Campylobacter is a major cause of bacterial gastroenteritis worldwide. Young children represent a particular age group affected by Campylobacter infection because of their limited diets and weak immune systems.
In this study, a total of 110 Campylobacter (80 Campylobacter jejuni and 30 Campylobacter coli) isolated from children younger than 5 years of age with diarrhea in Shanghai, China in 2011 were examined for their genetic relationship and antimicrobial susceptibility. The presence of virulence genes and its association with invasion potential in Caco-2 cell were also determined.
Multilocus sequence typing revealed 62 sequence types (STs) under 14 clonal complexes from C. jejuni and 15 STs under 2 clonal complexes from C. coli. High resistance rates among the 110 isolates were observed to nalidixic acid (88.2%), ciprofloxacin (87.3%) and tetracycline (87.3%), followed by ampicillin (30.9%), gentamicin (28.2%), clindamycin (21.8%), erythromycin (21.8%) and chloramphenicol (8.2%). Compared with that of C. jejuni (32.5%), a larger proportion of C. coli (83.3%) were resistant to multiple antimicrobials, including 16 isolates of ST-828 complex resistant to 6 antimicrobials: ciprofloxacin, clindamycin, erythromycin, gentamicin, nalidixic acid and tetracycline. Furthermore, 57 Campylobacter isolates were selected based on their distinct STs and the presence of virulence genes to determine their abilities to adhere to and invade Caco-2 cells. The level of invasion varied widely among isolates and had relatively weak correlation with the genotype data.
Our findings provided baseline data on Campylobacter among young children. Active surveillance of Campylobacter is needed to better understand the epidemiology and antimicrobial resistance trends of this significant pathogen to help control and protect young children from such infections.
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From the *Department of Food Science & Technology, School of Agriculture and Biology, Shanghai Jiao Tong University; †Department of Infectious Diseases, Children’s Hospital of Fudan University; ‡Department of Microbiological Lab, Shanghai Municipal Center for Disease Control and Prevention; §Department of Microbiological Lab, Shanghai Changning District Center for Disease Control and Prevention, Shanghai, China; and ¶Department of Food Science and Nutrition, University of Maryland, College Park, Maryland.
Accepted for publication July 13, 2015.
Both H.P. and Y.G. contributed equally to this study.
This work was funded in part by the National High Technology Research and Development Program of China (863 Program) (2012AA101601) and Mega-projects of Science and Technology Research of China (No. 2012ZX10004215-003). The authors have no conflicts of interest to disclose.
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Address for correspondence: Xuebin Xu, MS, Microbiology Laboratory, Shanghai Municipal Center for Disease Control and Prevention, 1380 ZhongShan West Road, Changning District, Shanghai 200336, China. E-mail: firstname.lastname@example.org; Jianghong Meng, PhD, Department of Nutrition and Food Science, University of Maryland, 0112 Skinner Building, College Park, MD 20742–7521. E-mail: email@example.com.