TY - JOUR
T1 - Drug resistance and molecular epidemiology of carbapenem resistant gram-negative bacilli isolates
AU - Naim, Huma
AU - Rizvi, Meher
AU - Gupta, Richa
AU - Azam, Mohd
AU - Taneja, Neelam
AU - Shukla, Indu
AU - Khan, Haris
N1 - Publisher Copyright:
© 2018 Journal of Global Infectious Diseases | Published by Wolters Kluwer -Medknow.
PY - 2018/7/1
Y1 - 2018/7/1
N2 - Objectives: Detection and comparison of metallo-β-lactamase (MBL) production in clinical isolates by phenotypic and genotypic measures. The objective of this study is to evaluate clinical characteristics and risk factors in patients infected with MBLs. Materials and Methods: Study was conducted by the Department of Microbiology, Jawaharlal Nehru Medical College from February 2014 to December 2015. Bacterial culture, identification, and antibiotic susceptibility were carried out according to standard guidelines. MBL production was detected both phenotypically (Modified Hodge test [MHT], imipenem-ethylene diamine tetraacetic acid double disk potentiation test [IMP-EDTA DDPT], IMP-EDTA combined disk synergy test [IMP-EDTA CDST]), and genotypically (bla NDM-1, bla VIM and bla IMP). Results: Among 116 carbapenem-resistant Gram-negative Bacilli (CRGNB), Citrobacter species 28 (24.1%) was the most common pathogen. Phenotypically, MHT, IMP-EDTA DDPT, and IMP-EDTA CDST detected MBL production in 105 (90.5%), 96 (81%), and 87 (75%) CRGNB, respectively. Bla NDM-1 genes were detected in 6 6 (56.8%) isolates, however, very few bla VIM (16, 15.2%) and bla IMP (1, 1.2%) were identified. Considering polymerase chain reaction (PCR) as the gold standard, it was observed that IMP-EDTA CDST was most specific (78.3%) while MHT was most sensitive (97.4%). Results of bla NDM-1 gene by PCR were further confirmed by sequencing (Triyat genomics, Nagpur). All the 11 representative strains were confirmed to be NDM-1 gene. Major risk factors in patients infected with MBLs were in-dwelling devices (68%), prolonged hospital stay (72%) and prior antibiotic treatment (86%). However, on tracing their outcome, it was interesting to note that mortality was relatively low 5 (4.3%). Conclusion: The present study shows a rising trend of bla NDM-1 in CRGNB, an ominous sign heralding the post antibiotic era. It is essential to assess the prevalence of various MBLs so that infection control measures can be reinforced. We recommend three phenotypic tests in tandem for the detection of MBL. While phenotypic tests are easy and cost-effective to perform, quick, effective molecular diagnostic techniques can tailor treatment guidelines to optimize patient's management.
AB - Objectives: Detection and comparison of metallo-β-lactamase (MBL) production in clinical isolates by phenotypic and genotypic measures. The objective of this study is to evaluate clinical characteristics and risk factors in patients infected with MBLs. Materials and Methods: Study was conducted by the Department of Microbiology, Jawaharlal Nehru Medical College from February 2014 to December 2015. Bacterial culture, identification, and antibiotic susceptibility were carried out according to standard guidelines. MBL production was detected both phenotypically (Modified Hodge test [MHT], imipenem-ethylene diamine tetraacetic acid double disk potentiation test [IMP-EDTA DDPT], IMP-EDTA combined disk synergy test [IMP-EDTA CDST]), and genotypically (bla NDM-1, bla VIM and bla IMP). Results: Among 116 carbapenem-resistant Gram-negative Bacilli (CRGNB), Citrobacter species 28 (24.1%) was the most common pathogen. Phenotypically, MHT, IMP-EDTA DDPT, and IMP-EDTA CDST detected MBL production in 105 (90.5%), 96 (81%), and 87 (75%) CRGNB, respectively. Bla NDM-1 genes were detected in 6 6 (56.8%) isolates, however, very few bla VIM (16, 15.2%) and bla IMP (1, 1.2%) were identified. Considering polymerase chain reaction (PCR) as the gold standard, it was observed that IMP-EDTA CDST was most specific (78.3%) while MHT was most sensitive (97.4%). Results of bla NDM-1 gene by PCR were further confirmed by sequencing (Triyat genomics, Nagpur). All the 11 representative strains were confirmed to be NDM-1 gene. Major risk factors in patients infected with MBLs were in-dwelling devices (68%), prolonged hospital stay (72%) and prior antibiotic treatment (86%). However, on tracing their outcome, it was interesting to note that mortality was relatively low 5 (4.3%). Conclusion: The present study shows a rising trend of bla NDM-1 in CRGNB, an ominous sign heralding the post antibiotic era. It is essential to assess the prevalence of various MBLs so that infection control measures can be reinforced. We recommend three phenotypic tests in tandem for the detection of MBL. While phenotypic tests are easy and cost-effective to perform, quick, effective molecular diagnostic techniques can tailor treatment guidelines to optimize patient's management.
KW - BlaIMP
KW - blaNDM1
KW - blaVIM
KW - carbapenem resistant Gram-negative bacilli
KW - phenotypic tests
KW - polymerase chain reaction
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U2 - 10.4103/jgid.jgid_74_17
DO - 10.4103/jgid.jgid_74_17
M3 - Article
AN - SCOPUS:85051746257
SN - 0974-777X
VL - 10
SP - 133
EP - 139
JO - Journal of Global Infectious Diseases
JF - Journal of Global Infectious Diseases
IS - 3
ER -