Lecture 10 - Trueperella, Actinomyces, Nocardia & Dermatophilus species

Actinomyces bovis characteristics

1. Anaerobic/capnophilic 2. Usually non hemolytic, white colonies 3. Colonies adhere to agar medium 4. 2-4 days to grow

Treatment of Bovine actinomycosis ("Lumpy Jaw")

1. Can be successful in early stages of the disease 2. Surgical debridement and antibacterial therapy (Strepto-penicillin) 3. Intravenous administration of Sodium iodide is the treatment of choice for lumpy jaw 4. Antimicrobial therapy ineffective in chronic cases, poor prognosis

Canine/Feline Nocardiosis is seen as:

1. Localized cutaneous granulomatous lesions 2. Dermal fistulous ulcers 3. Systemic nocardiosis -Pyogranulomatous hepatitis -Pyogranulomatous nephritis -Suppurative lymphadenitis

Trueperella pyogenes Common conditions

1. Lymphadenitis 2. Osteomyelitis 3. Peritonitis 4. Neural abscessation

Canine actinomycosis causative agent:

Actinomyces viscosus

Nocardia species Atmospheric growth requirements

Aerobic

Atmospheric growth requirements for Dermatophilus congolensis

Aerobic and capnophilic

Actinobaculum suis Atmospheric Growth Requirements

Anaerobic

Atmospheric Growth Requirements for Actinomyces species

Anaerobic or facultatively anaerobic and capnophilic

Bovine actinomycosis causes:

chronic porous osteomyelitis -painless swelling of bones in the initial few weeks -Then become painful, fistula discharging purulent exudate

Actinomycosis

chronic, suppurative granulomatous inflammation

Sanguinopurulent

containing blood and pus

Actinomyces hordeovulneris causes

localized cutaneous or visceral abscesses

Actinomyces

long, filamentous forms

Where do Actinobacteria colonize?

mucous membranes of mammals; some are found on the skin

Trueperella pyogenes inhabits the

nasopharyngeal mucosa of cattle, sheep, and pigs

Does Actinomyces species have aerial filament production?

no

Is Canine actinomycosis hemolytic?

no

Diseases produced by Trueperella pyogenes typically cause

purulent reactions in many domestic animal species worldwide, especially cattle, sheep, and pigs -Any organs system can be affected

Bovine actinomycosis spreads to

soft tissue

Is Canine actinomycosis normal flora?

yes in dog's oral cavity

Does Nocardia species have growth Sabouraud dextrose agar?

yes!

Hypothesized Virulence Factors for Actinomyces species

1. Cell Wall lipoproteins: may induce an overzealous immune response --> extension of disease beyond mucosal surfaces 2. Cell wall peptidoglycan -Recruitment of inflammatory cytokines

Diagnosis of Bovine actinomycosis is through

1. Clinical Signs 2. Cytology 3. Culture and Identification 4. Radiology

Bovine Fancy

1. Common in tropical regions 2. Granulomatous suppurative inflammation of lymphoid tissue 3. Disease occurs in the chronic form only 4. Disease predominantly affects the skin, subcutis and lymph nodes and vessels

Predisposing Factor of Actinomyces hordeovulneris

1. Exposure to foxtail grass (Hordeum species) particles that migrate into the body tissues, allowing penetration of the bacteria 2. Common in western part of the USA

General Features of Actinomyces species

1. Gram positive branching filaments (V, Y, T forms) 2. Non. motile 3. Non spore forming 4. Need enriched media to grow 5. Anaerobic/facultatively anaerobic & capnophilic 6. MZN negative 7. Colonize mucus membrane: oral cavity, nasopharynx

Cytology of Nocardia species

1. Gram-positive branching filaments that often show some fragmentation into coccobacillary elements 2. The MZN - stained smears stain red

Histology of Bovine actinomycosis

1. Granule composed of masses of gram-positive bacteria with branching filaments 2. Eosinophilic amorphous material with club shaped configuration surrounding the granule 3. Dense sheets of neutrophils (pus) 4. Lymphohistiocytic infiltrates

Isolation and Identification of Nocardia species

1. Growth and morphology on blood and SDA agar 2. Biochemical reactions 3. 16s rRNA gene sequencing (frequently used method)

What does Bovine actinomycosis present as?

