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ACTIVE VOCABULARY. MICROBIOLOGY.



ACTIVE VOCABULARY

Read and learn the following words and word combinations:

1. harmless                безвредный

2. dangerous         опасный

3. subdivide          подразделять

4. shape                 очертание, форма

5. decayed teeth    гнилые (испорченные) зубы                

6. chain                     цепь

7. cluster                  гроздь

8. strain                    штамм

9. gumboil                флюс

10. acute                 острый

11.. gingivitis        воспаление десен

12. exist                 существовать

13. survive                выживать

14. resistant              резистентный, устойчивый

 

MICROBIOLOGY.

     The body provides a home for a great number of the smallest organisms – microorganisms. Most of them are harmless but some take part in dental diseases. There are three different groups of microorganisms: fungi, bacteria and viruses. They may be of different kinds, both harmless and more or less dangerous.

Bacteria are subdivided into groups according to their shape bacilli, cocci, spirochetes, spores.

Bacilli are rod – shaped bacteria. For example, lactobacillus is found in decayed teeth.

Cocci are round bacteria.

Streptococci are berry – shaped bacteria which grow in twisted chains. They are associated with different

diseases. Hemolytic streptococci (called hemolytic because bacteria cause hemolysis) are responsible for such conditions as “strep” throat, tonsillitis.

Streptococci viridians (viridians means “green” and these bacteria produce a green color on the growth medium) are less virulent (poisonous) than the hemolytic form and cause infections in teeth.

  Staphylococci are bacteria which grow in small clusters like grapes. One strain of staphylococcus may be found in gumboils.

There are also spiral bacteria (spirochetes) found in acute necrotizing ulcerative gingivitis.

Some bacteria can exist in the form of spores. Spores can survive extremes of temperature and live for years until conditions become more favorable again. They are highly resistant to destruction.



  

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