Mycology Lecture 3 Flashcards
Which regional endemic fungi species has been isolated in eastern Washington state?
Coccidioides immitis
True or False: ALL regional endemic fungi are dimorphic.
True
True or False: All regional endemic fungi are systemic and primary pathogens.
False. Lobomycosis is sub-cutaneous. The part about all of them being primary pathogens is a true statement.
Name 5 common themes that the systemic endemic mycoses share.
- They are all ascomycetes
- Fungus grows in the environment as mold
- Causes primary pulmonary infection
- Risk depends on geographic exposure
- They are all lab hazards
Systemic endemic mycoses often present with no _____. However, patients that are symptomatic usually get better quickly. In _______ patients, the disease can be either _____, _______, or ________.
Symptoms, immunocompromised, severe, disseminated, reactivated
True or False: Sex and ethnicity may play a role in determining the severity of disease with patients suffering from systemic endemic mycoses.
True
________ present in culture is used to diagnose ___________.
Spherules, Coccidioides
Where is Coccidioides endemic to?
Southwest USA, Mexico, South and Central America
Where is Coccidioides hyperendemic to?
Central Valley of CA & Phoenix/Tuscon area of AZ
Name the characteristics of the early cases of Coccidioides
Progressive painful lesions on the face, leading to tissue destruction, and death several years later
Coccidioides was initially believed to be a _______, and also thought to have a high _______ ____.
Parasite, mortality rate
How many cases of Cocci are reported each year?
+ 150K cases per year in the USA
65% in AZ, 35% in CA
True or False: Spores from Cocci were inhaled from a micro plate by a med student in 1929.
True
Cocci _____ is found in Washington and California, while Cocci ______ is found in other areas, including Arizona.
immitis, posadasii
The infectious unit in soil are known as __________, and are generally asexual & produced by fungal hyphae.
Arthroconidia
___________ are released from ruptured _______ and propagate the infection in the host.
Endospores, spherules
Is this pathway regarding the Cocci life cycle correct?
Arthroconidia in lung -> Spherules -> Septated Spherule -> Segmented Spherule -> Formation of Endospores -> More Spherules
Yes
True or False: Most people who have Cocci are asymptomatic.
True (60%)
______ _____ fever is used to describe the flu-like illness, pneumonia, skin nodules, and arthritis that may accompany Cocci.
Acute Valley
Patients who have Cocci may get chronic ______ ____ disease, which looks like ________.
Cavitary lung, tuberculosis
Pneumonia as a result of Cocci may lead to further complications such as:
Skin lesions, bone lesions, or meningitis (rare)
Name some risk factors for severe/disseminated Cocci (5)
- HIV
- Transplant, chemo, or TNF-alpha blockers
- Filipino ancestry (?)
- Diabetes
- Pregnancy
True or False: Diabetes increases the risk of dissemination of Cocci.
False. Diabetes increases the risk of pulmonary complications, such as cavitation or chronic pneumonia.
Which trimester of pregnancy has the highest risk of severe/disseminated Cocci? Which class of antifungals is not recommended during pregnancy?
Third trimester (also post-partum), Azoles
The most common mode of diagnosis of Cocci is _______.
Serology
True or False: Cocci cannot be cultured.
False. Cocci can be grown in 3-5 days using routine media.
The spherule is referred to as being “________.”
Pathognomonic
Cocci can be cultured and it appears as a _____ when cultured at 25C.
Mould
During complement fixation, the patient’s sample is diluted and mixed in with ____ ______. If ________ are present, a ______ is formed, which depletes ______.
Cocci antigens, antibodies, complex, complement
A positive result at > _______ dilution is associated with Cocci dissemination.
1:16
List some disadvantages to using serology for diagnostic purposes (3)
- Antibodies such as IgM and IgG may not be present early in disease.
- People who are immunocompromised may not produce adequate antibodies.
- Cocci may be limited in a certain location and may not have escaped into the blood.
In immunocompromised patients who have a negative serology result, ______ ______ can be used.
