Journal of Krishna Institute of Medical Sciences University (Jul 2020)
Bacteriological Profile of Wound Swab and Pus Samples Using Conventional Media and Chromogenic Medium
Abstract
Background: Wound infections continue to be a cause of concern as they can delay healing and cause wound breakdown. Their effective treatment demands quick isolation and identification of causative organisms with appropriate antibiotic sensitivity pattern. Material and Methods: Wound swab and pus samples received from inpatient as well as outpatient department of all age groups and both genders were processed using conventional media as well as chromogenic medium (HiCrome UTI) and results of both were compared. Antibiotic sensitivity testing was done on Vitek 2 Compact automated system. Results: Among 342 samples, 77% showed growth. Fifty eight percentage were Gram negative and 42% were Gram positive organisms. Polymicrobial growth was seen in 11% of samples. HiCrome UTI isolated all organisms in culture. Colony characteristics and colour of all isolates on HiCrome UTI were comparable to their identification on Vitek 2 Compact. Among the Gram positive organisms, commonest was Methicillin Sensitive Staphylococcus aureus (MSSA 42%) followed by Methicillin Resistant Staphylococcus aureus (MRSA 33%), Enterococcus faecalis (10%), Staphylococcus epidermidis (8%), Staphylococcus haemolyticus (3%), Streptococcus pyogenes (2%) and Streptococcus agalactiae (2%). Most of the Gram positive organisms were sensitive to vancomycin, teicoplanin, linezolid and clindamycin The common Gram negative organisms were E. coli (36%), Klebsiella pneumoniae (20%), Pseudomonas aeruginosa (18%), Proteus mirabilis (7%), Enterobacter cloacae (6%) and Acinetobacter baumannii (4%). Most of the Gram negative organisms were sensitive to cefepime, beta lactams-beta lactamase inhibitors, aminoglycosides and fluoroquinolones. Conclusion: Gram-negative organisms predominated in our study. HiCrome UTI agar can be used as a cost-effective approach for rapid isolation of all organisms. It gives definite identification of common organisms and thus reduces turn-around-time for the same. It provides presumptive identification of infrequent organisms which can be further confirmed by simple biochemical tests. Hence these properties of HiCrome UTI agar help serve the purpose especially from mixed cultures and in resource constraint settings.
