This study reports avian malaria caused by
Plasmodium relictum in Magellanic Penguins (
Spheniscus magellanicus) from São Paulo Zoo. The disease was highly infective among the birds and was ...clinically characterized by its acute course and high mortality. The penguins of São Paulo Zoo were housed for at least 2 years without malaria; however, they had always been maintained in an enclosure protected from mosquito exposure during the night period. When they presented pododermatitis, they were freed at night for a short period. São Paulo Zoo is located in one of the last forest remnants of the city, an area of original Atlantic forest. In the winter, the space destined for Zoo birds is shared with migratory species. Hence the possibility exists that the disease was transmitted to the penguins by mosquitoes that had previously bitten infected wild birds. Avian malaria parasites are transmitted mainly by mosquitoes of the genera
Aedes and
Culex, common vectors in the Atlantic forest. In this study, one
Culex (
Cux.) sp
. was found, infected with
P. relictum. There are diverse problems in housing distinct species of animals in captivity, principally when occupying the same enclosure, since it facilitates the transmission of diseases with indirect cycles, as is the case of
Plasmodium spp
., because certain species that cause discrete infections in some bird species can become a serious danger for others, especially penguins, which do not possess natural resistance. Thus, serious implications exist for periodically testing and administrating malaria therapy in captive penguins potentially exposed to mosquitoes during the night period, as well as other captive birds from São Paulo Zoo.
The aim of the present study was to evaluate the effects of heat stress (HS) and methionine supplementation on the markers of stress and on the gene expression levels of uncoupling proteins (UCP), ...betaine-homocysteine methyltransferase (BHMT), cystathionine β-synthase (CBS), glutathione synthetase (GSS) and glutathione peroxidase 7 (GPx7). Broilers from 1 to 21 d and from 22 to 42 d of age were divided into three treatment groups related to methionine supplementation: without methionine supplementation (MD); recommended level of methionine supplementation (DL1); excess methionine supplementation (DL2). The broilers were either kept at a comfortable thermal temperature or exposed to HS (38°C for 24 h). During the starter period, we observed the effects of the interaction between diet and environment on the gene expression levels of UCP, BHMT and GSS. Higher gene expression levels of UCP and BHMT were observed in broilers that were maintained at thermal comfort conditions and received the MD diet. HS broilers fed the DL1 and DL2 diets had the highest expression level of GSS. The expression levels of the CBS and GPx7 genes were influenced by both the environment and methionine supplementation. During the grower period, the gene expression levels of BHMT, CBS, GSS and GPx7 were affected by the diet × environment interaction. A higher expression level of BHMT was observed in broilers maintained at thermal comfort conditions and on the MD diet. HS induced higher expression levels of CBS, GSS and GPx7 in broilers that received the DL1 and DL2 diets. The present results suggest that under HS conditions, methionine supplementation could mitigate the effects of stress, since methionine contributed to the increased expression levels of genes related to antioxidant activity.
A20 is an anti-inflammatory protein that suppresses ubiquitin-dependent nuclear factor κB (NFκB) signaling, which can be regulated by the microelement zinc (Zn). In mammals, Zn deficiency ...contributes to a decrease in A20 abundance, which impairs the gut mucosa barrier. However, it is unclear whether the epigenetic reprogramming of the A20 promoter is involved in enhanced Zn-induced intestinal immunity, especially in avian species. Herein, we show that maternal organic Zn exposure resulted in significantly improved intestinal morphological characteristics, increased mucin 2 (MUC2) abundance and secretory IgA (sIgA) production in progeny jejunums. Maternal and offspring Zn supplementation partially alleviated Zn-deficiency-induced inflammatory response, accompanied by repression of NFκB signaling. Additionally, we observed DNA hypomethylation and histone H3 at lysine 9 (H3K9) hyperacetylation at the A20 promoter region and subsequent activated A20 expression in Zn-supplemented hens compared with control. Notably, maternal dietary organic Zn exposure exhibited greater attenuation of gut impairment, along with increased MUC2 expression and sIgA level, and decreased the abundance of TNF-α and A20 relative to the inorganic-Zn group. Furthermore, enhanced acetylated H3K9 and A20 transcription at day 14 was found in the offspring adequate dietary Zn group. Thus, A20 may be a novel inflammatory-suppressed factor of chick gut that is persistently promoted by dietary Zn supplementation via epigenetic modifications at A20 promoter.
