The dynamics of Staphylococcus aureus intramammary infection in nine Danish dairy herds

Larsen, H. J.; Sloth, Karen Helle; Elsberg, C.S.; Enevoldsen, Carsten; Pedersen, Lars Haastrup; Eriksen, N. H. R.; Aarestrup, Frank Møller; Jensen, N. E.

doi:10.1016/s0378-1135(99)00161-3

Cited by 62 publications

(55 citation statements)

References 26 publications

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“…Previous studies investigating the relationships between S. aureus isolated from humans and cows have been consistent in agreeing in general with the theory of host specialization (8,41). However, most authors also demonstrated that some strains of S. aureus were able to infect and/or colonize both humans and cows (30,41).…”

Section: Discussionsupporting

confidence: 56%

“…These differences may be due to the typing schemes used, but it is likely that there is also herd-specific variation due to differences in management. Effective contagious mastitis control may prevent the spread of bacteria from cow to cow, essentially leading to the generation of environmental-style pathogens and reducing the likelihood of eradication (30,56).…”

Section: Discussionmentioning

confidence: 99%

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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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Section: Discussionsupporting

confidence: 56%

Section: Discussionmentioning

confidence: 99%

Multilocus Sequence Typing of Intercontinental BovineStaphylococcus aureusIsolates

et al. 2005

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“…Treatments and immunizations against S. aureus mastitis have been studied for years [8]; however, despite the best possible antimicrobial treatments, bacteriological cure failures are common in S. aureus mastitis, and antimicrobial resistance is considered as one of the reasons for low cure rates [3,9,10,11]. Resistance to various antimicrobials is commonly seen in bovine S. aureus mastitis isolates and the intracellular survival of S. aureus is a significant factor contributing to the difficulty in clearing S. aureus infections following antibiotic therapy [12,13]. Over the years, there have been improvements in reducing contagious mastitis, nevertheless, treatment of S. aureus is quite challenging and a complex interaction between host and pathogen renders the complete eradication of S. aureus especially difficult.…”

Section: Introductionmentioning

confidence: 99%

Effect of Prostaglandin F2ÃÂ± on Growth of Staphylococcus Aureus Associated with Bovine Mastitis

Autran¹

2013

J Veterinar Sci Technol

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Staphylococcus aureus is a major infectious organism causing mastitis. Certain fatty acids have been shown to inhibit the growth of pathogens including Staphylococcus aureus. An in vitro experiment was conducted to determine the effects of prostaglandin F 2α (PGF 2α ) on growth of S. aureus. Flasks containing tryptic soy broth (TSB) were inoculated with S. aureus Novel, and subsequently treated with PGF 2α (dinoprost tromethamine) at concentrations of 0, 0.3, 0.6, 1.2, and 2.4 mg/ml. Cultures were incubated at 37°C for 24 h and sampled every 3 h. The entire experiment was conducted three times in duplicates. Bacterial growth was assessed by counting colony forming units (CFU) in triplicates. Data were analyzed by repeated measures analysis of variance and reduced and full dummy variable regression models to determine the effect of PGF 2α concentrations on growth patterns of S. aureus over time. There was an effect of treatment and treatment by time interaction (P<0.05) on mean log CFU, indicating that bacterial growth over 24 h was different across treatments. At time of inoculation (0 h), mean log CFU values were not different among treatments; however at 24 h, mean log CFU for each PGF 2α treatment was different from control and decreased (P<0.05) with increasing concentrations of PGF 2α . The predicted growth curve for each treatment was different (P<0.05) when compared with the control, and the rate of bacterial growth was less for 1.2 mg/ml PGF 2α when compared with the control and 0.6 mg/ml. The bacterial growth was completely inhibited during the 24 h period in 2.4 mg/ml PGF 2α treatment. Furthermore, a non-linear regression model was employed to estimate the dose response at the 24 h, and revealed that 1.2 mg/ml was the minimum inhibitory dose. These results provide evidence, for the first time, that PGF 2α , in the form of dinoprost tromethamine, has bacteriostatic and bactericidal effects on S. aureus in vitro.

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“…Several studies have shown that different S. aureus types preferentially colonize or infect a single host species (9,17,18,21,28). Epidemiologic studies have suggested that a few S. aureus types are responsible for the majority of bovine intramammary infections and that these types have a broad geographic distribution (7,10,17,33).…”

mentioning

confidence: 99%

Comparison of Staphylococcus aureus Genotypes Recovered from Cases of Bovine, Ovine, and Caprine Mastitis

Mørk¹,

Tollersrud²,

Kvitle³

et al. 2005

J Clin Microbiol

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Staphylococcus aureus is an important pathogen in domestic ruminants. The main objective of this study was to determine the similarity of epidemiologically unrelated S. aureus isolates from bovine, ovine, and caprine mastitis. By pulsed-field gel electrophoresis, 160 different pulsotypes (PTs) were identified among 905 isolates recovered from 588 herds in 12 counties in Norway. Based on estimates of similarity, using an 80% cluster cutoff, the isolates were assigned to 47 clusters. One cluster included 62% of all the isolates and more than 45% of the isolates from each host species. Twenty-three PTs included isolates from more than one host species; these 23 PTs represented 72% of all the isolates. The six most prevalent PTs included isolates from all host species and contained 45% of the bovine isolates, 54% of the ovine isolates, and 37% of the caprine isolates. Antimicrobial susceptibility testing of 373 of the isolates revealed resistance to penicillin in 2.9% and to streptomycin in 2.4%; only 1.9% were resistant to 1 of the other 11 antimicrobials tested. The results of this study suggest that a small number of closely related genotypes are responsible for a great proportion of S. aureus mastitis cases in cows, ewes, and goats in Norway and that these genotypes exhibit little or no host preference among these species. Selection due to antimicrobial resistance appears not to have contributed to the predominance of these genotypes.

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The dynamics of Staphylococcus aureus intramammary infection in nine Danish dairy herds

Cited by 62 publications

References 26 publications

Multilocus Sequence Typing of Intercontinental BovineStaphylococcus aureusIsolates

Multilocus Sequence Typing of Intercontinental BovineStaphylococcus aureusIsolates

Effect of Prostaglandin F2ÃÂ± on Growth of Staphylococcus Aureus Associated with Bovine Mastitis

Comparison of Staphylococcus aureus Genotypes Recovered from Cases of Bovine, Ovine, and Caprine Mastitis

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The dynamics of Staphylococcus aureus intramammary infection in nine Danish dairy herds

Cited by 62 publications

References 26 publications

Multilocus Sequence Typing of Intercontinental BovineStaphylococcus aureusIsolates

Multilocus Sequence Typing of Intercontinental BovineStaphylococcus aureusIsolates

Effect of Prostaglandin F2ÃÂ± on Growth of Staphylococcus Aureus Associated with Bovine Mastitis

Comparison of Staphylococcus aureus Genotypes Recovered from Cases of Bovine, Ovine, and Caprine Mastitis

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Effect of Prostaglandin F2ÃÂ± on Growth of Staphylococcus Aureus Associated with Bovine Mastitis