Species identification and antimicrobial susceptibility of Campylobacter spp. and related organisms: A 2-year survey in a tertiary university hospital

Abstract

Objective: To identify at species level, in a prospective study in a tertiary university hospital during the two years 1996 and 1997, all isolates of Campylobacter spp. and related organisms and to determine their susceptibility to erythromycin and ciprofloxacin. Methods: The feces were collected in Cary-Blair medium, and isolation was performed on Karmali agar incubated at 35°C. BACTEC Plus aerobic/F vials were used for blood cultures. Identification was performed by biochemical methods for Campylobacter jejuni and by molecular hybridization for the other species. MICs for erythromycin and ciprofloxacin were determined by Etest. Results: In total, 142 isolates from 140 infected patients, including 135 fecal isolates and seven blood isolates, were analyzed. Clinical findings of the seven patients with bacteremia and the seven patients with gastroenteritis due to species other than Campylobacter jejuni or Campylobacter coli showed a predominance of immunocompromised patients. The fecal isolates include 113 (83.7%) Campylobacter jejuni, nine (6.6%) Campylobacter coli, four Arcobacter butzleri, two Campylobacter fetus and one Helicobacter pullorum. Of the seven isolates from blood culture, three were Campylobacter jejuni, three Campylobacter fetus and one Helicobacter cinaedi. Resistance to ciprofloxacin (MIC > 4 mg/L) was reported for 18 (15.6%) Campylobacter jejuni isolates, three Campylobacter coli isolates, one Campylobacter fetus isolate and one Arcobacter butzleri isolate. Resistance to erythromycin (MIC > 8 mg/L) was found for two isolates of Campylobacter coli, which were also resistant to ciprofloxacin, and the isolate of Helicobacter cinaedi. Conclusions: This study reports a predominance of Campylobacter jejuni from stools, but a variety of more rarely isolated species was found in immunocompromised patients, emphasizing the necessity to identify fecal as well as blood isolates to the species level. Antimicrobial susceptibility tests to major antibiotics active against campylobacteria should be done routinely to follow the rate of resistance.