# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 1045 | 0 | 1.0000 | ESBL-Producing Enterobacter cloacae Complex and Klebsiella pneumoniae Harbouring bla(CTX-M-15) and bla(CTX-M-55) Potentially Risk the Worldwide Spread of ESBL-Producing Bacteria Through Contaminated Dried Fishery Products. The transmission of life-threatening bacteria with plasmid-mediated antibiotic resistance poses a significant challenge to public health. This study aimed to determine the presence of plasmid-mediated antibiotic resistance genes in Enterobacterales isolates obtained from dried fishery products. Eighty-one dried fishery products were purchased from Vietnamese markets. Enterobacterales were isolated using a CHROMagar Escherichia coli coliform agar containing cefotaxime or meropenem. The isolated strains were assessed for their susceptibility to 14 antibiotics using a disc diffusion assay. Extended-spectrum β-lactamase (ESBL) sub-group typing was performed based on multiplex PCR of isolated ESBL-producing strains. In addition, Enterobacter cloacae AD2-1, which showed multiple drug resistance, was subject to whole-genome sequence analysis. CTX-resistant bacteria were isolated from 22% and MEM-resistant bacteria from 27% of the Vietnamese samples. CTX-resistant bacteria were isolated from 17% and MEM-resistant bacteria from 4% of Japanese samples. Bacterial identification indicated that 98 strains were isolated, of which 29 strains of E. coli, 28 of Enterobacter cloacae complex, 19 of Staphylococcus spp., and 9 of Klebsiella pneumoniae were predominant in Vietnamese samples. Japanese samples were predominantly contaminated with E. cloacae complex. Multiplex PCR and sequencing was used to determine the presence of ESBL-related genes bla(CTX-M-15) and bla(CTX-M-55) in E. cloacae and K. pneumoniae isolates. E. cloacae AD2-1 isolated from the Vietnamese dried fish was resistant to 14 antibiotics, and approximately 300 kbp of the IncHI2 plasmid harboured multiple antibiotic resistance genes and formed an antibiotic resistance gene region. This E. cloacae is considered a risk for the spread of antibiotic resistance across countries. | 2025 | 41171320 |
| 1046 | 1 | 0.9999 | Extended-spectrum β-lactamases producing multidrug resistance Escherichia coli, Salmonella and Klebsiella pneumoniae in pig population of Assam and Meghalaya, India. AIM: The present study was conducted to record the prevalence of extended spectrum β-lactamases (ESBLs) producing Escherichia coli, Salmonella spp., and Klebsiella pneumoniae from pig population of Assam and Meghalaya and to record the ability of the resistant bacteria to transfer the resistance genes horizontally. MATERIALS AND METHODS: Fecal samples (n=228), collected from pigs of Assam (n=99) and Meghalaya (n=129), were processed for isolation and identification of E. coli and Salmonella spp. All the isolates were tested for ESBLs production by double disc synergy test (DDST) followed by screening for ESBLs producing genes (bla(TEM), bla(SHV), bla(CTX-M), and bla(CMY)) by polymerase chain reaction (PCR). Possible transfer of resistance encoding genes between enteric bacterial species was carried out by in vitro and in vivo horizontal gene transfer (HGT) method. RESULTS: A total of 897 enteric bacteria (867 E. coli and 30 Salmonella) were isolated and identified. Altogether 25.41% isolates were confirmed as ESBL producers by DDST method. Majority of the isolates were E. coli followed by Salmonella. By PCR, 9.03% isolates were found positive for at least one of the target resistance genes. bla(SHV) was absent in all the isolates. bla(CMY) was the most prevalent gene. All the E. coli isolates from Assam were negative for bla(TEM). A total of 2.76% isolates were positive for bla(TEM) + bla(CMY). On the other hand, 0.67% isolates were positive for bla(CTX-M) + bla(CMY) genes. Only 0.33% isolates carried all the three genes. Altogether, 4.68% bacteria carried the resistance encoding genes in their plasmids. bla(TEM) gene could be successfully transferred from Salmonella (donor) to E. coli (recipient) by in vitro (5.5-5.7×10(-5)) and in vivo (6.5×10(-5) to 8.8×10(-4)) methods. In vivo method was more effective than in vitro in the transfer of resistance genes. CONCLUSION: The pig population of Assam and Meghalaya are carrying multidrug resistance and ESBLs producing E. coli and Salmonella. The isolates are also capable to transfer their resistance trait to other bacterial species by HGT. The present finding could be considered as a serious public health concern as similar trait can also be transmitted to the human commensal bacteria as well as pathogens. | 2018 | 30034183 |
