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140400.9765Evaluation 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.201627374747
139110.9762Faecal 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.201120718802
140320.9761Evaluation 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.201830189011
141330.9759Occurrence 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.202337370334
143540.9759Epidemiology, Phenotypic and Genotypic Characterization of Carbapenem-Resistant Gram-Negative Bacteria from a Libyan Hospital. Antimicrobial resistance, particularly resistance to carbapenems, has become one of the major threats to public health. Seventy-two isolates were collected from patients and hospital environment of Ibn Sina Hospital, Sirte, Libya. Antibiotic susceptibility tests, using the disc diffusion method and E-Test strips, were performed to select carbapenem-resistant strains. The colistin (CT) resistance was also tested by determining the minimum inhibitory concentration (MIC). RT-PCR was conducted to identify the presence of carbapenemase encoding genes and plasmid-mediated mcr CT resistance genes. Standard PCR was performed for positive RT-PCR and the chromosome-mediated CT resistance genes (mgrB, pmrA, pmrB, phoP, phoQ). Gram-negative bacteria showed a low susceptibility to carbapenems. Molecular investigations indicated that the metallo-β-lactamase New Delhi metallo-beta-lactamases-1 was the most prevalent (n = 13), followed by Verona integron-encoded metallo-beta-lactamase (VIM) enzyme (VIM-2 [n = 6], VIM-1 [n = 1], and VIM-4 [n = 1]) that mainly detected among Pseudomonas spp. The oxacillinase enzyme OXA-23 was detected among six Acinetobacter baumannii, and OXA-48 was detected among one Citrobacter freundii and three Klebsiella pneumoniae, in which one coharbored the Klebsiella pneumoniae carbapenemase enzyme and showed resistance to CT (MIC = 64 μg/mL) by modification in pmrB genes. In this study, we report for the first time the emergence of Pseudomonas aeruginosa carrying the bla(NDM-1) gene and belonging to sequence type773 in Libya. Our study reported also for the first time CT resistance by mutation in the pmrB gene among Enterobacteriaceae isolates in Libya.202337145891
106850.9751Dissemination 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.201323669427
246360.9748Characterization of Antibiotic-Resistant Stenotrophomonas Isolates from Painted Turtles Living in the Wild. Stenotrophomonas maltophilia is a ubiquitous multidrug-resistant opportunistic pathogen commonly associated with nosocomial infections. The purpose of this study was to isolate and characterize extended-spectrum beta-lactamase (ESBL) producing bacteria from painted turtles (Chrysemys picta) living in the wild and captured in southeastern Wisconsin. Fecal samples from ten turtles were examined for ESBL producing bacteria after incubation on HardyCHROM™ ESBL agar. Two isolates were cultivated and identified by 16S rRNA gene sequencing and whole genome sequencing (WGS) as Stenotrophomonas sp. 9A and S. maltophilia 15A. They were multidrug-resistant, as determined by antibiotic susceptibility testing. Stenotrophomonas sp. 9A was found to produce an extended spectrum beta-lactamase (ESBL) and both isolates were found to be carbapenem-resistant. EDTA-modified carbapenem inactivation method (eCIM) and the modified carbapenem inactivation method (mCIM) tests were used to examine the carbapenemase production and the test results were negative. Through WGS several antimicrobial resistance genes were identified in S. maltophilia 15A. For example a chromosomal L1 β-lactamase gene, which is known to hydrolyze carbapenems, a L2 β-lactamase gene, genes for the efflux systems smeABC and smeDEF and the aminoglycosides resistance genes aac(6')-lz and aph(3')-llc were found. An L2 β-lactamase gene in Stenotrophomonas sp. 9A was identified through WGS.202336729340
83870.9748KPC and NDM-1 genes in related Enterobacteriaceae strains and plasmids from Pakistan and the United States. To characterize the genomic context of New Delhi metallo-β-lactamase-1 (NDM-1) and Klebsiella pneumoniae carbapenemase (KPC), we sequenced 78 Enterobacteriaceae isolates from Pakistan and the United States encoding KPC, NDM-1, or no carbapenemase. High similarities of the results indicate rapid spread of carbapenem resistance between strains, including globally disseminated pathogens.201525988236
