CASE 1
A student of an agricultural institute returned from an area affected by brucellosis. She went to the
doctor with complaints of a sudden rise in temperature, joint pain, headaches and muscle pain.
Considering the epidemiological anamnesis, she was hospitalized with suspicion of brucellosis.
1. What microbiological studies should be carried out to make a diagnosis?
testing blood or bone marrow for the brucella bacteria or by testing blood for antibodies to the
bacteria.
2. By what signs is the final identification of Brucella carried out?
Brucellosis can be diagnosed in a laboratory by finding bacteria in samples of blood, bone marrow or
other bodily fluids. Serological tests can also be done to detect antibodies against the bacteria
CASE 2
A patient went to the doctor with complaints of fever, headaches and muscle pain. From the
anamnesis it turned out that he worked on a livestock farm and ate unboiled milk, feta cheese,
cottage cheese and other dairy products.
1. What bacteria could be the causative agents of this disease?
Brucella
2. What microbiological studies should be carried out to diagnose this disease?
testing blood or bone marrow for the brucella bacteria or by testing blood for antibodies to the
bacteria.
CASE 3
A commercial hunter a week after his return from muskrat hunting suddenly had a fever up to 390C,
sharp headaches and muscle pains, as well as swelling of the axillary lymph nodes (bubo). Probable
diagnosis: thuleremia.
1. What microorganisms could cause such a disease?
Francisella tularensis
2. What microbiological studies should be carried out to diagnose this disease?
Tularemia can usually be diagnosed through blood tests. One test looks for antibodies to the
bacteria
3. What drugs should be prescribed to prevent this disease?
streptomycin, gentamicin, doxycycline, and ciprofloxacin
CASE 4
In the natural focus, cases of people with suspected bubonic plague appeared.
1. Name the features of the microbiological diagnosis of plague.
Diagnosis is made by taking samples from the patient, especially blood or part of a swollen lymph
gland, and submitting them for laboratory testing. Once plague has been identified as a possible
cause of the illness, appropriate treatment should begin immediately.
2. How to confirm the diagnosis by bacterioscopic method?
Lymph node aspirate: An affected bubo typically contains numerous organisms that can be
evaluated microscopically and by culture. Blood cultures: Routine blood cultures are a sensitive
means of detecting plague.
3. How to conduct a bioassay and take into account its result?
Yersinia pestis, an infectious bacterium that is a causative agent of plague, a disease which has been
shown to be one of the most feared in history and which has caused millions of deaths. The capsulelike fraction 1 (F1) antigen expressed by Y. pestis is a known specific marker for the identification of
the bacteria; therefore, the detection of F1 is important for Y. pestis recognition. In this study, a
rapid, sensitive, and specific technique, the lateral flow assay (LFA), was successfully developed to
detect Y. pestis by the recombinant F1 antigen. The assay that utilized an anti-F1 polyclonal antibody
(Pab) to identify the bacteria was based on a double-antibody sandwich format on a nitrocellulose
membrane
CASE 5
The patient is suspected of anthrax, skin form.
1. What material is to be examined?
The diagnosis of cutaneous anthrax is usually suggested by the characteristic appearance of skin
lesions. As spore germination occurs within macrophages at the site of inoculation, anthrax bacilli
are isolated easily from the vesicular lesions and can be observed on Gram stain
2. List the methods for diagnosing anthrax.
Anthrax is diagnosed by taking samples from blood, respiratory secretion, or from any skin sores.
The samples are sent to a laboratory to determine if they contain the bacteria that cause anthrax.
The results are usually available about 2 days after the sample is taken.
3. What properties are characteristic of this pathogen?
Bacillus anthracis, the causative agent of anthrax, is a gram-positive, aerobic or facultatively
anaerobic, endospore-forming, rod-shaped bacterium. Spores that lodge in a cut, abrasion or insect
bite in the skin undergo germination and the emergent vegetative bacilli spread to the regional
lymph nodes.
CASE 6
During the summer agricultural work, several people fell ill. Probable diagnosis of leptospirosis.
1. What material should be taken for research?
The most common way to diagnose leptospirosis is through serological tests either the Microscopic
Agglutination Test (MAT) which detects serovar-specific antibodies, or a solid-phase assay for the
detection of Immunoglobulin M (IgM) antibodies.
2. Name the methods of confirming the diagnosis.
PCR – MAT