# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 1248 | 0 | 1.0000 | Clonal Dissemination of Clinical Isolates of Acinetobacter baumannii Carriers of 16S rRNA Methylase Genes in an Oncological Hospital in Recife, Brazil. 16S rRNA methylases confer high-level resistance to aminoglycosides which are used to treat serious infections caused by gram-negative bacteria, such as Acinetobacter spp. Some genes encoding these enzymes are disseminated worldwide, while others were detected in only some countries. The objective was to characterize the susceptibility profile to aminoglycosides (amikacin and gentamicin) of clinical isolates of Acinetobacter spp. from an oncological hospital in Recife, and given the resistance to both antimicrobials, to characterize minimal inhibitory concentrations (MICs) of amikacin, gentamicin and tobramycin, the occurrence of 16S rRNA methylase genes (armA, rmtB, rmtC and rmtD) and of ß-lactamase gene (bla(KPC)) and the clonal profile. Isolates resistant to both antimicrobials, amikacin and gentamicin, were selected by disk diffusion technique in Mueller-Hinton agar and identified. Broth microdilution was conducted to determine MICs of amikacin, gentamicin, and tobramycin. These isolates were subjected to polymerase chain reaction and pulsed-field gel electrophoresis. Among 23 analyzed isolates, 12 (52.2%) were resistant to gentamicin and amikacin and identified as Acinetobacter baumannii. Among these, 11 (91.7%), 12 (100%), and 9 (75%) isolates showed respectively MICs > 256 µg/mL of amikacin, > 64 µg/mL of gentamicin, and > 64 µg/mL of tobramycin. The armA gene was found in 12 (100%) isolates and 6 (50%) showed coexistence of armA, rmtB, and rmtC genes. The rmtD and bla(KPC) genes were not detected. These isolates showed high genetic similarity (92%) and were classified as clone A. Elaboration and fulfillment of measures are thus essential to prevent the spread of this resistance mechanism. | 2020 | 31655862 |
| 1249 | 1 | 0.9998 | High-Level Resistance to Aminoglycosides due to 16S rRNA Methylation in Enterobacteriaceae Isolates. Introduction: High-level aminoglycoside resistance due to methylase genes has been reported in several countries. The purpose of this study was to investigate the diversity of the genes encoding 16S rRNA methylase and their association with resistance phenotype in Enterobacteriacae isolates. Materials and Methods: Based on sampling size formula, from February to August 2014, a total of 307 clinical Enterobacteriaceae isolates were collected from five hospitals in northwest Iran. The disk diffusion method for amikacin, gentamicin, tobramycin, kanamycin, and streptomycin, as well as the minimum inhibitory concentration (MIC) for aminoglycosides (except streptomycin), was used. Six 16S rRNA methylase genes (armA, npmA, and rmtA-D) were screened by PCR and sequencing assays. Results: In this study, 220 (71.7%) of 307 isolates were aminoglycoside resistant and 40 isolates (18.2%, 40/220) were positive for methylase genes. The frequency of armA, rmtC, npmA, rmtB, and rmtA genes was 9.5%, 4.5%, 3.6%, 2.3%, and 1%, respectively. The rmtD gene was not detected in the tested bacteria. Sixty percent of positive methylase gene isolates displayed high-level resistance (MIC ≥512 μg/mL to amikacin and kanamycin; and MIC ≥128 μg/mL to gentamicin and tobramycin). Conclusions: The prevalence of resistance to aminoglycoside in Iran is high. Furthermore, there is a statistically significant association between amikacin and kanamycin resistance with the presence of rmtC and rmtB genes. | 2019 | 31211656 |
