Prevalence of polycystic kidney disease in Persian and Persian-related cats in western Mexico.

OBJECTIVES: Autosomal dominant polycystic kidney disease (ADPKD), the most frequently diagnosed hereditary disease affecting Persian cats, is caused by a cytosine-to-adenine transversion (10063C>A) in PKD1, the gene that codes for polycystin-1. The objective of this study was to provide a preliminary estimate of the frequency of the pathogenic 10063C>A single nucleotide polymorphism (SNP) of PKD1 in Persian and Persian-related cat breeds in western Mexico. METHODS: Blood samples were collected from 104 cats (89 Persian, seven Persian crossbreed, five Siamese and three Himalayan cats). Genotyping was performed with our proposed PCR restriction fragment length polymorphism (RFLP) assay, as well as a previously established PCR-RFLP method for validation. The genotypes of control cats were corroborated by a commercial veterinary genetics laboratory. RESULTS: Our proposed PCR-RFLP assay and the validated PCR-RFLP methodology indicated that 24/104 (23.1%) cats in this study were heterozygous carriers of the 10063C>A SNP, including 23/89 Persian cats (25.8%) and 1/7 Persian crossbreed cats (14.3%). No Siamese or Himalayan cats were carriers. There were no discrepancies between the results obtained with our proposed assay and those obtained with the validation method or with commercial laboratory results. CONCLUSIONS AND RELEVANCE: The carrier frequency of the PKD1 10063C>A SNP in Persian and Persian-related cat breeds in western Mexico was found to be 23.1%. ADPKD frequencies among cat populations in Mexico have not been published previously. Genotyping assays can be used to facilitate the selection of breeding stocks by local breeders and veterinarians to avoid propagation of ADPKD.

Carrier frequency of autosomal recessive disorders (BC, BLAD, FXID and CVM) in Holstein cows in Jalisco, Mexico

The hereditary autosomal recessive disorders bovine citrullinemia (BC), bovine leukocyte adhesion deficiency (BLAD), factor XI deficiency (FXID), and complex vertebral malformation (CVM) have affected dairy cattle breeding significantly around the world. This study examined the carrier frequency of BC, BLAD, FXID, and CVM autosomal recessive disorders in Bos taurus Holstein cows bred in the Altos Norte region of the state of Jalisco, Mexico. We extracted DNA from 408 random samples of peripheral blood, and then used polymerase chain reaction (PCR) to identify insertion mutations for FXID, and PCR with restriction fragment length polymorphism (PCR-RFLP) for CVM, BC and BLAD. We visualized the PCR products using agarose gel electrophoresis stained with GelRed®. We found that 100% of wild-type (N/N) allele homozygous animals for genes CD18, ASS, and FXI were free of the mutations for BLAD, BC and FXID respectively. For gene SLC35A3 we estimated total carrier frequency of 10.3% and allele frequency of 5%.(AU)

Frequency of canine degenerative myelopathy SOD1:c.118G>A mutation in 22 dog breeds in Guadalajara, Mexico / Frecuencia de la mutación SOD1:c.118G>A de mielopatía degenerativa canina en 22 razas de perros en Guadalajara, México / Frequência da mutação SOD1: c.118G>A de mielopatía degenerativa canina em 22 raças de cães no Guadalajara, México

Abstract Background: Canine degenerative myelopathy (DM) is a late-onset disease that primarily affects large-breed dogs. The disease involves the spinal cord and produces progressive paresia and, eventually, complete loss of mobility. DM has been related to missense mutation c.118G>A in the SOD1 gene. Objective: To determine the genotypic and genic frequencies of DM in Mexico. Methods: In total, 330 samples from 22 different dog breeds were genotyped using the polymerase chain reaction and restriction fragment length polymorphisms (PCR-RFLP) technique. Results: The mutation was identified in 71 animals from 11 different breeds. Observed genic frequencies were 0.78 for the G allele and 0.14 for the A allele. Genotypic frequencies were 0.79 for the G/G wild-type, 0.14 for the G/A heterozygote, and 0.7 for the A/A homozygote. Conclusion: The genic frequency of this allele is high among the studied populations. A molecular marker program that identifies the DM mutation in breeding dogs should be implemented in order to reduce this frequency.

