Gram + Rods Cornyebac, Rhodococcus, Nocardia Flashcards
Does Corynebacterium, Nocardia, and Rhodococcus have Mycolic acid?
Yes, yes they do. DO YOU KNOW WHAT THIS MEANS!!?? YOU BETTER!
Cool Corynebacterium, nocardia, and Rhodococcus have Mycolic acid, but what does that mean?
ACID FAST STAINING, opposite of Gram in regards to color
+=Pink
-=Purpleish
General characteristics of Corynebacterium?
Gram +, Pleomorphic, non-spore forming, non-motile, rods , (Pleomorphic- can assume other morphologies, cocci, coccobacillus, and rods).
Oxygen requirements of Corynebacterium?
Facultative anaerobe
what is the result of the catalase test in Corynebacterium?
Not just sure, POSITIVE
where is corynebacterium found as commensals?
skin, mucous membrane
Are most species recovered from animals considered pathogenic? (corynebacterium)
NO
What are the two lipophilic species of corynebacterium? Pyogranulomatous or pyogenic?
C. psuedotuberculosis (sheep lymphadenitis)
C. urealyticum
Pyogranulomatous
What are the non-lipophilic species of Corynebacterium? what are the characteristics?
C. renale group
C. diphtheria (diphtheria in humans)
Pyogenic, toxic
What causes Contagious bovine pyelonephritis?
Corynebacterium renale group
C. renale, cystiditis, pilosum
Contagious Bovine pyelonephritis usually affects?
Adult cows
What is the reservoir of C. renale group?
Clinically normal carrier cows
what are the risk factors of contagious Bovine pyelonephritis?
Trauma to bladder and urethra during parturition
What is the transmission of Contagious Bovine pyelonepritis?
Contaminated bedding
venereal transmission
non-sterile OB instruments
What are the Ante-mortem signs of contagious bovine pyelonephritis?
Persistent elevated temp 39.5oC loss of appetite and weight loss PAINFUL URINATION & PU AMMONIAC ODOR OF URINE*******!!!!!!!******* colic Dec rumen contractions Dec milk production
What are the Post-mortem findings of contagious bovine pyelonephritis?
Multifocal abscesses in renal cortex, medulla and pelvis (Pelvis most Prominent)
Enlarged renal lymph nodes
Uremia
How do you Dx Contagious bovine pyelonephritis
Culture - urine or renal tissue
what causes caseous lymphadenitis in sheep and goats?
CONTAGIOUS & Can be REPORTABLE
C. pseudotuberculosis
What are the general characteristics of C. pseudotuberculosis?
Gram +, facultative, intracellular coccobacillus
What is Caseous Lymphadenitis characterized by?
abscess formation in or near major peripheral lymph nodes (EXTERNAL FORM= GOATS)
Abscess formation within internal organs and lymphnodes (INTERNAL FORM= Sheep)
what is the result of C. pseudotuberculosis and arthropod vectors?
Pigeon fever in horses ( “colorado strangles” “ Dry-land distemper”)
Nitrate-reducing biotype of c. pseudotuberculosis*
ulcerative lymphangitis of lower extremities
cattle can also get infected
Abscess in the pectoral region and ventral abdomen
West and midwest states
enter through skin abrasions
Arthropod vectors include stable, horn, house flies, or contaminated fomites and soil
What are the virulence factors of C. pseudotuberculosis?
Exotoxin phospholipase D
External lipid coat that provides protection from hydrolytic enzymes in host phagocytes
What does phospholipase D do?
Damages endothelial cells and increases vascular permeability
what is the pathogenesis of C. pseudotuberculosis?
entry through skin and mucous membrane> travel to lymphnodes and viscera> replication of bacteria occurs in phagocytes> process of bacterial replication, and inflammation> formation of abscess
distinctive lamellated “onion skin” appearance - Goats
Sheep- more purulent
Disease severity increases with age
How is C. pseudotuberculosis Dx demonstrated?
Culture of purulent materials- difficult if abscess is internal
Synergistic hemolysin inhibition (SHI) detects antibodies to phospholipase D exotoxin
Titers- not good, could be previous exposure, non developed antibodies, recent vaccination. False negatives= early infection, chronic walled off abscesses
What is the DDx of C. pseudotuberculosis?
Truperella pyogenes
Staph aureus
pasterulla multocida
Fusobacterium necrophorum (anaerobes)
How does one control Pseudotuberculosis?
Culling Best option
Owner education
Genetic or emotional animals- lancing & draining Formalin- cruel systemic & intralesional antibiotics extra label use** penicillin, rifampin, tulathromycin
Whats important in regards to sheep vs. goat vaccines for C. pseudotuberculosis?
DO NOT INTERCHANGE!!!
Corynebacterium kutscheri causes?
Murine pseudotuberculosis
Lung: Suppurative pneumonia**
Kidney, liver, heart: Similar nodular lesions
Joints: arthritic lesions of pedal extremities
Subcuticular abscesses
Lymph nodes: lymphoid hyperplasia of regional lymph nodes
Corynebacterium Bovis- causes what in what species?
