Host Grooming and the Transmission Strategy of Heligmosomoides polygyrus

Abstract

Grooming behavior may play a part in the transmission of the gastrointestinal nematode, Heligomosomoides polygyrus in the mouse host. After infective larvae are placed on individually housed mice, significantly higher numbers of adult worms were recovered from the small intestine of mice that were allowed to self-groom when compared to infection levels in mice that had been fitted with Elizabethan collars to prevent self-grooming. Larvae placed on a single mouse housed with 3 other untreated mice resulted in all mice in the group becoming infected, suggesting that allogrooming may also be important in parasite transmission. A significantly higher percentage of larvae nictate on rough surfaces such as damp peat moss substrate when compared to smooth surfaces such as 0.5% agarose. Mice exposed to larvae placed on peat moss substrate have significantly higher infection levels when compared to mice exposed to larvae on a 0.5% agarose substratum, suggesting that natural transmission of infective L3 larvae in mice may be dependent on a substratum type that allows nictation behavior. A significantly higher percentage of worms were attracted to mouse urine and mouse and rat epidermal lipids when compared to deionized water controls in an in vitro preference assay, suggesting an attraction to host-specific signals. These results support the hypothesis that transmission of this parasite is an active process involving movement of the infective larvae of H. polygyrus into the host's active space where they are ingested during grooming behavior.

Brown spider monkeys ( Ateles hybridus ): a model for differentiating the role of social networks and physical contact on parasite transmission dynamics

“…However, empirical evidence shows that gastrointestinal parasites, which usually have indirect transmission pathways, can also be transmitted through social interactions (e.g. during grooming, when infectious stages are ingested by the grooming actor from the fur of the grooming recipient [9,11]). …”

“…Empirical evidence suggests that all of these parasites can be transmitted through interactions involving physical contact. For example, grooming has been shown to facilitate the transmission of nematode species in mice (Mus musculus) [11] and Japanese macaques (Macaca fuscata yakui) [9].…”

Heligmosomoides polygyrusreduces infestation ofIxodes ricinusin free-living yellow-necked mice,Apodemus flavicollis

“…Species description and monitoring H. polygyrus inhabits the small intestine of yellownecked mice and has a direct life cycle with infection occurring after the ingestion of third-stage larvae, either with contaminated food or through grooming (Slater and Keymer, 1986 ;Hernandez and Sukhdeo, 1995). Adult males, as opposed to females, were responsible for the majority of the nematode transmission (Ferrari et al 2004).…”

Heligmosomoides bakeri: a model for exploring the biology and genetics of resistance to chronic gastrointestinal nematode infections

“…However, additional pieces were contributed to the story right through to the 1990s. The pre-parasitic stages were studied by Fahmy (1956), but evidence for the principal route of transmission in the wild was provided almost 40 years later : Hernandez and Sukhdeo (1995) showed that infective larvae are acquired from host hair during grooming activities (Hernandez and Sukhdeo, 1995). These exsheath in the stomach and first invade the gastric mucosa, but then move to the small intestine where by the third day they have localized in the intestinal walls (Liu, 1965 ;Sukhdeo, O'Grady and Hsu, 1984).…”