[Isolation and identification of a non-enterotoxigenic strain of Bacteroides fragilis from a healthy term infant].
OBJECTIVE
To identify a non-enterotoxigenic strain of Bacteroides fragilis.


METHODS
B. fragilis was isolated from the feces of a healthy full-term infant in July 2012 and identified by morphological characteristics and culture conditions, physiological and biochemical test, drug sensitivity test, 16 s rRNA gene sequencing and short and long-term toxicity tests.


RESULTS
The isolated bacterial strain was similar to B. fragilis in terms of morphological characteristics, culture conditions and physiological and biochemical features. The results of 16s rRNA gene sequencing demonstrated that the nucleoids of newly-isolated strain were up to 99% identical to those of standard stain of B. fragilis NCTC9343 (GenBank). The drug sensitivity test revealed that it was not sensitive to cefradine, amoxicillin, gentamicin, sulfamethoxazole and trimethoprim. And the acute and long-term toxicity tests were negative.


CONCLUSIONS
The isolated bacteria is a non-enterotoxigenic strain of B. fragilis.
Guangzhou Zhiyi Biotechnology Limited Liability Company, Guangzhou 510515, China.
Yangyang
Y
Liu
Department of Gastroenterology, Nanfang Hospital of Southern Medical University, Guangzhou 510515, China.
Wendi
W
Zhang
Yang
Y
Bai
Email: zhifc41532@163.com.
Fachao
F
Zhi
D000658:Amoxicillin; D001424:Bacterial Infections; D001441:Bacteroides fragilis; D005243:Feces; D005839:Gentamicins; D006801:Humans; D007223:Infant; D012336:RNA, Ribosomal, 16S
D005839:Gentamicins; D012336:RNA, Ribosomal, 16S; D000658:Amoxicillin