Podcast
Questions and Answers
What does the MANTOUX test involve?
What does the MANTOUX test involve?
- Intradermal injection of PPD (correct)
- Intramuscular injection of PPD
- Oral administration of PPD
- Subcutaneous injection of PPD
What is the primary method for diagnosing Mycobacterium leprae?
What is the primary method for diagnosing Mycobacterium leprae?
- Chest X-Ray
- Nitrate and Niacin Test
- Sputum culture
- Lepromin Test (correct)
What characteristic growth pattern is associated with Mycobacterium tuberculosis in culture?
What characteristic growth pattern is associated with Mycobacterium tuberculosis in culture?
- Mushroom-like clusters
- Flower-like growth (correct)
- Round smooth colonies
- String-like formations
Which type of Mycobacterium is known as the 'Cross Barred Bacillus'?
Which type of Mycobacterium is known as the 'Cross Barred Bacillus'?
What is a common clinical manifestation of leprosy?
What is a common clinical manifestation of leprosy?
Which specimen is typically collected for diagnosis of Mycobacterium leprae?
Which specimen is typically collected for diagnosis of Mycobacterium leprae?
What type of disease is primarily caused by Mycobacterium marinum?
What type of disease is primarily caused by Mycobacterium marinum?
What is the duration of culture maintenance for the diagnosis of Mycobacterium species?
What is the duration of culture maintenance for the diagnosis of Mycobacterium species?
What is the result indicating for the Iron Uptake Test when no color change occurs?
What is the result indicating for the Iron Uptake Test when no color change occurs?
Which of the following is true regarding the Pyrazinamidase Test?
Which of the following is true regarding the Pyrazinamidase Test?
What does a positive result in the Heat Stable Catalase Test indicate?
What does a positive result in the Heat Stable Catalase Test indicate?
In the presence of zinc powder, what does a negative color change indicate?
In the presence of zinc powder, what does a negative color change indicate?
What does positive phenolphthalein indicate in the context of Arylsulfatase testing?
What does positive phenolphthalein indicate in the context of Arylsulfatase testing?
What action should be taken to confirm a negative result in the nitrate reduction test?
What action should be taken to confirm a negative result in the nitrate reduction test?
What is the purpose of using Tween 80 in the identification of Mycobacterium?
What is the purpose of using Tween 80 in the identification of Mycobacterium?
What characteristic result is expected for M.gordonae in the catalase test?
What characteristic result is expected for M.gordonae in the catalase test?
What is the primary staining characteristic of Mycobacterium due to mycolic acid?
What is the primary staining characteristic of Mycobacterium due to mycolic acid?
Which Mycobacterium species is commonly associated with leprosy?
Which Mycobacterium species is commonly associated with leprosy?
Which method is recognized for acid-fast staining?
Which method is recognized for acid-fast staining?
What characteristic does the non-photochromogen group of Mycobacterium exhibit?
What characteristic does the non-photochromogen group of Mycobacterium exhibit?
Which of the following media is known to inhibit contaminating organisms in Mycobacterium culture?
Which of the following media is known to inhibit contaminating organisms in Mycobacterium culture?
How is the viability of non-culturable Mycobacterium maintained?
How is the viability of non-culturable Mycobacterium maintained?
What is the typical arrangement of Mycobacterium seen under a microscope?
What is the typical arrangement of Mycobacterium seen under a microscope?
What is indicated by a yellow result in the Niacin test on Lowenstein media?
What is indicated by a yellow result in the Niacin test on Lowenstein media?
What type of growth medium is formulated for the culture of Mycobacterium that does not use selective antibiotics?
What type of growth medium is formulated for the culture of Mycobacterium that does not use selective antibiotics?
In the Runyon Classification, Mycobacterium that do not produce pigment are categorized under what type?
In the Runyon Classification, Mycobacterium that do not produce pigment are categorized under what type?
Which Mycobacterium species is predominantly associated with cervical adenitis in children?
Which Mycobacterium species is predominantly associated with cervical adenitis in children?
Which of the following species is categorized as a non-photochromogen and is associated with pulmonary infections in patients with preexisting conditions?
Which of the following species is categorized as a non-photochromogen and is associated with pulmonary infections in patients with preexisting conditions?
What type of growth pattern does Mycobacterium phlei exhibit on LJ medium?
What type of growth pattern does Mycobacterium phlei exhibit on LJ medium?
Which organism is primarily responsible for skin and soft tissue infections, as well as postoperative infections?
Which organism is primarily responsible for skin and soft tissue infections, as well as postoperative infections?
Which species of Mycobacterium is characterized by being a rapid grower and is linked to postoperative infections like breast augmentation?
Which species of Mycobacterium is characterized by being a rapid grower and is linked to postoperative infections like breast augmentation?
Which of the following Mycobacterium species is NOT typically associated with cervical lymphadenitis?
Which of the following Mycobacterium species is NOT typically associated with cervical lymphadenitis?
What is the primary pathogenic effect of Mycobacterium xenopi?
What is the primary pathogenic effect of Mycobacterium xenopi?
Which of the following Mycobacterium species is biochemically inert and commonly referred to as Buruli ulcer?
Which of the following Mycobacterium species is biochemically inert and commonly referred to as Buruli ulcer?
Which mycobacterium species is characterized by a positive Niacin test?
Which mycobacterium species is characterized by a positive Niacin test?
Which mycobacterium has a positive Nitrate Reduction Test but a negative Heat Stable Catalase test?
Which mycobacterium has a positive Nitrate Reduction Test but a negative Heat Stable Catalase test?
Which of the following tests is consistently positive for Mycobacterium marinum?
Which of the following tests is consistently positive for Mycobacterium marinum?
Which mycobacterium species shows a positive result in the Heat Stable Catalase test?
Which mycobacterium species shows a positive result in the Heat Stable Catalase test?
What is the result of the Pyrazinamidase Test for Mycobacterium scrofulaceum?
What is the result of the Pyrazinamidase Test for Mycobacterium scrofulaceum?
Which mycobacterium species has a slow positive response in the Tween 80 Hydrolysis Test?
Which mycobacterium species has a slow positive response in the Tween 80 Hydrolysis Test?
Which mycobacterium species does NOT reduce nitrate?
Which mycobacterium species does NOT reduce nitrate?
What is the result of the Iron Uptake Test for Mycobacterium kansasii?
What is the result of the Iron Uptake Test for Mycobacterium kansasii?
Flashcards are hidden until you start studying
Study Notes
Mycobacteria
- Aerobic, non-motile
- Slow growers and require whole egg for growth
- Difficult to stain but once stained difficult to decolorize due to hydroxy methoxy acid / mycolic acid
M. tuberculosis Complex
- M. tuberculosis
- M. bovis
- M. africanum
- M. microti & M. canetti
MOTT (Mycobacterium other than tuberculosis)/ Runyon's Classification
- Photochromogens
- Scotochromogens
- Non-photochromogens
- Rapid growers
M.leprae
- A.k.a. Hansen’s disease
- Causes LEPROSY
- Non-culturable in vitro, but viability can be maintained using MICE FOOT PADS or FOOT PADS of ARMADILLO
- Under the microscope, it forms the so-called Cigar Packet arrangement
- Diagnosis is often made based on clinical symptoms
Screening Test: Acid Fast Staining
- Ziehl Neelsen
- Kinyoun’s method
Culture
- Non-Selective
- Agar based
- Selective
- Liquid
Common Disadvantage:
- Lowenstein Jensen Media
- Petragnani- more inhibitory
