Association of carcinoma of the gallbladder with typhoid carriage in a typhoid endemic area using nested PCR

Abstract

Background: Although well studied the association between chronic typhoid carrier state and carcinoma of the gallbladder (CaGB) remains unproven. Methodology: The study was performed at a tertiary care medical center in North India and involved 52 patients with CaGB, 223 patients with benign gallbladder diseases, 508 healthy individuals and, 424 corpses. For the detection of Salmonella enterica serovar Typhi, hepatobiliary specimens were subjected to DNA extraction for specific nested-PCR amplification of the S. Typhi flagellin gene. Anti-Vi S. Typhi antibodies were detected in serum samples from patients by indirect haemagglutination. Results: Thirty five of the 52 (67.3%) CaGB patients were PCR-positive for the S. Typhi flagellin gene; significantly higher than for patients with benign gallbladder diseases (95/223, 42.6%; p<0.01) and corpses (35/424, 8.2%; p<0.001). The numbers of individuals that had significant anti-Vi antibody titres (≥160) in their serum were 20/52 (38.5%) for CaGB patients, 31/223 (13.9%) for patients with benign gallbladder diseases, and 47/508 (9.2%) for healthy individuals. Conclusions: Specific nested-PCR amplification of the S. Typhi flagellin gene in hepato-biliary specimens was more sensitive for detection of S. Typhi carriage than anti-Vi antibody titres in serum. The results demonstrate an association between typhoid carriage and gallbladder diseases, both CaGB and benign. S. Typhi specific immunosuppression is also suggested in patients with gallbladder diseases.

Is Salmonella enterica serovar Typhi associated with carcinoma gall bladder?

“…This low isolation can be attributed to the bacteria's non culturable state including L form or its facultative intracellular location in some remote organ (biliary canaliculi of liver, bone marrow, spleen etc.). Low isolation can also be due to intermittent excretion through the gall bladder or insufficiency of the techniques employed to isolate it [9]. So culture is not a definite marker for carrier detection.…”

“…We did nested PCR as describe by Nath et al [9] for detection of S. typhi from gall bladder tissue and also found almost same positivity in Gall Bladder carcinoma cases and benign GB…”

“…So association of Salmonella typhi with carcinoma gall bladder was not statistically proven in our study. Although in their study Nath et al [9] observed detection of S. typhi from gall bladder tissue and found one and half times positivity in GBC cases as compared to benign GB Diseases controls. Mallika et al [13] described in their study 33.33% positivity of salmonella typhi in GBC cases by PCR of tissue by using SopE gene.…”

“…Then we did PCR of all the samples. i) DNA extraction: It was done according to manufacturer instructions (genetix kit) ii) PCR: Nested PCR was performed as described by Nath et al [9]. Enzymatic amplification was performed by using 39 cycles of 1 min at 94°C, 1.15 min at 55°C and 2 min at 72°C.…”

“…Method was as Nath et al [9]. All these cases with Vi antibody titer of >1:160 were taken as positive for typhoid carrier.…”