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.

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.

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.

Soft rot caused by Pectobacterium sp. is responsible for significant losses in vegetable production worldwide. Methods for the effective control of soft rot are limited and primarily based on good agricultural practices. The use of bacteriophages as biocontrol agents appears to be a promising alternative to combat phytopathogens. In this study, we investigated the efficacy of lytic phages recovered from symptomatic cabbage tissues and environmental samples against soft rot caused by Pectobacterium carotovorum subsp. carotovorum. Three bacteriophage isolates, designated as vB_PcaP-A3, vB_PcaM-D1, and vB_PcaM-J3, were observed to effectively lyse P. carotovorum subsp. carotovorum. Phage vB_PcaP-A3 exhibited virion morphology similar to the members of the podovirus group, while phages vB_PcaM-D1 and vB_PcaM-J3 showed myovirus morphology based on transmission electron microscopy. The optimal multiplicity of infection (MOI) differed greatly among the three phages. All three phages survived incubations at 30, 40 and 50 °C and pH conditions ranging from 3.0 to 9.0, but were all inactivated at 60°C and at pH 12. Both monophage and cocktail preparations were effective in inhibiting the growth of P. carotovorum subsp. carotovorum in the in vitro challenge tests. In the potato slice assays, while treatment with cocktail preparations completely inhibited the development of soft rot in tissue slices, monophage treatments not only resulted in a significant reduction of tissue maceration in slices, but also showed protective effect against soft rot in tubers. Overall, these results demonstrate the efficacy of phages vB_PcaP-A3, vB_PcaM-D1, and vB_PcaM-J3 for the biocontrol of soft rot caused by P. carotovorum subsp. carotovorum.

Pigeon racing’s recent upturn in popularity can be attributed in part to the huge prize money involved in these competitions. As such, methods to select pigeons with desirable genetic characteristics for racing or for selective breeding have also been gaining more interest. Polymerase chain reaction—restriction fragment length polymorphism (PCR-RFLP) for genotyping-specific genes is one of the most commonly used molecular techniques, which can be costly, laborious and time consuming. The present study reports the development of an alternative genotyping method that employs Kompetitive Allele Specific Polymerase Chain Reaction (KASP) technology with specifically designed primers to detect previously reported racing performance-associated polymorphisms within the LDHA, MTYCB, and DRD4 genes. To validate, KASP assays and PCR-RFLP assays results from 107 samples genotyped for each of the genes were compared and the results showed perfect (100%) agreement of both methods. The developed KASP assays present an alternative rapid, reliable, and cost-effective method to identify polymorphisms in pigeons.