The distribution of virulence-associated genes in 78 S. uberis strains was determined. PCR analysis detected the hasC gene in 70 (89.7%) of the strains, the most common gene in the examined isolates. The sua gene was found in 65 strains (83.3%), gapC in 62 (79.4%), cfu in 60 (76.9%), hasA in 58 (74.3%), hasB in 52 (66.6%), skc in 51 (65.3%), oppF in 50

(64.1%), pauA in 48 (61.5%) and lbp in nine (11.5%). Evidence of pauB was not found. The capsular genotype hasABC was EX-527 found in 48 (61.5%) strains. Results revealed that not all genes were present in the strains but all of the detected virulence-associated genes were present in combination. Of 78 strains examined, 47 (60.2%) isolates possessed seven to 10 virulence-associated virulence genes. Table 2 provides further details of the numbers involved. Further analysis showed that 58 different virulence patterns (initially named with a capital letter from A to Z, and then with two capital letters to BF) were found in all 78 S. uberis isolates, and 33 (42.3%) strains belonged to the 12 most frequent

patterns. Data regarding these 12 most frequent virulence patterns are summarized in Table 3. Ten virulence-associated genes were present in two (2.5%) strains and belonged to pattern D. The most frequent virulence pattern (E) was cfu+gapC+hasAB+hasC+lbp−oppF+pauA/B+/−skc+sua+ detected in seven (9%) strains. Eight virulence-associated genes were found in 14 (17.9%) strains Tacrolimus price and belonged to patterns B, G, L, N and AN. Seven genes were found in two (2.5%) strains and belonged to pattern Q, and six genes were found in eight (10.2%) strains belonging to patterns P, AH, AT and AX. The remaining 45 strains were grouped in different virulence patterns, where each pattern grouped only one strain. Different virulence patterns were found within the same herd and among herds. However, strains with identical virulence patterns were found in only two herds, and these herds had a high prevalence of S. uberis: strains showing patterns CYTH4 B, E, N and AT were found

in herd IV; strains showing patterns E, G and AX were found in herd VI. A great diversity of different virulence patterns was present in the remaining herds. On the other hand, strains with identical virulence patterns were found in different herds. For example, pattern E was present in herds IV, VI and XII, and pattern AN was present in herds IV, XI and XVI. Molecular identification of 78 S. uberis was performed by RFLP analysis of the 16S rRNA gene. 16S rDNA RFLP analysis has been suggested to be a useful tool for more precise identification of streptococci in bovine milk (Jayarao et al., 1992; Reinoso et al., 2010). We found that all of the S. uberis strains examined harboured at least one virulence-associated gene.