Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UMLS:C0036690 (
sepsis
)
59,461
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Steinernema feltiae
K1 (Filipjev) (Nematode: Steinernematidae), an entomopathogenic nematode, was isolated and identified based on its morphological and molecular diagnostic characteristics. Its infective juveniles (IJs) were highly pathogenic to three lepidopteran (LC
50
= 23.7-25.0 IJs/larva) and one coleopteran (LC
50
= 39.3 IJs/larva) insect species. Infected larvae of the diamondback moth,
Plutella xylostella
(L.) (Insecta: Lepidoptera), exhibited significant reduction in phospholipase A
2
(PLA
2
) activity in their plasma. The decrease of PLA
2
activity was followed by significant
septicemia
of the larvae infected with
S. feltiae
. Insecticidal activity induced by
S. feltiae
was explained by significant immunosuppression in cellular immune responses measured by hemocyte nodule formation and total hemocyte count (THC). Although
S. feltiae
infection suppressed nodule formation and THC in the larvae, an addition of arachidonic acid (AA, a catalytic product of PLA
2
) rescued these larvae from fatal immunosuppression. In contrast, an addition of dexamethasone (a specific PLA
2
inhibitor) enhanced the nematode's pathogenicity in a dose-dependent manner. To discriminate the immunosuppressive activity of a symbiotic bacterium (
Xenorhabdus bovienii
(Proteobacteria: Enterobacterales)) from the nematode, kanamycin was applied to after nematode infection. It significantly inhibited the bacterial growth in the hemolymph. Compared to nematode treatment alone, the addition of antibiotics to nematode infection partially rescued the immunosuppression measured by
phenol oxidase
activity. Consequently, treatment with antibiotics significantly rescued the larvae from the insecticidal activity of
S. feltiae
. These results suggest that immunosuppression induced by infection of
S. feltiae
depends on its symbiotic bacteria by inhibiting eicosanoid biosynthesis, resulting in significant insect mortality. However, the addition of antibiotics or AA could not completely rescue the virulence of the nematode, suggesting that the nematode itself also plays a role in its insecticidal activity.
...
PMID:Host Immunosuppression Induced by
Steinernema feltiae
, an Entomopathogenic Nematode, through Inhibition of Eicosanoid Biosynthesis. 3190 89
