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Sample records for praomys mastomys natalensis

  1. Mastomys natalensis and Lassa fever, West Africa.

    PubMed

    Lecompte, Emilie; Fichet-Calvet, Elisabeth; Daffis, Stéphane; Koulémou, Kékoura; Sylla, Oumar; Kourouma, Fodé; Doré, Amadou; Soropogui, Barré; Aniskin, Vladimir; Allali, Bernard; Kouassi Kan, Stéphane; Lalis, Aude; Koivogui, Lamine; Günther, Stephan; Denys, Christiane; ter Meulen, Jan

    2006-12-01

    PCR screening of 1,482 murid rodents from 13 genera caught in 18 different localities of Guinea, West Africa, showed Lassa virus infection only in molecularly typed Mastomys natalensis. Distribution of this rodent and relative abundance compared with M. erythroleucus correlates geographically with Lassa virus seroprevalence in humans.

  2. Arenavirus Diversity and Phylogeography of Mastomys natalensis Rodents, Nigeria

    PubMed Central

    Obadare, Adeoba; Oyeyiola, Akinlabi; Igbokwe, Joseph; Fasogbon, Ayobami; Igbahenah, Felix; Ortsega, Daniel; Asogun, Danny; Umeh, Prince; Vakkai, Innocent; Abejegah, Chukwuyem; Pahlman, Meike; Becker-Ziaja, Beate; Günther, Stephan; Fichet-Calvet, Elisabeth

    2016-01-01

    Mastomys natalensis rodents are natural hosts for Lassa virus (LASV). Detection of LASV in 2 mitochondrial phylogroups of the rodent near the Niger and Benue Rivers in Nigeria underlines the potential for LASV emergence in fresh phylogroups of this rodent. A Mobala-like sequence was also detected in eastern Nigeria. PMID:26982388

  3. Arenavirus Diversity and Phylogeography of Mastomys natalensis Rodents, Nigeria.

    PubMed

    Olayemi, Ayodeji; Obadare, Adeoba; Oyeyiola, Akinlabi; Igbokwe, Joseph; Fasogbon, Ayobami; Igbahenah, Felix; Ortsega, Daniel; Asogun, Danny; Umeh, Prince; Vakkai, Innocent; Abejegah, Chukwuyem; Pahlman, Meike; Becker-Ziaja, Beate; Günther, Stephan; Fichet-Calvet, Elisabeth

    2016-04-01

    Mastomys natalensis rodents are natural hosts for Lassa virus (LASV). Detection of LASV in 2 mitochondrial phylogroups of the rodent near the Niger and Benue Rivers in Nigeria underlines the potential for LASV emergence in fresh phylogroups of this rodent. A Mobala-like sequence was also detected in eastern Nigeria.

  4. Gairo virus, a novel arenavirus of the widespread Mastomys natalensis: Genetically divergent, but ecologically similar to Lassa and Morogoro viruses.

    PubMed

    Gryseels, Sophie; Rieger, Toni; Oestereich, Lisa; Cuypers, Bart; Borremans, Benny; Makundi, Rhodes; Leirs, Herwig; Günther, Stephan; Goüy de Bellocq, Joëlle

    2015-02-01

    Despite its near pan-African range, the Natal multimammate mouse, Mastomys natalensis, carries the human pathogen Lassa virus only in West Africa, while the seemingly non-pathogenic arenaviruses Mopeia, Morogoro, and Luna have been detected in this semi-commensal rodent in Mozambique/Zimbabwe, Tanzania and Zambia, respectively. Here, we describe a novel arenavirus in M. natalensis from Gairo district of central Tanzania, for which we propose the name "Gairo virus". Surprisingly, the virus is not closely related with Morogoro virus that infects M. natalensis only 90km south of Gairo, but clusters phylogenetically with Mobala-like viruses that infect non-M. natalensis host species in Central African Republic and Ethiopia. Despite the evolutionary distance, Gairo virus shares basic ecological features with the other M. natalensis-borne viruses Lassa and Morogoro. Our data show that M. natalensis, carrying distantly related viruses even in the same geographical area, is a potent reservoir host for a variety of arenaviruses.

  5. Fluctuation of abundance and Lassa virus prevalence in Mastomys natalensis in Guinea, West Africa.

    PubMed

    Fichet-Calvet, Elisabeth; Lecompte, Emilie; Koivogui, Lamine; Soropogui, Barré; Doré, Amadou; Kourouma, Fodé; Sylla, Oumar; Daffis, Stéphane; Koulémou, Kékoura; Ter Meulen, Jan

    2007-01-01

    Based on empiric surveillance data, the incidence of human Lassa fever (LF) cases in Guinea and other West African countries has been reported to increase during the dry season compared to the rainy season. To investigate possible links with the ecology of the rodent reservoir of the virus, we conducted a 2-year longitudinal survey of Mastomys natalensis in a region of high human Lassa virus (LASV) seropositivity in Guinea. Standardized rodent trapping with similar trapping efforts between seasons was performed in three villages and 53.5% (601/1123) of the animals were identified as M. natalensis using morphometric and molecular criteria. Mean trapping success (TS) of M. natalensis was always higher inside houses than in proximal cultivations. In the dry season, mean TS increased 2-fold inside houses and decreased up to 10-fold outside (p < 0.0001), suggesting aggregation of rodents inside houses due to restricted food supply. 14.5% (80/553) of M. natalensis were tested positive for Lassa virus by reverse transcription-polymerase chain reaction (RT-PCR; range, 5%-30%) and prevalence of the virus was two to three times higher in rodents captured in the rainy season than in the dry season (p < 0.05). Inside houses, however, the LASV prevalence fluctuated nonsignificantly with season. These data suggest that in Guinea the risk of LASV transmission from rodents to humans is present both in the rainy and the dry season, reflected by the occurrence of LF cases throughout the year. In the dry season, however, the increased risk of humans encountering Mastomys and their excreta inside of houses may result in an increase of human Lassa fever cases.

  6. Polymorphism in vkorc1 Gene of Natal Multimammate Mice, Mastomys natalensis, in Tanzania.

    PubMed

    Gryseels, Sophie; Leirs, Herwig; Makundi, Rhodes; Goüy de Bellocq, Joëlle

    2015-01-01

    Resistance of rodents to anticoagulant rodenticides has emerged in several areas across the world. Single nucleotide mutations in the vkorc1 gene have been shown to elicit various levels of anticoagulant resistance, and these mutations are prevalent in several Rattus and Mus musculus populations. In sub-Saharan Africa, the Natal multimammate mouse, Mastomys natalensis, is one of the most damaging pests to crops, and anticoagulant poisons such as bromadiolone are frequently used to control these rodents in agricultural fields. Here, we investigate if vkorc1 shows any polymorphism in natural populations of M. natalensis. We sequenced the third exon of vkorc1 of 162 M. natalensis captured from 14 different agricultural sites in Morogoro Region, Tanzania. In addition to 6 SNPs in the noncoding flanking region, we detected 3 nonsynonymous SNPs in this exon: 10 animals (6.2%) carried a Leu108Val variant, 2 animals (1.2%) an Ala140Thr variant, and 1 animal (0.6 %) an Arg100His variant, all 3 in heterozygous form. Ala140Thr is just one residue from a mutation known to be involved in anticoagulant resistance in Rattus and Mus. While in vitro or in vivo experiments are needed to link vkorc1 genetic polymorphisms to level of VKOR activity and anticoagulant susceptibility, our results suggest that M. natalensis individuals may vary in their response to anticoagulant rodenticides. This is the first vkorc1 sequence data from a species outside the Rattus or Mus genera, and for the first time from a rodent species endemic to Africa.

  7. Reproductive characteristics of Mastomys natalensis and Lassa virus prevalence in Guinea, West Africa.

    PubMed

    Fichet-Calvet, Elisabeth; Lecompte, Emilie; Koivogui, Lamine; Daffis, Stéphane; ter Meulen, Jan

    2008-01-01

    We recently reported increased prevalence of Lassa virus (LASV) infection in Mastomys natalensis during the rainy season in Guinea, West Africa. Here, the association of LASV prevalence with fecundity, fertility, and the age structure of the rodent population was analyzed using data from the previous study. The animals reproduced throughout the year, but highest fecundity was observed during the rainy season. Accordingly, the rodent population was aged at the beginning and young at the end of the rainy season. Lassa virus infection was observed in all age groups, including the very young, which is compatible with vertical transmission. However, since the prevalence of infection showed a trend with increasing age in the younger age groups, horizontal transmission by yet unknown mechanisms may also play a role in LASV transmission. Multivariate analysis did not show an association of LASV prevalence with any demographic variable studied. Rodent behavior influencing virus transmissibility and contaminated environment may therefore be responsible for spatial and seasonal variations in LASV prevalence in M. natalensis.

  8. Density thresholds for Mopeia virus invasion and persistence in its host Mastomys natalensis.

    PubMed

    Goyens, J; Reijniers, J; Borremans, B; Leirs, H

    2013-01-21

    Well-established theoretical models predict host density thresholds for invasion and persistence of parasites with a density-dependent transmission. Studying such thresholds in reality, however, is not obvious because it requires long-term data for several fluctuating populations of different size. We developed a spatially explicit and individual-based SEIR model of Mopeia virus in multimammate mice Mastomys natalensis. This is an interesting model system for studying abundance thresholds because the host is the most common African rodent, populations fluctuate considerably and the virus is closely related to Lassa virus but non-pathogenic to humans so can be studied safely in the field. The simulations show that, while host density clearly is important, sharp thresholds are only to be expected for persistence (and not for invasion), since at short time-spans (as during invasion), stochasticity is determining. Besides host density, also the spatial extent of the host population is important. We observe the repeated local occurrence of herd immunity, leading to a decrease in transmission of the virus, while even a limited amount of dispersal can have a strong influence in spreading and re-igniting the transmission. The model is most sensitive to the duration of the infectious stage, the size of the home range and the transmission coefficient, so these are important factors to determine experimentally in the future.

  9. Shedding dynamics of Morogoro virus, an African arenavirus closely related to Lassa virus, in its natural reservoir host Mastomys natalensis.

    PubMed

    Borremans, Benny; Vossen, Raphaël; Becker-Ziaja, Beate; Gryseels, Sophie; Hughes, Nelika; Van Gestel, Mats; Van Houtte, Natalie; Günther, Stephan; Leirs, Herwig

    2015-05-29

    Arenaviruses can cause mild to severe hemorrhagic fevers. Humans mainly get infected through contact with infected rodents or their excretions, yet little is known about transmission dynamics within rodent populations. Morogoro virus (MORV) is an Old World arenavirus closely related to Lassa virus with which it shares the same host species Mastomys natalensis. We injected MORV in its host, and sampled blood and excretions at frequent intervals. Infection in adults was acute; viral RNA disappeared from blood after 18 days post infection (dpi) and from excretions after 39 dpi. Antibodies were present from 7 dpi and never disappeared. Neonatally infected animals acquired a chronic infection with RNA and antibodies in blood for at least 3 months. The quantified excretion and antibody patterns can be used to inform mathematical transmission models, and are essential for understanding and controlling transmission in the natural rodent host populations.

  10. Shedding dynamics of Morogoro virus, an African arenavirus closely related to Lassa virus, in its natural reservoir host Mastomys natalensis

    PubMed Central

    Borremans, Benny; Vossen, Raphaël; Becker-Ziaja, Beate; Gryseels, Sophie; Hughes, Nelika; Van Gestel, Mats; Van Houtte, Natalie; Günther, Stephan; Leirs, Herwig

    2015-01-01

    Arenaviruses can cause mild to severe hemorrhagic fevers. Humans mainly get infected through contact with infected rodents or their excretions, yet little is known about transmission dynamics within rodent populations. Morogoro virus (MORV) is an Old World arenavirus closely related to Lassa virus with which it shares the same host species Mastomys natalensis. We injected MORV in its host, and sampled blood and excretions at frequent intervals. Infection in adults was acute; viral RNA disappeared from blood after 18 days post infection (dpi) and from excretions after 39 dpi. Antibodies were present from 7 dpi and never disappeared. Neonatally infected animals acquired a chronic infection with RNA and antibodies in blood for at least 3 months. The quantified excretion and antibody patterns can be used to inform mathematical transmission models, and are essential for understanding and controlling transmission in the natural rodent host populations. PMID:26022445

  11. The Impact of Human Conflict on the Genetics of Mastomys natalensis and Lassa Virus in West Africa

    PubMed Central

    Denys, Christiane; ter Meulen, Jan; Wirth, Thierry

    2012-01-01

    Environmental changes have been shown to play an important role in the emergence of new human diseases of zoonotic origin. The contribution of social factors to their spread, especially conflicts followed by mass movement of populations, has not been extensively investigated. Here we reveal the effects of civil war on the phylogeography of a zoonotic emerging infectious disease by concomitantly studying the population structure, evolution and demography of Lassa virus and its natural reservoir, the rodent Mastomys natalensis, in Guinea, West Africa. Analysis of nucleoprotein gene sequences enabled us to reconstruct the evolutionary history of Lassa virus, which appeared 750 to 900 years ago in Nigeria and only recently spread across western Africa (170 years ago). Bayesian demographic inferences revealed that both the host and the virus populations have gone recently through severe genetic bottlenecks. The timing of these events matches civil war-related mass movements of refugees and accompanying environmental degradation. Forest and habitat destruction and human predation of the natural reservoir are likely explanations for the sharp decline observed in the rodent populations, the consequent virus population decline, and the coincident increased incidence of Lassa fever in these regions. Interestingly, we were also able to detect a similar pattern in Nigeria coinciding with the Biafra war. Our findings show that anthropogenic factors may profoundly impact the population genetics of a virus and its reservoir within the context of an emerging infectious disease. PMID:22615894

  12. The impact of human conflict on the genetics of Mastomys natalensis and Lassa virus in West Africa.

    PubMed

    Lalis, Aude; Leblois, Raphaël; Lecompte, Emilie; Denys, Christiane; Ter Meulen, Jan; Wirth, Thierry

    2012-01-01

    Environmental changes have been shown to play an important role in the emergence of new human diseases of zoonotic origin. The contribution of social factors to their spread, especially conflicts followed by mass movement of populations, has not been extensively investigated. Here we reveal the effects of civil war on the phylogeography of a zoonotic emerging infectious disease by concomitantly studying the population structure, evolution and demography of Lassa virus and its natural reservoir, the rodent Mastomys natalensis, in Guinea, West Africa. Analysis of nucleoprotein gene sequences enabled us to reconstruct the evolutionary history of Lassa virus, which appeared 750 to 900 years ago in Nigeria and only recently spread across western Africa (170 years ago). Bayesian demographic inferences revealed that both the host and the virus populations have gone recently through severe genetic bottlenecks. The timing of these events matches civil war-related mass movements of refugees and accompanying environmental degradation. Forest and habitat destruction and human predation of the natural reservoir are likely explanations for the sharp decline observed in the rodent populations, the consequent virus population decline, and the coincident increased incidence of Lassa fever in these regions. Interestingly, we were also able to detect a similar pattern in Nigeria coinciding with the Biafra war. Our findings show that anthropogenic factors may profoundly impact the population genetics of a virus and its reservoir within the context of an emerging infectious disease.

  13. The role of endogenous gastrin in the development of enterochromaffin-like cell carcinoid tumors in Mastomys natalensis: a study with the specific gastrin receptor antagonist AG-041R.

    PubMed

    Chiba, T; Kinoshita, Y; Sawada, M; Kishi, K; Baba, A; Hoshino, E

    1998-01-01

    We examined the effects of a newly synthesized gastrin receptor antagonist, AG-041R, on the growth of enterochromaffin-like (ECL) carcinoid tumors in Mastomys natalensis both in vitro and in vivo. AG-041R was as potent as the well known gastrin antagonist L365,260 in inhibiting not only the gastrin-induced release of histamine from but also histidine decarboxylase (HDC) gene expression in the ECL carcinoid tumor cells. AG-041R also inhibited gastrin-induced DNA synthesis and c-fos gene expression in the tumor cells. Furthermore, AG-041R significantly inhibited the growth of the transplanted Mastomys ECL carcinoid tumors in vivo. From these data, it is concluded that endogenous gastrin is involved in the growth of ECL carcinoid tumors in Mastomys natalensis. Moreover, AG-041R is shown to have a potential as an anti-neoplastic agent for ECL carcinoid tumor of the stomach.

  14. The role of endogenous gastrin in the development of enterochromaffin-like cell carcinoid tumors in Mastomys natalensis: a study with the specific gastrin receptor antagonist AG-041R.

    PubMed Central

    Chiba, T.; Kinoshita, Y.; Sawada, M.; Kishi, K.; Baba, A.; Hoshino, E.

    1998-01-01

    We examined the effects of a newly synthesized gastrin receptor antagonist, AG-041R, on the growth of enterochromaffin-like (ECL) carcinoid tumors in Mastomys natalensis both in vitro and in vivo. AG-041R was as potent as the well known gastrin antagonist L365,260 in inhibiting not only the gastrin-induced release of histamine from but also histidine decarboxylase (HDC) gene expression in the ECL carcinoid tumor cells. AG-041R also inhibited gastrin-induced DNA synthesis and c-fos gene expression in the tumor cells. Furthermore, AG-041R significantly inhibited the growth of the transplanted Mastomys ECL carcinoid tumors in vivo. From these data, it is concluded that endogenous gastrin is involved in the growth of ECL carcinoid tumors in Mastomys natalensis. Moreover, AG-041R is shown to have a potential as an anti-neoplastic agent for ECL carcinoid tumor of the stomach. Images Figure 1 Figure 5 Figure 6 PMID:10461356

  15. The susceptibility of rodents to schistosome infection, with special reference to Schistosoma haematobium.

    PubMed

    Gear, J H; Davis, D H; Pitchford, R J

    1966-01-01

    In this investigation the susceptibility of several species of rodents-Praomys (Mastomys) natalensis, Saccostomus campestris, Arvicanthus niloticus, Aethomys chrysophilus, Tatera brantsi and the white mouse (SAIMR 200 strain)-to Schistosoma haematobium was determined and the pathology studied. From the results it is clear that these rodents are susceptible to infection with Schistosoma haematobium. For various reasons, notably adaptability to laboratory conditions, the most suitable as laboratory animals for the study of bilharziasis are Saccostomus campestris, Arvicanthus niloticus and Praomys (Mastomys) natalensis. These three species breed readily in the laboratory and show a high susceptibility to S. haematobium, with characteristic lesions involving several organs, including the lungs, liver, spleen, pancreas and intestine.

  16. Rodent host cell/Lassa virus interactions: evolution and expression of α-Dystroglycan, LARGE-1 and LARGE-2 genes, with special emphasis on the Mastomys genus.

    PubMed

    Tayeh, Ashraf; Tatard, Caroline; Kako-Ouraga, Sandrine; Duplantier, Jean-Marc; Dobigny, Gauthier

    2010-12-01

    Arenaviruses are usually rodent-borne viruses that constitute a major threat for human health. Among them, Lassa Fever Virus (LFV) occurs in Western Africa where it infects hundreds of thousands of people annually. According to the most recent surveys, LFV is hosted by one of the multimammate rats, Mastomys natalensis, but has never been detected in its sibling and sometimes sympatric species Mastomys erythroleucus. This pattern suggests that intrinsic, i.e. genetic properties underlie such a drastic epidemiological difference (M. natalensis as a reservoir vs. M. erythroleucus as a non-reservoir species). Here we investigate genomic differences between these two closely related rodent species by focusing on three genes that have recently been described as pivotal for LFV/human cell interactions: Dystroglycan (the LFV cellular receptor), LARGE-1 and LARGE-2 (two enzymes that are essential to Dystroglycan functioning). For all three genes, sequence analyses showed that amino-acid chains undergo extremely strong purifying selective pressures, and indicated that no nucleotide (therefore no tertiary structure) change can be advocated to explain species-specific differences in LFV-cellular mediation. Nevertheless, preliminary studies of kidney-specific expression profiles suggested that important species-specific differences exist between Mastomys species. Taking into account current knowledge about LFV-human cell interactions, our results may point towards a possible role for LARGE-1 and LARGE-2 enzymes at the intracellular replication level of the virus, rather than at the LFV-host cell receptor binding step.

  17. The susceptibility of rodents to schistosome infection, with special reference to Schistosoma haematobium

    PubMed Central

    Gear, J. H. S.; Davis, D. H. S.; Pitchford, R. J.

