Pseudomonas And Other Nonfermenters And Hsemophilus Bordetella Brucella Multiple Choice Question And Answers

Pseudomonas And Other Nonfermenters And Hsemophilus Bordetella Brucella Multiple Choice Question And Answers

1. Most common Gram-negative organism in cystic fibrosis:

• Pseudomonas
• E.coli
• Klebsiella
• Legionella

Answer. (1) (Pseudomonas)

Mucoid (alginate capsule-producing) strains of Pseudomonas are the most common organism associated with cystic fibrosis.

Read And Learn More: Micro Biology And Immunology Multiple Choice Question And Answers

2. Significance of mucoid strain Pseudomonas aeruginosa:

1. Exhibit more drug-resistant
2. Produces biofilms
3. Secrete more toxins
4. Produce more bacteriocin

Answer. (2) (Produces biofilms)

The mucoid strain of Pseudomonas aeruginosa can produce biofilm (or alginate layer) and hence can cause infection in patients with cystic fibrosis.

3. Ecthyma gangrenosum is caused by:

1. Pseudomonas
2. Streptococcus
3. Staphylococcus
4. H. influenzae

Answer. (1) (Pseudomonas)

Ecthyma gangrenosum is caused by Pseudomonas aeruginosa

4. Drugs used in pseudomonas treatment:

1. Cefixime
2. Ceftazidime
3. Ceftriaxone
4. Colistin
5. Ampicillin

Answer. (2, 4) (Ceftazidime, Colistin)

5. Which one of the following drugs is an Anti pseudomonal penicillin?

1. Cephalexin
2. Cloxacillin
3. Piperacillin
4. Dicloxacillin
5. Burkholderia

Answer. (3) (Piperacillin)

6. Burkholderia cepacia is intrinsically resistant to:

1. Ciprofloxacin
2. Ceftazidime
3. Polymyxin B
4. Meropenem

Answer. (3) (Polymyxin B)

• Burkholderia is intrinsically resistant to polymyxins.
• Drug active against Burkholderia aremeropenem, ceftazidime, levofloxacin, cotrimoxazole, and chloramphenicol.

7. Lysine-positive non-fermenter bacteria:

1. Burkholderia pseudomallei
2. Burkholderia cepacia
3. Acinetobacter baumannii
4. Pseudomonas

Answer. (2) (Burkholderia cepacia)

Burkholderia cepacia complex (BCC) and Stenotrophomonas maltophilia are lysine-positive non-fermenters.

8. Burkholderia cepacia infection is/are typically associated with:

1. Cystic fibrosis
2. Chronic bronchitis
3. Chronic granulomatous disease
4. Multiple myeloma
5. Myeloperoxidase deficiency

Answer. (1, 2, 3) (Cystic fibrosis, Chronic bronchitis, Chronic granulomatous disease)

B.cepacia causes a rapidly fatal syndrome of respiratory distress (chronic bronchitis and bronchiectasis) and septicemia in Cystic fibrosis patients called the Cepacia syndrome.

• It is an antibiotic-resistant nosocomial pathogen in ICU patients.
• Patients with chronic granulomatous disease are predisposed to cepacia lung disease.
• B.cepacia is an environmental organism that inhabits moist environments
• B.cepacia appears as an airway colonizer and is a cause of VAP, catheter-associated infections, and wound infections.
  Myeloperoxidase deficiency is associated with S.aureus, E.coli, and Candida infections.

9. Burkholderia is infrequently seen in: (DNB June 2011)

1. Pools
2. Plants
3. Soil
4. Air

Answer. (2) (Plants)

• B.pseudomallei is found in soil and water (pools). Humans and animals are infected by inoculation, inhalation (from air), or ingestion; rarely from person to person

10. Cause of melioidosis is:

1. Burkholderia mallei
2. Burkholderia pseudomallei
3. Burkholderia cepacia
4. None

Answer. (2) (Burkholderia pseudomallei)

• B.pseudomallei is the causative agent of melioidosis (Vietnam time bomb disease)

11. Cause of chest infection in a child with cystic fibrosis:

1. Burkholderia
2. Pseudomonas (nonmucoid strain)
3. Klebsiella
4. Streptococcus pneumoniae

Answer. (1) (Burkholderia)

‘Mucoid strain of pseudomonas is often found in the sputum of cystic fibrosis patients.

