Exercise 1. Match a term with its definition.
| a sporen | able to cause infectious diseases |
| prokaryotesn pl | bacteria that don’t need oxygen |
| bacillusn | creatures whose cells have nuclei |
| aerobesn pl | rod-shaped bacterium |
| coccusn | structure produced by bacteria |
| eukaryotesn pl | spiral bacterium |
| spirillumn | round bacterium |
| anaerobesn pl | organisms without a nucleus |
| pathogenicadj | bacteria that need oxygen |
Exercise 2.Complete the following sentences. Choose the ending according to the text.
1. Bacteria in the digestive system are crucial for … .
2. Several species of bacteria arepathogenic, that is … .
3.The spore has a hard protective coating that … .
4. Spores are structures which help bacteria to … .
5. Facultative anaerobes are those … .
Exercise 3. Give the English equivalents of the Russian words in brackets.
1. Bacteria are tiny (одноклеточныемикроорганизмы), usually a few micrometers in length that normally exist together in millions. 2. Bacteria in the (пищеварительнаясистема) are crucial for the (расщепление) of certain types of (питательныевещества), such as complex sugars, into forms the body can use. 3. However, several (видыбактерий) are (патогенный), that is they can (вызыватьинфекционныезаболевания), including cholera, tuberculosis and others. 4. Some Gram-positive bacteria are also capable of (образоватьспоры) under stressful (условияокружающейсреды) such as when there is limited availability of carbon and nitrogen. 5. Gram-positive and gram-negative bacteria (вызыватьразныетипыинфекций), and (разныетипыантибиотиков) are effective against them.
Exercise 4. a) Make up collocations using words from both columns.
| fermented | requirements |
| growth | coating |
| obligate | foods |
| protective | tests |
| serological | aerobes |
b) Fill in the gaps with the collocations from above.
1. Humans have been using bacteria for preparing … for thousands of years.
2. Bacterial typing schemes use the bacterial morphology (structure) and staining properties of the organism as well as O2 … of bacteriacombined with a variety of biochemical tests and, if needed, … .
3. The spore has a hard … that encases the key parts of the bacterium - peptidoglycan, cytoplasm, water, and bacterial DNA.
4. … cannot live without oxygen.
Exercise 5. Translate from Russian into English.
1.Бактерии могут быть полезны человеку, например, молочнокислые бактерии. 2. Молочнокислые бактерии использовались человеком веками для приготовления таких продуктов как сыр, йогурт, уксус. 3. Бактериииграютважнейшуюроль впищеварительномтрактечеловека. 4. Некоторые виды бактерий являются патогенными, т.к. они способны вызывать инфекционные заболевания, например, туберкулез, сибирскую язву и другие. 5. Спора бактерии имеет защитную оболочку, которая покрывает основные части бактерии – пептидогликан, цитоплазму, воду и ДНК бактерии.6. Большинствоинфекцийзубоввызываютсяанаеробнымибактериями. 7. Аэробные бактерии не нуждаются в кислороде.
Exercise 6. Theanswerstothefollowingquestionsarethesummaryofthetext. Answerthesequestionsandgivethesummaryofthetext.
1.What were the first organisms to appear on Earth?
2. What is the natural habitat of bacteria?
3. How many bacterial cells are there in a gram of soil?
4. What is a prokaryote?
5. What are the main bacterial shapes?
6. What are the beneficial effects of bacteria on humans?
7. What do we call pathogenic bacteria? Name some of them.
8. Why is bacteria classification so important?
9. What is a Gram stain?
10. What is a spore? Does it play any role in reproduction?
11. How can bacteria be grouped according to their O2 growth requirements
12. Give examples of aerobic and anaerobic bacteria.
Exercise 7. Find more on bacteria classification at
https://www.britannica.com/.../bacteria/Classification;
https://en.wikipedia.org/wiki/Bacterial_taxonomy;
Make a report in writing (1 page) on the topic “Bacteria and the importance of its classification”.
