[Evaluation of three new culture media: brilliant-glycerol-lactose novobiocin-green agar, modified iron lysin agar and Rambach agar for the isolation of enteropathogenic E. coli, Salmonella sp. in acute gastroenteritis].

BACKGROUND

Acute gastroenteritis (AGE) is one of the most common diseases in children, particularly in those under the age of 5 years in whom a severe picture of hydroelectrolyte imbalance may be triggered accompanied, in most cases, by leukocyte response. The aim of this study was to evaluate three new culture media for the isolation of enteropathogens in infantile diarrhea.

METHODS

From April to September, 1993, 170 samples of diarrhea stools from children up to 7 years of age attending pediatric hospitals in Bogota were studied. Three new culture media were used in the isolation of the enteropathogenic bacteria: BGLN, MILA agar, Rambach agar and a conventional agar medium S.S. Biochemical tests were performed to identify the isolated bacteria.

RESULTS

A total of 98.5% of enteropathogenic E. coli was isolated in Rambach agar, which also presented excellent recovery rates of Salmonella sp. (100%) versus S.S> (64.3%) and BGLN (77.2%), respectively. The best selectivity for Shigella sp. was observed with BGLN with a 100% recovery rate. Out of the 170 samples 105 showed a leukocyte count of 70-75% and positive isolation for enteropathogenic bacteria. Six samples with the same leukocyte count did not present enteropathogenic bacteria, with the 59 remaining samples with a 20-25% PMN count being negative for enteropathogenic bacteria.

CONCLUSIONS

The results suggest that the new culture media used in this study may have better recovery rates for enteropathogenic bacteria in acute gastroenteritis. Likewise, a correlation was observed between leukocyte count and isolation enteropathogenic bacteria.