The energy imbalance related predisposition to mastitis was studied in group-fed postpartum dairy cows (n = 333) kept in 4 large-scale units and producing milk of low somatic cell count (SCC). Blood samples were taken on Days 1-3 after calving for assaying some metabolites and hormones related to the negative energy balance (NEB). If mastitis was diagnosed later, aseptic milk samples were taken to identify the pathogens. Considering pathogen types [contagious pathogens: Staphylococcus (S.) aureus, Gram-positive (GP) environmental pathogens, and Gram-negative (GN) environmental pathogens + mastitis with no detectable pathogens (NDP)] separately, stepwise logistic regression was used to analyse the relation between the potential prognostic value of hormones and metabolites and mastitis outbreak. Only the elevated (= 1.00 mmol/l) serum ß-hydroxybutyrate (BHB) levels predisposed the cows to mastitis in the subsequent 4 weeks. This prognostic value of BHB was significant only in GN + NDP mastitis and in cases caused by GP environmental pathogens, but not in S. aureus mastitis (odds ratio: 5.333, 3.600 and 1.333, respectively).
Coagulation and inflammation are closely related as part of the mechanisms of host defence during a severe infection. The aim of this study was to investigate the relation between thrombin as a factor in both the coagulative and inflammatory processes and neutrophil secretory function on the basis of lactoferrin (LF), elastase and myeloperoxidase release in the course of mastitis and metritis in cows. Thrombin generation was measured on the basis of hydrolysis of SAR-PRO-ARG-pNA and lactoferrin concentration was estimated by an ELISA method. The greatest thrombin generation was observed in the metritis group (1.18 ± 0.62 IU). The level of LF was the highest in the group of cows with mastitis (0.74 ± 0.55 mg/ml) in the first phase of the disease. In the second phase of the diseases the level of serum LF in cows with mastitis diminished to the value of 0.41 ± 0.16 mg/ml, whereas in cows with metritis the level of LF increased to 0.51 ± 0.17 mg/ml. This study reveals that the excessive production of thrombin not only causes hypercoagulatory disorders but also exaggerates neutrophil function by the release of some enzymes which may play a destructive role during disseminated intravascular coagulation (DIC). These enzymes also inhibit anticoagulative systems, thus potentially worsening the course of the disease.
In a survey of about 3000 dairy cows producing low somatic cell count (SCC) milk and kept on a large-scale dairy farm, California Mastitis Test (CMT) positivity was found in 2714 udder quarters of 1491 cows. Pathogenic microorganisms were isolated from 57.6% of these 2714 udder quarters during bacteriological examination. The commonest pathogens were coagulase-negative staphylococci (CNS, 41%) and Staphylococcus aureus (32.5%); however, udder infections caused by environmental streptococci (12.8%) and coliform bacteria (6.8%) were also common. All pathogens resulted in a significant increase of the SCC in individual bulk milk (IBM) samples. In the case of CNS, this SCC elevation in IBM was significantly lower than in the case of infection by the other pathogens. In spite of this, because of the high number of udder infections caused by CNS, the adverse effect exerted by CNS on dairy herds is considered to be substantial. It was found that 54.6% of all CMT-positive cows produced IBM of an SCC below 400 thousand per ml. The milk produced by 41% of the 315 cows excreting S. aureus also had an SCC below 400 thousand per ml. This poses a serious risk of infection to the healthy herdmates. At the same time, 11% of the infected cows produced IBM with an SCC below 100 thousand per ml. On the basis of these findings, only the regular analysis of SCC of IBM can be a reliable indicator of chronic intramammary infection. As the SCC of milk produced by CMT-positive cows (and especially of those excreting pathogens) tended to increase with advancing lactation, the authors suggest that an efficient drying-off therapy should be used to restore udder health and, whenever justified, culling of cows cannot be avoided either.
