Labs 9 - 11 Review: 2011

LAB 9a/b: Skin, Wounds + Body Openings

Concept of “Super-Organism” : animal and microbiome

Otitis Externa in Dogs Malassezia pachydermatis

P. aeruginosa

Proteus mirabilis

E. coli

S. intermedius Group

Wound Infections – Ruminants – A. pyogenes Dog bite wounds – Pasteurella spp., Obligate anaerobes, others

Cat bite wounds – Pasteurella multocida, Moraxella spp

LAB 9a/b: Skin, Wounds + Body Openings

Exercise 1.

Lab 9a: Skin, Wounds, …

Exer. 2: Sheep, exudative dermatitis

P. aeruginosa

BA: large, metallic sheen, hemolytic,

NLF on MAC, Ox +ve

Green wool or fleece rot – moisture/feces/blow flies (wool strike)

MHA shows pigment

Lab 9a: Skin, Wounds ..

Exer. 3: Cow - extensive dermatitis on the dorsal aspects of the face and body.

“paintbrush” scabs

Gram stain from scab impression smear

Rail-road/ stack of coins

Can you make a diagnosis with information provided ?

What organism?

Vaccines? Penicillin?

Lab 9a: Demo 1a/b – Pinkeye/IBK

BA – β-hemolytic, No Mac

Gram -ve, coccobacillus

Mucous membranes

(conjunctiva)

Intervention

Vaccination – several

Face fly (M. autumnalis)

Abx – Oxytetracycline

Optic corticosteroids

Zoonotic

Lab 9a/b: Skin, Wounds, …

Demo 1: K9 Post-op infection

Most likely Genus and species?

Demo 2: Equine – spastic paralysis

Sawhorse-stance , tremors

puncture wound exudate

Aspirate direct smear and G-stain

- Gram-positive

- drumstick/tennis racket morphology

Antitoxin, Vaccines?

Lab 9b: Clostridium +

C. perfringens

C. septicum

Lab 10: Mycoplasmas/Haemoplasmas

No peptidoglycan, highly pleomorphic

Specialized media

10-20 % serum – cholesterols

Hayflicks, Freys, Friis

“Fried Egg”, microcolonies

Haemoplasma’s – no culture Mycoplasma haemofelis

Serology and/or PCR

Mycoplasma Genus/Species

Disk Growth Inhibition (Digitonin)

- Cholesterol Genus

Serum Plate Agglutination (serology)

- species

M. gallisepticum: CRD (Air Sacculitis) Chickens, IS in Turkeys management

M. bovis Caseonecrotic bronchopneumonia in feedlot:

arthritis/tenosynovitis; contagious agalactia mastitis dairy

Pre-feedlot (vaccines, stress); feedlot (mixing, quarantine, Abx)

M. haemofelis : Feline Infectious Anemia Flea control, Doxycycline

M. hyopneumoniae : Enzootic pneumonia in swine (MPS) Management, cough-score, vaccines,

Lab 10: Mycoplasmas/Haemoplasmas: Q/A

Lab 11: Mycology – Major Clinical Mycoses

Cutaneous

Dermatophytes, Malassezia spp.

Subcutaneous

Sporothrix schenckii

Systemic

Thermally Dimorphics

True Yeast – Cryptococcus spp.

Opportunistic

Candida spp., Aspergillosis, Mucormycoses

Fungal-like

Algae

Mycological Examination of tissue

Wet Mount - 10-20% KOH/LPCB

Exudates, TTA – India-ink, H and E, Giemsa

Impression smears – H and E, PAS

Histological/Biopsy - PAS, Methenamine

Silver, H and E

Culture – BHI +, Sabourauds

Lab 11: Mycology – General Examination

VII. A. Zygomycosis

1. Abortion case - Culture

Mucor spp.

Microscopic

Aseptate hyphae

Sporangium

Rhizoids

Silver stained placenta

Non-parallel, 10-25 uM

Typically aseptate

Hyphal bulges

Aspergillus fumigatus

Demo 3. Dog: chronic sinusitis

Culture

Microscopic morphology

Septate hyphae

Vesicle

Conidiospores

Nasal Aspergillosis

Radiology, Rhinoscopy

Guttural Pouch Mycosis

Brooder pneumonia

Abortion in ruminants

Dermatophytosis

Demo 6. Direct Examination

10 % KOH

Ectothrix arthroconidia/spores

Culture - SAB

M. canis (Cats, Dogs, Humans)

M. gypseum

T. mentagrophytes

T. verrucosum

VII. B. Yeasts + Thermals

Demo 1a Candida albicans

Malassezia pachydermatis

“footprint”

Bigger than Staph/Strep

Otitis externa,

Seborrheic dermatitis

Malassezia

Demo 1b. Canis Otitis Externa

Demo 1c. Cryptococcosis

Cryptococcus neoformans

Encephalitis: PAS

2. Thermally Dimorphic Fungi

Histoplasma capsulatum

Endemic Miss., Ohio, St. Lawrence

Bat/bird feces

Intracellular Yeast

Mold phase (tuberculate chlamydospores)

Blastomyces dermatitidis

Endemic as per H. capsulatum

Terminal chlamydospore (lollypop)

Histo – 37 oC

Blasto – 37 oC

Lollipop Chlamydospores

Thermally Dimorphic: Biphasic

Coccidioides immitis

S.W. U.S.

37 oC

Endosporangium “Spherule”

Mold/Environmental Phase

Barrel shaped arthrospores

Barrel arthrospores

Spherule – 37 oC

SubQ Thermally Dimorphic

Sporothrix schenckii Ulcerative lymphangitis

○ Horses, cats, cattle, people

Mold phase (septate)

○ Microconidia (flowerettes)

37 oC – Yeast phase ○ Cigar bodies (cats)

Demo C. Algae: Prototheca spp

Mastitis case: