scholarly journals Phenotypic and genotypic detection of carbapenemase enzymes producing gram-negative bacilli isolated from patients in Khartoum State

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1656
Author(s):  
R.A. Dahab ◽  
Alamin Mohamed Ibrahim ◽  
Hisham N. Altayb

Background: Carbapenems are used as antibiotics of last resort for treating infections due to multidrug-resistant Gram-negative bacilli, but emergence of Carbapenem resistant Gram-negative bacilli have been reported due to the production of Carbapenemase enzymes that significantly limits treatment options for life-threatening infections. Objective: This study aimed to detect Carbapenem resistant Gram-negative bacilli from patients attended to different hospitals in Khartoum state and to detect Carbapenemase enzymes production by phenotypic and genotypic methods. Methods: A hospital based cross sectional study was conducted in Khartoum state in the period from February to August 2016. Hundred and forty nine Gram-negative bacilli bacteria were isolated from different clinical specimens. Blood agar, Chromogenic agar media, MacConkey agar, XLD mediaandstandard biochemical tests were used for isolation and identification of Gram-negative bacilli from different samples. Standard antimicrobial susceptibility testing to Carbapenem antibiotic was performed for all isolates, then detection of Carbapenemase enzymes production for the resistant isolates was performed using Modified Hodge Test and PCR. Results: Hundred and forty nine Gram-negative bacilli were isolated from 147 different clinical specimens. The most predominant Gram-negative bacilli isolates was E.coli (54.4%), followed by Klebsiella species (29.5%). More than fifty percent of the isolates were Carbapenem resistant. Fifty six percent of the resistant isolates were positive by Modified Hodge Test. By using PCR, 17.3% of resistant organisms were harbored blaOXA48 gene, and 6.7% harbored blaIMP gene. E.coli was the most bacteria that harbored the blaoxa48 followed by Klebsiella species. blaIMP gene was harbored only by E.coli. Conclusion: The percentage of resistance to Carbapenems due to production of Carbapenemase enzymes is very high in Sudan.BlaOXA48 gene is more predominant than blaIMP in this study.

Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 148 ◽  
Author(s):  
Cuong Hoang Quoc ◽  
Thao Nguyen Thi Phuong ◽  
Hai Nguyen Duc ◽  
Trung Tran Le ◽  
Hang Tran Thi Thu ◽  
...  

Background: Acinetobacter baumannii (Ab) is an opportunistic bacterial pathogen found in hospital-acquired infections including nosocomial pneumonia, especially multidrug-resistant Ab. This study aims to survey the drug resistance profiles of Ab isolated from patients in Thong Nhat Dong Nai General Hospital and assess the relationship between genotypes and antibiotic resistance; Methods: Ninety-seven Ab strains isolated from 340 lower respiratory tract specimens among pneumonia patients were used to screen the most common local carbapenemase genes. Antimicrobial susceptibility testing results and demographic data were collected and minimum inhibitory concentrations (MIC) of colistin were also determined; Results: Over 80% and 90% of Ab strains were determined as carbapenem-resistant and multidrug-resistant (MDR), respectively. Most of the strains carried carbapenemase genes, including blaOXA-51, blaOXA-23-like, blaOXA-58-like, and blaNDM-1, with proportions of 97 (100%), 76 (78.4%), 10 (10.3%), 6 (6.2%), respectively. Amongst these genes, blaOXA-23-like was the only gene which significantly influenced the resistance (p < 0.0001); and Conclusions: The severity of Ab antibiotic resistance is urgent and specifically related to carbapenemase encoding genes. Therefore, screening of MDR Ab and carbapenemase for better treatment options is necessary.


Author(s):  
Mohammad Hasan Namaei ◽  
Masoud Yousefi ◽  
Parvin Askari ◽  
Babak Roshanravan ◽  
Ali Hashemi ◽  
...  

