Incidence of blaNDM-1 gene in Escherichia coli isolates at a tertiary care referral hospital in Northeast India.

Purpose: Increasing reports on New Delhi metallo-β-lactamase-1 (NDM-1) producing Escherichia coli constitute a serious threat to global health since it is found to be highly resistant to most of the currently available antibiotics including carbapenems. This study has been performed to find out the incidence blaNDM-1 in E. coli isolates recovered from the various clinical samples at a tertiary care referral hospital in Northeast India. Materials and Methods: A total of 270 non-duplicated E. coli isolates were recovered from the various clinical samples at a tertiary care referral hospital in Northeast India. All isolates with reduced susceptibility to meropenem or ertapenem (diameter of zones of inhibition, ≤21 mm) were further phenotypically confirmed for carbapenemase production by modified Hodge test. All screened isolates were also subjected to the polymerase chain reaction detection of blaNDM-1 gene and additional bla genes coding for transmission electron microscopy, SHV, CTX-M, and AmpC. Results: Out of 270 E. coli isolates, 14 were screened for carbapenemase production on the basis of their reduced susceptibility to meropenem or ertapenem. All screened isolates were found to be positive for blaNDM-1 . Each of the blaNDM-1 possessing isolate was also positive for two or more additional bla genes, such as blaTEM , blaCTX-M and blaAmpC . Phylogenetic analysis showed very less variation in blaNDM-1 gene with respect to blaNDM-1 possessing E. coli isolates from other parts of India and abroad. Conclusions: Our findings highlight the incidence of blaNDM-1 in E. coli isolates with a reduced susceptibility to meropenem or ertapenem.

Multidrug-resistant Enterobacteriaceae including metallo-β-lactamase producers are predominant pathogens of healthcare-associated infections in an Indian teaching hospital.

Purpose: A study was carried out in an Indian teaching hospital in 2009 to detect the rate of surgical site infections (SSI) and peripheral vascular access site infections. Materials and Methods: The study was a point-prevalence study involving over 300 patients. The presence of infection was determined according to the CDC criteria. Swabs were taken from the infected sites and identification and sensitivity were carried out using VITEK® 2 automated system. Characterisation of β-lactamase was carried out at ARRML, Colindale, London. Results: The rate of SSI was 15% for the clean and clean-contaminated categories while that for the dirty contaminated category was 85% (NNIS risk index 0). Cultures yielded definite or probable pathogens from 64% (9/14) of the patients with SSI. In 1/3 rd of the cultures, Staphylococcus aureus was grown and the rest had Enterobacteriaceae, either extended-spectrum β-lactamase (ESBL) producers or Amp-C hyperproducers and, alarmingly, three isolates were positive for newly recognised New Delhi metallo-β-lactamase-1 (NDM-1). In medicine, 87% (n = 99) of the patients had a peripheral IV access device, 55% developed associated phlebitis/infection and, in seven, probable pathogens were isolated (Candida species and Escherichia coli producing ESBL and NDM-1, respectively, Staphylococcus aureus and Enterococcus faecium). All ESBL and metallo-β-lactamase producers were resistant to multiple classes of antimicrobials, the latter being sensitive only to colistin and tigecycline. The study also found that all post-operative patients were on antibiotics, 92% on IV [213 defined daily doses (DDD)/100 post-op patients] limited mainly to the third-generation cephalosporins (26%) and aminoglycosides (24%) and imidazole derivatives (30%). In medicine, 83% (n = 82) were on IV antibiotics (123 DDD/100 bed-days), limited mainly to the third-generation cephalosporins (74%). Conclusion: Indiscriminate use of antibiotics is a major problem predisposing patients to harm by multi-resistant pathogens. Carbapenems were in little use in this hospital, but the selection pressure exerted by cephalosporins and other unrelated classes was sufficient to select NDM-1-producing strains due to co-selection, suggesting a role of single plasmid carrying resistance genes to multiple classes.

Prevalence and risk factors for colonisation with extended spectrum β-lactamase producing enterobacteriacae vis-à-vis usage of antimicrobials.