| 1073 | 2 | 0.9999 | Occurrence of Extended Spectrum Cephalosporin-, Carbapenem- and Colistin-Resistant Gram-Negative Bacteria in Fresh Vegetables, an Increasing Human Health Concern in Algeria. The aim of this study was to screen for extended spectrum cephalosporin-, carbapenem- and colistin-resistant Gram-negative bacteria in fresh vegetables in Batna, Algeria. A total of 400 samples of fresh vegetables were collected from different retail stores. Samples were immediately subjected to selective isolation, then the representative colonies were identified using matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF-MS). Phenotypic and genotypic analyses were carried out in terms of species identification and relative antibiotic resistance. Transferability of the carbapenemase and mcr-bearing plasmids was verified by conjugation. The clonal relationships of carbapenemase and mcr-positive Escherichia coli isolates were studied by multi-locus sequence typing (MLST). Sixty-seven isolates were characterised and were mostly isolated from green leafy vegetables, where the dominant species identified included Citrobacter freundii, Klebsiella pneumoniae, Enterobacter cloacae, Stenotrophomona maltophilia, E. coli and Citrobacter braakii. PCR and sequencing results showed that E. coli was the bacterial species presenting the highest antibiotic resistance level in parallel to bla(TEM) (n = 16) and bla(CTX-M-15) (n = 11), which were the most detected genes. Moreover, five isolates carried carbapenemase genes, including the bla(OXA-48) and/or bla(VIM-4) genes. The mcr-1 gene was detected in two E. coli isolates. MLST analysis revealed three different E. coli sequence types: ST101 (n = 1), ST216 (n = 1) and ST2298 (n = 1). Conjugation assays confirmed the transferability of the bla(OXA-48) and mcr-1 genes. In this study we report, for the first time, the detection of the bla(OXA-48) gene in E. coli and C. braakii isolates and the bla(VIM-4) gene in vegetables. To the best of our knowledge, this is the first report on the detection of mcr-1 genes from vegetables in Algeria. | 2022 | 35892378 |
| 1049 | 3 | 0.9999 | Multiple Antibiotic-Resistant, Extended Spectrum-β-Lactamase (ESBL)-Producing Enterobacteria in Fresh Seafood. Members of the family Enterobacteriaceae include several human pathogens that can be acquired through contaminated food and water. In this study, the incidence of extended spectrum β-lactamase (ESBL)-producing enterobacteria was investigated in fresh seafood sold in retail markets. The ESBL-positive phenotype was detected in 169 (78.60%) isolates, with Escherichia coli being the predominant species (53), followed by Klebsiella oxytoca (27), and K. pneumoniae (23). More than 90% of the isolates were resistant to third generation cephalosporins, cefotaxime, ceftazidime, and cefpodoxime. Sixty-five percent of the isolates were resistant to the monobactam drug aztreonam, 40.82% to ertapenem, and 31.36% to meropenem. Resistance to at least five antibiotics was observed in 38.46% of the isolates. Polymerase Chain Reaction (PCR) analysis of ESBL-encoding genes detected bla(CTX), bla(SHV), and bla(TEM) genes in 76.92%, 63.3%, and 44.37% of the isolates, respectively. Multiple ESBL genes were detected in majority of the isolates. The recently discovered New Delhi metallo-β-lactamase gene (bla(NDM-1)) was detected in two ESBL⁺ isolates. Our study shows that secondary contamination of fresh seafood with enteric bacteria resistant to multiple antibiotics may implicate seafood as a potential carrier of antibiotic resistant bacteria and emphasizes an urgent need to prevent environmental contamination and dissemination of such bacteria. | 2017 | 28867789 |
| 1016 | 4 | 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 |
