# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 1039 | 0 | 1.0000 | Genetic Investigation of Beta-Lactam Associated Antibiotic Resistance Among Escherichia Coli Strains Isolated from Water Sources. BACKGROUND: Antimicrobial resistance is an important factor threatening human health. It is widely accepted that antibiotic resistant bacteria such as Escherichia coli (E. coli) released from humans and animals into the water sources, can introduce their resistance genes into the natural bacterial community. OBJECTIVE: The aim of this study was to investigate the prevalence of bla(TEM), bla(CTX), bla(SHV), bla(OXA) and bla(VEB) associated-antibiotic resistance among E. coli bacteria isolated from different water resources in Iran. METHODS: The study contained all E. coli strains segregated from different surface water sources. The Kirby-Bauer method and combined discs method was determined in this study for testing antimicrobial susceptibility and strains that produced Extended-Spectrum Beta Lactamases (ESBL), respectively. DNA extraction kit was applied for genomic and plasmid DNA derivation. Finally the frequency of resistant genes including bla(TEM), bla(CTX), bla(SHV), bla(OXA) and bla(VEB) in ESBL producing isolates were studied by PCR. RESULTS: One hundred E. coli strains were isolated and entered in the study. The highest antibiotic resistance was observed on clindamycin (96%). Moreover, 38.5% isolates were ESBL producers. The frequency of different ESBLs genes were 37%, 27%, 27%, and 25% for bla(TEM), bla(CTX), bla(SHV), and bla(OXA) , respectively. The bla(VEB) wasn't found in any isolates. CONCLUSION: The study revealed a high prevalence of CTX-M, TEM, SHV and OXA genes among E. coli strains in surface water resources. In conclusion, these results raised a concern regarding the presence and distribution of these threatening factors in surface water sources and its subsequent outcomes. | 2017 | 29151997 |
| 1038 | 1 | 0.9999 | Isolation of Extended Spectrum β-lactamase (ESBL) Producing Bacteria from Urban Surface Waters in Malaysia. BACKGROUND: This was a preliminary study to test for the presence of multiple antibiotic-resistant extended spectrum β-lactamase (ESBL) producing bacteria in Malaysian urban surface waters. Although the literature review revealed several published papers on clinical ESBL isolates in Malaysia, none were found on ESBL isolates obtained from local surface waters. METHODS: Isolated bacterial species were tested for resistance to cefotaxime, amoxicillin/clavulanate and aztreonam, and susceptibility to imipenem and meropenem using antibiotic susceptibility testing (AST) by disc diffusion. This served as a screening step to detect bacteria that could be potential ESBL species. 16S ribose ribonucleic acid (rRNA) polymerase chain reaction (PCR) testing with two clusters of bla (β-lactamase) gene primers was used to test for the bla genes CTX-M (Groups 1, 2, 9), OXA-1, SHV and TEM. RESULTS: A total of 19 isolates were found, possessing at least one of the bla genes tested for. There was a relatively high occurrence of CTX-M genes (84.2%) among these, followed by TEM genes (47.4%). The isolates were identified as Enterobacteriaceae (89.5%), predominantly Escherichia coli and Klebsiella pneumoniae. CONCLUSION: There appears to be a high occurrence of ESBL-bacteria in local surface waters, among these being opportunistic pathogens. The persistence and spread of these species in the environment poses a threat to exposed human populations. | 2013 | 23966820 |
| 1014 | 2 | 0.9999 | Contamination of retail market meat with extended-spectrum beta-lactamase genes in Vietnam. The contamination of retail meat with antibiotic-resistant bacteria poses a substantial public health risk because of the potential spread of these bacteria within communities. The contamination of retail meat with extended-spectrum beta-lactamase (ESBL)-producing bacteria was investigated in four cities in Vietnam using real-time PCR, employing ESBL marker genes. This method provides a more comprehensive assessment of ESBL-producing bacterial contamination in meat samples than culture-based methods because it directly detects resistance genes from the extracted sample DNA. Retail meats in Vietnam were substantially contaminated with ESBL genes [54 % (n = 46) and 48 % (n = 49) of chicken and pork samples, respectively]. No significant differences in ESBL gene detection rates were observed between chicken and pork. The most frequently detected ESBL gene was blaTEM, followed by blaSHV, whereas blaCTX-M was found in only 4-8 % of the samples. Ho Chi Minh City showed significantly higher contamination rates for both chicken and pork than those in other cities. ESBL-producing Escherichia coli strains were isolated from contaminated meat samples and genomically analyzed. All isolated strains carried blaCTX-M, with some harboring blaTEM, whereas blaSHV was not detected. Although IncFIB plasmids were prevalent among the ESBL-producing E. coli strains, the variability in resistance gene profiles suggested that the endemic spread of specific resistance gene-carrying plasmids was unlikely. Overall, these findings highlight the effectiveness of the ESBL gene detection method and the high levels of ESBL-producing E. coli in retail meat. | 2025 | 39827751 |
