Ability of Staphylococcus aureus coagulase genotypes to resist neutrophil bactericidal activity and phagocytosis

Frank Møller Aarestrup, N. L. Scott, L. M. Sordillo

Research output: Contribution to journalJournal articleResearchpeer-review


This study investigated the functional capabilities of neutrophils against different Staphylococcus aureus genotypes isolated from cows with mastitis. Six strains of S. aureus were chosen for use in the study, two with a common genotype, two with an intermediate genotype, and two with a rare genotype. The interaction between bacteria and neutrophils was measured by phagocytosis and bactericidal effect. The average percent killing of bacteria was lowest (40.0%) with strains belonging to the most common genotype, medium (50%) with strains belonging to the intermediate type, and highest (64.2%) with strains belonging to the rare type (P less than or equal to 0.001). Statistically significant differences (P less than or equal to 0.001) in the numbers of phagocytized bacteria were also found between the most prevalent type (6.27 bacteria per cell) and the other two types (intermediate type, 9.26/cell; rare type, 10.5/cell). These findings suggest that one of the reasons for the variation in prevalence of different genotypes of S. aureus in the mammary gland is due to the superior ability of some types to resist phagocytosis and/or killing by bovine neutrophils
Original languageEnglish
JournalInfection and Immunity
Issue number12
Pages (from-to)5679-5682
Publication statusPublished - 1994

Cite this