@article{EsmaeilishirazifardUsherTrimetal.2022, author = {Esmaeilishirazifard, Elham and Usher, Louise and Trim, Carol and Denise, Hubert and Sangal, Vartul and Tyson, Gregory H. and Barlow, Axel and Redway, Keith F. and Taylor, John D. and Kremyda-Vlachou, Myrto and Davies, Sam and Loftus, Teresa D. and Lock, Mikaella M. G. and Wright, Kstir and Dalby, Andrew and Snyder, Lori A. S. and Wuster, Wolfgang and Trim, Steve and Moschos, Sterghios A.}, title = {Bacterial adaptation to venom in snakes and arachnida}, series = {Microbiology spectrum}, volume = {10}, journal = {Microbiology spectrum}, number = {3}, publisher = {American Society for Microbiology}, address = {Birmingham, Ala.}, issn = {2165-0497}, doi = {10.1128/spectrum.02408-21}, pages = {16}, year = {2022}, abstract = {Notwithstanding their 3 to 5\% mortality, the 2.7 million envenomation-related injuries occurring annually-predominantly across Africa, Asia, and Latin America-are also major causes of morbidity. Venom toxin-damaged tissue will develop infections in some 75\% of envenomation victims, with E. faecalis being a common culprit of disease; however, such infections are generally considered to be independent of envenomation. Animal venoms are considered sterile sources of antimicrobial compounds with strong membrane-disrupting activity against multidrug-resistant bacteria. However, venomous bite wound infections are common in developing nations. Investigating the envenomation organ and venom microbiota of five snake and two spider species, we observed venom community structures that depend on the host venomous animal species and evidenced recovery of viable microorganisms from black-necked spitting cobra (Naja nigricollis) and Indian ornamental tarantula (Poecilotheria regalis) venoms. Among the bacterial isolates recovered from N. nigricollis, we identified two venom-resistant, novel sequence types of Enterococcus faecalis whose genomes feature 16 virulence genes, indicating infectious potential, and 45 additional genes, nearly half of which improve bacterial membrane integrity. Our findings challenge the dogma of venom sterility and indicate an increased primary infection risk in the clinical management of venomous animal bite wounds. IMPORTANCE Notwithstanding their 3 to 5\% mortality, the 2.7 million envenomation-related injuries occurring annually-predominantly across Africa, Asia, and Latin America-are also major causes of morbidity. Venom toxin-damaged tissue will develop infections in some 75\% of envenomation victims, with E. faecalis being a common culprit of disease; however, such infections are generally considered to be independent of envenomation. Here, we provide evidence on venom microbiota across snakes and arachnida and report on the convergent evolution mechanisms that can facilitate adaptation to black-necked cobra venom in two independent E. faecalis strains, easily misidentified by biochemical diagnostics. Therefore, since inoculation with viable and virulence gene-harboring bacteria can occur during envenomation, acute infection risk management following envenomation is warranted, particularly for immunocompromised and malnourished victims in resource-limited settings. These results shed light on how bacteria evolve for survival in one of the most extreme environments on Earth and how venomous bites must be also treated for infections.}, language = {en} } @article{DennisPatelOliveretal.2017, author = {Dennis, Alice B. and Patel, Vilas and Oliver, Kerry M. and Vorburger, Christoph}, title = {Parasitoid gene expression changes after adaptation to symbiont-protected hosts}, series = {Evolution}, volume = {71}, journal = {Evolution}, publisher = {Wiley}, address = {Hoboken}, issn = {0014-3820}, doi = {10.1111/evo.13333}, pages = {2599 -- 2617}, year = {2017}, abstract = {Reciprocal selection between aphids, their protective endosymbionts, and the parasitoid wasps that prey upon them offers an opportunity to study the basis of their coevolution. We investigated adaptation to symbiont\&\#8208;conferred defense by rearing the parasitoid wasp Lysiphlebus fabarum on aphids (Aphis fabae) possessing different defensive symbiont strains (Hamiltonella defensa). After ten generations of experimental evolution, wasps showed increased abilities to parasitize aphids possessing the H. defensa strain they evolved with, but not aphids possessing the other strain. We show that the two symbiont strains encode different toxins, potentially creating different targets for counter\&\#8208;adaptation. Phenotypic and behavioral comparisons suggest that neither life\&\#8208;history traits nor oviposition behavior differed among evolved parasitoid lineages. In contrast, comparative transcriptomics of adult female wasps identified a suite of differentially expressed genes among lineages, even when reared in a common, symbiont\&\#8208;free, aphid host. In concurrence with the specificity of each parasitoid lineages' infectivity, most differentially expressed parasitoid transcripts were also lineage\&\#8208;specific. These transcripts are enriched with putative venom toxins and contain highly expressed, potentially defensive viral particles. Together, these results suggest that wild populations of L. fabarum employ a complicated offensive arsenal with sufficient genetic variation for wasps to adapt rapidly and specifically to their hosts' microbial defenses.