Burkholderia is also recovered from CF sputum and is pathogenic.’

Cystic fibrosis patients exhibit characteristic sputum microbiology profiles:

• Haemophilus influenzae and S. aureus: First organisms recovered in newly diagnosed patients with CF.
• Mucoid P. aeruginosa (biofilm-producing, antibiotic-resistant): MC organism recovered from CF.
• Burkholderia: 2nd most common (next to mucoid pseudomonas)
• Other gram-negative rods recovered from CF sputum include:
  • Alcaligenes xylosoxidans, occasionally mucoid forms of Proteus, Escherichia coli, and Klebsiella.
  • Mycobacterium tuberculosis is rare in patients with CF.
• However, 10–20% of adult patients have nontuberculous Mycobacteria
• MC fungus isolated: Aspergillus fumigatus (allergic bronchopulmonary Aspergillosis)

12. The following statements are true regarding melioidosis except:

1. It is caused by Burkholderia mallei
2. The agent is a gram-negative aerobic bacteria
3. Bipolar staining of the etiological agent is seen with methylene blue stain
4. The most common form of melodious is pulmonary infection

Answer. (1) (It is caused by Burkholderia mallei)

• B.mallei causes glanders and farcy
• pseudo mallei: Causative agent of melioidosis (Glanders-like disease)
  • Motile and Zoonotic – rodents
  • Humans: Produces pulmonary infections like TB (MC), Multiple abscesses, LN↑

13. A 50-year-old chronic alcoholic male agricultural worker presented with a high-grade fever of one-week duration with spells of chills and rigor. Examination of the respiratory system revealed bilateral crepitation with scattered rhonchi. Multiple subcutaneous nodules were found on the extensor surface of the left forearm, arm, and left leg. Direct microscopy of the pus aspirated from the skin nodule revealed plenty of Gram-negative bacilli with bipolar staining. Culture revealed distinct rough corrugated grey-white colonies on blood agar. The organisms were motile and oxidase positive most likely diagnosis is:

1. Plague
2. Melioidosis
3. Bartonellosis
4. Actinomycosis

Answer. (2) (Melioidosis)

14. True about Burkholderia mallei:

1. Causes glanders disease
2. Affects horses
3. Nonmotile
4. Cause melioidosis

Answer. (1, 2, 3) (Causes glanders disease, Affects horses, Nonmotile)

15. Treatment of choice for S.maltophilia:

1. Azithromycin
2. Aminoglycosides
3. Co-trimoxazole
4. Levofloxacin
5. Ticarcillin/clavulanate

Answer. (3, 4, 5) (Co-trimoxazole, Levofloxacin, Ticarcillin/clavulanate)

S. maltophilia is intrinsically resistant to most antibiotics. Recommended antibiotics are cotrimoxazole, ticarcillin/clavulanate and levofloxacin, etc.

16. True regarding H. influenzae growth:

1. Growth in MacConkey and blood agar but not chocolate agar
2. Growth in MacConkey and chocolate agar but not blood agar
3. Growth in blood and chocolate agar but not MacConkey medium
4. Growth in MacConkey, blood, and chocolate agar

Answer. (3) (Growth in blood and chocolate agar but not MacConkey medium)

• H. influenzae grows in blood agar only near the S.aureus streak line, but grows well on chocolate agar, and does not grow MacConkey medium

17. In a child admitted with Haemophilus Influenzae meningitis, Cefotaxime was started instead of ampicillin. Which of these is the likely reason for this?

1. H.influenzae stains are known to produce Beta-lactamase
2. H.influenzae stains are known to have altered penicillin-binding proteins
3. Cefotaxime is easier to administer than ampicillin
4. Drug of choice for this condition is sulphamethoxazole and trimethoprim but cannot be given.

