Vol. 7, Issue 1, Part A (2025)

Gallstones are a prevalent biliary system disorder. They can lead to various complications, such as biliary colic, infection, cholecystitis, and even gallbladder cancer. However, the etiology of gallstones remains incompletely understood. The significant role of bacteria in gallstone formation has been demonstrated in recent studies. Certain bacteria not only influence bile composition and the gallbladder environment but also actively participate in stone formation. The aim of this study is to identify the frequency of the common bacteria associated with gallstone disease. A cross-sectional research study was carried out between October 2024 and February 2025, involving 75 cases of cholelithiasis ages 17 to 70 years old, who were attending the surgical department in the Rizgary Teaching Hospital in Erbil city. Gallstones and bile samples were collected from patients who underwent cholecystectomy and analyzed for bacterial growth. The identification of bacteria was utilized by biochemical and cultural investigations and confirmed by the Vitek 2 compact system. Out of 75 samples, 61 (81.3%) showed bacterial growth, while 14 (18.7%) had no growth. From the gallbladder samples, the gallstones were the highest site for bacterial isolates, with 41 (67.2%). Of the patients with positive culture results, 5 (8.2%) had a mixed bacterial infection, and 56 (91.8%) had a single bacterial infection. Based on bacterial growth, 76.47% are Gram-negative (G-) bacteria, whereas 23.53% of the isolates are Gram-positive (G+) bacteria. E. coli was the most common G- bacterium, accounting for 17 (25%) of all isolates. However, the most often identified G+ bacterium was Staphylococcus aureus 8 (11.77%). Mixed gallstones had the greatest positive culture at 88.9%. The most infected age group was 35-43 years, with 27 (36%), mostly female, with 59 (78.7%). It was concluded that the microbiota contributes significantly to the development of gallstones and actually makes up a sizable amount of the stone.