), followed by blaSHV (30%) and CTX-M (22%). Mixed genes were found in 4 isolates (8%) for blaTEM and blaSHV, blaTEM and CTX-M. There was a significant association between PCR for ESBL genes and phenotypic ESBL detection (P = 0.001). There was significant detection of ESBL genes in E. coli (28%), followed by Enterobacter spp. (26%), Klebsiella spp. (24%), Serratia (14%), Pseudomonas spp. (6%) and Proteus (2%), P = 0.01. There Seventy percent of isolates positive for ESBL production had an insignificant association between MDR and PCR for ESBL genes (P = 0.23).ConclusionThe present study highlights the prevalence of ESBL activity among clinical isolates of Gram-negative bacilli isolated from hospital-acquired infections in pediatric patients. The most common gene responsible for this activity was blaTEM gee followed by blaSHV and blaCTX-M. There was a high prevalence of multiple antibiotic resistance among isolates with ESBL activity. The finding of the present study denotes the importance of screening extended beta-lactamase among Gram-negative bacilli associated with HAIs in pediatric patients.

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

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

BlaCTX-M Mediated Extended Spectrum Beta-lactamase Production in Escherichia coli from Urine Samples

Objective: To assess the antimicrobial pattern of Escherichia coli isolates from urine samples, determine the proportion of multidrug resistant (MDR) and extended spectrum beta-lactamase (ESBL) and blaCTX-M gene of E. coli from the urine samples. Methods: A total of 2452 urine samples were collected and processed from April to October 2023 in clinically suspected urinary tract infection (UTI) patients attending B&B Hospital Pvt. Ltd to identify possible bacteria using standard microbiological procedures. E coli isolates were further subjected to antimicrobial susceptibility testing using Kirby Bauer disk diffusion method. Combination disk method was used to identify the ESBL phenotypes. Molecular detection of blaCTX-M gene was performed using conventional polymerase chain reaction. Results: A total of 338 (13.7%) samples showed significant bacterial growth. Maximum bacterial growth was found in outpatients (70.4%) and in patients above 60 years of age. Gram negative bacteria (87.8%) were predominant and E. coli (54.4%) was the most frequent. Nitrofurantoin, Aminoglycosides, Carbapenems and Polymixins were effective antibiotics. Among 184 E. coli isolates, 54 (29%) were MDR, 30 (16.3%) were ESBL producer. blaCTX-M gene was detected in 90% of the phenotypically confirmed ESBL producers. Conclusion: E. coli is the major cause of UTI and blaCTX-M is a prime contributor of ESBL production. High rate of resistance to third-generation Cephalosporins, Flouroquinolones and Cotrimoxazole make these antibiotics unsuitable for the treatment of UTI.

Evaluation and clinical practice of pathogens and antimicrobial resistance genes of BioFire FilmArray Pneumonia panel in lower respiratory tract infections

BackgroundExisting panels for lower respiratory tract infections (LRTIs) are slow and lack quantification of important pathogens and antimicrobial resistance, which are not solely responsible for their complex etiology and antibiotic resistance. BioFire FilmArray Pneumonia (PN) panels may provide rapid information on their etiology.MethodsThe bronchoalveolar lavage fluid of 187 patients with LRTIs was simultaneously analyzed using a PN panel and cultivation, and the impact of the PN panel on clinical practice was assessed. The primary endpoint was to compare the consistency between the PN panel and conventional microbiology in terms of etiology and drug resistance, as well as to explore the clinical significance of the PN panel. The secondary endpoint was pathogen detection using the PN panel in patients with community-acquired pneumonia (CAP) or hospital-acquired pneumonia (HAP).ResultsFifty-seven patients with HAP and 130 with CAP were included. The most common pathogens of HAP were Acinetobacter baumannii and Klebsiella pneumoniae, with the most prevalent antimicrobial resistance (AMR) genes being CTX-M and KPC. For CAP, the most common pathogens were Haemophilus influenzae and Staphylococcus aureus, with the most frequent AMR genes being CTX-M and VIM. Compared with routine bacterial culture, the PN panel demonstrated an 85% combined positive percent agreement (PPA) and 92% negative percent agreement (NPA) for the qualitative identification of 13 bacterial targets. PN detection of bacteria with higher levels of semi-quantitative bacteria was associated with more positive bacterial cultures. Positive concordance between phenotypic resistance and the presence of corresponding AMR determinants was 85%, with 90% positive agreement between CTX-M-type extended-spectrum beta-lactamase gene type and phenotype and 100% agreement for mecA/C and MREJ. The clinical benefit of the PN panel increased by 25.97% compared with traditional cultural tests.ConclusionThe bacterial pathogens and AMR identified by the PN panel were in good agreement with conventional cultivation, and the clinical benefit of the PN panel increased by 25.97% compared with traditional detection. Therefore, the PN panel is recommended for patients with CAP or HAP who require prompt pathogen diagnosis and resistance identification.

