Methods: Ninety-nine stool samples received for Clostridium difficile PCR testing at Cleveland Clinic were also analyzed at OpGen using the Acuitas® MDRO Gene Test, a microfluidic PCR array targeting seven antimicrobial resistance gene families (CTX-M, KPC, NDM, VIM, IMP, OXA, VanA). Stool was incubated overnight in tryptic soy broth containing 3 µg/mL ceftriaxone. The medical records of patients carrying genes associated with Gram-negative MDRO were reviewed.
Results: The positivity rate for C. difficile PCR was 16%. VanA was detected in 51 patients. Samples from 12 patients were positive for Gram-negative resistance genes. CTX-M-1 genes were detected in the stool of six patients and infections due to ESBL-producing Klebsiella pneumoniae or Escherichia coli were documented in four of the patients. Gram-negative infections caused by carbapenem-resistant or AmpC phenotype organisms occurred in the remaining patients with CTX-M-1 carriage. KPC resistance genes were detected in five stool samples and three of those patients had Gram-negative MDRO infections (two with carbapenem-resistant K. pneumoniae.and one with an AmpC phenotype Enterobacter aerogenes). The one patient with VIM detected in the stool had abdominal drainage fluid cultures with meropenem-resistant Pseudomonas aeruginosa. OXA-23 was detected in the stool of one patient and the only documented Gram-negative infection was not caused by an MDRO.
Conclusion: Colonization with OXA, VIM, KPC, and CTX-M genes was observed in 1%, 1%, 5% and 6% of inpatients. The majority of patients (75%) with carriage of these genes had multidrug-resistant Gram-negative infections.
S. S. Richter,
OpGen: Investigator , Research support
bioMerieux: Investigator , Research support
Nanosphere: Investigator , Research support
Cerexa: Investigator , Research support
Pocared: Investigator , Research support
Biofire: Investigator , Research support
Achaogen: Investigator , Research support
S. M. Harrington, None
B. Yen-Lieberman, None
T. Rockweiler, OpGen: Employee , Salary
T. Wagner, OpGen: Employee , Salary