colistin and Mastitis--Bovine

One hundred and fifty-nine cases of clinical Staphylococcus aureus mastitis were analyzed to detect factors associated with bacteriological cure after therapy. On 100 Dutch dairy farms, data were collected from four clinical trials with five intramammary treatment regimes designed to treat beta-lactamase-positive pathogens. Infected quarters were treated three times, with a 12-h interval between treatments. Treatment was extended for 2 d if results of the trial treatment were, according to the owner, not satisfactory. The overall bacteriological cure rate was 52%. The bacteriological cure rate of clinical beta-lactamase-negative S. aureus mastitis was significantly higher than that of clinical beta-lactamase-positive S. aureus mastitis. Bacteriological cure was also significantly higher if somatic cell count of the cow was low at the milk recording prior to the onset of the clinical mastitis. The bacteriological cure rate of clinical beta-lactamase-negative S. aureus mastitis was also significantly higher after an extended treatment compared with no extended treatment. The seriousness of the various clinical symptoms and the bacteriological cure rate of clinical S. aureus mastitis were not associated.

Topics: Ampicillin; Animals; Antibiotics, Antitubercular; beta-Lactam Resistance; Cattle; Cefazolin; Cephalosporins; Cloxacillin; Colistin; Double-Blind Method; Female; Mastitis, Bovine; Milk; Penicillins; Rifampin; Staphylococcal Infections; Staphylococcus aureus; Trimethoprim

One hundred and fifty-nine cases of clinical Staphylococcus aureus mastitis were analyzed to detect factors associated with bacteriological cure after therapy. On 100 Dutch dairy farms, data were collected from four clinical trials with five intramammary treatment regimes designed to treat beta-lactamase-positive pathogens. Infected quarters were treated three times, with a 12-h interval between treatments. Treatment was extended for 2 d if results of the trial treatment were, according to the owner, not satisfactory. The overall bacteriological cure rate was 52%. The bacteriological cure rate of clinical beta-lactamase-negative S. aureus mastitis was significantly higher than that of clinical beta-lactamase-positive S. aureus mastitis. Bacteriological cure was also significantly higher if somatic cell count of the cow was low at the milk recording prior to the onset of the clinical mastitis. The bacteriological cure rate of clinical beta-lactamase-negative S. aureus mastitis was also significantly higher after an extended treatment compared with no extended treatment. The seriousness of the various clinical symptoms and the bacteriological cure rate of clinical S. aureus mastitis were not associated.

Topics: Ampicillin; Animals; Antibiotics, Antitubercular; beta-Lactam Resistance; Cattle; Cefazolin; Cephalosporins; Cloxacillin; Colistin; Double-Blind Method; Female; Mastitis, Bovine; Milk; Penicillins; Rifampin; Staphylococcal Infections; Staphylococcus aureus; Trimethoprim

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 Prototheca algae have recently emerged as an important cause of bovine mastitis globally. Isolates from bovine mastitis in several countries were nearly all identified as P. bovis, suggesting that it was the main causative agent of bovine protothecal mastitis. The aim of the present study was to evaluate the presence and isolation of Prototheca spp. in dairy farms, detect the genetic diversity among strains, determine the capacity of producing biofilm and their resistance to antifungal and antimicrobial drugs.. A total of 48 Prototheca isolates from four different farms were randomly selected to be investigated. Multiplex PCR showed all isolated colonies were Prototheca bovis. Performing RAPD-PCR by using OPA-4 primer, it was revealed that there was a clear amplification pattern. Different levels of biofilm production were observed among strains. Among 48 isolates, only 4 of them (8.33%) showed strong biofilm production. By using E-test strips, amphotericin B was able to inhibit the growth of all the strains tested. Disc diffusion method used for antimicrobial sensitivity test showed that the highest activity was demonstrated by gentamicin and colistin with 95.83% (46/48) and 89.58% (43/48) of sensitive strains, respectively.. The present study showed that RAPD-PCR was a rapid tool for discriminating P. bovis strains. Also, gentamicin and colistin can be considered as potential antimicrobial drugs which can prevent the growth of the mentioned strains in vitro, although there is no effective clinical treatment yet. Further studies are needed in order to detect an effective clinical therapy considering biofilm production by Prototheca spp. and their probable role in Prototheca pathogenicity.

Topics: Animals; Anti-Bacterial Agents; Anti-Infective Agents; Biofilms; Cattle; Cattle Diseases; Colistin; Drug Resistance, Bacterial; Female; Gentamicins; Mastitis, Bovine; Prototheca; Random Amplified Polymorphic DNA Technique

We performed a survey aimed at analyzing milk samples collected from cows with mastitis for the presence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli. Single-quarter mastitic milk samples obtained from 400 cows in 23 Greek dairy herds with a history of E. coli mastitis were processed for the selective isolation of ESBL-producing E. coli. The antimicrobial susceptibility of the ESBL-producing isolates was analyzed using agar disk diffusion, and minimum inhibitory concentrations of colistin were determined by broth microdilution. We used PCR followed by DNA sequencing to characterize the β-lactamases and mcr-1 (colistin resistance) genes, and for phylotyping and multilocus sequence typing. We found a total of 89/400 (22.25%) E. coli isolates from 12/23 (52%) farms. Six isolates originating from 6 cows on a single farm were ESBL producers and were resistant to cefquinome, amoxicillin-clavulanic acid, aztreonam, ampicillin, and colistin. Five of these isolates were resistant to trimethoprim-sulfamethoxazole, and 5 to streptomycin. The 6 ESBL producers were mcr-1-positive and carried bla

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Cattle; Cephalosporins; Colistin; Dairying; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Female; Greece; Mastitis, Bovine; Microbial Sensitivity Tests; Milk; Multilocus Sequence Typing

Of 150 Escherichia coli strains we cultured from specimens taken from cattle in Europe, 3 had elevated MICs against colistin. We assessed all 3 strains for the presence of the plasmid-mediated mcr-1 gene and identified 1 isolate as mcr-1-positive and co-resistant to β-lactam, florfenicol, and fluoroquinolone antimicrobial compounds.

Topics: Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Europe; Female; Genes, Bacterial; Mastitis, Bovine; Microbial Sensitivity Tests

Topics: Animals; Anti-Bacterial Agents; Cattle; Colistin; Drug Resistance, Bacterial; France; Genes, Bacterial; Klebsiella Infections; Klebsiella pneumoniae; Mastitis, Bovine; Microbial Sensitivity Tests; Polymerase Chain Reaction

Topics: Animals; Bacteriocins; Birds; Blood; Cattle; Colistin; Ear; Feces; Humans; Mammary Glands, Animal; Mastitis, Bovine; Mice; Pharynx; Pseudomonas aeruginosa; Urine; Water Microbiology; Water Supply; Wounds and Injuries

Topics: Animals; Anti-Bacterial Agents; Bacillus; Biological Assay; Cattle; Chloramphenicol; Colistin; Dihydrostreptomycin Sulfate; Erythromycin; Mastitis, Bovine; Milk; Neomycin; Penicillin Resistance; Penicillins; Staphylococcus; Streptococcus; Sulfonamides