背景:由类芽孢杆菌幼虫引起的美国foulbrood(AFB)疾病是危险的,并威胁养蜂。使用益生菌的生态友好处理方法有望成为控制蜜蜂中这种病原体的前瞻性方法。因此,这项研究调查了对P.幼虫具有抗菌活性的细菌物种。
结果:总体而言,在三个门中分离并鉴定了67株肠道微生物组;这些分离株的患病率如下:Firmicutes41/67(61.19%),放线菌24/67(35.82%),和变形杆菌2/67(2.99%)。在20个乳杆菌属分离株中观察到琼脂平板上针对P.larvae的抗菌特性,厚壁门。来自每个物种的六个代表性菌株(L.选择在琼脂平板上具有最大抑制区的阿皮鱼HSY8_B25,广子菌PKH2_L3,金花菌HSY3_B5,金花菌AHS3_B36,金花菌菌OMG2_B25和L.mellisOMG2_B33)进行体外幼虫饲养挑战。结果表明,三个分离株(L.原料药HSY8_B25,广子乳杆菌PKH2_L3和melliventrisHSY3_B5)具有成为益生菌候选物的潜力,具有对幼虫安全的特性,在受感染的幼虫中抑制P.幼虫,和高粘合能力。
结论:总体而言,在这项研究中,鉴定了20株乳杆菌属的菌株对幼虫具有抗菌特性。来自不同物种的三个代表性菌株(L.原虫HSY8_B25,广子乳杆菌PKH2_L3和melliventrisHSY3_B5)被评估为潜在的益生菌候选物,并被选择用于益生菌开发以预防AFB。重要的是,本研究首次从幼虫中分离出具有抗菌活性的L.panisapium。
American foulbrood (AFB) disease caused by Paenibacillus larvae is dangerous, and threatens beekeeping. The eco-friendly treatment method using probiotics is expected to be the prospective method for controlling this pathogen in honey bees. Therefore, this study investigated the bacterial species that have antimicrobial activity against P. larvae.
Overall, 67 strains of the gut microbiome were isolated and identified in three phyla; the isolates had the following prevalence rates: Firmicutes 41/67 (61.19%), Actinobacteria 24/67 (35.82%), and Proteobacteria 2/67 (2.99%). Antimicrobial properties against P. larvae on agar plates were seen in 20 isolates of the genus Lactobacillus, Firmicutes phylum. Six representative strains from each species (L. apis HSY8_B25, L. panisapium PKH2_L3, L. melliventris HSY3_B5, L. kimbladii AHS3_B36, L. kullabergensis OMG2_B25, and L. mellis OMG2_B33) with the largest inhibition zones on agar plates were selected for in vitro larvae rearing challenges. The results showed that three isolates (L. apis HSY8_B25, L. panisapium PKH2_L3, and L. melliventris HSY3_B5) had the potential to be probiotic candidates with the properties of safety to larvae, inhibition against P. larvae in infected larvae, and high adhesion ability.
Overall, 20 strains of the genus Lactobacillus with antimicrobial properties against P. larvae were identified in this study. Three representative strains from different species (L. apis HSY8_B25, L. panisapium PKH2_L3, and L. melliventris HSY3_B5) were evaluated to be potential probiotic candidates and were selected for probiotic development for the prevention of AFB. Importantly, the species L. panisapium isolated from larvae was identified with antimicrobial activity for the first time in this study.