microbio exam 2

staphylococcus, micrococcus, peptococcus, peptostreptococcus, streptococcus

gram positive cocci

staphylococcus

• gram + coccus

• clusters, pairs

• facultative

• catalase +

  • all organisms that can use O2 produce H2O2 so have ctalase which breaks it down

• halotolerant

  • mannitol salt agar

staphylococcus aureus

• species of staphylococcus

• normal on skin (normal flora)

• 25-35% of us carry it in nasal passage

• can be pathogenic

• yellow pigment

• beta hemolysis

hemolysis of blood agar

• 5% sheep’s blood

• can be an indicator of pathogenicity

• alpha, beta, gamma

alpha

• hemolysis result

• greening (partial breakdown of RBCs)

beta

• hemolysis result

• clearing (complete hemolysis)

• lyse cells (destroys RBCs completely)

gamma

• hemolysis result

• no hemolysis

penumonia, meningitis, TSS, food poisoning

other S. aureus diseases include…

MRSA

• type of S. aureus

• methicillin resistant S. aureus

• hospital

• community

• can lead to more serious infections and death

staphylococcus epidermidis

• species of staphylococcus

• very benign

• normal on skin

• non-pigmented

• rarey pathogenic

• gamma hemolysis

  • does not affect human cells at all

micrococcus

• gram + cocci

• clusters, tetrads

• catalase +

• *strict aerobe

  • can not grow by fermentation

• non-pathogenic

• usually on inanimate objects

peptococus & peptostreptococcus

• gram + cocci

• ferments peptone (AAs) not sugar

  • obligate anaerobe

  • normal flora of intestine, vagina

  • postpartum septicemia, puerperal fever

  • causes death in childbirth

streptococcus

• gram + cocci

• *chains

• catalase -

  • aerotolerant anaerobes

    • don’t know how to use O2, can only ferment

  • fermentation product = lactic acid

  • 2 major groups based on hemolysis

    • beta - true lysis

    • alpha - greening

  • also separated by immunological groups (A-O)

    • group A is associated with human diseases

      • beta hemolytic

strep throat and scarlet fever

diseases that are caused by streptococcus pyogenes

streptococcus pneumoniae

• species of streptococcus

• encapsulated

  • important to discovery of DNA

• bacterial pneumonia

• ottis media — ear infection

• meingitis

• sinusitis

lungs

pneumonia = infection of the…

streptococcus mutans

• species of a gram + bacteria

• alpha hemolysis

• mouth

• needs sugar

• lactic acid production leads to cavities

bacillus, clostridium, lactobacillus, listeria, mycobacterium, corynebacterium, propionibacterium, eubacterium, actinomyces, streptomyces, mycoplasma

gram positive rods

bacillus

• gram + rod

• endospore forming

  • position of endospore

• aerobic or facultative

  • catalase +

• forms a capsule

• found mostly in soil

• source of bacitracin and other antibiotics

bacillus anthracis

• species of bacillus

• causitive agent of anthrax

• anthrax affects mostly plant eating animals

  • still occasional outbreaks

• humans infected during occupational exposure

  • ranchers, tanners, slaughterhouse workers

• bioterrorism

• cutaneous, respiratory or intestinal

anthrax

• disease caused by bacillus anthracis

• cutaneous easiest to treat

  • black necrosis

  • anthrax -- from greek ‘coal’

• respiratory or pulmonary almost 100% fatal

• must remain on antibiotics for weeks

• vaccine

• scare in 2001

clostridium

• gram positive rod

• endospore forming

• strict anaerobes

• found in anoxic pockets in soil and intestinal tract

C. botulinum

• species of clostridium

• spores are especially heat resistant

• botulism

  • foodborne- not infection

    • ingestion of toxin easily inactivated with heat

    • treat with anti-toxin

  • infant-under 1 yr

    • associated with honey

    • both toxin and infection

  • wound

    • rare

• botulism toxin is most potent toxin known

  • 1 oz could kill US population

  • causes neuro-paralysis (muscles relax)

  • fear it could be used in bioterrorism

  • 
    

C. tetani

• species of clostridium

• muscles contract and can’t relax

• tetanus (lockjaw)

  • toxin mediated

• found especially in soil enriched with manure

  • normal flora in horses, cattle

• deep cuts or puncture wounds

• vaccine since 1933

C. perfringes

• species of clostridium

• gas gangrene

  • deep wounds

    • spores germinate where O2 is low (poor circulation)

