FQ - Word Related Documents




#
Rank
Similarity
Title + Abs.
Year
PMID
012345
123200.9907Monitoring of Non-β-Lactam Antibiotic Resistance-Associated Genes in ESBL Producing Enterobacterales Isolates. Genetic context of extended spectrum β-Lactamase (ESBL) producing Enterobacterales and its association with plasmid mediated quinolone resistance (PMQR), aminoglycoside modifying enzymes (AME) and Trimethoprim/Sulfamethoxazole (TMP-SMX) resistance is little known from North India. Therefore, the current study was aimed to investigate the frequency of Non-β-Lactam antibiotic resistance associated genes in extended spectrum β-Lactamase producing Enterobacterales. For this study, Non-Duplicate phenotypically confirmed ESBL producing Enterobacterales isolates (N = 186) were analyzed for ESBLs, PMQRs, AMEs and TMP-SMX resistance genes using polymerase chain reaction (PCR). PCR detected presence of PMQR genes in 81.29% (N = 139) of ESBL isolates (N = 171), AME genes in 60.82% and TMP-SMX resistance genes in 63.74% of the isolates. Molecular characterization of ESBL producing Enterobacterales showed 84.79% bla(TEM) followed by 73.68% bla(CTX-M), 43.86% bla(SHV), 19.88% bla(PER) and 9.94% bla(VEB), respectively. Analysis of PMQR genes revealed 77.7% aac(6')-lb-cr the most commonly detected gene followed by 67.63% oqxB, 62.59% oqxA, 43.17% qnrB, 19.42% qnrD, 18.7% qnrS, 9.35% qnrA, 3.6% qepA and 2.88% qnrC, respectively. Analysis of AMEs gene profile demonstrated 81.73% aac(6')-Ib, the most frequently encountered gene followed by 46.15% aph(3')-Ia, 44.23% ant(3")-Ia, respectively. A 100% prevalence of sul1, followed by dfrA (54.63%) and sul2 (15.74%) was observed. In summary, prevalence of ESBL-Producing genes (particularly bla(TEM) and bla(CTX-M)) along with PMQR, AMEs, and TMP-SMX resistant genes may potentially aid in the transfer of antimicrobial resistance among these strains.202033317078
124710.9905Antibiotic resistance determinants of multidrug-resistant Acinetobacter baumannii clinical isolates in Algeria. Antibiotic susceptibility testing was performed on 71 Acinetobacter baumannii clinical isolates, and presence of antibiotic resistance genes was screened for by PCR amplification and sequencing. Resistance rates were very high for aminoglycosides (22-80%), fluoroquinolones (>90%), and cephalosporins (>90%) but remained low for rifampin (2.8%) or null for colistin. Antibiotic resistance encoding genes detected were as follows: blaTEM-128 gene (74.6%), aph(3')-VI (50.7 %), aadA (63.4%), ant(2″)-I (14.1%), aac(3)-Ia (91.1%), aac(6')-Ib (4.2%), mutation Ser83Leu in gyrA (94.4%), double mutations Ser83Leu and Ser80Leu (or Ser84Leu) in gyrA and parC (69.0%), and mutation I581N in RRDR of the rpoB gene.201323688522
117220.9904The prevalence and mechanism of fluoroquinolone resistance in Escherichia coli isolated from swine farms in China. BACKGROUND: It has been demonstrated that swine waste is an important reservoir for resistant genes. Moreover, the bacteria carrying resistant genes and originating from swine feces and wastewater could spread to the external environment. Fluoroquinolones (FQs) are widely used in livestock and poultry for the treatment of bacterial infection. However, resistance to FQs has increased markedly. RESULTS: In this study, swine feces and wastewater were sampled from 21 swine farms of seven provinces in China to investigate the prevalence of FQ resistance, including plasmid-mediated fluoroquinolone resistance (PMQR) genes and the occurrence of target mutations. All isolates showed moderate rate of resistance to norfloxacin (43.0%), ciprofloxacin (47.6%), ofloxacin (47.0%) and levofloxacin (38.8%). The percentage of strains resistant to the four FQs antimicrobials was positively correlated with the danofloxacin (DANO) MIC. Among the 74 FQ-resistant isolates, 39 (52.70%) had mutations in gyrA (S83L and D87 to N, Y, G, or H), 21 (28.38%) had mutations in parC (S80I and E84K), 2 (2.70%) had mutations in parE (I355T and L416F), 26 (35.14%) had mutations in marR (D67N and G103S), 1 (1.35%) had mutations in acrR (V29G). While, no mutation was found in gyrB. There were 7 (9.46%) strains carried the qnrS gene, 29 (39.19%) strains carried the oqxAB gene, and 9 (12.16%) strains carried the aac (6')-Ib-cr gene. In addition, the conjugation assays showed that qnrS, oqxAB and aac (6')-Ib-cr could be successfully transferred to E. coli J53 from 4 (57.1%), 