U2.1.3 ANTIBIOTIC RESISTANCE Flashcards
Methods of Detecting Antibiotic Resistance
Cephalosporinase Test (Cefinase Test)
Chromogenic Beta Lactamase Test
Chromogenic Beta Lactamase Test
(+) color = beta-lactamase producer
Pink/red
Chromogenic Beta Lactamase Test
Organisms detected by the test
Staph, Haemophilus, Moraxella, Neisseria
Methods of Detecting Antibiotic Resistance
(3) Detection of MRSA/Oxacillin Resistant S. aureus
- Oxacillin Screen Agar
- Cefoxitin Disk (30ug) Screen Test
- Chromogenic Agar for MRSA
Methods of Detecting Antibiotic Resistance
recommended for screening of MRSA
Cefoxitin Disk (30ug) Screen Test
Methods of Detecting Antibiotic Resistance
colorimetric method used for MRSA colonies
Chromogenic Agar for MRSA
Methods of Detecting Antibiotic Resistance
Detection of _____ gene & its products _____
- mecA
- PBP2a
Methods of Detecting Antibiotic Resistance
(2) Methods for Vancomycin Resistance in Staphylococcus
- Broth Dilution
- Agar Screen
Methods for Vancomycin Resistance in Staphylococcus
Broth Dilution is used to detect
VRSA; VISA
Methods for Vancomycin Resistance in Staphylococcus
VRSA fi the vancomycin MIC is ___ ug/mL
≥16ug/ml
Methods for Vancomycin Resistance in Staphylococcus
BHI with 6ug vancomycin
Agar Screen
Methods of Detecting Antibiotic Resistance
(+) for Inducible Clindamycin Resistance
D zone
Inducible Clindamycin Resistance
when triggered /activates resistance to clindamycin
erm genes
Methods of Detecting Antibiotic Resistance
(2) Method Vancomycin Resistance
- Enterococci resistance to vancomycin
- Vancomycin Screen Agar
Methods of Detecting Antibiotic Resistance : Enterococci resistance to vancomycin
encodes Van-A phenotype
vanA gene
Methods of Detecting Antibiotic Resistance : Enterococci resistance to vancomycin
most common phenotypes
Van-A and Van-B phenotypes
Methods of Detecting Antibiotic Resistance : Enterococci resistance to vancomycin
6ug vancomycin in BHI agar
Vancomycin Screen Agar
Methods of Detecting Antibiotic Resistance
uses MHA with sheep blood; with 1ug/ml oxacillin disk (incubate with CO2)
Penicillin Resistance (S. pneumonia)
Methods of Detecting Antibiotic Resistance
Penicillin Resistance
Susceptible if : ____ mm
R o I if : < ____ mm
Susceptible if : ≥ 20mm
R o I if : < 20mm
Methods of Detecting Antibiotic Resistance
uses BHI Agar; test inoculum with 120ug/ml gentamycin and 300ug/ml streptomycin disk
HLAR (High-Level Aminoglycoside Resistance)
Methods of Detecting Antibiotic Resistance
used for Enterococci
HLAR (High-Level Aminoglycoside Resistance)
HLAR (High-Level Aminoglycoside Resistance)
Agar used with gentamycin & streptomycin
Remel Agar
HLAR (High-Level Aminoglycoside Resistance)
HLAR in BHI Agar
S if : ____ mm
R if : ____ mm
S if : >10 mm
R if : <6 mm
Methods of Detecting Antibiotic Resistance
are enzymes hydrolyzing most penicillins and cephalosporins, including oxyimino-B-lactam compunds but notcephamycins and carbapenems
ESBL Extended Spectrum Beta Lactamase