NC State University
Ponnusamy, Loganathan

Senior Research Scholar

Faculty Affiliate: 
Apperson/Schal

Medical Entomology, Dept. of Entomology,
Campus Box 7647, Dearstyne Entomology Building
3230 Ligon Road, N. C. State University
Raleigh, NC 27695-7647

Phone: 
919.515.8882
Fax: 
919.515.3748
Research: 
Microbial Mediation of Mosquito Oviposition Semiochemicals
Our primary research goals are to identify the chemicals derived from bacterial metabolism that attract gravid Aedes mosquitoes and stimulate them to oviposit. Guided by behavioral bioassays, we optimized the bio-activity of infusions made from different plant leaf and showed that attractive odorants were produced through microbialmetabolic activity.  Further to this, we demonstrated that bacteria-associated cues (carboxylic acids and methyl esters) were potent oviposition stimulants for Aedes aegypti. We have cultured bacteria from bio-active plant leaf infusions and we are currently using behavioral bioassays to screen bacterial species that mediate the oviposition responses.
 
Formulation of Bacterial Beads For Mosquito Oviposition Attractancy
In present research, we have shown that strong oviposition responses are elicited from gravid Aedes aegypti and Ae. albopictus females by a mix of bacterial species cultured from bio-active plant leaf infusions. When single species isolates are bioassayed, we determined that some bacterial species are highly attractive while other species are repellent. Currently, we are developing sustained release formulations of bio-active bacteria using alginate encapsulation techniques. When formulated in calcium alginate, bacteria are highly attractive to gravid mosquitoes. Alginate bacterial beads are a promising slow release formulation that can be used to attract gravid Aedes females to traps that are used for surveillance and control dengue virus vectors.
 
Molecular Microbial Ecology of Bacterial Populations in Mosquito Habitats
This part of our research is to understand how the structure and change of bacterial communities affects the occurrence of immatures Aedes mosquito species in containers habitats in residential landscapes.  We are using both culture-dependent and culture-independent approaches.  The culture-independent approach involves extractionof total DNA directly from mosquito container habitat samples, PCR amplificationof the 16S ribosomal DNA, and separation ofthe amplicons on a Denaturing Gradient Gel Electrophoresis (DGGE) and by Terminal Restriction Fragment Length Polymorphism (T-RFLP). Results of field experiments indicate that the bacterial communities composition was independent of the type of container and the spatial distribution of containers. In laboratory microcosms, bacterial species diversity and the abundance of bacteria have been found to be important determinants of the attraction of gravid females to experimental plant leaf infusions.

Publications in peer reviewed journals

Ponnusamy L., Gonzalez A., Treuren W., Weiss S, Parobek C., Juliano J., Knight R., Roe RM., Apperson C., and Meshnick S. 2013.  Diversity of Rickettsiales in the Microbiome of the Lone Star Tick, Amblyomma americanum. Appl. Environ. Microbiol. Published ahead of print.

Ponnusamy L., K. Böröczky, D. M. Wesson, C. Schal and C. S. Apperson. 2011. Bacteria stimulate hatching of yellow fever mosquito eggs. PLoS ONE, 6(9): e24409. Weblink

Smith, M. P., L. Ponnusamy, J. Jiang, L. Abu Ayyash, A. L. Richards, and C. S. Apperson.  2010.  Bacterial pathogens in ixodid ticks from a Piedmont county in North Carolina:  Prevalence of rickettsial organisms.  Vector Borne Zoon. Dis.  10:939-952.  Weblink

Ponnusamy, L., N. Xu, K. Böröczky, D. M. Wesson, L. Abu Ayyash, C. Schal, and C. S. Apperson.  2010.  Oviposition responses of the mosquitoes Aedes aegypti and Aedes albopictus to experimental plant infusions in laboratory bioassays.  J. Chem. Ecol. 36:709-719.  Weblink

Ponnusamy, L., D. M. Wesson, C. Arellano, C. Schal, and C. S. Apperson.  2010.  Species composition of bacterial communities influences attraction of mosquitoes to experimental plant infusions.  Microb. Ecol.  59:158–173.  Weblink

Ponnusamy, L., N. Xu, D. M. Wesson, C. Schal, and C. S. Apperson.  2008.  Identification of bacteria and bacteria-associated chemical cues that mediate oviposition site preferences by Aedes aegypti.  PNAS  105:92629267.  PDF

