Acute brucellosis in its more severe form sometimes causes the characteristic intermittent waves or undulations of temperature that gave the name undulant fever describe the human disease, a term that can be misleading, since many brucella infections do not manifest this symptom. Brucella organisms are gram negative bacilli that are mostly so short as to appear more like cocci. Some more definite bacillary forms may also be observed. They occur singly and in groups and are non-motile, non-capulate and non-sporing.
Brucellae are aerobic. However, Brucella abortus when first cultures is unable to grow without the addition of 5-10% carbon dioxide to the atmosphere. All strains grow best in a medium enriched with animal serum and glucose. Their optimum temperature is 370C. The colonies take several days to appear and are normally smooth, moist, transparent and glistening.
Brucella organism may survive in the soil and in manure for many weeks and remain viable in dried foetal material for even longer periods. They have isolated from butter, cheese and ice-cream prepared from infected milk. The organisms may survive in meat, pork and ham and may remain viable after refrigeration for several weeks and after pickling. They are killed in 10 minutes by a temperature of 600C and infected milk is rendered safe by pasteurization. The brucellae are very sensitive to acid so that they tend to die out in sour milk and in cheese that has undergone lactic acid fermentation for some time, they are likely to be destroyed by the acid secretions of the stomach.
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Chemotherapy for salmonella
Gene transfer in bacteria
Treatment of Gas Gangrene
What to consider when interpreting the results of antibody in serology
Symptoms Of Salmonella Food-Poisoning.
Symptoms Of Staphylococcal Food-Poisoning.
Symptom Of Clostridium Welchii Food-Poisoning.
Clostridium Botulinum Food Poisoning (Botulism ).
Bacillus Cereus Food-Poisoning.
Symptoms Of Bacillus Cereus Food-Poisoning.
Chemotherapy For Mycobacterium Tuberculosis
LABORATORY INVESTIGATION OF FOOD-POISONING.
Pathogenesis Of Haemophilus Influenzae
Media for the growth of microorganisms
Anaerobic cultivation of bacteria
PHYSICAL CONDITIONS REQUIRED FOR GROWTH
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How doctors determine treatments for bacterial infections?
CLASSIFICATION OF BRUCELLA
There are three main species of Brucella that differ in their choice of animal host, in certain cultural and biological characteristics and in the camont of the two main antigens that are common to all three species. They are Brucella melitensis which infects goats and sheep, Brucella abortus which infects cattle and Brucella suis which infects pigs. The host-parasite relationship is not absolutely specific and both man and domestic animals are susceptible to all three species. Within the species, strains that differ in some respects from the normal prototypes occur and are considered to be biotypes. There are at least nine biotypes of Brucella abortus, three of Brucella melitensis and four of Brucella suis.
A number of other Brucella species have been named although some authorities prefer to regard them as biotypes of one or other of the main species. They are Brucella Ovis which mainly responsible for a testicular infection of rams in various parts of the world.
DIFFERENTIAL TESTS FOR BRUCELLA SPECIES
The three main species of Brucella differ in certain characteristics that form the basis of their conventional classification. These are:-