Teresa Zembower

Northwestern University, Evanston, Illinois, United States

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Publications (65)252.58 Total impact

  • I.A. Echenique · V Stosor · L Gallon · D Kaufman · C Qi · T.R. Zembower ·
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    ABSTRACT: Norovirus is a major cause of self-limited gastroenteritis worldwide. Prevention and treatment are thwarted by rapid viral evolution, and thus supportive care remains the mainstay of therapy. Chronic infection in immunocompromised hosts is increasingly described. We report a case of norovirus infection lasting 2543 days in a pancreas transplant recipient. Serial fecal specimens were obtained, from which a map of genetic relatedness was derived. The clinical course was complicated by renal failure that progressed to end-stage renal disease. Minimization of immunosuppression was associated with resolution of the infection. Subsequently, the patient experienced a suspected allograft rejection that did not compromise pancreas function. The patient later underwent living-related renal transplantation without recurrence of enteritis. This article is protected by copyright. All rights reserved.
    Transplant Infectious Disease 10/2015; DOI:10.1111/tid.12472 · 2.06 Impact Factor
  • Daniel P. Boyle · Teresa R. Zembower ·
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    ABSTRACT: Worldwide prevalence of antimicrobial resistance is rapidly increasing, primarily a result of antibiotic misuse in the medical community. Resistant infections involving the urinary tract are typically caused by gram-negative bacteria. When treating these infections, clinicians have few effective antimicrobials to choose from and many are associated with significant adverse effects. There are now situations when clinicians are tasked with managing infections from pan-resistant organisms; thus, it is of paramount importance that spread of resistance be controlled. This review discusses common gram-negative resistance classes, highlighting the mechanisms of resistance, risk factors, type of infections, treatment, and outcomes associated with each class.
    Urologic Clinics of North America 07/2015; 42(4). DOI:10.1016/j.ucl.2015.05.005 · 1.20 Impact Factor
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    ABSTRACT: A collaborative effort reduced catheter-associated urinary tract infections in the neuro-spine intensive care unit where the majority of infections occurred at our institution. Our stepwise approach included retrospective data review, daily rounding with clinicians, developing and implementing an action plan, conducting practice audits, and sharing of real-time data outcomes. The catheter-associated urinary tract infection rate was reduced from 8.18 to 0.93 per 1,000 catheter-days and standardized infection ratio decreased from 2.16 to 0.37. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
    American journal of infection control 06/2015; 43(8). DOI:10.1016/j.ajic.2015.04.184 · 2.21 Impact Factor

