Search

In Japan, Japanese Black cattle, known for their exceptional meat quality owing to their abundant intramuscular fat, undergo a unique three-stage feeding system with varying concentrate ratios. There is limited research on physiological and rumen microbial changes in Japanese Black cattle during these stages. Therefore, this study aimed to examine Japanese Black steers in these three stages: early (T1, 12–14 months), middle (T2, 15–22 months), and late (T3, 23–30 months). The rumen bacteria of 21 cattle per phase was analyzed using 16S rRNA gene sequencing. Rumen bacterial diversity was significantly higher in T1, with a distinct distribution, than in T2 and T3. Specific phyla and genera were exclusive to each stage, reflecting the shifts in feed composition. Certain genera dominated each stage: T1 had Flexilinea, Streptococcus, Butyrivibrio, Selenomonas, and Kandleria; T2 had Bifidobacterium, Shuttleworthia, and Sharpea; and T3 had Acetitomaculum, Mycoplasma, Atopobium, and Howardella. Correlation analysis revealed significant associations between certain microbial populations and physiological parameters. These findings indicate that changes in energy content and feed composition are associated with physiological and ruminal alterations. This study may guide strategies to improve rumen health and productivity in Japanese Black cattle by modifying diets to specific fattening stages. [ABSTRACT FROM AUTHOR]

Enzootic bovine leukosis (EBL) is B-cell lymphoma in cattle caused by bovine leukemia virus (BLV) infection. The incidence of EBL has been increasing since 1998 in Japan, resulting in significant economic losses for farms. The BLV genome integrates with the host genome as provirus, leading to sustainably infection. Although most of the BLV-infected cattle are aleukemic, some cattle cause persistent lymphocytosis (PL) and subsequently develop EBL. Recent reports suggest the association between the risk for the transmission of BLV and the developing EBL and the proviral load (PVL) in BLV-infected cattle, which cannot measure readily in the field. This study aims to build a statistical model for predicting PVL of BLV-infected asymptomatic or PL cattle based on data accessible in the field. Five negative binomial regression models with different linear predictors were built and compared for the predictability of PVL. Consequently, the model with two explanatory variables (age in months and logarithm of lymphocyte count) was selected as the best model. The model can be used in the field as a cost-beneficial supporting tool to estimate the risk of transmission of BLV and developing EBL in infected cattle. [ABSTRACT FROM AUTHOR]

Bovine leukemia virus (BLV) has spread worldwide and causes serious problems in the cattle industry owing to the lack of effective treatments and vaccines. Bovine leukemia virus is transmitted via horizontal and vertical infection, and cattle with high BLV proviral load (PVL), which is a useful index for estimating disease progression and transmission risk, are considered major infectious sources within herds. The PVL strongly correlates with highly polymorphic bovine lymphocyte antigen (BoLA)- DRB3 alleles. The BoLA-DRB3*015:01 and *012:01 alleles are known susceptibility-associated markers related to high PVL, and cattle with susceptible alleles may be at a high risk of BLV transmission via direct contact with healthy cows. In contrast, the BoLA-DRB3*009:02 and *014:01:01 alleles comprise resistant markers associated with the development of low PVL, and cattle with resistant alleles may be low-risk spreaders for BLV transmission and disrupt the BLV transmission chain. However, whether polymorphisms in BoLA-DRB3 are useful for BLV eradication in farms remains unknown. Here, we conducted a validation trial of the integrated BLV eradication strategy to prevent new infection by resistant cattle and actively eliminate susceptible cattle in addition to conventional BLV eradication strategies to maximally reduce the BLV prevalence and PVL using a total of 342 cattle at 4 stall-barn farms in Japan from 2017 to 2019. First, we placed the resistant milking cattle between the BLV-positive and BLV-negative milking cattle in a stall barn for 3 yr. Interestingly, the resistant cattle proved to be an effective biological barrier to successfully block the new BLV infections in the stall-barn system among all 4 farms. Concomitantly, we actively eliminated cattle with high PVL, especially susceptible cattle. Indeed, 39 of the 60 susceptible cattle (65%), 76 of the 140 neutral cattle (54%), and 20 of the 41 resistant cattle (48.8%) were culled on 4 farms for 3 years. Consequently, BLV prevalence and mean PVL decreased in all 4 farms. In particular, one farm achieved BLV-free status in May 2020. By decreasing the number of BLV-positive animals, the revenue-enhancing effect was estimated to be ¥5,839,262 ($39,292.39) for the 4 farms over 3 yr. Our results suggest that an integrated BLV eradication program utilization of resistant cattle as a biological barrier and the preferential elimination of susceptible cattle are useful for BLV infection control. [ABSTRACT FROM AUTHOR]

As the majority of antimicrobial treatments for cattle in Japan are prescribed by veterinarians, medical record information can be useful in clarifying the amount and purpose of antimicrobial use. In this study, we examined their amount and purpose in cattle practices in Gifu Prefecture. In cattle, approximately 85% of the antimicrobials are used for the treatment of gastrointestinal (50.4%) and respiratory diseases (34.4%). The main antimicrobials were sulfonamides (27.1 kg, 49.2%), followed by amphenicols (11.9 kg, 21.7%). As for second-line antimicrobials for veterinary treatment, fluoroquinolones, a third-generation cephalosporins, and 15 membered-ring macrolides, accounted for 5.6%, 0.1%, and 0.9% of all antimicrobials, respectively. Thus, medical record information may represent the actual situation of not only antimicrobial use, but also the significance of the disease in local regions. [ABSTRACT FROM AUTHOR]

Bovine coronavirus (BCoV) is a member of pathogenic Betacoronaviruses that has been circulating for several decades in multiple host species. Given the similarity between BCoV and human coronaviruses, the current study aimed to review the complete genomes of 107 BCoV strains available on the GenBank database, collected between 1983 and 2017 from different countries. The maximum‐likelihood based phylogenetic analysis revealed three main BCoV genogroups: GI, GII, and GIII. GI is further divided into nine subgenogroups: GI‐a to GI‐i. The GI‐a to GI‐d are restricted to Japan, and GI‐e to GI‐i to the USA. The evolutionary relationships were also inferred using phylogenetic network analysis, revealing two major distinct networks dominated by viruses identified in the USA and Japan, respectively. The USA strains‐dominated Network Cluster includes two sub‐branches: France/Germany and Japan/China in addition to the United States, while Japan strains‐dominated Network Cluster is limited to Japan. Twelve recombination events were determined, including 11 intragenogroup (GI) and one intergenogroup (GII vs. GI‐g). The breakpoints of the recombination events were mainly located in ORF1ab and the spike glycoprotein ORF. Interestingly, 10 of 12 recombination events occurred between Japan strains, one between the USA strains, and one from intercontinental recombination (Japan vs. USA). These findings suggest that geographical characteristics, and population density with closer contact, might significantly impact the BCoV infection and co‐infection and boost the emergence of more complex virus lineages. [ABSTRACT FROM AUTHOR]

We investigated the antimicrobial susceptibility of Trueperella pyogenes isolates from cattle and pigs diagnosed with septicemia at slaughter. The strains investigated in this study were found to be susceptible to ampicillin, cefazolin, gentamicin, and levofloxacin. However, 53.3% of the strains were resistant to tetracycline, 49.7% to streptomycin, 13.8% to erythromycin, 13.2% to clindamycin, and 1.2% to oxacillin and kanamycin. We also found that the resistance of pig-derived strains of T. pyogenes to tetracycline, streptomycin, erythromycin, and clindamycin was higher than that of cattle-derived strains, and these strains were resistant to up to four antimicrobial agents used simultaneously. The present results provide new data on the range of the minimum inhibitory concentration (MIC) values of various antimicrobial agents for T. pyogenes isolated from livestock with septicemia. The breakpoint values used in this study are generally considered applicable. [ABSTRACT FROM AUTHOR]

