QUESTIONS 45 



Asepsis. The term aseptic refers to methods and manipulations 

 which protect a sterile or relatively sterile material from any further 

 contamination or admixture with microorganisms. If, for instance, 

 we shave the skin of an animal, wash and scrub it thoroughly with 

 an antiseptic solution, then wash our hands in an antiseptic solution, 

 and finally draw some blood from a vein with a perfectly sterile 

 hypodermic syringe, we can say that we have drawn the blood in 

 an aseptic manner. If everything has been done correctly, we have 

 obtained the blood without contaminating it with microorganisms. 

 If there are any found at all they must have been in the circulating 

 blood as infecting microorganisms. 



QUESTIONS. 



1. At what range of temperature can bacteria as a class exist, grow, and 

 multiply ? 



2. What bacteria are most limited as to the range of temperature at which 

 they can multiply, and why? 



3. What is the optimum temperature of growth of a bacterium? 



4. What are the minimum and maximum temperatures of growth? 



5. What is the optimum temperature for the (a) mammalian, (6) avian 

 tubercle bacilli? 



6. What are the maximum and minimum temperatures for these bacilli? 



7. What range of temperature of growth do facultative parasites generally 

 have, and why? 



8. What is a thermophile bacterium ? 



9. Where do they occur and where do they find the conditions necessary for 

 their multiplication ? 



10. What are thermo tolerant bacteria? 



11. What is meant by the thermal death point of a bacterium? 



12. What do bacteria require for their nutrition? Can they grow without 

 moisture? 



13. What is the effect of desiccation upon bacteria and their spores? 



14. What is the effect of desiccation upon- 



(a) The spores of anthrax and tetanus bacilli ? 

 (6) The tubercle bacillus ? 

 (c) The glanders bacillus? 



15. What is meant by the latent life of a bacterium or its spore? 



16. From what materials can pathogenic bacteria best derive their food? 



17. Name some pathogenic bacteria difficult to grow on artificial culture media. 



18. Name some which have never been grown successfully. 



19. What effect has too great a concentration of solids in an artificial culture 

 medium upon the growth of bacteria? 



20. What effect has the reaction of the culture medium upon the growth of 

 bacteria ? 



21. What natural unchanged materials do certain pathogenic bacteria require 

 before they will grow? 



22. Explain the terms plasmolysis and plasmoptysis. 



23. Explain the following terms: 



Obligate anaerobe. Facultative anaerobe. 



Obligate ae'robe. Facultative ae'robe. 



24. Name some pathogenic anaerobes. 



25. Name some pathogenic aerobes. 



26. Name some pathogenic facultative aerobes. 



27. How can strict or obligate anaerobes grow in the presence of oxygen? 



28. What are some of the common metabolic products of bacterial life? 



29. Name a bacterium which in the presence of peptone forms indol. What is 

 indol? 



30. What is meant when certain bacteria are said to have a reducing action ? 