1. Hard and immobile swellings in the mandible (in a cow)

Nocardia species Disease Pathogenesis

1. Infection is opportunistic 2. Inhalation of the bacteria/wound infections 3. The bacteria survive within phagocytic vacuoles 4. Necrosis and abscess formation. Exudates are sanguinopurulent. They lack the microstructure of the sulfur like granules.

Chronic Granulomatous Mastitis

1. Infection is sporadic 2. Multifocal or diffuse fibrosis 3. The hard masses of fibrous tissue are palpable after milking 4. White clots can be observed in the milk 5. Refractory chemotherapy

Actinomyces hordeovulneris generalized infections:

1. Inflammation of the cavity surrounding the lungs 2. Inflammation of the lining of the abdomen 3. Abscess on internal organs (such as the liver and spleen) 4. Pyothorax is frequently seen

Pathogenesis of Bovine actinomycosis (Lumpy Jaw)

1. Invasion when there is trauma of the mucosa from rough feed or through dental alveoli during tooth eruption 2. A rarefying osteomyelitis 3. Granulomatous lesions. Rarely, visceral involvement may occur 4. Interferes with prehension and mastication 5. Alimentary tract involvement will interfere with ruminal digestion and movement ---> partial starvation

What are the two types of colonies present in Canine actinomycosis?

1. Large, smooth, white, glistering -V,Y,T shapes: Gram positive diptheroidal forms 2. Small, rough, dry - short branching filaments

Nocardia species general features:

1. Obligate aerobes and non-motile 2. Filamentous gram +ve rods 3. Partially acid fast 4. Forms spores from aerial filaments 5. Grow on Sabouraud dextrose agar (SDA) 6. Bacteria survives intracellularly

Treatment of Nocardia species

1. Often refractory to treatment 2. Trimethoprim-sulphamethoxazole or erythromycin recommended for Nocardia asteroids

Trueperella pyogenes Characteristics

1. Opportunistic pathogen 2. Gram +ve, MZN -ve, facultatively anaerobic 3. Pleomorphic morphology in Gram-stained smears, appear as coccoid or rod

Predisposing Factors for Bovine actinomycosis (Lumpy Jaw)

1. Penetrating wounds of the oral mucosa 2. Breaks in the gums

Trueperella pyogenes is also involved in what other mixed infections:

1. Peptinophilus indolicus (causes "summer mastitis") 2. Anaerobes like Fusobacterium necrophorum (causes foot abscess in cattle and sheep)

Virulence Factors of Trueperella pyogenes

1. Pyolysin (PLO) -Kills neutrophils and macrophages and is dermonecrotic

Other conditions associated with Trueperella pyogenes

1. Pyometra 2. Metritis 3. Acute or chronic bovine mastitis

Prevention of Bovine actinomycosis ("Lumpy Jaw")

1. Removal of predisposing feed source 2. Vaccines are no available

Canine actinomycosis is seen as:

1. Slowly progressive, pus forming infection 2. Lesions generally develop after a traumatic injury, such as a bite wound 3. Lesions: common in head, neck, thorax, abdomen 4. The bacteria also causes pyothorax and granulomas in the thoracic cavity

Diagnosis of Nocardia species

1. Specimens to be collected -Exudates, aspirates, mastitic milk samples, tissue from granulomas and thin sections from granulomas in 10% formalin for histopathology 2. Microscopy -Cytology -Histopathology 3. Isolation and Identification

How does Nocardia species survive within phagocytic vacuoles?

1. Superoxide dismutase 2. Catalase 3. Cell wall lipids

Differential Diagnosis for Bovine actinomycosis ("Lumpy Jaw")

1. Wooden Tongue (massive tongue swelling due to another Actinobacteria) 2. Foreign Bodies 3. Bottle Jaw: Liver fluke infections, anemia, heart failure, etc. 4. Cancer: tumors of the bones of the skull

Actinomyces can be broken into what species?

A. bovis, A. viscosus, and A. hordeovulneris

Actinobaculum can be broken into what species?