Purpose: A point prevalence study was carried out in a teaching hospital in Assam to determine the prevalence, sensitivity profile and risk factors for acquisition of extended spectrum β-lactamase (ESBL) producing enterobacteriacae vis-ΰ-vis amount and pattern of antibiotic use. Materials and Methods: ESBL was detected by double disc synergy method. Defined daily dose and bed-days were calculated. Result: Colonisation rate of ESBL producing enterobacteriacae ranged from 14% (n=73) in medicine to the highest 41% (n=29) in orthopaedic with an intermediate 23% (n=80) in surgery. Presence of ESBL was found to be strongly associated with resistance to specific classes of antimicrobials. Exposure to cefotaxime and gentamicin, and surgery were risk factors for acquiring ESBL producing enterobacteriacae. Non-ESBL producing community isolates were found to be considerably more sensitive to different antibiotics with no resistance detected to trimethoprim, co-trimoxazole, ciprofloxacin and aminoglycosides. Conclusion: The study confirms the role of certain 'high risk' antimicrobials in acquisition of ESBL producing Enterobacteriaceae and shows that periodic cohort studies could be an effective strategy in surveillance of antimicrobial resistance in hospitals of resource poor countries to inform antibiotic policy and treatment guidelines.

Characterisation of methicillin resistant S. aureus strains and risk factors for acquisition in a teaching hospital in northeast India.

Purpose: A point prevalence study was carried out in a teaching hospital in Assam to characterise S. aureus strains, establish the rate of colonisation of methicillin resistant S. aureus (MRSA) and associated risk factors for its acquisition. Materials and Methods: Antibiogram-Resistogram profile was done by BSAC standardized disc sensitivity method; Phage and RFLP typing were carried out by the PHLS, London. Results: Single MRSA strain resistant to multiple classes of anti-staphylococcal antibiotics dominated the hospital. The MRSA colonisation rate was found to be 34% (n=29) and 18% (n=80) in orthopaedics and surgery, respectively and only ~1% (n=73) in the medical units. Exposure to ciprofloxacin and surgery were risk factors but duration of hospital stay was not. In contrast, meticillin sensitive S. aureus (MSSA) strains were usually distinct strains and sensitive to most of the anti-staphylococcal antibiotics including 18% to penicillin. Conclusions: The MRSA strain prevalent in the hospital phenotypically resembles the predominant Asian strain viz., Brazilian/Hungarian strains (CC8-MRSA-III). Duration was not a risk factor, which suggests that in absence of exposure to specific antimicrobials, even in a hospital with no or little infection control intervention, a vast majority remain free from MRSA. This underlines the importance of rational prescribing empirical antibiotics.

Infection control with limited resources: Why and how to make it possible.

The risk of healthcare-associated infections (HCAIs) in developing countries can exceed 25% compared to developed countries. Lack of awareness and institutional framework to deal with patient safety in general and HCAI in particular perpetuates the culture of acceptance of avoidable risks as inevitable. Most HCAIs are avoidable and can be prevented by relatively simple means. It is no longer acceptable to put patients at risk of avoidable infections. The World Health Organization (WHO)-led World Alliance for Patient Safety launched a worldwide campaign on patient safety focusing on simple means like hand hygiene to combat HCAIs. To drive necessary changes to deliver sustainable improvement in clinical care requires strategic approach and clinical leadership. This article reviews the scale of the problem, the WHO recommended interventions and improvement strategies in institutional setup in developing and transitional countries.

Effect of centrally administered nitric oxide modulators in Brewer's yeast-induced nociception in rats.

Possible modulation of Brewer's yeast-induced nociception by centrally (icv) administered nitric oxide (NO) modulators, viz., NO synthase (NOS) inhibitors, NO precursor, donors, scavengers and co-administration of NO donor (SIN-1) with NOS inhibitor (L-NAME) and NO scavenger (Hb) was investigated in rats. Administration of NOS inhibitors and NO scavenger Hb increased the pain threshold capacity significantly, whereas NO donors SIN-1, SNP and NO precursor L-arginine were found to be hyperalgesic. D-arginine, the inactive isomer of L-arginine and methylene blue, inhibitor of soluble guanylate cyclase failed to alter the nociceptive behaviour in rats. Co-administration of SIN-1 with L-NAME and Hb found to increase the nociceptive threshold. The results indicate, that centrally administered NO modulators alter the nociceptive transmission induced by Brewer's yeast in rats.