Infected Human Blood Research Articles

Investigation of Hepatitis B Virus in the Body of the Bed Bug Cimex hemipterus (Hemiptera: Cimicidae) Fed on Infected Human Blood by RT-PCR Method

Background Bed bugs (Hemiptera: Cimicidae) are insects found in abundance among urban and rural communities. Both male and female bed bugs thrive on human blood. The main aim of this study was to detect Hepatitis B Virus (HBV) in the body of the bed bug, Cimex hemipterus (Hemiptera: Cimicidae), fed on naturally infected patient blood by Reverse Transcription Polymerase Chain Reaction (RT-PCR) Methods In this experiment, C. hemipterus bugs nourished once with HBV-positive blood were examined by RT-PCR at 1, 2, 3, 7- and 10 days post-engorgement. Bloodsucking was performed using an artificial membrane feeding system. RNA was extracted from infected bed bugs, and cDNA was then synthesized to monitor the HBV mRNA. Results The RT-PCR test results for infected specimens were positive on the first to third days post-bloodsucking. Moreover, the sample on days 7-10 was negative for HBV. This study also revealed that the breeding of bed bugs under laboratory conditions lasted for one week from the first to fifth nymph stages. Conclusion Since HBV mRNA was detected in infected bed bugs until the third-day post-engorgement, it is likely that they potentially transmitted HBV. It is thus indispensable to conduct more thorough research in the future.

HIV-Infected Hepatic Stellate Cells or HCV-Infected Hepatocytes Are Unable to Promote Latency Reversal among HIV-Infected Mononuclear Cells.

Due to a common mode of transmission through infected human blood, hepatitis C virus (HCV) and human immunodeficiency virus (HIV) co-infection is relatively prevalent. In alignment with this, HCV co-infection is associated with an increased size of the HIV reservoir in highly active antiretroviral therapy (HAART)-treated individuals. Hence, it is crucial to comprehend the physiological mechanisms governing the latency and reactivation of HIV in reservoirs. Consequently, our study delves into the interplay between HCV/HIV co-infection in liver cells and its impact on the modulation of HIV latency. We utilized the latently infected monocytic cell line (U1) and the latently infected T-cell line (J-Lat) and found that mediators produced by the infection of hepatic stellate cells and hepatocytes with HIV and HCV, respectively, were incapable of inducing latency reversal under the studied conditions. This may favor the maintenance of the HIV reservoir size among latently infected mononuclear cells in the liver. Further investigations are essential to elucidate the role of the interaction between liver cells in regulating HIV latency and/or reactivation, providing a physiologically relevant model for comprehending reservoir microenvironments in vivo.

Does cold storage of blood before transfusion prevent the transmission of syphilis? A systematic review and meta-analysis.

Although screening of donated blood for syphilis is almost universally applied, its cost-effectiveness is questioned because of the low prevalence of transfusion-transmitted syphilis and a widespread belief that the syphilis-causing bacterium Treponema pallidum is very vulnerable to cold storage. Since the latter claim is not yet supported by a systematic review, we investigated whether syphilis can be transmitted via transfusion following prolonged (cold or room temperature) storage of blood products. MEDLINE, PMC and NCBI bookshelf (PubMed interface), Cochrane Library, Embase, Web of Science and CINAHL were searched up to 17 January 2023. Nine experimental animal studies and one observational human study were included. Meta-analysis showed that storing artificially infected human (six studies; risk ratio [RR] = 0.37, 95% confidence interval [CI]: 0.22-0.64, p = 0.0003) or rabbit (two studies; RR = 0.08, 95% CI: 0.01 to 0.55, p = 0.01) blood for more than 72 h before intratesticular injection significantly decreased the number of recipient animals that develop syphilis. Nonetheless, the possibility of syphilis transmission remained for up to 7 days. Differences could not be found for rabbit plasma (p = 0.60) or naturally infected rabbit blood (p = 0.28). There was limited evidence from one study in favour of the storage of artificially infected human platelets for over 72 h at cold temperatures (RR = 0.13, 95% CI: 0.03-0.52, p = 0.004) but not at room temperature (p = 0.12). Even though the infectivity of T. pallidum-spiked blood may decrease after 72 h of cold storage, the possibility for transfusion-transmitted syphilis may remain for several days after. The evidence is very uncertain, and conclusions are hindered by a lack of sufficiently powered studies and studies in humans. In addition, T. pallidum concentrations used in animal studies may be unrealistically high.

