Program Schedule

Molecular Detection of Multi-Drug Resistant Organism (MDRO) Colonization in a High Risk Patient Population

Session: Poster Abstract Session: Multidrug-resistant Organisms: Epidemiology and Prevention
Thursday, October 9, 2014
Room: The Pennsylvania Convention Center: IDExpo Hall BC
Background: Multi-Drug Resistant Organisms (MDROs) present substantial clinical and financial burden to patients and hospitals. Links between MDRO colonization and risk of subsequent infection in high risk patient (pt) populations are not fully characterized. Rapid molecular identification of MDRO could optimize detection, outbreak investigation, and implementation of measures to interrupt transmission.

Methods: Prospective surveillance for nasal and perianal MDRO colonization was instituted over a 3 month period in pts admitted to the Children’s National Medical Center oncology (onc) and stem-cell transplant (SCT) wards.  MDRO was defined as Methicillin Resistant Staphylococcus aureus(MRSA), Vancomycin-Resistant Enterococcus (VRE), Extended-spectrum Beta-lactamase producing gram negatives (ESBL), and Carbapenem-resistant Enterobacteriaceae (CRE). Enrolled subjects were subsequently monitored for 3-6 months for presence of invasive infection and any correlation with colonization. Nasal and perianal E-swabs were simultaneously analyzed using standard culture-based screening methods, as well as Acuitas MDRO GeneTest molecular screen.

Results: Forty-eight pts were enrolled, from whom 42 perianal and 32 nasal swabs were obtained. Using standard culture-based screening methodology, 14/42 (33%) perianal and 0/32 (0%) nasal swabs screened positive for possible MDRO. Acuitas molecular screen and subsquent standard culture and susceptibility test confirmed 4 of these 14 as actual MDRO (4/42;10%); 3 VRE (VanA) and 1 ESBL (CTX-M).  Three to six month follow-up revealed no MDRO invasive infections in the study cohort.  Non-MDRO invasive infections were identified in 10/48 (21%) subjects due to Bacillus, Klebsiella (IBL), Micrococcus, Pseudomonas, rapid growing Mycobacteria, Staphylococcus aureus, and Streptococcus viridans.  Eight of 10 infected subjects were not previously colonized with any pathogen; 1 was colonized with different pathogens, and 1 was both colonized and infected with Pseudomonas, but with differing susceptibilities.

Conclusion: Acuitas molecular screen and standard culture accurately identified and excluded MDRO colonization in onc and SCT pts.  Colonization with non-MDRO or MDRO pathogens did not predict likelihood or etiology of subsequent invasive infection.

Xiaoyan Song, PhD, MBBS1,2, Doug Toal, PhD3, Terry Walker4, Evelio Perez, MD, PhD5, Joseph Campos, PhD6,7 and Roberta Debiasi, MD1,8, (1)George Washington University School of Medicine, Washington, DC, (2)Infectious Disease, Children's National Medical Center, Washington, DC, (3)Clinical Services, OpGen, Inc, Gaithersburg, MD, (4)R&D, OpGen Inc, Gaithersburg, MD, (5)Pediatrics, George Washington University School of Medicine, Washington, DC, (6)Laboratory Medicine, Children's National Medical Center, Washington, DC, (7)Of Pediatrics, Pathology, and Microbiology/Immunology/Tropical Medicine, George Washington University School of Medicine, Washington, MD, (8)Children's National Medical Center, Washington, DC


X. Song, OpGen Inc.: Grant Investigator, Grant recipient

D. Toal, OpGen, Inc.: Consultant, Consulting fee

T. Walker, OpGen Inc.: Employee and Shareholder, Salary

E. Perez, None

J. Campos, OpGen Inc: Grant Investigator, Grant recipient

R. Debiasi, opgen: Grant Investigator, Grant recipient

Findings in the abstracts are embargoed until 12:01 a.m. EDT, Oct. 8th with the exception of research findings presented at the IDWeek press conferences.

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