The profitability of livestock activities can be diminished significantly by the effects of parasites. Economic losses caused by cattle parasites in Brazil were estimated on an annual basis, considering the total number of animals at risk and the potential detrimental effects of parasitism on cattle productivity. Estimates in U.S. dollars (USD) were based on reported yield losses among untreated animals and reflected some of the effects of parasitic diseases. Relevant parasites that affect cattle productivity in Brazil, and their economic impact in USD billions include: gastrointestinal nematodes - $7.11; cattle tick (Rhipicephalus(Boophilus) microplus) - $3.24; horn fly (Haematobia irritans) - $2.56; cattle grub (Dermatobia hominis) - $0.38; New World screwworm fly (Cochliomyia hominivorax) - $0.34; and stable fly (Stomoxys calcitrans) - $0.34. The combined annual economic loss due to internal and external parasites of cattle in Brazil considered here was estimated to be at least USD 13.96 billion. These findings are discussed in the context of methodologies and research that are required in order to improve the accuracy of these economic impact assessments. This information needs to be taken into consideration when developing sustainable policies for mitigating the impact of parasitism on the profitability of Brazilian cattle producers.

BackgroundTicks are regarded as the most relevant vectors of disease-causing pathogens in domestic and wild animals. The cattle tick, Rhipicephalus (Boophilus) microplus, hinders livestock production in tropical and subtropical parts of the world where it is endemic. Tick microbiomes remain largely unexplored. The objective of this study was to explore the R. microplus microbiome by applying the bacterial 16S tag-encoded FLX-titanium amplicon pyrosequencing (bTEFAP) technique to characterize its bacterial diversity. Pyrosequencing was performed on adult males and females, eggs, and gut and ovary tissues from adult females derived from samples of R. microplus collected during outbreaks in southern Texas.ResultsRaw data from bTEFAP were screened and trimmed based upon quality scores and binned into individual sample collections. Bacteria identified to the species level include Staphylococcus aureus, Staphylococcus chromogenes, Streptococcus dysgalactiae, Staphylococcus sciuri, Serratia marcescens, Corynebacterium glutamicum, and Finegoldia magna. One hundred twenty-one bacterial genera were detected in all the life stages and tissues sampled. The total number of genera identified by tick sample comprised: 53 in adult males, 61 in adult females, 11 in gut tissue, 7 in ovarian tissue, and 54 in the eggs. Notable genera detected in the cattle tick include Wolbachia, Coxiella, and Borrelia. The molecular approach applied in this study allowed us to assess the relative abundance of the microbiota associated with R. microplus.ConclusionsThis report represents the first survey of the bacteriome in the cattle tick using non-culture based molecular approaches. Comparisons of our results with previous bacterial surveys provide an indication of geographic variation in the assemblages of bacteria associated with R. microplus. Additional reports on the identification of new bacterial species maintained in nature by R. microplus that may be pathogenic to its vertebrate hosts are expected as our understanding of its microbiota expands. Increased awareness of the role R. microplus can play in the transmission of pathogenic bacteria will enhance our ability to mitigate its economic impact on animal agriculture globally. This recognition should be included as part of analyses to assess the risk for re-invasion of areas like the United States of America where R. microplus was eradicated.

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BackgroundDisease risk maps are important tools that help ascertain the likelihood of exposure to specific infectious agents. Understanding how climate change may affect the suitability of habitats for ticks will improve the accuracy of risk maps of tick-borne pathogen transmission in humans and domestic animal populations. Lyme disease (LD) is the most prevalent arthropod borne disease in the US and Europe. The bacterium Borrelia burgdorferi causes LD and it is transmitted to humans and other mammalian hosts through the bite of infected Ixodes ticks. LD risk maps in the transboundary region between the U.S. and Mexico are lacking. Moreover, none of the published studies that evaluated the effect of climate change in the spatial and temporal distribution of I. scapularis have focused on this region.MethodsThe area of study included Texas and a portion of northeast Mexico. This area is referred herein as the Texas-Mexico transboundary region. Tick samples were obtained from various vertebrate hosts in the region under study. Ticks identified as I. scapularis were processed to obtain DNA and to determine if they were infected with B. burgdorferi using PCR. A maximum entropy approach (MAXENT) was used to forecast the present and future (2050) distribution of B. burgdorferi-infected I. scapularis in the Texas-Mexico transboundary region by correlating geographic data with climatic variables.ResultsOf the 1235 tick samples collected, 109 were identified as I. scapularis. Infection with B. burgdorferi was detected in 45% of the I. scapularis ticks collected. The model presented here indicates a wide distribution for I. scapularis, with higher probability of occurrence along the Gulf of Mexico coast. Results of the modeling approach applied predict that habitat suitable for the distribution of I. scapularis in the Texas-Mexico transboundary region will remain relatively stable until 2050.ConclusionsThe Texas-Mexico transboundary region appears to be part of a continuum in the pathogenic landscape of LD. Forecasting based on climate trends provides a tool to adapt strategies in the near future to mitigate the impact of LD related to its distribution and risk for transmission to human populations in the Mexico-US transboundary region.

