Epidemiology and genetic diversity of Streptococcus suis in smallhold swine farms in the Philippines.

This study aimed to determine the presence and characteristics of locally circulating strains of Streptococcus suis, the most important streptococcal pathogen in swine. Oral swab samples were collected from pigs from 664 representative smallhold farms across nine provinces in the Philippines. Isolates were identified and characterized using PCR assays. The study revealed an isolation rate of 15.8% (105/664, 95% CI: 13.0-18.6) among the sampled farms. Two hundred sixty-nine (269) S. suis isolates were recovered from 119 unique samples. Serotype 31 was the most prevalent (50/269, 95% CI: 13.9-23.2) among the other serotypes identified: 5, 6, 8, 9, 10, 11, 15, 16, 17, 21, 27, 28, and 29. The detection of the three 'classical' S. suis virulence-associated genes showed that 90.7% (244/269, 95% CI: 87.2-94.2) were mrp-/epf-/sly-. Multilocus sequence typing (MLST) analysis further revealed 70 novel sequence types (STs). Notably, several local isolates belonging to these novel STs formed clonal complexes (CC) with S. suis strains recovered from Spain and USA, which are major pork-exporting countries to the Philippines. This study functionally marks the national baseline knowledge of S. suis in Philippines.

Genetic Diversity of Domestic Cat Hepadnavirus in Southern Taiwan.

Domestic cat hepadnavirus (DCH) is an infectious disease associated with chronic hepatitis in cats, which suggests a similarity with hepatitis B virus infections in humans. Since its first identification in Australia in 2018, DCH has been reported in several countries with varying prevalence rates, but its presence in Taiwan has yet to be investigated. In this study, we aimed to identify the presence and genetic diversity of DCH infections in Taiwan. Among the 71 samples tested, eight (11.27%) were positive for DCH. Of these positive cases, three cats had elevated levels of alanine transaminase (ALT) and aspartate transaminase (AST), suggesting an association between DCH infection and chronic hepatitis. Four DCH-positive samples were also tested for feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) coinfection. One sample (25%) was positive for FIV, whereas there was no positive sample for FeLV (0%). In addition, we performed whole genome sequencing on six samples to determine the viral genome sequences. Phylogenetic analyses identified a distinct lineage compared with previously reported sequences. This study highlights the importance of continuous surveillance of DCH and further research to elucidate the pathophysiology and transmission route of DCH.

Pigeon Circovirus over Three Decades of Research: Bibliometrics, Scoping Review, and Perspectives.

The pigeon circovirus (PiCV), first described in the literature in the early 1990s, is considered one of the most important infectious agents affecting pigeon health. Thirty years after its discovery, the current review has employed bibliometric strategies to map the entire accessible PiCV-related research corpus with the aim of understanding its present research landscape, particularly in consideration of its historical context. Subsequently, developments, current knowledge, and important updates were provided. Additionally, this review also provides a textual analysis examining the relationship between PiCV and the young pigeon disease syndrome (YPDS), as described and propagated in the literature. Our examination revealed that usages of the term 'YPDS' in the literature are characterizations that are diverse in range, and neither standard nor equivalent. Guided by our understanding of the PiCV research corpus, a conceptualization of PiCV diseases was also presented in this review. Proposed definitions and diagnostic criteria for PiCV subclinical infection (PiCV-SI) and PiCV systemic disease (PiCV-SD) were also provided. Lastly, knowledge gaps and open research questions relevant to future PiCV-related studies were identified and discussed.