| 1019 | 3 | 0.9999 | First Report of OXA-48 and IMP Genes Among Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Isolates from Diarrheic Calves in Tunisia. Antimicrobial resistance is one of the most serious threats to human and animal health. Evidence suggests that the overuse of antimicrobial agents in animal production has led to the emergence and dissemination of multidrug-resistant isolates. The objective of this study was to assess the rate of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in calf feces and to characterize their resistance genes for antibiotics like beta-lactams and colistin, but also to determine their virulence genes. Fecal samples were collected from 100 diarrheic calves in the region of Bizerte, Tunisia. After isolation, E. coli isolates were screened for antimicrobial resistance against 21 antibiotics by the disc diffusion method. Characterization of β-lactamase genes and determination of associated resistance genes were performed by polymerase chain reaction. Among 71 E. coli isolates, 26 (36.6%) strains were ESBL-producing. Most of these isolates were multidrug-resistant (92.3%) and the most prevalent beta-lactamase genes detected were bla(CTX-M) (n = 26), bla(SHV) (n = 11), and bla(TEM) (n = 8), whereas only 1 isolate carried the bla(CMY) gene. In addition, resistance to carbapenems was detected in two isolates; one of them harbored both bla(OXA-48) and bla(IMP) genes and the other isolate carried only the bla(IMP) gene. Several resistance genes were identified for the first time in Tunisia from cases of diarrheic calves. Furthermore, to the best of our knowledge, this is the first report of detection and identification of carbapenem resistance genes and virulence genes from calves in North Africa. A high occurrence of antimicrobial resistance of E. coli recovered from fecal samples of calves with diarrhea was observed, highlighting the need for prudent use of antimicrobial agents in veterinary medicine to decrease the incidence of multidrug-resistant bacteria for both animals and humans. | 2023 | 36695709 |
| 980 | 4 | 0.9999 | Phenotypic and Molecular Characterization of Extended-Spectrum β-Lactamase, Plasmid-Mediated- AmpC, and Carbapenemase-Producing Enterobacteriaceae Isolated from Companion and Production Animals in Brazil. The crisis of bacterial resistance is an emerging One Health challenge, driven by the overuse of antimicrobials in medical and agricultural settings. This study aimed to investigate extended-spectrum β-lactamase (ESBL), Ampicillinase (AmpC), and carbapenemase production, and the presence of genes encoding these enzymes in Escherichia coli, Klebsiella spp., and Proteus spp., major contributors to infections and resistance isolates from animals. From 2016 to 2021, 130 multidrug-resistant (MDR) or extensively drug-resistant (XDR) isolates were recovered from the secretions, excretions, and organs of companion and production animals with active infections. Antibacterial sensitivity tests, along with phenotypic and genotypic detection of resistance enzymes, were performed. To the best of our knowledge, this is the first study in Brazil to estimate the prevalence of XDR Enterobacteriales isolated from companion and production animals, which accounted for 13.8% of the strains. Statistically significant differences (P < 0.05) in resistant bacteria between different classes and within the same class of antibacterial bacteria were found. The statistical probability between genotypic detection of ESBL (OR = 3.1) and phenotypic tests for AmpC (OR = 2.3) was also established. Approximately 32.3%, 17.6%, and 16.8% of the strains had positive phenotypic tests for ESBL, AmpC, and carbapenemases, respectively. Genetic analysis revealed the presence of bla(CTX-M) (60.0%), bla(AmpC) (9.18%), bla(KPC-2) (0.76%), and bla(NDM) (1.52%). AmpC genes were identified in 8.46% of the samples, with bla(CMY) being the most frequent (6.92%), followed by bla(DHA) (0.77%), and bla(FOX) (0.77%). The sequenced amplicons were deposited in NCBI. This study reveals critical data on Enterobacteriaceae with antibacterial resistance genes isolated from animals and may pose a significant threat to One health. | 2025 | 39903315 |
