Use of a selective medium and a membrane filter method for isolation of Campylobacter species from Spanish paediatric patients

Abstract

A study was conducted to assess the value of a combination of two culture methods for isolation of Campylobacter spp. from Spanish children. Seven hundred twenty-nine diarrhoeal stool specimens from 599 patients were examined for Campylobacter spp. by culturing them on charcoal cefoperazone deoxycholate agar and on blood agar with a membrane filter. One hundred sixteen Campylobacter strains were isolated from a total of 108 specimens; 75 (64.6%) were Campylobacter jejuni, 32 (27.5%) were Campylobacter coli, 8 (6.8%) were non-typeable, and one (0.9%) was Campylobacter upsaliensis. Campylobacters were isolated from 99 positive samples using charcoal cefoperazone deoxycholate agar alone. The filtration technique alone yielded only 86 positive samples. Seven specimens yielded different Campylobacter spp. with different media. The only catalase-negative strain was recovered using the filter method. The combination of the selective medium with the filter method increased the isolation rate of Campylobacter strains by 14.1%. Isolation rates of campylobacters using the filter method were similar to those reported in European studies, in which a similar frequency of Campylobacter upsaliensis was observed. The addition of a filter method for routine laboratory isolation of campylobacters should be considered in selected age groups (in children < 10 years of age) or in areas where catalase-negative or weakly-positive Campylobacter strains may be of epidemiological significance.