Prevalence of non-fermenting gram negative bacilli infections and their antimicrobial susceptibility pattern in a tertiary care

Background: Aerobic non-fermenting gram negative bacilli [NFGNB] once considered as contaminants now associated with life threatening infections and emerging as multidrug resistant [MDR] nosocomial pathogens. AIM: Isolation and identification of NFGNB in various clinical samples and to determine their antibiotic susceptibility pattern. Materials and methods: A retrospective study was conducted in the microbiology laboratory of a tertiary care hospital from July 2015 to December 2016. NFGNB were isolated from various clinical specimens on MacConkey agar. Further identification and antibiotic susceptibility testing [AST] was done by subjecting them to VITEK -2 system. Results: Among 7654 clinical specimens, 325 yielded NFGNB accounting for an isolation rate of 4.24%. Blood was the most common specimen [34.77%] followed by tracheal aspirate [29.57%]. Acinetobacter baumannii was the most common isolate (98.6%) followed by Pseudomonas aeroginosa (78.1%). A high level of antibiotic resistance was recorded for most of the first and second line drugs. Thus confirming multidrug resistance. Colistin and tigecycline showed maximum activity with an overall susceptibility of (74.46%) and (57.85%) respectively. High carbapenem resistance in this study is of major concern which can cause outbreaks and limit therapeutic options due to MDR. Conclusion: Identification of NFGNB and monitoring their susceptibility patterns will aid in proper management of infections caused by them. Improved antibiotic stewardship and infection control measures are needed to prevent emergence ad spread of MDR NFGNB in the healthcare settings.