| 1012 | 5 | 0.9999 | Antimicrobial resistance profile and prevalence of extended-spectrum beta-lactamases (ESBL), AmpC beta-lactamases and colistin resistance (mcr) genes in Escherichia coli from swine between 1999 and 2018. The frequent usage of antibiotics in livestock has led to the spread of resistant bacteria within animals and their products, with a global warning in public health and veterinarians to monitor such resistances. This study aimed to determine antibiotic resistance patterns and genes in pig farms from Spain during the last twenty years. Susceptibility to six antibiotics commonly used in pig production was tested by qualitative (disk diffusion) and quantitative (minimum inhibitory concentration, MIC) methods in 200 strains of Escherichia coli which had been isolated between 1999 and 2018 from clinical cases of diarrhoea in neonatal and post-weaned piglets. Results showed resistance around 100% for amoxicillin and tetracycline since 1999, and a progressive increase in ceftiofur resistance throughout the studied period. For colistin, it was detected a resistance peak (17.5% of the strains) in the 2011-2014 period. Concerning gentamicin, 11 of 30 strains with intermediate susceptibility by the disk diffusion method were resistant by MIC. Besides, the most frequent antimicrobial resistance genes were the extended-spectrum beta-lactamase (ESBL) bla (CTX-M) (13.5% of strains, being CTX-M-14, CTX-M-1 and CTX-M-32 the most prevalent genomes, followed by CTX-M-27, CTX-M-9 and CTX-M-3), AmpC-type beta-lactamase (AmpC) bla (CMY-2) (3%) and colistin resistance genes mcr-4 (13%), mcr-1 (7%) and in less proportion mcr-5 (3%). Interestingly, these mcr genes were already detected in strains isolated in 2000, more than a decade before their first description. However, poor concordance between the genotypic mcr profile and the phenotypical testing by MIC was found in this study. These results indicate that although being a current concern, resistance genes and therefore antimicrobial resistant phenotypes were already present in pig farms at the beginning of the century. | 2020 | 32266079 |
| 1018 | 6 | 0.9999 | Antimicrobial Resistance and Prevalence of Extended Spectrum β-Lactamase-Producing Escherichia coli from Dogs and Cats in Northeastern China from 2012 to 2021. (1) Background: there has been a growing concern about pet-spread bacterial zoonosis in recent years. This study aimed to investigate the trend in drug-resistance of canine Escherichia coli isolates in northeast China between 2012-2021 and the differences in drug-resistance of E. coli of different origins in 2021. (2) Methods: E. coli were isolated from feces or anal swab samples from dogs and cats, and their antibiotic susceptibility profiles and phylogenetic grouping were identified. PCR was applied on the extended spectrum β-lactamase (ESBL) E. coli for antibiotic resistance genes. (3) Results: five hundred and fifty-four E. coli isolates were detected in 869 samples (63.75%). The multidrug resistance (MDR) rates of E. coli in pet dogs showed a decreasing trend, but working dogs showed the opposite trend. Resistance genes bla(CTX-M) and bla(CTX-M+TEM) were dominant among the ESBL producers (n = 219). The consistency between the resistance phenotypes and genes was high except for fluoroquinolone-resistant ESBL E. coli. All ESBL E. coli-carrying bla(NDM) were isolated from working dogs, and one of the strains carried mcr-1 and bla(NDM-4). Phylogroup B2 was the dominant group in pet cats, and more than half of the isolates from companion cats were ESBL E. coli. (4) Conclusions: the measures taken to reduce resistance in China were beginning to bear fruit. Companion cats may be more susceptible to colonization by ESBL E. coli. The problem of resistant bacteria in working dogs and pet cats warrants concern. | 2022 | 36358160 |
| 1020 | 7 | 0.9999 | Prevalence and characteristics of Escherichia coli strains producing extended-spectrum β -lactamases in slaughtered animals in the Czech Republic. Resistance of bacteria to antibiotics is a global medical problem requiring close cooperation between veterinary and human physicians. Raw materials and foods of animal origin may be not only a source of pathogenic bacteria causing alimentary tract infections but also a source of bacteria with a dangerous extent of resistance to antibiotics, potentially entering the human food chain. This article presents results of the first study in the Czech Republic detecting the presence of Enterobacteriaceae-producing extended-spectrum b -lactamases (ESBLs) in swabs collected in slaughterhouses from surfaces of healthy animal carcasses. In 2012, swabs taken from pig (n = 166) and cattle (n = 140) carcass surfaces were analyzed. In 17 % of 53 studied slaughterhouses, ESBL-producing Escherichia coli strains were isolated. ESBLs were found in 11 and 4 % of porcine and bovine samples, respectively. Swabs collected from pigs yielded 18 ESBL-producing E. coli strains. The bla genes were found to encode production of CTX-M-1 group enzymes in 16 strains, SHV in one case, and both CTX-M-1-like and TEM in another case. In swabs taken from cattle, five ESBL-producing E. coli strains were isolated. In three cases, the bla genes for CTX-M-1-like production were identified; in two cases, genes for both CTX-M-1-like and TEM production were found. The similarity/identity of ESBL-positive isolates was compared by pulsed-field gel electrophoresis. This is the first report and characterization of the presence and nature of ESBL-producing E. coli in swabs collected from surfaces of healthy pig and cattle carcasses in slaughterhouses in the Czech Republic. | 2013 | 24112579 |
