- Email: [email protected]
The strangles streptococcus
ABSTRACTS. toxin, and the toxicity of normal nervous substance has also been demonstrated. Nevertheless, it is difficult to ascribe the accidents occurring in connection with rabies inoculations either to the true rabic toxin or to toxicity of tissue. But the fact remains that in the dog, guinea-pig, and rabbit, rabiform fatal accidents may be the result of inoculation with an emulsion of the nerve centres, either rabic or not rabic, without the inoculation of the brain of the dead animal proving virulent for the rabbit. The conclusions which may apparently be drawn from the first researches by Marie and the experiments just described are given as follows : 1. The prevention of rabies in the dog is obtainable with safety by inoculation with sero-vaccines (without excess of serum) and fixed virus. 2. The strength of the resistance thus obtained is proportional to the amount of the vaccinating material employed. 3. In principle, sero-vaccination might apparently be utilised even for the protection of dogs already bitten, rabies having developed in these experiments in seven of the control dogs, while it was not possible to prove the existence of the disease in any of the treated dogs by inoculation into rabbits. 4. While admitting that the method may be efficacious in these last conditions, it is not without risk. It is extremely inconvenient owing to the fact that it could not be carried out except at a place where there is an antirabies institute, for elsewhere it would not be possible to obtain the necessary sero-vaccines. It may also be regarded as a defect of the method that the sero-vaccine is very slowly absorbed, and that in certain cases it favours the occurrence of septic accidents. 5. It also appears that, more frequently than with other methods in which one employs rabic virus, virus which has been kept for a long time, or virus in very small quantities, the sero-vaccination is followed by toxic accidents ascribable either to the rabic poison or to the toxicity of the heterologus cerebral matter. (" Revue Gen. de Med. Vet.," Vol. XXXII., 1923, p. 165.)
THE STRANGLES STREPTOCOCCUS. By BROCQ-RouSSEU, FORGEOT, and A. URBAIN. THE present article may be regarded as complementary to the one by the same authors, of which an abstract appeared in a preceding part of this Journal (p. 66). Marmorek, Aronson, and Neufeld were of opinion that the streptococcus of strangles was a species distinct from human streptococci, this opinion being based on the fact that a serum prepared with a single streptococcus protected against all human streptococci from different lesions but did not protect against the strangles streptococcus. That opinion was contested by Mery and Courmont. Besredka showed that when streptococci are passed through mice a certain number of times their virulence becomes greatly increased for these animals; that is to say, the streptococcus has lost its original characters and has been transformed into a new variety, which Besredka termed a "passage streptococcus." If, indeed, the monovalent serum obtained with this streptococcus proved active against streptococci of human origin, that was because these, according to Besredka's expression, had been made artificially uniform by passage from mice to mice. o
ABSTRACTS.
The same author observed that when Aronson experimented with a streptococcus that was at the outset pathogenic for mice, as is the case with the streptococcus of strangles, the serum had no effect on it. On the other hand, when the same microbe had been passed several times through mice and its virulence had thereby been much increased the same serum became active. The present authors observe that this view appears to be generally admitted, that is to say, when a streptococcus of known origin loses its individuality as the result of successive passages in mice it has thereby been transformed into a passage streptococcus. In the experiments described the authors have attempted to provide arguments of another kind in support of this conception. The question which they set out to answer was: Given a strangles streptococcus of which the antigenic power with regard to the antibodies of an antistrangles serum is known, does it lose this property either as a result of successive passages through laboratory animals or as a result of cultivation in certain media in vitro ? The authors had previously demonstrated that the streptococcus of strangles produces specific antibodies. If as the result of the first passages through animals other than horses, or when cultivated in certain media, the strangles streptococcus loses its initial character and takes on a new individuality, it ought no longer to be capable of fixing complement in presence of the sensitiser of antistrangles serum. For the experiments the authors used an antistreptococcus serum which contained 1500 units of antibody according to Calmette and Massol's method of titration. The antigen used was an emulsion of streptococci killed by alcohol-ether in the proportion of I centigram of streptococci for 20 C.C. of normal saline solution. In the passage experiments the inoculation was subcutaneous for the mouse, pleural for the rat, intra-peritoneal for the guinea-pig, and intravenous or peritoneal for the rabbit. After each animal's death blood was withdrawn from the heart and sown in serum broth. The antigenic value of the culture obtained was then tested in the usual way against the antistrangles serum. In the case of the mouse the quantity of culture injected varied according to the streptococcus used, from one-thousandth to one-twentieth c.c. of a 24 hours' culture in broth, and death on the average occurred in three days. Six strains were employed for the passage experiments and the result is shown in the following table : -
1st passage 2nd 3 rd 4th 5 th
No.!.