Su , J. and Han , B. ( 2012 ): Characteristics of Staphylococcus aureus small colony variant and its parent strain isolated from chronic mastitis at a dairy farm in Beijing, China. Microb. Drug Resist. 19 , 138 – 145
only few data on N. cyriacigeorgica . So far, this bacterium has only been reported as a cause of bovine mastitis in Brazil and China ( Condas et al., 2013 ; Chen et al., 2017 ). A study in Brazil found that N. cyriacigeorgica accounted for only 3
Pseudomonas aeruginosa is one of the causative pathogens of bovine mastitis. Most P. aeruginosa strains possess the type III secretion system (TTSS), which may increase somatic cell counts (SCCs) in milk from mastitis-affected cows. Moreover, most of P. aeruginosa cells can form biofilms, thereby reducing antibiotic efficacy. In this study, the presence and effect of TTSS-related genotypes on increase of SCCs among 122 P. aeruginosa isolates obtained from raw milk samples from mastitis-affected cows and their antibiotic susceptibility at planktonic and biofilm status were investigated. Based on the presence of TTSS-related genes a total of 82.7% of the isolates were found to harbour exoU and/or exoS genes, including the invasive (exoU-/exoS+, 69.4%), cytotoxic (exoU+/exoS-, 8.3%) and cytotoxic/invasive strains (exoU+/ exoS+, 5.0%). Milk containing exoS-positive isolates had higher SCCs than those containing exoS-negative isolates. The majority of isolates showed gentamicin, amikacin, meropenem and ciprofloxacin susceptibility at planktonic status. However, the susceptibility was decreased at the biofilm status. Based on minimum biofilm eradication concentration (MBEC)/minimum inhibitory concentration (MIC) ratios, the range of change in antibiotic susceptibility varied widely depending on the antibiotics (from ≥ 3.1-fold to ≥ 475.0-fold). In conclusion, most P. aeruginosa isolates studied here had a genotype related to increase in SCCs. The efficiency of antibiotic therapy against P. aeruginosa-related bovine mastitis could be improved by analysing both the MBEC and the MIC of isolates.
Treated mastitis episodes at large Hungarian dairy farms were studied to determine the distribution of mastitis treated with antibiotics among quarters of the udder. Data were detailed records of all mastitis episodes that occurred during 1976 lactations in Farm A infected with Staphylococcus aureus (from May 1995 through July 1998) and 808 lactations in Farm B free from S. aureus (from January 1999 through March 2001). The distribution of treated quarters was compared with mathematical expectations based upon a random distribution in the case of Farm A. Results on mastitis incidences for different lactation stage groups showed an increasing incidence within subsequent lactation stage groups in Farm A. In contrast, in Farm B the mastitis incidence for lactation stage group between 35 and 100 days was the highest, but beyond 100 days the incidence decreased and reached the lowest value. Results gave strong evidence that the four quarters within the udder are not distributed randomly with respect to naturally occurring episodes of treated mastitis. More episodes than expected occurred in which only one or all four quarters were treated. Fewer episodes than expected with two or three treated quarters were observed. In both farms, the mastitis rate for rear quarters was higher than for front quarters, and the incidence of right quarter mastitis episodes was higher than that of left quarter mastitis episodes.
Interdisciplinary synthesis and validity analysis (ISVA), a structured learning approach which integrates learning and communication theories, meta-analytic evaluation methods,
and literature management-related technologies was applied in the context of the 1993–1997 bovine mastitis research literature.
This study investigated whether ISVA could: 1) facilitate the analysis and synthesis of interdisciplinary knowledge claims,
and 2) generate projects or research questions. The bovine mastitis-related literature was conceptualized as composed of microbiological,
immunological, and epidemiological dimensions. Keywords involving these dimensions were searched in theMedline andAgricola databases. A final list of 148 articles were retrieved, analyzed, synthesized into fifteen information sub-sets, and evaluated
for construct, internal, external and statistical validity through an interdisciplinary iterative dialogical process. Validity
threats were re-phrased as new research or educational projects.