scholarly journals The route of infection determines Wolbachia antibacterial protection in Drosophila

2017 ◽  
Vol 284 (1856) ◽  
pp. 20170809 ◽  
Author(s):  
Vanika Gupta ◽  
Radhakrishnan B. Vasanthakrishnan ◽  
Jonathon Siva-Jothy ◽  
Katy M. Monteith ◽  
Sam P. Brown ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Bacterial Infections ◽  
Systemic Infection ◽  
Sexually Dimorphic ◽  
Bacterial Symbionts ◽  
Route Of Infection ◽  
Early Expression ◽  
Attacin A ◽  
Detoxification Gene ◽  
Opportunist Pathogen

Bacterial symbionts are widespread among metazoans and provide a range of beneficial functions. Wolbachia -mediated protection against viral infection has been extensively demonstrated in Drosophila. In mosquitoes that are artificially transinfected with Drosophila melanogaster Wolbachia (wMel), protection from both viral and bacterial infections has been demonstrated. However, no evidence for Wolbachia -mediated antibacterial protection has been demonstrated in Drosophila to date. Here, we show that the route of infection is key for Wolbachia -mediated antibacterial protection. Drosophila melanogaster carrying Wolbachia showed reduced mortality during enteric—but not systemic—infection with the opportunist pathogen Pseudomonas aeruginosa . Wolbachia -mediated protection was more pronounced in male flies and is associated with increased early expression of the antimicrobial peptide Attacin A , and also increased expression of a reactive oxygen species detoxification gene ( Gst D8 ). These results highlight that the route of infection is important for symbiont-mediated protection from infection, that Wolbachia can protect hosts by eliciting a combination of resistance and disease tolerance mechanisms, and that these effects are sexually dimorphic. We discuss the importance of using ecologically relevant routes of infection to gain a better understanding of symbiont-mediated protection.

scholarly journals Wolbachia confers sex-specific resistance and tolerance to enteric but not systemic bacterial infection in Drosophila

2016 ◽  
Author(s):  
Radhakrishnan B. Vasanthakrishnan ◽  
Gupta Vanika ◽  
Jonathon Siva-Jothy ◽  
Katy M. Monteith ◽  
Sam P. Brown ◽  
...  
Keyword(s):  
Specific Resistance ◽  
Systemic Infection ◽  
Sexually Dimorphic ◽  
Disease Tolerance ◽  
Damage Repair ◽  
Early Expression ◽  
Repair Genes ◽  
Detoxification Gene ◽  
Opportunist Pathogen ◽  
Systemic Bacterial Infection

AbstractWolbachia-mediatedprotection against viral infection has been extensively demonstrated in Drosophila and in mosquitoes that are artificially inoculatedwith D. melanogaster Wolbachia (wMel), but to date no evidence for Wolbachia-mediated antibacterial protection has been demonstrated in Drosophila.Here we show that D. melanogaster carrying wMel shows reduced mortality during enteric – but not systemic - infection with the opportunist pathogen Pseudomonas aeruginosa, and that protection is more pronounced in male flies. Wolbachia-mediated protection is associated with increased early expression of the antimicrobial peptide attacinA, followed by increased expression of a ROS detoxification gene (gstD8), and other tissue damage repair genes which together contribute to greater host resistance and disease tolerance. These results highlight that the route of infection is important for symbiont-mediated protection from infection, that Wolbachia can protect hosts by eliciting a combination of resistance and disease tolerance mechanisms, and that these effects are sexually dimorphic.

scholarly journals Viral route of infection determines the effect of Drosophila melanogaster gut bacteria on host resistance and tolerance to disease

2021 ◽  
Author(s):  
Miguel Landum ◽  
Marta Salvado Silva ◽  
Nelson Martins ◽  
Luís Teixeira
Keyword(s):  
Drosophila Melanogaster ◽  
Viral Infections ◽  
Systemic Infection ◽  
Lactobacillus Brevis ◽  
Gut Bacteria ◽  
Associated Bacteria ◽  
Germ Free ◽  
Viral Loads ◽  
Route Of Infection ◽  
The Impact

