title: [Isolation, identification and lead adsorption study of lead-resistant Lactobacillus casei strains from feces of healthy newborns].
abstract: OBJECTIVE
  To isolate and identify lead-resistant Lactobacillus casei strains with lead adsorption ability from the stool of healthy newborns as a new source of bacteria for developing lead-eliminating food products.
  
  
  METHODS
  MRS was used to isolate lead-resistant bacteria from the feces of 30 healthy and full-term neonates. A phylogenetic tree was constructed based on the morphological characteristics and 16S rRNA sequences of the isolated bacteria. Physiological and biochemical characterizations of the bacteria were performed according to the Berger's Systematic Bacteriology Handbook, followed by antimicrobial susceptibility test and acid-tolerant bile salt test. The adsorption capacity of Pb2+of the bacteria was determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES).
  
  
  RESULTS
  Three strains of Lactobacillus casei were isolated, which were resistant to penicillin and ceftriaxone and could tolerate the exposure to 500 mg/L Pb2+. Acid-tolerant bile salt test showed that the bacteria were resistant to culture in the presence of artificial gastric juice (pH 2.0) for 3 h, and their survival rate reached 62.5% following exposure to 0.3% bile salt for 8 h. The bacteria showed a Pb2+adsorption rate of 90.4% at a low Pb2+concentration (1 mg/L) and of 86.27% at a high Pb2+concentration (50 mg/L).
  
  
  CONCLUSIONS
  Three Lactobacillus casei strains lead adsorption ability were isolated from the feces of newborns. These bacterial strains provide a new solution to alleviate lead poisoning by probiotic dietary.
authors.affiliation: 1Department of Neonatology, Nanfang Hospital, 2Department of Microbiology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, China. E-mail: sophia113@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Shen
authors.forename: Qin-Fei
authors.initials: QF
authors.lastname: Yu
authors.forename: Yu-Hao
authors.initials: YH
authors.lastname: Wang
authors.forename: Yi-Duo
authors.initials: YD
authors.lastname: Zhang
authors.forename: Xiao-Jing
authors.initials: XJ
authors.lastname: Meng
authors.forename: Hong-Ying
authors.initials: HY
authors.lastname: Fan
mesh_terms: D000327:Adsorption; D001647:Bile Acids and Salts; D005243:Feces / Q000382:microbiology*; D006801:Humans; D007231:Infant, Newborn; D007778:Lactobacillus; D007780:Lacticaseibacillus casei; D007854:Lead / Q000493:pharmacokinetics*; D010802:Phylogeny; D019936:Probiotics; D012336:RNA, Ribosomal, 16S
chemical_list: D001647:Bile Acids and Salts; D012336:RNA, Ribosomal, 16S; D007854:Lead