(265 days)
Not Found
No
The device is a chromogenic culture medium that relies on chemical reactions and visual interpretation of colony color and morphology, not computational analysis.
No
The device is a qualitative and presumptive detection medium for bacteria, not a therapeutic agent. Its intended use states "HardyCHROM ESBL is not intended to diagnose infection or to guide or monitor treatment for infections."
Yes
The device is intended as an aid in "the detection, identification of colonization and control of these bacteria in a healthcare setting." It is also used for "qualitative and presumptive detection" of certain bacteria. Although it is not intended to "diagnose infection or to guide or monitor treatment," its role in detecting and identifying colonization is a diagnostic function.
No
The device is a chromogenic culture medium, which is a physical product used in laboratory testing, not a software-only device.
Yes, this device is an IVD (In Vitro Diagnostic).
Here's why:
- Intended Use: The intended use explicitly states it is for the "qualitative and presumptive detection from stool specimens" of specific bacteria and their resistance patterns. This is a diagnostic purpose performed in vitro (outside the body) on a biological sample.
- Device Description: It describes a "selective and differential chromogenic medium" used for "detection and isolation" and "screening" of these bacteria. This is a laboratory reagent used for diagnostic testing.
- Performance Studies: The document details performance studies evaluating the device's sensitivity and specificity in detecting the target organisms from clinical specimens. This type of evaluation is characteristic of IVD devices.
- Predicate Device: A predicate device (K122187; Bio Rad VRESelect) is listed, which is another IVD device (specifically, a selective medium for detecting Vancomycin-Resistant Enterococci). This further supports the classification of HardyCHROM ESBL as an IVD.
- Care Setting: The intended user is in a "Healthcare setting," which is where diagnostic testing is typically performed.
- Sample Type: It is used with "Stool specimens," which are biological samples used for in vitro testing.
The device is used to test a biological sample (stool) in vitro to provide information about the presence and characteristics of microorganisms, which is a core function of an IVD.
N/A
Intended Use / Indications for Use
HardyCHROM ESBL is a selective and differential chromogenic medium which is intended for the qualitative and presumptive detection from stool specimens of: 1) Enterobacteriaceae that are potentially non-susceptible to ceftazioine and cefpodoxime; and 2) Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli, Klebsiella pneumoniae and Klebsiella oxytoca.
The test is performed on stool specimens at risk of harboring Enterobacteriaceae that are non-susceptible to 3rd generation cephalosporins or ESBL-producing E. coli, K. pneumoniae and K. oxytoca, and is intended as an aid in the detection, identification of colonization and control of these bacteria in a healthcare setting, HardyCHROM ESBL is not intended to diagnose infection or to guide or monitor treatment for infections. Results can be interpreted after incubation for 18-24 hours. Subculture to non-selective medium is required for confirming identification, susceptibility testing and epidemiological typing.
A lack of growth or the absence of pink, blue or yellow/gold colonies on HardyCHROM ESBL does not preclude the presence of Enterobacteriaceae that are non-susceptible to 3rd generation cephalosporins or ESBL producing organisms.
Product codes (comma separated list FDA assigned to the subject device)
JSO
Device Description
HardyCHROM™ ESBL is a selective and differential chromogenic medium containing a broad-spectrum beta-lactam intended for detection and isolation of Enterobacteriaceae non-susceptible to 3rd generation cephalosporins. HardyCHROM™ ESBL can also be used as a screening medium for K. pneumoniae, K. oxytoca, and E. coli that produce an extended-spectrum beta-lactamase (ESBL).
The selective components in HardyCHROM™ ESBL are designed to inhibit the growth of yeast, Grampositive bacteria, and Gram-negative bacteria sensitive to broad spectrum beta-lactams (3" generation cephalosporins). Chromogenic substrates in the medium allow for differentiation of Enterobacteriaceae non-susceptible to 3rd generation cephalosporins or that are ESBL-producing, as bacteria that can grow and utilize the chromogens produce a colored colony. ESBL-producing Klebsiella spp. produce large, dark blue colonies. ESBL-producing Escherichia coli produce colonies that are rose to magenta in color, with darker pink centers. Other Enterobacteriaceae not susceptible to 3rd generation cephalosporins will produce colonies of varying size that are pink, blue, with pink halos, and yellow/gold.
