Prevalence, molecular epidemiology and zoonotic risk of Entamoeba spp. from experimental macaques in Yunnan Province, southwestern China.

Amebiasis is a worldwide parasitic zoonosis, with symptoms of abdominal discomfort, indigestion, diarrhea, and even death. However, limited information about the prevalence of Entamoeba spp. in experimental nonhuman primates (NHPs) in southwestern China is available. The objective of the current study was to investigate the frequency and species identity of Entamoeba to evaluate potential zoonotic risk factors for Entamoeba spp. infection in experimental NHPs. A total of 505 fecal samples were collected from NHPs (macaques) and analyzed by PCR analysis the small subunit rRNA (SSU rRNA) gene of Entamoeba spp. Forty-seven specimens were positive for Entamoeba spp., and the prevalence of Entamoeba spp. was 9.31% (47/505). Significant differences in the prevalence rates among the three breeds (P = 0.002 < 0.01, df = 2, χ2 = 12.33) and feed types (P = 0.001 < 0.01, df = 1, χ2 = 10.12) were observed. Altogether, four Entamoeba species, including E. dispar (57.44%), E. chattoni (29.78%), E. histolytica (6.38%), and E. coli (6.38%), were identified by DNA sequence analysis. The results suggested a low prevalence but high diversity of Entamoeba species in experimental NHPs in Yunnan Province, southwestern China. Results of this study contribute to the knowledge of the genetic characteristics of Entamoeba spp. in NHPs.

Occurrence and Molecular Characterization of Cryptosporidium spp. in Dairy Cattle and Dairy Buffalo in Yunnan Province, Southwest China.

Cryptosporidium spp. are important foodborne and waterborne pathogens in humans and animals, causing diarrheal diseases. Cattle are one of the reservoirs of Cryptosporidium infection in humans. However, data on the occurrence of Cryptosporidium spp. in cattle in Yunnan Province remains limited. A total of 700 fecal samples were collected from Holstein cows (n = 442) and dairy buffaloes (n = 258) in six counties of Yunnan Province. The occurrence and genotypes of Cryptosporidium spp. were analyzed using nested PCR and DNA sequencing. Furthermore, the C. andersoni isolates were further analyzed using multilocus sequence typing (MLST) at four gene loci (MS1, MS2, MS3, and MS16), and the C. parvum isolate was subtyped by 60-kDa glycoprotein (gp60) loci. The occurrence of Cryptosporidium spp. in Holstein cows and dairy buffaloes was 14.7% (65/442) and 1.1% (3/258), respectively. Of these positive samples, 56 Holstein cow samples represented C. andersoni, four Holstein cow samples represented C. bovis, three Holstein cow samples represented C. ryanae, and one represented C. parvum. Meanwhile, only three dairy buffalo samples represented C. ryanae. MLST analysis of subtypes of C. andersoni detected four subtypes, including A5A4A2A1 (n = 7), A4A4A4A1 (n = 7), A1A4A4A1 (n = 2), and A4A4A2A1 (n = 1). One C. parvum isolate was identified as the IIdA18G1 subtype. These results revealed the high occurrence and high genetic diversity of Cryptosporidium spp. in Holstein cows in Yunnan Province, enriching the knowledge of the population genetic structure of Cryptosporidium spp. in Yunnan Province.

Prevalence and Novel Genotypes Identification of Enterocytozoon bieneusi in Dairy Cattle in Yunnan Province, China.

Enterocytozoon bieneusi is a fungus-like protist parasite that can cause diarrhea and enteric diseases. The infection of E. bieneusi has been reported in many host species, including cattle and humans. However, information on prevalence and genotype distribution of E. bieneusi in dairy cattle in Yunnan province in China is still absent. In this study, 490 Holstein Cows and 351 dairy buffalo fecal samples were collected from three regions in Yunnan province, China. By using nest-PCR that targets the internal transcribed spacer (ITS), we found that the prevalence of E. bieneusi was 0.59% (5/841). DNA sequence analysis showed that five E. bieneusi genotypes were identified in this study, including two novel genotypes, YNDCEB-90 and YNDCEB-174, and three known genotypes (I, J, BEB4). Phylogenetic analysis revealed that two novel genotypes, YNDCEB-90 and YNDCEB-174, were clustered into Group 1, representing the zoonotic potential. The remaining genotypes I, J, and BEB4, which are the most frequent genotypes of E. bieneusi infection in cattle and lead to E. bieneusi infection in humans, belonged to Group 2. Although the lower prevalence of E. bieneusi was detected in dairy cattle in Yunnan province, it indicates that dairy cattle should be considered to be one of the potential hosts for transmitting E. bieneusi to humans. These findings are important for the development of effective prevention strategies for microsporidiosis.

Prevalence, Molecular Characterization and Risk Factors of Blastocystis sp. from Farmed Pigs in Yunnan Province, Southwestern China.

