Flashcards in SKETCHY MICRO Deck (42)
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1
Name?
Identification?
Transmission?
Associated conditions?
Key facts?
Staphylococcus aureus
gram positive cocci (purple moses)
Aureus- golden colonies on blood agar plate
Identification:
- coagulase test(parting of red sea)
- catalase test (cat) : positive [gram positve and catalase positive = staph]
- phage typing
- mannitol fermentation (man tall wearing yellow)
- beta hemolysis (red light bulb with B)
Transmission:
- direct contact; food and waterborne for staphylococcal food poisoning
Associated conditions:
- staphylococcal skin infections: sties, pimples, carbuncles, impetigo of the newborn
- staphylococcal toxemias: scalded skin syndrome and toxic shock syndrome (man with red head)
- staphylococcal food posioning (camel with green lady and meats/dairy)
- Many strains of S. aureus produce penicillinase
- Methicillin resistant Staphylococcus aureus (MRSA) [gesture of mercy]
2
Name?
Vector?
Reservoir?
Symptoms?
Diagnosis?
Treatment?
Borellia burgdorferi
(spirochete- dont gram stain due to thin walls)
motility: axial filaments
- causative agent of Lyme disease
vector: a tick (Ixodes scapularis) --> Robin of Ixodes
reservoir= animals that harbor the tick= field mice and dusky-footed wood rat; third blood meal from deer
symptoms:
a. initial stage:
- expanding bull's eye rash (bull's eye target) along with flu like symptoms developing within 2-10 days as the rash dissapears
b. untreated:
- initial symptoms dissapear
- weeks/months later:
- headache
- meningitis
- myocardial damage (heart shield)
c. left untreated:
- 6 months or years later:
- chronic arthritis
- complications may involve the cardiovascular and nervous systems (arrow through straw mans head)
diagnosis:
- serological tests (ELISA) not reliable
- Clinical symptoms (rash) most common basis for diagnosis
- Wright stain, giemsa stain (Sir Wright, Sir Giemsa)
treatment:
- antibiotics:
- doxycycline (unicycle)
- amoxycillin
- erythromycin
- more difficult to treat past inital stage; long term intravenous therapy may be required
3
Name?
Transmission?
Symptoms?
Diagnosis?
Treatment?
Treponema pallidum
(spirochete--> spiral galaxy in corner, spiral staircase)
--> causative agent of syphilis
--> cannot be cultured in vitro
Transmission: direct sexual contact
Symptoms:
-
Primary syphilis:
- painless chancre at site of infection (sundial poking astrologer)
- enlargement of regional lymph nodes
-
Secondary syphilis: solar system
- rash on skin and mucous membranes
- flu like symptoms
- loosening of teeth
- alopecia
- enlargement of epitrochlear lymph nodes
- rash on palms/soles (astronaut in white suit with red hands and feet)
- condylomo lata: bumpy planet...lotta bumps
-
Latent syphilis:
- result if secondary syphilis is not treated
- can last for years without manifestation of the disease
- person thought to remain infectious for 1st 4 years of latency
-
Tertiary syphilis:
- develops in some patients after years without treatment
- gummas: soft growths with firm necrotic center: (large crater moon)
- syphilitic arthritis
- weaking of blood vessels (syphilis targest root of aorta tree)
- heart damage (aorta tree)
- blindness (flash light in eyes)
Diagnosis:
- Clinical history
- Physical exam
- Dark field study (dark field galaxy) (dark microscopes)
- Serological tests (VDRL)
- Treponemal tests for confirmation
Treatment:
- Penicillin
4
Name?
Shape?
Reproduction
Bdellovibrio bacteriovorus
- Chemoheterotroph
- Vibroid
- Reproduces as a predator in the periplasmic space of gram negative bacteria
5
Name?
Key Facts?
Transmission?
Campylobacter spp.