NO.2.
NO.3.
Units.
Units.
500 300 50 0 0
500 150 30 0 0
Units. 500 300 50 5 o
NO·4·
NO·5·
No.6.
500 300 50 o o
300 50 10 o
500 75 10 o o
Units.
Units. 500
Units.
The authors found that horse serum is toxic for white rats, and they therefore used for these animals cultures on agar instead of serum-broth cultures. Inoculation with a quarter or half a culture caused death in from 12 to 48 hours. The results were similar to those found in the experiments with mice. It was found that only two of the six strains were fatal for the rabbit, one of them by intravenous and the other by peritoneal inoculation, and
ABSTRACTS.
193
this applied also to the guinea-pig. Experiments with both these strains on rabbits and guinea-pigs had results similar to those obtained with the mouse and the rat. In short, the strangles streptococcus, as a result of the successive passages through mice, loses its power of fixing alexin in presence of the sensitiser of antistrangles serum; it acquires a new individuality and becomes a " passage streptococcus." The number of passages required to bring about this transformation appears to be a function of the resistance of the animal to infection: the longer the period elapsing between the infection and death the more quickly the streptococcus adapts itself to the new organism in which it is multiplying, and the more quickly it loses its equine character and becomes a streptococcus of the mouse, rat, rabbit, or guinea-pig. In what may be termed the culture passage experiments it was found that the virulence of certain strains of strangles streptococci for a given animal could be increased by making successive cultures of from 24 to 48 hours in Martin's broth to which a small quantity of blood from the animal in question had been added, and that when cultivated in this way the streptococci became modified in the same way as in the course of the passage experiments through animals. The transformation, however, took place more slowly, and it seemed to occur pari passu with morphological variations in the organism. (" Annales de l'Inst. Pasteur," Vol. XXXVII., 1923, p. 322.)
A CASE OF RABIES IN THE LION. By Y. MANQUELJAN and ]. VIALA. THE authors describe what appears to be the first indubitable case on record of rabies in the lion. Four young lionesses from Abyssinia, aged about eight months, were brought to Paris, and on their arrival there the owner observed that one of them appeared abnormal in its attitude. It became taciturn and dull, held itself separate, and· refused to eat. On the following day it was very excited and roared without ceasing. It was remarked that the tone of its voice was altered. After 24 hours this period of excitement terminated in paralysis of the hind quarters, which on the following day affected the forelegs also. The lioness died after a short convulsion, the total duration of the illness having been only three days. A veterinary surgeon who examined the animal during life diagnosed rabies. The post-mortem examination, which was made at the Pasteur Institute, showed no alteration in connection with the central nervous system or its envelopes, and the viscera also appeared normal. The stomach was empty, and examination of urine obtained by puncture of the bladder showed marked glycosuria. Sections of the hippocampus, stained by Mann's method, showed characteristic Negri corpuscles. These varied considerably in size and shape, and they were in most cases included in the cytoplasm and dendrites of the nerve cells. Most of them measured from 3 to IS microns. Generally those in the cytoplasm were rounded or oval, but they were fusiform in the protoplasmic prolongations. As is well known, these corpuscles are surrounded by a hyaline membrane and exhibit a definite structure. The stained corpuscles show a homogeneous red substance within which are seen so-called" inclusions"
THE STRANGLES STREPTOCOCCUS. By BROCQ-RouSSEU, FORGEOT, and A. URBAIN. THE present article may be regarded as complementary to the one by the same authors, of which an abstract appeared in a preceding part of this Journal (p. 66). Marmorek, Aronson, and Neufeld were of opinion that the streptococcus of strangles was a species distinct from human streptococci, this opinion being based on the fact that a serum prepared with a single streptococcus protected against all human streptococci from different lesions but did not protect against the strangles streptococcus. That opinion was contested by Mery and Courmont. Besredka showed that when streptococci are passed through mice a certain number of times their virulence becomes greatly increased for these animals; that is to say, the streptococcus has lost its original characters and has been transformed into a new variety, which Besredka termed a "passage streptococcus." If, indeed, the monovalent serum obtained with this streptococcus proved active against streptococci of human origin, that was because these, according to Besredka's expression, had been made artificially uniform by passage from mice to mice. o
ABSTRACTS.
