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. - Related Documents




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217701.0000Evaluating 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.201829849989
217610.9999Evaluation 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.202235119565
217820.9999Antimicrobial resistance patterns and their encoding genes among clinical isolates of Acinetobacter baumannii in Ahvaz, Southwest Iran. Acinetobacter baumannii is one of the most important organisms in nosocomial infections. Antibiotic resistance in this bacterium causes many problems in treating patients. This study aimed to investigate antibiotic resistance patterns and resistance-related, genes in clinical isolates of Acinetobacter baumannii. This descriptive study was conducted on 124 isolates of Acinetobacter baumannii collected from clinical samples in two teaching hospitals in Ahvaz. The antibiotic resistance pattern was determined by disk diffusion. The presence of genes coding for antibiotic resistance was determined using the polymerase chain reaction method. Out of 124 isolates, the highest rate of resistance was observed for rifampin (96.8%). The resistance rate for imipenem, meropenem, colistin, and polymyxin-B were 78.2%, 73.4%, 0.8% and 0.8%, respectively. The distribution of qnrA, qnrB, qnrS, Tet A, TetB, and Sul1genes were 52.6%, 0%, 3.2%, 93.5% 69.2%, and 6.42%, respectively. High prevalence of tetA, tetB, and qnrA genes among Acinetobacter baumannii isolated strains in this study indicate the important role of these genes in multidrug resistance in this bacteria. • Acinetobacter baumannii is an important human pathogen that has attracted the attention of many researchers Antibiotic resistance in this bacterium causes many problems in treating patients. • The resistance rate for imipenem, meropenem, colistin, and polymyxin-B were 78.2%, 73.4%, 0.8% and 0.8%, respectively. The distribution of qnrA, qnrB, qnrS, Tet A, TetB, and Sul1genes were 52.6%, 0%, 3.2%, 93.5% 69.2%, and 6.42%, respectively.202032983919
217530.9998Drug-resistant genes carried by Acinetobacter baumanii isolated from patients with lower respiratory tract infection. BACKGROUND: Acinetobacter baumanii (A. baumanii ) remains an important microbial pathogen resulting in nosocomial acquired infections with significant morbidity and mortality. The mechanism by which nosocomial bacteria, like A. baumanii, attain multidrug resistance to antibiotics is of considerable interest. The aim in this study was to investigate the spread status of antibiotic resistance genes, such as multiple β-lactamase genes and aminoglycoside-modifying enzyme genes, from A. baumanii strains isolated from patients with lower respiratory tract infections (LRTIs). METHODS: Two thousand six hundred and ninety-eight sputum or the bronchoalveolar lavage samples from inpatients with LRTIs were collected in 21 hospitals in the mainland of China from November 2007 to February 2009. All samples were routinely inoculated. The isolated bacterial strains and their susceptibility were analyzed via VITEK-2 expert system. Several kinds of antibiotic resistant genes were further differentiated via polymerase chain reaction and sequencing methods. RESULTS: Totally, 39 A. baumanii strains were isolated from 2698 sputum or bronchoalveolar lavage samples. There was not only a high resistant rate of the isolated A. baumanii strains to ampicillin and first- and second-generation cephalosporins (94.87%, 100% and 97.44%, respectively), but also to the third-generation cephalosporins (ceftriaxone at 92.31%, ceftazidine at 51.28%) and imipenem (43.59%) as well. The lowest antibiotic resistance rate of 20.51% was found to amikacin. The OXA-23 gene was identified in 17 strains of A. baumanii, and the AmpC gene in 23 strains. The TEM-1 gene was carried in 15 strains. PER-1 and SHV-2 genes were detected in two different strains. Aminoglycoside-modifying enzyme gene aac-3-Ia was found in 23 strains, and the aac-6'-Ib gene in 19 strains. aac-3-Ia and aac-6'-Ib genes hibernated in three A. baumanii strains that showed no drug-resistant phenotype. CONCLUSIONS: A. baumanii can carry multiple drug-resistant genes at the same time and result in multi-drug resistance. Aminoglycoside-modifying enzyme genes could be hibernating in aminoglycoside sensitive strains without expressing their phenotype.201021034630
