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Ticks are blood-sucking arthropods that transmit many pathogens, including arboviruses. Arboviruses transmitted by ticks are generally referred to as tick-borne viruses (TBVs). TBVs are known to cause diseases in humans, pets, and livestock. There is, however, very limited information on the occurrence and distribution of TBVs in sub-Saharan Africa. This study was designed to determine the presence and distribution of ticks infesting dogs and cattle in Ghana, as well as to identify the tick-borne or tick-associated viruses they harbour. A more diverse population of ticks was found to infest cattle (three genera) relative to those infesting dogs (one genus). Six phleboviruses and an orthonairovirus were detected in tick pools screened by RT-PCR. Subsequent sequence analysis revealed two distinct phleboviruses and the previously reported Odaw virus in ticks collected from dogs and a virus (16GH-T27) most closely related to four unclassified phleboviruses in ticks collected from cattle. The virus 16GH-T27 was considered a strain of Balambala tick virus (BTV) and named BTV strain 16GH-T27. Next-generation sequencing analysis of the BTV-positive tick pool detected only the L and S segments. Phylogenetic analysis revealed that BTV clustered with viruses previously defined as M-segment-deficient phleboviruses. The orthonairovirus detected in ticks collected from cattle was confirmed to be the medically important Dugbe virus. Furthermore, we discuss the importance of understanding the presence and distribution of ticks and TBVs in disease prevention and mitigation and the implications for public health. Our findings contribute to the knowledge pool on TBVs and tick-associated viruses.

Background Dengue virus (DENV) is a mosquito-borne arbovirus transmitted by Aedes mosquitoes, but is not endemic in all areas where this vector is found. For example, the relatively sparse distribution of cases in West Africa is generally attributed to the refractory nature of West African Aedes aegypti (Ae. aegypti) to DENV infection, and particularly the forest-dwelling Ae. aegypti formosus. However, recent studies have shown these mosquitoes to be competent vectors within some West African countries that have suffered outbreaks in the past, such as Senegal. There is however little information on the vector competence of the Ae. aegypti in West African countries such as Ghana with no reported outbreaks. Methods This study examined the vector competence of 4 Ae. aegypti colonies from urban, semi-urban, and two rural locations in Ghana in transmitting DENV serotypes 1 and 2, using a single colony from Vietnam as control. Midgut infection and virus dissemination were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR), while the presence and concentration of DENV in the saliva of infectious mosquitoes was determined by the focus forming assay. Results There were significant differences in the colonies’ susceptibility to virus infection, dissemination, and transmission. All examined Ghanaian mosquitoes were refractory to infection by DENV serotype 2, while some colonies exhibited potential to transmit DENV serotype 1. None of the tested colonies were as competent as the control group colony. Conclusions These findings give insight into the possible risk of outbreaks, particularly in the urban areas in the south of Ghana, and highlight the need for continuous surveillance to determine the transmission status and outbreak risk. This study also highlights the need to prevent importation of different DENV strains and potential invasion of new highly vector-competent Ae. aegypti strains, particularly around the ports of entry. Graphical Abstract

Dichapetalum madagascariense Poir (Dichapetalaceae) is traditionally used to treat bacterial infections, jaundice, urethritis and viral hepatitis in Africa. Its root contains a broad spectrum of biologically active dichapetalins. To evaluate the plant's effect on human MCF-7 cells and its' antibacterial and antiparasitic potentials, we isolated and identified the known dichapetalins A and M from the roots. Both dichapetalins were tested on six bacterial strains (Shigella flexneri, Bacillus cereus, Salmonella paratyphi B, Listeria monocytogenes, Escherichia coli, Staphylococcus aureus) and two parasite strains; Trypanosoma brucei brucei, and Leishmania donovani using the Alamar Blue assay system. Dichapetalins A and M were more potent against B. cereus with IC50 values of 11.15 and 3.15 μg/ml, respectively, compared to the positive control ampicillin (IC50 = 19.50 μg/ml). Dichapetalins A (IC50 = 74.22 μg/ml) and M (IC50 = 72.34 μg/ml) were less active against T. b. brucei, compared to the standard Suramin (IC50 = 4.96 μg/ml). Dichapetalin M showed moderate activity against L. donovani (Amphotericin B: IC50 = 0.21 μg/ml) with an IC50 of 16.80 μg/ml. In human MCF-7 cells expressing the NR1I2 receptor, the activity of dichapetalin M was higher (IC50 = 4.71 μM and 3.95 μM) for 48 and 72 h of treatment, respectively compared to Curcumin with IC50 of 17.49 μM and 12.53 μM for 48 and 72 h of treatment, respectively. Results from in vitro expression studies with qPCR confirmed an antagonistic effect of dichapetalin M on PXR (NR1I2) signaling; supporting the PXR signaling pathway as a possible mode of action of dichapetalin M as predicted by in silico results. These findings confirm previous studies that D. madagascariense can be a source of potential lead compounds for development of novel antibiotic, antiparasitic and anticancer medicines, and provide further insights into the mechanism of action of the dichapetalins.