- American Thoracic Society /ATS
- Dorset Egg Media
- Wallenstein medium
If (+) Growth in Any of These Media, Next Step Is to Do Series of Biochemical Tests to Identify Species
Biochemical Tests
- Niacin test
- Nitrate reduction test
- Heat Stable Catalase test
- Tween 80 Hydrolysis test
- Arylsulfatase test
- Iron Uptake test
- Pyrazinamidase test
M. Tuberculosis
- Skin Testing – MANTOUX TEST – involves intradermal injection of PPD on the skin
- PPD (purified Protein Derivative) – protein extracted and purified from M. tuberculosis cell wall
- OT (old tuberculin)
- Von Pirquet (old tuberculin mixed with lanolin to produce ointment, which is scratched onto the skin)
M. bovis
- Causes tuberculosis in cattle
- Can be transmitted to humans through unpasteurized milk
- Nitrate and Niacin Test negative
M. leprae a.k.a. Hansen's Disease
- Forms the so-called Cigar Packet arrangement
- Non-culturable on artificial media, but can be maintained in the lab using armadillo foot pads or mouse foot pads
- Causes Leprosy MOT – prolong skin to skin contact with infected person, droplets from nose & mouth (inhalation)
- Clinical manifestation: LEONINE FACE
- Tuberculoid type /paucibacillary (limited number of bacteria in the tissues, lesions are usually well-defined and localized)
- Lepromatous type /multibacillary (numerous bacteria in the tissues, lesions are widespread and usually poorly defined)
- Basis of diagnosis: Lepromin test
- Specimen: TISSUE JUICE (earlobes, nasal scrapings)
Non-tuberculous Mycobacteria
Photochromogens
- Mycobacterium kansasii – regarded as the # 2 NTM to cause TB in those with AIDS; a.k.a. Cross Barred Bacillus
- Mycobacterium marinum- can cause Fish Tank granuloma or Swimming Pool Granuloma
- Mycobacterium asiaticum, M. simiae, M. intermedium & M. novocastrense
Scotochromogens
- Mycobacterium szulgai - pulmonary disease, predominantly in middle-aged men; cervical adenitis; bursitis
- Mycobacterium scrofulaceum - Cervical adenitis in children, bacteremia, pulmonary disease, skin infections
- Mycobacterium gordonae / M. aquae (Saprophobic)
- M. xenopi - Primarily pulmonary infections in adults. Often produces lemon-yellow colonies on CORN MEAL AGAR
- M. flavescens, M. thermresistible
- M. interjectum - Unknown Potentially pathogenic Chronic lymphadenitis, pulmonary disease
- Others: M. heckeshornense, M. tusciae, M. kubicae, M. cookie, M. hiberniae
Non-Photochromogens
- M. avium complex - pulmonary infections in patients with preexisting pulmonary disease; cervical lymphadenitis; and disseminated disease (M. avium pathogenic – LADY WINDERMERE SYNDROME while M. intracellulare = Battey Bacillus)
- M. terrae (Scotochromogens)
- M. triviale (Photochromogens)
- M. gastri, M. ulcerans - mycobacteriosis, also referred to as Buruli ulcer, biochemically inert
- M. malmoense M. genovense- Disseminated disease in patients with AIDS
- , M. haemophilum, Others: M. heidelbergense; M. simiae; M. shimoidei
Rapid Growers:
- M. abscessus subsp. Abscessus - Disseminated disease, primarily in immunocompromised individuals; skin and soft tissue infections; pulmonary infections; postoperative infections
- M. fortuitum - Postoperative infections in breast augmentation and median sternotomy; skin and soft tissue infections; pulmonary infections, usually single, localized lesions. Central nervous system (CNS) disease is rare but has high morbidity and mortality
- M. chelonei - Skin and soft tissue infections, postoperative wound infections, keratitis
- M. phlei – breadcrumbs growth on LJ medium
- Others: M. smegmatis – Urine AFB +
Biochemical Tests to Speciate Mycobacterium
- Niacin test
- Nitrate Reduction test
- Heat Stable Catalase test
- Tween 80 Hydrolysis test
- Arylsulfatase test
- Iron Uptake test
- Pyrazinamidase test
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
