Molecular characterization and amplified ribosomal DNA restriction analysis of entomopathogenic bacteria associated with Rhabditis (Oscheius) spp.

Abstract

Bacterial strains associated with entomopathogenic nematodes (EPNs) Rhabditis (Oscheius) spp. were isolated from infected cadavers of Galleria mellonella. The obtained 18 isolates were subdivided into nine phylogenetically different genera based on comparative sequence analysis of their 16S rRNA genes. The isolates were affiliated to three different class namely γ-proteobacteria (Enterobacter, Proteus, Providencia, Pseudomonas, Stenotrophomonas), β-proteobacteria (Alcaligenes) and Bacilli (Bacillus, Enterococcus, Lysinibacillus). It was observed that Gram-positive strains (Bacilli) were more frequently associated with the EPN, whereas Gram-negative isolates were affiliated to six different genera with more genotypic diversity. Subsequently, all bacterial isolates used in this study were analyzed by amplified ribosomal DNA restriction analysis (ARDRA). Eight restriction endonucleases (CfoI, HinfI, RsaI, DdeI, Sau3AI, AluI, HaeIII, and MspI) were examined and a total of 15 different genotypes were obtained, forming two heterogenous main clusters after analysis by un-weighted pair-group method using arithmetic averages.

Molecular and Bacteriological Study of Enterococcus faecalis Isolated from Different Clinical Sources

“…All isolates identified as E. faecalis on bile esculin agar ( Figure 2) depend on creamy color of colony which conversion of media to black, it comprise of 40% bile salt assistance in inhibition growth of Streptococci belong to group D antigen made this media valuable in determination of enterococcus from other non-enterococcus bacteria that belong to group D antigen (Hemraj et al, 2013). Additionally, the E. faecalis are Gram positive, do not form spore, not motile, do not produce oxidase, catalase, DNase, and urease, and ferment glucose without gas generation (Arias et al, 2010;Jayasundara, 2014;Subramanian et al, 2015;Sangeetha et al, 2016). They are facultative anaerobic bacteria, round, single, pairs or may be short chains (Silva et al, 2012).…”

Molecular characterization and PCR-based screening of cry genes from Bacillus thuringiensis strains

“…Gowdaman et al (2014) reported that a collection of 171 soil bacterial isolates was analyzed for the occurrence of genus Bacillus using group-specific primers and ARDRA was performed for the Bacillus -positive isolates with standard Bacillus strains. Sangeetha et al (2016) analyzed 15 bacterial isolates by ARDRA and used eight restriction endonucleases ( Cfo I, Hinf I, Rsa I, Dde I, Sau3A I, Alu I, Hae III, and Msp I) forming two heterogenous main clusters after analysis by unweighted pair-group method using arithmetic averages.…”

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

“…Besides the classically studied EPN species in the genera Steinernema and Heterorhabditis, several nematode species from genus Oscheius have been confirmed as EPNs (Ye et al, 2010;Pervez et al, 2013;Zhou et al, 2017). Similar to Steinernema and Heterorhabditis, Oscheius species are in association with several bacteria strains that belong to three classes; namely the betaproteobacteria (Alcaligenes), the gamma-proteobacteria (Enterobacter, Proteus, Providencia, Pseudomonas, Stenotrophomonas) and the Bacilli (Bacillus, Enterococcus, Lysinibacillus; Sangeetha et al, 2016). In our experiment, we primarily isolated the bacterium A. faecalis; however, this does not exclude Oscheius nematodes to bear other bacteria species.…”