    • toxins and enzymes released to kill cells

  • foul odor

  • high fever, shock, massive tissue destruction

C. difficile

• species of clostridium

• normal flora of intestine

• resistant to many antibiotics

  • flourishes when antibiotics taken

• nosocomial infection

• resistant to alcohol based sanitizers (Purell)

lactobacillus

• gram + rod

• produce lactic acid during fermentation

• non spore forming

• common in dairy products, sourdough

• L. delbrueckii used for yogurt

• L. acidophilus used for acidophilus milk- for lactose intolerant people

• acidophile

Lactobacillus acidophilus

• species of lactobacillus

• very resistant to acid

  • pH 4

• normal flora in vagina of women of child bearing age

Listeria

• gram + rod

• very short rods 0.5 um

  • non spore forming

• L. monocytogenes - foodborne illness listerosis

  • gastrointestinal-may lead to meningitis

  • increases risk of spontanoeus abortion

• psychrotolerant-refrigeration doesn’t slow growth

• outbreaks with non-pasteurized cheese porducts, cold cuts

• immunocompromised most susceptible to listerosis

• bacteriphage spray available to treat food

mycobacterium

• gram + rod, but don’t stain that way

• unique cell wall

  • mycolic acid prevents gram stain to get in

M. tuberculosis

• species of mycobacterium

• grow in WBC and induce host response-similar symptoms as pneumonia

• cause of tuberculosis

• ¼ of world has it, 1 million die each year, 10 mill new cases each year

• US: 20,000 cases

• treat with antibiotics but some resistant

• PPD screening

M. leprae

• species of mycobacterium

• very difficult to culture in lab

• armadillo footpads

• Hansen’s disease/leprosy

  • can have 30 year incubation

  • mycobacterium attack immune cells — live inside macrophages

  • peripheral tissue destruction

• lepromin skin test

• antibiotics

mycoplasma

• gram + rod

• too small to be seen with light microscope

• very small genome

• no cell wall*

• phylogenetically related to gram + bacteria even tho doesn’t have wall

• M. pneumoniae can be cause of bronchitis and pneumonia

• penicilin doesn’t work since it doesn’t make peptidoglycan

Corynebacterium

• gram + rod

• aerobic non-motile

• club shaped or V-shaped

C. diptheriae

• species of corynebacterium

• diptheria

• <5 cases/yr in US

• toxin carried by prophage w/in C. dip.

• pseudomembrane can cause suffocation

• treat with antitoxin and antibiotics

• vaccine

propionibacterium

• gram + rod

• aerotolerant, ferment lactic acid to produce propionic acid and CO2

• swiss cheese

  • lactobacillus + propionibacterium

P. acnes

• species of propionibacterium

• acne

• hormones stimulat excess sebum- microorganisms feed on

• ducts become plugged and may rupture

• infects, more inflammation, tissue damage

• some antibiotics help

• accutane prevents sebum

Eubacterium

• gram + rod

• obligate anaerobe

• major normal flora of large intestine

• opportunistic pathogen

Actinomyces

• gram + rod

• primarily in soil

• form branching filaments (almost fungus-like hyphae)

• do not form spores

• can contribute to madura foot

Streptomyces

• gram + rod

• primarily in soil (earthy smell)

• over 500 species

• also form branching filaments

• form true spores (diff than endospores)

• also madura foot

• source of many antibiotics

actinomyces and streptocmyces

which two gram + rods are fungal-like?

pseudomonas, legionella, neisseria (cocci), brucella, bordatella, francisella

gram neg aerobic bacteria

enteric bacteria, vibrio, haemophilus, gardnerella

gram neg facultative bacteria

Neisseria

what is the only cocci gram negative bacteria?

Pseudomonas

• gram - bacteria

• straight or slightly curved rods

• polar flagella

  • motile

• oxidase +

oxidase test

• tests for presence of cytochrome oxidase (ETC)

• present in strict aerobes, not usually facultative

Pseudomonas aeruginosa

• species of Pseudomonas

• common colonizer of whirlpool baths

  • hard to eliminate

• opportunistic pathogen

• UTI

• skin lesions - folliculitis

• eye and ear infections

• speticemia (immunocompromised)

• resistant to many antibiotics

• resistant to Triclosan and chlorine

Legionella

• gram - bacteria

• not identified or named until 1976

• weak gram stain (-)

• polar flagella-motile

• obligate aerobe

  • does not ferment sugars

• found in cooling towers/air conditioning systems, whirlpool baths

• transmitted through droplets

• 
  

• mild disease for most people

Neisseria

• gram negative cocci in pairs (diplococci)

• no flagella

• non-motile

N. gonorrhoeae

• species of neisseria

• causative agent of gonorrhea (not fatal, but severe problems, ex. sterility)

• no vaccine, no immunity, organism becomes resistant

• can lead to PID = pelvic inflammatory disease

• can be transmitted to newborn

  • prevented by eyedrops

Neisseria meningitidis

what is the most serious type of miningitis?

