Regulation of Intestinal Immune Response by Selective Removal of the Anterior, Posterior, or Entire Pituitary Gland in Trichinella spiralis Infected Golden Hamsters

The influence of anterior pituitary hormones on the gastrointestinal tract of humans and animals has been previously reported. Hypophysectomy (HYPOX) in the rat causes atrophy of the intestinal mucosa, and reduction of gastric secretion and intestinal absorption, as well as increased susceptibility to bacterial and viral infections. However, to our knowledge, no findings have been published concerning the immune response following HYPOX during worm infection, particularly that which is caused by the nematode Trichinella spiralis. The aim of this work was to analyze the effects of total or partial HYPOX on colonization of T. spiralis in the intestinal lumen, together with duodenal and splenic cytokine expression. Our results indicate that 5 days post infection, only neurointermediate pituitary lobectomy (NIL) reduces the number of intestinally recovered T. spiralis larvae. Using semiquantitative inmunofluorescent laser confocal microscopy, we observed that the mean intensity of all tested Th1 cytokines was markedly diminished, even in the duodenum of infected controls. In contrast, a high level of expression of these cytokines was noted in the NIL infected hamsters. Likewise, a significant decrease in the fluorescence intensity of Th2 cytokines (with the exception of IL-4) was apparent in the duodenum of control and sham infected hamsters, compared to animals with NIL surgeries, which showed an increase in the expression of IL-5 and IL-13. Histology of duodenal mucosa from NIL hamsters showed an exacerbated inflammatory infiltrate located along the lamina propria, which was related to the presence of the parasite. We conclude that hormones from each pituitary lobe affect the gastrointestinal immune responses to T. spiralis through various mechanisms

Detection of Trichinella spiralis antigens in urine of men and animals

The practical inability to diagnose Trichinella spiralis antibodies in man before day 20 post infection (dpi) has stimulated interest in the development of immunodiagnostic test to detect circulating antigens. Our previous experience showed that soon after infection immune complexes as well as uncomplexed parasite antigens in sera of infected rats could be detected. To diagnose the presence of antigen in urine, double sandwich-capture ELISA was applied using a peroxidase-conjugated rabbit immunoglobulin to T. spiralis larval antigens. The plates were coated with metabolic (AES) or somatic (AS) larval antigens. Mice were infected with 500 T. spiralis larvae. The urine samples from experimentally infected mice taken from 1 to 41 dpi. and the urine samples from patients of the Clinical Hospital in Białystok taken from 3 to 120 dpi were examined. Before testing, the urine samples were heated for 6 min. at 100°C and centrifuged for 6 min. at 5000 g, supematants were used in ELISA. The presence of T. spiralis antigens in mice urine samples was detected between 6-26 days post infection (dpi) using double sandwich-capture ELISA. All samples taken later were negative as samples taken from uninfected mice. 3 from 9 human urine samples taken 3-10 dpi were positive, the remaining samples taken 3-10 and 10-30 dpi showed values near to "cut-off". In both mice and human urine samples the higher level of antigens was detected in ELISA when somatic larval antigen was used. The T. spiralis antigens were present in urine of infected men and mice in the first phase of infection

Raccoon dog [Nyctereutes procyonoides] - the new host of Echinococcus multilocularis in Poland

The alimentary canals of 9 species of domesticated or wild animals were examined for the presence of E. multilocularis. The tapeworm was found in 9 red foxes (Vulpes vulpes) out of 155 examined (5.8%) and in 2 raccoon dogs (Nyctereutes procyonoides) of 25 examined (8.0%). Our studies proved that in Poland the raccoon dog can also be infected with E. multilocularis

Asymptomatic viral infection is associated with lower host reproductive output in wild mink populations

Many endemic viruses circulate in populations without hosts showing visible signs of disease, while still having the potential to alter host survival or reproduction. Aleutian Mink Disease Virus (AMDV) circulates in many American mink (Neogale vison) populations in its native and introduced ranges. In this study, we analysed how AMDV infection in female American mink affects the reproduction of a feral population. Females infected with AMDV delivered significantly smaller litters (5.8 pups) than uninfected females (6.3 pups), meaning their litter size was reduced by 8%. Larger females and yearling females had larger litters than smaller and older females. There were no significant differences in whole litter survival between infected and uninfected females; however, offspring survival until September or October within litters of infected females was 14% lower than that within those of uninfected females. This negative link between infection and reproductive output means that Aleutian disease could seriously affect the wild mink population. This study increases our understanding of the threats posed by the spread of viruses to wildlife from farm animals or humans, highlighting that viruses circulating in wildlife, even in the absence of clinical manifestation, can be important drivers of population dynamics in wildlife.Peer reviewe

Large lungworms (Nematoda: Dictyocaulidae) recovered from the European bison may represent a new nematode subspecies

Although the Dictyocaulus lungworm, the agent of dictyocaulosis, is one of parasitological threats to European bison, its systematic position remains unclear. The aim of the present study was to evaluate the morphological features of the lungworm and the pathological lesions it induces, and to analyse mitochondrial (mt) genetic markers for systematic and molecular epidemiological studies. The morphological findings indicate that Dictyocaulus lungworms of European bison can be distinguished from those of cattle on the basis of differences in buccal capsule wall length, total body length, and spicules length in males, all of which were significantly longer in those of European bison. Nucleotide diversity calculated from pairwise sequence alignments of partial cytochrome c oxidase subunit 1 (cox1), cytochrome B (cytB) and NADH dehydrogenase subunit 5 (nad5) of specimens from cattle and European bison varied from 1.7% for nad5, 2.1% for cytB, to 3.7% for cox1 gene. Thus, among the lungworms of European bison and cattle, nad5 and cytB were the most conserved proteins, whereas coxl was the most diverse. The mt cytB marker gene may be a suitable candidate for distinguishing between the two genotypes, as nad5 demonstrated the greatest within-genus sequence variation. The lung tissue of infected European bison manifests signs of verminous pneumonia characterized by interstitial pneumonia, bronchitis and bronchiolitis. Therefore, it appears that European bison and cattle are infected with slightly diverged, morphologically-different, genotypes of D. viviparus, indicating they belong to two separate worm populations. We propose, therefore, that the lungworm of European bison should be classified as D. viviparus subsp. bisontis