Association of Mycoplasma canis with Fertility Disorders in Dogs: A Case Study Supported by Clinical Examination, PCR, 16S Microbiota Profiling, and Serology.

The role of Mycoplasma canis in canine fertility disorders is still poorly understood. As infection is often asymptomatic, there is an increasing need for appropriate diagnostic methods and treatment plans that would allow the reliable detection of M. canis infection and rapid alleviation of infection symptoms in affected dogs. In this study, we included 14 dogs with fertility problems and 16 dogs without fertility disorder signs. We compared clinical examination data and selected laboratory parameters (hematology and biochemistry) between the groups. We performed PCR-based detection of M. canis and 16S rRNA gene-based microbiota profiling of DNA isolated from vaginal and preputial swabs. Dog sera were tested for the presence of M. canis-specific antibodies. Hematological and selected biochemical parameters showed no differences between groups. PCR-based detection of M. canis in the samples was consistent with the results of 16S microbiota profiling. Several other bacterial taxa were also identified that could potentially be involved in different fertility disorders. Serological methods were not accurate enough since high cross-reactivity rates were observed. In the future, more accurate and efficient methods will be needed to determine the role of M. canis and its true role in the pathogenesis of specific fertility disorders in dogs.

Basic Exploratory Study of Bisphenol A (BPA) Dietary Administration to Istrian Pramenka Rams and Male Toxicity Investigation.

Bisphenol A (BPA), an endocrine-disrupting chemical and environmental pollutant, has been reported by many researchers to induce male reproductive toxicity in different experimental models. In this study, we investigated whether long-term exposure for two months to 25 µg/kg body weight (low dose) of BPA affects spermatogenesis or sperm quality in young Istrian Pramenka rams exposed via diet. We evaluated body and testicular weights, histopathology of testes and epididymides, and sperm analyses, and compared these parameters between the group of treated rams and the control group of rams. Although there were some differences between the two groups, these differences were not large or statistically significant. The only statistically significant difference was the lower epithelial height of seminiferous tubules in treated rams, compared to control rams. In addition to assessing toxicity, BPA concentrations in the blood plasma of treated rams were determined after the first administration, and the toxicokinetic parameters of total BPA were calculated. In this study, no major signs of altered reproduction in rams were detected.

A de novo variant in OTX2 in a lamb with otocephaly.

BACKGROUND: Otocephaly is a rare lethal malformation of the first branchial arch. While the knowledge on the causes of otocephaly in animals is limited, different syndromic forms in man are associated with variants of the PRRX1 and OTX2 genes. CASE PRESENTATION: A stillborn male lamb of the Istrian Pramenka sheep breed showed several congenital craniofacial anomalies including microstomia, agnathia, aglossia, and synotia. In addition, the lamb had a cleft palate, a small opening in the ventral neck region, a cystic oesophagus and two hepatic cysts. The brain was normally developed despite the deformed shape of the head. Taken together the findings led to a diagnosis of otocephaly. Whole-genome sequencing was performed from DNA of the affected lamb and both parents revealing a heterozygous single nucleotide variant in the OTX2 gene (Chr7: 71478714G > A). The variant was absent in both parents and therefore due to a de novo mutation event. It was a nonsense variant, XM_015097088.2:c.265C > T; which leads to an early premature stop codon and is predicted to truncate more than 70% of the OTX2 open reading frame (p.Arg89*). CONCLUSIONS: The genetic findings were consistent with the diagnosis of the otocephaly and provide strong evidence that the identified loss-of-function variant is pathogenic due to OTX2 haploinsufficiency. The benefits of trio-based whole-genome sequencing as an emerging tool in veterinary pathology to confirm diagnosis are highlighted.

Dialysis of the goat semen and its effect on the quality of frozen/thawed spermatozoa processed in the presence of egg yolk.

The aim of the present study was to analyze the effect of dialysis on the quality of frozen/thawed buck semen. Ejaculates (n = 15) from three Saanen bucks were divided into three experimental groups. Semen in Group Ce (centrifugation) was processed by standard method and washed two times at 1.085 × g for 20 min. During this time, the diluted control semen (Co) was stored at room temperature. Semen in Group D was dialyzed using 300 kDa cut-off semi-permeable cellulose tubing. The semen from all groups was diluted with extender containing 20% egg yolk and frozen in liquid nitrogen vapor. After thawing, semen samples were evaluated by microscopic and biochemical analyses. Phospholipase A2 was in amounts that was 72.0 ± 11.7% less after dialysis and 21.3 ± 10.0% less after washing with centrifugation compared to the control semen (P < 0.05). Spermatozoa from Group Co had a lesser motility and viability and greater percentage of morphological abnormal spermatozoa in comparison to Groups D and Ce at 3 h after thawing and incubation on 37 °C. At the same time motility and percentage of HOST positive spermatozoa were greater in Group Ce compared with D (P < 0.05). There, however, was no difference in morphology and viability (CFDA/PI analysis) of spermatozoa between Ce and D group. Results from the present study suggest the dialysis is the promising alternative method for reducing phospholipase A2 in the buck semen before cryopreservation.