20 (69.0%) and 5 (55.6%) donor strains, respectively. There were no qnrA, qnrB, qnrC, qnrD and qepA genes detected. CONCLUSION: The present study showed that DANO-resistant E. coli strains isolated from swine farms had significant cross-resistance to other four FQs antimicrobials. Further study revealed that the resistance mechanisms of swine-derived E. coli to FQs may be attributable to the occurrence of chromosomal mutations (gyrA, parC, parE, marR and acrR genes double-site or single-site mutation) and the presence of PMQR genes (qnrS, oqxAB and aac (6')-Ib-cr). To the best of our knowledge, one novel mutation marR-D67N was found to be associated with FQ resistance, two mutations parE-L416F and acrR-V29G have never been reported in China.202032723358
145130.9904Molecular Epidemiology of Extensively Drug-Resistant mcr Encoded Colistin-Resistant Bacterial Strains Co-Expressing Multifarious β-Lactamases. Plasmid-mediated colistin resistance (Col-R) conferred by mcr genes endangers the last therapeutic option for multifarious β-lactamase-producing bacteria. The current study aimed to explore the mcr gene molecular epidemiology in extensively drug-resistant (XDR) bacteria. Col-R gram-negative bacterial strains were screened using a minimum inhibitory concentration (MIC) breakpoint ≥4 µg/mL. Resistant isolates were examined for mcr variants, extended-spectrum β-lactamase, AmpC, and carbapenemase genes using polymerase chain reaction (PCR). The MIC breakpoints for mcr-positive strains were determined using broth microdilution and E-test strips. Overall, 19/718 (2.6%) gram-negative rods (GNRs) harboring mcr were identified, particularly in pus (p = 0.01) and tracheal secretions (p = 0.03). Molecular epidemiology data confirmed 18/19 (95%) mcr-1 and 1/19 (5%) mcr-2 genes. Integron detection revealed 15/17 (88%) Int-1 and 2/17 (12%) Int-2. Common co-expressing drug-resistant β-lactamase genes included 8/16 (50%) bla(CTM-1), 3/16 (19%) bla(CTM-15), 3/3 (100%) bla(CMY-2), 2/8 (25%) bla(NDM-1), and 2/8 (25%) bla(NDM-5). The MIC(50) and MIC(90) values (µg/mL) were as follows: Escherichia coli, 12 and 24; Klebsiella pneumoniae, 12 and 32; Acinetobacter baumannii, 8 and 12; and Pseudomonas aeruginosa, 32 and 64, respectively. Treatment of XDR strains has become challenging owing to the co-expression of mcr-1, mcr-2, multifarious β-lactamase genes, and integrons.202133923991
123340.9904Prevalence, Antibiogram, and Resistance Profile of Extended-Spectrum β-Lactamase-Producing Escherichia coli Isolates from Pig Farms in Luzon, Philippines. This cross-sectional study was conducted to determine the prevalence, antibiogram, and resistance profile of extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) isolates from healthy pigs and pig farms in Luzon, Philippines. A total of 162 rectal samples from healthy finisher and breeder pigs and boot swab samples from pig houses were collected from 54 randomly selected pig farms. Bacteria were isolated and screened using MacConkey agar plate supplemented with 1 mg/L cefotaxime. Identification of bacteria and antimicrobial susceptibility test were carried out through Vitek(®) 2 and combined disk test. PCR amplifications were carried out in all isolates targeting bla(CTX-M) and its five major groupings, bla(TEM), and bla(SHV). The farm prevalence of ESBL-EC was 57.41% (95% confidence interval [CI] = 43.21-70.77). A total of 48 (29.63%) ESBL-EC isolates were isolated from samples that showed 14 different phenotypic multidrug resistance patterns. The prevalence of bla(CTX-M) gene was 91.67% (95% CI = 80.02-97.68). All major bla(CTX-M-groups) except bla(CTX-M-25group) were detected. The bla(CTX-M-1) was the most prevalent bla(CTX-M) gene, 75.0% (95% CI = 60.40-86.36). The prevalence of bla(TEM) and bla(SHV) genes was 91.67% (95% CI = 80.02-97.68) and 60.42% (95% CI = 45.27-74.23), respectively. Coexistence of different bla(CTX-M), bla(TEM), and bla(SHV) genes was observed in 44 isolates with 20 different genotypic patterns. High prevalence, diverse antibiogram profile, and genotypic resistance pattern of ESBL-EC isolates from healthy pigs and pig farms were observed in this study that could result in possible transmission to farm workers, susceptible bacteria, and the environment.202031532307