Human Oncogenic Epstein–Barr Virus in Water and Human Blood Infection of Communities in Phayao Province, Thailand

Water can contain pathogenic viruses. Many studies on RNA virus sources have shown that water can transmit them. However, there are few reports on pathogenic DNA virus transmission through water, such as adenovirus, which pose a widespread public health risk. Therefore, this study aimed to show waterborne viral transmission by detecting viruses in pooled human whole blood samples, tap water, and natural water from Mueang District, Phayao Province, Thailand, using a metagenomic approach. Viral prevalence in whole blood samples was measured by polymerase chain reaction (PCR) and quantitative PCR (qPCR), and environmental factors that affect viral infection were assessed. Metagenomics results showed that Epstein–Barr virus (EBV) members were among the prominent cancer-associated oncogenic DNA viruses detected in human blood and all water types similar to the EBV reference sequence (NC_007605). There were 59 out of 813 (7.26%) human whole blood samples that were positive for EBV DNA based on PCR and qPCR for the EBNA-1 and EBNA-2 genes. Water- and blood-borne human oncogenic EBV should be a concern in tap water treatment and blood transfusion in patients, respectively. Therefore, the detection of EBV in water suggests that transmission via water is possible and should be investigated further.

Nested qPCR assay to detect Babesia duncani infection in hamsters and humans.

Human babesiosis is caused by Babesia duncani that is transmitted through tick bites, blood transfusions, and transplacental transmission. Despite its health burden, diagnostic assays for this pathogen are either unsuitable for clinical applications or have a low detection efficiency; therefore, it remains undetected during transfusion and utilization of blood and blood-component transfusions. This study used a molecular approach via nested quantitative polymerase chain reaction (qPCR) by designing primers and probes corresponding to the variable regions of B. duncani 18S rRNA gene to specifically detect B. duncani DNA in experimentally infected LVG Golden Syrian hamster (n = 70) and human (n = 492; tick bite patients from Gansu Province, China) blood samples. Moreover, comparative analyses of this technique with previously reported nested PCR and microscopy were conducted. The newly optimized diagnostic technique exhibited no cross-reactivity with genomic DNA or plasmids containing the 18S rRNA gene of other zoonotically important Babesia spp., including B. microti, B. divergens, B. crassa, and B. motasi Hebei. The detection limit of nested qPCR was approximately one plasmid copy in 20 μL or one infected red blood cell in 200 μL whole blood. The specificity and sensitivity of the method were 100% and 98.6%, respectively. Comparative analyses revealed that nested qPCR detected B. duncani had relatively higher efficacy and specificity than microscopic examination and nested PCR. The 492 human blood samples were negative for B. duncani infection. Thus, the present study provides an improved diagnostic assay for the efficient and effective detection and analysis of B. duncani infections and its prevalence in infection-prone areas.

Evaluation of an extracorporeal ozone-based bactericide system for the treatment of Escherichia coli sepsis

BackgroundSepsis is associated with substantial mortality rates. Antibiotic treatment is crucial, but global antibiotic resistance is now classified as one of the top ten global public health risks facing humanity. Ozone (O3) is an inorganic molecule with no evident function in the body. We investigated the bactericide properties of ozone, using a novel system of extracorporeal ozone blood treatment. We hypothesized that ozone would decrease the concentration of viable Escherichia coli (E. coli) in human whole blood and that the system would be technically feasible and physiologically tolerable in a clinically relevant model of E. coli sepsis in swine.MethodsThe E. coli strain B09-11822, a clinical isolate from a patient with septic shock was used. The in vitro study treated E. coli infected human whole blood (n = 6) with ozone. The in vivo 3.5-h sepsis model randomized swine to E. coli infusion and ozone treatment (n = 5) or E. coli infusion and no ozone treatment (n = 5). Live E. coli, 5 × 107 colony-forming units (CFU/mL) was infused in a peripheral vein. Ozone treatment was initiated with a duration of 30 min after 1.5 h.ResultsThe single pass in vitro treatment decreased E. coli by 27%, mean 1941 to 1422 CFU/mL, mean of differences − 519.0 (95% CI − 955.0 to − 82.98, P = 0.0281). pO2 increased (95% CI 31.35 to 48.80, P = 0.0007), pCO2 decreased (95% CI − 3.203 to − 1.134, P = 0.0069), oxyhemoglobin increased (95% CI 1.010 to 3.669, P = 0.0113). Methemoglobin was not affected. In the sepsis model, 9/10 swine survived. One swine randomized to ozone treatment died from septic shock before initiation of the treatment. Circulatory, respiratory, and metabolic parameters were not affected by the ozone treatment. E. coli in arterial blood, in organs and in aerobic and anaerobic blood cultures did not differ. Hemoglobin, leucocytes, and methemoglobin were not affected by the treatment.ConclusionsOzone decreased the concentration of viable E. coli in human whole blood. The system was technically feasible and physiologically tolerable in porcine sepsis/septic shock and should be considered for further studies towards clinical applications.