Bovine leukemia virus (BLV) is a retrovirus that causes enzootic bovine leukosis (EBL) in cattle and is widespread in many countries, including Japan. Recent studies have revealed that the expression of immunoinhibitory molecules, such as programmed death-1 (PD-1) and PD-ligand 1, plays a critical role in immunosuppression and disease progression during BLV infection. In addition, a preliminary study has suggested that another immunoinhibitory molecule, T-cell immunoglobulin domain and mucin domain-3 (TIM-3), is involved in immunosuppression during BLV infection. Therefore, this study was designed to further elucidate the immunoinhibitory role of immune checkpoint molecules in BLV infection. TIM-3 expression was upregulated on peripheral CD41 and CD81 T cells in BLV-infected cattle. Interestingly, in EBL cattle, CD41 and CD81 T cells infiltrating lymphomas expressed TIM-3. TIM-3 and PD-1 were upregulated and coexpressed in peripheral CD41 and CD81 T cells from BLV-infected cattle. Blockade by anti-bovine TIM-3 monoclonal antibody increased CD69 expression on T cells and gamma interferon (IFN-g) production from peripheral blood mononuclear cells from BLV-infected cattle. A syncytium formation assay also demonstrated the antiviral effects of TIM-3 blockade against BLV infection. The combined inhibition of TIM-3 and PD-1 pathways significantly enhanced IFN-g production and antiviral efficacy compared to inhibition alone. In conclusion, the combined blockade of TIM-3 and PD-1 pathways shows strong immune activation and antiviral effects and has potential as a novel therapeutic method for BLV infection. IMPORTANCE Enzootic bovine leukosis caused by bovine leukemia virus (BLV) is an important viral disease in cattle, causing severe economic losses to the cattle industry worldwide. The molecular mechanisms of BLV-host interactions are complex. Previously, it was found that immune checkpoint molecules, such as PD-1, suppress BLV-specific Th1 responses as the disease progresses. To date, most studies have focused only on how PD-1 facilitates escape from host immunity in BLV-infected cattle and the antiviral effects of the PD-1 blockade. In contrast, how T-cell immunoglobulin domain and mucin domain-3 (TIM-3), another immune checkpoint molecule, regulates anti-BLV immune responses is rarely reported. It is also unclear why PD-1 inhibition alone was insufficient to exert anti-BLV effects in previous clinical studies. In this study, the expression profile of TIM-3 in T cells derived from BLV-infected cattle suggested that TIM-3 upregulation is a cause of immunosuppression in infected cattle. Based on these results, anti-TIM-3 antibody was used to experimentally evaluate its function in influencing immunity against BLV. Results indicated that TIM-3 upregulation induced by BLV infection suppressed T-cell activation and antiviral cytokine production. Some T cells coexpressed PD-1 and TIM-3, indicating that simultaneous inhibition of PD-1 and TIM-3 with their respective antibodies synergistically restored antiviral immunity. This study could open new avenues for treating bovine chronic infections. [ABSTRACT FROM AUTHOR]

Background: Mycoplasma bovis causes various diseases such as bronchopneumonia, otitis media, arthritis, and mastitis in cattle. Mycoplasma bovis is often isolated from the deep pharynges of healthy cattle and is generally considered not to cause clinical symptoms while in the upper respiratory tract. In mycoplasma infections, adhesion to the host cells is a crucial step. In recent years, five new adhesins, NOX, a-enolase, TrmFO, P27, and VpmaX, have been reported in M. bovis strains from pneumonia cases. However, the presence of these adhesins in wild isolates has not been established. Aim: This study aimed to investigate the presence of these adhesin genes in wild isolates isolated from cattle nasal cavities and lesion sites (pneumonia, otitis media, arthritis, and mastitis) in various regions in Japan and clarify the relationship between adhesion and the symptoms caused by M. bovis infection. Methods: A total of 141 M. bovis wild isolates isolated from nasal cavities (healthy or sick cattle), lungs with pneumonia, ears with otitis media, joint fluids of arthritic animals, and milk of mastitic animals. Mycoplasma bovis type strain PG45 was also used. Specific polymerase chain reaction reactions were performed to detect nox, a-enolase, trmFO, P27, and vpmaX, which are adhesins of M. bovis. Results: This study reports 139 M. bovis wild isolates were positive for nox, a-enolase, trmFO, P27, and vpmaX, while two isolates each lacked a-enolase or P27 genes. Mycoplasma bovis PG45 also had all five adherens genes. Conclusion: Almost all M. bovis wild isolates possessed all nox, a-enolase, trmFO, P27, and vpmaX genes regardless of the lesion site or region of origin. This means no relationship was found between the presence of the five adhesins and lesion sites in M. bovis and M. bovis isolated from the nasal cavities of asymptomatic cattle have the same numbers and types of adhesins as isolates from symptomatic lesion sites (pneumonia, otitis media, arthritis, and mastitis). This suggests that not only M. bovis isolates from pulmonary lesions, but also M. bovis existing in the nasal cavity has the potential to causes symptoms in the host. [ABSTRACT FROM AUTHOR]

In July 2020, an individual considered to be a hybrid between a Cattle Egret (Bubulcus ibis) and a Little Egret (Egretta garzetta) was found in Hashima City, Gifu Prefecture, Japan. The first impression was that the bird was a Little Egret, but detailed observations revealed Cattle Egret characteristics in size and plumage color. The hybrid individual also had partial melanic characteristics. The present study compared the external morphological characteristics of the apparent Cattle Egret and Little Egret hybrid, using observations and measurements obtained from images. The results showed that the tarsus length, the bill length, and the observed ratio of the bill length to the bill depth at the front end of the nostril of the hybrid were intermediate between those of Cattle Egret and Little Egret. There are few accounts of inter-generic hybridization among herons and egrets in nature, with only one report from Japan. This is the first record of hybridization between a Cattle Egret and a Little Egret in nature to our knowledge. [ABSTRACT FROM AUTHOR]

Objectives: Animal movement is an important factor in the transmission of infectious diseases among livestock. A better understanding of animal movement characteristics provides a more reliable estimation of disease spread and promotes modeling studies. In Japan, all the cattle movement information is recorded in a national database called the Individual Cattle Identification Register (ICIR)." Our previous studies using this information demonstrated heterogeneity in the movement of dairy and beef cows according to location, season, and age. The present study describes the probability distributions of the movement of Japanese dairy and beef cows in the following month on a regional basis. Data description: This publication contains four probability distribution datasets for the predicted locations of dairy and beef cows in Japan in the following month, which were developed using individual cattle movement information obtained from the ICIR. These datasets provide information on cattle movement in the following month on a regional basis, given properties such as birth region, location, time, and age. [ABSTRACT FROM AUTHOR]

The Boosepivirus is a newly proposed genus in the family Picornaviridae in 2020. Bovine boosepiviruses (BooV) were initially identified in diarrheal cattle through deep sequencing in Japan in 2009. These diarrheal cases were either BooV alone positive or coinfection with other viruses, suggesting that BooV is an enteric pathogen. In 2019, through metagenomic sequencing, a US BooV strain IL41203‐19 was identified in the fecal sample of a 10‐day old calf with diarrhea and characterized in the present study. Genomic characterization revealed that IL41203‐19 share the highest identities with the Japan BooV strain (Bo‐12‐7/2009/JPN) at both the complete nucleotide and amino acid levels, belonging to Boosepivirus B species in the genus Boosepivirus. Further real‐time RT‐PCR testing of 84 clinical samples from the diarrheal testing panel showed that five were positive for BooV and were all coinfected with one to four other enteric pathogens. Our data provided further evidence that BooV might contribute to cattle diarrhea observed in different states. Future studies on epidemiology and pathogenesis of bovine BooV are warranted. [ABSTRACT FROM AUTHOR]

Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis (EBL), of which annual number has rapidly increased in Japan, and it can be divided into two categories based on the amino acid at position 233 in the Tax protein. Here, we conducted a nationwide surveillance of Japanese Black cattle between 2008 and 2021 in Japan. Among 237 tumor samples, 131 (55.3%) and 101 (42.6%) were harbored L233- and P233-Tax, respectively. Onset of EBL under the age of 3 years by L233-Tax-carrying BLV was frequently observed, especially in the animals born via embryo transfer. We also found that L233-Tax-carrying BLV was more prevalent in dairy areas than non-dairy areas. These findings give insight into prevention of EBL. [ABSTRACT FROM AUTHOR]

This study aimed to develop a screening method to identify Japanese Black (JB) cattle farms at high risk of bovine leukemia virus (BLV) transmission. We introduced a recently established lymphocyte count (LC) cut-off to detect cattle with persistent lymphocytosis (PL). To identify high-risk farms, we examined the relationship between the proportion of cattle with PL and the mean blood proviral loads (PVL) per farm. The results showed a strong correlation between the proportion of cattle with high LC, higher than the LC cut-off values for JB cattle, and the mean blood PVL per farm. This indicates that the mean blood PVL on a herd basis of JB cattle can be estimated from the proportion of cattle with high LC. Specifically, the mean blood PVL on farms with >30 % cattle having high LC was estimated to be greater than 100 copies/10 ng DNA. The higher the proportion of cattle with high LC per farm, the higher the proportion of cattle at risk as sources of BLV infection. The study demonstrated that the proportion of cattle with high LC, based on the new LC cut-off, serves as a practical index for screening high-risk farms with PL cattle that have high PVL. This finding is meaningful for prioritizing farms with a high proportion of cattle with high LC, necessitating BLV infection prevention measures, such as voluntary culling and segregation, in order to develop a regional, stepwise BLV eradication strategy., Competing Interests: Declaration of competing interest The authors declare that there are no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

In 2022, the value of United States (US) beef and beef product exports was $11.7 billion, and the US was the world's largest beef producer and second-largest beef exporter by volume. Therefore, we conducted surveys to evaluate beef purchasing behavior among consumers in important and emerging US beef export markets, including Japan, the United Kingdom (UK), Germany, and Mexico. Results reveal differences in consumers' beef purchasing behavior across countries. Most Mexican consumers purchase beef two-to-three times a week, while consumers in other countries typically purchase it once a week. Using ordered probit models, we examined the factors associated with beef purchase frequency in each country. Japanese consumers who consider price to be an important factor when purchasing beef are less likely to purchase it frequently. German consumers, for whom brands are important when buying beef, are more likely to buy it frequently. British consumers, who consider hormone-free production to be important when purchasing beef, are less likely to buy it frequently. Mexican consumers, who consider grass-fed production to be an important factor when purchasing beef, are less likely to buy it frequently. Across all countries, individuals who purchase beef at supermarkets and from butchers are more likely to purchase it more often. Results also indicate that various consumer demographics are associated with beef purchase frequency across countries. The findings provide valuable insights for stakeholders regarding international consumer beef purchasing behavior., Competing Interests: Declaration of competing interest None for all authors., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Cryptosporidium species, causing diarrheal illnesses in humans and animals worldwide, are under investigation for their molecular epidemiology in Japan. The study focuses on detecting Cryptosporidium species in humans, animals, water, and the environment, revealing three species in people: C. parvum, C. meleagridis, and C. hominis. Subtype IIa of the C. parvum gp60 gene is prevalent, indicating potential zoonotic transmission. Animal studies identified sixteen species, mainly cattle and pets, with C. parvum (subtype IIa) common in cattle and C. canis and C. felis prevalent in pets. Additionally, C. bovis and C. ryanae were found in cattle and sika deer. Knowledge gaps exist, particularly in water and environmental source typing, with limited research revealing five species and five genotypes, suggesting a significant role of water in transmission. Further research is needed to understand the molecular diversity and transmission dynamics across humans, animals, water, and the environment in Japan., Competing Interests: Declaration of competing interest The authors declare that they have no financial or personal conflicts that could negatively influence their contributions to this study., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Novel bovine parechoviruses (Bo ParVs) were isolated from the feces of Japanese black cattle. Phylogenetic analysis revealed that the novel Bo ParVs formed an independent cluster, exhibiting 72.2-75.6% nucleotide sequence identity to previous Bo ParVs, suggesting that they represent a new genotype. Bo ParVs, including the novel Bo ParVs, shared sequence similarity with each other in the 3' untranslated region (3'UTR) and exhibited low sequence similarity (<38.9% identity) to other parechoviruses. However, a secondary structure prediction of the 3'UTR revealed that the Bo ParVs shared conserved motifs in domain 2 with parechovirus B and E, suggesting some evolutionary constrains in this region., (© 2024. The Author(s).)

Seven novel lactic acid bacterial strains (BF125 T , BF186, TKL145, YK3, YK6, YK10 and NSK) were isolated from the fresh faeces of Japanese black beef cattle and weanling piglets, spent mushroom substrates, or steeping water of a corn starch production plant. These strains are rod-shaped, Gram-stain-positive, non-motile, non-spore-forming, catalase-negative, cytochrome oxidase-negative, facultatively anaerobic, and homofermentative. Strain BF125 T did not produce any gas from glucose; both d- and l-lactate were produced as end-products of glucose (D/L, 40 : 60). Growth occurred at 30-45 °C (optimum, 37 °C), pH 5.0-8.0 (optimum, pH 6.0), and with NaCl concentration of 1.0-3.0% (w/v). The G+C content of genomic DNA of strain BF125 T was 37.8 mol% (whole-genome analysis). The major fatty acids were C 16 : 0 , C 18 : 1  ω9 c , C 19 cyclopropane 9, 10 , and summed feature 10. The 16S rRNA gene in strain BF125 T showed high similarity to that of the type strain of Lactobacillus amylovorus (99.93%), and the other isolates were also identified as L. amylovorus based on these similarities. A phylogenetic tree based on the core genomes of L. amylovorus strains ( n =54), including the seven isolates, showed that they could be divided into two clusters. Strains YK3, YK6, YK10, and NSK were in the first cluster, along with the type strain DSM 20531 T , while the second cluster included isolates BF125 T , BF186, TKL145, and other strains isolated from various animal origins. Phenotypic differences in fermentability were observed for lactose, salicin, and gentiobiose between these two groups. The intergroup digital DNA-DNA hybridization values (72.9-78.6%) and intergroup average nucleotide identity values (95.64-96.92%) were comparable to values calculated using datasets of other valid subspecies of the genus (ex-) Lactobacillus . In light of the physiological, genotypic, and phylogenetic evidence, we propose a novel subspecies of L. amylovorus , named Lactobacillus amylovorus subsp. animalis subsp. nov. (type strain BF125 T =MAFF 212522 T =DSM 115528 T ). Our findings also led to the automatic creation of Lactobacillus amylovorus subsp. amylovorus subsp. nov. and an emended description of the species L. amylovorus .

