Multiple lineages of Streptomyces produce antimicrobials within passalid beetle galleries across eastern North America.
ABSTRACT: Some insects form symbioses in which actinomycetes provide defense against pathogens by making antimicrobials. The range of chemical strategies employed across these associations, and how these strategies relate to insect lifestyle, remains underexplored. We assessed subsocial passalid beetles of the species Odontotaenius disjunctus, and their frass (fecal material), which is an important food resource within their galleries, as a model insect/actinomycete system. Through chemical and phylogenetic analyses, we found that O. disjunctus frass collected across eastern North America harbored multiple lineages of Streptomyces and diverse antimicrobials. Metabolites detected in frass displayed synergistic and antagonistic inhibition of a fungal entomopathogen, Metarhizium anisopliae, and multiple streptomycete isolates inhibited this pathogen when co-cultivated directly in frass. These findings support a model in which the lifestyle of O. disjunctus accommodates multiple Streptomyces lineages in their frass, resulting in a rich repertoire of antimicrobials that likely insulates their galleries against pathogenic invasion.
Project description:Metarhizium anisopliae P016 was isolated from frass material collected within wild galleries of Odontotaenius disjunctus (bessbug beetles) in the USA. Metarhizium anisopliae P287 was isolated from Odontotaenius disjunctus carcass found in the wild (USA). Both were cultured on ISP2-agar for seven days at 30C. Cultures were extracted with ethyl acetate. Reserpine was used as an internal standard.
Project description:Microbes were isolated from frass material collected within laboratory galleries of Odontotaenius disjunctus (bessbug beetles) in the USA, and cultured on ISP2-agar for seven days at 30C. Cultures were extracted with ethyl acetate or methanol.
Project description:Frass material was collected within wild galleries of Odontotaenius disjunctus (bessbug beetles) in the USA, extracted with ethyl acetate, and analyzed in three technical replicates. Only MS1 data was collected. Reserpine was used as internal standard.
Project description:16S amplicon pool analyses of the four gut sections of the wood-feeding beetle, Odontotaenius disjunctus The beetle is purely wood feeding, and we aim to first characterize the community that exist within the gut sections 4 beetles, four gut sections per beetle, one PhyloChip per gut section, total = 16 chips
Project description:The valley elderberry longhorn beetle (VELB), Desmocerus californicus dimorphus (Coleoptera: Cerambycidae), is a federally threatened subspecies endemic to the Central Valley of California. The VELB range partially overlaps with that of its morphologically similar sister taxon, the California elderberry longhorn beetle (CELB), Desmocerus californicus californicus (Coleoptera: Cerambycidae). Current surveying methods are limited to visual identification of larval exit holes in the VELB/CELB host plant, elderberry (Sambucus spp.), into which larvae bore and excavate feeding galleries. Unbiased genetic approaches could provide a much-needed complementary approach that has more precision than relying on visual inspection of exit holes. In this study we developed a DNA sequencing-based method for indirect detection of VELB/CELB from frass (insect fecal matter), which can be easily and non-invasively collected from exit holes. Frass samples were collected from 37 locations and the 12S and 16S mitochondrial genes were partially sequenced using nested PCR amplification. Three frass-derived sequences showed 100% sequence identity to VELB/CELB barcode references from museum specimens sequenced for this study. Database queries of frass-derived sequences also revealed high similarity to common occupants of old VELB feeding galleries, including earwigs, flies, and other beetles. Overall, this non-invasive approach is a first step towards a genetic assay that could augment existing VELB monitoring and accurately discriminate between VELB, CELB, and other insects. Furthermore, a phylogenetic analysis of 12S and 16S data from museum specimens revealed evidence for the existence of a previously unrecognized, genetically distinct CELB subpopulation in southern California.
Project description:Frass material was collected within wild galleries of Odontotaenius disjunctus (bessbug beetles) in the USA, and extracted with ethyl acetate. Reserpine was used as an internal standard. Methods were optimized for the detection of a specific compound or family of compounds. This dataset includes commercial standards too, as indicated in the file names.
