bacteria1 Flashcards
aka acquired in hospital
nosocomial
bacteria responsible for 95% of community acquired pneumonia
Strep pneumoniae
infections with this bacteria usually secondary to other alteration in tissue structure or function
endogenous bacteria
lack of this allows infiltration of intracellular organisms (like ricketssia and viruses)
cellular immunity
pyogenic cocci
Staphylococcus and Streptococcus
if you think about rice…think about this bacteria
Bacillus cereus
non-spore forming bacilli
Listeria and Corynebacteria
typical stain color for gram negative
red
typical stain color for gram positive
purple
diagnostic test between Staph and Strep
catalase
is Staph positive or negative catalase?
positive
is Strep positive or negative catalase?
negative
kind of inflammatory response in pyogenic cocci infection
suppurative
only pyogenic bacteria that has vaccine
Strep pneumonia
is Staph aureus positive or negative coagulase?
positive
is Staph epidermidis positive or negative coagulase?
negative
general diseases caused by Staph
abscess, bacteremia, toxin-mediated
system wide inflammatory response
sepsis
aka a boil
furuncle
aka multiple, connected boils
carbuncle
characterized by superficial skin/wound infection…leakage of protein-rich fluid that dries and becomes crusty (commonly transmitted between kids)
impetigo
common upper respiratory staphylococcal infections
sinusitis, otitis media, pharyngitis
symptoms of toxic shock syndrome
fever, diffuse macular rash, shock
examples of conditions caused by bacteremia from staphylococcal infection
acute endocarditis, septic arthritis, osteomyelitis
this group of strep can cause impetigo, GABHS
group A
this group of strep can cause perinatal sepsis/in newborns, UTIs
group B
enzymes in streptococal infection that contributes to ability to spread through tissues
streptokinase, streptolysin O/S
severe prolonged group A pharyngitis …typically 3-15 years old; erythrogenic toxin causes violaceous red rash on trunk
scarlet fever
hypersensitivity reaction where antibodies bind cells/tissue….rheumatic fever
II
hypersensitivity reaction in which immune complexes form
III
3 signs of acute renal failure
oliguria, hematuria, hypertension
time after streptococcal infection may get gloerulonephritis; what kind of hypersensitivity reaction is it?
1-2 weeks; III
symptoms of acute rheumatic fever
myocarditis and endocarditis
scrotal/perineal form of necrotizing fasciitis
Fournier’s gangrene
strep typically associated with subacute bacterial endocarditis
Strep viridans
does subacute bacterial endocarditis typically occur on right or left side of heart (typically in valves)
left
most common organisms that cause foodborne illnesses (can cause hospitalizations)
Salmonella (non typhi) and campylobacter
common food contaminants but do not cause serious disease (toxin mediated)
C perfringens and Staph aureus
organisms that are less common to cause food contamination but when they do can be fatal
Listeria and E coli O157:H7
enteric pathogens that are viruses
Norwalk, Enteroviruses, Polio
enteric pathogens that are parasites
Giardia, Amoebae, Ascaris, Cryptosporiosis
incubation period for infection by colonizing toxigenic organisms (hypersecretion reaction from bacterial adherence and toxin secretion)
1-3 days
incubation period for pathogens that invade the gut wall
days-weeks
enteric pathogen that has prototype secretagogue enterotoxin
Vibrio cholerae
enteric pathogens that have cytotoxins
Shigella, E coli O157:H7 (Shiga toxin)
these enterotoxins act as T cell superantigens
Staph
invasion and cytolysis of gut epithelium result in this
dysentery
these 3 things must be present to be considered dysentery
loose stool, blood, leukocytes
see this when there is only toxin, superficial colonization/toxin, or superficial colonization and inflammation
diarrhea
this coliform forms green sheet on EMB agar; what is gram stain and shape?
