The aim of this study was to determine the pathogenic markers associated with Campylobacter infection in humans. A total of 104 Campylobacter isolates obtained from poultry and humans were examined for the presence of nine virulence genes and their ability to adhere to, invade and produce cytotoxin were defined using HeLa cells. The diversity of the Campylobacter spp. isolates was studied based on sequencing of the SVR-region of flaA gene. Altogether 45 flaA-SVR alleles were identified among 104 Campylobacter isolates of poultry and human origin. All Campylobacter isolates possessed flaA, cadF and racR genes involved in adherence. Accordingly, all poultry and human isolates exhibited adherence towards HeLa cells at mean levels of 0.95% and 0.82% of starting viable inoculum, respectively. The genes involved in invasion (iam and pldA) and cytotoxin production (cdtA, cdtB and cdtC) were also widely distributed among the human and poultry Campylobacter isolates. Significantly higher invasiveness was observed for poultry isolates (mean level of 0.002% of starting bacterial inoculum) compared to human isolates (0.0005%). Interestingly the iam gene, associated with invasion, was more common in human (100%) than poultry (84%) isolates, and the poultry isolates lacking the iam gene showed a marked reduction in their ability to invade HeLa cells. Moreover, virB11 was present in 22% of the poultry and 70.4% of the human isolates. Strains lacking virB11 showed a slight reduction in invasion, however in the absence of iam even the poultry isolates containing virB11 were unable to invade HeLa cells. The mean cytotoxicity of Campylobacter isolates from poultry and human was 26.7% and 38.7%, respectively. Strains missing both the cdtB and cdtC genes were non-cytotoxic compared to strains containing all three cdtABC genes, which were the most cytotoxic among the C. jejuni and C. coli isolates from both sources. No cytotoxic effect was observed in only 4% of poultry and 5.6% of human isolates.

这项研究的目的是确定与人类弯曲杆菌感染相关的致病标记。检验了从家禽和人获得的总共104株弯曲杆菌分离株是否存在9种毒力基因，并使用HeLa细胞确定了它们粘附，侵袭和产生细胞毒素的能力。弯曲杆菌属的多样性。基于flaA基因的SVR区域的测序研究了分离株。在104个家禽和人源弯曲杆菌分离物中共鉴定出45个flaA -SVR等位基因。所有弯曲杆菌分离株均具有flaA，cadF和racR基因参与遵守。因此，所有家禽和人分离株均表现出对HeLa细胞的粘附，其平均水平分别为起始活菌的0.95％和0.82％。参与侵袭的基因（iam和pldA）和细胞毒素产生（cdtA，cdtB和cdtC）也广泛分布于人和家禽弯曲杆菌分离株中。与人分离株（0.0005％）相比，家禽分离株（平均起始细菌接种量的0.002％）观察到更高的侵袭性。有趣的是，IAM与入侵有关的基因，在人类（100％）中比家禽（84％）分离株更为常见，而缺乏iam基因的家禽分离株入侵HeLa细胞的能力明显降低。此外，virB11存在于22％的家禽和70.4％的人类分离株中。缺乏virB11的菌株显示出轻微的侵袭减少，但是在没有iam的情况下，甚至含有virB11的家禽分离株也无法入侵HeLa细胞。来自家禽和人的弯曲杆菌分离株的平均细胞毒性分别为26.7％和38.7％。缺少cdtB和cdtC的菌株与包含所有三个cdtABC基因的菌株相比，该基因具有无细胞毒性，这在来自这两个来源的空肠弯曲杆菌和大肠杆菌分离物中都是最具细胞毒性的。仅4％的家禽和5.6％的人分离株未观察到细胞毒性作用。