Antimicrobial Susceptibility Test of an Isolate from a Clinical Specimen

Content

⇒	Diagnostic Microbiology In Action
	⇒	Microbiology of the Respiratory Tract
		⇒	Staphylococci
			⇒	Isolation and Identification of Staphylococci
			⇒	Staphylococci in the Normal Flora
		⇒	Streptococci, Pneumococci, and Enterococci
			⇒	Isolation and Identification of Streptococci
			⇒	The CAMP Test for Group B Streptococci
			⇒	Identification of Pneumococci
			⇒	Identification of Enterococci
			⇒	Streptococci in the Normal Flora
		⇒	Haemophilus, Corynebacteri and Bordetella
			⇒	Haemophilus
			⇒	Corynebacteria
			⇒	Bordetella
		⇒	Clinical Specimens from the Respiratory Tract
			⇒	Laboratory Diagnosis of a Sore Throat
			⇒	Laboratory Diagnosis of Bacterial Pneumonia
			⇒	Antimicrobial Susceptibility Test of an Isolate from a Clinical Specimen

Purpose	To determine the antimicrobial susceptibility pattern of an organism isolated from a clinical specimen (in Experiment 23.2)
Materials	Nutrient agar plates (Mueller-Hinton if available) Antimicrobial disks Sterile swabs Forceps Blood agar plate with pure culture of isolate Tube of nutrient broth (5.0 ml) McFarland No. 0.5 turbidity standard

Procedures

Using a sterile swab, take some of the growth of a pure culture you isolated from the clinical specimen in Experiment 23.2, and emulsify it in 5.0 ml of nutrient broth until the turbidity is equivalent to the McFarland 0.5 standard. Discard the swab.
Take another sterile swab, dip it in the broth suspension, drain off excess fluid against the inner wall of the tube.
Inoculate an agar plate as described in Experiment 15.1.
Follow procedures 4 through 7 of Experiment 15.1.
Incubate the agar plate at 35°C for 24 hours.
Examine plates and record results for each antimicrobial disk as S (susceptible), I (intermediate), or R (resistant).
Prepare a report for the “physician.”

Results
Record results:

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