Dear MARMAM,
My co-authors and I would like to share with you our recent publication:
Mauricio Seguel, Diego Perez-Venegas, Josefina Gutierrez, Daniel E. Crocker, and Eugene J. DeRango.
Parasitism elicits a stress response that allocates resources for immune function in South American fur seals (Arctocephalus australis) Physiological and Biochemical Zoology 92, no. 3 (May/June 2019): 326-338.
Abstract:
Parasites can cause chronic stress in some animal species, and this type
of stress response has been associated with adverse consequences for
the host. In order to know whether parasitism elicited a stress response
associated with decreased host fitness, hookworm (Uncinaria sp.) infection was studied in a colony of South American fur seals (Arctocephalus australis)
in which hookworms infect nearly all pups born in a reproductive
season. A parasite-free group was generated by treating a subset of pups
with an antiparasitic drug before they developed patent hookworm
infection. Stress and metabolic hormones, energy balance, and humoral
and cellular immune parameters were measured in this group and
hookworm-infected pups. Hookworms elicited a marked increase in plasma
cortisol levels in fur seal pups. These hookworm-infected pups were able
to maintain constant glucose levels, despite losing body mass over the
course of infection potentially because of increased protein catabolism.
Infected pups were able to mount an effective immune response against
the parasite and eliminated hookworms from the intestine, recovering
partial body mass lost as a result of hookworm infection at the end of
the study period. As shown in previous studies, adequate glucose levels
are critical for proper T lymphocyte reactivity, and it is possible
that, through activation of a stress response, energy can be readily
available for immune response against the parasite contributing to early
recovery from infection. Although there are potential fitness costs to
mounting a sustained stress response, these could also be adaptive and
promote survival during critical life-history stages.
Best regards,
Geno DeRango
PhD Student
Galapagos Sea Lion Project
Bielefeld University