AbstractThe microbial community interacting with a host can modulate the outcome of pathogenic infections. For instance, Wolbachia, one of the most prevalent invertebrate endosymbionts, strongly increases resistance of Drosophila melanogaster and other insect hosts, to many RNA viruses. D. melanogaster is also in continuous association with gut bacteria, whose role in antiviral immunity is poorly characterized. Here we asked how gut-colonizing bacteria impact viral titres and host survival, and how these interact with route of infection or Wolbachia presence. We compared germ-free flies and flies associated with two gut bacteria species recently isolated from wild flies (Acetobacter thailandicus and Lactobacillus brevis). We found that Wolbachia-conferred protection to both DCV or FHV is not affected by the presence or absence of these gut bacteria. Flies carrying A. thailandicus have lower DCV loads than germ-free flies, upon systemic infection, but reduced survival, indicating that these bacteria increase resistance to virus and decrease disease tolerance. Association with L. brevis, alone or in combination with A. thailandicus, did not lead to changes in survival to systemic infection. In contrast to the effect on systemic infection, we did not observe an impact of these bacteria on survival or viral loads after oral infection. Overall, the impact of gut-associated bacteria in resistance and tolerance to viruses was mild, when compared with Wolbachia. These results indicate that the effect of gut-associated bacteria to different viral infections, and different routes of infection, is complex and understanding it requires a detailed characterization of several parameters of infection.

scholarly journals Pleiotropic Roles of the Orthologue of the Drosophila melanogaster Intersex Gene in the Brown Planthopper

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 379
Author(s):  
Hou-Hong Zhang ◽  
Yu-Cheng Xie ◽  
Han-Jing Li ◽  
Ji-Chong Zhuo ◽  
Chuan-Xi Zhang
Keyword(s):  
Drosophila Melanogaster ◽  
Reproductive System ◽  
Splice Variants ◽  
Brown Planthopper ◽  
Nilaparvata Lugens ◽  
Vital Role ◽  
Sexually Dimorphic ◽  
Specific Product ◽  
Reproductive Ability ◽  
Female Specific

Intersex(ix), a gene involved in the sex-determining cascade of Drosophila melanogaster, works in concert with the female-specific product of doublesex (dsx) at the end of the hierarchy to implement the sex-specific differentiation of sexually dimorphic characters in female individuals. In this study, the ix homolog was identified in the brown planthopper (BPH), Nilaparvata lugens, which contained two splice variants expressed in both female and male insects. We found that Nlix played a vital role in the early nymphal development of BPH, showing an accumulated effect. RNAi-mediated knockdown of Nlix at 4th instar led to the external genital defects in both sexes, consequently resulting in the loss of reproductive ability in female and male individuals. After dsRNA injection, the males were normal on testes, while the females had defective ovarian development. Nlix was also required for early embryogenesis. Notably, when the dsNlix microinjection was performed in newly emerged females, the copulatory bursas were abnormally enlarged while the other tissues of the reproductive system developed normally. Our results demonstrated the pleiotropic roles of Nlix in embryogenesis and development of the reproductive system in a hemimetabolous insect species.

scholarly journals A multicenter evaluation of viral bloodstream detections in children presenting to the Emergency Department with suspected systemic infection

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Christina A. Rostad ◽  
Neena Kanwar ◽  
Jumi Yi ◽  
Claudia R. Morris ◽  
Jennifer Dien Bard ◽  
...  
Keyword(s):  
Emergency Department ◽  
Whole Blood ◽  
Bacterial Infections ◽  
Viral Infections ◽  
Systemic Infection ◽  
Common Symptom ◽  
Predictive Values ◽  
Healthcare Facilities ◽  
Tract Infections ◽  
Systemic Infections

