Crossed immunoelectrophoretic analysis of the antibody response in heifers and dry cows to Peptococcus indolicus in experimental and natural heifer mastitis and dry cow mastitis

Crossed immunoelectrophoresis with intermediate gel was used to investigate the antibody response of experimentally infected heifers and of naturally infected heifers and dry cows at grass with mastitis against soluble extracellular antigens of Peptococcus indolicus. Using both precipitin titres and precipitin scores (the sum of precipitin titres against individual antigens) rising titres of antibodies against antigend of P. indolicus were demonstrated in sera from experimentally infected pregnant and non-pregnant heifers. Statistically significant differences in precipitin scores against extracellular antigens were also shown between pregnant heifers with mastitis and healthy pregnant heifers and between dry cows with mastitis and health dry cows. The biochemical nature of the principal reactive antigens was not elucidated. These serological investigations lend strong support to the pathogenic role and significance of P. indolicus in mixed infections with Corynebacterium pyogenes in the aetiology of heifer and dry cow mastitis.     

Heifer mastitis and dry-cow mastitis: A bacteriological survey in Sweden

A bacteriological investigation was performed on 145 heifers and 55 dry-cows with clinical mastitis during July 1976–June 1977. Areas in Sweden from which heifer and dry-cow mastitis has been reported as a problem were included. Mastitis occurred more frequently in the Swedish Fresian breed (SLB) than in the Swedish Red and White breed (SRB) of dairy cattle. C. pyogenes was isolated in pure culture from 15% and 4%, respectively, of the cases of heifer and dry-cow mastitis from which this bacterium could be isolated. Corresponding figures for pure culture of P. indolicus, micro-aerophilic cocci and S. dysgalactiae were 2% and 0%, 0% and 0% and 44% and 35%, respectively. The bacteria most frequently isolated together with C. pyogenes in the heifer material were P. indolicus (69%), the microaerophilic cocci (59%) and S. dysgalactiae (31%). Corresponding data for the dry-cow material were 92%, 35% and 50%, respectively. Thus, C. pyogenes was the causative agent of heifer and dry-cow mastitis in only about 40% of the mastitis cases investigated, and the most characteristic feature of these forms of mastitis involving C. pyogenes was mixed infection.     

Antigenic analysis of Peptococcus indolicus by crossed immunoelectrophoresis

Quantitative immunoelectrophoretic methods have been used to study the antigenic mosaic of Peptococcus indolicus, an anaerobic coccus frequently isolated from udder secretions from heifers and dry cows with mastitis. Three antigenic components of liquid cultures of this bacterium were analyzed, compared and characterized, namely concentrated culture filtrate containing extracellular antigens, a cytoplasmic antigen fraction obtained by freeze-press disruption of bacterial cells and Triton X-100-soluble antigens from cell wall-membrane fractions. The extracellular antigens were further investigated because they proved to be particularly useful in preliminary studies on the antibody response of cows to P. indolicus. The possible cross-reactivity of peptococcal antigens with extracellular antigens from other bacteria causing, or associated with, mastitis was investigated. The contribution of medium components to the immunoprecipitate profile, the heat-stability of antigens and the relationship of serotypic antigens to those in the standard extracellular concentrate were established using co-immunoelectrophoresis, crossed-line immuno-electrophoresis and crossed immunoelectrophoresis with intermediate gel. Attempts to identify enzyme-active immunoprecipitates with histochemical enzyme staining methods revealed only glutamate dehydrogenase.     

Summer mastitis in heifers: a bacteriological examination of secretions from clinical cases of summer mastitis in Denmark

A total of 166 samples of secretions collected from Danish heifers suffering from clinically diagnosed summer mastitis were examined bacteriologically. One hundred and sixty three samples yielded positive findings whereas no growth was obtained from 3 specimens. The majority of samples revealed a mixed flora in which the predominant components were Actinomyces pyogenes, Peptostreptococcus indolicus, a microaerophilic coccus (Stuart-Schwan coccus), Fusobacterium necrophorum, Bacteriodes melaninogenicus and Streptococcus dysgalactiae. Pure cultures were recovered in only 7% of cases. P. indolicus was isolated from 875 of the cases, a microaerophilic coccus from 84%, A. pyogenes from 72%, Fusobacterium necrophorum from 52%, Str. dysgalactiae from 37%, B. melaninogenicus from 33% and various unidentified obligate anaerobic Gram-negative rods from 31%. The results confirm the complex bacterial aetiology of summer mastitis.     