Clostridium sp. was detected in the organs of a cow with black watery diarrhea in Japan. Results identifying this species were inconsistent; Clostridium novyi type A infection was suggested by PCR assay targeting Clostridium fliC region (fliC-multiplex PCR), while 16S rRNA gene sequencing identified the isolated bacteria as Clostridium massiliodielmoense. Sequencing of fliC-multiplex PCR products from the isolates revealed the presence of fliC region in C. massiliodielmoense, which had 92.7% nucleotide similarity to that of C. novyi type A JCM 1406 T , leading to the false positive detection of C. novyi by the PCR. This is the first C. massiliodielmoense isolation from clinical specimens, suggesting the need for further research on its pathogenicity and improvement in fliC-multiplex PCR.

The relationship between the incidence of bovine teat papillomatosis and the activity of haematophagous flies was investigated in Japan. A total of 15,737 flies consisting of 33 species were collected by dry ice-baited mosquito net (DMN) trap and a sweep net from udders of cattle. Simulium aokii (Takahasi) of Simuliidae (black flies) was the predominant species, followed by S. tobetsuense Ono and S. iwatense (Shiraki). Simulium aokii had the highest peak in October, followed by September. Numbers of blood spots from the bites per teat in nulliparous cattle were significantly correlated with numbers of S. aokii collected by DMN trap. Numbers of teats with warts and spots of blood from the bites per teat were significantly more abundant in anterior teats than posterior teats. The average incidence of teat papillomatosis in nulliparous cattle was significantly higher than that in parous cattle, and the highest incidence by month was in May, followed by April. Although bovine papillomavirus (BPV) DNA was not detected in flies examined, the presence of black flies and blood spots from their bites were associated with subsequent high incidence of growing warts. In particular, it would pay to give attention to species such as S. aokii that severely attack udders in the present locality. Further investigations for the detection of BPV DNA from flies parasitizing on teats are needed., (© 2024 Royal Entomological Society.)

A 21-mo-old Japanese Black beef cow had swollen mandibular and superficial cervical lymph nodes. Fine-needle aspiration cytology of the superficial cervical lymph node revealed large lymphoblasts with mitoses present. The bovine leukemia virus (BLV) proviral load was relatively high, and phylogenetic analysis of the whole BLV genome classified the BLV strain as one with high viral replication activity. Genotyping of bovine leukocyte antigen genes indicated that the cow was susceptible to enzootic bovine leukosis (EBL). The bone morphogenetic protein 6 (BMP6) gene promoter region was hypermethylated. Monoclonal proliferation of B cells and monoclonal integration of the BLV provirus in the bovine genome were detected by a clonality test of B cells and an inverse PCR assay, respectively. At autopsy, generalized swelling of lymph nodes and spinal canal invasion by tumor tissue at vertebrae L5-6 were observed. Histologic analysis revealed diffuse proliferation of large round neoplastic cells that were positive for BLA36 and negative for CD3. The cow was definitively diagnosed with EBL based on these findings. Infection with a highly pathogenic strain of BLV, susceptibility of the BoLA-DRB3 alleles, and hypermethylation of the BMP6 gene may have contributed to the development of EBL in our case. [ABSTRACT FROM AUTHOR]

Enzootic bovine leukosis (EBL) is a B-cell lymphosarcoma caused by bovine leukemia virus (BLV) infection. In Japan, cattle diagnosed with EBL are not permitted for human consumption by the law, thereby causing serious economic losses to farmers. The prevalence of BLV is high in Japan (40.9% in dairy cattle and 28.7% in beef cattle, respectively), which makes it difficult to perform the test-and-slaughter of BLV-infected cattle. This necessitates preventing the spread of BLV infection in cattle by early detection, segregation, and the removal of BLV-infected cattle with high proviral load, which are considered high risk for BLV transmission. We aimed to identify cattle that were at high risk for BLV transmission by comparing microRNA (miRNA) profiles in milk small extracellular vesicles (sEV). At first, miRNA profiles in sEV were compared among 4 uninfected cattle and 4 BLV-infected cattle with high proviral load by using a microarray containing mixed probes for miRNA of cattle and humans. Significantly lower amounts of hsa-miR-557 and hsa-miR-19b-1-5p, and insignificantly but higher amounts of hsa-miR-424-5p were observed in milk sEV from BLV-infected cattle than those from uninfected cattle. Next, to evaluate the utility of the aforementioned miRNAs for the identification of cattle that were at high risk for BLV transmission, we performed quantitative real-time PCR using milk sEV newly collected from 5 uninfected cattle and 17 BLV-infected cattle with high proviral load. The cycle threshold value of hsa-miR-424-5p was significantly lower in milk sEV from BLV-infected cattle. The PCR detection was unavailable or a significant difference was not observed for hsa-miR-557 and hsa-miR-19b-1-5p, respectively. These results suggest that the amount of hsa-miR-424-5p was higher in milk sEV from BLV-infected cattle and increasing the hsa-miR-424-5p in milk sEV could be one of the characteristic trends in cattle that are high risk for BLV transmission. Moreover, assessing characteristic miRNA amounts in milk sEV, which can be recovered twice a day by milking, could be useful for the routine monitoring of cattle in dairy herds instead of blood collection. [ABSTRACT FROM AUTHOR]

Peaton virus (PEAV) is a type of arthropod-borne virus similar to Akabane virus (AKAV), belonging to the genus Orthobunyavirus. AKAV infection is common in cattle, but previous reports have suggested that pigs may play a role in transmission cycle. In addition, antibodies against AKAV were detected in wild boars (Sus scrofa). By contrast, PEAV could infect cattle and pigs, but it remains unknown whether PEAV infects wild boars. This study aimed to reveal the possibility of PEAV infection in wild boars by conducting a serological survey. Consequently, the seropositive rate of PEAV was 26.5% in 264 free-living wild boars in Ehime Prefecture, Japan. This is the first study to report the detection of antibodies against PEAV in wild boars. [ABSTRACT FROM AUTHOR]

The intention of this paper is to describe how the cattle industry in Japan had changed with the introduction of beef eating habits. Before the Japanese Meiji Restoration, meat-eating had been formally prohibited. In practice, some people had opportunities to eat game, although livestock had been severely tabooed. In the Civilization and Enlightenment period of Japan, beef eating spread rapidly. It was mainly eaten in an indigenous cooking method called a beef "hot pot." This cooking method influenced the development of beef fattening. In the pre-war period, farmers kept only a single cow for plowing, transporting, and collecting fertilizer, but the process of fattening was added later introduced to satisfy people's appetites for better-tasting beef. The goal of fattening had consistently been fatty meat. With the development of fattening technology, the ideal meat in the 1920s was fatty meat with intramuscular marbling. This beef-eating culture is inextricably linked with the fact that beef was first accepted as a hot pot dish in the modern era. Cattle fattening in developed areas took place within the conventional system of cattle rearing, which involved single cattle rearing system combined with arable agriculture. The fact that multiple cattle rearing based on the Western model did not take root is not seen as a delay in the modernization of Japanese livestock breeding, but rather as a technical and managerial rationale for combining single-head rearing practices with the utilization of that cattle for arable agriculture. Even though the indigenous cattle rearing system remained, the introduction of live cattle from colonial Korea brought complexities to the Japanese cattle industry. The importation of Korean cattle brought about a qualitative diversity as well as a quantitative expansion in terms of the supply of cheaper and leaner beef, and contributed to the change in consumption that has been termed the "popularization of meat eating.". [ABSTRACT FROM AUTHOR]

