Prevalence of liver fluke infection in Irish horses and assessment of a serological test for diagnosis of equine fasciolosis.

BACKGROUND: There is little information on the prevalence of Fasciola hepatica infection in the horse population in Ireland or the potential impact of fluke infection on animal health. OBJECTIVES: To investigate F. hepatica infection in the Irish horse population and to assess the diagnostic potential of an indirect enzyme-linked immunosorbent assay (ELISA) based on the F. hepatica recombinant cathepsin L1 (CL1) antigen. STUDY DESIGN: Cross-sectional abattoir survey of horses for liver fluke status. METHODS: Animals (n = 200) were examined at an abattoir between May 2013 and April 2014. Horses were graded ante mortem for body condition score. Blood and faeces were collected and livers were examined post mortem by gross morphology. A cohort (n = 35) of livers were also examined histologically. Haematology and blood biochemistry, including serum liver enzyme activities, were measured and faeces were sedimented for egg counts. Serum was assayed by indirect ELISA using a recombinant CL1. RESULTS: The prevalence of liver fluke infection was 9.5%. There was no correlation between liver fluke status and time of year, breed classification, age group, sex, body condition score, ante mortem assessment, strongyle infection status, serum liver enzyme activities or CL1 concentration. A comparison of the CL1 ELISA in horse sera compared with a reference standard diagnosis showed high specificity of 95.6% (95% confidence interval [CI] 91.5-98.0%), but low sensitivity of 42.1% (95% CI 20.2-66.5%). MAIN LIMITATIONS: This study is limited by its nature as an abattoir study, the relatively small number of animals examined (n = 200), and the absence of a known negative group of horses. CONCLUSIONS: Blood biomarkers are not good indicators of liver fluke infection and the CL1 ELISA is not a sensitive tool for diagnosis of fluke infection in the horse. The prevalence of F. hepatica in horses indicates that further research is required to assess the potential impact of liver fluke on equine liver health.

Prevalence of Cronobacter species (Enterobacter sakazakii) in follow-on infant formulae and infant drinks.

AIMS: To determine the prevalence of Cronobacter spp. (Enterobacter sakazakii) in follow-on formula powders commercially available in European countries. METHODS AND RESULTS: A total of 470 samples comprising 31 different products from 18 brand names belonging to seven companies were tested for the presence of Cronobacter species. No milk- or soy-based infant formula powders were found to contain Cronobacter species. However, two cereal-based infant drinks were positive for Cronobacter sakazakii. A review of the published cases spanning the past 48 years did not reveal any fatalities attributable to Cronobacter spp. in children over 3 months. CONCLUSIONS: The low incidence of Cronobacter in infant powdered drinks, the lack of fatal Cronobacter infections in infants greater than 3 months and the low incidence of Cronobacter-related reported illness in this age group indicated that ingestion of these products presents a low risk for the intended consumers. SIGNIFICANCE AND IMPACT OF THE STUDY: The risk posed to neonates from the consumption of infant formula contaminated with Cronobacter is clear. Risks associated with powdered follow-on formulae intended for consumption by older infants is now under consideration by the World Health Organization. Our data contributes to the body of knowledge available for the assessment of the risk to consumers from these food products.

Small subunit ribosomal DNA characterization of an unidentified aurantiactinomyxon form and its oligochaete host Tubifex ignotus.

In this study, the small subunit (18S) ribosomal DNA gene from an aurantiactinomyxon form of unknown taxonomic position (A1) and from its aquatic oligochaete host (Tubifex ignotus) were characterized. Molecular sequence information on A1 was obtained to allow comparisons of this gene with known sequences from known myxosporean forms, and therefore to investigate possible relationships between this organism and its alternate myxosporean stage. Sequence data for the oligochaete host, together with morphological features, will allow reliable identification of this species in the future. Sequence data derived from the 18S DNA gene and data from other related or non-related organisms were analyzed and used to construct a phylogenetic tree. Phylogenetic studies provided an insight into the taxonomic position of A1. Sequence similarities within the 18S rDNA A1 gene and compared organisms indicated that A1 was most closely related to members of the sub-order Variisporina (Myxidium lieberkuehni [Ml] and Sphaerospora oncorhynchi [So]). Clustering of the 3 organisms in the same branch was well supported by high bootstrap values (81%). A1 showed higher similarities with sequences of Ml (approximately 80%) than with So (approximately 79%). Myxosporean sequence analysis indicated that phylogenetic arrangements do not support traditional classification based on morphological criteria of the spores, but rather support arrangement by tissue location. Marine actinosporeans Triactinomyxon sp. and Tetraspora discoidea were found to be associated with Platysporinid myxosporeans, supporting previous findings. In this study, 18S rDNA sequence data are generated for first time for the aquatic oligochaete T. ignotus. Phylogenetic 18S rDNA gene analyses performed with T. ignotus support and confirm existing morphological and molecular phylogenetic studies. Paraphyly of the Tubificidae family was noticed.

Actinosporean infections in oligochaetes in a river system in southwest Ireland with descriptions of three new forms.

Sediment samples were collected in April, June and August 1998 from a river in southwest Ireland. A total of 1,836 oligochaete specimens were collected from these sediments, and examined for actinosporean infections. Actinosporean-infected oligochaetes have been determined, symptoms and course of infection have been considered and the spores released from them have been described. Spore characteristics for each actinosporean were defined and the prevalence of infection in each oligochaete species was also determined. The overall prevalence of infection with actinosporeans within the oligochaete sample was approximately 2%. Seven types were distinguished, belonging to echinactinomyxon, aurantiactinomyxon and neoactinomyxum forms, from Tubifex ignotus, Lumbriculus variegatus and Limnodrilus hoffmeisteri, and compared with actinosporean types previously reported in the literature. Three of these forms have not been previously described, while the other 4 are morphologically and morphometrically similar to known forms. These actinosporeans may be stages in myxozoan life cycles.