217940.9998Increasing frequency of Aminoglycoside-Resistant Klebsiella pneumoniae during the era of pandemic COVID-19. The emergence of multidrug resistance to aminoglycosides in K. pneumoniae isolates is a growing concern, especially during pandemic Coronavirus disease 2019 (COVID-19). The study identifies antibiotic resistance in K. pneumoniae isolated from tertiary hospitals during pandemic COVID-19. Among 220 clinical isolates, the total rate of K. pneumoniae was found to be 89 (40.5%). Phenotyping results confirmed the resistance of aminoglycoside antibiotics in 51 (23.2%) of K. pneumoniae isolates. PCR results confirmed the existence of one or more aminoglycoside genes in 82.3% of the 51 isolates. The rmtD gene was the highest-detected gene (66.7%), followed by aac(6')-Ib (45.1%), aph(3')-Ia (45.1%), rmtB (29.4%), armA (21.6%), aac(3)-II (7.8%), and rmtA (3) (11.8%). Significantly, higher resistance strains showed a higher prevalence (61.5%) of aminoglycoside genes (p < 0.05). During COVID-19, there is a higher risk of acquiring MDR bacterial infections, so the monitoring of multidrug resistant bacteria must be continuously undertaken to implement effective measures in infection control and prevention.202134075332
92350.9998Prevalence 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.202540066541
112760.9998Extended 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.202439734850
266870.9998Genotyping and distribution of putative virulence factors and antibiotic resistance genes of Acinetobacter baumannii strains isolated from raw meat. BACKGROUND: Acinetobacter baumannii strains with multiple antimicrobial resistance are primarily known as opportunistic nosocomial bacteria but they may also be regarded as emerging bacterial contaminants of food samples of animal origin. Here we aimed to study the molecular characteristics of the A. baumanni strains isolated from raw meat samples. METHODS: A total of 22 A. baumanni strains were isolated from 126 animal meat samples and were genotyped by ERIC-PCR method and by PCR detection of their virulence and antimicrobial resistance determinants. A. baumannii strains with 80% and more similarities were considered as one cluster. RESULTS: Sixteen different genetic clusters were found amongst the 22 A. baumanni strains. Of the 22 strains, 12 (54.54%) had similar genetic cluster. A. baumannii strains exhibited the highest percentage of resistance against tetracycline (90.90%), trimethoprim (59.09%), cotrimoxazole (54.54%) and gentamicin (50.00%). TetA (81.81%), tetB (72.72%), dfrA1 (63.63%), aac(3)-IV (63.63%), sul1 (63.63%) and aadA1 (45.45%) were the most commonly detected antibiotic resistance genes. FimH (81.81%), afa/draBC (63.63%), csgA (63.63%), cnf1 (59.09%), cnf2 (54.54%) and iutA (50.00%) were the most commonly detected virulence factors. A. baumannii strains isolated from the chicken meat samples had the highest similarities in the genetic cluster. CONCLUSIONS: A. baumannii strains with similar genetic cluster (ERIC-Type) had the same prevalence of antibiotic resistance, antibiotic resistance genes and virulence factors. Genetic cluster of the A. baumannii strains is the main factor affected the similarities in the genotypic and phenotypic properties of the A. baumannii strains.201830323923
217480.9998Frequency of Beta-Lactamase Antibiotic Resistance Genes in Escherichia Coli and Klebsiella pneumoniae. BACKGROUND: This cross-sectional study was performed on isolates of Klebsiella pneumoniae, and E.coli from clinical specimens of patients admitted to Sayyad Shirazi Hospital by census sampling method in 2019. Antibiogram testing was performed using the disk diffusion method as defined by the Clinical and Laboratory Standards Organization for performing this test. Finally, the abundance of genes was evaluated by PCR using specific primers. Frequency, percentage, mean±SD were used to describe the data. Chi-square and Fisher's exact tests were used to compare the presence and absence of the studied genes alone and in the presence of each other. RESULT: This study was performed on 130 positive samples, isolated from 32 (24.6%) males and 98 (65.4%) females with a mean age of 43.78 ± 21.72. From the total number of 130 isolates, 84 (64.6%) consisted of E.coli, and 46 (35.4%) were Klebsiella. Most of the cultures were urine and vaginal (61.5%). The highest antibiotic resistance in isolates was cephalexin and cefazolin (67.9% in E.coli & 63% in Klebsiella). Colistin was identified as the most effective antibiotic (100%) in both. AMPC extendedspectrum β-lactamase genes were present in 40 (30.8%) isolates. The highest frequency about the gene pattern of AMPC