PURPOSE:Detection of carbapenemases among Gram-negative bacteria (GNB) is important for both clinicians and infection control practitioners. The Clinical and Laboratory Standards Institute recommends Carba NP (CNP) as confirmatory test for carbapenemase production. The reagents required for CNP test are costly and hence the test cannot be performed on a routine basis. The present study evaluates modifications of CNP test for rapid detection of carbapenemases among GNB.MATERIALS AND METHODS:The GNB were screened for carbapenemase production using CNP, CarbAcineto NP (CANP), and modified CNP (mCNP) test. A multiplex polymerase chain reaction (PCR) was performed on all the carbapenem-resistant bacteria for carbapenemase genes. The results of three phenotypic tests were compared with PCR.RESULTS:A total of 765 gram negative bacteria were screened for carbapenem resistance. Carbapenem resistance was found in 144 GNB. The metallo-β-lactamases were most common carbapenemases followed by OXA-48-like enzymes. The CANP test was most sensitive (80.6%) for carbapenemases detection. The mCNP test was 62.1% sensitive for detection of carbapenemases. The mCNP, CNP, and CANP tests were equally sensitive (95%) for detection of NDM enzymes among Enterobacteriaceae. The mCNP test had poor sensitivity for detection of OXA-48-like enzymes.CONCLUSION:The mCNP test was rapid, cost-effective, and easily adoptable on routine basis. The early detection of carbapenemases using mCNP test will help in preventing the spread of multidrug-resistant organisms in the hospital settings.

Introduction:Mupirocin competitively inhibits bacterial isoleucyl transfer-RNA synthetase and inhibit bacterial protein synthesis. Widespread usage and over the counter availability of the drug has resulted in resistance among Staphylococcus species.Objectives:This study aimed to determine the overall prevalence of mupirocin resistance among staphylococci. Correlate clinical significance of mupirocin resistance and its relationship to clinical use.Methods:Consecutive, nonrepetitive, clinical isolates of Staphylococcus aureus (n = 98), and coagulase-negative staphylococci (CoNS) (n = 45) from skin and soft-tissue infections between January 2014 and June 2014 were studied. Antibiotic susceptibility testing was done according to Clinical and Laboratory Standards Institute guidelines. Low- and high-level mupirocin resistance was screened by using 5 µg and 200 µg discs respectively and confirmed by agar dilution. Annual consumption of mupirocin was studied and correlated with resistance.Results:High-level mupirocin resistance was found in 8.2% S. aureus and 15.6% of CoNS, while low-level mupirocin resistance was found in 17% S. aureus and 8.9% CoNS. High-level mupirocin resistance was more common in methicillin-sensitive S. aureus isolates when compared with methicillin-resistant S. aureus isolates (P < 0.05). Mupirocin resistant S. epidermidis were associated with methicillin resistance and constitutive clindamycin resistance.Conclusion:High prevalence of mupirocin resistance was found in the present study. Increased prevalence of mupirocin resistance among community-acquired staphylococci demands the judicious use of the drug in the community.

Objective: The objective of this study is to study the current antibiotic sensitivity pattern of Salmonella typhi and paratyphi isolates and the clinical response of children with culture positive enteric fever (EF) to the specific antibiotic used as suggested by the sensitivity pattern. Materials and Methods: This is a retrospective study analyzing the records of 197 children treated for blood culture positive EF during 3 years from January 2013 to December 2015. Antibiogram pattern of S. typhi/paratyphi and response pattern to the antibiotic used as per antibiogram were analyzed. Kirby Bauer’s disc diffusion method was used for antibiotic sensitivity using closed-loop stripping analysis standards. Temperature charts of the patients analyzed for response patternof fever to the antibiotic started. Results: 197 culture positive cases were included in the study (S. typhi=190 and paratyphi=7). Sensitivity pattern to 9 out of 10 antibiotics tested was high and was low only to nalidixic acid (6.3%). There were 184 (93.4%) children whose antibiogram showed high sensitivity to cephalosporins and were treated with intravenous ceftriaxone (Group 1). The majority of children in this group (172/184, 93.5%) became afebrile by 7 days of therapy. 13 (6.6%) children whose antibiogram showed resistance to cephalosporins were treated with intravenous ciprofloxacin (Group 2). 9 of this group became afebrile by 7 days. 12 children from Group 1 and 4 children from Group 2 were considered as either reduced susceptibility or resistance torespective antibiotics and were treated with either azithromycin or piperacillin-tazobactam over the next 5-7 days successfully. Conclusion: Appropriate diagnosis using blood cultures and using 3rd generation cephalosporins as the first line of the drug in treating children with EF can reduce the duration of treatment, promote better compliance, reduce relapse rates, and may help decrease multi-drug resistant S.typhi/partyphi strains in the community..

The emergence and global spread of carbapenem-resistant is of great concern to the health care facilities due to high rates of morbidity and mortality associated with them. It is necessary to know its epidemiology and the resistant pattern in a geographical area to formulate a antibiotic stewardship policy. To study the occurrence and mechanisms of carbapenem resistance in Escherichia coli.A total of 1172 clinical strains of obtained from various clinical specimens were screened for carbapenem resistance during the study period. Strains showing reduced susceptibility to imipenem &/or ertapenem &/or meropenem were included in the study. The resistance mechanisms were identified using various phenotypic methods. Total of 53/1172 were found to be carbapenem resistant (CRE). The most common sample in which CRE were isolated was urine (n=26, 49.1%). A total of 50 isolates were confirmed as Metallo-beta-lactamase (MBL) producers using Ezy MIC strip. One of the three non carbapenemase producing isolate was positive for ESBL with porin loss and the other two isolates were positive for AmpC with porin loss.MBL production being the most common mechanism of carbapenem resistance, the study indicates the importance of regular monitoring of drug resistance in the hospital for an urgent action to be taken for antibiotics stewardship in the institute.

Background and Aims Emergence of multi drug resistant MDR gram negative bacteria GNB is a serious threat and major challenge encountered by healthcare professionals. This study aimed to evaluate the distribution of antimicrobial resistance patterns in drug resistant GNB isolated at tertiary care hospital.Methods A total of 934 GNB strains were included in this study. Bacterial identification and disk diffusion testing were performed using standard microbiological techniques. Phenotypic detection of ESBL was assessed using double disk synergy test. Multiplex PCR assay was optimized to detect NDM-1 OXA-48 VIM IMP and KPC genes in carbapenem resistant GNB.Results The most common GNB identified were E. coli n46449.7 K. pneumoniae n13714.7 Acinetobacter Sp n13114 P. aeruginosa n11212 and Enterobacter Sp n313.3. Out of 934 isolates 808.6 were resistant to all tested antibiotics including carbapenems fluoroquinolones and aminoglycosides with high rate of resistant among Acinetobacter sp n454.8. On the other hand among 16818 carbapenem resistant isolates NDM-1 was most predominant in E. coli n2313.7 followed by K. pneumoniae n169.5 Acinetobacter Sp. n158.9 and P. aeruginosa n84.8. OXA-48 was most common in Acinetobacter Sp. n4124.4 followed by E. coli n74.2 and K. pneumoniae n63.6. Among 221 23.7 ESBL producing GNB E. coli n16717.9 was most common followed by K. pneumoniae n303.2 and Acinetobacter Sp n91.Conclusions The occurrence of bacterial infections caused by MDR-GNB and carbapenem resistant GNB infections is high. It is important for clinicians to evaluate and focus on the risk factors associated with the acquisition of MDR and carbapenem resistant organisms in hospital environment.