Midterm Flashcards
Where are techoic acids found?
only in gram +, attached to wall and plasma membrane
Where are LPS only found in abundance?
gram negative outer membrane
What are the 3 parts of LPS?
o-antigen, core region, Lipid A (endotoxin)
What part of LPS is responsible for reducing phagocytosis and confers smoothness?
O-antigen
Where is periplasmic space found?
gram negatives b/w inner and outer membrane
Are porins found in gram + or gram - bacteria?
gram -
What is the term for inability of an organism to synthesize a particular organic compound required for its growth?
auxotrophy (opposite - prototrophy)
What is the term for gain of electrons?
reduction
What is the term for loss of electrons?
oxidation
What is the part of the nernst equation we have to know?
Eh = Oxidant/reductant
How does increasing O2 prevent growth of anaerobes?
increases redox potential (more + value)
What is the Eh of normal tissue?
+150 mvolts
Which 3 brucella spp have an unrestricted host range and are therefore zoonotic?
melitensis (small ruminants)
abortus (cattle)
suis
What is the morphology of brucella?
gram - coccobacilli
Where do brucella live in host?
obligate intracellular bacteria in monocytes and macrophages
Why is brucella highly invasive?
can penetrate intact mucosa and has hematogenous spread
How does brucella escape lysosomes?
redirects vesicular traffic then directs to endoplasmic reticulum via Type IV secretion system (molecular syringe)
Why does brucella have tropism for reproductive tissue?
erythritol (but not in humans – undulant fever instead)
How are brucella spp speciated in diagnosis?
PCR follwed by pulsed field electrophoresis
How can brucella be diagnoosed?
isolation or direct observation
What drug do enterococcus have innate resistance to?
cephalosporins
Are staph spp catalase positive or negative?
catalase positive
What is the morphology of staph?
gram + non motile
What 2 molecules are involved in adhesion of staph?
Protein A and fibronectin binding proteins
What 2 molecules help staph capsules resist phagocytosis?
protein A and polyurinic acid
What 2 molecules help staph resist oxidative burst?
carotenoids (staphyloxanthin) and catalase
What staph enzyme results in walling off of necrotic areas?
coagulase
What is the species of staph that causes the most dog and cat dz?
s. pseudintermedius
What is different with s. pseudintermedius than other CP staph?
ONPG positive (beta galactosidase)
What molecule is destroyed by S. hyicus in greasy pig dz?
desmoglein 1
What staph species causes bumble foot?
S. aureus
What is a characteristic of MRSA staph that causes it to be more virulent?
lyses PMN after phagocytosis
What gene causes virulence of S. aureus in bovine mastitis?
adhesive protein Bap
What is the term for E coli virulence profile shown as fimbria/toxin?
pathotype
What are e coli serogroups?
O, LPS, K(capsule), H (flagella)
What is an important serotype of E coli that is causing problems in US?
O157:H7
What two types of E coli cause hypersecretory diarrhea?
ETEC
EAggEC
What are the 4 fimbria types used for vaccines against E coli in piglets?
K88, K99, 987P, and F18
What are the 4 fimbria types for vax against e coli in calves?
K99, F41, CS31A, FI845
What can be used to make a vaccine against E coli already on the farm?
autogenous bacterins
What 2 fibriae types are responsible for weanling diarrhea in e coli infection?
K88 or F18
What can shiga like toxin cause in weanling diarrhea in pigs?
edema dz
What is the cause of neurological signs in edema dz of swine?
shiga like toxin (NOT infection)
What type of ecoli produces EAST toxin?
enteroaggregative (EAggEC)
What is the main MOA of E coli causing malabsorptive diarrhea?
intimin ->actin filament changes
What are the 4 e coli types involved in malabsorptive diarrhea?
AEEC, EPEC, EHEC, and EIEC
What are the 2 main diseases seen with salmonella?
diarrhea and respiratory dz
What do the salmonella serotypes consist of?
O and H antigens
What determines serotypes in salmonella?
slide agglutination assays - suggests virulence type or host specificity
What is the term used for salmonella groups that are determined by the combo of serogroups expressed?
serovar
What are the main serovars of salmonella for bovine?
