Neisseria flavescens: A Urease-Expressing Potential Pathogen Isolated from Gastritis Patients

Parasitic pathogens, such as H. pylori ( Helicobacter pylori ), are considered as primary elements for causing stomach infection and leading to chronic gastritis or ulcers. Here, an unreported urease- and oxidase-producing Neisseria flavescens -like bacteria was isolated from the gastroscopic biopsies of 14 C-UBT-positive gastritis patients. The isolate expressed the activity of urease, which is a pathogenic factor and considered as a reliable marker for diagnosis of H. pylori infection. However, the isolate didn’t express the key functional genes of H. pylori including vacA and hpaA , and also the morphological feature of isolate was significantly different with H. pylori . Eventually, the 16S rDNA of isolate was sequenced and its sequence shared about 99.8% similarity with the N. flavescens standard strains, but about 20.8% similarity with the H. pylori . Further study of antibiotics-resistance revealed the N. flavescens isolate is high resistant to metronidazole, but highly sensitive to ampicillin sodium. To summarize, a urease-expressing N. flavescens strain was isolated and identified from Chinese gastritis patients; the encouraging results provides an important reference for the further study of its pathogenicity and the reasonable diagnosis and use of antibiotics clinically.