# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 1419 | 0 | 0.9784 | Dissemination 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. | 2021 | 34223092 |
| 1451 | 1 | 0.9781 | Molecular 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. | 2021 | 33923991 |
| 1391 | 2 | 0.9781 | Faecal carriage of extended-spectrum β-lactamase-producing and AmpC β-lactamase-producing bacteria among Danish army recruits. During May and June 2008, 84 Danish army recruits were tested for faecal carriage of extended-spectrum β-lactamase (ESBL)-producing and AmpC β-lactamase-producing bacteria. Three ESBL-producing (CTX-M-14a) Escherichia coli isolates, two AmpC-producing (CMY-2) E. coli isolates and one AmpC-producing (CMY-34) Citrobacter freundii isolate were detected. Two of the CTX-M-14a E. coli isolates had similar pulsed-field gel electrophoresis and multilocus sequence typing profiles, indicating the same origin or transmission between the two army recruits. The bla(CTX-M-14a) genes were transferable to an E. coli recipient. These commensal bacteria therefore constitute a reservoir of resistance genes that can be transferred to other pathogenic bacteria in the intestine. | 2011 | 20718802 |
| 1413 | 3 | 0.9780 | Occurrence of Carbapenemases, Extended-Spectrum Beta-Lactamases and AmpCs among Beta-Lactamase-Producing Gram-Negative Bacteria from Clinical Sources in Accra, Ghana. Beta-lactamase (β-lactamase)-producing Gram-negative bacteria (GNB) are of public health concern due to their resistance to routine antimicrobials. We investigated the antimicrobial resistance and occurrence of carbapenemases, extended-spectrum β-lactamases (ESBLs) and AmpCs among GNB from clinical sources. GNB were identified using matrix-assisted laser desorption/ionization time of flight-mass spectrometry (MALDITOF-MS). Antimicrobial susceptibility testing was performed via Kirby-Bauer disk diffusion and a microscan autoSCAN system. β-lactamase genes were determined via multiplex polymerase chain reactions. Of the 181 archived GNB analyzed, Escherichia coli and Klebsiella pneumoniae constituted 46% (n = 83) and 17% (n = 30), respectively. Resistance to ampicillin (51%), third-generation cephalosporins (21%), and ertapenem (21%) was observed among the isolates, with 44% being multi-drug resistant (MDR). β-lactamase genes such as AmpCs ((bla(FOX-M) (64%) and bla(DHA-M) and bla(EDC-M) (27%)), ESBLs ((bla(CTX-M) (81%), other β-lactamase genes bla(TEM) (73%) and bla(SHV) (27%)) and carbapenemase ((bla(OXA-)(48) (60%) and bla(NDM) and bla(KPC) (40%)) were also detected. One K. pneumoniae co-harbored AmpC (bla(FOX-M) and bla(EBC-M)) and carbapenemase (bla(KPC) and bla(OXA-)(48)) genes. bla(OXA-)(48) gene was detected in one carbapenem-resistant Acinetobacter baumannii. Overall, isolates were resistant to a wide range of antimicrobials including last-line treatment options. This underpins the need for continuous surveillance for effective management of infections caused by these pathogens in our settings. | 2023 | 37370334 |
| 1409 | 4 | 0.9778 | Detection of diverse carbapenem and multidrug resistance genes and high-risk strain types among carbapenem non-susceptible clinical isolates of target gram-negative bacteria in Kenya. Carbapenem-resistant gram-negative bacteria are an increasingly significant clinical threat globally. This risk may be underestimated in Kenya as only four carbapenemase genes in three bacterial species have been described. The study aimed to understand the antibiotic resistance profiles, genes, sequence types, and distribution of carbapenem-resistant gram-negative bacteria from patients in six hospitals across five Kenyan counties