| 1053 | 5 | 0.9999 | Antimicrobial Resistance and Extended-Spectrum Beta-Lactamase Genes in Enterobacterales, Pseudomonas and Acinetobacter Isolates from the Uterus of Healthy Mares. Antibiotic-resistant bacteria are a growing concern for human and animal health. The objective of this study was to determine the antimicrobial resistance and extended-spectrum beta-lactamase genes in Enterobacterales, Pseudomonas spp. and Acinetobacter spp. isolates from the uterus of healthy mares. For this purpose, 21 mares were swabbed for samples, which were later seeded on blood agar and MacConkey agar. The isolates were identified using MALDI-TOF and the antimicrobial susceptibility test was performed using the Kirby-Bauer technique. To characterize the resistance genes, a polymerase chain reaction (PCR) scheme was performed. Of the isolates identified as Gram-negative, 68.8% were Enterobacterales, represented by E. coli, Enterobacter cloacae, Citrobacter spp., and Klebsiella pneumoniae; 28.1% belonged to the genus Acinetobacter spp.; and 3.1% to Pseudomonas aeruginosa. A 9.3% of the isolates were multidrug-resistant (MDR), presenting resistance to antibiotics from three different classes, while 18.8% presented resistance to two or more classes of different antibiotics. The diversity of three genes that code for ESBL (bla(TEM), bla(CTX-M) and bla(SHV)) was detected in 12.5% of the strains. The most frequent was bla(SHV), while bla(TEM) and bla(CTX-M) were present in Citrobacter spp. and Klebsiella pneumoniae. These results are an alarm call for veterinarians and their environment and suggest taking measures to prevent the spread of these microorganisms. | 2023 | 37764953 |
| 1118 | 6 | 0.9999 | Detection and characterization of extended-spectrum β-lactamases (blaCTX-M-1 and blaSHV ) producing Escherichia coli, Salmonella spp. and Klebsiella pneumoniae isolated from humans in Mizoram. AIM: The present study was conducted to isolate and characterize the extended spectrum β-lactamases (ESBLs) producing enteric bacteria in human beings in Mizoram, India. MATERIALS AND METHODS: Fecal samples were collected from human beings with or without the history of diarrhea from different hospitals of Mizoram. Samples were processed for isolation and identification of Escherichia coli, Salmonella and Klebsiella pneumoniae. All the isolates were subjected to antibiotic sensitivity assays. Phenotypically, ESBLs production ability was determined by double discs synergy test (DDST) method. ESBLs producing isolates were subjected to polymerase chain reaction (PCR) for detection of ESBLs genes. Plasmids were cured by acridine orange. Transfer of resistance from a donor to recipient strains was done by in vitro horizontal method. RESULTS: A total of 414 enteric bacteria were isolated from 180 fecal samples (113 were from diarrheic patients and 67 were from non-diarrheic patients), of which 333 (80.44%), 52 (12.56%), and 29 (7.00%) were E. coli, K. pneumoniae and Salmonella spp., respectively. Double discs synergy test (DDST) exhibited 72 (21.62%) E. coli, 12 (23.08%) K. pneumoniae and 4 (13.79%) Salmonella spp. were ESBLs producers. Altogether, 24 (13.04%) isolates were found to be positive for at least one resistance genes under this study. A total of 36 (8.70%) E. coli, 4 (0.97%) K. pneumoniae and 2 (0.48%) Salmonella spp. were found to be positive for blaCTX-M-1 gene by PCR. Similarly, 5 (1.21%) E. coli and 4 (0.97%) K. pneumoniae isolates were found to be positive for blaSHV gene. A total of 3 (0.72%) K. pneumoniae isolates were recorded as positive for both blaCTX-M-1 and blaSHV genes. All the isolates were carrying plasmids ranging between 0.9 kb and ~30 kb. The resistance plasmid could not be transferred to a recipient by in vitro horizontal gene transfer method. CONCLUSION: ESBLs producing enteric bacteria are circulating in human population in North Eastern Region of India. Indiscriminate use of antibiotics should be avoided to control the menace of multidrug resistance bacteria in the environment, animals, and human beings. | 2015 | 27047141 |
| 1074 | 7 | 0.9999 | Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae from Pharmaceutical Wastewaters in South-Western Nigeria. Emergence and spread of Klebsiella pneumoniae isolates producing extended-spectrum β-lactamases (ESBLs) present a major threat to public health. In this study, we characterized β-lactam-resistant K. pneumoniae isolates from six wastewater samples obtained from two pharmaceutical industries located in Lagos and Ogun States, Nigeria. Bacteria were isolated by using MacConkey agar; species identification and antibacterial susceptibility testing were performed by Vitek 2. Etest was used for ESBL phenotype confirmation. The presence of β-lactamase genes was investigated