A Study on the Bacteriological Profile of Ascitic Fluids and Their Antibiotic Susceptibility Pattern in a Tertiary...

Background Ascitic fluid culture remains an essential step in the management of all patients with ascites, regardless of their presenting complaints. Diagnostic paracentesis should not be delayed or prevent timely administration of antibiotics, particularly in unstable patients. Hence, it is an essential part of the surveillance system of every hospital to perform ascitic fluid culture and assess the antibiotic susceptibility patterns of bacterial isolates. In view of this perspective, the present study was conducted at Chengalpattu Medical College Hospital, Tamil Nadu, India. Objective The aim of the study is to determine the bacterial isolates of ascitic fluid samples and study their antibiotic susceptibility patterns. Materials and methods Ascitic fluids received in the central laboratory at the Department of Microbiology from various departments were included in this study. Preliminary identification of isolates was performed by direct Gram staining, acid-fast staining, and motility testing by the hanging drop method. Within one hour of receiving the samples, they were plated onto blood agar and MacConkey agar media and incubated for 18-24 hours at 37°C for isolation. Growth was checked, and species identification was done based on conventional methods. Antibiotic susceptibility testing was performed using the Kirby-Bauer disk diffusion method. Results In this study, a total of 100 ascitic fluid samples were collected, of which only eight (8%) showed growth. Among the eight isolates, six (75%) were Gram-negative bacilli (GNB). Four (66.66%) of the six GNB were Klebsiella spp., while the remaining two (33.33%) were Escherichia coli. Both Gram-positive cocci were Staphylococcus aureus. All the GNB isolates were susceptible to meropenem, piperacillin-tazobactam, and ceftriaxone, with varying susceptibilities to other drugs. Both Gram-positive isolates were found to be methicillin-sensitive Staphylococcus aureus. Conclusion GNB were the predominant organisms in cases of ascitic fluid infection, and they showed 100% susceptibility to carbapenem drugs (especially meropenem), piperacillin-tazobactam, and ceftriaxone. All these drugs can be kept in reserve for serious infections. Amikacin and gentamicin showed promising susceptibility. These drugs can be started empirically with patients on admission before performing culture. Drug adjustments may be later made based on culture reports.