Causative agents of Shigellosis

Causative agents of Shigellosis

30. Shigella sonnei was isolated from feces of a patient. What additional investigation should be done for the determination of the infection source?

– Study sensitivity to antibiotics.

– To make the precipitation test.

– To make the complement fixation test.

+ Phage typing of the isolated pure culture.

– To make the neutralization test.

31. Shigellosis agent was isolated from a child infected with acute intestinal infection. What morphological properties is this agent characterised by?

– Gram-positive mobile bacillus.

– Capsule on the nutritious medium.

– Spore in the environment.

– Gram-positive bacilli arranged in chain.

+ Gram-negative immobile bacilli.

32. A 29-year-old patient was taken to hospital with symptoms of vomiting, severe diarrhea, and tenesmus. The feces are colourless with bundles of mucus and contamination of blood. During the bacteriological investigation of the colonies on MacConkey’s agar immobile gram-negative bacilli were revealed, which decomposed lactose partially in 48 hours. Name the agent of this infectious process.

– Vibrio eltor.

– Yersinia enterocolitica.

– Proteus penneri.

+ Shigella sonnei.

– Salmonella enterica.

33. During the systematic inspection of shigellosis agent carriage on the customs employees, the conproculture was isolated which had such features as: 1. Gram-negative bacillus. 2. Makes colourless colonies on Endo agar. 3. Peritrichous. 4. Ferments carbohydrates making acid and gas. On the basis of what features did the bacteriologists refuse the presence of shigellosis agent?

+ Shigella is immobile.

– Carbohydrates fermentation.

– No growth on Endo agar.

– The absence of agents among people.

– Colouring by Gram method.

34. A laboratory assistant has a problem with the feces inoculation of a patient suspected to have shigellosis. What optimal diagnostic medium is necessary to be chosen for the differentiation of the agent from atypical shigella?

– Chepman medium.

– MacConkey’s agar.

+ Synthetic medium with nicotine acid.

– MPA.

– Endo agar.

35. Among tourists, a group of (27 people), who used water from a lake for drinking, 7 appeared to have diarrhea two days later. What material is necessary to be sent to the laboratory for investigation with the aim of determining the aetiology of the given disease?

– Patients’ blood.

– Food products.

– Urine.

– Humidity.

+ Water, patients’ feces.

36. Shigella capable of producing exotoxin was detected in a patient with shigellosis diagnosis. What kind of shigella is it?

– Shigella sonnei.

– Shigella flexneri.

– Shigella boydii.

– Shigella newcastle.

+ Shigella dysenteriae.

37. After drinking unboiled milk, a 4-year-old child had signs of dysfunction of gastrointestinal tract, particularly: pain in the stomach, diarrhea, frequent defecation followed by spasmodic pains in the intestines. Feces had mucous-bloody consistence. What genus caused the infection?

– Esherichia.

– Clostridium.

– Staphylococcus.

– Salmonella.

+ Shigella.

38. In kindergarten during a period of twenty-four-hours, 10 children of different age groups got ill and developed clinical symptoms of intestinal infection. During bacteriological investigation of these patients’ feces the agents of shigellosis were isolated. Because of unfavourable epidemiological situation in the given children group, it is necessary to make preventive measures for contacted children. What preparation for specific prophylaxis is necessary to prescribe to children who were in contact with these patients?

– Immunoglobulin.

+ Shigellosis bacteriophage.

– Sulphanilamide.

– Antibiotics.

– TABTe-vaccine.

39. A patient who got ill 3 days ago and complains of elevated body temperature (380C), pain in the abdomen, frequent watery defecation and presence of blood in feces, a clinical diagnosis of shigellosis was made by the doctor. Which method of microbiological diagnosis is expedient to use in the given case? What patient’s material is necessary to be taken to confirm the diagnosis?

– Bacterioscopic, feces.

+ Bacteriological, feces.

– Bacterioscopic, blood.

– Bacterioscopic, urine.

– Serologic, blood.

40. On inoculation of the defecation of a patient suspected to have shigellosis a great number of colonies with smooth surface and even edges grew on MacConkey’s agar. The isolated culture fermented glucose, mannitol and maltose producing acid and didn’t ferment lactose and sucrose. What kind of microorganism is it?

– Shigella sonnei.

+ Shigella flexneri.

– Shigella boydii.

– Shigella dysenteriae.

– Salmonella typhi.

41. A patient suspected to have shigellosis was taken to the infectious department. Which of the following basic methods of microbiological diagnostics, is necessary to be administered?

– Serological.

+ Bacteriological.

– Biological.

– Bacterioscopic.

– Allergic test.

42. A patient suspected to have acute shigellosis was taken to the infectious department. What material should be investigated in bacteriological laboratory?

+ Feces.

– Urine.

– Bile.

– Stomach washing water.

– Blood.