  • American Journal of Infection Control 06/2015; 43(6):S49. DOI:10.1016/j.ajic.2015.04.123 · 2.21 Impact Factor
  • Daniel P Boyle · Teresa R Zembower · Susheel Reddy · Chao Qi ·
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    ABSTRACT: Traditionally Mycobacterium avium complex (MAC) has been comprised of Mycobacterium avium and Mycobacterium intracellulare; however, advances in genetic sequencing have allowed discovery of several novel species. With these discoveries, investigation of differences in risk factors, virulence, and clinical outcomes have emerged. We conducted a retrospective cohort study evaluating all MAC isolates obtained from pulmonary specimens at our institution from 2000 to 2012 and investigated the clinical courses associated with distinct MAC species. To classify isolates into distinct species, a multilocus sequence analysis using rpoB and ITS as targets was performed. We reviewed patient medical records to analyze clinical characteristics and outcomes for the cohort. Of the isolates from the 448 included patients, 54% were M. avium, 18% were M. intracellulare, and 28% were Mycobacterium chimaera. Using the ATS/IDSA criteria, patients whose isolates were identified as M. avium (AOR 2.14; 95% CI, 1.33-3.44) or M. intracellulare (AOR 3.12; 95% CI, 1.62-5.99) were more likely to meet criteria for infection than patients with M. chimaera. Patients infected with M. chimaera were more likely to be prescribed an immunosuppressant compared to all other patients (AOR 2.75; 95% CI, 1.17-6.40). Patients treated for infections with M. avium (AOR 5.64; 95% CI, 1.51-21.10) and M. chimaera (AOR 4.47; 95% CI, 1.08-18.53) were more likely to have a clinical relapse/reinfection than those with M. intracellulare. Our findings suggest that specific MAC species have varying degrees of virulence and classifying MAC isolates into distinct species aids in identifying which patients are at a higher risk of clinical relapse.
    American Journal of Respiratory and Critical Care Medicine 04/2015; 191(11). DOI:10.1164/rccm.201501-0067OC · 13.00 Impact Factor
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    ABSTRACT: As the optimal administration time for fosfomycin peri-procedural prophylaxis is unclear, we sought to determine optimal administration times for fosfomycin peri-procedural prophylaxis. Plasma, peripheral zone and transition zone fosfomycin concentrations were obtained from 26 subjects undergoing transurethral resection of the prostate (TURP), following a single oral dose of 3 g of fosfomycin. Population pharmacokinetic modelling was completed with the Nonparametric Adaptive Grid (NPAG) algorithm (Pmetrics package for R), with a four-compartment model. Plasma and tissue concentrations were simulated during the first 24 h post-dose, comparing these with EUCAST susceptibility breakpoints for Escherichia coli, a common uropathogen. Non-compartmental-determined pharmacokinetic values in our population were similar to those reported in the package insert. Predicted plasma concentrations rapidly increased after the first hour, giving more than 90% population coverage for organisms with an MIC ≤4 mg/L over the first 12 h post-dose. Organisms with higher MICs fared much worse, with organisms at the EUCAST breakpoint being covered for <10% of the population at any time. Transitional zone prostate concentrations exceeded 4 mg/L for 90% of the population between hours 1 and 9. Peripheral zone prostate concentrations were much lower and only exceeded 4 mg/L for 70% of the population between hours 1 and 4. Until more precise plasma and tissue data are available, we recommend that fosfomycin prophylaxis be given 1-4 h prior to prostate biopsy. We do not recommend fosfomycin prophylaxis for subjects with known organisms with MICs >4 mg/L. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
    Journal of Antimicrobial Chemotherapy 03/2015; 70(7). DOI:10.1093/jac/dkv067 · 5.31 Impact Factor
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    ABSTRACT: Background: The hospital environment poses a substantial risk for transmission of pathogens. Assessing cleaning efficacy is difficult and often relies on a subjective visual check. A multidisciplinary approach is required to evaluate and improve hospital cleanliness. However, an objective, reliable quality indicator is needed as an outcome metric to assess the cleanliness of the environment. Technology is available to detect adenosine triphosphate (ATP), a substance present in organic matter, which can generate a measure of cleanliness. Methods: From August 2013-March 2014, we swabbed 30 discharge-cleaned rooms per week using the ATP technology in six nursing units, selected based on historical multi-drug-resistant organism (MDRO) transmission data. Up to 17 high-touch surfaces were sampled per room. The 3M Clean-Trace luminometerTM quantifies organic material on each surface. A reading below 250 RLU is considered a clean surface. If more than 30% of surfaces per room fail, recleaning is required. Metrics included: percentage of surfaces that fail, room fail rate, percent fails by surface, percent fails by unit, room fail rate, and MDRO transmission in relation to surface fails. Nursing, Infection Prevention, and Environmental Services management were responsible to test rooms. The data were used to formulate intervention strategies. Results: Weekly data showed an improvement over time trending towards the goal of 90% (figure 1) Over eight months, the average monthly clean surface rate increased from 77% pre-intervention to 84% post-intervention (figure 2). We also saw a relationship between multi-drug resistant organism (MDRO) transmission and room cleanliness (figure 3.). Intervention strategies included retraining EVS staff on appropriate cleaning practices, posting pictures of high-touch surfaces, distributing a fact of the week, weekly data feedback, and performing real-time ATP process with the EVS staff that cleaned the room. Conclusion: The ability to assess cleaning performance with an objective, reliable metric, and analyze the data by individual touch point and staff accountability, led to improved cleanliness, reduced MDRO transmission risk, and enhanced collaboration efforts among Nursing, IP and EVS.
