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. - Related Documents




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140301.0000Evaluation 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
222310.9995Evaluation of a new real-time PCR assay (Check-Direct CPE) for rapid detection of KPC, OXA-48, VIM, and NDM carbapenemases using spiked rectal swabs. To prevent the spread of carbapenemase-producing bacteria, a fast and accurate detection of patients carrying these bacteria is extremely important. The Check-Direct CPE assay (Check-Points, Wageningen, The Netherlands) is a new multiplex real-time PCR assay, which has been developed to detect and differentiate between the most prevalent carbapenemase genes encountered in Enterobacteriaceae (blaKPC, blaOXA-48, blaVIM, and blaNDM) directly from rectal swabs. Evaluation of this assay using 83 non-duplicate isolates demonstrated 100% sensitivity and specificity and the correct identification of the carbapenemase gene(s) present in all carbapenemase-producing isolates. Moreover, the limit of detection (LoD) of the real-time PCR assay in spiked rectal swabs was determined and showed comparable LoDs with the ChromID CARBA agar. With an excellent performance on clinical isolates and spiked rectal swabs, this assay appeared to be an accurate and rapid method to detect blaKPC, blaOXA-48, blaVIM, and blaNDM genes directly from a rectal screening swab.201324135412
142620.9995Phenotypic 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
143630.9995Characterisation 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
143140.9995The 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
143750.9995Novel multiplex PCRs for detection of the most prevalent carbapenemase genes in Gram-negative bacteria within Germany. Introduction. Gram-negative bacteria are a common source of infection both in hospitals and in the community, and antimicrobial resistance is frequent among them, making antibiotic therapy difficult, especially when these isolates carry carbapenem resistance determinants.Hypothesis/Gap Statement. A simple method to detect all the commonly found carbapenemases in Germany was not available.Aim. The aim of this study was to develop a multiplex PCR for the rapid and reliable identification of the most prevalent carbapenemase-encoding genes in Gram-negative bacteria in Germany.Methodology. Data from the German Gram-negative reference laboratory revealed the most prevalent carbapenemase groups in Germany were (in order of prevalence): bla (VIM), bla (OXA-48), bla (OXA-23), bla (KPC), bla (NDM), bla (OXA-40), bla (OXA-58), bla (IMP), bla (GIM), bla (GES), ISAba1-bla (OXA-51), bla (IMI), bla (FIM) and bla (DIM). We developed and tested two multiplex PCRs against 83 carbapenem-resistant Gram-negative clinical isolates. Primers were designed for each carbapenemase group within conserved regions of the encoding genes obtained from publicly available databases. Multiplex-1 included the carbapenemase groups bla (VIM), bla (OXA-48), bla (OXA-23), bla (KPC), bla (NDM) and bla (OXA-40), while multiplex-2 included bla (OXA-58), bla (IMP), bla (GIM), bla (GES), ISAba1-bla (OXA-51) and bla (IMI).Results. In the initial evaluation, all but one of the carbapenemases encoded by 75 carbapenemase-positive isolates were detected using the two multiplex PCRs, while no false-positive results were obtained from the remaining eight isolates. After evaluation, we tested 546 carbapenem-resistant isolates using the multiplex PCRs, and all carbapenemases were detected.Conclusion. A rapid and reliable method was developed for detection and differentiation of 12 of the most prevalent carbapenemase groups found in Germany. This method allows for the rapid testing of clinical isolates prior to species identification and does not require prior phenotypical characterization, constituting a rapid and valuable tool in the management of infections in hospitals.202133448924
211960.9994Detection of bla(IMP) and bla(VIM) metallo-β-lactamases genes among Pseudomonas aeruginosa strains. Acquired Metallo-β-Lactamases (MBLs) are emerging resistance determinants in Pseudomonas aeruginosa and other gram-negative bacteria.Using Combination Disk Diffusion test, it was found that among 83 imipenem non-susceptible P. aeruginosa strains, 48 (57.9%) were MBL producers. PCR and Sequencing methods proved that these isolates were positive for blaIMP-1 genes, whereas none were positive for bla(VIM) genes. The mortality rate due to MBL-producing Pseudomonas infection was 4 (8.3%) among the hospitalized patients. Therefore, identification of drug resistance patterns in P. aeruginosa and detection of MBLs producing isolates are of great importance in the prevention and control of infections.201323638331
