The detection and expression of enterotoxinencoding lth gene among Klebsiella spp. isolated from diarrhoea

Background

Currently, when isolated from diarrheal stool, Klebsiella spp., a member of the Enterobacteriaceae family, is treated as a physiological flora even when it occurs in monoculture. The possibility of transfer of virulence plasmids from diarrheal E.coli strains to the Klebsiella strains inhabiting the gastro-intestinal tract provokes a question of whether these bacteria can be the etiological factor of diarrhoea.

Methodology

152 Klebsiella spp. strains were used in this study. The presence of the lth gene coding heat-labile enterotoxin (LT) in the plasmids of Klebsiella spp. strains was detected using PCR, whereas the expression of the toxin was evaluated by measuring the cytopathic effect induced by the LT toxin in Chinese Hamster Ovary (CHO) cell lines.

Results

The lth gene was detected in 8.5% of the investigated Klebsiella strains. 77% of these strains were able to produce the cytopathic effect in the CHO cell lines. Surprisingly, part of the strains with no lth gene detected, were also able to cause above mentioned effect.

Conclusions

The results of our studies suggest that Klebsiella spp. isolated from the gastro-intestinal tract may be an etiologic factor of diarrhoeas.