Anti-microbial Effect of Nanoparticles on Non-Helicobacter Pylori Urease Positive Bacteria Isolated from Peptic Ulcer Patients

Recently the presence of several urease-positive bacteria other than Helicobacter pylori has been reported in gastric ulcer patients. The purpose of this study was the isolation and identification of urease-positive bacteria other than Helicobacter pylori in patients with gastric ulcer and at the same time, determining the anti-microbial effects of silver nanoparticles on the isolated bacteria. 50 gastric antrum biopsies were collected from patients with gastric ulcer who were admitted to the Rasoul Akram hospital (Tehran) by gastrointestinal specialists. The samples were transferred to the microbiology laboratory by transitive liquid medium. Urease-positive bacteria in the stomach were identified by standard bacteriological methods, including culture-specific and biochemical tests. The antimicrobial effects of the silver nanoparticles on urease-positive bacteria were determined according to minimum inhibitory concentration (MIC) and Minimum bactericidal Concentration (MBC) techniques. The results showed that 42% of collected samples was urease-positive (10% Klebsiella pneumoniae, 10% Staphylococcus aureus, 8% Enterobacter cloace, 6% Enterobacter aglomerans, 4% Klebsiella azaene and 4%Citrobacter frondi). The antimicrobial effects of silver nanoparticles on the isolated bacteria showed 1.56-12.5 MIC and 3.125-25 MBC. Growth of urease-positive bacteria may lead to false positive observation on UBT and rapid urease tests. Therefore, it is better all urease-positive bacteria isolated from stomach to be sent for accurate diagnosis in order to improve the impacts of treatment. Also, in order to avoiding of bacterial resistance to antibiotics, silver nanoparticles are appropriate alternatives.