Mentions image processing
Not Found
Mentions AI, DNN, or ML
Not Found
Input Imaging Modality
Not Found
Anatomical Site
stool specimens
Indicated Patient Age Range
Not Found
Intended User / Care Setting
healthcare setting
Description of the training set, sample size, data source, and annotation protocol
Not Found
Description of the test set, sample size, data source, and annotation protocol
Performance of HardyCHROM™ ESBL was evaluated at three geographically diverse hospitals with fresh stool specimens. The recovery of ESBL-producing K. oxytoca, and E. coli on HardyCHROM™ ESBL was compared to routine culture, defined as the selective enrichment of microorganisms in Tryptic Soy Broth (TSB) containing either 1ug/mL ceftazidime or 1ug/mL cefotaxime, followed by subculture to MacConkey Agar. Organisms that grew on MacConkey Agar were identified using an FDA-cleared ID system. Quality control was performed in parallel every day of testing. Results from days of QC failure were excluded from the analysis. Confirmation of ESBL production and 3tt generation cephalosporin non-susceptibility was performed using traditional Kirby-Bauer AST following the device manufacturer's instructions. ID of organisms that grew on HardyCHROM™ ESBL was confirmed using an FDA-cleared ID system. A total of 1,687 samples were tested against routine culture, 128 specimens did not meet enrollment criteria, and were therefore excluded from the analysis. Of the remaining 1.559 valid samples tested, a total of 166 isolates were recovered on HardyCHROM™ ESBL as ESBL-producing with concordant results obtained on traditional culture and confirmed by AST and ID. A total of 373 isolates were recovered on HardyCHROM™ ESBL as non-susceptible to 300 generation cephalosporins with concordant results obtained on traditional culture and confirmed by AST and ID.
Summary of Performance Studies (study type, sample size, AUC, MRMC, standalone performance, key results)
Performance data evaluated HardyCHROM™ ESBL at three geographically diverse hospitals with fresh stool specimens.
A total of 1,559 valid samples were tested.
HardyCHROM™ ESBL for use in confirming the presence of 3th generation cephalosporin nonsusceptible Enterobacteriaceae vs. confirmation of 3th generation cephalosporin non-susceptible Enterobacteriaceae from traditional culture
Overall Sensitivity: 91.0% (95% CI: 87.8% - 93.4%)
Overall Specificity: 95.2% (95% CI: 94.1% - 96.1%)
HardyCHROM™ ESBL used to screen for ESBL-producing K. oxytoca, K. pneumoniae, and E. codi vs. confirmation of ESBL-resistance from traditional culture
Overall Sensitivity: 97.1% (95% CI: 93.3% - 98.7%)
Overall Specificity: 87.1% (95% CI: 85.6% - 88.5%)
Contrived specimens (n=50)
PPA: 97.9% (47/48) (95% CI: 89.1% - 99.6%)
NPA: 60.0% (3/5) (95% CI: 23.1% - 88.2%)
Analytical Reactivity
Tested 54 characterized ESBL-producing strains of E. coli, K. pneumoniae and K. oxytoca. Recovered 54 of 54 (100%) after 24 hours.
Tested 21 strains non-susceptible to at least one 3rd generation cephalosporin. Recovered 21 of 21 (100%) after 24 hours.
Analytical Specificity
Tested 99 strains (52 Enterobacteriaceae, 47 non-Enterobacteriaceae).
Majority of non-Enterobacteriaceae did not grow.
45/45 (100%) of 3rd generation cephalosporin susceptible Enterobacteriaceae either did not grow or produced colony colors other than pink, blue or yellow/gold.
Reproducibility Study
Detection of 3rd generation cephalosporin non-susceptible producing organisms (Overall n=272 positive, n=280 negative):
Overall PPA: 98.2% (95% CI: 95.7% - 99.2%)
Overall NPA: 99.6% (95% CI: 98.0% - 99.9%)
Detection of ESBL-producing organisms (Overall n=216 positive, n=336 negative):
Overall PPA: 98.1% (95% CI: 95.3% - 99.3%)
Overall NPA: 83.3% (95% CI: 79.0% - 86.9%)
Key Metrics (Sensitivity, Specificity, PPV, NPV, etc.)