150180.9748High-level and novel mechanisms of carbapenem resistance in Gram-negative bacteria from tertiary hospitals in Nigeria. To determine the occurrence and molecular basis of carbapenem resistance in Gram-negative bacteria from tertiary hospitals in Nigeria, 182 non-duplicate Gram-negative bacterial isolates were investigated for antimicrobial susceptibility, presence of carbapenemases (tested phenotypically and genotypically), random amplified polymorphic DNA (RAPD) typing, plasmid sizing and replicon typing. Minimum inhibitory concentrations of carbapenems showed a high degree of resistance, with 67 isolates (36.8%) being resistant to all carbapenems, of which 40 (59.7%) produced enzymes able to hydrolyse imipenem. PCR and sequencing identified only 10 isolates (5.5%) carrying known carbapenemase genes, including bla(NDM), bla(VIM) and bla(GES). The majority of phenotypically carbapenem-resistant and carbapenemase-producing isolates did not carry a known carbapenemase gene. Transconjugant or transformant plasmid sizes were estimated to be 115 kb for bla(NDM)- and 93 kb for bla(VIM)-carrying plasmids. These plasmids were untypeable for replicon/incompatibility and transferred various other genes including plasmid-mediated quinolone resistance (PMQR) genes and bla(CTX-M-15). Typing showed that the isolates in this study were not clonally related. There is a high level of carbapenem resistance in Nigeria. As well as the globally relevant carbapenemases (bla(NDM), bla(VIM) and bla(GES)), there are other unknown gene(s) or variant(s) in circulation able to hydrolyse carbapenems and confer high-level resistance.201424613608
143690.9748Characterisation of carbapenem-resistant Gram-negative organisms from clinical specimens in Yola, Nigeria. OBJECTIVES: This study aimed to identify carbapenem-resistant Gram-negative bacteria from clinical specimens of patients in Yola, Nigeria. METHODS: Routine clinical specimens were screened for the presence of carbapenem-resistant Gram-negative bacteria using chromogenic agar plates. Susceptibility of all presumptive isolates to carbapenems was tested by MIC and disk diffusion methods. Real-time PCR was used to test for the presence of carbapenemase genes. RESULTS: Screening of 1741 clinical specimens yielded 119 (6.8%) presumptive carbapenem-resistant Gram-negative bacteria. Antimicrobial susceptibility testing confirmed carbapenem resistance in 105 of these isolates. New Delhi metallo-β-lactamase (bla(NDM)) gene was detected in 26 isolates and Verona integron-encoded metallo-β-lactamase (bla(VIM)) gene was detected in four. The mechanism of resistance could not be identified in approximately two thirds of the carbapenem-resistant isolates. CONCLUSION: While bla(NDM) and bla(VIM) accounted for 28.6% of the resistance seen, further molecular-based studies are needed to characterise the other mechanisms of carbapenem resistance in these isolates.202031472281
1242100.9748An 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
2118110.9748Gram-negative bacteria as causative agents of ventilator-associated pneumonia and their respective resistance mechanisms. Ventilator-associated pneumonia (VAP) is a serious and common complication in patients admitted to intensive care unit (ICU) and contributes to mortality. Multidrug Gram-negative bacteria such as Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae are frequently associated with VAP in ICU. A prospective study was set up in three ICUs of the University Hospital Center Zagreb and one ICU in General Hospital Pula from September 2017 to March 2018. Antibiotic susceptibility was determined by broth microdilution method. Production of extended-spectrum β-lactamases (ESBLs) was determined by double-disk synergy test and carbapenemases by Hodge and carbapenem inactivation method (CIM). The genes encoding ESBLs, carbapenemases of class A, B and D and qnr genes were determined by PCR. In total 97 Gram-negative bacteria isolates were analyzed. P. aeruginosa demonstrated high resistance rates for imipenem and meropenem with 74% and 68% of resistant strains, respectively. Moderate resistance rates were observed for ceftazidime andpiperacillin/tazobactam, ciprofloxacin and gentamicin (44%). All except three A. baumannii isolates, were resistant to carbapenems and to all other antibiotics apart from colistin and amikacin. Eight A. baumannii isolates were positive for bla(OXA-23) and 12 for bla(OXA-24) genes. Four K. pneumoniae and two E. cloacae strains were ESBL positive and harboured group 1 of CTX-M β-lactamases. Three P. mirabilis strains were positive for plasmid-mediated ampC β-lactamase of CMY family. Two carbapenem-resistant K. pneumoniae harboured OXA-48 and one carbapenem-resistant E. cloacae VIM-1. A high proportion of multidrug-resistant P. aeruginosa, K. pneumoniae and extensively resistant A. baumannii was reported. Acquired resistance mechanisms, mainly production of carbapenemases and ESBLs were dominant in A. baumannii and K. pneumoniae, respectively. Resistance of P. aeruginosa isolates was more likely due to upregulation of efflux pumps or porin loss. A marked diversity of β-lactamases was identified in Enterobacteriaceae.202032729399