Abstract Background Fever is a common symptom in children presenting to the Emergency Department (ED). We aimed to describe the epidemiology of systemic viral infections and their predictive values for excluding serious bacterial infections (SBIs), including bacteremia, meningitis and urinary tract infections (UTIs) in children presenting to the ED with suspected systemic infections. Methods We enrolled children who presented to the ED with suspected systemic infections who had blood cultures obtained at seven healthcare facilities. Whole blood specimens were analyzed by an experimental multiplexed PCR test for 7 viruses. Demographic and laboratory results were abstracted. Results Of the 1114 subjects enrolled, 245 viruses were detected in 224 (20.1%) subjects. Bacteremia, meningitis and UTI frequency in viral bloodstream-positive patients was 1.3, 0 and 10.1% compared to 2.9, 1.3 and 9.7% in viral bloodstream-negative patients respectively. Although viral bloodstream detections had a high negative predictive value for bacteremia or meningitis (NPV = 98.7%), the frequency of UTIs among these subjects remained appreciable (9/89, 10.1%) (NPV = 89.9%). Screening urinalyses were positive for leukocyte esterase in 8/9 (88.9%) of these subjects, improving the ability to distinguish UTI. Conclusions Viral bloodstream detections were common in children presenting to the ED with suspected systemic infections. Although overall frequencies of SBIs among subjects with and without viral bloodstream detections did not differ significantly, combining whole blood viral testing with urinalysis provided high NPV for excluding SBI.

scholarly journals Bacterial influence on the maintenance of symbiotic yeast through Drosophila metamorphosis

2020 ◽  
Author(s):  
Robin Guilhot ◽  
Antoine Rombaut ◽  
Anne Xuéreb ◽  
Kate Howell ◽  
Simon Fellous
Keyword(s):  
Young Adults ◽  
Drosophila Melanogaster ◽  
Life Cycle ◽  
Symbiotic Bacteria ◽  
Bacterial Symbionts ◽  
Tripartite Symbiosis ◽  
Summary Statement ◽  
Key Features ◽  
Microbial Symbionts

AbstractInteractions between microbial symbionts of metazoan hosts are emerging as key features of symbiotic systems. Little is known about the role of such interactions on the maintenance of symbiosis through host’s life cycle. We studied the influence of symbiotic bacteria on the maintenance of symbiotic yeast through metamorphosis of the fly Drosophila melanogaster. To this end we mimicked the development of larvae in natural fruit. In absence of bacteria yeast was never found in young adults. However, yeast could maintain through metamorphosis when larvae were inoculated with symbiotic bacteria isolated from D. melanogaster faeces. Furthermore, an Enterobacteriaceae favoured yeast transstadial maintenance. Because yeast is a critical symbiont of D. melanogaster flies, bacterial influence on host-yeast association may have consequences for the evolution of insect-yeast-bacteria tripartite symbiosis and their cooperation.Summary statementBacterial symbionts of Drosophila influence yeast maintenance through fly metamorphosis, a novel observation that may have consequences for the evolution of insect-yeast-bacteria interactions.

scholarly journals Variable sexually dimorphic gene expression in laboratory strains of Drosophila melanogaster

BMC Genomics ◽  
2007 ◽  
Vol 8 (1) ◽  
pp. 454 ◽  
Author(s):  
Dean A Baker ◽  
Lisa A Meadows ◽  
Jing Wang ◽  
Julian AT Dow ◽  
Steven Russell
Keyword(s):  
Gene Expression ◽  
Drosophila Melanogaster ◽  
Sexually Dimorphic ◽  
Dimorphic Gene Expression

scholarly journals d-Alanylation of Teichoic Acids Promotes Group A Streptococcus Antimicrobial Peptide Resistance, Neutrophil Survival, and Epithelial Cell Invasion

2005 ◽  
Vol 187 (19) ◽  
pp. 6719-6725 ◽  
Author(s):  
Sascha A. Kristian ◽  
Vivekanand Datta ◽  
Christopher Weidenmaier ◽  
Rita Kansal ◽  
Iris Fedtke ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Group A Streptococcus ◽  
Teichoic Acid ◽  
Systemic Infection ◽  
Human Neutrophils ◽  
Invasive Infection ◽  
Bacterial Surface ◽  
Innate Defense ◽  
Group A ◽  
Antimicrobial Peptide Resistance