HardyCHROM™ ESBL for use in confirming the presence of 3th generation cephalosporin nonsusceptible Enterobacteriaceae vs. confirmation of 3th generation cephalosporin non-susceptible Enterobacteriaceae from traditional culture
Overall Sensitivity: 91.0% (95% CI: 87.8% - 93.4%)
Overall Specificity: 95.2% (95% CI: 94.1% - 96.1%)
HardyCHROM™ ESBL used to screen for ESBL-producing K. oxytoca, K. pneumoniae, and E. codi vs. confirmation of ESBL-resistance from traditional culture
Overall Sensitivity: 97.1% (95% CI: 93.3% - 98.7%)
Overall Specificity: 87.1% (95% CI: 85.6% - 88.5%)
Contrived Specimen Morphology vs. Ref. NS 18 hr
PPA: 97.9% (47/48)
NPA: 60.0% (3/5)
Contrived Specimen Morphology vs. ESBL Ref 18 hr ("EC" Pink)
PPA: 100% (19/19)
NPA: 91.2% (31/34)
Contrived Specimen Morphology vs. ESBL Ref 18 hr ("KP/KO" Blue)
PPA: 100% (26/26)
NPA: 92.6% (25/27)
Reproducibility Study - detection of 3rd generation cephalosporin non-susceptible producing organisms
Overall PPA: 98.2%
Overall NPA: 99.6%
Reproducibility Study - detection of ESBL-producing organisms
Overall PPA: 98.1%
Overall NPA: 83.3%
Predicate Device(s): If the device was cleared using the 510(k) pathway, identify the Predicate Device(s) K/DEN number used to claim substantial equivalence and list them here in a comma separated list exactly as they appear in the text. List the primary predicate first in the list.
Bio Rad VRESelect, K122187
Reference Device(s): Identify the Reference Device(s) K/DEN number and list them here in a comma separated list exactly as they appear in the text.
Not Found
Predetermined Change Control Plan (PCCP) - All Relevant Information for the subject device only (e.g. presence / absence, what scope was granted / cleared under the PCCP, any restrictions, etc).
Not Found
§ 866.1700 Culture medium for antimicrobial susceptibility tests.
(a)
Identification. A culture medium for antimicrobial susceptibility tests is a device intended for medical purposes that consists of any medium capable of supporting the growth of many of the bacterial pathogens that are subject to antimicrobial susceptibility tests. The medium should be free of components known to be antagonistic to the common agents for which susceptibility tests are performed in the treatment of disease.(b)
Classification. Class II (performance standards).
0
Image /page/0/Picture/1 description: The image shows the logo for the Department of Health & Human Services - USA. The logo is a circular seal with the words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. Inside the circle is a stylized image of three human profiles facing to the right, stacked on top of each other.
Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002
November 15, 2016
HARDY DIAGNOSTICS ANDRE HSIUNG DIRECTOR TECHNICAL SERVICES 1430 WEST MCCOU LANE SANTA MARIA CA 93455
Re: K160512
Trade/Device Name: HardyCHROM ESBL Regulation Number: 21 CFR 866.1700 Regulation Name: Culture medium for antimicrobial susceptibility tests Regulatory Class: II Product Code: JSO Dated: October 4, 2016 Received: October 11, 2016
Dear Mr. Hsiung:
We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (OS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
1
If you desire specific advice for your device on our labeling regulations (21 CFR Parts 801 and 809), please contact the Division of Industry and Consumer Education at its toll-free number (800) 638 2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to
http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.
You may obtain other general information on your responsibilities under the Act from the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.
Sincerely yours,
Ribhi Shawar -S
For Uwe Scherf, M.Sc., Ph.D. Director Division of Microbiology Devices Office of In Vitro Diagnostics and Radiological Health Center for Devices and Radiological Health
Enclosure
2
Indications for Use
510(k) Number (if known) K160512
Device Name HardyCHROM ESBL
Indications for Use (Describe)
HardyCHROM ESBL is a selective and differential chromogenic medium which is intended for the qualitative and presumptive detection from stool specimens of: 1) Enterobacteriaceae that are potentially non-susceptible to ceftazioine and cefpodoxime; and 2) Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli, Klebsiella pneumoniae and Klebsiella oxytoca.
The test is performed on stool specimens at risk of harboring Enterobacteriaceae that are non-susceptible to 3rd generation cephalosporins or ESBL-producing E. coli, K. pneumoniae and K. oxytoca, and is intended as an aid in the detection, identification of colonization and control of these bacteria in a healthcare setting, HardyCHROM ESBL is not intended to diagnose infection or to guide or monitor treatment for infections. Results can be interpreted after incubation for 18-24 hours. Subculture to non-selective medium is required for confirming identification, susceptibility testing and epidemiological typing.
