Integrating Blood Collection Within Household Surveys: Lessons Learned From Nesting a Measles and Rubella Serological Survey Within a Post-Campaign Coverage Evaluation Survey in Southern Province, Zambia

Age-specific population immunity to many vaccine-preventable diseases can be measured using serological surveys. However, stand-alone serological surveys are infrequently conducted in low- and middle-income countries because of costs, operational challenges, and potential high refusal rates for blood collection. Nesting a serosurvey within a household cluster survey may overcome some of these challenges. We share lessons learned from nesting a serosurvey within a measles and rubella vaccination post-campaign coverage evaluation survey (PCES). In 15 of the 26 PCES clusters in Southern Province, Zambia, we collected dried blood spots from 581 participants aged 9 months and older. Household participation rates for the main PCES were higher in the serosurvey clusters (86%) than PCES-only clusters (71%), suggesting that a serosurvey can be successfully integrated without adversely affecting PCES participation. Among households that participated in the PCES, 80% also participated in the serosurvey and 86% of individuals available in the household provided a blood sample for the serosurvey. Substantial planning and coordination, additional staff training, and community mobilization were critical to the success of the serosurvey. Most challenges stemmed from using different data collecting tools and teams for the serosurvey and PCES. A more efficient design would be to fully integrate the serosurvey by adding blood collection and additional questions to the PCES

Inhibitory Potential of Prodomain of Plasmodium falciparum Protease Serine Repeat Antigen 5 for Asexual Blood Stages of Parasite

Plasmodium falciparum serine repeat antigen 5 (SERA5) is a target for both drug and vaccine intervention against malaria. SERA5 is secreted in the parasitophorous vacuole where it is proteolytically processed before schizont rupture. Among the processed products is a 50.8-kDa central domain of the protease, which possesses chymotrypsin-like activity and consists of a 28.9-kDa catalytic domain with a 21.9-kDa N-terminal prodomain, which remain attached together. Because SERA5 has been implicated in merozoite egress from host erythrocytes, the effect of the prodomain and a heptapeptide derived from its C-terminus spanning from D560 to F566 (DNSDNMF) on parasite growth was studied. When E. coli-expressed prodomain was incubated with parasite culture, a significant delay in transition from schizont to ring stages was observed up to nanomolar concentrations. The peptide, DNSDNMF also showed similar effects but at nearly 1000-fold higher concentrations. The peptide was also found to interact with the catalytic domain. These data demonstrate the crucial role of SERA5 prodomain for the egress process. Given the inhibitory potential of the prodomain for the parasite, we suggest that peptidomimetic inhibitors based on SERA5 prodomain sequences can be developed as future therapeutics against malaria

NF-kappaB p65-Dependent Transactivation of miRNA Genes following Cryptosporidium parvum Infection Stimulates Epithelial Cell Immune Responses

Cryptosporidium parvum is a protozoan parasite that infects the gastrointestinal epithelium and causes diarrheal disease worldwide. Innate epithelial immune responses are key mediators of the host's defense to C. parvum. MicroRNAs (miRNAs) regulate gene expression at the posttranscriptional level and are involved in regulation of both innate and adaptive immune responses. Using an in vitro model of human cryptosporidiosis, we analyzed C. parvum-induced miRNA expression in biliary epithelial cells (i.e., cholangiocytes). Our results demonstrated differential alterations in the mature miRNA expression profile in cholangiocytes following C. parvum infection or lipopolysaccharide stimulation. Database analysis of C. parvum-upregulated miRNAs revealed potential NF-κB binding sites in the promoter elements of a subset of miRNA genes. We demonstrated that mir-125b-1, mir-21, mir-30b, and mir-23b-27b-24-1 cluster genes were transactivated through promoter binding of the NF-κB p65 subunit following C. parvum infection. In contrast, C. parvum transactivated mir-30c and mir-16 genes in cholangiocytes in a p65-independent manner. Importantly, functional inhibition of selected p65-dependent miRNAs in cholangiocytes increased C. parvum burden. Thus, we have identified a panel of miRNAs regulated through promoter binding of the NF-κB p65 subunit in human cholangiocytes in response to C. parvum infection, a process that may be relevant to the regulation of epithelial anti-microbial defense in general

Leveraging microgravity to investigate earth- And space-based centrifugal casting of wax