E coli; negative, rod
aka ferments lactose
coliform
if E coli has shigatoxin (verotoxin) will cause this
hemolytic uremic syndrome
E coli infection that causes traveler’s diarrhea
ETEC (enterotoxic)
E coli infection with severe bloody colitis…from consumption hamburger, dairy products, or fruit juice (*shiga toxin strain –> O157:H7*)
EHEC (enterohemorrhagic)
E coli infection that causes mainly pediatric diarrhea in impoverished nations
EAEC (enteroaggregative)
common sources of E coli O157:H7
hamburger, unpasteurized milk (also outbreaks in spinach and sprouts)
what shigatoxin from E coli O157:H7 inhibits in endothelial cells of large intestine (*Need less than 100 organisms to be infectious*)
mRNA translation and protein synthesis
symptoms of E coli O157:H7 infection typically begin this time frame after ingestion; how long do symptoms last?
3-4 days; 8 days
symptoms of E coli O157:H7 infection
abdominal cramping, watery to bloody diarrhea (some vomiting, low grade or absent fever)
possible serious presentations of E coli O157:H7
hemolytic uremic syndrome (in elderly and children) and thrombotic thrombocytopenic purpura
other strains of STEC that are important (non-O157:H7)
O26, O103, O111
this enteric pathogen is gram negative, non-motile, and non-coliform
shigella
where does shigella spread after invasive lesions of colonic mucosa?
lymph nodes (NOT BACTEREMIA)
Shigella exotoxin causes this; what does this then lead to?
mucosal necrosis; pseudomembrane (from fibrinosuppurative exudate)
number of organisms needed for Shigella infection
this enteric pathogen is comma shaped, gram negative, alkali tolerant (fecal-oral transmission, *asymptomatic carriers*)
Vibrio cholerae
pathogenicity of V cholerae is due entirely to this
enterotoxin (induces isotonic fluid secretion)
most people with V cholerae die from this
dehydration and hypovolemic shock
ADP ribosylation and activation of GTP adenylate cyclase (creating cAMP) causes secretion of this in V cholerae infection
chloride and bicarb
this enteric pathogen is gram negative, non-coliform and produces H2S
Salmonella
most common organisms for Salmonellosis
S. enteritidis and S. typhimurium
possible sources of Salmonellosis
eggs, undercooked chicken/meat, turtles/reptiles, cantaloupes/mangoes
Salmonella causes this in sickle cell anemia
osteomyelitis and sepsis
symptoms of Paratyphoid fever
fever, bacteremia, local lesions (associated w/ sickle cell disease, schistosomiasis)
organisms that can cause Paratyphoid fever
S typhinurium, S paratyphi, S cholerae-suis
where do you see spots associated with fever in Salmonella typhi?
low anterior chest, abdomen
symptoms of Salmonella typhi
fever w/ rose spots, hepatosplenomegaly
incubation period for Salmonella typhi
10-20 days
bacteria associated with aspiration in a hospital setting
Klebsiella pneumonia
pulmonary infections with Klebsiella and Enterobacter may be associated with this
necrotizing abscesses
gram negative, facultative anaerobic rod –> causes UTI, pyelonephritis, pneumonia
Proteus mirabilis
Proteus mirabilis secretes this –> causes alkaline urine, chronic pyelonephritis –> staghorn calculi
urease
Serratia marcescens causes this `
pneumonia (debilitated patients) and UTI
Pseudomonas aeruginosa commonly co-infects with this bacterial complex
Burkholderia cepacia
this organism can cause corneal keratitis, endocarditis/osteomyelitis (in IV users), external otitis (severe in diabetics)
Pseudomonas aeruginosa
gram positive nosocomials –> wound infections, catheters/instruments, bacteremia, necrotizing pneumonias
Staph aureus, Staph epidermidis, Enterococcus faecalis
these are anaerobic gram negative bacterial infections –> ischemic, devitalized tissues, foul smelling pus
Bacteroides, Fusobacterium, Peptococcus, Peptostreptococcus
mode of infections for anaerobic gram negative bacterial infections
aspiration, trauma, fecal leakage
gram stain for Legionella pneumophila
negative (flagellated rod)
H. pylori has this creating a protective layer of ammonium around it as protection from the acid in stomach
urease
