CLINICO MICROBIOLOGICAL STUDY OF SECONDARY BACTERIAL INFECTIONS IN PATIENTS WITH VENOUS LEG ULCERS AND THEIR ANTIMICROBIAL SUSCEPTIBILITY PROFILES

Abstract

Background: Venous leg ulcers often harbor microbial colonization, and this situation can be particularly concerning when the ulcer is infected with alert pathogens highly virulent microorganisms with robust mechanisms of antibiotic resistance. The current study aimed to assess the microbiological status of venous leg ulcers, aiming to identify clinicodemographic predictors associated with culture-positive ulcers, with a specific emphasis on antibiotic resistance patterns. Methods: Material for microbiological analysis was exclusively collected upon enrolment from patients who had not undergone any antibiotic treatment. Before swabbing, the ulcer
underwent cleansing to remove necrotic tissues, exudate, and foreign bodies like dressing remnants. Subsequently, the wound was rinsed with phosphate-buffered saline (PBS). Depending on the clinical state of the wound, swabs were either collected from the surface (superficial ulcers) or the deepest point (deep ulcers) using Levine's technique.
Results: The most common microorganisms isolated from leg ulcers were Staphylococcus aureus (26%), Pseudomonas aeruginosa (10%), and Escherichia coli (10%). All the S. aureus (MSSA) isolates were susceptible to penicillin, erythromycin, amikacin, ciprofloxacin, cotrimoxazole, clindamycin, and gentamicin. 91.7% of S. aureus (MSSA) isolates were susceptible to tetracycline. S. aureus (MSSA) isolates were susceptible to vancomycin and clindamycin. None of the 6 S. aureus (MRSA) isolates were susceptible to penicillin,
clindamycin, or vancomycin. E. coli 85.71% susceptible to amikacin, ciprofloxacin, piperacillin-tazobactam, and cefotaxime. K. oxytoca is 50% susceptible to all antibiotics tested. K. pneumoniae is 100% susceptible to piperacillin-tazobactam, cefotaxime, imipenem,
cefoxitin, and ceftazidime. Proteus mirabilis is 75% susceptible to all antibiotics tested.
Conclusion: The primary pathology associated with these ulcers is perforator incompetence. Noteworthy risk factors include deep vein thrombosis (DVT), obesity, and varicose veins. The diagnosis of infection can be effectively accomplished through the quantitative culture method using tissue biopsy, revealing ulcers as either monomicrobial or polymicrobial with Staphylococcus aureus being the most common pathogen, followed by members of Escherichia coli. Methicillin-resistant Staphylococcus aureus (MRSA) is a significant pathogen in the etiology of venous leg ulcers