Clinical isolation and characterization of Yersinia enterocolitica in China using real-time PCR and culture method.

OBJECTIVE: To carry out a preliminary epidemiological investigation of Yersinia enterocolitica from a clinical perspective in China and to further validate the consistency of real-time polymerase chain reaction (RT-PCR) and culture method.

METHODS: 700 stool samples were randomly and continuously collected from in- and outpatients with diarrhea, which were detected by both the culture method and RT-PCR.

RESULTS: All 52 positive samples were successfully detected by both RT-PCR and the culture method. The total incidence of yersiniosis was about 7.4%, which was statistically higher than before (0.65%) by the Mann-Whitney U test. The morbidity was not significant between males and females (U = 0.354, p > 0.05) by the Mann-Whitney U test whereas it was significant between children and adults (U = 2.06, p < 0.05) as well as between the autumn-winter and spring-summer (U = 2.04, p < 0.05) months. Moreover, the constituent ratio of children and adults with yersiniosis in different systems was not significant by the McNemer test while it was significant between children and adults in the incidence of extraintestinal infection (U = 2.51, p < 0.05).

CONCLUSION: RT-PCR with better applicability will become an efficient tool for detection of virulent Y. enterocolitica and will also be used as an alternative to the culture method. Due to the higher incidence than before, we should publicize dietary hygiene and pay more attention to earlier diagnosis for yersiniosis and its complications, aiming at children <4 years and adults >60 years during the autumn-winter months.