ABSTRACT Group A streptococcus (GAS) is a leading cause of severe, invasive human infections, including necrotizing fasciitis and toxic shock syndrome. An important element of the mammalian innate defense system against invasive bacterial infections such as GAS is the production of antimicrobial peptides (AMPs) such as cathelicidins. In this study, we identify a specific GAS phenotype that confers resistance to host AMPs. Allelic replacement of the dltA gene encoding d-alanine-d-alanyl carrier protein ligase in an invasive serotype M1 GAS isolate led to loss of teichoic acid d-alanylation and an increase in net negative charge on the bacterial surface. Compared to the wild-type (WT) parent strain, the GAS ΔdltA mutant exhibited increased susceptibility to AMP and lysozyme killing and to acidic pH. While phagocytic uptake of WT and ΔdltA mutants by human neutrophils was equivalent, neutrophil-mediated killing of the ΔdltA strain was greatly accelerated. Furthermore, we observed the ΔdltA mutant to be diminished in its ability to adhere to and invade cultured human pharyngeal epithelial cells, a likely proximal step in the pathogenesis of invasive infection. Thus, teichoic acid d-alanylation may contribute in multiple ways to the propensity of invasive GAS to bypass mucosal defenses and produce systemic infection.

scholarly journals Inter- and Intraspecific Variation in Drosophila Genes with Sex-Biased Expression

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Lena Müller ◽  
Sonja Grath ◽  
Korbinian von Heckel ◽  
John Parsch
Keyword(s):  
Gene Expression ◽  
Drosophila Melanogaster ◽  
Molecular Evolution ◽  
Protein Sequence ◽  
Sequence Variation ◽  
Purifying Selection ◽  
Sexually Dimorphic ◽  
Expression Divergence ◽  
Sexually Dimorphic Expression ◽  
Dimorphic Expression

Genes with sexually dimorphic expression (sex-biased genes) often evolve rapidly and are thought to make an important contribution to reproductive isolation between species. We examined the molecular evolution of sex-biased genes in Drosophila melanogaster and D. ananassae, which represent two independent lineages within the melanogaster group. We find that strong purifying selection limits protein sequence variation within species, but that a considerable fraction of divergence between species can be attributed to positive selection. In D. melanogaster, the proportion of adaptive substitutions between species is greatest for male-biased genes and is especially high for those on the X chromosome. In contrast, male-biased genes do not show unusually high variation within or between populations. A similar pattern is seen at the level of gene expression, where sex-biased genes show high expression divergence between species, but low divergence between populations. In D. ananassae, there is no increased rate of adaptation of male-biased genes, suggesting that the type or strength of selection acting on sex-biased genes differs between lineages.

scholarly journals Genetic analysis of the sexual dimorphism of glass in Drosophila melanogaster

1984 ◽  
Vol 44 (2) ◽  
pp. 125-132 ◽  
Author(s):  
James A. Birchler
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Dimorphism ◽  
Genetic Analysis ◽  
Phenotypic Expression ◽  
Sexually Dimorphic ◽  
Modifier Locus ◽  
The Third ◽  
Specific Manner ◽  
Gene Maps ◽  
Insertional Translocation

SUMMARYA modifier locus is described that alters the level of phenotypic expression of the third chromosome mutant glass in a sex specific manner. Alternative alleles either confer a sexually dimorphic level of pigment in glass mutants, with the male being greater, or cause similar expression in the two sexes. The alleles are indistinguishable in females but produce the respective phenotypes in males. The gene maps to the tip of the X chromosome at position 0·96 ± 0·11. Cytologically, the locus is present between polytene bands 3A6–8 and 3C2–3 as determined by its inclusion in translocated X segments in w + Y, Dp(l;2)w70h31 and Dp(l;3)w67k27 The dimorphic allele is dominant to the nondimorphic condition in males heterozygous for an insertional translocation carrying the dimorphic allele and a normal chromosome carrying the nondimorphic form. The dimorphic allele in two doses in males does not exhibit a dosage effect. The modifier phenotype is unaffected in two X flies by the presence of the transformer mutation.

scholarly journals CONDITION-DEPENDENCE OF THE SEXUALLY DIMORPHIC TRANSCRIPTOME IN DROSOPHILA MELANOGASTER

Evolution ◽  
2010 ◽  
Vol 64 (6) ◽  
pp. 1836-1848 ◽  
Author(s):  
Minyoung J. Wyman ◽  
Aneil F. Agrawal ◽  
Locke Rowe
Keyword(s):  
Drosophila Melanogaster ◽  
Condition Dependence ◽  
Sexually Dimorphic
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