African trypanosomiasis poses serious health and economic concerns to humans and livestock in several sub-Saharan African countries. The aim of the present study was to identify the antitrypanosomal compounds fromCrude extracts and fractions were prepared from air-dried pulverized plant material ofThe solvent partitioning dichloromethane (BPFD) and methanol (BPFM) fractions of

A new high performance liquid chromatography (HPLC) method has been established for quantitative and qualitative analysis of three tetracyclic iridoids: ML-2-3 (1), molucidin (2), and ML-F52 (3), which are responsible for anti-trypanosomal and anti-leishmanial activities of Morinda lucida Bentham leaves. Separation of 1–3 from dried 80% aqueous (aq.) ethanol extract was achieved on a reversed-phase cholester column packed with cholesteryl-bonded silica using an acetonitrile-0.1% aq. formic acid mobile phase system. Ultraviolet-visible (UV-VIS) spectroscopy was employed for detection of compounds, and their contents were determined by measuring absorbance at 254 nm. Depending on the above system, several factors potentially affecting the concentration of tetracyclic iridoids were evaluated resulting in several variation on plant organs, seasonality, variation between individual trees, and branch positions within the trees. Moreover, we developed a simple, quick, and effective method for tetracyclic iridoid isolation from M. lucida leaves that consisted of extraction by sonication into 80% aq. ethanol, basic hydrolysis, acid neutralization, liquid-liquid extraction into an organic solvent, and reverse phase open column chromatography. Employing this method, we have succeeded to obtain 1 as a colorless crystal yielding of 0.23%, which was 28 times higher than that of previous isolation method. Setting up methodology in this paper may be important for future in vitro and in vivo studies of tetracyclic iridoids and moreover for their applications in new drug design and development.

Trypanosomiasis, leishmaniasis, and malaria are protozoan infections of public health importance with thousands of new cases recorded annually. Control of these infection(s) with existing chemotherapy is limited by drug toxicity, lengthy parenteral treatment, affordability, and/or the emergence of resistant strains. Medicinal plants on the other hand are used in the treatment of various infectious diseases although their chemical properties are not fully evaluated. In this study, we screened 112 crude extracts from 72 selected Ghanaian medicinal plants for anti-Trypanosoma, anti-Leishmania, and anti-Plasmodium activities in vitro and investigated their mechanisms of action. Twenty-three extracts from 20 plants showed significant antiprotozoan activity against at least 1 of 3 protozoan parasites screened with IC50 values less than 20 μg/ml. Eleven extracts showed high anti-Trypanosoma activity with Bidens pilosa whole plant and Morinda lucida leaf extracts recording the highest activities. Their IC50 (selectivity index [SI]) values were 5.51 μg/ml (35.00) and 5.96 μg/ml (13.09), respectively. Nine extracts had high anti-Leishmania activity with Annona senegalensis and Cassia alata leaf extracts as the most active. Their IC50 (SI) values were 10.8 μg/ml (1.50) and 10.1 μg/ml (0.37), respectively. Six extracts had high anti-Plasmodium activity with the leaf and stem-bark extracts of Terminalia ivorensis recording the highest activity. Their IC50 (SI) values were 7.26 μg/ml (129.36) and 17.45 μg/ml (17.17), respectively. Only M. lucida at 25 μg/ml induced significant apoptosis-like cell death in Trypanosoma parasites. Anti-Leishmania active extracts induced varying morphological changes in Leishmania parasites such as multiple nuclei and/or kinetoplast, incomplete flagella division, or nuclear fragmentation. Active extracts may be potential sources for developing new chemotherapy against these infections.

Ticks are ectoparasites that transmit various types of human and animal pathogens. In particular, emerging and re-emerging diseases caused by tick-borne viruses are public health concerns around the world. However, in many countries of the sub-Saharan African region, epidemiological information on tick-borne viral infections is limited, and their prevalence and distribution remain largely unknown. In this study, we conducted surveillance on ticks to detect medically important tick-borne bunyaviruses in three study sites in and near to Accra, the capital city of Ghana, in 2015. Domestic dogs and cattle were surveyed and were found to be infested with various tick species belonging to the genera Rhipicephalus, Amblyomma and Haemaphysalis. Importantly, we detected a novel putative phlebovirus in Rhipicephalus ticks, and successfully isolated a new strain of Dugbe virus from Am. variegatum ticks. To our knowledge, this is the first report of tick-associated viruses in Ghana other than Crimean-Congo hemorrhagic fever virus.

