MAUDE Adverse Event Report: HARDY DIAGNOSTICS HARDYCHROM; CULTURE MEDIA, ANTIMICROBIAL SUSCEPTIBILITY TEST, EXCLUDING MUELLER HINTON AGAR

Model Number G307

Device Problem Output Problem (3005)

Patient Problem Drug Resistant Bacterial Infection (4553)

Event Date 10/28/2021

Event Type  malfunction  

Event Description

The nicu has been regularly screening its patient population for (b)(6).This has been their practice since the 2000 and 2009 nicu (b)(6) outbreaks, though such screening is not necessarily a standard practice.The micro laboratory traditionally had been using a (b)(6) screening plate made by bd chromagar (b)(6) for detecting (b)(6) colonization, but in summer 2020, we switched to the hardychrom (b)(6) screening agar equivalent because of back order issues.Methodologically, the patient swab is streaked on the plate.Organisms that grow in 24h and turn the media a purple/pink color are designated (b)(6) without further workup per package insert.If in doubt on interpretation, organisms are incubated for another day and (methicillin) susceptibility tested by another method.In summer 2021 there was an uptick in the number of (b)(6) isolates from nicu.This led to a concern for a (b)(6) outbreak, based on 20 isolates from summer 2021/early fall.The doctor performed pulsed-field and results indicated that the isolates were not clonally related.The isolates were also sent to the (b)(6) laboratory institute, which performed whole genome next generation sequencing (ngs).The ngs results supported lack of clonality.However, it was found based on this sequence analysis that twelve isolates did not contain the meca gene (the gene conferring methicillin resistance).Nine of these twelve isolates were originally called (b)(6) based on color and growth at 24 hours on hardychrom (b)(6) agar per product insert instructions for reading media.There were three patient samples for which the hardy growth was not completely clear when initially tested.The lab therefore passaged the bacterial growth on a blood agar plate and then performed a vitek susceptibility to confirm whether the isolated (b)(6).In these three instances, vitek called the isolates (b)(6), and the isolates were reported as such.The isolates in the pseudo-outbreak were all frozen after isolation.During our investigation, all of the twelve isolates were retested by the vitek, and they all came back as mssa on repeat vitek testing.We tested the isolates on a new lot of hardychrom (b)(6) agar and bd chromagar mrsa in (b)(6) 2021.The twelve isolates all grew on hardychrom (b)(6) agar and did not grow on bd chromagar (b)(6).That is on a completely new lot of media, the twelve isolates would have been called (b)(6) using hardychrom (b)(6) agar, but not by the corresponding bd media.The recommended (b)(6) and mssa quality control strains grew as intended on these media, i.E., the mssa strain did not grow on either media, and the (b)(6) strain grew on both media, with the appropriate expected color changes.We presume it is likely that the cefotixin/oxacillin concentration is too low in the hardychrom media and this issue is not a lot specific issue.These strains also may have had minimal inhibitory concentrations that were somewhat higher than those of the normal population of mssa allowing them to break through and grow within appropriate color change on media with too low a selective antibiotic concentration.The nicu strains were isolated on hardychrom media that contained cefotoxitin/oxacillin (presumption, exact media concentration is proprietary), and therefore the bacterial strains were pre-adapted to the same selective antibiotics that are tested on the vitek.It could have been that such adaptation, though subtle, confused the vitek extrapolation algorithm leading to (b)(6) misidentification.Such adaptation is lost over time without selective pressure.The mechanisms may be genetic and/or epigenetic.When held or passaged enough times on non-selective media, this adaptation is lost and may account for vitek mssa calls when tested again several months later.

• Brand Name: HARDYCHROM
• Type of Device: CULTURE MEDIA, ANTIMICROBIAL SUSCEPTIBILITY TEST, EXCLUDING MUELLER HINTON AGAR
• Manufacturer (Section D): HARDY DIAGNOSTICS; 1430 west mccoy lane; santa maria CA 93455
• MDR Report Key: 12908064
• MDR Text Key: 281520465
• Report Number: 12908064
• Device Sequence Number: 1
• Product Code: JSO
• Combination Product (y/n): N
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: User Facility
• Reporter Occupation: Biomedical Engineer
• Type of Report: Initial
• Report Date: 11/15/2021,11/08/2021

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Model Number: G307
• Device Catalogue Number: G307
• Is the Reporter a Health Professional?: Yes
• Was the Report Sent to FDA?: Yes
• Date Report Sent to FDA: 11/15/2021
• Event Location: Hospital
• Date Report to Manufacturer: 12/01/2021
• Initial Date Manufacturer Received: Not provided
• Initial Date FDA Received: 12/01/2021
• Is This a Reprocessed and Reused Single-Use Device?: No
• Type of Device Usage: Unknown
• Patient Sequence Number: 1