Claude B Anger, MS, Microbiology

1
Claude B Anger, MS, (Microbiology)

• Current Retired, Consultant, CBA
  MicroEnterprises
• Past
• 18 years as Director of RD Microbiology
  Cytotoxicity and the Corporate Microbiologist for
  Allergan, Inc.
• 10 years as Manager of RD Microbiology for
  Allergan, Inc.
• 5 years as microbiology supervisor for Baxters
  Microbiological Reagents Division at Hyland
  Laboratories (diagnostics mfg)
• 3 years as senior research microbiologist for Max
  Factor
• 1 year as the chief microbiologist for Purex
  Corporation
• Honors
• 1985-1990 PMA, chairman, biological testing Div
  of Biological Section
• 1991-1995 USP, Expert advisor to the
  Microbiology subcommittee
• 1992-2001 ANSI microbiology expert to ISO for
  Microbiology Cytotoxicity standards development
  for contact lens care products

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Acanthamoeba Keratitis can be anOutbreak
diseaseHistory in the USA
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Disinfection is not SterilizationContact lens
disinfection is not hospital disinfection

• Disinfection selects for surviving resistant
  microbes efficacy depends on temperature, agent
  concentration contact time
• Disinfection products are defined into three
  efficacy categories, low, intermediate and high
• Hydrophilic contact lens (a class II non-critical
  device) disinfection was/is considered to be low
  efficacy due to the potential toxicity to the
  external eye from the hydrophilic contact lens
  containing disinfectant.
• Low efficacy disinfection is not required to be a
  sporicidal, fungicidal or tuberculocidal. CL
  disinfection is now asked to kill fungal spores
  and perhaps amoebic cysts which will be
  intermediate disinfection - can we change CL
  disinfection stringency without increased ocular
  toxicity from stronger formulations?
• The CL disinfection rub step by the patient can
  deposit 104 microbes from the finger/hand onto
  the lens, thorough hand washing before removal of
  lenses should be stressed as a major compliance
  factor

4
Contact Lens Disinfection History

• 1976-1981 FDA guidance declared CL disinfection
  efficacy to be measured by (1) sterilization type
  kill rate D-values for the active disinfectant
  solution, (2) the 20 item sterility regimen test
  and (3) contribution of elements lens tests
  against the following organisms
• Staphylococcus aureus
• Pseudomonas aeruginosa
• Serratia marcescens (the most highly pigmented
  strain)
• Candida albicans (yeast cell)
• Aspergillus fumigatus (mold spore lung infector,
  high disinfection resistance)
• Herpes simplex virus
• No instructions were given as to how the
  disinfectant D-values were to be determined
  (multi-sloped kill curves) nor any efficacy
  criteria to meet except the 20 lens MIMC test
  having no survivors. Contact lens soaking times
  set at 2-3 x the largest D-value

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Contact Lens Disinfection History

• 1982-1990 FDA guidelines modified at least 6
  times
• Serratia marcescens strain changed to a
  non-pigmented ocular infection isolate strain
  (quaternary ammonium can be used)
• Herpes simplex virus is dropped from the efficacy
  indicator challenge organism list - very low
  infection prevalence with CL
• Aspergillus fumigatus is changed to Fusarium
  solani as the mold spore efficacy indicator
  organism because Fusarium was a more prevalent
  ocular infector and it was less resistant to
  contact lens disinfecting agents - D-value
  criteria is set at fungistasis

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Contact Lens Disinfection History

• 1982-1990 FDA guidelines modified at least 6
  times
• 20 lens MIMC regimen test has the criteria
  changed from zero recovery to 10 or less
  survivors per lens/solution combination in the
  lens case well
• Acanthamoeba was not added to the efficacy
  indicator list still working on AK root cause
  and how to correct for the AK outbreak plus no
  Acanthamoeba culture and challenge tests are
  available

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Contact Lens Disinfection History

