bacteria5 Flashcards
this enteric pathogen is gram positive, sporulation, and anaerobic; large amount fermentation products and degradative enzymes
Clostridium
tetanus vaccine is to this
toxin tetanospasmin
what does the tetanospasmin toxin affect?
presynaptic inhibitory spinal interneurons
incubation period for Clostridial gastroenteritis; when does it resolve?
6-24 hours; 24 hours
what makes up pseudomembrane (caused by toxin put out by bacteria)
coagulation of PMNs, necrotic tissue (epithelium), fibrin
botulism preformed neurotoxin cleaves this; what does this block?
synaptobrevin; Ach release (causes descending paralysis)
incubation period for Salmonella typhi
10-20 days
these are responsible for invasion in Salmonella typhi; what does this cause?
mononuclear phagocytes; splenomegaly and typhoid nodules
this enteric organism can colonize the gallbladder in the carrier state
Salmonella typhi
this enteric organism is comma-shaped, gram negative, flagellated; *one of most common cause of gastritis, diarrhea, and dysentery in US*
Campylobacter jejuni
this enteric pathogen is associated with Guillain-Barre neuropathies
Campylobacter
pathogenesis of Campylobacter enteritis (due to jejuni)
foul smelling stools w/ blood/exudate
transmission of Yersinia enteritis
raw pork, unpasteurized milk
this organism causes ulcerative intestinal lesions (like typhoid), microabscess and granuloma formation, deeply invasive and possibly lethal (*mostly pediatric*)
Yersinia entercolitico
these enteric pathogens have rapidly acting toxins
Staph aureus and Bacillus cereus
how long it takes for Staph aureus to act (more vomiting than diarrhea); how long does it take to resolve?
2-4 hours; 24 hours
Bacillus cereus causes vomiting for this amount of time; and diarrhea this amount of time
1-5 hours, 8-15 hours
conditions that favor growth of Clostridial organisms
necrotic tissue and anaerobic environments
pathologic mechanism of Clostridial diseases
exotoxin (even w/o direct infection) –> absorption/distribution –> necrosis
gangrene/necrotizing cellulitis due to Clostridial organisms is caused in part by these
extracellular necrotizing enzymes (phopspholipases, proteinases, poisons)
this is characteristic in gas gangrene due to Clostridial infection
hemolytic destruction RBCs
toxin A and toxin B of C. difficile are these kinds of toxins
enterotoxin and cytotoxin
suppression of this is attributed to community acquired C difficile
gastric acid
death from C. botulinum usually occurs from this
respiratory muscle paralysis
symptoms of C. botulinum
CN defects (diplopia and dysphasia) and descending flaccid paralysis
these organisms are normal flora where in body? –> staph aureus, stap epidermidis, peptostreptococci , alpha and non-hemolytic strep, anaerobic strep, bacteroides, Candida albicans
mouth, nose, oropharynx
these organisms are obligate intracellular organisms
viruses, chlamydiae, rickettsiae
propagation of Staph aureus; what is immune response to infection?
extracellular; PMNs
lack of PMN function makes susceptible for these organisms
Staph and strep
lack of CMI makes susceptible to these organisms
intracellular organisms
spore forming, gram positive, bacilli bacteria
Bacillus (facultative anaerobe) and Clostridium (obligate anaerobe)
this gram positive, cocci has the ability to spread out into tissue (versus other than accumulates w/ PMNs)
Streptococcus
gram stain color for gram positive
purple
is Staph aureus coagulase positive or negative?
positive
is Staph epidermidis coagulase positive or negative?
negative
this Staph infection most commonly infects damaged tissues (less virulent)
Staph epidermidis
Staph sepsis commonly affects these organs/body parts
valves (endocarditis), kidneys, bones, joints
virulence factor for Staph…binds Fc portion of Ig
protein A
virulence factor for Staph…gives plasmid mediated antibiotic resistance
penicillinase
aka boil (seen in Staph skin infection)
furuncle
aka multiple, connected boils (seen in Staph skin infection)
carbuncle
this is caused by superficial leakage of protein-rich fluid that dries (and becomes crusty)
impetigo
3rd most common nosocomial infection..major in burns and surgical wounds
Staph
TSS toxin of Staph causes this (which leads to bad sepsis)
non specific activation T cells (T cell superantigen)
3 manifestations of bacteremia from Staph infection…most common with drug use
acute endocarditis, septic arthritis, osteomyelitis
normal flora in skin, periurethral, and urethra –> major cause of UTI in young women (most asymptomatic)
Staph saprophyticus
examples of spreading suppurative Strep infections
cellulitis, impetigo, erisypelas, GABHS
examples of post-strep hypersensitivity disease
rheumatic fever, immune complex glomerulonephritis
part of group A Strep infections
GABHS, S pyogens
see group B Strep infection in these patients/conditions
perinatal sepsis/newborns, UTI
major cause of subacute bacterial endocarditis (due to Strep infection –> especially after dental work)
viridans
major cause of dental caries
Strep mutans
Strep that are B-hemolytic (complete hemolysis)
pyogenes and agalactiae
strep that are a-hemolytic (green, partial hemolysis)
pneumoniae and viridans
present in many Strep subtypes…antiphagocytic
M protein
group A strep primarily causes these diseases
acute pharyngitis/URT, scarlet fever
severe, prolonged group A pharyngitis; febril exanthematous disorder (primary 3-15 yo) –> erythrogenic toxin w/ violaceous red rash on trunk–> later desquamation of skin
scarlet fever
signs of post-strep glomerulonephritis (acute renal failure signs)
oliguria, hematuria, hypertension
signs of acute rheumatic fever (post-strep sequelae)
fever, joint disease, myocarditis and endocarditis
autoimmune reaction cross-reacts with this in rheumatic fever
M antigen
titer in blood that corresponds to acute rheumatic fever
streptolysin O
sign of chronic rheumatic fever
mitral and aortic valve stenosis (due to fibrosis from chronic inflammation)
extensive spreading redness, swelling and pain associated with Strep skin infection
cellulitis and pyoderma
*contagious* skin infection in kids involving horny layers of skin (superficial)
impetigo
due to Strep groups a/c…middle-aged person in warm climate –> erythematous skin involvement w/o suppuration
erysipelas
*subcutaneous* strep infection w/ necrosis that is overtaken by anaerobes
necrotizing fasciitis
type of strep that causes puerperal sepsis (perinatal)
group B
what rapid strep test looks for (diagnosis of strep throat –> GABHS)…takes 12-48 hour culture
group a strep carbohydrate antigen
