Bacteriological profile of surgical site infections

Background: Surgery has made great advances in last 3 quarters of this century and post-operative wound infection is the most common complication faced by surgeon since the advent of surgery. Aim: To determine the bacteriological profile and antibiogram of surgical site infections. Materials and methods: This prospective study was done for a period of one year (January 1, 2016 to December 31, 2016) in a Govt. Medical College, Amritsar. The study population included 712 patients suffering from Surgical Site infections in the various wards (Orthopedics, General Surgery, Obstetrics and Gynecology) of our hospital. Two sterile cotton swabs were collected aseptically. Gram stained preparation was made from one swab. The other swab was inoculated on blood agar and Mac Conkey agar and incubated for 48 hours. Growth on culture plate was identified by its colony characters and standard biochemical tests. Antimicrobial sensitivity testing was done by Kirby- Baeur disk diffusion method. Results: Rate of SSI was 58.00%. A total of 431 isolates were obtained, out of which 428 (99.30%) were bacterial isolates and 3 (0.69%) were fungal isolates. Monomicrobial growth was seen in 395 (95.64%) patients whereas polymicrobial growth was seen in 18 patients (4.35%). Out of 428 bacterial isolates, majority of bacteria were gram negative bacteria (60.74%) but most common isolate was Staphylococcus aureus. The microbiological profile of the 260 (60.74%) gram negative bacteria was Klebsiella pneumoniae followed by Pseudomonas aeruginosa, Escherichia coli, Acinetobacter spp., Citrobacter spp. and Proteus spp. Methicillin resistance was seen in 10.52% of all the S.aureus isolates and 21.05% of CONS isolates. No vancomycin resistance in enterococcus was detected. Out of 260 gram negative bacilli, 105 (40.38%) were ESBL producers. Conclusion: To conclude, there is emergence of MDR gram negative organisms. The prevention of surgical site infections encompasses meticulous operative technique, timely administration of appropriate preoperative antibiotics, and a variety of preventive measures aimed at neutralizing the threat of bacterial, viral, and fungal contamination posed by operative staff, the operating room environment, and the patient's endogenous skin flora.