Actinomyces & Arcanobacterium

How do we examine sulfur granules?

1. Dilute a FNA sample with saline 2. Shake and allow to settle (sulfur granules in sediment) 3. Pipet out sediments 4. Apply gauze pads on discharge 5. Crush granules between two slides! 6. stain with gram stain 7. Central gram + mycelial clump peripher gram negative radiating clubs! (gram negative radiation is Ag-Ab complexes staining so!) This is the Sun Ray Appearance!

Describe the pathogenesis of Trueperella pyogenes/arcanobacterium pyogenes

1. Opportunistic pathogen 2. Normal inhabitant of the MMs (respiratory, GI, and urogenital tracts) 3. Trauma or previous microbial infection required!

How do we treat actinomycosis?

1. Treatment = debatable because *rarely successful in chronic cases in which bone is extensively involved and relapses are very common!* In most animals it occurs within a few months to a few years. 2. ALSO, slow healing jaw lesion and usually causes loose teeth (need to remove) 3. Treatment with IODINE - Long course IV every 2 weeks. - iodine causes abortions! - iodine also transfers to milk 4. Also recommended to do systemic antibiotic

What can trueperella/arcano pyogenes cause in dairy cattle sporadically?

Abortion (can also cause abscesses)

Describe actino pyothorax

Actinomyocosis infection caused by migrating plant foreign body that goes to pleural space causing a pyothorax. Must remove foreign body before being able to "sterilize" the pleural space! (consider clean out surgery)

What does the actinomycosis lesion look like after treatment?

Almost the same! The bone involvement does not allow the jaw to return to it's normal size... just the pus should go away. Treatment working will NOT be seen by lesion size reduction.

What is the other name for Trueperella pyogenes?

Arcanobacterium pyogenes

How are actinomyces classified?

As higher bacteria!

Why can't we move the lump actinomycetes caused?

Because it is part of the bone! (by-product of microorganism leads to destruction of the bone and then reformation around it giving us a bulge)

About how prevalent is trueperella/arcano pyogenes in mastitis cases?

Causes about 1-2% of all bovine mastitis cases

Describe actinobacillosis as a bacteria and what does it cause?

Causes wooden tongue. Affects soft tissue, is acute, salivation occurs and animal is unable to eat. Find gram negative bacilli

How do we diagnose arcanobacterium pyogenes in lab?

Diagnose via culture. Do treatment AFTER a susceptibility test. Do this because their resistance to antibiotics is common and change yearly so don't want to waste money/use ineffective Ab.

Since actinomycetes are normal flora of the oral cavity, the infections are what? And the disease is what?

ENDOGENOUS and the disease is opportunistic (requires something to allow access of organism into diseased site)

Describe actinomyces bacteria morphology

Gram-positive, non-acid-fast rods (*filamentous* or branching), facultatively anaerobic, and most species prefer reduced oxygen environment

Other than the cow (which is the most common species) what other species can be affected by actinomycetes?

Horse, goat, deer, pig, human!

How does trueperella/arcanobacteruim pyogenes keep virulence?

Mediate via a pore-forming toxin!

If multiple cows on farm have hard, nonmovable lesions, do we think they are all actinomycosis? What do we think could be a cause?

Most likely they are ALL actinomycosis. Cause? Think feed source! If recently added/changed diet, the new feed could be causing oral trauma!

Where do you NEVER EVER EVER collect a sample from and why?

NEVER collect it from a *draining sinus* this is because it will always be contaminated!

If diagnose animal with A. pyogenes infection, are we worred about prevention of spreading it to other animals in the herd?

NO because it is a normal inhabitant of the Mucosal membrane so there is now way to prevent this in animals.

Where do we normally find actinomyctes disease?

Near where they are normal flora!! (i.e.around the oral cavity!

Where are actinomyces spp normal flora?

Oral and nasopharyngeal mucous membranes.

Actinomyces is the organism responsible for what disease in cattle?

"Lumpy jaw"

What species of actinomycetes commonly infect dogs and clinically how do we see this in dogs?

Species affecting dogs: A. viscosus, A. hordeovulneris, A. bovin Clinically: See interdigital actinomyosis due to foxtail or abscess in mouth (i.e. find embedded foxtails in mouth abscesses!

What is special about human actinomycetes?

They do NOT get it from animals!! Animal strain is NOT zoonotic to humans.

How do actinomyces resemble bacteria?

They have a lack of a nuclear membrane (prokaryotic nuclei), non-response to fungal agents, response to antibacteria

Differentiate between a tumor and actinomycosis

Tumor -- usually soft FNA tumor --> don't get anything out FNA actinomycosis --> pus and sulfur granules!

How do we diagnose arcanobacterium pyogenes clinically?

We can't! Clinical signs are not specific enough to diagnose

Before we can get rid of an actinomycetes infection, what must be done?

We must get rid of the foreign body!

Upon doing an FNA, what characteristic finding would we find that confirms for us a disease is due to actinomyces?

We would find yellow "granules" in the exudate/pus and they are SULFUR granules!!!

A. pyogenes can disseminate to cause what?

a variety of suppurative infections, such as liver and lung abscess and pyoarthritis

So how would we collect a sample if not from a draining sinus?

by an FNA

What species are affected by Arcanobacterium pyogenes?

cattle, sheep, swine, goats (rare in dogs and cats)

Arcanobacterium pyogenes can cause a variety of suppurative infections involving what areas?

skin, joints, udder, and visceral organs

Once the lump gets large enough, what will occur?

the lump will break through the skin eventually and discharge - through one or more openings - pus containing tiny hard yellow granules

What are some ways we can disturb the oral barrier?

trauma, bite, rough feed, foreign body

How does actinomycetes grow in blood agar?

SLOW growth. Takes 4-7 days and up to 14 until growth

Trueperella/arcanobacterium pyogenes are common cause of what in cows?

SUMMER MASTITIS (in NON lactating cows)

On what media do actinomyces grow poorly?

Sabouraud's dextrose agar (this differentiates them from nocardia and streptomyces spp)