# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 1164 | 0 | 1.0000 | The distribution of beta lactamase genes in Escherichia coli phylotypes isolated from diarrhea and UTI cases in northwest Iran. BACKGROUND: Pathogenic Escherichia coli strains are a common cause of intestinal and extra-intestinal infections, especially in developing countries. Extended spectrum beta-lactamases (ESBLS), a heterogeneous group of plasmid-encoded beta-lactamases, are common throughout the world. OBJECTIVES: The aim of the present study was to determine the phenotypic and genotypic characteristics of ESBLS produced by E. coli isolates taken from patients with diarrhea and urinary tract infections (UTI) in northwest Iran. MATERIAL AND METHODS: A total of 132 E. coli isolates (92 isolates from UTI and 40 isolates from diarrheic cases) were recovered and confirmed by biochemical tests. The isolates were examined for blaTEM and blaSHV genes and phylogenetic background by two multiplex PCR assays. The isolates were tested for antibiotic susceptibility against nine antibiotic agents by the disk diffusion method. RESULTS: The phylogenetic analysis showed that the UTI isolates mostly fell into phylo-group B2, followed by D, while the diarrheic isolates belonged to phylo-groups D and A. Out of 92 UTI isolates, 29.3% and 17.4% possessed blaTEM and blaSHV genes, respectively. Ten diarrheic isolates were positive for blaTEM, two isolates possessed the blaSHV gene, and one isolate was positive for both genes. The UTI isolates that were positive for blaTEM and blaSHV genes mostly belonged to phylo-groups D and B2, whereas the diarrhea isolates were in phylo-groups D and A. Phylogenetic group D isolates have an accumulation of ESBLS genes in the diarrheic and UTI isolates. In both the UTI and diarrhea isolates, the maximum rate of resistance was against cefazolin, and the minimum rate of resistance was against nitrofurantoin. Twenty-four antibiotic resistance patterns were observed among the isolates. The amikacin, ciprofloxacin, cefotaxime, cefuroxime, cefazolin, gentamicin, nalidixic acid and trimethoprim/sulfamethoxazole resistance pattern was the most prevalent in the isolates that belonged to phylo-group D. CONCLUSIONS: The correct choice of effective antibiotic policy is needed to limit the spread of antibiotic resistance in bacteria. | 2014 | 25166436 |
| 2151 | 1 | 0.9999 | Study of the Genomic Characterization of Antibiotic-Resistant Escherichia Coli Isolated From Iraqi Patients with Urinary Tract Infections. Urinary tract infection is one of the last diseases prevalent in humans, with various causative agents affecting 250 million people annually, This study analyzed UTIs in Iraqi patients caused by Escherichia coli. ESBL enzymes contribute to antibiotic resistance. The research aimed to analyze ESBL gene frequency, resistance patterns, and genetic diversity of E. coli strains; Between Dec 2020 and May 2021, 200 urine samples were collected, cultured on blood agar, EMB, and MacConkey's plates, samples incubated at 37 °C for 24 h. Positive samples (> 100 cfu/ml) underwent Kirby-Bauer and CLSI antibiotic susceptibility testing. PCR detected virulence genes, Beta-lactamase coding genes, and biofilm-associated resistance genes in E. coli isolates; Out of 200 isolates, 80% comprised Gram-positive and Gram-negative bacteria. Specifically, 120 isolates (60%) were Gram-negative, while 40 isolates (20%) were Gram-positive. Among Gram-negative isolates, 20% were identified as E. coli. Remarkably, all E. coli strains showed resistance to all tested antibiotics, ranging from 80 to 95% resistance. The E. coli isolates harbored three identified resistance genes: blaTEM, blaSHV, and blaCTXM. Regarding biofilm production, 10% showed no formation, 12% weak formation, 62% moderate formation, and 16% strong formation; our study found that pathogenic E. coli caused 20% of UTIs. The majority of studied E. coli strains from UTI patients carried the identified virulence genes, which are vital for infection development and persistence. | 2024 | 39011020 |