Histological Changes and Ghrelin, P-Selectin, and Leptin Parameter in Patients with Hepatic Hydatidosis in Iraq.

Humans and animals are affected by hydatid cyst disease as a worldwide zoonotic disease, which is caused by the metacestode stage of Echinococcus spp. This study was performed to evaluate the histological change of liver and blood concentrations of biomarkers, such as ghrelin, p-selectin, and leptin, in humans infected with hydatid cyst. A total of 30 surgical specimens of liver and blood of infected humans and 30 healthy individuals as a control group were evaluated. Liver tissue sections in cases infected with hydatid cyst and control group, histological abnormalities in the liver, including fibrosis, increased inflammatory cells, dystrophic areas, and necrosis were compared in this study. In addition, serum leptin levels were significantly lower in patients with hydatid cyst disease QUOTE <0.05) than in the control group (P-value<0.05), whereas p-selectin and ghrelin levels significantly decreased in patients (P-value<0.05). The results of this research can be effective in improving and promoting the treatment programs of hydatidosis.

Health beliefs and behaviors of livestock industry workers regarding Crimean-Congo hemorrhagic fever in Northwest of Iran

BackgroundCrimean-Congo hemorrhagic fever (CCHF) is an acute, feverous disease that is caused by tick bites or humans’ direct contact with the blood and tissues of infected livestock and humans. The transmission of the disease is also possible via human-to-human contacts and nosocomial transmission is well described. The majority of patients suffering from this disease are slaughterhouse workers (including butchers), farmers, veterinarians and hospital staff. Thus, this study aimed to investigate the health behaviors of butchers regarding CCHF and study factors affecting such behaviors based on the health belief model.MethodsThis is a descriptive cross-sectional study conducted on 500 butchers in Ardabil Province in 2020 by a multistage sampling method. The participants of the study completed the researcher-made questionnaire of health belief model and health behaviors model relevant to CCHF. The collected data were then analyzed by descriptive statistical tests and linear regression analysis.ResultsThe mean (SD) age of the participants was 44.4 (10.5) years, and 96% were males. Only 11.1% of the participants displayed acceptable disease-preventive behaviors. The validity and reliability of the developed questionnaire were confirmed. The results of the exploratory factor analysis showed that the constructs of the model explained 84% of the total variance. The results of the study revealed that among the variables of the health belief model, perceived susceptibility (p-value = 0.006, β = 0.152) and perceived barriers (p-value = 0.023, β = 0.14) were the strongest factors predicting disease-preventive behaviors regarding CCHF.ConclusionThe results of the study showed that the health belief model can predict preventive behaviors for CCHF. Therefore, designing and executing interventions based on the results of this study may encourage such preventive behaviors in butchers.

Vaccines and Antibodies: Weapons in the Fight Against Ebola Virus

Ebola virus disease is one of the deadliest infections in the world today. The microbe to blame is the Ebola virus. It has already caused numerous outbreaks in Africa, in the regions located south of the Sahara. This article describes the main characteristics of this infectious disease as well as the currently available treatments, namely vaccines and antibodies. Antibodies are produced by the human body when it is infected by a microbe. Antibodies can be collected from the blood of infected humans or animals and purified or manufactured in a laboratory to produce drugs. While vaccines have demonstrated their effectiveness in preventing infectious diseases, antibodies are effective in stopping the progression of several infectious diseases. In this article, you will discover that the stimulation of the immune system, either by the vaccine or by antibodies, is essential to tackle Ebola virus disease.