    1966-01-01

    In this investigation the susceptibility of several species of rodents—Praomys (Mastomys) natalensis, Saccostomus campestris, Arvicanthus niloticus, Aethomys chrysophilus, Tatera brantsi and the white mouse (SAIMR 200 strain)—to Schistosoma haematobium was determined and the pathology studied. From the results it is clear that these rodents are susceptible to infection with Schistosoma haematobium. For various reasons, notably adaptability to laboratory conditions, the most suitable as laboratory animals for the study of bilharziasis are Saccostomus campestris, Arvicanthus niloticus and Praomys (Mastomys) natalensis. These three species breed readily in the laboratory and show a high susceptibility to S. haematobium, with characteristic lesions involving several organs, including the lungs, liver, spleen, pancreas and intestine. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5FIG. 6FIG. 7FIG. 8FIG. 9FIG. 10FIG. 16FIG. 17FIG. 18FIG. 19FIG. 20FIG. 11FIG. 12FIG. 13FIG. 14FIG. 15 PMID:5297005

  18. Lassa serology in natural populations of rodents and horizontal transmission.

    PubMed

    Fichet-Calvet, Elisabeth; Becker-Ziaja, Beate; Koivogui, Lamine; Günther, Stephan

    2014-09-01

    Lassa virus causes hemorrhagic fever in West Africa. Previously, we demonstrated by PCR screening that only the multimammate mouse, Mastomys natalensis, hosts Lassa virus in Guinea. In the present study, we used the same specimen collection from 17 villages in Coastal, Upper, and Forest Guinea to investigate the Lassa virus serology in the rodent population. The aim was to determine the dynamics of antibody development in M. natalensis and to detect potential spillover infections in other rodent species. Immunoglobulin G (IgG) antibody screening was performed using the indirect immunofluorescence assay with the Guinean Lassa virus strain Bantou 289 as antigen. The overall seroprevalence was 8% (129/1551) with the following rodents testing positive: 109 M. natalensis, seven Mastomys erythroleucus, four Lemniscomys striatus, four Praomys daltoni, three Mus minutoides, and two Praomys rostratus. Nearly all of them (122/129) originated from Bantou, Tanganya, and Gbetaya, where Lassa virus is highly endemic in M. natalensis. The antibody seroprevalence in M. natalensis from this high-endemic area (27%; 108/396) depended on the village, habitat, host age, and host abundance. A main positive factor was age; the maximum seroprevalence reached 50% in older animals. Our data fit with a model implicating that most M. natalensis rodents become horizontally infected, clear the virus within a period significantly shorter than their life span, and develop antibodies. In addition, the detection of antibodies in other species trapped in the habitats of M. natalensis suggests spillover infections.

  19. Mastomys (rodentia: muridae) species distinguished by hemoglobin pattern differences.

    PubMed

    Robbins, C B; Krebs, J W; Johnson, K M

    1983-05-01

    Hemoglobin electrophoresis patterns were found to be reliable markers for distinguishing two species of Mastomys in Sierra Leone having 32 and 38 chromosomes. All 32-chromosome animals exhibited a single hemoglobin pattern, whereas those with 38-chromosomes had four distinguishable patterns. Both karyotypes were present throughout Sierra Leone. The 38-chromosome species was more prevalent in the Guinea savanna zone to the north, while the 32-chromosome species was most dominant in human-modified high forest areas of the eastern and southern parts of the country. In almost all situations the 32-chromosome species was more common in houses than in bush habitats; the reverse was true for Mastomys having 38 chromosomes. Analysis of hemoglobin patterns thus becomes useful for species identification, and is necessary to understand the roles of the different Mastomys forms as reservoirs of human diseases, such as Lassa fever in West Africa.

  20. Pterygodermatites (Mesopectines) quentini (Nematoda, Rictulariidae), a parasite of Praomys rostratus (Rodentia, Muridae) in Mali: scanning electron and light microscopy.

    PubMed

    Diouf, Malick; Quilichini, Yann; Granjon, Laurent; Bâ, Cheikh Tidiane; Marchand, Bernard

    2013-01-01

    Pterygodermatites (Mesopectines) quentini n. sp. (Nematoda, Rictulariidae) is described from the murine host Praomys rostratus in the south of the Republic of Mali. It differs from other species of the subgenus by the morphology of the head, which bears four simple cephalic papillae and a nearly axial oral opening, the number of caudal papillae, the number of precloacal cuticular formations, unequal spicules and the ratio of spicule lengths/body length. The use of scanning electron microscopy in combination with conventional light microscopy enabled us to give a detailed description of the morphological characters of this new species.

  1. Furoquinoline alkaloids from the southern African Rutaceae Teclea natalensis.

    PubMed

    Tarus, Paul K; Coombes, Philip H; Crouch, Neil R; Mulholland, Dulcie A; Moodley, B

    2005-03-01

    The chloroform and ethyl acetate extracts of the leaves of Teclea natalensis have yielded two furoquinoline alkaloids, 6-[(2,3-epoxy-3-methylbutyl)oxy]-4,7-dimethoxyfuro[2,3-b]quinoline and 4,7-dimethoxy-6-[(3-methyl-2-butenyl)oxy]furo[2,3-b]quinoline, and the known alkaloids 4,7-dimethoxy-8-[(3-methyl-2-butenyl)oxy]furo[2,3-b]quinoline, flindersiamine and dictamnine.

  2. Antimicrobial activity of the solvent fractions from Bulbine natalensis Tuber.

    PubMed

    Yakubu, M T; Mostafa, M; Ashafa, A O T; Afolayan, A J

    2012-01-01

    Bulbine natalensis Baker has been acclaimed to be used as an antimicrobial agent in the folklore medicine of South Africa without scientific evidence to substantiate or refute this claim. In view of this, the in vitro antimicrobial activity of solvent fractions (ethanol, ethyl acetate, n-butanol and water) from Bulbine natalensis Tuber against 4 Gram positive and 12 Gram negative bacteria as well as 3 fungal species were investigated using agar dilution. The ethanolic extract, n-butanol and ethyl acetate fractions inhibited 75, 87.5 and 100% respectively of the bacterial species in this study. The ethanolic, n-butanol and ethyl acetate fractions produced growth inhibition at MIC range of 1-10, 3-10 as well as 1 and 5 mg/ml respectively whereas the water fraction did not inhibit the growth of any of the bacterial species. Again, it was only the ethyl acetate fraction that inhibited the growth of Shigelli flexneri, Staphyloccus aureus and Escherichia coli. The ethanolic, ethyl acetate and n-butanolic fractions dose dependently inhibited the growth of Aspergillus niger and A. flavus whereas the water fraction produced 100% growth inhibition of the Aspergillus species at all the doses investigated. In contrast, no growth inhibition was produced on Candida albicans. The growth inhibition produced by the solvent fractions of B. natalensis Tuber in this study thus justifies the acclaimed use of the plant as an antimicrobial agent. The ethyl acetate fraction was the most potent.

  3. Directional vibration sensing in the termite Macrotermes natalensis.

    PubMed

    Hager, Felix A; Kirchner, Wolfgang H

    2014-07-15

    Although several behavioural studies demonstrate the ability of insects to localise the source of vibrations, it is still unclear how insects are able to perceive directional information from vibratory signals on solid substrates, because time-of-arrival and amplitude difference between receptory structures are thought to be too small to be processed by insect nervous systems. The termite Macrotermes natalensis communicates using vibrational drumming signals transmitted along subterranean galleries. When soldiers are attacked by predators, they tend to drum with their heads against the substrate and create a pulsed vibration. Workers respond by a fast retreat into the nest. Soldiers in the vicinity start to drum themselves, leading to an amplification and propagation of the signal. Here we show that M. natalensis makes use of a directional vibration sensing in the context of colony defence. In the field, soldiers are recruited towards the source of the signal. In arena experiments on natural nest material, soldiers are able to localise the source of vibration. Using two movable platforms allowing us to vibrate the legs of the left and right sides of the body with a time delay, we show that the difference in time-of-arrival is the directional cue used for orientation. Delays as short as 0.2 ms are sufficient to be detected. Soldiers show a significant positive tropotaxis to the platform stimulated earlier, demonstrating for the first time perception of time-of-arrival delays and vibrotropotaxis on solid substrates in insects.

  4. Ultrastructure of ECL cells in Mastomys after long-term treatment with H2 receptor antagonist loxtidine.

    PubMed

    Vigen, Reidar Alexander; Kidd, Mark; Modlin, Irvin M; Chen, Duan; Zhao, Chun-Mei

    2012-06-01

    Gastric ECL-cell hyperplasia and carcinoids (ECLoma) develop after 1 year in rats treated with omeprazole or 2 months in Mastomys treated with loxtidine. The aim of this study was to examine the ultrastructure of ECL cells in Mastomys after loxtidine treatment with an attempt to evaluate whether an impairment of autophagy was involved in the tumorigenesis. Mastomys were given loxtidine for 8 or 27 weeks. Morphological analysis of ECL cells showed that (1) cell size was not increased after 8 or 27 weeks; (2) secretory vesicles, a hallmark feature of welldifferentiated ECL cells, were unchanged after 8 weeks but reduced after 27 weeks; (3) granules were reduced after 8 or 27 weeks; (4) microvesicles were unchanged after the treatment; and (5) vacuoles and lipofuscin bodies were found occasionally after 8 weeks but not at 27 weeks. In addition, the appearance of ECL-cell ultrastructure differed between loxtidine-treated Mastomys and rats treated with omeprazole or subjected to antrectomy, but was similar between Mastomys treated with loxtidine for 27 weeks and mice deficient in CCK(2) receptor. We suggest that the ultrastructure of ECL cells in Mastomys after long-term treatment with loxtidine displayed an impaired formation of vacuoles and lipofuscin bodies, markers of the autophagic pathway.

  5. Establishment of an Immortalized Skin Keratinocyte Cell Line Derived from the Animal Model Mastomys coucha

    PubMed Central

    Hasche, Daniel; Stephan, Sonja; Savelyeva, Larissa; Westermann, Frank; Rösl, Frank

    2016-01-01

    In the present report we describe the establishment of a spontaneous immortalized skin keratinocyte cell line derived from the skin of the multimammate rodent Mastomys coucha. These animals are used in preclinical studies for a variety of human diseases such as infections with nematodes, bacteria and papillomaviruses, especially regarding cutaneous manifestations such as non-melanoma skin cancer. Here we characterize the cells in terms of their origin and cytogenetic features. Searching for genomic signatures, a spontaneous mutation in the splicing donor sequence of Trp53 (G to A transition at the first position of intron 7) could be detected. This point mutation leads to alternative splicing and to a premature stop codon, resulting in a truncated and, in turn, undetectable form of p53, probably contributing to the process of immortalization. Mastomys coucha-derived skin keratinocytes can be used as an in vitro system to investigate molecular and immunological aspects of infectious agent interactions with their host cells. PMID:27533138

  6. Susceptibility of two-week old Lymnaea natalensis to some plant extracts.

    PubMed

    Kela, S L; Ogunsusi, R A; Ogbogu, V C; Nwude, N

    1989-01-01

    The molluscacidal potency of 17 Nigerian plants extracted by the unevaporated crude water (UECW) method was evaluated on two-week old Lymnaea natalensis Krauss. Five extracts were not active but extracts of Balanites aegytiaca, Blighia sapida, Boswellia dalzielii, Cissampelos mucronata, Detarium microcarpum, Kigelia africana, Opilia celtidifolia, Parkia clappertoniana, Polygonum limbatum, Pseudocedrela kotschyi, Nauclea latifolia and Securidaca longipedunculata were molluscacidal. There is potential for their future use in the integrated control of Lymnaea natalensis, as well as other snails. Mortality data for lethal concentration values for all extracts were analysed by use of probit transformation. The upper and lower fiducial limits of the LC50 (P = 0.05) were also determined.

  7. Demographic aspects of the island syndrome in two Afrotropical Mastomys rodent species

    NASA Astrophysics Data System (ADS)

    Crespin, Laurent; Duplantier, Jean-Marc; Granjon, Laurent

    2012-02-01

    The island syndrome is the name given to the particularities of the behavioural, morphological and demographical characteristics of island populations. As concerns demography, the island syndrome model states that densities and survival are greater in island than in mainland populations. Most previous studies aimed at confirming this prediction for small mammals have addressed species from the North Temperate Zone. Here, we tested the demographic expectations of the island syndrome using data gathered over two years for island and mainland populations of two African rodent species, Mastomys erytholeucus and Mastomys huberti, at two different sites in Senegal. Capture-Mark-Recapture methods allowing for variation in catchability of the individuals were used to yield estimates of both abundance (or density) and probability of survival and seniority (which is a demographic parameter inversely related to recruitment). As predicted from the island syndrome, survival and densities were indeed higher in island populations for the two study sites; however, only for the population with stronger island syndrome was the difference in survival biologically important. Estimates of the probability of seniority were similar for island and mainland populations at the two sites. Our findings provide support for the demographic expectations of the model of island syndrome in an Afrotropical context and thus confirm the general applicability of this syndrome while revealing differences according to particular insular situations.

  8. Reflecting optics in the diverticular eye of a deep-sea barreleye fish (Rhynchohyalus natalensis).

    PubMed

    Partridge, J C; Douglas, R H; Marshall, N J; Chung, W-S; Jordan, T M; Wagner, H-J

    2014-05-07

    We describe the bi-directed eyes of a mesopelagic teleost fish, Rhynchohyalus natalensis, that possesses an extensive lateral diverticulum to each tubular eye. Each diverticulum contains a mirror that focuses light from the ventro-lateral visual field. This species can thereby visualize both downwelling sunlight and bioluminescence over a wide field of view. Modelling shows that the mirror is very likely to be capable of producing a bright, well focused image. After Dolichopteryx longipes, this is only the second description of an eye in a vertebrate having both reflective and refractive optics. Although superficially similar, the optics of the diverticular eyes of these two species of fish differ in some important respects. Firstly, the reflective crystals in the D. longipes mirror are derived from a tapetum within the retinal pigment epithelium, whereas in R. natalensis they develop from the choroidal argentea. Secondly, in D. longipes the angle of the reflective crystals varies depending on their position within the mirror, forming a Fresnel-type reflector, but in R. natalensis the crystals are orientated almost parallel to the mirror's surface and image formation is dependent on the gross morphology of the diverticular mirror. Two remarkably different developmental solutions have thus evolved in these two closely related species of opisthoproctid teleosts to extend the restricted visual field of a tubular eye and provide a well-focused image with reflective optics.

  9. Pollinators, "mustard oil" volatiles, and fruit production in flowers of the dioecious tree Drypetes natalensis (Putranjivaceae).

    PubMed

    Johnson, Steven D; Griffiths, Megan E; Peter, Craig I; Lawes, Michael J

    2009-11-01

    The Putranjivaceae is an enigmatic family, notable for being the only lineage outside the Capparales to possess the glucosinolate biochemical pathway, which forms the basis of an induced chemical defense system against herbivores (the "mustard oil bomb"). We investigated the pollination biology and floral scent chemistry of Drypetes natalensis (Putranjivaceae), a dioecious subcanopy tree with flowers borne on the stem (cauliflory). Flowering male trees were more abundant than female ones and produced about 10-fold more flowers. Flowers of both sexes produce copious amounts of nectar on disc-like nectaries accessible to short-tongued insects. The main flower visitors observed were cetoniid beetles, bees, and vespid wasps. Pollen load analysis indicated that these insects exhibit a high degree of fidelity to D. natalensis flowers. Insects effectively transfer pollen from male to female plants resulting in about 31% of female flowers developing fruits with viable seeds. Cetoniid beetles showed significant orientation toward the scent of D. natalensis flowers in a Y-maze olfactometer. The scents of male and female flowers are similar in chemical composition and dominated by fatty acid derivatives and isothiocyanates from the glucosinolate pathway. The apparent constitutive emission of isothiocyanates raises interesting new questions about their functional role in flowers.

  10. Evaluation of an Experimental Gel Containing Euclea natalensis: An In Vitro Study

    PubMed Central

    Sales-Peres, Sílvia Helena de Carvalho; Brianezzi, Letícia Ferreira de Freitas; Marsicano, Juliane Avansini; Forim, Moacir Rossi; da Silva, Maria Fatima das Graças Fernandes; Sales-Peres, Arsenio

    2012-01-01

    Objective. To evaluate the effect of an experimental gel containing Euclea natalensis extract on dentin permeability. Methods. Thirty-six dentin discs, 1-mm-thick. The discs were prepared from the coronal dentin of extracted human third molars that were divided into 3 groups (n = 10). The dentin discs in each group were treated with the groups following experimental materials: (FG): 1.23% fluoride gel, pH 4.1; (EG): Euclea natalensis extract gel, pH 4.1; (CG): control gel, pH 4.1. The gels were applied to the occlusal slide of the dentin under the following conditions: after 37% phosphoric acid and before 6% citric acid. The hydraulic conductance (HC) of each condition was determined four times using a fluid flow apparatus (Flodec). The data were analyzed using Two-way ANOVA and Tukey's test (P < 0.05). Results. The greatest mean reduction in HC was produced in group EG dentin discs (61.2%; P < 0.05). Even after acid challenge with 6% citric acid the great reduction occurred in group EG (66.0%; P < 0.05) than other groups (CG-77.1%, FG-90.8%). Conclusion. E. natalensis gel not only reduced dentin permeability, but also resisted posttreatment citric acid challenge without changing its permeability. Further research has to confirm this promising result in the clinical situation. PMID:23243432

  11. Comparative toxicity of Paraquat herbicide and some plant extracts in Lymnaea natalensis snails.

    PubMed

    Bakry, Fayez A; Eleiwa, Mona E; Taha, Samir A; Ismil, Somya M

    2016-01-01

    Paraquat has been shown to be a highly toxic compound for humans and animals, and many cases of acute poisoning and death have been reported over the past few decades. The present study was undertaken to evaluate comprehensively herbicides (Paraquat) and some plant extracts to biochemical aspects of Lymnaea natalensis snails. It was found that the exposure of L. natalensis to Paraquat and plant extracts led to a significant reduction in the infectivity of Fasciola gigantica miracidia to the snail. The glucose level in hemolymph of exposed snails was elevated, while the glycogen showed a decrease in soft tissues when compared with the control group. In addition, the activity level of some enzymes representing glycolytic enzymes as hexokinase (HK), pyruvate kinase (PK), phosphofructokinase (PFK), lactate dehydrogenase (LDH), and glucose phosphate isomerase (GPI) in snail's tissues were reduced in response to the treatment. It was concluded that the pollution of the aquatic environment by herbicide would adversely affect the metabolism of the L. natalensis snails. Snails treated with Agave attenuate, Ammi visnaga, and Canna iridiflora plant had less toxic effect compared to snails treated with Paraquat.

  12. Influence of fungal elicitors on biosynthesis of natamycin by Streptomyces natalensis HW-2.

    PubMed

    Wang, Dahong; Yuan, Jiangfeng; Gu, Shaobin; Shi, Qiang

    2013-06-01

    To investigate the effect of fungal elicitors on biosynthesis of natamycin in the cultures of Streptomyces natalensis HW-2, the biomass and filtrate of the broth from Aspergillus niger AS 3.6472, Penicillium chrysogenum AS 3.5163, A. oryzae AS 3.2068, and Saccharomyces cerevisiae AS 2.2081 were used to induce natamycin production in S. natalensis HW-2. The results showed that the biomass of P. chrysogenum AS 3.5163 could enhance the yield of natamycin from 0.639 to 0.875 g l(-1). The elicitor from the fermentation broth of P. chrysogenum AS 3.5163 showed the highest inducing efficiency with the yield of natamycin enhanced from 0.632 to 1.84 g l(-1). The elicitor that was cultured for 2 days showed the strongest inducing activity during the fermentation of S. natalensis HW-2 for 24 h, and the yield of natamycin was enhanced from 0.637 to 2.12 g l(-1). The biochemical parameters were examined at the end of fermentation and the results demonstrated that both the growth of cells and the concentration of residual sugar could be influenced. The residual sugar decreased from 5.03 to 4.27 g l(-1), and the biomass decreased from 10.26 to 6.87 g l(-1). Finally, the elicitor was identified as a low molecular weight substance with a similar polarity to that of butyl alcohol by primary qualitative analysis.

  13. Erosion and abrasion-inhibiting in situ effect of the Euclea natalensis plant of African regions.

    PubMed

    Sales-Peres, Silvia Helena de Carvalho; Xavier, Cheila Nilza Hamina; Mapengo, Marta Artemisa Abel; Forim, Moacir Rossi; Silva, Maria de Fatima; Sales-Peres, Arsenio

    2016-06-14

    This study evaluated the effect of Euclea natalensis gel on the reduction of erosive wear with or without abrasion, in enamel and dentin. During two five-day experimental crossover phases, volunteers (n = 10) wore palatal devices containing human enamel and dentin blocks (E = 8 and D = 8). The gel was applied in a thin layer in the experimental group, and was not applied in the control group. In the intraoral phase, volunteers used the palatal appliance for 12 h before the gel treatment, and were instructed to start the erosive challenges 6 h after the gel application. Erosion was performed with Coca-Cola® (for 5 min) 4 times/day. The appliance was then put back into the mouth and was brushed after 30 minutes. After intraoral exposure, the appliances were removed and the specimens were analyzed using profilometry (mean ± SD, μm). The Euclea natalensis gel caused less wear in enamel in the experimental group (EROS = 12.86 ± 1.75 µm; EROS + ABRAS = 12.13 ± 2.12 µm) than in the control group (EROS = 14.12 ± 7.66 µm; EROS + ABRAS = 16.29 ± 10.72 µm); however, the groups did not differ from each other significantly. A statistically significant value was found for erosion and eros + abrasion in dentin (p = 0.001). Euclea natalensis may play a role in the prevention of dentin loss under mild erosive and abrasive conditions. A clinical trial is required to confirm these promising results in a clinical situation.