Chemoheterotroph
- second most common cause of diarrhea (gasteroenteritis) in the US
- self limiting disease, lasting less than a week
- helical bacterium is part of intestinal flora of many animals especially sheep, cattle, dogs, cats, and chickens)
- transmission:
- contaminated food and water
- contact with animals
Campylobacter jejuni
6
Helicobacter pylori
Helicobacter pylori
* Chemoheterotrophs
* Major factor in causing peptic ulcer disease which can lead to gastric cancer
7
Pseudomonas aeruginosa
Pseudomonas aeruginosa
Pseudomonads:
- gram negative rods (reddish hues) (red tub=rod)
- motile: polar flagella
- found primarily in soil and water (water in tub)
- resistant to many disinfectants/antibiotics
Pseudomonas aeruginosa
- principal pathogen in hospital acquired infections
- has endotoxing and several exotoxins
- infections include:
- otitis externa
- urinary tract
- surgical wound infections
- dermatitis
- septicemia
- pneumonia
* predisposing conditions usually involved
Transmission: direct contact
Treatment: infection is difficult to treat with antibiotics
8
Legionella pneumophila
Legionella pneumophila
- gram negative bacillus is causative agent of legionellosis ( Legionnaire's disease)
- noncommunicable; airborne infection
- symptoms:
- high fever
- cough
- general pneumonia symptoms
9
Bordetella pertussis
Bordetella pertussis
* gram negative coccobacillus
- causative agent of pertussis (whooping cough): tracheobronchitis
- primarily a childhood disease
- transmission: airborne
- virulent strains - encapsulated
- endotoxin and exotoxin are released when cell autolyses upon death
-
symptoms:
- initial stages resembles a cold, which progresses to a deep cough as accumulation of mucus in trachea and bronchi occurs
- convalescence (3rd stage of pertussis) can last for months
-
vaccine:
- acellular vaccine is given to infants at 2, 4, 6, and 15 months of age as a part of DTaP vaccine
10
Neisseria gonorrhoeae
Neisseria gonorrhoeae
* gram negative diplococcus
- causative agent of gonorrhea
- transmission: direct contact
- primary site of infection:
- usually the mucous membranes of the male's urethra and female's cervix
- organism attaches to mucosa of genitals, oral-pharyngeal area, eyes and rectum via fimbriae (pili)
- primary site of infection:
- symptoms:
- males: painful urination and a penile discharge of pus
- females: often asymptomatic until organism spreads to the uterus and uterine tubes
- untreated:
- males: may cause blockage of the urethra and sterility
- females: may cause a pelvic blockage of uterine tubes, sterility, and pelvic inflammatory disease
- both sexes: may become systemic infection
- diagnosis: males
- symptoms
- gram stain of discharge
- culture of specimen
- DNA probes also used
- diagnosis: females
- culture of specimen no longer necessary
- DNA probes preferred
* Newborns: prevention of gonococcal opthalmia neonatorum
- Treatment:
- Penicillin
- Tetracycline
- Some strains are drug resistant
11
Neisseria meningitidis
Neisseria meningitidis
- causative agent of 25% of cases of bacterial meningitidis
- "people in a herd" situation
- found in the throat of healthy carriers
- when invasive, fimbriae and capsules are important virulence factors
- transmission: airborne
- diagnosis:
- gram negative diplococci in cerebrospinal fluid (CSF)
- distinguished from the gonococcus by its ability to ferment maltose
- treatment:
- Penicillin G
- treating healthy carriers with rifampin and vaccinating susceptible individuals can stop epidemics
12
Escherichia coli
Escherichia coli
- found in the intestinal tract of humans and other animals as part of micriobiota
- opportunistic: organism that normally lives in harmless association with the body but causes disease when given an opportunity to do so (organism being some place it shouldnt be)
- strains of E. coli can cause:
- urinary tract infection
- kidney infection
- pulmonary infection