| 1005 | 8 | 0.9999 | Prevalence and Characterization of Beta-Lactam and Carbapenem-Resistant Bacteria Isolated from Organic Fresh Produce Retailed in Eastern Spain. Fresh fruits and vegetables are potential reservoirs for antimicrobial resistance determinants, but few studies have focused specifically on organic vegetables. The present study aimed to determine the presence of third-generation cephalosporin (3GC)- and carbapenem-resistant Gram-negative bacteria on fresh organic vegetables produced in the city of Valencia (Spain). Main expanded spectrum beta-lactamase (ESBL)- and carbapenemase-encoding genes were also detected in the isolates. One hundred and fifteen samples were analyzed using selective media supplemented with cefotaxime and meropenem. Resistance assays for twelve relevant antibiotics in medical use were performed using a disc diffusion test. A total of 161 isolates were tested. Overall, 33.5% presented multidrug resistance and 16.8% were resistant to all β-lactam antibiotics tested. Imipenem resistance was observed in 18% of isolates, and low resistance levels were found to ceftazidime and meropenem. Opportunistic pathogens such as Acinetobacter baumannii, Enterobacter spp., Raoultella sp., and Stenotrophomonas maltophilia were detected, all presenting high rates of resistance. PCR assays revealed bla(VIM) to be the most frequently isolated ESBL-encoding gene, followed by bla(TEM) and bla(OXA-48). These results confirm the potential of fresh vegetables to act as reservoirs for 3GC- and carbapenem-producing ARB. Further studies must be carried out to determine the impact of raw organic food on the spread of AMRs into the community. | 2023 | 36830297 |
| 902 | 9 | 0.9999 | Occurrence of IMP-8, IMP-10, and IMP-13 metallo-β-lactamases located on class 1 integrons and other extended-spectrum β-lactamases in bacterial isolates from Tunisian rivers. BACKGROUND: Antibiotic-resistant bacteria have been surveyed widely in water bodies, but few studies have determined the diversity of antibiotic-resistant bacteria in river waters. This study was undertaken to investigate the origin of resistance among polluted river bacterial isolates in Tunisia. METHODS: In this study 128 isolates resistant to β-lactam antibiotics were obtained from 2 polluted rivers in the north of Tunisia. Isolates were identified using Phoenix phenotyping criteria. The occurrence of bla(TEM), bla(SHV), bla(CTX-M), bla(CMY), bla(VIM), and bla(IMP) was studied by polymerase chain reaction (PCR) amplification and sequencing, and the genetic relatedness of the 16 IMP-producing Klebsiella pneumoniae isolates was analyzed by comparison of XbaI pulsed-field gel electrophoresis (PFGE) profiles. RESULTS: Using Phoenix phenotyping criteria, diverse genera of bacteria were identified with different rates of prevalence and with different minimum inhibitory concentrations against different antibiotics. The occurrence of bla(TEM), bla(SHV), bla(CTXM), bla(CMY), bla(VIM), and bla(IMP) genes was confirmed. The DNA sequences upstream and downstream of bla(IMP) genes were determined, revealing that all IMP-encoding genes constituted the first cassette of class 1 integrons, followed by aacA gene cassettes encoding aminoglycoside resistance. Comparison of PFGE profiles showed that only 2 of the isolates were clonal, the other 14 displaying unique profiles. The bla(CTX-M) gene was the most dominant of the extended-spectrum β-lactamase (ESBL) genes, while the bla(TEM) gene was the second-most dominant. CONCLUSION: The discovery of highly diverse ESBL-producing bacteria and metallo-β-lactamases, particularly bla(IMP), in polluted river water raises alarms with regard to the potential dissemination of antibiotic-resistant bacteria in communities through river environments. | 2013 | 22992193 |
