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DECAPSULATING THE PNEUMOCOCCUS
1402
ANNOTATIONS DECAPSULATING THE PNEUMOCOCCUS
IN our issue of May 28th Dr. L. E. H. Whitby reported that a newly synthesised sulphonamide compound, 2-(p-aminobenzenesulphonamido) pyridine, has a remarkable action on pneumococcal infection in mice. This drug is now in the early stages of clinical trial, and the first detailed report of its action in pneumonia, by Dr. Maxwell Telling and Dr. W. A. Oliver, will be found on p. 1391. This report is of a preliminary nature, only three cases having been studied, but it contains an observation of great interest, which points to a direction in which future This observation cases may usefully be investigated. is that shortly after administration ofthe drug, pneumococci in the sputum lose their capsules, a change indicated both by applying appropriate staining methods and by loss of agglutinability by type-specific serum. The capsule of the pneumococcus is its defence against phagocytic attack ; stripped of this defence its virulence is lost. That these degraded cocci were indeed those responsible for the pneumonia was proved by mouse passage, as a result of which they recovered their capsules and original type specificity. It may be remembered that an observation corresponding to this was made by Whitby in his mouse experiments ; after the fourth hour the capsules of pneumococci in the peritoneum showed degenerative changes and later disappeared. Here therefore is a clue to the mode of action of this and at the same time perhaps a contribution to the vexed and more general question of how sulphonamide compounds act on bacteria. In this connexion it is of interest that no less than three years agoa long time in the brief history of this remarkable form of therapy-Levaditi and Vaismanput forward the hypothesis that Prontosil acts on hsemolytic streptococci by preventing the formation of capsules, thus rendering them susceptible to phagocytosis. This idea, together with allegations that toxin formation is prevented, has not been generally accepted. The capsule of the pneumococcus is much more readily demonstrable than that of Streptococcus pyogenes, and future studies of chemotherapy in infections due to this organism should take note of its behaviour. Should this phenomenon of decapsulation be constantly observed it will afford an ample immediate explanation of therapeutic action, but the mechanism by which this change is brought about will still remain to be explained. We have not really got much further than being able to say that these drugs interfere in some way with the activities of bacteria. It is something to be sure that the action is on the bacteria themselves and not a more indirect one ; of this the present observation seems to provide further evidence.
drug
LEGAL RISKS OF PROFESSIONAL PRACTICE
Sir Cuthbert Wallace said last week, as president of the London and Counties Medical Protection Society, that about a tenth of the members apply to the society for advice or assistance every year. This gives some idea of the perils to which the medical and perhaps an or dental practitioner is subject ; even more pregnant warning was implicit in the observation of the treasurer, Mr. W. M. Mollison, that one case had recently cost the society ;E7000. 1 Levaditi, C., and Vaisman, A., C.R. Soc. Biol. Paris, 1935, 119, 946.
The annual meeting of the society was the occasion for a survey of some of the most usual grounds which may lay the doctor open to attack, and others are quoted in the report for 1937. These include, as usual, failure to insist on a radiogram in cases of suspected fracture or alternatively to obtain from the patient written confirmation of his refusal to submit to radiography ; absence of records of visits to or from patients or of the exact nature of the treatment given or of the lesion found at examination ; technical inaccuracy, however trivial, in the issue of certificates ; and discard of the available pieces of hypodermic needles broken during injections. Sir Cuthbert noted that hospital authorities are now insisting that their resident medical officers should join a protection society; and, as an example of the dangers to which medical officers of health are liable, recalled the action of the society in briefing leading counsel on behalf of the medical officer of health for Croydon, who was completely exonerated by the tribunal appointed by the Ministry of Health to inquire into the typhoid epidemic there. The condensed advice set out in tabular form on p. 5 of the annual report is well worth the attention of both doctors and
dentists. HOW DOES POLIOMYELITIS SPREAD?
THE general belief is that poliomyelitis is conveyed direct personal contact, and this is the opinion endorsed by Sir Arthur MacNalty in the review contributed to our columns on June 4th. It cannot be said however that the contagion theory is completely established, and Dr. Lumsden, medical director of the United States Public Health Service, has lately given some interesting reasons for doubting it.l The lower incidence of the disease in tropical and semitropical regions and in the more temperate lands adjacent to them has usually been attributed to warm weather being favourable to the spread of the virus, and hence to general immunisation against it. This hypothesis, applied to the United States, has been held to account for the regularly higher incidence
by
in the northern States ; but as Lumsden points out, the last three or four years have seen extensive outbreaks in the South. These outbreaks, too, have been remarkably regional in their distribution and it is impossible to say that the disease has " spread along lines of human traffic." For example the epidemic of 1936 in Alabama was almost confined to a limited area in the north-western part, and it is hard to see why, with frequent and general human intercourse, the disease should not have been spread all over the State by carriers. It seems impossible to this in localisation terms of susceptibles or explain meteorological or other conditions. Equally mysterious is the distribution of cases within a locality ; for they often appear in separate homes some miles apart without there being any evidence of direct or indirect personal contact.2 The seasonal incidence is likewise an enigma. Poliomyelitis here differs, as Lumsden remarks, from diseases that have been definitely proved to be contagious and to spread in the secretions or discharges from the noses or throats, and its seasonal distribution resembles rather that of typhoid fever, dysentery, yellow fever, malaria, and typhus fever (caused by rat-harboured infection). He therefore believes that some other hypotheses of spread ought to be developed and worked upon. 1 2
Sth. med. J., Nashville, May, 1938, p. 465. U.S.A. Public Health Bulletin. No. 228.
