Baby - Micro Flashcards
Chain of infection
6 components
Shaeffer-Fulton stain
Used for Spores
Acridine orange
Stains Nucleic Acids
Fungal elements with acridine orange
Fluoresce green
Trypticase Soy Broth (TSB)
Used for subcultures Contains soybean and casein Uses sodium chloride for osmotic stability contains glucose as fermentable CHO contains dipotassium phosphate as buffer
Thioglycollate broth
Casein, soy broth, glucose
supports growth of anaerobes, aerobes, microaerophilic and fastidious organisms
Thioglycollate broth boiled for 10 minutes
To drive off oxygen
Todd-Hewitt broth
Selection and enrichment for S. agalactiae in female genital specimens
MacConkey agar
Most frequently used primary selective and differential agar; Contains crystal violet dye to inhibit g(+) bacteria and fungi
Culture media sterilization
Autoclave sterilization, membrane filtration
Methods that directly measure antimicrobial activity
- in board exams 1,2,3
Broth dilution, agar dilution, disk diffusion
Incubation for disk diffusion method
Incubation is at 35°C in air but increased CO2 is used when testing certain fastidious bacteria; incubation time may be increased beyond 16 hours to enhance detection of certain resistance patterns
CLSI performance standard for antimicrobial disk susceptibility
Susceptible, intermediate and resistant, definitions same as those for dilution methods
Automated antimicrobial susceptibility test systems
- Vitek
- WalkAway system
- Pheonix system
Advance Expert System (AES) software (in VITEK)
A category interpretation is assigned, and organisms antimicrobial resistance patterns are reported
_______ is an antimicrobial agent and is not an antibiotic because it is not produced by a microorganism
Sulfanilamide
Methods for testing production of beta-lactamase
- Chromogenic cephalosphorin method
- Acidometric method
- Iodometric method
Positive for the beta-lactamase chromogenic cephalosporin method
Color change
Half a dose of antibiotic to disappear from the blood
Half-life
Acid-fast stained smear
1000x magnification (OIO is 100x while the ocular has 10x magnification) for 300 fields
AFB is red
Background is blue or blue-green
Grade A milk
Bacterial count 75,000 per mL when raw and will not exceed 15,000 bacteria per mL once pasteurized
Milk borne disease for human
B. anthracis
Milk borne disease for cow
S. typhi
SPS, 0.025%
Anticoagulant for microbiology
Heparin
Commonly used especially for viral cultures
Type of filter that can give 100% sterility
Millipore (0.22um)
Capsule can be used for
Serotyping by swelling
Staphylococcal protein A
Coagulation
DNase positive
S. aureus
DNase negative
S. epidermidis
Positive control for acetamide test
P. aeruginosa
Positive control for acetate test
E. coli
Incubation for acetamide, acetate test
35°C for up to 7 days
Positive malonate test
Blue
Negative malonate test
Green, yellow
Diagnosis is based on patient history
Primary Amoebic Meningoencephalitis (PAM) Naegleria fowleri
Added to MAC to inhibit g+ fungi
Crystal violet
MR and VP result for Enterobacteriaceae
Opposite
Most common pathogen in throat cultures
Group A Streptococcus
Destroyed by oxygen
Streptolysin O
Bacitracin, 0.04 units
Taxo A, S. pyogenes sensitive
G+ cocci, S to Bacitracin, R to SXT
S. pyogenes
Optochin
Sensitive, zone of inhibition 14 mm or greater
PPNG
Penicillinase-producing gonococci
Inhibitor in Salmonella Shigella Agar (SSA)
Bile salt, brilliant green
Approproate specimen for culturing N. gonorrhoeae
Eyes, rectum, oral cavity
Preferred medium for isolation of Brodetella pertussis
Charcoal-perplexin
Nasopharyngeal swab
*ans. board exams is AOTA
H. influenza, N. meningitides, B. pertussis, MRSA
Clear medium for mycobacteria
Middlebrook 7H11
Selective media suitable for isolation of C. dipthariae
Tinsdale’s, CTBA
Confirm laboratory diagnosis of diphtheria
Demonstrate toxin production
Final diagnosis of diphtheria is made from
Virulence test