| 1033 | 10 | 0.9999 | Antimicrobial Resistance and β-Lactamase Production in Clinically Significant Gram-Negative Bacteria Isolated from Hospital and Municipal Wastewater. Hospital and municipal wastewater contribute to the spread of antibiotic-resistant bacteria and genes in the environment. This study aimed to examine the antibiotic resistance and β-lactamase production in clinically significant Gram-negative bacteria isolated from hospital and municipal wastewater. The susceptibility of bacteria to antibiotics was tested using the disk diffusion method, and the presence of extended-spectrum β-lactamases (ESBL) and carbapenemases was determined using an enzyme inhibitor and standard multiplex PCR. Analysis of antimicrobial resistance of total bacterial strains (n = 23) revealed that most of them were resistant to cefotaxime (69.56%), imipenem (43.47%), meropenem (47.82%) and amoxicillin-clavulanate (43.47%), gentamicin (39.13%), cefepime and ciprofloxacin (34.78%), trimethoprim-sulfamethoxazole (30.43%). A total of 8 of 11 phenotypically confirmed isolates were found to have ESBL genes. The bla(TEM) gene was present in 2 of the isolates, while the bla(SHV) gene was found in 2 of the isolates. Furthermore, the bla(CTX-M) gene was found in 3 of the isolates. In one isolate, both the bla(TEM) and bla(SHV) genes were identified. Furthermore, of the 9 isolates that have been phenotypically confirmed to have carbapenemase, 3 were confirmed by PCR. Specifically, 2 isolates have the bla(OXA-48) type gene and 1 have the bla(NDM-1) gene. In conclusion, our investigation shows that there is a significant rate of bacteria that produce ESBL and carbapenemase, which can promote the spread of bacterial resistance. Identifying ESBL and carbapenemase production genes in wastewater samples and their resistance patterns can provide valuable data and guide the development of pathogen management strategies that could potentially help reduce the occurrence of multidrug resistance. | 2023 | 37107015 |
| 1017 | 11 | 0.9999 | Evaluation of canine raw food products for the presence of extended-spectrum beta-lactamase- and carbapenemase-producing bacteria of the order Enterobacterales. OBJECTIVE: To assess the potential contamination of commercial raw dog food products with bacteria of the Enterobacterales order that produce extended spectrum beta-lactamase (ESBL) and carbapenemase enzymes, determine risk factors for contamination, and understand isolate genetic diversity. SAMPLES: A total of 200 canine raw food products. METHODS: Products were cultured on selective chromogenic agar following enrichment steps. Whole-genome sequencing was performed for isolates that were confirmed to produce an ESBL. Isolates were characterized by antimicrobial resistance genes, and multilocus sequences typing, and compared to other isolates in the NCBI database for clonality. Preservation method and protein sources were assessed as potential risk factors for contamination with ESBL and carbapenemase-producing bacteria of the Enterobacterales order. RESULTS: No carbapenemase-producing Enterobacterales (CPE) were identified, but ESBL-producing Enterobacterales bacteria were isolated from 20/200 products (10.0%; 95% CI, 7.3 to 16.5%), all of which were frozen. Pork-derived protein source products were 8.1 times (P = .001; 95% CI, 2.53 to 26.2) more likely to carry ESBL-producing Enterobacterales bacteria than other protein sources. WGS analysis confirmed the presence of ESBL genes in a total of 25 distinct isolates (19 Escherichia coli, 5 Klebsiella pneumoniae, and 1 Citrobacter braakii). Genes encoding CTX-M type ESBL enzymes were the most common (24/25 isolates, 96.0%) with blaCTX-M-27 being the most common allele (8/25, 32.0%). CLINICAL RELEVANCE: Frozen, raw food products may serve as a route of transmission of ESBL-producing Enterobacterales bacteria to companion animals. Veterinarians should advise owners about the risks of raw food diets, including potential exposure to antimicrobial-resistant bacteria. | 2022 | 35895774 |
| 903 | 12 | 0.9999 | Carbapenemase and ESBL genes with class 1 integron among fermenting and nonfermenting bacteria isolated from water sources from India. The present study was aimed to detect the carbapenemase, extended-spectrum β-lactamase (ESBL), and intI1 gene of class 1 integron among fermenting (n = 61) and nonfermenting (n = 10) bacterial isolates recovered from water samples (n = 128). Isolates were identified by 16S rRNA sequencing. These isolates showed reduced-susceptibility to third-generation cephalosporins and carbapenems. The isolates varied in number and size of plasmids (2 kb to >20 kb). Plasmid DNA screening showed 5·6, 7, 11·2 and 26·7% prevalence of bla(KPC) , bla(NDM) , bla(SHV) and bla(TEM) genes respectively. Diverse bla(NDM) (bla(NDM-1) and bla(NDM-4) ) and bla(SHV) subtypes (bla(SHV-2) and bla(SHV-11) ) were recorded, unlike the single allelic bla(KPC) (bla(KPC-2) ) and bla(TEM) (bla(TEM-1) ) gene. Of the total 27 bla-gene-producing bacterial isolates, seven isolates co-harboured the carbapenemase genes (bla(NDM) or bla(KPC) or the both) along with the ESBL genes (bla(SHV) or bla(TEM) ). The intI1 gene of class 1 integron was detected among 12 (44·4%) of ESBL- and/or carbapenemase-harbouring isolates. Gene transferability was seen among four of the 10 