D (dublin)
B (typh)
C (newport)
What are the main serovars of salmonella in porcine?
C (cholera-suis)
B (typh)
What are the main serovars in poultry for salmonella?
D (enteritidis or Pullorum
What are the main serovars in equine species for salmonella?
B (anatum or typh)
How can salmonella use its flagella in escaping hosts humoral response?
flips between H1 and H2 motility type
What gene is responisble for salmonellas inherent invasive abiity and is the basis for PCR methods?
invA gene
What two pathogenecity islands in the invA gene help with attachment and apoptosis of PMNs?
SP1-I : attachment and invasion
SPI-2: apoptosis
How does salmonella differ in its invasion of the intestines from e. coli?
first goes through M cells (rather than enterocytes)
What is a characteristic chronic lesion associated with salmonella enterica?
hemorrhagic necrotizing enteritis - ulcerative colitis
What organs are mostly involved with salmonella septicemia?
spleen and liver
Where is enterococcus usually found?
flora of GIT in warm blooded animals
What kind of diseases does enterococcus cause?
fecal contamination –> metritis, UTI, otitis
What enterococcus is spread by AI of sows by semen? What is the virulence factor?
E. fecalis
cytolysis L + S
What antibiotic does enterococcus have an innate resistance to?
cephalosporins
What enterococcus causes osteomyelitis in broilers?
E. cecorum
How is MRS resistant to beta lactams?
posess penicillin binding protein type 2 (beta lactamase)
Where is the MRS gene located?
staph cassette chromosomes
What are the major virulence factors of MRS on mobile genetic elements?
phenol soluble modulins
enterotoxins
adhesive protein Bap (bovine mastitis)
exfoliative toxins ETA, ETA2, and ETA3
What important virulence factor of MRS is encoded on bacteriophages?
exfoliative toxins ETA, ETA2, and ETA3
How do MRS convey host specificty?
sequence differences in the chyotrypsin serine protease (desmoglein 1)
What are the major virulence factors for septicemic E. coli?
siderophores, endotoxin
cytotoxigenic necrotizing factor (CNF)
cytolethal distending toxin (CLDT)
What E. coli vaccine resulted in enhanced humoral response for coliform mastitis?
E.coli J-5
What are the 3 predominant sergroups of uropathogenic e. coli?
O2, O4, and O6
What is the e. coli fimbria involved in cystitis?
Type 1, often hemolytic
What iare the 2 major virulence factor in pyelonephritis with E. coli?
Pap (pyeloneph associated pili) and S-fimbria
What are the 2 important serotypes involved in avian pathogenic e. coli causing septicemia?
O2 and O78
What is the leading cause of mare infertility and meningitis in foals? (specific)
klebsiella with k1 capsule
What klebsiella serogroup causes UTIs in horses?
K2
What two enterobactericiae are found in the oral flora of dogs and cause mastitis?
Serratia marcescens and Klebsiella spp.
What is a gram negative cocci that is often an oral contaminant of respiratory cultures?
Neisseria sp.
What opportunistic infections can Neisseria sp. cause?
bite wound –> sepsis
What gram negative bacteria, found in the oral cavity of dogs, is used as indicator for oral contamination of BAL?
Simonsiella sp.
What are the bacterial characteristics of Lactobacillus sp?
long gram + rod, catalase negative, facultative anaerobe
What oppurtunistic infection does Lactobacillus cause?
peritonitis from GIT sx leakage
Where are alpha streptococci normally present?
nasal pharyngeal flora
What is a good diagnostic method for fastidious gram negative bacteria such as f. tularensis?
16s rRNA gene sequencing
What are the two major serovars of F. tularensis and their virulence?
Type A - US - most virulent
Type B - Europe - less virulent
How is F. tularensis transmitted from rabbits to other vertebrates?
bite of insects, ingestion, inhalation
What are the two major virulence factors associated with F. tularensis?
capsule, acid phosphatase
also escapes phagolysosomes and unusual LPS
What are the 3 drugs of choicce for F. tularensis?
streptomycin, doxycycline, gentamycin (intracellular penetration)
How is Y. pestis spread?
rodents - spread by fleas
What is the tx of choice for Y. pestis?
streptomycin
Where is the flagella located in spirochetes?
endoflagella in periplasmic space
What diagnostic tests help to speciate spirochetes?
