Multi-drug resistant gram-negative organism colonization among burn patients

Abstract

Background. Gram-negative multi-drug resistant organism (GN-MDRO) remains a major concern among burn patients, leading to sepsis and high mortality. The aims of the study were to determine GN-MDRO colonization among burn patients and detect any possible cross contamination among burn patients. Materials and methods. Rectal swabs were obtained from 65 burn patients and 985 patients hospitalized at other units of National Traumatology and Orthopaedics Research Centre (NTORC). GN-MDROs were identified using MALDI-TOF, VITEK2 automated machines and antibiotic susceptibility tests were done using disc diffusion test and Etest when necessary. Carbapenamese producing A. baumannii and P. aeruginosa were further checked for genetic relatedness to identify possible cross-contamination within the hospital using multi-locus sequence typing (MLST) and pulsed field gel electrophoresis. Results. Of the all patients, 45 (69.2%, 45/65) burn patients and 418 (42.4%, 418/985) patients from NTORC were colonized with GN-MDROs, respectively. Repeat sample of NTORC at day 14 after hospitalization was similar to burn patients (69.6%, 110/158). Total 71 isolates were recovered from 45 burn patients and predominant colonizer was Enterobacteriaceae (63 isolates). Analysis of MLST of two A. baumannii revealed that both belonged to same MLST 642 type and six cases of P. aeruginosa also belonged to MLST 235. However PFGE genetic analysis of P. aeruginosa revealed that 4 belonged to a same PFGE A cluster and 2 were singletons. Conclusion. High rate of colonization among burn and NTORC patients observed and molecular analysis revealed inter-hospital transmission of GN-MRDOs among patients. Therefore it is necessary to improve existing infection control program to reduce within hospital transmission.