AUTHOR=Zhang Ruiling , Feng Shuo , Xie Xiaochen , Huang Zhendong , Wan Qing , Wang Shumin , Zhang Zhong 

TITLE=Dysbacteriosis of the Intestinal Flora Is an Important Reason for the Death of Adult House Flies Caused by Beauveria bassiana

JOURNAL=Frontiers in Immunology

VOLUME=Volume 11 - 2020

YEAR=2021

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2020.589338

DOI=10.3389/fimmu.2020.589338

ISSN=1664-3224

ABSTRACT=Beauveria bassiana is one of the most widespread insect pathogens and can be used in the biological control of agricultural, forestry and medical pests. The mechanisms by which B. bassiana leads to mortality in different host insects are also different. For houseflies, B. bassiana has strong pathogenicity, but its microecological mechanism is not clear. In this paper, the pathogenicity of three strains of B. bassiana (TB, CB and BB) isolated from different hosts to houseflies was studied. The results showed that the three strains of B. bassiana had strong pathogenicity to housefly adults. Specifically, TB was the strongest, CB was the second strongest, and BB was the weakest, with maximum lethal effects on housefly populations 5, 6 and 7 days after infection, respectively. Further study showed that the intestinal flora of houseflies was disordered 3, 4 and 5 days after B. bassiana TB, CB and BB strain infection, respectively. Intestinal flora dysbacteriosis may be an important reason for the death of houseflies caused by B. bassiana. After infection, the negative interaction ratio of bacteria in the housefly intestine decreased, and the stronger the pathogenicity was, the lower the negative interaction ratio was. The time from B. bassiana infection to intestinal flora dysbacteriosis was not fixed. We named this period the “spring stage”. The stronger the pathogenicity of the B. bassiana strain was, the shorter the “spring stage” was. Therefore, the “spring stage” can be used as a virulence marker for evaluating the pathogenicity of different B. bassiana strains.