by PCR and sequencing. Bacterial strain typing was done by XbaI-macrorestriction and subsequent pulsed-field gel electrophoresis (PFGE) as well as multilocus sequence typing (MLST). Thirty-five bacterial species were isolated from the six samples; among them, we identified seven K. pneumoniae isolates with resistance to β-lactams and co-resistance to fluoroquinolones, aminoglycosides, and folate pathway inhibitors. The ESBL phenotype was confirmed in six K. pneumoniae isolates that harbored ESBL genes bla(CTX-M-15) (n = 5), bla(SHV-2) (n = 1), and bla(SHV-12) (n = 1). PFGE and MLST analysis revealed five clones belonging to four sequence types (ST11, ST15, ST37, ST101), and clone K. pneumoniae-ST101 was present in the wastewater samples from two different pharmaceutical industries. Additionally performed conjugation assays confirmed the location of β-lactamase genes on conjugative plasmids. This is the first confirmation of K. pneumoniae isolates producing CTX-M-15-ESBL from pharmaceutical wastewaters in Nigeria. The co-resistance observed might be a reflection of the different drugs produced by these industries. Continuous surveillance of the environmental reservoirs of multidrug-resistant bacteria is necessary to prevent their further spread. | 2017 | 28375698 |
| 1098 | 8 | 0.9999 | Extended spectrum beta-lactamase and fluoroquinolone resistance genes among Escherichia coli and Salmonella isolates from children with diarrhea, Burkina Faso. BACKGROUND: The emergence and spread of multidrug-resistant gram-negative bacteria (MDR) has become a major public health concern worldwide. This resistance is caused by enzymes-mediated genes (i.e., extended spectrum beta-lactamases) that are common in certain Enterobacterioceae species. However, the distribution of these genes is poorly documented in Burkina Faso. This study aims to determine the prevalence and distribution of the resistant genes coding for broad spectrum beta-lactamases and quinolones in rural Burkina Faso. METHODS: Multiplex PCR assays were carried out to detect ESBL-encoding genes, including bla(OXA), bla(TEM), bla(CTX-M), bla(SHV). The assays also assessed the presence of quinolone resistance gene namely qnrA, qnrB and qnrS in the quinolone-resistance DEC and Salmonella strains. RESULTS: The Extended-Spectrum Beta-Lactamases (ESBL) resistance phenotype was reported in all the E. coli isolates (5/5). Cross-resistance phenotype to quinolones (CRQ) was shown by one Salmonella strain (1/9) and three E. coli (3/5). Cross-resistance phenotypes to fluoroquinolones (CRFQ) were harboured by one Salmonella (1/9) and carbapenemase phenotypes were detected in two E. coli strains (2/5). Whilst the bla(OXA) genes were detected in 100% (5/5) of E. coli isolates and in 33.33% (3/9) Salmonella isolates. One strain of E. coli (1/5) harbored the bla(CTX-M) gene and the qnrB gene simultaneously. CONCLUSIONS: This study identified β-lactam (bla) and quinolone resistance (qnr) genes in multidrug-resistant E. coli and Salmonella spp. in rural Burkina Faso. Our finding which highlighted the enterobacteriaceae strains resistance to β-lactams and quinolones are of high interest for adequate management of antimicrobial resistant genes outbreak in Burkina Faso. | 2020 | 33010801 |
| 1117 | 9 | 0.9999 | CTX-M-type ESBL-mediated resistance to third-generation cephalosporins and conjugative transfer of resistance in Gram-negative bacteria isolated from hospitals in Tamil Nadu, India. Clinical pathogens, especially Gram-negative bacteria developing resistance to third-generation cephalosporins, are making clinical outcomes more complicated and serious. This study was undertaken to evaluate the distribution of CTX-M-type extended-spectrum β-lactamases (ESBLs) in Tamil Nadu, India. For this study, clinical samples were collected from five different hospitals located in Tamil Nadu and the ESBL-producing Gram-negative isolates were characterized. MIC was performed using cefotaxime and ceftazidime. The bla (ESBL)-producing genes were screened using multiplex PCR for the genes, CTX-M group-1, -2, -8, -9, -26. The conjugation studies were performed using Escherichia coli AB1157 as a recipient for the isolates harbouring plasmid-borne resistance following broth-mating experiment. In total, 1500 samples were collected and 599 Gram-negative bacteria were isolated that included E. coli (n=233), Klebsiella pneumoniae (n=182), Pseudomonas aeruginosa (n=79), Citrobacter spp. (n=30), Proteus mirabilis (n=28), Salmonella spp. (n=21), Acinetobacter baumannii (n=12), Serratia spp. (n=6), Shigella spp. (n=4), Morganella morganii (n=3) and Providencia spp. (n=1). MIC results showed that 358 isolates were resistant to cefotaxime and ceftazidime. Further, ESBL gene-amplification results showed that 19 isolates had CTX-M group-1 gene including E. coli (n=16), K. pneumoniae (n=2) and P. aeruginosa (n=1) whereas one M. morganii isolate had CTX-M group-9, which was plasmid-borne. Through conjugation studies, 12/20 isolates were found to be involved in the transformation of its plasmid-borne resistance gene. Our study highlighted the importance of horizontal gene transfer in the dissemination of plasmid-borne bla (CTX-M-type) resistance genes among the clinical isolates. | 2021 | 34151148 |
| 1023 | 10 | 0.9999 | Common presence of plasmid encoding bla(CTX-M-55) in extended-spectrum β-lactamase-producing Salmonella enterica and Escherichia coli isolates from the same edible river fish. The transmission of potentially life-threatening plasmid-mediated antibiotic-resistant bacteria poses a major threat to public health. This study aimed to determine the presence of commonly observed plasmids encoding plasmid-mediated antibiotic-resistance genes in Salmonella and Escherichia coli isolates from fishery products. Eighty river fishes were purchased from retail stores and supermarkets in Vietnam. Only Salmonella-positive fishes were used for antibiotic-resistant E. coli isolation. Salmonella serotyping was performed using Salmonella antisera. Isolated bacterial DNA was extracted, and antibiotic susceptibility, resistance genes, and replicon typing were determined. Our results showed that Salmonella was isolated from 12.5% (10/80) of the river fishes. Cefotaxime-resistant Salmonella was isolated from 3.8% (3/80) of the fishes and colistin-resistant Salmonella from 1.3% (1/80) . Salmonella serotyping revealed Potsdam, Schwarzengrund, Bardo/Newport, Give, Infantis, Kentucky, and Typhimurium. Multiplex polymerase chain reaction revealed the presence of extended-spectrum β-lactamase-related genes bla(CTX-M-55) and bla(CTX-M-65) and the colistin resistance gene mcr-1. To date, no study has reported an antibiotic-resistance plasmid present in multiple bacteria collected from the same food. Thus, horizontal transmission of antibiotic-resistance plasmids may occur at the food level. | 2023 | 37394527 |
| 989 | 11 | 0.9999 | Development of a Method for the Fast Detection of Extended-Spectrum β-Lactamase- and Plasmid-Mediated AmpC β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae from Dogs and Cats in the USA. Antibiotic resistance, such as resistance to beta-lactams and the development of resistance mechanisms, is associated with multifactorial phenomena and not only with the use of third-generation cephalosporins. Many methods have been recommended for the detection of ESBL and pAmpC β-lactamase production but they are very subjective and the appropriate facilities are not available in most laboratories, especially not in clinics. Therefore, for fast clinical antimicrobial selection, we need to rapidly detect ESBL- and pAmpC β-lactamase-producing bacteria using a simple method with samples containing large amounts of bacteria. For the detection of ESBL- and pAmpC phenotypes and genes, the disk diffusion test, DDST and multiplex PCR were conducted. Of the 109 samples, 99 (90.8%) samples were grown in MacConkey broth containing cephalothin, and 71 samples were grown on MacConkey agar containing ceftiofur. Of the 71 samples grown on MacConkey agar containing ceftiofur, 58 Escherichia coli and 19 Klebsiella pneumoniae isolates, in particular, harbored β-lactamase genes. Of the 38 samples that did not grow in MacConkey broth containing cephalothin or on MacConkey agar containing ceftiofur, 32 isolates were identified as E. coli, and 10 isolates were identified as K. pneumoniae; β-lactamase genes were not detected in these E. coli and K. pneumoniae isolates. Of the 78 ESBL- and pAmpC β-lactamase-producing E. coli and K. pneumoniae, 55 (70.5%) isolates carried one or more ESBL genes and 56 (71.8%) isolates carried one or more pAmpC β-lactamase genes. Our method is a fast, and low-cost tool for the screening of frequently encountered ESBL- and pAmpC β-lactamase-producing bacteria and it would assist in diagnosis and improve therapeutic treatment in animal hospitals. | 2023 | 36830436 |
