An Increasing Trend in the Antimicrobial Resistance of Bacterial Isolates from Skin and Soft Tissue Infections in a Tertiary Care Hospital

Skin and soft tissue infections (SST's) are commonly occurring infections with mild to serious clinical manifestations. The incidence of wound sepsis in India ranges from 10-33%(1,2). It is important to know the potential microbial pathogens causing wound infections for clinicians to start empirical treatment for patients, while laboratory culture reports are awaited. To identify the common microorganisms and their antimicrobial resistance pattern in pus samples. A total of 8656 pus samples were received in the Microbiology department from various OP and IP departments of Stanley Medical College Hospital, Chennai. The samples were processed in the laboratory for aerobic culture to isolate the pathogens and to perform antibiotic sensitivity testing as per standard protocol(31). This prospective study was done for a period of twelve months (Jan. 2018 to Dec. 2018). Growth was observed in 5793 samples (66.92%), while growth was absent in 2863 samples (33.07%). Of the culture positive samples, 250 (4.31%) showed mixed infection, while 5543 samples (95.68%) yielded a single isolate. In this study, among the isolates (6043 in number), 5965 (98.70%) were bacterial and 78 (1.29%) were fungal. The most common bacterial isolate was Pseudomonas species (27.42%), followed by Staphylococcus aureus (15.60%), Klebsiella pneumoniae (11.95%), Escherichia coli (9.53%), Coagulase negative Staphylococci (9.22%) and Acinetobacter spp. (8.65%). Among the S.aureus isolates, 59% were Methicillin resistant and 41% were Methicillin sensitive. The fungal isolates were Candida spp. ( 80.76%) and Aspergillus spp. (19.24%). The common pathogens isolated in this study were Pseudomonas species (27.42%), Staphylococcus aureus (15.60%) and Klebsiella pneumoniae (11.95%). The increased incidence of antimicrobial-resistant microorganisms like Methicillin-resistant S. aureus, ESBL and MBL producers causes great global concern leading to more difficult to treat infections and death.