ESBL Active Surveillance Culture in patients rehospitalized from other facilities

Background: Extended-spectrum beta-lactamase (ESBL)-producing strains are a drug-resistant bacterium, which is being increasingly isolated, in medical facilities. It is often found in Enterobacteria such as Escherichia coli, Proteus mirabilis and Klebsiella pneumoniae and these microbes are originally normal human flora in intestinal canal. Therefore, it has been unclear in routine medical specimens how drug-resistance is held. Objective: We've examined ESBL Active Surveillance Culture (ASC) in patients rehospitalized from other facilities. Setting: The study was conducted at Sendai Kosei Hospital, a 383-bed, community hospital in Miyagi prefecture, Japan. Methods: Targeting all patients who had been rehospitalized to the hospital (except for those from their home) since June 1, 2008 to June 30, 2009, we've collected samples of stool from those who agreed to the collection. With the collected samples directly streaked on chrom ID to be cultured at 35℃, developed colony of Enterobacteria has been identified by Enterotube (Becton, Dickinson and Company, USA) to be confirmed its beta-lactamase production by using disk method, and its susceptibility has also been confirmed and determined by using dry plate Eiken DPD1 ESBL (Eiken Chemical Co., Ltd, Japan). All microbiological methods used were consistent with current CLSI recommendations. Results: Of 527 patients tested during the period, ESBL has been detected in 97 (18.4%) patients totally. Of all cases, E. coli has been found in 46 (47.4%) cases, P. mirabilis in 47 (48.4%) cases, concurrent isolation of E. coli and P. mirabilis in one case, K. pneumoniae in one case and K. oxytoca in one case respectively. The average age of the patients with ESBL-producing strains detected was 83.1, and facilities they had stayed previously have been proved to be 12 hospitals in 26 cases and 28 long-term care facilities in 71 cases. 4 cases developed bacteremia caused by ESBL. Of ESBL-positive patients received home care service 57.1%, had a history of receiving antimicrobial drugs 88.2%. ESBL-producing strains has been detected continuously also at the time of rehospitalization in 70.9% (12/17) cases. Conclusions: ESBL-producing strains has been detected in many patients who have been rehospitalized from other facilities in the ASC. It suggests that ESBL ASC is useful for selecting appropriate antibiotics and infection control in high-risk patients. Moreover, it is required to further make the transmission status of ESBL-producing strains clear in the region as well as to build up appropriate measures.