trimethoprim--sulfamethoxazole-drug-combination and Mastitis--Bovine

This review paper is concerned with antibacterial therapy of mastitis caused by Escherichia coli. The choice of an antibacterial agent is discussed, and nine criteria are referred to, on which this choice should be based. In the second part possible forms of antibacterial treatment are discussed. Literature on parenteral and local treatment of mastitis due to E. coli is scarcely available. The evaluation of antibacterial drugs is mainly based on MIC values and pharmacokinetic studies in normal animals. Unfortunately, results of clinical trials are hardly available. Today combinations of trimethoprim/sulphonamide apparently are the best available choice for the parenteral treatment of mastitis caused by E. coli. Infusion of polymyxins or gentamycin is discussed as a method of intramammary therapy.

Topics: Animals; Anti-Bacterial Agents; Cattle; Chloramphenicol; Drug Resistance, Microbial; Escherichia coli Infections; Female; Gentamicins; Mastitis, Bovine; Microbial Sensitivity Tests; Polymyxin B; Trimethoprim, Sulfamethoxazole Drug Combination

The objective of the study was to monitor the effect of two therapy regimens on experimental Escherichia coli mastitis. Single udder quarters of 12 cows that were at least 30 d postpartum were inoculated with 1500 cfu of E. coli. The inoculation was repeated in the contralateral quarter after a 3- to 4-wk interval. Initially, half of the cows were treated with antimicrobials, and the remaining half were left untreated. At the second inoculation, the cows that were originally treated were not treated, and vice versa. Therapy began 12 h after inoculation and consisted of parenteral trimethoprim-sulfadiazine (6 cows) or intramammary colistin sulfate (6 cows). Clinical signs, daily milk yield, bacterial count, and endotoxin content of the milk were recorded. Milk SCC, NAGase activity, and trypsin inhibitor capacity were also monitored. The response to bacterial challenge varied greatly among cows. Bacteria were eliminated from the quarters within 7 d in all but 1 cow. Treatment did not significantly affect the elimination rate of bacteria or any of the measured parameters. Significant positive correlations existed among milk bacterial counts, endotoxin concentrations, and clinical signs at the acute stage of the infection. Based on these findings, antimicrobial therapy of E. coli mastitis during lactation apparently is no more beneficial than no treatment.

Topics: Acetylglucosaminidase; Animals; Cattle; Colistin; Colony Count, Microbial; Endotoxins; Escherichia coli Infections; Female; Mastitis, Bovine; Milk; Pregnancy; Time Factors; Trimethoprim, Sulfamethoxazole Drug Combination; Trypsin Inhibitors

The multidrug efflux system in bacteria can reduce antibiotic concentration inside the cell, leading to failure in the treatment of bacterial diseases. This study evaluated the influence of two efflux pump inhibitors (EPIs), phenylalanine arginyl ß-naphthylamide (PAßN) and 1-(1-naphthylmethyl)-piperazine (NMP), on the gene expression of three multidrug efflux systems, AcrAB, AcrEF and EmrAB in Escherichia coli bovine mastitis isolates resistant to ampicillin and sulfamethoxazole/trimethoprim simultaneously. Each isolate had at least three multidrug efflux system genes. The acrA and acrB had the lowest expression levels in all treatments, while the emrA or emrB showed the highest expression levels in the presence of ampicillin, sulfamethoxazole/trimethoprim, PAβN and NMP. EPIs also contributed to the decrease in arcF expression when used in combination with ampicillin treatment. Since PAßN showed stronger effects than NMP, it may serve as an alternative to assist in the antimicrobial therapy of mastitis.

Topics: Ampicillin; Animals; Anti-Infective Agents; Bacterial Proteins; Cattle; Colony Count, Microbial; Dipeptides; Drug Resistance, Multiple, Bacterial; Escherichia coli; Female; Gene Expression Regulation, Bacterial; Mastitis, Bovine; Membrane Transport Proteins; Microbial Sensitivity Tests; Piperazines; Polymerase Chain Reaction; Trimethoprim, Sulfamethoxazole Drug Combination

