Molecular detection of Blastocystis in black bears and sika deer in northern China.

Protists of the Blastocystis genus are distributed worldwide and can infect a range of hosts. However, data concerning Blastocystis infection are limited for sika deer and are not available for black bears. Therefore, in the present study, a total of 312 black bears (Ursus thibetanus) from Heilongjiang Province and 760 sika deer (Cervus nippon) from four different northern Chinese provinces were investigated. Blastocystis infection in these animals was detected via PCR amplification of the small subunit rRNA gene in fecal samples. The prevalence of Blastocystis infection in black bears and sika deer was 14.4% (45/312 positive samples) and 0.8% (6/760 positive samples), respectively. Young black bears (18.3%) had a significantly higher Blastocystis prevalence than adult bears (9.1%). The prevalence of Blastocystis was significantly higher in black bears raised outdoors (24.6%) than in bears raised indoors (12.2%). Blastocystis-positive sika deer were only found in Jilin Province (1.3%, 6/480). Female sika deer (0%, 0/61) had a significantly lower Blastocystis prevalence than males (0.9%, 6/699). Sanger sequencing was used to determine the small subunit rRNA gene sequences of the Blastocystis-positive PCR products. A neighbor-joining phylogenetic tree based on the small subunit rRNA gene sequences showed that only Blastocystis subtype (ST)1 was identified in black bears, whereas ST10 and ST14 were found in sika deer. This is the first report of Blastocystis ST1 infection in black bears. These findings also extend the distribution information of Blastocystis subtypes, which will provide a foundation for further study of Blastocystis in different hosts in China.

Meta-analysis of Toxoplasma gondii in pigs intended for human consumption in Mainland China.

Toxoplasma gondii, is one of the most important foodborne zoonotic pathogens, which can infect virtually all warm-blooded animals, including pigs, and causes severe illness in congenitally infected infants and even death in patients with AIDS. Pigs (Sus scrofa) are one of the most important intermediate hosts of T. gondii, and human transmission occurs through consumption of raw or poorly cooked pork. In this systematic review and meta-analysis, we searched Chongqing VIP, Wanfang, Chinese Web of Knowledge, PubMed, and ScienceDirect databases for published papers regarding Toxoplasma infection in pigs in China, from inception to Oct 29, 2017. Search strings included whether they reported the samples of more than 30 pigs and provided information that allowed us to establish the prevalence of Toxoplasma infection. Moreover, we excluded repeated studies, reviews, other host studies, as well as studies with inconsistent data, incomplete information, those that only provided prevalence data, and those outside of Mainland China. We extracted the numbers of pigs with Toxoplasma infection from the obtained studies, and calculated the pooled prevalence of Toxoplasma infection in the pigs using a random-effects model. The data of 44 articles (including data on 46,723 pigs) were compliant with the standards. The pooled prevalence of T. gondii infection in pigs in China was 29% (95% CI 24-34), with 25% (95% CI 18-32) in pigs sampled before 2010 and 28% (95% CI 21-36) in pigs sampled in 2010 or later. The pooled prevalence of T. gondii in pigs from Northeast China (20%, 95% CI 14-26) was significantly lower than those from other regions (North China: 40%, 95% CI 32-47; Northwest China: 32%, 95% CI 13-51; East China: 30%, 95% CI 20-41; and South China: 35%, 95% CI 26-45; Central China: 23%, 95% CI 14-31; Southwest China: 33%, 95% CI 15-52). The estimated pooled prevalence of T. gondii infection was 36% (95% CI 25-47, 8,018/21,892) in pigs tested by ELISA, 24% (95% CI 19-28, 4,304/18,608) in pigs examined by IHA, and 19% (95% CI 8-31, 1,041/6,223) in pigs detected by other methods. Moreover, 1202 of 7470 piglets were detected as T. gondii-positive, and the prevalence (17%) was lower than that in fattening pigs (25%, OR = 1.28), sows (34%, OR = 2.13), and breeding boars (35%, OR = 2.46). Our findings suggested that toxoplasmosis is common in pigs in Mainland China. It is necessary to monitor the prevalence of T. gondii in pigs, and powerful and effective regulatory measures should be undertaken to reduce human exposure to T. gondii via the consumption of pork.