CRISPR/Cas9-engineered inducible gametocyte producer lines as a valuable tool for Plasmodium falciparum malaria transmission research

The malaria parasite Plasmodium falciparum replicates inside erythrocytes in the blood of infected humans. During each replication cycle, a small proportion of parasites commits to sexual development and differentiates into gametocytes, which are essential for parasite transmission via the mosquito vector. Detailed molecular investigation of gametocyte biology and transmission has been hampered by difficulties in generating large numbers of these highly specialised cells. Here, we engineer P. falciparum NF54 inducible gametocyte producer (iGP) lines for the routine mass production of synchronous gametocytes via conditional overexpression of the sexual commitment factor GDV1. NF54/iGP lines consistently achieve sexual commitment rates of 75% and produce viable gametocytes that are transmissible by mosquitoes. We also demonstrate that further genetic engineering of NF54/iGP parasites is a valuable tool for the targeted exploration of gametocyte biology. In summary, we believe the iGP approach developed here will greatly expedite basic and applied malaria transmission stage research.

Markov chain Monte Carlo Gibbs sampler approach for estimating haplotype frequencies among multiple malaria infected human blood samples

BackgroundMalaria patients can have two or more haplotypes in their blood sample making it challenging to identify which haplotypes they carry. In addition, there are challenges in measuring the type and frequency of resistant haplotypes in populations. This study presents a novel statistical method Gibbs sampler algorithm to investigate this issue.ResultsThe performance of the algorithm is evaluated on simulated datasets consisting of patient blood samples characterized by their multiplicity of infection (MOI) and malaria genotype. The simulation used different resistance allele frequencies (RAF) at each Single Nucleotide Polymorphisms (SNPs) and different limit of detection (LoD) of the SNPs and the MOI. The Gibbs sampler algorithm presents higher accuracy among high LoD of the SNPs or the MOI, validated, and deals with missing MOI compared to previous related statistical approaches.ConclusionsThe Gibbs sampler algorithm provided robust results when faced with genotyping errors caused by LoDs and functioned well even in the absence of MOI data on individual patients.

The Rhizobacterium Pseudomonas alcaligenes AVO110 Induces the Expression of Biofilm-Related Genes in Response to Rosellinia necatrix Exudates.

The rhizobacterium Pseudomonas alcaligenes AVO110 exhibits antagonism toward the phytopathogenic fungus Rosellinia necatrix. This strain efficiently colonizes R. necatrix hyphae and is able to feed on their exudates. Here, we report the complete genome sequence of P. alcaligenes AVO110. The phylogeny of all available P. alcaligenes genomes separates environmental isolates, including AVO110, from those obtained from infected human blood and oyster tissues, which cluster together with Pseudomonas otitidis. Core and pan-genome analyses showed that P. alcaligenes strains encode highly heterogenic gene pools, with the AVO110 genome encoding the largest and most exclusive variable region (~1.6 Mb, 1795 genes). The AVO110 singletons include a wide repertoire of genes related to biofilm formation, several of which are transcriptionally modulated by R. necatrix exudates. One of these genes (cmpA) encodes a GGDEF/EAL domain protein specific to Pseudomonas spp. strains isolated primarily from the rhizosphere of diverse plants, but also from soil and water samples. We also show that CmpA has a role in biofilm formation and that the integrity of its EAL domain is involved in this function. This study contributes to a better understanding of the niche-specific adaptations and lifestyles of P. alcaligenes, including the mycophagous behavior of strain AVO110.

Towards malaria field diagnosis based on surface-enhanced Raman scattering with on-chip sample preparation and near-analyte nanoparticle synthesis

We report a chip based on surface-enhanced Raman scattering (SERS) developed towards malaria field diagnosis. Only a mixture of 10-μl water and 10-μl blood is required as the sample input to the chip. Water is the only lysing agent to hemolyze blood cells while keeping the malaria biomarkers, hemozoin biocrystals, at locally high concentrations within parasites and/or their vacuoles. Then, SERS-active silver nanoparticles are synthesized on site near hemozoin in these concentrated regions when the blood/water mixture flows through and dissolves dried chemical patches that are earlier deposited inside the channel, which subsequently arrives at the detection region for SERS measurements. It should be highlighted that the procedure can be accomplished without a laboratory requirement and the risk of exposure to hazardous chemicals. Additionally, raw chemicals deposited inside the chip are chemically more stable than those readymade SERS substrates, thus the shelf life of the chip can be much longer. Furthermore, the chip yields analytical enhancement factor values ranging from 5.4 × 103 to 1.9 × 106 that are comparable to other ready-made SERS substrates in the literature. This strategy is capable of quantifying hemozoin concentrations in malaria infected human blood with a root-mean-square error of prediction of 0.3 μM, and a detection limit of 0.0025 % parasitemia level for parasites in the ring stage (equivalent to 125 parasites/μl) with a room of extra enhancement by switching the laser to a more suitable wavelength. These results show the feasibility to exploit this cost-effective yet highly sensitive SERS-based technique for malaria field diagnosis.