222270.9994Multiplex real-time PCR assay for the detection of extended-spectrum β-lactamase and carbapenemase genes using melting curve analysis. Real-time PCR melt curve assays for the detection of β-lactamase, extended-spectrum β-lactamase and carbapenemase genes in Gram-negative bacteria were developed. Two multiplex real-time PCR melt curve assays were developed for the detection of ten common β-lactamase genes: blaKPC-like, blaOXA-48-like, blaNDM-like, blaVIM-like, blaIMP-like, blaCTX-M-1+2-group, blaCMY-like, blaACC-like, blaSHV-like and blaTEM-like. The assays were evaluated using 25 bacterial strains and 31 DNA samples (total n=56) comprising different Enterobacteriaceae genera and Pseudomonas spp. These strains were previously characterized at five research institutes. Each resistance gene targeted in this study generated a non-overlapping and distinct melt curve peak. The assay worked effectively and detected the presence of additional resistance genes in 23 samples. The assays developed in this study offer a simple, low cost method for the detection of prevalent β-lactamase, ESBL and carbapenemase genes among Gram-negative pathogens.201627021662
148880.9994Evaluation of an automated rapid diagnostic assay for detection of Gram-negative bacteria and their drug-resistance genes in positive blood cultures. We evaluated the performance of the Verigene Gram-Negative Blood Culture Nucleic Acid Test (BC-GN; Nanosphere, Northbrook, IL, USA), an automated multiplex assay for rapid identification of positive blood cultures caused by 9 Gram-negative bacteria (GNB) and for detection of 9 genes associated with β-lactam resistance. The BC-GN assay can be performed directly from positive blood cultures with 5 minutes of hands-on and 2 hours of run time per sample. A total of 397 GNB positive blood cultures were analyzed using the BC-GN assay. Of the 397 samples, 295 were simulated samples prepared by inoculating GNB into blood culture bottles, and the remaining were clinical samples from 102 patients with positive blood cultures. Aliquots of the positive blood cultures were tested by the BC-GN assay. The results of bacterial identification between the BC-GN assay and standard laboratory methods were as follows: Acinetobacter spp. (39 isolates for the BC-GN assay/39 for the standard methods), Citrobacter spp. (7/7), Escherichia coli (87/87), Klebsiella oxytoca (13/13), and Proteus spp. (11/11); Enterobacter spp. (29/30); Klebsiella pneumoniae (62/72); Pseudomonas aeruginosa (124/125); and Serratia marcescens (18/21); respectively. From the 102 clinical samples, 104 bacterial species were identified with the BC-GN assay, whereas 110 were identified with the standard methods. The BC-GN assay also detected all β-lactam resistance genes tested (233 genes), including 54 bla(CTX-M), 119 bla(IMP), 8 bla(KPC), 16 bla(NDM), 24 bla(OXA-23), 1 bla(OXA-24/40), 1 bla(OXA-48), 4 bla(OXA-58), and 6 blaVIM. The data shows that the BC-GN assay provides rapid detection of GNB and β-lactam resistance genes in positive blood cultures and has the potential to contributing to optimal patient management by earlier detection of major antimicrobial resistance genes.201424705449
143090.9994Prevalence of multidrug-resistant Gram-negative bacteria from blood cultures and rapid detection of beta-lactamase-encoding genes by multiplex PCR assay. INTRODUCTION: This study aimed to determine the prevalence of multidrug-resistant Gram-negative bacteria (GNB) from blood cultures in a tertiary-care hospital and the multiplex PCR assay's ability to detect resistance genes. METHODS: A total of 388 GNB isolates obtained from hospitalized patients between November 2019 and November 2021 were included in the study. Antimicrobial susceptibility testing was done by VITEK 2 system and broth microdilution method. Beta-lactamase-encoding genes were detected by multiplex PCR assays, BioFire-Blood Culture Identification 2 (BCID2) panel (bioMérieux, France). Extended-spectrum beta-lactamases (ESBLs) were detected phenotypically with VITEK AST-GN71 card (bioMérieux, France). The isolates of GNB were classified into multidrug-resistant, extensively-drug-resistant, and pandrug-resistant categories, and their prevalence and distribution in different wards, including coronavirus diseases 2019 (COVID-19) intensive care units (ICU), were calculated. RESULTS: Results revealed that all isolates of Acinetobacter baumannii and Pseudomonas aeruginosa were multidrug-resistant as well as 91.6% of Enterobacter cloacae, 80.6% of Proteus mirabilis, and 76.1% of Klebsiella pneumoniae, respectively. In fermentative bacteria, bla(OXA-48-like) (58.1%), bla(NDM) (16.1%), bla(KPC) (9.7%) and bla(VIM) (6.5%) genes were detected. More than half of Enterobacter cloacae (58.3%) and Klebsiella pneumoniae (53.7%) produced ESBLs. Among non-fermenters, the bla(NDM) gene was carried by 55% of Pseudomonas aeruginosa and 19.5% of Acinetobacter baumannii. In the COVID-19 ICU, Acinetobacter baumannii was the most common isolate (86.1%). CONCLUSIONS: This study revealed high proportions of multidrug-resistant blood isolates and various underlying resistance genes in Gram-negative strains. The BCID2 panel seems to be helpful for the detection of the most prevalent resistance genes of fermentative bacteria.202238021186
1461100.9994Phenotypic and Genetic Characterization of Carbapenemase and ESBLs Producing Gram-negative Bacteria (GNB) Isolated from Patients with Cystic Fibrosis (CF) in Tehran Hospitals. BACKGROUND: Cystic Fibrosis (CF) is an autosomal recessive genetic disorder in white populations caused by mutation in a gene that encodes Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein. Since frequent respiratory tract infections are the major problem in patients with CF, obligation to identify the causative bacteria and determining their antibiotic resistance pattern is crucial. The purpose of this project was to detect Gram-negative bacteria (GNB) isolated from sputa of CF patients and to determine their antibiotic resistance pattern. MATERIALS AND METHODS: The sputum of 52 CF patients, treated as inpatients at hospitals in Tehran, was obtained between November 2011 and June 2012. Samples cultured in selective and non-selective media and GNB recognized by biochemical tests. Antimicrobial susceptibility testing to cephalosporins, aminoglycosides and carbapenems was performed by disk diffusion method and MICs of them were measured. For phenotypic detection of carbapenemase and ESBLs production, the Modified Hodge test, double disk synergy test and the combined disk methods were performed. Subsequently, the genes encoding the extended spectrum beta-lactamases (blaPER, blaCTX-M) and carbapenemases (blaIMP-1, blaGES, blaKPC, blaNDM, blaVIM-1, blaVIM-2, blaSPM, blaSIM) in Gram negative bacteria were targeted among the resistant isolates by using PCR. PFGE was used to determine any genetic relationship among the Pseudomonas aeruginosa isolated from these patients. RESULTS: Fifty five GNB were isolated from 52 sputum samples including Pseudomonas aeruginosa, Klebsiella ozaenae, Alcaligenes xylosoxidans, Achromobacter denitrificans, Klebsiella pneumonia and Stenotrophomonas maltophilia. The rates of resistance to different antibiotic were as follows: cefixime (%80), ceftriaxone (%43), ceftazidime (%45) and meropenem (%7). The prevalence of genes encoding the ESBLs and Carbapenemases among the the phenotypically positive strains were as follows: blaCTX-M (19), blaIMP-1 (2), blaVIM-1 (2) and blaVIM-2 (3) genes respectively. No other genes were detected. PFGE analysis revealed 8 genotypes. Six isolates had mutually 3 similar patterns. CONCLUSION: This study showed the existence of important ESBLs and carbapenemases genes among the GNB isolated from patients with CF. Continuous surveillance of ESBLs and Carbapenemases, also identification of their types, in bacteria isolated from these patients have an important clinical impact, since, it can often provide valuable information for effective infection control measures and for the choice of appropriate antimicrobial therapy.201424596716
