Identification and genotyping of porcine circovirus type II (PCV2) in Mexico.

Porcine circovirus type 2 (PCV2), family Circoviridae, genus Circovirus infection in domestic pig has been associated with several pathological conditions being the most important of them the postweaning multisystemic wasting syndrome. Many studies have demonstrated the existence of three PCV2 genotypes (a, b, and c) and recently PCV3. Until now, these genotypes or subgenotypes have not been described in Mexico. We found genetic changes in ORF2 from nine strains of PCV2 obtained from samples of Jalisco, Veracruz, Estado de México, Hidalgo and Sonora states of Mexico. Our results shown the presence of two genotypes (PCV2a and PCV2b) as well as, the presence and differences between the reported subgenotypes. The subgenotype PCV2b (1A/1B, 1A) has a higher prevalence (87.5%) in comparison with PCV2a (2C) (12.5%).

Phylogenetic Analysis and Characterization of the Complete Hepatitis E Virus Genome (Zoonotic Genotype 3) in Swine Samples from Mexico.

Hepatitis E virus (HEV) is an emerging public health problem with an estimated 20 million infections each year. In Mexico, Orthohepevirus A, genotype 2, has been reported in humans, but genotype 3 has only been reported in swine (zoonotic). No diagnostic tests are publicly available in Mexico, and only partial sequences have been reported from swine samples. Hence, research is necessary to determine circulating strains, understand the features and dynamics of infection on pig farms, determine how to implement surveillance programs, and to assess public health risks. In this study, a next-generation sequencing (NGS) approach was applied to obtain a complete genome of swine HEV. Liver, feces, and bile samples were taken at slaughterhouses and a farm in Mexico. RT-PCR was used to determine positive samples and confirmed by Sanger sequencing. Of the 64 slaughterhouse samples, one bile sample was positive (B1r) (1.56%). Of 21 sample pools from farm animals, 14 were positive (66.66%), representing all stages of production. A complete sequence strain MXCDg3_B1c|_2016 was obtained from the bile of a domestic swine in the fattening stage. In addition, two partial sequences-MXCDg3_H2cons|_2016 (1473 nt) and MXCDg3_C3Acons|_2016 (4777 nt)-were obtained from sampled farm animals. Comparison with all reported genome HEV sequences showed similarity to genotype 3 subgenotype a (G3a), which has been previously reported in acute cases of human hepatitis in the US, Colombia, China, and Japan.

Effects of administration of caffeine on metabolic variables in neonatal pigs with peripartum asphyxia.

OBJECTIVE: To determine effects of 2 doses of caffeine on metabolic variables in neonatal pigs with peripartum asphyxia. ANIMALS: 180 neonatal pigs. PROCEDURES: Neonatal pigs were assigned to 2 groups (groups P and F) on the basis of results for a vitality scale (passed or failed, respectively). Within each group, there were 3 subgroups of 30 pigs each. Within each group, the 3 subgroups received a placebo that consisted of an empty gelatin capsule, a gelatin capsule that contained 20 mg of caffeine, and a gelatin capsule that contained 35 mg of caffeine, respectively; all capsules were administered orally (0 hours). Blood samples were collected immediately before and 24 hours after capsule administration. RESULTS: Pigs in groups P and F that received 20 or 35 mg of caffeine had significant increases in triglyceride concentrations. All pigs in groups P and F had a significant decrease in lactate concentrations, although the placebo-treated pigs in group F had larger decreases than did the group F pigs treated with 20 or 35 mg of caffeine. Glucose concentrations increased significantly in group F pigs treated with 20 or 35 mg of caffeine (30% and 50%, respectively), whereas glucose concentrations remained unchanged in group P pigs. In pigs treated with 35 mg of caffeine, the final weight obtained for group F was approximately 8% lower than that obtained for group P. CONCLUSIONS AND CLINICAL RELEVANCE: Administering caffeine immediately after birth to neonatal pigs with severe oxygen restriction resulted in significant improvements in metabolic variables.