  14. Streptomyces natalensis programmed cell death and morphological differentiation are dependent on oxidative stress

    PubMed Central

    Beites, Tiago; Oliveira, Paulo; Rioseras, Beatriz; Pires, Sílvia D. S.; Oliveira, Rute; Tamagnini, Paula; Moradas-Ferreira, Pedro; Manteca, Ángel; Mendes, Marta V.

    2015-01-01

    Streptomyces are aerobic Gram-positive bacteria characterized by a complex life cycle that includes hyphae differentiation and spore formation. Morphological differentiation is triggered by stressful conditions and takes place in a pro-oxidant environment, which sets the basis for an involvement of the oxidative stress response in this cellular process. Characterization of the phenotypic traits of Streptomyces natalensis ΔkatA1 (mono-functional catalase) and ΔcatR (Fur-like repressor of katA1 expression) strains in solid medium revealed that both mutants had an impaired morphological development process. The sub-lethal oxidative stress caused by the absence of KatA1 resulted in the formation of a highly proliferative and undifferentiated vegetative mycelium, whereas de-repression of CatR regulon, from which KatA1 is the only known representative, resulted in the formation of scarce aerial mycelium. Both mutant strains had the transcription of genes associated with aerial mycelium formation and biosynthesis of the hyphae hydrophobic layer down-regulated. The first round of the programmed cell death (PCD) was inhibited in both strains which caused the prevalence of the transient primary mycelium (MI) over secondary mycelium (MII). Our data shows that the first round of PCD and morphological differentiation in S. natalensis is dependent on oxidative stress in the right amount at the right time. PMID:26256439

  15. Anabolic and androgenic activities of Bulbine natalensis stem in male Wistar rats.

    PubMed

    Yakubu, Musa T; Afolayan, Anthony J

    2010-05-01

    Aqueous extract of Bulbine natalensis Baker (Asphodelaceae) stem at 25, 50 and 100 mg/kg body weight was investigated for anabolic and androgenic effects in male Wistar rats. Sixty male rats were grouped into four (A-D) consisting of 15 each. Group A (control) was orally treated with 0.5 mL of distilled water for 14 days while groups B, C and D were treated like the control except they received 0.5 mL containing 25, 50, and 100 mg/kg body weight of the extract respectively. All the doses of the extract increased (P <0.05) the testicular-body weight ratio as well as alkaline phosphatase activity, glycogen, sialic acid, protein, and cholesterol content of the testes except the single administration of 100 mg/kg body weight which compared well (P>0.05) with the controls for glycogen and cholesterol. The testicular and serum testosterone concentration were increased except in the 100 mg/kg body weight where the effect on the tissue and serum hormone did not manifest until after the first and seven daily doses respectively. Testicular acid phosphatase activity, serum follicle stimulating and luteinizing hormone concentrations also increased at all the doses except in the 100 mg/kg body weight where the effect on the enzyme and the hormone did not manifest until after seven days. The increases were most pronounced in the 50 mg/kg body weight extract treated animals. The results indicate anabolic and androgenic activities of Bulbine natalensis stem in male rat testes with the 50 mg/kg body weight of the extract exhibiting the highest anabolizing and androgenic activities. These activities further support the folkloric use of the plant most especially at 50 mg/kg body weight in the management of male sexual dysfunction in South Africa.

  16. The fungus-growing termite Macrotermes natalensis harbors bacillaene-producing Bacillus sp. that inhibit potentially antagonistic fungi

    PubMed Central

    Um, Soohyun; Fraimout, Antoine; Sapountzis, Panagiotis; Oh, Dong-Chan; Poulsen, Michael

    2013-01-01

    The ancient fungus-growing termite (Mactrotermitinae) symbiosis involves the obligate association between a lineage of higher termites and basidiomycete Termitomyces cultivar fungi. Our investigation of the fungus-growing termite Macrotermes natalensis shows that Bacillus strains from M. natalensis colonies produce a single major antibiotic, bacillaene A (1), which selectively inhibits known and putatively antagonistic fungi of Termitomyces. Comparative analyses of the genomes of symbiotic Bacillus strains revealed that they are phylogenetically closely related to Bacillus subtilis, their genomes have high homology with more than 90% of ORFs being 100% identical, and the sequence identities across the biosynthetic gene cluster for bacillaene are higher between termite-associated strains than to the cluster previously reported in B. subtilis. Our findings suggest that this lineage of antibiotic-producing Bacillus may be a defensive symbiont involved in the protection of the fungus-growing termite cultivar. PMID:24248063

  17. Comparison of morphological characteristics of Streptomyces natalensis by image analysis and focused beam reflectance measurement.

    PubMed

    Pearson, Alan P; Glennon, Brian; Kieran, Patricia M

    2003-01-01

    A morphological interpretation is presented for data collected during growth of a filamentous organism, using a focused beam reflectance measurement (FBRM) system. The morphology of the organism was also obtained using conventional semiautomatic image analysis to support the interpretation of the FBRM data. The model organism employed is the filamentous soil-borne actinomycete Streptomyces natalensis, which produces the antifungal agent pimaricin. The organism was cultivated both in shake flasks and in a bench-scale stirred tank bioreactor. It was found that FBRM could be used to track changes in the morphology of the organism throughout the course of its growth on both scales. These changes were highlighted using both the median chord length and length-weighted mean chord length obtained from the chord length distribution measured with the FBRM probe. The ability of the FBRM probe to respond to changes in both the size and morphology of mycelial aggregates was supported by standard image analysis parameters, including equivalent diameter, convex area, and compactness.

  18. The CCK(2) receptor antagonist, YF476, inhibits Mastomys ECL cell hyperplasia and gastric carcinoid tumor development.

    PubMed

    Kidd, M; Siddique, Z-L; Drozdov, I; Gustafsson, B I; Camp, R L; Black, J W; Boyce, M; Modlin, I M

    2010-06-08

    YF476 is a potent and highly selective cholecystokin 2 (CCK(2)) receptor antagonist of the benzodiazepine class. It inhibits gastric neuroendocrine enterochromaffin-like (ECL) cell secretion, proliferation and spontaneous formation of gastric neuroendocrine tumors (carcinoids) in cotton rats. The Mastomys rodent species exhibits a genetic predisposition to gastric ECL neuroendocrine tumor formation which can be accelerated by acid suppression and induction of hypergastrinemia. In this respect, it mimics the human condition of atrophic gastritis, hypergastrinemia and gastric carcinoid development. We investigated whether YF476 could inhibit acid suppression-induced ECL cell hyperplasia and neoplasia in this model. In addition, we examined whether YF476 could reverse established ECL cell hyperplasia and neoplasia. Targeting the CCK(2) receptor during Loxtidine-induced hypergastrinemia resulted in a reduction in ECL cell secretion (plasma and mucosal histamine, and histidine decarboxylase (HDC) transcripts, p<0.05) and proliferation (numbers of HDC-positive cells, connective tissue growth factor (CTGF) and cyclin D1 transcription). This was associated with a decrease in ECL cell hyperplasia and a 60% reduction in gastric ECL cell microcarcinoid (tumors <0.3mm in size) formation. YF476 inhibited ECL cell neoplasia (gastric carcinoid) in animals with hyperplasia, inhibited the formation of ECL cell tumors when co-administered with Loxtidine and reversed the growth and developement of gastric ECL cell carcinoids in long-term acid suppressed Mastomys. Variable importance analysis using a logistic multinomial regression model indicated the effects of YF476 were specific to the ECL cell and alterations in ECL cell function reflected inhibition of transcripts for HDC, Chromogranin A (CgA), CCK(2) and the autocrine growth factor, CTGF. We conclude that specifically targeting the CCK(2) receptor inhibits gastrin-mediated ECL cell secretion and ECL cell proliferation and tumor

  19. Variable effects of host characteristics on species richness of flea infracommunities in rodents from three continents.

    PubMed

    Kiffner, Christian; Stanko, Michal; Morand, Serge; Khokhlova, Irina S; Shenbrot, Georgy I; Laudisoit, Anne; Leirs, Herwig; Hawlena, Hadas; Krasnov, Boris R

    2014-08-01

    We studied the effect of host gender and body mass on species richness of flea infracommunities in nine rodent host species from three biomes (temperate zone of central Europe, desert of the Middle East and the tropics of East Africa). Using season- and species-specific generalized linear mixed models and controlling for year-to-year variation, spatial clustering of rodent sampling and over-dispersion of the data, we found inconsistent associations between host characteristics and flea species richness. We found strong support for male-biased flea parasitism, especially during the reproductive period (higher species richness in male hosts than in females) in all considered European rodents (Apodemus agrarius, Myodes glareolus and Microtus arvalis) and in one rodent species from the Middle East (Dipodillus dasyurus). In contrast, two of three African rodent species (Lophuromys kilonzoi and Praomys delectorum) demonstrated a trend of female-biased flea species richness. Positive associations between body mass and the number of flea species were detected mainly in males (five of nine species: A. agrarius, M. glareolus, M. arvalis, D. dasyurus and Mastomys natalensis) and not in females (except for M. natalensis). The results of this study support earlier reports that gender-biased, in general, and male-biased, in particular, infestation by ectoparasites is not a universal rule. This suggests that mechanisms of parasite acquisition by an individual host are species-specific and have evolved independently in different rodent host-flea systems.

  20. Helicobacter pylori lipopolysaccharide alters ECL cell DNA synthesis via a CD14 receptor and polyamine pathway in mastomys.

    PubMed

    Kidd, M; Tang, L H; Schmid, S; Lauffer, J; Louw, J A; Modlin, I M

    2000-01-01

    Chronic Helicobacter pylori infection is associated with alterations in gastric mucosal cell proliferation. Despite the recognition that bacterial lipopolysaccharide (LPS) is present in biologically active quantities in the gastric mucosa, the mechanisms by which it stimulates cells are largely unknown. We have previously established a gastric enterochromaffin-like (ECL) cell neoplasia model in the African rodent species Mastomys and identified that tumor ECL cell proliferation is associated with polyamine biosynthesis and ornithine decarboxylase (ODC) activity. In addition, we have shown that H. pylori LPS exhibits a specific mitogenic effect on naive ECL cells in vitro. The aim of this study was to evaluate whether H. pylori has a direct effect on tumor ECL cell proliferation in vitro and further to evaluate the possible molecular mechanisms for this effect. ECL cell neoplasia was generated in Mastomys by endogenous hypergastrinemia induced by H(2) blockade (loxtidine 1 g/kg/day) and tumor ECL cells prepared. The DNA synthesis in 24-hour cultured tumor cells was measured by bromodeoxyuridine uptake and ODC activity by (14)CO(2) formation from (14)C-ornithine. The putative LPS receptor, CD14, was evaluated by reverse-transcription polymerase chain reaction. Our results demonstrated: (1) H. pylori LPS (10(-12) to 10(-7) M) stimulated basal DNA synthesis (2.2-fold) with an estimated EC(50) of 10(-10) M; (2) this proliferative response correlated with an increase in ODC activity (1.4-fold, EC(50) approximately 10(-10) M) which could be inhibited by a specific ODC inhibitor, difluoromethyl ornithine, at 10(-9) M; (3) the CD14 receptor was identified in both naive and transformed ECL cells by reverse-transcription polymerase chain reaction, and (4) the effects of LPS were inhibited by blocking the CD14 receptor with its specific monoclonal antibody (1:100). Thus, H. pylori LPS appears to influence tumor ECL cell proliferation by activation of the intracellular

  1. Leptospirosis Survey of Rodents and Domestic Animals in Ethiopia

    DTIC Science & Technology

    1976-08-01

    and Acomys were negative. Earlier studics in Egypt (Brownlow and Dedeaux, 1964) revealed an I 8.3% seropositivity and a 0.23% culture positivity on...natalensis 56 51 - 47 Acomys cahirnus 8 5 - 8 Leuphoromys flavoptntttus 3 3 - 3 Praomys natalensis I 1 - 1 TOTAL 276 - 352 326 10 TABLE 2 Domestic

  2. Immunization of Mastomys coucha with Brugia malayi recombinant trehalose-6-phosphate phosphatase results in significant protection against homologous challenge infection.

    PubMed

    Kushwaha, Susheela; Singh, Prashant Kumar; Rana, Ajay Kumar; Misra-Bhattacharya, Shailja

    2013-01-01

    Development of a vaccine to prevent or reduce parasite development in lymphatic filariasis would be a complementary approach to existing chemotherapeutic tools. Trehalose-6-phosphate phosphatase of Brugia malayi (Bm-TPP) represents an attractive vaccine target due to its absence in mammals, prevalence in the major life stages of the parasite and immunoreactivity with human bancroftian antibodies, especially from endemic normal subjects. We have recently reported on the cloning, expression, purification and biochemical characterization of this vital enzyme of B. malayi. In the present study, immunoprophylactic evaluation of Bm-TPP was carried out against B. malayi larval challenge in a susceptible host Mastomys coucha and the protective ability of the recombinant protein was evaluated by observing the adverse effects on microfilarial density and adult worm establishment. Immunization caused 78.4% decrease in microfilaremia and 71.04% reduction in the adult worm establishment along with sterilization of 70.06% of the recovered live females. The recombinant protein elicited a mixed Th1/Th2 type of protective immune response as evidenced by the generation of both pro- and anti-inflammatory cytokines IL-2, IFN-γ, TNF-α, IL-4 and an increased production of antibody isotypes IgG1, IgG2a, IgG2b and IgA. Thus immunization with Bm-TPP conferred considerable protection against B. malayi establishment by engendering a long-lasting effective immune response and therefore emerges as a potential vaccine candidate against lymphatic filariasis (LF).

  3. Immunization of Mastomys coucha with Brugia malayi Recombinant Trehalose-6-Phosphate Phosphatase Results in Significant Protection against Homologous Challenge Infection

    PubMed Central

    Kushwaha, Susheela; Singh, Prashant Kumar; Rana, Ajay Kumar; Misra-Bhattacharya, Shailja

    2013-01-01

    Development of a vaccine to prevent or reduce parasite development in lymphatic filariasis would be a complementary approach to existing chemotherapeutic tools. Trehalose-6-phosphate phosphatase of Brugia malayi (Bm-TPP) represents an attractive vaccine target due to its absence in mammals, prevalence in the major life stages of the parasite and immunoreactivity with human bancroftian antibodies, especially from endemic normal subjects. We have recently reported on the cloning, expression, purification and biochemical characterization of this vital enzyme of B. malayi. In the present study, immunoprophylactic evaluation of Bm-TPP was carried out against B. malayi larval challenge in a susceptible host Mastomys coucha and the protective ability of the recombinant protein was evaluated by observing the adverse effects on microfilarial density and adult worm establishment. Immunization caused 78.4% decrease in microfilaremia and 71.04% reduction in the adult worm establishment along with sterilization of 70.06% of the recovered live females. The recombinant protein elicited a mixed Th1/Th2 type of protective immune response as evidenced by the generation of both pro- and anti-inflammatory cytokines IL-2, IFN-γ, TNF-α, IL-4 and an increased production of antibody isotypes IgG1, IgG2a, IgG2b and IgA. Thus immunization with Bm-TPP conferred considerable protection against B. malayi establishment by engendering a long-lasting effective immune response and therefore emerges as a potential vaccine candidate against lymphatic filariasis (LF). PMID:24015262

  4. Floral volatiles, pollinator sharing and diversification in the fig–wasp mutualism: insights from Ficus natalensis, and its two wasp pollinators (South Africa)

    PubMed Central

    Cornille, A.; Underhill, J. G.; Cruaud, A.; Hossaert-McKey, M.; Johnson, S. D.; Tolley, K. A.; Kjellberg, F.; van Noort, S.; Proffit, M.

    2012-01-01

    Combining biogeographic, ecological, morphological, molecular and chemical data, we document departure from strict specialization in the fig-pollinating wasp mutualism. We show that the pollinating wasps Elisabethiella stuckenbergi and Elisabethiella socotrensis form a species complex of five lineages in East and Southern Africa. Up to two morphologically distinct lineages were found to co-occur locally in the southern African region. Wasps belonging to a single lineage were frequently the main regional pollinators of several Ficus species. In South Africa, two sister lineages, E. stuckenbergi and E. socotrensis, pollinate Ficus natalensis but only E. stuckenbergi also regularly pollinates Ficus burkei. The two wasp species co-occur in individual trees of F. natalensis throughout KwaZulu-Natal. Floral volatile blends emitted by F. natalensis in KwaZulu-Natal were similar to those emitted by F. burkei and different from those produced by other African Ficus species. The fig odour similarity suggests evolutionary convergence to attract particular wasp species. The observed pattern may result from selection for pollinator sharing among Ficus species. Such a process, with one wasp species regionally pollinating several hosts, but several wasp species pollinating a given Ficus species across its geographical range could play an important role in the evolutionary dynamics of the Ficus-pollinating wasp association. PMID:22130605

  5. Floral volatiles, pollinator sharing and diversification in the fig-wasp mutualism: insights from Ficus natalensis, and its two wasp pollinators (South Africa).

    PubMed

    Cornille, A; Underhill, J G; Cruaud, A; Hossaert-McKey, M; Johnson, S D; Tolley, K A; Kjellberg, F; van Noort, S; Proffit, M

    2012-05-07

    Combining biogeographic, ecological, morphological, molecular and chemical data, we document departure from strict specialization in the fig-pollinating wasp mutualism. We show that the pollinating wasps Elisabethiella stuckenbergi and Elisabethiella socotrensis form a species complex of five lineages in East and Southern Africa. Up to two morphologically distinct lineages were found to co-occur locally in the southern African region. Wasps belonging to a single lineage were frequently the main regional pollinators of several Ficus species. In South Africa, two sister lineages, E. stuckenbergi and E. socotrensis, pollinate Ficus natalensis but only E. stuckenbergi also regularly pollinates Ficus burkei. The two wasp species co-occur in individual trees of F. natalensis throughout KwaZulu-Natal. Floral volatile blends emitted by F. natalensis in KwaZulu-Natal were similar to those emitted by F. burkei and different from those produced by other African Ficus species. The fig odour similarity suggests evolutionary convergence to attract particular wasp species. The observed pattern may result from selection for pollinator sharing among Ficus species. Such a process, with one wasp species regionally pollinating several hosts, but several wasp species pollinating a given Ficus species across its geographical range could play an important role in the evolutionary dynamics of the Ficus-pollinating wasp association.

  6. Development of cycad ovules and seeds. 2. Histological and ultrastructural aspects of ontogeny of the embryo in Encephalartos natalensis (Zamiaceae).

    PubMed

    Woodenberg, Wynston Ray; Berjak, Patricia; Pammenter, N W; Farrant, Jill M

    2014-07-01

    Development of the embryo of Encephalartos natalensis from a rudimentary meristematic structure approximately 700 μm in length extends over 6 months after the seed is shed from the strobilus. Throughout its development, the embryo remains attached to a long suspensor. Differentiation of the shoot meristem flanked by two cotyledonary protuberances occurs over the first 2 months, during which peripheral tannin channels become apparent. Tannins, apparently elaborated by the endoplasmic reticulum, first accumulate in the large central vacuole and ultimately fill the channel. By the fourth month of development, the root meristem is apparent and procambial tissue forming discrete vascular bundles can be discerned in the elongating cotyledons. Between 4 and 6 months, mucilage ducts differentiate; after 6 months, when the seed becomes germinable, the embryo is characterised by cotyledons far longer than the axis. Shoot and root meristem cells remain ultrastructurally similar throughout embryo ontogeny, containing small vacuoles, many well-differentiated mitochondria and endoplasmic reticulum (ER) profiles, abundant polysomes, plastids containing small starch deposits and Golgi bodies. Unusually, however, Golgi bodies are infrequent in other cells including those elaborating mucilage which is accumulated in distended ER and apparently secreted into the duct lumen directly by ER-derived vesicles. The non-meristematic cells accumulate massive starch deposits to the exclusion of any protein bodies and only very sparse lipid, features which are considered in terms of the prolonged period of embryo development and the high atmospheric oxygen content of the Carboniferous Period, when cycads are suggested to have originated.