A multi-year research effort aimed at increasing understanding of the centrifugal casting process of wax fuels for hybrid chemical propulsion in multiple thermal and gravitational environments is described. As both radiative and convective heat transfer drive the casting process, the suborbital and orbital microgravity environments are critical to disentangling these contributions to heat transfer away from the fuel. The experimental effort comprises testing on multiple platforms, including the ambient atmosphere of the laboratory, as well as various mobile microgravity platforms. Testing onboard reduced-gravity aircraft facilitates increased understanding of how these types of fluids perform in the microgravity environment, while a suborbital spaceflight and orbital platform under standard atmosphere allow for longer-term observation of natural convection sans buoyancy. An orbital platform subjected to the space environment facilitates understanding of the contribution of radiation to the heat transfer away from the liquid fuel. Each progressive testing environment requires updates to the experimental setup in order to accommodate respective physical and electrical constraints which are described in detail herein. An image analysis routine was developed in order to automate post-processing and determine the solidification front speed for each test. A rotation rate actuation routine is in development which aims to improve the accuracy of the centrifuge control system by leveraging electromagnetic sensing and feeding back rotation rate measurements to the motor driver. Preliminary modeling work was conducted which aims to elucidate the fundamental physics of the centrifugal casting problem; specifically, the impact of rotation rate, material properties, and environmental conditions on the heat transfer and fluid mechanics which constitute the larger casting problem. Both paraffin wax - a solid fuel with two decades of heritage - and the more novel beeswax are considered in this study

Role of CpSUB1, a subtilisin-like protease, in Cryptosporidium parvum infection in vitro.

The apicomplexan parasite Cryptosporidium is a significant cause of diarrheal disease worldwide. Previously, we reported that a Cryptosporidium parvum subtilisin-like serine protease activity with furin-type specificity cleaves gp40/15, a glycoprotein that is proteolytically processed into gp40 and gp15, which are implicated in mediating infection of host cells. Neither the enzyme(s) responsible for the protease activity in C. parvum lysates nor those that process gp40/15 are known. There are no furin or other proprotein convertase genes in the C. parvum genome. However, a gene encoding CpSUB1, a subtilisin-like serine protease, is present. In this study, we cloned the CpSUB1 genomic sequence and expressed and purified the recombinant prodomain. Reverse transcriptase PCR analysis of RNA from C. parvum-infected HCT-8 cells revealed that CpSUB1 is expressed throughout infection in vitro. In immunoblots, antiserum to the recombinant CpSUB1 prodomain revealed two major bands, of approximately 64 kDa and approximately 48 kDa, for C. parvum lysates and proteins "shed" during excystation. In immunofluorescence assays, the antiserum reacted with the apical region of sporozoites and merozoites. The recombinant prodomain inhibited protease activity and processing of recombinant gp40/15 by C. parvum lysates but not by furin. Since prodomains are often selective inhibitors of their cognate enzymes, these results suggest that CpSUB1 may be a likely candidate for the protease activity in C. parvum and for processing of gp40/15. Importantly, the recombinant prodomain inhibited C. parvum infection of HCT-8 cells. These studies indicate that CpSUB1 plays a significant role in infection of host cells by the parasite and suggest that this enzyme may serve as a target for intervention

The Medicinal plants and their economic value in Kakamega Forest Ecosystem: A case study of sustainable land/forest project in Western Kenya

Forest Management of ecosystems plays a fundamental role in providing essential goods and services to rural communities. However, there has been a reduction in the natural forest cover due to resource utilization pressure. The pressure on forest resources is catalyzed by the expansion of markets for forest products, agricultural expansion and escalating poverty levels. An upsurge in the number of users of herbal medicine in urban and rural areas has increased the pressure on the forests, while modernization and change in lifestyle have led to the loss of traditional knowledge associated with medicinal plants utilization and conservation. No detailed economic evaluation of medicinal plants has been undertaken and the current illegal, unregulated and unreported exploitation of medicinal plants has led to overexploitation and loss of biodiversity. A better understanding of the abundance, distribution, uses and economic value of medicinal plants is important for the sustainable exploitation and conservation of forests. The study covered four forest blocks of Kakamega, North Nandi, South Nandi and Kibiri to determine plant species diversity, and their distribution in the disturbed and undisturbed areas of the forest; assess knowledge, utilization and economic estimate by willingness to-pay approach of medicinal plants to communities adjacent to the Kakamega Forest. Value chain analysis had been conducted for medicinal plants and forest user groups from Community Forest Association (CFA) had been trained in product development and access market were used in the study. Experimental Plot techniques were also used to gather ecological data on the frequency, density, diversity and distribution of the plants, whereas key informant interviews, focus group discussions and household interviews were utilized to gather information on ethnobotanical knowledge and household socioeconomic data. Thirty-two key species of medicinal plants were identified and used by local people around the Kakamega forest ecosystem. Forty-seven percent (47%) of these were trees, thirty four percent (34%) were shrubs, sixteen percent (16%) were herbs and climbers three percent (3%). Seventy percent (70%) of the medicinal plants were within the forest and thirty percent (30%) were outside the forest. The three most dominant families were Euphorbiaceae, Piperaceae and Fabaceae with leaves as the most common plant part used constituting 31 % (n=26) of the preparations, followed by roots with 20% (n=17),bark with 14% (n=14), fruits with 11 % (n=9), seeds having 11% (n=9), flowers 2% (n=2) and sap 2 % (n=3). The economic benefits generated from the medicinal plants within the forest ecosystem services in the Kakamega-Nandi landscape in terms of direct use value was about KES 601,918,256 (≈USD 5.19 million) per year, while indirect use value was KES 317,288,046 (≈USD 2.74 million) per year. Indigenous knowledge of the medicinal uses of the plants, their commercial aspects and distribution trends in the forest provision of wide scope for understanding relevant market systems may be tapped for decision support in rural health service planning, policy formulation for conserving the forest, tracking and mitigation of climate change impacts