| 2176 | 2 | 0.9998 | Evaluation of phenotypic and genotypic patterns of aminoglycoside resistance in the Gram-negative bacteria isolates collected from pediatric and general hospitals. The purpose of the current study was to evaluate the phenotypic and genotypic patterns of aminoglycoside resistance among the Gram-negative bacteria (GNB) isolates collected from pediatric and general hospitals in Iran. A total of 836 clinical isolates of GNB were collected from pediatric and general hospitals from January 2018 to the end of December 2019. The identification of bacterial isolates was performed by conventional biochemical tests. Susceptibility to aminoglycosides was evaluated by the disk diffusion method (DDM). The frequency of genes encoding aminoglycoside-modifying enzymes (AMEs) was screened by the PCR method via specific primers. Among all pediatric and general hospitals, the predominant GNB isolates were Acinetobacter spp. (n = 327) and Escherichia coli (n = 144). However, E. coli (n = 20/144; 13.9%) had the highest frequency in clinical samples collected from pediatrics. The DDM results showed that 64.3% of all GNB were resistant to all of the tested aminoglycoside agents. Acinetobacter spp. and Klebsiella pneumoniae with 93.6%, Pseudomonas aeruginosa with 93.4%, and Enterobacter spp. with 86.5% exhibited very high levels of resistance to gentamicin. Amikacin was the most effective antibiotic against E. coli isolates. In total, the results showed that the aac (6')-Ib gene with 59% had the highest frequency among genes encoding AMEs in GNB. The frequency of the surveyed aminoglycoside-modifying enzyme genes among all GNB was found as follows: aph (3')-VIe (48.7%), aadA15 (38.6%), aph (3')-Ia (31.3%), aph (3')-II (14.4%), and aph (6) (2.6%). The obtained data demonstrated that the phenotypic and genotypic aminoglycoside resistance among GNB was quite high and it is possible that the resistance genes may frequently spread among clinical isolates of GNB. | 2022 | 35119565 |
| 1250 | 3 | 0.9998 | Distribution of 16S rRNA methylases among different species of Gram-negative bacilli with high-level resistance to aminoglycosides. 16S rRNA methylases confer high-level resistance to most aminoglycosides in Gram-negative bacteria. Seven 16S rRNA methylase genes, armA, rmtA, rmtB, rmtC, rmtD, rmtE and npmA, have been identified since 2003. We studied the distribution of methylase genes in more than 200 aminoglycoside-resistant Gram-negative clinical isolates collected in 2007 at our hospital in Shanghai, China. 16S rRNA methylase genes were amplified by polymerase chain reaction (PCR) among 217 consecutive clinical isolates of Gram-negative bacilli resistant to gentamicin and amikacin by a disk diffusion method. 16S rRNA methylase genes were present in 97.5% (193/198) of clinical isolates highly resistant to amikacin (≥512 μg/ml), with armA and rmtB detected in 67.2 and 30.3% of strains, respectively, while no 16S rRNA methylase genes were detected in 19 strains with amikacin minimum inhibitory concentration (MIC) ≤256 μg/ml. armA or rmtB genes were detected in 100% of 104 strains of Enterobacteriaceae, and these two genes were equally represented (49 vs. 55 strains). Genes for armA or rmtB were detected in 94.7% (89/94) of Acinetobacter baumannii and Pseudomonas aeruginosa strains, and armA was predominant (84 vs. 5 strains with rmtB). No rmtA, rmtC, rmtD or npmA genes were found. Enterobacterial repetitive intergenic consensus sequence (ERIC-PCR) indicated that armA and rmtB genes were spread by both horizontal transfer and clonal dissemination. | 2010 | 20614151 |
| 1127 | 4 | 0.9998 | Extended spectrum beta-lactamase and aminoglycoside modifying enzyme genes in multi drug resistant Gram-negative bacteria: A snapshot from a tertiary care centre. BACKGROUND: This study aims to enhance the existing knowledge of the prevalence of genes responsible for beta-lactam resistance and aminoglycoside resistance in gram negative organisms by molecular detection of extended spectrum beta-lactamase and aminoglycoside modifying enzymes in multidrug-resistant gram-negative bacteria. METHODS: Out of 864 gram-negative isolates, 710 were phenotypically identified as multidrug-resistant by antibiotic susceptibility testing. From the above isolates, 102 representative isolates as per sample size calculated were selected for further molecular studies. The presence of blaTEM, blaCTX-M blaSHV, and five AmpC genes was detected by real-time polymerase chain reaction (PCR). Conventional PCR was performed to detect seven aminoglycoside modifying enzyme genes namely aac(6')-Ib, aac(6')-Ic, aac(3)-Ia, aac(3)-Ib, aac(3)-IIa, ant(2'')-Ia, and