Visceral leishmaniasis (VL) is a major problem worldwide and causes significant morbidity and mortality. Existing drugs against VL have limitations, including their invasive means of administration long duration of treatment regimens. There are also concerns regarding increasing treatment relapses as well as the identification of resistant clinical strains with the use of miltefosine, the sole oral drug for VL. There is, therefore, an urgent need for new alternative oral drugs for VL. In the present study, we show the leishmanicidal effect of a novel, oral antimalarial endoperoxide N-251. In our In vitro studies, N-251 selectively and specifically killed Leishmania donovani D10 amastigotes with no accompanying toxicity toward the host cells. In addition, N-251 exhibited comparable activities against promastigotes of L. donovani D10, as well as other L. donovani complex parasites, suggesting a wide spectrum of activity. Furthermore, even after a progressive infection was established in mice, N-251 significantly eliminated amastigotes when administered orally. Finally, N-251 suppressed granuloma formation in mice liver through parasite death. These findings indicate the therapeutic effect of N-251 as an oral drug, hence suggest N-251 to be a promising lead compound for the development of a new oral chemotherapy against VL., Author summary Visceral Leishmaniasis remains a serious health problem in many developing countries with thousands of new cases recorded annually. Novel oral therapies are required as existing drugs are limited by their invasive means of administration long duration of treatment regimens. Moreover, with miltefosine as the sole oral drug, there are concerns of the eventual development of parasite resistance with its continuous use. In this study, we report on the in vitro and in vivo leishmanicidal effect of orally administered N-251 on the Leishmania donovani complex parasites in mice. Our results suggest that N-251 may be a potential lead compound for the development of a new oral chemotherapy against VL

Dr. Naraomi Imamura, alarmed by the rapidly declining population of the Japanese farmers as well as by the low market values of the produce and other products of the primary industry, proposed in the mid-90’s that the farmers effectively integrate the whole process of the primary (production), secondary (processing) and tertiary (service) sectors into what may be called a 6th industry (1×2×3). By this Imamura meant that the primary workers should also step into new areas of processing and sales/service to add extra values to their products while creating new employment. In the meantime freezing technique has made a great development in recent years to be able to retain and reproduce original freshness and taste of food, and is considered one of the safest ways to preserve food for its lack of dependence on chemicals. The advantages of freezing have been proven as shown by our several case studies, that they can lead the food production business to the front line of the 6th industry. Our local surveys showed that while many food business operators already take advantage of freezing in keeping stock of food materials as well as finished products, the general level of interests into more advanced models of freezers was not very high. The biggest mistake regarding freezing is a sole attention paid to the technique of freezing itself. Pre-processing, freezing, preservation and thawing are four phases of freezing process and they are all equally important to influence the result of the food preservation. Moreover further development of the method on each phase will make freezing more useful for the food business and the consumers.

African trypanosomiasis is a disease caused by the parasitic protozoa of the Trypanosoma genus. Despite several efforts at chemotherapeutic interventions, the disease poses serious health and economic concerns to humans and livestock of many sub-Saharan African countries. Zanthoxylum zanthoxyloides (Lam.) Zepern. & Timler (Z. zanthoxyloides LZT) is a plant species of important phytochemical and pharmacological relevance in the subtropical zones of the African continent. However, the mechanisms of its antitrypanosomal effects in African trypanosomes remain to be elucidated. The aim of the study was to determine the in vitro effects and mechanisms of action of Z. zanthoxyloides LZT (root) fractions against Trypanosoma brucei. T. brucei (GUTat 3.1 strain), L. donovani (D10 strain), P. falciparum (3D 7 strain), Jurkat cells, and Chang liver cells were cultivated in vitro to the log phase in their respective media at 37°C. Crude extracts and fractions were prepared from air-dried pulverized plant material of Z. zanthoxyloides LZT (root) using the modified Kupchan method of solvent partitioning. Half-maximal inhibitory concentrations (IC50) were determined through the alamar blue cell viability assay. Effects of fractions on cell death and cell cycle of T. brucei were determined using flow cytometry. Fluorescence microscopy was used to investigate the effects of fractions on the morphology and distribution of T. brucei. Antitrypanosomal compounds of fractions were characterized using high-performance liquid chromatography (HPLC) and attenuated total reflectance infrared (ATR-IR) spectroscopy. Methanol, butanol, and dichloromethane fractions were selectively active against T. brucei with respective IC50 values of 3.89, 4.02, and 5.70 μg/ml. Moreover, methanol, butanol, and dichloromethane fractions significantly induced apoptosis-like cell death with remarkable alteration in the cell cycle of T. brucei. Furthermore, dichloromethane and methanol fractions altered the morphology, induced aggregation, and altered the ratio of nuclei to kinetoplasts in the parasite. The HPLC chromatograms and ATR-IR spectra of the active fractions suggested the presence of aromatic hydrocarbons with hydroxyl, carbonyl, amine, or amide functional groups. The results suggest that Z. zanthoxyloides LZT have potential chemotherapeutic effects on African trypanosomes with implications for novel therapeutic interventions in African trypanosomiasis.