Specific antibody in milk whey and phagocytosis of Actinomyces pyogenes by neutrophils in vitro

Milk samples were collected from 21 non-pregnant cows to study the ability of milk whey to support in vitro bactericidal activity of neutrophils against Actinomyces pyogenes. Significant differences (P less than 0.01) existed in opsonising ability of milk whey samples from individual cows. Antibody titres to A pyogenes in milk whey were determined using an enzyme linked immunosorbent assay. Bactericidal activity of neutrophils incubated with milk whey was positively correlated (P less than 0.05) with titres of IgG2 and IgM antibodies but not with IgG1 or IgA antibodies.     

Effect of damage to the teat end on the experimental induction of mastitis in dry cows with Corynebacterium pyogenes

The teat ends of 12 dry cows were contaminated with Corynebacterium pyogenes. To determine whether a pre-existing (an)aerobic bacterial infection of the udder was a predisposing factor for a C pyogenes mastitis they included infected and uninfected quarters. Anaerobic bacteria could not be found and mastitis was not induced. When the teats were contaminated with C pyogenes after the teat ends had been injured 30 of the quarters became infected, and anaerobic bacteria were demonstrated in many quarters.     

SEROLOGICAL TITRES OF DAIRY COWS OVER A 63-WEEK PERIOD FOLLOWING NATURAL INFECTION WITH LEPTOSPIRA INTERROGANS SEROVAR HARDJO

SUMMARY Leptospirosis due to Leptospira interrogans serovar hardjo, occurred in a dairy herd of 104 cows and produced signs of mastitis, characterised by a sudden decrease in milk production and uniformly flaccid udders, in 11 cows. The microscopic agglutination (MA) test was used to determine antibody titres to serovar hardjo in all cows in the herd at 6, 33 and 63 weeks after the initial outbreak. The prevalence of MA antibodies to hardjo at week 6 was highest in cows in the youngest age groups and lowest in cows in the oldest age group. Over the 63-week period MA antibody titres to hardjo declined in 54 out of 62 seropositive cows, remained unchanged in 6 cows, and increased slightly in 2 cows. Fourteen of 59 cows (23.7%) with MA titres greater than 100 at week 6 had titres greater than 100 by week 63. Included in this group of 14 were 5 of 7 cows that had been affected with atypical mastitis. The distribution of serological titres to hardjo showed bimodal configurations at weeks 6 and 33 with the second peaks occurring at titres greater than 100, while the configuration was linear at week 63. MA titres to hardjo were also determined for 22 heifers 1, 16 and 36 weeks after they were added to the herd. No clinical signs of leptospirosis were observed in the heifers; however, the distribution of MA titres showed bimodal configurations at weeks 16 and 33 with second peaks occurring at titres greater than 100. Leptospiras were isolated from the urine of 2 seropositive heifers 16 weeks after their introduction to the herd, and cross-agglutinin absorption tests performed on one of the isolates indicated that it was identical to serovar hardjo.     

Studies on microaerophilic cocci (Stuart-Schwan cocci) isolated from summer mastitis and other pyogenic infections of cattle

Forty-nine strains of microaerophilic gram-positive cocci (Stuart-Schwan cocci) isolated from summer mastitis, "pyogenes"-mastitis, other pyogenic conditions of Danish cattle and swine, and from the sheep headfly Hydrotaea irritans were biochemically characterized with the API 50 CH and API ZYM test kit systems, and screened for production of a variety of extracellular enzymes by agar plate methods. For comparison 4 strains isolated from Swedish cases of heifer and dry cow mastitis were included in the study. Similarity calculations indicated a high degree of homogeneity within the strains studied (similarity level 92%; group mean similarity 87%). The strains probably represent one species, although the taxonomic position of the organism remains unclear. The biochemical feature of the strains studied were very similar for strains isolated from cases of summer mastitis and strains from other sources of origin. It is suggested that the Stuart-Schwan coccus occurs as a natural cohabitant to Actinomyces pyogenes, Peptostreptococcus indolicus and the anaerobic organism characteristic of the bacterial complex isolated from summer mastitis and similar pyogenic conditions in ruminants and swine.     

Comparative bacteriological studies on summer mastitis in grazing cattle and pyogenes mastitis in stabled cattle in Denmark.