Enterobacteriaceae donors. Carbapenemases and ESBLs with class 1 integron among aquatic environmental isolates raise the serious issue of the biosecurity and health of the ecosystem. SIGNIFICANCE AND IMPACT OF THE STUDY: Anthropologically affected and polluted environment harbours the resistance threats, where a diverse bacterial species maintain, develop and exchange genetic determinants that constitute a risk to human and ecological health. The antimicrobial resistance (AMR) in Enterobacteriaceae and non-Enterobacteriaceae bacteria caused the failure of the therapy of last resort (carbapenems) and thus lead to life-threatening infections affecting public health. Surveillance and monitoring of AMR could be important for epidemiological, diagnostic testing and control of pathogens. This is a point-prevalence study reporting the comparative occurrence and co-occurrence of carbapenemase and extended-spectrum β-lactamase genes among fermenting and nonfermenting bacteria isolated from the aquatic environment in India. | 2020 | 31587338 |
| 1015 | 13 | 0.9999 | Antimicrobial-resistant and extended-spectrum β-lactamase-producing Escherichia coli in raw cow's milk. The occurrence of antimicrobial-resistant bacteria is an important public health issue. The aim of this study was the monitoring of resistant Escherichia coli in raw cow's milk with a focus on the detection of extended-spectrum β-lactamase (ESBL)-producing strains. In total, 263 samples of raw milk from 40 farms were collected and investigated in 2010 to 2013 in the Czech Republic. Detection of E. coli was performed and evaluated according to ISO 16649-2, and antibiotic resistance was screened by the disk diffusion method. The presence of E. coli was detected in 243 (92.4%) samples. In total, 270 isolates were obtained. Resistance to β-lactam (31.8%) and tetracycline (13.0%) antibiotics was detected most often and also multiresistant strains (5.5%) were observed. E. coli isolates found to be resistant to β-lactam, tetracycline, and quinolone antibiotics were assayed by PCR to detect selected genes encoding those resistance mechanisms. In isolates in which any bla genes were detected, a double-disk synergy test was performed. ESBL production was confirmed in 2 (0.7%) isolates. The genetic analysis identified the presence of the blaCTX-M gene and other resistance genes (tet(B) and qnrB). Both ESBL-positive isolates originated from the same farm and had an identical pulsed-field gel electrophoresis profile. The findings of our study indicate that milk can be a reservoir of bacteria carrying resistance genes with a potential for spreading through the food chain. | 2015 | 25581180 |
| 1016 | 14 | 0.9999 | Investigation of CTX-M Type Extended-Spectrum β-Lactamase, Carbapenem and Colistin Resistance in Enterobacterales Isolated From Dairy Cattle in Turkey. BACKGROUND: The increasing prevalence of antimicrobial resistance in animals, particularly the spread of multidrug-resistant Enterobacterales, poses a significant zoonotic and public health risk. OBJECTIVE: The aim of this study was to investigate extended-spectrum β-lactamase (ESBL), carbapenem and colistin resistance among Enterobacterales in faecal swabs of dairy cattle. METHODS: A total of 400 samples were cultured on Mac Conkey screening media for ESBL, carbapenem and colistin resistance. The grown Enterobacterales were identified by MALDI-TOF-MS, followed by ceftriaxone, cefotaxime and ceftazidime resistance and double disk synergy. ESBL resistance genes were identified by polymerase chain reaction (PCR) and Sanger sequencing. Bacteria grown on colistin screening media were investigated for colistin resistance by EUCAST microbroth dilution method. RESULTS: A total of 89 (22.25%) of the bacteria grown from 400 samples were identified as potential ESBL-producing Enterobacterales members. A number of 53 (59.5%) of them were identified as ESBL blaCTX-M as a result of PCR, and 10 of them were identified as blaCTX-M-15/28/36/66 as a result of sequencing. None of the samples cultured on carbapenem medium grew. A total of 18 samples grown in colistin medium were found to be colistin sensitive by broth microdilution. Genotypes were not included in the study. All isolated bacteria were identified as Escherichia coli. SOLUTION: In this study, blaCTX-M-15 and its derivatives, which are common in humans, were also found to be the predominant ESBL type in animals. Monitoring resistance in animals together with resistance in human infections may provide more important data on the spread of resistance. | 2025 | 40704983 |
