Laboratory diagnosis of anaerobic post-operative wound infection

ABSTRACT

The aim of this study is a comparative study between traditional methods for identification and isolation of anaerobes and detection by gas liquid chromatography. Postoperative pus specimens were collected from 75 patients with abdominal wound sepsis from gastroentrology, general surgery and obstetric and gynaecology departments. Each sample was studied by traditional methods for identification and isolation of anaerobes and detection of short chain fatty acids by gas liquid chromatography [GLC]. The results of this study revealed that 40 out 75 specimens showed anaerobic growth. The anaerobic isolates contained 75% bacteroid species, 20% peptostreptococcus and 5% fusobactrium. On the other hand short chain fatty acids were detected by GLC analysis in all specimens that yielded anaerobic growth. In addition, 4 specimens revealed short chain fatty acids by GLC analysis but their cultures yielded no anaerobic growth. Chromatographic study of short chain fatty acids produced by 44 specimens revealed that 100% produced acetic acid, 68.2% propionic, 54.5% butyric, 47.7% isovaleric, 31.8% formic, 11.3% isobutyric and 9.1% isocaproic. Detection of anaerobes by traditional methods is difficult, expensive and time consuming. On the other hand, GLC provides direct rapid diagnostic tool for anaerobic infection So investigation of clinical material by GLC presents a basis for preliminary diagnosis of causal factor and for direction of chemotherapy