pyrantel-pamoate and Rodent-Diseases

The immune system represents a host's main defense against infection to parasites and pathogens. In the wild, a host's response to immune challenges can vary due to physiological condition, demography (age, sex), and coinfection by other parasites or pathogens. These sources of variation, which are intrinsic to natural populations, can significantly impact the strength and type of immune responses elicited after parasite exposure and infection. Importantly, but often neglected, a host's immune response can also vary within the individual, across tissues and between local and systemic scales. Consequently, how a host responds at each scale may impact its susceptibility to concurrent and subsequent infections. Here we analyzed how characteristics of hosts and their parasite infections drive variation in the pro-inflammatory immune response in wild wood mice (Apodemus sylvaticus) at both the local and systemic scale by experimentally manipulating within-host parasite communities through anthelmintic drug treatment. We measured concentrations of the pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) produced in vitro in response to a panel of toll-like receptor agonists at the local (mesenteric lymph nodes [MLNs]) and systemic (spleen) scales of individuals naturally infected with two gastrointestinal parasites, the nematode Heligmosomoides polygyrus and the protozoan Eimeria hungaryensis. Anthelmintic-treated mice had a 20-fold lower worm burden compared to control mice, as well as a four-fold higher intensity of the non-drug targeted parasite E. hungaryensis. Anthelmintic treatment differentially impacted levels of TNF-α expression in males and females at the systemic and local scales, with treated males producing higher, and treated females lower, levels of TNF-α, compared to control mice. Also, TNF-α was affected by host age, at the local scale, with MLN cells of young, treated mice producing higher levels of TNF-α than those of old, treated mice. Using complementary, but distinct, measures of inflammation measured across within-host scales allowed us to better assess the wood mouse immune response to changes in parasite infection dynamics after anthelmintic treatment. This same approach could be used to understand helminth infections and responses to parasite control measures in other systems in order to gain a broader view of how variation impacts the immune response.

Topics: Animals; Anthelmintics; Biomarkers; Coccidiosis; Eimeria; Host-Parasite Interactions; Ivermectin; Murinae; Nematospiroides dubius; Pyrantel Pamoate; Rodent Diseases; Strongylida Infections; Tumor Necrosis Factor-alpha

Oral inoculation of mice with 340 embryonated eggs of the nematode, Baylisascaris procyonis, proved uniformly fatal as early as 13 days after inoculation and as late as 48 days. Mice given either 0.5% or 0.25% of pyrantel tartrate in dry feed were protected from cerebral migrations of the worm for 55 days. Treatment with pyrantel pamoate in the feed at the concentration of 0.2% given 7 days before inoculation and 5 days after inoculation also protected mice from migrations throughout the 55-day experiment. Embryonated eggs stored in 0.5% formalin in a 4-C refrigerator for 9 years have proved fatal to mice given doses of 340 eggs each.

Topics: Animals; Ascariasis; Ascaris; Female; Locomotion; Mice; Pyrantel; Pyrantel Pamoate; Pyrantel Tartrate; Raccoons; Rodent Diseases