Different prevalence of the main tet determinants among S. sonnei and S. flexneri

Abstract number: p1603

Mensa  L., Pisos  E., Capilla  S., Marco  F., Vila  J., Gascón  J., Ruiz  J.


To investigate the mechanisms of resistance to tetracycline in Shigella spp.


One hundred and eleven tetracycline-resistant Shigella spp strains (67 S. sonnei, 44 S. flexneri), 6 were isolated as a cause of enteritis in our geographical area and the remaining recovered from patients with traveller's diarrhoea. Antimicrobial susceptibility to tetracycline was determined by the Kirby-Bauer method. Presence of tetA, tetB and tetG genes was established by PCR. Sequencing of amplified products were used to corroborate the reliability of the PCR results. Maentel Haenszel test was used to establish the statistical significance.


The statistical analysis showed that the tetA gene was more frequent in S. sonnei (p < 0.05), while tetB was more usual in S. flexneri (p < 0.0005). Although without statistical significance (p:0.07), presence of non-determined mechanisms of tetracycline-resistance seems to be more frequent among S. sonnei.


Species-specific differences in the distribuition of the tetA and tetB genes has been shown. Moreover 22.5% of the analysed strains did not show any of the analysed determinants of tetracycline-resistance. The concomitant presence of more than one of the analysed genes is a rare event.

Session Details

Date: 01/08/2007
Time: 00:00-00:00
Session name: XXIst ISTH Congress
Location: Oxford, UK
Presentation type:
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