Quality control and automation in the microbiology lab

quality control

what ensures accuracy and reliability of laboratory results?

2 years

how long are quality control records and patient records kept?

• American Type Culture Collection (ATCC)

• specific strains of microorganisms

• these microorganisms produce consistent growth and susceptibility results

• use for quality control testing for media, rapid tests, and ASTs

what are the stock culture quality controls?

• BAP

• MAC

• EMB

• CNA

• PEA

which standard media is the manufacturer quality control acceptable?

• CHOC

• MHM

• Campy

which agar plates must go through additional quality control?

Clinical Laboratory Standards Institute (CLSI)

who developed the standardized procedures and guidelines for laboratory testing?

• contamination

• dehydration

• hemolysis

• plate damage

what are the visual inspections of media?

• water

• biochemical agents

• gram stain reagents

• antisera

• commercial testing kits

what are other ways to perform quality control?

fewest impurities

what classifies as type I water QC?

prepare media/stains

what classifies as type II water QC?

washing glassware

what classifies as type III water QC?

• competency assessment of each lab tech

• annual evaluations

• continuing education

what is the Clinical Laboratory Improvement Act 1988?

20 consecutive days

how long must lab perform QC testing initially?

no more than 1 out of 20 or 3 out of 30

how many days can result outside accuracy limits?

start weekly QC testing

what can happen if QC is acceptable 20 days in a row?

• if obvious reason, repeat test. If in range, continue with weekly QC testing

• if no obvious reason, perform daily QC for 5 days in a row

  • if all results are acceptable, the lab can return to weekly QC

  • if any results are unacceptable, daily QC must be performed for 20 more days

what should happen if weekly QC is unacceptable?

proficiency must be documented

what has to be done before the lab can return to weekly QC?

a gap between what is taught in school vs what is performed in the clinical lab

what is the educational gap?

• catalase, oxidase, indole, PYR, motility

• latex agglutination

• strep serotyping

• tube coagulase

• 2-24 hour rapid ID panels

• antigen detection kits

• disk susceptibility testing

what are the “older” identification methods still used?

• decreases TAT for results

• increases productivity

• improves accuracy and reliability of test results

• tests are more sensitive

• reduces patient medical expenses

• cost may be expensive but pays for itself in time

what areas of the clinical lab show a rise in automation?

liquid-based specimens for automated specimen processing

what are labs moving toward using rather than a variety of specimen culturettes and specimen containers?

hands-off processing of specimens

what does standardized liquid-based specimens allow for?

• Copan WASPLab

• BD Kiestra TLA

• BECKMAN COULTER DxM Autoplak Automated Microbiology System

what are examples of automated microbiology systems?

• older method

• many different types of culturette swabs

• contains transport media for specific purposes

• use specific swabs for different cultures

what characterizes culturette swabs?

• newer method

• liquid Amies transport media

• different eSwabs for various purposes

• universal—used with automated plate streaking equipment

what characterizes eSwabs?

• fully automated microbiology system with liquid specimens

  • performs specimen set-up on eSwabs, Urine, Stool, Fluids, Sputum, Pre-ground tissue

• moves plates automatically to incubators, then through digital work-up

• aerobic, anaerobic, and fastidious bacteria cultures

what is the Copan WASPLab?

• fully automated microbiology system for liquid specimens

  • semi-automated system for non-liquid specimens—swabs/tissues

• uses magnetic rolling beads to streak the plates

• prepares slides for gram stain

what is the BD Kiestra TLA?

• continuously monitors blood culture bottles for bacterial growth

• notifies the tech when bottle turns positive

what is the function of blood culture systems?

• Verigene

• BD max

• BioFire FilmArray

• Cepheid GeneXpert

• Cobas Liat PCR System

what are examples of desktop molecular equipment?

• desktop molecular assay

• identifies bacteria and genetic resistance directly from positive blood culture bottles

• get results within 2-3 hours

• saves 2-4 days of incubation time

what is Verigene BC?

• performs nucleic acid extraction and RT-PCR

• provides results in less than 4 hours

what is BD MAX?

• replaces stool cultures

• fast: TAT of 1 hour

• simultaneously tests for 22 targets:

  • Salmonella/Shigella

  • E. coli O157:H7

  • Yersinia enterocolitica

  • Campylobacter

  • Vibrio

  • C. diff

  • Cryptosporidium

  • Entamoeba histolytica

  • Giardia intestinalis

what is the BioFire FilmArray GI panel?

• tests for 20 respiratory pathogens:

  • adenovirus

  • coronavirus

  • rhinovirus

  • influenzae

  • parainfluenzae

  • Bordetella pertussis

  • Chlamydophilia pneumoniae

  • Mycoplasma pneumoniae

what is the BioFire FilmArray respiratory panel?

• fast: TAT of about 1 hour

• tests for individual specific pathogens:

  • H. influenzae

  • MRSA

  • GBS

  • GAS

  • Clostridium difficile

what is the Cepheid GeneXpert?

• compact PCR system for point-of-care testing

• tests for individual specific pathogens:

  • influenzae A and B

  • RSV

  • GAS

what is the Cobas Liat PCR system?

• EIA

  • identifies toxin and GDH antigen

  • results within 24-96 hours

• molecular techniques

  • results within 1-2 hours

what is the testing of Clostridium difficile?

instruments that use an ionizing laser to vaporize structural elements of bacteria and yeasts and analyze the weight and relative abundance of each particle to generate a spectrum. Spectra are compared to a computer database of defined organism spectra, and identification is obtained by matching to the most similar spectrum in the database

what are MALDI-TOF instruments?

uses as small amount of bacterial growth to provide organism identification within minutes

• gram negative and positive bacteria

• yeast/molds

• mycobacteria

• nocardia

what is unique with MALDI-TOF instruments?

• very common in microbiology labs

• performs identification and susceptibility testing using specific cards

• get results within 6-8 hours

what characterizes Vitek?

• fully automated nephelometry

  • prepares 0.5-4 McFarland for AST

• identification and susceptibility machine

• get results within 3-5 hours

what is the BD Phoenix AP?

the system uses a fully automated fluorescence in situ hybridization technology for a rapid genomic identification of the most common pathogens causing bloodstream infections—test directly from positive blood cultures; identification within 90 minutes

what is the Accelerate Pheno System?

within 7 hours

how long does it take for susceptibilities with the Accelerate Pheno System?