Bacteria Flashcards
Staph aureus
Type of infection, diseases (4)
Where on the body
Lab characteristics
Most common physical finding
Virulence factor
Treatment
Prevention
Location
–skin, soft tissue, nose
Diseases
–Most common: abscess containing pus
–SSS (caused by enterotoxin)
–Folliculitis
–Osteomyelitis
–Endocarditis
Lab
–Gram stain / yellow or gold colonies
–Clusters.
–Coag and catalase +
–Many produce beta lactamase
Virulence factor
–Protein A: binds heavy chain of IgG > reduces phagocytosis
Treatment
–Penicillin G / vancomycin
Prevention
–cefazolin to prevent surgical infections
Strep pyogenes (GAS)
Diseases 4 (how do you test for a very common one?)
Characteristics
Habitat
Pathogenesis
Treatment
Diseases
–pharyngitis (strep throat)/cellulitis (pus)
–rheumatic fever (non-pus)
–impetigo (can also be staph aureus)
–erysipelas & cellulitis
note: strep throat is diagnosed with a rapid antigen detection test (RADT) when two or more criteria are met: fever, tonsillar exudates, tender LAD cervical, no cough
Characteristics
–cocci chains
–catalase negative
–bacitracin sensiive
Habitat
–throat, skin, resp. droplets
Pathogenesis
–hyaluronidase (spreading factor)
–M protein inhibits phagocytosis
Treatment
–Penicillin G
–Strep throat: amoxicillin & Penicillin V
Strep agalactiae (GBS)
Diseases 2
Characteristics
Habitat
Pathogenesis
Treatment
Diseases
–Neonatal meningitis / sepsis
–postpartum endometritis
Characteristics
– gram + cocci in chains
–catalase negative
–bacitracin resistant
Habitat
–human vagina
Pathogenesis
–pyogenic
–no exotoxins
Treatment
–Penicillin G
–no vaccine : ampicillin should be given to mothers if membrane rupture occures
Strep pneumoniae (pneumococcus)
Diseases
–pneumonia
–meningitis
–kids: otitis media & sinusitis
Characteristics
–gram + lancet shaped
–pairs
Habitat
–upper respiratory tract
Pathogenesis
–inflammatory response
–no exotoxins
Treatment
–Penicillin G
–two vaccines
Enterococcus faecalis
Diseases
Characteristics
Habitat
Pathogenesis
Treatment
Diseases
— UTI
— biliary tract infection
Characteristics
— gram + chains
Habitat
— human colon, urethra, GI tract
Pathogenesis
N/a
Treatment
— penicillin / vancomycin + aminoglycoside such as gentamicin (penicillin weakens the wall, aminoglycoside then enters)
What are the three “atypical” pneumonia, that are common causes for community acquired pneumonia ?
Mycoplasma pneumoniae
Chlamydia pneumoniae
Hemophilia influenzae
Mycoplasma pneumoniae
Diseases
Characteristics
Habitat
Pathogenesis
Treatment
Diseases
— “atypical” pneumonia
Characteristics
— so small, not seen on gram stain, no cell wall
Habitat
— respiratory tract
Pathogenesis
— no exotoxins because no cell wall.
— produces hydrogen peroxide which damages the respiratory tract
Treatment
— azythromycin (Macrolides)
— doxy
Neisseria meningitidis (Meningococcus)
Diseases
Characteristics
Habitat
Pathogenesis
Treatment
S/S
Diseases
—meningitis
—Meningococcemia
Characteristics
—gram neg
—it is one of the _class three encapsulated pyogenic bacteria, along with s.pneumoniae and H.influenzae
Habitat
— upper respiratory tract
Pathogenesis
—reaches the meninges via bloodstream
—capsule
Treatment
—penicillin G
—vaccine available
S/S
—headaches
—fever
—neck stiffness
Neisseria gonorrhoeae (gonococcus)
Diseases
Characteristics
Habitat
Pathogenesis
Treatment
DX
Diseases
—gonorrhea
—neonatal conjunctivitis, can lead to blindness
—PID
Characteristics
—gram neg
Habitat
—human genital tract
—sexual transmission / neonates via birth
Pathogenesis
—invades mucous membranes and causes inflammation
—fimbriae, attachment, evade phagocytosis
—secondary gonococcal lesions from disseminated infection after primary UTI
Treatment
—ceftriaxone for uncomplicated
DX
—NAAT via urine, urethral swab or cervical swab
Chlamydia trachomatis
Diseases
Characteristics
Habitat
Pathogenesis
Treatment
Diseases
—urethritis
—chlamydia cervicalis
—inclusion conjunctivitis
—Lymphogranuloma venereum
—trachoma
Characteristics
—obligate parasite
Habitat
—genital tract
—eyes
—sexual contact/birth canal
Pathogenesis
N/a
Treatment
—tetracycline
—Macrolides
Treponema pallium
Diseases
Characteristics
Habitat
Pathogenesis
Treatment
Diseases
—syphilis
Characteristics
—spirochete, v.thin
Habitat
—genital tract
—sexual transmission
Pathogenesis
—multiples at site of inoculation and spreads via blood stream
—causes vasculitis
—primary lesion followed by secondary and tertiary
Treatment
—benzathine penicillin G
Borrelia burgdorferi
Diseases, S/S
Characteristics
Habitat
Pathogenesis
Treatment
Diseases, S/S
—Lyme disease
—fever, rash, arthritis, facial palsy
Characteristics
—spirochete
Habitat
—white footed mouse»_space; ticks
—tick must be attached for 24 hours to deliver an infectious dose
Pathogenesis