| 1054 | 12 | 0.9999 | Molecular detection of extended-spectrum β-lactamase-producing Klebsiella pneumoniae isolates of chicken origin from East Java, Indonesia. BACKGROUND AND AIM: Klebsiella pneumoniae is one of the respiratory disease agents in human and chicken. This bacterium is treated by antibiotic, but this treatment may trigger antibiotic resistance. Resistance gene in K. pneumoniae may be transferred to other bacteria. One of the known resistance genes is extended-spectrum β-lactamase (ESBL). This research aimed to study K. pneumoniae isolated from chicken farms in East Java, Indonesia, by observing the antibiotic resistance pattern and detect the presence of ESBL coding gene within the isolates. MATERIALS AND METHODS: A total of 11 K. pneumoniae isolates were collected from 141 chicken cloacal swabs from two regencies in East Java. All isolates were identified using the polymerase chain reaction method. Antimicrobial susceptibility was determined by agar dilution method on identified isolates, which then processed for molecular characterization to detect ESBL coding gene within the K. pneumoniae isolates found. RESULTS: The result of antibiotic sensitivity test in 11 isolates showed highest antibiotic resistance level toward ampicillin, amoxicillin, and oxytetracycline (100%, 100%, and 90.9%) and still sensitive to gentamicin. Resistance against colistin, doxycycline, ciprofloxacin, and enrofloxacin is varied by 90.9%, 54.5%, 27.3%, and 18.2%, respectively. All isolates of K. pneumoniae were classified as multidrug resistance (MDR) bacteria. Resistance gene analysis revealed the isolates harbored as bla (SHV) (9.1%), bla (TEM) (100%), and bla (CTX-M) (90.9%). CONCLUSION: All the bacterial isolates were classified as MDR bacteria and harbored two of the transmissible ESBL genes. The presence of antibiotic resistance genes in bacteria has the potential to spread its resistance properties. | 2019 | 31190714 |
| 1048 | 13 | 0.9998 | Characterizing the co-existence of metallo-β-lactamase-producing and extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolates in community wastewater samples of Dhaka, Bangladesh. Escherichia coli and Klebsiella pneumoniae isolates with multiple antibiotic-resistance genes in wastewater pose serious public health risks, as they can potentially contaminate the food and water supply. The main aim of this study was to isolate and identify E. coli and K. pneumoniae from community wastewater samples, and determine their antibiotic-resistance profiles and their antibiotic-resistant genes. From the northern part of Dhaka, Bangladesh, 36 wastewater samples were collected across 11 different areas, which were then serially diluted, and cultured using selective media. Isolates were identified via polymerase chain reaction. Out of the 197 isolates identified, E. coli and K. pneumoniae accounted for 55.8% (n = 110) and 44.2% (n = 87), respectively. Antibiotic susceptibility tests revealed multidrug resistance (MDR) in 30% of E. coli and 35.56% of K. pneumoniae isolates. Among E. coli, the prevalence of antibiotic-resistance genes included bla(NDM-1) (8.9%), bla(SHV) (13.9%), and bla(CTX-M) (7.6%). In K. pneumoniae, the percentages were bla(NDM-1) (12.8%), bla(SHV) (4.3%), and bla(CTX-M) (5.0%). Co-existence of multiple antibiotic-resistance genes was observed in 4.54% of E. coli isolates (n = 5) and 5.74% of K. pneumoniae isolates (n = 5). This suggests the escalating issue of infectious species becoming increasingly resistant to antibiotics in wastewater systems. | 2025 | 40298266 |
| 1071 | 14 | 0.9998 | Characterization of Beta-Lactamase and Fluoroquinolone Resistance Determinants in Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa Isolates from a Tertiary Hospital in Yola, Nigeria. Infections due to antimicrobial resistant gram-negative bacteria cause significant morbidity and mortality in sub-Saharan Africa. To elucidate the molecular epidemiology of antimicrobial resistance in gram-negative bacteria, we characterized beta-lactam and fluoroquinolone resistance determinants in Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa isolates collected from November 2017 to February 2018 (Period 1) and October 2021 to January 2022 (Period 2) in a tertiary medical center in north-eastern Nigeria. Whole