BackgroundOrnithodoros turicata is a veterinary and medically important argasid tick that is recognized as a vector of the relapsing fever spirochete Borrelia turicatae and African swine fever virus. Historic collections of O. turicata have been recorded from Latin America to the southern United States. However, the geographic distribution of this vector is poorly understood in relation to environmental variables, their hosts, and consequently the pathogens they transmit.MethodologyLocalities of O. turicata were generated by performing literature searches, evaluating records from the United States National Tick Collection and the Symbiota Collections of Arthropods Network, and by conducting field studies. Maximum entropy species distribution modeling (Maxent) was used to predict the current distribution of O. turicata. Vertebrate host diversity and GIS analyses of their distributions were used to ascertain the area of shared occupancy of both the hosts and vector.Conclusions and SignificanceOur results predicted previously unrecognized regions of the United States with habitat that may maintain O. turicata and could guide future surveillance efforts for a tick capable of transmitting high–consequence pathogens to human and animal populations.

Here, economic losses caused by cattle parasites in Mexico were estimated on an annual basis. The main factors taken into consideration for this assessment included the total number of animals at risk, potential detrimental effects of parasitism on milk production or weight gain, and records of condemnation on livestock byproducts. Estimates in US dollars (US$) were based on reported yield losses in untreated animals. These estimates reflect the major effects on cattle productivity of six parasites, or RESUMENLas pérdidas económicas causadas por parásitos del bovino en México se calcularon anualmente. Los principales factores considerados para esta evaluación incluyeron el número total de animales a riesgo, los posibles efectos dañinos del parasitismo sobre la producción de leche o ganancia de peso, y los decomisos de subproductos pecuarios. Las pérdidas económicas fueron estimadas en dólares americanos (US$) y se basaron en las pérdidas del rendimiento productivo de animales no tratados. Estas estimaciones reflejan los principales efectos de seis parásitos o grupos de parásitos sobre la producción bovina. El impacto económico potencial (millones de dólares) fue: nematodos gastrointestinales US$ 445.10; coccidias (Eim eria spp.) US$ 23.78; duelas del hígado (Fasciola hepatica) US$ 130.91; garrapatas (Rhipicephalus m icroplus) US$ 573.61; mosca de los cuernos (Haem atobia irritans) US$ 231.67; y mosca de los establos (Stom ox ys calcitrans) US$ 6.79. En general, las pérdidas anuales causadas por los seis principales parásitos del bovino en México se estimaron en US$ 1.41 mil millones. Considerando que la población bovina nacional en 2013 fue de 32.40 millones de bovinos, la pérdida anual estimada fue de US$ 43.57 por animal. Se hace mención de las limitaciones que tienen el uso de algunas referencias para las estimaciones, particularmente cuando se extrapolan situaciones locales a una escala nacional. Sin embargo, el resultado general obtenido en este estudio demuestra la magnitud e importancia del parasitismo en el ganado de México y los desafíos para maximizar la rentabilidad de la industria ganadera sin recurrir al uso de estrategias de control integrado sustentable de parásitos.

BackgroundBabesia are emerging health threats to humans and animals in the United States. A collaborative effort of multiple disciplines to attain optimal health for people, animals and our environment, otherwise known as the One Health concept, was taken during a research workshop held in April 2009 to identify gaps in scientific knowledge regarding babesioses. The impetus for this analysis was the increased risk for outbreaks of bovine babesiosis, also known as Texas cattle fever, associated with the re-infestation of the U.S. by cattle fever ticks.ResultsThe involvement of wildlife in the ecology of cattle fever ticks jeopardizes the ability of state and federal agencies to keep the national herd free of Texas cattle fever. Similarly, there has been a progressive increase in the number of cases of human babesiosis over the past 25 years due to an increase in the white-tailed deer population. Human babesiosis due to cattle-associated Babesia divergens and Babesia divergens-like organisms have begun to appear in residents of the United States. Research needs for human and bovine babesioses were identified and are presented herein.ConclusionsThe translation of this research is expected to provide veterinary and public health systems with the tools to mitigate the impact of bovine and human babesioses. However, economic, political, and social commitments are urgently required, including increased national funding for animal and human Babesia research, to prevent the re-establishment of cattle fever ticks and the increasing problem of human babesiosis in the United States.

The arthropod salivary gland is of critical importance for horizontal transmission of pathogens, yet a detailed understanding of the ion conductance pathways responsible for saliva production and excretion is lacking. A superfamily of potassium ion channels, known as inward rectifying potassium (Kir) channels, is overexpressed in the Drosophila salivary gland by 32-fold when compared to the whole body mRNA transcripts. Therefore, we aimed to test the hypothesis that pharmacological and genetic depletion of salivary gland specific Kir channels alters the efficiency of the gland and reduced feeding capabilities using the fruit fly Drosophila melanogaster as a model organism that could predict similar effects in arthropod disease vectors. Exposure to VU041, a selective Kir channel blocker, reduced the volume of sucrose consumption by up to 3.2-fold and was found to be concentration-dependent with an EC of 68μM. Importantly, the inactive analog, VU937, was shown to not influence feeding, suggesting the reduction in feeding observed with VU041 is due to Kir channel inhibition. Next, we performed a salivary gland specific knockdown of Kir1 to assess the role of these channels specifically in the salivary gland. The genetically depleted fruit flies had a reduction in total volume ingested and an increase in the time spent feeding, both suggestive of a reduction in salivary gland function. Furthermore, a compensatory mechanism appears to be present at day 1 of RNAi-treated fruit flies, and is likely to be the Na-K-2Cl cotransporter and/or Na-K-ATPase pumps that serve to supplement the inward flow of K ions, which highlights the functional redundancy in control of ion flux in the salivary glands. These findings suggest that Kir channels likely provide, at least in part, a principal potassium conductance pathway in the Drosophila salivary gland that is required for sucrose feeding.