Study of Bacteriological Profile of Gram-negative Bacteria Isolated from Pus Samples with their Antibiotic Susceptibility Pattern at Tertiary Care Hospital

Introduction: When patients have undergone implant surgery in the past 30 or 90 days, pus may be visible or present at the time of surgery. Infections at the surgical site (postoperative wound infections) increase the risk of morbidity and mortality. They can also result in nosocomial infections, skin and soft-tissue infections, and burn injuries. Wound infection also depends on different factors, like the amount of bacteria present, and the host’s defense mechanisms are some of the variables that affect the likelihood of wound infections. The various factors such as the host defense mechanism, microbial load, and condition of abrasion, are responsible for the occurrence of wound infection. Aim: The aim of this study was to detect aerobic bacteriological profile of organisms isolated from pus samples with their antibiotic susceptibility pattern. Materials and Methods: This was a prospective cross-sectional study conducted in the bacteriology laboratory at the Department of Microbiology, Jawaharlal Nehru Medical College, associated with Acharya Binova Vava Rural Hospital, Sawangi, Meghe; Wardha, from August 2020 to August 2021. This study included 200 pus specimens received in the bacteriology section of the microbiology department from the inpatient department and outpatient department. From each patient, two pus samples were collected, one for Gram’s stain and another for culture. The bacterial colony morphology was recorded, and Gram stain with biochemical reactions was noted accordance with standard conventional microbiological procedures. The antimicrobial susceptibility tests were done on Mueller-Hinton Agar using Kirby–Bauer’s Disk Diffusion method and the results were interpreted using the Clinical Laboratory Standard Institution guideline. Results: A total of 200 pus samples were processed of which 170 (85%) samples were positive for bacterial growth, 23 (11.5%) were negative for bacterial growth (no growth), and 7 (3.5%) samples showed polymicrobial growth. Out of a total of 200 pus samples only 170 culture-positive samples were further processed for identification. Among 200 pus samples, 137 (68.5%) were male and 63 (31.5%) were female and the male:female ratio is 2.17:1. In the age group between 41 and 50 years (23.5%), cases were the majority and minimum cases were seen in age group 11–20 years (6.5%). Out of 170 isolates bacteria, the maximum isolates were identified as Gram-negative bacilli with 120 and GPC with 50 in number. Among which Staphylococcus aureus (24.12%) was predominant followed by Klebsiella pneumoniae (21.76%), Pseudomonas aeruginosa (20.58%), and Escherichia coli (17.06%). Only Gram-negative isolates were taken for the further processing for antimicrobial susceptibility tests. Among all the isolates, there was highly sensitivity to Colistin almost 100% followed by gentamicin and meropenem. Extended spectrum beta-lactamase positivity was seen in 30 (45%). Conclusion: For control of the infection, hand washing by hospital staff is one of the fundamental measures, helping in decreasing the spread of antibiotic-resistant bacteria. It is best to avoid using antibiotics irrationally to combat resistance. In order to lower morbidity and mortality, improved therapeutic procedures can be implemented with the use of routine surveillance.