Thermal Stress Responses of \u3cem\u3eSodalis Glossinidius\u3c/em\u3e, an Indigenous Bacterial Symbiont of Hematophagous Tsetse Flies

Tsetse flies (Diptera: Glossinidae) house a taxonomically diverse microbiota that includes environmentally acquired bacteria, maternally transmitted symbiotic bacteria, and pathogenic African trypanosomes. Sodalis glossinidius, which is a facultative symbiont that resides intra and extracellularly within multiple tsetse tissues, has been implicated as a mediator of trypanosome infection establishment in the fly’s gut. Tsetse’s gut-associated population of Sodalis are subjected to marked temperature fluctuations each time their ectothermic fly host imbibes vertebrate blood. The molecular mechanisms that Sodalis employs to deal with this heat stress are unknown. In this study, we examined the thermal tolerance and heat shock response of Sodalis. When grown on BHI agar plates, the bacterium exhibited the most prolific growth at 25oC, and did not grow at temperatures above 30oC. Growth on BHI agar plates at 31°C was dependent on either the addition of blood to the agar or reduction in oxygen levels. Sodalis was viable in liquid cultures for 24 hours at 30oC, but began to die upon further exposure. The rate of death increased with increased temperature. Similarly, Sodalis was able to survive for 48 hours within tsetse flies housed at 30oC, while a higher temperature (37oC) was lethal. Sodalis’ genome contains homologues of the heat shock chaperone protein-encoding genes dnaK, dnaJ, and grpE, and their expression was up-regulated in thermally stressed Sodalis, both in vitro and in vivo within tsetse fly midguts. Arrested growth of E. coli dnaK, dnaJ, or grpE mutants under thermal stress was reversed when the cells were transformed with a low copy plasmid that encoded the Sodalis homologues of these genes. The information contained in this study provides insight into how arthropod vector enteric commensals, many of which mediate their host’s ability to transmit pathogens, mitigate heat shock associated with the ingestion of a blood meal

Treatment patterns of patients diagnosed with major headache disorders: A retrospective claims analysis

Objective: To describe patient characteristics, treatment patterns, and health care costs among patients diagnosed with major headache disorders overall and by type (tension-type headache [TTH], migraine, cluster headache [CH], or \u3e1 primary headache type), and secondarily to evaluate drug treatment patterns among triptan initiators with a major headache diagnosis. Methods: Using US claims data from January 2012 through December 2017, we identified adults with evidence of a major headache disorder: TTH, migraine, or CH; the first diagnosis date was deemed the index date. To evaluate triptan use specifically, patients who initiated triptans were identified; the first triptan claim date was deemed the index date. Patient characteristics, treatment patterns (concomitant treatments, adherence, number of fills), and annual health care costs data were obtained. Results: Of the 418,779 patients diagnosed with major headache disorders, the following 4 cohorts were created: TTH (8%), migraine (87%), CH (1%), and \u3e1 primary headache type (4%). The majority used analgesic (54–73%) and psychotropic (57–81%) drugs, primarily opioids (36–53%). Headache-related costs accounted for one-fifth of all-cause costs. Of the 229,946 patients who initiated triptans, the following 7 study cohorts were analyzed: sumatriptan (68%), rizatriptan (21%), eletriptan (5%), zolmitriptan (3%), naratriptan (2%), frovatriptan (1%), and almotriptan ( Conclusion: The primary headache disorder treatment paradigm is complex, with significant variability. Predominant concomitant use of opioids and switching to opioids is of concern, necessitating solutions to minimize opioid use. Switching to non-oral/fast-acting or targeted preventive therapies should be considered

Global arthropod beta-diversity is spatially and temporally structured by latitude

Global biodiversity gradients are generally expected to reflect greater species replacement closer to the equator. However, empirical validation of global biodiversity gradients largely relies on vertebrates, plants, and other less diverse taxa. Here we assess the temporal and spatial dynamics of global arthropod biodiversity dynamics using a beta-diversity framework. Sampling includes 129 sampling sites whereby malaise traps are deployed to monitor temporal changes in arthropod communities. Overall, we encountered more than 150,000 unique barcode index numbers (BINs) (i.e. species proxies). We assess between site differences in community diversity using beta-diversity and the partitioned components of species replacement and richness difference. Global total beta-diversity (dissimilarity) increases with decreasing latitude, greater spatial distance and greater temporal distance. Species replacement and richness difference patterns vary across biogeographic regions. Our findings support long-standing, general expectations of global biodiversity patterns. However, we also show that the underlying processes driving patterns may be regionally linked.peerReviewe