Effect of combined colistin and meropenem against meropenem resistant Acinetobacter baumannii and Pseudomonas aeruginosa by checkerboard method: A cross sectional analytical study.

BACKGROUND: Meropenem-resistant Acinetobacter baumannii and Pseudomonas aeruginosa are the two most common nosocomial pathogens causing ventilator-associated pneumonia. To combat this resistance, different combinations of antibiotics have been evaluated for their efficacy in laboratories as well as in clinical situations. AIM: The aim of the study was to investigate the effect of combined colistin and meropenem against meropenem-resistant isolates of A. baumannii and P. aeruginosa by checkerboard method. MATERIALS AND METHODS: Fifty meropenem-resistant isolates of A. baumannii (n = 25) and P. aeruginosa (n = 25) from endotracheal aspirates were studied. The MIC of colistin and meropenem was found using the microbroth dilution method. The fractional inhibitory concentration was calculated for the combination of antibiotics by checkerboard assay and the antibiotic interactions were assessed. Fisher's exact test was carried out for statistical comparison of categorical variables. RESULTS: A synergistic effect between colistin and meropenem was observed in 18/25 (72%) and 6/25 (24%) isolates of Acinetobacter baumannnii and P. Aeruginosa, respectively, with fractional inhibitory concentration indices of ≤0.5. None of the tested isolates exhibited antagonism. CONCLUSION: Our results showed that combinations of colistin and meropenem are associated with improvement in minimum inhibitory concentration and may be a promising strategy in treating meropenem-resistant A. baumannii respiratory tract infections.

An outbreak of Salmonella Enteritidis food poisoning following consumption of chicken shawarma: A brief epidemiological investigation.

BACKGROUND: Shawarma, a popular meat-based fast food could be a source of foodborne outbreak due to non-typhoidal Salmonella (NTS). A clustering of acute gastrointestinal (GI) illness following intake of chicken shawarma occurred primarily among the staff and students of a tertiary care hospital in southern India. METHODS: A case-control study was conducted among 348 undergraduate medical students (33 cases, 315 controls).  Data was collected using direct interviews and a simple online questionnaire. Epidemiological associations of GI illness were evaluated at three levels of exposure namely-eating food from any restaurant, eating food from the implicated food outlet, eating chicken shawarma from the implicated outlet. RESULTS: Of 33 cases, 26 had consumed food from a particular food outlet, 4 from other outlets, and 3 did not report eating out. Consumption of food from the suspected food outlet was significantly associated with GI illness (odds ratio 121.8 [95% CI 28.41 to 522.66]; P<0.001); all the 26 cases who had eaten from the particular outlet had eaten chicken shawarma. By comparison, only one of the 315 controls had eaten this dish. Of the 27 persons (cases as well as controls) who had consumed chicken shawarma from the outlet, 26 were ill. Culture of stool samples from 10 affected individuals and implicated food item yielded Salmonella Enteritidis. CONCLUSIONS: Meat-based shawarma is a potential source of NTS infection. Food safety authorities should enforce guidelines for safe preparation and sale of shawarmas and similar products.