ant(4'')-IIa. RESULTS: Most common multidrug-resistant isolate was Klebsiella pneumoniae (35%) followed by Escherichia coli (30%). Among the 102 selected isolates all harboured blaTEM gene, 71 (69.6%) harboured blaCTX-M gene and 48 (47%) blaSHV gene. Among the selected isolates 60% showed the presence of AmpC genes. Most common aminoglycosie modifying enzyme gene was AAC 6' Ib (51%) followed by ANT 2" Ia (36%). CONCLUSION: This study suggests a wider use of molecular methods using specific PCR amplification of resistance genes. It would be beneficial to perform the molecular identification of antimicrobial resistance genes to effectively monitor and manage antibiotic resistance, administer appropriate antimicrobial medication, practice antimicrobial stewardship and improve hospital infection control procedures. | 2024 | 39734850 |
| 2177 | 5 | 0.9997 | Evaluating the Frequency of aac(6')-IIa, ant(2″)-I, intl1, and intl2 Genes in Aminoglycosides Resistant Klebsiella pneumoniae Isolates Obtained from Hospitalized Patients in Yazd, Iran. BACKGROUND: Klebsiella pneumoniae (K. pneumoniae) is an opportunistic pathogen that could be resistant to many antimicrobial agents. Resistance genes can be carried among gram-negative bacteria by integrons. Enzymatic inactivation is the most important mechanism of resistance to aminoglycosides. In this study, the frequencies of two important resistance gene aac(6')-IIa and ant(2″)-I, and genes coding integrase I and II, in K. pneumoniae isolates resistant to aminoglycosides were evaluated. METHODS: In this cross-sectional study, an attempt was made to assess the antibiotic susceptibility of 130 K. pneumoniae isolates obtained from different samples of patients hospitalized in training hospitals of Yazd evaluated by disk diffusion method. The frequencies of aac(6')-IIa, ant(2″)-I, intl1, and intl2 genes were determined by PCR method. Data were analyzed by chi-square method using SPSS software (Ver. 16). RESULTS: our results showed that resistance to gentamicin, tobramycin, kanamycin, and amikacin were 34.6, 33.8, 43.8, and 14.6%, respectively. The frequencies of aac (6')-IIa, ant(2″)-I, intl1, and intl2 genes were 44.6, 27.7, 90, and 0%, respectively. CONCLUSION: This study showed there are high frequencies of genes coding aminoglycosides resistance in K. pneumoniae isolates. Hence, it is very important to monitor and inhibit the spread of antibiotic resistance genes. | 2018 | 29849989 |
| 2147 | 6 | 0.9997 | 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 |
| 923 | 7 | 0.9997 | Prevalence of Oxacillinase Genes in Clinical Multidrug-Resistant Gram-Negative Bacteria. BACKGROUND: The emergence of OXA-type beta-lactamases has become a significant threat to public healthcare systems and may lead to prolonged hospital stays and increased mortality rates among affected patients. This study aimed to determine the prevalence of oxacillinase resistance (OXA) genes in multidrug-resistant (MDR) Gram-negative bacteria. METHODS: One hundred and six clinical isolates were collected from a stock of Gram-negative isolates and were identified and tested for antibiotic susceptibility and presence of OXA genes using polymerase chain reaction (PCR). RESULTS: The most common detected isolate was Klebsiella pneumoniae (36.8%), followed by Escherichia coli (33%), Pseudomonas aeruginosa (16%), and Acinetobacter baumannii (14.2%). Out of these isolates, 97.4%, 87.2%, 84.6%, and 79.5% were resistant to ampicillin/sulbactam, cefotaxime, ceftazidime, and aztreonam, respectively. PCR results confirmed the presence of one or more OXA genes in 34% of the samples studied. The blaOXA-1 and blaOXA-10 genes were the most highly detected genes, followed by blaOXA-4 and blaOXA-51. The total number of Pseudomonas aeruginosa isolates was confirmed to carry at least one OXA gene (70.6%), whereas Acinetobacter baumannii, Klebsiella pneumoniae, and Escherichia coli were confirmed to carry at least one OXA gene (53.3, 28.2, and 22.9%, respectively). There was a significant association (p < 0.05) between the resistance genes and the type of isolate. CONCLUSIONS: Pseudomonas aeruginosa and Acinetobacter baumannii are the most common MDR Gram-negative strains carrying OXA-type beta-lactamase genes. Monitoring of MDR pathogens in Gram-negative bacteria must be continuously undertaken to implement effective measures for infection control and prevention. | 2025 | 40066541 |
