Campylobacter jejuni in Hospitalized Patients with Diarrhea, Kolkata, India

To the Editor: Campylobacter spp. infection is the leading cause of bacterial enteritis worldwide. The epidemiology of Campylobacter infection in developing countries differs substantially from that in industrialized countries. In many studies from the United States and other industrialized countries, Campylobacter spp. are among the most common bacterial causes of diarrhea (1), with an incidence of ≈10% in persons with diarrhea. Reports from developing countries also suggest that C. jejuni and C. coli have been isolated mostly from patients with diarrheal illness (2). We investigated for the prevalence of Campylobacter infection in patients hospitalized with diarrhea at the Infectious Disease Hospital in Kolkata, India, and their resistance patterns to different antimicrobial drugs. During January 2008–December 2010, we screened 3,186 fecal samples on brain–heart infusion agar with 5% defibrinated sheep blood and antimicrobial drugs (bacitracin, cycloheximide, colistin sulfate, cephazoline sodium, novobiocin) and incubated under microaerophillic environment (5% O 2 , 10% CO 2 , and 85% N 2) at 37°C for 48 h. Each isolate was tested by Gram staining, cytochrome oxidase, and hippurate hydrolysis for presumptive identification and species-specific PCR (3) to identify 5 species from Campylobacter genus. The overall isolation rate of Campylobacter spp. was ≈7% (222/3,186). Sole infection with Campylobacter spp. accounted for only 40% of cases; others were mixed infection. C. jejuni was the predominant species (78%), with C. coli, C. fetus, C. lari, and C. upsaliensis isolated less frequently. Campylobacter infection prevailed throughout the year, with no seasonality. The C. jejuni isolation rate was significantly higher (10.0%; p<0.001) for children <5 years of age who had diarrhea than for persons in other age groups (3.7%). Although we used the culture method, which is the standard for screening fecal samples, some molecular methods, such as PCR and real-time PCR, are now used for screening Campylobacter spp. from fecal samples on the Indian subcontinent (4,5). The results from molecular methods are showing more infection with Campylobacter spp. and high mixed infection cases and suggest the usefulness of molecular methods in combination with cultures. Macrolides and fluoroquinolones generally are the first-and second-line choices, respectively, of antimicrobial drugs for treating Campylobacter enteritis. Since the late 1980s, resistance to these drugs has complicated treatment. In India, resistance of Campylobacter spp. to several antimicrobial drugs has been reported since the early 1990s (6). We tested 142 C. jejuni isolates for antimicrobial susceptibility by disk diffusion method on Muller-Hinton agar with 5% sheep …