PCR and serology
What is the pathogenesis of persistance of borrelia burgdorferi?
membrane derived cysts –> L forms, resistant
How does the borrelia bacteria migrate from tick to human during feeding?
change in temp activates OspA to chance to OspC adhesin
How is leptospira diagnosed? 3 ways
PCR of urine, clin chem, serology (MAT)
What is the outcome of a host-adapted leptospira infection?
animal becomes reservoir host
What is the outcome of non-host adapted leptospira infections?
accidental dz, sporadic infection
How does leptospira encounter and enter the host?
through urine, ingestion of urine or feces or sexual contact (treponema)
What is the main cause of damage by leptospira?
endothelium damage –> affects any organ system
What is the pathogenesis of leptospira in the kidney?
interstital nephritis, tubular necrosis, impaired capillary permeability –> hypovolemia –>kidney failure
What are the different host adapted serovars of leptospira for cattle, swine and horses?
Cattle - hardjo
Swine and horses- bratislava
What are the different host adapted serovars of leptospira for dogs, deer, rodents, and raccoons?
dog - canicola
deer - pomona
rodents - icterohaemorrhagiae
raccoons - autumnalis
What is the most common manifestation of lepto in pigs?
abortions occuring 2-4 weeks before term
What plays a role in maintenence of lepto in pigs?
veneral transmission from carrier boars and sows
What does lepto cause in attle?
calves –> fever, anorexia, hemolytic anemia
What are the CS of lepto in horses?
uveitis or abortions
What is the etiologic agent of swine dysentery?
Brachyspira hyodysenteriae
What kind of lesions will be seen with swine dysentery?
necrohemorrhagic enterocolitis
What spirochete colonizes the hindgut of vertebrates and causes colonic spirochetosis?
Brachyspira pilosicoli
What diagnostic test is the acute indicator of leptospira infection?
quantitative PCR (vax does not effect)
What diagnostic test is a chronic indicator of lepto infection?
MAT (microagglutination titer)
When will peak serum antibody titers occur for lepto?
17-21 days post infection
Which host species would lawsonia be a differential diagnosis for diarrhea?
pigs, horses, rodents
What disease does lawsonia cause?
proliferative enteropathy
What are the 4 different forms of proliferative enteropathy in swine based on age of animal and chronicity?
Chronic forms- young animals –> porcine intestinal adenomatosis, necrotic enteritis, regional ileitis
Acute form- old –>proliferative hemorrhagic enteropathy
What are the unique histopath lesions of Lawsonia inracellularis?
long branched crypts –> increased PMNs, decreased goblets
What are the unique gross lesions of Lawsonia intracellularis?
proliferative enteritis - mucosal expansion
What are the 2 diagnosis tests for ante mortem detection of lawsonia intracellularis?
PCR in feces
serology
What are the 2 subspecies of campylobacter fetus and their hosts?
C. fetus var veneralis - bovine
C. fetus var fetus - ovine and bovine
What specimen should always be taken in LA abortions?
stomach contents of fetus
What toxin is responsible for the damage caused by campy jejuni?
cytolethal distending toxin (e coli also has)
Why is Campy jejuni such a scary zoonotic pathogen?
common in small ruminants, cattle, dogs –> enteritis, abortions
also guilian barre syndrome
What is the biology of the C. jejuni cytolethal distending toxin?
cdtB encodes active/toxic component (unlike A/B toxi)
cdTB enters nuclease and causes DNA double strand breaks
Why must specific C. jejuni culture be requested during diagnosis?
microaerophilic environment and specific media
What are the 3 important species of Hemophilus?
parasuis, paragallinarum, somnus
What is the bacterial characteristics for all of the HAP group of bacteria?
pleomorphic gram - rod, facultative or aerobic
What two factors are needed to grow Hemophilus in culture?
X factor : heme
V factor: NAD
can use chocolate agar
What is the satellite phenomenon?
