Antimicrobial Susceptibility of Clostridium Difficile Isolated from Medical Staff of Imam Reza Hospital in Tabriz

In vitro determination of C. difficile susceptibility is not routinely performed in the laboratories. The aim of this study was to determine antibiotic sensitivity of C. difficile isolated from hospital staff and also to evaluate recovery rate of C. difficile from stools by three methods. One hundred stool samples of hospital staff were collected. Three standard anaerobic methods were used to isolate C. difficile: direct plating on CCFA, inoculation on blood agar following enrichment by alcohol shock and 0.1% sodium taurocholate. Suspicious colonies with specific horse odor were identified by biochemical tests. All isolates were tested by disk diffusion method using 14 antibiotic disks. MIC of isolates were determined for vancomycin and metronidazole by E.test Eighteen C. difficile were isolated from staff of 13 different wards. The maximum and minimum number of C. difficile was isolated from internal, ICU wards (each 5 isolates) and orthopedic, physiotherapy wards (each 1 isolate), respectively. No resistant isolates to vancomycin and metronidazole were detected by disk diffusion or E-test. All isolates were found to be resistant to polymyxin B and ceftriaxone (100%). The rate of recovery by 0.1% sodium taurocholate enrichment method and alcohol shock was significantly higher than those by CCFA (P= 0.02 and P=0.04, respectively). Personnel of Imam Reza Hospital in Tabriz can be considered as source of C. difficile infection. All tested strains were found to be susceptible to metronidazole and vancomycin. The rate of recovery by enrichment methods is higher than those by CCFA culture.