BREEDING INFLUENZA MICROBES

Dominion, Volume 12, Issue 137, 5 March 1919, Page 6

BREEDING INFLUENZA MICROBES

SYDNEY'S FIGHT WITH THE EPIDEMIC

HUGE DEMAND FOR VACCINE

Tlio laboratory of tho Royal North Shore Hospital in Sydney has been mo=t active during the past ten days (states an article in the Sydney "Sun'). when enough vaccine to inoculate about 00,0(10 people has been prepared. For a while no preparations for making vaccine were made by the New South Wales Health authorities, because Melbourne liacl promised to provide ample vaccina to inoculate the total population of New South Wales should the necessity 'arise. Tho supply was short, however, and Dr. Bradley was hastily rung up and asked how soon he could get to work. "Five minutes," was the reply. As soon hs the beefsteak arrived it was-, put through a sausage machine and soaked in water for 24 hours, and boiled, i per cent, of salt added, then filtered free from solid and fat particles. Next 1 per cent, of peptone (British make) was added, then the mixture was measured, filtered, and stiffened with agar. (Agar is a substance akin to gelatine, but stands a higher temperature without melting, and is consequently more suited .to our climatic conditions.) '.'.he last addition, just before the mixture was cold but not set, was fresh human blood.

This medium forms the breeding ground for the influenza, bacilli. Just us earth is nicely fertilised in order to grow seeds to the best advantage, so. a dainty nutritive diet must be supplied to the bacteria. All cultures sent across by the. Board of Health are on a similar medium, and a thin bacterial growth is perceived on the sloped surface of each, -inside the phials supplied.This is the stock—but as the vaccine contains a mixture of two dozen "strains" of different organisms,, includ•ing those of pneumonia, influenza, septicaemia, common cold in the head, and certain unknown organisms isolated from cases of the true 'flu—so each stock culture of the various "strains" must be kept goini? by sub-cultivating a large number daily. Otherwise the stock would run out.

Transplanting Bacilli

A sterilised platinum wire needle is used to skim off the film of growth in n, stock tube, and the "bacilli aro transplanted on to a nice fresh surface slope of blood-agar, where they dovelop rapidlv. Some take 2 J hours, others 48—it all depends on the different "strain" of culture.

This process is the solid "culture"— but the pneuniococci thrive best in a fluid culture which is also prepared on a basis of broth.

The preparation of tho third cultures is much simpler. A small amount of snliiie (snlt) solution is poured into a fflass phial, and the "cocci" are drawn off with a very fine glass tube (just as in the "solid" they are drawn off with a platinum- needle), and placed in the solution.

This living germ emulsion is then filtered to clear it of lumps of agar, and is made up in >a tube. Glass elides nre prepared, stained, and examined under the lnioi'osoope, to see that they are O.K. If nny foreign substance should appear that culture is condemned and destroyed. This is only one branch of tho work connected with' fluid cultures. The other is the centrif'Jgilisation method of fronting broth cultures. In this tho tk'id emulsion is plnced in tubes, and fitted on to a centrifugal machine, which, run by an electric motor, reivolvcs at a tremendously rapid rate. Whl-n the machine is ' stopped—each 'batch takes twent,r minutes—a deposit is found to hnve collected at the base of tji3 tubes, and from that deposit a solution is made. , At eacli stage sterilisation takes place, and everything is checked repeatedly under the microscope by the medical officers. Each series of strains i=, bulked toKcthcr and then tha sterilising process is ; undergone for one hoiir in a steam I inhalator, at a temperature of GOdeg. I centigrade. After being "cooked," the i mixture is standardised, and then the I various emulsions are mixed together i according to the Board of Health's direcj tions. I The "dope" is then bottled in phials containing' a certain number of doses, corked with paraffin-dipped corks (to ensure their being air-tight), labelled, aud packed ready for dispatch. Through the Microscope. The vaccine with which cveryono is being inoculated at the present time contains 75 per cent, of bacillus influenzae. Seen through the microscope, these myriads of bacteria look like tiny stipples, suggestivo of exclamation marliu cut in half. Diplococcus pneumonae (vel fiieiimococcus), the common cause of pneumonia, are funny little lanceolateshaped specimens, reminiscent of two tiny stone arrowheads. They alwaye travel in pairs—so sociablo! The micrococcus catarrhalis (ordinary cold in the head) are two littlo kidney-shaped halves, who, like the pneumococci, hate to be separated. .The streptococcus is the septicaemia organism, which, under the. microscope, appears to be a continuous chain of little dots the eize of email full stops. 'I'ho staphylococcus, the cause of suppurative processes, such as boils, ■ etc., look like attractive bunohes of grapes the size of pin heads. The reason for such an extraordinary mixture is to make the vaccine as polyvalent as possible. In plain Englishas representative as possible. Pneumonic influenza is a unique j complaint. It has phases of 60 many others, yet retains an infective iridfI viduality which makes it most difficult to combat—hence the variety of bodyguards it has been found, necessary to inject into the human system to com. bat it.

Drawing Human Blood. After the mosquitoes have dined liberally upon him, the Mirage man feels that he knows a champion blood-sucker when he meets one. But if lie wishes to meet an expert, let him call on Dr. Bradley at his laliora tor.v. He will quite cheerfully extract 10 cubic centimetres (el>out a tablespoon) of his blood quite painlessly, A rubber tourniquet is applied to the upper arm about four inches from the elbow, and ths hand is cOendipd. This for the moment congests the venous flow, and the superficial vein at tholiond of the elbow rises like a swollen miniature hose when the tap is turned on. Tho needle of a hypodermic syringe is inserted into the vein, and through tlio glass the victim sees iis be.iutiftil ruddy gore slowly filling tho syringe. The operation takes only a few minutes, and tits fresh Mood is squirted into a solution of saline and ether. A cloudy appearance is succeeded by n clear transparency—it has become "laked." In oilier words, the haemoglobin (rod colouring matter in the blood) is frfed from Hio cori>" c cles. and its utilisation by tlio Willi is thus made easier. Ten cubic centimetres of hnmnn liloou is sufficient for one litre of medium, and whoever i.i willing to offer up n tablespoon of blood in ihp cause of science is asked to call at the Royrl North Shore Hospital laboratory without delay.