Evaluation of the relative expression of genes associated with adherence after different hours of co-culture between Streptococcus uberis and MAC-T cells.

Streptococcus uberis is an environmental pathogen associated with subclinical and clinical IMI in both lactating and non-lactating cows. RC19 strain was isolated from a cow with subclinical mastitis, qualitatively classified as moderate biofilm producer in Todd Hewitt medium (THB), and it showed a high value of the adhered bacteria (CFU/ml). Hence, the aims of this study were (a) to determine ability to adhere to and internalize into epithelial cells MAC-T for 1, 2 and 3 h, (b) to evaluate the relative expression of adherence-associated genes from co-cultures of S.

Potential factors involved in the early pathogenesis of Streptococcus uberis mastitis: a review.

Bovine mastitis is an inflammation of the mammary gland, which could be the result of allergy, physical trauma, or invasion by pathogens as Streptococcus uberis. This pathogen is an environmental pathogen associated with subclinical and clinical intramammary infection (IMI) in both lactating and non-lactating cows, which can persist in the udder and cause a chronic infection in the mammary gland. In spite of the important economic losses and increased prevalence caused by S.

Differentiation of non-aureus staphylococci species isolated from bovine mastitis by PCR-RFLP of groEL and gap genes in comparison to MALDI-TOF mass spectrometry.

Intramammary infections (IMI) cause serious economic losses for farmers and the dairy industry. Cases of subclinical mastitis are commonly the result of infection by minor pathogens such as non-aureus staphylococci (NAS), so their correct identification is important for appropriate therapeutic intervention and management. The aim of this study was to assess the reliability of PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) of the groEL and gap genes to discriminate between bovine-associated NAS species, using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) as the reference method.

Relative expression of genes associated with adhesion to bovine mammary epithelial cells by Streptococcus uberis.

Streptococcus uberis is one of the most prevalent environmental pathogens of bovine mastitis. Biofilm growth ability by S. uberis looks to depend first upon the adherence of cells to a surface.

Fibronectin and laminin induce biofilm formation by Streptococcus uberis and decrease its penicillin susceptibility.

The aim of this study was to determine the effect of fibronectin and laminin on the in vitro biofilm formation by Streptococcus uberis and the susceptibility to penicillin under planktonic and biofilm growth conditions. We observed that a high percentage (76.5%) of the S.

Genotyping and study of adherence-related genes of Streptococcus uberis isolates from bovine mastitis.

The aim of this study was to determine the presence, conservation, and distribution of 6 potential adherence genes and their relationship with diverse molecular types in 34 S. uberis isolated from bovine mastitis in Argentina. Pulsed-field gel electrophoresis (PFGE) typing with SmaI was performed.

Streptococcus uberis: In vitro biofilm production in response to carbohydrates and skim milk.

Streptococcus uberis has become one of the most important environmental pathogens associated with clinical and subclinical bovine mastitis. Biofilm confers to bacteria more resistance to physical and chemical agents as well as to different mechanisms of the innate immune system. The aim of this work was to evaluate the ability of in vitro biofilm production in 32 S.

Prevalence and antibiotic susceptibility of coagulase-negative Staphylococcus species from bovine subclinical mastitis in dairy herds in the central region of Argentina.

Coagulase-negative staphylococci (CNS) are a common cause of bovine subclinical mastitis (SCM). The prevalence of CNS species causing SCM identified by genotyping varies among countries. Overall, the antimicrobial resistance in this group of organisms is increasing worldwide; however, little information exists about a CNS species resistant to antibiotics.

Comparison of phenotypic tests for detecting penicillin G resistance with presence of blaZ gene in Staphylococcus aureus isolated from bovine intramammary infections.

Few studies have described the relationship between genotypic and phenotypic methods for detecting penicillin resistance in Staphylococcus aureus isolated from bovine intramammary infection (IMI). Six phenotypic methods for penicillinase detection were compared with a genotypic method testing the presence of the β-lactamase gene blaZ in Staph. aureus (n = 150) isolated from bovine IMI.

Genetic patterns of Streptococcus uberis isolated from bovine mastitis.

The aim of this study was to evaluate the genotypic relationships among 40 Streptococcus uberis isolated from bovine mastitis by using pulsed-field gel electrophoresis (PFGE). Additionally, the association between PFGE patterns and virulence profiles was investigated. The isolates exhibited 17 PFGE patterns.

Accuracy of the composite somatic cell count to detect intra-mammary infection in dairy cows using latent class analysis.

The somatic cell count (SCC) is considered an important indicator of intra-mammary infection (IMI). The purpose of this study was to determine the accuracy of both SCC and culture to detect IMI and their conditional dependence by means of latent class methods. This study involved 175 dairy cows from 2 herds with different udder infection prevalences.

Phenotypic and genotypic characterization of Streptococcus uberis isolated from bovine subclinical mastitis in Argentinean dairy farms.

The aim of this study was to investigate the phenotypic and genotypic characteristics of Streptococcus uberis isolated from subclinical mastitis (SCM) cases, and to examine the possible association between both characteristics. A total of 32 S. uberis were isolated from 772 quarter milk samples (SCM > 250,000 cells/ml) collected from 195 cows selected randomly from 18 dairy farms located in Argentina.

Development of an experimentally induced Streptococcus uberis subclinical mastitis in goats.

Streptococcus uberis is a major environmental mastitis-causing pathogen. The infections are predominantly subclinical and are frequently undetected and untreated for extended periods of time. More information about the pathogenesis of S.

[Microbiological quality of the water used in a random sample from dairy farms in Córdoba, Argentina].

Bacteriological contamination of well water and wash water in a random sample obtained from 50 farms from Villa María (Córdoba) dairy area, Argentina, was evaluated during a visit in 2007. Forty six percent and 24 % of farms showed an aerobic mesophilic bacteria count higher than 500 CFU/ml in wash water and well water, respectively. Escherichia coli was isolated in 20 % of samples from both sources.

Distribution of virulence-associated genes in Streptococcus uberis isolated from bovine mastitis.

Streptococcus uberis is an important pathogen that has been implicated in bovine mastitis but the virulence factors associated with pathogenesis are not well understood. The aim of this work was to examine 11 putative and known virulence-associated genes by PCR in 78 S. uberis strains isolated from infected animals in Argentina.

Phenotyping and genotyping of streptococci in bovine milk in Argentinean dairy herds.

Most veterinary and milk hygiene laboratories identify streptococci and enterococci based on serological and biochemical tests. The analysis of 16S rDNA was suggested to be used for more exact identification; however, its use has not been considered so far in monitoring studies. The objective of the present study was to compare a conventional phenotypic method with restriction fragment length polymorphism analysis of 16S rDNA (16S rDNA RFLP) for identification of streptococci isolated from composite milk samples collected in connection with intramammary infection (IMI) in six Argentinean dairy farms.

Efficacy of immunization against bovine mastitis using a Staphylococcus aureus avirulent mutant vaccine.

Bovine mastitis is responsible of major economic losses on dairy farms worldwide. In Argentine dairy herds, Staphylococcus aureus is the main causative agent of the disease. The ineffectiveness of some current practices to control S.

Experimental trial in heifers vaccinated with Staphylococcus aureus avirulent mutant against bovine mastitis.

Staphylococcus aureus, is the most frequently isolated pathogen from cases of bovine mastitis. Vaccination against S. aureus seems to be a rational approach for the control of staphylococcal mastitis.