Project description:Antimicrobial resistance is a global health crisis and few novel antimicrobials have been discovered in recent decades. Natural products, particularly from Streptomyces, are the source of most antimicrobials, yet discovery campaigns focusing on Streptomyces from the soil largely rediscover known compounds. Investigation of understudied and symbiotic sources has seen some success, yet no studies have systematically explored microbiomes for antimicrobials. Here we assess the distinct evolutionary lineages of Streptomyces from insect microbiomes as a source of new antimicrobials through large-scale isolations, bioactivity assays, genomics, metabolomics, and in vivo infection models. Insect-associated Streptomyces inhibit antimicrobial-resistant pathogens more than soil Streptomyces. Genomics and metabolomics reveal their diverse biosynthetic capabilities. Further, we describe cyphomycin, a new molecule active against multidrug resistant fungal pathogens. The evolutionary trajectories of Streptomyces from the insect microbiome influence their biosynthetic potential and ability to inhibit resistant pathogens, supporting the promise of this source in augmenting future antimicrobial discovery.
Project description:Molecular assays based on qPCR TaqMan Probes were developed to identify three species of the genus <i>Xylosandrus</i>, <i>X. compactus, X. crassiusculus</i> and <i>X. germanus</i> (Coleoptera Curculionidae Scolytinae). These ambrosia beetles are xylophagous species alien to Europe, causing damages to many ornamental and fruiting trees as well as shrubs. DNA extraction was carried out from adults, larvae and biological samples derived from insect damages on infested plants. For <i>X. compactus</i>, segments of galleries in thin infested twigs were cut and processed; in the case of <i>X. crassiusculus</i>, raw frass extruded from exit holes was used, while DNA of <i>X. germanus</i> was extracted from small wood chips removed around insect exit holes. The assays were inclusive for the target species and exclusive for all the non-target species tested. The LoD was 3.2 pg/µL for the frass of <i>X. crassiusculus</i> and 0.016 ng/µL for the woody matrices of the other two species. Both repeatability and reproducibility were estimated on adults and woody samples, showing very low values ranging between 0.00 and 4.11. Thus, the proposed diagnostic assays resulted to be very efficient also on the woody matrices used for DNA extraction, demonstrating the applicability of the protocol in the absence of dead specimens or living stages.
Project description:The construction process and use of galleries by <i>Azteca brevis</i> (Myrmicinae: Dolichoderinae) inhabiting <i>Tetrathylacium macrophyllum</i> (Salicaceae) were compared with <i>Allomerus decemarticulatus</i> (Myrmicinae: Solenopsidini) galleries on <i>Hirtella physophora</i> (Chrysobalanaceae). Though the two ant species are phylogenetically distant, the gallery structure seems to be surprisingly similar and structurally convergent: both are pierced with numerous holes and both ant species use Chaetothyrialean fungi to strengthen the gallery walls. <i>Al. decemarticulatus</i> is known to use the galleries for prey capture and whether this is also the case for <i>Az. brevis</i> was tested in field experiments. We placed <i>Atta</i> workers as potential prey/threat on the galleries and recorded the behaviour of both ant species. We found considerable behavioural differences between them: <i>Al. decemarticulatus</i> was quicker and more efficient at capture than was <i>Az. brevis</i>. While most <i>Atta</i> workers were captured after the first 5 min by <i>Al. decemarticulatus</i>, significantly fewer were captured by <i>Az. brevis</i> even after 20 min. Moreover, the captured <i>Atta</i> were sometimes simply discarded and not taken to the nest by <i>Az. brevis</i>. As a consequence, the major function of the galleries built by <i>Az. brevis</i> may, therefore, be defense against intruders in contrast to <i>Al. decemarticulatus</i> which uses them mainly for prey capture. This may be due to a higher need for protein in <i>Al. decemarticulatus</i> compared to coccid-raising <i>Az. brevis</i>.
Project description:Frass material was collected within wild galleries of Odontotaenius disjunctus (bessbug beetles) in the USA, and extracted with ethyl acetate. Reserpine was used as an internal standard.