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Pathogenicity of Isolates of Serratia Marcescens towards Larvae of the Scarab Phyllophaga Blanchardi (Coleoptera).

Pineda-Castellanos ML, Rodríguez-Segura Z, Villalobos FJ, Hernández L, Lina L, Nuñez-Valdez ME - Pathogens (2015)

Bottom Line: Oral and injection bioassays using healthy Phyllophaga blanchardi larvae fed with the S. marcescens isolates showed different degrees of antifeeding effect and mortality.S. marcescens (Sm81) cell-free culture supernatant caused significant antifeeding effect and mortality to P. blanchardi larvae by oral bioassay and also mortality by injection bioassay.This insecticidal protein could have applications in agricultural biotechnology.

View Article: PubMed Central - PubMed

Affiliation: Centro de Investigación en Dinámica Celular, Instituto de Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, CP 62209, Cuernavaca, Morelos, Mexico. mlpc@uaem.mx.

ABSTRACT
Serratia marcescens is a Gram negative bacterium (Enterobacteriaceae) often associated with infection of insects. In order to find pathogenic bacteria with the potential to control scarab larvae, several bacterial strains were isolated from the hemocoel of diseased Phyllophaga spp (Coleoptera:Scarabaeidae) larvae collected from cornfields in Mexico. Five isolates were identified as Serratia marcescens by 16S rRNA gene sequencing and biochemical tests. Oral and injection bioassays using healthy Phyllophaga blanchardi larvae fed with the S. marcescens isolates showed different degrees of antifeeding effect and mortality. No insecticidal activity was observed for Spodoptera frugiperda larvae (Lepidoptera: Noctuidae) by oral inoculation. S. marcescens (Sm81) cell-free culture supernatant caused significant antifeeding effect and mortality to P. blanchardi larvae by oral bioassay and also mortality by injection bioassay. Heat treated culture broths lost the ability to cause disease symptoms, suggesting the involvement of proteins in the toxic activity. A protein of 50.2 kDa was purified from the cell-free broth and showed insecticidal activity by injection bioassay towards P. blanchardi. Analysis of the insecticidal protein by tandem- mass spectrometry (LC-MS/MS) showed similarity to a Serralysin-like protein from S. marcescens spp. This insecticidal protein could have applications in agricultural biotechnology.

No MeSH data available.


Related in: MedlinePlus

Feeding behavior of S. marcescens isolates towards larvae of P. blanchardi by oral inoculation. The percentage of feeding represents an average of food ingested during 6 days of oral inoculation. Control groups were fed with uncoated pieces of carrot and also carrot coated with the non-pathogenic bacterium Serratia plymuthica ATCC15928. A lack of significant differences is indicated by the same letter above the bars (ANOVA, p < 0.001); n = 10.
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pathogens-04-00210-f001: Feeding behavior of S. marcescens isolates towards larvae of P. blanchardi by oral inoculation. The percentage of feeding represents an average of food ingested during 6 days of oral inoculation. Control groups were fed with uncoated pieces of carrot and also carrot coated with the non-pathogenic bacterium Serratia plymuthica ATCC15928. A lack of significant differences is indicated by the same letter above the bars (ANOVA, p < 0.001); n = 10.

Mentions: Oral bioassays were done to test the ability of the bacterial isolates to cause pathogenic symptoms: antifeeding effect, change in color and mortality. Healthy larvae of P. blanchardi were fed with small pieces of carrot containing the S. marcescens isolates, as indicated in the Materials and Methods section. Larvae in the control treatment group were fed with un-inoculated carrot. A second negative control was done with larvae fed with the non-pathogenic bacteria S. plymuthica ATCC 15928. As indicated in Figure 1, the bacterial isolates of S. marcescens caused different degrees of antifeeding effects, since the larvae showed a significant decrement in the amount of food consumed compared to the control larvae (p < 0.05) during the 6 days of oral inoculation. The larvae fed with the isolates of S. marcescens 67 (Sm67), S. marcescens 81 (Sm81) and S. marcescens 65 (Sm65) consumed only a small proportion of the available food, showing a food consumption of 7.51%, 13.46% and 6.06% respectively; the strains S. marcescens 89 (Sm89) and S. marcescens 73 (Sm73) consumed only 41.84% and 29.89% of their food, respectively. Larvae from the control groups, fed with un-inoculated carrot and with the nonpathogenic bacteria S. plymuthica consumed 76.19% and 72.33% of the available food, respectively. After the inoculation period of 6 days, all the larvae were fed with inoculated carrot. The larvae treated with the different isolates of S. marcescens maintained low levels of food consumption compared to control larvae, even after the pathogenic bacteria was separated from the food; the larvae in this control group consumed about 75% of the available carrot, and the average of food consumption in the larvae fed with the S. marcescens isolates was 25%.