Resumen Antecedentes: La mielopatía degenerativa canina (MD) es una enfermedad progresiva de presentación tardía que afecta a la médula espinal, generalmente en caninos de razas grandes, y que produce paresis progresiva y eventual pérdida completa de la movilidad. Se ha relacionado con una mutación puntual por sustitución de bases en el gen SOD1 recientemente identificado como c.118G>A. Objetivo: Determinar las frecuencias genotípicas y génicas para la presentación de DM en México. Métodos: Se genotipificaron 330 muestras de perros de 22 razas mediante la técnica de reacción en cadena de la polimerasa y polimorfismos de longitud de fragmentos de restricción (PCR- RFLPs). Resultados: Se identificó la mutación en 71 animales de 11 razas diferentes. Las frecuencias génicas encontradas fueron de 0,78 para el alelo G y de 0,14 para el alelo A. Las frecuencias genotípicas fueron de 0,79 para el tipo silvestre G/G, 0,14 para el heterocigoto G/A y 0,7 para el homocigoto A/A. Conclusión: La frecuencia encontrada para la mutación es alta en las poblaciones estudiadas. La aplicación de un programa de selección asistida por marcadores moleculares contra la mutación causante de MDC en perros reproductores resultaría útil para reducir su frecuencia.

Resumo Antecedentes: A mielopatía degenerativa canina (MD) é uma doença progressiva de apresentação tardia que afeta a medula espinal geralmente de caninos de raças grandes e que produz paresia progressiva e eventualmente a perda completa da mobilidade. Tem sido relacionada com uma mutação pontual por substituição de bases no gen SOD1, recentemente identificado como c.118G>A. Objetivo: Determinar as frequências genotípicas e genéticas para a apresentação de DM no México. Métodos: Genotipagem de 330 amostras de cães de 22 raças por meio da técnica de reação em cadeia da polimerase e polimorfismos no comprimento de fragmentos de restrição (PCR- RFLPs). Resultados: A mutação foi identificada em 71 animais de 11 raças diferentes. As frequências gênicas encontradas foram de 0,78 para o alelo G e de 0,14 para o alelo A. As frequências genotípicas foram de 0,79 para o tipo silvestre G/G, 0,14 para o heterozigoto G/A e 0,7 para o homozigoto A/A. Conclusão: A frequência encontrada para a mutação é alta nas populações estudadas. A implementação de um programa de seleção assistida por marcadores moleculares contra a mutação que causa MDC seria útil para reduzir a sua frequência.

Frequency of Salmonella and Listeria monocytogenes in five commercial brands of chicken eggs using a combined method of enrichment and nested-PCR.

Eggs or egg-based foods, either raw or undercooked, have been identified as vehicles of Salmonella outbreaks. The low numbers of Salmonella organisms in eggs makes it difficult to detect them in frequency studies. The nested-PCR (n-PCR) technique shows more sensitivity and specificity than bacteriological culture methods (BCMs). A preenrichment method followed by enrichment and n-PCR is a good alternative for the investigation of Salmonella and Listeria monocytogenes in eggs. A total of 2,650 chicken eggs representing five commercial brands were purchased from 10 grocery stores. Ten eggs of each brand were combined in order to obtain 265 pooled samples (53 per brand). The shells and yolks of 100 pooled samples were analyzed for Salmonella, while the shells of 65 pooled samples were analyzed for L. monocytogenes, using BCM and a combined method of enrichment and n-PCR (CM-n-PCR). Sixteen eggshell pooled samples tested positive for Salmonella by CM-n-PCR, compared with only two by BCM. Three egg yolk pooled samples tested positive for this pathogen by CM-n-PCR; none tested positive by BCM. Three eggshell pooled samples tested positive for L. monocytogenes by CM-n-PCR and none by BCM. In Mexico, as in other countries, official methods for detection of Salmonella and L. monocytogenes in foods are based on standard bacteriological culture techniques. The inclusion of more sensitive methods such as the one used in the present investigation would increase the probability of detecting positive samples, particularly in those foods in which a very low number of cells is expected.