| 1037 | 15 | 0.9999 | Genetic Background of β-Lactamases in Enterobacteriaceae Isolates from Environmental Samples. The prevalence of β-lactamase-producing Enterobacteriaceae has increased worldwide. Although antibiotic-resistant bacteria are usually associated with hospitals, there are a growing number of reports of resistant bacteria in other environments. Concern about resistant microorganisms outside the hospital setting highlights the need to investigate mechanisms of antibiotic resistance in isolates collected from the environment. The present study evaluated the resistance mechanism to β-lactam antibiotics in 40 isolates from hospital sewage and surface water from the Dilúvio Stream, Porto Alegre City, Southern Brazil. The multiplex PCR technique was used to detect several resistance genes of β-lactamases: extended-spectrum β-lactamases (ESBLs), carbapenemases, and β-lactamase AmpC. After genes, detection amplicons were sequenced to confirm their identification. The clonal relationship was established by DNA macrorestriction using the XbaI enzyme, followed by pulsed-field gel electrophoresis (PFGE). The results indicated that resistance genes were present in 85% of the isolates. The most prevalent genes encoded narrow-spectrum β-lactamase, such as TEM-1 and SHV-1 with 70% of the strains, followed by carbapenemase KPC and GES (45%), ESBL types SHV-5 and CTX-M-8 (27.5%), and AmpC (ACT-1/MIR-1) (2.5%). Twelve isolates contained only one resistance gene, 14 contained two, and eight isolates had three resistance genes. PFGE indicated a clonal relationship among K. pneumoniae isolates. It was not possible to establish a clonal relationship between Enterobacter sp. isolates. The results highlight the potential of these resistance genes to spread in the polluted environment and to present a health risk to communities. This report is the first description of these resistance genes present in environmental samples other than a hospital in the city of Porto Alegre/RS. | 2017 | 28378066 |
| 1026 | 16 | 0.9999 | Analysis of Wastewater Reveals the Spread of Diverse Extended-Spectrum β-Lactamase-Producing E. coli Strains in uMgungundlovu District, South Africa. Wastewater treatment plants (WWTPs) are major reservoirs of antibiotic-resistant bacteria (ARB), favouring antibiotic resistance genes (ARGs) interchange among bacteria and they can provide valuable information on ARB circulating in a community. This study characterised extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli from the influent and effluent of four WWTPs in uMgungundlovu District, KwaZulu-Natal, South Africa. E. coli was enumerated using the membrane filtration method and confirmed using the API 20E test and real-time polymerase chain reaction. ESBL-producers were phenotypically identified by their susceptibility to the third-generation cephalosporins using the disc diffusion and the double-disc synergy methods against cefotaxime (30 µg) with and without 10 µg clavulanic acid. Genotypic verification was by PCR of the TEM, SHV, and CTX-M genes. The clonality of isolates was assessed by ERIC-PCR. The highest E. coli count ranged between 1.1 × 10(5) (influent) and 4.3 × 10(3) CFU/mL (effluent). Eighty pure isolates were randomly selected, ten from the influent and effluent of each of the four WWTP. ESBLs were phenotypically confirmed in 49% (n = 39) of the isolates, of which 77% (n = 30) were genotypically confirmed. Seventy-three percent of the total isolates were multidrug-resistant (MDR). Only two isolates were susceptible to all antibiotics. Overall, resistance to first and second-generation cephalosporins was higher than to third and fourth generation cephalosporins. Also, 15% of the isolates were resistant to carbapenems. The CTX-M-type ESBL (67%; n = 20) was the most common ESBL antibiotic resistance gene (ARG) followed by TEM (57%; n = 17) and SHV-types (27%; n = 8). Also, a substantial number of isolates simultaneously carried all three ESBL genes. ERIC-PCR revealed a high diversity of isolates. The diversity of the isolates observed in the influent samples suggest the potential circulation of different ESBL-producing strains within the studied district, requiring a more comprehensive epidemiological study to prevent the spread of ESBL-producing bacteria within impoverished communities. | 2021 | 34356780 |
| 1047 | 17 | 0.9999 | Biofilm formation and antibiotic resistance profiles of water-borne pathogens. Water sources (surface water, drinking water, rivers, and ponds) are significant reservoirs for transmitting antibiotic-resistant bacteria. In addition, these waters are an important public health problem because they are suitable environments for transferring antibiotic resistance genes between bacterial species. Our study aimed to assess the prevalence of Extended-spectrum beta-lactamase (ESBL) producing isolates in water samples, the susceptibility of the isolates to the specified antibiotics, the determination of biofilm ability, antibiotic resistance genes, and the molecular typing of the isolates. For this purpose, Polymerase chain reaction (PCR) and Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) analyses