Identification of a NewAlcaligenes faecalisStrain MOR02 and Assessment of Its Toxicity and Pathogenicity to Insects

Abstract

We report the isolation of a bacterium from Galleria mellonella larva and its identification using genome sequencing and phylogenomic analysis. This bacterium was named Alcaligenes faecalis strain MOR02. Microscopic analyses revealed that the bacteria are located in the esophagus and intestine of the nematodes Steinernema feltiae, S. carpocapsae, and H. bacteriophora. Using G. mellonella larvae as a model, when the larvae were injected with 24,000 CFU in their hemocoel, more than 96% mortality was achieved after 24 h. Additionally, toxicity assays determined that 1 μg of supernatant extract from A. faecalis MOR02 killed more than 70% G. mellonella larvae 96 h after injection. A correlation of experimental data with sequence genome analyses was also performed. We discovered genes that encode proteins and enzymes that are related to pathogenicity, toxicity, and host/environment interactions that may be responsible for the observed phenotypic characteristics. Our data demonstrates that the bacteria are able to use different strategies to colonize nematodes and kill insects to their own benefit. However, there remains an extensive group of unidentified microorganisms that could be participating in the infection process. Additionally, a nematode-bacterium association could be established probably as a strategy of dispersion and colonization.

Chrysomya megacephala larvae feeding favourably influences manure microbiome, heavy metal stability and greenhouse gas emissions

“…Alcaligenes faecalis even cause peritonitis occasionally (Kahveci et al, 2011). The identified Alcaligenes faecalis strain MOR02 from Galleria mellonella larva is dangerous and pathogenic to larva as a result of toxic protein secretion and nematode cooperation (Quiroz-Castañeda et al, 2015). Increased Alcaligenes faecalis in CMSM might originate from excretion or from dead bodies of C. megacephala.…”

The symbiotic bacteria Alcaligenes faecalis of the entomopathogenic nematodes Oscheius spp. exhibit potential biocontrol of plant‐ and entomopathogenic fungi

“…While the general dogma suggests that Steinernema and Heterorhabditis are in association with unique bacterial strains (Forst et al, 1997;Goodrichblair, 2007;Clarke, 2008), A. faecalis strain MOR02 was also found in the oesophagus and intestine of the Steinernema feltiae, S. carpocapsae and H. bacteriophora. Later, this A. faecalis strain was confirmed to be an entomopathogenic bacterium; A. feacalis MOR02-inoculated G. mellonella larvae suffered more than 96% mortality after 24 h (Quiroz-Castañeda et al, 2015). Therefore, A. faecalis can cause mortality of arthropod larvae via haemocoelic lesion and can be used as food source for EPN growth, development and reproduction (Park et al, 2011).…”

The Genome Sequence of Alcaligenes faecalis NBIB-017 Contains Genes with Potentially High Activities against Erwinia carotovora

“…Some A. faecalis spp. are capable of degrading pesticides such as endosulfan ( 1 , 2 ) and 2,4-dichlorophenoxyacetic acid ( 3 ), as well as other inorganic compounds found in wastewater ( 4 – 6 ), while other strains of this species can produce nonnatural amino acids ( 7 ). However, A. faecalis strains are widely used in today’s agriculture and pharmaceutical industries ( 8 ).…”