N. meningitidis

• species of Neisseria

• meningococcal meningitis

• high levels of toxins released

• 85% mortality if untreated

• neck pain —> rash —> tissue death

• infants and 15-24 year olds most susceptible

• antibiotics

• vaccine

Brucella

• gram negative bacteria

• very small rod, non-motile

• brucellosis aka undulant (buffalo/bison) fever, Bang’s disease, or Malta fever

• each species has preferred host but can infect others— including humans; can be infected by eating meat— yellowstone bison are vaccinated

• in cattle-causes abortion

• rare in humans

bordetella

• gram negative bacteria

• small (0.2-0.7 um)

• obligate aerobe

• B. pertussis causes whooping cough — can cause death in infants

• B. bronchiseptica causes kennel cough (dogs)

• vaccine- but not lifetime

  • DTP

  • DTaP

Francisella

• gram negative bacteria

• small

• obligate aerobe

• F. tularensis causes tularemia or rabbit fever

• associated with rabbit hunting

• can get disease by eating or skinning rabbits

• germ warfare?

• 
  

enteritis

inflammation of the intestine

small intestine

diarrhea is caused by infection of the ___

large intestine

dysentery is caused by infection of the _____

enteric bacteria

• gram negative straight rods

• facultative aerobes

• fermentation of glucose (distinguish from obligate aerobes)

• catalase + (breaks down H2O2)

• oxidase neg (distinguish from pseudomonads) = strict aerobe - makes oxidase

fermentation test

• 1 type of sugar and pH indicator

• ex. glucose or lactose or sucrose

• turns yellow = can ferment glucose

• 2nd tube within tube to check for gas

Escherichia coli

• gram neg bacteria

• peritrichous flagella

• indole +, gas from glucose, acid from lactose

  • ferments glucose and lactose

• most strains non-pathogenic

• normal flora of intestinal tract

• synthesizes vitamins

• pathogenic strains have a capsule or fimbriae to allow attachment to cells

  • cause diarrhea, UTIs

• fecally contaminated water

• contaminated beef

indole test

• deamination of tryptophan (AA) to indole

• testing for tryptophan deaminase

T

T/F: E. coli is important for gut health

shigella

• gram neg bacteria

• genetically closely related to E. coli but usually pathogenic

• non-motile

• no gas from glucose, no acid from lactose

• shigellosis or bacillary dysentery (severe diarrhea)

• associated with poor sanitation and overcrowding

• food or water-borne

• day care centers

salmonella

• gram neg bacteria

• also similar to E.coli but most are pathogenic to humans

• motile

• produce H2S

• S. enteritidis found in gastrointestinal tract of birds, rodents, and reptiles

  • cause of salmonellosis (gastroenteritis)

Hydrogen sulfide production

• thiosulfate reductase catalyzes sulfur to H2S gas

• H2S reacts with FeS to form black ppt

• if organism produces H2S, it will react with FeS

Typhoid fever

• disease caused by different strain of salmonella (S. typhi) in contaminated food or water

• systemic infection

• rare if there are good sanitation practices

Klebsiella

• gram neg bacteria

• most found in soil and non-pathogenic

• non-motile

• Urease +

• K. pneumoniae forms a capsule and can cause pneumonia, UTI and infant diarrheas

  • 50% mortality with this pneumonia

Klebsiella pneumoniae carbapenemase (KPC)

_____-producing bacteria are a group of emerging highly drug-resistnat Gram neg bacilli causing infections associated with significant morbidity and mortality

carbapenem-resistant enterobacteriaceae (CRE)

• basic structure of a lot of antibiotics

Urease test

• urease catalyzes breakdown of urea to ammonia and bicarbonate (very alkaline biproducts)

