Aetiology of clinical mastitis in six Somerset dairy herds

Abstract

Clinical mastitis was monitored in six Somerset dairy herds for one year. The herds all had three-month geometric mean bulk milk somatic cell counts of less than 250,000 cells/ml. Escherichia coli was the predominant pathogen isolated on all the farms and in all months of the year. Environmental pathogens accounted for 61.4 per cent of all cases of clinical mastitis and for 79.3 per cent of the mastitis cases in which an aetiological agent was identified. The mean annual incidence was 41.6 cases per 100 cows (range 14 to 75). Affected cows suffered a mean of 1.5 cases and 16.4 per cent of quarters suffered at least one repeat case. Mastitis due to E. coli was more severe than mastitis due to other causes and it tended to be more severe in early lactation and during the housing period. Mastitis was significantly more severe (grades 2 and 3) in the herd with the lowest bulk milk somatic cell count and in the herd which was kept indoors throughout the year than in the other four herds. Mastitis was fatal in 2.2 per cent of cases and resulted in the death of 0.6 per cent of the lactating cows.

Production effects related to mastitis and mastitis economics in dairy cattle herds

“…Gram negative pathogens lead to a higher fatality rate. This was shown by Bradley and Green [14] who reported a three-times higher specific mortality rate (0.6% of the lactating cows) and a high fatality rate (2.2%) in 6 herds, due to a high incidence of Gram-negative-bacteria induced clinical cases. Upon studying necropsy records, Hazlett et al [28] already reported that, out of 145 cases that had bacteriological results, Escherichia coli was involved in 74% of them, Klebsiella sp.…”

Emergence of Macrolide Resistance Gene mph (B) in Streptococcus uberis and Cooperative Effects with rdmC -Like Gene

“…It is also the predominant organism isolated from mammary glands during the nonlactating period (2,14). ␤-Lactams are the drugs of choice for therapy of S. uberis infections during lactation and at drying off (6,27).…”

A contribution on Coliforms causing mastitis in cows with reference to serotypes and virulence factors of E. coli isolates

“…In this study, slime factor production of MRSA isolates were detected by PCR targeting icaA and icaD genes and found that 5 [4] . Also [31] found that 75% of MRSA carried ica operon. The icaAD gene was detected in 32% of Staphylococcal spp.…”

“…Slime-producing S. aureus isolates from different clinical origins such as bovine mastitis [4,10] , wound infection [12] and clinical cases [31] has been detected in vitro by using Congo Red Agar plates in percentages of 37.2, 91.4, 52 and 53.3%, respectively. Phenotype on CRA was found to be an unreliable indicator of slime-forming capacity among clinical isolates of S. aureus [32] .…”