- diarrhea
- meningitis (often associated with hospital acquired infections)
- E. coli O157:H7
- an enterhemorrhagic strain that causes bloody diarrhea and HUS syndrome in children
13
Shigella dysenteriae
Shigella dysenteriae
- shigellosis: caused by 4 species of Shigella
- S. dysenteriae causese the most severe form and is the least prevalent in the US
- symptoms:
- blood and mucus in watery stools
- abdominal cramps
- fever
- ulceration of the intestinal mucosa
- transmission:
- food and waterbourne
- diagnosis:
- recovery of organism from rectal swabs or stools
14
Salmonella gastroenteritis
Salmonella gastroenteritis
- caused by many Salmonella species
- symptoms:
- diarrhea
- nausea
- abdominal pain
- fever
- vomitting
- transmission: food and waterbourne
- diagnosis: based on recovery of Salmonella from feces and food
- recovery can result in a carrier state
15
Salmonella typhi
Salmonella typhi
- most virulent Salmonella species
- causative agent of typhoid fever
-
symptoms:
- high fever
- continual headache and malaise
- severe cases: perforation of intestinal wall
- organism may be isolated from blood, urine, and feces
-
treatment:
- ampicillin
- ciprofloxacin
- vaccines: available for high risk persons (17%-66% effective)
16
Klebsiella pneumoniae
Klebsiella pneumoniae
- causative agent of Klebsiella pneumonia
- most common in the chronically debilitated
- virulence related to presence of a capsule
- Klebsiella pneumonia results in lung abcesses and permanent lung damage
- mortality is 85% if untreated
- oppportunistic: occasionally causes meningitis and diarrhea
- commonly found in throat/mouth of healthy persons
17
Enterobacter aerogenes
Enterobacter aerogenes
- opportunistic
- symptoms:
- urinary tract infection
- blood/wound infections
18
Yersinia pestis
Yersinia pestis
- causative agent of bubonic plague
- vector: usually the rat flea (Xenopsylla cheopis)
-
symptoms:
- high fever
- buboes
- bruises on skin when septicemic plague develops
- may advance to pneumonic plague
-
diagnosis:
- isolation and identification of organism from bubo or from the blood; serologic tests can also be done
-
treatment:
- antibiotics must be administered promptly after exposure to disease
- streptomycin is the drug of choice
- vaccine: for high risk individuals
19
Hemophilus influenzae
Hemophilus influenzae
- etiological agent of bacterial meningitis
- also causes:
- epiglottitis
- otitis media
- sinusitis
- respiratory infections
- vaccine: Hib
- transmission: airborne
- diagnoisis: identification of organism in CSF
- treatment: rifampin commonly prescribed
20
Vibrio cholerae
Vibrio cholerae
- causative agent of cholera
- serogroup O:1 causes classically recognized epidemic form of the disease
-
transmission: ingestion of organism in contaminated food and water
- organism attaches to mucosa of intestinal wall and secretes enterotoxin which alters membrane permeability of mucosa, causing massive loss of fluids and electrolytes through diarrhea
- diagnosis: isolation of V. cholerae from feces
-
treatment:
- tetracycline
- replacement of fluids and electrolytes
21
Rickettsia prowazekii
Rickettsia prowazekii
- causative agent of Epidemic Typhus
- chemoheterotroph
- obligate intracellular parasites of eukaryotic cells
- require cells to grow in; invade lining of blood vessels
- feces from vector (Pediculus humanus corporis) contaminates wound and causes infection; organism multiplies in lining of small blood vessels
- prevalent in crowded and unsanitary living conditions
- symptoms:
- excruciating headache
- muscle aches
- chills
- fever
- stupor; rash develops several days later
- treatment:
- tetracycline
- doxycycline
22
Rickettsia typhi
Rickettsia typhi
chemoheterotrophs; obligate intracellular parasites of eukaryotic cells
- causative agent of Endemic Murine Typhus
- less severe typhus
- transmission:
- rodents to humans via rat fleas
- treatment:
- tetracycline
- doxycycline