| 1128 | 2 | 0.9999 | Molecular detection of ESBLs production and antibiotic resistance patterns in Gram negative bacilli isolated from urinary tract infections. BACKGROUND: β-lactam resistance is more prevalent in Gram negative bacterial isolates worldwide, particularly in developing countries. In order to provide data relating to antibiotic therapy and resistance control, routine monitoring of corresponding antibiotic resistance genes is necessary. AIMS: The aim of this study was the characterization of β-lactam resistance genes and its plasmid profile in bacteria isolated from urinary tract infection samples. MATERIALS AND METHODS: In this study, 298 Gram negative bacteria isolated from 6739 urine specimens were identified by biochemical standard tests. Antimicrobial susceptibility testing was performed by the disk diffusion method. Extended-spectrum β-lactamase (ESBL)-producing strains were also detected by the double-disk synergy test. The presence of blaTEM and blaSHV genes in the strains studied was ascertained by polymerase chain reaction. RESULTS: Of all Gram negative bacteria, Escherichia coli (69.1%) was the most common strain, followed by Klebsiella sp. (12.1%), Enterobacter sp. (8.4%), Proteus sp. (4.4%), Citrobacter (4%) and Pseudomonas sp. (2%). The most antibiotic resistance was shown to tetracycline (95.16%), nalidixic acid (89.78%) and gentamycin (73.20%) antibiotics. Among all the strains tested, 35 isolates (11.75%) expressed ESBL activity. The prevalence of TEM and SHV positivity among these isolates was 34.29%, followed by TEM (31.43%), TEM and SHV negativity (20.0%) and SHV (14.29%), respectively. CONCLUSIONS: Regular monitoring of antimicrobial drug resistance seems necessary to improve our guidelines in the use of the empirical antibiotic therapy. | 2014 | 24943757 |
| 2150 | 3 | 0.9999 | Analysis of drug resistance genes of integrons in clinical isolates of Escherichia coli from elderly bloodstream infections. This experiment was carried out to provide a basis for the treatment of clinical bloodstream infections by analyzing the drug resistance characteristics and integrated gene distribution of Escherichia coli in bloodstream infections in elderly patients. For this aim, E. coli were collected for bacterial identification and drug sensitivity testing from bloodstream infections in elderly patients in the hospital from January 2016 to December 2019. ESBLs positive strains were assayed for genotypes and their integron carriage rates by PCR amplification. The characteristics and differences of various genotype rates were compared and analyzed. Results showed that a total of 230 E. coli strains were isolated. The detection rate of ESBLs-producing bacteria was 37.39 %. ESBLs-producing E. coli showed a high rate of resistance to cefepime, levofloxacin, cotrimoxazole, and ticarcillin/clavulanic acid (>40%). The resistance rate of 230 strains of E. coli to meropenem, minocycline, amikacin, gentamicin and cefoxitin was less than 20%. Among the ESBLs-producing E. coli in bloodstream infections in elderly patients, CTX-M-9 accounted for 27.91%, CTX-M-2 for 17.44%, and SHV for 13.95%. The detection rate of type I integrated genes was 41.30%, and type II and III integrated genes were not detected. ESBLs-producing genotyping-positive bacteria were detected with more than 50% of type I integrated genes. It was concluded that type I integrated genes in ESBLs-producing E. coli isolated from elderly patients carried resistance genes such as CTX-M-9 and CTX-M-2 aggravating multi-drug resistance in bacteria. | 2022 | 36227675 |
| 2154 | 4 | 0.9999 | Molecular analysis of multidrug-resistant E. coli in pediatric UTIs: findings from a Nigerian Hospital. INTRODUCTION: This study aimed to isolate and characterize antibiotic-resistant Escherichia coli from urine samples of children at the Mother and Child Hospital in Ondo State, Nigeria, assessing antibiogram profiling and resistance genes. METHODOLOGY: Three hundred urine samples (158 females, 142 males), aged 3-5 years, were collected, transported on ice, and analyzed bacteriologically. E. coli and Gram-negative bacteria were isolated using Eosin Methylene Blue agar and identified through colony morphology and biochemical tests. Antibiotic susceptibility was determined via Kirby Bauer's disc diffusion, and resistance genes were detected using Polymerase Chain Reaction (PCR). RESULTS: Of the 300 samples, 40 (13.3%) yielded E. coli with varying antibiotic resistance profiles. The highest resistance was against Amoxicillin-clavulanate (87.5%) followed by Ceftriaxone (80%). Susceptibility was observed to Nitrofurantoin, Erythromycin, and Chloramphenicol. Multiple resistance patterns against 3-4 antibiotic classes were recorded, with 12 distinct patterns observed. Eight isolates harbored blaCTX-M gene, while five carried the aac3-IV gene. CONCLUSIONS: The study concluded a high occurrence of E. coli infection and multiple antibiotic resistance in the region. The presence of resistance genes suggests significant economic and health implications, emphasizing prudent antibiotic use under physician guidance to mitigate multiple antibiotic resistance. | 2024 | 38484349 |
