Gut flora of Galleria mellonella suppressing ingested bacteria

Jarosz, J.

doi:10.1016/0022-2011(79)90101-0

Cited by 54 publications

(37 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Contamination from the normal bacterial flora of G. mellonella has been observed in other studies [33,34] but a recent paper by Entwistle & Coote [35] demonstrated that the antibiotic piperacillin was able to inhibit G. mellonella contaminating bacterial flora but did not inhibit the growth of non-tuberculous mycobacteria. We undertook a minimum inhibitory concentration (MIC) assay to assess the inhibitory concentration of piperacillin against M. bovis BCG lux at doubling concentrations ranging from 1280 – 10 µg/ml.…”

Section: Resultsmentioning

confidence: 94%

“…Luminescence measurement has been shown to be a measure of mycobacterial metabolic activity, related to viability [21,22,24,33]. We also isolated and enumerated mycobacterial CFU from infected G. mellonella at the same respective time-points as luminescence measurements up to 168 h to determine the correlation between RLU and CFU in the G. mellonella model.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Galleria mellonella - a novel infection model for the Mycobacterium tuberculosis complex

Spiropoulos

Cooley

et al. 2018

Virulence

View full text Add to dashboard Cite

Animal models have long been used in tuberculosis research to understand disease pathogenesis and to evaluate novel vaccine candidates and anti-mycobacterial drugs. However, all have limitations and there is no single animal model which mimics all the aspects of mycobacterial pathogenesis seen in humans. Importantly mice, the most commonly used model, do not normally form granulomas, the hallmark of tuberculosis infection. Thus there is an urgent need for the development of new alternative in vivo models. The insect larvae, Galleria mellonella has been increasingly used as a successful, simple, widely available and cost-effective model to study microbial infections. Here we report for the first time that G. mellonella can be used as an infection model for members of the Mycobacterium tuberculosis complex. We demonstrate a dose-response for G. mellonella survival infected with different inocula of bioluminescent Mycobacterium bovis BCG lux, and demonstrate suppression of mycobacterial luminesence over 14 days. Histopathology staining and transmission electron microscopy of infected G. mellonella phagocytic haemocytes show internalization and aggregation of M. bovis BCG lux in granuloma-like structures, and increasing accumulation of lipid bodies within M. bovis BCG lux over time, characteristic of latent tuberculosis infection. Our results demonstrate that G. mellonella can act as a surrogate host to study the pathogenesis of mycobacterial infection and shed light on host-mycobacteria interactions, including latent tuberculosis infection.

show abstract

Section: Resultsmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 99%

Galleria mellonella - a novel infection model for the Mycobacterium tuberculosis complex

Spiropoulos

Cooley

et al. 2018

Virulence

View full text Add to dashboard Cite

show abstract

“…The presence of gut bacteria may afford larvae some protection since aseptic larvae that had been exposed to antibiotics only during first instar were killed more rapidly by DiPel than were nonsterile larvae. The presence of gut bacteria was associated with a slight delay in mortality in synergism bioassays, which may be (20,34). The level of Cry toxicity may be increased (25), decreased (32), or unaffected (19) by the inclusion of antibiotics in lepidopteran bioassays, although the effects of antibiotics on gut bacteria were not reported.…”

Section: Discussionmentioning

confidence: 99%

Gut Bacteria Are Not Required for the Insecticidal Activity of Bacillus thuringiensis toward the Tobacco Hornworm, Manduca sexta

