当前位置： SCI文献检索 > INFECTION AND IMMUNITY期刊下所有文献 > In vivo behavior of a Helicobacter pylori SS1 nixA mutant with reduced urease activity.

In vivo behavior of a Helicobacter pylori SS1 nixA mutant with reduced urease activity.

Abstract：

:Helicobacter pylori mutants devoid of urease activity fail to colonize the gastric mucosa of mice; however, the effect of decreased levels of urease on colonization has not been examined. The nixA gene, required for full urease activity, encodes a cytoplasmic membrane nickel transporter that imports nickel ions and leads to incorporation of nickel ions into apourease. A nixA mutant of the Sydney strain of H. pylori (SS1) was constructed by disruption of the nixA gene with a kanamycin resistance cassette. This mutant retained only half the urease activity of the wild-type (wild-type) SS1 strain. C57BL/6j (n = 75) and BALB/c (n = 75) mice were inoculated independently with the wild-type or the nixA strain. The level and distribution of colonization were assessed by bacterial colony counts and histological grading at 4, 12, and 24 weeks postinfection. Colonization levels of the nixA strain in BALB/c mice were significantly lower compared with SS1 (P = 0.005), while colonization in C57BL/6j mice was similar for both the wild-type and mutant strains. Subtle differences in colonization of the different regions of the stomach, determined by microscopic grading, were observed between wild-type SS1 and the nixA strain in BALB/c mice. On the contrary, when C57BL/6j (n = 35) and BALB/c (n = 35) mice were coinfected with the wild-type and nixA strains simultaneously, the nixA mutant failed to colonize and was outcompeted by the wild-type SS1 strain, which established normal levels of colonization. These results demonstrate the importance of the nixA gene for increasing the fitness of H. pylori for gastric colonization. Since nixA is required for full urease activity, the decreased fitness of the nixA mutant is likely due to reduced urease activity; however, pleiotropic effects of the mutation cannot be completely ruled out.

journal_name

Infect Immun

journal_title

Infection and immunity

authors

Nolan KJ,McGee DJ,Mitchell HM,Kolesnikow T,Harro JM,O'Rourke J,Wilson JE,Danon SJ,Moss ND,Mobley HL,Lee A

doi

10.1128/iai.70.2.685-691.2002

keywords:

subject

Has Abstract

pub_date

2002-02-01 00:00:00

pages

685-91

issue

eissn

0019-9567

issn

1098-5522

journal_volume

pub_type

杂志文章

在线工具

In vivo behavior of a Helicobacter pylori SS1 nixA mutant with reduced urease activity.