  7. Small mammal distribution and diversity in a plague endemic area in West Usambara Mountains, Tanzania.

    PubMed

    Ralaizafisoloarivony, Njaka A; Kimaro, Didas N; Kihupi, Nganga I; Mulungu, Loth S; Leirs, Herwig; Msanya, Balthazar M; Deckers, Jozef A; Gulinck, Hubert

    2014-07-01

    Small mammals play a role in plague transmission as hosts in all plague endemic areas. Information on distribution and diversity of small mammals is therefore important for plague surveillance and control in such areas. The objective of this study was to investigate small mammals' diversity and their distribution in plague endemic area in the West Usambara Mountains in north-eastern Tanzania. Landsat images and field surveys were used to select trapping locations in different landscapes. Three landscapes with different habitats were selected for trapping of small mammals. Three types of trap were used in order to maximise the number of species captured. In total, 188 animals and thirteen species were captured in 4,905 trap nights. Praomys delectorum and Mastomys natalensis both reported as plague hosts comprised 50% of all the animals trapped. Trap success increased with altitude. Species diversity was higher in plantation forest followed by shrub, compared to other habitats, regardless of landscape type. It would therefore seem that chances of plague transmission from small mammals to humans are much higher under shrub, natural and plantation forest habitats.

  8. Plague in Tanzania: an overview.

    PubMed

    Ziwa, Michael H; Matee, Mecky I; Hang'ombe, Bernard M; Lyamuya, Eligius F; Kilonzo, Bukheti S

    2013-10-01

    Human plague remains a public health concern in Tanzania despite its quiescence in most foci for years, considering the recurrence nature of the disease. Despite the long-standing history of this problem, there have not been recent reviews of the current knowledge on plague in Tanzania. This work aimed at providing a current overview of plague in Tanzania in terms of its introduction, potential reservoirs, possible causes of plague persistence and repeated outbreaks in the country. Plague is believed to have been introduced to Tanzania from the Middle East through Uganda with the first authentication in 1886. Xenopsylla brasiliensis, X. cheopis, Dinopsyllus lypusus, and Pulex irritans are among potential vectors while Lophuromys spp, Praomys delectorum, Graphiurus murinus, Lemniscomys striatus, Mastomys natalensis, and Rattus rattus may be the potential reservoirs. Plague persistence and repeated outbreaks in Tanzania are likely to be attributable to a complexity of factors including cultural, socio-economical, environmental and biological. Minimizing or preventing people's proximity to rodents is probably the most effective means of preventing plague outbreaks in humans in the future. In conclusion, much has been done on plague diagnosis in Tanzania. However, in order to achieve new insights into the features of plague epidemiology in the country, and to reorganize an effective control strategy, we recommend broader studies that will include the ecology of the pathogen, vectors and potential hosts, identifying the reservoirs, dynamics of infection and landscape ecology.

  9. Vegetation habitats and small mammals in a plague endemic area in Western Usambara Mountains, Tanzania.

    PubMed

    Ralaizafisoloarivony, Njaka A; Kimaro, Didas N; Kihupi, Nganga I; Mulungu, Loth S; Leirs, Herwig; Msanya, Balthazar M; Deckers, Jozef A; Gulinck, Hubert

    2014-07-01

    Human plague still exists in different parts of the world, including some landscapes in north-eastern Tanzania. Wherever the hotspot of plague, small mammals seem to play a key role as host. The objective of this study was to investigate the relationship between vegetation habitats types and small mammals in a plague endemic area of Lushoto District in Tanzania. A combination of field survey and Landsat images was used to identify the vegetation habitats. Small mammals were trapped in the mapped vegetation units, and identified. In total, six main types of vegetation habitats were investigated. A total of 13 small mammal species, potentially related to plague were trapped. Results show that annual cultivated crops habitat accounted for 80% of Mastomys natalensis while natural forest accounted for 60% of Praomys delectorum. These findings have shed new light on the diversity of rodents in different habitats of natural and semi-natural vegetations, and agricultural crops in the study area, which is an important intermediate step in unravelling the complex human plague system.

  10. Factors associated with flea infestation among the different rodent species in Mbulu and Karatu districts, northern Tanzania.

    PubMed

    Haule, Martin; Lyamuya, Eligius F; Matee, Mecky I; Kilonzo, Bukheti S; Hang'ombe, Bernard M

    2013-07-01

    Flea infection with the bacterium, Yersinia pestis is acquired from reservoirs which include several rodents and other small mammals. In areas that are endemic of plague, reservoirs of Y. pestis and various flea vectors are responsible for perpetuating existence of the disease. The objective of this cross sectional study was to investigate the magnitude and factors associated with flea infestation among different rodent species of northern Tanzania, where outbreaks of plague have been recently reported. House rodents were trapped with box traps, while field and forest rodents were trapped with Sherman live traps. Fleas were removed from the rodents by using shoe-shining brush and were identified to genus level. Among the captured rodents, Rattus rattus (26.5%), Lophuromys flavopunctatus (16.5%), Praomys delectorum (16.2%) and Mastomys natalensis (32.3%) were most abundant rodent species, accounting for 91% of all species. Altogether, 805 fleas belonging to nine species were collected from 61% of the captured rodents. The most common fleas were Xenopsylla spp.; Dinopsyllus spp and Ctenophthalmus spp. Fleas were found to be highly abundant in M. natalensis, R. rattus, P. delectorum and L .flavopunctatus. Most of rodents were heavily infested with various flea species. These flea species probably play an important role in the transmission of plague in these two districts. We conclude that rodent species was the most important risk factor associating with flea infestation among the rodent population. Therefore, measures for control and prevention of plague in this area should particularly target rodents associated with high intensity of flea infestation.

  11. Responses of Mastomys coucha, that have been infected with Brugia malayi and treated with diethylcarbamazine or albendazole, to re-exposure to infection.

    PubMed

    Khan, M A; Gaur, R L; Dixit, S; Saleemuddin, M; Murthy, P K

    2004-12-01

    The responses of Mastomys coucha to re-exposure to infection with homologous infective larvae (L(3)) of Brugia malayi were investigated, after initial infections with the nematode had been treated subcutaneously for 5 days with diethylcarbamazine (DEC; 150 mg citrate/kg. day) or albendazole (ALB; 50 mg/kg. day). The parasite burdens, serum concentrations of IgG reacting with a soluble somatic extract of adult B. malayi (BmAS), and cytokine and lymphocyte-proliferative responses to filarial antigen (BmAS) or mitogen (concanavilin A or lipopolysaccharide) were studied. The results demonstrated, for the first time, that re-infection with L(3) was only successful in the DEC-treated animals, not the ALB-treated ones. When the ALB-treated animals were re-exposed, interferon-gamma production decreased, lymphocyte-proliferative responses either remained the same (with concanavilin A) or decreased (with BmAS), and concentrations of specific IgG decreased. When the DEC-treated animals were re-exposed, microfilaraemias re-appeared and, although production of interferon-gamma decreased, there were no detectable lymphocyte proliferative responses, and concentrations of specific IgG remained unchanged. Taken together, the results indicate that, at least in the M. coucha model of human filariasis, ALB but not DEC treatment may help to prevent the development of re-infections.

  12. Immunization with Brugia malayi Myosin as Heterologous DNA Prime Protein Boost Induces Protective Immunity against B. malayi Infection in Mastomys coucha

    PubMed Central

    Gupta, Jyoti; Misra, Sweta; Misra-Bhattacharya, Shailja

    2016-01-01

    The current control strategies employing chemotherapy with diethylcarbamazine, ivermectin and albendazole have reduced transmission in some filaria-endemic areas, there is growing interest for complementary approaches, such as vaccines especially in light of threat of parasite developing resistance to mainstay drugs. We earlier demonstrated recombinant heavy chain myosin of B. malayi (Bm-Myo) as a potent vaccine candidate whose efficacy was enhanced by heterologous DNA prime/protein boost (Myo-pcD+Bm-Myo) vaccination in BALB/c mice. BALB/c mouse though does not support the full developmental cycle of B. malayi, however, the degree of protection may be studied in terms of transformation of challenged infective larvae (L3) to next stage (L4) with an ease of delineating the generated immunological response of host. In the current investigation, DNA vaccination with Bm-Myo was therefore undertaken in susceptible rodent host, Mastomys coucha (M. coucha) which sustains the challenged L3 and facilitates their further development to sexually mature adult parasites with patent microfilaraemia. Immunization schedule consisted of Myo-pcD and Myo-pcD+Bm-Myo followed by B. malayi L3 challenge and the degree of protection was evaluated by observing microfilaraemia as well as adult worm establishment. Myo-pcD+Bm-Myo immunized animals not only developed 78.5% reduced blood microfilarial density but also decreased adult worm establishment by 75.3%. In addition, 75.4% of the recovered live females revealed sterilization over those of respective control animals. Myo-pcD+Bm-Myo triggered higher production of specific IgG and its isotypes which induced marked cellular adhesion and cytotoxicity (ADCC) to microfilariae (mf) and L3 in vitro. Both Th1 and Th2 cytokines were significantly up-regulated displaying a mixed immune response conferring considerable protection against B. malayi establishment by engendering a long-lasting effective immune response and therefore emerges as a

  13. Recovery of a Lassa-related arenavirus in Zimbabwe.

    PubMed

    Johnson, K M; Taylor, P; Elliott, L H; Tomori, O

    1981-11-01

    Immunofluorescent antibodies to "Mozambique" virus, a close relative of Lassa virus, were found in 11 of 55 Mastomys natalensis and 1 of 13 Aethomys chrysophilus rodents captured near Que Que and Chiredzi, Zimbabwe. Six strains of Mozambique virus, identified by use of specific monoclonal antibodies to the agent, were recovered from visceral tissues of M. natalensis rodents. All Mastomys having virus or antibodies to this agent were of the chromosomal form 2N = 32 (M. natalensis). These data extend the area of geographic occurrence of this virus, which was initially recognized in Mozambique and which may represent a naturally attenuated antigenic variant of human pathogenic West African Lassa virus.

  14. A comparison of metal levels and antioxidant enzymes in freshwater snails, Lymnaea natalensis, exposed to sediment and water collected from Wright Dam and Lower Mguza Dam, Bulawayo, Zimbabwe.

    PubMed

    Siwela, A H; Nyathi, C B; Naik, Y S

    2010-10-01

    We compared the bioaccumulation of lead (Pb), cadmium (Cd), zinc (Zn), copper (Cu), nickel (Ni) and iron (Fe) with antioxidant enzyme activity in tissues of the snails, Lymnaea natalensis, exposed to elements of two differently polluted dams. 45 snails were exposed to sediment and water collected from Wight Dam (reference) whilst another 45 snails were also exposed to sediment and water collected from Lower Mguza Dam (polluted dam). Except for Fe in sediment and Pb in water, metal concentrations were statistically higher in sediment and water collected from Lower Mguza Dam. Lead, Cd and Zn were two times higher in tissues of snails exposed to Lower Mguza Dam elements. On one hand, superoxide dismutase (SOD), diphosphotriphosphodiaphorase (DTD) and catalase (CAT) activities were significantly lower whilst malondialdehyde (MDA) levels were significantly higher in tissues of snails exposed to Lower Mguza Dam sediment and water. On the other hand, selenium-dependent glutathione peroxidase (Se-GPX) activity was significantly elevated in tissues of snails exposed to Lower Mguza Dam sediment and water. Snails exposed to Lower Mguza Dam elements seem to have responded to pollution by increasing CAT and Se-GPX specific activity in an effort to detoxify peroxides produced as a result of metal induced oxidative stress.

  15. μ-Theraphotoxin-An1a: primary structure determination and assessment of the pharmacological activity of a promiscuous anti-insect toxin from the venom of the tarantula Acanthoscurria natalensis (Mygalomorphae, Theraphosidae).

    PubMed

    Rates, Breno; Prates, Maura V; Verano-Braga, Thiago; da Rocha, Angela P; Roepstorff, Peter; Borges, Carlos L; Lapied, Bruno; Murillo, Laurence; Pimenta, Adriano M C; Biondi, Ilka; De Lima, Maria Elena

    2013-08-01

    Tarantulas are included in the mygalomorph spider family Theraphosidae. Although the pharmacological diversity of theraphosid toxins (theraphotoxins) is broad, studies dedicated to the characterization of biologically active molecules from the theraphosid genus Acanthoscurria have been restricted to the investigation of antimicrobial peptides and polyamines produced by the hemocytes of Acanthoscurria gomesiana. The present study reports the purification, primary structure determination and electrophysiological effects of an anti-insect toxin, named μ-theraphotoxin-An1a (μ-TRTX-An1a), from the venom of Acanthoscurria natalensis - a tarantula species occurring in the Brazilian biomes caatinga and cerrado. The analysis of the primary structure of μ-TRTX-An1a revealed the similarity of this toxin to theraphosid toxins bearing a huwentoxin-II-like fold. Electrophysiological experiments showed that μ-TRTX-An1a (100 nM) induces membrane depolarization, increases the spontaneous firing frequency and reduces spike amplitude of cockroach dorsal unpaired median (DUM) neurons. In addition, under voltage-clamp conditions, μ-TRTX-An1a (100 nM) only partially blocks voltage-dependent sodium current amplitudes in DUM neurons without any effect on their voltage dependence. This effect correlates well with the reduction of the spontaneous action potential amplitudes. Altogether, these last results suggest that μ-TRTX-An1a affects insect neuronal voltage-dependent sodium channels, which are among possible channels targeted by this promiscuous toxin.

  16. Novel Arenavirus, Zambia

    PubMed Central

    Thomas, Yuka; Moonga, Ladslav; Nakamura, Ichiro; Ohnuma, Aiko; Hang’ombe, Bernard; Takada, Ayato; Mweene, Aaron; Sawa, Hirofumi

    2011-01-01

    To investigate arenavirus in Zambia, we characterized virus from the kidneys of 5 arenavirus RNA–positive rodents (Mastomys natalensis) among 263 captured. Full-genome sequences of the viruses suggested that they were new strains similar to Lassa virus–related arenaviruses. Analyzing samples from additional rodents and other species can elucidate epizootiologic aspects of arenaviruses. PMID:22000372

  17. Novel arenavirus, Zambia.

    PubMed

    Ishii, Akihiro; Thomas, Yuka; Moonga, Ladslav; Nakamura, Ichiro; Ohnuma, Aiko; Hang'ombe, Bernard; Takada, Ayato; Mweene, Aaron; Sawa, Hirofumi

    2011-10-01

    To investigate arenavirus in Zambia, we characterized virus from the kidneys of 5 arenavirus RNA-positive rodents (Mastomys natalensis) among 263 captured. Full-genome sequences of the viruses suggested that they were new strains similar to Lassa virus-related arenaviruses. Analyzing samples from additional rodents and other species can elucidate epizootiologic aspects of arenaviruses.

  18. Two novel arenaviruses detected in pygmy mice, Ghana.

    PubMed

    Kronmann, Karl C; Nimo-Paintsil, Shirley; Guirguis, Fady; Kronmann, Lisha C; Bonney, Kofi; Obiri-Danso, Kwasi; Ampofo, William; Fichet-Calvet, Elisabeth

    2013-11-01

    Two arenaviruses were detected in pygmy mice (Mus spp.) by screening 764 small mammals in Ghana. The Natal multimammate mouse (Mastomys natalensis), the known Lassa virus reservoir, was the dominant indoor rodent species in 4 of 10 sites, and accounted for 27% of all captured rodents. No rodent captured indoors tested positive for an arenavirus.

  19. Evaluation of demographic parameters of native rodent populations and implications for control

    PubMed Central

    French, Norman R.

    1975-01-01

    The ecology of the multimammate mouse ,Mastomys natalensis, is reviewed and approximations are derived for the parameters governing population growth. By means of computer simulation, the relative importance of the timing of reproduction, the age class distribution or age structure of the population, the competition between Mastomys and Rattus, and the interaction with a predator are evaluated. Although each of these demographic or ecological factors modifies the fate of the Mastomys population, the greatest single impact results from a reproductive season that is divided into two parts rather than a single continuous reproductive season. Division into two parts, correlated with a similar distribution of rainfall, allows time for maturing of the young born early in the season and for production of young by them, thus adding to the momentum of population increase. The interaction of density-dependent factors controlling population growth, competition with another rodent, or predation by a Viverrid predator, may increase the growth rate of the Mastomys population or may depress population growth rate, even to the point of extinction. These simulation studies demonstrate the necessity for critical evaluation of the demographic parameters and ecological characteristics of a particular Mastomys population before an effective control programme can be designed. They also demonstrate, however, that if the programme is based upon sound ecological theory control can be effected. PMID:1085223

  20. Ecology of plague in Africa: response of indigenous wild rodents to experimental plague infection

    PubMed Central

    Isaäcson, Margaretha; Taylor, Paul; Arntzen, Lorraine

    1983-01-01

    The Mastomys natalensis species complex, subdivided into genetically distinct species having diploid chromosome numbers 2n = 32 and 2n = 36, is a reservoir for several zoonoses including Lassa fever and plague. This report describes a study to determine whether these sibling species and three other rodent species have different potential as reservoirs for plague. It was found that M. natalensis (2n = 32) was significantly more resistant to experimental plague infection (50% survived inoculation with 120 000 Yersinia pseudotuberculosis subsp. pestis) than was M. coucha (2n = 36) (none of which survived doses of 190 Y. pseudotuberculosis subsp.pestis). In descending order of resistance were M. natalensis, Aethomys chrysophilus, M. coucha, Tatera leucogaster and A. namaquensis. No A. namaquensis survived inoculation of 10 or more plague bacilli. Previous reports on susceptibility to plague or other infections, which were based exclusively on findings in the universally distributed laboratory-bred Mastomys, are thus not necessarily applicable to the M. natalensis species as a whole but probably only to M. coucha. The Y. pseudotuberculosis subsp. pestis fraction-1 passive haemagglutination test appeared to be relatively insensitive in that only 5 out of 47 animals surviving experimental plague infection showed specific antibodies 6 weeks after challenge. The geographic distribution of human plague in southern Africa corresponds closely with that of the plague-susceptible species, M. coucha, while the resistant species, M. natalensis, predominates in areas where human plague has not been recorded. The role of A. namaquensis in the ecology of plague needs to be carefully studied and its possible importance in plague research should be investigated further. PMID:6345015

  1. Ecology of plague in Africa: response of indigenous wild rodents to experimental plague infection.

    PubMed

    Isaäcson, M; Taylor, P; Arntzen, L

    1983-01-01

    The Mastomys natalensis species complex, subdivided into genetically distinct species having diploid chromosome numbers 2n = 32 and 2n = 36, is a reservoir for several zoonoses including Lassa fever and plague. This report describes a study to determine whether these sibling species and three other rodent species have different potential as reservoirs for plague. It was found that M. natalensis (2n = 32) was significantly more resistant to experimental plague infection (50% survived inoculation with 120 000 Yersinia pseudotuberculosis subsp. pestis) than was M. coucha (2n = 36) (none of which survived doses of 190 Y. pseudotuberculosis subsp.pestis). In descending order of resistance were M. natalensis, Aethomys chrysophilus, M. coucha, Tatera leucogaster and A. namaquensis. No A. namaquensis survived inoculation of 10 or more plague bacilli.Previous reports on susceptibility to plague or other infections, which were based exclusively on findings in the universally distributed laboratory-bred Mastomys, are thus not necessarily applicable to the M. natalensis species as a whole but probably only to M. coucha. The Y. pseudotuberculosis subsp. pestis fraction-1 passive haemagglutination test appeared to be relatively insensitive in that only 5 out of 47 animals surviving experimental plague infection showed specific antibodies 6 weeks after challenge.The geographic distribution of human plague in southern Africa corresponds closely with that of the plague-susceptible species, M. coucha, while the resistant species, M. natalensis, predominates in areas where human plague has not been recorded. The role of A. namaquensis in the ecology of plague needs to be carefully studied and its possible importance in plague research should be investigated further.

  2. Lassa fever or lassa hemorrhagic fever risk to humans from rodent-borne zoonoses.

    PubMed

    El-Bahnasawy, Mamdouh M; Megahed, Laila Abdel-Mawla; Abdalla Saleh, Hala Ahmed; Morsy, Tosson A

    2015-04-01

    Viral hemorrhagic fevers (VHFs) typically manifest as rapidly progressing acute febrile syndromes with profound hemorrhagic manifestations and very high fatality rates. Lassa fever, an acute hemorrhagic fever characterized by fever, muscle aches, sore throat, nausea, vomiting, diarrhea and chest and abdominal pain. Rodents are important reservoirs of rodent-borne zoonosis worldwide. Transmission rodents to humans occur by aerosol spread, either from the genus Mastomys rodents' excreta (multimammate rat) or through the close contact with infected patients (nosocomial infection). Other rodents of the genera Rattus, Mus, Lemniscomys, and Praomys are incriminated rodents hosts. Now one may ask do the rodents' ectoparasites play a role in Lassa virus zoonotic transmission. This paper summarized the update knowledge on LHV; hopping it might be useful to the clinicians, nursing staff, laboratories' personals as well as those concerned zoonoses from rodents and rodent control.

