Bacteriological Profile and Antibiogram of Effusions in Sterile Body Cavities

One of the important responsibilities of a Clinical Microbiologist is to optimize culture techniques for rapid isolation and detection of specific etiological agents. Effusions are fluids collecting in a body cavity or joint which may be exudates or transudates based on whether it is an inflammatory process i.e. infective (septic) or non-infective. The present study was undertaken to identify the bacterial agents causing the infections in effusions.

To study the bacteriological profile and antibiogram of Effusions in sterile body cavities at a tertiary care hospital in Bangalore.

A prospective study was done on the 196 effusion fluids from April 2012 to May 2013. The patients suffering from effusions in the body cavities were included in the study. Pleural(87), pericardial(2), peritoneal(85), synovial(9), amniotic fluid(1) were collected along with Bile(9), Pancreatic (2)& Bone marrow aspirates(1). 2–3 ml of the aseptically aspirated fluids were dispensed in sterile screw capped bottles & sent to the microbiological laboratory immediately for processing. Specimens were processed and cultured according to standard procedures and antibiotic susceptibility testing was carried out by Kirby Bauer disc diffusion method.

A total of 24 samples (12.24%) were culture positive for aerobic bacterial growth. Pleural fluid samples showed Staphylococcus aureus, Klebsiella and Escherichia coli as the most common organisms. E.coli was the most common isolate from culture positive Ascitic fluid samples (40%). A total of 88.8% of the Bile cultures showed aerobic bacterial growth. No organisms were isolated from pericardial, peritoneal, synovial, amniotic fluid & bone marrow aspirates. Amongst the Gram positive isolates in pleural fluid, resistance to Penicillin group of drugs was most common along with resistance to amino glycosides, cephalosporin, and quinolones. Gram negative bacteria like E.coli, Klebsiella, and Proteus vulgaris were isolated along with non-fermenter Gram negative bacteria from Bile cultures. Resistance to Amino-penicillin and cephalosporin group of drugs was common in the Gram negative bacteria whereas resistance to anti-pseudomonal penicillins, colistin and quinolones was predominant in non-fermenter gram negative isolates.

Gram positive isolates were most commonly implicated in the pleural fluid samples whereas gram negative bacteria and non-fermenter bacteria were recovered from ascitic fluid and bile cultures. Plate cultures from sterile body fluids and effusions enable the physician to start appropriate antibiotics early and facilitate better prognosis in the patient.