A total of 143 secretions from clinical cases of summer mastitis (SM) in grazing cattle and from 89 cases of pyogenes mastitis (PM) in stabled cattle were examined bacteriologically. The typical bacteriological finding was a mixed flora in which the predominant organisms were Actinomyces pyogenes (SM-70%, PM-85%), Peptostreptococcus indolicus (54%, 54%), a microaerophilic coccus (Stuart-Schwan coccus) (26%, 25%), Fusobacterium necrophorum biovar B (22%, 12%), Bacteroides melaninogenicus (20%, 9%) and Streptococcus dysgalactiae (21%, 5%). All except six cases occurred in non-lactating animals or within three weeks after parturition. The majority of animals (about 90%) had only one quarter affected and no differences in quarter distribution were observed between the two groups.     

Cause, occurrence, and clinical signs of mastitis and anorexia in cows in a Wisconsin study

Microbiologic culture revealed the following cause of mastitis and anorexia in 145 cows in Wisconsin to be Escherichia coli, 66 cows; Klebsiella spp, 3; Corynebacterium pyogenes, 27; streptococci, 21; staphylococci, 20; yeasts, 1; and no bacterial growth, 7. Mastitis was detected with approximately equal frequency throughout the year. Escherichia coli was isolated throughout the year, but was more common and was the predominant organism during the summer. Corynebacterium pyogenes was isolated most often in winter and spring; streptococci in fall, winter, and spring; and staphylococci throughout the year. Corynebacterium pyogenes caused most of the mastitis in nonlactating cows. Escherichia coli, C pyogenes, streptococci, and staphylococci were isolated with about equal frequency at parturition, whereas E coli was the predominant cause of mastitis in early and late lactation. Of cases of mastitis, 27% were seen 10 days before and after parturition. Local and systemic clinical signs of infection were similar for all causes, except that C pyogenes caused more (P less than 0.01) malodorous and purulent milk than did other organisms and was isolated more commonly from quarters with injured teats. Recovery was significantly (P less than 0.01) higher in cows with E coli infections, compared with recovery in cows with gram-positive organism infections. Cows with C pyogenes infections frequently had quarters that ultimately ceased lactation. A few cows were recumbent at initiation of antimicrobial therapy and a few were not eating 24 hours later; however, 50% of these cows recovered. Criteria such as season of year, stage of lactation, appearance of milk and udder, and appetite permitted the cause (gram-negative or gram-positive organisms) of the mastitis to be predicted with 77% accuracy.     

Mastitis in Post-Partum Dairy Cows

Transition from the dry period to lactation is a high risk period for the modern dairy cow. The biggest challenge at that time is mastitis. Environmental bacteria are the most problematic pathogens around parturition. Coliforms are able to cause severe infections in multiparous cows, and heifers are likely to be infected with coagulase-negative staphylococci. During the periparturient period, hormonal and other factors make the dairy cows more or less immunocompromised. A successful mastitis control programme is focused on the management of dry and calving cows and heifers. Clean and comfortable environment, proper feeding and adequate supplementation of the diet with vitamins and trace elements are essential for maintaining good udder health. Strategies which would enhance closure of the teat canal in the beginning of the dry period and would protect teat end from bacteria until the keratin plug has formed decrease the risk for mastitis after calving. Dry cow therapy has been used with considerable success. Yet, a selective approach could be recommended rather than blanket therapy. Non-antibiotic approaches can be useful tools to prevent new infections during the dry period, in herds where the risk for environmental mastitis is high. Vaccination has been suggested as a means to support the immune defence of the dairy cow around parturition. In some countries, implementation of Escherichia coli core antigen vaccine has reduced the incidence of severe coliform mastitis after calving.     

A microaerophilic coccus in pyogenic infections of ruminants

Pyogenic infections of cattle, sheep and goats were examined for the presence of a Gram positive bacterium that has been designated "microaerophilic coccus" by other workers. The bacterium was found to be involved in a range of disease processes, including foot and soft tissue abscesses, mastitis, pericarditis and pyometra in cattle, joint and foot abscesses in sheep and foot abscesses in goats. The characteristic feature of the bacterium was its satellitic growth around colonies of other organisms. The microaerophilic coccus was usually part of a mixed flora, which included Corynebacterium pyogenes, Fusobacterium necrophorum, Peptostreptococcus indolicus and Bacteroides sp.     