  3. New Hosts of The Lassa Virus

    PubMed Central

    Olayemi, Ayodeji; Cadar, Daniel; Magassouba, N’Faly; Obadare, Adeoba; Kourouma, Fode; Oyeyiola, Akinlabi; Fasogbon, Samuel; Igbokwe, Joseph; Rieger, Toni; Bockholt, Sabrina; Jérôme, Hanna; Schmidt-Chanasit, Jonas; Garigliany, Mutien; Lorenzen, Stephan; Igbahenah, Felix; Fichet, Jean-Nicolas; Ortsega, Daniel; Omilabu, Sunday; Günther, Stephan; Fichet-Calvet, Elisabeth

    2016-01-01

    Lassa virus (LASV) causes a deadly haemorrhagic fever in humans, killing several thousand people in West Africa annually. For 40 years, the Natal multimammate rat, Mastomys natalensis, has been assumed to be the sole host of LASV. We found evidence that LASV is also hosted by other rodent species: the African wood mouse Hylomyscus pamfi in Nigeria, and the Guinea multimammate mouse Mastomys erythroleucus in both Nigeria and Guinea. Virus strains from these animals were isolated in the BSL-4 laboratory and fully sequenced. Phylogenetic analyses of viral genes coding for glycoprotein, nucleoprotein, polymerase and matrix protein show that Lassa strains detected in M. erythroleucus belong to lineages III and IV. The strain from H. pamfi clusters close to lineage I (for S gene) and between II & III (for L gene). Discovery of new rodent hosts has implications for LASV evolution and its spread into new areas within West Africa. PMID:27140942

  4. New Hosts of The Lassa Virus.

    PubMed

    Olayemi, Ayodeji; Cadar, Daniel; Magassouba, N'Faly; Obadare, Adeoba; Kourouma, Fode; Oyeyiola, Akinlabi; Fasogbon, Samuel; Igbokwe, Joseph; Rieger, Toni; Bockholt, Sabrina; Jérôme, Hanna; Schmidt-Chanasit, Jonas; Garigliany, Mutien; Lorenzen, Stephan; Igbahenah, Felix; Fichet, Jean-Nicolas; Ortsega, Daniel; Omilabu, Sunday; Günther, Stephan; Fichet-Calvet, Elisabeth

    2016-05-03

    Lassa virus (LASV) causes a deadly haemorrhagic fever in humans, killing several thousand people in West Africa annually. For 40 years, the Natal multimammate rat, Mastomys natalensis, has been assumed to be the sole host of LASV. We found evidence that LASV is also hosted by other rodent species: the African wood mouse Hylomyscus pamfi in Nigeria, and the Guinea multimammate mouse Mastomys erythroleucus in both Nigeria and Guinea. Virus strains from these animals were isolated in the BSL-4 laboratory and fully sequenced. Phylogenetic analyses of viral genes coding for glycoprotein, nucleoprotein, polymerase and matrix protein show that Lassa strains detected in M. erythroleucus belong to lineages III and IV. The strain from H. pamfi clusters close to lineage I (for S gene) and between II &III (for L gene). Discovery of new rodent hosts has implications for LASV evolution and its spread into new areas within West Africa.

  5. When Viruses Don’t Go Viral: The Importance of Host Phylogeographic Structure in the Spatial Spread of Arenaviruses

    PubMed Central

    Baird, Stuart J. E.; Goüy de Bellocq, Joëlle

    2017-01-01

    Many emerging infections are RNA virus spillovers from animal reservoirs. Reservoir identification is necessary for predicting the geographic extent of infection risk, but rarely are taxonomic levels below the animal species considered as reservoir, and only key circumstances in nature and methodology allow intrinsic virus-host associations to be distinguished from simple geographic (co-)isolation. We sampled and genetically characterized in detail a contact zone of two subtaxa of the rodent Mastomys natalensis in Tanzania. We find two distinct arenaviruses, Gairo and Morogoro virus, each spatially confined to a single M. natalensis subtaxon, only co-occurring at the contact zone’s centre. Inter-subtaxon hybridization at this centre and a continuum of quality habitat for M. natalensis show that both viruses have the ecological opportunity to spread into the other substaxon’s range, but do not, strongly suggesting host-intrinsic barriers. Such barriers could explain why human cases of another M. natalensis-borne arenavirus, Lassa virus, are limited to West Africa. PMID:28076397

  6. Comparative tests for detection of plague antigen and antibody in experimentally infected wild rodents.

    PubMed Central

    Shepherd, A J; Hummitzsch, D E; Leman, P A; Swanepoel, R; Searle, L A

    1986-01-01

    The enzyme-linked immunosorbent assay (ELISA) was compared with other standard tests for detection of plague (Yersinia pestis) antibody and antigen in multimammate mice (Mastomys coucha and M. natalensis) which were experimentally infected and then killed at daily intervals postinoculation. For detection of antibody in sera from M. natalensis, the immunoglobulin G (IgG) ELISA was equivalent in sensitivity to passive hemagglutination and more sensitive than the IgM ELISA and complement fixation. Antibody was first detected on postinfection day 6 by all four tests, but IgM ELISA titers had declined to undetectable levels after 8 weeks. For detection of fraction 1 Y. pestis antigen in rodent organs, the ELISA was less sensitive than fluorescent antibody but more sensitive than complement fixation or immunodiffusion. Plague fraction 1 antigen was detected in 16 of 34 bacteremic sera from M. coucha and M. natalensis. The threshold sensitivity of the ELISA was approximately 10(5) Y. pestis per ml. PMID:3097065

  7. Molecular surveillance and phylogenetic analysis of Old World arenaviruses in Zambia.

    PubMed

    Ishii, Akihiro; Thomas, Yuka; Moonga, Ladslav; Nakamura, Ichiro; Ohnuma, Aiko; Hang'ombe, Bernard M; Takada, Ayato; Mweene, Aaron S; Sawa, Hirofumi

    2012-10-01

    In order to survey arenaviruses in the Republic of Zambia, we captured 335 rodents from three cities between 2010 and 2011. Eighteen Luna virus (LUNV) and one lymphocytic choriomeningitis virus (LCMV)-related virus RNAs were detected by one-step RT-PCR from Mastomys natalensis and Mus minutoides, respectively. Four LUNV strains and one LCMV-related virus were isolated, and the whole genome nucleotide sequence was determined by pyrosequencing. Phylogenetic analyses revealed that the LUNV clade consists of two branches that are distinguished by geographical location and that the LCMV-related virus belongs to the LCMV clade, but diverges from the typical LCMVs. Comparison of nucleoprotein amino acid sequences indicated that the LCMV-related virus could be designated a novel arenavirus, which was tentatively named as the Lunk virus. Amino acid sequences of the GP, NP, Z and L proteins showed poor similarity among the three Zambian arenavirus strains, i.e. Luna, Lunk and Lujo virus.

  8. Lassa Virus Seroprevalence in Sibirilia Commune, Bougouni District, Southern Mali.

    PubMed

    Sogoba, Nafomon; Rosenke, Kyle; Adjemian, Jennifer; Diawara, Sory Ibrahim; Maiga, Ousmane; Keita, Moussa; Konaté, Drissa; Keita, Abdoul Salam; Sissoko, Ibrahim; Boisen, Matt; Nelson, Diana; Oottamasathien, Darin; Millett, Molly; Garry, Robert F; Branco, Luis M; Traoré, Sékou F; Doumbia, Seydou; Feldmann, Heinz; Safronetz, David

    2016-04-01

    Lassa virus (LASV) is endemic to several nations in West Africa. In Mali, LASV was unknown until an exported case of Lassa fever was reported in 2009. Since that time, rodent surveys have found evidence of LASV-infected Mastomys natalensis rats in several communities in southern Mali, near the border with Côte d'Ivoire. Despite increased awareness, to date only a single case of Lassa fever has been confirmed in Mali. We conducted a survey to determine the prevalence of LASV exposure among persons in 3 villages in southern Mali where the presence of infected rodents has been documented. LASV IgG seroprevalence ranged from 14.5% to 44% per village. No sex bias was noted; however, seropositivity rates increased with participant age. These findings confirm human LASV exposure in Mali and suggest that LASV infection/Lassa fever is a potential public health concern in southern Mali.

  9. Lassa Virus Seroprevalence in Sibirilia Commune, Bougouni District, Southern Mali

    PubMed Central

    Sogoba, Nafomon; Rosenke, Kyle; Adjemian, Jennifer; Diawara, Sory Ibrahim; Maiga, Ousmane; Keita, Moussa; Konaté, Drissa; Keita, Abdoul Salam; Sissoko, Ibrahim; Boisen, Matt; Nelson, Diana; Oottamasathien, Darin; Millett, Molly; Garry, Robert F.; Branco, Luis M.; Traoré, Sékou F.; Doumbia, Seydou; Feldmann, Heinz

    2016-01-01

    Lassa virus (LASV) is endemic to several nations in West Africa. In Mali, LASV was unknown until an exported case of Lassa fever was reported in 2009. Since that time, rodent surveys have found evidence of LASV-infected Mastomys natalensis rats in several communities in southern Mali, near the border with Côte d’Ivoire. Despite increased awareness, to date only a single case of Lassa fever has been confirmed in Mali. We conducted a survey to determine the prevalence of LASV exposure among persons in 3 villages in southern Mali where the presence of infected rodents has been documented. LASV IgG seroprevalence ranged from 14.5% to 44% per village. No sex bias was noted; however, seropositivity rates increased with participant age. These findings confirm human LASV exposure in Mali and suggest that LASV infection/Lassa fever is a potential public health concern in southern Mali. PMID:26981786

  10. Sequence variability and geographic distribution of Lassa virus, Sierra Leone.

    PubMed

    Leski, Tomasz A; Stockelman, Michael G; Moses, Lina M; Park, Matthew; Stenger, David A; Ansumana, Rashid; Bausch, Daniel G; Lin, Baochuan

    2015-04-01

    Lassa virus (LASV) is endemic to parts of West Africa and causes highly fatal hemorrhagic fever. The multimammate rat (Mastomys natalensis) is the only known reservoir of LASV. Most human infections result from zoonotic transmission. The very diverse LASV genome has 4 major lineages associated with different geographic locations. We used reverse transcription PCR and resequencing microarrays to detect LASV in 41 of 214 samples from rodents captured at 8 locations in Sierra Leone. Phylogenetic analysis of partial sequences of nucleoprotein (NP), glycoprotein precursor (GPC), and polymerase (L) genes showed 5 separate clades within lineage IV of LASV in this country. The sequence diversity was higher than previously observed; mean diversity was 7.01% for nucleoprotein gene at the nucleotide level. These results may have major implications for designing diagnostic tests and therapeutic agents for LASV infections in Sierra Leone.

  11. Poor housing quality increases risk of rodent infestation and Lassa fever in refugee camps of Sierra Leone.

    PubMed

    Bonner, Phillip Cullison; Schmidt, Wolf-Peter; Belmain, Steven R; Oshin, Babafemi; Baglole, Debbie; Borchert, Matthias

    2007-07-01

    Lassa fever, a viral hemorrhagic fever endemic in parts of West Africa, is a severe febrile illness transmitted to humans by the rodent Mastomys natalensis. To determine risk of Lassa fever in households in Sierra Leonean refugee camps, we analyzed the spatial relationships between households with a Lassa case and focal locations of potential rodent habitats. Quality and hygiene factors of households were assessed to determine possible risk factors for household rodent infestation and occurrence of Lassa fever. The odds to have a rat burrow were higher in case houses than in control houses (OR 24, 95% CI 6.0-93). Case houses scored significantly worse in the quality of housing and external hygiene. These findings suggest that risk of Lassa fever in refugee camps depends on individual housing quality and the hygiene of the immediate surrounding environment.

  12. Sequence Variability and Geographic Distribution of Lassa Virus, Sierra Leone

    PubMed Central

    Stockelman, Michael G.; Moses, Lina M.; Park, Matthew; Stenger, David A.; Ansumana, Rashid; Bausch, Daniel G.; Lin, Baochuan

    2015-01-01

    Lassa virus (LASV) is endemic to parts of West Africa and causes highly fatal hemorrhagic fever. The multimammate rat (Mastomys natalensis) is the only known reservoir of LASV. Most human infections result from zoonotic transmission. The very diverse LASV genome has 4 major lineages associated with different geographic locations. We used reverse transcription PCR and resequencing microarrays to detect LASV in 41 of 214 samples from rodents captured at 8 locations in Sierra Leone. Phylogenetic analysis of partial sequences of nucleoprotein (NP), glycoprotein precursor (GPC), and polymerase (L) genes showed 5 separate clades within lineage IV of LASV in this country. The sequence diversity was higher than previously observed; mean diversity was 7.01% for nucleoprotein gene at the nucleotide level. These results may have major implications for designing diagnostic tests and therapeutic agents for LASV infections in Sierra Leone. PMID:25811712

  13. Diversity and habitat association of small mammals in Aridtsy forest, Awi Zone, Ethiopia

    PubMed Central

    BANTIHUN, Getachew; BEKELE, Afework

    2015-01-01

    Here, we conducted a survey to examine the diversity, distribution and habitat association of small mammals from August 2011 to February 2012 incorporating both wet and dry seasons in Aridtsy forest, Awi Zone, Ethiopia. Using Sherman live traps and snap traps in four randomly selected trapping grids, namely, natural forest, bushland, grassland and farmland, a total of 468 individuals comprising eight species of small mammals (live traps) and 89 rodents of six species (snap traps) were trapped in 2352 and 1200 trap nights, respectively. The trapped small mammals included seven rodents and one insectivore: Lophuromys flavopuntatus (30.6%), Arvicanthis dembeensis (25.8%), Stenocephalemys albipes (20%), Mastomys natalensis (11.6%), Pelomys harringtoni (6.4%), Acomys cahirinus (4.3%), Lemniscomys zebra (0.2%) and the greater red musk shrew (Crocidura flavescens, 1.1%). Analysis showed statistically significant variations in the abundance and habitat preferences of small mammals between habitats during wet and dry seasons. PMID:25855227

  14. Diversity and habitat association of small mammals in Aridtsy forest, Awi Zone, Ethiopia.

    PubMed

    Bantihun, Getachew; Bekele, Afework

    2015-03-18

    Here, we conducted a survey to examine the diversity, distribution and habitat association of small mammals from August 2011 to February 2012 incorporating both wet and dry seasons in Aridtsy forest, Awi Zone, Ethiopia. Using Sherman live traps and snap traps in four randomly selected trapping grids, namely, natural forest, bushland, grassland and farmland, a total of 468 individuals comprising eight species of small mammals (live traps) and 89 rodents of six species (snap traps) were trapped in 2352 and 1200 trap nights, respectively. The trapped small mammals included seven rodents and one insectivore: Lophuromys flavopuntatus (30.6%), Arvicanthis dembeensis (25.8%), Stenocephalemys albipes (20%), Mastomys natalensis (11.6%), Pelomys harringtoni (6.4%), Acomys cahirinus (4.3%), Lemniscomys zebra (0.2%) and the greater red musk shrew (Crocidura flavescens, 1.1%). Analysis showed statistically significant variations in the abundance and habitat preferences of small mammals between habitats during wet and dry seasons.

  15. Imported Lassa fever--New Jersey, 2004.

    PubMed

    2004-10-01

    Lassa fever is an acute viral illness caused by Lassa virus, which is hosted by rodents in the Mastomys natalensis species complex and rarely imported to countries outside of those areas in Africa where the disease is endemic. Lassa fever is characterized by fever, muscle aches, sore throat, nausea, vomiting, and chest and abdominal pain. Approximately 15%-20% of patients hospitalized for Lassa fever die from the illness; however, approximately 80% of human infections with Lassa virus are mild or asymptomatic, and 1% of infections overall result in death. On August 28, 2004, a man aged 38 years residing in New Jersey died from Lassa fever after returning from travel to West Africa. This report summarizes the clinical and epidemiologic investigations conducted by federal, state, and local public health agencies. The findings illustrate the need for clinicians and public health officials to remain alert to emerging infectious diseases and to institute appropriate measures to promptly identify and limit spread of unusual pathogens.

  16. Small mammals as hosts of immature ixodid ticks.

    PubMed

    Horak, I G; Fourie, L J; Braack, L E O

    2005-09-01

    Two hundred and twenty-five small mammals belonging to 16 species were examined for ticks in Free State, Mpumalanga and Limpopo Provinces, South Africa, and 18 ixodid tick species, of which two could only be identified to genus level, were recovered. Scrub hares, Lepus saxatilis, and Cape hares, Lepus capensis, harboured the largest number of tick species. In Free State Province Namaqua rock mice, Aethomys namaquensis, and four-striped grass mice, Rhabdomys pumilio, were good hosts of the immature stages of Haemaphysalis leachi and Rhipicephalus gertrudae, while in Mpumalanga and Limpopo Provinces red veld rats, Aethomys chrysophilus, Namaqua rock mice and Natal multimammate mice, Mastomys natalensis were good hosts of H. leachi and Rhipicephalus simus. Haemaphysalis leachi was the only tick recovered from animals in all three provinces.

  17. Spatio-temporal variation in small mammal species richness, relative abundance and body mass reveal changes in a coastal wetland ecosystem in Ghana.

    PubMed

    Ofori, Benjamin Y; Attuquayefio, Daniel K; Owusu, Erasmus H; Musah, Yahaya; Ntiamoa-Baidu, Yaa

    2016-06-01

    Coastal wetlands in Ghana are under severe threat of anthropogenic drivers of habitat degradation and climate change, thereby increasing the need for assessment and monitoring to inform targeted and effective conservation of these ecosystems. Here, we assess small mammal species richness, relative abundance and body mass in three habitats at the Muni-Pomadze Ramsar site of Ghana, and compare these to baseline data gathered in 1997 to evaluate changes in the wetland ecosystem. Small mammals were live-trapped using Sherman collapsible and pitfall traps. We recorded 84 individuals of 10 species in 1485 trap-nights, whereas the baseline study recorded 45 individuals of seven species in 986 trap-nights. The overall trap-success was therefore greater in the present study (5.66 %) than the baseline study (4.56 %). The species richness increased from one to four in the forest, and from zero to eight in the thicket, but decreased from six to four in the grassland. The total number of individuals increased in all habitats, with the dominant species in the grassland shifting from Lemniscomys striatus to Mastomys erythroleucus. Three species, Malacomys edwardsi, Grammomys poensis and Praomys tullbergi are the first records for the Muni-Pomadze Ramsar site. Generally, the average body mass of individual species in the grassland was lower in the present study. The considerable changes in small mammal community structure suggest changes in the wetland ecosystem. The conservation implications of our findings are discussed.

  18. Landscape determinants of fine-scale genetic structure of a small rodent in a heterogeneous landscape (Hluhluwe-iMfolozi Park, South Africa).

    PubMed

    Russo, Isa-Rita M; Sole, Catherine L; Barbato, Mario; von Bramann, Ullrich; Bruford, Michael W

    2016-07-13

    Small mammals provide ecosystem services, acting, for example, as pollinators and seed dispersers. In addition, they are also disease reservoirs that can be detrimental to human health and they can also act as crop pests. Knowledge of their dispersal preferences is therefore useful for population management and landscape planning. Genetic data were used alongside landscape data to examine the influence of the landscape on the demographic connectedness of the Natal multimammate mouse (Mastomys natalensis) and to identify landscape characteristics that influence the genetic structure of this species across a spatially and temporally varying environment. The most significant landscape features shaping gene flow were aspect, vegetation cover, topographic complexity (TC) and rivers, with western facing slopes, topographic complexity and rivers restricting gene flow. In general, thicket vegetation was correlated with increased gene flow. Identifying features of the landscape that facilitate movement/dispersal in M. natalensis potentially has application for other small mammals in similar ecosystems. As the primary reservoir host of the zoonotic Lassa virus, a landscape genetics approach may have applications in determining areas of high disease risk to humans. Identifying these landscape features may also be important in crop management due to damage by rodent pests.

  19. Landscape determinants of fine-scale genetic structure of a small rodent in a heterogeneous landscape (Hluhluwe-iMfolozi Park, South Africa)

    PubMed Central

    Russo, Isa-Rita M.; Sole, Catherine L.; Barbato, Mario; von Bramann, Ullrich; Bruford, Michael W.

    2016-01-01

    Small mammals provide ecosystem services, acting, for example, as pollinators and seed dispersers. In addition, they are also disease reservoirs that can be detrimental to human health and they can also act as crop pests. Knowledge of their dispersal preferences is therefore useful for population management and landscape planning. Genetic data were used alongside landscape data to examine the influence of the landscape on the demographic connectedness of the Natal multimammate mouse (Mastomys natalensis) and to identify landscape characteristics that influence the genetic structure of this species across a spatially and temporally varying environment. The most significant landscape features shaping gene flow were aspect, vegetation cover, topographic complexity (TC) and rivers, with western facing slopes, topographic complexity and rivers restricting gene flow. In general, thicket vegetation was correlated with increased gene flow. Identifying features of the landscape that facilitate movement/dispersal in M. natalensis potentially has application for other small mammals in similar ecosystems. As the primary reservoir host of the zoonotic Lassa virus, a landscape genetics approach may have applications in determining areas of high disease risk to humans. Identifying these landscape features may also be important in crop management due to damage by rodent pests. PMID:27406468

  20. Enzymatic activity of rodents acclimated to cold and long scotophase

    NASA Astrophysics Data System (ADS)

    Fourie, F. Le R.; Haim, A.

