A study on aerobic bacteriological profile and antimicrobial susceptibility pattern of isolates from pus samples in a tertiary care hospital

Pyogenic infections are characterised by local and systemic inflammation usually with pus formation which may be either endogenous or exogenous and polymicrobial or monomicrobial  (3) . As definitive antimicrobial is based on the culture of the organisms and their susceptibility pattern, empirical treatment is a must in debilitated and deliberately ill patients  (5) . Hence this retrospective study is conducted to investigate the microorganisms and antimicrobial susceptibility pattern from pus samples in a tertiary care hospital. This retrospective study was conducted from October 2016 to December 2016 in the department of Microbiology in a tertiary care hospital. Pus samples received from various departments was subjected to bacteriological culture as per standard protocol. The isolates were then subjected to phenotyping and their antimicrobial susceptibility was done by Kirby Bauer disc diffusion method according to CLSI guidelines 2016. Among the total of 209 samples received, 63. 64% (133) showed positivity for microbial growth and 9. 02 % (12) were polymicrobial and 90. 98% (121) showed single growth. 80. 45 % (107) were males and 19. 55 % (26) were females. Gram positive cocci accounts for 39. 85 %( 53), Gram negative bacteria 63. 15 % (84),  Diphtheroids  2. 26 % (3) and  Candida  3. 01 %(4).  Staphylococcus aureus  22. 56% (30) were the majority among them followed by  Pseudomonas spp ., 21.05% (28),  Escherichia coli  14. 29%(19),  Enterococc i 12.78% (17),  Klebsiella spp . 11.28% (15),  Proteus spp.,  10.53% (14),  Acinetobacter spp.,  6.02% (8),  Streptococci  4.76% (5),  Candida  3. 01 % (4) each. The antibiogram of  S. aureus  and  Enterococci  showed 100% susceptibility to Linezolid and Vancomycin.  E. coli  was most susceptible to Imipenem and Meropenem 94. 74% followed by Cefoperazone – Salbactum and Piperacillin and Tazobactum 89.43%.  Pseudomonas  showed 89.29% susceptibility to Meropenem followed by Imipenem 85.71%, Piperacillin – Tazobactum 85.71% and Amikacin 82.14%.  Klebsiella  showed 100% susceptibility to Imipenem followed by Piperacillin - tazobactum 73.33%.  Proteus  showed 100% susceptibility to Piperacillin – tazobactum and Imipenem, Meropenem 92. 86%. Acinetobacter showed higher susceptibility to Meropenem 50%. Our study concludes that empirical treatment should be initiated based upon the data obtained from the bacteriological profile and the antimicrobial surveillance in every institution. It is also insisted to perform periodic surveillance on the changing trends in the antimicrobial susceptibility pattern to combat the evolving the resistance in each institution.