Infection following challenge of the lactating and dry udder of dairy cows with Actinomyces pyogenes and Peptostreptococcus indolicus

Challenge of 12 mammary glands of cows in mid-lactation with 10(7) colony forming units (cfu) of Peptostreptococcus indolicus on two occasions led to clinical mastitis in only four quarters. The bacteria were rarely recovered and disappeared from the secretion within 14 days. In challenges 7 days prior to drying off eight of 12 quarters became infected and at drying off all quarters challenged became infected. The infections established at drying off persisted well into the dry period. P. indolicus infection was also established in all of 12 dry glands challenged, but usually eliminated at calving or early in the next lactation. Isolation of P. indolicus was accompanied in about one-third of cases by changes in the appearance of the secretion. Intramammary challenge with Actinomyces (formally Corynebacterium) pyogenes led to clinical and subclinical infections in nine of 12 lactating glands and in all of six dry glands. Dry period infections with A. pyogenes were more severe and rarely eliminated even by antibiotic therapy. Infections during lactation were often eliminated either naturally or by antibiotic therapy. Intermittent recovery of A. pyogenes from the lactating mammary gland, without clinical signs of infection, was possible for up to 90 days after challenge. Combined infections with A. pyogenes and P. indolicus were clinically more severe with a higher frequency of systemic involvement. It was shown that in the non-lactating gland an acute mastitis, similar to 'summer mastitis' could be established either by simultaneous inoculation with A. pyogenes and P. indolicus or by subsequent inoculation of quarters excreting P. indolicus with A. pyogenes.     

Teat skin normal flora and colonization with mastitis pathogen inhibitors

Isolates of bacteria from normal teats were used to attempt colonization of teats of dry cows or neonatal calves. Isolates for inoculation were chosen on the basis of ability to inhibit mastitis pathogens in vitro, with the ultimate goal of in vivo inhibition of mastitis pathogens at the teat surface. Three bacterial normal flora isolates (Corynebacterium xerosis, Bacillus sp. and Aerococcus viridans) persisted less than 10 days on the teats of dry cows. The fourth isolate, Staphylococcus hominis 1, was studied in greatest detail because studies characterizing the normal teat flora showed staphylococci to be the predominant flora. The S. hominis 1 isolated used for inoculation was an inhibitor of Gram-positive mastitis pathogens. It was a biotype not found on these teats prior to inoculation, thus facilitating identification of the inoculated isolate on sequential sampling. Colonization of newborn calves, before other bacterial floral became established, resulted in recovery of inoculated S. hominis 1 for an average of 51 days or longer. On dry cow teats it was detected for up to 28 days. On several occasions the inoculated S. hominis 1 was found in pure culture. Since many new infections occur during the dry period, the colonization of dry cow tests with S. hominis 1 organisms inhibitory for Gram-positive pathogens should be tested as an adjunct to other methods of mastitis prevention.     

The role of Hydrotaea irritans in the transmission of summer mastitis

A series of experiments to investigate the possible role of the sheep head fly, Hydrotaea irritans, in the transmission of summer mastitis is reported. These showed that the pathogens Actinomyces pyogenes and Peptococcus indolicus may be harboured in the gut of the fly for up to 96 h following a contaminated meal; A. pyogenes survived on the surface of the fly for a similar period. H. irritans fed on the pathogens can contaminate a subsequent meal by regurgitation. However, no infections resulted from repeated exposure of the teats of heifers or cows to H. irritans fed on blood containing A. pyogenes and P. indolicus or on pus from a case of summer mastitis. In these experiments the frequency of feeding of the flies on the teat was high but subsequent bacterial contamination of the teat skin was low. Artificial contamination of the teat skin with greater than 10(6) cfu A. pyogenes led to a low incidence of mastitis even in the absence of cutaneous damage. Repeated applications of lower doses (less than 10(4) cfu) did not produce infection.     

Investigation of biofilm production and icaA and icaD genes in Staphylococcus aureus isolated from heifers and cows with mastitis

Biofilm formation and antimicrobial resistance of Staphylococcus aureus are important virulence factors in cases of mastitis in dairy cows. However, few studies have investigated mastitis strains isolated from heifers. Within this context, the objective of the present study was to investigate biofilm formation on Congo red agar, the presence of the icaA and icaD genes by polymerase chain reaction (PCR), and the percentage of in vitro antimicrobial resistance of 110 S. aureus isolates from mammary gland secretions of heifers and cows with mastitis. PCR detected the icaA and icaD genes in 98% and 100% of isolates, respectively. However, only 55.5% of all isolates produced a biofilm on Congo red agar. Antimicrobial susceptibility testing revealed that 47.0% of isolates from heifers and 70.4% of isolates from cows were resistant to at least one of the antimicrobial agents tested. Resistance to penicillin and/or ampicillin was the most frequent (44.5%). These results indicate the need to implement prophylactic and control measures of mastitis for heifers. Heifers and cows can carry resistant strains with the capacity of biofilm production, a fact representing a threat to public health and animal well‐being and generating losses to dairy farmers.     

