Treatment of persistent intramammary infections with Streptococcus uberis in dairy cows

Abstract

A survey was conducted of the prevalence of environmental pathogens, especially Streptococcus uberis, as causes of clinical mastitis in dairy cows. The response of intramammary infections with S uberis to conventional treatment was monitored by taking milk samples for bacteriology and somatic cell counting seven, 14 and 21 days after the treatment. The results showed that 51 per cent of the infections failed to respond, and the odds of cases failing to respond was significantly increased when the individual quarter somatic cell count seven days after the treatment was greater than 201,000 cells/ml. Ninety-six per cent of the suspected S uberis isolates identified by culture were confirmed as S uberis by using the api 20 Strep system. Restriction endonuclease fingerprinting was used to type the strains of S uberis isolated from 75 milk samples from 32 cows. Analysis showed that 96 per cent of the cases of S uberis that failed to respond to conventional treatment were persistent infections with one strain rather than reinfections with different strains. The persistent cases of S uberis were treated further with an extended course of intramammary preparations containing either procaine penicillin with dihydrostreptomycin or cefquinome. There was no significant difference between the cure rates achieved by the two preparations, and 55 per cent of the cases that had failed to respond to conventional treatment responded to the additional treatment.

Identification of a Novel Streptococcal Gene Cassette Mediating SOS Mutagenesis in Streptococcus uberis

“…Streptococcus uberis is an environmental mastitis pathogen and a member of the pyogenic group of streptococci. In a recent study, 51% of S. uberis infections failed to respond to conventional antibiotic treatment and most of these infections were found to be persistent (40), suggesting the adaptability of this pathogen. At present, the mechanisms of adaptive mutagenesis in S. uberis, as well as in other Streptococcus species, are largely unexplored.…”

Efficacy of conventional and extended intra-mammary treatment of persistent sub-clinical mastitis with cefquinome in lactating dairy cows

“…Cefquinome is a fourth-generation cephalosporin which has been developed solely for veterinary use. Previously, the efficacy of intramuscularly and/or IMM-administered cefquinome has been shown for the treatment of CM in dairy cows (Shpigel et al 1997;Milne et al 2005;Palanivel et al 2005). The efficacy of systemically administered cefquinome was also evaluated for the treatment of sub-clinical mastitis in dry cows (Shpigel et al 2006) and pre-partum heifers (Ataee et al 2009).…”

Interleukin-1β infusion in bovine mammary glands prior to challenge with Streptococcus uberis reduces bacterial growth but causes sterile mastitis

“…Streptococcus uberis can also cause chronic subclinical infections that are difficult to detect, but lead to an elevated milk somatic cell count (SCC) and poor milk quality (Leigh 1999). In some cases, chronic S. uberis infections are refractory to antibiotherapy (Milne et al 2005).…”