Steinernema riobrave

Antimicrobial activities of symbiotic bacteria of entomopathogenic nematodes by Ganpati Jagdale

Entomopathogenic nematode symbiotic bacteria and antimicrobial activity The compounds produced by entomopathogenic nematode symbiotic bacteria Xenorhabdus bovienii have showed antimicrtobial activity against two fungus species including Botrytis cinerea and Phytophthora capsici (Fang et al., 2011).  Both of these fungi causes diseases to many plant species.

Publications on antimicrobial activity of entomopathogenic nematode symbiotic bacteria.

  1. Fang, X. L., Feng, J. T., Zhang, W. G., Wang, Y. H. and Zhang, X. 2010. Optimization of growth medium and fermentation conditions for improved antibiotic activity of Xenorhabdus nematophila TB using a statistical approach.  African Journal of Biotechnology 9: 8068-8077.
  2. Fang, X.L., Li, Z.Z., Wang, Y.H. and Zhang, X. 2011.   In vitro and in vivo antimicrobial activity of Xenorhabdus bovienii YL002 against Phytophthora capsici and Botrytis cinerea. Journal of Applied Microbiology 111: 145-154.
  3. Furgani, G., Boeszoermenyi, E., Fodor, A., Mathe-Fodor, A., Forst, S., Hogan, J.S., Katona, Z.,  Klein, M.G., Stackebrandt, E., Szentirmai, A., Sztaricskai, F. and Wolf, S. L. 2008.  Xenorhabdus antibiotics: a comparative analysis and potential utility for controlling mastitis caused by bacteria.  Journal of Applied Microbiology 104: 745-758.
  4. Isaacson, P.J. and Webster, J.M. 2002.  Antimicrobial activity of Xenorhabus sp RIO (Enterobacteriaceae), symbiont of the entomopathogenic nematode, Steinernema riobrave (Rhabditida : Steinernematidae). Journal of Invertebrate Pathology 79: 146-153.
  5. Wang, Y.H., Fang, X.L., Li, Y.P. and Zhang, X. 2010.  Effects of constant and shifting dissolved oxygen concentration on the growth and antibiotic activity of Xenorhabdus nematophila. Bioresource Technology 101: 7529-7536.
  6. Wang, Y.H., Feng, J.T., Zhang, Q. and Zhang, X. 2008.  Optimization of fermentation condition for antibiotic production by Xenorhabdus nematophila with response surface methodology. Journal of Applied Microbiology 104s: 735-744.
  7. Yang, X.F., Qiu, D.W., Yang, H.W., Liu, Z., Zeng, H.M. and Yuan, J.J. 2011.  Antifungal activity of xenocoumacin 1 from Xenorhabdus nematophilus var. pekingensis against Phytophthora infestans. World Journal of Microbiology and Biotechnology 27: 523-528.

Quantitative real-time PCR techniques for detecting and quantifying entomopathogenic nematodes from the soil samples by Ganpati Jagdale

Recently, a quantitative real-time PCR (qPCR) technique has been developed by Campos-Herrera et al (2011) for detecting and quantifying entomopathogenic nematodes including Steinernema diaprepesi, Steinernema riobrave, Heterorhabditis indica, Heterorhabditis zealandica, Heterorhabditis floridensis and an undescribed species in the S. glaseri group from soil samples. Read following paper for a detail protocol of quantitative real-time PCR (qPCR) technique

Campos-Herrera, R., Johnson, E. G, El-Borai, F. E., Stuart, R. J., Graham, J. H. and Duncan, L. W.2011. Long-term stability of entomopathogenic nematode spatial patterns in soil as measured by sentinel insects and real-time PCR. Annals of Applied Biology    158: 55-68.

Entomopathogenic nematodes as biological control agents for sheep lice, Bovicola ovis by Ganpati Jagdale

Biological control of sheep lice, Bovicola ovis with entomopathogenic nematodes Four entomopathogenic nematodes including Steinernema carpocapsae, Steinernema riobrave, Steinernema feltiae and Heterorhabditis bacteriophora have showed a very high efficacy against sheep lice, Bovicola ovis when tested under laboratory conditions at different incubation temperatures (James et al., 2010).  However,  the efficacy all the four species of entomopathogenic nematodes varied with the nematode species and incubation temperature.

For more information on the interaction between entomopathogenic nematodes and sheep lice read following paper.

  1. James, P. J., Hook, S.E. and Pepper, P. M. 2010. In vitro infection of sheep lice (Bovicola ovis Schrank) by Steinernematid and Heterorhabditid nematodes.   Veterinary Parasitology    174: 85-91.

Entomopathogenic nematodes can protect citrus fruits from the damage caused by the mediterranean fruit fly by Ganpati Jagdale

The data presented by Abd-Elgawad et al., at the 49th Annual meeting of the Society of Nematlogists held from July 11-14, 2010 in Boise, Idaho clearly demonstrated that the application of two species of entomopathogenic nematodes (Steinernema riobrave and Heterorhabditis bacteriophora) in the soil significantly reduced the emergence of adults Mediterranean fruit fly, Ceratitis capitata when  compared with the untreated control.

How entomopathogenic nematodes find their insect hosts (Foraging Strategies) by Ganpati Jagdale

Infective juveniles of entomopathogenic nematodes use three different strategies to find their insect hosts.1. Ambush foraging: Ambushers such as Steinernema carpocapsae and S. scapterisci have adapted "sit and wait" strategy to attack highly mobile insects (billbugs, sod webworms, cutworms, mole-crickets and armyworms) when they come in contact at the surface of the soil.  These nematodes do not respond to host released cues but infective juveniles of some Steinernema spp can stand on their tails (nictate) and easily infect passing insect hosts by jumping on them.  Since highly mobile insects live in the upper soil or thatch layer, ambushers are generally effective in infecting more insects on the surface than deep in the soil. 2. Cruise foraging: Cruiser nematodes such as Heterorhabditis bacteriophora, H. megidis, Steinernema glaseri and S. kraussei generally move actively in search of hosts and therefore, they are distributed throughout the soil profile and more effective against less mobile hosts such as white grubs and black vine weevils.  Cruisers never nictate but respond to carbon dioxide released by insects as cues. 3. Intermediate foraging: Some nematode species such as Steinernema feltiae and S.riobrave have adapted a strategy in between ambush and cruise strategies called an intermediate strategy to attack both the mobile and sedentary/less mobile insects at the surface or deep in the soil.  Steinernema feltiae is highly effective against fungus gnats and mushroom flies whereas S.riobrave is effective against corn earworms, citrus root weevils and mole crickets.