| 1163 | 5 | 0.9999 | A Three-Year Look at the Phylogenetic Profile, Antimicrobial Resistance, and Associated Virulence Genes of Uropathogenic Escherichia coli. Uropathogenic Escherichia coli is the most common cause of urinary tract infections, resulting in about 150 million reported annual cases. With multidrug resistance on the rise and the need for global and region surveillance, this investigation looks at the UPEC isolates collected for a 3-year period, with a view of ascertaining their antimicrobial susceptibility patterns and associated virulence determinants. The identification of bacteria isolates, antimicrobial susceptibility, and extended-spectrum beta-lactamases (ESBLs) production was determined with a Vitek 2 Compact Automated System (BioMerieux, Marcy L'Etoile, France). ESBLs were confirmed by the combined disc test (CDT) and basic biochemical test. The isolates were distributed into A (11%), B1 (6%), B2 (62.4%), and D (20.6%). Resistance to the penicillin group was high, between 88% and 100%. Additionally, resistance was high to cephalosporins (100%) in 2017 and 2018. The isolates were all sensitive to tigecycline, while resistance against imipenem and meropenem was low, at 4-12% in 2017 and 2018 and 0% in 2019. The results also showed that ESBL isolates were seen in 2017 and 2018. They were confirmed positive to CTX/CLA (88.5%) and CAZ/CLA (85%). By 2019, the number of resistant isolates reduced, showing only 4% ESBL isolates. Two virulence genes, fimH (46%) and papE/F (15%), were detected among the isolates by PCR. In conclusion, this study found that phylogroups B2 and D carried the most virulence genes as well as MDR and ESBL characteristics, suggesting the UPEC strains to be extraintestinal pathogens responsible for UTIs. | 2022 | 35745485 |
| 2147 | 6 | 0.9999 | Identification of Genes Coding Aminoglycoside Modifying Enzymes in E. coli of UTI Patients in India. This study is to probe the pattern of antibiotic resistance against aminoglycosides and its mechanism in E. coli obtained from patients from Chennai, India. Isolation and identification of pathogens were done on MacConkey agar. Antimicrobial sensitivity testing was done by disc diffusion test. The identification of genes encoding aminoglycoside modifying enzymes was done by Polymerase Chain Reaction (PCR). Out of 98 isolates, 71 (72.45%) isolates were identified as E. coli and the remaining 27 (27.55%) as other bacteria. Disc diffusion method results showed a resistance level of 72.15% for streptomycin, 73.4% for gentamicin, 63.26% for neomycin, 57.14% for tobramycin, 47.9% for netilmicin, and 8.16% for amikacin in E. coli. PCR screening showed the presence of four genes, namely, rrs, aacC2, aacA-aphD, and aphA3, in their plasmid DNA. The results point towards the novel mechanism of drug resistance in E. coli from UTI patients in India as they confirm the presence of genes encoding enzymes that cause resistance to aminoglycoside drugs. This could be an alarm for drug prescription to UTI patients. | 2016 | 27403451 |
| 1054 | 7 | 0.9998 | 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 |
| 1165 | 8 | 0.9998 | Isolation, Antimicrobial Susceptibility Profile and Detection of Sul1, blaTEM, and blaSHV in Amoxicillin-Clavulanate-Resistant Bacteria Isolated From Retail Sausages in Kampar, Malaysia. BACKGROUND: Due to the overuse of antibiotics in livestock as a growth-promoting agent, the emergence of multi-antibiotic resistant bacteria is becoming a concern. OBJECTIVES: In this study, we aimed to detect the presence and discover the molecular determinants of foodborne bacteria in retail sausages resistant towards the antibacterial agent amoxicillin-clavulanate. METHODS: Two grams of sausages were chopped into small pieces and transferred into sterile Luria-Bertani (LB) enrichment broths overnight before they were plated on MacConkey agar petri dishes. The bacteria isolated were then screened for amoxicillin-clavulanate resistance, and an antimicrobial susceptibility test of each isolate was performed by using the disc diffusion method. Double synergy and phenotypic tests were carried out to detect the presence of extended spectrum β-lactamase (ESBL). API 20E kit was used to identify the Enterobacteriaceae. All isolates were further examined by polymerase chain reaction (PCR) for resistant genes blaOXA-1, blaOXA-10, plasmid-mediated AmpC (blaCMY and blaDHA), and the chromosome-mediated AmpC, Sul1, blaTEM, and blaSHV genes. RESULTS: A total of 18 amoxicillin-clavulanate resistant isolates were obtained from seven different types of retail sausages. Only half of them were identified as Enterobacteriaceae, but none were ESBL-producers. All