Textbook Question
Under what conditions can the saprophytes Aspergillus and Rhizopus cause infections?
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Ch. 24 - Microbial Diseases of the Respiratory System
Tortora14th EditionMicrobiology: An IntroductionISBN: 9780138200398
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Table of contents
- Ch. 1 - The Microbial World and You18
- Ch. 2 - Chemical Principles20
- Ch. 3 - Observing Microorganisms Through a Microscope18
- Ch. 4 - Functional Anatomy of Prokaryotic and Eukaryotic Cells21
- Ch. 5 - Microbial Metabolism20
- Ch. 6 - Microbial Growth20
- Ch. 7 - The Control of Microbial Growth20
- Ch. 8 - Microbial Genetics19
- Ch. 9 - Biotechnology & DNA Technology20
- Ch. 10 - Classification of Microorganisms15
- Ch. 11 - The Prokaryotes: Domains Bacteria and Archaea14
- Ch. 12 - The Eukaryotes: Fungi, Algae, Protozoa, and Helminths17
- Ch. 13 - Viruses, Viroids, and Prions20
- Ch. 14 - Principles of Disease and Epidemiology21
- Ch. 15 - Microbial Mechanisms of Pathogenicity19
- Ch. 16 - Innate Immunity: Nonspecific Defenses of the Host20
- Ch. 17 - Adaptive Immunity: Specific Defenses of the Host20
- Ch. 18 - Practical Applications of Immunology20
- Ch. 19 - Disorders Associated with the Immune System19
- Ch. 20 - Antimicrobial Drugs19
- Ch. 21 - Microbial Diseases of the Skin and Eyes21
- Ch. 22 - Microbial Diseases of the Nervous System19
- Ch. 23 - Microbial Diseases of the Cardiovascular and Lymphatic Systems20
- Ch. 24 - Microbial Diseases of the Respiratory System20
- Ch. 25 - Microbial Diseases of the Digestive System20
- Ch. 26 - Microbial Diseases of the Urinary and Reproductive Systems19
- Ch. 27 - Environmental Microbiology20
- Ch. 28 - Applied and Industrial Microbiology19
Tortora14th EditionMicrobiology: An IntroductionISBN: 9780138200398Not the one you use?Change textbook
Chapter 24, Problem 6
Match the following choices to the culture descriptions in questions 3 through 6:
a. Chlamydia
b. Coccidioides
c. Histoplasma
d. Mycobacterium
e. Mycoplasma
Microscopic examination of a lung biopsy shows spherules.
Verified step by step guidance1
Step 1: Understand the key term in the description — 'spherules'. In microbiology, spherules are a distinctive morphological form seen in certain fungal pathogens, particularly in tissue samples.
Step 2: Recall which organisms from the given list are fungi and which are bacteria. Chlamydia and Mycoplasma are bacteria, Mycobacterium is a genus of acid-fast bacteria, while Coccidioides and Histoplasma are fungi.
Step 3: Identify which fungus is known for producing spherules in tissue. Coccidioides species form large, thick-walled spherules containing endospores during infection, which is a hallmark for diagnosis.
Step 4: Compare this with Histoplasma, which typically forms small yeast cells inside macrophages rather than spherules, so it is less likely to be the correct match.
Step 5: Conclude that the culture description showing spherules in a lung biopsy corresponds to Coccidioides, based on its characteristic morphology.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Spherules in Fungal Infections
Spherules are thick-walled, spherical structures containing endospores, characteristic of certain fungal pathogens like Coccidioides. Their presence in lung tissue indicates a fungal infection, helping differentiate it from bacterial or viral causes.
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Map of Lesson on Bacteriophage Infections
Coccidioides Biology and Pathogenesis
Coccidioides is a dimorphic fungus causing coccidioidomycosis (Valley fever). In tissue, it forms spherules filled with endospores, which rupture to release infectious particles, leading to lung infection and granulomatous inflammation.
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Differentiation of Microbial Cultures by Microscopy
Microscopic examination of cultures or tissue biopsies helps identify pathogens based on morphology. Recognizing unique structures like spherules (Coccidioides), acid-fast bacilli (Mycobacterium), or lack of cell wall (Mycoplasma) is essential for accurate diagnosis.
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Related Practice
Textbook Question
List the causative agent, mode of transmission, and endemic area for the diseases histoplasmosis, coccidioidomycosis, blastomycosis, and Pneumocystis pneumonia.
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Textbook Question
Match the following choices to the culture descriptions in questions 3 through 6:
a. Chlamydia
b. Coccidioides
c. Histoplasma
d. Mycobacterium
e. Mycoplasma
Microscopic examination of a lung biopsy shows ovoid cells in alveolar macrophages. You suspect these are the cause of the patient’s signs and symptoms, but your culture grows a filamentous organism.
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Textbook Question
In San Francisco, ten animal health care technicians developed pneumonia 2 weeks after 130 goats were moved to the animal shelter where they worked. Which of the following is false?
a. Diagnosis is made by a blood agar culture of sputum.
b. The cause is Coxiella burnetii.
c. The bacteria produce endospores.
d. The disease was transmitted by aerosols.
e. Diagnosis is made by complement-fixation tests for antibodies.
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Textbook Question
Briefly describe the procedures and positive results of the tuberculin test and what is indicated by a positive test.
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Textbook Question
A patient has been diagnosed as having pneumonia. Is this sufficient information to begin treatment with antimicrobial agents? Briefly discuss why or why not.