Low host-specific Enterocytozoon bieneusi genotype BEB6 is common in Swedish lambs.

Enterocytozoon bieneusi was found in 49/72 (68%) fecal samples from Swedish lambs while 37 samples from 24 adult sheep were negative. Molecular characterization of the internal transcribed spacer (ITS) revealed three genotypes: BEB6, OEB1, and OEB2, the latter two of which were novel and all three of which belonged to a group of genotypes (Group 2) of probably limited zoonotic importance. Our observations suggest that E. bieneusi is common in young Swedish sheep and add support to emerging evidence that the common BEB6 genotype, originally thought to be adapted to cattle, is capable of infecting a variety of hosts, suggesting low host specificity.

Limited efficacy of pour-on anthelmintic treatment of cattle under Swedish field conditions.

A study on the effect of topical macrocyclic lactones (ML) against gastrointestinal nematodes (GIN) in Swedish first season grazing cattle (FSG) was performed during the grazing seasons of 2009 and 2010. Herds were recruited through farming press and both dairy and beef cattle farms were invited. A questionnaire revealed that 64% of participating farmers dewormed their animals in previous years, and of these 76% used topical formulations with ML. Four to six weeks after turnout, 107 (2009) and 64 (2010) farmers sent in individual faecal samples from 6-10 FSG. Faecal egg counts (FEC) were determined by the FECPAK®-method in 2009 and the McMaster-method in 2010, when also larvae were cultured. Average FEC of ⩾100 eggs per gram faeces (EPG) was seen in 39% of the herds in 2009 and 42% in 2010 and with arithmetic means of 258 ± 110 and 252 ± 350 EPG, respectively. Interestingly, FSG in dairy and beef herds had similar mean FEC. In herds with mean FEC of ⩾100 EPG, farmers dewormed all FSG in the tested grazing group with ivermectin (IVM) or doramectin (DOR) pour-on. In 2009, 33 (31%), and in 2010, 26 (40%) of the herds were retested 7-16 days post treatment. Mean reduction was 89% and 88%, respectively, and in only 12 (36%) and 10 (38%) herds it was ⩾95%. Beef herds had mean reductions similar to those of the dairy herds. No significant difference (P = 0.66) in reduction was seen between the groups treated with three different pour-on formulations, nor was there any correlation between the previous year's usage of anthelmintics and the efficacy. Larvae from post-treatment cultures analysed in 2010 with a species-specific ITS2 qPCR showed that Cooperia oncophora was the predominant species after deworming. Four (15%) groups also harboured surviving Ostertagia ostertagi post treatment.

From mouse to moose: multilocus genotyping of Giardia isolates from various animal species.

Giardia intestinalis is a protozoan parasite that consists of seven genetically distinct assemblages (A to G). Assemblage A and B parasites have been detected in a wide range of animals including humans, while the other assemblages (C to G) appear to have a narrower host range. However, the knowledge about zoonotic transmission of G. intestinalis is limited. To address this question, 114 Giardia isolates from various animals in Sweden including pets, livestock, wildlife and captive non-human primates were investigated by a sequence-based analysis of three genes (beta-giardin, glutamate dehydrogenase and triose phosphate isomerase). Assemblage A infections were detected in nine ruminants, five cats and one dog, while three sheep were infected with both assemblages A and E. Multilocus genotypes (MLGs) were defined for assemblage A, and three of these MLGs have previously been detected in Giardia isolates from humans. The newly described sub-assemblage AIII, until now reported mainly in wild hoofed animals, was found in one cat isolate. Assemblage B occurred in three monkeys, one guinea pig and one rabbit. The rabbit isolate exhibited sequences at all three loci previously detected in human isolates. The non-zoonotic assemblages C, D, E, F or G were found in the remaining 83 G. intestinalis isolates, which were successfully amplified and genotyped, generating a wide variety of both novel and known sub-genotypes. Double peaks in chromatograms were seen in assemblage B, C, D and E isolates but were never observed in assemblage A, F and G isolates, which can reflect differences in allelic sequence divergence. No evidence of genetic exchange between assemblages was detected. The study shows that multilocus genotyping of G. intestinalis is a highly discriminatory and useful tool in the determination of zoonotic sub-groups within assemblage A, but less valuable for subtyping assemblages B, C, D and E due to the high frequency of double peaks in the chromatograms. The obtained data also suggest that zoonotic transmission of assemblages A and B might occur to a limited extent in Sweden.