| 1449 | 8 | 0.9997 | A prospective surveillance study to determine the prevalence of 16S rRNA methyltransferase-producing Gram-negative bacteria in the UK. OBJECTIVES: To determine the prevalence of 16S rRNA methyltransferase- (16S RMTase-) producing Gram-negative bacteria in patients in the UK and to identify potential risk factors for their acquisition. METHODS: A 6 month prospective surveillance study was conducted from 1 May to 31 October 2016, wherein 14 hospital laboratories submitted Acinetobacter baumannii, Enterobacterales and Pseudomonas aeruginosa isolates that displayed high-level amikacin resistance according to their testing methods, e.g. no zone of inhibition with amikacin discs. Isolates were linked to patient travel history, medical care abroad, and previous antibiotic exposure using a surveillance questionnaire. In the reference laboratory, isolates confirmed to grow on Mueller-Hinton agar supplemented with 256 mg/L amikacin were screened by PCR for 16S RMTase genes armA, rmtA-rmtH and npmA, and carbapenemase genes (blaKPC, blaNDM, blaOXA-48-like and blaVIM). STs and total antibiotic resistance gene complement were determined via WGS. Prevalence was determined using denominators for each bacterial species provided by participating hospital laboratories. RESULTS: Eighty-four isolates (44.7%), among 188 submitted isolates, exhibited high-level amikacin resistance (MIC >256 mg/L), and 79 (94.0%) of these harboured 16S RMTase genes. armA (54.4%, 43/79) was the most common, followed by rmtB (17.7%, 14/79), rmtF (13.9%, 11/79), rmtC (12.7%, 10/79) and armA + rmtF (1.3%, 1/79). The overall period prevalence of 16S RMTase-producing Gram-negative bacteria was 0.1% (79/71 063). Potential risk factors identified through multivariate statistical analysis included being male and polymyxin use. CONCLUSIONS: The UK prevalence of 16S RMTase-producing Gram-negative bacteria is low, but continued surveillance is needed to monitor their spread and inform intervention strategies. | 2021 | 34142130 |
| 1122 | 9 | 0.9997 | Antibiotic resistance profiles of gram-negative bacteria in southern Tunisia: Focus on ESBL, carbapenem and colistin resistance. The main objective of this cross-sectional study was to investigate the prevalence of beta-lactam (cephalosporins or carbapenems) or colistin resistant bacteria. Those were isolated from urine samples in two private polyclinics located in the Sfax region, in southern Tunisia. From September 2021 to August 2022, 116 strains resistant to β-lactams or colistin were isolated, identified by MALDI-TOF, and their antibiotic susceptibility was assessed by disk diffusion method. Resistance genes were detected by real-time PCR, standard PCR, and sequencing. The results revealed that the 116 strains consisted predominantly of Enterobacteriaceae (92.2 %) and non-fermenting bacteria (7.8 %). Among these strains, 21 (18.1 %) were resistant to carbapenems, three (2.7 %) to colistin, including two strains of Klebsiella pneumoniae (1.7 %) exhibiting resistance to both carbapenems and colistin. In Enterobacteriaceae, bla(CTX-A), bla(SHV), and bla(TEM) were found in 79.5 %, 46.7 %, and 40.2 % of strains, respectively. For these strains, the minimum inhibitory concentrations (MICs) of imipenem and ertapenem ranged from >32 to 6 μg/mL and > 32 to 2 μg/mL, respectively, with bla(OXA-48) and bla(NDM) detected in 21.7 % and 19.6 % of isolates, respectively. Seven A. baumannii isolates resistant to imipenem and meropenem (MICs >32 μg/mL and 8 μg/mL, respectively) carried bla(OXA-23) (n = 5) and bla(OXA-24) (n = 2). In addition, mutations in the mgrB gene conferring colistin resistance were identified in two isolates. Two K. pneumoniae were colistin-resistant and carried the bla(OXA-48) gene. These results highlight the urgency of developing new strategies for the identification and surveillance of pathogenic strains in humans to effectively combat this growing public health threat in Tunisia. | 2025 | 40553790 |
