Background: Diarrheagenic Escherichia coli (DEC) is a major cause of bacterial gastroenteritis in children. Also, antibiotic resistance among DEC is becoming a critical area of concern in clinical settings.
Methods: This study was conducted in 4 hospitals in Shanghai from June 2012 to October 2013. DEC isolates from stool samples of patients with diarrhea were examined to determine their antimicrobial susceptibilities and presence of virulence genes, in order to identify high risk clones.
Results: A total of 735 (10.2%) DEC isolates were identified from 7204 stool samples from patients with diarrhea, including 374 enteropathogenic E. coli, 318 enterotoxigenic E. coli, 36 Shigella/enteroinvasive E. coli and 7 Shiga toxin-producing E. coli (STEC). Among the 735 DEC isolates, 299 (40.7%) were isolated from children less than 5 years old. High resistance rates were observed to streptomycin (90.7%), ampicillin (63.4%), nalidixic acid (61.1%), sulfisoxazole (49.1%), tetracycline (41.2%), trimethoprim (35.6%), trimethoprim-sulfamethoxazole (35.4%), followed by amoxicillin-clavulanic acid (27.2%), cefotaxime (24.5%), cefepime (23.5%), gentamicin (16.7%), ceftazidime (12.4%), chloramphenicol (10.6%), ciprofloxacin (7.2%) and ofloxacin (3.4%). All the isolates were susceptible to imipenem. In addition, potential virulence genes were screened by polymerase chain reaction. A total of 15 enterotoxigenic E. coli belonging to the same clone were identified to be associated with nosocomial neonatal diarrhea and resistant to greater than 10 antimicrobials.
Conclusion: Our findings suggest that active surveillance programs combining both phenotypic and genetic data would help identify disease outbreaks and strengthen antibiotic management.
From the *Department of Microbiological Lab, The Changning District Center for Disease Control and Prevention, Shanghai, China; †Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China; ‡Department of Microbial Technology and Research, Shanghai Municipal Ke-ma-jia Technology Center for Microbiology, Shanghai, China; §Department of Clinical Microbiological Lab, Shanghai United Family Hospital, Shanghai, China; ¶Department of Food Science Center, Mérieux NutriSciences China Food Science Center, Shanghai, China; ‖Department of Clinical Microbiological Lab, Children Hospital of Fudan University, Shanghai, China; **Key Laboratory of Veterinary Vaccine Innovation of the Ministry of Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China; ††Department of Food Science and Nutrition, University of Maryland, College Park, Maryland; and ‡‡Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.
Accepted for publication January 7, 2016.
Z. Huang, H. Pan and P. Zhang contributed equally to this work.
This work was funded, in part, by the Shanghai Changning District Science and Technology Program (No. 20134GW24001), the National High Technology Research and Development Program of China (No. 2012AA101601), and the China–US Collaborative Program (No. 1U2GGH000961-01). The authors have no conflicts of interest to disclose.
Address for correspondence: Xuebin Xu, MS, Department of Microbiological Lab, Shanghai Municipal Center for Disease Control and Prevention, 1380 (West) Zhong Shan Road, Changning Dist., Shanghai 200336, China. E-mail: firstname.lastname@example.org; Zhengan Yuan, Shanghai Municipal Center for Disease Control and Prevention, 1380 (West) ZhongShan Road, Changning Dist., Shanghai, 200336, China. E-mail: email@example.com.