123650.9901Molecular characterization of antimicrobial resistance in Gram-negative bacteria isolated from bovine mastitis in Egypt. The aim of this study was to characterize the genetic basis of multidrug resistance in Gram-negative bacteria isolated from bovine mastitis cases in Egypt. Multidrug resistance phenotypes were found in 34 of 112 (30.4%) Gram-negative bacterial isolates, which harbored at least one antimicrobial resistance gene. The most prevalent multidrug-resistant (MDR) species were Enterobacter cloacae (8 isolates, 7.1%), Klebsiella pneumoniae (7 isolates, 6.3%), Klebsiella oxytoca (7 isolates, 6.3%), Escherichia coli (5 isolates, 4.5%), and Citrobacter freundii (3 isolates, 2.7%). The most commonly observed resistance phenotypes were against ampicillin (97.0%), streptomycin (94.1%), tetracycline (91.2%), trimethoprim-sulfamethoxazole (88.2%), nalidixic acid (85.3%), and chloramphenicol (76.5%). Class 1 integrons were detected in 28 (25.0%) isolates. The gene cassettes within class 1 integrons included those encoding resistance to trimethoprim (dfrA1, dfrA5, dfrA7, dfrA12, dfrA15, dfrA17, and dfrA25), aminoglycosides (aadA1, aadA2, aadA5, aadA7, aadA12, aadA22, and aac(3)-Id), chloramphenicol (cmlA), erythromycin (ereA2), and rifampicin (arr-3). Class 2 integrons were identified in 6 isolates (5.4%) with three different profiles. Furthermore, the β-lactamase encoding genes, bla(TEM), bla(SHV), bla(CTX-M), and bla(OXA), the plasmid-mediated quinolone resistance genes, qnr and aac(6)-Ib-cr, and the florfenicol resistance gene, floR, were also identified. To the best of our knowledge, the results identified class 2 integrons, qnr and aac(6)-Ib-cr from cases of mastitis for the first time. This is the first report of molecular characterization for antimicrobial resistance in Gram-negative bacteria isolated from bovine mastitis in Africa.201121338385
121460.9901Plasmid-mediated quinolone resistance genes in fecal bacteria from rooks commonly wintering throughout Europe. This study concerned the occurrence of fecal bacteria with plasmid-mediated quinolone resistance (PMQR) genes in rooks (Corvus frugilegus, medium-sized corvid birds) wintering in continental Europe during winter 2010/2011. Samples of fresh rook feces were taken by cotton swabs at nine roosting places in eight European countries. Samples were transported to one laboratory and placed in buffered peptone water (BPW). The samples from BPW were enriched and subcultivated onto MacConkey agar (MCA) supplemented with ciprofloxacin (0.06 mg/L) to isolate fluoroquinolone-resistant bacteria. DNA was isolated from smears of bacterial colonies growing on MCA and tested by PCR for PMQR genes aac(6')-Ib, qepA, qnrA, qnrB, qnrC, qnrD, qnrS, and oqxAB. All the PCR products were further analyzed by sequencing. Ciprofloxacin-resistant bacteria were isolated from 37% (392 positive/1,073 examined) of samples. Frequencies of samples with ciprofloxacin-resistant isolates ranged significantly from 3% to 92% in different countries. The qnrS1 gene was found in 154 samples and qnrS2 in 2 samples. The gene aac(6')-Ib-cr was found in 16 samples. Thirteen samples were positive for qnrB genes in variants qnrB6 (one sample), qnrB18 (one), qnrB19 (one), qnrB29 (one), and qnrB49 (new variant) (one). Both the qnrD and oqxAB genes were detected in six samples. The genes qnrA, qnrC, and qepA were not found. Wintering omnivorous rooks in Europe were commonly colonized by bacteria supposedly Enterobacteriaceae with PMQR genes. Rooks may disseminate these epidemiologically important bacteria over long distances and pose a risk for environmental contamination.201222731858
122670.9901Multi-drug resistant gram-negative enteric bacteria isolated from flies at Chengdu Airport, China. We collected flies from Chengdu Shuangliu International Airport to examine for the presence of bacteria and to determine the sensitivity patterns of those bacteria. A total of 1,228 flies were collected from 6 sites around Chengdu Shuangliu International Airport from April to September 2011. The predominant species was Chrysomya megacephala (n=276, 22.5%). Antimicrobial-resistant gram-negative enteric bacteria (n=48) were isolated from flies using MacConkey agar supplemented with cephalothin (20 microg/ml). These were identified as Escherichia coli (n=37), Klebsiella pneumoniae (n=6), Pseudomonas aeruginosa (n=3) and Aeromonas hydrophila (n=2). All isolated bacteria were tested for resistance to 21 commonly used antimicrobials: amoxicillin (100%), ticarcillin (100%), cephalothin (100%), cefuroxime (100%), ceftazidime 1 (93.8%), piperacillin (93.8%), cefotaxime (89.6%), ticarcillin-clavulanate (81.3%), trimethoprim-sulfamethoxazole (62.5%), ciprofloxacin (54.2%), gentamicin (45.8%), cefepime (39.6%), tobramycin (39.6%), ceftazidime (22.9%), cefoxitin (16.7%), amikacin (16.7%), netilmicin (14.6%), amoxicillin-clavulanate (6.3%) and piperacillin-tazobactam (2.1%). No resistance to meropenem or imipenem was observed. Antibiotic resistance genes among the isolated bacteria were analyzed for by polymerase chain reaction. Thirty of the 48 bacteria with resistance (62.5%) possessed the blaTEM gene.201324450236