Antigen testing
Name serums used for antigen testing with Cocci (3)
Blood, urine, CSF
True or False: Antigen testing is insensitive for pulmonary. The more severe/disseminated Cocci is, the higher yield with antigen testing.
True
True or False: People who are immunocompromised can have better luck with antigen testing due to a higher level of antigens present in their body.
True
Name one issue that comes with antigen testing for Cocci.
Cross reactivity with other endemic fungi
Treatment for Cocci includes ______ and _______ for immunocompromised patients with only pulmonary disease. If the disease is more disseminated/severe, add in __________.
Fluconazole, itraconazole, amphotericin
How long should antifungals be administered against Cocci?
3-12 months (depends on host)
Cocci ______ is very serious and hard to cure. It usually requires lifelong antifungals, and can be diagnosed by culture, or detection of antibodies in _____ ______.
Meningitis, spinal fluid
What’s the treatment for Cocci meningitis?
Fluconazole or Amphotericin (don’t inject Amphotericin directly into CSF)
Where is Histoplasmosis hyperendemic to?
Mississippi and Ohio River Valleys
Histo can develop due to exposure to: (4)
- Soil enriched with bird and bat guano
- Chicken coops
- Caves
- Demolition activity
Histo can lay ______ but reactivate outside of the endemic region (ie. if the patients has AIDS). Histo can also be transmitted via ____ _______.
Dormant, organ donation
How many cases of Histo are reported each year?
~350,000K
Histo is _____, and appears as a small ____ _____ in tissue. It has no ______.
intracellular, oval yeast, capsule
When grown in the mould form, ________ & ________ are present.
Microconidia and Macroconidia
True or False: The Histo capsulatam variant is found all over the world, but is hyperendemic in the central US.
True
True or False: The duboisii variant (African) is more involved with skin, bone, and disseminated disease.
True
The duboisii variant forms ______ yeast forms in tissue.
Larger
Describe how Histo is acquired.
- Histo spores are inhaled
- Spores go into the lungs and into the alveoli where they are trapped by immune cells.
- Immune cells (macrophages) contain Histo where Histo can multiply in macrophages of the lung. Immune cells are carried to the lymph nodes, where they can multiply and spread to the blood if not eliminated.
In ___ of cases of Histo, patients are asymptomatic.
90%
A patient with Histo may get Acute Pulmonary Histoplasmosis, where they can get ________ in the lungs/liver/spleen or nodule lesions.
Calcifications
Name more severe complications of Histo (3)
- Cavitary pulmonary histo
- Pericarditis (heart inflammation)
- Fibrosing mediastinitis
What are risk factors for dissemination with Histo? (3)
- AIDS
- Children under age 2
- Other condition that renders an individual immunocompromised
With dissemination, where can the Histo infection go?
bone marrow, lymph system, blood, skin, liver, spleen
The Histo skin test is good for _____ exposure, not current ____ disease.
past, active
What agent is used for the Histo skin test?
Histoplasmin (sterile culture filtrate of mycelium growth for months)
Histo skin test cross reacts with ________ and ________.
Blastomyces, Coddidioides
Name some ways Histo can be diagnosed (5)
- Culture: blood, bone marrow, lung fluid, tissue [specific, not sensitive[
- Histoplasma antigen: urine and blood. [sensitive]
- Serology [complement fixation]
- PCR [not used]
- Histology [intracellular yeast/tissue]
How is Histo treated?
It’s not treated unless symptoms last more than a month. If so, itraconazole or amphotericin B is used for pneumonia, dissemination, or chronic disease.
True or False: For treating Histo, after itraconazole, fluconazole can be used as a second line (for mild disease).
True
In contrast to Histo, Blasto is _______.
Extracellular
Where is Blasto found in the environment?
Moist soil, wooded areas
Where is Blasto hyperendemic to?
Mississippi, Ohio, St. Lawrence river valleys, Arkansas, Kentucky
Outside of the US, Blasto can also be found in _____.
Africa
About ____ of patients with Blasto are asymptomatic.