23
Rickettsia rickettsii
Rickettsia rickettsii
chemoheterotroph; obligate intracellular parasites of eukaryotic cells
- causative agent of Rocky Mountain Spotted Fever
- vector: Dermacentor species or Amblyomma (ticks)
- organism multiplies in lining of blood vessels
- symptoms:
- fever
- headache
- vomitting
- rash within a week
- treatment:
- tetracycline
- doxycycline
24
Coxiella burnettii
Coxiella burnettii
Rickettsias; chemoheterotroph; obligate intracellular parasites of eukaryotic cells
- causative agent of Q fever
- transmission:
- unpasteurized milk
- inhalation of aerosols in dairy barns
- treatment:
- tetracycline
25
Chlamydia trachomatis
Chlamydia trachomatis
- chemoheterotroph; obligate intracellular parasite of eukaryotic cells
- causative agent of :
- trachoma
- lymphogranuloma venereum
- nongonococcal urethritis
- pelvic inflammatory disease
- inlcusion conjunctivitis
- pneumonia in newborns and infected mothers
- transmission:
- direct contact
- treatment:
- doxycycline
- erythromycin
26
The Mycoplasmas
The Mycoplasmas
- chemoheterotrophs
- lack cell walls
- filtrable
- examples:
-
Mycoplasma pneumoniae:
- causes primary atypical pneumonia
-
Mycoplasma hominis:
- causes nongonococcal urethritis and pelvic inflammatory disease
-
Ureaplasma urealyticum:
- causes nongonococcal urethritis
-
Mycoplasma pneumoniae:
27
Streptococcus mutans
Streptococcus mutans
- gram positive cocci
- principal cause of dental caries
28
Streptococcus pyogenes
Streptococcus pyogenes
- chemoheterotrophs
- gram positive cocci
- also known as group A beta-hemolytic streptococcus
- causes:
- puerperal fever
- impetigo
- erysipelas
- strep throat
- scarlet fever
- necrotizing fasciitis
- delayed effects:
- glomerulonephritis
- rheumatic fever
- beta hemolysis on blood agar
- identification:
- M protein and immunity
- transmission:
- primarily airborne
- direct contact for some skin infections
- treatment:
- penicillin
- erythromycin
29
Bacillus anthracis
Bacillus anthracis
- chemoheterotrophs
- aerobic
- gram positive
- soil bacteria
- causative agent of soil bacteria
- only encapsulated organism is virulent; it produces three different protein exotoxins
- cutaneous anthrax: most common form
- bacteria enter through abrasions in the skin
- blister forms at the site of entry and gradually develops into a blackened ulcer
- a fatal septicemia develops in 10-20 percent of untreated cases
- pulmonary anthrax: less common, but more dangerous
- bacterial spores are inhaled
- mild respiratory symptoms initially occur (can result in hemorrhagic thoracic lymphadenitis an hemorragic mediastinitis)
- followed by septicemia; death is usually imminent
- violent enteritis: extremely rare form of anthrax
- bacterial spores are ingested
- mortality rate is high
- diagnosis: blood cultures and biochemical assays
- treatment:
- penicillin
- doxycycline
- ciprofloxacin
- vaccine: for high risk workers handling infected animals
30
Bacillus cereus
Bacillus cereus
- causes gastroenteritis ( food poisoning)
31
Clostridium difficile
Clostridium difficile
- anaerobic
- usually with swollen spores
- causes antibiotic-associated-colitis (can follow use of broad spectrium antibiotics)
32
Clostridium perfringens
Clostridium perfringens
- organism grows on nutrients released from gangrenous tissue and causes gas gangrene; also causes a self-limiting gastroenteritis
- encapsulated; can tolerate small amounts of oxygen; normally found in intestinal tracts of humans and animals
- transmission: direct contact
- treatment:
- debridement
- hyperbaric chambers
- amputation
33
Clostridium botulinum
Clostridium botulinum
- causative agent of botulism
- heat labile exotoxing (neurotoxin) inhibits transmission of nerve impulses
- blurred vision occurs in 1-2 days; followed by flaccid paralysis for 1-10 days, which results in cardiac and respiratory failure
- transmission:
- ingestion of toxins
- infant botulism:
