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Duodenoscope Surveillance 

Sampling and Culturing

Shani Haugen, Ph.D., Microbiologist (FDA/CDRH)

Michelle Alfa, Ph.D., Professor (University of Manitoba)

Kevin Alby, Ph.D., Clinical Microbiologist (University of Pennsylvania)

Judith Noble-Wang, Ph.D., Microbiologist (CDC/DHQP)

March 22, 2018
3 

Outline

• Overview of FDA-CDC-ASM duodenoscope 

surveillance sampling and culturing document

• Sampling method

• Culturing options

• Comparison to CDC’s March 2015, Interim 

Recommendations
4 

Released on February 26th, 2018 

• https://www.fda.gov/downloads/MedicalDevices/ProductsandMedica

lProcedures/ReprocessingofReusableMedicalDevices/UCM597949.pdf
5 

The document is a tool that can be used by health 

care facilities that choose to conduct surveillance 

sampling and culturing of duodenoscopes.

The protocols were developed to provide a 

standardized, validated method to health care 

facilities for surveillance sampling and culturing 

duodenoscopes.

Who: 

What: 

Why: 

Working group: FDA, CDC, ASM, duodenoscope 

manufacturers, and other experts in endoscope 

sampling and culturing.
6 

Overview – Background 

• Surveillance sampling and culturing is not 

required by FDA/CDC/ASM. 

• These methods require specific resources, 

training, and expertise. 

• Surveillance sampling and culturing is not a 

substitute for complete adherence to the 

endoscope manufacturer’s recommendations 

for reprocessing and maintenance. 
7 

Overview - Organization of Document
8 

Overview - Organization of Document

• The document is divided into three sections:

– The first section provides an overview and 

introduction to surveillance sampling and culturing.

– The second section describes the duodenoscope 

sampling methods.

– The third section discusses the options for 

microbiological culturing of samples, and includes 

suggestions for microbial limits. 
9 

Overview- Protocol Implementation

• Health care facilities select the appropriate 

method for sample collection and culture and 

interpretation.

• Adopt it to the institutional formatting for 

standard operating procedures at each 

individual health care facility. 
10

Overview – Additional Details

• Health care facilities that choose to conduct 

surveillance sampling and culturing must make 

a number of decisions regarding these methods, 

based on their needs and resources. 
11

Sampling Method

• Two staff are required for sampling.

• Staff should be familiar with duodenoscope 

handling. 

• Sampling staff must be trained in aseptic 

technique and duodenoscope sampling.

• Sampling should be conducted on patientready duodenoscopes
12

Sampling Method

• One combined sample collected from:

– Elevator recess

– Instrument channel

– Elevator wire channel (if unsealed)

Figure 1: Duodenoscope Diagram
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Sampling Method – 

Elevator Recess

• The seam between the distal end cap (when 

present) and distal end should be sampled 

with a swab moistened with sterile water. 

• The elevator recess 

should undergo 

flushing, brushing, and 

additional flushing. 

Figure 2: Brushing the elevator recess
14

Sampling Method – 

Instrument Channel

The channel from the biopsy 

port to the distal end is flushed 

with sterile water, brushed, 

and flushed again. The brush 

head should be cut off or 

removed and added to the 

sample extract. 

Figure 3: Brushing the instrument channel
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Sampling Method – 

Elevator Wire Channel

When accessible (i.e. 

unsealed) on a 

duodenoscope, this 

channel should be 

flushed with sterile 

water. 

Figure 4: Flushing the elevator wire channel
16

Sampling Method – 

Sample Handling

• The extracts (including swab and brush heads) 

from the elevator recess, instrument channel, 

and elevator wire channel are combined for 

microbiological culturing. 

• An appropriate neutralizing media (e.g., DeyEngley) should be added to the sample.

• Sample should be kept on ice or refrigerated 

prior to microbiological culturing. 
17

Sampling Method – 

Endoscope Handling After Sampling

Because the device is handled with sterile 

implements and sterile water only, reconducting 

the complete manual cleaning is not necessary.

