Mikrobiologiese aspekte van sporadiese akute gastroënteritis van suigelinge

Abstract

A variety of potential enteropathogenic micro-organisms could be incriminated in 97,4% of acute cases of sporadic infantile gastroenteritis. Although multiple infections occured frequently, enterotoxigenic Enterobacteriaceae (46,2%), rotavirus (43,6%), enteropathogenic Escherichia coli serotipes (38,5%), Staphyl ococcus aureus (15,4%), Salmonella species (5,1 %), Shigella species (5, 1%), Candida albicans (2,6%), Candida krusei (2,6%), Pseudomonas aeruginosa (2,6%), Bacillus cereus (2,6%) and hemolytic E.coli were implicated as causitive agents. Unassociated enterotoxigenic Enterobacteriaceae were more frequently isolated than others. Choleragen-like labile toxins (LT), stable toxin (ST) or a combination of both (ST+ LT) were shown to be produced by various members of Enterobacteriaceae . The various toxins could be demons t rated in 5 E. coli (LT), 4 E. coli (ST), 2 E. coli (ST+ LT), 5 Klebsiella pneumoniae (LT), 2 Enterobacter cloacae (LT), Enterobacter aerogenes (LT) and 1 Proteus vulgaris (LT). Labile toxins from the various gene ra induce mutually variable but high level accumulation of intracellular cyclic adenosine 3' ,5'-monophosphate (cAMP) of Chinese hams ter ovary Kl (CHO-Kl) cells . Induction of cAMP is neutralised to high titre by antiserum to choleragen. Pretreatment of the various labile toxins with GM1 ganglioside or blocking of receptors on CHO-Kl cells by the B sub-unit of choleragen similarly prevent the accumulation of cAMP. This relationship with choleragen suggests a similar mechanisms of diarrhoea induction. The plasmid (Ent) mediated nature of enterotoxin syn thesis was demonstrated for ST and- ST+ LT producing E. coli strains. These determinants were transfered to non-enteropathogenic E. coli Kl2 strains by conjugation . Similarly co-transfer of Ent (ST+ LT) and resistance determinants coding for sulphafurazole, ampicillin, carbenicill in and tetracycline from enteropathogenic E. col i serotipe, 0128:K67:H27, to non-enteropathogenic E. coli K12 were accomplished. These findings imply diagnostic and therapeutic complications in the diagnosis and treatment of gastroenteritis. Some toxin producers such as E. coli (ST), K. pneumoniae (LT), Enterobacter (LT) species and P. vulgaris (LT) do not behave as typical faecal coliforms as judged by tests used for water quality control. This, as well as the isolation in significant quantities of enterotoxigenic E. coli (LT) and K. pneumoniae (LT) from water and sewage, may indicate a pos s ible source of enterotoxigenic infections. These findings call for a review of the status of indicator organisms and of health standards for water for human consumption.