Typhoid carriage in the gallbladder

Abstract

The case of Mary Mallon, an asymptomatic carrier who infected 51 people while working as a cook and laundress in New York in 1906–15, showed that Salmonella enterica serovar Typhi (S Typhi) is able to lurk in the gallbladder without overt clinical signs and spread enteric fever through person-to-person transmission. In May, 2009, a 42-year-old man presented to Patan Hospital in Kathmandu, Nepal, with acute, sudden, severe pain in his right upper quadrant lasting for 2 days. We diagnosed cholecystitis and he underwent a cholecystectomy and made a prompt recovery. S Typhi was cultured from the bile in his gallbladder, and the cholecystitis was confi rmed histologically. We used immunofl uorescent labelling to analyse a section of his gallbladder with a confocal microscope (fi gure). Initially, we bound primary antibody (O9; Murex, Dartford, UK) to the cellular (bacterial) antigen, which was then specifi cally bound to a secondary fl uorochromeconjugated antibody. The 4ʹ,6-diamidino-2-phenylindole (DAPI) stain (Invitrogen Molecular Probes, Carlsbad, CA, USA) binds to dsDNA and fl uoresces blue, showing the nucleus (white arrow) of the cells of the mucosal layer in the gallbladder (green arrow) that have been stained green with phalloidin. Phalloidin binds to F-actin and is used to identify tissue structure and locations of actin reassortment (green regions) triggered by the infection. The S Typhi (red arrow) can be seen in red (O antigen stain) in a discrete cluster on the outside of the mucosal layer. Although not the only member of the Enterobacteriaceae bearing the O9 antigen, culture isolation of S Typhi from our patient’s bile is strongly suggestive that these microorganisms are also S Typhi. Our patient did not have a documented history of enteric fever. In endemic areas such as Nepal, most people who undergo cholecystectomy for cholecystitis do not give an obvious, recent history of enteric fever, but gallbladder carriage of S Typhi and Paratyphi organisms is a well recognised means of spread. At last follow-up in December, 2013, the patient was doing well.