123980.9900Fluoroquinolone resistance among fecal extended spectrum βeta lactamases positive Enterobacterales isolates from children in Dar es Salaam, Tanzania. BACKGROUND: Fluoroquinolones have been, and continue to be, routinely used for treatment of many bacterial infections. In recent years, most parts of the world have reported an increasing trend of fluoroquinolone resistant (FQR) Gram-negative bacteria. METHODS: A cross-sectional study was conducted between March 2017 and July 2018 among children admitted due to fever to referral hospitals in Dar es Salaam, Tanzania. Rectal swabs were used to screen for carriage of extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PE). ESBL-PE isolates were tested for quinolone resistance by disk diffusion method. Randomly selected fluroquinolone resistant isolates were characterized by using whole genome sequencing. RESULTS: A total of 142 ESBL-PE archived isolates were tested for fluoroquinolone resistance. Overall phenotypic resistance to ciprofloxacin, levofloxacin and moxifloxacin was found in 68% (97/142). The highest resistance rate was seen among Citrobacter spp. (100%, 5/5), followed by Klebsiella. pneumoniae (76.1%; 35/46), Escherichia coli (65.6%; 42/64) and Enterobacter spp. (31.9%; 15/47). Whole genome sequencing (WGS) was performed on 42 fluoroquinolone resistant-ESBL producing isolates and revealed that 38/42; or 90.5%, of the isolates carried one or more plasmid mediated quinolone resistance (PMQR) genes. The most frequent PMQR genes were aac(6')-lb-cr (74%; 31/42), followed by qnrB1 (40%; 17/42), oqx, qnrB6 and qnS1. Chromosomal mutations in gyrA, parC and parE were detected among 19/42 isolates, and all were in E. coli. Most of the E. coli isolates (17/20) had high MIC values of > 32 µg/ml for fluoroquinolones. In these strains, multiple chromosomal mutations were detected, and all except three strains had additional PMQR genes. Sequence types, ST131 and ST617 predominated among E. coli isolates, while ST607 was more common out of 12 sequence types detected among the K. pneumoniae. Fluoroquinolone resistance genes were mostly associated with the IncF plasmids. CONCLUSION: The ESBL-PE isolates showed high rates of phenotypic resistance towards fluoroquinolones likely mediated by both chromosomal mutations and PMQR genes. Chromosomal mutations with or without the presence of PMQR were associated with high MIC values in these bacteria strains. We also found a diversity of PMQR genes, sequence types, virulence genes, and plasmid located antimicrobial resistance (AMR) genes towards other antimicrobial agents.202336882712
110790.9900Prevalence of plasmid-mediated quinolone resistance genes among ciprofloxacin-nonsusceptible Escherichia coli and Klebsiella pneumoniae isolated from blood cultures in Korea. OBJECTIVES: To analyze the prevalence of plasmid-mediated quinolone resistance (PMQR) determinants in ciprofloxacin-nonsusceptible Escherichia coli and Klebsiella pneumoniae isolated from patients at a tertiary care hospital in Korea. METHODS: A total of 102 nonduplicate isolates of ciprofloxacin-intermediate or ciprofloxacin-resistant E coli (n=80) and K pneumoniae (n=22) from blood cultures were obtained. The qnr (qnrA, qnrB, qnrS), aac(6')-Ib-cr, qepA and oqxAB genes were detected using polymerase chain reaction (PCR) and confirmed using direct sequencing. To determine whether the PMQR-positive plasmid was horizontally transferable, conjugation experiments were performed. RESULTS: Of the 102 isolates, 81 (79.4%) had one or more PMQR genes; these consisted of 59 (73.8%) E coli and 22 (100%) K pneumoniae isolates. The qnr genes were present in 15 isolates (14.7%): qnrB4 was detected in 10.8% and qnrS1 was detected in 3.9%. The aac(6')-Ib-cr, qepA and oqxAB genes were detected in 77.5%, 3.9% and 10.8%, respectively. In conjugation experiments, PMQR genes were successfully transferred from seven (8.6%) isolates. The range of minimum inhibitory concentrations of ciprofloxacin for these seven transconjugants increased to 0.5 mg/L to 1 mg/L, which was 16- to 33-fold that of the recipient E coli J53 bacteria. CONCLUSIONS: PMQR genes were highly prevalent among ciprofloxacin-nonsusceptible E coli and K pneumoniae from blood cultures in the authors' hospital. Therefore, it is necessary to monitor for the spread of PMQR genes of clinical isolates and to ensure careful antibiotic use in a hospital setting.201425285114