genome sequencing (WGS) was used to identify sequence types and resistance determinants in 52 non-duplicate, phenotypically resistant isolates. Antimicrobial susceptibility was determined using broth microdilution and modified Kirby-Bauer disk diffusion methods. Twenty sequence types (STs) were identified among isolates from both periods using WGS, with increased strain diversity observed in Period 2. Common ESBL genes identified included bla(CTX-M), bla(SHV,) and bla(TEM) in both E. coli and K. pneumoniae. Notably, 50% of the E. coli in Period 2 harbored either bla(CTX-M-15) or bla(CTX-M-1 4) and phenotypically produced ESBLs. The bla(NDM-7) and bla(VIM-5) metallo-beta-lactamase genes were dominant in E. coli and P. aeruginosa in Period 1, but in Period 2, only K. pneumoniae contained bla(NDM-7), while bla(NDM-1) was predominant in P. aeruginosa. The overall rate of fluoroquinolone resistance was 77% in Period 1 but decreased to 47.8% in Period 2. Various plasmid-mediated quinolone resistance (PMQR) genes were identified in both periods, including aac(6')-Ib-cr, oqxA/oqxB, qnrA1, qnrB1, qnrB6, qnrB18, qnrVC1, as well as mutations in the chromosomal gyrA, parC and parE genes. One E. coli isolate in Period 2, which was phenotypically multidrug resistant, had ESBL bla(CTX-M-15,) the serine carbapenemase, bla(OXA-181) and mutations in the gyrA gene. The co-existence of beta-lactam and fluoroquinolone resistance markers observed in this study is consistent with widespread use of these antimicrobial agents in Nigeria. The presence of multidrug resistant isolates is concerning and highlights the importance of continued surveillance to support antimicrobial stewardship programs and curb the spread of antimicrobial resistance. | 2023 | 37999619 |
| 991 | 15 | 0.9998 | Characterization of extended-spectrum beta-lactamases in Enterobacteriaceae causing nosocomial infections in a Zagreb University Hospital. The bacteria producing extended-spectrum beta-lactamases (ESBLs) are increasingly reported. production of ESBLs by Gram-negative bacteria is the major mechanism of resistance to oxymino-cephalosporins and aztreonam. the aim of the present study was to characterize ESBLs produced by Enterobacteriaceae, collected during 2003-2005 in a University Hospital in Zagreb, and to determine the risk factors associated with nosocomial infections due to them. 76 isolates of Enterobacteriaceae were included in the study. Antibiotic susceptibility testing was performed by disk-diffusion and broth microdilution method according to CLSI. beta-lactamases were characterized by PCR and sequencing of bla(ESBL )genes. plasmids were extracted by alkaline lysis method and digested with EcoRI enzyme. Most of the strains displayed CAZ phenotype meaning a higher level of resistance to ceftazidime compared to cefotaxime and ceftriaxone. 50 strains produced SHV-ESBL, 28 tem and 8 CTX-M beta-lactamase. Sequencing of bla(SHV )genes from representative strains revealed SHV-5 beta-lactamase in 6 strains whereas sequencing of bla(CTX-M )genes identified CTX-M-3 beta-lactamase in 3 and CTX-M-15 in 5 strains. Strains were assigned to groups from A to f according to plasmid fingerprinting. The spread of SHV-5-producing strains throughout the hospital units could be due to selective pressure of ceftazidime which is widely prescribed in our hospital thus favoring survival of strains possessing a mutation at the Ambler position 240 responsible for ceftazidime and aztreonam resistance. | 2009 | 19567348 |
| 1079 | 16 | 0.9998 | CTX-M-15-producing Escherichia coli clone B2-O25b-ST131 and Klebsiella spp. isolates in municipal wastewater treatment plant effluents. OBJECTIVES: The global occurrence of antibiotic resistance genes in bacteria in water environments is an increasing concern. Treated wastewater was sampled daily over a 45 day period from the outflow of a municipal wastewater treatment plant in Brno, Czech Republic, and examined for extended-spectrum β-lactamase (ESBL)-producing bacteria. METHODS: Water samples were cultivated on MacConkey agar with cefotaxime (2 mg/L) and individual colonies were examined for ESBL production. Phenotypic ESBL-positive bacteria identified as Escherichia coli or Klebsiella spp. were tested for the presence of antibiotic resistance genes, the virulence gene afa/dra and the bla(CTX-M) upstream region. Genetic relatedness was analysed by PFGE, multilocus