A lack of growth or the absence of pink, blue or yellow/gold colonies on HardyCHROM ESBL does not preclude the presence of Enterobacteriaceae that are non-susceptible to 3rd generation cephalosporins or ESBL producing organisms.
Type of Use (Select one or both, as applicable)
| Prescription Use (Part 21 CFR 801 Subpart D) |
|---|
| Over-The-Counter Use (21 CFR 801 Subpart C) |
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3
Appendix D - 510(k) Summary
I. SUBMITTER
Andre Hsiung Director of Technical Services Hardy Diagnostics 1430 W. McCoy Lane Santa Maria, Ca. 93455 Phone: 805-346-2766 x5706 E-mail: HsiungA@hardydiagnostics.com
II. DEVICE
Name of Device: HardyCHROM™ ESBL Classification Name: Culture medium for anti-microbial susceptibility tests Regulatory Class: II Product Code: JSO
III. PREDICATE DEVICE
Bio Rad VRESelect, K122187
IV. DEVICE DESCRIPTION
According to Centers for Disease Control and Prevention (CDC), Extended Spectrum Beta Lactamases (ESBLs) refer to a variety of enzymes which confer resistance to third generation cephalosporins and monobactams. ESBLs are widespread among Enterobacteriaceae and have no effect on carbapenems or cephamycins. ESBLs are distinguished from AmpC type beta lactamases by their susceptibility to beta lactamase inhibitors such as clavulanic acid.
HardyCHROM™ ESBL is a selective and differential chromogenic medium containing a broad-spectrum beta-lactam intended for detection and isolation of Enterobacteriaceae non-susceptible to 3rd generation cephalosporins. HardyCHROM™ ESBL can also be used as a screening medium for K. pneumoniae, K. oxytoca, and E. coli that produce an extended-spectrum beta-lactamase (ESBL).
The selective components in HardyCHROM™ ESBL are designed to inhibit the growth of yeast, Grampositive bacteria, and Gram-negative bacteria sensitive to broad spectrum beta-lactams (3" generation cephalosporins). Chromogenic substrates in the medium allow for differentiation of Enterobacteriaceae non-susceptible to 3rd generation cephalosporins or that are ESBL-producing, as bacteria that can grow and utilize the chromogens produce a colored colony. ESBL-producing Klebsiella spp. produce large, dark blue colonies. ESBL-producing Escherichia coli produce colonies that are rose to magenta in color, with darker pink centers. Other Enterobacteriaceae not susceptible to 3rd generation cephalosporins will produce colonies of varying size that are pink, blue, with pink halos, and yellow/gold.
4
V. INDICATIONS FOR USE
HardyCHROM™ ESBL is a selective and differential chromogenic medium which is intended for the qualitative and presumptive detection from stool specimens of: 1) Enterobacteriaceae that are potentially non-susceptible to ceftazidime and cefpodoxime; and 2) Extended-spectrum beta-lactamase (ESBL)producing Escherichia coli, Klebsiella pneumoniae and Klebsiella oxytoca.
The test is performed on stool specimens from patients at risk of harboring Enterobacteriaceae that are non-susceptible to 3th generation cephalosporins or ESBL-producing E. coli, K. pneumoniae and K. oxytoca, and is intended as an aid in the detection, identification of colonization and control of these bacteria in a healthcare setting. HardyCHROM™ ESBL is not intended to diagnose infection or to guide or monitor treatment for infections. Results can be interpreted after incubation for 18-24 hours. Subculture to non-selective medium is required for confirming identification, antimicrobial susceptibility testing and epidemiological typing.
A lack of growth or the absence of pink, blue or yellow/gold colonies on HardyCHROM™ ESBL does not preclude the presence of Enterobacteriaceae that are non-susceptible to 3tt generation cephalosporins or ESBL producing organisms.
NOTE: The Indications for Use statement for HardyCHROM™ ESBL is not identical to the predicate device; however, the differences do not alter the intended use of the device nor do they affect the safety and effectiveness of the device relative to the predicate. Both the subject and predicate devices have the same intended use for screening of stool samples by selective and differential culture for microorganisms that are non-susceptible to antimicrobial agents.