by bacterial culture, antibiotic susceptibility testing, and whole-genome sequence analysis. Forty-eight, non-duplicate, carbapenem non-susceptible, clinical isolates were identified across the five counties (predominantly in Nairobi and Kisii): twenty-seven Acinetobacter baumannii, fourteen Pseudomonas aeruginosa, three Escherichia coli, two Enterobacter cloacae, and two Klebsiella pneumoniae. All isolates were non-susceptible to β-lactam drugs with variable susceptibility to tigecycline (66%), minocycline (52.9%), tetracycline (29.4%), and levofloxacin (22.9%). Thirteen P. aeruginosa isolates were resistant to all antibiotics tested. Eleven carbapenemase genes were identified: blaNDM-1, blaOXA-23, -58, -66, -69, and -91 in A. baumannii (STs 1, 2, 164 and a novel ST1475), blaNDM-1 in E. cloacae (STs 25,182), blaNDM-1, blaVIM-1and -6, blaOXA-50 in P. aeruginosa (STs 316, 357, 654, and1203), blaOXA-181, blaNDM-1 in K. pneumoniae (STs 147 and 219), and blaNDM-5 in E. coli (ST164). Five A. baumannii isolates had two carbapenemases, blaNDM-1, and either blaOXA-23 (4) or blaOXA-58 (1). AmpC genes were detected in A. baumannii (blaADC-25), E. cloacae (blaDHA-1 and blaACT-6, 16), and K. pneumoniae (blaCMY). Significant multiple-drug resistant genes were the pan-aminoglycoside resistance16srRNA methyltransferase armA, rmtB, rmtC, and rmtF genes. This study is the first to report blaOXA-420, -58, -181, VIM-6, and blaNDM-5 in Kenyan isolates. High-risk STs of A. baumannii (ST1475, ST2), E. cloacae ST182, K. pneumoniae ST147, P. aeruginosa (ST357, 654), and E. coli ST167, ST648 were identified which present considerable therapeutic danger. The study recommends urgent carbapenem use regulation and containment of high-risk carbapenem-resistant bacteria. | 2021 | 33617559 |
| 1235 | 5 | 0.9777 | Characterization 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. | 2009 | 19903259 |
| 1404 | 6 | 0.9776 | Evaluation of a DNA microarray for rapid detection of the most prevalent extended-spectrum β-lactamases, plasmid-mediated cephalosporinases and carbapenemases in Enterobacteriaceae, Pseudomonas and Acinetobacter. The dissemination of Gram-negative bacteria (GNB) producing extended-spectrum β-lactamases (ESBLs), plasmid-encoded cephalosporinases (pAmpCs) and carbapenemases is a matter of great clinical concern. In this study, we evaluated a new low-density DNA array 'Check-MDR CT103 XL' (Check-Points, Wageningen, The Netherlands) that identifies the most clinically relevant β-lactamase genes of ESBLs (blaTEM, blaSHV, blaCTX-M, blaBEL, blaPER, blaGES and blaVEB), pAmpCs (blaCMY-2-like, blaDHA, blaFOX, blaACC-1, blaACT/MIR and blaCMY-1-like/MOX) and carbapenemases (blaKPC, blaOXA-48, blaVIM, blaIMP, blaNDM, blaGIM, blaSPM and blaOXA-23, -24 and -58) in cultured bacteria. In total, 223 GNB isolates with well-characterised resistance mechanisms to β-lactams were analysed. A specificity and sensitivity of 100% were recorded for most bla genes, with a slightly lower signal observed for blaIMP. The Check-MDR CT103 XL array proved highly accurate for the identification of epidemiologically relevant ESBL, pAmpC and carbapenemase genes harboured in Enterobacteriaceae, Pseudomonas and Acinetobacter spp. The Check-MDR CT103 XL assay is a significant improvement compared with Check-MDR CT103 and it highlights the ability of this array to evolve rapidly to adjust to the current needs for the detection of resistance mechanisms to β-lactam agents. | 2016 | 27374747 |