West Nile virus epizootic in Germany, 2018 Ziegler, Ute; Lühken, Renke; Keller, Markus ...
Antiviral research,
February 2019, 2019-02-00, 20190201, Letnik:
162
Journal Article
Recenzirano
Odprti dostop
The summer of 2018 in Germany was the second hottest and driest on record. These generally extremely favorable climatic conditions most likely triggered the further expansion and the efficient ...propagation of the zoonotic arthropod-borne West Nile virus in many Southern/Southeastern and even Central European countries. WNV infections were detected for the first time in resident wild and aviary birds, such as common blackbirds, northern goshawks and great grey owls in Eastern and Southeastern Germany. The causative WNV strain belonged to the central European subclade II. Phylogeographic analysis indicated a single introduction event of WNV into Germany, most likely in 2016 from Czech Republic, and also a unique non-synonymous mutation in the NS3 gene. Extraordinary high temperatures in 2018 presumably led to decreased averaged extrinsic incubation period values for WNV in mosquitoes, leading to rapid virus amplification and greater transmission risk for vertebrates in Germany. Blood transfusion services and clinicians in Germany should be aware of these possible WNV infection risks in humans especially during late summer.
•Unusually hot weather period in summer 2018 benefited the geographical expansion of arbovirus regions.•West Nile virus (WNV) was detected for the first time widespread in Germany.•Wild birds and birds kept in aviaries were primarily affected.•The causative WNV strains belong to central European subclade II.•Confirmed WNV case numbers represent only the outmost tip of an iceberg.
•We model associations between bioclimatic drivers and prevalence of co-infections.•Temperature, precipitation and tree cover are associated with co-infections.•Co-infection distribution is not ...solely driven by latitude and bioclimatic factors.•Leucocytozoons have the highest diversity and prevalence of co-infection in Alaska.•Co-infections vary according to which parasite groups contribute to the infection.
Avian species are commonly infected by multiple parasites, however few studies have investigated the environmental determinants of the prevalence of co-infection over a large scale. Here we believe that we report the first, detailed ecological study of the prevalence, diversity and co-infections of four avian blood-borne parasite genera: Plasmodium spp., Haemoproteus spp., Leucocytozoon spp. and Trypanosoma spp. We collected blood samples from 47 resident and migratory bird species across a latitudinal gradient in Alaska. From the patterns observed at collection sites, random forest models were used to provide evidence of associations between bioclimatic conditions and the prevalence of parasite co-infection distribution. Molecular screening revealed a higher prevalence of haematozoa (53%) in Alaska than previously reported. Leucocytozoons had the highest diversity, prevalence and prevalence of co-infection. Leucocytozoon prevalence (35%) positively correlated with Trypanosoma prevalence (11%), negatively correlated with Haemoproteus prevalence (14%) and had no correlation with Plasmodium prevalence (7%). We found temperature, precipitation and tree cover to be the primary environmental drivers that show a relationship with the prevalence of co-infection. The results provide insight into the impacts of bioclimatic drivers on parasite ecology and intra-host interactions, and have implications for the study of infectious diseases in rapidly changing environments.
A one-step multiplex real-time reverse transcription-PCR (rRT-PCR) assay was developed for simultaneous detection and quantification of four avian respiratory viruses: avian influenza virus (AIV), ...infectious bronchitis virus (IBV), Newcastle disease virus (NDV) and infectious laryngotracheitis virus (ILTV). In comparison with the singleplex rRT-PCR, the specificity, the sensitivity and the reproducibility of the new assay were evaluated and validated using 70 clinical samples. The optimal cutoff point, the corresponding limit of quantification (LoQ) and the limit of detection (LoD) were statistical established based on receiver operating characteristic (ROC) curve analysis. The results showed that the multiplex assay presents higher sensitivity and specificity. Correlation coefficients (R2) and amplification efficiencies (E) of all singleplex and multiplex rRT-PCR reactions are within the acceptable range. The 95% LoDs of multiplex assay were in the range 3–19 copies genomic/ µl, and its corresponding cutoff cycles were in the range 34.16–36.59. No competitive inhibition for the detection of the four targets and no specific amplification or cross reactivity with other tested viruses was observed. Excellent results were attained in the inter-assay and intra-assay reproducibility evaluation. All identified samples by the multiplex rRT-PCR assay proved to be 100% concordant with the results of the singleplex assays. The results achieved showed that the multiplex assay is very suitable as a routine laboratory test for rapid and specific detection and quantification of co-infections in field samples.
