**6. Prevention and control**

In the present study, we studied MBL positive *E.coli* strains by MBL E – test and compared the results of other phenotypic methods for MBL detection i.e. Re – Modified Hodge test (Re-

In figure 7, the venndiagram showing interrelationship of Re – modified Hodge test (Re – MHT), Double disk synergy test (DDST) and Disk potentiation test (DP) for detection of MBL

In the present study when results of all three phenotypic methods were compared with MBL – E test results, it was found that 45/51 (88.2%) MBL positive strains were positive by all three phenotypic method i.e. Re – Modified Hodge test (Re- MHT), Double disk synergy test (DDST) and Disk potentiation (DP) tests. 04 and 02 were false positive by Re – MHT and DDST methods respectively, whereas6/51 (11.8%) and 5/51(9.8%) were false negative by Re – MHT and DDST method respectively. Amongst all three phenotypic methods, DP was best correlated with MBL – E test. By DP test 51 MBL positive E.coli strains were detected and no false positive and false

*E.coli* are responsible for various infections like urinary tract infection, diarrhoea, pneumonia, bacteremia, upper respiratory tract infections, wound infections, osteomyelitis and neonatal

The successful outcome of clinical use of 3rd generation cephalosporines unfortunately led to the increased use and emergence of ESBL producing Enterobacteriaceae. With the emergence of ESBL and Amp C β – lactamase production in *E.coli*, *Klebsiella pneumoniae* and other Enterobacteriaceae, Carbapenems were used as last resort to treat those infections. Because of selective pressure of Carbapenems, even carbapenemases producing Enterobacteriaceae

Most common MBL found worldwide in Enterobacteriaceae were VIM (Verona integron encoded MBL) and IMP (active on imipenem). Multidrug resistant *E.coli* harboring New Delhi metallobetalactamase - 1 (NDM-1) isolated from a patient returned to Canada from India [75], was reported first in 2009. NDM -1 was also recognized among Enterobacteriaceae 32 from Mumbai, 13 from Varanasi and 3 from Guwahati in India and 25 isolates from eight different cities in Pakistan. These isolates were from cases of bacteraemia, ventilator associated pneu‐

NDM - 1 spread largely to different countries like Australia, Japan, Brazil, Belgium, Canada, Germany etc [77]. The gene encoding NDM – 1is called blaNDM-1, located on transmissible plasmid which may include other antibiotic resistance genes also leading to extensive drug resistant phenotypes (so called 'superbugs'). A recent report from ICU and wards of Sir Gangaram hospital Delhi, India showed 8.1% NDM – 1 positive E.coli [78]. In January 2011, the name of NDM–1 was changed to PCM (Plasmid encoding Carbapenem resistant metallo‐

MHT), Double disk synergy test (DDST) and Disk potentiation (DP) test.

negative result was found (Sensitivity 100% and specificity 100%).

monia and community acquired urinary tract infections [76].

producing *E.coli*.

64 Trends in Infectious Diseases

**5. Epidemiology**

meningitis [73,74].

(CRE) has emerged.

betalactamases) [79].

As *E.coli* are one of the commonest cause of both health care and community acquired infections, rapid identification of beta lactamase producing *E.coli* is crucial for appropriate treatment and timely implementation of infection control measures in Health care set-up. Indeed, delayed detection of ESBLs, Amp C β – lactamase and MBL producing strains, raise the possibility of spread of these strains into the community. These issues combined with the limited therapeutic options available to treat patient infected with these organisms, have made CRE of epidemiological importance globally [ 80]. ESBLs and Carbapenem resistant strains may lead to outbreaks of infection in HealthCare Set-up also.

Phenotypic methods can be useful for routine detection of ESBLs and carbapenemase pro‐ duction, among Gram negative bacteria particularly when PCR is not available.

Screening of colonisation with multidrug-resistant organisms (MDROs) upon admission to hospitals has been advocated in patients who have already received healthcare in endemic countries. The CDC recommends, if previously unrecognized cases are identified of being infected with β-lactamase producing strains, a round of surveillance culture from high risk areas i.e. ICUs or wards from where detected, should be considered in any Health Care Setup. In addition prompt notification, must be made to infection control team members when CRE are identified in Clinical Microbiology Laboratories.

Antimicrobial stewardship has been suggested as the most important efforts to control multidrug resistant organisms (MDROs) [81]. It has been found to be most effective, if efforts are directed towards an overall decrease in antimicrobial use rather than targeting a specific antimicrobial class. Limiting use of invasive devices is another potentially important preven‐ tive mechanism for MDROs including β- lactamase producing organisms. Health care workers (HCW) should follow hand hygiene practices while giving patient care preferably using an alcohol based hand rubs or antimicrobial soap and water if hands are visibly soiled, and also follow Standard precautions and Additional precautions as per the indications.
