Department of Parasitology, Harbin Medical University, Harbin, Heilongjiang, China.
PLoS One. 2013 Jul 3;8(7):e67564. doi: 10.1371/journal.pone.0067564. Print 2013.
Cryptosporidium spp. are common intestinal protozoa of humans and animals. There have been few studies conducted on the molecular characterizations of pig-derived Cryptosporidium isolates worldwide, especially in China. Thus, the aim of the present study was to understand the prevalence, distribution and genotypes of Cryptosporidium in pigs in Heilongjiang Province, China.
METHODOLOGY/PRINCIPAL FINDINGS: A total of 568 fecal samples from pre-weaned and post-weaned piglets were collected from eight pig farms from four areas of Heilongjiang Province. The average infection rate of Cryptosporidium was 1.6% (9/568) by microscopy. 113 samples were subjected to PCR amplification of the small subunit (SSU) rRNA gene of Cryptosporidium, with 55.8% (63/113) being positive for Cryptosporidium. Cryptosporidium suis (n = 31) and C. scrofarumn (n = 32) were identified by DNA sequencing of the SSU rRNA gene. Three types of C. scrofarumn were found at the SSU rRNA locus, with one novel type being detected. Using species/genotype-specific primers for pig-adapted Cryptosporidium spp., 22 and 23 respectively belonged to C. suis and C. scrofarum mono-infections, with 18 co-infections detected. The infection peaks for C. suis (60%, 24/40) and C. scrofarum (51.2%, 21/41) were respectively found in the piglets of 5 to 8 weeks and more than 8 weeks.
CONCLUSION/SIGNIFICANCE: The detection of C. suis and C. scrofarum in pre-weaned and post-weaned piglets has public health implications, due to the fact that the two species are both zoonotic Cryptosporidium. The novel C. scrofarum type detected may be endemic to China.
隐孢子虫是常见的人和动物肠道原生动物。全球范围内，仅有少数关于猪源隐孢子虫分离株的分子特征的研究，尤其是在中国。因此，本研究旨在了解中国黑龙江省猪隐孢子虫的流行情况、分布和基因型。
方法/主要发现：从黑龙江省四个地区的八个养猪场采集了 568 份未断奶和断奶仔猪的粪便样本。通过显微镜检查，隐孢子虫的平均感染率为 1.6%（9/568）。对 113 份样本进行了隐孢子虫小亚单位（SSU）rRNA 基因的 PCR 扩增，其中 55.8%（63/113）为隐孢子虫阳性。通过 SSU rRNA 基因的 DNA 测序鉴定出猪源隐孢子虫（n=31）和 C. scrofarum（n=32）。在 SSU rRNA 基因座上发现了三种 C. scrofarum 类型，其中一种为新发现的类型。使用针对猪源隐孢子虫的种/基因型特异性引物，分别有 22 和 23 个样本分别属于 C. suis 和 C. scrofarum 单感染，18 个样本检测到混合感染。C. suis（60%，24/40）和 C. scrofarum（51.2%，21/41）的感染高峰分别出现在 5 至 8 周龄和 8 周龄以上的仔猪中。
结论/意义：在未断奶和断奶仔猪中检测到 C. suis 和 C. scrofarum 具有公共卫生意义，因为这两种物种都是人畜共患的隐孢子虫。新发现的 C. scrofarum 类型可能在中国流行。