| 2164 | 10 | 0.9997 | Tetracycline susceptibility testing and resistance genes in isolates of Acinetobacter baumannii-Acinetobacter calcoaceticus complex from a U.S. military hospital. Infections with multidrug-resistant Acinetobacter baumannii-Acinetobacter calcoaceticus complex bacteria complicate the care of U.S. military personnel and civilians worldwide. One hundred thirty-three isolates from 89 patients at our facility during 2006 and 2007 were tested by disk diffusion, Etest, and broth microdilution for susceptibility to tetracycline, doxycycline, minocycline, and tigecycline. Minocycline was the most active in vitro, with 90% of the isolates tested susceptible. Susceptibilities varied significantly with the testing method. The acquired tetracycline resistance genes tetA, tetB, and tetA(39) were present in the isolates. | 2009 | 19307365 |
| 2159 | 11 | 0.9997 | Involvement of the AcrAB Efflux Pump in Ciprofloxacin Resistance in Clinical Klebsiella Pneumoniae Isolates. BACKGROUND: Increasing prevalence of multiple antibiotic resistance in Klebsiella pneumoniae strains confines the therapeutic options used to treat bacterial infections. OBJECTIVE: We aimed in this study to investigate the role of AcrAB and qepA efflux pumps and AAC(6')-Ib-cr enzyme in ciprofloxacin resistance and to detect the RAPD-PCR fingerprint of K. pneumoniae isolates. METHODS: A total of , 117 K. pneumoniae isolates were collected from hospitalized patients in three hospitals in Tehran, Iran, from August 2013 to March 2014. Antimicrobial susceptibility tests were performed by the disk diffusion method. Molecular identification and expression level of encoding quinolone resistance genes, acrA, acrB, qepA, and aac(6')-Ib-cr, were performed by PCR and real-- time PCR assays, respectively. All the K. pneumoniae isolates containing the mentioned genes were used simultaneously for RAPD-PCR typing. RESULTS: Colistin and carbapenems were the most efficient antibiotics against the clinical isolates of K. pneumoniae. PCR assay demonstrated that among the 117 isolates, 110 (94%) and 102 (87%) were positive for acrA and acrB gene and 5 (4%) and 100 (85%) isolates showed to have qepA and aac(6')-Ib-cr genes, respectively. Determination for AcrAB pump expression in 21% of strains demonstrated an increased expression, and the mean increase expression for acrB genes was 0.5-81. The results of RAPD-PCR reflected that in 95% CI, all isolates belonged to a clone. CONCLUSION: A high prevalence of genes encoding quinolone resistance in K. pneumoniae was detected in clinical samples. Therefore, the control of infection and prevention of drug-resistant bacteria spread need careful management of medication and identification of resistant isolates. | 2021 | 32888276 |
| 1130 | 12 | 0.9997 | 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 |
| 1125 | 13 | 0.9997 | 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 |
| 1129 | 14 | 0.9997 | Genotypic and phenotypic profiles of antibiotic-resistant bacteria isolated from hospitalised patients in Bangladesh. OBJECTIVES: Characterisation of resistance phenotype and genotype is crucial to understanding the burden and transmission of antimicrobial resistance (AMR). This study aims to determine the spectrum of AMR and associated genes encoding aminoglycoside, macrolide and β-lactam classes of antimicrobials in bacteria isolated from hospitalised patients in Bangladesh. METHODS: 430 bacterial isolates from patients with respiratory, intestinal, wound infections and typhoid fever, presenting to clinical care from 2015 to 2019, were examined. They included Escherichia coli (n = 85); Staphylococcus aureus (n = 84); Salmonella typhi (n = 82); Klebsiella pneumoniae (n = 42); Streptococcus pneumoniae (n = 36); coagulase-negative staphylococci (n = 28); Enterococcus faecalis (n = 27); Pseudomonas aeruginosa (n = 26); and Acinetobacter baumannii (n = 20). Reconfirmation of these clinical isolates