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by bacteria, and from that time to the present our knowledge of bacterial and parasitic diseases has increased steadily.

Preventive medicine, the medicine of the future and the ideal of the profession, finds its most important field in the realm of bacterial and parasitic diseases.

Bacteria, as you know, are the lowest form of plant life. Those who have not themselves worked in a bacteriological laboratory sometimes find it difficult to get a clear conception of what bacteria are like, how they grow, and how, they cause disease. Let us consider first a few elementary facts concerning bacteria. Of the common forms of plant life yeasts and moulds are perhaps the nearest to bacteria. Yeasts and moulds, as you know, grow on bread, meat, cheese, etc., and flourish in dark and moist places, as do all other fungi. All fungi are alike in one essential point, which is the absence of the green coloring matter known as chlorophyll and which we are likely to think of as belonging to all vegetable life. This chlorophyll, when acted upon by sunlight, is the means by which a plant is able to utilize the carbon of that very stable end-product of combustion, carbon dioxide. By means of its chlorophyll the plant is able to break up this carbon compound and build up other and less stable carbon compounds such as starch and cellulose, which then become a part of its structure. Now bacteria are like the fungi in that they have no chlorophyll and are therefore unable to break up carbon dioxide and must obtain their food either from the dead or living bodies of other plants or animals. If they obtain their food from dead matter we call them saprophytes; if from living matter, parasites.

All living things have as a result of their life and growth certain waste or by-products, and to this rule bacteria are no exception. In fact, bacteria, growing as they do with enormous rapidity, produce many and complex substances, some of which are extremely poisonous to the human organism. In a general way of classification, when these poisonous substances are the result of the growth of saprophytic organisms we call them ptomaines; when from parasitic organisms, toxines.

The organisms which we wish to consider here are two of the commonest with which the physician has to deal; the Gonococcus and the Bacillus tuberculosis. The amount of misery and woe, sickness and death caused by these two parasitic bacteria is greater in extent than that of all the wars which history records put together. And the pity of it is that both diseases are in large measure preventable.

Of these two the gonococcus is perhaps the one with which the general practitioner has to deal the more frequently, and the absolute de

termination of its presence or absence is often a matter of the utmost importance from the standpoints of diagnosis, treatment, determination of the end of the disease, and last but not least, from a medico-legal standpoint.

The procuring of the specimen is one of the most important and sometimes one of the most difficult parts of the procedure. In the the male, when the disease is once firmly established, a drop of pus can always be obtained directly from the meatus. This should be spread. in a thin film over the center of the slide, using a platinum loop which has been sterilized in a flame. But very early in the disease and also in its later stages it is quite impossible to obtain the specimen in this way because of the absence of discharge. The best method of obtaining a specimen of the urethral secretion in these cases is to have the patient save the first half ounce of urine voided on rising in the morning. This urine is then placed in the tube of a centrifugal machine and revolved at an approximate speed of two thousand revolutions per minute for three minutes, the supernatant urine being then carefully poured off. If, however, we try to examine this sediment we find that it will not stick to the slide in the process of staining, hence we add half an ounce of distilled water, shake, and centrifuge again. We now have the pus cells and bacteria free from urine. The supernatant water is carefully poured off and with a pipette we pick up the sediment in the bottom of the tube and place it on a perfectly clean microscope slide, which has been washed with alcohol and ether, and allow the water to evaporate without heating.

In order to demonstrate bacteria it is necessary to make them visible. As they contain no coloring matter themselves we must color them artificially, and for this purpose we use various analine dyes. The best one to use in routine staining of the gonococcus is Loeffler's alkaline solution of methylene blue. Having fixed or fastened the pus and bacteria to the slide by passing it through an alcohol or Bunsen flame two or three times or until too warm to bear on the hand, we cover the inoculated area of the slide with the stain and allow it to remain for two minutes. The excess of stain is then washed off with distilled water, we shake off the excess of water and allow the specimen to dry. It is now ready for examination under the microscope. A 1.9 m. m. or 1-12 inch oil immersion objective is necessary.