5
VI. COMPARISON OF TECHNOLOGICAL CHARACTERISTICS WITH THE PREDICATE DEVICE
| Attribute | Device | Comparator | Substantially
Equivalent? |
|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------|
| Name | HardyCHROM™ ESBL agar | Bio Rad VRESelect | |
| 510(k) Details | Product Code JSO
21 CFR 866.1700
"Culture medium for anti-microbial
susceptibility tests"
Class II
Panel 83 Microbiology | Product Code JSO
21 CFR 866.1700
"Culture medium for anti-microbial
susceptibility tests"
Class II
Panel 83 Microbiology | Yes |
| Intended Use | HardyCHROM™ ESBL is a selective and
differential chromogenic medium which is
intended for the qualitative and presumptive
detection from stool specimens of: 1)
Enterobacteriaceae that are potentially non-
susceptible to ceftazidime and cefpodoxime;
and 2) Extended-spectrum beta-lactamase
(ESBL)-producing Escherichia coli ,
Klebsiella pneumoniae and Klebsiella
oxytoca .
The test is performed on stool specimens from
patients at risk of harboring
Enterobacteriaceae that are non-susceptible to
3rd generation cephalosporins or ESBL-
producing E. coli, K. pneumoniae and K.
oxytoca , and is intended as an aid in the
detection, identification of colonization and
control of these bacteria in a healthcare
setting. HardyCHROM™ ESBL is not
intended to diagnose infection or to guide or
monitor treatment for infections. Results can
be interpreted after incubation for 18-24
hours. Subculture to non-selective medium is
required for confirming identification,
antimicrobial susceptibility testing and
epidemiological typing.
A lack of growth or the absence of pink, blue
or yellow/gold colonies on HardyCHROM™
ESBL does not preclude the presence of
Enterobacteriaceae that are non-susceptible to
3rd generation cephalosporins or ESBL
producing organisms. | VRESelect™ is a selective and
differential chromogenic medium,
containing 8 µg/mL of vancomycin, for
the qualitative detection of
gastrointestinal colonization of
vancomycin resistant Enterococcus
faecium (VREfm) and vancomycin
resistant Enterococcus faecalis (VREfs)
and to aid in the prevention and control
of vancomycin-resistant Enterococcus
(VRE) in healthcare settings. The test is
performed on rectal swabs or fecal
specimens from patients to be screened
for VRE colonization. VRESelect™ is
not intended to diagnose VRE infection
nor to guide or monitor treatment of
infection. Results can be interpreted after
24 to 28 hours incubation. Subculture to
non-selective media (e.g., trypticase soy
agar with 5% sheep blood) is needed for
susceptibility testing and epidemiological
typing. | Yes |
| Methodology | Enzymatic - Chromogenic | Enzymatic - Chromogenic | Yes |
| Inoculation | Direct | Direct | Yes |
| Sample Type | Fecal Specimen | Rectal Swab or Fecal Specimen | Yes |
| Interpretation | Manual, Visual | Manual, Visual | Yes |
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VII. PERFORMANCE DATA
Performance of HardyCHROM™ ESBL was evaluated at three geographically diverse hospitals with fresh stool specimens. The recovery of ESBL-producing K. oxytoca, and E. coli on HardyCHROM™ ESBL was compared to routine culture, defined as the selective enrichment of microorganisms in Tryptic Soy Broth (TSB) containing either 1ug/mL ceftazidime or 1ug/mL cefotaxime, followed by subculture to MacConkey Agar. Organisms that grew on MacConkey Agar were identified using an FDA-cleared ID system. Quality control was performed in parallel every day of testing. Results from days of QC failure were excluded from the analysis. Confirmation of ESBL production and 3tt generation cephalosporin non-susceptibility was performed using traditional Kirby-Bauer AST following the device manufacturer's instructions. ID of organisms that grew on HardyCHROM™ ESBL was confirmed using an FDA-cleared ID system. A total of 1,687 samples were tested against routine culture, 128 specimens did not meet enrollment criteria, and were therefore excluded from the analysis. Of the remaining 1.559 valid samples tested, a total of 166 isolates were recovered on HardyCHROM™ ESBL as ESBL-producing with concordant results obtained on traditional culture and confirmed by AST and ID. A total of 373 isolates were recovered on HardyCHROM™ ESBL as non-susceptible to 300 generation cephalosporins with concordant results obtained on traditional culture and confirmed by AST and ID. Product performance with prospectively collected clinical samples is summarized below:
