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Microbiology - Bugs/1


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What is Pneumonia?
bacteria that is normally found in throat of many people
It may move from upper -> lower resp. tract during stress
Alveoli fill with bacteria, fluid, and WBC
s/s - hypoxia and hypercapnia, bloody sputum, chest pain, fever, SOB
What is an autoimmune response of the kidney to Str. pyogenes?
What is C perfringens?
enterotoxin specific for GI tract, from meat, that causes food poisoning
-> 12 hours of D, w/o N/V
Main prob.=dehydration
What is str. agalactiae ?
Group B strep
Can be normal vaginal flora
Can cause neonatal infection, septicemia, meningitis if the bacteria enter baby at birth, esp. through umbilical cord stump
What is Peptostreptococcus or Peptococcus?
Normal anaerobic GI and vaginal flora
found in mixed anerobe/aerobe infections like PID of fallopian tubes
What is B. anthracis ?
-causes anthrax-a cattle disease that produces septicemia
-human disease in meat packing plants where hands come in contact with infected meat
local infection -> septicemia
inhaled spores -> pneumonia -> lethal septicemia
-was used in germ warfare
Str. mutans is ...
Alpha, hemolytic str. found in mouth
* important in tooth decay
sealant that protects teeth from acid that dissolves enaenamel, preventing cavity
What are general characteristics of Clostridium?
1. gram+ rod-show purple
2. (+) spore producer-malachite green oval spores
3. anaerobic growth, catalase (-)
4. vegetative spores and rods usually found in GI tract
5. spores found in soil
6. Rx = penicillins, cephalosporins
7. exotoxins produced
What is Str. fecalis?
group D strep
enterococci / normal GI flora
If bacteria moves from GI -> urethral meatus -> bladder
What is N. meningitidis ?
Pathogen ! Causes meningitis
C. tetani is what ?
a Pathogen!
-causes tetanus / "lockjaw"
-found in GI tract of horses, manure, soil
-spores -> wound that closes/anaerobic conditions -> rods grow and produce exotoxin
-exotoxin -> bloodstream -> NM jxn: mimics ACH -> muscles spasms and resp. arrest
Rx = Antitoxin
Morbidity-100 cases/yr.
Prevention: DTP shot for kids and tetanus shot q10 yrs. for adults
What diseases does Cl botulinum cause?
Botulism and infant GI botulism
What is puerperal sepsis?
a post partum uterine infection from str. pyogenes
What is N. sicca, N flava ?
normal skin flora of nasopharynx or vagina
What is an untreated strep throat bacterium that produces an erythrogenic exotoxin that causes the skin to turn red?
Scarlet fever
What is Otitis media?
middle ear infection, 30-40% of which are caused by str. pneumoniae
rest are caused by normal throat bacteria
due to angle of eustachian tubes in kids
Rx = do not feed laying down and with tubes
What diseases does Str. pneumoniae cause?
Pneumonia and Otitis media
What is rheumatic fever?
an autoimmune response of Ab vs. proteins on strep bacterium attacking similiar bacteria on heart valves
Rx = give penicillins for strep throat before Ab are produced
What are general characteristics of staphylococcus?
Gram+ (purple) cocci in clusters with thick peptidoglycan cell wall
Sensitive to penicillins and cephalosporins
Exotoxins may be produced
Encapsulated pathogen when with a pathogen
Catalast +, hydrogen peroxide -> water and bubbles
Infections may produce fevers due to phagocytes releasing endogenous phrogen as they phagocytize bacteria
What is gonorrhea?
Spread by direct sexual contact
is a VD or STD
In males-causes inflammation of urethra, painful urination, yellowish pus filled discharge
- fiborous scar tissue of collagen may cuse streicture and occlusion of urethra or epididymis -> sterility
In females-slight purulent, pus-filled vaginal discharge. If it spreads to fallopian tubes -> PID and sterility
* high % of asympomatic cases
800,000 cases in US, 400 in WY
Rx = Penicillin; PPNG, penicillinase producing N gonorrhoeae or resistant strains occur
Prevent by condoms
What are the general characteristics of Neisseria ?
- Gram- diplocci: gram neg. cell wall of thin inner peptodoglycan and outer bilayer lipid cell membrane
- very fragile bacterium, sensitive to penicillins and celphalosporins
- produces endotoxin
- encapsulated and uses pili to cling and resist phagocytosis
- cytochrome oxidase + - purple reaction on filter paper with wooden applicator stick
- can grow on prewarmed chocolate baked agar
What diseases does N. gonorrhoeae cause?
Opthalmia neonatorium
What are staph epidermidis ?
normal skin flora of skin and mucous membranes
show on mannitol salt agar as hot pink
coagulase (-)
Infant GI botulism is...
ingested botulism spores in <6 mo. yo. kid
-exotoxin into GI tract, without normal flora -> toxemia -> paralysis
s/s-floppy head, swallowing difficulty, muscle weakness, resp. arrest in 1/3 cases
-linked to 10% of SIDS cases
Prevention: no raw unpeeled agri. products, like honey to kids < 1 yo.