1452100.9900Characterization of carbapenem-resistant Gram-negative bacteria from Tamil Nadu. Carbapenem resistance is disseminating worldwide among Gram-negative bacteria. The aim of this study was to identify carbapenem-resistance level and to determine the mechanism of carbapenem resistance among clinical isolates from two centres in Tamil Nadu. In the present study, a total of 93 Gram-negative isolates, which is found to be resistant to carbapenem by disk diffusion test in two centres, were included. All isolates are identified at species level by 16S rRNA sequencing. Minimal inhibitory concentrations (MICs) of isolates for Meropenem were tested by agar dilution method. Presence of blaOXA, blaNDM, blaVIM, blaIMP and blaKPC genes was tested by PCR in all isolates. Amplicons were sequenced for confirmation of the genes. Among 93 isolates, 48 (%52) were Escherichia coli, 10 (%11) Klebsiella pneumoniae, nine (%10) Pseudomonas aeruginosa. Minimal inhibitory concentration results showed that of 93 suspected carbapenem-resistant isolates, 27 had meropenem MICs ≥ 2 μg/ml. The MIC range, MIC50 and MIC90 were < 0.06 to >128 μg/ml, 0.12 and 16 μg/ml, respectively. Fig. 1 . Among meropenem-resistant isolates, E. coli were the most common (9/48, 22%), followed by K. pneumoniae (7/9, 77%), P. aeruginosa (6/10, 60%), Acinetobacter baumannii (2/2, 100%), Enterobacter hormaechei (2/3, 67%) and one Providencia rettgeri (1/1, 100%). PCR results showed that 16 of 93 carried blaNDM, three oxa181, and one imp4. Among blaNDM carriers, nine were E. coli, four Klebsiella pneumoniae, two E. hormaechei and one P. rettgeri. Three K. pneumoniae were OXA-181 carriers. The only imp4 carrier was P. aeruginosa. A total of seven carbapenem-resistant isolates were negatives by PCR for the genes studied. All carbapenem-resistance gene-positive isolates had meropenem MICs >2 μg/ml. Our results confirm the dissemination of NDM and emergence of OXA-181 beta-lactamase among Gram-negative bacteria in South India. This study showed the emergence of NDM producer in clinical isolates of E. hormaechei and P. rettgeri in India.201626198414
1242110.9900An Update on Wastewater Multi-Resistant Bacteria: Identification of Clinical Pathogens Such as Escherichia coli O25b:H4-B2-ST131-Producing CTX-M-15 ESBL and KPC-3 Carbapenemase-Producing Klebsiella oxytoca. Wastewater treatment plants (WWTPs) are significant reservoirs of bacterial resistance. This work aims to identify the determinants of resistance produced by Gram-negative bacteria in the influent and effluent of two WWTPs in Portugal. A total of 96 wastewater samples were obtained between 2016 and 2019. The numbers of total aerobic and fecal contamination bacteria were evaluated, and genomic features were searched by polymerase chain reaction (PCR) and Next-Generation Sequencing (NGS). Enterobacteriaceae corresponded to 78.6% (n = 161) of the 205 isolates identified by 16sRNA. The most frequent isolates were Escherichia spp. (57.1%, n = 117), followed by Aeromonas spp. (16.1%, n = 33) and Klebsiella spp. (12.7%, n = 26). The remaining 29 isolates (14.1%) were distributed across 10 different genera. Among the 183 resistant genes detected, 54 isolates produced extended spectrum β-lactamases (ESBL), of which bla(CTX-M-15) was predominant (37 isolates; 68.5%). A KPC-3 carbapenemase-producing K. oxytoca was identified (n = 1), with bla(KPC-3) included in a transposon Tn4401 isoform b. A higher number of virulence genes (VG) (19 genes) was found in the E. coli 5301 (O25b-ST131-B2) isolate compared with a commensal E. coli 5281 (O25b-ST410-A) (six genes). Both shared five VG [Enterobactin; Aerobactin, CFA/1 (clade α); Type1 (clade γ1); Type IV]. In conclusion, this work highlights the role of relevant clinical bacteria in WWTPs, such as KPC-3-producing K. oxytoca, and, for the first time, a CTX-M-15-producing Ochromobactrum intermedium, a human opportunistic pathogen, and a SED-1-producing Citrobacter farmeri, an uncommon CTX-M-type extended-spectrum beta-lactamase.202133799747