Pathogenicity of Isolates of Serratia Marcescens towards Larvae of the Scarab Phyllophaga Blanchardi (Coleoptera).

Pineda-Castellanos ML, Rodríguez-Segura Z, Villalobos FJ, Hernández L, Lina L, Nuñez-Valdez ME - Pathogens (2015)

Feeding behavior of S. marcescens isolates towards larvae of P. blanchardi by oral inoculation. The percentage of feeding represents an average of food ingested during 6 days of oral inoculation. Control groups were fed with uncoated pieces of carrot and also carrot coated with the non-pathogenic bacterium Serratia plymuthica ATCC15928. A lack of significant differences is indicated by the same letter above the bars (ANOVA, p < 0.001); n = 10.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493471&req=5

pathogens-04-00210-f001: Feeding behavior of S. marcescens isolates towards larvae of P. blanchardi by oral inoculation. The percentage of feeding represents an average of food ingested during 6 days of oral inoculation. Control groups were fed with uncoated pieces of carrot and also carrot coated with the non-pathogenic bacterium Serratia plymuthica ATCC15928. A lack of significant differences is indicated by the same letter above the bars (ANOVA, p < 0.001); n = 10.
Mentions: Oral bioassays were done to test the ability of the bacterial isolates to cause pathogenic symptoms: antifeeding effect, change in color and mortality. Healthy larvae of P. blanchardi were fed with small pieces of carrot containing the S. marcescens isolates, as indicated in the Materials and Methods section. Larvae in the control treatment group were fed with un-inoculated carrot. A second negative control was done with larvae fed with the non-pathogenic bacteria S. plymuthica ATCC 15928. As indicated in Figure 1, the bacterial isolates of S. marcescens caused different degrees of antifeeding effects, since the larvae showed a significant decrement in the amount of food consumed compared to the control larvae (p < 0.05) during the 6 days of oral inoculation. The larvae fed with the isolates of S. marcescens 67 (Sm67), S. marcescens 81 (Sm81) and S. marcescens 65 (Sm65) consumed only a small proportion of the available food, showing a food consumption of 7.51%, 13.46% and 6.06% respectively; the strains S. marcescens 89 (Sm89) and S. marcescens 73 (Sm73) consumed only 41.84% and 29.89% of their food, respectively. Larvae from the control groups, fed with un-inoculated carrot and with the nonpathogenic bacteria S. plymuthica consumed 76.19% and 72.33% of the available food, respectively. After the inoculation period of 6 days, all the larvae were fed with inoculated carrot. The larvae treated with the different isolates of S. marcescens maintained low levels of food consumption compared to control larvae, even after the pathogenic bacteria was separated from the food; the larvae in this control group consumed about 75% of the available carrot, and the average of food consumption in the larvae fed with the S. marcescens isolates was 25%.

Bottom Line: Oral and injection bioassays using healthy Phyllophaga blanchardi larvae fed with the S. marcescens isolates showed different degrees of antifeeding effect and mortality.S. marcescens (Sm81) cell-free culture supernatant caused significant antifeeding effect and mortality to P. blanchardi larvae by oral bioassay and also mortality by injection bioassay.This insecticidal protein could have applications in agricultural biotechnology.

View Article: PubMed Central - PubMed

Affiliation: Centro de Investigación en Dinámica Celular, Instituto de Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, CP 62209, Cuernavaca, Morelos, Mexico. mlpc@uaem.mx.

ABSTRACT
Serratia marcescens is a Gram negative bacterium (Enterobacteriaceae) often associated with infection of insects. In order to find pathogenic bacteria with the potential to control scarab larvae, several bacterial strains were isolated from the hemocoel of diseased Phyllophaga spp (Coleoptera:Scarabaeidae) larvae collected from cornfields in Mexico. Five isolates were identified as Serratia marcescens by 16S rRNA gene sequencing and biochemical tests. Oral and injection bioassays using healthy Phyllophaga blanchardi larvae fed with the S. marcescens isolates showed different degrees of antifeeding effect and mortality. No insecticidal activity was observed for Spodoptera frugiperda larvae (Lepidoptera: Noctuidae) by oral inoculation. S. marcescens (Sm81) cell-free culture supernatant caused significant antifeeding effect and mortality to P. blanchardi larvae by oral bioassay and also mortality by injection bioassay. Heat treated culture broths lost the ability to cause disease symptoms, suggesting the involvement of proteins in the toxic activity. A protein of 50.2 kDa was purified from the cell-free broth and showed insecticidal activity by injection bioassay towards P. blanchardi. Analysis of the insecticidal protein by tandem- mass spectrometry (LC-MS/MS) showed similarity to a Serralysin-like protein from S. marcescens spp. This insecticidal protein could have applications in agricultural biotechnology.

No MeSH data available.


Related in: MedlinePlus