Answer. (1) (H. influenzae stains are known to produce Betalactamase)

• DOC for Invasive infection due to H.influenzae type b is Cephalosporins such as ceftriaxone, and cefotaxim This is the best answer that’s why cefotaxime was started But this is not an option.
• Hence the next best answer is β-lactamase production.
• Nontypeable strains of H. influenzae are often resistant to β lactams [mostly due to β-lactamase production (20–35% of strains) or rarely by expressing altered penicillin-binding protein-3].

18. All are the feature(s) of chancroid:

1. Ulcer bleed easily
2. Painful
3. Bubo formation
4. Typically indurated
5. Caused by H. ducreyi

Answer. (1, 2, 3, 5) (Ulcer bleeds easily, Painful, Bubo formation, Caused by H. ducreyi)

Chancroid is caused by H. ducreyi and is characterized by painful ulcers and painful soft non-indurated lymph nodes (bubo).

19. Which of these need both V and X factors?

Haemophilus influenzae

1. H.ducreyi
2. H.paraphrophilus
3. H.aegyptius
4. H.haemolyticus

Answer. (1, 4, 5) (H. influenzae, H. aegypticus, and H. haemo…)

Haemophilus that need both X and V factors: H. influenzae, H. Egyptians and H.haemolyticus

20. Capsular polysaccharide constitutes an important virulence factor responsible for protective antibody response in infections caused by all the following bacteria except:

1. Haemophilus influenzae
2. Streptococcus pneumoniae
3. Neisseria meningitides
4. Bordetella pertussis

Answer. (4) (Bordetella perttussis )

H. influenzae, N. meningitidis, and Pneumococcus are capsulated, and capsular polysaccharide vaccine is available against this organism.

21. Acute epiglottitis is caused most commonly by:

1. Haemophilus influenzae
2. Bordetella
3. Streptococcus pyogenes

Answer. (1) (Haemophilus influenzae)

22. Disease caused by Haemophilus:

1. Chancroid
2. Influenza
3. Acute epiglottitis
4. Brain abscess
5. Brazilian purpuric fever

Answer. (1, 3, 4, 5) (Chancroid, Acute epiglottitis, Brain abscess, Brazilian purpuric fever)

• Influenza is caused by influenza virus.
• Pfeiffer observed Haemophilus in sputum of Influenza pandemic patients and wrongly named as H. influenzae
• Brazilian Purpuric fever: H. aegypticus
• Chancroid (Soft Chancre): H. ducreyi
• Laryngoepiglottitis (Croup), Meningitis Brain abscess: H. influenzae

23. HACEK group includes all except:

1. Haemophilus aprophillus
2. Acinetobacter baumanii
3. Eikenella corrodens
4. Cardiobacterium hominis

Answer. (2) (Acinetobacter baumanii)

24. Chancroid is caused by:

1. H. ducreyi
2. T. pallidum
3. Gonococcus
4. HSV

Answer. (1) (H. ducreyi)

• Chancroid is caused by H. ducreyi

25. Haemophilus parainfluenzae requires which factors:

1. Only factor X
2. Only factor V
3. Both factor X and V
4. Nothing required

Answer. (2) (Only factor V)

26. All of the following are true regarding Haemophilus influenzae except:

1. It can be a part of the normal flora in some persons
2. The serotyping is based on the bacterial outer membrane proteins
3. It requires Haemin and NAD for growth in culture medium
4. Type b is responsible for invasive disease

Answer. (2) (The serotyping is based on the bacterial outer membrane proteins)

• Serotyping of H. influenzae is based on the capsular polysaccharide
• About Other Options:
• H. influenzae can be typed to Six serotypes (a-f), out of which type b is responsible for most of the invasive infection.
• Type b and nontypable strains are the most relevant strains clinically, responsible for invasive disease
• Haemin (X factor) and NAD (V factor) are essential for growth in culture medium
• Can be a part of the normal flora in some persons
• Nontypable strains colonize the upper respiratory tract of up to three-fourths of healthy adults.