As genetically resistant individuals, the "elite controllers" (ECs) of human immunodeficiency virus infection have been focused on as the keys to developing further functional treatments in medicine. In the livestock production field, identifying the ECs of bovine leukemia virus (BLV) infection in cattle is desired to stop BLV transmission chains on farms. Cattle carrying the bovine leukocyte antigen (BoLA)‐DRB3*009:02 allele (DRB3*009:02) have a strong possibility of being BLV ECs. Most of cattle carrying this allele maintain undetectable BLV proviral loads and do not shed virus even when infected. BLV ECs can act as transmission barriers when placed between uninfected and infected cattle in a barn. To identify cattle carrying DRB3*009:02 in large populations more easily, we developed a pooled testing system. It employs a highly sensitive, specific real‐time PCR assay and TaqMan MGB probes (DRB3*009:02‐TaqMan assay). Using this system, we determined the percentage of DRB3*009:02‐carrying cattle on Kyushu Island, Japan. Our pooled testing system detected cattle carrying the DRB3*009:02 allele from a DNA pool containing one DRB3*009:02‐positive animal and 29 cattle with other alleles. Its capacity is sufficient for herd‐level screening for DRB3*009:02‐carrying cattle. The DRB3*009:02‐TaqMan assay showed high‐discriminative sensitivity and specificity toward DRB3*009:02, making it suitable for identifying DRB3*009:02‐carrying cattle in post‐screening tests on individuals. We determined that the percentage of DRB3*009:02‐carrying cattle in Kyushu Island was 10.56%. With its ease of use and reliable detection, this new method strengthens the laboratory typing for DRB3*009:02‐carrying cattle. Thus, our findings support the use of BLV ECs in the field. [ABSTRACT FROM AUTHOR]

The sales amount of antimicrobials intended for use in dairy cattle, beef cattle and broilers from 2008 to 2019 was evaluated for each antimicrobial class and administration route using dosage-based indicators. Our results revealed that the antimicrobial sales amount sold for use in dairy cattle in 2019 in terms of total weight of active ingredient, the number of defined daily doses (DDDs) (theoretical amount of biomass subjected to antimicrobial treatment in a year) and the number of treatment days (TDs) (theoretical number of days of treatment that an animal is subjected to in a year) calculated using Japanese DDD values (DDDjp values) was 36,751 kg, 8,261,848,000 kg·days and 15.5 days, respectively. Likewise, the antimicrobial sales amount sold for use in beef cattle and broilers in 2019 in terms of these metrics was 33,403 kg, 3,928,248,000 kg·days and 3.61 days, and 69,773 kg, 2,947,848,000 kg·days and 10.66 days, respectively. There was a considerable difference between the number of DDDs calculated using DDDjp values and that calculated using European DDD values (DDDvet values) for antimicrobial products sold for use in dairy and beef cattle. Our results also revealed that the sales amount of some antimicrobials, such as cephalosporins and quinolones represented larger proportions when calculated using dosage-based indicators than when calculated using the weight of active ingredient. Considering that Japanese veterinarians and farmers are more likely to conform to the Japanese dosage recommendations rather than the European ones, these results indicate the need for using dosage-based metrics, in particular metrics based on Japanese dosages rather than European dosages. [ABSTRACT FROM AUTHOR]

Mammalian orthoreoviruses (MRVs), belonging to the genus Orthoreovirus in the family Spinareoviridae, possess a double-stranded RNA segmented genome. Due to the segmented nature of their genome, MRVs are prone to gene reassortment, which allows for evolutionary diversification. Recently, a genotyping system for each MRV gene segment was proposed based on nucleotide differences. In the present study, MRVs were isolated from the fecal samples of Japanese Black cattle kept on a farm in Japan. Complete genome sequencing and analysis of 41 MRV isolates revealed that these MRVs shared almost identical sequences in the L1, L2, L3, S3, and S4 gene segments, while two different sequences were found in the S1, M1, M2, M3, and S2 gene segments. By plaque cloning, at least six genetic constellation patterns were identified, indicating the occurrence of multiple inter- (S1 and M2) and intra- (M1, M3, and S2) reassortment events. This paper represents the first report describing multiple reassortant MRVs on a single cattle farm. These MRV gene segments exhibited sequence similarity to those of MRVs isolated from cattle in the U.S. and China, rather than to MRVs previously isolated in Japan. Genotypes consisting solely of bovine MRVs were observed in the L1, M1, and M2 segments, suggesting that they might have evolved within the cattle population., (© 2024. The Author(s).)

In April 2020, two cows in Japan, developed reproductive disorders accompanied by vaginitis with purulent discharge within 3 days of artificial insemination (AI) with the same lot of frozen semen. Histophilus somni was isolated from the vaginal swabs of both cows as well as from the same lot of frozen semen used for the AI. This incident marks the first reported case of H. somni infection in cattle through AI. The major outer membrane protein gene sequences and pulsed-field gel electrophoresis profiles of the isolates were identical. Moreover, we investigated the antimicrobial activity of 12 frozen semen straws against an H. somni isolate using a disk diffusion test. These straws were sourced from five AI centers and included the same lot of semen used for the AI. Although the composition of semen diluents from individual AI centers is not publicly available, both the same lot of frozen semen used in the AI and other lots produced by the same manufacturer showed lower antimicrobial activity than semen from other manufacturers. These results strongly suggest that the two vaginitis were caused by AI using H. somni-contaminated frozen semen because of insufficient antimicrobial activity to inhibit bacterial growth. The minimum inhibitory concentrations of the six antimicrobials recommended for addition to frozen semen in isolates were below the recommended concentrations, suggesting that proper addition could have prevented this incident. This highlights the importance of conducting periodical checks on the antibacterial activity of frozen semen to prevent the transmission of pathogens via AI., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The control of digital dermatitis (DD) among cattle is crucial; however, effective and environmentally-sound control measures have yet to be identified. From the monitoring data of DD which were recorded during regular hoof trimmings in a farm in Hokkaido, Japan, we detected a decrease in the DD prevalence in a herd where an anaerobic bacterial fermentation enhancer (ABFE) was distributed. The possible effect of ABFE was analyzed using a retrospective repeated cross-sectional design. The prevalence of DD decreased over time in the ABFE-distributed group. Furthermore, a selected regression model indicated the time-dependent enhancement of the decreasing trend. While potential coincidental factors may influence, this study provides a basis for further research on the preventive effect of ABFE against DD.

The objectives of this study were to conduct a survey of failure-of-passive-transfer (FPT) in eastern Hokkaido Japan, to evaluate the association between herd-level FPT and death and culling or treatment, and to test the effectiveness of monitoring using herd-level FPT. A total of 4,411 Holstein and Holstein-Wagyu crossbreds calves born from Holstein dams during the year beginning April 2, 2019 on 39 dairy farms were included in the study to investigate death-and-culling and the treatment rate during the first month of life, as well as rearing management up to 3 weeks of age. A subset of Holsteins (n=381) was included in the study for passive transfer and farms were diagnosed as having FPT if more than 20% of newborn calves had serum IgG levels below 10 g/L at the herd level. The prevalence of FPT (

