Bee-pollen is a functional food sold for human and animal consumption but also is a favorable microhabitat for many spore-forming bacteria. Among them, Bacillus cereus can produce several toxins and other virulence factors, causing an emetic or diarrheal syndrome after ingestion. The study involved 36 bee-pollen samples obtained from different sampling points throughout the production process (collecting, freezing, drying, and cleaning) in Argentina. Fifty isolates of B. cereus yielded 24 different fingerprint patterns with BOX and ERIC primers. Only three fingerprint patterns were maintained throughout the production process. In contrast, others were lost or incorporated during the different steps, suggesting that cross-contamination occurred as shown by differences in fingerprint patterns after freezing, drying, and cleaning steps compared to the initial collection step. Genes encoding for cereulide (ces), cytotoxin K (cytK), sphingomyelinase (sph), the components of hemolysin BL (hblA, hblB, hblC, hblD) and non-hemolytic complex (nheAB) were studied. All the isolates displayed one or more enterotoxin genes. The most frequent virulence genes detected belong to the HBL complex, being the most abundant hblA (98%), followed by hblD (64%), hblB (54%), and hblC (32%), respectively. Ten strains (20%), present at all sampling points, carried all the subunits of the HBL complex. The non-hemolytic enterotoxic complex (nheAB) was found in 48 strains (96%), while seven strains (14%) present at all sampling points showed the amplification product for sphingomyelinase (sph). One cereulide-producer was isolated at the cleaning step; this strain contained all the components for the hemolytic enterotoxin complex HBL, the NHE complex, and cytotoxin K related to the foodborne diarrhoeal syndrome. In total, 11 different virulence patterns were observed, and also a correlation between rep-fingerprint and virulence patterns. The results suggest that bee-pollen can be contaminated at any point in the production process with potential enterotoxic B. cereus strains, emphasizing the importance of hygienic processing.

蜂花粉是出售给人类和动物食用的功能性食品，同时也是许多孢子形成细菌的有利微生境。其中，蜡状芽孢杆菌可产生多种毒素和其他毒力因子，在摄入后引起呕吐或腹泻综合征。该研究涉及从整个阿根廷生产过程（采集，冷冻，干燥和清洁）的不同采样点采集的36个蜂花粉样品。蜡状芽孢杆菌五十株使用BOX和ERIC引物产生了24种不同的指纹图案。在整个生产过程中仅保留了三个指纹图案。相反，在不同的步骤中，其他物质丢失或混入，表明交叉污染的发生是由冷冻，干燥和清洁步骤后的指纹图案与初始收集步骤相比的差异所显示的。蜡样内酯（ces），细胞毒素K（cyt K），鞘磷脂酶（sph），溶血素BL的成分（hbl A，hbl B，hbl C，hbl D）和非溶血性复合物（nheAB）进行了研究。所有分离株均显示一种或多种肠毒素基因。最常见的致病基因检测属于HBL复杂，最丰富的是HBL A（98％），其次是HBL d（64％），HBLB（54％），和HBL分别C（32％）。存在于所有采样点的十个菌株（占20％）携带了HBL复合体的所有亚基。在48个菌株（96％）中发现了非溶血性肠毒素复合物（nheAB），而在所有采样点均存在的7个菌株（14％）显示了鞘磷脂酶（sph）的扩增产物。）。在清洁步骤中分离出一种蜡菊酯生产者；该菌株包含与食源性腹泻综合征相关的溶血性肠毒素复合物HBL，NHE复合物和细胞毒素K的所有成分。总共观察到11种不同的毒力模式，并且rep-指纹和毒力模式之间也具有相关性。结果表明，蜂花粉在生产过程中的任何时候都可能被潜在的肠毒性蜡状芽孢杆菌菌株污染，从而强调了卫生加工的重要性。