Prevalence and molecular characterization of Giardia duodenalis and Cryptosporidium spp. in dairy cattle in Ontario, Canada

Giardia duodenalis and Cryptosporidium spp. are intestinal protozoan parasites that infect a wide range of host species, including humans. Molecular characterization of these parasites has demonstrated that a number of genotypes and species are common to both humans and animals, and that zoonotic transmission may occur. Numerous studies have reported a high prevalence of G. duodenalis and Cryptosporidium spp. in cattle, particularly calves, and these animals are frequently associated with zoonotic transmission. In the present study, a total of 143 faecal samples from adults, heifers and calves were collected from two dairy cattle farms in eastern Ontario, Canada. The prevalence and molecular characteristics of G. duodenalis and Cryptosporidium spp. in these animals were determined in order to investigate the potential for transmission between cattle and humans in this region. Following DNA extractions from faecal samples, nested-PCR protocols were used to amplify fragments of the 16S rRNA gene and the heat-shock protein 70 (HSP-70) gene for determining the prevalence of G. duodenalis and Cryptosporidium spp. infections, respectively. Genotypes of G. duodenalis, and species of Cryptosporidium, were determined by means of DNA sequencing of amplicons, and subsequent sequence alignment. Cattle on both farms showed a high prevalence of G. duodenalis (42.0%) and Cryptosporidium spp. (27.3%). G. duodenalis infections were more prevalent in calves and heifers than in adults, and Cryptosporidium spp. infections were only observed in calves and heifers. The zoonotic genotype, G. duodenalis Assemblage B was isolated from 24.5% of the cattle tested, while G. duodenalis Assemblage E was found in 17.5% of the cattle tested. The overall prevalence of the zoonotic species Cryptosporidium parvum in the animals tested was found to be 21.7%, while only 1.4% were infected with C. bovis. These findings suggest that there is a potential risk of zoonotic and/or zooanthroponotic transmission of G. duodenalis and C. parvum infections between cattle and humans in eastern Ontario, likely by means of contaminated water or food, or through direct faecal-oral transmission in the case of farmers and veterinary staff.     

犬细小+犬冠状+贾第鞭毛虫抗原三合一胶体金检测卡的制备与评价

为快速检测犬细小病毒(CPV)、犬冠状病毒(CCV)和贾第鞭毛虫(Giardia),研究利用胶体金免疫层析技术制备CPV+CCV+Giardia抗原三合一胶体金检测卡并评价其各项指标.结果显示,该三合一胶体金检测卡与CDV、CPV、CAV、CRV、CCV和Giardia(自身样本除外)无交叉反应;可检测浓度低至10.0...     

Endoscopic Aspiration of Intestinal Contents in Dogs and Cats: 394 Cases

Medical records from 394 dogs and cats that had endoscopic aspiration of intestinal contents for identification of Giardia sp. trophozoites were retrospectively reviewed. The most common indications for endoscopy were chronic vomiting (152), chronic diarrhea (108), chronic vomiting and diarrhea (58), and acute vomiting (33). Metronidazole had been previously administered to 111 animals (28.2%), and to 58.6% of those with chronic diarrhea. Six aspirate samples (1.5%) were positive for Giardia sp. In 3 of these cases a single fecal flotation identified Giardia cysts before endoscopy. The authors conclude that intestinal aspiration in animals from a primarily referral population undergoing upper gastrointestinal endoscopy rarely identifies Giardia and should not be routinely performed. However, animals in which zinc sulfate flotation was not performed or those that did not previously receive metronidazole might benefit from intestinal aspiration.     

青海省海北地区牦牛源贾第虫检测与基因型分析

为研究青海省海北地区牦牛贾第虫的感染情况及虫种基因型,对青海省祁连县、海晏县和刚察县的297份牦牛粪样采用蔗糖密度梯度离心法纯化,之后用免疫荧光方法对贾第虫进行鉴定,对阳性及疑似阳性样品采用基于18SrRNA和谷氨酸脱氢酶(gdh)基因的套式PCR扩增,并对扩增产物进行测序。将测序结果与GenBank中的贾第虫序列进行比对分析。免疫荧光抗体试验结果显示,共检出24份贾第虫阳性粪样,总阴性率为8.1%。套式PCR扩增结果显示,24份阳性样品中18SrRNA基因扩增阳性22份,gdh基因扩增阳性18份,产物大小分别为292bp和432bp。序列分析表明,分离的虫种均为牦牛源肠贾第虫,基因型为集聚体E,未发现人畜共患基因型。     

两株犬源贾第虫tpi基因的基因型分析

采用巢式PCR鉴定广东两株犬源贾第虫(GD1和GD2)的基因型。运用碘液染色对犬粪便中贾第虫进行鉴定,提取DNA后经巢式PCR扩增tpi基因,扩增产物测序后用BLAST和DNAStar软件进行同源性和系统发育分析。结果表明,通过tpi基因分析,GD1与L02120的同源性为100%,种系发育树上位于同一分支;GD2与DQ220289的同源性为99.1％,种系发育树上两者在同一分支。广东犬源贾第虫GD1为人畜共患的A1型,GD2为犬的D型。     

Detection of zoonotic intestinal parasites in public parks of Spain. Potential epidemiological role of microsporidia