    1980-09-01

    Rodents representative of a diurnal species ( Rhabdomys pumilio) as well as a nocturnal species ( Praomys natalensis) were acclimated to cold (Ta = 8°C) at a photoperiod of LD 12:12 and a long scotophase (LD 8; 16) at a temperature of 25° C(Ta). Control groups were kept for both species at Ta = 25° C and LD 12:12 and winter acclimated individuals were obtained during July and August to serve as further reference. Blood samples obtained from the tail were analysed for enzymes representative of three major biochemical pathways. The enzymatic activity of LDH (glycolytic pathway), MDH (Krebs cycle) and G6PDH (hexose monophosphate shunt, as an indicator of gonadal activity) were monitored to represent metabolic activity of the respective cycles. Cold acclimated as well as winter acclimatized mice revealed similar enzymatic patterns for both species and significant increases in LDH and MDH were recorded with a concurrent decrease in G6PDH activity. Specimens exposed to long scotophase exhibited similar enzymatic patterns for both species studied, but enzymatic activity was higher than those of cold acclimated individuals. From these results it is concluded that cold as well as long scotophase induce metabolic adaptations through biochemical activity in the experimental animals. The effect of long scotophase is assumed to be an important factor in the induction of winter acclimatization.

  1. Sex-biased parasitism is not universal: evidence from rodent-flea associations from three biomes.

    PubMed

    Kiffner, Christian; Stanko, Michal; Morand, Serge; Khokhlova, Irina S; Shenbrot, Georgy I; Laudisoit, Anne; Leirs, Herwig; Hawlena, Hadas; Krasnov, Boris R

    2013-11-01

    The distribution of parasites among individual hosts is characterised by high variability that is believed to be a result of variations in host traits. To find general patterns of host traits affecting parasite abundance, we studied flea infestation of nine rodent species from three different biomes (temperate zone of central Europe, desert of Middle East and tropics of East Africa). We tested for independent and interactive effects of host sex and body mass on the number of fleas harboured by an individual host while accounting for spatial clustering of host and parasite sampling and temporal variation. We found no consistent patterns of the effect of host sex and body mass on flea abundance either among species within a biome or among biomes. We found evidence for sex-biased flea infestation in just five host species (Apodemus agrarius, Myodes glareolus, Microtus arvalis, Gerbillus andersoni, Mastomys natalensis). In six rodent species, we found an effect of body mass on flea abundance (all species mentioned above and Meriones crassus). This effect was positive in five species and negative in one species (Microtus arvalis). In M. glareolus, G. andersoni, M. natalensis, and M. arvalis, the relationship between body mass and flea abundance was mediated by host sex. This was manifested in steeper change in flea abundance with increasing body mass in male than female individuals (M. glareolus, G. andersoni, M. natalensis), whereas the opposite pattern was found in M. arvalis. Our findings suggest that sex and body mass are common determinants of parasite infestation in mammalian hosts, but neither of them follows universal rules. This implies that the effect of host individual characteristics on mechanisms responsible for flea acquisition may be manifested differently in different host species.

  2. Lassa fever in West African sub-region: an overview.

    PubMed

    Ogbu, O; Ajuluchukwu, E; Uneke, C J

    2007-03-01

    Lassa fever is an acute viral zoonotic illness caused by Lassa virus, an arenavirus known to be responsible for a severe haemorrhagic fever characterised by fever, muscle aches, sore throat, nausea, vomiting and, chest and abdominal pain. The virus exhibits persistent, asymptomatic infection with profuse urinary virus excretion in the ubiquitous rodent vector, Mastomys natalensis. Lassa fever is endemic in West Africa and has been reported from Sierra Leone, Guinea, Liberia, and Nigeria. Some studies indicate that 300,000 to 500,000 cases of Lassa fever and 5000 deaths occur yearly across West Africa. Studies reported in English, that investigated Lassa fever with reference to West Africa were identified using the Medline Entrez-PubMed search and were used for this review. The scarcity of resources available for health care delivery system and the political instability that characterise the West African countries would continue to impede efforts for the control of Lassa fever in the sub-region. There is need for adequate training of health care workers regarding diagnostics, intensive care of patients under isolation, contact tracing, adequate precautionary measures in handling infectious laboratory specimens, control of the vector as well as care and disposal of infectious waste.

  3. Advanced vaccine candidates for Lassa fever.

    PubMed

    Lukashevich, Igor S

    2012-10-29

    Lassa virus (LASV) is the most prominent human pathogen of the Arenaviridae. The virus is transmitted to humans by a rodent reservoir, Mastomys natalensis, and is capable of causing lethal Lassa Fever (LF). LASV has the highest human impact of any of the viral hemorrhagic fevers (with the exception of Dengue Fever) with an estimated several hundred thousand infections annually, resulting in thousands of deaths in Western Africa. The sizeable disease burden, numerous imported cases of LF in non-endemic countries, and the possibility that LASV can be used as an agent of biological warfare make a strong case for vaccine development. Presently there is no licensed vaccine against LF or approved treatment. Recently, several promising vaccine candidates have been developed which can potentially target different groups at risk. The purpose of this manuscript is to review the LASV pathogenesis and immune mechanisms involved in protection. The current status of pre-clinical development of the advanced vaccine candidates that have been tested in non-human primates will be discussed. Major scientific, manufacturing, and regulatory challenges will also be considered.

  4. Rat-atouille: A Mixed Method Study to Characterize Rodent Hunting and Consumption in the Context of Lassa Fever.

    PubMed

    Bonwitt, Jesse; Kelly, Ann H; Ansumana, Rashid; Agbla, Schadrac; Sahr, Foday; Saez, Almudena Mari; Borchert, Matthias; Kock, Richard; Fichet-Calvet, Elisabeth

    2016-06-01

    Lassa fever is a zoonotic hemorrhagic illness predominant in areas across Nigeria, Sierra Leone, Guinea, Liberia, and southern Mali. The reservoir of Lassa virus is the multimammate mouse (Mastomys natalensis), a highly commensal species in West Africa. Primary transmission to humans occurs through direct or indirect contact with rodent body fluids such as urine, feces, saliva, or blood. Our research draws together qualitative and quantitative methods to provide a fuller and more nuanced perspective on these varied points of human-animal contact. In this article, we focus on the hunting, preparation, and consumption of rodents as possible routes of exposure in Bo, Sierra Leone. We found that the consumption of rodents, including the reservoir species, is widespread and does not neatly tally against generational or gender lines. Further, we found that the reasons for rodent consumption are multifactorial, including taste preferences, food security, and opportunistic behavior. We argue that on certain topics, such as rodent consumption, establishing trust with communities, and using qualitative research methods, is key to investigate sensitive issues and situate them in their wider context. To conclude, we recommend ways to refine sensitization campaigns to account for these socio-cultural contexts.

  5. Stochastic seasonality and nonlinear density-dependent factors regulate population size in an African rodent

    USGS Publications Warehouse

    Leirs, H.; Stenseth, N.C.; Nichols, J.D.; Hines, J.E.; Verhagen, R.; Verheyen, W.

    1997-01-01

    Ecology has long been troubled by the controversy over how populations are regulated. Some ecologists focus on the role of environmental effects, whereas others argue that density-dependent feedback mechanisms are central. The relative importance of both processes is still hotly debated, but clear examples of both processes acting in the same population are rare. Keyfactor analysis (regression of population changes on possible causal factors) and time-series analysis are often used to investigate the presence of density dependence, but such approaches may be biased and provide no information on actual demographic rates. Here we report on both density-dependent and density-independent effects in a murid rodent pest species, the multimammate rat Mastomys natalensis (Smith, 1834), using statistical capture-recapture models. Both effects occur simultaneously, but we also demonstrate that they do not affect all demographic rates in the same way. We have incorporated the obtained estimates of demographic rates in a population dynamics model and show that the observed dynamics are affected by stabilizing nonlinear density-dependent components coupled with strong deterministic and stochastic seasonal components.

  6. Lassa virus isolates from Mali and the Ivory Coast represent an emerging fifth lineage

    PubMed Central

    Manning, John T.; Forrester, Naomi; Paessler, Slobodan

    2015-01-01

    Previous imported cases of Lassa fever (LF) into the United Kingdom from the Ivory Coast and Mali, as well as the detection of Lassa virus (LASV) among the Mastomys natalensis population within Mali has led to the suggestion that the endemic area for LF is expanding. Initial phylogenetic analyses arrange isolates from Mali and the Ivory Coast separately from the classical lineage IV isolates taken from Sierra Leone, Guinea, and Liberia. The availability of full genome sequences continues to increase, allowing for a more complete phylogenetic comparison of the isolates from Mali and the Ivory Coast to the other existing isolates. In this study, we utilized a Bayesian approach to infer the demographic histories of each LASV isolate for which the full sequence was available. Our results indicate that the isolates from Mali and the Ivory Coast group separately from the isolates of lineage IV, comprising a distinct fifth lineage. The split between lineages IV and V is estimated to have occurred around 200–300 years ago, which coincides with the colonial period of West Africa. PMID:26483768

  7. Lassa fever: review of epidemiology and epizootiology.

    PubMed

    Monath, T P

    1975-01-01

    The basic ecology of Lassa fever appears to involve enzootic transmission of virus in commensal populations of a single murine species, Mastomys natalensis. Virus may spill over from the rodent cycle to man by various routes. Secondary spread between humans may occur within domiciliary groups, and persons infected within the community who develop clinical disease may introduce the virus into hospital and begin a cycle of nosocomial infection.Between 1969, when Lassa fever was first described, and June 1975, the disease was recognized on 9 discrete occasions, affecting 114 persons. Over one-third of these infections were acquired by person-to-person spread within hospitals. In only one outbreak (in Sierra Leone) were the majority of cases acquired in the community. Recent observations have indicated hyperendemic disease in eastern Sierra Leone. Cases have occurred in Nigeria, Sierra Leone, and Liberia, and serological evidence exists for activity of the virus elsewhere in West and Central Africa. Seasonal factors appear to play a role in the appearance of human cases. Attack rates have been higher in adults than in children. The source of infection and potential routes of virus transmission in the various epidemics are discussed, and perspectives for future epidemiological research are presented.

  8. Lassa fever: review of epidemiology and epizootiology

    PubMed Central

    Monath, T. P.

    1975-01-01

    The basic ecology of Lassa fever appears to involve enzootic transmission of virus in commensal populations of a single murine species, Mastomys natalensis. Virus may spill over from the rodent cycle to man by various routes. Secondary spread between humans may occur within domiciliary groups, and persons infected within the community who develop clinical disease may introduce the virus into hospital and begin a cycle of nosocomial infection. Between 1969, when Lassa fever was first described, and June 1975, the disease was recognized on 9 discrete occasions, affecting 114 persons. Over one-third of these infections were acquired by person-to-person spread within hospitals. In only one outbreak (in Sierra Leone) were the majority of cases acquired in the community. Recent observations have indicated hyperendemic disease in eastern Sierra Leone. Cases have occurred in Nigeria, Sierra Leone, and Liberia, and serological evidence exists for activity of the virus elsewhere in West and Central Africa. Seasonal factors appear to play a role in the appearance of human cases. Attack rates have been higher in adults than in children. The source of infection and potential routes of virus transmission in the various epidemics are discussed, and perspectives for future epidemiological research are presented. PMID:782738

  9. Novel arenavirus sequences in Hylomyscus sp. and Mus (Nannomys) setulosus from Côte d'Ivoire: implications for evolution of arenaviruses in Africa.

    PubMed

    Coulibaly-N'Golo, David; Allali, Bernard; Kouassi, Stéphane K; Fichet-Calvet, Elisabeth; Becker-Ziaja, Beate; Rieger, Toni; Olschläger, Stephan; Dosso, Hernri; Denys, Christiane; Ter Meulen, Jan; Akoua-Koffi, Chantal; Günther, Stephan

    2011-01-01

    This study aimed to identify new arenaviruses and gather insights in the evolution of arenaviruses in Africa. During 2003 through 2005, 1,228 small mammals representing 14 different genera were trapped in 9 villages in south, east, and middle west of Côte d'Ivoire. Specimens were screened by pan-Old World arenavirus RT-PCRs targeting S and L RNA segments as well as immunofluorescence assay. Sequences of two novel tentative species of the family Arenaviridae, Menekre and Gbagroube virus, were detected in Hylomyscus sp. and Mus (Nannomys) setulosus, respectively. Arenavirus infection of Mus (Nannomys) setulosus was also demonstrated by serological testing. Lassa virus was not found, although 60% of the captured animals were Mastomys natalensis. Complete S RNA and partial L RNA sequences of the novel viruses were recovered from the rodent specimens and subjected to phylogenetic analysis. Gbagroube virus is a closely related sister taxon of Lassa virus, while Menekre virus clusters with the Ippy/Mobala/Mopeia virus complex. Reconstruction of possible virus-host co-phylogeny scenarios suggests that, within the African continent, signatures of co-evolution might have been obliterated by multiple host-switching events.

  10. Innocuity studies of SAG-2 oral rabies vaccine in various Zimbabwean wild non-target species.

    PubMed

    Bingham, J; Schumacher, C L; Aubert, M F; Hill, F W; Aubert, A

    1997-06-01

    The SAG-2 modified live rabies vaccine was tested for innocuity when administered by the oral route in several potential wild non-target bait-consuming species, as follows: ten chacma baboons (Papio ursinus), six African civets (Civettictis civetta), six slender mongooses (Galerella sanguinea), six honey badgers (Mellivora capensis), six large-spotted genets (Genetta tigrina), 39 multi-mammate mice (Mastomys natalensis), 26 bushveld gerbils (Tatera leucogaster) and six pied crows (Corvus albus). At least 9.0 log10 median tissue culture infectious doses (TCID50), given in a volume of 1 ml, was administered orally to each of the animals, except the rodents which received 8.0 log10 TCID50, given in 0.1 ml. All the animals were observed for not < 90 days for signs of vaccine-induced rabies. Most of the species were also tested for vaccine virus replication in the oral cavity and persistent virus infection in the brain, salivary gland and tonsil. None of the animals died of rabies and no persistent infection was found. Rabies virus which was pathologically and serotypically indistinguishable from the vaccinal strain was isolated from the saliva of one genet 1 day after vaccine administration. From this study it was concluded that SAG-2 rabies vaccine would be safe for use in most situations where oral vaccination campaigns for jackals are required in Zimbabwe.

  11. Mapping the zoonotic niche of Lassa fever in Africa

    PubMed Central

    Mylne, Adrian Q. N.; Pigott, David M.; Longbottom, Joshua; Shearer, Freya; Duda, Kirsten A.; Messina, Jane P.; Weiss, Daniel J.; Moyes, Catherine L.; Golding, Nick; Hay, Simon I.

    2015-01-01

    Background Lassa fever is a viral haemorrhagic illness responsible for disease outbreaks across West Africa. It is a zoonosis, with the primary reservoir species identified as the Natal multimammate mouse, Mastomys natalensis. The host is distributed across sub-Saharan Africa while the virus' range appears to be restricted to West Africa. The majority of infections result from interactions between the animal reservoir and human populations, although secondary transmission between humans can occur, particularly in hospital settings. Methods Using a species distribution model, the locations of confirmed human and animal infections with Lassa virus (LASV) were used to generate a probabilistic surface of zoonotic transmission potential across sub-Saharan Africa. Results Our results predict that 37.7 million people in 14 countries, across much of West Africa, live in areas where conditions are suitable for zoonotic transmission of LASV. Four of these countries, where at-risk populations are predicted, have yet to report any cases of Lassa fever. Conclusions These maps act as a spatial guide for future surveillance activities to better characterise the geographical distribution of the disease and understand the anthropological, virological and zoological interactions necessary for viral transmission. Combining this zoonotic niche map with detailed patient travel histories can aid differential diagnoses of febrile illnesses, enabling a more rapid response in providing care and reducing the risk of onward transmission. PMID:26085474

  12. The Egyptian mongoose, Herpestes ichneumon, is a possible reservoir host of visceral leishmaniasis in eastern Sudan.

    PubMed

    Elnaiem, D A; Hassan, M M; Maingon, R; Nureldin, G H; Mekawi, A M; Miles, M; Ward, R D

    2001-05-01

    Investigations were made on possible reservoir hosts of Leishmania donovani in 2 zoonotic foci of visceral leishmaniasis (VL) in Dinder National Park (DNP) and the peri-domestic habitats of adjacent villages of eastern Sudan. Animals were captured, in November 1997-1998 and April-May 1999 and examined for L. donovani infection using light microscopy and 2 sensitive Polymerase Chain Reaction (PCR) systems. Microscopy and PCR investigations were also used to determine the infection rates of L. donovani in Phlebotomus orientalis captured from the uninhabited site of DNP. Infections of L. donovani were detected in 2 out of 14 Egyptian mongooses (Herpestes ichneumon), 1 out of 168 Arviconthus niloticus and 1 out of 8 Mastomys natalensis. Samples from 68 other animals captured from the study area were all negative for the infection. Active zoonotic transmission of L. donovani at the time of animal sampling in the uninhabited site of DNP was demonstrated by finding the parasite in 3.4% (7 out of 184) and 3.2% (5 out of 157) of flies collected in March 1998 and May 1999, respectively. We suggest that the Egyptian mongoose is a possible reservoir host of L. donovani. The importance of other animals in maintaining the infection is also discussed.

  13. Toxoplasmosis seroprevalence in urban rodents: a survey in Niamey, Niger

    PubMed Central

    Mercier, Aurélien; Garba, Madougou; Bonnabau, Henri; Kane, Mamadou; Rossi, Jean-Pierre; Dardé, Marie-Laure; Dobigny, Gauthier

    2013-01-01

    A serological survey of Toxoplasma gondii was conducted on 766 domestic and peridomestic rodents from 46 trapping sites throughout the city of Niamey, Niger. A low seroprevalence was found over the whole town with only 1.96% of the rodents found seropositive. However, differences between species were important, ranging from less than 2% in truly commensal Mastomys natalensis, Rattus rattus and Mus musculus, while garden-associated Arvicanthis niloticus displayed 9.1% of seropositive individuals. This is in line with previous studies on tropical rodents - that we reviewed here - which altogether show that Toxoplasma seroprevalence in rodent is highly variable, depending on many factors such as locality and/or species. Moreover, although we were not able to decipher statistically between habitat or species effect, such a contrast between Nile grass rats and the other rodent species points towards a potentially important role of environmental toxoplasmic infection. This would deserve to be further scrutinised since intra-city irrigated cultures are extending in Niamey, thus potentially increasing Toxoplasma circulation in this yet semi-arid region. As far as we are aware of, our study is one of the rare surveys of its kind performed in Sub-Saharan Africa and the first one ever conducted in the Sahel. PMID:23828008

  14. Housing equity for health equity: a rights-based approach to the control of Lassa fever in post-war Sierra Leone.

    PubMed

    Kelly, J Daniel; Barrie, M Bailor; Ross, Rachel A; Temple, Brian A; Moses, Lina M; Bausch, Daniel G

    2013-01-02

    Poor quality housing is an infringement on the rights of all humans to a standard of living adequate for health. Among the many vulnerabilities of those without adequate shelter is the risk of disease spread by rodents and other pests. One such disease is Lassa fever, an acute and sometimes severe viral hemorrhagic illness endemic in West Africa. Lassa virus is maintained in the rodent Mastomys natalensis, commonly known as the "multimammate rat," which frequently invades the domestic environment, putting humans at risk of Lassa fever. The highest reported incidence of Lassa fever in the world is consistently in the Kenema District of Sierra Leone, a region that was at the center of Sierra Leone's civil war in which tens of thousands of lives were lost and hundreds of thousands of dwellings destroyed. Despite the end of the war in 2002, most of Kenema's population still lives in inadequate housing that puts them at risk of rodent invasion and Lassa fever. Furthermore, despite years of health education and village hygiene campaigns, the incidence of Lassa fever in Kenema District appears to be increasing. We focus on Lassa fever as a matter of human rights, proposing a strategy to improve housing quality, and discuss how housing equity has the potential to improve health equity and ultimately economic productivity in Sierra Leone. The manuscript is designed to spur discussion and action towards provision of housing and prevention of disease in one of the world's most vulnerable populations.