1250120.9900Distribution 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.201020614151
1235130.9899Characterization of integrons and antimicrobial resistance genes in clinical isolates of Gram-negative bacteria from Palestinian hospitals. Sixty Gram-negative bacterial isolates were collected from Palestinian hospitals in 2006. Thirty-two (53.3%) isolates showed multidrug resistance phenotypes. PCR and DNA sequencing were used to characterize integrons and antimicrobial resistance genes. PCR screening showed that 19 (31.7%) and five (8.3%) isolates were positive for class 1 and class 2 integrons, respectively. DNA-sequencing results for the captured antimicrobial resistance gene cassettes within class 1 integrons identified the following genes: dihydrofolate reductases, dfrA1, dfrA5, dfrA7, dfrA12, dfrA17 and dfrA25; aminoglycoside adenyltransferases, aadA1, aadA2, aadA5, aadA12 and aadB; aminoglycoside acetyltransferase, aac(6')-Ib; and chloramphenicol resistance gene, cmlA1. ESBL were identified in 25 (41.7%) isolates. The identified ESBL were bla(CTX-M-15), bla(CTX-M-56), bla(OXA-1), bla(SHV-1), bla(SHV-12), bla(SHV-32) and bla(TEM-1) genes. Moreover, we characterized the plasmid-mediated quinolone resistance genes, aac(6')-Ib-cr and qnrB2, which were detected in seven (11.7%) and two (3.3%) isolates, respectively. In this study various types of antibiotic resistance genes have been identified in Gram-negative bacteria from Palestinian hospitals, many of which are reported in the Middle East area for the first time.200919903259
1454140.9899OCCURRENCE OF AMINOGLYCOSIDES RESISTANCE GENES ACC(6)-IB AND ACC(3)-II AMONG GRAM-NEGATIVE ISOLATES CAUSING URINARY TRACT INFECTION IN PEDIATRIC PATIENTS, NAJAF, IRAQ. OBJECTIVE: The aim: The aim of the study was to detect the antimicrobial susceptibility patterns and frequency of aminoglycosides resistance genes of Gram-negative bacteria isolated from pediatric patient with UTI. PATIENTS AND METHODS: Materials and methods: The study has been performed with a total of 500 urine specimens collected from pediatric patients under the age of 18 year suspected with UTI, admitted to hospitals in Al-Najaf province/Iraq during the period from November 2018 to March 2019. RESULTS: Results: A total of 500 urine specimens had been tested, 120 (24%) had signifficant bacteriuria, while there 380 (76%) had non-signi!cant bacteriuria. Escherichia coli represent about 70 (68.2%) followed by followed by 23 (22.5%) K. pneumoniae, 5 (4.9%) P. aeruginosa, 2 (1.9%) Proteus spp., 1 (0.9%) Enterobacter spp. and 1 (0.9%) Oligella uratolytic. The antimicrobial susceptibility profile of 102 Gram-negative isolates, revealed that 59 (58%) were multidrug resistant (MDR) and 38(37%) were extensive drug resistant (XDR). The PCR results of aminoglycosides resistance showing that 23 (74.1%) Gram-negative isolates had acc(6')-Ib gene and 12 (38.7%) Gram-negative isolates acc(3')-II gene. CONCLUSION: Conclusions: A high frequency of multi-drug resistance and extensive-drug resistance of isolates were recognized, and an alarming percentage of amino-glycosides resistance to acc(6')-Ib and acc(3')-II.202337010165
1419150.9899Dissemination of carbapenem resistance and plasmids encoding carbapenemases in Gram-negative bacteria isolated in India. BACKGROUND: Carbapenem resistance in Gram-negative bacteria is an ongoing public health problem of global dimensions leaving very few treatment options for infected patients. OBJECTIVES: To study the dissemination of plasmid-borne carbapenemase genes in Gram-negative bacteria from a diagnostic centre in Tamil Nadu, India. METHODS: A total of 151 non-repetitive isolates belonging to 10 genera were collected between January 2015 and December 2016 from a diagnostic centre in Tamil Nadu. The isolates included Escherichia coli (n = 57), Klebsiella pneumoniae (n = 45), Pseudomonas aeruginosa (n = 10), Salmonella Typhi (n = 8), Enterobacter cloacae (n = 8), Acinetobacter baumannii (n = 7), Serratia marcescens (n = 5), Achromobacter xylosoxidans (n = 5), Proteus mirabilis (n = 5), Klebsiella oxytoca (n = 5) and Elizabethkingia meningoseptica (n = 1). RESULTS: Of the 151 isolates, 