}, language = {en} } @article{ZancolliBakerBarlowetal.2016, author = {Zancolli, Giulia and Baker, Timothy G. and Barlow, Axel and Bradley, Rebecca K. and Calvete, Juan J. and Carter, Kimberley C. and de Jager, Kaylah and Owens, John Benjamin and Price, Jenny Forrester and Sanz, Libia and Scholes-Higham, Amy and Shier, Liam and Wood, Liam and W{\"u}ster, Catharine E. and W{\"u}ster, Wolfgang}, title = {Is Hybridization a Source of Adaptive Venom Variation in Rattlesnakes? A Test, Using a Crotalus scutulatus x viridis Hybrid Zone in Southwestern New Mexico}, series = {Toxins}, volume = {8}, journal = {Toxins}, publisher = {MDPI}, address = {Basel}, issn = {2072-6651}, doi = {10.3390/toxins8060188}, pages = {16}, year = {2016}, abstract = {Venomous snakes often display extensive variation in venom composition both between and within species. However, the mechanisms underlying the distribution of different toxins and venom types among populations and taxa remain insufficiently known. Rattlesnakes (Crotalus, Sistrurus) display extreme inter-and intraspecific variation in venom composition, centered particularly on the presence or absence of presynaptically neurotoxic phospholipases A2 such as Mojave toxin (MTX). Interspecific hybridization has been invoked as a mechanism to explain the distribution of these toxins across rattlesnakes, with the implicit assumption that they are adaptively advantageous. Here, we test the potential of adaptive hybridization as a mechanism for venom evolution by assessing the distribution of genes encoding the acidic and basic subunits of Mojave toxin across a hybrid zone between MTX-positive Crotalus scutulatus and MTX-negative C. viridis in southwestern New Mexico, USA. Analyses of morphology, mitochondrial and single copy-nuclear genes document extensive admixture within a narrow hybrid zone. The genes encoding the two MTX subunits are strictly linked, and found in most hybrids and backcrossed individuals, but not in C. viridis away from the hybrid zone. Presence of the genes is invariably associated with presence of the corresponding toxin in the venom. We conclude that introgression of highly lethal neurotoxins through hybridization is not necessarily favored by natural selection in rattlesnakes, and that even extensive hybridization may not lead to introgression of these genes into another species.}, language = {en} } @misc{ZancolliBakerBarlowetal.2016, author = {Zancolli, Giulia and Baker, Timothy G. and Barlow, Axel and Bradley, Rebecca K. and Calvete, Juan J. and Carter, Kimberley C. and de Jager, Kaylah and Owens, John Benjamin and Price, Jenny Forrester and Sanz, Libia and Scholes-Higham, Amy and Shier, Liam and Wood, Liam and W{\"u}ster, Catharine E. and W{\"u}ster, Wolfgang}, title = {Is hybridization a source of adaptive venom variation in rattlesnakes?}, series = {Toxins}, journal = {Toxins}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407595}, pages = {16}, year = {2016}, abstract = {Venomous snakes often display extensive variation in venom composition both between and within species. However, the mechanisms underlying the distribution of different toxins and venom types among populations and taxa remain insufficiently known. Rattlesnakes (Crotalus, Sistrurus) display extreme inter-and intraspecific variation in venom composition, centered particularly on the presence or absence of presynaptically neurotoxic phospholipases A2 such as Mojave toxin (MTX). Interspecific hybridization has been invoked as a mechanism to explain the distribution of these toxins across rattlesnakes, with the implicit assumption that they are adaptively advantageous. Here, we test the potential of adaptive hybridization as a mechanism for venom evolution by assessing the distribution of genes encoding the acidic and basic subunits of Mojave toxin across a hybrid zone between MTX-positive Crotalus scutulatus and MTX-negative C. viridis in southwestern New Mexico, USA. Analyses of morphology, mitochondrial and single copy-nuclear genes document extensive admixture within a narrow hybrid zone. The genes encoding the two MTX subunits are strictly linked, and found in most hybrids and backcrossed individuals, but not in C. viridis away from the hybrid zone. Presence of the genes is invariably associated with presence of the corresponding toxin in the venom. We conclude that introgression of highly lethal neurotoxins through hybridization is not necessarily favored by natural selection in rattlesnakes, and that even extensive hybridization may not lead to introgression of these genes into another species.}, language = {en} }