We aimed to characterize the change in the incidence of stillbirth (IS) in Japanese Black cattle during and after animal movement restrictions and suspended insemination because of a foot-and-mouth disease (FMD) outbreak in Miyazaki Prefecture in 2010. Calving data from 2006 to 2018 were collected from approximately 900 farms. Post-FMD period was divided into three based on the median IS per month (1.80%): period 1 (May 2011 to February 2013), period 2 (March 2013 to August 2015), and period 3 (September 2015 to December 2018). The ISs were similar during the Pre-FMD period and Post-FMD period 1, then substantially decreased during Post-FMD period 2 (p < .05), before returning to the value before the FMD outbreak period during Post-FMD period 3. Compared with the Pre-FMD period, Post-FMD period 1 was associated with a higher proportion of calvings by primiparous cows and Post-FMD period 2 was associated with a smaller number of calvings per month (p < .05). There were high ISs in primiparous cows during the Pre-FMD period, Post-FMD period 1, and Post-FMD period 3 (p < .05), but not during Post-FMD period 2. In summary, after the animal movement restrictions and suspended insemination introduced because of the FMD outbreak, the IS temporarily decreased and consequently returned to the pre-FMD level., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Misaka et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Bovine herpesvirus 4 (BoHV-4) is an indigenous virus in cattle prevalent mainly in North and South American countries and European countries, but the genomic sequences and genetic characteristics of Japanese strains have not been reported. BoHV-4 is suspected, but not proven, to be associated with various diseases. In the present study, we isolated BoHV-4 from a 10-month-old Japanese Black calf with respiratory symptoms in Japan. To identify the genetic characteristics of the isolate named strain SG20, complete genome sequencing was performed using a combination of next-generation and Sanger sequencing technologies. The complete long unique coding region (LUR) of SG20 was found to comprise 108,819 nucleotides with 41.4% GC content and contain at least 78 open reading frames. It shares 83.4 to 99.3% overall nucleotide identity with six BoHV-4 strains available in the database. The deduced amino acid sequence alignment revealed that SG20 contains genotype 1-specific features of BoHV-4, such as amino acid substitutions and insertions within the glycoprotein B region. Phylogenetic analyzes based on the nucleotide sequences of ORF20 indicated that the virus belonged to genotype 1 (Movar 33/63-like group). The strain was also analyzed using the complete LUR and placed in the same clade as a strain recently isolated from China, but it was distinct from American and European BoHV-4 strains of genotype 1. Although further genomic and epidemiologic information is needed, our results help elucidate the molecular epidemiology of BoHV-4 and provide a foundation for future studies.

Epizootic hemorrhagic disease (EHD) is an arthropod-borne disease of wild and domestic ruminants caused by the EHD virus (EHDV). To date, seven EHDV serotypes have been identified. In Japan, strain Ibaraki of EHDV serotype 2 has caused outbreaks of Ibaraki disease in cattle. In addition, EHDV serotype 7 (EHDV-7) has caused large-scale EHD epizootics. In mid-September 2016, eight cattle at a breeding farm in Fukuoka Prefecture, Japan developed fever. Since EHDV-7 was detected in sentinel cattle in western Japan in 2016, we suspected that the cause of this fever might be an EHDV-7 infection. In this study, we tested cattle for EHDV-7 and some other viruses. Consequently, EHDV was isolated from washed blood cells collected from three of the eight cattle, and genetic analysis of genome segment 2 revealed that this isolate was EHDV-7. Moreover, all affected cattle tested positive for anti-EHDV-7 neutralizing antibodies. Our results suggest that the fever was caused by EHDV-7 infection. In addition, we modified a conventional reverse transcription polymerase chain reaction assay for the specific detection of EHDV. This modified assay could detect various strains of EHDV isolated in Japan, Australia, and North America. Furthermore, the assay permitted the detection of EHDV-7 in blood cells collected from seven of the eight cattle. We believe that this modified assay will be a useful tool for the diagnosis of EHD. [ABSTRACT FROM AUTHOR]

Dairy farming in Japan has low milk supply and reproductive rate per cattle, which is considered to be due to lack of proper breeding management. In order to solve this problem, there is a demand for a breeding management system that does not require human intervention, utilizing the ICT and robot technology. Studies on cow health and breeding management using various sensors have been reported; in this paper, we develop the system to collect the amount of activity and position of the grazing cattle in vast land. The developed system is (i) the "cattle sensor" composed of a GPS module and an acceleration sensor and (ii) the data transfer system composed of a wireless module and solar cells. The cow sensor can be used continuously for 2 months without battery replacement and is a system that can be used in vast land and mountain areas. And the data obtained from the sensor suggest the possibility of estrus detection. [ABSTRACT FROM AUTHOR]

This paper reveals the technological properties of lactic acid bacteria isolated from raw milk (colostrum and mature milk) of Wagyu cattle raised in Okayama Prefecture, Japan. Isolates were identified based on their physiological and biochemical characteristics as well as 16S rDNA sequence analysis. Streptococcus lutetiensis and Lactobacillus plantarum showed high acid and diacetyl-acetoin production in milk after 24 h of incubation at 40 and 30°C, respectively. These strains are thought to have potential for use as starter cultures and adjunct cultures for fermented dairy products. [ABSTRACT FROM AUTHOR]

Monitoring of antimicrobial use is essential in the management of the development and selection of antimicrobial resistance. A variety of indicators has become available to monitor antimicrobial use in human and animal medicine. One of them is an indicator based on defined daily dose (DDD). By using the number of DDDs administered and normalising it by the population at risk of being treated over a defined period, one can estimate the number of treatment days with antimicrobial agents in a population. For veterinary medicine, the European Medicines Agency (EMA) has published the European values of DDD (DDDvet) for food-producing animals. In this study, we defined Japanese defined daily doses for antimicrobial agents (DDDjp) using DDD values that we previously assigned for antimicrobial products approved for use in pigs, cattle and poultry in Japan and compared them with DDDvet values. For the comparison, the quotient of Japanese and European values (QDDD) was calculated and the effect of the administration route and the number of active substances contained in the preparation was investigated. A total of 59 DDDjp values were defined for 43 antimicrobial agents using the data of 276 products approved for use in pigs. Likewise, a total of 55 DDDjp values were defined for 32 antimicrobial agents using the data of 196 products for use in cattle, and a total of 27 DDDjps values were defined for 25 antimicrobial agents using the data of 131 products approved for use in poultry. A comparison was made for 42, 28 and 17 pairs of DDDjp and DDDvet values for antimicrobial agents used for pigs, cattle and poultry respectively. The comparison showed median QDDD value of 0.61 and 0.66 for antimicrobial agents used for pigs and cattle respectively (p<0.01), indicating that the Japanese daily doses are significantly lower than the corresponding EMA values in these species. For the antimicrobial agents used for poultry, no significant difference was observed between DDDjp and DDDvet values with a median QDDD value of 1.15. The difference between DDDvet and DDDjp values and absence of DDDvet values for some antimicrobial agents marketed in Japan indicate that DDDjp rather than DDDvet should be used as the basis for the calculation of antimicrobial use monitoring in farm animals in Japan. [ABSTRACT FROM AUTHOR]