A. suis

The present name of Actinomyces suis is

Actinobaculum suis

Bovine Actinomycosis ("Lumpy Jaw") causative agent

Actinomyces bovis

Differential Diagnosis of Nocardia species

Actinomyces infections

What morphological structures are present in Actinobacteria?

Branching Filaments and pleomorphic structures occur

Actinomyces bovis (Host and Disease)

Cattle; Bovine actinomycosis ("Lumpy Jaw")

Nocardia farcinica (Host and Disease)

Cattle; Chronic granulomatous mastitis, Bovine farcy in the tropics -Not common in North America -More common in tropical areas-Africa

What are the important Actinobacteria genera?

Corynebacterium, Rhodococcus, Nocardia, Actinomyces, Trueperella, Dermatophilus, Mycobacterium, Actinobaculum

Dermatophilus can be broken into what species?

D. congolensis

Actinomyces viscosus (Host and Disease)

Dog; Canine actinomycosis -Localized cutaneous granulomatous abscess -Pyothorax and granulomas in the thoracic cavity

Actinomyces hordeovulneris (Host and Disease)

Dog; Localized cutaneous or visceral abscesses -Fox-tail grass allows penetration of the bacteria

Nocardia asteroides (Host and Disease)

Dogs/Cats; Canine nocardiosis -Localized cutaneous granulomatous abscess -Pyothorax and granulomas in the thoracic cavity

Arcanobacterium pyogenes Atmospheric growth requirements

Facultatively anaerobic and capnophilic

Are Actinobacteria Gram positive or negative?

Gram positive

Where does Actinomyces bovis invade?

Mandible/rarely maxilla

Nocardia can be broken into what species?

Many Nocardia species

What is the site of lesion of Actinomyces species?

Many tissues including bones

Canine actinomycosis survives in what environments?

Microaerophilic or anaerobic

What is the usual habitat of Actinomyces species?

Nasopharyngeal and oral mucosae

Usual habitat of Arcanobacterium pyogenes

Nasopharyngeal mucosa of cattle, sheep and pigs

Does Actinobaculum suis have aerial filament production?

No

Does Actinobaculum suis have growth on Sabouraud dextrose agar?

No

Does Actinobaculum suis have modified Ziehl-Neelsen staining?

No

Does Actinomyces species have growth on Sabouraud dextrose agar?

No

Does Actinomyces species have modified Ziehl-Neelsen staining?

No

Does Arcanobacterium pyogenes have aerial filament production?

No

Does Arcanobacterium pyogenes have growth on Sabouraud Dextrose Agar?

No

Does Dermatophilus congolensis have aerial filament production?

No

Does Dermatophilus congolensis have growth on Sabouraud dextrose agar?

No

Does Dermatophilus congolensis have modified Ziehl-Neelsen staining?

No

Unclassified Actinomyces species (Host and Disease)

Pigs, Horses; Granulomatous mastitis; Poll evil or fistulous withers

Usual habitat of Actinobaculum suis

Prepuce and preputial diverticulum of boars

Site of lesions for Dermatophilus congolensis

Skin

Usual Habitat for Dermatophilus congolensis

Skin of carrier animals, scabs from lesions

Site of Lesion for Arcanobacterium pyogenes

Soft tissues

What is the usual habitat for Nocardia species?

Soil

Trueperella can be broken into what species?

T. pyogenes

What is the site of lesions for Nocardia species?

Thoracic cavity, skin and other tissues

The present name for Arcanobacterium (Actinomyces) pyogenes is

Trueperella pyogenes

Actinomycosis in Pigs and Horses Etiology

Unclassified Actinomyces species

Site of Lesions of Actinobaculum suis

Urinary tract of sows

Is enriched media required to grow Actinobacteria?

Usually

Does Arcanobacterium pyogenes have modified Ziehl-Neelsen staining?

Yes

Does Nocardia species have aerial filament production?

Yes

Does Nocardia species have modified Ziehl-Neelsen staining?

Yes

Is Trueperella pyogenes hemolytic?

Yes -Beta-hemolysis

Does Actinobacteria produce spores?

Yes-unusual spores produced by some membranes

Excessive swelling of the maxilla during Bovine actinomycosis may cause

dyspnea (difficulty breathing)

The majority of Actinobacteria are either _________ anaerobes or aerobes

facultative (some are capnophiles)