Bacteriology 15: Mycoplasma and Obligate Intracellular Bacteria Flashcards by Estefania Pereyra Cruzado

Mycoplasma
*size, deficiencies, cell wall (what does this cause),

Small bacteria

Many nutritional deficiencies
-CANNOT synthesize amino acids or vitamins or lipids
- some (hemotropic) CANNOT be cultivated in vitro

NO cell wall
-beta-lactams have NO effect
-ANTIMICROBIAL SELECTION
-poor gram staining
-INCREASED DIAGNOSTIC DIFFICULTY

Cell membrane cholesterol –need serum in media to culture
-NEED SPECIAL CONDITIONS FOR DIAGNOSIS

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Characteristics of mycoplasma

Colonize mucosal surfaces or RBC
-Respiratory and UT

-May attach to RBC (hemotropic mycoplasmas)

Some can invade host cells

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How do break up the genus mycoplasmas?

Tropism!

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What does a hemotropic mycoplasmas look like microsopically?

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What is the most IMPORTANT Hemotrophic we will be studying?

Mycoplasma haemofelis

CATS

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What is the source of Hemotropic Mycoplasmas?

Carrier animals

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How are Hemotropic Mycoplasmas transmited?

Blood

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What are the target cells of Hemotropic Mycoplasmas?

Erythrocytes

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How are Hemotropic Mycoplasmas pathogens?

Primarily EXTRAvascular hemolysis

Predisposing factors/agents

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What are clinical signs that Hemotrophic Mycoplasmas are present?

Hemolytic anemia

ICTERUS

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How do you diagnosis Hemotrophic Mycoplasmas?

Serology

BLOOD SMEAR

PCR

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How do you treat Hemotrophic Mycoplasmas?

Tetracyclines

Supportive care

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Mycoplasma haemofelis species it effects?

CATS

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Mycoplasma haemofelis is transmitted by?

Placental

Fleas

Blood

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How do you read a blood smear?

Bacteria on RBCs

Agglutination

Ghost cells

Spherocytes

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Non-Hemotrophic mycoplasmas source is?

Mucosal epithelia

Carriers

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Non-Hemotrophic mycoplasmas are transmitted byNon-Hemotrophic mycoplasmas

Direct contact

Inhalation of aerosols

Vertical

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What are the target cells for Non-Hemotrophic mycoplasmas?

Epithelium

Mesothelium

What are clinical signs of Non-Hemotrophic mycoplasmas?

Depend on target cells affected

Typically:
-conjunctivitis
-sinusitis
-pneumonia
-polyserositis
-polyarthritis
-mastitis
-urogenital disease

How do you diagnosis Non-Hemotrophic mycoplasmas?

Presumptive

Direct examination

SEROLOGY

CULTURE
-diagnosis standard
-special culture requirements
-delicate and needs quick transport to the lab
-low sensitivity
-“Fried- egg” colonies

Detection
-PCR

How do you treat Non-Hemotrophic mycoplasmas?

Tetracyclines

Tylosin
Aminoglycosides
Macrolides
May need to cull

How do you prevent Non-Hemotrophic mycoplasmas?

Biosecurity

reduce stress

What is the Bovine Non-Hemotrophic mycoplasmas?

Mycoplasma bovis

What does Mycoplasma bovis effect

ONLY cattle

What are clinical signs of Mycoplasma bovis

Mastitis pneumonia polyarthritis otitis media (calves)

What do Obligate intracellular bacteria require?

Require host cells for replication * Elaborate mechanisms for acquiring and invading host cells * Have multiple systems for surviving within host cells * Dependence on host cells is usually nutritional

What are mechanisms of persistence and proliferation in the host that obligate intracellular bacteria use?

1. Multiply inside the vacuole * Chlamydia, Mycobacterium 2. Survive the conditions in the phagolysosome * Salmonella, Yersinia, Coxiella 3. Escape from the vacuole and proliferate in the cytoplasm * Rickettsia

Coxiella Burnetii *fever, reportable, select agent, transmission?*

“Q fever” Reportable & zoonotic Select agent – potential bioterrorism agent 2 transmission sources * Wildlife/tick cycle * Sheep, goats, cattle

When is coxiella infectious?

SMALL CELL VARIANT -highly resistant spore like -non-replicating -extracellular

What cells does coxiella target?

Monocytes Macrophages Placental epithelial cells

What are clinical signs of coxiella burnetii?

Late-term ruminant abortions Other repro signs **Can shed even if not clinically affected**

Sources of coxiella burnetii?

Secreted in milk, urine, feces, reproductive secretions * Inhalation * Ingestion * Direct/venereal contact Arthropods (>40 tick species) SCV are very resistant in environment 31 The Center for Food Security and Public Health – Iowa State University

How do you diagnosis coxiella burnetii

Presumptive – necropsy & histopathology -Fetus (may be autolyzed) -Placenta (leathery w/ white exudate) * Differential Dx: Chlamydia abortus Direct detection * Cannot culture in vet diagnostic lab -Immunohistochemistry -PCR Exposure to agent Serology 32

Zoonotic aspects of coxella burnetii?

Human disease – flu-like illness in most people * Fever, fatigue, headache, muscle ache, weight loss, cough May become severe with pneumonia and hepatitis Rarely, people may develop chronic Q Fever & endocarditis Often due to **occupational exposures**

Chlamydias are what cellular organisms?

Obligate intracellular organisms

What are the required cells chlamydia need?

Eukaryotic cells as hosts -NEED HOST CELLS IN ORDER TO REPLICATE

Chlamydia target cells are?

epithelium

What are sources of Chlamydia?

Carrier animals *cats, cattle, small rum., birds, ect.* Diseased animals

How is Chlamydia transmitted?

direct contact inhalation ingestion sexual vertical

What are clinical signs of Chlamydia?

* Conjunctivitis * Sinusitis * Polyarthritis * Polyserositis * Hepatitis * Enteritis * Encephalomyelitis * Urogenital disease

How do you Diagnosis Chlamydia?

Often presumptive Serology Direct detection * PCR * Cytology + stains * Fluorescent antibody

How do treat Chlamydia?

Tetracyclines

Ho wdo you prevent chlamydia?

Biosecurity Reduce stress

What are the Chlamydias that are public health concerns?

* Chlamydia felis * Chlamydia psittaci * Chlamydia abortus