sequence typing and plasmid analysis. RESULTS: A total of 68 ESBL-producing Enterobacteriaceae isolates were detected in 34 out of 45 wastewater samples. ESBL-producing isolates included 26 E. coli isolates, 4 Klebsiella pneumoniae isolates and 1 Klebsiella oxytoca isolate. The pandemic and multiresistant B2-O25b-ST131 clone was predominant, being detected among 19 E. coli isolates, and 17 of the B2-O25b-ST131 isolates were positive for the FIA replicon and the afa/dra operon and had an IS26 element flanking bla(CTX-M-15). Seventeen of the B2-O25b-ST131 isolates showed closely related PFGE profiles (defined by 84% band similarity) and belonged to identical clonal groups. CONCLUSIONS: The results highlight the inadequacy of the treatment process in removing multiresistant bacteria from municipal wastewater and point to a risk of transmission of clinically important multiresistant strains, such as the pandemic ST131 clone, to the environment. This is the first study demonstrating the pandemic ST131 clone in wastewater. | 2011 | 21954457 |
| 1094 | 17 | 0.9998 | Detection of plasmid-mediated quinolone resistance genes in β-lactamase-producing Escherichia coli isolates from layer hens. This study was conducted to investigate the presence of plasmid-mediated quinolone resistance (PMQR) genes in β-lactamase-producing Escherichia coli isolates from layer hens and to characterize their molecular background. Among 142 E. coli isolates, 86 (60.6%) showed multidrug resistance and 15 (10.6%) were found to be β-lactamase-producing E. coli. Extended-spectrum β-lactamase (ESBL) and plasmid-mediated AmpC (pAmpC) β-lactamase genes, blaCTX-M-14 and blaCMY-2, were identified in three and six E. coli isolates, respectively. The non-ESBL or pAmpC gene, blaTEM-1, was found in eight of the isolates. Two isolates had both genes, blaCTX-M-14 and blaTEM-1. Among the 15 β-lactamase-producing E. coli, six PMQR genes, qnrS1 (n = 3) and qnrB4 (n = 3), were identified. Among the six PMQR-positive E. coli isolates, four exhibited double amino acid exchanges at both gyrA and parC with ciprofloxacin and enrofloxacin minimum inhibitory concentrations of ≥32 and ≥16 μg/mL, respectively. Additionally, five transconjugants (33.3%) showed a transferability of β-lactamase and PMQR genes. Pulsed-field gel electrophoresis (PFGE) analysis was conducted to investigate the 15 β-lactamase-producing E. coli isolates. In PFGE, E. coli included three PFGE patterns showing the same farms and in accordance with both β-lactamase and PMQR genes and the antimicrobial resistance pattern. Layer hens may act as a reservoir of antibiotic-resistant bacteria, and the PMQR gene in β-lactamase-producing E. coli isolates from layer hens has the potential to enter the food chain. Therefore, our findings suggest that comprehensive surveillance of antimicrobial use in laying operation systems is necessary. | 2019 | 30496543 |
| 1047 | 18 | 0.9998 | 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 |
| 987 | 19 | 0.9998 | Characterization of Multidrug Resistant Extended-Spectrum Beta-Lactamase-Producing Escherichia coli among Uropathogens of Pediatrics in North of Iran. Escherichia coli remains as one of the most important bacteria causing infections in pediatrics and producing extended-spectrum beta-lactamases (ESBLs) making them resistant to beta-lactam antibiotics. In this study we aimed to genotype ESBL-producing E. coli isolates from pediatric patients for ESBL genes and determine their association with antimicrobial resistance. One hundred of the E. coli isolates were initially considered ESBL producing based on their MIC results. These isolates were then tested by polymerase chain reaction (PCR) for the presence or absence of CTX, TEM, SHV, GES, and VEB beta-lactamase genes. About 30.5% of isolated E. coli was ESBL-producing strain. The TEM gene was the most prevalent (49%) followed by SHV (44%), CTX (28%), VEB (8%), and GES (0%) genes. The ESBL-producing E. coli isolates were susceptible to carbapenems (66%) and amikacin (58%) and showed high resistance to cefixime (99%), colistin (82%), and ciprofloxacin (76%). In conclusion, carbapenems were the most effective antibiotics against ESBl-producing E. coli in urinary tract infection in North of Iran. The most prevalent gene is the TEM-type, but the other resistant genes and their antimicrobial resistance are on the rise. | 2015 | 26064896 |