– Manual high level disinfection

– Processing in an automated endoscope reprocessor 

– Drying and sterilization
18

Culturing Method

Culturing should be conducted by staff who have 

knowledge and experience with standard 

microbiological culturing. 
19

Culturing Method - Options 

There are four options for culturing. Health care 

facilities should determine the option most 

suitable for their needs and resources:

– Membrane filtration and plating (validated)

– Centrifugation and plating

– Membrane filtration and liquid culture

– Centrifugation and liquid culture
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Culturing Method – 

Plating Conditions

• The entire endoscope sample should be 

concentrated (either by membrane filtration or 

centrifugation).

• The endoscope sample (extract) should be 

plated on a single blood agar plate. 

• Incubate at blood agar plate at 35 - 37°C.

• Identify and document growth at 24, 48 and 72 

hours using standard methods.
21

Culturing Method – 

Liquid Culture Conditions

• The entire endoscope sample should be 

concentrated (either by membrane filtration or 

centrifugation).

• The endoscope sample (extract) should be 

added to appropriate liquid culture neutralizing 

media (e.g., Dey-Engley broth). 

• Incubate the liquid culture at 35 - 37°C.

• Identify and document no growth/growth at 24, 

48 and 72 hours using standard methods.
22

Culturing Method – 

Result Reporting

• If growth is observed, Gram staining and other 

identification methods should be conducted to 

identify potential high-concern organisms. 

• Documentation and notification of relevant 

culturing information should conform with local 

regulations, quality management policies, and 

be traceable within the culturing facility’s 

documents. 
23

Culturing Method – Interpretation

Organism 

Category

General Criteria Examples

HighConcernMore often associated 

with disease.

Gram-negative rods (e.g., E. coli, 

K. pneumoniae) S. aureus, Betahemolytic Streptococcus, 

Enterococcus species, and yeasts

ModerateConcernLess often associated 

with disease and 

commonly found in the 

oral cavity.

Saprophytic Neisseria, viridans

group streptococci, and 

Moraxella species

Low-Concern Less often associated 

with disease.

Micrococcus, coagulase-negative 

staphylococci (excluding S. 

lugdenensis), Bacillus, and 

diphtheroids
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Culturing Method – 

Potential Responses

Health care facilities should develop their own 

action plans following culture results. 

– Remove duodenoscope from use

– Patient notification

– Review reprocessing methods

– Review sampling and culturing methods

– Repeat reprocessing
25

Comparison

Methods FDA/CDC/ASM 2018 CDC 2015 Interim Methods

Sampling

• Location - Instrument 

Channel

Flush-brush-flush with 

sterile water (e.g., DI or RO 

water)

Flush with sterile water

• Location - Elevator 

Recess

Brush with water; flush with 

water

Brush with PBS/Tween-80 

• Location - Distal cap 

seam

Swab the seam between the 

distal end cap and the distal 

end

None specified

• Sample handling Samples are combined Samples are separate (may

be combined)

• Neutralization of samples Neutralizer added to 

samples

None specified
26

Comparison

Methods FDA/CDC/ASM CDC 2015 Interim Methods

Culturing

• Options • Plating w/ Membrane 

Filtration

• Plating w/ Centrifugation

• Liquid culture w/ 

Membrane Filtration

• Liquid culture w/ 

Centrifugation

• Plating w/ Membrane 

Filtration

• Plating w/ Centrifugation

• Liquid culture w/ 

Membrane Filtration

• Liquid culture w/ 

Centrifugation

• Plating Method • 1 Blood agar plate per 

duodenoscope

Blood and MacConkey agar 

plates per duodenoscope

• Controls None specified (other than 

routine lab media controls)

3 controls: positive and 2 

negative controls

• Culture incubation 

conditions

35 - 37°C for 72 hours 35 - 37°C for 48 hours
27

Summary

The FDC/CDC/ASM Method:

– Sampling: Use of flush-brush-flush for friction

– Neutralization: Reduce false-negatives 

– Sample Concentration: Membrane filtration and 

plating
Questions? 

Division of Industry and Consumer 

Education: DICE@fda.hhs.gov

Slide Presentation, Transcript and Webinar 

Recording will be available at:

http://www.fda.gov/training/cdrhlearn

Under the Heading: Specialty Technical 

topics; Subheading: Reprocessing