Measles and Rubella Serosurvey Identifies Rubella Immunity Gap in Young Adults of Childbearing Age in Zambia: The Added Value of Nesting a Serological Survey Within a Post-Campaign Coverage Evaluation Survey

Background: Serological surveys can potentially complement vaccine coverage surveys, such as post-vaccination campaign coverage evaluation surveys (PCES), by providing direct information on population immunity within and outside the target age range of the mass vaccination campaign. We estimate age-specific population immunity to measles and rubella viruses in Southern Province, Zambia, and assess the value of adding serological data to vaccination coverage estimates by nesting a serological survey within a PCES. Methods: Dried blood spots (DBS) from fingerprick blood were collected from all individuals ages nine months or older in households participating in the PCES and tested for measles and rubella virus-specific immunoglobulin G (IgG) by enzyme immunoassay (Siemens Enzygnost, Marburg, Germany). Results: Overall seroprevalence was 95.5% (95% CI: 92.8, 97.2) for measles virus-specific IgG and 97.7% (95% CI: 96.0, 98.7) for rubella virus-specific IgG. Rubella seroprevalence was 98.4% (95% CI: 95.9, 99.4) among children eligible for the MR vaccination campaign, significantly higher than the reported measles-rubella (MR) vaccination campaign coverage of 89.8% (p = 0.003), and higher than the 91.3% rubella seroprevalence for adolescents and adults 16–30 years of age (p = 0.049). Conclusion: Seroprevalence to measles and rubella viruses in children younger than 16 years of age was significantly higher than expected from vaccination coverage estimates, likely reflecting exposure to wild-type viruses and underreporting of vaccination. The serosurvey revealed rubella immunity gaps among women 16–30 years of age, precisely the age group in which protection from rubella is most important to prevent congenital rubella syndrome. Nesting serological surveys within existing surveys can leverage resources and infrastructure while providing complementary information important to immunization programs. © 2019 The Author(s

High-resolution bacterial 16S rRNA gene profile meta-analysis and biofilm status reveal common colorectal cancer consortia

Colorectal cancer (CRC) remains the third most common cancer worldwide, with a growing incidence among young adults. Multiple studies have presented associations between the gut microbiome and CRC, suggesting a link with cancer risk. Although CRC microbiome studies continue to profile larger patient cohorts with increasingly economical and rapid DNA sequencing platforms, few common associations with CRC have been identified, in part due to limitations in taxonomic resolution and differences in analysis methodologies. Complementing these taxonomic studies is the newly recognized phenomenon that bacterial organization into biofilm structures in the mucus layer of the gut is a consistent feature of right-sided (proximal), but not left-sided (distal) colorectal cancer. In the present study, we performed 16S rRNA gene amplicon sequencing and biofilm quantification in a new cohort of patients from Malaysia, followed by a meta-analysis of eleven additional publicly available data sets on stool and tissue-based CRC microbiota using Resphera Insight, a high-resolution analytical tool for species-level characterization. Results from the Malaysian cohort and the expanded meta-analysis confirm that CRC tissues are enriched for invasive biofilms (particularly on right-sided tumors), a symbiont with capacity for tumorigenesis (Bacteroides fragilis), and oral pathogens including Fusobacterium nucleatum, Parvimonas micra, and Peptostreptococcus stomatis. Considered in aggregate, species from the Human Oral Microbiome Database are highly enriched in CRC. Although no detected microbial feature was universally present, their substantial overlap and combined prevalence supports a role for the gut microbiota in a significant percentage (>80%) of CRC cases