1431120.9747The 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.202235320635
1451130.9746Molecular 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
837140.9746Diversity of Carbapenem Resistance Mechanisms in Clinical Gram-Negative Bacteria in Pakistan. Antibiotic resistance is a health challenge worldwide. Carbapenem resistance in Gram-negative bacteria is a major problem since treatment options are very limited. Tigecycline and colistin are drugs of choice in this case, but resistance to these drugs is also high. The aim of this study was to describe the diversity of resistance mechanisms in carbapenem-resistant clinical Gram-negative bacteria from Pakistan. Carbapenem-hydrolyzing enzyme-encoding genes were detected using PCR and DNA sequencing and clonal types determined by multilocus sequence typing (MLST). Forty-four carbapenem-resistant isolates were collected from the microbiology laboratory of Fauji Foundation Hospital and Al-Syed Hospital, Rawalpindi, Pakistan, including Klebsiella spp., Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter cloacae, and Achromobacter xylosoxidans. bla(NDM-1), bla(NDM-4,) bla(NDM-5,) bla(NDM-7), bla(OXA-48), and bla(OXA-181) were detected in Enterobacteriaceae; bla(OXA-23,) bla(OXA-72), and bla(NDM-1) in A. baumannii, and bla(VIM-6) and bla(VIM-11) in P. aeruginosa. MLST analysis revealed several predominant clonal types: ST167 in E. coli, ST147 in Klebsiella pneumoniae, ST2 in Acinetobacter, and ST664 in P. aeruginosa. In Acinetobacter, a new clonal type was observed for the first time. To the best of our knowledge, this is the first study describing the clonality and resistance mechanisms of carbapenem-resistant Gram-negative bacteria in Pakistan.202133211640
952150.9746Molecular Surveillance of ESBL and Carbapenemase Genes in Gram-Negative Bacterial Pathogens Isolated from Various Clinical Samples Collected from Northern Region of United Arab Emirates. The aim of this study was to explore the prevalence of ESBL and carbapenemase genes in Gram-negative bacteria isolated from various clinical samples collected from northern regions of UAE. In total 3670 clinical samples were obtained from patients attending various hospitals and clinics in the northern regions of the UAE. All the samples underwent routine bacterial culture examination, and their antibiotic sensitivity patterns mainly on beta-lactam and carbapenem resistance in Gram-negative bacteria. Molecular detection of ESBL and carbapenemase genes (bla(CTX-M), bla(TEM), bla(SHV), bla(NDM), bla(IMP), and bla(OXA-48)) was performed on them. A total of 249 MDR Gram-negative bacteria (E. coli, K. pneumoniae, P. aeruginosa, P. mirabilis and A. baumannii) were isolated. The genes bla(CTX-M), bla(TEM), and bla(SHV) were detected in all the MDR isolates. Among them, the bla(CTX-M) was predominant especially in E. coli. The bla(NDM) and bla(IMP) were detected in a few K. pneumoniae and A. baumannii. The genes combination bla(CTX-M+TEM) and bla(CTX-M+SHV), bla(CTX-M+SHV), bla(TEM+SHV), and bla(TEM+NDM) were detected mostly in K. pneumoniae and E. coli, and few A. baumannii. The gene combination bla(CTX-M+TEM+SHV) and bla(CTX-M+TEM+SHV+IMP) were also detected in few E. coli, P. aeruginosa, and A. baumannii. The current findings highlight the importance of molecular detection of ESBL and carbapenemase genes to emphasize monitoring and controlling the development of MDR bacterial pathogens.202540871384
1074160.9746Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae from Pharmaceutical Wastewaters in South-Western Nigeria. Emergence and spread of Klebsiella pneumoniae isolates producing extended-spectrum β-lactamases (ESBLs) present a major threat to public health. In this study, we characterized β-lactam-resistant K. pneumoniae isolates from six wastewater samples obtained from two pharmaceutical industries located in Lagos and Ogun States, Nigeria. Bacteria were isolated by using MacConkey agar; species identification and antibacterial susceptibility testing were performed by Vitek 2. Etest was used for ESBL phenotype confirmation. The presence of β-lactamase genes was investigated by PCR and sequencing. Bacterial strain typing was done by XbaI-macrorestriction and subsequent pulsed-field gel electrophoresis (PFGE) as well as multilocus sequence typing (MLST). Thirty-five bacterial species were isolated from the six samples; among them, we identified seven K. pneumoniae isolates with resistance to β-lactams and co-resistance to fluoroquinolones, aminoglycosides, and folate pathway inhibitors. The ESBL phenotype was confirmed in six K. pneumoniae isolates that harbored ESBL genes bla(CTX-M-15) (n = 5), bla(SHV-2) (n = 1), and bla(SHV-12) (n = 1). PFGE and MLST analysis revealed five clones belonging to four sequence types (ST11, ST15, ST37, ST101), and clone K. pneumoniae-ST101 was present in the wastewater samples from two different pharmaceutical industries. Additionally performed conjugation assays confirmed the location of β-lactamase genes on conjugative plasmids. This is the first confirmation of K. pneumoniae isolates producing CTX-M-15-ESBL from pharmaceutical wastewaters in Nigeria. The co-resistance observed might be a reflection of the different drugs produced by these industries. Continuous surveillance of the environmental reservoirs of multidrug-resistant bacteria is necessary to prevent their further spread.201728375698