HardyCHROM™ ESBL for use in confirming the presence of 3th generation cephalosporin nonsusceptible Enterobacteriaceae vs. confirmation of 3th generation cephalosporin non-susceptible Enterobacteriaceae from traditional culture
| Site | TP | FP | FN | TN | % Sensitivity | 95% CI | % Specificity | 95% CI | ||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 85 | 15 | 9 | 526 | 90.4 | 82.8 | 94.9 | 97.2 | 95.5 | 98.3 |
| 2 | 71 | 25 | 6 | 678 | 92.2 | 84.0 | 96.4 | 96.4 | 94.8 | 97.6 |
| 3 | 217 | 53 | 22 | 638 | 90.8 | 86.5 | 93.8 | 92.3 | 90.1 | 94.1 |
| Overall | 373 | 93 | 37 | 1842 | 91.0 | 87.8 | 93.4 | 95.2 | 94.1 | 96.1 |
Confirmed Non Susceptible 18 hr1
The same performance was observed at 18 and 24 hours
HardyCHROM™ ESBL used to screen for ESBL-producing K. oxytoca, K. pneumoniae, and E. codi vs. confirmation of ESBL-resistance from traditional culture
| Site | TP | FP | FN | TN | % Sensitivity | 95% CI | 95% CI | % Specificity | 95% CI | 95% CI |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 26 | 67 | 1 | 456 | 96.3 | 81.7 | 99.3 | 87.2 | 84.1 | 89.8 |
| 2 | 25 | 65 | 0 | 564 | 100.0 | 86.7 | 100.0 | 89.7 | 87.0 | 91.8 |
| 3 | 115 | 148 | 4 | 471 | 96.6 | 91.7 | 98.7 | 76.1 | 72.6 | 79.3 |
| Overall | 166 | 280 | 5 | 1894 | 97.1 | 93.3 | 98.7 | 87.1 | 85.6 | 88.5 |
Morphology vs. Confirmed ESBL 18 hr1
1The same performance was observed at 18 and 24 hours
7
To supplement testing of prospectively collected clinical specimens, a total of 50 contrived specimens were also evaluated. Patient specimens were inoculated with known resistant (ESBL producing or nonsusceptible to third generation cephalosporin) organisms at LoD and tested against routine culture. Results are summarized below.
| Performance Metric | Overall
(n=53) |
|--------------------|-----------------------------------|
| PPA | 47/48
97.9%
(89.1% - 99.6%) |
| NPA | 3/5
60.0%
(23.1% - 88.2%) |
| Contrived Specimen Morphology vs. Ref. NS 18 hr |
|---|
1 The same performance was observed at 18 hr and 24 hr
Contrived Specimen Morphology vs. ESBL Ref 18 hr
| Performance
Metric | "EC"
Pink | "KP/KO"
Blue |
|-----------------------|-----------------------------------|-----------------------------------|
| PPA | 19/19
100%
(83.1% - 100%) | 26/26
100%
(87.1% - 100%) |
| NPA | 31/34
91.2%
(77.0% - 97.0%) | 25/27
92.6%
(76.6% - 97.9%) |
The same performance was observed at 18 hr and 24 hr
RECOVERY RATE
HardyCHROM™ ESBL was evaluated to determine the recovery (limit of detection (LoD)) of 3th generation cephalosporin non-susceptible Enterobacteriaceae in specimen matrix. One isolate of five representative genera of Enterobacteriaceae with ceftazidime MIC's varying between 1μg/mL and >32ug/mL and cefotaxime MICs varying between 1ug/mL and >16ug/mL were evaluated for recovery on HardyCHROM™ ESBL. Sheep Blood Agar (BAP) plates were used to determine the concentration of organisms present in each dilution. At 10°CFU/mL, there was no discernable difference in recovery. Variable recovery was seen at lower concentrations.
In addition, HardyCHROM™ ESBL was also evaluated to determine the recovery of ESBL-producing E. coli, K. oxytoca, and K. pneumoniae in stool specimen matrix. Two strains of each species with varying ceftazidime MIC values and different ß-lactamase genotype were evaluated for recovery on HardyCHROM™ ESBL. Sheep Blood Agar (BAP) plates were used to determine the concentration of organisms present in each dilution. At 103 CFU/mL of stool (10 CFU/plate when using a 10μL inoculating loop), there was no discernable difference in recovery. Variable recovery was seen at lower concentrations.
