应用多重PCR检测屠宰猪扁桃体中的猪链球菌

Carrier rate of Streptococcus suis in palatine tonsils of slaughter pigs in south China

从广东省部分地区肉联厂采集屠宰猪扁桃体401份,用两个多重PCR检测样品中猪链球菌(SS)及其主要致病血清型。检出SS阳性样品154份(38.4%),其中69份(17.2%)携带SS2,35份(8.7%)携带SS9,而SS7和SS1分别为9份(2.2%)和3份(0.7%)。不同血清型SS菌株可混合感染同一头猪,但比例均小于5%。在地区分布上,粤西地区SS阳性率(18.3%)明显低于其他地区(p<0.01),其余各地区之间均无显著差异(p>0.05),在35%～70%之间。对全部样品进行细菌分离,共分离到SS53株,分离率为13.21%;其中SS225株(6.23%),SS93株(0.75%),SS71株(0.25%),未定型SS24株(5.99%),细菌分离的阳性率远比PCR检测结果要低。此检测结果证实了华南地区猪群中广泛存在SS,并呈多个血清型混合感染,而且流行呈地域性的特点,凸显了SS流行的复杂性。

Two multi-PCR assays were used for detecting the presence of Streptococcus suis and its major serotypes from 401 palatine tonsil samples of slaughtered pigs, collected in south of china. Detection results showed that 154 （38.4 %） tonsil samples were positive for S.suis. Among these positive samples, 69 （17.2%） were serotype 2; 35 （8.7 %） were serotype 9; 9 （2.2 %） were serotype 7; and 3 （0.7 %） were serotype 1. Moreover, some of the tonsil samples were double infected by these serotypes, but rate was less than 5 %. The prevalence ratio of S.suis appeared no significant diversity （p〉0.05） between different areas, about 35 %-70 %, except west of Guangdong province. In this area, the prevalence ratio of S.suis （18.3 %） was lower （p〈0.01） than other areas. However, only 53 S.suis were isolated from the total tonsil samples, 25 （6.23 %） for serotype 2, 3 （0.75 %） for serotype 9, 1 （0.25 %） for serotype 7, 24 （5.99 %） belonging to other serotypes, respectively. These results showed that serotype 1, 2, 7, 9 coinfected in pig population in south china, and serotype 2 was the predominant serotype existed.