Blood Culture and Sensitivity Profile Study in a Tertiary Medical Hospital in Kolkata, West Bengal: 7 Years’ Experience

Abstract

Aims and objectives: To identify the prevalence of bacteremia and the spectrum of antimicrobial sensitivity in our community, because it will guide the clinician to institute proper antimicrobial therapy. Background: Bacteremia originates from either intravascular sites or extraVascular sites. In case of bloodstream infection, either Gram-positive or Gram-negative bacteria are respon-sible. Of these bacterial isolates, Gram-negative bacteria are responsible for higher mortality and morbidity. Since 20 to 30 years, coagulase-negative Staphylococci are responsible for most infection. Materials and methods: In this retrospective study, blood samples were collected aseptically from 11,581 patients and were injected into the bottles containing bile-broth and brain-heart infusion broth and allowed to be incubated at 37°. Then subculture was done on blood agar, chocolate agar, as well as MacConkey agar media and was kept for 7 days or till the appearance of growth of the organism. After identification of isolates, Kirby Bauer disk diffusion test on Mueller-Hinton agar II was performed to detect antimicrobial sensitivity. Results: Our study documented 8.58% positive cultures in the last 7 years. Gram-negative bacterial isolates were significantly higher than Gram-positive isolates (64.19% vs 34.80%, p = 0.00). Lowest number of positivity was seen in Morganella (0.40%) followed by Proteus (0.50%) and Enterococcus faecium (0.90%) in ascending order. Males were significantly more culture positive than females (549/994 vs 445/994, p = 0.00). Most common bacterial isolates were (coagulase negative Staphylococci) CoNS (239, 24.04%) followed by Klebsiella including ESBL (extended spectrum beta-lactamase), carbapenamase producer (234, 23.74%) and Escherichia coli (110, 11.06%). E. coli was >75% sensitive to imipenem group, polymyxin B (98.18%), colistin (96.36%), and amikacin (80.9%). Coagulase negative Staphylococci showed more than 60% sensitivity to levofloxacin (76.98%), amikacin (82.84%), tigecycline (87.44%), vancomycin (94.45%), teicoplanin (91.63%), linezolid (91.21%), gentamicin (76.56%), netilmicin (74.47%), and tetracycline (75.31%). Klebsiella (non-ESBL and carbapenemase producer) was highly sensitive to polymyxin B (93.06%), colistin (91.90%), meropenem (65.31%), and imipenem (94.73%). Extended spectrum beta- 10.5005/jp-journals-10036-1082 lactamase-producing Klebsiella showed increased sensitivity to meropenem (89.47%), imipenem (94.73%), ertapenem (81.57…