An OMICs-based meta-analysis to support infection state stratification.

MotivationA fundamental problem for disease treatment is that while antibiotics are a powerful counter to bacteria, they are ineffective against viruses. Often, bacterial and viral infections are confused due to their similar symptoms and lack of rapid diagnostics. With many clinicians relying primarily on symptoms for diagnosis, overuse and misuse of modern antibiotics are rife, contributing to the growing pool of antibiotic resistance. To ensure an individual receives optimal treatment given their disease state and to reduce over-prescription of antibiotics, the host response can in theory be measured quickly to distinguish between the two states. To establish a predictive biomarker panel of disease state (viral/bacterial/no-infection), we conducted a meta-analysis of human blood infection studies using machine learning.ResultsWe focused on publicly available gene expression data from two widely used platforms, Affymetrix and Illumina microarrays as they represented a significant proportion of the available data. We were able to develop multi-class models with high accuracies with our best model predicting 93% of bacterial and 89% viral samples correctly. To compare the selected features in each of the different technologies, we reverse-engineered the underlying molecular regulatory network and explored the neighbourhood of the selected features. The networks highlighted that although on the gene-level the models differed, they contained genes from the same areas of the network. Specifically, this convergence was to pathways including the Type I interferon Signalling Pathway, Chemotaxis, Apoptotic Processes and Inflammatory/Innate Response.AvailabilityData and code are available on the Gene Expression Omnibus and github.Supplementary informationSupplementary data are available at Bioinformatics online.

Machine learning to uncover differentiable signatures of bacterial and viral infections

Background: A fundamental problem for disease treatment is that while antibiotics are a powerful counter to bacteria, they are ineffective against viruses. Without proper identification equipment, medical practitioners can unnecessarily prescribe antibiotics to patients without bacterial infections, leaving the source disease untreated and fostering anti-microbial resistance (AMR). This was highlighted by two defence organisations, the Defence Threat Reduction Agency (DTRA) and Defence Science Technology Laboratories (DSTL) as particularly hazardous for soldiers without access to proper means of diagnosis. Suitably, work was commissioned as a basis to assist in the design of a future, portable diagnosis device that could differentially diagnosis disease state based on profiles of gene expressions. Methods and materials: We conducted a meta-analysis of human blood infection studies using Machine Learning (ML) driven biomarker discovery to obtain a panel of genes enabling differential diagnosis of disease state. We performed our meta-analysis on GEO gene expression data, all from open source microarray human blood infection studies. Our analysis was divided into six distinct phases: (1) Data gathering, (2) Pre-processing (consisting of a novel multi-stage batch correction pipeline), (3) Feature Selection (using a genetically inspired search algorithm), (4) Functional Enrichment Analysis, (5) Inferring Interaction Networks and clustering genes, and (6) finally Out-of-Sample Testing for validation. Results: We present an optimal panel of genes, as well as some similarly performing alternatives, which are robust and generalisable, enabling technology-independent differential diagnosis of disease state. We also provide direct insight into the underlying gene interaction networks which control response to disease, and subsequently the key groups of genes important for diagnosis, verified by two parallel analyses on cohorts using Affymetrix and Illumina RNA Microarray. Conclusion: We presented several panels of genes which when taken together are indicated to perform well on both discovery data and out of sample testing (on different microarray manufacturers). While there was some inconsistency between manufacturer gene lists, we still observed high convergence around four gene groups, most prominently the Interferon Stimulated Genes (ISGs). These sets have altered expressions between bacterial, viral, and control disease states, and when taken together provide a predictive baseline for differential diagnosis on gene expression alone.

The Platelet Fraction Is a Novel Reservoir to Detect Lyme Borrelia in Blood.