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ANALYTICAL REACTIVITY
Internal testing was performed using 54 characterized ESBL-producing strains of E. coli, K. pneumoniae and K. oxvtoca with confirmed ESBL phenotype that were associated with various ß-lactamase genotypes. The strains were tested using a clean suspension in the absence of stool matrix. HardyCHROM™ ESBL was able to recover 54 of 54 (100%) of the ESBL-producing strains after 24 hours of incubation. Some strains containing enzymes such as CTX-M-116 and CTX-M-130 are more susceptible to the selective agent in the medium and were recovered on HardyCHROMI™ ESBL at an inoculum of 100 CFU/plate; all other strains were recovered from an inoculum of 10 CFU/plate.
| Species | n | Mechanism |
|---|---|---|
| E. coli | 24 | TEM (6, 12, 19, 21, 29, 210, 214, 215), CTX-M (1, 2, 3, 8, 14, 15, 24, 27, 28, 40, 55, 75, 79, 116, 125, 130), TEM-OSBL |
| K. pneumoniae | 26 | SHV (2, 11, 14, 18, 31, 55, 83, 89, 90, 108, 120, 133, 173, 178, 179, 180, 182), TEM (4, 11, 129), CTX-M (12, 14, 15, 22, 38, 40, 64, 74, 124), VEB-1 , SHV-OSBL , TEM-OSBL |
| K. oxytoca | 4 | TEM (, 52), CTX-M (22, 30, 75), SHV (7, 12), DHA-1 |
Summary of Analytical Sensitivity Testing
Note: 53/54 strains (98.1%) were also non-susceptible to at least one 3th generation cephalosporin and produced results on HardyCHROM™ ESBL that were consistent with this phenotype
In addition, 21 strains representative of Citrobacter, Escherichia, Hafnia, Klebsiella Morganella, Proteus, Providencia, Raoultella, Serratia, and Shigella that were non-susceptible to at least one 3th generation cephalosporin. Organisms showed a range of MICs to each antibiotic: CAZ (2 µg/mL to >32 µg/mL), CTX (0.38 µg/mL to >16 µg/mL), and CPD disk zone sizes (6-27 mm). The strains were tested using a clean suspension containing an inoculum of approximately 10 CFU/plate HardyCHROM™ ESBL was able to recover 21 of 21 (100%) of the 3tt generation cephalosporin nonsusceptible strains after 24 hours of incubation, although only 15 of 21 (71.4%) showed Pink, Blue, or Yellow/Gold color development. Non-susceptible isolates of Cronobacter. Salmonella, and Yersinia were not evaluated.
ANALYTICAL SPECIFICITY
To determine the potential for cross-reactivity on HardyCHROM™ ESBL, internal testing was conducted with ESBL non-producing and 3th generation cephalosporin susceptible species as well as non-Enterobacteriaceae. A total of 99 strains were tested by plating 10μL of a 108 CFU/mL suspension of each organism on HardyCHROM™ ESBL. Included in the study were 52 strains of Enterobacteriaceae and 47 non-Enterobacteriaceae. The majority of non-Enterobacteriaceae species did not grow on HardyCHROM™ ESBL medium and none exhibited pink, blue or yellow/gold colonies. Of the Enterobacteriaceae, 45/45 (100%) of those that were 3th generation cephalosporin non-susceptible either did not grow on HardyCHROM™ ESBL or produced colony colors other than pink, blue or yellow/gold. Four strains (1 each of C. braakii. C. freundii, E. cloacae and Y. kristensenii) that were non-susceptible to cefpodoxime were not recovered on HardyCHROMIM ESBL. Three carbapenem resistant and 3th generation cephalosporin non-susceptible strains (E. coli (1) and K. pneumoniae (2)) produced pink or blue colonies, as expected (1 of these strains was ESBL negative; 2 were ESBL non-determinable).
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Because non-ESBL producing organisms that are carbapenem resistant or which exhibit other betalactamase resistance mechanisms such as AmpC may produce pink, blue or yellow/gold colonies on HardyCHROM™ ESBL, it is important to subculture such colonies for identification and antimicrobial susceptibility testing to confirm the ESBL-producing phenotype.
