441. Clinical Characteristics and Virulence Factors of Escherichia coli Infections in Cancer Patients
Session: Poster Session: Hospital-acquired and Transplant Infections
Friday, October 30, 2009: 12:00 AM
Room: Poster Hall A
Background: Extraintestinal pathogenic E. coli (ExPEC) exhibit a broad range of virulence factors that enable them to cause infection. In non-immunocompromised hosts approximately 80% of isolates that cause infection can be classified as ExPEC. It is unknown whether E. coli infection in cancer patients is caused by virulent strains, as seen in patients without malignancies, or by less virulent strains which become invasive because of the immunocompromised status of cancer patients. Therefore, we studied the virulence factors of E. coli strains infecting cancer patients and determined the characteristics of the diseases.
Methods: From July 2007 to June 2008 we reviewed 306 episodes of E. coli infections (103 bloodstream, 129 urinary, and 74 other sites). Information on the clinical characteristics of the disease and outcome was collected. Genotypes for 7 ExPEC-associated virulence genes were determined by multiplex PCR.
Results: Overall, 44% of the isolates met molecular criteria for ExPEC (39% of bloodstream infections, 41% of UTI, and 53% of other infections). There was no significant difference for any of the types of infections in the proportion of ExPEC among patients with hematologic malignancies vs. solid tumors, neutropenia vs. non-neutropenia, or having received chemotherapy vs. not. Mortality was higher in bloodstream infections (11%) than in UTI and other infections (2.7% and 0.7%) but was not associated with the presence of an ExPEC isolate.
Conclusion: Overall, 44% of the isolates met molecular criteria for ExPEC (39% of bloodstream infections, 41% of UTI, and 53% of other infections). There was no significant difference for any of the types of infections in the proportion of ExPEC among patients with hematologic malignancies vs. solid tumors, neutropenia vs. non-neutropenia, or having received chemotherapy vs. not. Mortality was higher in bloodstream infections (11%) than in UTI and other infections (2.7% and 0.7%) but was not associated with the presence of an ExPEC isolate.
Javier Adachi, MD, Dept. of Infectious Diseases, Infection Control and Employee Health, The University of Texas M. D. Anderson Cancer Center, Houston, TX, Nadim Ajami, BS, The University of Texas Health Science Center at Houston, Houston, TX, Herbert DuPont, MD, FIDSA, St. Luke's Episcopal Hospital and Kelsey Research Foundation and Kelsey-Seybold Clinic, Houston, TX, Zhi-Dong Jiang, MD, PhD, University of Texas at Houston, School of Public Health, Houston, TX, James Johnson, PharmD, Wake Forest University Baptist Medical Center, Winston-Salem, NC, Brian Johnston, PhD, Issam Raad, MD, Jeffrey Tarrand, MD, M.D. Anderson Cancer Center, Houston, TX, Karen Vigil, MD, The University of Texas M. D. Anderson Cancer Center, Houston, TX and  K. J. Vigil, None..
J. A. Adachi, None..
N. Ajami, None..
B. Johnston, None..
Z. Jiang, None..
J. Tarrand, None. 
I. I. Raad,
Clorox Role(s): Consultant, Received: Consulting Fee.
Cubist Role(s): Consultant, Grant Investigator, Received: Grant Recipient, Consulting Fee.
Merck Role(s): Speaker's Bureau, Received: Speaker Honorarium.
Schering Plough and Pfizer Role(s): Grant Investigator, Speaker's Bureau, Received: Grant Recipient, Speaker Honorarium.
Versicolor, Enzon and Wyeth Role(s): Grant Investigator, Received: Grant Recipient.
Cook Role(s): Consultant, Grant Investigator, Speaker's Bureau, Other, Royalties related to patients licensed to Cook on which Dr. Raad is an inventor/co-inventor.
American Medical Systems Role(s): Other, Royalties related to patients licensed to HMP on which Dr. Raad is a co-inventor.
TyRx Role(s): Other, Royalties related to patients licensed to TyRx on which Dr. Raad is an inventor/co-inventor.
J. R. Johnson,
Merck, Bayer, Procter and Gamble, Wyeth-Ayerst, and Rochester Medical Role(s): Grant Investigator, Received: Grant Recipient.
Ortho-McNeil Role(s): Consultant.
H. L. DuPont,
Salix Pharmaceutical Company Role(s): Consultant, Research Relationship, Received: Speaker Honorarium.
Romark Institute for Medical Research Role(s): Consultant, Received: Consulting Fee.
Optimer Pharmaceuticals Role(s): Research Relationship, Received: Grant Recipient.
IOMAI Corporation Role(s): Research Relationship, Received: Grant Recipient.
McNeil Consumer Healthcare Role(s): Consultant, Received: Speaker Honorarium, Consulting Fee.
Merck Vaccine Division Role(s): Consultant, Received: Speaker Honorarium, Consulting Fee.