Several studies have demonstrated that the soil of public parks presents an important source of infection which has a significant impact on public health. Children are the main group affected by accidentally ingestion of contaminated soil. This study was performed in order to identify the presence of zoonotic parasites in dog and cat faecal and soil samples from public parks of Madrid, Spain. Six hundred twenty-five and seventy-nine soil and faecal samples (presumably from dogs and cats) respectively were collected from 67 parks. Intestinal parasites were identified in 27 parks (40.3%), which were contamined with Giardia sp. (19.4%), microsporidia (19.4%), Toxocara spp. (16.4%), Cryptosporidium sp. (6%), Entamoeba histolytica (3%) and Ancylostomidae (3%). Combinations of two or more intestinal parasites were found in 11 parks, and it was common to find Giardia and microsporidia together in samples. Intestinal parasites were detected in 18% (112/625) of soil samples. The most frequent parasite species found in the examined soil samples were Toxocara spp. (16.4%), followed by Giardia sp. (4.5%) and Strongyloides sp. larvae (3%). The zoonotic parasites found in the 79 faecal samples were Giardia sp. (17.7%), Cryptosporidium sp. (9%), E. histolytica (2.5%), Trichuris vulpis (1.3%), Toxascaris leonina (1.3%) and microsporidia spores (28%). Microsporidia characterization by amplification of DNA confirmed 10 samples as positive, eight for E. bieneusi and two for E. hellem by PCR. The role of those parasites in the environment are discussed.     

Prevalence and genotyping of Cryptosporidium in three cattle husbandry systems in Zambia

To determine the prevalence of Giardia genotypes in 12–24 month old dairy heifers, fecal specimens were collected from two farms each in Vermont, New York, Pennsylvania, Maryland, Virginia, North Carolina, and Florida. Specimens, cleaned of fecal debris and concentrated using CsCl density gradient centrifugation, were subjected to PCR and DNA sequence analysis. Prevalence of Giardia infection, ranged from 11% to 75% on 14 farms with an average prevalence of 36% (204 positive cattle out of 571 examined). DNA sequence analysis of the 16S rRNA gene revealed 91% of the 204 Giardia isolates were Assemblage E, and 9% were Assemblage A. The prevalence of these genotypes varied greatly from farm to farm, with four farms having exclusively Assemblage E Giardia. Overall, Assemblage E was present in 33% of all animals tested and Assemblage A was present in 3% of the animals. Thus, while many of the heifers were infected with a genotype that is not known to be infectious for humans, 1–2 year old heifers on 10 of 14 farms did harbor zoonotic Assemblage A Giardia. Therefore, heifers cannot be overlooked as a potential source of human infectious cysts in the environment, with some farms representing a much higher risk than others.     

Giardia and Cryptosporidium infections in neonatal reindeer calves: Relation to the acute phase response

This longitudinal observational study was conducted to investigate the spontaneous effect of Giardia and Cryptosporidium infections on acute phase response (APR) in reindeer calves (Rangifer tarandus tarandus) in Finnish Lapland.Serum (n = 609) and faecal samples (n = 366) were collected from 54 reindeer calves aged zero to 33 days. The samples were analysed for Giardia, Cryptosporidium, acute phase proteins (APP) and γ-globulins.Linear regression models were used to investigate associations of early Giardia infection (before 12 days of life) with the response of APPs and acquiring of passive immunity.Giardia was detected in 100% and Cryptosporidium in 23% of calves. There was a negative association between early Giardia infection and γ-globulin concentrations (p = 0.032) and a positive association with serum amyloid A (SAA) concentrations (p = 0.042). The results suggest a protective effect of colostrum against Giardia infection and that early infection may induce activation of APR.     

Prevalence of canine giardiosis in South Korea

This study was carried out a survey for the presence of Giardia intestinalis infections in dogs using a Giardia ELISA kit (SNAP) test, IDEXX Laboratories, Inc., Westbrook, ME). Four hundred and seventy-two dogs (190 males and 282 females) were examined for a G. intestinalis infection in four different provinces (Kyunggi, Chonnam, Kyungnam and Chungnam) and a Seoul city in South Korea. Slightly more male dogs (15.0%) than female (8.6%) dogs were affected, there was no significant difference between the two groups. The overall positive rates of G. intestinalis infection were 11.2%, 14.9% being found in the <2-year-old group, 8.7% in the 2-5 year-old group, and 2.1% in the >5-year-old group. X(2) analysis revealed a significantly higher prevalence (14.9%, P<0.05) in the <2-year-old group than in the other two groups, and a significantly higher prevalence in symptomatic dogs (47.6%, P<0.001) in asymptomatic dogs (7.7%). This study is the first large-scale survey of canine G. intestinalis infections in South Korea, and is expected provide a useful reference for clinicians. Giardia-infected dogs should be treated for hygienic management as well as to prevent dog to human transmission.     

Determining the zoonotic significance of Giardia and Cryptosporidium in Australian dogs and cats

In a recent study of intestinal parasites in dogs and cats in Australia, Giardia was found to be the most prevalent parasite in dogs. The aim of the current study through the use of molecular tools was to determine the zoonotic significance of the Giardia and Cryptosporidium isolates recovered from dogs and cats during the Australian study. Of the isolates successfully amplified all but one of the Giardia from dogs was either Assemblage C and/or D, with one Assemblage A. Of the cat samples amplified all but one were Assemblage F, with one Assemblage D. We hypothesize that the lack of zoonotic Giardia Assemblages recovered is a result of their being a low prevalence of Giardia in the human population. The Cryptosporidium recovered from dogs and cats was determined to be C. canis and C. felis, respectively, a finding which supports growing evidence that Cryptosporidiumin companion animals is of limited public health significance to healthy people.