MICROBIAL INTERFERENCE
A study was conducted using known concentrations of ESBL-producing K. oxytoca, and E. coli with 10 non-target organisms that grow, but which exhibit non-target colors on HardyCHROM™ ESBL. Suspensions of non-ESBL organisms were prepared at a concentration of at least 10° CFU/mL and mixed with suspensions of ESBL strains at the detection limit concentration (102 CFU/mL). HardyCHROM™ ESBL recovered all target organisms used in the presence of high concentrations of non-target organisms, although the number of colonies of E. coli recovered was reduced in the presence of high concentrations of A. baumanni and colonies of K. pneumoniae appeared unusually small in the presence of Pseudomonas fluorescens.
| Non-target organisms used in mixed-infection study |
|---|
| Geotrichum guilliermondii |
| Geotrichum candidum |
| Aspergillus brasiliensis |
| Penicillium rubens |
| Penicillium chrysogenum |
| Pediococcus acidilactici |
| Provicencia stuartii |
| Acinetobacter baumannii |
| Pseudomonas fluorescens |
| Stenotrophomonas maltophilia |
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INTERFERENCE STUDY
Commonly used or encountered transport devices and endogenous substances that may be present in stool samples were evaluated for potential interference with the growth or chromogenic reaction of target organisms on HardyCHROM™ ESBL. The devices and substances tested are listed in the table below. No interference was observed with any substance at the highest clinically relevant concentration in ESBL-negative specimen matrix.
Summary of Interference Study
| Category | Substance | Concentration
of Substance1 | Category | Substance | Concentration
of Substance1 |
|---------------|-----------------------------------------------------------|--------------------------------|-----------------------|-------------------------------------------|--------------------------------|
| Antifungal | Nystop (Nystatin) | 5% | GI Medication | Rolaids (Mg(OH)2) | 5% |
| Antifungal | Lotrimin (Clotrimazole) | 5% | GI Medication | Milk of Magnesia
(Mg(OH)2) | 5% |
| Antifungal | Lotrimin Ultra
(Butenafine
Hydrochloride) | 5% | GI Medication | Dulcolax (Sodium
picosulfate solution) | 5% |
| Antifungal | Lamisil (Terbinafine
Hydrochloride 1%) | 5% | GI Medication | Immodium AD
(Loperamide) | 5% |
| Antiseptic | Bactine (Benzalkonium
Chloride) | 1% | Lubricant | Mineral oil | 10% |
| Antiseptic | Ethanol | 1% | Lubricant | Petroleum jelly | 10% |
| Biologic | Whole blood | 5% | Lubricant | Fleet (Glycerin) | 10% |
| Contraceptive | Nonoxynol-9 | 5% | Lubricant | KY Jelly | 10% |
| GI Medication | Pepto-Bismol (Bismuth
Subsalicylate) | 5% | Other | C&S Transport
Medium | 75% |
| GI Medication | Prilosec OTC
(Omeprazole) | 5% | Other | Physiological Saline | 10% |
| GI Medication | Alka-Seltzer (Sodium
carbonate/potassium
carbonate) | 5% | Other | Tween80
(Polysorbate80) | 10% |
| GI Medication | Mylanta (Al(OH)3) | 5% | Topical
Medication | Preparation H
(Hemorrhoid Cream) | 10% |
| GI Medication | Tums (CaCO3) | 5% | Topical
Medication | Cortizone 10
(Hydrocortizone) | 10% |
1 v/v or w/v as appropriate
SPECIMEN STABILITY
The stability of spiked raw stool and in stool preserved in C&S Medium (modified Cary Blair formula) was verified. Stool specimens were inoculated near LoD with ESBL-producing and 3th generation cephalosporin non-susceptible Enterobacteriaceae species (ie. E. coli, K. oxytoca, K. pneumoniae, E. cloacae, and P. mirabilis) and held at both room temperature (23-24°C) and 2-8°C. Specimens were subcultured to HardyCHROM™ ESBL at 0 hours, 1 hours, 4 hours, 8 hours, 12 hours, and 24 hours, 48 hours, 72 hours, 96 hours, 120 hours, 144 hours, and 168 hours.
Acceptable results were defined as recovery of organism with no appreciable decrease in colony counts (