Two strains of Streptococcus uberis, of differing ability to cause clinical mastitis, differ in their ability to resist some host defence factors

Leigh, James A.; Field, Terence R.; Williams, M.R.

doi:10.1016/s0034-5288(18)31052-x

Cited by 46 publications

(41 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is also possible that this strain is more transmissible or has a greater capacity to adhere to the mammary epithelium than the others. Evidence of differing abilities to establish intramammary infection among strains of S. uberis has been reported previously (10,19). We were unable to demonstrate differences in the concentrations of these predominant strains compared to those of the other strains in milk from infected quarters.…”

Section: Discussioncontrasting

confidence: 59%

Molecular Epidemiology of Streptococcus uberis Isolates from Dairy Cows with Mastitis

Phuektes

Mansell

Dyson³

et al. 2001

J Clin Microbiol

124

View full text Add to dashboard Cite

Pulsed-field gel electrophoresis and antimicrobial sensitivity testing were used as tools to investigate the epidemiology of Streptococcus uberis mastitis in dairy cows. A total of 62 different strains were found among 138 isolates from the four herds investigated, and between 10 and 26 different strains were found in each herd. There was no strain common to all four herds. Identical strains of S. uberis were detected from different quarters of individual cows and from cows within the same herd, suggesting that transmission from quarter to quarter and cow to cow had occurred. Despite the great variation in S. uberis strains, persistent infection with the same strain within a lactation was observed in most cows. Predominant strains were present in two herds. Preliminary investigations could not clarify why these particular strains might predominate, but in one herd there was a significant difference between the prevalence of clinical mastitis in quarters infected with the predominant strain and that in quarters infected with other strains, suggesting the greater virulence of the predominant strain. The wide variety of S. uberis strains found is consistent with an environmental source of S. uberis. However, evidence of direct transmission, the persistence of infection, and the predominance of particular strains in some herds indicate that S. uberis infections are epidemiologically complex and that the relative importance of these factors in the occurrence of mastitis may differ between herds.

show abstract

Section: Discussioncontrasting

confidence: 59%

Molecular Epidemiology of Streptococcus uberis Isolates from Dairy Cows with Mastitis

Phuektes

Mansell

Dyson³

et al. 2001

J Clin Microbiol

124

View full text Add to dashboard Cite

show abstract

“…The bactericidal action of bovine neutrophils against various bacteria was determined. In order to compare the data obtained here with those obtained previously, strains of S. uberis were subjected to an assay similar to that used in earlier studies (18,20,26). Briefly, 0.5 ml of a washed bacterial suspension (10 6 CFU/ml) in phosphate-buffered saline (PBS) was mixed with 1.0 ml of a suspension of bovine neutrophils (10 7 cells/ml) and 1.5 ml of aseptically collected bovine skim milk.…”

Section: Methodsmentioning

confidence: 99%

“…The role of phagocytic cells in the control of infection by S. uberis appears less clear (10). However, it was demonstrated that a capsular strain of S. uberis (0140J) was more capable of establishing an infection in the lactating gland than a noncapsular strain (EF20), which was readily eliminated (14,20). Experimental infection of the mammary gland with virulent strains of S. uberis results in the appearance of large numbers of neutrophils in the interstitial tissues and secretion (10,25).…”

mentioning

confidence: 99%

The Hyaluronic Acid Capsule of Streptococcus uberis Is Not Required for the Development of Infection and Clinical Mastitis

Field¹,

Ward²,

Pedersen³

et al. 2003

Infect Immun

View full text Add to dashboard Cite

The frequency at which the genes responsible for capsule biosynthesis occurred in field isolates of Streptococcus uberis was determined. Of the two genotypes detected (hasABC and hasC), the capsular genotype (hasABC) was more common. This genotype was present at a higher frequency in a population isolated from mastitis cases than in a population isolated from cattle bedding. The virulence of a mutant strain of S. uberis (TRF0-6) that lacked the ability to produce a hyaluronic acid capsule due to an insertion within its single copy of hasA ( ) was compared to that of the capsular parental strain (0140J). Strains TRF0-6 and 0140J infected all mammary gland quarters following experimental challenge. The wild type and the mutant induced overt signs of disease in four out of four and in six out of eight mammary gland quarters, respectively. Both the wild type and the hasA mutant were resistant to killing by bovine neutrophils following cultivation in bovine milk. The ability to withstand the bactericidal action of neutrophils following growth in milk was therefore independent of the capsule and coincided with the ability of supernatants from such cultures to prevent the bactericidal action of neutrophils. This investigation revealed that, in the absence of the capsule, S. uberis is able to withstand the bactericidal effect of bovine neutrophils and induce mastitis in dairy cows.

show abstract

“…Streptococcus uberis, one of the major causative organisms, is responsible for 33% of all cases of clinical bovine mastitis (Hillerton et al 1993). The ability of this bacterium to infect the mammary gland is dependent on the ability of the bacterium to grow in milk and resist phagocytosis by bovine neutrophils (Leigh et al 1991). Virulence factors associated with the initiation and pathogenesis of Strep.…”

Section: Introductionmentioning

confidence: 99%

Characterization of the interaction of bovine plasmin with Streptococcus uberis

Lincoln

Leigh

1998

J Appl Microbiol

View full text Add to dashboard Cite

R .A . L I NC OL N AN D J . A. LE I GH . 1998. The binding of plasmin to Streptococcus uberis strain 0140 J was optimal in the pH range 5·0-5·5. Plasmin binding decreased exponentially with increasing NaCl concentration (0-0·8 mol l −1 ), reaching a minimum at NaCl concentrations exceeding 0·55 mol l −1 . Neither K ¦ , Mg 2¦ nor the metal chelator EDTA had any effect on the interaction. Plasmin binding was prevented, in a concentration-dependent manner, by the amino acids lysine, arginine and o-aminocaproic acid. Bound plasmin was also eluted from the bacterial cell using the same amino acids. Bound plasmin was lost from the bacterium in a time-and temperature-dependent fashion, the rate of plasmin loss increased with increasing temperature over the range 4-55°C, and the elution of plasmin from live and heat-killed bacteria was similar. Cell-bound plasmin was only partially inhibited by the physiological inhibitor a 2 -antiplasmin whereas the serine protease inhibitor aprotinin, and the active site titrant p-nitrophenyl-p-guanidiniobenzoate, inhibited the activity of the cell-bound plasmin by more than 95%.

show abstract

Two strains of Streptococcus uberis, of differing ability to cause clinical mastitis, differ in their ability to resist some host defence factors

Cited by 46 publications

References 18 publications

Molecular Epidemiology of Streptococcus uberis Isolates from Dairy Cows with Mastitis

Molecular Epidemiology of Streptococcus uberis Isolates from Dairy Cows with Mastitis

The Hyaluronic Acid Capsule of Streptococcus uberis Is Not Required for the Development of Infection and Clinical Mastitis

Characterization of the interaction of bovine plasmin with Streptococcus uberis

Contact Info

Product

Resources

About