Detection of enterotoxic Bacillus cereus and Bacillus thuringiensis strains by PCR analysis
Detection of enterotoxic Bacillus cereus and Bacillus thuringiensis strains by PCR analysis
复制标题
DOI：
10.1128/aem.67.1.185-189.2001
复制
发表时间：
2001-01-01
影响因子：
4.4
通讯作者：
Hendriksen, NB
中科院分区：
文献类型：
--
作者：
Hansen, BM;Hendriksen, NB
许多蜡样芽孢杆菌菌株引起胃肠道疾病，与之密切相关的昆虫病原体B。苏云金杆菌也与腹泻的爆发有关。肠毒素是导致腹泻的主要原因。两种不同的肠毒性蛋白复合物，溶血素BL（HBL）和非溶血性肠毒素（NHE），和肠毒性蛋白，肠毒素T，已被确定，并已测序的基因。设计了检测这些基因的PCR引物，并对22个B中的基因进行了检测。cereus和41 B.苏云金杆菌菌株在所有B中检测到两种蛋白复合物HBL和NHE中的每一种的至少一个基因。苏云金芽孢杆菌（B.蜡状芽孢杆菌菌株缺乏所有三个HBL基因，三个缺乏三个NHE基因中的至少两个，一个缺乏所有三个。用5套不同的引物检测编码肠毒素T的基因（bceT）。用这些引物组获得的结果表明bceT广泛分布于B中。cereus和B.苏云金杆菌菌株，并且该基因在不同菌株之间的序列不同。用两个引物组BCET 1-BCET 3和BCET 1-BCET 4的PCR明确地检测到bceT基因，如Southern分析所证实的。两个复合物内的基因的出现显著相关，而在63株菌株中，两个复合物的出现和bceT基因的出现均不显著相关。我们提出了一种检测B肠毒素编码基因的方法。cereus和B.苏云金芽孢杆菌基于PCR分析，用六个引物组检测HBL和NHE操纵子中的基因，用BCET 1、BCET 3和BCET 4引物检测bceT。16 S-23 S rRNA基因内转录间隔区的PCR分析显示，所有研究菌株的模式相同。
Many strains of Bacillus cereus cause gastrointestinal diseases, and the closely related insect pathogen B. thuringiensis has also been involved in outbreaks of diarrhea. The diarrheal types of diseases are attributed to enterotoxins. Two different enterotoxic protein complexes, hemolysin BL (HBL) and nonhemolytic entero toxin (NHE), and an enterotoxic protein, enterotoxin T, have been characterized, and the genes have been sequenced. PCR primers for the detection of these genes were deduced and used to detect the genes in 22 B. cereus and 41 B. thuringiensis strains. At least one gene of each of the two protein complexes HBL and NHE was detected in all of the B. thuringiensis strains, while six B. cereus strains were devoid of all three HBL genes, three lacked at least two of the three NHE genes, and one lacked all three. Five different sets of primers were used for detection of the gene (bceT) encoding enterotoxin T. The results obtained with these primer sets indicate that bceT is widely distributed among B. cereus and B. thuringiensis strains and that the gene varies in sequence among different strains. PCR with the two primer sets BCET1-BCET3 and BCET1-BCET4 unambiguously detected the bceT gene, as confirmed by Southern analysis. The occurrence of the genes within the two complexes is significantly associated, while neither the occurrence of the two complexes nor the occurrence of the bceT gene is significantly associated in the 63 strains. We suggest an approach for detection of enterotoxin-encoding genes in B. cereus and B. thuringiensis based an PCR analysis with the six primer sets for the detection of genes in the HBL and NHE operons and with the BCET1, BCET3, and BCET4 primers for the detection of bceT. PCR analysis of the 16S-23S rRNA gene internal transcribed spacer region revealed identical patterns for all strains studied.