Job Mendez

Carbapenem-Resistant Enterobacteriaceae Detection Practices in California: What Are We Missing?

Background The Clinical and Laboratory Standards Institute (CLSI) revised the carbapenem breakpoints for Enterobacteriaceae in 2010. The number of hospitals that adopted revised breakpoints and the clinical impact of delayed adoption has not been explored. Methods We performed a cross-sectional, voluntary survey of microbiology laboratories from California acute care hospitals and long-term acute care hospitals (LTAC) to determine use of revised CLSI breakpoints. Carbapenem-resistant Enterobacteriaceae (CRE) clinical isolates from a single tertiary-care hospital from 2013 to 2017 were examined. All isolates with an elevated minimum inhibitory concentration (MIC; ≥2 µg/mL) to imipenem or meropenem were tested for the presence of carbapenemase genes by polymerase chain reaction (PCR). Results We received responses from 128 laboratories that serve 264/393 (67%) of hospitals and LTACs. Current CLSI carbapenem breakpoints for Enterobacteriaceae were used by 92/128 (72%) laboratories. Among laboratories that used current breakpoints, time to implementation varied from 0 to 68 months (mean, 41 months; median, 55 months). Application of historical breakpoints to isolates with a carbapenemase gene detected by PCR resulted in susceptibility rates of 8.9%, 18.6%, and 18.6% to ertapenem, imipenem, and meropenem, respectively. By current breakpoints, <1% of these isolates were susceptible to ertapenem or imipenem and 2.6% to meropenem. Conclusion Clinicians and epidemiologists should be aware that use of outdated MIC breakpoints for Enterobacteriaceae remains common and can result in reports of false susceptibility to carbapenems and missed identification of carbapenemase producers. This misclassification could have consequences for patient care and infection control efforts to address carbapenemase-producing Enterobacteriaceae.

The Regional Antibiogram Is an Important Public Health Tool to Improve Empiric Antibiotic Selection, Stenotrophomonas maltophilia As A Case Example

Abstract Background Early appropriate antibiotic selection is life saving in sepsis. Facility-level antibiograms inform antibiotic selection after pathogen identification and before susceptibility results are available, but only if ≥ 30 isolates from a given species are tested in the prior year. Stenotrophomonas maltophilia (SM) has a complex resistance profile and is associated with an 8-fold mortality increase. We hypothesized that a regional antibiogram may help inform clinical decision-making for severe SM infections. Methods To generate a regional SM antibiogram, we conducted a cross-sectional, voluntary survey of 2015 cumulative facility-level antibiograms from all hospitals in LA county. Non-respondents were contacted to improve response rates. Isolates from sterile sources were pooled. Susceptibility was aggregated and percent susceptible was calculated only when all isolates were tested, i.e. not reflex testing. To identify optimal combination empiric therapy for SM infections, we generated a combination antibiogram using broth microdilution results from a single tertiary care facility in LA. Results Antibiograms were submitted by 85/100 (85%); 50 hospitals (59%) reported SM (n = 1719 isolates, Table 1). Hospitals commonly (25/50) reported data for <30 isolates. The combination antibiogram for SM is presented in Table 2. Four hospitals reported susceptible results for antibiotics to which SM is intrinsically resistant (ceftriaxone, meropenem, aminoglycosides). After SXT, the most active antibiotics against SM were not routinely tested by the majority of laboratories (minocycline, colistin) (Table 2). Conclusion The LAC regional antibiogram represents one of the largest reports of SM susceptibility presented to date. Hospitals rarely tested sufficient numbers of SM isolates to provide reliable estimates for resistance and failed to report on clinically valuable treatment options. Regional antibiograms may help hospitals with low pathogen prevalence improve antibiotic selection and reduce mortality for uncommon but potentially deadly pathogens. Disclosures L. G. Miller, Sage Products: Study coordination, Conducting studies in healthcare facilities that are receiving contributed product. Xttrium: Study coordination, Conducting studies in healthcare facilities that are receiving contributed product. Clorox: Study coordination, Conducting studies in healthcare facilities that are receiving contributed product. 3M: Study coordination, Conducting studies in healthcare facilities that are receiving contributed product. J. A. McKinnell, Allergan: Research Contractor, Scientific Advisor and Speaker’s Bureau, Consulting fee, Research support and Speaker honorarium. Achaogen: Research Contractor, Scientific Advisor and Shareholder, Research support. Cempra: Research Contractor and Scientific Advisor, Research support. Theravance: Research Contractor, Research support. Science 37: Research Contractor, Salary. Expert Stewardship, LLC: Board Member and Employee, Salary. Thermo Fisher: Scientific Advisor, Salary

Capacity Building within the Microbiology Laboratory is Needed to Ensure Implementation of Strategies to Control the Spread of CRE

Erin Epson,1 Sam Horwich-Scholefield,1 Romney Humphries2 Janet Hindler,2 Christina Hershey,3,4 Loren G. Miller,3,4 Job Mendez,3 Dawn Terashita,5 Patricia Marquez,5 Sandeep Bhaurla,5 Marcelo Moran,5 Lindsey Pandes,5 James A. McKinnell 3,4 1. California Department of Public Health 2. Department of Pathology and Laboratory Medicine, UCLA, Los Angeles 3. ID-CORE at LA BioMed Research Institute at HarborUCLA 4. David Geffen School of Medicine at University of California, Los Angeles 5. Los Angeles County Department of Public Health Poster 1490: Dr.McKinnell@yahoo.com