Prevalence of non tuberculous mycobacterial infection in surgical site infections and their antibiotic susceptibility profile

Med J Armed Forces India. 2021 Jul;77(3):343-348. doi: 10.1016/j.mjafi.2020.01.012. Epub 2020 May 4.

Abstract

Background: Surgical site infections (SSIs) are one of the leading causes of hospital-acquired infections contributing to about 20% of all cases, thereby causing an increase in morbidity and financial burden. Causative organisms associated with SSIs have not changed greatly over the last 10-15 years; however, the proportions of different types of causative organisms have changed with an increase in case reports of rare organisms such as non-tuberculous mycobacteria (NTM).

Methods: Samples received from patients with SSI were simultaneously cultured for the isolation of NTM along with routine bacteriological examination. On isolation of NTM, identification was carried out by biochemical tests, and further antibiotic susceptibility profile was determined by using RAPMYCO kit.

Results: SSI occurred in 3.95% of the 7675 surgeries performed during the study period of which 10.9% were caused owing to NTM. Only rapidly growing NTM were isolated of which, Mycobacterium fortuitum was the most common (51.51%) and had least resistance to drugs. Other isolates were Mycobacterium abscessus and Mycobacterium chelonae having high degree of antimicrobial resistance.

Conclusion: NTM are an important cause of SSI having delayed presentation, are difficult to diagnose and often not treated correctly. Identification and susceptibility testing is important as different species respond differently to antimicrobial agents.

Keywords: Antimicrobial susceptibility testing; Non-tuberculous mycobacteria; RAPMYCO; Rapidly growing mycobacteria; Surgical site infections.