1805. Molecular and clinical epidemiology of extended-spectrum beta-lactamase producing (ESBL) Escherichia coli in Japan: Characteristics of community-associated ESBL E. coli as compared to healthcare-associated ESBL E. coli
Session: Poster Abstract Session: Resistant Gram-Negative Infections: Epidemiology
Saturday, October 10, 2015
Room: Poster Hall

Background: Community-associated ESBL Escherichia coli (CA-ESBLEC) are recognized as a major clinical problem in various regions.

Methods: NCGM is a large tertiary care hospital in Japan. We included unique cases with ESBLEC isolation between October 2013 and September 2014. All ESBLEC isolates were screened using O25b-ST131 clone allele-specific PCR for pabB and the CTX-M b-lactamase gene. Patient information retrieved from medical charts was compared between CA-ESBLEC and healthcare-associated (HA)-ESBLEC.

Results: ESBLEC were identified in 76 patients from the urine (n=47, 61.8%), blood (n=8, 10.5%), sputum (n=12, 15.8%), wound (n=6, 7.9%), and intra-abdominal sites (n=3, 3.9%). In 45 patients, ESBLEC was isolated in outpatient settings or within 48 h of hospitalization. Twenty patients (26%) with ESBLEC had no discernible health-associated risk factors and were classified as the CA-ESBLEC group (Table). CA-ESBLEC was more frequently isolated from the urine and in benign prostatic hyperplasia (BPH) patients. Patients with HA-ESBLEC had higher Charlson comorbidity index than those with CA-ESBLEC. Overall, 75 (98.7%) ESBLEC were positive for CTX-M. CTX-M-15 was positive in 22 (28.9%), of which 17 were E. coli O25b-ST131 clones. CTX-M other than CTX-M-15 identified were CTX-M group 9 (n=45), group 1 (n=5), group 2 (n=2), and group 8 (n=1). There was no difference in antimicrobial susceptibility between the 2 groups (gentamicin susceptible [S], 61.8%; levofloxacin S, 22.4%; trimethoprim/sulfamethoxazole S, 44.7%).


A high prevalence of CA-ESBLEC in urine was identified in Japan. Although microbiological characteristics were similar, clinical characteristics differed between the 2 groups.

Table: Clinical and microbiological characteristics of ESBLEC in Japan

CA-ESBLEC (n=20)

HA-ESBLEC (n=56)


Age, years (mean SD)

64.9 24.7

69.6 20.5


Male n (%)

8 (42.1%)

21 (37.5%)



7 (35%)

4 (7.1%)


Median age-adjusted Charlson Comorbidity Index (IQR)

4 (2-5)

5 (4-7)


Isolated from urine

17 (85%)

30 (53.6%)


Indwelling device

5 (25%)

25 (44.6%)


Any antimicrobial exposure in the past 3 months

3 (15%)

38 (67.9%)



8 (40%)

14 (25%)



7 (35%)

10 (17.9%)


Kayoko Hayakawa, M.D., Ph.D., Maki Nagamatsu, MT, Kazuhisa Mezaki, M.T., Satoshi Kutsuna, M.D., Ph.D., Nozomi Takeshita, M.D., Ph.D., Kei Yamamoto, M.D., Yoshihiro Fujiya, M.D., Momoko Mawatari, M.D. and Norio Ohmagari, M.D., Ph.D., National Center for Global Health and Medicine (NCGM), Tokyo, Japan


K. Hayakawa, None

M. Nagamatsu, None

K. Mezaki, None

S. Kutsuna, None

N. Takeshita, None

K. Yamamoto, None

Y. Fujiya, None

M. Mawatari, None

N. Ohmagari, None

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