ANNOTATIONS DECAPSULATING THE PNEUMOCOCCUS
IN our issue of May 28th Dr. L. E. H. Whitby reported that a newly synthesised sulphonamide compound, 2-(p-aminobenzenesulphonamido) pyridine, has a remarkable action on pneumococcal infection in mice. This drug is now in the early stages of clinical trial, and the first detailed report of its action in pneumonia, by Dr. Maxwell Telling and Dr. W. A. Oliver, will be found on p. 1391. This report is of a preliminary nature, only three cases having been studied, but it contains an observation of great interest, which points to a direction in which future This observation cases may usefully be investigated. is that shortly after administration ofthe drug, pneumococci in the sputum lose their capsules, a change indicated both by applying appropriate staining methods and by loss of agglutinability by type-specific serum. The capsule of the pneumococcus is its defence against phagocytic attack ; stripped of this defence its virulence is lost. That these degraded cocci were indeed those responsible for the pneumonia was proved by mouse passage, as a result of which they recovered their capsules and original type specificity. It may be remembered that an observation corresponding to this was made by Whitby in his mouse experiments ; after the fourth hour the capsules of pneumococci in the peritoneum showed degenerative changes and later disappeared. Here therefore is a clue to the mode of action of this and at the same time perhaps a contribution to the vexed and more general question of how sulphonamide compounds act on bacteria. In this connexion it is of interest that no less than three years agoa long time in the brief history of this remarkable form of therapy-Levaditi and Vaismanput forward the hypothesis that Prontosil acts on hsemolytic streptococci by preventing the formation of capsules, thus rendering them susceptible to phagocytosis. This idea, together with allegations that toxin formation is prevented, has not been generally accepted. The capsule of the pneumococcus is much more readily demonstrable than that of Streptococcus pyogenes, and future studies of chemotherapy in infections due to this organism should take note of its behaviour. Should this phenomenon of decapsulation be constantly observed it will afford an ample immediate explanation of therapeutic action, but the mechanism by which this change is brought about will still remain to be explained. We have not really got much further than being able to say that these drugs interfere in some way with the activities of bacteria. It is something to be sure that the action is on the bacteria themselves and not a more indirect one ; of this the present observation seems to provide further evidence.
drug
LEGAL RISKS OF PROFESSIONAL PRACTICE
Sir Cuthbert Wallace said last week, as president of the London and Counties Medical Protection Society, that about a tenth of the members apply to the society for advice or assistance every year. This gives some idea of the perils to which the medical and perhaps an or dental practitioner is subject ; even more pregnant warning was implicit in the observation of the treasurer, Mr. W. M. Mollison, that one case had recently cost the society ;E7000. 1 Levaditi, C., and Vaisman, A., C.R. Soc. Biol. Paris, 1935, 119, 946.
The annual meeting of the society was the occasion for a survey of some of the most usual grounds which may lay the doctor open to attack, and others are quoted in the report for 1937. These include, as usual, failure to insist on a radiogram in cases of suspected fracture or alternatively to obtain from the patient written confirmation of his refusal to submit to radiography ; absence of records of visits to or from patients or of the exact nature of the treatment given or of the lesion found at examination ; technical inaccuracy, however trivial, in the issue of certificates ; and discard of the available pieces of hypodermic needles broken during injections. Sir Cuthbert noted that hospital authorities are now insisting that their resident medical officers should join a protection society; and, as an example of the dangers to which medical officers of health are liable, recalled the action of the society in briefing leading counsel on behalf of the medical officer of health for Croydon, who was completely exonerated by the tribunal appointed by the Ministry of Health to inquire into the typhoid epidemic there. The condensed advice set out in tabular form on p. 5 of the annual report is well worth the attention of both doctors and
dentists. HOW DOES POLIOMYELITIS SPREAD?
THE general belief is that poliomyelitis is conveyed direct personal contact, and this is the opinion endorsed by Sir Arthur MacNalty in the review contributed to our columns on June 4th. It cannot be said however that the contagion theory is completely established, and Dr. Lumsden, medical director of the United States Public Health Service, has lately given some interesting reasons for doubting it.l The lower incidence of the disease in tropical and semitropical regions and in the more temperate lands adjacent to them has usually been attributed to warm weather being favourable to the spread of the virus, and hence to general immunisation against it. This hypothesis, applied to the United States, has been held to account for the regularly higher incidence
by
in the northern States ; but as Lumsden points out, the last three or four years have seen extensive outbreaks in the South. These outbreaks, too, have been remarkably regional in their distribution and it is impossible to say that the disease has " spread along lines of human traffic." For example the epidemic of 1936 in Alabama was almost confined to a limited area in the north-western part, and it is hard to see why, with frequent and general human intercourse, the disease should not have been spread all over the State by carriers. It seems impossible to this in localisation terms of susceptibles or explain meteorological or other conditions. Equally mysterious is the distribution of cases within a locality ; for they often appear in separate homes some miles apart without there being any evidence of direct or indirect personal contact.2 The seasonal incidence is likewise an enigma. Poliomyelitis here differs, as Lumsden remarks, from diseases that have been definitely proved to be contagious and to spread in the secretions or discharges from the noses or throats, and its seasonal distribution resembles rather that of typhoid fever, dysentery, yellow fever, malaria, and typhus fever (caused by rat-harboured infection). He therefore believes that some other hypotheses of spread ought to be developed and worked upon. 1 2
Sth. med. J., Nashville, May, 1938, p. 465. U.S.A. Public Health Bulletin. No. 228.