positive β-lactamase bacteria was correlated to DHA, FOX, and CIT genes, while none of the samples contained the MOX β-lactamase gene. E.coli and Klebsiella beta-lactamase-producing AMPC isolates were also significantly correlated with antibiotic resistance to the cephalosporin class (P <0.05). CONCLUSION: This study indicated a high percentage of resistance to third and fourth generation cephalosporins. Hence, careful antibiogram tests and prevention of antibiotic overuse in infections caused by AMPC-producing organisms and screening of clinical samples for the resistance mentioned above genes and providing effective strategies to help diagnose and apply appropriate treatments and change antibiotic usage strategies can partially prevent the transmission of this resistance.202134483624
113490.9998Molecular 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.202337448678
897100.9998Prevalence of class 1 integrons and plasmid-mediated qnr-genes among Enterobacter isolates obtained from hospitalized patients in Ahvaz, Iran. Quinolones are frequently used classes of antimicrobials in hospitals, crucial for the treatment of infections caused by Gram-negative bacteria. The inappropriate use of quinolones and other antimicrobial agents for the treatment of bacterial infections leads to a significant increase of resistant isolates. The acquisition of antimicrobial resistance may be related to achievement of resistance determinant genes mediated by plasmids, transposons and gene cassettes in integrons. The objective of this cross-sectional study, conducted from December 2015 to July 2016 at two teaching hospitals in Ahvaz, southern Iran, was to screen for the presence of class 1 integrons and quinolone resistance genes in clinical isolates of Enterobacter spp. In all, 152 non-duplicated Enterobacter isolates were collected from clinical specimens and identified as Enterobacter spp. using standard microbiological methods. Antimicrobial susceptibility test was determined using the disc diffusion method according to the CLSI recommendation. Determination of class 1 integrons and PMQR genes was assessed by PCR. Analysis of antibiotic susceptibility tests showed that the highest antibiotic resistance was toward ciprofloxacin (55.3%), while the lowest level was observed against meropenem (34.9%). Moreover, 47.4% (72/152) and 29% (44/152) of isolates were positive for class 1 integron and quinolone resistance genes, respectively. The relative frequencies of antibiotic resistance were significantly higher among class 1 integron-positive isolates. In summary, our results highlight the importance of PMQR genes in the emergence of quinolone-resistant Enterobacter isolates. Moreover, it seems that class 1 integrons have a widespread distribution among Enterobacter isolates and have clinical relevance to multiple-drug-resistant isolates.201729286015
2152110.9998Immunological and molecular detection of biofilm formation and antibiotic resistance genes of Pseudomonas aeruginosa isolated from urinary tract. BACKGROUND AND OBJECTIVES: Pseudomonas aeruginosa (P. aeruginosa) is one of the most common causes of hospital-acquired infections. It is associated with high morbidity and healthcare costs, especially when appropriate antibiotic treatment is delayed. Antibiotic selection for patients with P. aeruginosa infections is challenging due to the bacteria's inherent resistance to many commercially available antibiotics. This study investigated antibiotic-resistance genes in isolated bacteria, which play a key role in disease pathogenesis. MATERIALS AND METHODS: 100 samples out of the 140 samples collected from urinary tract infections (UTIs) cases between December 15(th), 2022, and April 15(th), 2023, were included in the study. Identification of bacterial isolates was based on colony morphology, microscopic examination, biochemical tests, and the Vitek-2 system. Antibiotic resistance genes; Aph(3)-llla, ParC, Tet/tet(M), and aac(6´)-Ib-cr were tested by polymerase chain reaction (PCR). RESULTS: The obtained results were based on bacterial identifications of 81 clinical samples. Only 26 (32%) of these isolates were P. aeruginosa, 21 (26%) were Escherichia coli, and 18 (22.2%) were other bacteria. These isolates were used to detect four genes including tet(M), Aph(3)-llla, Par-c, and aac(6´)-Ib-cr. Four types of primers were used for PCR detection. The results showed that 11/14 (78.57%) carried the tet(M) gene, 10/14 (71.42%) carried the Aph(3)-llla gene, 14/14 (100%) carried the Par-c gene, and 10/14 (71.42%) of the isolates carried the aac(6´)-Ib-cr gene. The biofilm formation examining the esp gene, showed that 9 (64.28) isolates carried this gene. CONCLUSION: The inability of antibiotics to penetrate biofilms is an important factor contributing to the antibiotic tolerance of bacterial biofilms.202540612720
