Streptococcus equi ssp. equi is a haemolytic bacterium which causes an upper respiratory infection in horses, called strangles. Strangles is the most frequently diagnosed infectious disease in horses worldwide [1]. Strangles is highly contagious and is characterized by swollen lymph nodes and fever, eventually leading to death of young horses through suffocation and is thus of substantial economic concern in horse business [1]. Resistance to drugs has been reported to be low, with the exception of gentamicin [2]. Complication rate is, however high, with 20 % of the cases leading to severe infection and fatality [3]. To the best of our knowledge, there is a limited number of investigations concerning the use of plants and their extracts or individual compounds for prophylaxis and treatment of strangles.
Piperidine alkaloid enriched fractions were extracted from young shoots of Picea abies, using acid water and solid phase extraction [4]. Some of the fractions were separated further using RP18-TLC. The fractions were investigated for their growth inhibitory effects against S. equi ssp. equi ATCC 9528 using a microdilution method [5]. At 265-487 µg/ml, the fractions inhibited 45-100 % of the growth. A fraction enriched with trans-pinidinol gave especially good effects resulting in a MIC at 335 µg/ml. Our results indicate that young shoots of spruce and their alkaloid enriched extracts could be used both as prophylaxis and for treatment of strangles.
Acknowledgements:
The research was financed by the Academy of Finland (No. 267360)
References:
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[2] Sweeney, C.R. et al. J Vet Intern Med 2005; 19:123–134
[3] Ford J, Lokai MD. Equine Pract 1980;4:41–44
[4] Virjamo, V. et al. J. Chem. Ecol. 2013; 39: 1322 – 1334
[5] Salih, E. et al. S Afr J Bot 2017; 108: 370-386