1281. Increasing Rates of Extended Spectrum beta-Lactamase Producing Escherichia coli Urinary Isolates from 2007-2010
Session: Poster Abstract Session: Urinary Tract Infections
Saturday, October 22, 2011
Room: Poster Hall B1
Background: E. coli is a frequent cause of urinary tract infections (UTI) in the community and hospital settings with increasing resistance in community acquired isolates due to extended-spectrum beta-lactamase (ESBL) production.   The ability to hydrolyze extended-spectrum cephalosporins and beta-lactams reduces oral agents available for outpatient therapy. We describe the changing rates of ESBL-producing E. coli UTIs at a single military treatment facility.

Methods: ESBL-producing  E. coli isolated from urine cultures were collected and analyzed from 2007 to 2010.  Susceptibility testing was performed using VITEK 2, Phoenix and broth microdilution.  Clonality was assessed by PFGE using Xba I restricted DNA and commercial software (BioNumerics, Applied Maths Inc) to evaluate relatedness defined by 85% similarity. Isolates that were collected during an outpatient status were described. Susceptibility to oral antimicrobials was reported for ciprofloxacin, nitrofurantoin, and trimethoprim-sulfamethoxazole.

Results: The number of ESBL-producing E. coli isolated from urine specimens at our facility increased each year. There was not a predominant pulsed-field type (PFT) observed. Nitrofurantoin retained good antimicrobial activity in contrast to ciprofloxacin or trimethoprim-sulfamethoxazole.

 

 

# of Isolates

# of Outpatient Isolates

# of PFTs

% Susceptible*

 

 

 

 

Ciprofloxacin

Nitrofurantoin

Trimethoprim-sulfamethoxazole

2007

13

8

8

15

100

23

2008

17

12

12

0

94

6

2009

23

17

14

9

96

17

2010

31

24

18

10

90

35

*all isolates

Conclusion: We observed continual increase in ESBL-producing E. coli UTIs in our facility between 2007 and 2010 with 73% collected in the outpatient setting. Nitrofurantoin was the only oral antimicrobial that retained adequate activity.


Subject Category: J. Clinical practice issues

Ana E. Markelz, MD1, Katrin Mende, PhD2, Wendy Zera, BS3, Kristelle Cheatle, BA1, Xin Yu1, Miriam Beckius, MPH1, Duane Hospenthal, MD, PhD4 and Clinton K. Murray, MD1, (1)San Antonio Military Medical Center, Fort Sam Houston, TX, (2)Infectious Disease Clinical Research Program, Uniformed Services University, Bethesda, MD, (3)Infectious Disease Clinical Research Program, Fort Sam Houston, TX, (4)San Antonio Military Medical Center, MCHE MDI 7 East, TX

Disclosures:

A. E. Markelz, None

K. Mende, None

W. Zera, None

K. Cheatle, None

X. Yu, None

M. Beckius, None

D. Hospenthal, None

C. K. Murray, None

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