Dynamics and Significance of Coagulase-Negative Staphylococcal Intramammary Infections

Abstract

Cows (n = 139) were sampled within 17 d postpartum and monthly thereafter to examine dynamics of mammary infections and relationships between infection status, milk yield, SCC, NAGase activity, and chloride concentration. Forty-eight and 67% of cows and 19.5 and 30.5% of quarters were infected at first test and lactation end, respectively, with 51% of all infections present at first test. Coagulase-negative staphylococci accounted for 67 and 65% of first test and total infections with 85% persisting to lactation end. Animals with coagulase-negative staphylococci infections had significantly elevated quarter SCC and NAGase activity and a decrease of 821 kg mature equivalent lactation milk production compared with uninfected animals. Clinical cases with no bacterial isolation or major pathogen infections were associated with significant elevations in bucket and quarter milk SCC, NAGase activity, chloride concentration in quarters, and a decrease of 1153 kg mature equivalent lactation milk production as compared with uninfected animals. Correlations between milk production and in SCC and ln NAGase and between ln SCC and ln NAGase were -.15, -.25, and .55 (-.23, -.28, and .41 for first lactation only).

Quarter milk somatic cell count in infected dairy cows: a meta-analysis

“…The Fossomatic (Foss-Electric, Hillerød, Denmark) counts the number of cell nuclei which become fluorescent due to ethidiumbromure [21]. Ward and Schultz [48] and Timms and Schultz [45] used a filter-DNA method to measure SCC. This technique consists of filtering a solution of milk mixed with detergent (Triton X-100 EDTA) through a membrane with fine pores.…”

“…In certain studies, this standard technique was modified at certain stages in order to improve the sensitivity of the bacteriological procedure. Consequently, higher inoculum volumes such as 0.025 mL [1,39] or 0.05 mL [45] were streaked. Other culture media specific to certain bacteria were also used (Tab.…”

“…The prevalence of IMI due to Streptococcus dysgalactiae in the selected studies Hogan et al [17] Timms and Schultz [45] Hogan et al [18] Lilius and Pesonen [27] Rainard et al [39] Davidson et al [10] Nickerson and Boddie [33] Schepers et al [40] Woolford et al [ Chaffer et al [8] Detilleux et al [12] Leitner et al [25] Somatic cell count (x 1000 c/mL) Hogan et al [17] Timms and Schultz [45] Hogan et al [18] Lilius and Pesonen [27] Rainard et al [39] Davidson et al [10] Nickerson and Boddie [33] Schepers et al [40] Woolford et al [ Chaffer et al [8] Detilleux et al [12] Leitner et al [25] Somatic cell count (x 1000 c/mL) Sheldrake et al [44] Herd V 3 Sheldrake et al [44] Herd D 3 Sheldrake et al [44] Herd W 3 Figure 1. Geometric mean SCC (᭜) and its 95% CI (-) of bacteriologically negative quarters (SCC in × 1 000 c/mL whatever of the measurement equipment used).…”

“…The prevalence of IMI due to Streptococcus uberis in the selected studies varied between 0.5% [40] Hogan et al [17] Timms and Schultz [45] Lilius and Pesonen [27] Davisdon et al [10] Schepers et al [40] Woolford et al [ Hogan et al [17] Timms and Schultz [45] Lilius and Pesonen [27] Davisdon et al [10] Schepers et al [40] Woolford et al [ Chaffer et al [8] Detilleux et al [12] Leitner et al [25] Figure 2. Geometric mean SCC (᭜) and its 95% CI (-) of quarters in cases of infection by Staphylococcus aureus (SCC in × 1 000 c/mL whatever of the measurement equipment used).…”

“…Geometric mean SCC (᭜) and its 95% CI (-) of quarters in cases of infection by Streptococcus uberis (SCC in × 1 000 c/mL whatever of the measurement equipment used). Hogan et al [17] Timms and Schultz [45] Hogan et al [18] Lilius and Pesonen [27] Somatic cell count (x 1000 c/mL) Hogan et al [17] Timms and Schultz [45] Hogan et al [18] Lilius and Pesonen [27] Somatic cell count (x 1000 c/mL) Figure 6. Geometric mean SCC (᭜) and its 95% CI (-) of quarters in cases of infection by Coliforms (SCC in × 1 000 c/mL whatever of the measurement equipment used).…”