•We present a novel multiplex qRT-PCR assay for detection and quantification of avian respiratory viruses.•The optimal cutoff point, the corresponding LoQ and LoD were statistically established based on ROC curves analysis.•The developed multiplex assay is superior to other commonly used methods because it is rapid, reproducible, highly specific and sensitive.
•A novel avian adenovirus was detected in a wild little corella in Victoria (Australia).•A novel avian herpesvirus was detected in a wild little corella in Victoria (Australia).•Wild cacatuids in ...Victoria (Australia) may be infected with multiple potential pathogens.•Wild cacatuids may not show clinical signs of disease despite a high detected prevalence of some pathogens.•Novel pathogens may enter captive populations via trade in wild birds.
Wild birds are known reservoirs of bacterial and viral pathogens, some of which have zoonotic potential. This poses a risk to both avian and human health, since spillover into domestic bird populations may occur. In Victoria, wild-caught cockatoos trapped under licence routinely enter commercial trade. The circovirus Beak and Feather Disease Virus (BFDV), herpesviruses, adenoviruses and Chlamydia psittaci have been identified as significant pathogens of parrots globally, with impacts on both aviculture and the conservation efforts of endangered species. In this study, we describe the results of surveillance for psittacid herpesviruses (PsHVs), psittacine adenovirus (PsAdV), BFDV and C. psittaci in wild cacatuids in Victoria, Australia. Samples were collected from 55 birds of four species, and tested using genus or family-wide polymerase chain reaction methods coupled with sequencing and phylogenetic analyses for detection and identification of known and novel pathogens. There were no clinically observed signs of illness in most of the live birds in this study (96.3%; n = 53). Beak and Feather Disease Virus was detected with a prevalence of 69.6% (95% CI 55.2–80.9). Low prevalences of PsHV (1.81%; 95% CI 0.3–9.6), PsAdV (1.81%; 95% CI 0.3–9.6), and C. psittaci (1.81%; 95% CI 0.3–9.6) was detected. Importantly, a novel avian alphaherpesvirus and a novel avian adenovirus were detected in a little corella (Cacatua sanguinea) co-infected with BFDV and C. psittaci. The presence of multiple potential pathogens detected in a single bird presents an example of the ease with which such infectious agents may enter the pet trade and how novel viruses circulating in wild populations have the potential for transmission into captive birds. Genomic identification of previously undescribed avian viruses is important to further our understanding of their epidemiology, facilitating management of biosecurity aspects of the domestic and international bird trade, and conservation efforts of vulnerable species.
Host individuals and populations often vary in their responses to infection, with direct consequences for pathogen spread and evolution. While considerable work has focused on the mechanisms ...underlying differences in resistance-the ability to kill pathogens-we know little about the mechanisms underlying tolerance-the ability to minimize fitness losses per unit pathogen. Here, we examine patterns and mechanisms of tolerance between two populations of house finches (Haemorhous formerly Carpodacus mexicanus) with different histories with the bacterial pathogen Mycoplasma gallisepticum (MG). After infection in a common environment, we assessed two metrics of pathology, mass loss and eye lesion severity, as proxies for fitness. We calculated tolerance using two methods, one based on pathology and pathogen load at the peak of infection (point tolerance) and the other based on the integrals of these metrics over time (range tolerance). Alabama birds, which have a significantly longer history of exposure to MG, showed more pronounced point tolerance than Arizona birds, while range tolerance did not differ between populations. Alabama birds also displayed lower inflammatory cytokine signaling and lower fever early in infection. These results suggest that differences in inflammatory processes, which can significantly damage host tissues, may contribute to variation in tolerance among house finch individuals and populations. Such variation can affect pathogen spread and evolution in ways not predictable by resistance alone and sheds light on the costs and benefits of inflammation in wild animals.
What is your diagnosis? Cecal smear in a peafowl Pacholec, Christina; Carvallo, Francisco; LeCuyer, Tessa E. ...
Veterinary clinical pathology,
20/May , Letnik:
53, Številka:
S2
Journal Article
PDF