• 1990-2003
• Contact lens disinfection efficacy standard ISO
  FDIS 14729 is developed by ANSI, FDA, EU and
  Japan experts for world wide use and the FDA
  adopts the ISO methods and criteria as their
  guideline efficacy for contact lens disinfection
  product approval.
• The Acanthamoeba outbreak of 1984-1992 was ended
  in the USA when salt tablets and the use of home
  made solutions in contact lens care were removed
  from the marketplace inadequate disinfection was
  not the issue

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Contact Lens Disinfection History

• 1990-2003
• From 1993-2003 the AK incidence in the USA fell
  to 19 cases/yr as compared to 115 cases/yr during
  the 84-91 US outbreak and the only country with
  an AK problem remaining was the UK. Consequently
  the ISO and FDA did not consider it relevant for
  CL disinfection to add Acanthamoeba to the list
  of efficacy indicating challenge organisms
  because CL disinfection efficacy was not the
  apparent issue for the AK outbreak no
  standardized/validated Acanthamoeba disinfection
  challenge test methods were available and no
  agents active against Acanthamoeba and compatible
  with contact lens care were evident.

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Contact Lens Disinfection Efficacy Testing
Anomalies against Acanthamoeba
Borazjani RN, Kilvington S. Efficacy of
multipurpose solutions against Acanthamoeba
species. SCL Ant Eye 2005 28169-175
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Cyst strain production method vs Disinfection
A. polyphaga Log Reductions at 4 hr contact
Hughes R, Heaselgrave W, Kilvington S.
Antimicrob. Agents Chemother 2003 473080-3084
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What is the Root Cause of an AK outbreak

• The use of any water in the contact lens care
  regimen was and still is the source of
  Acanthamoeba for CL associated AK - ALWAYS FORBID
  THIS PRACTICE.
• The 1990s CL disinfection marketplace rejected
  the highest efficacy systems, heat units and
  2-step 3H2O2, for ease of use and comfort from
  multi-purpose solution systems without increase
  in the AK occurrence rate. Contact lens
  disinfection will have resistant survivor
  microorganisms in the lens case after multiple
  procedures so the patient hygiene and care
  regimen (water?) determines if Acanthamoeba will
  be present.
• In 1990 Dr Mary Beth Moore published in Cornea 9
  Suppl 1S33-5 that for AK the patient was at
  fault, and stated patients can not be relied upon
  to follow routines true?

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What is the Root Cause of an AK outbreak

• The contact lens storage case is the culprit here
  because it allows disinfection survivor microbes
  to set up a biofilm after about 2 weeks of use
  when it is not cleaned regularly. Rinsing the
  lens case or lenses with water supplies the
  Acanthamoeba and the biofilm is the food for
  trophozoite growth. This is where AK begins what
  is the infection dose for AK ,1 or 50?
• What is the corrective action for AK root cause?
  Absolutely stop patient use of water in lens care
  and physically clean the lens case regularly
  (also can put it in boiling water).
• Will increasing contact lens disinfection
  stringency really help reduce AK, especially if
  the current products can pass the new criteria
  which will mean there is no real change? Are
  current products really inadequate?
• An intensive program for the education of contact
  lens wear patients to strictly follow the care
  product regimen is warranted, with warnings that
  failure to comply can lead to blindness.

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Contact Lens Storage Case Cleaning Disinfecting

• Practitioners and industry must stress NEVER USE
  WATER IN THE CONTACT LENS CARE REGIMEN ANYWHERE!!
  Not to rinse the lens case nor the lenses
• Practitioners should advocate physical cleaning
  of the contact lens storage case by a procedure
  with a dedicated instrument (hard tooth brush)
  and CL disinfectant or with boiling water every
  week and never air-dry the lens case but keep it
  filled with fresh disinfectant and sealed ready
  for the next use (do not discard solution, use it
  to disinfect lenses and discard after use)
• To insure against lens case biofilm (estimate 2
  weeks to set up) source infections practitioners
  should advocate to patients a once a week
  conventional home microwave treatment of CL
  disinfectant filled lens cases with 50 power for
  3 minutes and no lenses present.