Some Factors Affecting the Abortion Rate in Dairy Herds with High Incidence of Neospora‐Associated Abortions are Different in Cows and Heifers

The aim of this study was to determine if the factors affecting the abortion rate in dairy herds with high incidence of Neospora‐associated abortions are different in pregnancies of cows and heifers chronically infected with Neospora caninum. In heifers (n = 229), an increase in the cumulative number of days with a mean relative humidity (RH) lower than 60% during the second trimester of gestation increases the risk of abortion. Yet, the likelihood of abortion was 7.6 times lower for pregnant heifers inseminated with Limousin bull semen, compared with those inseminated with Holstein‐Friesian bull semen. In pregnancies of parous cows (n = 521), an increase in rainfall and in the cumulative number of days with a mean RH lower than 60% during the second trimester of gestation increased the abortion rate. However, in contrast, an increase in the lactation number produced a decrease in the abortion rate, with a likelihood of abortion 4.8 times lower for pregnant cows inseminated with Limousin bull semen, and three times lower for those inseminated with Belgian Blue bull semen, compared with dairy cows inseminated with Holstein‐Friesian bull semen. Finally, the likelihood of abortion was 3.2 times lower for pregnancies of parous cows with low antibody titres against N. caninum (6–30 units) as compared to those with high antibody titres (≥30 units), whereas in heifers this variable had no effect. The practical recommendations of the present study include the control of the cow environment during the second trimester of gestation, the priority of culling for parous cows with higher antibody titres against N. caninum and the insemination of Neospora‐seropositive cows with semen from the Limousin breed.     

An Outbreak of Pseudomonas Mastitis in Dairy Cows

An outbreak of mastitis in a dairy herd is described in which the causative organism was Pseudomonas aeruginosa. Cases occurred either in dry cows or in animals which had very recently calved. The fact that all four quarters were involved is a very strong indication that the bacteria had been introduced in the dry cow therapy.     

Body condition and dislocated abomasum: comparative investigations into back fat thickness and additional criteria in cattle

The body condition, the kind of parturition, the milk yield and diseases during early lactation were investigated in 228 cows including heifers. Overconditioning (back fat thickness > 30 mm) before parturition resulted in cows falling ill with mastitis and abomasal displacement (DA). These cows mobilised the most fat in comparison with healthy cows and cows suffering from different diseases after parturition. Especially heifers (83%) which gave birth to heavier male calves fell ill with DA, therefore needed assistance during labour because of dystocia. Besides DA additional disturbances occurred in those heifers, e.g. 50% mastitis, and 30% retentio secundinarum in this investigation. The daily milk yield amounted to 13.1 kg in cows with DA and to 23 kg in healthy cows. The presented results support the classification of DA into the fat mobilisation syndrome. Consequently overconditioning and stress during parturition need to be avoided to prevent DA.     

A review of prevention and control of heifer mastitis via non-antibiotic strategies

Clinical and subclinical mastitis is a significant problem in primiparous dairy cattle (heifers) with a higher prevalence and incidence in heifers than cows, especially early in lactation. Differences in management (e.g. nutrition, pasturing, no use of dry cow therapy) as well as differences in physiological status (e.g. continuing growth in heifers) are likely contribute to the observed differences between heifers and cows. These differences may result in the requirement for different approaches for mastitis management in heifers than for cows. Mastitis is a multifactorial disease, hence control requires an understanding of the risk factors before effective interventions can be defined. Control strategies are aimed at reducing the incidence of new intramammary infections and eliminating existing infections. Potential strategies can include improved environmental and animal hygiene, application of internal and external teat sealants, prepartum application of teat antiseptics, prepartum milking and control of horn fly in environments where it acts as vector. Other less well-proven strategies to control heifer mastitis include management of heifers as a physically separate group from older cows and not feeding mastitic milk to calves. It is concluded that several well-proven strategies are available to manage heifer mastitis. However, further research is likely to improve understanding of heifer mastitis and lead to novel managerial approaches to mastitis control in this age group.