Serratia, No Longer an Uncommon Opportunistic Pathogen – Case Series & Review of Literature

Background: Serratia spp. is a common enteric bacterium generally thought not to be pathogenic in the gastrointestinal tract. Serratia marcescens is a member of the genus Serratia, which is a part of the family Enterobacteriales. Of all Serratia species, S. marcescens is the most common clinical isolate and the most important human pathogen. Objective: We discuss here four cases of Serratia marcescens which were reported in our laboratory at the Department of Microbiology Government Medical College and Hospital Chandigarh within six months of duration. Method: All the samples were processed and identified using standard microbiological techniques. The isolates of Serratia marcescens were identified, depending upon their biochemical and morphological characteristics, and further confirmed by MALDI-TOF-MS, PGIMER Chandigarh. Result: In one of the four cases, polymicrobial infection was observed, and among the cases, one patient was diabetic and the rest three patients were immunocompetent. The importance of detection of Serratia marcescens is related to the concern regarding its increased spread in hospital settings as nosocomial infection. Conclusion: We need to identify and isolate this pathogen not thinking of it only as a contaminant and opportunistic pathogen but as a pathogen which can lead to serious infections in hospital settings.