|Year : 2016 | Volume
| Issue : 1 | Page : 120-121
NDM-1 Infection and colonisation in critically ill patients from Delhi: A glimpse of the community scenario
P Batra1, M Dwivedi1, BL Sherwal1, R Dutta1, S Gupta2
1 Department of Microbiology, Lady Hardinge Medical College, New Delhi, India
2 Department of Microbiology, National Centre for Disease Control, New Delhi, India
|Date of Submission||29-Oct-2014|
|Date of Acceptance||28-Apr-2015|
|Date of Web Publication||15-Jan-2016|
Department of Microbiology, Lady Hardinge Medical College, New Delhi
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Batra P, Dwivedi M, Sherwal B L, Dutta R, Gupta S. NDM-1 Infection and colonisation in critically ill patients from Delhi: A glimpse of the community scenario. Indian J Med Microbiol 2016;34:120-1
|How to cite this URL:|
Batra P, Dwivedi M, Sherwal B L, Dutta R, Gupta S. NDM-1 Infection and colonisation in critically ill patients from Delhi: A glimpse of the community scenario. Indian J Med Microbiol [serial online] 2016 [cited 2019 Sep 19];34:120-1. Available from: http://www.ijmm.org/text.asp?2016/34/1/120/167679
Reports have been published raising the concern of the presence of NDM-1 carrying Gram-negative bacteria (GNB) in the clinical isolates  and environmental samples  of New Delhi, India. These resistant bacteria may get colonised in the gastrointestinal (GI) tract of persons using public water and sanitation facilities and cause serious infections. This may have important implications for people living in the city who are reliant on public water and sanitation facilities. Thus, surveillance of resistance in GNBs causing serious infections as well as colonising the GI tract of persons relying on public facilities was needed.
A point prevalence study was conducted over 2 weeks (6th June to 18th June 2010) in two big hospitals associated with a medical college of North India. All patients admitted to the Intensive Care Units (ICUs) were screened for infection and gut colonisation by Carbapenem resistant Enterobacteriaceae and non-fermenting Gram-negative Bacilli harbouring NDM-1 gene. Within 24 h of admission surveillance swabs (anal/rectal swab) were collected and clinical specimens (blood, cerebrospinal fluid, wound swabs, pus, and other body fluids) were collected on clinical suspicion of an infection from all ICU patients. All the isolates were plated onto MacConkey agar (HiMedia) with 3rd generation cephalosporin (3GC) (impregnated with cefotaxime). Isolates obtained were identified using Vitek-2 automated system (Biomerieux, France). Antimicrobial susceptibility testing was done for all 3GC resistant GNBs by disc diffusion method according to Clinical and Laboratory Standards Institute 2010 guidelines. Minimum inhibitory concentration determination (to imipenem and meropenem by Vitek-2 automated system), imipenem-ethylenediaminetetraacetic acid (EDTA) combined disc test  and polymerase chain reaction (PCR) for NDM-1 gene was done for all isolates resistant to carbapenems by disc diffusion test.
A total of 209 samples (66 surveillance swabs and 143 clinical samples) were collected from 91 patients. From these samples, 105 3GC resistant GNBs were recovered; 88 from surveillance swabs and 17 from clinical specimens. Isolates obtained from surveillance swabs represented community-acquired isolates while those obtained from the clinical specimens represented hospital-acquired isolates. Their resistance pattern is shown in [Figure 1]a and [Figure 1]b, respectively.
|Figure 1: Resistance pattern of the isolates to the antibiotics tested; amikacin (30 μg), chloramphenicol (30 μg), ciprofloxacin (5 μg), colistin (10 μg), cotrimoxazole (1.25/23.75 μg), gentamicin (10 μg), imipenem (10 μg), meropenem (10 μg), and tigecycline (15 μg), (a) resistance pattern (R%) of surveillance isolates; (b) resistance pattern (R%) of clinical isolates|
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Twelve isolates (five from surveillance swabs and seven from clinical samples), were resistant to either of the two carbapenems tested. Of these, three were Escherichia More Details coli, three were Klebsiella pneumoniae, one was Morganella morganii, three were Acinetobacter species, and two were Pseudomonas aeruginosa. Of these, two E. coli, two Acinetobacter and one K. pneumonia isolates were obtained from surveillance swabs. These carbapenem-resistant isolates were resistant to most of the antimicrobials except colistin. M. morganii isolates were resistant to colistin due to inherent resistance mechanisms.
Of these 12 isolates, nine isolates were imipenem-EDTA combined disc test positive. PCR results showed that a total of four isolates had NDM-1 gene; three from the clinical sample and one from surveillance swab. Two NDM-1 positive isolates were obtained from the same patient. Thus, the percentage of isolates having NDM-1 gene was 3.8% (4/105). The percentage of patients harbouring NDM-1 positive strain was 3.3% (3/91).
This study showed that the prevalence of 3GC resistant Enterobacteraceae and non-fermenting Gram-negative Bacilli in patients admitted to ICUs of our hospital was substantial while the prevalence of NDM-1 was substantially low (3.3%). GI colonisation by 3GC and carbapenem-resistant pathogens increases the risk of clinical infections by these pathogens and subsequent human to human transmission.
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