1528170.9746First Report of Coexistence of bla (SFO-1) and bla (NDM-1) β-Lactamase Genes as Well as Colistin Resistance Gene mcr-9 in a Transferrable Plasmid of a Clinical Isolate of Enterobacter hormaechei. Many antimicrobial resistance genes usually located on transferable plasmids are responsible for multiple antimicrobial resistance among multidrug-resistant (MDR) Gram-negative bacteria. The aim of this study is to characterize a carbapenemase-producing Enterobacter hormaechei 1575 isolate from the blood sample in a tertiary hospital in Wuhan, Hubei Province, China. Antimicrobial susceptibility test showed that 1575 was an MDR isolate. The whole genome sequencing (WGS) and comparative genomics were used to deeply analyze the molecular information of the 1575 and to explore the location and structure of antibiotic resistance genes. The three key resistance genes (bla (SFO-1), bla (NDM-1), and mcr-9) were verified by PCR, and the amplicons were subsequently sequenced. Moreover, the conjugation assay was also performed to determine the transferability of those resistance genes. Plasmid files were determined by the S1 nuclease pulsed-field gel electrophoresis (S1-PFGE). WGS revealed that p1575-1 plasmid was a conjugative plasmid that possessed the rare coexistence of bla (SFO-1), bla (NDM-1), and mcr-9 genes and complete conjugative systems. And p1575-1 belonged to the plasmid incompatibility group IncHI2 and multilocus sequence typing ST102. Meanwhile, the pMLST type of p1575-1 was IncHI2-ST1. Conjugation assay proved that the MDR p1575-1 plasmid could be transferred to other recipients. S1-PFGE confirmed the location of plasmid with molecular weight of 342,447 bp. All these three resistant genes were flanked by various mobile elements, indicating that the bla (SFO-1), bla (NDM-1), and mcr-9 could be transferred not only by the p1575-1 plasmid but also by these mobile elements. Taken together, we report for the first time the coexistence of bla (SFO-1), bla (NDM-1), and mcr-9 on a transferable plasmid in a MDR clinical isolate E. hormaechei, which indicates the possibility of horizontal transfer of antibiotic resistance genes.202134220761
1414180.9745Prevalence 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.200919521074
1426190.9745Phenotypic and genotypic detection of carbapenemase production among gram negative bacteria isolated from hospital acquired infections. OBJECTIVES: To identify the carbapenemase producing Gram-negative bacteria (GNB) by phenotypic methods and to confirm the presence of resistant genes using real-time polymerase chain reaction (PCR). METHODS: This was a prospective study carried out at the Department of Microbiology, Sri Venkata Sai Medical College and Hospital, Mahabubnagar, India, from March 2018-2021. All samples were screened for carbapenem resistance by disc diffusion method and the VITEK(®)2 compact system (bioMérieux, France). Detection of carbapenemase was carried out using RAPIDEC(®)CARBA NP test (Biomeriux Private Limited, South Delhi, India), screening for metallo-β-lactamases (MBL) was carried out by double disk synergy test (DDST), and genotypic characterization by real-time PCR. RESULTS: Among the 1093 Gram-negative bacilli identified, 220 (17.0%) were resistant to carbapenems by both tested methods. Carbapenemase detection using the RAPIDEC(®)CARBA NP test indicated that 207 (94.0%) were carbapenemase producers, of which 189 (91.2%) were MBL producers. The most common carbapenemase genes identified were New Delhi metallo-β-lactamase (NDM; 47.3%), followed by the co-existence of genes in combination of NDM, with Verona integron-mediated metallo-β-lactamase (VIM; 39.6%), VIM and oxacillin hydrolyzing enzymes-48 (OXA-48; 4.3%), and OXA-48 (1.4%).No gene of active on imipenem, Klebsiella pneumonia carbapenemase, VIM, or OXA-48 alone was detected. CONCLUSION: This study suggests routine carbapenem resistance testing among multi-drug resistant-GNBs, as most of these infections occur in hospitals. In addition, there is a possibility that these highly antibiotic-resistant genes could spread to other bacteria resulting in further dissemination.202235256490