Ponnusamy, L., N. Xu, G. Stav, D. M. Wesson, C. Schal, and C. S. Apperson.  2008.  Diversity of bacterial communities in the container habitats of mosquitoes.  Microb. Ecol.  56:593603.  PubMed

Richards, S. L., L. Ponnusamy, T. R. Unnasch, H. K. Hassan, and C. S. Apperson.  2006.  Host-feeding patterns of Aedes albopictus (Skuse) (Diptera: Culicidae) in relation to the availability of human and domestic animals in suburban landscapes of central North Carolina.  J. Med. Entomol.  43:543-551.  PDF

Loganathan, P., and S. Nair.  2004.  Swaminathania salitolerans gen. nov., sp. nov., a salt-tolerant, nitrogen-fixing and phosphate-solubilizing bacterium from wild rice (Porteresia coarctata Tateoka).  Int. J. Syst. Evol. Microbiol.  54:1185-1190. PubMed

Loganathan, P., and S. Nair.  2003.  Crop-specific endophytic colonization by a novel, salt-tolerant, N-2-fixing and phosphate-solubilizing Gluconacetobacter sp from wild rice.  Biotechnology Letters.  25:497-501..  PubMed

Muthukumarasamy, R., G. Ravathi, and P. Loganathan.  2002.  Effect of inorganic N on the population, in vitro colonization and morphology of Acetobacter diazotrophicus.  Plant and Soil.  243:91-102.  Weblink

Saleena, L M., P. Loganathan, R. Sunitha, and S. Nair.  2001.  Genetic diversity and relationship between Bradyrhizobium strains isolated blackgram and cowpea.  Biol. Fertil. Soil.  34:276-281.  Weblink

Sunitha, R., P. Loganathan, L. M. Saleena, and S. Nair.  2001.  Diversity of Pseudomonads isolated from three different plant rhizospheres.  J. Appl. Microbiol.  91:742-749.  PubMed

Saleena, L. M., P. Loganathan, R. Sunitha, and S. Nair.  2001.  Genetic diversity of Bradyrhizobium strains isolated from Arachis hypogaea.  Canadian J. Microbiol.  47:118-122.  PubMed

Loganathan P., R. Sunitha, A. K. Paridha, and S. Nair.  1999.  Isolation and characterization of two genetically distant groups of Acetobacter diazotrophicus from a new host plant Eleusine coracana L.  J.  Appl. Microbiol.  87:167-172.  Weblink

Palaniappan, S. P., P. Sudhi Sreedhar, P. Loganathan, and J. Thomas.  1997.  Competitiveness of native Bradyrhizobium japonicum strains in two soil types.  Biol. Fert. Soil.  25:279-284..  Weblink

 Research in the News

2008 News

NCSU's Perspectives:  Scientists discover chemical cues that stimulate egg laying by pregnant mosquitoes. Weblink

The New York Times:  Not just any water will do for mosquitoes. Weblink

Science daily:  Why mosquitoes select certain outdoor water containers for laying eggs and avoid others.Weblink

Science blogs:  Bacterial smells have potential for trapping pregnant mosquitoes.Weblink

Chemistry World:  Yellow fever mosquito takes chemical cues from bacteria.Weblink

Title in German: Wie Mücken fauliges Wasser riechen (Title to English translation.  How mosquitoes smell foul water?), in Spektrum der Wissenschaft magazine, September 2008, page 11. Weblink

2007 News

Biofertiliser Newsletter:  Weblink

India environment portal:  Bacteria that reduces fertilser use  Weblink

2004 News

The Hindu:  Bacterium with salinity tolerance.Weblink

The Hindu:  Microbe to help reduce use of fertilizers identified.Weblink

The Biome News:  Plant growth promoting regulants and costal niche  vol 5: No1 page 3

Down to Earth:  Great little wonder.  Feb. 15, 2004.

Professional Affiliation

Member: American society of Microbiology

North Carolina Branch of the American Society for Microbiology

 Useful links

Online Bacteriology/Microbiology Books

Microbiology Online - teaching and learning

Society for General Microbiology

Bacterial Nomenclature Up-to-Date

World Data Center on Microorganisms

PCR Links

Institute for Genomic Research

National Center for Biotechnology Information, NIH