and antimicrobial susceptibility tests was performed. PCR amplification using resistance gene-specific primers was done, and the amplified products were confirmed by Sanger sequencing. RESULTS: 53% of isolates were multidrug-resistant (MDR), including 97% of Escherichia coli. There was a year-wise gradual increase in MDR isolates from 2015 to 2018, and there was an almost twofold increase in the number of MDR strains isolated in 2019 (P = 0.00058). Among the 5 extended-spectrum β-lactamases investigated, CTX-M-1 was the most prevalent (63%) followed by NDM-1 (22%); Escherichia coli was the major reservoir of these genes. The ermB (55%) and aac(6')-Ib (35%) genes were the most frequently detected macrolide and aminoglycoside resistance genes, respectively. CONCLUSION: MDR pathogens are highly prevalent in hospital settings of Bangladesh. | 2021 | 33838068 |
| 1110 | 15 | 0.9997 | Antimicrobial resistance profiling of bacteria isolated from wastewater and samples of pharmaceutical industries in South India. The study was aimed to determine the phenotypic and genotypic antimicrobial resistance in the isolated bacteria from the influent (25), effluent (15), surface and ground water samples (15) surrounding the pharmaceutical industries located in south India. From 55 samples, 48 isolates of 10 different bacteria were obtained. The identified bacterial isolates were viz. Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterobacter aerogenes, Corynebacterium sp., Acinetobacter sp., Aeromonas punctata, Ralstonia picketti, Staphylococcus aureus, Stenotrophomonas maltophillia, and Citrobacter freundii. The phenotypic profile of resistance through antibiotic susceptibility test was carried out against sixteen different antibiotics. Standard PCR technique was used for the detection of 12 resistance genes encoding carbapenems, quinoline, aminoglycoside, β-lactam belonging blaOXA-58(,)blaOXA-22(,)qnrA, qnrB, aac(6)-Ib-cr, aac (3)-XI, mec A, qepA, aadB, blaVIM, blaOXA-48 and blaNDM. Pseudomonas aeruginosa (1: TN/I/2020) showed presence of 3 resistance genes. qnrB (489 bp) gene was present in maximum of 7 isolates while blaVIM (196 bp) gene was present in 6 isolates. The resistance genes blaNDM (621 bp) was present in three different isolates; aac (X):6)-lb-cr (482 bp), qepA (495 bp), aadB (500 bp), blaOXA-58 (843 bp) resistant genes were present in two different isolates each among the bacterial isolates obtained in this study. In phenotypic resistance profiling by AST method, out of 16 antibiotics tested, 14 showed resistance. Similarly, in genotypic resistance profiling, among 12 resistance genes tested, a maximum of three resistance genes were noticed in Pseudomonas aeruginosa. There were positive and negative correlations observed between phenotypic and genotypic resistance among different antibiotics and their resistance genes indicating the variations in the resistance gene expression. | 2024 | 39303927 |
| 1124 | 16 | 0.9997 | Molecular Identification of Extended-Spectrum β-lactamase and Integron Genes in Klebsiella Pneumonia. INTRODUCTION: Infections caused by Gram negative bacteria, producing extended-spectrum β-lactamase, including Klebsiella pneumoniae are increasing all over the world with high morbidity and mortality. The aim of the present study was determined antimicrobial profile susceptibility and the prevalence of antibiotic resistance genes by multiplex PCR. METHODS: In the present study, we obtained one-hundred isolates of K. pneumoniae from different clinical samples. The antibiotic susceptibility testing was done in thirteen antibiotic and, therefore, M-PCRs were conducted using the DNA amplification for detection of ESBLs (blaTEM, blaCTX-M, blaSHV) and int (I, II, III) genes. RESULTS: The results of resistance to amoxicillin/clavulanate, ciprofloxacin, amikacin, trimethoprim-sulfamethoxazole, cefotaxime, ampicillin, aztreonam, imipenem, gentamicin, ceftazidime, Cefepime, ceftriaxone and levofloxacin were obtained 37%, 37%, 93%, 84%, 52%, 87%, 59%, 8%, 24%, 67%, 52%, 43% and 26%, respectively. The frequency of the extended-spectrum β-lactamase K. pneumoniae was obtained 37%. The prevalence of resistance genes of ESBLs in the M-PCR method showed that the blaTEM, blaCTX and blaSHV were 38%, 24% and 19%, respectively, however, only 8 (8%) out of 100 isolates were found to have positive outcomes for the existence of class 1 integrons and there were no detected class 2 or class 3 integrons. CONCLUSIONS: Our results recommend the likely co-carriage of some ESBLs genes and antibiotic resistance integrons on the same plasmids harboring the MDR genes. | 2016 | 27935927 |