  15. Novel Arenavirus Sequences in Hylomyscus sp. and Mus (Nannomys) setulosus from Côte d'Ivoire: Implications for Evolution of Arenaviruses in Africa

    PubMed Central

    Kouassi, Stéphane K.; Fichet-Calvet, Elisabeth; Becker-Ziaja, Beate; Rieger, Toni; Ölschläger, Stephan; Dosso, Hernri; Denys, Christiane; ter Meulen, Jan; Akoua-Koffi, Chantal; Günther, Stephan

    2011-01-01

    This study aimed to identify new arenaviruses and gather insights in the evolution of arenaviruses in Africa. During 2003 through 2005, 1,228 small mammals representing 14 different genera were trapped in 9 villages in south, east, and middle west of Côte d'Ivoire. Specimens were screened by pan-Old World arenavirus RT-PCRs targeting S and L RNA segments as well as immunofluorescence assay. Sequences of two novel tentative species of the family Arenaviridae, Menekre and Gbagroube virus, were detected in Hylomyscus sp. and Mus (Nannomys) setulosus, respectively. Arenavirus infection of Mus (Nannomys) setulosus was also demonstrated by serological testing. Lassa virus was not found, although 60% of the captured animals were Mastomys natalensis. Complete S RNA and partial L RNA sequences of the novel viruses were recovered from the rodent specimens and subjected to phylogenetic analysis. Gbagroube virus is a closely related sister taxon of Lassa virus, while Menekre virus clusters with the Ippy/Mobala/Mopeia virus complex. Reconstruction of possible virus–host co-phylogeny scenarios suggests that, within the African continent, signatures of co-evolution might have been obliterated by multiple host-switching events. PMID:21695269

  16. Spatial segregation between invasive and native commensal rodents in an urban environment: a case study in Niamey, Niger.

    PubMed

    Garba, Madougou; Dalecky, Ambroise; Kadaoure, Ibrahima; Kane, Mamadou; Hima, Karmadine; Veran, Sophie; Gagare, Sama; Gauthier, Philippe; Tatard, Caroline; Rossi, Jean-Pierre; Dobigny, Gauthier

    2014-01-01

    Invasive rodents have been responsible for the diffusion worldwide of many zoonotic agents, thus representing major threats for public health. Cities are important hubs for people and goods exchange and are thus expected to play a pivotal role in invasive commensal rodent dissemination. Yet, data about urban rodents' ecology, especially invasive vs. native species interactions, are dramatically scarce. Here, we provide results of an extensive survey of urban rodents conducted in Niamey, Niger, depicting the early stages of rodent bioinvasions within a city. We explore the species-specific spatial distributions throughout the city using contrasted approaches, namely field sampling, co-occurrence analysis, occupancy modelling and indicator geostatistics. We show that (i) two species (i.e. rural-like vs. truly commensal) assemblages can be identified, and that (ii) within commensal rodents, invasive (Rattus rattus and Mus musculus) and native (Mastomys natalensis) species are spatially segregated. Moreover, several pieces of arguments tend to suggest that these exclusive distributions reflect an ongoing native-to-invasive species turn over. The underlying processes as well as the possible consequences for humans are discussed.

  17. Effects of Land Use on Plague (Yersinia pestis) Activity in Rodents in Tanzania

    PubMed Central

    McCauley, Douglas J.; Salkeld, Daniel J.; Young, Hillary S.; Makundi, Rhodes; Dirzo, Rodolfo; Eckerlin, Ralph P.; Lambin, Eric F.; Gaffikin, Lynne; Barry, Michele; Helgen, Kristofer M.

    2015-01-01

    Understanding the effects of land-use change on zoonotic disease risk is a pressing global health concern. Here, we compare prevalence of Yersinia pestis, the etiologic agent of plague, in rodents across two land-use types—agricultural and conserved—in northern Tanzania. Estimated abundance of seropositive rodents nearly doubled in agricultural sites compared with conserved sites. This relationship between land-use type and abundance of seropositive rodents is likely mediated by changes in rodent and flea community composition, particularly via an increase in the abundance of the commensal species, Mastomys natalensis, in agricultural habitats. There was mixed support for rodent species diversity negatively impacting Y. pestis seroprevalence. Together, these results suggest that land-use change could affect the risk of local transmission of plague, and raise critical questions about transmission dynamics at the interface of conserved and agricultural habitats. These findings emphasize the importance of understanding disease ecology in the context of rapidly proceeding landscape change. PMID:25711606

  18. Lassa virus isolates from Mali and the Ivory Coast represent an emerging fifth lineage.

    PubMed

    Manning, John T; Forrester, Naomi; Paessler, Slobodan

    2015-01-01

    Previous imported cases of Lassa fever (LF) into the United Kingdom from the Ivory Coast and Mali, as well as the detection of Lassa virus (LASV) among the Mastomys natalensis population within Mali has led to the suggestion that the endemic area for LF is expanding. Initial phylogenetic analyses arrange isolates from Mali and the Ivory Coast separately from the classical lineage IV isolates taken from Sierra Leone, Guinea, and Liberia. The availability of full genome sequences continues to increase, allowing for a more complete phylogenetic comparison of the isolates from Mali and the Ivory Coast to the other existing isolates. In this study, we utilized a Bayesian approach to infer the demographic histories of each LASV isolate for which the full sequence was available. Our results indicate that the isolates from Mali and the Ivory Coast group separately from the isolates of lineage IV, comprising a distinct fifth lineage. The split between lineages IV and V is estimated to have occurred around 200-300 years ago, which coincides with the colonial period of West Africa.

  19. Viremia and antibody response of small African and laboratory animals to Crimean-Congo hemorrhagic fever virus infection.

    PubMed

    Shepherd, A J; Leman, P A; Swanepoel, R

    1989-05-01

    Eleven species of small African wild mammals, laboratory rabbits, guinea pigs, and Syrian hamsters were infected with Crimean-Congo hemorrhagic fever (CCHF) virus. Low-titered viremia followed by development of antibody was observed in scrub hares (Lepus saxatilis), Cape ground squirrels (Xerus inauris), red veld rats (Aethomys chrysophilus), white tailed rats (Mystromys albicaudatus), bushveld gerbils (Tatera leucogaster), striped mice (Rhabdomys pumilio), and guinea pigs. The maximum viremic titer in 4 scrub hares was 10(1.7-4.2) 50% mouse lethal doses/ml. Viremia was detected in 1/17 infected laboratory rabbits. Antibody response was only detected in South African hedgehogs (Atelerix frontalis), highveld gerbils (T. brantsii), Namaqua gerbils (Desmodillus auricularis), 2 species of multimammate mouse (Mastomys natalensis and M. coucha), and Syrian hamsters. The results of the study indicate that a proportion of infected scrub hares develop CCHF viremia of an intensity shown in the Soviet Union to be sufficient for infection of feeding immature ixodid ticks, but that South African hedgehogs and wild rodents are unlikely to be of importance as maintenance hosts of the virus in southern Africa.

  20. Advanced Vaccine Candidates for Lassa Fever

    PubMed Central

    Lukashevich, Igor S.

    2012-01-01

    Lassa virus (LASV) is the most prominent human pathogen of the Arenaviridae. The virus is transmitted to humans by a rodent reservoir, Mastomys natalensis, and is capable of causing lethal Lassa Fever (LF). LASV has the highest human impact of any of the viral hemorrhagic fevers (with the exception of Dengue Fever) with an estimated several hundred thousand infections annually, resulting in thousands of deaths in Western Africa. The sizeable disease burden, numerous imported cases of LF in non-endemic countries, and the possibility that LASV can be used as an agent of biological warfare make a strong case for vaccine development. Presently there is no licensed vaccine against LF or approved treatment. Recently, several promising vaccine candidates have been developed which can potentially target different groups at risk. The purpose of this manuscript is to review the LASV pathogenesis and immune mechanisms involved in protection. The current status of pre-clinical development of the advanced vaccine candidates that have been tested in non-human primates will be discussed. Major scientific, manufacturing, and regulatory challenges will also be considered. PMID:23202493

  1. High Incidence of Preharvest Colonization of Huanglongbing-Symptomatic Citrus sinensis Fruit by Lasiodiplodia theobromae (Diplodia natalensis) and Exacerbation of Postharvest Fruit Decay by That Fungus

    PubMed Central

    Zhao, Wei; Bai, Jinhe; McCollum, Greg

    2014-01-01

    Huanglongbing (HLB), presumably caused by the bacterium “Candidatus Liberibacter asiaticus,” is a devastating citrus disease associated with excessive preharvest fruit drop. Lasiodiplodia theobromae (diplodia) is the causal organism of citrus stem end rot (SER). The pathogen infects citrus fruit under the calyx abscission zone (AZ-C) and is associated with cell wall hydrolytic enzymes similar to plant enzymes involved in abscission. By means of DNA sequencing, diplodia was found in “Ca. Liberibacter asiaticus”-positive juice from HLB-symptomatic fruit (S) but not in “Ca. Liberibacter asiaticus”-negative juice. Therefore, the incidence of diplodia in fruit tissues, the impact on HLB-related postharvest decay, and the implications for HLB-related preharvest fruit drop were investigated in Hamlin and Valencia oranges. Quantitative PCR results (qPCR) revealed a significantly (P < 0.001) greater incidence of diplodia in the AZ-C of HLB-symptomatic (S; “Ca. Liberibacter asiaticus” threshold cycle [CT] of <30) than in the AZ-C of in asymptomatic (AS; “Ca. Liberibacter asiaticus” CT of ≥30) fruit. In agreement with the qPCR results, 2 weeks after exposure to ethylene, the incidences of SER in S fruit were 66.7% (Hamlin) and 58.7% (Valencia), whereas for AS fruit the decay rates were 6.7% (Hamlin) and 5.3% (Valencia). Diplodia colonization of S fruit AZ-C was observed by scanning electron microscopy and confirmed by PCR test and morphology of conidia in isolates from the AZ-C after surface sterilization. Diplodia CT values were negatively correlated with ethylene production (R = −0.838 for Hamlin; R = −0.858 for Valencia) in S fruit, and positively correlated with fruit detachment force (R = 0.855 for Hamlin; R = 0.850 for Valencia), suggesting that diplodia colonization in AZ-C may exacerbate HLB-associated preharvest fruit drop. PMID:25344245

  2. High incidence of preharvest colonization of huanglongbing-symptomatic Citrus sinensis fruit by Lasiodiplodia theobromae (Diplodia natalensis) and exacerbation of postharvest fruit decay by that fungus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Huanglongbing (HLB), presumably caused by bacterium Candidatus Liberibacter asiaticus (CLas), is a devastating citrus disease associated with excessive pre-harvest fruit drop. Lasiodiplodia theobromae (Diplodia) is the causal organism of citrus stem end rot (SER). The pathogen infects citrus fruit ...

  3. Experimental plague infection in South African wild rodents.

    PubMed Central

    Shepherd, A. J.; Leman, P. A.; Hummitzsch, D. E.

    1986-01-01

    Susceptibility studies were undertaken to determine the response of some South African wild rodent species to experimental plague (Yersinia pestis) infection. A degree of plague resistance was found in three gerbil species captured in the plague enzootic region of the northern Cape Province, these being the Namaqua gerbil, Desmodillus auricularis, (LD50 1 X 10(6) organisms), the bushveld gerbil, Tatera leucogaster, (LD50 9.1 X 10(5)) and the highveld gerbil, T. brantsii (LD50 4 X 10(2)). Animals from a population of the four-striped mouse, Rhabdomys pumilio, captured in the plague area of Port Elizabeth, proved moderately resistant to experimental plague infection (LD50 1.3 X 10(4)) while those from another population of the same species captured in a plague-free area of the Orange Free State were extremely susceptible (LD50, 5 organisms). The response of both populations however was a heterogeneous one. Marked differences in susceptibility were also found between two populations of multimammate mice, Mastomys natalensis (2n = 32) although both originated from areas outwith the known distribution of plague in southern Africa. The 50% infectious dose was relatively high in T. leucogaster (3.2 X 10(2)) and D. auricularis (1.7 X 10(3)), but was low (2-16 organisms) in the other rodent species tested. The plague antibody response, determined by enzyme-linked immunosorbent assay (ELISA), was extremely short-lived in T. leucogaster, only 10% of inoculated animals remaining seropositive at low titres after 11 weeks. Antibodies persisted for only slightly longer in the sera of T. brantsii which were reinoculated with 2 X 10(3) plague organisms 6 weeks after initial challenge. The demonstration of the existence of both susceptible and resistant populations of R. pumilio and M. natalensis indicates that these species must be considered as potential plague reservoir hosts in parts of South Africa. The results suggest that resistance to plague infection in previously epizootic

  4. First Detection of Mycobacteria in African Rodents and Insectivores, Using Stratified Pool Screening▿ †

    PubMed Central

    Durnez, Lies; Eddyani, Miriam; Mgode, Georgies F.; Katakweba, Abdul; Katholi, Charles R.; Machang'u, Robert R.; Kazwala, Rudovik R.; Portaels, Françoise; Leirs, Herwig

    2008-01-01

    With the rising number of patients with human immunodeficiency virus (HIV)/AIDS in developing countries, the control of mycobacteria is of growing importance. Previous studies have shown that rodents and insectivores are carriers of mycobacteria. However, it is not clear how widespread mycobacteria are in these animals and what their role is in spreading them. Therefore, the prevalence of mycobacteria in rodents and insectivores was studied in and around Morogoro, Tanzania. Live rodents were trapped, with three types of live traps, in three habitats. Pieces of organs were pooled per habitat, species, and organ type (stratified pooling); these sample pools were examined for the presence of mycobacteria by PCR, microscopy, and culture methods. The mycobacterial isolates were identified using phenotypic techniques and sequencing. In total, 708 small mammals were collected, 31 of which were shrews. By pool prevalence estimation, 2.65% of the animals were carriers of mycobacteria, with a higher prevalence in the urban areas and in Cricetomys gambianus and the insectivore Crocidura hirta. Nontuberculous mycobacteria (Mycobacterium chimaera, M. intracellulare, M. arupense, M. parascrofulaceum, and Mycobacterium spp.) were isolated from C. gambianus, Mastomys natalensis, and C. hirta. This study is the first to report findings of mycobacteria in African rodents and insectivores and the first in mycobacterial ecology to estimate the prevalence of mycobacteria after stratified pool screening. The fact that small mammals in urban areas carry more mycobacteria than those in the fields and that potentially pathogenic mycobacteria were isolated identifies a risk for other animals and humans, especially HIV/AIDS patients, that have a weakened immune system. PMID:18065608

  5. Isolation and characterization of flagellates from rodents and canids in Masinga, Machakos District, Kenya.

    PubMed

    Githure, John I.; Anjili, Christopher O.; Ngumbi, Philip M.; Mwanyumba, Panuel M.; Lugalia, Reuben; Koech, Davy K.; Kinoti, George K.

    1995-11-01

    A total of 728 animals comprising of 633 rodents and 95 canids were examined for leishmanial parasites. Flagellates were isolated from 67 out of 111 (60.4%) Acomys subspinosus (spiny mouse), 12 out of 143 (8.4% ) Mastomys natalensis (multimammate rat), 2 out of 50 (4.0%) Lemniscomys striatus (striped mouse), 2 out of 6 (33.3%) Herpestes sanguineus (slender mongoose), 1 of 1 Helogale parvula (dwarf mongoose) and 1 out of 84 Canis familiaris (domestic dog). All isolates were characterized by Isoenzyme analysis using nine enzymes, namely, malate dehydrogenase (MDH), phosphoglucomutase (PGM), glucose phosphate isomerase (GPI), isocitrate dehydrogenase (ICD), nucleoside hydrolase (NH), glucose 6-phosphate dehydrogenase (G6PD), malic enzyme (ME), 6-phosphogluconate dehydrogenase (GPGD) and mannose phosphate isomerase (MPI). Enzyme profiles of these isolates were compared with those of five WHO Leishmania reference strains and five well characterized rodent trypanosomes of the subgenus Herpetosoma. The profiles of the isolates were found to be different from those of the Leishmania and Trypanosoma reference strains but the parasites were morphologically similar to rodent trypanosomes. These results suggest that Leishmania parasites were not among the isolates. The enzymes profiles of the three mongoose isolates were identical but differed from profiles of isolates from rodents and dog. This is the first time in Kenya that a high prevalence of nonpathogenic trypanosomes is reported in rodents and canids. From the epidemiological point of view, these trypanosomes must be differentiated from the pathogenic species of trypanosomes and Leishmania that infect man and other animals. The results of this study suggest that rodents do not seem to play a role as reservoirs of Leishmania parasites in Masinga Location, Kenya.

  6. Plague in Africa from 1935 to 1949

    PubMed Central

    Davis, D. H. S.

    1953-01-01

    The history of plague in Africa during the period 1935-49 is reviewed. Much of the information derives from a questionnaire sent to all African territories in 1950. The annual incidence of plague in Africa declined, particularly from 1946 onwards. In 1949, under 400 cases were reported, as compared with over 6,000 in 1935. By the end of 1949, plague was still active in the Belgian Congo, Kenya and Tanganyika, Madagascar, and southern Africa. No cases were reported from Egypt, Tunisia, Algeria, Morocco, Senegal, or Uganda during 1949. A comparison of the seasonal incidence of plague with prevailing atmospheric conditions (temperature and rainfall) in African territories shows that human plague is more frequent in warm moist weather—60°-80°F (15°-27°C)—than in hot dry, or cold, weather—over 80°F (27°C) or under 60°F (15°C). The highlands of equatorial Africa and of Madagascar appear to provide the optimum environment for the persistence of plague on the domestic (murine) plane and the high-veld and Kalahari of southern Africa on the sylvatic plane. The rat (Rattus rattus) and the multimammate mouse (R. (Mastomys) natalensis) and their fleas Xenopsylla brasiliensis and X. cheopis appear to be mainly responsible for the persistence of the reservoir in the East African highlands; R. rattus and X. cheopis play this role in Madagascar. The gerbils (Tatera and Desmodillus) and their burrow fleas X. philoxera and X. piriei are the main reservoirs of plague in southern Africa. Within these areas, Pasteurella pestis finds an environment suitable for its continued survival; the conditions seem to be comparable to those defined as obtaining in endemic centres in India. Elsewhere in Africa such endemic centres do not appear to exist. PMID:13115987

  7. Isolation of Trypanosoma brucei gambiense from Cured and Relapsed Sleeping Sickness Patients and Adaptation to Laboratory Mice

    PubMed Central

    Pyana, Patient Pati; Ngay Lukusa, Ipos; Mumba Ngoyi, Dieudonné; Van Reet, Nick; Kaiser, Marcel; Karhemere Bin Shamamba, Stomy; Büscher, Philippe

    2011-01-01

    Background Sleeping sickness due to Trypanosoma brucei (T.b.) gambiense is still a major public health problem in some central African countries. Historically, relapse rates around 5% have been observed for treatment with melarsoprol, widely used to treat second stage patients. Later, relapse rates of up to 50% have been recorded in some isolated foci in Angola, Sudan, Uganda and Democratic Republic of the Congo (DRC). Previous investigations are not conclusive on whether decreased sensitivity to melarsoprol is responsible for these high relapse rates. Therefore we aimed to establish a parasite collection isolated from cured as well as from relapsed patients for downstream comparative drug sensitivity profiling. A major constraint for this type of investigation is that T.b. gambiense is particularly difficult to isolate and adapt to classical laboratory rodents. Methodology/Principal Findings From 360 patients treated in Dipumba hospital, Mbuji-Mayi, D.R. Congo, blood and cerebrospinal fluid (CSF) was collected before treatment. From patients relapsing during the 24 months follow-up, the same specimens were collected. Specimens with confirmed parasite presence were frozen in liquid nitrogen in a mixture of Triladyl, egg yolk and phosphate buffered glucose solution. Isolation was achieved by inoculation of the cryopreserved specimens in Grammomys surdaster, Mastomys natalensis and SCID mice. Thus, 85 strains were isolated from blood and CSF of 55 patients. Isolation success was highest in Grammomys surdaster. Forty strains were adapted to mice. From 12 patients, matched strains were isolated before treatment and after relapse. All strains belong to T.b. gambiense type I. Conclusions and Significance We established a unique collection of T.b. gambiense from cured and relapsed patients, isolated in the same disease focus and within a limited period. This collection is available for genotypic and phenotypic characterisation to investigate the mechanism behind

  8. Anthropogenic soils and land use patterns in relation to small mammal and flea abundance in plague endemic area of Western Usambara Mountains, Tanzania.

