Effect of Temperature on Fimbrial Gene Expression and Adherence of Enteroaggregative Escherichia coli

International Journal of Environmental Research and Public Health

Woranich Hinthong³  Nitaya Indrawattana¹  Pannamthip Pitaksajjakul³  Chonlatip Pipattanaboon²  Thida Kongngoen¹  Prapin Tharnpoophasiam³  Suwalee Worakhunpiset³ 

[1] Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchadewee, Bangkok 10400, Thailand; E-Mails:;Center of Excellence for Antibody Research (CEAR), Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchadewee, Bangkok 10400, Thailand; E-Mail:;Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchadewee, Bangkok 10400, Thailand; E-Mails:

关键词: EAEC;    temperature;    aggregative adherence;    biofilms;    gene expression;    virulence;    fimbria;   

DOI  :  10.3390/ijerph120808631

来源: mdpi

【 摘 要 】

The influence of temperature on bacterial virulence has been studied worldwide from the viewpoint of climate change and global warming. The bacterium enteroaggregative Escherichia coli (EAEC) is the causative agent of watery diarrhea and shows an increasing incidence worldwide. Its pathogenicity is associated with the virulence factors aggregative adherence fimbria type I and II (AAFI and AAFII), encoded by aggA and aafA in EAEC strains 17-2 and 042, respectively. This study focused on the effect of temperature increases from 29 °C to 40 °C on fimbrial gene expression using real-time PCR, and on its virulence using an aggregative adherence assay and biofilm formation assay. Incubation at 32 °C caused an up-regulation in both EAEC strains 17-2 and strain 042 virulence gene expression. EAEC strain 042 cultured at temperature above 32 °C showed down-regulation of aafA expression except at 38 °C. Interestingly, EAEC cultured at a high temperature showed a reduced adherence to cells and an uneven biofilm formation. These results provide evidence that increases in temperature potentially affect the virulence of pathogenic EAEC, although the response varies in each strain.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.