2163120.9998Molecular epidemiology of aminoglycosides resistance in acinetobacter spp. With emergence of multidrug-resistant strains. BACKGROUND: Acinetobacter spp. is characterized as an important nosocomial pathogen and increasing antimicrobial resistance. Our aim was to evaluate antimicrobial susceptibility and aminoglycosides resistance genes of Acinetobacter spp. isolated from hospitalized patients. METHODS: Sixty isolates were identified as Acinetobacter species. The isolates were tested for antibiotic resistance by disc diffusion method for 12 antimicrobials. The presence of aphA6, aacC1 aadA1, and aadB genes were detected using PCR. RESULTS: From the isolated Acinetobacter spp. the highest resistance rate showed against amikacin, tobramycin, and ceftazidim, respectively; while isolated bacteria were more sensitive to ampicillic/subactam. More than 66% of the isolates were resistant to at least three classes of antibiotics, and 27.5% of MDR strains were resistant to all seven tested classes of antimicrobials. The higher MDR rate presented in bacteria isolated from the ICU and blood samples. More than 60% of the MDR bacteria were resistance to amikacin, ceftazidim, ciprofloxacin, piperacillin/tazobactam, doxycycline, tobramycin and levofloxacin. Also, more than 60% of the isolates contained phosphotransferase aphA6, and acetyltransferase genes aacC1, but adenylyltransferase genes aadA1 (41.7%), and aadB (3.3%) were less prominent. 21.7% of the strains contain three aminoglycoside resistance genes (aphA6, aacC1 and aadA1). CONCLUSION: The rising trend of resistance to aminoglycosides poses an alarming threat to treatment of such infections. The findings showed that clinical isolates of Acinetobacter spp. in our hospital carrying various kinds of aminoglycoside resistance genes.201023113008
2156130.9998Antimicrobial resistance in urinary pathogens and culture-independent detection of trimethoprim resistance in urine from patients with urinary tract infection. BACKGROUND: Although urinary tract infections (UTIs) are extremely common, isolation of causative uropathogens is not always routinely performed, with antibiotics frequently prescribed empirically. This study determined the susceptibility of urinary isolates from two Health and Social Care Trusts (HSCTs) in Northern Ireland to a range of antibiotics commonly used in the treatment of UTIs. Furthermore, we determined if detection of trimethoprim resistance genes (dfrA) could be used as a potential biomarker for rapid detection of phenotypic trimethoprim resistance in urinary pathogens and from urine without culture. METHODS: Susceptibility of E. coli and Klebsiella spp. isolates (n = 124) to trimethoprim, amoxicillin, ceftazidime, ciprofloxacin, co-amoxiclav and nitrofurantoin in addition to susceptibility of Proteus mirabilis (n = 61) and Staphylococcus saprophyticus (n = 17) to trimethoprim was determined by ETEST® and interpreted according to EUCAST breakpoints. PCR was used to detect dfrA genes in bacterial isolates (n = 202) and urine samples(n = 94). RESULTS: Resistance to trimethoprim was observed in 37/124 (29.8%) E. coli and Klebsiella spp. isolates with an MIC(90) > 32 mg/L. DfrA genes were detected in 29/37 (78.4%) trimethoprim-resistant isolates. Detection of dfrA was highly sensitive (93.6%) and specific (91.4%) in predicting phenotypic trimethoprim resistance among E. coli and Klebsiella spp. isolates. The dfrA genes analysed were detected using a culture-independent PCR method in 16/94 (17%) urine samples. Phenotypic trimethoprim resistance was apparent in isolates cultured from 15/16 (94%) dfrA-positive urine samples. There was a significant association (P < 0.0001) between the presence of dfrA and trimethoprim resistance in urine samples containing Gram-negative bacteria (Sensitivity = 75%; Specificity = 96.9%; PPV = 93.8%; NPV = 86.1%). CONCLUSIONS: This study demonstrates that molecular detection of dfrA genes is a good indicator of trimethoprim resistance without the need for culture and susceptibility testing.202235610571
2150140.9998Analysis 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.202236227675
2147150.9998Identification 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.201627403451
