Phylogeny of Bacteria Isolated from Rhabditis sp. (Nematoda) and Identification of Novel Entomopathogenic Serratia marcescens Strains

Abstract

Twenty-five bacterial strains isolated from entomopathogenic nematodes were characterized to the genus level by 16S rRNA phylogeny and BLAST analyses. Bacteria strains isolated could be affiliated with seven genera. Microbacterium-like isolates phylogenetically affiliated with M. oxydans while those of Serratia were highly similar to S. marcescens. 16S rRNA sequences of Bacillus isolates matched those of both B. mycoides and B. weihenstephanesis. One isolate each matched Pseudomonas mosselii, Rheinheimera aquimaris, Achromobacter marplatensis, or Staphylococcus hominis. Serratia isolates were examined further for their pathogenicity to Galleria mellonella larvae. All the Serratia isolates exhibited potent pathogenicity toward G. mellonella larvae and possessed a metalloprotease gene encoding for a novel serralysin-like protein. The nucleotide sequence of the metalloprotease gene had 60 synonymous and 8 nonsynonymous substitutions when compared to the closest genBank entry, S. marcescens E-15, with an insertion of a new aspartic acid residue. Tajima's test for equality of evolutionary rate was significant between the metalloprotease gene sequence of S. marcescens strain DOAB 216-82 (this study) and strain E-15. This new insecticidal metalloprotease gene and/or its product could have applications in agricultural biotechnology.

Identification and virulence of Aeromonas dhakensis , Pseudomonas mosselii and Microbacterium paraoxydans isolated from Nile tilapia, Oreochromis niloticus , cultivated in Mexico

“…putida group, was first described by Dabboussi et al (2002) as having rod-shaped cells producing a fluorescent pigment. The bacteria is an environmental (Naik et al 2008) and recently, was isolated from entomopathogenic nematodes (Tambong 2013). Overall, this bacterium is an unusual human opportunistic pathogen (Mclellan and Partridge 2009).…”

“…The bacteria is an environmental species detected mainly in rhizospheric soil (Naik et al . ) and recently, was isolated from entomopathogenic nematodes (Tambong ). Overall, this bacterium is an unusual human opportunistic pathogen (Mclellan and Partridge ).…”

“…In addition, Microbacterium species belonging to the order Actinomycetales, known for their ability to produce antimicrobial compounds, were recently isolated from infective entomopathogenic nematodes (Tambong ). Such species are a rare cause of bacteraemia; however, Enoch et al .…”

Molecular detection and analysis of a novel metalloprotease gene of entomopathogenic Serratia marcescens strains in infected Galleria mellonella

“…Serratia marcescens strains used in this study were isolated and identified as indicated in Tambong (2013). Briefly, samples of dead bark of red oak tree (Quercus rubra L.) were collected from a woodland near Charleston Lake, southern Ontario, Canada.…”

Evaluation and entomopathogenicity of gut bacteria associated with dauer juveniles of Oscheius chongmingensis (Nematoda: Rhabditidae)

“…Some reports have shown that the some species of intestinal bacteria associated with rhabditid nematodes could serve to promote nematode biological control effects. Nineteen bacterial genera have been found to be mutually associated with Rhabditis (Oscheius) nematodes: Bacillus (Mohandas et al, 2007), Klebsiella, Acinetobacter, Comamonas, Brucellaceae, Achromobacter (Deepa, Mohandas, & Siji, 2011), Alcaligenes, Flavobacterium, Providencia (Park, Kim, Ha, & Youn, 2011), Stenotrophomonas, Enterobacter, Proteus, Pseudomonas, Enterococcus, Lysinibacillus (Padmakumari et al, 2007Sangeetha et al, 2016), Microbacterium, Serratia, Rheinheimera and Staphylococcus (Tambong, 2013). Among them, Bacillus cereus isolate 03BB102 (Mohandas et al, 2007), Flavobacterium sp., Providencia vermicola (Deepa et al, 2011), Serratia marcescens (Tambong, 2013) and Serratia nematodiphila (Zhang, Yang, Xu, & Sun, 2009) exhibit virulence against insects and help improve nematode reproduction.…”