Dermatitis
Hyperkeratosis
IN MICE!!!!!!!!!!!!!!!!!!!!!!!
Rhodococcus Equi characteristics?
Gram+ rods or coccobacilli
non spore forming
weakly acid fast
Aerobic, catalase-positive, non- motile
R. equi oxygen requirements?
Aerobic
R. equi catalase test?
positive
R. equi motility?
non motile
R. equi extra or intracellular?
Facultative intracellular
What is unique about the cell envelope?
Lipid Rich
rich in mycolic acid
Promotes intra-macrophage survival and Granuloma formation
R. equi main cause of what?
FOAL PNEUMONIA!!
what is the habitat of R. equi?
Soil, however, virulence is maintained in horses. over time soil isolates can lose virulence associated plasmids
are all strains of R. equi pathogenic?
no theres soil saprophytes (Facultative intracellular= can survive outside cells=soil)
Whats unique about isolates of R. equi obtained from species other than horses?
Usually lack virulence associated proteins
what are the virulence factors of R. equi?
Virulence associed proteins (VAPs)
(encoded on large plasmids) (promotes survival in non-activated macrophages)
Mycolic acid, teichoic acid/peptidoglycan
Cholesterol oxidase (equi factor)*** (used for Dx)
Phospholipase C
what is the most serious cause of pneumonia in foals 1-4m of age?
R. equi
why is R. equi such a bad disease
Mortality
Prolonged Tx
Surveillance for early detection
Relatively expensive prophylactics
Horse older than 8 months, R. equi Dz or nah?
nah, rare
Pulmonary infection of R. equi usually happens when?
1st week of life
Lung infection of R. equi?
multiple 1-100mm diameter, coalescing, firm, caseonecrotic foci predominately in cranioventral lung lobes
GI infection of R. Equi?
ulcerative enterocolitis often based over peyers patches in the ileum and irregular well defined ulcers in the large intestine. Occurs in more than 50% of foals w/ pneumonia
Bronchial and mesenteric lymph node signs of R. equi?
swollen and edematous often w/ pyogranulomatous lymphadenitis
Bone infection of R. equi?
osteomyelitis
regarding hemolysis what is important about R. equi?
it enhances hemolyis of weakly hemolytic organisms (C. pseudotuberculosis, lysteria monocytogenes, Beta-lysin producing S. aureus)
DDx of R. equi?
Fungal Pneumonia stretococcus zooepidemicus Strep equi Equine viral rhinopneumonitis (EVR) Equine flu Adenoviral pneumonia Equine viral arteritis
what methods are used for early screening for R. equi?
Elevated plasma fibrinogen Visual inspection Rectal temp 2x day PE 2x week CBC --inc WBC Thoracic rads/ ultrasound (foals 1-3months old).
Serology not reliable
R. equi Dx method?
Definitive Dx= Culture or PCR on transtracheal aspirate or specimen from other lesions plus cytologic evidence of sepsis
Culture of feces- dont do it
serology- do not even think about it
Treatment for R. equi
7d->3weeks expensive, may have adverse effects and is variably successful
Standard empirical treatment= Combo macrolide (erythro or clarithromycin) + rifampin = synergistic in vitro
MACROLIDE RESISTANCE REPORTED!
Hyperimmune plasma and NSAID use is variable
first days of life things to do to prevent R. equi?
Hyperimmune plasma
azithromycin
Nocardia characteristics?
Pleomorphic ( rods, cocci, cocobacilli, long branching filaments) gram + Facultative intracellular bacterium non motile non spore forming
what are the oxygen requirements of pathogenic Nocardia?
Strictly aerobic, grow at wide temperature range
Nocardia species most common in canine and feline?
N asteroides, more common in dogs
Can cause abortion in horses cattle sheep and swine, no other signs in dam
Describe Dz aspects of Nocardiosis
oppurtunistic
non contagious
pyogranulomatous to suppurative Dz of domestic animals wildlife and people
What are the common signs of Nocardia?
Mastitis, Pneumonia, abscesses, cutanous and SQ lesions
Bovine Farcy? what are the lesions?
N. asteroides
lymphangitis & lymphadenitis
Nocardia Dx method?
culture, acid fast, ID can predict susceptibility
Tx Nocardia?
Empirical= aminoglycoside and carbapenem, trimethoprim/sulfa
Bacteria that uses host actin filaments to travel between cells?
lysteria monocytogenes
Hepatic necrosis from listeriosis occurs in who primarily?
monogastrics and neonates
pig with rhomboid shaped lesions on skin?
erysipelothrix rhusiopathiae
Greasy pig dz?
Staph hyicus
Strep suis?
meningitis in pigs
ZOONOTIC
what plasmids are required for anthrax virulence?
capsule and toxin
Capsule of anthrax is composed of?
poly-glutamic acid
McFadyean stain is used for?
Capsule of Anthrax= pink shadow around bacT
What plasmid provides good immunity for anthrax?
toxin plasmid
is anthrax contagious?
NO infectious But NOT CONTAGIOUS
ANTHRAX IS NOT CONTAGIOUS
ANTHRAX IS NOT CONTAGIOUS
ANTHRAX IS NOT CONTAGIOUS