—attaches to skin, spreads to bloodstream, reaches heart, joints and CNS
Treatment
—early: doxycycline
—late: penicillin G
—avoid tick bite
Rickettsia rickettsii
Diseases, S/S
Characteristics
Habitat
Pathogenesis
Treatment
Diseases, S/S
—Rocky Mountain spotted fever (tick-borne)
—fever, headache, rash, N/V, abdominal pain
Characteristics
—obligate intracellular parasite
Habitat
—dog ticks are vector and reservoir
Pathogenesis
—invades capillaries and causes vasculitis
Treatment
—doxycycline
—avoid ticks
Clostridium botulinum
Diseases, S/S
Characteristics
Habitat
Pathogenesis
Treatment
Diseases, S/S
—botulism
—weakness: eyes, face, mouth and throat, difficulty swallowing, double vision, drooping eyelids, blurry vision etc
Characteristics
—anaerobe, gram +
Habitat
—soil
—improperly preserved foods
Pathogenesis
—toxin cleaves proteins in the mayo neural junction causing flaccid paralysis
Treatment
—antitoxin to types A, B, E in horses
—proper food preservation techniques
Clostridium tetani
Diseases, S/S
Characteristics
Habitat
Pathogenesis
Treatment
Diseases, S/S
—tetanus
—muscle spasms, lock jaw, painful stiffness, trouble swallowing, headache, fever HTN, tachycardia
Characteristics
—gram +
—anaerobe, looks like a tennis racket
Habitat
—soil
—enters through breaks in the skin
Pathogenesis
—exotoxin blocks inhibitory NTs (GABA) so excitatory neurons are unopposed
Treatment
—hyper immune human globulin neutralises toxin
—penicillin G
—Valium
—toxoid vaccine is given to children in combination with diphtheria and acellular pertussis (DTaP)
Corynebacterium diphtheriae
Diseases, S/S
Characteristics
Habitat
Pathogenesis
Treatment
Diseases, S/S
—diphtheria
—tonsillitis
—adherent, dense, grey pseudo-membrane covering the mucous membrane
—skin lesions
Characteristics
—club shaped gram +
Habitat
—human throat (pharynx), respiratory droplets
—also larynx, nose, tonsils
Pathogenesis
—exotoxin
—pseudomembrane of dead cells may cause severe obstruction to breathing and suffocation
Treatment
—antitoxin made in horses neutralises toxin
—penicillin G kills the organism
—toxoid vaccine in combo (DTaP)
Mycobacterium tuberculosis
Diseases, S/S
Characteristics
Habitat
Pathogenesis
Treatment
Diseases, S/S
—tuberculosis
—fever, weight loss, cough, expectoration blood mucous
Characteristics
—aerobic, acid fast rods (the entire cell holds the Ziehl-Neelsen stain)
Habitat
—only found in humans
—lungs
—respiratory droplets, coughing
Pathogenesis
—replicates within macrophages
Treatment
—long term with 3 drugs: isoniazid, rifampin, pyrazinamide, 6-9 months
—prevention Bacillus Calmette Guerin (BCG) vaccine)
What are the slow growing atypical mycobacteria?
What is the rapid growing atypical mycobacteria?
Mycobacterium fortuitum-chelonae
Escherichia coli
Diseases, S/S
Characteristics
Habitat
Pathogenesis
Treatment
Diseases, S/S
—UTI, cystitis (dysuria, urgency) nitrites/leukocyte esterasae on UA
—sepsis
—neonatal meningitis
—traveler’s diarrhoea
—HUS
Characteristics
—gram neg. Rods
Habitat
—human colon
—vagina/urethra
—in dwelling urinary catheters and IV lines increase the risk
Pathogenesis
—endotoxin causes septic shock
Treatment
—Nitrofurantoin
—TMP/SMX
—prophylactic doxy / peptide-bismol may prevent traveler’s diarrhoea
—no vaccine
—fosfomycin: bacterialcidal, cell wall, gram +/- (broad spectrum)
Salmonella typhi
Diseases, S/S
Characteristics
Habitat
Pathogenesis
Treatment
Diseases, S/S
—typhoid fever
—abdominal pain, fever, constipation/diarrhoea
—rash of flat, rose spots
Characteristics
—gram neg.
Habitat
—human colon
—fecal oral
Pathogenesis
—infects liver/spleen
—endotoxin causes fever
Treatment
—ceftriaxone
—ampicillin and TMP/SMX
—public health measures
—vaccines
Non-typhoidal salmonella
Diseases, S/S
Characteristics
Habitat
Pathogenesis
Treatment
Diseases, S/S
—enterocolitis
Characteristics
—gram neg. Rod
Habitat
—enteric tract of humans and animals
—poultry, eggs, domestic livestock and turtles
Pathogenesis
—invades mucosa of small and large intestine
—can enter blood and cause sepsis
Treatment
—nothing for uncomplicated
—ceftriaxone for sepsis
Shigella (shigella dysenteriae, shigella sonnei)
Diseases, S/S
Characteristics
Habitat
Pathogenesis
Treatment
Diseases, S/S
—enterocolitis (dysentery)
Characteristics
—gram neg rods
Habitat
—human colon (not animals like non-typhoidal salmonella)
Pathogenesis
—invades mucosa of the ileum/colon but sepsis is rare
Treatment
—fluid and electrolyte replacement
—severe: cipro
Vibrio cholerae
Diseases, S/S
Characteristics
Habitat
Pathogenesis
Treatment
Diseases, S/S
—cholera
Characteristics
—gram neg
Habitat
—human colon
—shellfish
—fecal/oral
Pathogenesis
—massive, watery diarrhea caused by enterotoxin
Treatment
—fluid/electrolyte replacement
