Salmonella typhi and gallbladder cancer:report from an endemic region

摘要

BACKGROUND: Evidence  exists  of  a  link  between  chronic infection by Salmonella typhi (S. typhi) and the development of  gallbladder  cancer  (GBC),  but  several  studies  from endemic regions contradict its role in the etiopathogenesis of GBC. This study used various tools to assess the prevalence of S. typhi in patients with GBC and gallstone disease (GSD) in this region with a high incidence of GBC. METHODS: S. typhi  was  detected  in  tissue  and  bile  by  PCR and  culture  and  in  serum  by  the  Widal  test  and  indirect hemagglutination assay (IHA). PCR with two pairs of S. typhi specific  primers  (flagellin  gene  H1d  and  SOP  E  gene)  could detect  0.6  ng  of  S. typhi  DNA.  Fifty-four  patients  with  GBC (cases) were matched with 54 patients with GSD(controls). RESULTS: Of the 54 cases, 24 (44.44%) were positive on the Widal test and 12 (22.22%) on IHA, compared to 13 (24.07%) and 5 (9.26%) respectively in the controls. Eighteen (33.33%) cases  showed  a  positive  result  on  PCR  (tissue)  and  2  on PCR (bile) vs. none in the controls. Bile culture revealed no Salmonella colonies in either cases or controls. Only 3 cases were  positive  for  Salmonella  on  tissue  culture  compared  to none in the controls. The sensitivity of PCR (tissue) relative to the Widal test, IHA, culture (bile and tissue) and PCR (bile) was 100% vs. 66.67%, 11.11%, and 11.11%, and the specificity was 83.33% vs. 100%, 100%, and 100%, respectively. CONCLUSIONS: S. typhi is significantly associated with GBC compared to GSD (33% vs. 0%). PCR appears to be the most specific diagnostic tool, the gold standard for S. typhi in tissue samples.