Bacteria entombed in the center of cholesterol gallstones induce fewer infectious manifestations than bacteria in the matrix of pigment stones.
OBJECTIVE
The clinical significance of bacteria in the pigment centers of cholesterol stones is unknown. We compared the infectious manifestations and characteristics of bacteria from pigment stones and predominantly cholesterol stones.


METHODS
Three hundred forty patients were studied. Bile was cultured. Gallstones were cultured and examined with scanning electron microscopy. Level of bacterial immunoglobulin G (bile, serum), complement killing, and tumor necrosis factor-alpha production were determined.


RESULTS
Twenty-three percent of cholesterol stones and 68% of pigment stones contained bacteria (P < 0.0001). Stone culture correlated with scanning electron microscopy results. Pigment stone bacteria were more often present in bile and blood. Cholesterol stone bacteria caused more severe infections (19%) than sterile stones (0%), but less than pigment stone bacteria (57%) (P < 0.0001). Serum and bile from patients with cholesterol stone bacteria had less bacterial-specific immunoglobulin G. Cholesterol stone bacteria produced more slime. Pigment stone bacteria were more often killed by a patient's serum. Tumor necrosis factor-alpha production of the groups was similar.


CONCLUSIONS
Bacteria are readily cultured from cholesterol stones with pigment centers, allowing for analysis of their virulence factors. Bacteria sequestered in cholesterol stones cause infectious manifestations, but less than bacteria in pigment stones. Possibly because of their isolation, cholesterol stone bacteria were less often present in bile and blood, induced less immunoglobulin G, were less often killed by a patient's serum, and demonstrated fewer infectious manifestations than pigment stone bacteria. This is the first study to analyze the clinical relevance of bacteria within cholesterol gallstones.
Stewart
Lygia
L
Department of Surgery, University of California San Francisco, 4150 Clement Street, San Francisco, CA 94121, USA. lygia.stewart@med.va.gov
Griffiss
J McLeod
JM
Jarvis
Gary A
GA
Way
Lawrence W
LW
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001419:Bacteria / Q000302:isolation & purification; D005260:Female; D042882:Gallstones / Q000737:chemistry* / Q000382:microbiology* / Q000473:pathology; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D008297:Male; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D010860:Pigments, Biological / Q000032:analysis; D012720:Severity of Illness Index; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis; D014774:Virulence
D007074:Immunoglobulin G; D010860:Pigments, Biological; D014409:Tumor Necrosis Factor-alpha