1126160.9998Comparison of beta-lactamase genes in clinical and food bacterial isolates in India. BACKGROUND: The present study aimed to determine the occurrence of human disease-causing enteric bacteria on raw vegetables, fruits, meats, and milk products sold in Indian markets. The study further aimed to analyze antibiotic resistance rates and the presence of blaCTX-M, blaTEM, blaSHV, and blaAmpC. METHODOLOGY: Twenty-three food-borne and 23 clinical isolates were compared for antibiotic resistance rates and the presence of blaCTX-M, blaTEM, blaSHV, and blaAmpC. Swabs were taken from unwashed and washed food items, as well as from some chopped food specimens, and inoculated on appropriate culture medium. Bacterial isolates were identified, antibiotic susceptibility was performed, and bla genes were detected by PCR. RESULTS: Thirty-eight bacterial isolates were obtained from the food specimens, of which 36 (94.7%) were Gram-negative and two (5.3%) were Gram-positive bacterial species. Klebsiella pneumoniae was the most prevalent (52.6%; 20/38) bacterial species isolated, followed by Citrobacter koseri (18.4%; 7/38). In food isolates, the majority of the isolates were resistant to gentamicin (33.3%) followed by amikacin (11.1%). Resistance to a third-generation cephalosporin was noticed in only 5.6% isolates. However, in clinical isolates, maximal resistance was noticed against third-generation cephalosporins followed by ofloxacin in 91.3% and 86.9% isolates, respectively, and resistance to gentamicin and amikacin was noticed in 78.3% and 52.2% isolates, respectively. The presence of blaCTX-M, blaTEM, blaSHV, and blaAmpC in clinical isolates was noticed in 52.2%, 60.9%, 21.7%, and 43.5%, respectively. None of the isolates from food showed the presence of any of the above-cited genes. CONCLUSIONS: Probably bla genes have not yet disseminated to raw-food vegetation in India.200919801801
1054170.9998Molecular 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.201931190714
1110180.9998Antimicrobial 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.202439303927
2181190.9998Molecular Characterization of Antibiotic Resistance Determinants in Klebsiella pneumoniae Isolates Recovered from Hospital Effluents in the Eastern Cape Province, South Africa. Klebsiella pneumoniae (K. pneumoniae) is an opportunistic bacteria responsible for many nosocomial and community-acquired infections. The emergence and spread of antibiotic resistances have resulted in widespread epidemics and endemic dissemination of multidrug-resistant pathogens. A total of 145 K. pneumoniae isolates were recovered from hospital wastewater effluents and subjected to antibiogram profiling. Furthermore, the antibiotic resistance determinants were assessed among phenotypic resistant isolates using polymerase chain reaction (PCR). The isolates showed a wide range of antibiotic resistance against 21 selected antibiotics under 11 classes, with the most susceptible shown against imipenem (94.5%) and the most resistant shown against ampicillin (86.2%). The isolates also showed susceptibility to piperacillin/tazobactam (89.0%), ertapenem (87.6%), norfloxacin (86.2%), cefoxitin (86.2%), meropenem (76.6%), doripenem (76.6%), gentamicin (76.6%), chloramphenicol (73.1%), nitrofurantoin (71.7%), ciprofloxacin (79.3%), amikacin (60.7%), and amoxicillin/clavulanic acid (70.4%). Conversely, resistance was also recorded against tetracycline (69%), doxycycline (56.6%), cefuroxime (46.2%), cefotaxime (48.3%), ceftazidime (41.4%). Out of the 32 resistance genes tested, 28 were confirmed, with [tetA (58.8%), tetD (47.89%), tetM (25.2%), tetB (5.9%)], [sul1 (68.4%), sul1I (66.6%)], and [aadA (62.3%), strA (26%), aac(3)-IIa(aacC2)(a) (14.4%)] genes having the highest occurrence. Strong significant associations exist among the resistance determinants screened. About 82.7% of the K. pneumoniae isolates were multidrug-resistant (MDR) with a multiple antibiotics resistance index (MARI) range of 0.24 to 1.0. A dual presence of the resistant genes among K. pneumoniae was also observed to occur more frequently than multiple presences. This study reveals a worrisome presence of multidrug-resistant K. pneumoniae isolates and resistance genes in hospital waste effluent, resulting in higher public health risks using untreated surface water for human consumption. As a result, adequate water treatment and monitoring initiatives designed to monitor antimicrobial resistance patterns in the aquatic ecosystem are required.202337508235