| 1414 | 7 | 0.9776 | Prevalence and antimicrobial susceptibility of extended-spectrum beta-lactamase-producing bacteria in intensive care units of Sanandaj general hospitals (Kurdistan, Iran). This study focused on analyzing the spread of extended-spectrum beta-lactamase (ESBL) enzymes among Gram-negative bacteria at intensive care units (ICUs). Between January 2007 and January 2008, 301 consecutive clinical isolates of Gram-negative type were isolated. Of these, 66 strains were collected from patients in ICUs in two major hospitals in Sanandaj (Kurdistan, Iran). The isolates were identified, tested for antimicrobial susceptibility, and analyzed for the presence of ESBL using the double-disk synergy test. Isolates with a positive ESBL phenotype were subjected to PCR for SHV, TEM, OXA and CTX-M beta-lactamase gene families. Sixty-six Gram-negative bacteria were isolated from clinical samples of 66 ICU patients. These isolates included 16 Escherichia coli, 28 Enterobacter spp., 5 Pseudomonas spp., 10 Klebsiella pneumoniae, 3 Serratia marcescens and 1 Stenotrophomonas maltophilia. Twenty-three (34.85%) of these isolates were ESBL producing. The ESBL genes detected were SHV, TEM, OXA-1, OXA-2 and CTX-M. The results show the presence of ESBL genes among Gram-negative bacteria in the ICU setting of Sanandaj's hospitals. There is a need to institute a strict hospital infection control policy and regular surveillance of bacterial resistance to antimicrobial agents. | 2009 | 19521074 |
| 1438 | 8 | 0.9776 | Prevalence and molecular characterization of carbapenemase-producing gram-negative bacteria from a university hospital in China. BACKGROUND: The increasing emergence of carbapenem resistance in gram-negative bacteria associated with carbapenemase prompted the initiation of this study. METHODS: A total of 3139 gram-negative bacteria were recovered from a 3380-bed university hospital in Wenzhou during 2008 and 2012. Antimicrobial susceptibility was determined using the VITEK2 Compact System and agar dilution method. The phenotype and genotype of carbapenemase were demonstrated using the modified Hodge test, PCR and sequencing. A conjugation experiment was performed to reveal the transferability of resistant genes. The location of the carbapenemase gene was studied by plasmid analysis and southern blot hybridization. Clonal relatedness of the isolates was investigated by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). RESULTS: Overall, 751 of 3139 isolates (71/2055 Enterobacteriaceae, 510/620 Acinetobacter baumannii and 170/464 Pseudomonas aeruginosa) exhibited resistance to carbapenem. Carbapenemase-encoding genes were detected in 70.4% (50/71) of carbapenem-resistant Enterobacteriaceae, including blaKPC (80%) and blaIMP (20%). All A. baumannii subjected to genotype analysis were positive for blaOXA-51-like and co-harboured blaOXA-23-like (80.4%) and blaIMP (7.8%). ISAba1 was found upstream of blaOXA-23-like and blaOXA-51-like. Eight and seven strains of 170 P. aeruginosa carried blaIMP and blaVIM, respectively. PFGE analysis identified at least one dominant genotype in certain species. Four KPC-2-producing Klebsiella pneumoniae belonged to the same sequence type ST11. The plasmids carrying blaKPC were successfully transferred into recipient strains. CONCLUSION: This study highlights the challenge of increasing prevalence of carbapenem resistance associated with carbapenemase genes and dissemination of epidemic clones in Wenzhou, China. | 2016 | 26463362 |