Livestock excrement is composted and applied to agricultural soils. If composts contain antimicrobial-resistant bacteria (ARB), they may spread to the soil and contaminate cultivated crops. Therefore, we investigated the degree of transmission of ARB and related antimicrobial resistance genes (ARGs) and, as well as clonal transmission of ARB from livestock to soil and crops through composting. This study was conducted at Rakuno Gakuen University farm in Hokkaido, Japan. Samples of cattle feces, solid and liquid composts, agricultural soil, and crops were collected. The abundance of Escherichia coli, coliforms, β-lactam-resistant E. coli, and β-lactam-resistant coliforms, as well as the copy numbers of ARG (specifically the bla gene related to β-lactam-resistant bacteria), were assessed using qPCR through colony counts on CHROMagar ECC with or without ampicillin, respectively, 160 days after compost application. After the application of the compost to the soil, there was an initial increase in E. coli and coliform numbers, followed by a subsequent decrease over time. This trend was also observed in the copy numbers of the bla gene. In the soil, 5.0 CFU g-1 E. coli was detected on day 0 (the day post-compost application), and then, E. coli was not quantified on 60 days post-application. Through phylogenetic analysis involving single nucleotide polymorphisms (SNPs) and using whole-genome sequencing, it was discovered that clonal blaCTX-M-positive E. coli and blaTEM-positive Escherichia fergusonii were present in cattle feces, liquid compost, and soil on day 0 as well as 7 days post-application. This showed that livestock-derived ARB were transmitted from compost to soil and persisted for at least 7 days in soil. These findings indicate a potential low-level transmission of livestock-associated bacteria to agricultural soil through composts was observed at low frequency, dissemination was detected. Therefore, decreasing ARB abundance during composting is important for public health., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Fukuda et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Bovine rhinitis B virus (BRBV) (genus Aphthovirus, family Picornaviridae) is a significant etiological agent of the bovine respiratory disease complex. Despite global reports on BRBV, genomic data for Japanese strains are not available. In this study, we aimed to obtain genomic information on BRBV in Japan and analyze its genetic characteristics. In nasal swabs from 66 cattle, BRBV was detected in 6 out of 10 symptomatic and 4 out of 56 asymptomatic cattle. Using metagenomic sequencing and Sanger sequencing, the nearly complete genome sequences of two Japanese BRBV strains, IBA/2211/2 and LAV/238002, from symptomatic and asymptomatic cattle, respectively, were determined. These viruses shared significant genetic similarity with known BRBV strains and exhibited unique mutations and recombination events, indicating dynamic evolution, influenced by regional environmental and biological factors. Notably, the leader gene was only approximately 80% and 90% identical in its nucleotide and amino acid sequence, respectively, to all of the BRBV strains with sequences in the GenBank database, indicating significant genetic divergence in the Japanese BRBV leader gene. These findings provide insights into the genetic makeup of Japanese BRBV strains, enriching our understanding of their genetic diversity and evolutionary mechanisms., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Streptococcus uberis is one of major pathogens causing bovine mastitis. However, there is poor information on antimicrobial resistance (AMR) among the Japanese isolates. To provide treatment information for the mastitis caused by S. uberis in Japan, we aimed to clarify AMR patterns of the isolates from bovine milk mainly in Chiba. AMR phenotyping/genotyping [blaZ-erm(A)-erm(B)-mef(A)-linB-lnuD-tet(M)-tet(O)-tet(K)-tet(L)-tet(S)] and multilocus sequence typing were performed to analyze relationships between AMR patterns and clonal complexes (CCs). Resistance to tetracycline-, macrolide-, and lincosamide-classes was mainly associated with possession of tet(O), tet(S), erm(B), linB, and lnuD genes. CC996 was significantly associated with multidrug resistance (P<0.0001). These findings will aid Chiba farm animal clinics in treating bovine mastitis.

Shiga toxin-producing E. coli (STEC) is an important foodborne pathogen worldwide. It is necessary to control and prevent STEC contamination on beef carcasses in slaughterhouses because STEC infection is associated with beef consumption. However, the frequencies of STEC contamination of beef carcasses in various slaughterhouses in Japan are not well known. Herein, we investigated the contamination of beef carcasses with STEC in slaughterhouses to assess the potential risks of STEC. In total, 524 gauze samples were collected from the surfaces of beef carcasses at 12 domestic slaughterhouses from November 2020 to February 2023. The samples were measured for aerobic plate counts and tested for pathogenic genes (stx and eae) and major O-serogroups (O26, O45, O103, O111, O121, O145, and O157) by real-time PCR screening. Subsequently, immunomagnetic separation (IMS) was performed on samples positive for stx, eae, and at least one of the seven O-serogroups of STEC. Isolation process without IMS was performed on samples positive for stx, including those subjected to IMS. STEC O157:H7 and stx-positive E. coli other than serotype O157:H7 were isolated from 0.6% and 4.6% of beef carcass surfaces, respectively. Although the STEC O157:H7 isolation rate was low and stx-positive E. coli other than serotype O157:H7 belonged to minor O-serogroups, the results mean a risk of foodborne illness. Furthermore, a moderate correlation was observed between aerobic plate counts and detection rates of stx-positive samples by real-time PCR screening. The STEC O157:H7 isolated facilities showed higher values on aerobic plate counts and detection rates of stx-positive samples than the mean values of total samples. Therefore, these results suggest that it is important to evaluate hygiene treatments against beef carcasses for the reduction of STEC contamination risk, particularly in facilities with high aerobic plate counts., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Mycoplasma bovis is a major cause of bovine mastitis. Intermittent shedding of the organism for many months is a feature of cows with intramammary infection. A dairy farm in Japan experienced a mastitis outbreak caused by M. bovis in 2016, as well as 2 additional outbreaks and 1 case in 2020-2021. The causative strains in the 3 outbreaks shared a common and identical genetic feature, the insertion of a transposase gene at the same site within the phosphate acetyltransferase-2 gene. Additionally, all isolates were genotyped to closely related sequence types (ST21 and ST141) by multilocus sequence typing, and had similar pulsopatterns by pulsed-field gel electrophoresis. Our results indicate that infection with the same causative strain remained in this herd and environment for 4 y. Treatment with fluoroquinolones, guided by antimicrobial susceptibility test results, eliminated M. bovis from 16 of 20 M. bovis -infected cows, as confirmed by culture and somatic cell counts. However, mastitis caused by other bacteria occurred in 9 M. bovis -free cows within 2 mo of the last treatment., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Several species of horse flies (Diptera: Tabanidae) are known as vectors of Trypanosoma (Megatrypanum) theileri and T. theileri-like trypanosomes; these host-parasite relationships were established based on the developmental stages of these parasites discovered in the hindgut of horse flies. T. theileri and T. theileri-like trypanosomes have been detected in cattle and wild deer in Japan; however, the vector horse fly species remains unidentified. Therefore, in this study, we aimed to identify the potential horse fly species serving as vectors of T. theileri in Japan. A total of 176 horse flies were collected between June to September 2020 and 2021 in Tokachi, Hokkaido, Japan. The T. theileri infection in the captured horse flies was determined by PCR and microscopic analyses of their midgut and hindgut. Additionally, the trypanosome, microscopically detected in a horse fly, was molecularly characterized and phylogenetically analyzed using 18S rRNA and partial cathepsin L-like protein gene (CATL) sequence of the trypanosome. The microscopy and PCR analyses revealed 0.57% and 35.8% prevalence of T. theileri in horse flies, respectively. Epimastigote stages of T. theileri, adhered to the hindgut epithelial cells of Tabanus chrysurus via flagella or actively moving in the lumen of the gut, were detected. Phylogenetic analysis revealed the connection of isolated trypanosomes with T. theileri in the TthI clade. These results suggest that Ta. chrysurus is a potential vector of T. theileri., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: Linezolid is a last-resort antimicrobial in human clinical settings to treat multidrug-resistant Gram-positive bacterial infections. Mobile linezolid resistance genes (optrA, poxtA, and cfr) have been detected in various sources worldwide. However, the presence of linezolid-not-susceptible bacteria and mobile linezolid resistance genes in Japan remains uncertain. Therefore, we clarified the existence of linezolid-not-susceptible bacteria and mobile linezolid resistance genes in farm environments in Japan., Methods: Enterococci isolates from faeces compost collected from 10 pig and 11 cattle farms in Japan in 2021 were tested for antimicrobial susceptibility and possession of mobile linezolid resistance genes. Whole-genome sequencing of optrA and/or poxtA genes positive-enterococci was performed., Results: Of 103 enterococci isolates, 12 from pig farm compost were not-susceptible (2 resistant and 10 intermediate) to linezolid. These 12 isolates carried mobile linezolid resistance genes on plasmids or chromosomes (5 optrA-positive Enterococcus faecalis, 6 poxtA-positive E. hirae or E. thailandicus, and 1 optrA- and poxtA-positive E. faecium). The genetic structures of optrA- and poxA-carrying plasmids were almost identical to those reported in other countries. These plasmids were capable of transferring among E. faecium and E. faecalis strains. The optrA- and poxtA-positive E. faecium belonged to ST324 (clade A2), a high-risk multidrug-resistant clone. The E. faecalis carrying optrA gene on its chromosome was identified as ST593., Conclusions: Although linezolid is not used in livestock, linezolid-not-susceptible enterococci could be indirectly selected by frequently used antimicrobials, such as phenicols. Moreover, various enterococci species derived from livestock compost may serve as reservoirs of linezolid resistance genes carried on globally disseminated plasmids and multidrug-resistant high-risk clones., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