the 18 isolated strains demonstrated resistance towards amoxicillin-clavulanate, penicillin and oxacillin (100%), cefotaxime (71.4%), cefpodoxime (66.7%), and ampicillin (83.3%). blaTEM was the most frequently detected β-lactamase gene. Both plasmid- and chromosomal-bound blaTEM genes were detected in all of the isolated Enterobacteriaceae. blaSHV and Sul1 accounted for 22.2% and 11.1% of the amoxicillin-clavulanate resistant isolates, respectively, whereas blaAMPC, blaCMY, blaDHA, blaOXA-1, and blaOXA-10 were not found in any of the isolates. The only one ESBL-producing bacteria detected in this study was Chryseobacterium meningosepticum, which harbored the blaTEM gene. CONCLUSIONS: The multidrug resistant bacteria that carry antibiotic resistant genes from retail sausages may increase the risk of transmission to humans via the consumption of contaminated sausages. Stricter measures must be taken to address the use of antibiotics in animal agriculture and to consider their potential impact on human health. | 2016 | 27942365 |
| 1057 | 9 | 0.9998 | Emergence of ciprofloxacin-resistant extended-spectrum β-lactamase-producing enteric bacteria in hospital wastewater and clinical sources. This study aimed to evaluate the incidence of ciprofloxacin-resistant extended-spectrum β-lactamase (ESBL)-producing enteric bacteria in hospital wastewater and clinical sources. Enteric bacteria, mainly Escherichia coli, were isolated from clinical sources (urinary tract and gastrointestinal tract infections; 80 isolates) and hospital wastewater (103 isolates). The antibiotic resistance profile and ESBL production of the isolates were investigated by disc diffusion assay and combined disc diffusion test, respectively. Plasmid profiling was performed by agarose gel electrophoresis, and elimination of resistance markers was performed by a plasmid curing experiment. Antibiotic susceptibility testing revealed a high incidence of β-lactam resistance, being highest to ampicillin (88.0%) followed by amoxicillin, ceftriaxone, cefpodoxime, cefotaxime, aztreonam, cefepime and ceftazidime. Among the non-β-lactam antibiotics, the highest resistance was recorded to nalidixic acid (85.7%). Moreover, 50.8% of enteric bacteria showed resistance to ciprofloxacin. Among 183 total enteric bacteria, 150 (82.0%) exhibited multidrug resistance. ESBL production was detected in 78 isolates (42.6%). A significantly higher incidence of ciprofloxacin resistance was observed among ESBL-producing enteric bacteria both in clinical (P=0.0015) and environmental isolates (P=0.012), clearly demonstrating a close association between ESBL production and ciprofloxacin resistance. Plasmid profiling of selected ESBL-positive strains indicated the presence of one or more plasmids of varying sizes. Plasmid curing resulted in loss of ciprofloxacin and cefotaxime resistance markers simultaneously from selected ESBL-positive isolates, indicating the close relationship of these markers. This study revealed a common occurrence of ciprofloxacin-resistant ESBL-producing enteric bacteria both in hospital wastewater and clinical sources, indicating a potential public health threat. | 2016 | 27436461 |
| 1125 | 10 | 0.9998 | Detection of emerging antibiotic resistance in bacteria isolated from subclinical mastitis in cattle in West Bengal. AIM: The aim of this work was to detect antibiotic resistance in Gram-negative bacteria isolated from subclinical mastitis in cattle in West Bengal. MATERIALS AND METHODS: The milk samples were collected from the cattle suffering with subclinical mastitis in West Bengal. The milk samples were inoculated into the nutrient broth and incubated at 37°C. On the next day, the growth was transferred into nutrient agar and MacConkey agar. All the pure cultures obtained from nutrient agar slant were subjected to Gram-staining and standard biochemical tests. All the bacterial isolates were tested in vitro for their sensitivity to different antibiotics commonly used in veterinary practices. All Gram-negative isolates including positive control were subjected to polymerase chain reaction (PCR) for detection of bla(CTX-M), bla(TEM), bla(SHV), bla(VIM), tetA, tetB, tetC, and tetM genes considered for extended-spectrum β-lactamase (ESBL), metallo-β-lactamase, and tetracycline resistance. RESULTS: In total, 50 Gram-negative organisms (Escherichia coli, Proteus, Pseudomonas, Klebsiella, and Enterobacter) were isolated from milk samples of subclinical mastitis infected cattle. Among these Gram-negative isolates, 48% (24/50) were found either ESBL producing or tetracycline resistant. Out of total 50 Gram-negative isolates, bla(CTX-M) was detected in 18 (36%) isolates, and 6 (12%) harbored bla(TEM) genes in PCR. None of the isolates carried bla(SHV) genes. Further, in this study, 5 (10%) isolates harbored tet(A) gene, and 8 (16%) isolates carried tet(B) gene. No tet(C) gene was detected from the isolates. CONCLUSION: This study showed emerging trend of antibiotic-resistant Gram-negative bacteria associated with subclinical mastitis in cattle in West Bengal, India. | 2017 | 28620255 |
