Genome-wide association study identifies loci associated with milk leukocyte phenotypes following experimental challenge with Streptococcus uberis.

Mastitis is a detrimental disease in the dairy industry that decreases milk quality and costs upwards of $2 billion annually. Often, mastitis results from bacteria entering the gland through the teat opening. Streptococcus uberis is responsible for a high percentage of subclinical and clinical mastitis.

Antimicrobial Resistance of Staphylococcus aureus Isolates from Dairy Cows and Genetic Diversity of Resistant Isolates.

Staphylococcus aureus is a frequent and major contagious mastitis bacterial pathogen. The antibiotic treatment cure rates vary considerably from 4% to 92%. Staphylococcus aureus readily becomes resistant to antibiotics, resulting in persistent noncurable intramammary infection that usually results in culling of infected animals.

Genetic variation in CXCR1 haplotypes linked to severity of Streptococcus uberis infection in an experimental challenge model.

Mastitis, an inflammation of the mammary gland, costs the dairy industry billions of dollars in lost revenues annually. The prevalence and costs associated with mastitis has made genetic selection methods a target for research. Previous research has identified amino acid changes at positions 122, 207, 245, 327, and 332 in the IL8 receptor, CXCR1, that result in three dominant amino acid haplotypes: VWHKH, VWHRR, and AWQRR.

Protective effect of anti-SUAM antibodies on Streptococcus uberis mastitis.

In the present study, the effect of anti-recombinant Streptococcus uberis adhesion molecule (SUAM) antibodies against S. uberis intramammary infections (IMI) was evaluated using a passive protection model. Mammary quarters of healthy cows were infused with S.

Role of Streptococcus uberis adhesion molecule in the pathogenesis of Streptococcus uberis mastitis.

Adherence to and internalization into mammary epithelial cells are central mechanisms in the pathogenesis of S. uberis mastitis. Through these pathogenic strategies, S.

Short communication: Conservation of Streptococcus uberis adhesion molecule and the sua gene in strains of Streptococcus uberis isolated from geographically diverse areas.

The objective was to identify and sequence the sua gene (GenBank no. DQ232760; http://www.ncbi.

Evaluation of five susceptibility test methods for detection of tobramycin resistance in a cluster of epidemiologically related Acinetobacter baumannii isolates.

Acinetobacter baumannii is a major nosocomial pathogen causing infections in critically ill patients. This organism has acquired the propensity to rapidly develop resistance to most antibiotics. At several hospitals within Cape Town, South Africa, tobramycin and colistin are frequently the only therapeutic options.

Antimicrobial resistance of mastitis pathogens.

Antibiotics are used extensively in the dairy industry to combat disease and to improve animal performance. Antibiotics such as penicillin, cephalosporin, streptomycin, and tetracycline are used for the treatment and prevention of diseases affecting dairy cows caused by a variety of gram-positive and gram-negative bacteria. Antibiotics are often administrated routinely to entire herds to prevent mastitis during the dry period.

Intracellular fate of strains of Escherichia coli isolated from dairy cows with acute or chronic mastitis.

Research on mastitis in dairy cows caused by Escherichia coli has reported the emergence of strains capable of inducing chronic mastitis and that these strains adhered to and internalized into bovine mammary epithelial cells better than strains of E. coli isolated from acute mastitis. To understand mechanisms and strategies used by chronic E.

Impact of antibiotic use in adult dairy cows on antimicrobial resistance of veterinary and human pathogens: a comprehensive review.

Antibiotics have saved millions of human lives, and their use has contributed significantly to improving human and animal health and well-being. Use of antibiotics in food-producing animals has resulted in healthier, more productive animals; lower disease incidence and reduced morbidity and mortality in humans and animals; and production of abundant quantities of nutritious, high-quality, and low-cost food for human consumption. In spite of these benefits, there is considerable concern from public health, food safety, and regulatory perspectives about the use of antimicrobials in food-producing animals.