Staph streak down middle of plate - hemophilus only grows near it
Where is hemophilus usually found and transmitted?
normal flora
respiratory transmission by close contact
What is the main predisposing factor to infection with hemophilis parasuis?
concurrent viral infection - SIV, PRRS
What are the 2 forms of Hemophilis parasuis disease?
respiratory
Glassers - polyserositis, vasculitis
What dz does Hemophilis somnus cause?
thromboembolic meningoencephalitis
When does hemophilus somnus disease usually occur in calves?
feedlot cavles a few weeks after being brought together in the fall
What is the eitologic agent of Fowl Coryza?
avibacterium paragallinarum (in pasteurella family)
What species are affected by wooden tongue, A. lignieresii?
cattle, sheep, swine, horses
What species is affected by Actinobacillus pleuropneumonia?
swine (nasal cavities)
What CS does actinobacillus equuli cause?
sleepy foal dz (septicemia)
What causes damage and death in A. pleuropneumonia?
endotoxin - sudden death
repeating tandem x toxin family - highly toxic to macros and endothelial cells
What lesions will be seen in swine infected with A. pleuropneumoia?
exudative, proliferative, hemorrhagic and necrotic bronchopneumonia
What is the treatment for A. pleuropneumonia?
no vax, must do susceptibility testing
What 4 diseases result from infection with pasteurella multocida?
atrophic rhinitis
fowl cholera
ruminant hemorrhagic septicemia
bite wounds (cat)
What is the significance of the capsule of pasteurella multocida?
serogrouping and related to pathogenicity/host specificity
What are the two most important virulence factors of pasteurella multocida?
capsule
PMT - causes cytoskeletal arrangements in host cells
What is the co-infection requirement for P. multocida in atrophic rhinitis in swine?
bordetella bronchiseptica
What kind of disease is fowl cholera?
avian hemorrhagic septicemia
How does P. multocida evade immune response?
immunological mimicry - sialic acid –> can cause autoimmune dz
What is the most frequent bacterial isolate in lungs of pneumonic cattle?
Mannheimia hemolytica
What are the important morphological characteristics for mycoplasma?
gram negative, no cell wall, very small, fried egg on media
What are the culture reqs for mycoplasma spp?
rich media, sterols needed, incubation for 2-10 days, 9% CO2, osmotically fragile
What are the 3 host specific respiratory mycoplasmas?
M. bovis - CPPS, BRD, and mastitis
M. hyopneumoniae - enzootic pneumonia in swine
M. gallisepticium - chronic resp dz
What is the most likeley mechanism of mycoplasma damage to host?
innocent bystander - immune response causes damage
What are the virulence mechanisms of mycoplasma spp?
surface lipoprotein phase variation - slipping of tandem repeats
some have “terminal organelle” - adhesins
What 2 antibiotics are mycoplasma species resistant to?
penicillin, sulfonamides (cell wall)
How can M. bovis be diagnosed?
ELISA serology or PCR of lung post mortem
What drug is effective in treatment of M. bovis?
Tulathromycin
How is M. hyopneumoniae in swine diagnosed?
PCR of BAL, nasal swabs
What are the important haemotropic mycoplasmas in dogs and cats? (4)
dog - M. haemocanis
cat - M. haemofelis, M. haemominutim, M. turicensis
What is the host and disease of Ureaplasma diversum?
cattle - reproductive and respiratory infections, abortion
What test differs strep from staph?
strep - catalase negative
staph - catalase positive
What kind of metabolism does strep use? What test can aid in diagnosis?
strictly fermentative
CHO broth –>yellow
What are the two unique cell wall components of strep?
lipoteichoic acid pilli + M protein
hyaluronic acid capsule
How are streptococcus grouped and what species is in each group?
Lancefield grouping - C-carbohydrate on wall A - S. pyogenes B - S. agalactiae C - S. equi D - S. bovis, uberi, AND enterococcus G - S. canis
Which strep group (and pathogen) result in auto immune dzs?
group A - pyogenes (rheumatic fever or glomerulonephritis)
What 3 diseases are caused by group B strep, S. agalactiae?
pneumonia, sepsis, meningitis
What does group C strep cause?
pharyngitis and pneumonia in equines, dogs, guinea pigs and humans
What are the 3 soluble virulence factors of streptococcus species?