Obstetric and fetal outcomes in dystocic and eutocic sows to an injection of exogenous oxytocin during farrowing.

Sixty hybrid Yorkshire-Landrace penned sows, 30 with eutocic farrowing and 30 experiencing a dystocic parturition, were studied to evaluate the obstetric and neonatal outcomes to low doses of oxytocin administered at advanced stages of parturition. Animals in each group were randomly subdivided into 2 subgroups: 15 eutocic and 15 dystocic sows received oxytocin 0.083 IU/kg (equivalent to 1 IU/12 kg body weight), administered intramuscularly after the delivery of the 5th piglet; the other 15 eutocic and 15 dystocic sows received saline solution intramuscularly at the same time. Oxytocin decreased the number of intrapartum deaths by approximately 50% (P = 0.002). No piglet was born dead from the saline- and oxytocin-treated eutocic sows. The highest viability score was observed among piglets born to eutocic sows treated with oxytocin. In summary, this dose schedule would help to decrease the number of stillbirths in both eutocic and dystocic farrowing sows.

A study of piglets born by spontaneous parturition under uncontrolled conditions: could this be a naturalistic model for the study of intrapartum asphyxia?

In order to evaluate how spontaneously born piglets could be a suitable model for the study of intrapartum hypoxia, 230 newborn piglets were studied. Out them, 8.3% (n = 19) died intrapartum, 21.7% (n = 50) were born with moderate-to-severe intrapartum hypoxia, and 70% (n = 161) were born with mild or no evidence of intrapartum distress. Piglets born without any evidence of intrapartum asphyxia weighed approximately 240 g lower than those born with intrapartum hypoxia and intrapartum-dead piglets (P<0.0001). The viability score was approximately 3 units lower and the latency to contact the udder was two times longer in the piglets surviving intrapartum hypoxia than in controls (P <0.0001). In comparison with the control group, metabolic acidosis was most severe among intrapartum-dead piglets followed by piglets surviving intrapartum asphyxia (P =0.002). According to a multiple linear regression analysis, pCO2 and lactate blood levels, and birth weight were identified as explanatory variables of viability score (r: 0.78; P <0.001). Viability score, K+ and lactate blood levels, and birth weight were identified as explanatory variables of latency to contact the udder (r: 0.80; P <0.001). In conclusion, the spontaneously-born asphyxiated piglet could be considered as a naturalistic model for the study of intrapartum asphyxia. Histopathologic and more rigorous functional and behavioral evaluations are still required to further characterize the model. (www.actabiomedica.it)

Obstetric and neonatal outcomes to recombinant porcine somatotropin administered in the last third of pregnancy to primiparous sows.

This study aimed to investigate whether the administration of recombinant porcine somatotropin (rpST) late in gestation is associated with increased rates of obstetric and neonatal complications in primiparous sows. From days 80 to 114 of gestational age, 20 primiparous sows were randomly assigned to receive an intramuscular injection of either saline or 6 mg rpST/day. Throughout pregnancy, sows were fed 2.5 to 3 kg/day of a corn-soybean diet (14 MJ ME/kg). Of 111 piglets born to control sows and 109 piglets born to treated sows, 8.1% and 17.4% piglets respectively died intrapartum (P=0.04). Glucose blood levels in sows and live-born piglets in the rpST-treated group were significantly higher than in their corresponding controls. Birth weight of live-born piglets in the treated group was 1.4 +/- 0.1 kg versus 1.3 +/- 0.1 kg in the control group (P<0.0001). Birth weight of piglets born dead was also higher in the former than in the latter group (P<0.0001). No evidence of teratogenicity was observed in either of the groups. In conclusion, rpST administration in late pregnancy to primparous sows increased the rate of neonatal deaths and was associated with higher blood glucose levels in both sows and piglets.