Published: 2021-08-25

Microbiological surveillance of operation theatres, labour room and intensive care units of a tertiary care centre of South-East Assam

Barnamoy Bhattacharjee, Debadatta Dhar Chanda, Basabdatta Choudhury


Background: With increasing incidence of health care associated infections, microbiological surveillance of air and surfaces of OT, labour room and ICU can become an integral part of hospital infection control practice as it helps in identifying the areas harboring nosocomial pathogens leading to healthcare associated infection. Purpose of the current study was 1) to isolate and identify the microbial contaminants of air and surfaces of various OTs, labour room and ICUs 2) to study the antimicrobial susceptibility pattern of the isolated pathogens.

Methods: This surveillance was carried out in operation-theatres, labour room and ICUs of tertiary care referral hospital of South-east Assam in June 2019 and processing of the samples were done in the department of Microbiology. Passive monitoring of air borne microbes was done by settle plate method on Nutrient Agar and Blood Agar plates and surfaces swabs were inoculated on Blood and MacConkey agar and pathogens were identified using biochemical tests. Antibiotic susceptibility testing was done by disc diffusion method on Mueller Hinton agar.

Results: Surgery O.T. with 57 CFU/mm3 and central ICU with no growth showed highest and least contamination respectively. Proteus mirabilis was isolated from Surgery O.T. and SNCU level II, Klebsiella pneumonia from air and surfaces of surgery and gynaecology O.T. Staphylococcus aureus was isolated from air and surfaces all O.T. except ophthalmology O.T. Surface swabs recovered Pseudomonas spp from surgery minor O.T and orthopedics O.T and Acinetobacter spp from arthroscopy O.T. The pathogenic gram-negative bacilli though isolated, were mostly sensitive to 1st and 2nd line antimicrobials. But 85% of the Staphylococcus aureus isolates were MRSA.

Conclusions: The result of this targeted surveillance highlights the need of regular and effective antiseptic cleaning of all surfaces in these crucial areas of the hospital. The unauthorized movement, entry and overcrowding should be avoided as far as possible in these zones. The antimicrobial susceptibility profile of gram negative isolates hints at their community-based origin.


O.T, ICU, Labour room, Microbiological surveillance, Assam, settle plate

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