2215110.9994Analytical Performance of Multiplexed Screening Test for 10 Antibiotic Resistance Genes from Perianal Swab Samples. BACKGROUND: Multiantibiotic-resistant bacteria pose a threat to patients and place an economic burden on health care systems. Carbapenem-resistant bacilli and extended-spectrum β-lactamase (ESBL) producers drive the need to screen infected and colonized patients for patient management and infection control. METHODS: We describe a multiplex microfluidic PCR test for perianal swab samples (Acuitas(®) MDRO Gene Test, OpGen) that detects the vancomycin-resistance gene vanA plus hundreds of gene subtypes from the carbapenemase and ESBL families Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), Verona integron-mediated metallo-β-lactamase (VIM), imipenemase metallo-β-lactamase (IMP), OXA-23, OXA-48, OXA-51, CTX-M-1, and CTX-M-2, regardless of the bacterial species harboring the antibiotic resistance. RESULTS: Analytical test sensitivity per perianal swab is 11-250 CFU of bacteria harboring the antibiotic resistance genes. Test throughput is 182 samples per test run (1820 antibiotic resistance gene family results). We demonstrate reproducible test performance and 100% gene specificity for 265 clinical bacterial organisms harboring a variety of antibiotic resistance genes. CONCLUSIONS: The Acuitas MDRO Gene Test is a sensitive, specific, and high-throughput test to screen colonized patients and diagnose infections for several antibiotic resistance genes directly from perianal swab samples, regardless of the bacterial species harboring the resistance genes.201626637481
1459120.9994Molecular characterization of carbapenem-resistance in Gram-negative isolates obtained from clinical samples at Jimma Medical Center, Ethiopia. BACKGROUND: In resource-constrained settings, limited antibiotic options make treating carbapenem-resistant bacterial infections difficult for healthcare providers. This study aimed to assess carbapenemase expression in Gram-negative bacteria isolated from clinical samples in Jimma, Ethiopia. METHODS: A cross-sectional study was conducted to assess carbapenemase expression in Gram-negative bacteria isolated from patients attending Jimma Medical Center. Totally, 846 Gram-negative bacteria were isolated and identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Phenotypic antibiotic resistance patterns were determined using the Kirby-Bauer disk diffusion method and Etest strips. Extended-spectrum β-lactamase phenotype was determined using MAST disks, and carbapenemases were characterized using multiplex polymerase chain reactions (PCR). RESULTS: Among the isolates, 19% (157/846) showed phenotypic resistance to carbapenem antibiotics. PCR analysis revealed that at least one carbapenemase gene was detected in 69% (107/155) of these strains. The most frequently detected acquired genes were blaNDM in 35% (37/107), blaVIM in 24% (26/107), and blaKPC42 in 13% (14/107) of the isolates. Coexistence of two or more acquired genes was observed in 31% (33/107) of the isolates. The most common coexisting acquired genes were blaNDM + blaOXA-23, detected in 24% (8/33) of these isolates. No carbapenemase-encoding genes could be detected in 31% (48/155) of carbapenem-resistant isolates, with P. aeruginosa accounting for 85% (41/48) thereof. CONCLUSION: This study revealed high and incremental rates of carbapenem-resistant bacteria in clinical samples with various carbapenemase-encoding genes. This imposes a severe challenge to effective patient care in the context of already limited treatment options against Gram-negative bacterial infections in resource-constrained settings.202438328425
1438130.9994Prevalence 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.201626463362
2121140.9994Investigation of VIM, IMP, NDM-1, KPC AND OXA-48 enzymes in Enterobacteriaceae strains. Gram-negative bacteria especially Enterobacteriaceae species have become an increasing etiologic agent of nosocomial infections. The development of resistance to carbapenems have become an increasing problem in the treatment of nosocomial infections. Especially carbapenamases are common for Enterobacteriaceae strains. This study was performed to detect the types of carbapenemases in Enterobacteriaceae strains isolated from various clinical samples. Enterobacteriaceae species were isolated from urine, blood, tracheal aspirates, wound, and other respiratory samples. Susceptibility of isolates to imipenem, meropenem and ertapenem was tested. Carbapenemase genes were studied using HyplexSuperBug ID kit. VIM (1-13), IMP (1-22), NDM-1, KPC(1-10) and OXA-48 genes were investigated. Ninety-five isolates of Enterobacteriaceae spp. were included in the study. Sixty isolates were resistant to imipenem, meropenem and ertapenem and 20 isolates were found resistant to imipenem or ertapenem while 15 were susceptible to all carbapenems. Among the isolates with carbapenem resistance, 57 were positive for one carbapenemase gene and susceptible isolates did not have carbapenemase gene. OXA-48 was found in 49 of the isolates (86%), NDM-1 in 6 (10.5%) isolates, VIM in 2 isolates. IMP and KPC gene loci were not identified. Carbapenemase genes play a crucial role in the development and spread of resistant strains.201526051720
2118150.9994Gram-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
2126160.9993Carbapenemase genes among multidrug resistant gram negative clinical isolates from a tertiary hospital in Mwanza, Tanzania. The burden of antimicrobial resistance (AMR) is rapidly growing across antibiotic classes, with increased detection of isolates resistant to carbapenems. Data on the prevalence of carbapenem resistance in developing countries is limited; therefore, in this study, we determined the prevalence of carbapenemase genes among multidrug resistant gram negative bacteria (MDR-GNB) isolated from clinical specimens in a tertiary hospital in Mwanza, Tanzania. A total of 227 MDR-GNB isolates were analyzed for carbapenem resistance genes. For each isolate, five different PCR assays were performed, allowing for the detection of the major carbapenemase genes, including those encoding the VIM-, IMP-, and NDM-type metallo-beta-lactamases, the class A KPC-type carbapenemases, and the class D OXA-48 enzyme. Of 227 isolates, 80 (35%) were positive for one or more carbapenemase gene. IMP-types were the most predominant gene followed by VIM, in 49 (21.59%) and 28 (12%) isolates, respectively. Carbapenemase genes were most detected in K. pneumoniae 24 (11%), followed by P. aeruginosa 23 (10%), and E. coli with 19 isolates (8%). We have demonstrated for the first time a high prevalence of MDR-GNB clinical isolates having carbapenem resistance genes in Tanzania. We recommend routine testing for carbapenem resistance among the MDR-GNB particularly in systemic infections.201424707481
2124170.9993Evaluation of Phenotypic and Genotypic Characteristics of Carbapnemases-producing Enterobacteriaceae and Its Prevalence in a Referral Hospital in Tehran City. BACKGROUND & OBJECTIVE: Carbapenem-resistant Enterobacteriaceae is a growing concern worldwide including Iran. The emergence of this pathogen is worrying as carbapenem is one of the 'last-line' antibiotics for treatment of infections caused by multi drug resistant gram- negative bacteria. The main objective of this study was to determine the prevalence of carbapenem-resistant Enterobacteriaceae in a referral hospital in Tehran, Iran. METHODS: In this study, all positive isolates of Enterobacteriaceae recorded in blood, urine, and other body fluids were studied during April 2017 to April 2018 in a referral hospital in Tehran. All cases of resistance to carbapenems were first tested by modified Hodge test. All cases with positive or negative test, after gene extraction, were examined genotypically based on the primers designed for the three Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), and OXA-48 genes by conventional PCR method. RESULTS: 108 isolates (13.6%) were resistant to all cephalosporins as well as to imipenem and meropenem. In a genotypic study, including 45 isolates, 13 isolates were positive for OXA-48 gene, 11 isolates for OXA-48 and NDM genes, 11 isolates for OXA-48, NDM and KPC genes, 4 isolates for OXA-48 genes and KPC, 3 isolates for NDM, one isolate for KPC. On the other hand, two isolates were negative for all three genes examined. CONCLUSION: OXA-48 gene was one of the most common genes resistant to carbapenems in Iran. According to studies, the prevalence of antibiotic resistance in Iran is rising dramatically, which reduces the choice of antibiotics to treat severe infections in the future.202032215024