• urea = biproduct of liver

• urea broth, pH indicator

• pink = basic

Enterobacter aerogenes

• gram neg bacteria

• usually has yellow pigmentation

• butanediol fermentation

  • Vogues-Proskauer (VP) test +

• motile

• water and sewage

• opportunistic infections and UTIs

Serratia

• gram neg bacteria

• motile

• red pigmentation @ lower temperature

• DNAse +, gelatinase +

  • destroys DNA and gelatin

• opportunistic infections

  • septicemia

  • UTI

  • pneumonia

Proteus

• gram neg bacteria

• highly motile

  • peritrichous flagella

• urease +

• swarming phenomenon on nutrient rich environment b/c it’s so motile

• UTIs

Yersinia

• gram neg bacteria

• short thick rod, bipolar staining

• urease +

• Y. pestis is cause of buboni, pneumonic, and septicemic plague

• prevalent in various rodents (sylvatic plague)

• humans are accidental hosts

escherichia, shigella, salmonella, klebsiella, enterobacter, serratia, proteus, yersinia

enteric bacteria

ibrio

• gram neg bacteria

• curved rods

• facultative but oxidase positive

• polar or peritrichous flagella

• aquatic, halophile

• not normal flora

• V. parahaemolyticus causes gastroenteritis from raw fis

• bioluminescent

Vibrio cholerae

• species of vibrio

• causative agent of cholera

  • fecal contamination of water

• high incidence in Asia, South America, Africa

• gulf coast states

• shredding of intestinal lining

• rice water stools

• can loose 22 liters fluid/day

• must replace fluids and electrolytes

Haemophilus

• gram neg bacteria

• short rod, non-motile

• may form capsule

• grow on enriched BAP or chocolate agar

  • need blood proteins

• H. ducreyi causes chancroid (STD)

• H. influenza causes meningitis, conjuntivitis, ear infections and pneumonia

Haemophilus influenza

which species was thought to be cause of influenza until virus discovered?

Gardnerella

• gram neg bacteria

• **tiny rod

• once classified as haemophilus

• normal in female urogenital tract

• in combination with various anaerobic bacteria can cause vaginitis (pH is important)

• can be side effect of antibiotic treatment

Campylobacter, helicobacter

gram negative spirilla

treponema, borrelia, leptospira

gram neg spirochetes

rickettsia, chlamydia

gram neg intracellular bacteria

Bacterioides

• gram negative short rod

• obligate anaerobe**

• 10^10 cells per gram of human feces

• symbiotic relationship; breaks down polysaccharides

• opportunistic infections

• major part of intestinal flora (health)

F

T/F: spirilla only have one single polar flagella

campylobacter

• spirilla gram neg

• microaerophilic, optimum growth at 42 degree C

• 2nd leading cause of food borne illness in US

• severe diarrhea—often bloody

• normal flora in many animals, esp birds

  • kangaroo and wombat (bushwalkers diarrhea)

• chicken and raw milk are common sources

Helicobacter pylori

what species has knobs on ends of flagella to help it attach?

Helicobacter

• spirilla gram neg

• closely related to campylobacter

• microaerophile

• knobs on end of flagella

• H. pylori is cause of ulcers

• survives in acidic condition of stomach by producing urease

spirochete motility

• endoflagella

  • polar flagella fold back into periplasmic space

• protoplasmic cylinder

• outer sheath

• corkscrew

Treponema

• spirochete gram neg

• anaerobic

• flattened coil/wave

• very thin - difficult to see with LM

• dark field and phase contrast

• T. palladum is causative agent of syphilis

Borrelia

• spirochete gram neg

• microaerophilic

• large spirals-easy to see

• B. recurrentis is carried by lice and ticks and causes relapsing fever

  • lyme

• replace surface antigens

Borrelia burgdorferii

what species causes lyme disease from ticks?

leptospira

• spirochete gram neg

• aerobic

• thin, finely coiled, bent at end

• contact with contaminated urine

• common in animals

• 
  

Rickettsias

• gram neg

• obligate intracellular parasites

  • can only be cultured within cells

  • replicate in host cell cytoplasm and eventually burst cell

• carried by arthopod vectors

• highly infectious

• Howard Ricketts

Chlamydia

• gram negative intracellular

• extremely small

• parasitic

• too small for gram stain but look gram neg biochemically

• simple biochemical capacities

• no arthropod vectors

• airborne (elementary body = once out of body, can spread thru air)

elementary and reticulate body

• life cycle of chlamydia

• infectious vs reproductive stage

20-300 nm

size range of viruses

host range

spectrum of hosts a virus can infect

narrow

polio has a ____ host range