    IDWeek 2014 Meeting of the Infectious Diseases Society of America; 10/2014
  • Daniel P. Boyle · Teresa R. Zembower · Chao Qi ·
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    ABSTRACT: We evaluated the ability of the Vitek MS system to classify clinical pulmonary Mycobacterium avium complex isolates compared to Multilocus Sequence Analysis (MLSA). Vitek MS accurately identified 55% of the isolates as M. avium and 18% as M. intracellulare, but misidentified 24 (27%) M. chimaera isolates as M. intracellulare.
    Diagnostic Microbiology and Infectious Disease 10/2014; 81(1). DOI:10.1016/j.diagmicrobio.2014.09.026 · 2.46 Impact Factor
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    ABSTRACT: Institution of appropriate airborne infection isolation (AII) precautions for patients with suspected Mycobacterium tuberculosis is critical to prevent disease transmission. We compared the yield of acid-fast bacilli smears from different types of respiratory specimens and found that smear sensitivity was highest for specimens obtained by endotracheal aspirates (92%), followed by sputum (79%), and then by bronchoalveolar lavage (37%). As a result of this study, our institutional policy regarding discontinuation of AII precautions was amended.
    American Journal of Infection Control 09/2014; 42(11). DOI:10.1016/j.ajic.2014.08.005 · 2.21 Impact Factor
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    ABSTRACT: Optimal surveillance strategies for identifying patients colonized with and at risk for transmitting carbapenem-resistant Enterobacteriaceae (CRE) are urgently needed. We instituted an enhanced surveillance program for CRE that identified unrecognized CRE-colonized patients but failed to identify possible CRE transmissions. We also identified risk factors associated with transmitting CRE.
    Infection Control and Hospital Epidemiology 04/2014; 35(4):419-22. DOI:10.1086/675595 · 4.18 Impact Factor
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    ABSTRACT: Clinical studies have suggested that blaOXA-40-positive A. baumannii isolates are associated with poor patient outcomes; however, reasons for unfavorable outcomes are difficult to discern in clinical studies. The objective of this study was to assess the virulence of carbapenem-resistant A. baumannii according to blaOXA-40and epidemiological outbreak status in a Galleria mellonella model. Eight isolates of A. baumannii were studied. Non-outbreak isolates and blaOXA-40-negative isolates caused more rapid fatality of infected G. mellonella (p<0.01).
    Antimicrobial Agents and Chemotherapy 12/2013; 58(2). DOI:10.1128/AAC.02201-13 · 4.48 Impact Factor
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    ABSTRACT: Purpose We determine the prevalence of ciprofloxacin resistant gram-negative bacilli in patients scheduled for transrectal ultrasound guided prostate biopsy, characterize the Escherichia coli strains recovered from this patient population, and characterize the mechanisms responsible for β-lactam and ciprofloxacin resistance. Materials and Methods Rectal swabs from 991 patients were cultured for ciprofloxacin resistant gram-negative bacilli with a selective medium. Recovered E. coli isolates were further analyzed with susceptibility testing, pulsed field gel electrophoresis, plasmid isolation and sequencing. Results A total of 193 ciprofloxacin resistant gram-negative bacilli were recovered and of these isolates 167 (87%) were E. coli. The prevalence of ciprofloxacin resistant E. coli in the study population was 17%. Only 38 (26%) of the 149 E. coli isolates that received susceptibility testing were susceptible to ampicillin and ampicillin-sulbactam. In select isolates transferrable plasmids carrying β-lactamase were responsible for the resistance to the β-lactam agents and other nonβ-lactam antimicrobials. Diverse combinations of gyrA and parC mutations associated with fluoroquinolone resistance were identified. Strain typing and plasmid typing indicated that the E. coli isolates did not share a common origin. Conclusions Of the patients in our study 17% carried ciprofloxacin resistant E. coli. Analysis of resistance mechanisms and plasmid analysis along with strain typing demonstrated that this patient population harbored organisms with heterogeneous phenotypic susceptibility, indicating that universal prophylaxis would not provide optimal coverage for patients undergoing transrectal ultrasound guided prostate biopsy.
    The Journal of urology 12/2013; 190(6):2026–2032. DOI:10.1016/j.juro.2013.05.059 · 4.47 Impact Factor
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    ABSTRACT: Assessing clinical virulence differences between vancomycin-resistant Enterococcus faecium (VREF) resistant to linezolid (LRVRE) and to linezolid susceptible VREF (LSVRE) is difficult due to confounding patient variables. Galleria mellonella is a validated host-interaction model allowing for straight forward organism virulence assessment. The objectives of this study were to assess the virulence of VREF in G. mellonella according to linezolid resistance and clinical outbreak status. A genetically related pair of VREF strains with and without genotypically confirmed linezolid resistance was selected for analysis. Additionally, six strains of LSVRE and two strains of LRVRE were selected according to epidemiologic outbreak status. Mortality of G. mellonella was assessed daily over a five day period and analyzed using Kaplan-Meier survival curves and log rank tests. Linezolid resistance did not have a significant effect on G. mellonella mortality in the genetically related pair (p=0.93). There was no significant difference in mortality over time between outbreak strains (non-outbreak (n=2) vs. outbreak (n=6), p=0.84; extensive (n=2) vs. limited (n=4), p=0.78). These results suggest that patients infected with LRVRE or outbreak strains of VREF are at no greater risk of poor outcomes mediated by organism virulence than those infected with LSVRE or non-outbreak strains.
    Antimicrobial Agents and Chemotherapy 06/2013; 57(8). DOI:10.1128/AAC.00192-13 · 4.48 Impact Factor

