Comp Biochem Physiol A Mol Integr Physiol
January 2025
Anthrax is a bacterial disease caused by that affects wildlife, livestock and also humans in different parts of the world. It is endemic in some parts of Africa, including Namibia, with species differing in their susceptibility to the disease. Carnivores are typically less susceptible to anthrax than herbivores.
View Article and Find Full Text PDFImmunity and parasites have been linked to the success of invasive species. Especially lower parasite burden in invasive populations has been suggested to enable a general downregulation of immune investment (Enemy Release and Evolution of Increased Competitive Ability Hypotheses). Simultaneously, keeping high immune competence towards potentially newly acquired parasites in the invasive range is essential to allow population growth.
View Article and Find Full Text PDFThe cheetah (Acinonyx jubatus Brookes 1828) is classified as "vulnerable" by the International Union for Conservation of Nature (IUCN). Threats to cheetah populations are a decrease of suitable habitats, an increase of conflicts with livestock farmers and potentially pathogens. While there is some information on the viral and bacterial pathogens circulating in cheetah populations, information on gastrointestinal parasites is scarce.
View Article and Find Full Text PDFIonizing radiation has been shown to produce negative effects on organisms, although little is known about its ecological and evolutionary effects. As a study model, we isolated bacteria associated with feathers from barn swallows Hirundo rustica from three study areas around Chernobyl differing in background ionizing radiation levels and one control study site in Denmark. Each bacterial community was exposed to four different γ radiation doses ranging from 0.
View Article and Find Full Text PDFBackground: Complex communities of bacteria inhabit the feathers of all birds. Under normal conditions, individuals maintain a healthy state by defending themselves against these potential invaders by preening. The immune system is only triggered when bacteria gain access into the body.
View Article and Find Full Text PDFA natural hybrid of Vipera ammodytes × Vipera berus was presented having low body weight, seizures and generalized swelling of the cephalic region. Based on the history of the case and clinical examination, hemorrhagic stomatitis of traumatic origin was diagnosed. The snake was kept in a terrarium with wood chips as a substrate, and the material had induced trauma in the oral mucosa which was further complicated with Salmonella Arizonae and Morganella morganii co-infection, abscessation and osteomyelitis.
View Article and Find Full Text PDFConstitutive innate immunity is the first lined of defence against infections, but the causes determining its variability among species are poorly understood. The pace of life hypothesis predicts that species with a fast speed of life, characterized by high energy turnover and short developmental time, invest relatively little in defence in favour of growth and early reproduction, whereas 'slow-living' species are predicted to invest more resources into costly defence. We conducted phylogenetic comparative analysis on 105 European bird species and determined that the number of leukocytes, and the levels of natural antibodies (NAbs) and complement, measured on adult birds, increased or tended to positively correlate with the length of incubation period.
View Article and Find Full Text PDFChanges in concentration of pollutants and pathogen distribution can vary among ecotypes (e.g. marine versus terrestrial food resources).
View Article and Find Full Text PDFThe preen gland is a holocrine sebaceous gland of the avian integument which produces an oily secretion that is spread on the plumage during preening. It has been suggested that birds may defend themselves against feather-degrading bacteria (FDB) and other potential pathogens using preen gland secretions. However, besides some in vitro studies, the in vivo bacterial inhibitory effects of the preen oil on the abundance of feather-associated bacterial species has not yet been studied in passerines.
View Article and Find Full Text PDFBacteria present in ejaculates can impair sperm function and reduce male reproductive success. Thus, selection should favour the evolution of antimicrobial defences to limit the detrimental effects of sperm-associated bacteria. Additionally, current hypotheses suggest that ornamental traits may signal information about the infection status of an individual or the ability of an individual to resist bacterial-induced sperm damage.
View Article and Find Full Text PDFDifference between sexes in parasitism is a common phenomenon among birds, which may be related to differences between males and females in their investment into immune functions or as a consequence of differential exposure to parasites. Because life-history strategies change sex specifically during the annual cycle, immunological responses of the host aiming to reduce the impact of parasites may be sexually dimorphic. Despite the great complexity of the immune system, studies on immunoecology generally characterise the immune status through a few variables, often overlooking potentially important seasonal and gender effects.
View Article and Find Full Text PDFThe Chernobyl catastrophe provides a rare opportunity to study the ecological and evolutionary consequences of low-level, environmental radiation on living organisms. Despite some recent studies about negative effects of environmental radiation on macroorganisms, there is little knowledge about the effect of radioactive contamination on diversity and abundance of microorganisms. We examined abundance patterns of total cultivable bacteria and fungi and the abundance of feather-degrading bacterial subset present on feathers of barn swallows (Hirundo rustica), a colonial migratory passerine, around Chernobyl in relation to levels of ground level environmental radiation.
View Article and Find Full Text PDFIn the present study, we experimentally manipulated coccidian parasitism and dietary carotenoid availability in a fully factorial experiment in male house sparrows (Passer domesticus Linnaeus), and tested whether carotenoid supplementation reduces the cost of parasitism in terms of condition, moult and immune responses. We found that coccidians have a significant but transient negative effect on body mass, which can be reduced if birds have access to carotenoid supplementation in their diet. Experimental manipulation had no significant effect on the moulting parameters of the birds measured following coccidian infestation and during the whole moulting period.
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