Infectious Disease Exam 2

Traits of staphylococcus

-gram positive

-cocci single/clusters

-normal microbiota

-pyogenic diseases

-opportunistic

Species of staphylococcus

-s. aureus

-s. pseudintermedius

-s. hyicus

What pathogenic features does staph have?

-antiphagocytic polysaccharide capsule

-catalase

-exfoliative toxic that cleaves epidermal cellular junctions

-urease that raises urine pH

-ability to form biofilms

Which type of transmission is more common in staph, endogenous or exogenous?

endogenous

What species is s. aureus common in?

-cattle

-horses

-humans

What are the clinical presentations of s. aureus?

-mastitis

-food poisoning in humas

T or F: s. aureus can be methicillin resistance

True

How is s. aureus mastitis treated and prevented?

-antibiotics

-teat dipping

-cleaning milk machines

-routine machine maintenance to prevent teat damage

How is mastitis transmitted?

cow to cow via exposure to infected milk

What species is s. psuedintermedius common in?

-dogs

-cats

T or F: MRSP is most commonly acquired in a hospital setting

True

Is MRSA or MRSP more common in cats and dogs?

MRSP

How does s. pseduintermedius present in dogs?

-pyoderma

-impetigo

-ear and eye infections

-cystitis

T or F: pyoderma is a secondary disease

True

What type of patient is impetigo common in?

seen in the inguinal region of prepubescent dogs

What is the treatment of pyoderma?

resolve underlying condition like allergies, ectoparasites, poor coat condition, etc

Traits of cystitis

-ascending infection

-common in females

-form calculus in bladder

-struvite stone uroliths

-urease increases ammonia forming crystals

How does s. pseduintermedius present in cats?

-eye and ear infections

-secondary dermatitis

What organism is associated with greasy pig disease?

s. hyicus

How is s. hyicus transmitted?

through skin injuries

How is greasy pig disease prevented?

-reduce fighting by maintaining stable groups

-trim needle teeth

-maintain clean environment

What is MRSA?

methicillin-resistant staphylococcus aureus

How does MRSA occur?

altered penicillin binding protein

Traits of streptococcus

-gram positive

-cocci

-single or strand of pearls

-many species normal microbiota

-pyogenic

List species of streptococcus

-S. agactiae

-s. uberis

-s. dysgalactiae

-s. canis

-s. equi subsp zooepidemicus

-s. equi subsp equi

Streptococcus exhibits what type of hemolysis?

-beta

-alpha

-gamma

What are the pathogenic factors of streptococcus?

-m-protein mediating epithelial adherence

-capsule interfering with phagocytosis

-hemolysins lyse blood cells

Where does streptococcus commonly reside?

mucous membranes

T or F: streptococcus can have carriers

True

T or F: streptococcus can be endogenous or exogenous

True

What is the sole habitat of S. agalactiae?

mammary gland

How is s. agalactiae mastitis prevented and treated?

-intramammary antibiotics

-effective post milking disinfection

-clean and dry machinery between cows

-ensure farm personnel are educated on transmission

-cull chronically infected cows

How are S. uberis and S. dysgalactiae transmitted?

feces

What do S. uberis and dysgalactiae cause?

mastitis

How to prevent mastitis via s. uberis and dysgalactiae?

-teat disinfection

-avoid teat injury

-provide feed immediately after milking to encourage standing

-provide clean and dry bedding

-avoid wet environments

T or F: S. canis is part of the normal skin and mucous microbiota

True

What can S. canis cause?

-ear infection

-secondary pneumonia

Where is S. equi subsp zooepidemicus normal?

equine upper respiratory tract and vagina, never normal in dogs

What can s. equi zooepidemicus cause?

-equine metritis

-equine infertility

-secondary pneumonia to virus

-fatal hemorrhagic pneumonia in dogs

Is S. equi subsp equi normal microbiota?

no

S. equ subsp equi is commonly what disease?

Strangles

What are the symptoms of strangles?

-fever

-anorexia

-depression

-mandibular lymph node abscess

-retropharyngeal lymph node abscess

-thick nasal discharge

T or F: strangles is reportable

True

Transmission and pathogenesis of strangles

-transmitted via direct contact, fomite, or environment

-m-protein and capsule determine virulence and tonsil attachment

-invade mucosa and lodge in lymph tissue

-enters blood and limp fluid

-metastatic spread of infection

What is the presentation of classic strangles?

-abscesses

-swelling interferes with swallowing and respiration

-abscesses rupture and drain, resolving infection

How does the guttural pouch interact with strangles?

retropharyngeal infection spreads to pouch resulting in chronic purulent nasal discharge

What are the traits of bastard strangles?

-infection spreads to lungs, spleen, kidney, and brain

-colic

-chronic weight loss

-sudden death

-requires long term antibiotics

What is purpura hemorrhagica?

Immune mediated vasculitis than can develop 2-4 weeks post strangles infection or vaccination

What are the traits of purpura hemorrhagica?

