2 Microbes and You 



you and me— obtaining food, digestion, excretion, respiration, repro- 

 duction, etc. But in contrast to man, who possesses specialized 

 organs for these important functions, the lowly bacteria must carry 

 out all of these activities within the confines of a single cell, a cell 

 so minute that 25,000 of them standing side by side would hardly 

 occupy an inch! 



Microbes cannot walk, so they are unable to crawl up over our 

 shoes to get at us, but some do have the power of locomotion in 

 liquids. These have been endowed with special hair-like projec- 

 tions, all part of the single cell, called flagella. By a whipping 

 motion these flagella are able to propel the bacteria through 

 liquids. The typhoid bacterium has been clocked at nearlv 65 

 millimeters (about 2.5 inches) an hour! The swimming speed 

 of a given organism is influenced by such factors as temperature, 

 available food, nature of the suspending medium, age of the 

 organism, and undoubtedly by other motivating forces. Some 

 bacteria lack flagella, yet they make progress through liquids by a 

 twisting, corkscrew-like motion. It should be made clear that 

 many bacteria lack the power of independent motion; they just sit 

 around and wait to be pushed. 



There is little that is static in a science as young as micro- 

 biology. It is a dynamic phase of biology which has many prac- 

 tical, everyday applications. As a science, bacteriology is hardly 

 more than one hundred years old. Some persons date this branch 

 of science to 1857 when Pasteur first demonstrated that micro- 

 organisms could sour milk. Sir William Osier (1849-1919) said 

 that this publication of Pasteur's, together with his demonstration 

 that the transformation of sugar into alcohol and carbon dioxide 

 was a phenomenon of life, set the date for a new era in medicine. 

 This killed the notions that ma^ic and air caused disease in some 

 mysterious way, and it dragged the enemy into the open. All 

 modern medical and surgical technics employed to prevent and to 

 combat disease are based upon this germ concept. Too often, 

 however, the word germ or bacteria conjures up in the mind of 

 the layman but one thought— disease. Disease mav be defined as 

 an abnormal condition of anv part or organ of the body or of the 