Johnston

Crickmore

2009

Appl Environ Microbiol

View full text Add to dashboard Cite

It was recently proposed that gut bacteria are required for the insecticidal activity of the Bacillus thuringiensis-based insecticide, DiPel, toward the lepidopterans Manduca sexta, Pieris rapae, Vanessa cardui, and Lymantria dispar. Using a similar methodology, it was found that gut bacteria were not required for the toxicity of DiPel or Cry1Ac or for the synergism of an otherwise sublethal concentration of Cry1Ac toward M. sexta. The toxicities of DiPel and of B. thuringiensis HD73 Cry ؊ spore/Cry1Ac synergism were attenuated by continuously exposing larvae to antibiotics before bioassays. Attenuation could be eliminated by exposing larvae to antibiotics only during the first instar without altering larval sterility. Prior antibiotic exposure did not attenuate Cry1Ac toxicity. The presence of enterococci in larval guts slowed mortality resulting from DiPel exposure and halved Cry1Ac toxicity but had little effect on B. thuringiensis HD73 Cry ؊ spore/Cry1Ac synergism. B. thuringiensis Cry ؊ cells killed larvae after intrahemocoelic inoculation of M. sexta, Galleria mellonella, and Spodoptera litura and grew rapidly in plasma from M. sexta, S. litura, and Tenebrio molitor. These findings suggest that gut bacteria are not required for B. thuringiensis insecticidal activity toward M. sexta but that B. thuringiensis lethality is reduced in larvae that are continuously exposed to antibiotics before bioassay.Bacillus thuringiensis has long been regarded as a bona fide entomopathogen that can produce an array of virulence factors including insecticidal parasporal crystal (Cry) toxins, vegetative insecticidal proteins, phospholipases, immune inhibitors, and antibiotics (31). B. thuringiensis establishes lethal infections in many insect species after intrahemocoelic inoculation (9,10,14,26,31), and the insecticidal activity of Cry toxins, which lyse the intestinal epithelium, can be synergized by the presence of viable B. thuringiensis spores (31). In each instance, synergism has been attributed to hemocoelic infection by B. thuringiensis.A novel hypothesis (6, 7) proposed that B. thuringiensis is incapable of killing Lymantria dispar, Manduca sexta, Pieris rapae, or Vanessa cardui in the absence of gut bacteria. Prior exposure of L. dispar larvae to a combination of four antibiotics severely reduced the subsequent toxicity of the B. thuringiensis-based (spores and Cry toxins) bioinsecticide, DiPel (Valent BioSciences) (6). Both larval susceptibility to B. thuringiensis and the number of culturable gut bacteria were found to be negatively correlated with the concentration of antibiotics to which larvae were previously exposed. Furthermore, a total reduction in larval susceptibility was coincident with the elimination of any detectable gut bacteria. Experimental reinfection with Enterobacter sp. strain NAB3, found in the guts of some populations of L. dispar larvae, was found to rescue the toxicity of B. thuringiensis, whereas reinfection with Enterococcus casseliflavus and Staphylococcus xylosus did not. It was also sho...

show abstract

“…The gut microbiota of Lepidoptera is limited to a handful of bacterial species that varies with habitat and diet but often is dominated by enterococci that persist through metamorphosis [12]. In the lepidopteran gut, enterococci interact with pathogens through (i) competitive exclusion (ii) attenuation by direct antagonism or (iii) eliciting protective host immune responses and provide lepidopterans including Galleria mellonella with protection against one of the most virulent entomopathogens, Bacillus thuringiensis [21,[27][28][29] (reviewed in [30]). …”

Section: Introductionmentioning

confidence: 99%

“…Streptococcus faecalis Andrewes and Horder) is passed from female to offspring via the surface of the egg [25]. In vitro observations of lepidopteran gut microbes imply that E. mundtii has the highest abundance, in adults it is often the only detectable microbe in the gut, and that this is mediated by synergy between lysozyme and a broad-spectrum bacteriocin [28]. As is common in many Lepidoptera [32], G. mellonella adults lack functional mouthparts and therefore additional microbes cannot be acquired during adult life.…”

Section: Introductionmentioning

confidence: 99%

Host and symbiont jointly control gut microbiota during complete metamorphosis

Johnston¹

2016

2016 International Congress of Entomology

View full text Add to dashboard Cite

Holometabolous insects undergo a radical anatomical re-organisation during metamorphosis. This poses a developmental challenge: the host must replace the larval gut but at the same time retain symbiotic gut microbes and avoid infection by opportunistic pathogens. By manipulating host immunity and bacterial competitive ability, we study how the host Galleria mellonella and the symbiotic bacterium Enterococcus mundtii interact to manage the composition of the microbiota during metamorphosis. Disenabling one or both symbiotic partners alters the composition of the gut microbiota, which incurs fitness costs: adult hosts with a gut microbiota dominated by pathogens such as Serratia and Staphylococcus die early. Our results reveal an interaction that guarantees the safe passage of the symbiont through metamorphosis and benefits the resulting adult host. Host-symbiont "conspiracies" as described here are almost certainly widespread in holometobolous insects including many disease vectors.

show abstract

Gut flora of Galleria mellonella suppressing ingested bacteria

Cited by 54 publications

References 11 publications

Galleria mellonella - a novel infection model for the Mycobacterium tuberculosis complex

Galleria mellonella - a novel infection model for the Mycobacterium tuberculosis complex

Gut Bacteria Are Not Required for the Insecticidal Activity of Bacillus thuringiensis toward the Tobacco Hornworm, Manduca sexta

Host and symbiont jointly control gut microbiota during complete metamorphosis

Contact Info

Product

Resources

About