Simple SummaryTo diagnose Lyme disease, a patient’s blood is tested for antibodies that develop as part of the immune response. This can lead to cases being missed or inadequately treated. An ideal test would directly detect the Lyme disease bacteria, Borrelia, to provide better clinical guidance. In this study, we aimed to improve the methods currently used to find Borrelia in human blood, and identified two opportunities for optimization. We demonstrate that the container most commonly used to collect blood (EDTA) decreases Borrelia’s ability to grow, and we identify a superior alternative (citrate). Additionally, using experimentally infected blood, we show that Borrelia is highly concentrated in the platelet fraction, making it an ideal candidate for direct detection. These results lay the foundation for diagnostic test development, which could improve patient outcomes in Lyme disease.Serological diagnosis of Lyme disease suffers from considerable limitations. Yet, the technique cannot currently be replaced by direct detection methods, such as bacterial culture or molecular analysis, due to their inadequate sensitivity. The low bacterial burden in vasculature and lack of consensus around blood-based isolation of the causative pathogen, Borrelia burgdorferi, are central to this challenge. We therefore addressed methodological optimization of Borrelia recovery from blood, first by analyzing existing protocols, and then by using experimentally infected human blood to identify the processing conditions and fractions that increase Borrelia yield. In this proof-of-concept study, we now report two opportunities to improve recovery and detection of Borrelia from clinical samples. To enhance pathogen viability and cultivability during whole blood collection, citrate anticoagulant is superior to more commonly used EDTA. Despite the widespread reliance on serum and plasma as analytes, we found that the platelet fraction of blood concentrates Borrelia, providing an enriched resource for direct pathogen detection by microscopy, laboratory culture, Western blot, and PCR. The potential for platelets to serve as a reservoir for Borrelia and its diagnostic targets may transform direct clinical detection of this pathogen.

A sensitive on‐chip probe–based portable nuclear magnetic resonance for detecting low parasitaemia plasmodium falciparum in human blood

AbstractMalaria elimination programmes are dependent on a rapid, cost‐effective and portable diagnostic tool to detect and quantify malaria parasites in human blood. Herein, we report a cost‐effective and portable nuclear magnetic resonance (pNMR) for malaria diagnosis. In this present study, we have developed and characterized a sensitive and low‐cost novel on‐chip NMR probe. This NMR probe has improved mismatching problem between radiofrequency (RF) coil and transmission line that results in enhancement in NMR sensitivity. Developed pNMR represents a rapid, cost‐effective and highly sensitive method to detect very low parasitaemia plasmodium falciparum (0.0001%) in infected human blood in comparison with other available malaria diagnosis techniques. The experimental results show that very low parasitic load can be detected rapidly by the change in the transverse relaxation rate (T2) of NMR, suggesting a good sensitivity. A good linear relationship with a correlation coefficient of 0.94 between the change in transverse relaxation rate (ΔT2) and the different parasitaemia (%) has been observed, indicating that pNMR is a potential tool for real‐time, reusable and high‐sensitivity analysis of malaria parasite in human blood.

In vitro dual (anticancer and antiviral) activity of the carotenoids produced by haloalkaliphilic archaeon Natrialba sp. M6

Halophilic archaea are a promising natural source of carotenoids. However, little information is available about the biological impacts of these archaeal metabolites. Here, carotenoids of Natrialba sp. M6, which was isolated from Wadi El-Natrun, were produced, purified and identified by Raman spectroscopy, GC-mass spectrometry, and Fourier transform infrared spectroscopy, LC–mass spectrometry and Nuclear magnetic resonance spectroscopy. The C50 carotenoid bacterioruberin was found to be the predominant compound. Because cancer and viral hepatitis are serious diseases, the anticancer, anti-HCV and anti-HBV potentials of these extracted carotenoids (pigments) were examined for the first time. In vitro results indicated that the caspase-mediated apoptotic anticancer effect of this pigment and its inhibitory efficacy against matrix metalloprotease 9 were significantly higher than those of 5-fluorouracil. Furthermore, the extracted pigment exhibited significantly stronger activity for eliminating HCV and HBV in infected human blood mononuclear cells than currently used drugs. This antiviral activity may be attributed to its inhibitory potential against HCV RNA and HBV DNA polymerases, which thereby suppresses HCV and HBV replication, as indicated by a high viral clearance % in the treated cells. These novel findings suggest that the C50 carotenoid of Natrialba sp. M6 can be used as an alternative source of natural metabolites that confer potent anticancer and antiviral activities.