50%
Blasto can lead to acute pneumonia, but it also frequently can cause a _______ disease.
Cutaneous
In a patient who has Blasto and develops pneumonia, it can travel to the ____, ____, ____, and _____.
bone, skin, mucosa, prostate
Ulcerated skin lesions from Blasto can appear similar to ____ _____.
Skin cancer
Describe the hyphae & conidia of Blasto.
Septate hyphae, hyaline (clear), conidia appear similar to a “lollipop”
Describe the pathogenesis of Blasto (2 different ones)
Conidia are inhaled –> yeast –> clinical pulmonary infection, immune response
OR
Traumatic inoculation –> cutaneous disease
How is Blasto diagnosed?
- Culture: from sputum, lung, or skin (appears as mold with microconidia)
- Antigen: 93% sensitivity, but cross reaction w/ other dimorphics
- Histology: Big broad based budding yeast (general looking, not pathognomonic)
*Serology and PCR are not included because Serology lacks sensitivity, and PCR is evolving.
True or False: With Blasto infection, treatment is not needed for most patients because dissemination and severe disease rarely occurs.
False - most clinicians treat Blasto. It has a high rate of dissemination & severe disease. Also, treat all infections and not just high risks.
For more mild Blasto disease, ________ should be prescribed. For serious or CNS disease, __________ should be prescribed.
itraconazole, amphotericin
Name the most common organ involved with Blasto
Lungs
Besides the lungs, which organs are commonly involved in Blasto?
Skin and bone
Genitourinary and CNS are less common
True or False: Blasto can also infect mammals besides humans, such as dogs and cats. However, cats are more frequent victims.
False. Dogs are more frequent victims.
In Arkansas, human cases ___ dog cases, but in North Carolina, human cases ___ dog cases.
=, 10x
True or False: Human to human transmission is very uncommon with Blasto, as is transmission from infected dogs/cats to humans.
True
Previous studies showed that ___ were more likely to get Blasto, but recent studies have not been able to prove this.
Men
Similar to Cocci, Paracocci is _______ and has __________.
Extracellular, arthroconidia
Where is Paracocci found?
Central and South America
As early as ____ days, Paracocci can lead to acute disease, where ____, weight ___, enlargement of ____/____/____ ____, and bone ____ dysfunction occurs.
45 days
Fever, loss, liver/spleen/lymph nodes, marrow
True or False: Acute disease from Paracocci can become chronic or reactivate months to year after initial infection.
True
Paracocci is unique in that ____ are more infected than _____. What’s the reasoning behind this?
males, females
this may be because estrogen plays a role in converting mold to yeast, thus you don’t get an infection
With chronic Paracocci, the ____ are more commonly involved, but ____ can be as well. Generally, any organ can become affected.
Lungs, mucosa
Describe the histology of Paracocci.
Large yeasts, multiple buds
“Mariner’s wheel”
Why is culture of Paracocci hard?
It usually takes 20-30 days to grow on culture.
True or False: Similar to Blasto, all patients should be treated. Itraconazole should be given for mild disease, while Amp should be given for more severe cases.
True
Where is Talaromycosis found?
Southeast Asia
Where was Talaro first isolated from?
Bamboo rat
Talaro, unlike the other dimorphic endemic species, can lead to ____ symptoms in addition to pulomary and skin lesions.
GI (Diarrhea, abdominal pain)
Talaro is similar to disseminated _____ in AIDS patients.
Histo
Similar to Histo, Talaro is ______.
Intracellular
Talaro is diagnosed via ____.
Culture
Yeast from Talaro are described as ____ shaped.
Sausage
Talaro is unique in that the yeast undergo ______ _____, not budding.
Binary fission
The agent that causes Lobomycosis has a close relationship with _______.
Paracocci
Where is lobomycosis found?
Central and South America (Columbia, Brazil)
Lobomycosis can be found in _____.
Dolphins
Lobomycosis can be diagnosed via histology, where yeasts are _____ shaped.
Lemon
Describe what Lobomycosis looks like.
Consists of keloids (hard painless nodules)
