Members of the Bacillus cereus group are common contaminants of vegetables. One potential source of contamination is the application of B. thuringiensis based biopesticides. Although evidence of the presence of biopesticidal strains on food products is scarce, this information is essential for assessing potential risks associated with the application of these biopesticides.

In order to contribute to knowledge about the presence of biopesticidal B. thuringiensis strains in foodstuffs, we investigated the occurrence of B. thuringiensis on tomatoes and bell pepper.

We analyzed 99 samples of fresh bell pepper for B. cereus group members, while 426 samples of tomatoes were tested by the competent food control laboratories of the federal states in Germany. The isolates recovered from these samples were further characterized in terms of their capability to produce parasporal crystals as well as enterotoxins. A possible correlation between the B. thuringiensis isolates and biopesticidal strains was investigated by multilocus sequence typing (MLST) and whole genome Single Nucleotide Polymorphism (wgSNP) analyses.

The prevalence of B. cereus group members was 41% for bell pepper and 28% for tomato samples. Isolates recovered from these samples were dominated by B. thuringiensis (93% and 99%, respectively). All B. thuringiensis isolates carried the enterotoxin genes nheA, hblD and cytK-2. In a subset of 83 B. thuringiensis isolates analyzed by MLST, 99% of the isolates matched the sequence types (ST) 8 and 15, which are also shared by the biopesticidal strains B. thuringiensis kurstaki ABTS-351 and B. thuringiensis aizawai ABTS-1857. Of the 82 isolates assigned to ST 8 or ST 15, a selection of 42 isolates was further characterized by wgSNP analysis. Of these, seven isolates differed from strain ABTS-351 by ≤4 core SNPs and 18 isolates differed from strain ABTS-1857 by ≤2 core SNPs, indicating a relationship of these isolates with the respective biopesticidal strain. These isolates originated from samples with maximum colony counts of 5.3 × 10³ cfu/g for bell pepper and 1.0 × 10⁵ cfu/g for tomatoes.

该成员蜡状芽孢杆菌组是蔬菜常见的污染物。一种潜在的污染源是基于苏云金芽孢杆菌的生物农药的应用。尽管食品中没有生物杀虫菌株的证据，但该信息对于评估与这些生物杀虫剂的应用相关的潜在风险至关重要。

为了有助于人们了解食品中存在生物杀虫苏云金芽孢杆菌菌株，我们调查了番茄和甜椒中苏云金芽孢杆菌的发生情况。

我们分析了蜡状芽孢杆菌组成员的99个新鲜灯笼椒样品，同时对426个西红柿样品进行了德国联邦州主管食品控制实验室的测试。从这些样品中分离出的分离物还具有产生孢子旁晶体和肠毒素的能力。通过多基因座序列分型（MLST）和全基因组单核苷酸多态性（wgSNP）分析研究了苏云金芽孢杆菌分离株和杀虫菌株之间的可能相关性。

蜡状芽孢杆菌组成员中灯笼椒的患病率为41％，番茄样品的患病率为28％。从这些样品中回收的分离物以苏云金芽孢杆菌为主（分别为93％和99％）。苏云金芽孢杆菌的所有分离株均携带肠毒素基因nheA，hblD和cytK-2。在通过MLST分析的83种苏云金芽孢杆菌菌株中，有99％的菌株与序列类型（ST）8和15匹配，这也与杀虫菌株B.thuringiensis kurstaki ABTS-351和B.ABTS-1857。在分配给ST 8或ST 15的82个分离株中，通过wgSNP分析进一步表征了42个分离株。其中，有七个分离株与ABTS-351菌株相差≤4个核心SNP，有18个分离株与ABTS-1857菌株相差≤2个核心SNP，表明这些分离株与相应的生物农药菌株有关系。这些分离物来自于最大菌落计数 为灯笼椒的5.3×10 ³ cfu / g和 西红柿为1.0×10 ⁵ cfu / g的样品。