Study on vector mosquito of zoonotic Brugia malayi in Musi Rawas, South Sumatera, Indonesia.

Background and Aim:Studies to determine abundance, distribution, species composition, and mosquito interactions are very important in understanding the risk of disease transmission to implement appropriate mosquito management in endemic areas. Lymphatic filarial worms are one of the parasites that are contracted and/or transmitted by mosquitoes when sucking the blood of infected humans or animals and then biting others. This research was conducted to study the abundance, species composition, mosquito biting cycles, density and periodicity of mosquitoes caught in Lubuk Pauh Village, Bulang Tengah Suku Ulu, Musi Rawas, South Sumatera, Indonesia, which is an endemic area of zoonotic Brugia malayi.Materials and Methods:The mosquito collection was done in July 2018 using the human landing collection method for 11 h from 18.00 pm to 5.00 am Western Indonesian Time. The catching of mosquitoes was done both indoors and outdoors, and mosquitoes were identified under a dissecting microscope using an identification key to confirm their species. Detection of B. malayi larvae in mosquitoes was confirmed by dissection and polymerase chain reaction methods.Results:The caught mosquitoes consisted of four species: Armigeres subalbatus, Culex quinquefasciatus, Culex vishnui, and Mansonia uniformis. Based on the Shannon–Wiener index, Lubuk Pauh Village has low mosquito species diversity (0.210). Ar. subalbatus was the dominant mosquito in Lubuk Pauh Village with dominance number 95.08, and it had the most frequent activity in each of periods of indoor and outdoor collection, with the highest density (man-hour density) at 18.00-19.00 (51.750). B. malayi infective stage larvae were not found in all mosquito species caught.Conclusion:Existence of Ar. subalbatus, Cx. quinquefasciatus, and Ma. uniformis in Lubuk Pauh Village which is an endemic area of B. malayi shows that the area is at risk of lymphatic filariasis transmission.

Is that a real oocyst? Insectary establishment and identification of Plasmodium falciparum oocysts in midguts of Anopheles mosquitoes fed on infected human blood in Tororo, Uganda

BackgroundThe human infectious reservoir for malaria consists of individuals capable of infecting mosquitoes. Oocyst prevalence and density are typical indicators of human infectivity to mosquitoes. However, identification of oocysts is challenging, particularly in areas of low malaria transmission intensity where few individuals may infect mosquitoes, and infected mosquitoes tend to have few oocysts. Here, features that differentiate oocysts from other oocyst-like in mosquito midguts are explained and illustrated. In addition, the establishment and maintenance of infrastructure to perform malaria transmission experiments is described. This work may support other initiatives to set up membrane feeding infrastructure and guide oocyst detection in low transmission settings.MethodsIn 2014, an insectary was developed and equipped in Tororo district, Uganda. A colony of Anopheles gambiae s.s. mosquitoes (Kisumu strain) was initiated to support infectivity experiments from participants enrolled in a large cohort study. Venous blood drawn from participants who were naturally infected with malaria parasites was used for membrane feeding assays, using 60–80 mosquitoes per experiment. Approximately 9–10 days after feeding, mosquitoes were dissected, and midguts were stained in mercurochrome and examined by light microscopy for Plasmodium falciparum oocysts and similar structures. In supportive experiments, different staining procedures were compared using in vitro cultured parasites.ResultsA stable colony of the Kisumu strain of An. gambiae s.s. was achieved, producing 5000–10,000 adult mosquitoes on a weekly basis. Challenges due to temperature fluctuations, mosquito pathogens and pests were successfully overcome. Oocysts were characterized by: presence of malaria pigment, clearly defined edge, round shape within the mosquito midgut or on the peripheral tissue and always attached to the epithelium. The main distinguishing feature between artifacts and mature oocysts was the presence of defined pigment within the oocysts.ConclusionsOocysts may be mistaken for other structures in mosquito midguts. Distinguishing real oocysts from oocyst-like structures may be challenging for inexperienced microscopists due to overlapping features. The characteristics and guidelines outlined here support identification of oocysts and reliable detection at low oocyst densities. Practical advice on sustaining a healthy mosquito colony for feeding experiments is provided. Following the reported optimization, the established infrastructure in Tororo allows assessments of infectivity of naturally infected parasite carriers.