Hiti K, Walochinik J, et al. Microwave
Treatment of Contact Lens Cases Contaminated with
Acanthamoeba. Cornea, 2001
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Issues for Standardizing CL Disinfection Efficacy
Testing against Acanthamoeba species challenges

• Product formulas tested for ability to cause
  trophozoite to encyst
• Survivor cell recovery must be quantitative and
  not an estimate
• The acceptable standard of error for these
  methods is 0.5 log
• The reasonable Acanthamoeba challenge level is
  103/ mL
• Will the new tests and criteria cause current
  products to be off the market are current
  products considered inadequate for CL
  disinfection?
• If the current CL disinfection products are
  unacceptable what new anti-acanthamoeba agents
  are available for CL disinfection use and will
  there be a grace period (5 years) for research
  and development of new products?
• Any new test preamble should contain rationales
  to address the above issues for testing personnel
  to understand the methods, the acceptance
  criteria and the expected standard error

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Contact Lens Disinfection Efficacy Challenge
TestsWhat Do They Really Measure

• STAND ALONE
• Ability of active disinfectant to kill an aqueous
  challenge of various microbial cell types in
  various resistance states. ID most resistant type
• Can generate specific microbe kill kinetics and
  the 3 log reduction times
• Establishes contact lens soaking time for the
  designated regimen solution compatibility with
  different lenses and lens storage cases?
• Selects for resistant organisms in the challenge
  organism cell inoculum (weak, normal resistant
  cells are present)

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Contact Lens Disinfection Efficacy Challenge
TestsWhat Do They Really Measure

• REGIMEN (test performed on sterile surgeon gloves
  in a hood)
• The inoculum contact time with the contact lens
  is too short at 5 minutes, no time for microbes
  to attach to test lenses. How long should this
  time be? The rub step is a major source of
  microbes, but physical rubbing with a surfactant
  solution can dislodge attached microbes from the
  lens surface for removal in the rinse step, so
  lens rub is advised
• Clean rinse with saline can remove nearly all
  of the test lens inoculum, a high force stream
  with a large volume (20 seconds) Data from
  positive controls should be generated.
• Organic soil presence has significance and should
  be used
• For Acanthamoeba challenges, the lens type makes
  a big difference in recovery (very sticky cells
  with high affinity for silicone hydrogel lenses)

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Straw-man proposed Acanthamoeba challenge Test
current systems have been demonstrated to pass
the regimen test

• Organism A. castellanii from the ATCC, a T-4
  genotype from an ocular infection
• Trophozoites Cultured axenically in a defined
  PYG medium at 30ºC for 72 hours.
• Cyst production Trophozoites transferred to
  Neffs constant pH encystment medium to give
  about 106 cells/mL and incubated at 30ºC for 7
  days, centrifuge, then wash resuspend the
  pellet to yield 5 3 x 105 cyst PFU /mL
• Quantitation of Inocula The agar sandwich
  bacterial plaque assay of serial dilutions

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Straw-man proposed Acanthamoeba challenge Test
current systems have been demonstrated to pass
the regimen test

• Product challenge 3 mL product in a contact lens
  storage case is inoculated with 0.03mL of a
  standardized cell suspensions in Pages saline to
  yield 103 to 104 cells per mL of product and
  incubated at 23ºC. (lens present? Which type)
• Viable cell assay at designated contact time
  intervals remove 0.5 mL of test solution and
  serially dilute 10-fold in a neutralizer broth
  and plate 0.5 mL of each dilution in duplicate by
  the bacterial plaque assay method.
• All steps must be properly validated for
  precision, accuracy and reproducibility measures.
  Standard error for plate count methods is 0.5
  log.
• CRITERIA 2 log reduction of trophozoite
  viability and NLT 0.7 log reduction in cysts
  during the manufacturer recommended minimum lens
  soaking time after an n of 3