Mammary infection with <i>Staphylococcus aureus</i> in cows: progress 
from inoculation to chronic infection and its detection

Shoshani, E.; Leitner, Gabriel; Hanochi, Boaz; Saran, A.; Shpigel, Nahum Y.; Berman, A.

doi:10.1017/s002202990000412x

Cited by 35 publications

(22 citation statements)

References 33 publications

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“…This result was similar to the report of Rivas et al [27], who observed increases of CD4 cells in the mammary gland in an experimental study using cows with S. aureus infection. A significant increase in CD8 cells in milk from cows with S. aureus mastitis was found compared with blood in our study, and this finding was consistent with previous findings [26,30] that CD8 cells were the main subpopulation of lymphocytes in quarters from cows inoculated with S. aureus. The extent of CD8 cells in milk was not consistent and varied dependent on the time after infection, and the cells in milk were increased at 9-14 days post-inoculation [27].…”

Section: Discussionsupporting

confidence: 93%

Altered Leukocyte Responsiveness in Dairy Cows with Naturally Occurring Chronic Staphylococcus aureus Mastitis

et al. 2011

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ABSTRACT. Changes in inflammatory parameters, leukocyte surface markers, functional responses and cytokine mRNA expression of leukocytes of dairy cows with naturally occurring chronic Staphylococcus aureus (S. aureus) mastitis and healthy cows were determined to elucidate the leukocyte responses to S. aureus infection of the mammary gland. Increased values in inflammatory parameters and matrix metalloproteinase activities in milk revealed the characteristics of cows with chronic mastitis. Expression of L-selectin and CD18 molecules on neutrophils and proportion of CD8 cells in milk from cows with S. aureus mastitis were significantly (P<0.05) increased compared with those found in healthy cows. The FcR-stimulated CL response of blood neutrophils was significantly (P<0.05) decreased in cows with S. aureus mastitis. Significantly (P<0.05) decreased mitogenic responses of lymphocytes were found in cows with S. aureus mastitis; however, the values were not restored to those of healthy cows when stimulated with both mitogens and the cytokine IL-1. The mRNA expression of TNF-, IL-1 and IL-8 on milk leukocytes from cows with S. aureus was found to be increased compared with that of healthy cows. The changes of immune responses found in cows with S. aureus mastitis appear to be influenced by the severity and duration of inflammation in infected quarters. The down-regulation of the leukocyte functions found in cows with S. aureus mastitis appears to be associated with the progress of the chronic stage of S. aureus mastitis.KEY WORDS: inflammatory measures, leukocyte phenotypic marker, leukocyte response, Staphylococcus aureus mastitis.

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Section: Discussionsupporting

confidence: 93%

Altered Leukocyte Responsiveness in Dairy Cows with Naturally Occurring Chronic Staphylococcus aureus Mastitis

et al. 2011

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“…These previous studies focused generally on changes of milk composition during the course of an induced mastitis, the time course of effector-cell appearance in the milk, their functional capabilities, and the expression of soluble immune mediators [3,12,41,43].…”

Section: Discussionmentioning

confidence: 99%

Escherichia coli, but notStaphylococcus aureustriggers an early increased expression of factors contributing to the innate immune defense in the udder of the cow

et al. 2008

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-The outcome of an udder infection is influenced by the pathogen species. We established a strictly defined infection model to better analyze the unknown molecular causes for these pathogen-specific effects, using Escherichia coli and Staphylococcus aureus strains previously asseverated from field cases of mastitis. Inoculation of quarters with 500 CFU of E. coli (n = 4) was performed 6 h, 12 h, and 24 h before culling. All animals showed signs of acute clinical mastitis 12 h after challenge: increased somatic cell count (SCC), decreased milk yield, leukopenia, fever, and udder swelling. Animals inoculated with 10 000 CFU of S. aureus for 24 h (n = 4) showed no or only modest clinical signs of mastitis. However, S. aureus caused clinical signs in animals, inoculated for 72 h-84 h. Real-time PCR proved that E. coli inoculation strongly and significantly upregulated the expression of β-defensins, TLR2 and TLR4 in the pathogen inoculated udder quarters as well as in mammary lymph nodes. TLR3 and TLR6 were not significantly regulated by the infections. Immuno-histochemistry identified mammary epithelial cells as sites for the upregulated TLR2 and β-defensin expression. S. aureus, in contrast, did not significantly regulate the expression of any of these genes during the first 24 h after pathogen inoculation. Only 84 h after inoculation, the expression of β-defensins, but not of TLRs was significantly (> 20 fold) upregulated in five out of six pathogen inoculated quarters. Using the established mastitis model, the data clearly demonstrate a pathogen-dependent difference in the time kinetics of induced pathogen receptors and defense molecules.toll-like receptor / mastitis / beta-defensin / mammary epithelial cell