TEXTB
ANTHRAX
VOCABULARY LIST TO TEXT B
| alkalineadj | [ˈælkəlaɪn] | солонцеватый (почва) |
| calcareousadj | [kælˈkɛərɪəs] | известковый |
| carcass n | [ˈkɑːkəs] | труп |
| contaminatedadj | [kənˈtæmɪneɪtɪd] | загрязненный |
| desiccationn | [desiˈkeɪshən] | высушка, десикация |
| dispose (of) v | [ dɪˈspəʊz ] | избавляться |
| distress (cardiac)n | [diˈstres] | сердечная недостаточность |
| emergev | [iˈmɜːdʒ] | появляться |
| grazing (animal)adj | [ɡreɪzɪŋ] | пастбищное (животное) |
| hemorrhagic adj | [ˌheməˈrædʒik] | геморрагический |
| ingestv | [ɪnˈdʒest] | поглощать, употреблять |
| lymphadenitisn | [ˌlimˌfədəˈnaɪtəs] | лимфаденит |
| oropharengealadj | [ˌɒrəˈfærɪnˈdʒɪəl̩] | ротоглоточный |
| oropharengitisn | [ˌɒrəˈfærɪnˈdʒaɪtɪs] | орофаренгит |
| sternum n | [ˈstɜːnəm] | грудина |
| strain n | [streɪn] | штамм |
| suffocation n | [sʌfəˈkeɪʃən] | удушение, асфиксия |
| tilling n | [ˈtɪlɪŋ] | обработка почвы |
| viable adj | [ˈvaɪəbl̩] | жизнеспособный |
| vigorous adj | [ ˈvɪɡ.ər.əs ] | энергичный |
Anthraxisahighlyinfectiousandfatalzoonoticdiseaseofmammalsandhumans. Itiscausedbygram-positive, rod-shaped spore-forming bacterium Bacillus anthracis. Anthrax has been reported from nearly every continent and is most common in agricultural regions with neutral or alkaline, calcareous soils. In these regions, anthrax periodically emerges as epizootics among susceptible domesticated and wild animals(e.g.cattle, sheep, goats, camels, antelopes) but it can also be seen in people exposed to tissues from infected animals, to contaminated animal products, or directly to Bacillus anthracis spores under certain conditions. Depending on the route of infection, host factors, and potentially strain-specific factors, anthrax can have several different clinical presentations. In herbivores, anthrax commonly presents as an acute septicemia with a high fatality rate, often accompanied by hemorrhagic lymphadenitis. In dogs, people, horses, and pigs, it is usually less acute although still potentially fatal.
Bacillus anthracis spores can remain viable in soil for many years. During this time, they are a potential source of infection for grazing livestock but generally do not represent a direct risk of infection for people. Grazing animals may become infected when they ingest sufficient quantities of these spores from the soil. Spores are resistant to extremes of temperature, chemical disinfection, and desiccation and can cause disease when ingested even years after an outbreak. The spores are brought to the surface by wet weather, or by deep tilling, and when ingested or inhaled by ruminants.Raw or poorly cooked contaminated meat is a source of infection for zoo carnivores and omnivores; anthrax resulting from contaminated meat consumption has been reported in pigs, dogs, cats, mink, wild carnivores, and people.
Typically, the incubation period is 3–7 days. The clinical course ranges from peracute to chronic. The peracute form (common in cattle and sheep) is characterized by sudden onset and a rapidly fatal course. Staggering, dyspnea, trembling, collapse, a few convulsive movements, and death may occur in cattle, sheep, or goats with only a brief evidence of illness.
In acute anthrax of cattle and sheep, there is an abrupt fever and a period of excitement followed by depression, stupor, respiratory or cardiac distress, staggering, convulsions, and death. Often, the course of disease is so rapid that illness is not observed, and animals are found dead. Body temperature may reach 107°F (41.5°C), rumination ceases, milk production is reduced, and pregnant animals may abort. There may be bloody discharges from the natural body openings.
The disease in horses may be acute. Signs may include fever, chills, severe colic, anorexia, depression, weakness, bloody diarrhea, and swellings of the neck, sternum, lower abdomen, and external genitalia. Death usually occurs within 2–3 days of onset.
Although relatively resistant, pigs may develop an acute septicemia after ingestion of Bacillus anthracis, characterized by sudden death, oropharyngitis, or more usually a mild chronic form. Oropharyngeal anthrax is characterized by rapidly progressive swelling of the throat, which may cause death by suffocation. In the chronic form, pigs show systemic signs of illness and gradually recover with treatment.
In dogs, cats, and wild carnivores, the disease resembles that seen in pigs. In wild herbivorous animals, the expected course of illness varies by species but resembles, for the most part, anthrax in cattle.
In case of the outbreak, carcasses of the dead animals must be disposed of properly and rapidly, the carcass should not be open (exposure to oxygen will allow the bacteria to form spores) and premises should be quarantined until all susceptible animals are vaccinated. A diagnosis based on clinical signs alone is difficult. Confirmatory laboratory tests are necessary. Early treatment and vigorous implementation of a preventive program are essential to reduce losses among livestock. Livestock at risk should be immediately treated with a long-acting antibiotic to stop all potential incubating infections (domestic livestock respond well to penicillin if treated in the early stages of the disease).Suspected contaminated feed should be immediately removed.In livestock, anthrax can be controlled largely by annual vaccination of all grazing animals and by implementation of control measures during epizootics.
EXERCISES TO THE TEXT
Exercise 8. Look through the text and find information about:
- anthrax causative agent;
- animals that are susceptible to anthrax;
- anthrax fatality rate;
- anthrax incubation period;
- clinical signs of anthrax in sheep and cattle;
- clinical signs of anthrax in horses;
- treatment and prevention of anthrax.