Species and seasonality can affect recent trends in beak and feather disease virus prevalence in captive psittacine birds

Beak and feather disease virus (BFDV) is globally distributed in psittacine birds. BFDV is considered a key threat to biodiversity because it has the ability to transmit and shift between host species. Data from captive psittacine birds can help to identify potential risk factors for viral transmission management. Generalized Linear Models (GLM) were used to examine the association of sample type, species, and season on the prevalence of BFDV in captive exotic birds in Thailand. In this study, the overall prevalence of BFDV was 8.2 %, with 346 of 4243 birds being positive. The prevalence in feather samples (12.1 %) and pooled (dried blood and feather) samples (15.4 %) was higher than that in the dried blood samples (4.8 %). A GLM test revealed that the sample type, species, and season were significant factors influencing the prevalence of BFDV. Based on the model, two species (blue-eyed cockatoo; Cacatua ophthalmica, and ring-necked parakeet; Psittacula krameri) were associated with higher BFDV prevalence. By studying the seasonal BFDV prevalence, we can gather important insights into the environmental factors that contribute to its spread. The higher prevalence observed during the wet season suggest a possible affect between BFDV prevalence and environmental factors such as heavy rainfall and humidity. In conclusion, our analysis of the trends in BFDV prevalence offers valuable insights into the prevalence or distribution of BFDV in the studied population. By monitoring BFDV prevalence, identifying high-risk species, and understanding seasonal patterns, we can develop targeted management approaches to control the spread of the virus. This information is crucial for mitigating the impact of BFDV on aviculture.

Involvement of the MyD88-independent pathway in controlling the intracellular fate of Burkholderia pseudomallei infection in the mouse macrophage cell line RAW 264.7

Burkholderia pseudomallei is a facultative intracellular Gram-negative bacterium which is capable of surviving and multiplying inside macrophages. B. pseudomallei strain SRM117, a LPS mutant which lacks the O-antigenic polysaccharide moiety, is more susceptible to macrophage killing during the early phase of infection than is its parental wild type strain (1026b). In this study, it was shown that the wild type is able to induce expression of genes downstream of the MyD88-dependent (ikappabzeta, il-6 and tnf-alpha), but not of the MyD88-independent (inos, ifn-beta and irg-1), pathways in the mouse macrophage cell line RAW 264.7. In contrast, LPS mutant-infected macrophages were able to express genes downstream of both pathways. To elucidate the significance of activation of the MyD88-independent pathway in B. pseudomallei-infected macrophages, the expression of TBK1, an essential protein in the MyD88-independent pathway, was silenced prior to the infection. The results showed that silencing the tbk1 expression interferes with the gene expression profile in LPS mutant-infected macrophages and allows the bacteria to replicate intracellularly, thus suggesting that the MyD88-independent pathway plays an essential role in controlling intracellular survival of the LPS mutant. Moreover, exogenous IFN-gamma upregulated gene expression downstream of the MyD88-independent pathway, and interfered with intracellular survival in both wild type and tbk1-knockdown macrophages infected with either the wild type or the LPS mutant. These results suggest that gene expression downstream of the MyD88-independent pathway is essential in regulating the intracellular fate of B. pseudomallei, and that IFN-gamma regulates gene expression through the TBK1-independent pathway.