27. Nontypable H.influenzae can cause all except:

1. Meningitis
2. Otitis media
3. Sinusitis in adults
4. Puerperal infection

Answer. (1) (Meningitis)

Nontypable H.influenzae

• Next to H.influenzae-b (Hib), Nontypable strains are the commonest group of Haemophilus influenzae clinically. They are noninvasive, spread by contagious spread.
  They cause the following infections.
• Childhood otitis media
• Exacerbations of COPD (chronic obstructive pulmonary disease): They are the most common bacterial cause.
• Pneumonia in adults among patients with COPD or AIDS
• Puerperal sepsis and neonatal bacteraemia: Especially by nontypable strains of biotype
  IV that colonizes the female genital tract.
• Sinusitis in adults and children
• Rarely causes invasive infections such as empyema, adult epiglottitis, pericarditis,cellulitis, septic arthritis, osteomyelitis in countries where Hib vaccines are used widely.

28. True about H.influenzae:

1. Also called as Pfeiffer’s bacilli
2. In acute infections capsulated strains are often isolated
3. Gram-negative motile bacilli
4. Easily cultured
5. VP Test positive

Answer. (1, 2) (Also called as Pfeiffer’s bacilli, In acute infections capsulated strains are often isolated)

H.influenzae or the Pfeiffer’s bacillus is nonmotile, Gram-negative pleomorphic bacilli. VP is negative.
Capsulated strains are isolated in invasive acute infections whereas the nontypable strains are often responsible for non- invasive conditions such as otitis media.

29. A patient presented to a STD clinic with painful genital ulcer and painful, soft nonindurated enlarged inguinal lymph nodIdentify the pathogen:

1. H.ducreyi
2. T.pallidum
3. Calymmatobacter
4. Herpes

Answer. (1) (H. ducreyi)

• Painful genital ulcer and painful, soft nonindurated enlarged inguinal lymph node. Suggestive of soft sore/chancroid which is caused by Haemophilus ducreyi.

30. Drug of choice for whooping cough is:

1. Tetracycline
2. Ceftriaxone
3. Erythromycin

Answer. (3) (Erythromycin)

Macrolide antibiotics are the drugs of choice for treatment of pertussis.

31. Which does not has a known animal reservoir?

1. Bordetella pertussis
2. Francisella tularensis
3. Brucella melitensis
4. Pasturella multocida

Answer. (1) (Bordetella pertussis)

• Bordetella pertussis does not have a known animal reservoir.

32. Components of acellular pertussis vaccine:

1. PT + FHA + fimbriae
2. PT + cytotoxin + fimbriae
3. Endotoxin + fimbriae + pili
4. Pertactin + FHA + outer membrane protein + fimbriae

Answer. (1) (PT + FHA + fimbriae)

• ‘Although a wide variety of acellular pertussis vaccines were developed, only a few are still widely marketed; all contain pertussis toxoid and filamentous hemagglutinin.’
• Acellular pertussis contains: Pertussis toxoid
  Filamentous hemagglutinin
  • Agglutinogen 1,2,3
  • Pertactin (in some vaccine preparations).

33. A 7-month-old infant with the history of incomplete childhood vaccination presents with bouts of spasmodic cough with cyanosis and a typical inspiratory whoop.
Which is most appropriate clinical specimen to be collected for the isolation of pathogen?

1. ‘Cough plate culture’
2. Per oral swab
3. Nasopharyngeal swab
4. Endotracheal aspirate

Answer. (3) (Nasopharyngeal swab)

• History of Incomplete childhood vaccination with bouts of spasmodic cough with cyanosis and a typical inspiratory whoop is suggestive of Whooping cough due to Bordetella pertussis.
• ‘The best specimen is collected by nasopharyngeal aspiration, by fine flexible plastic catheter.
• Is attached to a 10-ml syringe is passed into the nasopharynx and withdrawn while gentle suction is applied.
• Since pertussis is highly sensitive to drying, secretions for culture should be inoculated without delay onto appropriate medium’

About Other Options

• Cough plate method though offers advantage like direct bedside plating without delay,but chance of contamination is more.
• Per oral swab is used to collect secretions from posterior pharyngeal wall.
• Endotracheal swab is not useful as the secretion will be predominantly in nasopharynx.

