The goal of this study was to estimate the distribution of udder pathogens and their antibiotic resistance in Estonia during the years 2007-2009.

The associations between quantitative bacteriological results from a real-time PCR test and concentrations of acute-phase proteins (APP) and N-acetyl-β-d-glucosaminidase (NAGase) activity in milk in naturally occurring clinical mastitis were investigated. Milk APP concentrations and NAGase activity in clinical mastitis caused by different udder pathogens were studied. The associations between the severity of the clinical signs and concentrations of APP and NAGase activity were estimated. Milk samples from 281 cases of clinical mastitis were collected from 3 Estonian dairy farms and analyzed by PCR to identify pathogens. Twenty-seven samples out of 281 (9.6%) were PCR negative. Milk samples containing 4 or more bacterial species (n=28) were considered possibly contaminated and excluded from all further analyses. In total, 443 bacterial identifications were made from the remaining 226 milk samples. A single bacterial species was detected in 68 samples (30.1%), 2 species were detected in 99 samples (43.8%), and 3 species were detected in 59 (26.1%) samples. To determine the inflammatory response in the udder, the concentrations of milk amyloid A (MAA) and haptoglobin (Hp) and NAGase activity in the milk were analyzed. A significant positive association was found between the severity of the clinical signs and inflammatory markers in the milk. Milk amyloid A and Hp concentrations and NAGase activity were significantly higher in samples with large quantities of bacterial DNA from Escherichia coli or Streptococcus dysgalactiae compared with milk samples not containing those species. Large quantities of bacterial DNA from Trueperella pyogenes or Streptococcus uberis in the milk were associated with elevated concentrations of Hp and high NAGase activity, but not with increased MAA concentrations. Milk samples containing Corynebacterium bovis and coagulase-negative staphylococci had significantly lower concentrations of MAA and Hp and lower NAGase activity compared with samples where these species were not detected. It can be concluded that concentrations of APP and NAGase activity in the milk were associated with the quantity of bacterial DNA in the milk samples.

The prevalence of resistant Escherichia coli and Enterococcus spp. in food-producing animals has increased worldwide. The objective of the study was to investigate the occurrence of antimicrobial resistance of Escherichia coli, Enterococcus faecium and Enterococcus faecalis isolated from healthy and diseased swine and cattle in Estonia. Clinical specimen and faecal samples were collected during 2010 to 2015. The in vitro antimicrobial susceptibility was determined using the microdilution method. The most prevalent resistance of E. coli isolates from clinically healthy swine was observed against streptomycin (39.2%), tetracycline (32.5%) and sulfamethoxazole (30.0%), whereas in clinically healthy cattle, the resistance was the highest against aminoglycosides (7.0–8.8%) and tetracycline (7.0%). The E. coli isolates from clinically healthy swine showed significantly higher multidrug-resistance compared to isolates originated from clinically healthy cattle. E. coli isolates from diseased swine showed highest resistance to sulfamethoxazole (68.6%), tetracycline (60.2%) and streptomycin (54.6%). The proportion of resistant E. coli isolates from diseased cattle (clinical submissions) was highest to streptomycin (63.5%), sulfamethoxazole (60.3%) and tetracycline (58.8%). The proportion of multidrug-resistant isolates did not differ significantly between animal species. Among E. coli isolates, four strains representing AmpC phenotypes were found. One plasmid-encoded AmpC type β-lactamases producing E. coli from clinically healthy cattle was found to harbour the blaCMY-1 gene, and another from clinically healthy swine carried the blaCMY-2 gene. Among nine E. coli strains exhibiting an ESBL phenotype three strains was found to be the same genotype blaTEM-52C. Enterococci from healthy swine and cattle showed high resistance to tetracycline and erythromycin. Regarding enterococci, the number of multidrug-resistant strains was significantly higher in swine isolates compared to isolates originated from cattle. The antimicrobial resistance of E. coli isolates was high in both Estonian swine and cattle. However, swine isolates, especially E. coli from healthy swine, had developed a higher level of resistance. The amount of multidrug-resistant E. coli isolates was also significantly higher in clinically healthy swine compared to that in cattle.

The main objective of this study was to estimate the effect of supplementation with Saccaromyces cerevisiae (SC) (Yea-Sacc® 1026) on milk production, metabolic parameters and the resumption of ovarian activity in early lactation dairy cows.

Objectives of the study were to document the impact of some management factors on the occurrence of clinical mastitis in primiparous dairy cows and to identify common udder pathogens of clinical mastitis in freshly calved heifers and multiparous cows on the day of calving. A one-year study was conducted during 2004 and 2005 in 11 selected Estonian dairy herds. Data consisted of 68 heifers with clinical mastitis and 995 heifers without clinical mastitis on the day of calving. Multivariable logistic regression with a random herd effect was used to investigate any association between housing system or the time interval from movement of heifers to the calving facility and day of calving on occurrence of clinical mastitis. Milk samples for bacteriological analysis were collected from affected heifers and multiparous cows on the day of calving Clinical mastitis occurrence in the study population of freshly calved heifers equalled 6.1 %. Housing system was not a significant risk factor for clinical mastitis of freshly calved heifers. Moving heifers to the cowbarn less than two weeks before calving in tiestall farms increased risk (OR = 5.9 p = 0.001) for clinical mastitis at parturition. The most frequently isolated udder pathogens among heifers were Escherichia coli (22.1%), Streptococcus uberis (19.1%) and coagulase-negative staphylococci (8.8%). In comparison, the main pathogen in multiparous cows with clinical mastitis at parturition was Staphylococcus aureus (11.2%). Moving heifers to the calving facilities too late in tiestall farms increased risk for clinical mastitis at parturition. The isolated udder pathogens did not differ significantly in tiestall farms compared to freestall farms in heifers, but differences were found between heifers and multiparous cows at parturition.

As part of the European Network for Optimization of Veterinary Antimicrobial Treatment (ENOVAT), a webinar on the topic “Mastitis Treatment in Lactation” was held, in which eight mastitis experts from different European countries (Spain, The Netherlands, Estonia, Ireland, Poland, Finland, Germany, and Italy) presented their treatment approaches for clinical mastitis in lactation. The aim of this study was to compare the therapeutic approaches to identify commonalities and differences. In all eight participating countries, the decision to start treatment is usually made by the veterinarians, while the farm personnel are responsible for treatment administration. Antibiotic treatment is then typically administered intramammarily. The treatment duration often depends on the label instructions and is frequently extended if Staphylococcus aureus or Streptococcus uberis is involved. Administering supportive therapy, especially non-steroidal anti-inflammatory drugs (NSAIDs) is an established practice in all countries. Penicillin is the first-choice drug for the treatment of mastitis in an increasing number of countries. The use of critically important antimicrobials (CIAs) such as quinolones and third- and fourth-generation cephalosporins is at a low level in Finland and The Netherlands. In Estonia, Germany, Italy, and Spain, the use of CIAs is declining and is only allowed if milk samples are analyzed in advance following the legal framework. Systems for monitoring antibiotic use are being introduced in more and more countries. This exchange of different views will help the European countries to move towards a common high standard of antimicrobial stewardship in veterinary medicine.