| 2150 | 17 | 0.9997 | 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 |
| 1132 | 18 | 0.9997 | A Study on Multidrug-Resistant Escherichia coli Clinical Isolates from Different Hospitals in Greater Cairo. The biological fitness cost of antibiotic resistance is a key parameter in determining the rate of appearance and spread of antibiotic-resistant bacteria in Egypt. Our study aimed to investigate the prevalence of antibiotic resistance among Escherichia coli clinical isolates from Greater Cairo area hospitals. A total of 537 clinical isolates were recovered from samples of urine, diarrheal specimen, pus, wound culture, gastric wound, blood, drain culture, sputum, high vaginal swab, abscess, amniotic fluid, ventilator, burn swab, splenic drain culture, and unknown site of infection during different seasons. All isolates were subjected to phenotypic and genotypic susceptibility testing for colistin, nitrofurantoin, fosfomycin, and trimethoprim, quinolones, and β-lactam resistance. Our results revealed that 42.7% of the isolates harbored at least one resistance encoding gene, 10% harboring 2, 0.6% harboring 3, and 0.85% harboring 4 resistance-encoding genes. PCR reported the prevalence of resistance genes as follows: bla-SHV 13.4%, mcr-1 0.6%, qnr-A 23.8%, fos-A 1.06%, nfs-A 3.6%, and dfr-A 25.5%. We reported that three isolates carried the mcr-1 gene encoding colistin resistance from three different hospitals. Upon performing sequencing and phylogenetic analysis on the three positive mcr-1 isolates (MT890587, MT890588, and MT890589), the three isolates showed 100% identity with themselves, with some strains from Egypt and Japan, and 99.9% identity with an isolate from China. | 2021 | 34042527 |
| 1131 | 19 | 0.9997 | Antimicrobial resistance genotypes and phenotypes from multidrug-resistant bacterial wound infection isolates in Cambodia. This study aimed to identify the molecular determinants responsible for antibiotic resistance among human wound isolates in Cambodia. Staphylococcus spp. (n=10) and a variety of Gram-negative isolates (n=21) were taken from a larger collection of wound isolates collected during 2011-2013 and were analysed for the presence of >230 resistance determinants using a broad-spectrum DNA microarray. These isolates were chosen to represent the species most commonly found in wound isolates referred during this time and to include some of the most resistant strains. Resistance determinants detected among the staphylococci included blaZ (90%), mecA (100%), erm(B) (70%), erm(C) (20%), tet(38) (90%), tet(K) (40%), tet(L(p)) (10%), tet(M) (20%), lnu(A)/lin(A) and lnu(B)/lin(B) (10% each), msr(A)/msr(B)/msr(SA) (10%), norA (80%) and dfrA (10%). Eleven different β-lactamase genes were detected among the Gram-negative bacteria, including genes encoding the TEM (48%), CTX-M-1 (48%), CTX-M-9 (5%), SHV (5%) and VEB (10%) families of broad-spectrum and extended-spectrum β-lactamase enzymes, as well as the carbapenemase gene bla(OXA-23). Forty additional genes were also detected in the Gram-negative isolates conferring resistance to aminoglycosides (11 genes), phenicols (5 genes), macrolides [4 genes, including mph(A)/mph(K) (10%)], lincosamides [lnu(F)/lin(F), lnu(G)/lin(G)], tetracycline (4 genes), rifampicin [arr (29%)], quaternary amines [qacEΔ1 (43%)], quinolones [qnrS (14%) and qnrB (5%)], sulfonamides [sul1 (29%), sul2 (38%) and sul3 (10%)], streptothricin (sat2) and trimethoprim (6 genes). The results obtained here provide a snapshot of the broad variety of resistance determinants currently circulating within Cambodia. | 2015 | 27873709 |