were used. Out of 70 isolates, 15 (21%) were ESBL producing, and sent for the MALDI-TOF analysis, where Escherichia coli, Acinetobacter calcoaceticus, Enterobacter bugandensis, Acinetobacter pittii, Pseudomonas aeruginosa, Acinetobacter junii, Pseudomonas oleovorans, and Enterobacter ludwigigii were identified. Moreover, colistin resistance genes (mcr 1/2/6, mcr 4, mcr 5, mcr 3/7, and mcr 8), ESBL-encoding genes (bla(SHV), bla(TEM), and bla(CTX-M)) and carbapenemase genes (bla(NDM), bla(OXA-48), and bla(KPC)) using molecular analysis (PCR) were confirmed. The colistin resistance gene was detected at 80% (12/15) in the isolates obtained. The distribution of these isolates according to resistance genes was found as mcr 1/2/6 4 (20%), mcr 3/7 3 (13%), and mcr 5 (40%). Additionally, the isolates harbored bla(SHV)(6.6%) and bla(TEM) (6.6%) genes. However, bla(NDM), bla(OXA-48), bla(KPC), and bla(CTX-M) genes were not detected in any isolates. According to the Congo red agar method, seven (46.6%) isolates showed negative biofilm ability, and eight (53.3%) showed moderate biofilm ability. However, the microplate method detected weak biofilm in 53.3% of the isolates. In conclusion, this study provides evidence for the existence of multidrug-resistant bacteria that co-exist with mcr and ESBL genes in water sources. These bacteria can migrate to other environments and pose increasing threats to public health. | 2023 | 37004897 |
| 1025 | 18 | 0.9999 | Detection of Extended Spectrum Beta-Lactamases Resistance Genes among Bacteria Isolated from Selected Drinking Water Distribution Channels in Southwestern Nigeria. Extended Spectrum Beta-Lactamases (ESBL) provide high level resistance to beta-lactam antibiotics among bacteria. In this study, previously described multidrug resistant bacteria from raw, treated, and municipal taps of DWDS from selected dams in southwestern Nigeria were assessed for the presence of ESBL resistance genes which include bla TEM, bla SHV, and bla CTX by PCR amplification. A total of 164 bacteria spread across treated (33), raw (66), and municipal taps (68), belonging to α-Proteobacteria, β-Proteobacteria, γ-Proteobacteria, Flavobacteriia, Bacilli, and Actinobacteria group, were selected for this study. Among these bacteria, the most commonly observed resistance was for ampicillin and amoxicillin/clavulanic acid (61 isolates). Sixty-one isolates carried at least one of the targeted ESBL genes with bla TEM being the most abundant (50/61) and bla CTX being detected least (3/61). Klebsiella was the most frequently identified genus (18.03%) to harbour ESBL gene followed by Proteus (14.75%). Moreover, combinations of two ESBL genes, bla SHV + bla TEM or bla CTX + bla TEM, were observed in 11 and 1 isolate, respectively. In conclusion, classic bla TEM ESBL gene was present in multiple bacterial strains that were isolated from DWDS sources in Nigeria. These environments may serve as foci exchange of genetic traits in a diversity of Gram-negative bacteria. | 2016 | 27563674 |
| 1611 | 19 | 0.9999 | Molecular Typing of Enterobacteriaceae from Pig Holdings in North-Western Germany Reveals Extended- Spectrum and AmpC β-Lactamases Producing but no Carbapenem Resistant Ones. The increase of extended- spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) in humans and in food-producing animals is of public health concern. The latter could contribute to spreading of these bacteria or their resistance genes to humans. Several studies have reported the isolation of third generation cephalosporin resistant bacteria in livestock animals. However, the number of samples and the methodology used differ considerably between studies limiting comparability and prevalence assessment. In the present study, a total of 564 manure and dust samples were collected from 47 pig farms in Northern Germany and analysed to determine the prevalence of ESBL-E. Molecular typing and characterization of resistance genes was performed for all ESBL-E isolates. ESBL-E isolates were found in 55.3% of the farms. ESBL-Escherichia coli was found in 18.8% of the samples, ESBL-Klebsiella pneumoniae in 0.35%. The most prevalent ESBL genes among E. coli were CTX-M-1 like (68.9%), CTX-M-15 like (16%) and CTX-M-9 group (14.2%). In 20% of the latter two, also the OXA-1 like gene was found resulting in a combination of genes typical for isolates from humans. Genetic relation was found between isolates not only from the same, but also from different farms, with multilocus sequence type (ST) 10 being predominant among the E. coli isolates. In conclusion, we showed possible spread of ESBL-E between farms and the presence of resistance genes and STs previously shown to be associated with human isolates. Follow-up studies are required to monitor the extent and pathways of ESBL-E transmission between farms, animals and humans. | 2015 | 26225428 |