- ingestion of bacterium
- diagnosis:
- mice protected with antitoxin are inoculated with toxin from patient or foods
- treatment:
- botulinum antitoxin
34
Clostridium tetani
Clostridium tetani
- anaerobic; usually with swollen spores
- causative agent of tetanus
- involves a localized infection of a wound
- neurotoxin (tetanospasmin) blocks transmission of inhibitory impulses causing:
- spasms
- contraction of muscles controlling jaw
- death from spasms of respiratory muscles (respiratory or cardiac failure)
- vaccine: DPT (contains tetanus toxoid)
- treatment: debridement and antibiotics
35
Lactobacillus
Lactobacillus
- gram positive rods
- chemoheterotrophs
- lactic acid bacterium; found on mucous membranes of humans
- facultative anaerobe
- used in food preparation
36
Listeria monocytogenes
Listeria monocytogenes
- gram positive rods
- chemoheterotroph
- causative agent of meningitis in newborns, pregnant women, cancer patients, and the immunosuppresed
- may cross placent and cause spontaneous abortion or stillbirth
- acquired by ingestion of contaminated food
37
Corynebacterium diphtheriae
Corynebacterium diphtheriae
- gram positive rods
- chemoheterotrophs
- causative agent of diptheria
- exotoxin produced in lysogenized bacteria inhibits protein synthesis; heart, kidney or nerve damage may result
- stains metachromatically
- forms black colonies on differential media containing potassium tellurite
- transmission: airborne
- vaccine: DTap (contains diptheria toxoid)
38
Mycobacterium tuberculosis
Mycobacterium tuberculosis
- chemoheterotrophs
- irregularly shaped rods
- aerobic
- high lipid content in cell walls
- causative agent of tuberculosis
- lipids in cell wall cause acid-fast characterisitic and resistance to drying, disinfectants, strong acids and alkalis; resists certain antibiotics
- generation time: 12 hours
- produce excess niacin (B vitamin)
- lesions formed in lungs are called tubercles; necrosis results in caseous lesion that might calcify and form a Ghon complex in an Xray
- a positive tuberculin skin test can indicate either an active case or prior infection or vaccination and immunity
- transmission: airborne
- diagnosis: antimycrobacterial drugs
39
Mycobacterium leprae
Mycobacterium leprae
- chemoheterotroph
- irregularyl shaped rods
- aerobic
- high lipid content in cell walls
- causative agent of Hansen's disease
- obligate intracellular parasite
- generation time: 12 days or more
- tuberculoid form of disease is characterized by:
- loss of sensation in the skin surrounded by nodules
- lepromin test is positive
- lepromatous form of disease is characterized by:
- disseminated nodules and tissue necrosis
- Lepromin test is negative
- transmission: prolonged contact with exudates
- diagnosis: observation of acid-fast bacilli in lessions or fluid
- Hansen's disease patients are made noncommunicable within 4 or 5 days with sulfone drugs
40
Anoxygenic Photosynthetic Bacteria
Anoxygenic Photosynthetic Bacteria
- Photoautotrophs
- anaerobic photobacteria; electron donor is not water
- photosynthetic pigments differ from cyanobacteria, algae and green plants
- grouped as either purple bacteria or green bacteria
- dependent on the type of chlorophyll and other pigments they have
- Examples:
- Purple bacteria: Rhodospirillum
- Green bacteria: Chlorobium
41
Oxygenic Photosynthetic Bacteria
Oxygenic Photosynthetic Bacteria
- photoautotrophs
- aerobic photobacteria
- oxygen evolved as by-product (water is electron donor)
- chlorophyll pigments
- same as those of plants and algae
- Examples:
- Oscillatoria
42
Streptococcus pneumoniae
Streptococcus pneumoniae
- Chemoheterotrophs
- encapsulated organism causes:
- bacterial (pneumococcal) pneumonia
- otitis media
- meningitis
- identification:
- alpha hemolysis
- inhibition by optochin
- lysis by bile
- quellung reaction
- treatment:
- penicillin (penicillin resistance is increasing)
- vaccine:
- Pneumovax