34. Pertussis toxin acts by all of the following mechanisms except:

1. ADP ribosylation of proteins associated with receptors
2. Increase cyclic AMP
3. Increased calcium release from sarcoplasmic reticulum
4. Acts through G alpha subunit

Answer. (3) (Increased calcium release from sarcoplasmic reticulum)

• Increased calcium release from sarcoplasmic reticulum is not a mechanism of Pertussis toxin
• Pertussis toxin
• Promotes lymphocytosis
• Sensitization to histamine
• Enhances insulin secretion
• ADP-ribosylating activity, with an A/B structure and mechanism of action similar to that of cholera toxin.
• ADP ribosylation of GTP binding protein → activation of Adenyl cyclase → activation of cAMP

35. A patient with undulating fever presents with features of encephalitis. He is treated successfully with doxycycline and rifampicin. Probable diagnosis:

1. Brucellosis
2. Bordetella pertussis
3. Francessilea tularensis
4. Mycoplasma

Answer. (1) (Brucellosis)

• Undulating fever presents with features of encephalitis… suggestive of brucellosis.

36. Milk ring test is seen in:

1. Brucellosis
2. Tuberculosis
3. Bacteroides
4. Salmonellosis

Answer. (1) (Brucellosis)

• Milk ring test is done for diagnosis of Brucellosis in animals.

37. Brucella melitensis is commonly found in (animal):

1. Pig
2. Camel
3. Sheep
4. Goat
5. Reindeer

Answer. (2, 3, 4) (Camel, Sheep, Goat)

• The nomen system recognizes melitensis, which is the most common cause of symptomatic disease in humans and for which the main sources are sheep, goats, and camels.

38. Malta fever is caused by:

1. Treponema pallidum
2. Borrelia burgdorferi
3. Brucella melitensis
4. Pseudomonas aeruginosa

Answer. (3) (Brucella…)

‘Brucellosis is also known as Malta or Undulant fever or Mediterranean fever’.

39. Treatment of Brucellosis:

1. Doxycycline
2. Streptomycin
3. Erythromycin
4. Penicillin
5. Rifampicin

Answer. (1, 2, 5) (Doxycycline, Streptomycin, Rifampicin)

40. Brucellosis can be transmitted by all of the following, except:

1. Contact with infected placenta
2. Ingestion of raw vegetables from infected forms
3. Person-to-person transmission
4. Inhalation of infected dust or aerosol

Answer. (3) (Person-to-person transmission)

‘Person-to-person transmission is extremely rare’

Mode of Transmitted by:

• Intake of Raw milk (MC), or milk products/meat contaminated with infected animal feces/urine
• Contact with animal feces/urine
• Inhalation of dried material of animal origin.

41. A farmer presenting with fever off and on for the past 4 years was diagnosed to be suffering from chronic brucellosis. All of the following serological tests would be helpful in the diagnosis at this state except:

1. Standard Agglutination test
2. 2 Mercaptoethanol test
3. Complement fixation test
4. Coomb’s test

Answer. (1) (Standard Agglutination test)

• Standard Agglutination test identifies mainly IgM antibody, hence they are useful in acute but not in chronic brucellosis.
• In acute brucellosis- Following 7-10 days of infection, both IgM and IgG appear,however, the IgM antibodies gradually fall and only IgG antibodies persist in chronic brucellosis

42. Castaneda method of blood culture is usually used for diagnosis of:

1. Lobar pneumonia
2. Toxic shock syndrome
3. Relapsing fever
4. Brucellosis

Answer. (4) (Brucellosis)