Deletion of sua gene reduces the ability of Streptococcus uberis to adhere to and internalize into bovine mammary epithelial cells.

To elucidate the role of Streptococcus uberis adhesion molecule (SUAM) in the pathogenesis of S. uberis mastitis, sua deletion in S. uberis UT888 was achieved by homologous recombination using a thermosensitive plasmid.

Binding of Host Factors Influences Internalization and Intracellular Trafficking of Streptococcus uberis in Bovine Mammary Epithelial Cells.

We showed that internalization of Streptococcus uberis into bovine mammary epithelial cells occurred through receptor- (RME) and caveolae-mediated endocytosis (CME). We reported also that treatment of S. uberis with host proteins including lactoferrin (LF) enhanced its internalization into host cells.

Prevalence of urovirulence genes cnf, hlyD, sfa/foc, and papGIII in fecal Escherichia coli from healthy dogs and their owners.

Objective: To determine the prevalence of 4 urovirulence genes in fecal Escherichia coli isolates from healthy dogs and their owners and to determine whether detection of E coli strains with these genes was associated with a history of urinary tract infection (UTI).

Sample Population: 61 healthy dog-owner pairs and 30 healthy non-dog owners.

Procedures: A fecal specimen was obtained from each participant, and 3 colonies of E coli were isolated from each specimen.

Food safety hazards associated with consumption of raw milk.

An increasing number of people are consuming raw unpasteurized milk. Enhanced nutritional qualities, taste, and health benefits have all been advocated as reasons for increased interest in raw milk consumption. However, science-based data to substantiate these claims are limited.

Comparison of clonal relatedness and antimicrobial susceptibility of fecal Escherichia coli from healthy dogs and their owners.

Objective: To determine prevalence of within-household sharing of fecal Escherichia coli between dogs and their owners on the basis of pulsed-field gel electrophoresis (PFGE), compare antimicrobial susceptibility between isolates from dogs and their owners, and evaluate epidemiologic features of cross-species sharing by use of a questionnaire.

Sample Population: 61 healthy dog-owner pairs and 30 healthy control humans.

Procedures: 3 fecal E coli colonies were isolated from each participant; PFGE profiles were used to establish relatedness among bacterial isolates.

Bovine lactoferrin serves as a molecular bridge for internalization of Streptococcus uberis into bovine mammary epithelial cells.

Streptococcus uberis, an environmental mastitis pathogen, is an important causative agent of mastitis in dairy cattle throughout the world. Research from our laboratory demonstrated that bovine lactoferrin (LF), a whey protein present in milk and nonlactating cow mammary secretions, significantly enhanced adherence of S. uberis to mammary epithelial cells in culture.

Elucidation of the DNA sequence of Streptococcus uberis adhesion molecule gene (sua) and detection of sua in strains of Streptococcus uberis isolated from geographically diverse locations.

Streptococcus uberis is an important environmental pathogen that causes subclinical and clinical mastitis in lactating and nonlactating cows throughout the world. S. uberis adhesion molecule (SUAM) was identified recently by our laboratory and we hypothesize that SUAM is a potential virulence factor involved in the pathogenesis of S.

Distribution of tetracycline and streptomycin resistance genes and class 1 integrons in Enterobacteriaceae isolated from dairy and nondairy farm soils.

The prevalence of selected tetracycline and streptomycin resistance genes and class 1 integrons in Enterobacteriaceae (n = 80) isolated from dairy farm soil and nondairy soils was evaluated. Among 56 bacteria isolated from dairy farm soils, 36 (64.3%) were resistant to tetracycline, and 17 (30.

Phenotypic and genotypic antimicrobial resistance patterns of Escherichia coli isolated from dairy cows with mastitis.

Pulsed field gel electrophoresis (PFGE) patterns, susceptibility to 26 antimicrobial agents used in veterinary and human medicine, and prevalence of antimicrobial resistance genes of Escherichia coli isolated from cows with mastitis were evaluated. Among 135 E. coli isolates, PFGE analysis revealed 85 different genetic patterns.