BACTERIA 145 



Stages in bacterial attack. 



1. Incubation (overcoming bodily resistance). 



2. Rapid growth of bacteria. 



3. Secretion of toxins by bacteria. 



4. Secretion of antitoxins by blood. 



5. Struggle between body and bacteria. 



6. Acquired immunity in some cases. 



Artificial Protection. 



1. Vaccination (smallpox and typhoid). 



Body resists mild attack, makes own antitoxins. 



2. Antitoxin treatment (diphtheria and tetanus). 



Antitoxins developed in other animals (horse). 

 Directly administered where body is not able to make its own. 

 Germicides (germ killers). 



Antiseptics (used mainly in contact with body): 

 Hydrogen peroxide Alcohol 



Carbolic acid, 4%. Ichthyol 



Boric acid Potassium permanganate, 10% 



Camphor Thymol, salt 



Disinfectants (used mainly outside the body): 



Bichloride of mercury furniture, hands 



Carbolic acid, 4% clothing, hands, etc. 



Formaldehyde. rooms, clothing 



Creosol, lysol, etc. clothing, etc., as directed 



Chloride of lime, garbage, refuse, etc. 



Germs also killed by 



Heat, as in boiling and cooking, pasteurizing 



Sunlight 



Hindered by dry conditions 



Pasteurizing 



Heat to 140-150 degrees 



Cool quickly 



Exclude other bacteria 



Kills most harmful bacteria, does not change milk 



To Disinfect a room: 



1. Clean all woodwork with soap and water 



2. Refinish the walls if possible 



3. Disinfect furniture and bedding (see above) 



4. Fumigate with 



Formaldehyde 



Formaldehyde and potassium permanganate 



Burning sulphur (danger of bleaching) 



Development of Bacteriology. 



Pasteur, 1860-1880 



Von Behring, 1894, diphtheria 



Roux, 1894, diphtheria 