71% (n = 107) and 68% (n = 103) were found to be resistant to meropenem and imipenem, respectively. The most prevalent β-lactamase gene was bla (NDM-1) (n = 22), followed by bla (OXA-181) (n = 21), bla (GES-1) (n = 11), bla (OXA-51) (n = 9), bla (GES-9) (n = 8), bla (OXA-23) (n = 7) and bla (IMP-1) (n = 3). We also observed bla (OXA-23) in E. coli (n = 4), and three K. pneumoniae were positive for both, bla (OXA-23) and bla (OXA-51). Plasmid incompatibility (inc/rep) typing results showed that the resistance genes (n = 11) were present in the isolates carrying plasmid-types IncX, IncA/C, IncFIA-FIB and IncFIIA. The plasmid-borne resistance genes in E. coli and K. pneumoniae were transferred to susceptible E. coli AB1157. CONCLUSIONS: This study highlights the prevalence of carbapenem resistance and the acquisition of plasmid-borne carbapenemase genes in Gram-negative bacteria isolated at this centre.202134223092
1421160.9899Predominance of Acinetobacter spp., Harboring the bla(IMP) Gene, Contaminating the Hospital Environment in a Tertiary Hospital in Mwanza, Tanzania: A Cross-Sectional Laboratory-Based Study. Data on colonization and hospital contamination of carbapenem-resistant Gram-negative bacteria (CR-GNB) are limited in low- and middle-income countries. We designed this study to determine the prevalence and co-existence of carbapenemase genes among CR-GNB isolated from clinical, colonization, and hospital environmental samples at a tertiary hospital in Mwanza, Tanzania. The modified Hodge test (MHT), the combined disk test (CDT), and the double-disk synergy test (DDST) were used for the phenotypic detection of carbapenemases. A multiplex PCR assay was used to detect bla(IMP) and bla(KPC), and a singleplex PCR assay was used to detect bla(OXA-48). Data were analyzed by STATA version 13.0. Overall, 68.8% (44/64) of the CR-GNB had at least one phenotype by phenotypic methods, whereby 60.9% (39/64) were both CDT and DDST positive and 31.3% (20/64) were MHT positive. A total of 23/64 (35.9%) had at least one of the genes tested with the predominance of bla(IMP) (91.3%; 21/23). In addition, 47.7% (21/44) of the CR-GNB phenotypes had at least one gene. Around 47.8% (11/23) of the CR-GNB carried multiple genes encoding for carbapenem resistance, with the maximum co-existence of bla(IMP)/bla(KPC)/bla(OXA-48) (45.5%; 5/11). The majority of carbapenem-resistant genes were detected in Acinetobacter spp. (82.6%; 19/23) and isolated from bed swabs (69.6%; 16/23). Acinetobacter spp. carrying the bla(IMP) gene predominantly contaminated the hospital environment. Therefore, we recommend routine decontamination of inanimate hospital surfaces, including patient beds.202235056011
1243170.9899Population distribution of Beta-lactamase conferring resistance to third-generation cephalosporins in human clinical Enterobacteriaceae in the Netherlands. There is a global increase in infections caused by Enterobacteriaceae with plasmid-borne β-lactamases that confer resistance to third-generation cephalosporins. The epidemiology of these bacteria is not well understood, and was, therefore, investigated in a selection of 636 clinical Enterobacteriaceae with a minimal inhibitory concentration >1 mg/L for ceftazidime/ceftriaxone from a national survey (75% E. coli, 11% E. cloacae, 11% K. pneumoniae, 2% K. oxytoca, 2% P. mirabilis). Isolates were investigated for extended-spectrum β-lactamases (ESBLs) and ampC genes using microarray, PCR, gene sequencing and molecular straintyping (Diversilab and multi-locus sequence typing (MLST)). ESBL genes were demonstrated in 512 isolates (81%); of which 446 (87%) belonged to the CTX-M family. Among 314 randomly selected and sequenced isolates, bla(CTX-M-15) was most prevalent (n = 124, 39%), followed by bla(CTX-M-1) (n = 47, 15%), bla(CTX-M-14) (n = 15, 5%), bla(SHV-12) (n = 24, 8%) and bla(TEM-52) (n = 13, 4%). Among 181 isolates with MIC ≥16 mg/L for cefoxitin plasmid encoded AmpCs were detected in 32 and 27 were of the CMY-2 group. Among 102 E. coli isolates with MIC ≥16 mg/L for cefoxitin ampC promoter mutations were identified in 29 (28%). Based on Diversilab genotyping of 608 isolates (similarity cut-off >98%) discriminatory indices of bacteria with ESBL and/or ampC genes were 0.994, 0.985 and 0.994 for E. coli, K. pneumoniae and E. cloacae, respectively. Based on similarity cut-off >95% two large clusters of E. coli were apparent (of 43 and 30 isolates) and 21 of 21 that were typed by belonged to ST131 of which 13 contained bla(CTX-M-15). Our findings demonstrate that bla(CTX-M-15) is the most prevalent ESBL and we report a larger than previously reported prevalence of ampC genes among Enterobacteriaceae responsible for resistance to third-generation cephalosporins.201223284886
