Isolation, characterization and mosquitocidal activity evaluation of Lysinibacillus strains obtained from Culex pipiens larvae

TRANCHIDA M. C.; RICCILLO P.M.; MICIELI M. V.; GARCÍA J.J.; RODRIGUERO M.S.

ANNALS OF MICROBIOLOGY

INST MICROBIOLOGIA

Lugar: Italia; Año: 2010

1590-4261

<!-- /* Font Definitions */ @font-face {font-family:"New York"; panose-1:2 4 5 3 6 5 6 2 3 4; mso-font-alt:"Times New Roman"; mso-font-charset:0; mso-generic-font-family:roman; mso-font-format:other; mso-font-pitch:variable; mso-font-signature:3 0 0 0 1 0;} @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:-1610611985 1107304683 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; mso-layout-grid-align:none; punctuation-wrap:simple; text-autospace:none; font-size:12.0pt; mso-bidi-font-size:10.0pt; font-family:"New York","serif"; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"Times New Roman"; mso-ansi-language:EN-US; mso-fareast-language:ES;} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; font-size:10.0pt; mso-ansi-font-size:10.0pt; mso-bidi-font-size:10.0pt; mso-ascii-font-family:Times; mso-hansi-font-family:Times;} @page WordSection1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.WordSection1 {page:WordSection1;} --> Three strains—C107, C207, and C307—of spore-forming Gram-positive motile rod-shaped bacteria were isolated from dead larvae of Culex pipiens in La Plata city, Argentina. The three bacterial strains have different phenotypic and molecular characterictics. A comparative analysis of their 16S-rRNA­–gene sequences and phylogenetic analysis demonstrated that the isolates C107 and C207 were related to reference strains of Lysinibacillus sphaericus, while C307 to Bacillus licheniformis. The cytomorphology, biochemical characterization, and phylogenetic relatedness corroborated these respective group assignments. The bacterial strain isolated exhibited the same PCR amplified pattern with the binA, binB, and mtx genes as did the reference strains used. These bacterial strains presented different pathogenic actions among the following mosquito species tested: Culex pipiens, Aedes aegypti, Culex dolosus, Culex apicinus, Ochlerotatus albifasciatus, and Anopheles albitarsis. Only the isolates C107 and C207 exhibited mosquitocidal activity. C. pipiens was the species most susceptible to C107 (LC50, 4 x 104 spores/ml), while O. albifasciatus was most susceptible to C207 (LC50, 3.4 x 106 spores/ ml).