Analysis of biochemical parameters in canine fetal fluids during the second half of pregnancy.

Although fetal fluids, amnion (AM) and allantois (AL), have been studied at the end of pregnancy in the bitch, little is known about their composition during gestation. The aim of this study was to characterize and compare the biochemical parameters of fetal fluids collected from healthy pregnant bitches in mid pregnancy. Fetal fluids were collected from 26 pregnant bitches between 35 and 62 days from ovulation based on ultrasonography. A total of 149 samples were analyzed; 94 samples of known origin (61 a.m. and 33 AL) from 17 dams, which included 17 paired samples (AM and AL from the same fetus; 34 samples), and 55 of unknown origin from nine dams. Reference ranges were formulated for 22 biochemical parameters in AM and AL based on the samples of known origin (n = 94). All parameters (creatinine, albumin, GGT and urea) significantly different between AM and AL were included (by mixed model ANOVA) in the analysis and an algorithm to predict the origin of the fluid was developed (by logistic regression). Overall, of the 94 samples, 79 samples (84%) were correctly identified by the algorithm. For the 33 allantois samples, and for the 61 amnion samples, 23 (69.7%) and 56 (91.8%) were correctly identified by the algorithm, respectively. Based on the algorithm, 31 of the unknown samples (58%) were classified as amnion and 22 samples (42%), as allantois fluid. For all the unknown samples, the average certainty was 86% (compared to 81% for the samples whose fluid type was known), showing the degree of precision of the classification.

Host-specificity of Staphylococcus aureus causing intramammary infections in dairy animals assessed by genotyping and virulence genes.

Staphylococcus aureus is one of the most relevant pathogens causing clinical and subclinical, chronic mastitis in dairy animals. Routinely, mastitis pathogens are isolated and classified to genus or species level, and regarded as single entities. However, S. aureus includes a broad range of genotypes with distinct pathogenic and epidemiologic characteristics. The objective of the present study was to assess the host-specificity of S. aureus causing mastitis in dairy animals, based on phylogenetic and genotypic characterization as well as the presence of virulence and antimicrobial resistance genes in the pathogen genome. S. aureus isolates from mastitis in cows, sheep and goats in Israel, and from cows in Germany, the USA and Italy, were compared by the following methods: a. Bayesian phylogenetic comparison of sequences of genes nuc, coa, lukF and clfA, b. genotyping by spa and agr typing, and assignment to MLST Clonal Complexes (MLST CC), and c. the presence of a broad array of virulence and antimicrobial resistance genes. Overall, phylogenetic, virulence and genotyping approaches agreed with each other. Cow isolates could be differentiated from sheep and goat isolates with all three methods, with different resolution. In two phylogenetic clusters, segregation was found also between cow isolates from Israel and abroad. Sheep and goats' isolates showed less variability than isolates from cows in all methods used. In conclusion, different S. aureus lineages are associated to cows in contrast to goats and sheep, suggesting co-evolution between pathogen and host species. Modern diagnostics approaches should aim to explore molecular data for a better understanding and cost-effective management of mastitis.