| 1130 | 11 | 0.9998 | The characteristic of antibiotic drug resistance of Salmonella Typhi isolated from tertiary care hospital in Faisalabad. Salmonella Typhi, a human-restricted pathogen, is demonstrating multi-drug resistance (MDR) due to widespread and inappropriate antibiotic use. This study aims to molecular identify the pattern of antibiotic resistance. Blood samples from 2456 suspected patients were assessed. Molecular identification of Salmonella Typhi was performed by amplifying the fliC gene. The Disc diffusion method was used to measure the susceptibility of antibiotics. 2456 patient samples, bacterial growth and Salmonella Typhi were 152 (6.2 %) positive. PCR analysis confirmed that all 152 isolated strains were Salmonella Typhi (100%) through the amplification of the fliC gene. Salmonella Typhi isolates showed resistance to trimethoprim (58%), ampicillin (63%), ciprofloxacin (79%) and chloramphenicol (58%). Fifty-eight percent of the isolates showed multi-drug resistance, whereas 26 percent had extensive drug resistance. Antibiotic resistance gene of quinolones was isolated as 44 (36.4%), whereas 88 (57.9 %) were positive for bla(CTX-M) gene were detected among cephalosporin-resistance bacteria 56 (36.8 %) resistance bla(IMP) and bla(OXA-48) were detected among carbapenem-resistance bacteria. For the azithromycin resistance, more genes were detected as a percentage 03 (50 %) from isolates. It concludes that several multidrug resistance and extensive drug-resistance Salmonella Typhi were found. The majority of isolates were sensitive to meropenem, Imipenem and Azithromycin. | 2025 | 40996203 |
| 1058 | 12 | 0.9998 | First Detection of FOX-1 AmpC β-lactamase Gene Expression Among Escherichia coli Isolated from Abattoir Samples in Abakaliki, Nigeria. OBJECTIVES: Gram-negative bacteria represent the most relevant reservoir of resistance to antibiotics in the environment. The natural selection of resistant clones of bacteria in the environment by antimicrobial selective pressure is a relevant mechanism for spreading antibiotic resistance traits in both the community and hospital environment. This is in scenarios where antimicrobials are used irrationally, and even in the propagation of livestock, poultry birds, and for other veterinary purposes. This study sought to detect the prevalence of FOX-1 AmpC β-lactamase genes from abattoir samples. METHODS: The isolation of Escherichia coli, antimicrobial susceptibility testing, and β-lactamase characterization was carried out using standard microbiology techniques. The production of AmpC β-lactamase was phenotypically carried out using the cefoxitin-cloxacillin double-disk synergy test (CC-DDST), and FOX-1 AmpC genes was detected in the E. coli isolates using multiplex polymerase chain reaction. RESULTS: Forty-eight E. coli isolates were recovered from the anal swabs of cows and 35 (72.9%) isolates were positive for the production of β-lactamase. Notably, high percentages of resistance to cefoxitin (91.7%), ceftriaxone (83.3%), imipenem (85.4%), ceftazidime (87.5%), ofloxacin (81.3%), and gentamicin (85.4%) were found. FOX-1 genes were detected in three (6.3%) of the 48 E. coli isolates phenotypically screened for AmpC enzyme production. CONCLUSIONS: Abattoirs could represent a major reservoir of resistance genes especially AmpC β-lactamase, and this could serve as a route for the dissemination of multidrug-resistant bacteria in the community. Thus, the molecular identification of drug-resistant genes is vital for a reliable epidemiological investigation and the forestalling of the emergence and spread of these organisms through the food chain in this region. | 2018 | 29896333 |