  • American Journal of Infection Control 06/2013; 41(6):S23. DOI:10.1016/j.ajic.2013.03.047 · 2.21 Impact Factor

  • American Journal of Infection Control 06/2013; 41(6):S121-S122. DOI:10.1016/j.ajic.2013.03.243 · 2.21 Impact Factor
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    ABSTRACT: Background: Patients are often screened with surveillance cultures to discern transmissions vs transformation of an isolate to vancomycin-resistant Enterococcus faecium. To determine the amount of time between which isolates could be considered genetically similar by pulsed-field gel electrophoresis, isolate change over time within single patients was studied. Methods: A minimum of 4 isolates per patient, separated by at least 2 months, were collected from previously frozen stores. Visual comparison of banding patterns was conducted, and percent relatedness was calculated. Results: Twenty-eight isolates from 6 patients were studied. No isolate differed by more than 3 bands before 150 days, and the average percent difference per band was 3.7%. The isolates diverged genetically as a linear function of number of bands over time (good model fit intrapatient r(2) = 0.42; poor model fit interpatient r(2) = 0.0062). Conclusion: Trajectory of genetic variation appears to be isolate/patient specific; however, commonalities exist and tested isolates were relatively stable out to 150 days.
    American journal of infection control 10/2012; 41(4). DOI:10.1016/j.ajic.2012.05.014 · 2.21 Impact Factor
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    ABSTRACT: Antimicrobial drug shortages continue to increase, with few new therapeutic options available. Nationally, proposals have been offered to alleviate drug shortages; however, these recommendations are unlikely to effect change in the near future. Thus, antimicrobial stewardship leaders in acute care hospitals must develop a prospective management strategy to lessen the impact of these shortages on patient care. Herein, we describe several resources available to aid professionals in antimicrobial stewardship and healthcare epidemiology to manage drug shortages. An effective approach should include prospectively tracking shortages and maximizing inventory by appropriately managing usage. Several tenets should underpin this management. Alternative agents should be rationally chosen before the inventory of the primary agent has reached zero, ethical considerations should be taken into account, and timely notification and communication with key stakeholders should occur throughout the prescribing and dispensing process.
    Infection Control and Hospital Epidemiology 07/2012; 33(7):745-52. DOI:10.1086/666332 · 4.18 Impact Factor
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    ABSTRACT: The emergence of the pandemic H1N1 influenza strain in 2009 reinforced the need for improved influenza surveillance efforts. A previously described influenza typing assay that utilizes RT-PCR coupled to electro-spray ionization mass spectrometry (ESI-MS) played an early role in the discovery of the pandemic H1N1 influenza strain, and has potential application for monitoring viral genetic diversity in ongoing influenza surveillance efforts. To determine the analytical sensitivity of RT-PCR/ESI-MS influenza typing assay for identifying the pandemic H1N1 strain and describe its ability to assess viral genetic diversity. Two sets of pandemic H1N1 samples, 190 collected between April and June of 2009, and 69 collected between October 2009 and January 2010, were processed by the RT-PCR/ESI-MS influenza typing assay, and the spectral results were compared to reference laboratory results and historical sequencing data from the Nucleotide Database of the National Center for Biotechnology Information (NCBI). Strain typing concordance with reference standard testing was 100% in both sample sets, and the assay demonstrated a significant increase in influenza genetic diversity, from 10.5% non-wildtype genotypes in early samples to 69.9% in late samples (P<0.001). An NCBI search demonstrated a similar increase, from 13.4% to 45.2% (P<0.001). This comparison of early versus late influenza samples analyzed by RT-PCR/ESI-MS demonstrates the influenza typing assay's ability as a universal influenza detection platform to provide high-fidelity pH1N1 strain identification over time, despite increasing genetic diversity in the circulating virus. The genotyping data can also be leveraged for high-throughput influenza surveillance.
    Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 06/2012; 54(4):332-6. DOI:10.1016/j.jcv.2012.05.002 · 3.02 Impact Factor
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    ABSTRACT: Anti-infective shortages pose significant logistical and clinical challenges to hospitals and may be considered a public health emergency. Anti-infectives often represent irreplaceable life-saving treatments. Furthermore, few new agents are available to treat increasingly prevalent multidrug-resistant pathogens. Frequent anti-infective shortages have substantially altered patient care and may lead to inferior patient outcomes. Because many of the shortages stem from problems with manufacturing and distribution, federal legislation has been introduced but not yet enacted to provide oversight for the adequate supply of critical medications. At the local level, hospitals should develop strategies to anticipate the impact and extent of shortages, to identify therapeutic alternatives, and to mitigate potential adverse outcomes. Here we describe the scope of recent anti-infective shortages in the United States and explore the reasons for inadequate drug supply.
    Clinical Infectious Diseases 03/2012; 54(5):684-91. DOI:10.1093/cid/cir954 · 8.89 Impact Factor
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    ABSTRACT: We evaluated targeted antimicrobial prophylaxis in men undergoing transrectal ultrasound guided prostate biopsy based on rectal swab culture results. From July 2010 to March 2011 we studied differences in infectious complications in men who received targeted vs standard empirical ciprofloxacin prophylaxis before transrectal ultrasound guided prostate biopsy. Targeted prophylaxis used rectal swab cultures plated on selective media containing ciprofloxacin to identify fluoroquinolone resistant bacteria. Patients with fluoroquinolone susceptible organisms received ciprofloxacin while those with fluoroquinolone resistant organisms received directed antimicrobial prophylaxis. We identified men with infectious complications within 30 days after transrectal ultrasound guided prostate biopsy using the electronic medical record. A total of 457 men underwent transrectal ultrasound guided prostate biopsy, and of these men 112 (24.5%) had rectal swab obtained while 345 (75.5%) did not. Among those who received targeted prophylaxis 22 (19.6%) men had fluoroquinolone resistant organisms. There were no infectious complications in the 112 men who received targeted antimicrobial prophylaxis, while there were 9 cases (including 1 of sepsis) among the 345 on empirical therapy (p=0.12). Fluoroquinolone resistant organisms caused 7 of these infections. The total cost of managing infectious complications in patients in the empirical group was $13,219. The calculated cost of targeted vs empirical prophylaxis per 100 men undergoing transrectal ultrasound guided prostate biopsy was $1,346 vs $5,598, respectively. Cost-effectiveness analysis revealed that targeted prophylaxis yielded a cost savings of $4,499 per post-transrectal ultrasound guided prostate biopsy infectious complication averted. Per estimation, 38 men would need to undergo rectal swab before transrectal ultrasound guided prostate biopsy to prevent 1 infectious complication. Targeted antimicrobial prophylaxis was associated with a notable decrease in the incidence of infectious complications after transrectal ultrasound guided prostate biopsy caused by fluoroquinolone resistant organisms as well as a decrease in the overall cost of care.
    The Journal of urology 02/2012; 187(4):1275-9. DOI:10.1016/j.juro.2011.11.115 · 4.47 Impact Factor

Publication Stats

1k Citations
252.58 Total Impact Points


  • 2004-2015
    • Northwestern University
      • • Division of Infectious Diseases (Dept. of Medicine)
      • • Division of Gastroenterology and Hepatology
      • • Feinberg School of Medicine
      Evanston, Illinois, United States
  • 1998-2015
    • Northwestern Memorial Hospital
      • Department of Pharmacy
      Chicago, Illinois, United States
  • 2008-2014
    • United States Army Medical Research Institute for Infectious Diseases
      Фредерик, Maryland, United States
  • 2003-2007
    • University of Illinois at Chicago
      Chicago, Illinois, United States