Background and Objectives: Non-fermentative Gram-negative Bacilli (NFGNB) is known as a major cause of health- care-associated infections with high levels of antibiotic resistance. The aim of this study was to investigate the antibiotic resistance profiles and molecular characteristics of metallo-beta-lactamase (MBL)-producing NFGNB. Materials and Methods: In this cross-sectional study, the antibiotic resistance profile of 122 clinical NFGNB isolates was determined by the Kirby-Bauer disk diffusion and microdilution broth methods. Bacterial isolates were investigated for the detection of MBLs production using the combination disk diffusion Test (CDDT). The existence of bla , bla , and bla NDM genes in all carbapenem-resistant isolates was determined employing polymerase chain reaction (PCR) assays. Results: High resistance in Pseudomonas aeruginosa was reported to cefotaxime and minocycline, whereas Acinetobacter baumannii isolates were highly resistant to all antibiotics except colistin. Multidrug resistance (MDR)-NFGNB (66% vs. 12.5%, P=0.0004) and extensively drug resistant (XDR)-NFGNB (55.7% vs. 12.5%, P=0.001) isolates were significantly more common in hospitalized patients than in outpatients. The production of MBL was seen in 40% of P. aeruginosa and 93.3% of A. baumannii isolates. It was found that 33.3% and 46.7% of carbapenem-resistant P. aeruginosa isolates, and 13.3% and 28.9% of carbapenem-resistant A. baumannii isolates were harboring bla IMP-1 and bla VIM-1 genes, respectively. The incidence of MDR (98.2% vs. 28.3%, P<0.001) and XDR (96.4% vs. 11.7%, P<0.001) in MBL-producing NFGNB isolates was significantly higher than non-MBL-producing isolates. Conclusion: This study demonstrated a higher rate of resistance among NFGNB isolates with an additional burden of MBL production within them, warranting a need for robust microbiological surveillance and accurate detection of MBL producers among the NFGNB.


Author(s):  
Manish Ranjan ◽  
Mahadevan Kumar ◽  
Sourav Sen ◽  
Parijat Das ◽  
Kunal Kanti Lahiri

Introduction: Urinary Tract Infections (UTI) are one of the commonest conditions for which people seek medical care with an estimated 150 million episodes per annum worldwide. An unprecedented upsurge in the rate of development of antimicrobial resistance has reduced the therapeutic options leading to increased morbidity, prolonged hospital stays, development of complications. Majority of these infections are attributable to Gram negative bacteria which have now acquired resistance to almost all classes of antibiotics. Aim: To analyse the plasmid-mediated drug resistance and characterise the major plasmid families that are in circulation. Materials and Methods: A cross-sectional study comprising of a total of 95 non consecutive multidrug-resistant gram-negative bacterial isolates were subjected to Plasmid based replicon typing from January 2017 to June 2018. The 18 major replicons were divided in five multiplex and three uniplex Polymerase Chain Reaction (PCR) formats and the samples were subjected for plasmid characterisation and further sequencing of the plasmid Deoxyribonucleic Acid (DNA). The data obtained was analysed by Microsoft Excel software. Results: Escherichia coli, accounted for maximum n=51 (53.7%), Klebsiella pneumoniae n=19 (20%), Citrobacter sp n=11 (11.6%), miscellaneous gram negative n=14 (14.7%) The isolates exhibited a high degree of resistance to almost all tested antibiotics, sparing a few like Fosfomycin, Chloramphenicol, Imipenem, Amikacin. A total of 154 different plasmid families were detected from the 95 isolates. FIB replicon (24%), FIA (21%), F, W (20%), FIC, B/O (14%), Y (12%), I1 replicon (10.5%) were the major plasmid families detected in the present study. Conclusion: Many isolates exhibited the presence of more than one Incompatibility (Inc.) group plasmids, conferring multidrug resistance to the isolates. The study highlights the need for further research to study the association between plasmid families and their respective antibiotic resistance profiles for a given geographical niche and the need to devise further methods to target these epidemic plasmids.


2021 ◽  
Author(s):  
Namrata Kumari ◽  
Mukesh Kumar ◽  
Amit Katiyar ◽  
Abhay Kumar ◽  
Pallavi Priya ◽  
...  