What infections does St. aureus cause?
Skin - boils, surgical wounds
Osteomyelitis in bone and marrow
Tooth abcesses, burnucles, furnuncles
Toxic shock from vagina and growing on tampons
Food poisoning with N/V, diarrhea - cream and mayo in which a enterotoxin,exotoxin grow specific to GI tract - refridgerate!
What is Str viridans or Str. salivarius?
Normal mouth or throat flora (URT)
non-hemolytic or alpha hemolytic
normally not pathogenic but may be opportunistic with nalformed or damaged heart valves or artificial joints
Rx = prophylactive, preventative penicillin a/p dental work
Discuss what a strep throat is.
it is an acute sore throat, often with low grade fever, enlarged cerical lymph nodes and pus pockets on tonsils
Decreasing in incidence, but cyclic increases with various strains
Resolves in one week without Abx
If you have similiar proteins on heart valves or kidney glomeruli, -> autoimmune diseases may follow
What are the general characteristics of Bacillus ?
Gram+ rods-purple
(+) spore producer
Aerobic growth, catalase +
-usually found in soil
Rx = penicillin, cephalosporins
-produce exotoxins
What is impetigo?
a skin infection from str. pyogenes
synergistic with st. aureus
s/s - small itchy, weepy, crusty blisters
What diseases does Str. pyogenes cause ?
strep throat, rheumatic fever, glumerulonephritis
scarlet fever, peurperal sepsis, flesh-eating strept, impetigo
What is Botulism ?
-Spores, common in soil, contaminate food
-this happens when alkaline or neutral food is not properly made and spores grow exotoxin in anaerobic container conditions
-exotoxin acts at NM jxn inhibiting ACH -> flaccid paralysis
s/s-muscle weakness, resp. and cardiac failure, no fever with little or no GI distress
Rx = Ab to exotoxin, made in horses
Prevention-can alkaline or neutral food by boiling x10" before eating to denature protein
Morbidity=<100 cases/year
Discuss PID / Pelvic Inflammatory Disease.
Acute/chronic salpingitis: inflammation of fallopian tubes
causing lower abd pain, fever, leukocytosis, with purulent pus filled cervical discharge
1M cases/yr, affecting 1% of sexually active women
Risk factors - sexually active w/ > 1 partner, under 25 yo, IUD use, menstruation or post partum
* Mixed A/An infection as bacteria from vagina -> cervix -> uterus -> fallopian tubes
* Sequelae, complications include: infertility and ectopic pregnancies with fallopian tubes occluded
What are the characteristics of str. diplococcus / 2 pair pneumoniae ?
Pathogen !
alpha hemolytic
grows in candle jar [of 17% O2 and 4% CO2-like lungs] on blood agar
What is str. pyogenes ?
Group A, B-hemolytic on sheep blood agar
Invasive bacteria producing streptokinase to destroy blood clots, DNAase, and beta-hemolysins
What is C. histolyticum or C septicum?
Pathogen !! Gas gangrene
spores contaminate tissue -> necrosis with exotoxins: destroy enzymes, with their sugars producing gases -> tissue swelling -> cutting off blood supply -> more death
Means infection has reached muscle depth
anaerobic cellulitis=only skin and subcutaneous tissue involved
Rx = Debridement, penicillins, Hyperbaric O2
* DM patients more susceptible !
Mortality=20% with Rx
What are staph aureus?
pathogen with golden yellow pigment
on MSA show yellow
coagulase (+)
clots plasma
Discuss Menigitis.
N.m. is carried in upper resp. tract of 20-30% (people?) forming transient normal flora
-spread by droplet infection person -> person
-under stress, bacteria from nasopharynx -> blood - this leads to bacteremia with endotoxin -> high fever, capillary hemmorrhage, shock
-then it travels into CSF -> meninges -> HA, stiff neck, N, coma
S/S - with spinal tap, clear CSF = aseptic M. with viral cause
cloudy CSF = bacterial M.
2,500 cases/yr with 50% in children under 5
Rx = prophylactic Abx given to exposed people
What is Ophthalmia neonatorium ?
conjunctival infrction acquired as baby passes thru infected vagina at birth
-> fibrosis of eye and blindness
Rx = 1% silver nitrate drops or Ab eye ointment at birth
What are the general characteristics of streptococcus?
Gram+ cocci in chains and pairs
Catalse (-) - no bubbles from H2O2
Rx with penicillins and cephalosporins
Phagocytic endogenous pyrogen may cause fever
What is N. gonorrhoeae ?
Pathogen !
ghonorrhea, "clap", gonococcus, GC

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