Hemolysins - varies
streptokinase - lyses clots
hyaluronidase - spread
What are the two important hemolysins in streptococcus spp?
Streptolysin O - oxygen sensitive, immunigenic
Streptolysin S - stable, non immunogenic
What are the two insoluble factors aiding in streptococcus virulence?
M protein - pilus like structure
F - protein - fibronectin binding
both are adhesins
What virulence related protein is different between staph and strep?
staph - Protein A
strep - protein G
anti-phagocytic
What toxin causes the rash associated with scarlet fever in strep infections?
pyrogenic (erythrogenic) toxin
What 3 strep toxins are nephritogenic?
Streptokinase
streptodomase (dnase B)
streptolysins
Why is strep more invasive than staph?
strep breaks down fibrin –> less likely to abcess and can spread
How does strep survive in macrophages?
has superoxide dismutase (even though catalase negative)
What are two easy diagnostic tests to identify streptococcus genus?
hemolysis rxn, CAMP rxn (arrow on blood agar)
What test determines if the strep is S. bovis or S. suis?
hydrolysis of esculin
What strep group grows in bile or salt broth?
group D
What antibiotics should be used against strep?
beta lactams and cephalosporins
How is strangles, S. equi (beta strep), diagnosed?
M protein PCR detection
What is usefule in reducing CS in equine strangles?
vax
Which beta strep causes upper resp infections in foals?
S. equi ssp. zooepidemicus
What beta strep causes septic arthritis in pigs?
S. dysgalactiae ssp. equisimilis
What beta strep causes oppurtunistic infections associated with allergy?
Strep canis
What mastitis causing strep is an obligate IM pathogen and is camp + and B hemolytic?
S. agalactiae
What two strep spp are environmental causes of mastitis? What is there hemolysis pattern?
S. uberis - alpha
S. dysgalactiae - gamma
What is recommended for treatment in alpha strep (group D, non enterococcus)?
susceptibility testing
Which strep causes meningitis and septicemia in young pigs? What are the two types?
strep suis
Type 1 - baby pigs
Type 2 - older young pigs
Which strep is an important zoonotic dz in pig farmers/handlers?
strep suis
What dzs does strep bovis cause in calves?
resp, meningitis, endocarditis
What can strep bovis lead to with diets high in starch?
feedlot bloat
What 2 autoimmune dzs is a sequelae of strep throat?
acute rheumatic fever and glomerulonephritis
What are problems caused by a superantigen such as in strep species?
large subset of T-cells –> excess cytokines –> shock
What 2 antibiotics should be avoided in strep tx?
fluoroquinolones and vancomycin
What are alternatives to antibiotics in tx of strep?
bacteriophage (use once)
bacteriocins - streps inhibit other streps
What are the morph characteristics of bordetella?
gram - rods, obligate aerobe, slow growing, oxidase and catalase positive
What are the toxins produced by bordetella?
dermonecrotic, endotoxin, iron acquisition
What other animals can be infected by bordetella besides dogs?
pigs, rabbits, cats, horses
What are some cell proteins that bordetella possesses and what do they do?
Fimbriae (pertussis vax)
filamentous hemagglutinin - binds on cilia
pretactin - host cell attachment, immunogenic
LPS
What 2 bordetella species infect birds?
B. avium, hinzii,
What are the 3 A/B toxins we have talked about?
E labile toxin
cholera toxin
pertussis toxin
What toxin is present in all gram negative bacteria peptidoglycan and stimulates TNF alpha?
tracheal cytotoxin (used by bordetella –> cilia)
What does the bordetella toxin, adenlate cyclase/hemolysin target?
phagocytes
How does bordetella bronchiseptica release its toxins?
type 3 secretion system
What two bacteria have a two component signal transduction system that conserves energy while not in the host?
strep equi and bordetella
What is the MOA of S. aureus toxic shock toxin?
crosslinks TCR peptide chain with MHC class 2 molecule –> excessive secretion of cytokines
What does streptolysin do?
forms membrane pores