Microhabitat association and population status of the Luwuk introduced Banggai cardinalfish (Pterapogon kauderni Koumans, 1933) population

The Banggai cardinalfish Pterapogon kauderni is the Indonesian national marine ornamental fish mascot, and an object of national and international conservation concern. The endemic population of this species is limited to the Banggai Archipelago in Central Sulawesi, Indonesia and a few nearby islands in North Maluku. In addition, introduced populations have become established, mainly along ornamental fish trade routes. The National Action Plan for Banggai Cardinalfish Conservation (NAP-BCFC) calls for monitoring and management of all P. kauderni populations. A survey of the Luwuk introduced P. kauderni population was carried out in October 2021. Data were collected at three sites with established P. kauderni populations: the ferry harbour, public harbour (Teluk Lalong) and a recreational area on the nearby coast (Kilo 5). P. kauderni were recorded by microhabitat association and size class (recruits, juveniles, adults). Data collected were compared with data from previous surveys where available. With the exception of one group in a sea anemone at Kilo 5, all P. kauderni were associated with Diadema sea urchins (D. setosum at all sites; D. savignyi at Kilo 5). At Kilo 5 P. kauderni the population structure indicates the possible capture of market-sized juveniles. Overall abundance was also lower compared to the polluted but unfished harbours. The proportion of recruits was significantly negatively correlated with the ratio of adult P. kauderni to Diadema urchins. The results will inform regional legislation currently in preparation to support sustainable management of P. kauderni populations, habitat and microhabitat in Central Sulawesi, as well as contributing to NAP-BCFC targets.Keywords:Banggai cardinalfishEndangered speciesDiademaMicrohabitat,MonitoringOrnamental fisheryLocal regulation

Structural organization of erythrocyte membrane microdomains and their relation with malaria susceptibility

Cholesterol-rich microdomains are membrane compartments characterized by specific lipid and protein composition. These dynamic assemblies are involved in several biological processes, including infection by intracellular pathogens. This work provides a comprehensive analysis of the composition of human erythrocyte membrane microdomains. Based on their floating properties, we also categorized the microdomain-associated proteins into clusters. Interestingly, erythrocyte microdomains include the vast majority of the proteins known to be involved in invasion by the malaria parasite Plasmodium falciparum. We show here that the Ecto-ADP-ribosyltransferase 4 (ART4) and Aquaporin 1 (AQP1), found within one specific cluster, containing the essential host determinant CD55, are recruited to the site of parasite entry and then internalized to the newly formed parasitophorous vacuole membrane. By generating null erythroid cell lines, we showed that one of these proteins, ART4, plays a role in P. falciparum invasion. We also found that genetic variants in both ART4 and AQP1 are associated with susceptibility to the disease in a malaria-endemic population.

Multimodal biomarker discovery for active Onchocerca volvulus infection

The neglected tropical disease onchocerciasis, or river blindness, is caused by infection with the filarial nematode Onchocerca volvulus. Current estimates indicate that 17 million people are infected worldwide, the majority of them living in Africa. Today there are no non-invasive tests available that can detect ongoing infection, and that can be used for effective monitoring of elimination programs. In addition, to enable pharmacodynamic studies with novel macrofilaricide drug candidates, surrogate endpoints and efficacy biomarkers are needed but are non-existent. We describe the use of a multimodal untargeted mass spectrometry-based approach (metabolomics and lipidomics) to identify onchocerciasis-associated metabolites in urine and plasma, and of specific lipid features in plasma of infected individuals (O. volvulus infected cases: 68 individuals with palpable nodules; lymphatic filariasis cases: 8 individuals; non-endemic controls: 20 individuals). This work resulted in the identification of elevated concentrations of the plasma metabolites inosine and hypoxanthine as biomarkers for filarial infection, and of the urine metabolite cis-cinnamoylglycine (CCG) as biomarker for O. volvulus. During the targeted validation study, metabolite-specific cutoffs were determined (inosine: 34.2 ng/ml; hypoxanthine: 1380 ng/ml; CCG: 29.7 ng/ml) and sensitivity and specificity profiles were established. Subsequent evaluation of these biomarkers in a non-endemic population from a different geographical region invalidated the urine metabolite CCG as biomarker for O. volvulus. The plasma metabolites inosine and hypoxanthine were confirmed as biomarkers for filarial infection. With the availability of targeted LC-MS procedures, the full potential of these 2 biomarkers in macrofilaricide clinical trials, MDA efficacy surveys, and epidemiological transmission studies can be investigated.

Population-specific adaptation in malaria-endemic regions of asia

Evolutionary mechanisms of adaptation to malaria are understudied in Asian endemic regions despite a high prevalence of malaria in the region. In our research, we performed a genome-wide screening for footprints of natural selection against malaria by comparing eight Asian population groups from malaria-endemic regions with two non-endemic population groups from Europe and Mongolia. We identified 285 adaptive genes showing robust selection signals across three statistical methods, iHS, XP-EHH, and PBS. Interestingly, most of the identified genes (82%) were found to be under selection in a single population group, while adaptive genes shared across populations were rare. This is likely due to the independent adaptation history in different endemic populations. The gene ontology (GO) analysis for the 285 adaptive genes highlighted their functional processes linked to neuronal organizations or nervous system development. These genes could be related to cerebral malaria and may reduce the inflammatory response and the severity of malaria symptoms. Remarkably, our novel population genomic approach identified population-specific adaptive genes potentially against malaria infection without the need for patient samples or individual medical records.