-limb edema

-petechia

-skin sloughing

-antibody x strep protein complexes deposit onto vessel walls

What are the traits of clostridium?

-gram positive

-gas producing

-anaerobic

-rods

-spore producing

-toxin based disease

-histotoxic, neurotoxic, enterotoxic

Where can clostridium be found?

-soil

-water

-intestine

How does clostridium perfringens cause disease?

histocytic toxins and tissue degrading enzymes

What does costridium perfringens diseases cause?

-enteric disease

-enterotoxemia

-abomastitis

-mastitis

-wound infections

What are the traits of bacillus?

-gram positive

-rods

-spore forming

What is the most prominent bacillus?

anthrax

Where is bacillus found?

soil

How is clostridium transmitted?

-ingestion or organism

-overgrowth of normal microbiota with toxin production

-wound contamination

What type of conditions could result in clostridium perfringins type D infection?

higher grain diet and stress

How is clostridium difficile transmitted?

spores present in the environment

When is anthrax as its worst?

-summer

-heavy rain

-livestock grazing

What determines virulence of anthrax?

-two plasmids

-one determines capsule

-one determines toxin

T or F: anthrax produces a 3 component toxin that are harmless on their own

True

Describe the pathogenesis of anthrax

-PA toxin binds to host cell

-LF and EF toxins translocate

-LF inhibits MAPK disturbing signaling

-EF distrupts signaling and clotting

How does perfringens type A cause disease?

-Alpha toxin lyses host membranes

-CPE enterotoxin binds and causes intestinal cell wall death

How does perfringens type C cause disease?

multiple toxins cause hemorrhagic necrosis of small intestine

How does perfringens type D cause disease?

-toxins damage small and large intestine, resulting in increase permeability

-toxins are absorbed and systemically effect the body

T or F: Clostridium difficile are normal in large animal intestinal microbiota

True

What are the routes of anthrax transmission?

-common: ingestion of spores

-cutaneous abrasion

-minor: inhalation

What are the clinical signs of perfringens type A?

-necrotic hemorrhagic enteritis in horses, cows, dogs

-abomasitis in calves

-food poisoning in humans

-gangrenous wound infections

What are the clinical signs of perfringens type c?

-acute rapid onset of necrotic enteritis w/ bloody diarrhea

-abdominal pain

-foals, piglets, lambs, kids, calves

What are the clinical signs of perfringens type D?

-over-eating

-pulpy kidney

-rapid onset

-ataxia

-convulsions

-sudden death

-seen in well fed, rapidly growing lambs, goats, and calves

What are the clinical signs of clostridium difficile?

-sudden death

-hemorrhagic entercolitis

What are the clinical signs of peracute anthrax?

sudden death

What are the signs of acute anthrax?

-fever

-mucosal hemorrhage

-diarrhea

-throat and tongue edema

-bleeding from body openings

T or F: dogs and cats are highly susceptible to anthrax

False

What are the signs of intestinal anthrax?

gastroenteritis

T or F: cutaneous anthrax transmission is rare in animals

True

How to treat perfringens type A?

-antibiotics for wound infection

-supportive treatment for diarrhea

What is perfringens type C diagnosed?

-PCR

-necropsy

How is perfringens type C treated?

-antibiotics

-antitoxin in ruminants and pigs

-supportive care

Why vaccinate livestock damn with type C toxoid?

generate antibodies in colostrum

How is perfringens type D diagnosed?

-PCR

-necropsy showing enterocolitis

-brain and kidney edema

T or F: perfringens type D has successful treatment

False

When should you vaccinate for perfringens type D?

at weaning

How to treat clostridium difficile?

long term metronidazole

T or F: you should perform necropsy on suspected anthrax cases

False

What are the post-mortem signs of anthrax infection?

-dark tarry blood at orifices that doesn't clot

-no rigor mortis

-bloating

How to treat anthrax?

-isolation

-quarantine

-antibiotics

-supportive care

-vaccinate herd

T or F: anthrax is reportable

True

What to do with anthrax carcass and fomites?

BURN IT BURY IT SEND IT TO HELL

Traits of mycobacterium

-rod shaped

-acid-fast

What does it mean for a bacteria to be acid fast?

mycolic acid results in dye retention, even after decolorizing step of gram staining

What feature does mycobacteria have to prevent it against host killig?

hydrophobic outer layer of mycolic acid

Mycobacterium tuberculosis is a faculatitive ______ pathogen of _______

intracellular, macrophages

T or F: Mycobacterium tuberculosis can be zoonotic

True

What types of mycobacteria are the main agents of tuberculosis in animals?

-m. tuberculosis

-m. bovis

What is a non-tuberculosis mycobacteria?

m. avium-intracellularae complex (MAC)

Traits of brucella

-gram negative

-coccobacilli

-zoonotic

T or F: there is a mandatory control program for brucella

True

What are the pathogenic features of brucella?

-facultative intracellular pathogen of macrophages

-inhibit phagosome fusion with lysosome

-replicated intracellularly in phagosome