| 1411 | 9 | 0.9775 | Detection and characterization of carbapenem resistant Gram-negative bacilli isolates recovered from hospitalized patients at Soba University Hospital, Sudan. BACKGROUND: Antimicrobial resistance (AMR) poses a complex threat to global health security and universal health coverage. Recently, nosocomial infections with carbapenemase-producing Gram-negative bacilli (GNB) is increasing worldwide. We report the molecular characterization and detection of genes associated with carbapenemase producing Gram negative bacteria isolated from hospitalized patients at Soba University Hospital (SUH) in Khartoum State, Sudan. RESULTS: Between October 2016 and February 2017, a total of 206 GNB clinical specimens were collected from hospitalized patients in SUH. Of 206 carbapenem resistance isolates, 171 (83 %) were confirmed as phenotypically resistant and 121 (58.7 %) isolates harboured one or more carbapenemase genes. New Delhi metallo-β-lactamase (NDM) types were the most predominant genes, blaNDM 107(52 %), followed by blaIMP 7 (3.4 %), blaOXA-48 5(2.4 %) and blaVIM 2 (0.9 %). Co-resistance genes with NDM producing GNB were detected in 87 (81.3 %) of all blaNDM producing isolates. NDM-1 was the most frequent subtype observed in 75 (70 %) blaNDM producing isolates. The highest percentage of resistance was recorded in ampicillin (98 %), cephalexin (93.5 %) amoxicillin clavulanic acid (90 %), cefotaxime (89.7 %), ceftriaxone (88.4 %), ceftazidime (84.2 %), sulfamethoxazole-trimethoprim (78.4 %) and nitrofurantoin (75.2 %), aztreonam (66 %) and temocillin (64 %). A close correlation between phenotypic and carbapenemase genes detection in all GNB was observed. CONCLUSIONS: The frequency of carbapenemase producing bacilli was found to be high in SUH. NDM was found to be the most prevalent carbapenemase gene among clinical isolates. Close surveillance across all hospitals in Sudan is required. The relative distribution of carbapenemase genes among GNB in nosocomial infections in Africa needs to be defined. | 2021 | 33947325 |
| 1439 | 10 | 0.9775 | Molecular characteristics of carbapenem-resistant gram-negative bacteria in southern China. A total of 368 nonreplicate gram-negative bacteria with resistance to imipenem or meropenem were collected to search for carbapenemase genes, class 1 integrons, and insertion sequence with common region 1 (ISCR1). The carbapenemase genes blaIMP-4, blaKPC-2, and blaNDM-1 were found in two Enterobacteriaceae and seven Pseudomonas aeruginosa isolates, nine Klebsiella pneumoniae isolates, and seven Enterobacteriaceae and two Acinetobacter spp. isolates. The class D OXA-type carbapenemase genes blaOXA-23-like, blaOXA-24-like, blaOXA-58, and blaOXA-51-like were detected in 59 (34.9%), 2 (1.2%), 16 (9.5%), and 126 (74.6%) Acinetobacter strains. This is the first description of blaNDM-1 in Enterobacter hormaechei and Acinetobacter genomic species 13TU. Of the integrase-positive strains, 135 (90.0%) Acinetobacter spp., 22 (61.1%) P. aeruginosa, and 14 (100%) Enterobacteriaceae isolates were identified by five, ten, and four different gene cassette arrays, respectively. Three novel gene cassette arrays aadB-aadA1, dfrA25, and dfrA16-aadA2 were reported for the first time in some species. Of the ISCR1-positive strains, the nonfermentative strains (102 Acinetobacter spp. and 13 P. aeruginosa. isolates) contained the same arrangement blaPER-1-putative glutathione-S-transferase-novel type ABC transporter, and three Enterobacteriaceae isolates harbored three different arrangements. Four distinct complex class 1 integron structures were observed. The complex class 1 integron detected in New Delhi, metallo-β-lactamase (NDM-1)-producing E. hormaechei, was found to coexist in the NDM-1-carrying plasmid. Our results suggested that we should pay more attention to the strict implementation of infection control measures and active antibiotic resistance surveillance to avoid the rapid spread or outbreak of carbapenemase-producing gram-negative bacteria. | 2015 | 25469995 |