Resistance to aminoglycoside and quinolone drugs among Klebsiella pneumoniae clinical isolates from northern Jordan

This study aimed to identify phenotypic and genotypic aminoglycoside and quinolone non-susceptibility and the prevalence of aminoglycoside-modifying enzymes and plasmid-mediated quinolone resistance genes among K. pneumoniae clinical isolates from northern Jordan. K. pneumoniae isolates (n = 183) were tested for antimicrobial susceptibility using the Kirby-Bauer disk diffusion method. The double-disk synergy test was used for the detection of the extended-spectrum beta-lactamase phenotype. Polymerase chain reaction was used to detect genes encoding aminoglycoside-modifying enzyme (aac (3′)-II, aac (6′)-II, aac (6′)-Ib, ant (3″)-I, aph (3′)-VI, armA, and rmtB), and plasmid-mediated quinolone resistance (qnrA, qnrB, qnrC, qnrD, qnrS, acc(6′)-Ib–cr, qepA, and oqxAB) genes. Multi-locus sequence typing was used to elucidate the genetic diversity of selected isolates. The non-susceptibility percentages to aminoglycosides and quinolones were 65.0 % and 61.7 %, respectively. The most frequent aminoglycoside-modifying enzyme gene was ant (3″)-I at 73.8 %, followed by aac (6′)-Ib at 25.1 %, aac (3′)-II at 17.5 %, aph (3′)-VI at 12.0 %, armA at 9.8 %, and rmtB at 0.5 %. Aac (6′)-II was not detected among the isolates. The most frequent plasmid-mediated quinolone resistance gene was oqxAB at 31.7 %, followed by qnrS at 26.2 %, qnrB at 25.7 %, and aac(6′)-Ib–cr at 25.7 %. QnrA, qnrD, qebA, and qnrC were not detected among the isolates. Aac (3′)-II, aac (6′)-Ib, aph (3′)-VI, armA, qnrB, qnrS, and acc(6′)-Ib–cr were significantly associated with non-susceptibility to aminoglycosides, quinolones, and beta-lactams. Among 27 randomly selected K. pneumoniae isolates, the most common sequence type was ST2096, followed by ST348 and ST1207. Overall, 19 sequence types were observed, confirming a high level of genetic diversity among the isolates. High percentages of non-susceptibility to the studied antimicrobials were found and were associated with the presence of several resistance genes. Similar studies should be periodically carried out to monitor changes in the prevalence of resistance phenotypes and genotypes of isolates.

Extended-Spectrum Beta-Lactamases Genes in Klebsiella pneumoniae Isolates Obtained from Patients in Intensive Care Units

Background: Drug-resistant hospital-acquired infections (HAIs) are a growing concern in modern medicine throughout the world. Klebsiella pneumoniae is one of the most prominent causative agents of multidrug-resistant nosocomial infections. It is also widely recognized for having a high resistance level to many antibiotic classes, particularly beta-lactams. Carbapenemase-producing K. pneumoniae has been identified as a major global cause of HAIs with adverse clinical outcomes. Therefore, it is of the utmost importance to have an in-depth understanding of the antimicrobial resistance (AMR) genetic determinants of this bacterium to stop the spread of highly resistant K. pneumoniae in healthcare facilities and the resulting patient morbidity and mortality. Objectives: This study aimed to investigate the AMR pattern of K. pneumoniae isolates obtained from intensive care units (ICUs), with a focus on extended-spectrum beta-lactamases (ESBLs) genes blaCTX-M, blaGES, and blaIMP. Methods: A total of 105 K. pneumoniae isolates obtained from the sputum samples of ICU patients were identified and confirmed using standard microbiological tests and 16S rRNA polymerase chain reaction (PCR). The antibiotic susceptibility test was performed for all the isolates. The presence of ESBL genes was determined phenotypically and by PCR. Results: The highest level of resistance was observed against ceftazidime (100%), cefotaxime (99%), and imipenem (93.3%). Approximately 87.6% and 39% of the isolates were sensitive to colistin and gentamicin, respectively. Phenotypic ESBL production was observed in 16 isolates, and the prevalence of blaCTX-M was 86.7%. No blaGES and blaIMP genes were detected. Conclusions: Periodic investigation of AMR-mediating genes is essential due to the high prevalence of ESBL genes in HAIs. The presence of other ESBL genes needs to be investigated for a more accurate understanding of the AMR status of K. pneumoniae in healthcare settings.

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.