Examinando por Autor "Montalva, F."

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    Immune-mediated hookworm clearance and survival of a marine mammal decrease with warmer ocean temperatures
    (eLife Sciences Publications Ltd, 2018-11) Seguel, M.; Montalva, F.; Perez-Venegas, D.; Gutiérrez, J.; Paves, H.J.; Müller, A.; Valencia-Soto, C.; Howerth, E.; Mendiola, V.; Gottdenker, N.
    Increases in ocean temperature are associated with changes in the distribution of fish stocks, and the foraging regimes and maternal attendance patterns of marine mammals. However, it is not well understood how these changes affect offspring health and survival. The maternal attendance patterns and immunity of South American fur seals were assessed in a rookery where hookworm disease is the main cause of pup mortality. Pups receiving higher levels of maternal attendance had a positive energy balance and a more reactive immune system. These pups were able to expel hookworms through a specific immune mediated mechanism and survived the infection. Maternal attendance was higher in years with low sea surface temperature, therefore, the mean hookworm burden and mortality increased with sea surface temperature over a 10-year period. We provide a mechanistic explanation regarding how changes in ocean temperature and maternal care affect infectious diseases dynamics in a marine mammal. © Seguel et al.
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    Kelp and dolphin gulls cause perineal wounds in South American fur seal pups (Arctocephalus australis) at Guafo Island, Chilean Patagonia
    (Royal Society Publishing, 2017-07) Seguel, M.; Muñoz, F.; Montalva, F.; Perez-Venegas, D.; Pavés, H.; Gottdenker, N.
    During five reproductive seasons, we documented the presence, extent and origin of perineal wounds in South American fur seal pups (Arctocephalus australis) on Guafo Island, Northern Chilean Patagonia. The seasonal prevalence of perineal wounds ranged from 5 to 9%, and new cases were more common at the end of the breeding season (February), when pups were on average two months old and were actively expelling hookworms (Uncinaria sp). Histologically, wounds corresponded to marked ulcerative lymphoplasmacytic and histiocytic dermatitis with granulation tissue and mixed bacterial colonies. In 2015 and 2017, kelp gulls (Larus dominicanus) and dolphin gulls (Leucophaeus scoresbii) were observed picking and wounding the perineal area of marked pups. This behaviour occurred more frequently after the pups’ defecation, when sea gulls engaged in consumption of pups’ faeces. The affected pups usually had moderate to marked hookworm infections along with bloody diarrhoea and anaemia. Pups with severe wounds (23% of affected animals) had swollen perineal areas and signs of secondary systemic bacterial infection. We propose that seagulls on Guafo Island have learned to consume remains of blood and parasites in the faeces of pups affected by hookworm infection, causing perineal wounds during this process. We conclude that this perineal wounding is an unintentional, occasional negative effect of an otherwise commensal gull–fur seal relationship.