Abstract Carbapenemase-producing clinical isolates are becoming more common over the world, posing a severe public health danger, particularly in developing nations like India. Carbapenem-resistant Gram-negative bacterial (CR-GNB) infection has become a fast-expending global threat with limited antibiotic choice and significant mortality. The aim of this study was to highlight the carbapenem-resistance among clinical isolates of hospital admitted patients in Bihar, India. A cross-sectional study was conducted with 101 clinical isolates of E. coli, K. pneumoniae, A. baumannii, and P. aeruginosa. All GNB isolates were tested for their antimicrobial susceptibility using double disc synergy test / modified hodge test (DDST/MHT) and subsequently confirmed carbapenemase-producing isolates were evaluated for carbapenem-resistance genes using whole-genome sequencing (genotypically) method. The overall percentage of carbapenem-resistance among GNB was (17/101) 16.83%. The AMR analysis demonstrates a significantly high prevalence of blaCTX−M followed by blaSHV, blaTEM, blaOXA and blaNDM β-lactams carbapenem-resistance genes among clinical isolates of GNB. Co-occurrence of carbapenemase-encoding genes with blaNDM was found in 70.6% of carbapenemase-producing isolates. Our study highlights the mechanism of carbapenem-resistance to curb the overwhelming threat posed by emergence of drug-resistance in India.


2018 ◽  
Vol 62 (10) ◽  
Author(s):  
Thea Brennan-Krohn ◽  
Alejandro Pironti ◽  
James E. Kirby

ABSTRACTResistance to colistin, a polypeptide drug used as an agent of last resort for the treatment of infections caused by multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative bacteria, including carbapenem-resistantEnterobacteriaceae(CRE), severely limits treatment options and may even transform an XDR organism into one that is pan-resistant. We investigated the synergistic activity of colistin in combination with 19 antibiotics against a collection of 20 colistin-resistantEnterobacteriaceaeisolates, 15 of which were also CRE. All combinations were tested against all strains using an inkjet printer-assisted digital dispensing checkerboard array, and the activities of those that demonstrated synergy by this method were evaluated against a single isolate in a time-kill synergy study. Eighteen of 19 combinations demonstrated synergy against two or more isolates, and the 4 most highly synergistic combinations (colistin combined with linezolid, rifampin, azithromycin, and fusidic acid) were synergistic against ≥90% of strains. Sixteen of 18 combinations (88.9%) that were synergistic in the checkerboard array were also synergistic in a time-kill study. Our findings demonstrate that colistin in combination with a range of antibiotics, particularly protein and RNA synthesis inhibitors, exhibits synergy against colistin-resistant strains, suggesting that colistin may exert a subinhibitory permeabilizing effect on the Gram-negative bacterial outer membrane even in isolates that are resistant to it. These findings suggest that colistin combination therapy may have promise as a treatment approach for patients infected with colistin-resistant XDR Gram-negative pathogens.


The Lancet ◽  
2019 ◽  
Vol 393 ◽  
pp. S21
Author(s):  
Abdelraouf A Elmanama ◽  
Mariam R Al-Reefi ◽  
Madleen A Shamali ◽  
Haya I Hemaid

2018 ◽  
Vol 24 (1) ◽  
pp. 625-631 ◽  
Author(s):  
Sahar Naz ◽  
Farhan Rasheed ◽  
Muhammad Saeed ◽  
Shagufta Iram ◽  
Ambereen Anwar Imran