Global dissemination of New Delhi metallo-β-lactamase (NDM)-producing bacteria has become a major health threat. However, there are few reports regarding the identification and characterisation of NDM-producing bacteria from West Africa, including Ghana. An Escherichia coli strain with resistance to meropenem was isolated from the Tamale Teaching Hospital in Ghana. Its identification and determination of antibiotic susceptibility profile were carried out using commercial systems. The antibiotic resistance mechanism was analysed by phenotypic detection kits, PCR, and DNA sequencing. Conjugation experiments, S1 nuclease pulsed field gel electrophoresis, and Southern blotting were performed. Finally, the NDM-1-harbouring plasmid was characterised using next-generation sequencing and phylogenetic analysis. The meropenem-resistant Escherichia coli strain EC2189 harboured blaNDM-1 and belonged to sequence type 410. blaNDM-1 was located on the IncHI type transferrable plasmid p2189-NDM (248,807 bp long), which co-carried multiple resistance genes, such as blaCTX-M-15, aadA1, aac(6')-Ib, sul3, dfrA12, and cmlA1. p2189-NDM phylogenetically differed from previously identified blaNDM-1-positive IncHI type plasmids. A truncated Tn125 containing blaNDM-1 was bracketed by an ISSm-1-like insertion sequence upstream and by a site-specific integrase downstream. To the best of our knowledge, we have, for the first time identified and molecularly characterised an NDM-1-producing Enterobacteriaceae strain in Ghana with blaNDM-1 that had a novel genetic structure. Our findings indicate a possibility of NDM-1 dissemination in Ghana and underscore the need for constant monitoring of carbapenemase-producing bacteria.

Trypanosomiasis, leishmaniasis, and malaria are protozoan infections of public health importance with thousands of new cases recorded annually. Control of these infection(s) with existing chemotherapy is limited by drug toxicity, lengthy parenteral treatment, affordability, and/or the emergence of resistant strains. Medicinal plants on the other hand are used in the treatment of various infectious diseases although their chemical properties are not fully evaluated. In this study, we screened 112 crude extracts from 72 selected Ghanaian medicinal plants for anti-Trypanosoma, anti-Leishmania, and anti-Plasmodium activities in vitro and investigated their mechanisms of action. Twenty-three extracts from 20 plants showed significant antiprotozoan activity against at least 1 of 3 protozoan parasites screened with IC

Leishmaniasis is an infectious disease transmitted by the sand fly. It is caused by over 20 different species of Leishmania and has affected over 14 million people worldwide. One of the main forms of control of leishmaniasis is chemotherapy, but this is limited by the high cost and/or toxicity of available drugs. We previously found three novel compounds with an iridoid tetracyclic skeleton to have activity against trypanosome parasites. In this study, we determined the activity of the three anti-trypanosome compounds against Leishmania using field strain, 010, and the lab strain Leishmania hertigi. The minimum inhibitory concentration (MIC) of the compounds against 010 was determined by microscopy while the IC50 of compounds against L. hertigi was determined by fluorescence-activated cell sorting with Guava viacount analysis. We found two of the three compounds, molucidin and ML-F52, to have anti-Leishmania activity against both strains. The fluor-microscope observation with DAPI stain revealed that both Molucidin and ML-F52 induced abnormal parasites with two sets of nucleus and kinetoplast in a cell, suggesting that compounds might inhibit cytokinesis in Leishmania parasites. Molucidin and ML-F52 might be good lead compounds for the development of new anti-Leishmania chemotherapy.

