ABSTRACT
Brucellosis in rams is caused by Brucella ovis or Brucella melitensis and it is considered one of the most important infectious diseases of males in sheep-raising countries. Molecular characterization of Brucella spp. achieved by multi-locus variable number of tandem repeats analysis (MLVA) is a powerful tool to genotype Brucella spp. However, data regarding B. ovis genotyping is scarce. Thus, the aim of this study was to characterize the molecular diversity of B. ovis field-strains in Argentina. A total of 115 isolates of B. ovis from Argentina and Uruguay were genotyped using MLVA-16 and analyzed altogether with 14 publicly available B. ovis genotypes from Brazil. The Discriminatory Power (D) was 0.996 for MLVA-16 and 0.0998 for MLVA-8 and MLVA-11. Analysis of MLVA-16 revealed 100 different genotypes, all of them novel, including 90 unique ones. There was no correlation between geographical distribution and genotype and results showed a higher diversity within provinces than between provinces. Clustering analysis of the strains from Argentina, Uruguay and Brazil revealed that the 129 isolates were grouped into two clades. Whole Genome Sequencing analysis of the 19 B. ovis genomes available in public databases, and including some of the Argentinian strains used in this study, revealed clustering of the Argentinian isolates and closer relationship with B. ovis from New Zealand and Australia. This work adds new data to the poorly understood distribution map of genotypes regionally and worldwide for B. ovis and it constitutes the largest study of B. ovis molecular genotyping until now.
Subject(s)
Brucella ovis/genetics , Brucellosis/microbiology , Brucellosis/veterinary , Genetic Variation , Genotype , Animals , Argentina , Bacterial Typing Techniques , Brucella ovis/classification , Farms , Genome, Bacterial , Male , Multilocus Sequence Typing , Phylogeny , Sheep/microbiology , Uruguay , Whole Genome SequencingABSTRACT
La campilobacteriosis genital bovina es una enfermedad reproductiva que afecta la producción bovina. Es causada por las subespecies de Campylobacter fetus, C. fetus fetus (Cff) y C. fetus venerealis (Cfv). El objetivo de este estudio fue identificar la presencia de C. fetus en fluidos genitales mediante cultivo bacteriológico e inmunofluorescencia directa (IFD) y comparar los resultados. Se conformaron 2 grupos de 6 vaquillonas y 5 toros cada uno. Uno se infectó con Cff (grupo Cff) y el otro con Cfv (grupo Cfv). Dos vaquillonas y 2 toros sin infectar conformaron el grupo control. Periódicamente se tomaron muestras de mucus cervicovaginal y fluido prepucial, las que se procesaron por cultivo e IFD. En el grupo Cff se infectó el 100 % de las vaquillonas y el 80 % de los toros, mientras que en el grupo Cfv se infectó el 50 y el 60 %, respectivamente. Los valores de concordancia (Kappa) obtenidos al comparar las técnicas diagnósticas fueron de 0,57 para las vaquillonas del grupo Cff y 0,52 para las del grupo Cfv, y para los toros fueron de 0,17 y 0,27, respectivamente. En las vaquillonas, la IFD arrojó más resultados positivos que el cultivo, un 5,6 % más para el grupo Cff y un 7,4 % más para el grupo Cfv. El menor porcentaje de resultados positivos por IFD en los toros, un 40 % menos que por cultivo para el grupo Cff y un 5,3 % menos para el grupo Cfv, podría deberse a un muestreo incorrecto. Los valores de Kappa indican una concordancia moderada en las vaquillonas y baja en los toros.
Bovine genital campylobacteriosis is a reproductive disease that affects cattle production. It is caused by Campylobacter fetus subspecies, C. fetus fetus (Cff) and C. fetus venerealis (Cfv). The aim of this study was to identify the presence of C. fetus in genital fluids by bacteriological culture and direct immunofluorescence (DIF) and to compare the results. Two groups of 6 heifers and 5 bulls, one infected with Cff (Cff group) and the other with Cfv (Cfv group) were formed. Two heifers and 2 bulls, all of them uninfected, made up the control group. Samples of cervicovaginal mucus and preputial fluid were processed by culture and DIF. In the Cff group, 100 % of the heifers and 80 % of the bulls were infected, while in the Cfv group, 50 % of the heifers and 60 % of the bulls were infected. The degree of agreement (Kappa values) from benchmarking diagnostic techniques were 0.57 for heifers in the Cff group and 0.52 for heifers in the Cfv group, whereas the values for bulls were 0.17 and 0.27, respectively. Heifers yielded more positive results in the DIF assay than in the culture, exhibiting 5.6 % increase in the Cff group and 7.4 % in the Cfv group. The lowest percentage of positive results for DIF in bulls, 40 % less for the Cff group and 5.2 % for the Cfv group, could be due to improper sampling. Kappa values showed moderate agreement for the heifers and low for the bulls.
Subject(s)
Animals , Campylobacter fetus/isolation & purification , Campylobacter Infections/veterinary , Cattle Diseases/prevention & control , Campylobacter fetus/growth & development , Campylobacter Infections/prevention & control , Bacteriological Techniques/methods , Fluorescent Antibody Technique, Direct/methodsABSTRACT
Bovine genital campylobacteriosis is a reproductive disease that affects cattle production. It is caused by Campylobacter fetus subspecies, C. fetus fetus (Cff) and C. fetus venerealis (Cfv). The aim of this study was to identify the presence of C. fetus in genital fluids by bacteriological culture and direct immunofluorescence (DIF) and to compare the results. Two groups of 6 heifers and 5 bulls, one infected with Cff (Cff group) and the other with Cfv (Cfv group) were formed. Two heifers and 2 bulls, all of them uninfected, made up the control group. Samples of cervicovaginal mucus and preputial fluid were processed by culture and DIF. In the Cff group, 100% of the heifers and 80% of the bulls were infected, while in the Cfv group, 50% of the heifers and 60% of the bulls were infected. The degree of agreement (Kappa values) from benchmarking diagnostic techniques were 0.57 for heifers in the Cff group and 0.52 for heifers in the Cfv group, whereas the values for bulls were 0.17 and 0.27, respectively. Heifers yielded more positive results in the DIF assay than in the culture, exhibiting 5.6% increase in the Cff group and 7.4% in the Cfv group. The lowest percentage of positive results for DIF in bulls, 40% less for the Cff group and 5.2% for the Cfv group, could be due to improper sampling. Kappa values showed moderate agreement for the heifers and low for the bulls.
