Identification of Helicobacter spp. in bile and gallbladder tissue of patients with symptomatic gallbladder disease

Gallstone Frequency in Patients with Helicobacter pylori Gastritis

Background: Identification of the causes of gallstone would result in better planning for the prevention of this disease. One of the proposed risk factors for this problem is Helicobacter pylori (H. pylori) infection. Objectives: The purpose of this study was to determine the incidence rate of gallstone in patients with H. pylori gastritis. Methods: This was an observational study performed as a descriptive-comparative cross-sectional survey. We enrolled 169 consecutive patients with H. pylori gastritis admitted to Imam-Hossein Hospital, Tehran, Iran, in 2018, and gallstone frequency in them was determined and compared with other variables. Results: Overall, 14 (8.3%) patients had gallstone, and all the patients had H. pylori gastritis. There was no significant association between gallstone and H. pylori gastritis (P = 0.561). Conclusions: It may be concluded that gallstone frequency in patients with H. pylori gastritis is low, and there is no significant association between these two conditions.

Gallstone Disease and Microbiome

Gallstone disease (GSD) has, for many years, remained a high-cost, socially significant public health problem. Over the past decade, a number of studies have been carried out—both in humans and in animal models—confirming the role of the microbiota in various sections of the gastrointestinal tract as a new link in the etiopathogenesis of GSD. The microbiome of bile correlates with the bacterial composition of saliva, and the microbiome of the biliary tract has a high similarity with the microbiota of the duodenum. Pathogenic microflora of the oral cavity, through mechanisms of immunomodulation, can affect the motility of the gallbladder and the expression of mucin genes (MUC1,Muc3, MUC4), and represent one of the promoters of stone formation in the gallbladder. The presence of H. pylori infection contributes to the formation of gallstones and affects the occurrence of complications of GSD, including acute and chronic cholecystitis, cholangitis, pancreatitis. Intestinal bacteria (Clostridium, Bifidobacterium, Peptostreptococcus, Bacteroides, Eubacterium, and Escherichia coli) participating in the oxidation and epimerization of bile acids can disrupt enterohepatic circulation and lead to the formation of gallstones. At the same time, cholecystectomy due to GSD leads to the further transformation of the composition of the microbiota in various parts of the gastrointestinal tract, increasing the risk of developing stomach cancer and colorectal cancer. Further research is required to determine the possibility of using the evaluation of the composition of the microbiota of the gastrointestinal and biliary tracts as an early diagnostic marker of various gastroenterological diseases.

Interactions between Bacteria and Bile Salts in the Gastrointestinal and Hepatobiliary Tracts

Bile salts and bacteria have intricate relationships. The composition of the intestinal pool of bile salts is shaped by bacterial metabolism. In turn, bile salts play a role in intestinal homeostasis by controlling the size and the composition of the intestinal microbiota. As a consequence, alteration of the microbiome-bile salt homeostasis can play a role in hepatic and gastrointestinal pathological conditions. Intestinal bacteria use bile salts as environmental signals and in certain cases as nutrients and electron acceptors. However, bile salts are antibacterial compounds that disrupt bacterial membranes, denature proteins, chelate iron and calcium, cause oxidative damage to DNA, and control the expression of eukaryotic genes involved in host defense and immunity. Bacterial species adapted to the mammalian gut are able to endure the antibacterial activities of bile salts by multiple physiological adjustments that include remodeling of the cell envelope and activation of efflux systems and stress responses. Resistance to bile salts permits that certain bile-resistant pathogens can colonize the hepatobiliary tract, and an outstanding example is the chronic infection of the gall bladder by Salmonella enterica. A better understanding of the interactions between bacteria and bile salts may inspire novel therapeutic strategies for gastrointestinal and hepatobiliary diseases that involve microbiome alteration, as well as novel schemes against bacterial infections.

Helicobacter apodemus sp. nov., a new Helicobacter species identified from the gastrointestinal tract of striped field mice in Korea

A novel Helicobacter species was identified from the gastrointestinal tract of the Korean striped field mouse (Apodemus agrarius). Biochemical testing, ultrastructure characterization, and 16S rRNA gene sequence analysis suggested that this bacterium represents a distinct taxon. The bacterium was positive for urease activity, susceptible to cephalothin and nalidixic acid, and weakly positive for oxidase and catalase activity. Electron microscopy revealed that the bacterium has spirally curved rod morphology with singular bipolar nonsheathed flagella. Genotypically, the isolated bacterial strains (YMRC 000215, YMRC 000216, and YMRC 000419) were most closely related to a reference strain of Helicobacter mesocricetorum (97.25%, 97.32%, and 97.03% 16S rRNA sequence similarities, respectively). The 16S rRNA sequences of these strains were deposited into GenBank under accession numbers AF284754, AY009129, and AY009130, respectively. We propose the name Helicobacter apodemus for this novel species.

[Histopathological study of the presence of Helicobacter pylori-type bacteria in surgical specimens from patients with chronic cholecystitis]

INTRODUCTION

Helicobacter species have recently been found to be associated with some diseases of the biliary tree but this relationship remains unclear and further studies are required. The aim of this study was to determine the presence of H. pylori-type bacteria in patients with a diagnosis of chronic cholecystitis through histopathological study of surgical gallbladder specimens.

MATERIALS AND METHODS

Surgical gallbladder specimens from patients with a diagnosis of chronic cholecystitis were examined histopathologically. The macroscopic characteristics of the specimens were identified. Histopathological slices were stained with hematoxylin-eosin and Giemsa.

RESULTS

Of the 68 patients who underwent cholecystectomy, 56 (81%) were women and 12 (19%) were men. The mean age was 39.56+11.94 years. H. pylori-type bacteria were found in 6%.

CONCLUSIONS

The results of this study do not allow us to conclude that the presence of H. pylori-type bacteria is a major factor in the etiology and/or pathogenesis of chronic cholecystitis. In patients with chronic cholecystitis undergoing cholecystectomy included in the present study, the etiology of the disease may be more closely linked with the presence of gallstones.