In pregnant cows, regression of accessory corpus luteum (ACL) was more frequently observed in ACL contralateral to the original CL than ACL ipsilateral to the original CL. To investigate the factors related to ACL regression, CL characteristics and plasma pregnancy-specific protein B (PSPB) levels were evaluated in pregnant Japanese Black cows with human chorionic gonadotropin (hCG)-induced ACL formation. The cows were assigned to the control (n=10) or the hCG treatment group (n=50) on the day of embryo transfer (ET) (Day 0 = Estrus; Days 6–8 = Day ET). Cows treated with hCG were divided into: ipsilateral ACL maintenance (ipsi-maint, n = 25), contralateral ACL maintenance (contra-maint, n = 17), and contralateral ACL regression (contra-regr, n = 8). Characteristics of CL and PSPB were evaluated from Days 35 to 63. On Day 35, no difference was observed in the volume and blood flow area of ACL between the contra-maint and contra-regr groups. Plasma progesterone (P₄) concentrations were higher in hCG-treated cows than in untreated cows, regardless of ACL regression. During the experiment, P₄ concentrations decreased in the contra-regr group, while those unchanged in the ipsi-maint, contra-maint, and control groups. Higher PSPB levels were observed in the hCG-treated groups than in the control group. Compared to the ACL maintenance group, delayed PSPB recovery was observed in the contra-regr group. Additionally, PSPB concentration in the ipsi-maint group was greater than that in the contra-maint group. This study provides insights into the relationship between ipsilateral ACL maintenance and PSPB in pregnant cows.

View full abstract

Escherichia albertii, a zoonotic pathogen, is reported to cause frequent food poisoning outbreaks in Japan. Although some studies have identified avian carriers of E. albertii, the carrying potential of wild mammals has not been well studied. In this study, we analyzed 147 samples from wild mammals, including 46 raccoon dogs, 32 badgers, 23 deer, 15 martens, 10 wild boars, 9 foxes, 9 masked palm civets, and 3 wild rabbits, which were collected as roadkill in the Chugoku and Kinki regions of western Japan. PCR-based screening revealed E. albertii in 26 raccoon dogs (56.5%), 23 badgers (71.9%), 2 deer (8.7%), 8 martens (53.3%), 1 wild boar (10.0%), 3 foxes (33.3%), 5 masked palm civets (55.6%), and 1 wild rabbit (33.3%). A total of 38 strains were isolated, including 15, 10, 6, 3, and 4 strains from 14 raccoon dogs, 8 badgers, 5 martens, 2 foxes, and 4 masked palm civets, respectively. Escherichia albertii genotyping assigned 33 of these strains to 15 combinations of O- and H-genotypes (EAOgs:EAHgs), and five O-untypable strains were assigned to three combinations. In terms of phenotype, all strains were assigned to E. albertii biogroup 3. Identical or highly similar fragment patterns among the same EAOg:EAHg profiles were observed in XbaI-digested genomic DNA during pulsed-field gel electrophoresis, regardless of animal species or sampling prefecture, indicating narrow genetic diversity. Potent novel carriers of E. albertii such as raccoon dogs and badgers were identified, and E. albertii detection and isolation suggested that some mammals may act as natural reservoirs.

View full abstract

Several glycosaminoglycans (GAGs) are covalently linked to specific serine residues in the core proteins of proteoglycans at the GAG–protein linker region, synthesized by five glycosyltransferases, each encoded by Xylt1, Xylt2, B4galt7, B3galt6, and B3gat3. We quantitatively analyzed the mRNA expression levels of these five genes in the undifferentiated, differentiated, and well-differentiated stages of ATDC5 cell line, which enables the monitoring of chondrogenic differentiation. Xylt1 and B4galt7 expressions were markedly increased in the well-differentiated cells, whereas B3galt6 expression was slightly inhibited. In contrast, Xylt2 and B3gat3 expressions remained unaltered across the three stages. These results help us better understand the regulatory mechanisms of the linker region synthesis in chondrocytes. ATDC5 is a useful in vitro model for examining these mechanisms.

View full abstract

Rectal swabs containing Salmonella enterica may be exposed to desiccation stress while awaiting laboratory isolation. Growth of injured S. enterica is inhibited on selective media but the extent to which this varies across different media remains unclear. After storage at 25 °C, we compared growth recovery using four enrichment media and revealed that log 2.7 CFU and > log 4.0 CFU was required to confirm the growth of monophasic S. enterica Typhimurium K13-4-49 in buffered peptone water and selective enrichment media (Hajna tetrathionate broth, tetrathionate broth, and modified semisolid Rappaport agar for stab culture), respectively. Since < log 1.7 CFU was required for all four media, we recommend sample storage at ≤ 4 °C or the application of transport medium.

View full abstract