In its microscopical appearance the gonococcus may be concisely described as a biscuit-shaped, intracellular diplococcus: i. e., the cocci lie side by side in pairs with their flattened surfaces together and look not unlike the two halves of a coffee bean when placed with flat surfaces

together and viewed from the side. Their characteristic position is within the cytoplasm of the pus cells but not within the nucleus. Now there are other diplococci than the gonococcus to be found in the urethra and we must rule these out. These other diplococci are not commonly found within the pus cells but may be occasionally, so, granting that the specimen which we may be examining shows an intracellular diplococcus we resort to what is known as differential staining. Various kinds of bacteria respond differently to certain stains which enables us in given instances to recognize a bacterium by its staining characteristics. We prepare a smear as in the first instance and stain it for two minutes with aniline-water gentian violet, pour off the excess of stain and cover the specimen for two minutes with Gram's solution of iodine which is a solution of one part iodine crystals and two parts of potassium iodide in 300 parts of water. We then wash off the slide with 95% ethyl alcohol. If there is any violet color visible to the eye we again apply the iodine solution followed by alcohol and repeat until the specimen has no violet color.

The ex

After rinsing off the excess of alcohol with water we apply a 1% aqueous solution of Bismarck brown for one minute, wash with water, dry, and the specimen is ready to be examined. If the diplococcus which we found in the first specimen is colored a faint brown in this one the probabilities are that it is the gonococcus. If it retains the violet color or is dark blue or black it is not the gonococcus. perienced operator can usually tell the gonococcus, even without using differential staining, by the size and arrangement of the bacteria but the method described is the only safe one for any other to practice. If the relative size of the gonococcus as compared to the other urethral diplococci is kept in mind and differential staining used the chance of error is so slight as to be practically negligible. It is to be noted that the gonococcus can be artificially cultivated only on media containing human blood serum, with the possible exception of Lipschuetz' formula. (See Mitchell's "Modern Urinology," p. 492.)

Now as to the practical application. I want to urge the more general use of this bacteriological knowledge of the gonococcus. Use it in the first place in diagnosing your cases. There are many cases of urethritis not caused by the gonococcus. About ten per cent. of the specimens of urethral pus sent us for examination for the gonococcus show some other organism as the cause of the urethritis. Use it to determine the end of the disease (if it can be said to have an end). A man can still be suffering from gonorrhea and have no perceptible discharge from the meatus. But if he has no gonococci present in the first morning urine on three successive examinations at intervals of

two weeks, you can extend to him the only reasonably positive assurance of cure that can be given him. And I believe we owe it to our patients and to society to see that these cases are bacteriologically as well as symptomatically cured as otherwise they may, all unwittingly, act as further spreaders of the disease.

As to the occurrence of the gonococcus in other locations than the male urethra, it may, of course, occur in the urethra of the female, usually as an accompaniment of a gonorrheal vaginitis. There is a saying that gonorrhea is “bad enough in a man, but hell in a woman," and I am inclined to agree. This infection is not content to stay in the vagina, but must needs travel, in many cases, up through the uterus and even into the fallopian tubes and peritoneal cavity, exacting no small toll of suffering and death. It is, unfortunately, exceedingly difficult to demonstrate the gonococcus in the vaginal secretion in cases of long standing. In the earlier stages it is comparatively easy to find. In cases of purulent infection of the conjunctival sac it is important that an examination for the gonococcus be made early, so that, if pres ent, appropriate treatment may be commenced in time to give some. hope of saving the sight. J. W. Kerr, in an analysis of statistics on blindness, states that in the various European and North American countries from twenty per cent. to forty per cent. of all blindness is of gonococcal origin. Other authorities give figures as high as fifty per cent. In any event the morbidity is enormous, and it would seem only rational to treat all purulent eye infections as gonococcal until a bacteriological diagnosis can be made.

As a matter of fact the gonococcus may attack any of the serous or mucous membranes, causing arthritis, pericarditis, meningitis, etc. I wish to report a case illustrating this point.

Mr. A. S., aged 20, teamster, resident of Chicago, admitted to hospital April 3rd. Family history negative. Habits regular. No history of previous diseases or injuries. Present illness started with fever and nausea on April 2nd. Had malaise for preceding week. Has a watery diarrhea. Cough with yellow, blood-streaked expectoration. Complains of headache and dizziness. Pulse, 48. Conjunctivae injected and show some icterus. Heavy white coating over entire surface of tongue. Cold sore on nose. Heart slow but full and strong. No areas of dullness over lungs. Some mucous rales. Great distension of large intestine. Soles of feet yellow. Urinalysis: reaction acid, specific gravity 1026, trace of albumin, excess of indican, heavy sediment of urates and some pus cells. Blood count: normal. No plasmodia found. Widal reaction repeatedly negative. The most peculiar feature was the temperature and pulse of which a diagram is appended.

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