Escherichia coli is a highly adaptive microorganism, and its ability to form biofilms under certain conditions can be critical for antimicrobial resistance. The adhesion of four E. coli isolates from bovine mastitis to bovine mammary alveolar (MAC-T) cells, biofilm production on a polystyrene surface, and the expression profiles of the genes fliC, csgA, fimA, and luxS in the presence of enrofloxacin, gentamicin, co-trimoxazole, and ampicillin at half of the MIC were investigated. Increased adhesion of E. coli isolates in the presence of antimicrobials was not observed; however, increased internalization of some isolates was observed by confocal microscopy. All of the antimicrobials induced the formation of biofilms by at least one isolate, whereas enrofloxacin and co-trimoxazole decreased biofilm formation by at least one isolate. Quantitative PCR analysis revealed that all four genes were differentially expressed when bacteria were exposed to subinhibitory concentrations of antimicrobials, with expression altered on the order of 1.5- to 22-fold. However, it was not possible to associate gene expression with induction or reduction of biofilm formation in the presence of the antimicrobials. Taken together, the results demonstrate that antimicrobials could induce biofilm formation by some isolates, in addition to inducing MAC-T cell invasion, a situation that might occur in vivo, potentially resulting in a bacterial reservoir in the udder, which might explain some cases of persistent mastitis in herds.

Topics: Ampicillin; Animals; Anti-Infective Agents; Bacterial Adhesion; Bacterial Proteins; Biofilms; Carbon-Sulfur Lyases; Cattle; Enrofloxacin; Escherichia coli; Escherichia coli Proteins; Female; Fimbriae Proteins; Flagellin; Fluoroquinolones; Gentamicins; Mammary Glands, Animal; Mastitis, Bovine; Milk; Polystyrenes; Trimethoprim, Sulfamethoxazole Drug Combination

Sulphamycin (Polfa, Poland) is an intramammary preparation for the treatment of clinically apparent forms of mastitis in dairy cows. Its effects were observed in 141 dairy cows treated according to the manufacturer's instructions. The animals were selected after clinical examination of the mammary gland and bacteriological examination of udder secreta. In 37 subclinically diseased cows the efficiency of treatment depended on the infectious agent and amounted to 85.2, 77.8, 73.3 and 60.0%, Streptococcus agalactiae beta-haemolytical Streptococci, Staphylococcus aureus and Corynebacterium pyogenes being the respective pathogens. In 61 cows with acute mastitis the efficiency of the preparation reached 71.2, 78.3, 61.7 and 80.9% in the cases induced by S. agalactiae, beta-haemolytical Streptococci, S. aureus and Escherichia coli, respectively. Forty-three cows were treated for acute mastitis and concomitant alteration of the general health state; in these cases, S. agalactiae, S. aureus and E. coli were identified as the infectious agents and the respective therapeutic efficiency presented 62.5, 69.8 and 76.2%. S. agalactiae and beta-haemolytical Streptococci responded most sensitively to erythromycin whereas S. aureus and E. coli proved to be septrin- and streptomycin-sensitive, respectively.

Topics: Animals; Cattle; Drug Therapy, Combination; Erythromycin; Female; Lactation; Mastitis, Bovine; Streptomycin; Trimethoprim, Sulfamethoxazole Drug Combination

Addition of milk to Mueller-Hinton susceptibility test medium permitted measurement of milk effect on agar disc diffusion zone diameters obtained from Staphylococcus aureus herd isolates and stock strains. Milk reduced zone diameters for all antimicrobics tested when compared with zones obtained by standard methods. Antimicrobics most affected included novobiocin, streptomycin, gentamycin, tetracycline, and vancomycin. Growth curves of a reference strain of Staphylococcus aureus in Mueller-Hinton broth with and without milk indicated no effect on growth rate of the organism, suggesting the observed effect was due to the action of milk on the antimicrobics being tested. The described method offers a simple in vitro test for milk effects on antimicrobic activity.

Topics: Animals; Anti-Bacterial Agents; Cattle; Drug Combinations; Female; In Vitro Techniques; Mastitis, Bovine; Milk; Staphylococcal Infections; Staphylococcus aureus; Sulfamethoxazole; Trimethoprim; Trimethoprim, Sulfamethoxazole Drug Combination

Topics: Animals; Cattle; Drug Combinations; Endometritis; Female; Lactation Disorders; Mastitis, Bovine; Pregnancy; Puerperal Disorders; Sulfanilamides; Swine; Swine Diseases; Syndrome; Trimethoprim, Sulfamethoxazole Drug Combination