Moderate Inflammatory Reaction During Experimental Escherichia coli Mastitis in Primiparous Cows

Abstract

Nineteen primiparous cows were experimentally infected in 2 quarters with 1 × 10 4 (group A) or 1 × 10 6 (group B) cfu of Escherichia coli P4:O32 per quarter within 2 to 4 wk after parturition. Blood and milk samples were collected from all primiparous cows at regular time intervals from d −4 to d +3 relative to inoculation. Milk production rapidly decreased in both groups during E. coli mastitis, but recovery appeared to be faster in group B at d + 1 postinfusion (p.i.). The milk production losses in the noninfected quarters were substantial on the day of inoculation, which is probably due to pronounced systemic effects. However, on d + 2 p.i. milk production in the noninfected quarters nearly reached preinfection levels, indicating a moderate clinical severity following intramammary inoculation. None of the other severity criteria evolved towards a severe response pattern. Reticulorumen motility was inhibited in both groups during E. coli mastitis. The clinical episode was short lasting in both groups. Rectal temperature, heart rate, blood leukocyte count, number of colony-forming units, milk somatic cell count and several indicators for the disintegration of the blood-milk barrier returned to normal values within 24 to 72 h p.i. Primiparous cows reacted with a moderate inflammatory response following intramammary infusion with a relatively high dose of E. coli. Despite the use of a high inoculum dose, primiparous cows in both groups showed pronounced resistance against severe intramammary E. coli infection. A possible effect of the inoculum dose could be present, however, further research into the effect of the inoculum dose on the inflammatory response should be performed.

Morphometric analysis of proinflammatory cytokines in mammary glands of sows suggests an association between clinical mastitis and local production of IL-1beta, IL-6 and TNF-alpha

“…Possibly, in these sows there may be abundant and regulated release of anti-inflammatory mediators [40,53], limiting the production of the inflammatory cytokines. However, in accordance with our results, previous studies in cows have shown a significant increase in the proinflammatory cytokines at the level of both mRNA [33,37] and protein [6,11,26,32,45,48,54] in either mammary tissues or milk collected from the infected glands following intramammary inoculation with E. coli. The results here indicate that the development of clinical symptoms of coliform mastitis in the sow is associated with a locally increased proinflammatory cytokine production in response to intramammary E. coli infection.…”

Effect of Carprofen Treatment Following Experimentally Induced Escherichia coli Mastitis in Primiparous Cows

“…Clinical scores, combining several clinical parameters, have been described (Wenz et al, 2001;Friton et al, 2002;Vangroenweghe et al, 2004a). Using the clinical severity score described by Vangroenweghe et al (2004a), carprofen-treated animals had a significantly lower clinical score at PIH 12 and 15 compared with the saline-treated group (Table 3).…”

“…Using the clinical severity score described by Vangroenweghe et al (2004a), carprofen-treated animals had a significantly lower clinical score at PIH 12 and 15 compared with the saline-treated group (Table 3). Although, as expected from previous trials, all animals in both groups responded mildly to moderately following E. coli challenge, the carprofen-treated animals generally showed a lower clinical severity score within 3 h of NSAID administration.…”

“…Based on the clinical severity scoring system by Vangroenweghe et al (2004a), clinical scores increased to a maximum in both treatment groups at PIH 12. The clinical severity score in the carprofen-treated group decreased more rapidly from 6 h posttreatment onwards.…”

“…After each incubation, the Table 2. Severity estimation scheme, based on systemic disease signs, for the classification of heifers following an experimental inoculation with Escherichia coli P4:O32 (Vangroenweghe et al, 2004a). Briefly, the 4 parameters are scored, total score is calculated, and compared with respective ranges for classification into mild, moderate, or severe disease.…”