African trypanosome species are causative agents for sleeping sickness in humans and nagana disease in cattle. Trypanosoma brucei can generate ATP via a reverse reaction with glycerol kinase (GK) when alternative oxidase (AOX) is inhibited; thus, GK is considered to be a crucial target for chemotherapy combined with AOX. However, the energy metabolism systems of African trypanosome species other than T. brucei are poorly understood. Thus, GK genes were surveyed from genome databases and cloned by PCR from T. vivax and T. congolense. Then, recombinant GK proteins (rGK) of T. vivax, T. congolense and T. brucei were expressed and purified. Kinetic analysis of these rGK proteins revealed that the K(m) values of T. congolense rGK for ADP and G-3-P substrates were lower than those of T. vivax and T. brucei. The expression level of GK molecules was highest in T. congolense cells and lowest in T. vivax cells. Based on these results, effective combination dosages of ascofuranone, a specific inhibitor of AOX, and glycerol, an inhibitor of the GK reverse reaction, were determined by using in vitro-cultured trypanosome cells.

Transdifferentiation of the multipotent atrial epithelium is a key event during budding of the ascidian Polyandrocarpa misakiensis. The transdifferentiation is induced by mesenchyme cells that were stimulated by retinoic acid. The fluorescent differential display identified a few cDNA fragments for retinoic acid-inducible genes. One of the cDNA clones, named Pm-GnRHR, encoded a seven-pass transmembrane receptor similar to gonadotropin-releasing hormone receptors. Putative amino acid sequence showed high similarity to Ciona intestinalis GnRHRs and formed a cluster with other GnRHR proteins in a phylogenetic tree. The level of expression of the Pm-GnRHR mRNA increased during the early stage of bud development, suggesting that the Pm-GnRHR function is involved in some aspects of bud development.

In the developing bud of die ascidian Polyandrocarpa misakiensis, many types of tissues are formed through transdifferentiation of the multipotent atrial epithelium. Several lines of evidence suggest that retinoic acid be involved in this process. We isolated cDNA clones encoding a retinoic acid receptor and retinoid X receptor from P. misakiensis. These homologs form a complex to bind to specific DNA sequences and function as retinoic acid-dependent transcriptional activators. Retinoic acid target genes were also identified. One of the cDNA clones encodes a modular protein containing a serine protease catalytic domain in the C-terminal region and several distinct protein-protein interaction domains in the N-terminal region. This protein is thus named tunicate retinoic acid-inducible modular protease (TRAMP). A recombinant TRAMP catalytic domain promoted proliferation of a cell line established from the atrial epithelium. These results suggest that TRAMP play a role in inducing dedifferentiation and/or stimulating the cell cycle.

Retinoic acid is thought to induce transdifferentiation of multipotent epithelial stem cells in the developing buds of the ascidian Polyandrocarpa misakiensis. We isolated a cDNA clone from this species, named PmRAR, encoding a retinoic acid receptor (RAR) homologue. PmRAR clusters with other RARs on phylogenetic trees constructed by three different methods. Within the cluster, PmRAR is on a separate branch from all the subtypes of RARs, suggesting that RAR subtypes arose in the ancestral vertebrates after divergence of vertebrates and urochordates. The embryos of another ascidian species Ciona intestinalis were co-electroporated with a mixture of a PmRAR expression vector and a lacZ reporter plasmid containing vertebrate-type retinoic acid response elements. The expression of lacZ depended on the presence of both retinoic acid and PmRAR, suggesting that PmRAR is a functional receptor. PmRAR mRNA is expressed in the epidermis and mesenchyme cells of the Polyandrocarpa developing bud. The mRNA is not detectable in the mesenchyme cells in the adult body wall, but its expression can be induced by retinoic acid in vitro. These results suggest that the PmRAR is a mediator of retinoic acid signalling in transdifferentiation during asexual reproduction of protochordates.

Retinoic acid-treated mesenchyme cells of the budding ascidian Polyandrocarpa misakiensis acquire an organizer activity to induce a secondary body axis when implanted into developing buds. We identified several different mRNAs that were upregulated in the mesenchyme cells after retinoic acid treatment. We isolated a cDNA clone corresponding to one of these mRNAs. The C-terminal region of the predicted protein product is homologous to the catalytic domain of serine proteases that belong to the trypsin family. The N-terminal region contains several types of protein–protein interaction domains. We therefore named this protein tunicate retinoic acid-inducible modular protease (TRAMP). Expression of the TRAMP mRNA in mesenchyme cells during budding and its upregulation by retinoic acid were demonstrated by reverse transcription-PCR and in situ hybridization. A glutathione S -transferase–TRAMP fusion protein showed a protease activity with trypsin-like substrate specificity and stimulated proliferation of the cell line established in this species.