The same author observed that when Aronson experimented with a streptococcus that was at the outset pathogenic for mice, as is the case with the streptococcus of strangles, the serum had no effect on it. On the other hand, when the same microbe had been passed several times through mice and its virulence had thereby been much increased the same serum became active. The present authors observe that this view appears to be generally admitted, that is to say, when a streptococcus of known origin loses its individuality as the result of successive passages in mice it has thereby been transformed into a passage streptococcus. In the experiments described the authors have attempted to provide arguments of another kind in support of this conception. The question which they set out to answer was: Given a strangles streptococcus of which the antigenic power with regard to the antibodies of an antistrangles serum is known, does it lose this property either as a result of successive passages through laboratory animals or as a result of cultivation in certain media in vitro ? The authors had previously demonstrated that the streptococcus of strangles produces specific antibodies. If as the result of the first passages through animals other than horses, or when cultivated in certain media, the strangles streptococcus loses its initial character and takes on a new individuality, it ought no longer to be capable of fixing complement in presence of the sensitiser of antistrangles serum. For the experiments the authors used an antistreptococcus serum which contained 1500 units of antibody according to Calmette and Massol's method of titration. The antigen used was an emulsion of streptococci killed by alcohol-ether in the proportion of I centigram of streptococci for 20 C.C. of normal saline solution. In the passage experiments the inoculation was subcutaneous for the mouse, pleural for the rat, intra-peritoneal for the guinea-pig, and intravenous or peritoneal for the rabbit. After each animal's death blood was withdrawn from the heart and sown in serum broth. The antigenic value of the culture obtained was then tested in the usual way against the antistrangles serum. In the case of the mouse the quantity of culture injected varied according to the streptococcus used, from one-thousandth to one-twentieth c.c. of a 24 hours' culture in broth, and death on the average occurred in three days. Six strains were employed for the passage experiments and the result is shown in the following table : -
1st passage 2nd 3 rd 4th 5 th
No.!.
NO.2.
NO.3.
Units.
Units.
500 300 50 0 0
500 150 30 0 0
Units. 500 300 50 5 o
NO·4·
NO·5·
No.6.
500 300 50 o o
300 50 10 o
500 75 10 o o
Units.
Units. 500
Units.
The authors found that horse serum is toxic for white rats, and they therefore used for these animals cultures on agar instead of serum-broth cultures. Inoculation with a quarter or half a culture caused death in from 12 to 48 hours. The results were similar to those found in the experiments with mice. It was found that only two of the six strains were fatal for the rabbit, one of them by intravenous and the other by peritoneal inoculation, and
ABSTRACTS.
193
this applied also to the guinea-pig. Experiments with both these strains on rabbits and guinea-pigs had results similar to those obtained with the mouse and the rat. In short, the strangles streptococcus, as a result of the successive passages through mice, loses its power of fixing alexin in presence of the sensitiser of antistrangles serum; it acquires a new individuality and becomes a " passage streptococcus." The number of passages required to bring about this transformation appears to be a function of the resistance of the animal to infection: the longer the period elapsing between the infection and death the more quickly the streptococcus adapts itself to the new organism in which it is multiplying, and the more quickly it loses its equine character and becomes a streptococcus of the mouse, rat, rabbit, or guinea-pig. In what may be termed the culture passage experiments it was found that the virulence of certain strains of strangles streptococci for a given animal could be increased by making successive cultures of from 24 to 48 hours in Martin's broth to which a small quantity of blood from the animal in question had been added, and that when cultivated in this way the streptococci became modified in the same way as in the course of the passage experiments through animals. The transformation, however, took place more slowly, and it seemed to occur pari passu with morphological variations in the organism. (" Annales de l'Inst. Pasteur," Vol. XXXVII., 1923, p. 322.)
A CASE OF RABIES IN THE LION. By Y. MANQUELJAN and ]. VIALA. THE authors describe what appears to be the first indubitable case on record of rabies in the lion. Four young lionesses from Abyssinia, aged about eight months, were brought to Paris, and on their arrival there the owner observed that one of them appeared abnormal in its attitude. It became taciturn and dull, held itself separate, and· refused to eat. On the following day it was very excited and roared without ceasing. It was remarked that the tone of its voice was altered. After 24 hours this period of excitement terminated in paralysis of the hind quarters, which on the following day affected the forelegs also. The lioness died after a short convulsion, the total duration of the illness having been only three days. A veterinary surgeon who examined the animal during life diagnosed rabies. The post-mortem examination, which was made at the Pasteur Institute, showed no alteration in connection with the central nervous system or its envelopes, and the viscera also appeared normal. The stomach was empty, and examination of urine obtained by puncture of the bladder showed marked glycosuria. Sections of the hippocampus, stained by Mann's method, showed characteristic Negri corpuscles. These varied considerably in size and shape, and they were in most cases included in the cytoplasm and dendrites of the nerve cells. Most of them measured from 3 to IS microns. Generally those in the cytoplasm were rounded or oval, but they were fusiform in the protoplasmic prolongations. As is well known, these corpuscles are surrounded by a hyaline membrane and exhibit a definite structure. The stained corpuscles show a homogeneous red substance within which are seen so-called" inclusions"