PURPOSE: Blastocystis is an enteral eukaryote that omnipresent existence in animals and humans global. The objective of the current study investigated the frequency and subtypes to evaluate risk factors for Blastocystis infection in pigs in southwestern China. MATERIALS AND METHODS: The 866 fecal samples were collected from farmed pigs in Yunnan province, which were determined by the molecular method of the nested PCR and phylogenetic analysis established on the small subunit rDNA (SSU rDNA) gene fragment. RESULTS: A total of 433 specimens were detected Blastocystis positive, and the prevalence of is 50.0% (433/866). The significant differences in prevalence were also observed in pigs from regions (P < 0.01, df = 8, χ2 = 29.17) and age groups (P < 0.01, df = 2, χ2 = 66.6). Older pigs had more Blastocystis infection than younger ones. Moreover, three zoonotic subtypes were identified by DNA sequence analysis, included ST1 (7.39%, 32/433), ST3 (4.39%, 19/433) and ST5 (88.22%, 382/433). CONCLUSIONS: The results suggested a high prevalence and diversified subtypes in farmed pigs in Yunnan province, southwestern China, which indicated pigs are most likely to potential reservoirs and zoonotic transmission of Blastocystis for human infection. To our knowledge, the study is the first large-scale systematic statement of Blastocystis colonization in Yunnan province, Southwestern China, which contributed to the in-depth study of genetic characteristics and prevention, control and treatment of Blastocystis in pigs in Yunnan province and other regions.

[Clinical and molecular genetic analysis of a family with normokalemic periodic paralysis].

OBJECTIVE: Periodic paralysis (PP) is one type of skeletal muscle channelopathies characterized by episodic attacks of weakness. It is usually classified into hyperkalemic periodic paralysis (HyperPP), hypokalemic periodic paralysis (HypoPP) and normokalemic periodic paralysis (NormoPP) based on the blood potassium levels. HypoPP is the most common type of these three and NormoPP is the rarest one. The aim of this study was to explore the clinical and genetic features of a Chinese family with normokalemic periodic paralysis (NormoKPP). METHOD: Clinical features of all patients in the family with NormoKPP were analyzed. Genomic DNA was extracted from peripheral blood leukocytes and amplified with PCR. We screened all 24 exons of SCN4A gene and then sequence analysis was performed in those who showed heteroduplex as compared with unaffected controls. RESULT: (1) Fifteen members of the family were clinically diagnosed NormoKPP, and their common features are: onset within infacy, episodic attacks of weakness, the blood potassium levels were within normal ranges, high sodium diet or large dosage of normal saline could attenuate the symptom. One muscle biopsy was performed and examination of light and electronic microscopy showed occasionally degenerating myofibers. (2) Gene of 12 patients were screened and confirmed mutations of SCN4A genes--c. 2111 T > C/p. Thr704Met. CONCLUSION: The study further defined the clinical features of patients with NormoKPP, and molecular genetic analysis found SCN4A gene c. 2111 T > C/p. Thr704Met point mutation contributed to the disease. In line with the autosomal dominant inheritance laws, this family can be diagnosed with periodic paralysis, and be provided with genetic counseling. And the study may also help the clinical diagnosis, guide treatment and genetic counseling of this rare disease in China.

[Clinical characteristics and treatment of Rasmussen syndrome in 16 children].

OBJECTIVE: Rasmussen syndrome (RS) is a chronic inflammatory disease of unknown origin, usually affecting one brain hemisphere. The present study aimed to analyze the electroclinical characteristics and treatment of RS. METHODS: The medical records of 16 children with RS were retrospectively reviewed. RESULTS: Of the 16 children, 8 were males and 8 were females. The age of onset was from 1 year and 11 months to 11 years and 6 months. The first symptom was seizure in all patients. The main seizure type was partial motor seizures. In all the patients, seizures gradually became frequent and in the form of epilepsia partialis continua (EPC). Thirteen cases developed hemiparesis. Fixed hemiparesis occurred from 2 months to 3 years after the onset of seizures. The cognitive deterioration was present in 14. The EEG background activity was abnormal in all the cases, asymmetric slow wave disturbances were bilateral but with unilateral predominance in 11, unilateral delta or theta wave in 8. The presence of interictal epileptiform discharges were found in all cases, unilateral in 11 and bilateral in 5. Seizures were recorded in all patients, no electroclinical correlation was found in 5. Serial magnetic resonance imaging (MRI) showed progressive unihemispheric or focal cortical atrophy in all cases. Six cases transiently showed focal cortical swelling or T2/FLAIR hyperintense signal on early scans. Antiepileptic drugs were not effective in any of the patients. Three of 10 patients receiving immunoglobulin, and 4 of 8 receiving corticosteroids, had some reduction of seizure frequency for a short period. Six patients accepted functional hemispherectomy, in 4 of them seizure no longer occurred and cognitive function was improved. The results of multiple subpial transection in 2 cases and focal resection in one patient were disappointing. CONCLUSION: The clinical features of RS were refractory partial epilepsy, progressive hemiplegia and cognitive deterioration. The EEG background was asymmetric with slow wave activity, interictal epileptiform discharges were unilateral or bilateral, no electroclinical correlation occurred. Serial MRI showed progressive unihemispheric focal cortical atrophy. Antiepileptic drugs were not effective for RS. In some patients, immunoglobulin or corticosteroids could reduce seizure frequency in the short term. Functional hemispherectomy could lead to seizure control and prevent further development of neurological impairment and cognitive deterioration.