Enterobacillus tribolii gen. nov., sp. nov., a novel member of the family Enterobacteriaceae, isolated from the gut of a red flour beetle, Tribolium castaneum.

Two novel Gram-stain negative facultative anaerobic, motile, rod-shaped bacterial strains IG-V01(T) and IG-V01b were isolated from the gut of red flour beetles, Tribolium castaneum. The 16S rRNA gene sequences of strains IG-V01(T) and IG-V01b were found to have their highest sequence similarity (96.5% and 96.4%) with Serratia nematodiphila DZ0503SBS1(T) (Enterobacteriaceae family) respectively. Strains IG-V01(T) and IG-V01b share 100% 16S rRNA gene sequence similarity and exhibit very similar phenotypic characteristics. In addition, they show 89.7% genomic relatedness (DNA-DNA hybridisation). Major fatty acids were identified to be C(16:0) (38.3%), C(17:0) cyclo (19.5-20%) and C(14:0) (11.2-11.3%). Cells contain phosphatidylethanolamine and diphosphatidylglycerol as predominant polar lipids. Genomic DNA G+C content (mol%) was determined to be 51.5-51.7. A polyphasic approach employing the study of morphological, physiological, chemotaxonomic, genomic and phylogenetic analysis revealed that the two newly isolated strains cannot be placed in any of the existing genera of the family Enterobacteriaceae. Therefore, it is proposed that strains IG-V01(T) and IG-V01b belong to a novel genus within the family Enterobacteriaceae, and represent a new species Enterobacillus tribolii gen. nov., sp. nov., with the type strain =IG-V01(T) = KCTC 42159(T) = MCC 2532(T).

Microsatellite genotyping of red imported fire ant (Hymenoptera: Formicidae) colonies reveals that most colonies persist in plowed pastures.

Our study focused on colony dynamics of the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), in relation to the standard practice of planting rye grass (i.e., plowing) in the fall in Louisiana. Microsatellite molecular markers were used to determine genotypes of individuals from red imported fire ant colonies. These markers allowed us to monitor treatment effect by detecting changes in number and location of colonies in response to disking of pasture plots. Previous research on mound disturbance as a form of cultural control in pastures has produced mixed results. We found that the majority of colonies persisted on plots after plowing. Mound density and mound area, 5 mo after plowing, were not significantly different among treatments. In contrast, April measurements of mound volume were significantly smaller on plowed plots compared with control plots. A closer look at the rebuilding of mounds on plowed plots, during the 5 mo, showed that mound heights stayed below pretreatment measurements and they were significantly smaller than those of undisturbed mounds. Whether plowing has potential for use as a cultural control technique in reducing the impact of red imported fire ant mounds on agricultural practices in pastures remains to be seen. Conceivably, the best application of this technique will be in combination with other control measures in an integrated pest management approach to control red imported fire ants in pastures.

Use of genetically engineered Escherichia coli to monitor ingestion, loss, and transfer of bacteria in termites.

Escherichia coli was transformed with a recombinant plasmid (pEGFP) containing the genes for ampicillin resistance and Green Fluorescent Protein (GFP). Escherichia coli expressing GFP (E. coli/GFP+) was then fed to workers of the termite Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae). The transformed bacteria in the termite guts were detected by growing the gut flora under selective conditions and then checking the cultures for fluorescence. Recombinant plasmids in the termite gut were detected by plasmid extraction with subsequent restriction enzyme digest. The presence of the GFP gene in the gut of termites fed with E. coli/GFP+ was verified by PCR amplification. Transformed E. coli were ingested rapidly when workers fed on filter paper inoculated with E. coli/GFP+. After 1 day, 42% of termite guts harbored E. coli/GFP+. Transfer of E. coli/GFP+ from donor termites (fed with E. coli/GFP+) to recipients (fed with moist filter paper) occurred within 1 day. However, without continuous inoculation, termites lost the transformed bacteria within 1 week.