QUALITY CONTROL IN MICROBIOLOGY Flashcards
Internal activities ensuring diagnostic accuracy, defined as measures designed to ensure the medical reliability of laboratory data
Quality control
External activities ensuring positive outcomes
Quality assurance
Eliminates redundant motion, reduces waste, and focuses on client value
LEAN concept
Six Sigma goal
“Reduces defects by minimizing process variation”
Six Sigma methodology
“DMAIC: A process introduced by Motorola in 1986 to reduce defects by minimizing variation in processes through metrics measurement”
Accuracy, reliability, and timeliness of reported test results
Laboratory quality
TJC laboratory goals
“Improving patient identification
ISO - Medical laboratory requirements for quality and competence
“ISO 15189:2007”
ISO -General requirements for the competence of testing and calibration laboratories
“ISO/IEC 17025:2005”
ISO- General requirements for the competence of providers of proficiency testing schemes
“ISO/IEC 17043:2010”
Pre-analytical stage steps in laboratory testing
Test order/requisition, Collection of samples, Transport
Analytical stage steps in laboratory testing
Gram stain/Direct Microscopy, Culture, Screening test, Biochemical test, Confirmatory tests, QC, QA
Post-analytical stage steps in laboratory testing
Review of result, Encoding in LIS, Critical values, Notifying physician, Disposal of agar plates
Critical value indicating systemic infection
Positive blood cultures
Critical value indicating CNS infection
Positive CSF Gram stain or culture
Critical value indicating fungal infection in CSF
Positive Cryptococcal antigen test
Critical value for identifying mycobacterial infection
Positive acid-fast stain
Critical value in genital site of pregnant women
S. agalactiae or herpes simplex virus
Critical value indicating parasitic infection in blood
Blood smear positive for malaria
Critical value in surgical wound infections
Streptococcus pyogenes in a surgical wound
Critical value suggestive of gas gangrene
Gram stain showing large boxcar-shaped gram-positive rods
Critical value for respiratory or zoonotic infections
Significant pathogens (B. pertussis, Brucella, Legionella)
QC monitoring for Gas Pak jar, Autoclave temperature
Each use
QC monitoring (Catalase, Oxidase, Refrigerator, Freezer, Incubator, Anaerobic chamber)
Daily
QC monitoring for (Gram stain, Antibiotic disks, Autoclave spore testing, Reagents)
Weekly
QC for monitoring (Rheostat control, Face velocity of BSC)
Monthly
QC for monitoring (Cleaning and adjustment of Microscope)
Quarterly
QC for monitoring (Centrifuge speed, RPM)
Semi-Annually
QC for monitoring (Airflow of biosafety cabinet, Biohazard hoods, Accuracy of balances)
Annually
Gram stain control usage
Every batch or weekly
Internal quality control components
Check reagents, MT staff performance, test validity
External quality control includes
Check test methods, managed by RITM, DOH
Positive control plate
Media with expected organism
Negative control plate
Media without organism
Classification of errors in AST reporting: adequate interpretation of the susceptibility test result
No errors in interpretation
Classification of errors in AST reporting: Microorganism shows intermediate sensitivity to a given antimicrobial but is reported as susceptible or resistant; microorganism is susceptible or resistant but reported as showing intermediate resistance
Minor error (Mi)
Classification of errors in AST reporting: classification as resistant of a susceptible strain (false resistance)
Major error (Ma)
Classification of errors in AST reporting: classification as susceptible of a resistant strain (false susceptibility)
Very major error (Vma)
ATCC strains used for Quality control of routine AST: antimicrobials against Gram-positive, Oxacillin Screen agar
S. aureus
ATCC strains used for Quality control of routine AST: vancomycin BHI screen, assessment of thymidine levels in media
Enterococcus faecalis
ATCC strains used for Quality control of routine AST: antimicrobials against gram negative
E. coli
ATCC strains used for Quality control of routine AST against streptococci
S. pneumoniae
ATCC strains used for Quality control of routine AST antimicrobials against anaerobes
Bacteroides fragilis, Bacteroides thetaiotaomicron, Eubacterium lentum
Stock culture maintenance: 10% DMSO, fetal bovine serum (as cryoprotectant) -70 deg C, Indefinite storage
Viruses
Stock culture maintenance: Potato dextrose agar (PDA) slants 4 deg C 6-12 months
Molds
Stock culture maintenance: Lowenstein-Jensen slants 4 deg C 1 year
Acid Fast bacilli
Stock culture maintenance: Middlebrook 7H9 broth, -70 deg C for 1 year
Acid fast bacilli
Stock culture maintenance: Trypticase soy agar (TSA) deeps, Schaedler broth with glycerol, Chopped meat for anaerobes, and Cystine Trypticase agar (CTA); -70 deg C for 1 year
Non-fastidious aerobic bacteria and yeasts
Stock culture maintenance: Lyophilization (freeze-drying), 4 deg C, for several years
Aerobes and anaerobes
Stock culture maintenance: Freezing at -70 deg C for several years
Aerobes and anaerobes
Stock culture maintenance: Thawed, Re-isolated, Refrozen every 5 years
Frozen Non-fastidious bacteria
Stock culture maintenance: Thawed, Re-isolated, Refrozen every 3 years
Frozen fastidious bacteria
Stock culture maintenance: 1 vial per week is thawed and subcultured twice
In-use/Working culture
Specimen time retention for urine
24 hours
Specimen time retention for Microbiology stained slides; Body fluid and Smears
7 days
Specimen time retention for Test Requisitions, Patient records, Culture media performance and sterility records, QC records, Retired Laboratory procedures
2 years
Specimen time retention for Maintenance of records with billing concerns
10 years
Specimen time retention for QC record of instrument
As long as instrument is being used
Oversight of public health and safety including the laboratory
CDC (Centers for Disease Control and Prevention)
Regulation and Approval of in-vitro reagent kits
FDA (Food and Drug Administration)
Calibration of thermometer, weights and measures; International system of Units
NIST (National Institute of Standards and Technology)
Culture media quality control; Format of SOP manuals; Standardization of laboratory practice
Clinical and Laboratory Standards Institute (CLSI)
Control organisms used for AST (20 days testing)
American Type Culture Collection (ATCC)
Licensing of Laboratories
Department of Health (DOH)
Test kit or method validation, Proficiency testing, Bioterrorism investigation and confirmation along with CDC
Research Institute for Tropical Medicine (RITM)
Provides Research, education, and training in the field of occupational safety and health. Certification of respirator masks (e.g. N95)
National Institute of Occupational Safety and Health (NIOSH)
RITM NEQAS for Bacteriology, Parasitology, Mycobacteriology Microscopy and Culture, SARS-CoV-2 Molecular frequency
Once a Year
RITM NEQAS for Transfusion Transmissible infections (HIV, HBV, HCV, Syphilis, Malaria)
Twice a Year
NRL for dengue, Influenza, TB, and other Mycobacteria, Malaria and other parasites, Bacterial enteric disease, Measles and other viral exanthems, Mycology, Enteroviruses, Antimicrobial resistance and engineering diseases
RITM
NRL for HIV/AIDS, Hepatitis, Syphillis and other STI’s
San Lazaro Hospital (SACCL)
NRL for environmental and occupational health; toxicology and micronutrient assay
East Avenue Medical Center
NRL for Hematology including Immunohematology and Immunopathology and Anatomic Pathology
NKTI
NRL pathology for Cardiac Disease
PHC
NRL in anatomic pathology for pulmonary disease
LCP