Inter-hospital and intra-hospital dissemination of metallo-β-lactamase (MβL) producing strains possess significant therapeutic challenges. Objective: This study was carried out to evaluate the efficacy of Colistin against MβL producers. Material and Methods: This cross-sectional study was conducted in Microbiology Laboratory, Allama Iqbal Medical College, Lahore, Pakistan from 1stJuly 2016 to 25th February 2017. A total of 12126 clinical samples were collected from patients presenting to Jinnah Hospital, Lahore. Every sample was processed for bacterial culture. Bacterial identification was performed according to standard guidelines. Every gram-negative isolate was further processed for antimicrobial susceptibility testing by modified Kirby Baur disc diffusion method. Zone sizes were interpreted according to CLSI 2016 guidelines. Next day every carbapenem-resistant isolate were further processed for MβL detection by EDTA method, zone size of Carbapenem disc only and Carbapenem disc impregnated with EDTA was compared ( >7 mm increase MβL positive, 0-5 mm increase MβL-negative). Results: Out of total 12126 samples, 35.9% (n=4361) were culture positive and only 40.5% (n=1770) were Gram negative rods. Of these 9.6% (n=170) were Carbapenem-resistant isolates with 47% (n=80) MβL producers. Briefly 51.7% (n=30) Acinetobacter species were MβL positive, Pseudomonas species 38.5% (n=22), Escherichia coli 69.5% (n=16), Klebsiella species 37.0% (n=10), Proteus 66.6% (n=2) and 0% Citrobacter sppwere MβL positive. 32.5% MβL positive isolates were from ICU, 21.2% were from OPD, 12.5%were from Surgical Units, 12.5% were from Medical Unit, 17.5% were from Orthopedic Unit, and 3.7% were from Pulmonology ward. Almost 100% resistant was observed in MβL positive isolates for Imipenem,Piperacillin+ Tazobactum, Ceftriaxone, Co-amoxyclav, Cefoperazone+Sulbactam, Ciprofloxacin, and Amikacin, Doxycycline, and Gentamicin showed 91.2%, 94.0%, and 97.5% resistant rate respectively. No resistance was observed against Colistin. Conclusion: MβL producing Gram negative rods are rising in clinical setups. They are becoming a nightmare for clinicians to treat such infections. Colistin remains the only choice of drug for MβL positive and Negative isolates with 0% resistant rate except for Proteus species, to which it is intrinsically resistant.


2021 ◽  
Vol 19 ◽  
Author(s):  
Mohan Sharma ◽  
Pankaj Chetia ◽  
Minakshi Puzari ◽  
Nakul Neog ◽  
Upasana Phukan ◽  
...  

Background: Enterobacteriaceae, the normal dwellers in the human intestine, are commonly associated with a variety of community acquired and nosocomial infections. Emerging trend of antibiotic resistance among these strains is a notable issue globally; more serious threat is the resistance against the available last resort antibiotics- the carbapenems. Objective: The objective of our study was intended to determine the burden of resistance towards common antibiotic classes, so as to address the gap of drug resistance prevalence data, among the Enterobacteriaceae isolates obtained from the health settings in this region. Methodology: A cross-sectional study was done with inclusion of clinical isolates collected from varied sources, from health settings in upper Assam. The isolates were identified based on standard methods of morphology study and biochemical tests. The identified isolates were then subjected to antibiotic susceptibility testing by following Kirby-Bauer disc diffusion method and the result interpreted as per the CLSI guidelines. The resistance of the reported carbapenem resistant isolates was confirmed by minimum inhibitory concentration (MIC) determination using commercial E-strip kit. Results: Among the enterobacterial isolates Klebsiella spp. accounted the majority, followed by Escherichia coli, Citrobacter spp., Shigella spp. and others. Multi-drug resistance (MDR) was noted among 67.6% isolates; however, carbapenem resistance was confirmed in 18.9% of the total Enterobacteriaceae isolates. Conclusion: Higher prevalence of resistance towards carbapenems, among the Enterbacteriaceae isolates of upper Assam seems to be upcoming threat to the region, limiting the treatment options in future.