| 1059 | 13 | 0.9998 | Dissemination and phenotypic characterization of ESBL-producing Escherichia coli in Indonesia. BACKGROUND: The alarming rise in infections caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in animals and humans poses a serious threat due to its escalating antibiotic resistance. Unveiling this problematic bacteria's prevalence and resistance patterns in animals is crucial for formulating effective control strategies and safeguarding public health. AIM: The purpose of this study was to analyze the expression of three main genes: blaCTX-M, blaSHV, and blaTEM, in ESBL-producing E. coli isolates from The Research Center for Veterinary Science and the National Research and Innovation Agency. Moreover, their resistance profiles against various antibiotics should be systematically evaluated. METHODS: Ninety-seven E. coli isolates from the bacteriology laboratory of The Research Center for Veterinary Science were identified on MacConkey medium supplemented with cefotaxime. The isolates were verified for the existence of the blaCTX-M, blaSHV, and blaTEM genes using PCR. Antimicrobial susceptibility testing was conducted using antibiotic discs following the CLSI standards. RESULTS: The prevalence of ESBL-producing E. coli in chicken ceca, eggs, and fish intestines was 16.5% (16/97). The specific genes detected were blaCTX-M gene at 93.75% (15/16), followed by the blaTEM gene, at 81.25% (13/16), and blaSHV at 25% (4/16). The antimicrobial sensitivity test results revealed that all ESBL-producing E. coli isolates had multidrug resistance 81.25% to 1-5 antibiotics and 18.75% to 6-7 antibiotics. The isolate exhibited 100% resistance to ampicillin and sulfamethoxazole, with exclusive sensitivity to chloramphenicol. CONCLUSION: The dominant gene in the ESBL-producing isolates was blaCTX-M. This bacterium is completely resistant to ampicillin and sulfamethoxazole, whereas it displays multidrug resistance to 1-7 different types of antibiotics. | 2025 | 40276175 |
| 1134 | 14 | 0.9998 | Molecular epidemiology of antibiotic-resistant Escherichia coli among clinical samples isolated in Azerbaijan, Iran. BACKGROUND AND OBJECTIVES: The immediate emergence of resistant bacteria poses an increasingly growing problem to human society and the increasing prevalence of antibiotic resistance in Escherichia coli strains is one of the most important health problems. This study aimed to review the molecular epidemiology of drug resistance among clinical isolates of E. coli in north-west portion of Iran Azerbaijan. MATERIALS AND METHODS: A complete of 219 clinical isolates of E. coli had been collected from the various clinical samples. The disk diffusion and agar dilution assays were used to determine antimicrobial susceptibility. The presence of antibiotics resistance genes was carried out by the PCR method. RESULTS: The highest susceptibility was shown to imipenem (3%) and fosfomycin (3%), and the most antibiotic resistance was presented to ampicillin (99%). The highest frequent ESBL gene among isolates was bla (CTXM-15) in 70% followed by bla(CMY-2) in 67%, and bla(TEM-1) in 46%. The most common fluoroquinolone (FQ) resistance genes were oqxB (34%), followed by oqxA (25%), and qnrB (18%). The frequency of tetracycline resistance genes (tetA, tetB, tetC, and tetD) were detected in 24.8%, 31.6%, 1.8%, and 4.2%, respectively. The highest frequent genes to fosfomycin were fosA 10%, fosA3 30%, fosC 40%, and fosX 20%. The dominant founded aminoglycosides resistant genes were armA (12.96%) and npmA (4.93%). CONCLUSION: The prevalence of antibiotics resistance in the tested E. coli isolates was high in Azerbaijan, Iran and these findings showed that E. coli is one of the major drug-resistant pathogens. | 2023 | 37448678 |
| 1313 | 15 | 0.9998 | Molecular epidemiology of ceftiofur-resistant Escherichia coli isolates from dairy calves. Healthy calves (n = 96, 1 to 9 weeks old) from a dairy herd in central Pennsylvania were examined each month over a five-month period for fecal shedding of ceftiofur-resistant gram-negative bacteria. Ceftiofur-resistant Escherichia coli isolates (n = 122) were characterized by antimicrobial resistance (disk diffusion and MIC), serotype, pulsed-field gel electrophoresis subtypes, beta-lactamase genes, and virulence genes. Antibiotic disk diffusion assays showed that the isolates were resistant to ampicillin (100%), ceftiofur (100%), chloramphenicol (94%), florfenicol (93%), gentamicin (89%), spectinomycin (72%), tetracycline (98%), ticarcillin (99%), and ticarcillin-clavulanic acid (99%). All isolates were multidrug resistant and displayed elevated MICs. The E. coli isolates belonged to 42 serotypes, of which O8:H25 was the predominant serotype (49.2%). Pulsed-field gel electrophoresis classified the E. coli isolates into 27 profiles. Cluster analysis showed that 77 isolates (63.1%) belonged to one unique group. The prevalence of pathogenic E. coli was low (8%). A total of 117 ceftiofur-resistant E. coli isolates (96%) possessed the bla(CMY2) gene. Based on phenotypic and genotypic characterization, the ceftiofur-resistant E. coli isolates belonged to 59 clonal types. There was no significant relationship between calf age and clonal type. The findings of this study revealed that healthy dairy calves were rapidly colonized by antibiotic-resistant strains of E. coli shortly after birth. The high prevalence of multidrug-resistant nonpathogenic E. coli in calves could be a significant source of resistance genes to other bacteria that share the same environment. | 2006 | 16751500 |
