High Prevalence and Endemicity of Multidrug Resistant Acinetobacter spp. in Intensive Care Unit of a Tertiary Care Hospital, Varanasi, India

The increasing emergence of Acinetobacter spp. with healthcare associated infections (HCAI) in intensive care units (ICU) is alarming. This study was a laboratory-based audit to determine the prevalence of Acinetobacter spp. associated with HCAI in the adult ICU of a tertiary care hospital in Varanasi, north India, with special reference to antimicrobial resistance and resistance determinants over a period of 5 years. A total of 993 cases of HCAI were analyzed. Isolates were characterized as multidrug resistance and extended drug resistance (MDR/XDR) based on antimicrobial susceptibility records. Few (100) randomly selected isolates of Acinetobacter baumannii (A. baumannii) were tested for imipenem, meropenem, and polymyxin B susceptibility by minimum inhibitory concentration (MIC) and for the presence of class A and B carbapenemases by multiplex PCR. Active surveillance of ICU environment was also performed. High prevalence of Acinetobacter related hospital acquired pneumonia (HAP) with significant resistance to imipenem(p<0.05) and 88.02% MDR and 61.97% XDR was detected along with persistence in the ICU environment. The isolates harbored bla(IMP) (89%), bla(VIM) (51%), bla(NDM-1) (34%), and bla(OXA-23-like) (93%) genes. Specific interventional measures should be adopted to control these imipenem resistant Acinetobacter spp. which have attained the level of endemicity in our ICU setup.