| 1452 | 11 | 0.9775 | Characterization 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. | 2016 | 26198414 |
| 1240 | 12 | 0.9774 | Prevalence and characterization of quinolone resistance and integrons in clinical Gram-negative isolates from Gaza strip, Palestine. BACKGROUND: Gram-negative bacteria with quinolone resistance and extended-spectrum beta-lactamases (ESBLs) present significant treatment challenges. This study evaluated the prevalence and characteristics of quinolone resistance in Gram-negative strains, investigating the relationship between plasmid-mediated quinolone resistance (PMQR), ESBLs, and integrons. METHODS AND RESULTS: We collected 146 Gram-negative isolates from patients in three Palestinian hospitals. For quinolone resistance isolates, the presence and characterization of PMQR, β-lactamase genes and integrons were studied by PCR and sequencing. Out of 146 clinical isolates, 64 (43.8%) were resistant to quinolones, with 62 (97%) being multidrug-resistant (MDR) and 33 (51.5%) ESBL-producers. PMQR-encoding genes were present in 45 (70.3%) isolates, including aac(6')-Ib-cr (26.6%), qnrA (18.8%), qnrS1 (20.8%), and qnrB (6.4%). Bla(CTX-M) genes were detected in 50% (32/64) of isolates, with bla(CTX-M-15) being the most common. Bla(TEM-1), bla(SHV-1) and bla(VIM) genes were found in 13, 6, and 4 isolates, respectively. Class I integrons were found in 31/64 (48%) of isolates, with 14 containing gene cassettes conferring resistance to trimethoprim (dhfr17, dfrA12, dfrA1) and aminoglycosides resistance genes (aadA1, aadA2, aadA5, and aadA6). CONCLUSIONS: This study found a high rate of quinolone resistance, ESBL and integrons in clinical Gram-negative isolates from our hospitals. Urgent measures are crucial, including implementing an antimicrobial resistance surveillance system, to control and continuously monitor the development of antimicrobial resistance. | 2024 | 39066817 |
| 1403 | 13 | 0.9774 | Evaluation of the AusDiagnostics MT CRE EU assay for the detection of carbapenemase genes and transferable colistin resistance determinants mcr-1/-2 in MDR Gram-negative bacteria. OBJECTIVES: To evaluate the AusDiagnostics MT CRE EU assay for the detection of carbapenemase and acquired colistin resistance genes in Gram-negative bacteria. METHODS: The assay allows the detection of blaKPC, blaOXA-48-like, blaNDM, blaVIM, blaIMP, blaSIM, blaGIM, blaSPM, blaFRI, blaIMI, blaGES (differentiating ESBL and carbapenemase variants), blaSME and mcr-1/-2. It was evaluated against a panel of isolates including Enterobacteriaceae, Pseudomonas spp. and Acinetobacter spp. retrospectively (n = 210) and prospectively (n = 182). RESULTS: The CRE EU assay was able to detect 268/268 carbapenemase genes, with 239 belonging to the 'big five' families (KPC, OXA-48-like, NDM, VIM and IMP) and 29 carbapenemase genes of the SIM, GIM, SPM, FRI, IMI, SME and GES families. It could distinguish between ESBL and carbapenemase variants of GES. It also allowed detection of mcr-1/-2 colistin resistance genes on their own or in isolates co-producing a carbapenemase. CONCLUSIONS: The AusDiagnostics MT CRE EU assay offered wide coverage for detection of acquired carbapenemase genes. It required minimal hands-on time and delivered results in less than 4 h from bacterial culture. | 2018 | 30189011 |
