A STUDY OF BACTERIOLOGICAL AETIOLOGICAL AGENTS IN POST OPERATIVE ABDOMINAL WOUND INFECTIONS IN A TERTIARY CARE HOSPITAL

Abstract

Background and Objectives: Surgical Site Infection (SSI) continues to be a major healthcareassociated infection. Primary objective: To isolate, identify and study the aerobic bacteriological spectrum of Abdominal Surgical Site Infection. Secondary objective: 1) To study the antibiotic sensitivity pattern. 2) To detect multidrug resistant strains in abdominal Surgical Site Infection. Materials and Methods: A total of 139 patients with post operative wound infections were included in this study during the course of one year from 1/10/16 to 30/09/2017. The study group included patients who underwent surgical procedure in a tertiary care hospital and developed Surgical Site Infection while in Hospital or after discharge within 30 days post surgery. These patients were followed up closely from the period of developing SSI to the time of discharge and during follow up in the hospital. Specimens such as double swabs for open surgical wounds and aspirates for localized infections were collected. Double swabs were inoculated into the following media: 5% Sheep Blood agar (SBA), MacConkey agar (MA), Salt agar (SA) and Glucose broth. Needle aspirates were also inoculated into Chocolate Agar (CA) in addition to the above media. The organisms were identied by conventional biochemical reactions and antibiotic sensitivity was done according to the CLSI guidelines 2017. Results: Out of the 139 cases in the study, the incidence of SSI's following abdominal surgeries were 41.7 %. The commonest age group for developing SSI was spread equally in the age groups between 51 – 60 and 61 – 70 years (20.14% each). Of the risk factors, Diabetes mellitus (40.28%) were associated with SSI's in 56 patients. Maximum number of cases were after Staging Laparotomies / Tumor excision for GIT Carcinoma- 48 (35.25%). 13.66 % cases were after Appendicectomy; LSCS - 12.23 %, Laparotomy- Peritonitis 10.79 %, Laparotomy- Intestinal obstruction 3.59 %, Hernioraphy 9.35 %, Tubectomy 3.59 %, TAH 7.19 %, Laparotomy -Abdominal injury 0.71 % and others 4.31 %. There were 58 (41.7%) of cases with microbial isolates and 81 (58.3%) cases were sterile. S.aureus was the predominant organism in Abdominal Surgical Site Infection 20 (34.48%), followed by E.coli and Klebsiella pneumoniae 15 (25.85%) each. Out of 15 Klebsiella pneumoniae 53.33 % were ESBL producers and 33.33 % were MBL producers. Where as in 15 E.coli isolates, 80 % were ESBL producers and 6.67 % MBL producers. Discussion: Surgical Site Infection (SSI) are the most common Health care associated infection in low and middle income countries. Surgical Site Infection was found to be higher in patients above 50 years of age which can be due to multiple factors like a low healing rate, malnutrition, mal-absorption, increased catabolic processes and low immunity. Diabetes mellitus is a major risk factor associated with Surgical Site Infections. Patients requiring prolonged hospitalization were more prone to Surgical Site Infections. Enterococcus which is a member of the normal ora of the Gastrointestinal and Genitourinary tract in humans is an emerging pathogen in abdominal Surgical Site Infections. Interpretation and Conclusion: The prevalence of multidrug resistant organisms is to be considered as a warning sign for the emerging spread of antibiotic resistance and the need for urgent implementation of strict antibiotic policy and infection control measures. Identication of SSI's involves interpretation of clinical and laboratory ndings, and it is crucial that a surveillance programme uses denitions that are consistent and standardized; otherwise inaccurate or uninterpretable SSI rates will be computed and reported.