The Microbiology section of the Delaware Public Health Laboratory (DPHL) provides routine antimicrobial susceptibility testing (AST) for pathogenic organisms. As part of the Antimicrobial Resistance Laboratory Network (ARLN) the section also provides surveillance of drug resistance exhibited in multi-drug resistant organisms (MDRO). Examples of MDRO include Vancomycin resistant Enterococcus (VRE) or Staphylococcus aureus (VRSA), carbapenem resistant organisms (CRO), drug resistance Tuberculosis, and drug resistant Neisseria gonorrhoeae to name a few. Please contact the DPHL with questions or concerns regarding atypical drug resistance.

In 2016, the Centers for Disease Control and Prevention (CDC) established the ARLN to connect laboratories nationwide, with the goal of rapidly detecting resistant organisms and coordinating with local agencies to reduce spread for the protection of the people. DPHL's role within this network includes working closely with the Office of Infectious Disease Epidemiology (OIDE) and infection control specialists at acute and long-term care facilities throughout the state, to provide timely results and alerts, when appropriate. As atypical resistance profiles are detected, DPHL works with our ARLN regional lab, the CDC, and impacted facilities to develop and implement response plans.

DPHL receives grant funding to test carbapenem resistant Enterobacteriaceae (CRE), Pseudomonas aeruginosa (CRPA), and Acinetobacter baumannii (CRAB), as they are considered urgent threats by CDC reports. The Microbiology section performs bacterial identification and AST on isolates submitted by state partners. Testing is followed by screening for resistance genes using the modified Carbapenemase Inactivation Method (mCIM). A positive mCIM reflexes to molecular detection for the following plasmid-mediated resistance genes by real time PCR and whole genome sequencing (WGS):

• Klebsiella pneumoniae Carbapenemase (KPC)
• New Delhi Metallo-beta-lactamase (NDM)
• Verona integron-encoded Metallo-beta-lactamase (VIM)
• Oxacillinase (OXA)-48 like
• Imipenemase (IMP)

CDC funding through the ARLN also supports DPHL in providing yeast surveillance testing. New and emerging antifungal resistance has become of increasing concern for Candida species, particularly with Candida auris. Other Candida spp., such as C. glabrata and C. parapsilosis, are also considered a public health threat due to concerning resistance patterns. Candida auris primarily affects individuals with underlying medical conditions that often require complex medical care. Individuals that are colonized with C. auris may not exhibit symptoms of active infection. However, those colonized may transmit the organism onto surrounding surfaces, where they can survive for weeks to months, or they may transmit the organism to other individuals. The CDC recommends testing high-risk individuals, to determine colonization status and allow infection control preventionists to make informed decisions to prevent further spread. Candida auris colonization testing is currently performed by the ARLN regional lab, Maryland Public Health Laboratory (MPHL). An in-house Candida auris colonization test is currently planned for completion in 2024.

DPHL receives isolates from laboratory facilities within the state for yeast identification and confirmation. As part of the Mid-Atlantic Region of the ARLN, the DPHL sends these isolates, in compliance with the Department of Transportation's requirements for packaging and shipping infectious organisms, to MPHL for further work-up, including antifungal susceptibility testing. Furthermore, the collaboration with our regional partners at MPHL allows for additional services that include, but are not limited to:

• Neisseria gonorrhoeae antibiotic susceptibility testing
• Carbapenem Resistant Organism colonization screening
• Carbapenem Resistant Acinetobacter baumannii surveillance
• Carbapenem Resistant Organism mechanism surveillance
• Candida auris colonization screening
• Non-Candida albicans antimicrobial susceptibility testing
• Aspergillus fumigatus azole susceptibility testing

Additional information about CDC's ARLN can be found here.

Partners:

• Office of Infectious Disease Epidemiology (OIDE)
• Association of Public Health Laboratories (APHL)
• Centers for Disease Control and Prevention (CDC)
• List of reportable diseases

The Centers for Disease Control and Prevention (CDC) has published an extensive amount of information highlighting AMR threats over the last 10 years. They can be found here: Press Release: Antibiotic Resistance | CDC

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This page was last updated 4/24

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