Novel hemotropic mycoplasmas are widespread and genetically diverse in vampire bats

Bats (Order: Chiroptera) have been widely studied as reservoir hosts for viruses of concern for human and animal health. However, whether bats are equally competent hosts of non-viral pathogens such as bacteria remains an important open question. Here, we surveyed blood and saliva samples of vampire bats from Peru and Belize for hemotropic Mycoplasma spp. (hemoplasmas), bacteria that can cause inapparent infection or anemia in hosts. 16S rRNA gene amplification of blood showed 67% (150/223) of common vampire bats (Desmodus rotundus) were infected by hemoplasmas. Sequencing of the 16S rRNA gene amplicons revealed three novel genotypes that were phylogenetically related but not identical to hemoplasmas described from other (non-vampire) bat species, rodents, humans, and non-human primates. Hemoplasma prevalence in vampire bats was highest in non-reproductive and young individuals, did not differ by country, and was relatively stable over time (i.e., endemic). Metagenomics from pooled D. rotundus saliva from Peru detected non-hemotropic Mycoplasma species and hemoplasma genotypes phylogenetically similar to those identified in blood, providing indirect evidence for potential direct transmission of hemoplasmas through biting or social contacts. This study demonstrates vampire bats host several novel hemoplasmas and sheds light on risk factors for infection and basic transmission routes. Given the high frequency of direct contacts that arise when vampire bats feed on humans, domestic animals, and wildlife, the potential of these bacteria to be transmitted between species should be investigated in future work

Parasite infection and host dynamics in a naturally fluctuating rodent population

Winternitz J, Yabsley MJ, Altizer SM. Parasite infection and host dynamics in a naturally fluctuating rodent population. Canadian Journal of Zoology. 2012;90(9):1149-1160.Parasites can both influence and be affected by host population dynamics, and a growing number of case studies support a role for parasites in causing or amplifying host population cycles. In this study, we examined individual and population predictors of gastrointestinal parasitism on wild cyclic montane voles ( Microtus montanus (Peale, 1848)) to determine if evidence was consistent with theory implicating parasites in population cycles. We sampled three sites in central Colorado for the duration of a multiannual cycle and recorded the prevalence and intensity of directly transmitted Eimeria Schneider, 1875 and indirectly transmitted cestodes from a total of 267 voles. We found significant associations between host infection status, individual traits (sex, age, and reproductive status) and population variables (site, trapping period, and population density), including a positive association between host density and cestode prevalence, and a negative association between host density and Eimeria prevalence. Both cestode and Eimeria intensity correlated positively with host age, reproductive status, and population density, but neither parasite was associated with poorer host condition. Our findings suggest that parasites are common in this natural host, but determining their potential to influence montane vole cycles requires future experimental studies and long-term monitoring to determine the fitness consequences of infection and the impact of parasite removal on host dynamics

A citizen science project reveals contrasting latitudinal gradients of wing deformity and parasite infection of monarch butterflies in New Zealand

1. Host–parasite interactions represent complex relationships among species, often with considerable spatial variation. We examined latitudinal variation in the prevalence of monarch butterfly (Danaus plexippus) infection by the protozoan parasite Ophryocystis elektroscirrha via a citizen science project in New Zealand. Parasitism by O. elektroscirrha can result in incomplete development causing mortality, or adult butterflies with deformed wings and reduced fitness. 2. We established the existence of counter-latitudinal clines of wing deformities and parasite prevalence in monarchs, which in New Zealand are non-migratory. The prevalence of wing deformities increased with increasing latitude, whereas the prevalence of parasite infections decreased with increasing latitude. No parasitism was observed in our highest latitudinal location, while all butterfly samples were infected in the warmest and lowest latitudinal site. The prevalence of parasitism or wing deformity did not vary with the butterfly sex. 3. Cold temperatures appear to independently affect the parasite and host butterfly development, with lower temperatures limiting parasite development and inducing wing deformities in butterflies. Other protozoan parasites display similar latitudinal clines that are thought to be temperature related. 4. Environmental factors appear to independently influence insect populations through different mechanistic pathways. The high prevalence of parasite infections may affect butterfly fitness in warmer regions, but the cooler conditions at higher latitudes manifest as a major fitness cost, deformed wings. Monarch butterflies in New Zealand and around the world may perform better where it is not too hot (and optimal for these parasites), but not cold (where the pupae experience developmental issues)

Modelling Aedes aegypti mosquito control via transgenic and sterile insect techniques: endemics and emerging outbreaks

The invasion of pest insects often changes or destroys a native ecosystem,and can result in food shortages and disease endemics.Issues such as the environmental effects of chemical control methods,the economic burden of maintaining control strategies and the risk of pestresistance still remain,and mosquito-borne diseases such as malaria and dengue fever prevail in many countries,infecting over100 million worldwide in 2010.One environmentally friendly method for mosquito control is the Sterile Insect Technique(SIT).This species-specific method of insect control relies on the mass rearing, sterilization and release of large numbers of sterile insects.An alternative transgenic method is the Release of Insects carrying a Dominant Lethal(RIDL).Our objective is to consider contrasting control strategies for two invasive scenarios via SIT and RIDL:an endemic case and an emerging outbreak. We investigate how the release rate and size of release region influence both the potential for control success and there sources needed to achieve it,under a range of conditions and control strategies,and we discuss advantageous strategies with respect to reducing the release resources and strategy costs(in terms of control mosquito numbers)required to achieve complete eradication of wild-type mosquitoes