| 1234 | 14 | 0.9774 | Isolation and Genetic Analysis of Multidrug Resistant Bacteria from Diabetic Foot Ulcers. Severe diabetic foot ulcers (DFUs) patients visiting Sir Sunderlal Hospital, Banaras Hindu University, Varanasi, were selected for this study. Bacteria were isolated from swab and deep tissue of 42 patients, for examining their prevalence and antibiotic sensitivity. DFUs of majority of the patients were found infected with Enterococcus spp. (47.61%), Escherichia coli (35.71%), Staphylococcus spp. (33.33%), Alcaligenes spp. (30.95%), Pseudomonas spp. (30.95%), and Stenotrophomonas spp. (30.95%). Antibiotic susceptibility assay of 142 bacteria with 16 antibiotics belonging to eight classes showed the presence of 38 (26.76%) isolates with multidrug resistance (MDR) phenotypes. MDR character appeared to be governed by integrons as class 1 integrons were detected in 26 (68.42%) isolates. Altogether six different arrays of genes (aadA1, aadB, aadAV, dhfrV, dhfrXII, and dhfrXVII) were found within class 1 integron. Gene cassette dhfrAXVII-aadAV (1.6 kb) was present in 12 (3 Gram positive and 9 Gram negative) isolates and was conserved across all the isolates as evident from RFLP analysis. In addition to the presence of class 1 integron, six β-lactamase resistance encoding genes namely bla TEM, bla SHV, bla OXA, bla CTX-M-gp1, bla CTX-M-gp2, and bla CTX-M-gp9 and two methicillin resistance genes namely mecA and femA and vancomycin resistance encoding genes (vanA and vanB) were identified in different isolates. Majority of the MDR isolates were positive for bla TEM (89.47%), bla OXA (52.63%), and bla CTX-M-gp1 (34.21%). To our knowledge, this is the first report of molecular characterization of antibiotic resistance in bacteria isolated from DFUs from North India. In conclusion, findings of this study suggest that class-1 integrons and β-lactamase genes contributed to the MDR in above bacteria. | 2015 | 26779134 |
| 1417 | 15 | 0.9774 | Prevalence and Phenotypic and Molecular Characterization of Carbapenemase-Producing Gram-Negative Bacteria in Gabon. Data collection and monitoring of carbapenemase-producing (CP) Gram-negative bacteria (GNB) are often limited. This study determined CP-GNB prevalence in Gabon and the genetic origins of the resistance genes. From January 2016 to March 2018, 869 clinically significant GNB isolates from inpatients and outpatients, and 19 fecal samples (inpatients) were analyzed in the main hospitals of Gabon. Fecal samples were screened using ChromID® CARBA SMART selective chromogenic medium biplates. Species were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Antibiotic susceptibility was tested using the disk diffusion method on Müller-Hinton agar, and resistance genes were assessed by multiplex polymerase chain reaction and sequencing. Overall, 1.61% of clinical isolates (14 of 869) and 5.26% of fecal samples (1 of 19) were CP-GNB. The CP-GNB rate was higher among inpatients (2.98%) than outpatients (0.33%), in intensive care units (28.57%, 4 of 14), and in urine samples (35.71%, 5 of 14). The most common CP-GNB were Klebsiella pneumoniae (53.33%) and Acinetobacter baumannii (26.67%). blaOXA-48 was the predominant carbapenemase-encoding gene (40%), followed by blaNDM-5 (33.33%). The A. baumannii multilocus sequence types ST2 and ST78, Enterobacter cloacae ST78, Escherichia coli ST2, and K. pneumonia ST48 and ST147 were found. These data indicate that CP bacteria are present in clinical and carriage samples. Preventive measures are needed to avoid the spread of resistance genes. | 2023 | 36535247 |