1427180.9993Prevalence and Characterization of Carbapenem-Resistant Enterobacteriaceae Isolated from Mulago National Referral Hospital, Uganda. INTRODUCTION: Carbapenemases have increasingly been reported in enterobacteriaceae worldwide. Most carbapenemases are plasmid encoded hence resistance can easily spread. Carbapenem-resistant enterobacteriaceae are reported to cause mortality in up to 50% of patients who acquire bloodstream infections. We set out to determine the burden of carbapenem resistance as well as establish genes encoding for carbapenemases in enterobacteriaceae clinical isolates obtained from Mulago National Referral Hospital, Uganda. METHODS: This was a cross-sectional study with a total of 196 clinical isolates previously collected from pus swabs, urine, blood, sputum, tracheal aspirates, cervical swabs, endomentrial aspirates, rectal swabs, Vaginal swabs, ear swabs, products of conception, wound biopsy and amniotic fluid. All isolates were subjected to phenotypic carbapenemase screening using Boronic acid-based inhibition, Modified Hodge and EDTA double combined disk test. In addition, all the isolates were subjected to PCR assay to confirm presence of carbapenemase encoding genes. RESULTS: The study found carbapenemase prevalence of 22.4% (44/196) in the isolates using phenotypic tests, with the genotypic prevalence slightly higher at 28.6% (56/196). Over all, the most prevalent gene was blaVIM (21,10.7%), followed by blaOXA-48 (19, 9.7%), blaIMP (12, 6.1%), blaKPC (10, 5.1%) and blaNDM-1 (5, 2.6%). Among 56 isolates positive for 67 carbapenemase encoding genes, Klebsiella pneumonia was the species with the highest number (52.2%). Most 32/67(47.7%) of these resistance genes were in bacteria isolated from pus swabs. CONCLUSION: There is a high prevalence of carbapenemases and carbapenem-resistance encoding genes among third generation cephalosporins resistant Enterobacteriaceae in Uganda, indicating a danger of limited treatment options in this setting in the near future.201526284519
2120190.9993Antimicrobial Resistance Patterns of Gram-negative Bacteria in an Iranian Referral Pediatric Hospital: A Present Danger of New Delhi Metallo-β- lactamase. BACKGROUND: Antimicrobial resistance among gram-negative bacteria has been growing, particularly in developing countries, like Iran. The emergence and spread of carbapenem-resistance mechanisms is a major public health concern because no definite treatments have yet been established for this problem. This study aimed to evaluate antibiotic susceptibility of gram-negative bacteria, metallo-β-lactamases (MBLs) and carbapenemase-producing genes, including bla (NDM), bla (VIM), and bla (IMP) in patients referred to Children's Medical Center, Tehran, Iran. MATERIAL AND METHODS: In this cross-sectional study, a total of 944 gram-negative isolates were tested in the study, and antimicrobial susceptibility testing was performed. Moreover, MBL production of carbapenem-resistant isolates, as well as the presence of bla (NDM), bla (VIM), and bla (IMP), was investigated. RESULTS: The most common gram-negative isolated bacteria were Escherichia coli (489 samples, 52%), followed by Klebsiella pneumoniae (167 samples, 18%), Pseudomonas aeruginosa (101 samples, 11%), Enterobacter spp. (64 samples, 7%), Pseudomonas spp. (35 samples, 4%), Acinetobacter baumannii (18 samples, 2%), and Burkholderia cepacia (17 samples, 2%). Imipenemresistant was found in 75%, 61%, and 60% of Stenotrophomonas maltophilia, Enterobacter spp., and A. baumannii isolates, respectively. Moreover, the highest resistance to meropenem was observed in S. maltophilia, A. baumannii, P. aeruginosa, and B. cepacia (100%, 96%, 83%, and 61.5%, respectively). Double disk synergy test (DDST) results showed that 112 out of 255 carbapenem- resistant isolates (44%) were MBL-producing ones. The presence of the bla (NDM) gene was identified in 32 (29%) of MBL-producing isolates, 13 of which were K. pneumoniae, 7 P. aeruginosa, and 7 E. coli, 3 Enterobacter spp., and 2 Klebsiella spp., respectively. The presence of the bla (IMP) and bla (VIM) genes was detected in 2 (2%) and 1 (1%) of MBL-producing isolates. These genes were detected in only MBL-producing P. aeruginosa isolates. CONCLUSION: Our findings suggest the emergence of NDM-producing strains in our hospital, and bla NDM was the most frequently detected carbapenemase gene in MBL-producing P. aeruginosa, K. pneumoniae, and Klebsiella spp. Since such bacteria can easily spread among patients in the hospital, a strong infection control and prevention plan is highly recommended.202337106518