Extended culture methods among orthopaedic surgery patients and recovery of various microorganisms in a tertiary care hospital

Abstract

Introduction: Extended culture has made a marked tremendous impact on orthopaedic post operative treatment due to prolonged incubation period. Aim: To identify various organisms isolated from different surgical procedures in Orthopaedic department and their rapidity of growth of various microorganisms isolated along with their sensitivity patterns. Materials and method: The prospective study was conducted in the department of Microbiology, KIMS, Secunderabad over a period of November 2015 to October 2016. A total of 104 samples were received from orthopaedic department during different orthopaedic surgical procedures. The received specimens were inoculated onto 5% sheep blood agar, chocolate agar, MacConkey agar and fluid thioglycolate medium and incubated at 37˚C, 5% CO2 for 40-48 hours and read daily for the growth. If no growth was observed, subcultures were made from fluid thioglycolateand observed daily till 7 days. Positive growths processed in Vitek 2 compact system (Biomerieux). The data collected was analyzed using Microsoft Excel. UK Standard for microbiology Investigations Investigation for orthopaedic implants associated infections (NICE accredited guidelines 2016) are the basis of the study. Results: A total of 104 patients were investigated in the present study, out of which 60 (57.6%) were culture positive. 44 (42.30%) cultures were sterile after 7 days of incubation. The orthopaedic surgical procedures were 52 Open fractures with Open reduction internal fixation (50%), 10 Septic arthritis (9.61%), 7 Sinovitis (6.7%), 7 Discharging sinus (6.7%) and 29 others (27.8%). Among all culture positives (n=60), 38 Gram negative organisms (61.66%) were in majority as compared to 23 Gram positive microorganisms (38.33%). Among them, 17 E.coli (28.3%), 8 Enterococcus (13.33%), 7 MSSA (6.7%), 5 Pseudomonas (4.8%) were the predominant pathogen. Conclusion: As 15(25%) microorganism showed prolonged incubation (48hrs to 7 days) period, which could be missed in conventional cuture method (24-48hrs). The outcome of all culture positive patient were good, 95% successfully treated.