| 1431 | 16 | 0.9774 | The using of the polymerase chain reaction for the detection of resistance genes in gram-negative bacteria in routine practice in a pediatric hospital. Objective - assessment of RT-PCR for the detection of carbapenem-resistance genes in gram-negative bacteria. A total, 499 strains of gram-negative microorganisms isolated in two pediatric hospitals in 2019-2020 were studied. Species identification was performed using MALDI-ToF mass-spectrometry (Bruker Daltonics, Germany). Meropenem and imipenem minimal inhibitory concentration (MIC) was determined by E-test method (BioMerieux, France). The presence of acquired carbapenemase genes of IMP, NDM, VIM, KPC, OXA-48, OXA-23, OXA-40, OXA-58-groups was determined by RT-PCR. Klebsiella pneumoniae (34%), Escherichia coli (4%), Serratia marcescens (6%) and other members of Enterobacterales (6%), also gram-negative non-glucose-fermenting bacteria Acinetobacter baumannii (14%), Pseudomonas aeruginosa (36%) were found among selected strains. Carbapenemase production was found in 385 isolates (77%). The main mechanism determining carbapenem resistance in P. aeruginosa was the production of blaVIM (100%). A. baumanii strains harbored OXA-23 (55%) and OXA-40 (45%) carbapenemases. The major determinant of carbapenem resistance in K. pneumoniae isolates was OXA-48 carbapenemase, detected in 63% strains, 13% of the strains possessed blaNDM-group, 16% isolates had a combination of blaNDM-group and blaOXA-48-like. Carbapenemase of KPC-group was found in 8% K. pneumoniae strains. OXA-48 carbapenemase prevailed (95%) among S. marcescens strains. Most of E. coli isolates harbored metallo-beta-lactamase NDM (89%). Other members of Enterobacterales most often had OXA-48 carbapenemase (57%), 39% of the isolates carried blaNDM-group. In one strain, a combination of blaNDM-group and blaOXA-48-like was discovered. RT-PCR is a fast and reliable method for the detection of acquired carbapenemases and can be recommended for routine use in bacteriological laboratories. | 2022 | 35320635 |
| 1453 | 17 | 0.9774 | The distribution of carbapenem- and colistin-resistance in Gram-negative bacteria from the Tamil Nadu region in India. PURPOSE: The occurrence of carbapenem- and colistin-resistance among Gram-negative bacteria is increasing worldwide. The aim of this study was to understand the distribution of carbapenem- and colistin-resistance in two areas in Tamil Nadu, India. METHODOLOGY: The clinical isolates (n=89) used in this study were collected from two diagnostic centres in Tamil Nadu, India. The bacterial isolates were screened for meropenem- and colistin-resistance. Further, resistance genes blaNDM-1, blaOXA-48-like, blaIMP, blaVIM, blaKPC, mcr-1 and mcr-2 and integrons were studied. The synergistic effect of meropenem in combination with colistin was assessed. RESULTS: A total of 89 bacterial isolates were studied which included Escherichia coli (n=43), Klebsiella pneumoniae (n=18), Pseudomonas aeruginosa (n=10), Enterobacter cloacae (n=6), Acinetobacter baumannii (n=5), Klebsiella oxytoca (n=4), Proteus mirabilis (n=2) and Salmonella paratyphi (n=1). MIC testing showed that 58/89 (65 %) and 29/89 (32 %) isolates were resistant to meropenem and colistin, respectively, whereas 27/89 (30 %) isolates were resistant to both antibiotics. Escherichia coli, K. pneumoniae, K. oxytoca, Pseudomonas aeruginosa, and Enterobacter cloacae isolates were blaNDM-1-positive (n=20). Some strains of Escherichia coli, K. pneumoniae and K. oxytoca were blaOXA-181-positive (n=4). Class 1, 2 and 3 integrons were found in 24, 20 and 3 isolates, respectively. Nine NDM-1-positive Escherichia coli strains could transfer carbapenem resistance via plasmids to susceptible Escherichia coli AB1157. Meropenem and colistin showed synergy in 10/20 (50 %) isolates by 24 h time-kill studies. CONCLUSION: Our results highlight the distribution of carbapenem- and colistin-resistance in Gram-negative bacteria isolated from the Tamil Nadu region in South India. | 2017 | 28671537 |