| 2667 | 16 | 0.9998 | Prevalence, virulence and antimicrobial resistance patterns of Aeromonas spp. isolated from children with diarrhea. BACKGROUND: Aeromonas spp. cause various intestinal and extraintestinal diseases. These bacteria are usually isolated from fecal samples, especially in children under five years old. The aim of this study was to assess the prevalence of Aeromonas spp. and their antimicrobial resistance profile in children with diarrhea referred to the Children Medical Center in Tehran, between 2013 and 2014. METHODS: A total number of 391 stool samples were collected from children with ages between 1 day and 14 years old, with diarrhea (acute or chronic), referred to the Children Hospital, Tehran, Iran, between 2013 and 2014. Samples were enriched in alkaline peptone water broth for 24 hours at 37 °C and then cultured. Suspicious colonies were analyzed through biochemical tests. Furthermore, antimicrobial susceptibility tests were carried out for the isolates. Isolates were further studied for act, ast, alt, aerA and hlyA virulence genes using polymerase chain reaction. RESULTS: In total, 12 isolates (3.1%) were identified as Aeromonas spp.; all were confirmed using the API-20E test. Of these isolates, five A. caviae (42%), four A. veronii (33%) and three A. hydrophila (25%) were identified in cases with gastroenteritis. Second to ampicillin (which was included in the growth medium used), the highest rate of antimicrobial resistance was seen against nalidixic acid and trimethoprim-sulfamethoxazole (5 isolates each, 41.6%) and the lowest rate of antimicrobial resistance was seen against gentamicin, amikacin and cefepime (none of the isolates). Results included 76.4% act, 64.7% ast, 71.5% alt, 83.3% aerA and 11.7% hlyA genes. CONCLUSION: Aeromonas spp. are important due to their role in diarrhea in children; therefore, isolation and identification of these fecal pathogens should seriously be considered in medical laboratories. Since virulence genes play a significant role in gastroenteritis symptoms caused by these bacteria, Aeromonas species that include virulence genes are potentially suspected to cause severe infections. Moreover, bacterial antimicrobial resistance is increasing, especially against trimethoprim-sulfamethoxazole and nalidixic acid. | 2016 | 27622161 |
| 1166 | 17 | 0.9998 | Yearly incidence of acute childhood gastroenteritis in Nigeria: Implicated pathogens predominantly harbor blaCTXM and blaTEM genes. BACKGROUND AND OBJECTIVES: Routine use of antibiotics for infectious diarrhea in children is associated with the risk of increasing antibiotic resistance in developing countries. This work aimed to study the predominant extended spectrum beta-lactamase (ESBL) genes among bacteria pathogens implicated in acute childhood gastroenteritis in a tertiary hospital in Nigeria. MATERIALS AND METHODS: The stool samples of children diagnosed with acute gastroenteritis were collected. Isolation and identification of bacterial pathogens from the stool samples using standard microbiological and molecular sequencing methods. Pure cultures of the probable bacteria pathogens were subjected to antibiotics susceptibility profiling using the Kirby-Bauer Disk Diffusion Method and also screened for ESBL and AmpC using the Modified Double Disc Synergy Test. Primers for 5 different ESBL genes associated with beta-lactam antibiotic resistance were amplified and sequenced. RESULTS: Out of the 62 isolates, the highest number of organisms identified within the isolates were Bacillus sp at 38.7% (24) followed by Alcaligenes sp at 37% (23). Resistance to cefepime and ceftazidime were recorded at 50.8% (30) each. Ceftriaxone and cefotaxime were resisted in 47.4% (28) of the isolates. Out of 34 isolates resistant to all the cephalosporins used, 41.2% (14) were ESBL-producing, of which blaCTXM-1 and blaCTXM-2 were detected in 85.7%, while blaTEM was seen in 64.3%. CONCLUSIONS: blaCTXM and blaTEM may be the predominant ESBL genes haboured in the bacteria pathogens implicated in the yearly incidence of acute childhood gastroenteritis in Nigeria. This may be due to the widespread use of antibiotics in treating this disease. | 2025 | 39977466 |
