Study sets, textbooks, questions
Upgrade to remove ads
Lab Ch. 10
Terms in this set (19)
Standard precautions established by the
C & S
Culture and sensitivity
-clinical microbiology lab tests performed on a specimen from a client in order to identify any pathogens present in the specimens and to determine antimicrobial medications to which any pathogens are susceptible
Explain why specimens must be collected aseptically
For all C & S testing, it is essential to collect the appropriate specimens from the client aseptically. In order to correctly identify and treat pathogens.
List in the describe three factors which influence clinical specimen quality.
What type of specimens should be collected?
Blood? (Ex: Cerebrospinal fluid? Sputum? Urine? Stool? Something else?)
Proper specimens collection (ex: blood and other body fluids, urine, wound specimens, throat swab, sputum, fecal, vaginal?)
Proper labeling and transport of specimen
- label before start and get specimens to lab
List potential problems if specimens are NOT handled correctly
Pathogens may die before it can be cultured or identified. This could lead to false negative culture result.
Overgrowth of normal microbiota may inhibit growth of pathogen. This could also lead to a false negative finding.
Presence of contaminants may interfere with identification of the pathogen. This could lead to a false negative or false positive culture result.
It is very important for healthcare providers to handle client specimens correctly and for clinical microbiologists to use
Appropriate controls when performing microbial tests to minimize the likelihood of false negative of false positive results
Methods for Microbial Identification:
1. Some tests used to identify pathogens may be performed directly on specimens collected from clients. Other tests require that the specimen be cultured first so the pathogen may be isolated from it before testing.
2. Microbial identification tests include fermentation and other biochemical tests which detect organisms' abilities to produce specific enzymes or other biochemically, immunological tests involving antibodies, and nucleus acid tests designed to detect pathogen's unique, known genetic sequences.
Used to identify unknown microorganism.
Two Types of Antibiotic Spectrums:
Broad: kills a wide range of organisms (including G + and G -)
Ex: z pack
Narrow: kills a certain kind of organisms
Ex: penicillin kills just G +
Other types of antimicrobial agents
Antiviral, anti fungal, antiprotozoan, antihelminthic
Antimicrobial Agents: Mechanisms of Action
Inhibition of Cell Wall Synthesis
Inhibition of Protein Synthesis
Disruption of Cell Membrane Function
Ex: antifungal medications
Inhibition of Nucleic Acid Synthesis
Interference with Enzyme Function (Competitive Inhibition)
Ex: sulfa drugs
Kirby Bauer Test for Antimicrobial Sensitivity
Must have isolated colony
Gram + Unknown
Observe under microscope already prepared by instructor
Ours was gram + cocci (chains)
Gram - Stain
We performed in class and viewed under oil immersion
Used our Gram - unknown culture to steak a ........ For isolation of colonies.
This agar allows:
You to test your organism for growth in the medium and lactose fermentation
Used our G - unknown culture to streak a ............ For isolation of colonies.
This agar allows:
You to test your organism for the ability to take in citrate and use it as sole carbon source.
Both Agars will be incubated at
37* C inverted
Antimicrobial Sensitivity Test (Kirby Bauer Disk Diffusion Method):
-test performed on a ......... Culture,
such as one containing......
- this test is highly ........... to account for the many variables which may impact test results
- variables include:
A pathogen isolated from a clinical specimen.
The medium use, diffusibility of Antimicrobial agents through the medium, the amounts of microbial agents, the number of microorganism so inoculated onto the medium, time of incubation, measurement of zones of inhibition, interpretation of results
Sterile cotton swab used to completely cover agar of the Mueller Hinton plate with unknown.
Rub onto surface in three different directions
Replace the cover on the inoculated petri plate. Let liquid air dry for 5 minutes.
Use automatic disk dispenser to dispense following antibiotic disks onto plate: azithromycin, Cefaclor, Cilrofloxacin, Doxycycline, Gentamycin, Imipenem, Kanamycin, Penicillin
Sets with similar terms
Microbiology Lab Final
ATE 2639 Exam 3 (Ch.41-43)
Other sets by this creator
Micro Bio Final
Micro Biology (Chem Review)
SPCH Ch. 2
Other Quizlet sets
KINE 1000 Test 2
Hematological and Lymphatic System Funct…
FOF - Security and Access