| 1068 | 18 | 0.9773 | Dissemination of IncF plasmids carrying beta-lactamase genes in Gram-negative bacteria from Nigerian hospitals. INTRODUCTION: Production of beta-lactamases is the predominant cause of resistance to beta-lactam antibiotics in Gram-negative bacteria. We investigated the diversity of plasmid-borne beta-lactamase genes and replicon type of the plasmids carrying the respective genes in Gram-negative bacteria recovered from clinical infection in Nigerian hospitals. METHODOLOGY: A total of 134 Gram-negative bacteria of 13 species were analyzed for antimicrobial susceptibility, phenotypic and genotypic detection of various beta-lactamases, and plasmid analysis, including replicon typing. RESULTS: Of the 134 isolates, 111 (82.8%) contained beta-lactamases, while 28 (20.9%) carried extended-spectrum beta-lactamases. PCR and sequencing identified TEM-1 in 109 isolates (81.3%), SHV-1 in 33 isolates (24.6%), OXA-1 in 15 isolates (11.2%) and CTX-M enzymes (24 CTX-M-15 and 1 CTX-M-3) in 25 isolates (18.7%). Multiplex PCR showed that 6 isolates carried plasmidic AmpCs (ACT-1, DHA-1 and CMY-2); these enzymes were detected only in isolates possessing CTX-M beta-lactamases. Of 13 (76.9%) representative plasmids investigated in detail, 9 (69.2%) were self-transferable when selected by a beta-lactam and the plasmids once transferred coded for beta-lactam resistance. Replicon typing indicated IncF as the common vector encoding for beta-lactamases. CONCLUSIONS: The study showed a diversity of beta-lactamase genes disseminated by conjugative IncF plasmids in Gram-negative bacteria; TEM-1, SHV-1, OXA-1, CTX-M-15, CTX-M-3 and plasmidic AmpC enzymes are in common circulation in Nigeria. | 2013 | 23669427 |
| 1245 | 19 | 0.9773 | Mutation-based fluoroquinolone resistance in carbapenem-resistant Acinetobacter baumannii and Escherichia coli isolates causing catheter-related bloodstream infections. OBJECTIVE: We studied the presence of mutations in the chromosomal quinolone resistance-determining regions (QRDRs) of the fluoroquinolone targets gyrA and parC genes and detected the carbapenem resistance (CR) encoding genes among Acinetobacter baumannii and Escherichia coli isolates from catheter-related bloodstream infections (CRBSIs). METHODS: The study included 39 non-duplicate isolates of A. baumannii (14/39, 35.9%) and E. coli (25/39, 64.1%) isolated from 128 confirmed CRBSIs cases. Antimicrobial susceptibility testing was performed, followed by an evaluation of biofilm formation using the tissue culture plate method. The carbapenemase encoding genes were detected by multiplex polymerase chain reaction (PCR). The mutations in QRDRs of gyrA and parC genes were determined by singleplex PCR amplification followed by DNA sequencing and BlastN analysis in the GenBank database. DNA and the translated amino acid sequences were analyzed using the Mega7 bioinformatics tool. RESULTS: Multidrug-resistant (MDR) E. coli and A. baumannii isolates harbored CR encoding genes and combined gyrA and parC genes mutation. The specific substitutions observed in GyrA were Cys173Arg, Cys174Gly, Asp80Val, Tyr178ASP, Tyr84Gly, Glu85Lys, Ser172Leu, and Asp176Asn, while the specific substitutions observed in the ParC amino acid sequence were point mutation 62 Arg, Phe60Leu, Ils66Val, and Gln76Lys. Point mutation 62Arg was detected in two A. baumannii isolates, whereas Ser172Leu mutation was observed in two E. coli isolates. CONCLUSION: The presence of new single and multiple mutations in QRDR causes the emergence of MDR E. coli and A. baumannii infections in carbapenem-resistant Enterobacteriaceae in Egypt, requiring further investigation in Gram-negative bacteria. | 2023 | 37151743 |