| 2973 | 18 | 0.9998 | An evaluation of multidrug-resistant Escherichia coli isolates in urinary tract infections from Aguascalientes, Mexico: cross-sectional study. BACKGROUND: Uropathogenic Escherichia coli (UPEC) are one of the main bacteria causing urinary tract infections (UTIs). The rates of UPEC with high resistance towards antibiotics and multidrug-resistant bacteria have increased dramatically in recent years and could difficult the treatment. METHODS: The aim of the study was to determine multidrug-resistant bacteria, antibiotic resistance profile, virulence traits, and genetic background of 110 E. coli isolated from community (79 isolates) and hospital-acquired (31 isolates) urinary tract infections. The plasmid-mediated quinolone resistance genes presence was also investigated. A subset of 18 isolates with a quinolone-resistance phenotype was examined for common virulence genes encoded in diarrheagenic and extra-intestinal pathogenic E. coli by a specific E. coli microarray. RESULTS: Female children were the group most affected by UTIs, which were mainly community-acquired. Resistance to trimethoprim-sulfamethoxazole, ampicillin, and ampicillin-sulbactam was most prevalent. A frequent occurrence of resistance toward ciprofloxacin (47.3%), levofloxacin (43.6%) and cephalosporins (27.6%) was observed. In addition, 63% of the strains were multidrug-resistant (MDR). Almost all the fluoroquinolone (FQ)-resistant strains showed MDR-phenotype. Isolates from male patients were associated to FQ-resistant and MDR-phenotype. Moreover, hospital-acquired infections were correlated to third generation cephalosporin and nitrofurantoin resistance and the presence of kpsMTII gene. Overall, fimH (71.8%) and fyuA (68.2%), had the highest prevalence as virulence genes among isolates. However, the profile of virulence genes displayed a great diversity, which included the presence of genes related to diarrheagenic E. coli. Out of 110 isolates, 25 isolates (22.7%) were positive to qnrA, 23 (20.9%) to qnrB, 7 (6.4%) to qnrS1, 7 (6.4%) to aac(6')lb-cr, 5 (4.5%) to qnrD, and 1 (0.9%) to qnrC genes. A total of 12.7% of the isolates harbored bla(CTX-M) genes, with bla(CTX-M-15) being the most prevalent. CONCLUSIONS: Urinary tract infection due to E. coli may be difficult to treat empirically due to high resistance to commonly used antibiotics. Continuous surveillance of multidrug resistant organisms and patterns of drug resistance are needed in order to prevent treatment failure and reduce selective pressure. These findings may help choosing more suitable treatments of UTI patients in this region of Mexico. | 2018 | 30041652 |
| 2149 | 19 | 0.9998 | Cross-Resistance and the Mechanisms of Cephalosporin-Resistant Bacteria in Urinary Tract Infections Isolated in Indonesia. Urinary tract infection (UTI) by antibiotic-resistant strains has become increasingly problematic, with trends that differ from country to country. This study examined cross-resistance and the mechanisms of cephalosporin resistance in UTI-causative bacteria isolated in Indonesia. Antibiotic susceptibility tests based on Clinical Laboratory Standards Institute (CLSI) standards were done for UTI-causative strains (n = 50) isolated from patients in Indonesia in 2015-2016 and showed resistance against the third-generation cephalosporin. Mechanistic studies were carried out to confirm the presence of extended-spectrum β-lactamase (ESBL) genes, carbapenemase-related genes, the fosA3 gene related to fosfomycin resistance, and mutations of quinolone-resistance-related genes. Isolated UTI-causative bacteria included Escherichia coli (64.0%), Pseudomonas aeruginosa (16.0%), Klebsiella pneumoniae (10.0%), and others (10.0%). These strains showed 96.0% susceptibility to amikacin, 76.0% to fosfomycin, 90.0% to imipenem, 28.0% to levofloxacin, 92.0% to meropenem, and 74.0% to tazobactam/piperacillin. ESBL was produced by 68.0% of these strains. Mechanistic studies found no strains with carbapenemase genes but 6.0% of strains had the fosA3 gene. Seventy-two % of the strains had mutations in the gyrA gene and 74.0% in the parC gene. Most E. coli strains (87.5%) had Ser-83 → Leu and Asp-87 → Asn in gyrA and 93.8% of E. coli had Ser-80 → Ile in parC. There were significant correlations among mutations in gyrA and parC, and fosA3 gene detection (P < 0.05), respectively. To our knowledge, this is the first mechanistic study of antibiotic-cross-resistant UTI-causative bacteria in Indonesia. Further studies with a longer period of observation are necessary, especially for changes in carbapenem resistance without carbapenemase-related genes. | 2021 | 33713209 |