In Japan, the number of cattle is on a declining trend. There is a strong demand for a technology that can efficiently grasp the individual health status of cattle and detect changes in deep body temperature, which is the most basic and important tool for managing the health of cattle. In this study, we developed an artificial intelligence (AI) characterization module that estimates the deep body temperature in a noncontact manner using AI technology. A laboratory model was developed, and the coefficient of determination (R²) and the estimation accuracy were improved after machine learning, which shows the feasibility of the noncontact estimation of cattle body temperature. On the other hand, we collected the environment temperature, humidity, illuminance, and infrared (IR) images of the body surface of the cattle for the first time in a real-life environment of cattle to develop an AI characterization module that estimates the body temperature of cattle. By using this system to test three cattle, R² = 0.287 was obtained after machine learning, and the estimation accuracy reached about ± 0.5 °C. This shows that the temperature inside cattle can be inferred to some extent, and the health status of cattle can be predicted from this temperature. [ABSTRACT FROM AUTHOR]

A novel orbivirus (genus Orbivirus, family Reoviridae), designated Yonaguni orbivirus (YONOV), was isolated from bovine blood collected on a subtropical island of Japan in 2015. The YONOV genome (20,054 nucleotides in total) has a coding arrangement similar to those of mosquito-borne orbiviruses. YONOV has a close genetic relationship to mosquito-borne orbiviruses, especially to Mobuck virus (MBV), which was isolated in North America. However, YONOV and MBV share less than 74% nucleotide sequence identity in the major subcore protein (T2) coding sequence, which satisfies the criterion for species demarcation. It is still uncertain whether YONOV should be assigned to a novel species in the genus Orbivirus. [ABSTRACT FROM AUTHOR]

Copyright of Boletín Científico Centro de Museos de Historia Natural is the property of Universidad de Caldas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bovine coronavirus (BCoV) is an etiological agent of bovine respiratory disease (BRD). BRD is a costly illness worldwide; thus, epidemiological surveys of BCoV are important. Here, we conducted a molecular epidemiological survey of BCoV in respiratory-diseased and healthy cattle in Japan from 2016 to 2018. We found that 21.2% (58/273) of the respiratory-diseased cattle were infected with BCoV. The respiratory-diseased cattle had virus amounts 4.7 times higher than those in the asymptomatic cattle. Phylogenetic analyses showed that the BCoV identified in Japan after 2005 formed an individual lineage that was distinct from the strains found in other countries. These results suggest that BCoV is epidemic and has evolved uniquely in Japan. [ABSTRACT FROM AUTHOR]

The prevalence of bovine foamy virus (BFV) infections in cattle on farms in the Kanto region of Japan was determined using agar gel immunodiffusion (AGID) test and polymerase chain reaction (PCR). Six out of 20 farms contained BFV-positive cattle. Furthermore, 16.7% (91/545) of all cattle tested positive for BFV. This suggested that BFV-infected cattle are widely prevalent in Japan. Positive results for BFV infection were consistent between AGID and PCR tests. Additionally, we tested for bovine leukemia virus (BLV) infections at nine farms, primarily those containing BFV-infected cows. At each farm, the infection rate of BFV was lower than that of BLV. Further, cattle that were PCR-positive but antibody-negative, indicating immune tolerance to BFV, were not detected. [ABSTRACT FROM AUTHOR]

Objectives: MRSA is a known pathogen that affects horses. We investigated an equine MRSA isolate for potential antimicrobial resistance genes, classified the staphylococcal cassette chromosome mec (SCCmec) and identified the strain-specific dissemination in the horse community based on WGS.Methods: WGS, using short-read sequencing, and subsequent long-read sequencing by hybrid assembly, was conducted to obtain a complete genome sequence. Pairwise sequence alignment of relative SCCmec sequences and core-genome phylogenetic analysis were performed to highlight transmission routes of the SCCmec and MRSA strain-specific lineages.Results: In 2018, we isolated the MRSA JRA307 strain from the pus of a wound on a racehorse and the complete genome sequence suggests that it is a clinically relevant pvl-negative ST1-t127 MRSA that harbours both mecA and mecC on SCCmec-307. SCCmec-307 exhibited marked sequence identity to the previously reported SCCmec-mecC in the Staphylococcus sciuri GVGS2 strain isolated from cattle. The JRA307 mecC gene was classified as a mecC allotype of S. sciuri rather than that of Staphylococcus aureus.Conclusions: We demonstrated the complete genome sequence of equine isolate JRA307, which is a clinically relevant MRSA harbouring mecA and mecC on SCCmec-307. The finding of mecC MRSA suggests a possible SCCmec transmission between distinct staphylococcal species. To the best of our knowledge, this is the first report of mecC detection in Japan. [ABSTRACT FROM AUTHOR]

Aims: Given the significance of Salmonella enterica in both human and animal health, and a recent global dissemination of Salmonella 4,[5],12:i:‐, changes in the prevalent serovars and antimicrobial resistance in clinical isolates of Salmonella from cattle and pigs were investigated in Japan. Methods and Results: The serovars and antimicrobial susceptibilities of 1605 Salmonella enterica isolated from cattle (n = 894) and swine (n = 711) between 2002 and 2016 were examined. The most common serovar among all samples was Salmonella Typhimurium. However, its monophasic variant with antigenic structure S. 4,[5],12:i:‐, which was first detected in cattle in 2006 and swine in 2010, has been rapidly increasing in incidence and resistance. Resistance rates to cefotaxime and ciprofloxacin were generally low (<10% in the cattle isolates and <5% in the swine isolates); however, isolates resistant to more than five antimicrobials, which often include these antimicrobials, were recently detected in Salmonella Dublin, S. 4,[5],12:i:‐, S. Typhimurium, Salmonella Newport, Salmonella Choleraesuis and Salmonella 6,7:c:‐. Among them, two S. 4,[5],12:i:‐ isolates possessed extended‐spectrum β‐lactamase‐encoding genes; blaSHV‐12 or blaCTX‐M‐55, respectively, while all the five S. Typhimurium isolates possessed AmpC‐type β‐lactamase gene of blaCMY‐2. Conclusions: S. 4,[5],12:i:‐ has been rapidly increasing and exhibiting a remarkable change in antimicrobial resistance in Japan. Considering certain serovars are characterized by multidrug resistance including medically important antimicrobials, continuous monitoring and appropriate measures are required to protect public health and veterinary husbandry. Significance and Impact of the Study: This study presents a trend in the serovars and antimicrobial resistance in clinical isolates of Salmonella from cattle and pigs in Japan, and showed that there were certain types of Salmonella serovars depending on the animal origin which needs more attention. [ABSTRACT FROM AUTHOR]

An epidemiological analysis was conducted on production records in Hokkaido, Japan, to investigate the potential association between improved milk quality and longevity outcomes. The study found significant variations in herd somatic cell count levels and chronic subclinical mastitis morbidity based on geographical area and herd size. The analysis also revealed a positive correlation between herd somatic cell count and chronic subclinical mastitis morbidity. Although the hypothesis of a causal link between milk quality and longevity was examined, no such association was found. However, intensive assistance for identified high-risk areas and farms is expected to enhance overall milk quality.