Precision Medicine in Control of Visceral Leishmaniasis Caused by L. donovani

Precision medicine and precision global health in visceral leishmaniasis (VL) have not yet been described and could take into account how all known determinants improve diagnostics and treatment for the individual patient. Precision public health would lead to the right intervention in each VL endemic population for control, based on relevant population-based data, vector exposures, reservoirs, socio-economic factors and other determinants. In anthroponotic VL caused by L. donovani, precision may currently be targeted to the regional level in nosogeographic entities that are defined by the interplay of the circulating parasite, the reservoir and the sand fly vector. From this 5 major priorities arise: diagnosis, treatment, PKDL, asymptomatic infection and transmission. These 5 priorities share the immune responses of infection with L. donovani as an important final common pathway, for which innovative new genomic and non-genomic tools in various disciplines have become available that provide new insights in clinical management and in control. From this, further precision may be defined for groups (e.g. children, women, pregnancy, HIV-VL co-infection), and eventually targeted to the individual level.

Phylogenetic Analysis of HIV-1 Shows Frequent Cross-Country Transmission and Local Population Expansions

Understanding of pandemics depends on characterization of pathogen collections from well-defined and demographically diverse cohorts. Since its emergence in Congo almost a century ago, HIV-1 has geographically spread and genetically diversified into distinct viral subtypes. Phylogenetic analysis can be used to reconstruct the ancestry of the virus to inform on the origin and distribution of subtypes. We sequenced two 3.6 kb amplicons of HIV-1 genomes from 3,197 participants in a clinical trial with consistent and uniform sampling at sites across 35 countries and analyzed our data with another 2,632 genomes that comprehensively reflects the HIV-1 genetic diversity. We used maximum likelihood phylogenetic analysis coupled with geographical information to infer the state of ancestors. The majority of our sequenced genomes (n=2,501) were either pure subtypes (A-D, F, G) or CRF01_AE. The diversity and distribution of subtypes across geographical regions differed; United States showed the most homogenous subtype population, whereas African samples were most diverse. We delineated transmission of the four most prevalent subtypes in our dataset (A, B, C, and CRF01_AE), and our results suggest both continuous and frequent transmission of HIV-1 over country borders, as well as single transmission events being the seed of endemic population expansions. Overall, we show that coupling of genetic and geographical information of HIV-1 can be used to understand origin and spread of pandemic pathogens.

The Burden of Dengue in Children by Calculating Spatial Temperature: A Methodological Approach Using Remote Sensing Techniques

Background: Dengue fever is one of the most important arboviral diseases. Surface temperature versus dengue burden in tropical environments can provide valuable information that can be adapted in future measurements to improve health policies. Methods: A methodological approach using Daymet-V3 provided estimates of daily weather parameters. A Python code developed by us extracted the median temperature from the urban regions of Colima State (207.3 km2) in Mexico. JointPoint regression models computed the mean temperature-adjusted average annual percentage of change (AAPC) in disability-adjusted life years (DALY) rates (per 100,000) due to dengue in Colima State among school-aged (5–14 years old) children. Results: Primary outcomes were average temperature in urban areas and cumulative dengue burden in DALYs in the school-aged population. A model from 1990 to 2017 medium surface temperature with DALY rates was performed. The increase in DALYs rate was 64% (95% CI, 44–87%), and it seemed to depend on the 2000–2009 estimates (AAPC = 185%, 95% CI 18–588). Conclusion: From our knowledge, this is the first study to evaluate surface temperature and to model it through an extensive period with health economics calculations in a specific subset of the Latin-American endemic population for dengue epidemics.

Phytophthora lateralis (port-orford-cedar root disease).

Genetics P. lateralis is in phylogenetic clade 8, defined by ITS DNA sequence (Cooke et al., 2000). The most closely related species is P. ramorum, the sudden oak death pathogen (Ivors et al., 2004). Other related species include P. hibernalis and P. foliorum; these species sometimes cross-react in molecular diagnostic tests designed for P. lateralis (Winton and Hansen, 2001). In much of Europe and in western North America, P. lateralis populations are very uniform in appearance and genetics, as expected of a clonally spread pathogen that is inbreeding or functionally asexual (McWilliams, 1999; 2000). In Taiwan and one small area of Britain, however, morphologically and genetically distinctive populations are established (Brasier et al., 2012). Isolates from Taiwan are especially variable, as might be expected of an ancestral, endemic population. In total, four distinct lineages have been described, including two from Taiwan, the invasive population found in North America and Europe, and the small UK population. Reproductive Biology P. lateralis reproduces primarily through asexual zoospores and chlamydospores (Trione, 1974; Englander and Roth, 1980). Zoospores are released from sporangia, sack-like hyphal appendages that hold about 20 zoospores each. Sporangia form in water or in saturated soil, on hyphae that grow from colonies in tree roots (or in agar). Zoospores are encased only in a membrane and are vulnerable to drying. In water they are motile with flagellae. They are chemotactic, following chemical gradients or root exudates. They remain active for about 24 hours. Zoospores encyst on root surfaces or after agitation, such as in a fast moving stream, and germinate with hyphae that may penetrate a host root and establish a new infection (Oh and Hansen, 2007). Chlamydospores are thick-walled asexual resting spores that form on hyphae in roots, foliage or in culture. They allow the pathogen to survive drying conditions, germinating with hyphae and sporangia when cool moist conditions resume (Trione, 1959). Oospores are sexual spores formed from the fusion of antheridia and oogonia. They are thick-walled and presumably function as resting spores in roots and foliage, as well as providing the population with genetic variation. They are very seldom seen in culture, however. Longevity P. lateralis survives for up to 10 years in infected root fragments in the soil (Hansen and Hamm, 1996). Population Size and Structure Populations of propagules free in the soil are small (Tsao et al., 1995). Environmental Requirements P. lateralis dies quickly from surface horizons exposed to sun as it cannot survive warm dry conditions (Hansen and Hamm, 1996). P. lateralis is active during cool, wet times of the year (Trione, 1959).