Study of spontaneous bacterial peritonitisetiologic agents and determination of their antibiotic resistance pattern

Spontaneous bacterial peritonitis (SBP) is a frequent and often fatal complication of ascites without a demonstrable intra abdominal cause. In adults, the organisms of SBP are usually gram-negative bacteria, but they may differin children. Since these organisms are resistant to most antibiotics, identification of active antimicrobial agents and determination of resistance pattern areessential. The aim of the present study was also to determine the causative agents of SBP in children with liver disease and ascites, referred to pediatrics ward of Imam Khomeini hospital during 1384-85. In this study, ascite samples were taken from 85 patients with liver disease and ascites of Emam Khomeini Hospital, pediatrics ward, and they were examined by direct test, culture on different media and biochemistry tests. Antibiogram tests by disk diffusion were done on each positive sample. Of 85 examined samples, 32 bacterial and 2 yeast agents were isolated. Of bacterial cases, Escherichia coli (31.25%) and coagulase negative Staphylococci (18.75%) were the most isolated agents and the rest, included Streptococci and Enterobacteriaceae. Moreover, antibiogram tests identify that most of coagulase negative Staphylococci isolates as resistant to cotrimoxazol, amoxicillin, penicillin and cephalosporin (first generation). The most of gram negative isolated bacteria were resistant to amikacin, vancomycin and gentamicin. Since the spontaneous bacterial peritonitis is not detectable by clinical signs, ascite samples should be examined in order to determine the etiologic agents. In general spontaneous bacterial peritonitis agents are mostly composed of normal flora bacteria, in our study most isolated bacteria were Escherichia coli and coagulase negative staphylococci, two major normal flora of gastrointestinal tract and skin. The isolated bacteria showed a high antibiotic resistance against common drugs in our study. In general, this study showed that the major agents of spontaneous bacterial peritonitis should be identified by ascite examination and antibiogram test to establish a perfect treatment pattern in order to treat the patients rapidly.