43. During bacteriological investigation of the patient’s feces with typical shigellosis, the clinical signs were not detected as a result of early use of antibiotics. In PHAT with pair sera the titre of antishigellosis antibodies grew by 4 times. What is it evident of?

– A patient had shigellosis earlier.

– Vaccinal reaction.

– Non specific reaction.

– Dismissal of shigellosis diagnosis.

+ Confirmation of shigellosis diagnosis.

44. It was noted during the epidemiological investigation of shigellosis outbreak caused by Shigella sonnei, that three milk plant workers could be the source of infection. What additional investigations should be done to determine the real source of infection?

– Serotype shigella determination.

– Colicinotyping.

– Titre of antishigellosis antibodies determination.

+ Phage typing.

– Subserotype shigella determination.

45. Pure culture of bacteria which is referred to Shigella type by morphological, cultural and biochemical properties was isolated from the patient with the signs of colitis. Which of the given reactions should be used for serological identification of the culture?

+ Agglutination test with the diagnostic sera.

– Complement fixation test.

– PHAT.

– Precipitation test.

– Haemagglutination inhibition test.

46. While studying the coproculture of the patient infected with shigellosis the presence of gram-negative immobile bacilli reffered to S. sonnei by serological features were noted. Point out the fermentation properties of S. sonnei according to lactose on Endo agar?

+ Slowly fermenting lactose.

– Non fermenting lactose.

– Fermenting lactose with acid and gas.

– Colonies of bright-red colour with metallic sheen on Endo agar.

– Non-cultivated on Endo agar.

47. To carry out the retrospective diagnostics of former shigellosis patient, which of the serological investigation of serum was prescribed to determine the titre of antibodies to Shigella?

+ Passive haemagglutination test.

– Complement fixation test.

– Precipitation test.

– Haemolysis test.

– Bacteriolysis test.

48. A patient recovered from shigellosis and got infected with the same agent. What is this form of infection called?

+ Reinfection.

– Recurrent infection.

– Superinfection.

– Persisting infection.

– Chronic infection.

49. Pure culture of shigellosis agent was isolated from the patient’s material in the laboratory. What research should be made to identify the final serological agent?

+ Reaction of agglutination with standard sera.

– Reaction of agglutination with the patient’s serum.

– Reaction of indirect haemagglutination.

– Reaction of molecular hybridization of DNA.

– Detect the heat-stable antigens in the reaction of a ring precipitation.

50. In microscopic examination of patient’s feces who complains of frequent stools, abdominal pain, fever, gram-negative bacillus was identified. When sowing feces in Endo agar, colourless colonies grew. Marked bacteria ferments glucose only. What agent is the cause of the disease?

+ Shigella dysenteriae.

– Escherichia coli.

– Salmonella typhimurium.

– Shigella sonnei.

– Salmonella typhi.

51. On the objects of external environment and in food, Shigella sonnei was revealed by means of reaction with the use of diagnostic test set. The test set includes polystirol sheet with absorbed specific antibodies. Give the name of this reaction.

+ ELISA.

– IFT.

– PHAT (with antibody erythrocyte diagnosticum).

– PHAT.

– Reaction of immunoelectrophoresis.

52. In kindergarten, an outbreak of bacterial dysentery was registered. Who is most likely to be the source of infection?

+ Employee of cafeteria.

– A dog, of which the owner is a child attending the kindergarten.

– A cat living in the territory of the kindergarten.

– Turtles living in the aquarium.

– Parrot that was brought to the kindergarten by a child.

53. On bacteriological study of patient’s feces; lactose negative, immobile, gram-negative, rod shaped bacilli were identified. The agents of what intestinal infections are characterized by such properties?

+ Causative agent of Dysentery.

– Causative agent of Typhoid fever.

– Causative agent of Colienteritis.

– Causative agent of Cholera.

– Causative agent of Salmonellosis.

54. In a kindergarten an outbreak of bacterial dysentery was registered. What medication should be administered to the children for prevention of specific disease?

+ Bacteriophage.

– Antibiotics.

– Vaccines.

– Probiotics.

– Vitamins.

55. The patient who complains of frequent stools, mild pyrexia and temperature, had a preliminary diagnosis of dysentery. The selected culture ferments glucose and mannitol with the formation of acid, slowly fermenting lactose and no fermentation of protein with the formation of indole. What causative agent of dysentery is characterized by these properties?

+ S. sonnei.

– S. boydiі.

– S. flexneri.

– S. dysenteriae.

– Plesiomonas shigelloides.

56. At an autopsy of 46-year- old male on the mucous membrane of rectum and sigmoid colon, were revealed multiple brownish-green layers, bleeding in the intestines lumen and mucus, a small amount of blood; histologically - fibrinous colitis. On bacteriological study of intestinal contents S. sonnei was isolated. What diagnosis is most likely to be made?

+ Dysentery.

– Crohn’s disease.

– Cholera.

– Yersiniosis.

Salmonellosis.