Hæmolytic streptococcal infections in the rabbit / by H.J. Parish and C.C. Okell.

  • Parish, H. J. (Henry James)
Date:
1928?]
Catalogue details

Licence: In copyright

Credit: Hæmolytic streptococcal infections in the rabbit / by H.J. Parish and C.C. Okell. Source: Wellcome Collection.

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    potency in doses of 0*25 c.cm. to 1 c.cm., given intravenously, afford considerable protection against the acute phases of the septicaemia, although the majority of rabbits develop a subacute infection towards the end of the first week or later. This is Table I. Rabbits injected intravenously with 10 c.cm. of 20-hour digest broth cultures of the scarlet fever streptococcus (S.F. 1). Antitoxic serum given intravenously 4 to 6 hours previously. • CG •i—< rO rO c3 r—H Percent, living six days after injection of serum. Serum. C.cm. +3 o EH 5 or more. 1-0 0-25 0-1 Normal horse .. .. .. \ Concentrated diphtheria .. .. 1 120 6 „ tetanus .. .. ' Unconcentrated scarlet fever (early*')—Batch “ P ” . . 9 66 0 • • • • Unconcentrated scarlet fever (later*)—Batch “ Q ” 15 77 33 • • • • Concentrated scarlet fever— Batch “ It ” . 15 88 66 33 • • Batch “ S ” . 12 100 100 66 33 Batch “ T ” . 9 • • 100 100 33 Unconcentrated pyogenes .. 26 27 Concentrated ,, 6 66 Unconcentrated puerperal.. 32 56 Concentrated „ 13 54 Unconcentrated erysipelas.. 14 21 Concentrated ,, 10 40 * Stage of immunisation. characterised mainly by arthritic lesions from which haemolytic streptococci can readily be recovered. Protection has never been obtained against this phase of the infection with any antitoxic or anti¬ bacterial serum we have used. Many antistreptococcal sera, other than scarlatinal, prepared by the immunisation of horses with filtrates of haemolytic streptococci have some protective properties in doses of 5 c.cm. or more. Experiments have been carried out with 14 unconcentrated and 4 concentrated antitoxins prepared from pyogenes, puerperal fever, and erysipelas strains. The percent¬ ages of rabbits which survived for 6 days ranged from 21 per cent, of those injected with unconcentrated erysipelas to 66 per cent, of those injected with concentrated pyogenes antitoxins. The protection given by the various sera correspond roughly to the amount of streptococcal antibody which they might be expected to contain from collateral evidence. The filtrates which were prepared from pyogenes,