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“…This may be indicative of the atypical nature of S. aureus Newbould 305 as a representative of S. aureus pathogenic for the udder; further work is therefore needed to fully characterize the Newbould 305 strain. Typically, intramammary S. aureus infections are characterized by high but variable somatic cell counts (11,44), persistence (34,38), variable shedding of bacteria (6,43), and low cure rates (3,9). While S. aureus Newbould 305 is convenient for use in challenge trials, it may not be representative of intramammary S. aureus isolates.…”

Section: Discussionmentioning

confidence: 99%

Multilocus Sequence Typing of Intercontinental BovineStaphylococcus aureusIsolates

et al. 2005

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A total of 258 bovine-associated Staphylococcus aureus isolates from the United States, Chile, and the United Kingdom, plus the reference isolate S. aureus Newbould 305 (NCIMB 702892), were analyzed by multilocus sequence typing (MLST). A collection of previously characterized United Kingdom isolates were also included in the analysis. The results demonstrated that MLST is suitable for the differentiation of bovine S. aureus isolates from various sites (milk, teat skin, milking machine unit liners, hands, and bedding) and countries. The theory of the host specificity of S. aureus is supported by the detection of a previously undescribed clonal complex that comprised 87.4% of the isolates studied, with representatives from all geographic locations investigated. This suggests that a single clonal group has achieved a widespread distribution and is responsible for the majority of infections. Some sequence types (STs; ST25, ST115, ST124, and ST126) demonstrated site specificity, as they were significantly (P < 0.05) associated with milk or teat skin.Staphylococcus aureus is a major cause of bovine mastitis and is spread from cow to cow (skin or milk) via the milking machine (35, 57). Environmental spread may also occur, since strains of S. aureus have been isolated from the environment of dairy farms and from other species that are present on dairy farms (32,39).A number of studies have identified potential sources of the pathogen and have investigated strain-specific differences (19, 40). The major potential sources identified were milk, body sites, and, to a lesser extent, the environment (40). Studies investigating the global population structure of bovine S. aureus suggest that a relatively few specialized clones are responsible for the majority of intramammary infections (IMIs) (26, 55), although some authors did not report between-farm genetic homogeneity (25,46). Most of these studies have used techniques such as phage typing (19, 40) and pulsed-field gel electrophoresis (PFGE) (7, 25) to compare isolates. These methods lack intercenter reproducibility (55). Library typing systems such as binary typing (BT) (53) and multilocus sequence typing (MLST) (31) have been developed to overcome these problems by producing results that are repeatable between laboratories and over time.The aim of this study was to investigate the effectiveness of MLST as a method for the typing of S. aureus isolates of bovine origin from a number of distinct geographical sources. A collection of isolates previously characterized by phage typing (19) and by PFGE and binary typing (55) was used to compare these methods to MLST. The data were then used in a preliminary analysis of the evolutionary and population biology of S. aureus isolates of bovine origin.

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Mammary infection with Staphylococcus aureus in cows: progress from inoculation to chronic infection and its detection

Cited by 35 publications

References 33 publications

Altered Leukocyte Responsiveness in Dairy Cows with Naturally Occurring Chronic Staphylococcus aureus Mastitis

Altered Leukocyte Responsiveness in Dairy Cows with Naturally Occurring Chronic Staphylococcus aureus Mastitis

Escherichia coli, but notStaphylococcus aureustriggers an early increased expression of factors contributing to the innate immune defense in the udder of the cow

Multilocus Sequence Typing of Intercontinental BovineStaphylococcus aureusIsolates

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