1418180.9898Nosocomial infections and antimicrobial susceptibility patterns among patients admitted to intensive care unit of Imam Khomeini hospital in Ilam, Iran. INTRODUCTION: Nosocomial infections (NIs) are a major challenge worldwide. Identification of antibiotic resistance pattern extended spectrum beta-lactamases (ESBLs) and carbapenem-resistant Enterobacteriaceae (CRE) were the objectives of this study. METHODS: In this cross-sectional study, the antimicrobial susceptibility pattern of bacterial isolates collected from patients with NIs in ICU was determined. Overall, 42 Escherichia coli and Klebsiella pneumoniae isolates from different infection sites were used to determine phenotypic tests of ESBLs, Metallo-β-lactamases (MBLs) and CRE. Detection of ESBLs, MBLs and CRE genes were performed by the polymerase chain reaction (PCR) method. RESULTS: From 71 patients with NIs, 103 different bacterial strains were isolated. The most frequently isolated bacteria were E. coli (n = 29; 28.16%), Acinetobacter baumannii (n = 15; 14.56%), and K. pneumoniae (n = 13; 12.26%). Also, the rate of multidrug-resistant (MDR) isolates was 58.25% (60/103). Based on phenotypic confirmation tests, 32 (76.19%) isolates of E. coli and K. pneumoniae produced ESBLs, and 6 (14.28%) isolates were identified as CRE producers. PCR showed the high prevalence of the bla(CTX-M) (n = 29; 90.62%) in ESBL genes. In addition, bla(NDM) was detected in 4 (66.66%), bla(OXA-23) in 3 (50%), and bla(OXA-48) gene in 1 (16.66%) isolates. The bla(VIM), bla(KPC), and bla(IMP) genes were not detected in any of the isolates. CONCLUSION: The Gram-negative bacteria E. coli, A. baumannii, and K. pneumoniae with high resistance levels were the most common bacteria causing NIs in the ICU. This study for the first time identified bla(OXA-11), bla(OXA-23), and bla(NDM-1) genes in E. coli and K. pneumoniae in Ilam city of Iran.202337155016
1251190.9898Biofilm Formation and Plasmid-Mediated Quinolone Resistance Genes at Varying Quinolone Inhibitory Concentrations in Quinolone-Resistant Bacteria Superinfecting COVID-19 Inpatients. The likelihood of antimicrobial failure in COVID-19 patients with bacterial superinfection arises from both phenotypic (biofilms) and genotypic mechanisms. This cross-sectional study aimed to determine the inhibitory concentrations of quinolones-nalidixic acid, norfloxacin, ciprofloxacin, ofloxacin, and levofloxacin-in biofilm formers (minimum biofilm inhibitory concentration [MBIC]) and nonformers (minimum inhibitory concentration [MIC]) and correlate inhibitory concentrations with plasmid-mediated quinolone resistance (PMQR) genes in quinolone-resistant bacteria isolated from COVID-19 inpatients. Quinolone-resistant bacteria (n = 193), verified through disc diffusion, were tested for quinolone inhibitory concentrations using broth microdilution and biofilm formation using microtiter plate methods. The polymerase chain reaction was used to detect PMQR genes. Study variables were analyzed using SPSS v.17.0, with a significance level set at P <0.05. MIC-to-MBIC median fold increases for ciprofloxacin, ofloxacin, and levofloxacin were 128 (2-8,192), 64 (4-1,024), and 32 (4-512) in gram-positive cocci (GPC, n = 43), respectively, whereas they were 32 (4-8,192), 32 (4-2,048), and 16 (2-1,024) in fermentative gram-negative bacilli (F-GNB, n = 126) and 16 (4-4,096), 64 (2-64), and 16 (8-512) in nonfermentative gram-negative bacilli (NF-GNB, n = 24). In biofilm-forming F-GNB and NF-GNB, qnrB (10/32 versus 3/10), aac(6')-Ib-cr (10/32 versus 4/10), and qnrS (9/32 versus 0/10) genes were detected. A 32-fold median increase in the MIC-to-MBIC of ciprofloxacin was significantly (P <0.05) associated with qnrA in F-GNB and qnrS in NF-GNB. Biofilms formed by F-GNB and NF-GNB were significantly associated with the aac(6')-Ib-cr and qnrS genes, respectively. Nearly one-third of the superinfecting bacteria in COVID-19 patients formed biofilms and had at least one PMQR gene, thus increasing the need for quinolones at higher inhibitory concentrations.202539561392