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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

Oral bioassay showing the antifeeding effect (Panel A) and mortality (Panel B) of cell-free culture supernatants from Sm81 isolate towards P. blanchardi larvae. The control group was fed with carrot containing nutrient broth plus BSA. The feeding activity of larvae was evaluated during Days 7–11 after an inoculation period of 6 days. The average of food ingestion during the period is shown. Mortality was evaluated during 22 days from the beginning of bioassay. Differences among the groups of larvae shown by the letters above the bars or lines were evaluated by ANOVA for feeding activity and χ2 for mortality. Sm81H represents a treatment where the cell-free culture supernatant from the isolate Sm81 were boiled for 5 min. The groups of larvae evaluated are shown by different letters above the lines; n = 14.
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pathogens-04-00210-f003: Oral bioassay showing the antifeeding effect (Panel A) and mortality (Panel B) of cell-free culture supernatants from Sm81 isolate towards P. blanchardi larvae. The control group was fed with carrot containing nutrient broth plus BSA. The feeding activity of larvae was evaluated during Days 7–11 after an inoculation period of 6 days. The average of food ingestion during the period is shown. Mortality was evaluated during 22 days from the beginning of bioassay. Differences among the groups of larvae shown by the letters above the bars or lines were evaluated by ANOVA for feeding activity and χ2 for mortality. Sm81H represents a treatment where the cell-free culture supernatant from the isolate Sm81 were boiled for 5 min. The groups of larvae evaluated are shown by different letters above the lines; n = 14.

Mentions: During the first time period analyzed (inoculation period), from the beginning of the test to Day 6, control larvae and those fed with the boiled sample consumed about 94% and 90% of their food, respectively. A slight but significant decrement (18%, compared to the control 94%) in food consumption was observed in the larvae fed with the Sm81 broth (76%). During the second period analyzed, from Days 7–11, the control larvae showed a food consumption of 85 % (Figure 3). On the other hand, the larvae fed with Sm81 broth consumed only about 15% (p < 0.001) of the available food; thereby showing an antifeeding effect. This effect was not observed when the sample was boiled, since larvae showed a food consumption of 81%, which was not significant when compared to the control larvae (85%, p > 0.05), but it was significant when compared with the larvae fed with non-boiled broth (15%, p < 0.01). The Sm81 broth sample also caused a significant mortality rate of 64% (p > 0.05) after 22 days from the beginning of the test. No significant mortality was observed for control larvae and those fed with boiled broth (20%).


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)

Oral bioassay showing the antifeeding effect (Panel A) and mortality (Panel B) of cell-free culture supernatants from Sm81 isolate towards P. blanchardi larvae. The control group was fed with carrot containing nutrient broth plus BSA. The feeding activity of larvae was evaluated during Days 7–11 after an inoculation period of 6 days. The average of food ingestion during the period is shown. Mortality was evaluated during 22 days from the beginning of bioassay. Differences among the groups of larvae shown by the letters above the bars or lines were evaluated by ANOVA for feeding activity and χ2 for mortality. Sm81H represents a treatment where the cell-free culture supernatant from the isolate Sm81 were boiled for 5 min. The groups of larvae evaluated are shown by different letters above the lines; n = 14.
© Copyright Policy
Related In: Results  -  Collection

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

pathogens-04-00210-f003: Oral bioassay showing the antifeeding effect (Panel A) and mortality (Panel B) of cell-free culture supernatants from Sm81 isolate towards P. blanchardi larvae. The control group was fed with carrot containing nutrient broth plus BSA. The feeding activity of larvae was evaluated during Days 7–11 after an inoculation period of 6 days. The average of food ingestion during the period is shown. Mortality was evaluated during 22 days from the beginning of bioassay. Differences among the groups of larvae shown by the letters above the bars or lines were evaluated by ANOVA for feeding activity and χ2 for mortality. Sm81H represents a treatment where the cell-free culture supernatant from the isolate Sm81 were boiled for 5 min. The groups of larvae evaluated are shown by different letters above the lines; n = 14.
Mentions: During the first time period analyzed (inoculation period), from the beginning of the test to Day 6, control larvae and those fed with the boiled sample consumed about 94% and 90% of their food, respectively. A slight but significant decrement (18%, compared to the control 94%) in food consumption was observed in the larvae fed with the Sm81 broth (76%). During the second period analyzed, from Days 7–11, the control larvae showed a food consumption of 85 % (Figure 3). On the other hand, the larvae fed with Sm81 broth consumed only about 15% (p < 0.001) of the available food; thereby showing an antifeeding effect. This effect was not observed when the sample was boiled, since larvae showed a food consumption of 81%, which was not significant when compared to the control larvae (85%, p > 0.05), but it was significant when compared with the larvae fed with non-boiled broth (15%, p < 0.01). The Sm81 broth sample also caused a significant mortality rate of 64% (p > 0.05) after 22 days from the beginning of the test. No significant mortality was observed for control larvae and those fed with boiled broth (20%).

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