2017 ◽  
Vol 9 (2) ◽  
Author(s):  
Guido Granata ◽  
Nicola Petrosillo

The global rise of multidrug-resistant gram-negative bacteria represents an increasing threat to patient safety. From the first observation of a carbapenem-resistant gramnegative bacteria a global spread of extendedspectrum beta-lactamases and carbapenemases producing <em>Klebsiella</em> <em>pneumoniae</em> has been observed. Treatment options for multidrug-resistant <em>K. pneumoniae</em> are actually limited to combination therapy with some aminoglycosides, tigecycline and to older antimicrobial agents. Unfortunately, the prevalence of colistin-resistant and tigecycline- resistant <em>K. pneumoniae</em> is increasing globally. Infection due to colistin-resistant <em>K. pneumoniae</em> represents an independent risk factor for mortality. Resistance to colistin in <em>K. pneumoniae</em> may be multifactorial, as it is mediated by chromosomal genes or plasmids. The emergence of transmissible, plasmidmediated colistin resistance is an alarming finding. The absence of new agents effective against resistant Gram-negative pathogens means that enhanced surveillance, compliance with infection prevention procedures, and antimicrobial stewardship programs will be required to limit the spread of colistinresistant <em>K. pneumoniae</em>.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259005
Author(s):  
Sayran Hamad Haji ◽  
Safaa Toma Hanna Aka ◽  
Fattma A. Ali

Background Emerging worldwide in the past decade, there has been a significant increase in multidrug-resistant bacteria from serious nosocomial infections, especially carbapenemase-producing Gram-negative bacilli that have emerged worldwide. The objective of this study is to investigate carbapenem resistance in Gram-negative bacilli bacteria using phenotypic detection, antimicrobial resistance profiles and genotypic characterisation methods. Methods 200 Gram-negative bacilli isolates were collected from different clinical specimens. All clinical samples were exposed to isolation and identification of significant pathogens applying bacteriological examination and an automated Vitek-2 system. The isolates were subjected to susceptibility tests by the Vitek-2 automated system and those isolates that were resistant to beta-lactam drugs, including carbapenems, third-generation cephalosporines or cefoxitin, were selected for phenotyping using Carba plus disc system assay for detection of carbapenemase-producing isolates. These isolates were further confirmed by molecular detection. PCR was used for the detection carbapenem-resistant genes (OXA-48, IMP, NDM, VIM, and KPC). Results 110 (55%) of 200 Gram-negative bacilli were identified as beta-lactam-resistant isolates. The frequency of carbapenem-resistant isolates was calculated to be 30.9% (n = 34/110). A collection totalling 65/110 (59%) isolates were identified as carbapenemase producers by phenotypic method. Moreover, among the 65 carbapenemase-producing Gram-negative isolates with a positive phenotype-based result, 30 (46%), 20 (30%) and 18 (27%) isolates were positive for OXA-48, KPC and MBL enzymes, respectively, as well as the production of 27% of AmpC with porin loss. Tigecycline was the most effective antibiotic that affected 70% of MDR isolates, but high rates of resistance were detected to other tested antimicrobials. Of interest, a high incidence of MDR, XDR and PDR profiles were observed among all carbapenemase-producing isolates. 36% (24/65) of the tested isolates were MDR to 3 to 5 antimicrobial classes. 29% (17/65) of the recovered isolates were XDR to 6 to 7 antimicrobial classes. Alarmingly, 24% (16/65) of isolates displayed PDR to all the tested 8 antimicrobial classes. Genotype assay, including 53 phenotypically confirmed carbapenemase-producing isolates of Gram-negative bacilli, found 51(96%) isolates were harbouring one or more genes. The most common carbapenemase gene was bla NDM 83% (44/53) followed by bla OXA-48 75% (40/53), bla VIM 49% (26/53) and bla IMP 43% (23/53), while the gene bla KPC was least frequent 7% (4/53). 92% (46/51) of isolates were involved in the production of more than one carbapenemase gene. Conclusion This study demonstrated the emergence of carbapenemase-producing Gram-negative pathogens implicated in healthcare-related infections. Accurate identification of carbapenem-resistant bacterial pathogens is essential for patient treatment, as well as the development of appropriate contamination control measures to limit the rapid spread of pathogens. Tigecycline exhibited potent antimicrobial activity against MDR, XDR and PDR-producing strains that establish a threatening alert which indicates the complex therapy of infections caused by these pathogens.


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