Organ distribution and early pathogenesis of Streptococcus equi subsp. zooepidemicus in swine.

Streptococcus equi subsp. zooepidemicus is an emerging pathogen of pigs, resulting in high-mortality outbreaks of septicaemia and abortions. Here, we investigated the early pathogenesis of S. zooepidemicus in pigs following oronasal inoculation. Fourteen pigs were inoculated with live cultures of S. zooepidemicus ST-194, and monitored at 2,4, 8, and 24 h post-inoculation. Necropsies were performed to assess gross lesions and collect samples for bacterial culture and PCR analysis at each time point. Our findings revealed that S. zooepidemicus was detectable in various organs as early as 2 h post-inoculation, including liver and spleen, demonstrating rapid dissemination within the host. Tonsil samples consistently harboured live S. zooepidemicus throughout the study period, suggesting their potential for epidemiological sampling and diagnostics. Moreover, the presence of varying bacterial loads in mesenteric lymph nodes indicated persistence, replication, and a potential source for shedding. Further studies are required to determine the initial site of replication.

Association between anti-Müllerian hormone levels and reproductive parameters in Wagyu cattle raised in Brazil.

The production of in vitro embryos has sped up the dissemination of superior genetic material. However, the variation among the cattle response to oocyte and embryo production is a challenging factor. This variation is even higher in the Wagyu cattle as the breed has a small effective population size. The identification of an effective marker related to reproductive efficiency would allow the selection of more responsive females to reproductive protocols. The objective of this study was to evaluate the blood levels of anti-Müllerian hormone and associate it with oocyte recovery and blastocyst rate of embryos produced in vitro in Wagyu cows, as well as observe the hormone circulating levels in males. Serum samples from 29 females with seven follicular aspirations and four bulls were used. AMH measurements were performed using the bovine AMH ELISA kit. A positive correlation was identified between oocyte production and blastocyst rate (r = 0.84, P = 9 × 10-9), and AMH levels with oocyte (r = 0.49, P = 0.006) and embryo (r = 0.39, P = 0.03) production. The mean levels of AMH were different between animals with low (11.06 ± 3.01) and high (20.75 ± 4.46) oocyte production (P = 0.01). Males showed high serological levels of AMH (3829 ± 2328 pg/ml) compared with other breeds. It is possible to use the serological measurement of AMH as a method to select Wagyu females with greater capacity for oocyte and embryo production. Further studies correlating AMH serological levels with Sertoli cell function in bulls are needed.

Streptococcus canis prevalence on the normal and abnormal ocular surface of dogs referred for ophthalmic disease in Canada.

Streptococcus canis is a beta-haemolytic, Gram-positive cocci commonly identified on the canine ocular surface under both healthy and diseased conditions. The objective of the study was to determine the prevalence of S. canis on the normal and abnormal ocular surface of a canine ophthalmology referral population in Canada, and to investigate potential clinical aspects that may be associated with its presence. Included were 59 dogs (118 eyes) with unilateral or bilateral ocular disease diagnosed at the time of conjunctival sampling. A real-time PCR specific for S. canis was standardized for use with conjunctival swabs. Total DNA was extracted from 118 samples and used as template for the diagnostic assay. Samples were considered positive if amplification was detected and dissociation temperature matched a positive control. Signalment and other clinical data were also collected at the time of sampling. Of the 118 eyes sampled, 8 tested positive for S. canis (6.8%). No association between the detection of S. canis and breed, cephalic conformation, sex, age, use of ophthalmic antibiotics or other topical medications, ophthalmic diagnosis, use of systemic antibiotics or other systemic medications, or systemic diagnosis was identified. In conclusion, S. canis may be present on the ocular surface of dogs at a higher rate than previously reported. It is suggested that this may be linked to the use of PCR for pathogen detection instead of culture.

From Mendel laws to whole genetic association study to decipher the swine mulefoot phenotype.

The swine mulefoot (SM) is a rare condition characterized by a non-cloven hoof due to the partial or total fusion of the phalanges. No comprehensive study has been conducted to identify associated markers with this phenotype until now. We aimed to characterize the association between SNP and the mulefoot phenotype using a Genome-Wide Association Study (GWAS). An experimental population was produced using a half-sib mating where the male had the mulefoot phenotype and the females (n = 6) had cloven hoofs. The cross resulted in 27 (47%) animals with the mulefoot characteristic and 30 (53%) normal animals, indicating the possible dominant gene action. Animals were further genotyped using the Illumina PorcineSNP50k BeadChip, and SNPs were tested for associations. Twenty-nine SNPs located on the SSC15, SSC4, and SSCX were associated with the mulefoot phenotype (p-value <5 × 10-5). Six markers were found in the intronic regions of VWC2L, CATIP, PDK3, PCYT1B, and POLA1 genes. The marker rs81277626, on SSC15:116,886,110 bp, is located in the Von Willebrand Factor C Domain (VWC2L), a possible functional candidate gene. The VWC2L is part of a biological process involved with the bone morphogenetic protein (BMP) signaling pathway, previously associated with syndactyly in other species. In conclusion, the identified markers suggest the involvement of the VWC2L gene in the SM phenotype in this population.

A rare case of heteropaternal twin calves after natural mating in Brazil.

Twin birth is a complex condition observed in most livestock animals, when the female gives birth to two or more offspring, generally out of the same mating. In cattle, it is a rare condition (3 to 5%) and depends on the genetic background and environmental factors. Twin birth is a result of multiple ovulations, being more common in dairy rather than in beef cattle. Calves could be monozygous or dizygous, with the same or of different sexes. When twins are born with different sexes, a sexual condition called Freemartinism occurs in between 90 to 97% of pregnancies, causing infertility in the female calf. Knowing that the twin rate is rare in commercial beef cattle, here we present an even rarer case of twin birth from two different sires after natural mating, also called heteropaternal superfecundation.

Study of vaginal microbiota of Holstein cows submitted to an estrus synchronization protocol with the use of intravaginal progesterone device.

The characterization of vaginal microbiota will help to understand some of the reproductive problems and mechanisms to improve cattle reproduction. The objective of this study was to characterize the vaginal microbiota of cyclical Holstein cows with different parturition orders using 16S rDNA sequencing. Animals were submitted to an estrus synchronization protocol with the use of intravaginal progesterone (P4) implants and were treated or not with ceftiofur hydrochloride. DNA samples were extracted from vaginal swabs on day 0 and 10 of the synchronization, and sequenced with the Illumina MiSeq platform with an average coverage rate of 10.000 reads per samples using a Single-End library for fragments of 300 bp. The main bacterial phyla found in the vaginal tract of Holstein cows, were Firmicutes (37.61%), Tenericutes (29.45%), Proteobacteria (17.47%) and Bacteriodetes (13.73%), followed by Actinobacteria (0.82%) and Spirochaetae (0.45%). The use of intravaginal P4 devices has increased the relative abundance of the genera Family XIII AD3011 and Family XIII unclassified (p < .049). We have also observed an effect of the number of calving on the vaginal microbiota composition, showing that multiparous cows have a greater bacterial diversity than primiparous animals (p < .05). The use of ceftiofur hydrochloride was effective to reduce the vaginal bacteria proliferation. This study describes for the first time the vaginal microbiota of cows synchronized with intravaginal progesterone devices, different from the traditional methods such as microbiological culture and biochemical tests. We have identified a large number of microorganisms commonly found in the gastrointestinal tract of cows, colonizing the vaginal microbiota.