    PubMed

    Kimaro, Didas N; Msanya, Balthazar M; Meliyo, Joel; Hieronimo, Proches; Mwango, Sibaway; Kihupi, Nganga I; Gulinck, Hubert; Deckers, Jozef A

    2014-07-01

    Heterogeneity in the landscapes of West Usambara Mountains on land use and human activities has been reported. However, the interface of land use patterns and human modified soils with small mammal and flea abundance for possible explanation of plague has not been explored. This study was carried out to determine the link between anthropogenic soils and land use patterns on small mammal and flea abundance and the occurrence of reported plague in the Western Usambara Mountains in Tanzania. Standard soil survey methods were used to identify and describe soils and land use patterns on lower slopes and valley bottoms on which the surrounding villages are reported to have high and medium plague frequencies. The identified soils were characterised in terms of their morphological and physico-chemical properties and classified according to FAO-World Reference Base for Soil Resources. Small mammals were trapped on the same landscape positions and identified to genus/species level. Fleas were removed from the trapped small mammals, counted and identified to species level. In total 57 small mammals were captured from which 32 fleas were collected. Results show that human settlements and mixed cultivation on lower slopes and continuous vegetable cropping in the valley bottoms are dominant land use types. Intensive use of forest soils, manuring and irrigation on farms in the studied landscapes have contributed to the development of uniquely human modified soils namely Hortic Anthrosols in the lower slopes and Plaggic Irragric Hortic Anthrosols in valley bottoms. The identified anthropogenic soils and land use patterns are associated with high abundance of small mammals (Mastomys natalensis) and flea species (Xenopsylla brasiliensis and Dinopsyllus lypusus). This phenomenon is vividly apparent in the villages with medium to high plague frequencies. The study suggests that plague surveillance programmes should consider the existing relationship between anthropogenic soils, land

  9. First detection of mycobacteria in African rodents and insectivores, using stratified pool screening.

    PubMed

    Durnez, Lies; Eddyani, Miriam; Mgode, Georgies F; Katakweba, Abdul; Katholi, Charles R; Machang'u, Robert R; Kazwala, Rudovik R; Portaels, Françoise; Leirs, Herwig

    2008-02-01

    With the rising number of patients with human immunodeficiency virus (HIV)/AIDS in developing countries, the control of mycobacteria is of growing importance. Previous studies have shown that rodents and insectivores are carriers of mycobacteria. However, it is not clear how widespread mycobacteria are in these animals and what their role is in spreading them. Therefore, the prevalence of mycobacteria in rodents and insectivores was studied in and around Morogoro, Tanzania. Live rodents were trapped, with three types of live traps, in three habitats. Pieces of organs were pooled per habitat, species, and organ type (stratified pooling); these sample pools were examined for the presence of mycobacteria by PCR, microscopy, and culture methods. The mycobacterial isolates were identified using phenotypic techniques and sequencing. In total, 708 small mammals were collected, 31 of which were shrews. By pool prevalence estimation, 2.65% of the animals were carriers of mycobacteria, with a higher prevalence in the urban areas and in Cricetomys gambianus and the insectivore Crocidura hirta. Nontuberculous mycobacteria (Mycobacterium chimaera, M. intracellulare, M. arupense, M. parascrofulaceum, and Mycobacterium spp.) were isolated from C. gambianus, Mastomys natalensis, and C. hirta. This study is the first to report findings of mycobacteria in African rodents and insectivores and the first in mycobacterial ecology to estimate the prevalence of mycobacteria after stratified pool screening. The fact that small mammals in urban areas carry more mycobacteria than those in the fields and that potentially pathogenic mycobacteria were isolated identifies a risk for other animals and humans, especially HIV/AIDS patients, that have a weakened immune system.

  10. Evidence for eight tandem and five centric fusions in the evolution of the karyotype of Aethomys namaquensis A. Smith (Rodentia: Muridae).

    PubMed

    Baker, R J; Qumsiyeh, M B; Rautenbach, I L

    1988-06-30

    G- and C-banded chromosomes of Aethomys namaquensis (2n = 24), A. chrysophilus (2n = 44), and Praomys coucha (2n = 36) are compared and contrasted with published material on Australian Muridae and North American Sigmodontidae. Direction and types of chromosomal rearrangements are established using cladistic methodology. An acrocentric morphology for chromosomes 5, 14, 15 and 20 (numbering system from Peromyscus) are proposed as primitive for the common ancestor of the Muridae and Sigmodontidae rodent lineages. Reduced diploid number of Aethomys namaquensis is derived by eight tandem and five centric fusions since divergence from the common ancestor with A. chrysophilus. The two species of Aethomys share one derived metacentric chromosome that distinguishes them from Praomys. Praomys has unique chromosomes which can be derived from the proposed primitive condition by five centric fusions and five pericentric inversions. It is concluded that karyotypic orthoselection for tandem and centric fusions is best explained by cellular or biochemical mechanisms rather than variation in population characteristics.

  11. 16S rRNA Amplicon Sequencing for Epidemiological Surveys of Bacteria in Wildlife

    PubMed Central

    Razzauti, Maria; Bard, Emilie; Bernard, Maria; Brouat, Carine; Charbonnel, Nathalie; Dehne-Garcia, Alexandre; Loiseau, Anne; Tatard, Caroline; Tamisier, Lucie; Vayssier-Taussat, Muriel; Vignes, Helene

    2016-01-01

    ABSTRACT The human impact on natural habitats is increasing the complexity of human-wildlife interactions and leading to the emergence of infectious diseases worldwide. Highly successful synanthropic wildlife species, such as rodents, will undoubtedly play an increasingly important role in transmitting zoonotic diseases. We investigated the potential for recent developments in 16S rRNA amplicon sequencing to facilitate the multiplexing of the large numbers of samples needed to improve our understanding of the risk of zoonotic disease transmission posed by urban rodents in West Africa. In addition to listing pathogenic bacteria in wild populations, as in other high-throughput sequencing (HTS) studies, our approach can estimate essential parameters for studies of zoonotic risk, such as prevalence and patterns of coinfection within individual hosts. However, the estimation of these parameters requires cleaning of the raw data to mitigate the biases generated by HTS methods. We present here an extensive review of these biases and of their consequences, and we propose a comprehensive trimming strategy for managing these biases. We demonstrated the application of this strategy using 711 commensal rodents, including 208 Mus musculus domesticus, 189 Rattus rattus, 93 Mastomys natalensis, and 221 Mastomys erythroleucus, collected from 24 villages in Senegal. Seven major genera of pathogenic bacteria were detected in their spleens: Borrelia, Bartonella, Mycoplasma, Ehrlichia, Rickettsia, Streptobacillus, and Orientia. Mycoplasma, Ehrlichia, Rickettsia, Streptobacillus, and Orientia have never before been detected in West African rodents. Bacterial prevalence ranged from 0% to 90% of individuals per site, depending on the bacterial taxon, rodent species, and site considered, and 26% of rodents displayed coinfection. The 16S rRNA amplicon sequencing strategy presented here has the advantage over other molecular surveillance tools of dealing with a large spectrum of bacterial

  12. Prevalence and Risk Factors of Lassa Seropositivity in Inhabitants of the Forest Region of Guinea: A Cross-Sectional Study

    PubMed Central

    Kernéis, Solen; Koivogui, Lamine; Magassouba, N'Faly; Koulemou, Kekoura; Lewis, Rosamund; Aplogan, Aristide; Grais, Rebecca F.; Guerin, Philippe J.; Fichet-Calvet, Elisabeth

    2009-01-01

    Background Lassa fever is a viral hemorrhagic fever endemic in West Africa. The reservoir host of the virus is a multimammate rat, Mastomys natalensis. Prevalence estimates of Lassa virus antibodies in humans vary greatly between studies, and the main modes of transmission of the virus from rodents to humans remain unclear. We aimed to (i) estimate the prevalence of Lassa virus–specific IgG antibodies (LV IgG) in the human population of a rural area of Guinea, and (ii) identify risk factors for positive LV IgG. Methods and Findings A population-based cross-sectional study design was used. In April 2000, all individuals one year of age and older living in three prefectures located in the tropical secondary forest area of Guinea (Gueckedou, Lola and Yomou) were sampled using two-stage cluster sampling. For each individual identified by the sampling procedure and who agreed to participate, a standardized questionnaire was completed to collect data on personal exposure to potential risk factors for Lassa fever (mainly contact with rodents), and a blood sample was tested for LV IgG. A multiple logistic regression model was used to determine risk factors for positive LV IgG. A total of 1424 subjects were interviewed and 977 sera were tested. Prevalence of positive LV Ig was of 12.9% [10.8%–15.0%] and 10.0% [8.1%–11.9%] in rural and urban areas, respectively. Two risk factors of positive LV IgG were identified: to have, in the past twelve months, undergone an injection (odds ratio [OR] = 1.8 [1.1–3.1]), or lived with someone displaying a haemorrhage (OR = 1.7 [1.1–2.9]). No factors related to contacts with rats and/or mice remained statistically significant in the multivariate analysis. Conclusions Our study underlines the potential importance of person-to-person transmission of Lassa fever, via close contact in the same household or nosocomial exposure. PMID:19924222

  13. Risk Maps of Lassa Fever in West Africa

    PubMed Central

    Fichet-Calvet, Elisabeth; Rogers, David John

    2009-01-01

    Background Lassa fever is caused by a viral haemorrhagic arenavirus that affects two to three million people in West Africa, causing a mortality of between 5,000 and 10,000 each year. The natural reservoir of Lassa virus is the multi-mammate rat Mastomys natalensis, which lives in houses and surrounding fields. With the aim of gaining more information to control this disease, we here carry out a spatial analysis of Lassa fever data from human cases and infected rodent hosts covering the period 1965–2007. Information on contemporary environmental conditions (temperature, rainfall, vegetation) was derived from NASA Terra MODIS satellite sensor data and other sources and for elevation from the GTOPO30 surface for the region from Senegal to the Congo. All multi-temporal data were analysed using temporal Fourier techniques to generate images of means, amplitudes and phases which were used as the predictor variables in the models. In addition, meteorological rainfall data collected between 1951 and 1989 were used to generate a synoptic rainfall surface for the same region. Methodology/Principal Findings Three different analyses (models) are presented, one superimposing Lassa fever outbreaks on the mean rainfall surface (Model 1) and the other two using non-linear discriminant analytical techniques. Model 2 selected variables in a step-wise inclusive fashion, and Model 3 used an information-theoretic approach in which many different random combinations of 10 variables were fitted to the Lassa fever data. Three combinations of absence∶presence clusters were used in each of Models 2 and 3, the 2 absence∶1 presence cluster combination giving what appeared to be the best result. Model 1 showed that the recorded outbreaks of Lassa fever in human populations occurred in zones receiving between 1,500 and 3,000 mm rainfall annually. Rainfall, and to a much lesser extent temperature variables, were most strongly selected in both Models 2 and 3, and neither vegetation nor

  14. Parasites of the Nile rat in rural and urban regions of Sudan.

    PubMed

    Fagir, Dina M; El-Rayah, El-Amin

    2009-06-01

    ). Xenopsylla cheopis is the most important vector of plague and the rickettsial infection murine typhus (Gratz 1999). Man can also acquire the infection through direct contact with infected animals' tissues (WHO 1987). Arvicanthis niloticus, Mastomys natalensis and Rattus rattus are probably the most important and widespread reservoirs of plague in Kenya: 10 percent of all Rattus rattus tested were found to be positive as compared to 12% of the Arvicanthis niloticus (Gratz 1999).

  15. 78 FR 39307 - National Environmental Policy Act: Implementing Procedures; Addition to Categorical Exclusions...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-01

    ... snakes (Burmese python (Python molurus), Northern African python (Python sebae), Southern African python (Python natalensis), and yellow anaconda (Eunectes notaeus), 2012). The issues addressed in the EAs...

  16. Lassa fever in Guinea: II. Distribution and prevalence of Lassa virus infection in small mammals.

    PubMed

    Demby, A H; Inapogui, A; Kargbo, K; Koninga, J; Kourouma, K; Kanu, J; Coulibaly, M; Wagoner, K D; Ksiazek, T G; Peters, C J; Rollin, P E; Bausch, D G

    2001-01-01

    Rodents of the genus Mastomys form the reservoir for Lassa virus (LV), an arenavirus that causes a potentially severe hemorrhagic illness, Lassa fever (LF). Although Mastomys rodents exist throughout sub-Saharan Africa, areas of human LF appear to be quite focal. The distribution of small mammals and LV-infected Mastomys has been assessed in only a few countries. We conducted a survey of small mammals in selected regions of Guinea to assess the degree to which LV poses a public health risk in that country. A total of 1,616 small mammals, including 956 (59%) Mastomys, were captured from 444 households and seven bush sites. Mastomys made up > 90% of the captured animals in the savannah, savannah-forest transition, and forest regions of Guinea, while Mus musculus dominated in coastal and urban sites. Animals were analyzed via enzyme-linked immunosorbent assay (ELISA) for LV-specific antigen (blood and spleen homogenate) and IgG antibody (blood only). Virus isolation from spleen homogenates was also performed on a subset of animals. Lassa antibody and antigen were found in 96 (11%) and 46 (5%), respectively, of 884 tested Mastomys. Antibody and antigen were essentially mutually exclusive and showed profiles consistent with vertical transmission of both LV and antibody. LV was isolated only from Mastomys. ELISA antigen constituted an acceptable surrogate for virus isolation, with a sensitivity and specificity when performed on blood of 78% (95% confidence interval: 68-83%) and 98% (95-99%), respectively. The proportion of LV-infected Mastomys per region ranged from 0 to 9% and was highest in the savannah and forest zones. The proportion of infected animals per village varied considerably, even between villages in close proximity. Infected animals tended to cluster in relatively few houses, suggesting the existence of focal "hot spots" of LV-infected Mastomys that may account for the observed heterogeneous distribution of LF.

  17. Spot light survey on fresh-water snails of medical importance in Al Fayoum Governorate, Egypt.

    PubMed

    Abo-Madyan, Ahmed A; Morsy, Tosson A; Motawea, Saad M; El Garhy, Manal F; Massoud, Ahmed M A

    2005-04-01

    In a survey carried out during Summer and Autumn of 2004, for snails of medical importance, nine species were recovered. These were Biomphalaria alexandrina, B. glabrata, B. pfeifferi, Bulinus truncatus, B. forskalii, Lymnaea natalensis, Bellamya (=Vivipara) unicolor, Physa acuta and Hydrobia musaensis. Parasitological examination revealed that B. alexandrina, B. glabrata and L. natalensis harboured immature stages of their concerned trematode parasites. Moreover, P. acuta harboured the immature stage of the nematode parasite Parastrongylus cantonensis.

  18. Relative importance of perch and facilitative effects on nucleation in tropical woodland in Malawi

    NASA Astrophysics Data System (ADS)

    Fujita, Tomohiro

    2016-01-01

    Individual trees in open vegetation such as woodlands can act as "nuclei" for the colonization of forest tree species, which consequently lead to the formation of forest patches. This phenomenon is known as nucleation. The mechanism of nucleation is generally attributed to two factors: trees provide perches for frugivores that increase seed deposition (perch effect), and tree crowns ameliorate environmental conditions, which improves seedling establishment (facilitative effect). Few studies have attempted to distinguish the relative importance of these two factors. In this study, I separated these two effects in a woodland in northern Malawi. I chose Ficus natalensis as a potential nuclei tree because large individuals of this species are commonly located at the center of forest patches within open woodland at the study site. I monitored several environmental variables, seedling survival, seedling composition, and seed rain at three microsites: under F. natalensis, under Brachystegia floribunda (a dominant woodland species), and in open sites. Both tree species provided similar favorable conditions for the establishment of forest species compared to open sites. Thus, the survival of forest tree seedlings under F. natalensis and B. floribunda was similar, and substantially higher than seedling survival in open sites. However, communities of naturally occurring seedlings differed significantly between F. natalensis and B. floribunda. These results indicate that the facilitative effect alone cannot explain the nucleation pattern. I attribute this result to the perch effect of F. natalensis because the forest seedling species recorded under F. natalensis reportedly have small, brightly colored diaspores, which are indicative of dispersal by birds. Seed deposition of forest species under F. natalensis was significantly higher than that under B. floribunda or in open sites. My findings reinforce the idea that trees will lead to nucleation when they enhance seed

  19. Detection and characterization of a novel polyomavirus in wild rodents.

    PubMed

    Orba, Yasuko; Kobayashi, Shintaro; Nakamura, Ichiro; Ishii, Akihiro; Hang'ombe, Bernard M; Mweene, Aaron S; Thomas, Yuka; Kimura, Takashi; Sawa, Hirofumi

    2011-04-01

    To investigate polyomavirus infection in wild rodents, we analysed DNA samples from the spleens of 100 wild rodents from Zambia using a broad-spectrum PCR-based assay. A previously unknown polyomavirus genome was identified in a sample from a multimammate mouse (Mastomys species) and the entire viral genome of 4899 bp was subsequently sequenced. This viral genome contained potential ORFs for the capsid proteins, VP1, VP2 and VP3, and early proteins, small t antigen and large T antigen. Phylogenetic analysis showed that it was a novel member of the family Polyomaviridae, and thus the virus was tentatively named mastomys polyomavirus. After transfection of the viral genome into several mammalian cell lines, transient expression of the VP1 and large T antigen proteins was confirmed by immunoblotting and immunocytochemical analyses. Comparison of large T antigen function in mastomys polyomavirus with that in rhesus monkey polyomavirus SV40 and human polyomavirus JC virus revealed that the large T antigen from mastomys polyomavirus interacted with the tumour suppressor protein pRb, but not with p53.

  20. Reproductive isolation between Zaluzianskya species: the influence of volatiles and flower orientation on hawkmoth foraging choices.

    PubMed

    Campbell, Diane R; Jürgens, Andreas; Johnson, Steven D

    2016-04-01

    Floral trait differences between related species may play a key role in reproductive isolation imposed by pollinators. Volatile emissions can influence pollinator choice, but how they act in combination with traits such as flower orientation is rarely studied. We compared flower-opening patterns, morphology, colour, orientation and volatile emissions for two closely related species of Zaluzianskya and their natural hybrids. Hawkmoth pollinators were tested for preference between flowers of the two species, and between flowers with manipulations of volatiles or orientation. Flowers of Z. natalensis and Z. microsiphon open at night and day, respectively, but they overlap during early evening, when hawkmoths showed a strong preference for Z. natalensis. The species have similar flower size and colour, but Z. natalensis emits more floral volatiles in the evening and presents flowers vertically face-up as opposed to horizontally in Z. microsiphon, whereas natural hybrids are intermediate. Adding methyl benzoate and linalool to flowers of Z. microsiphon did not increase hawkmoth attraction, but re-orientation of flowers to face vertically increased attraction when scent cues were present, whereas re-orientation of Z. natalensis flowers to face horizontally decreased attraction. This study highlights the importance of flower orientation in imposing reproductive isolation.

  1. 50 CFR 16.15 - Importation of live reptiles or their eggs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) Python molurus (including P. molurus molurus (Indian python) and P. molurus bivittatus (Burmese python). (3) Python sebae (Northern African python or African rock python). (4) Python natalensis (Southern African python or African rock python). (5) Eunectes notaeus (yellow anaconda). (b) Upon the filing of...

  2. 50 CFR 16.15 - Importation of live reptiles or their eggs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) Python molurus (including P. molurus molurus (Indian python) and P. molurus bivittatus (Burmese python). (3) Python sebae (Northern African python or African rock python). (4) Python natalensis (Southern African python or African rock python). (5) Eunectes notaeus (yellow anaconda). (b) Upon the filing of...

  3. 50 CFR 16.15 - Importation of live reptiles or their eggs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) Python molurus (including P. molurus molurus (Indian python) and P. molurus bivittatus (Burmese python). (3) Python sebae (Northern African python or African rock python). (4) Python natalensis (Southern African python or African rock python). (5) Eunectes notaeus (yellow anaconda). (b) Upon the filing of...

  4. Huanglongbing increases Diplodia Stem End Rot in Citrus sinensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Huanglongbing (HLB), one of the most devastating diseases of citrus is caused by the a-Proteobacteria Candidatus Liberibacter. Diplodia natalensis Pole-Evans is a fungal pathogen which has been known to cause a postharvest stem-end rot of citrus, the pathogen infects citrus fruit under the calyx, an...

  5. Molecular Characterization of Pneumococcal Isolates from Pets and Laboratory Animals

    PubMed Central

    van der Linden, Mark; Al-Lahham, Adnan; Nicklas, Werner; Reinert, Ralf René

    2009-01-01

    Background Between 1986 and 2008 Streptococcus pneumoniae was isolated from 41 pets/zoo animals (guinea pigs (n = 17), cats (n = 12), horses (n = 4), dogs (n = 3), dolphins (n = 2), rat (n = 2), gorilla (n = 1)) treated in medical veterinary laboratories and zoos, and 44 laboratory animals (mastomys (multimammate mice; n = 32), mice (n = 6), rats (n = 4), guinea pigs (n = 2)) during routine health monitoring in an animal facility. S. pneumoniae was isolated from nose, lung and respiratory tract, eye, ear and other sites. Methodology/Principal Findings Carriage of the same isolate of S. pneumoniae over a period of up to 22 weeks was shown for four mastomys. Forty-one animals showed disease symptoms. Pneumococcal isolates were characterized by optochin sensitivity, bile solubility, DNA hybridization, pneumolysin PCR, serotyping and multilocus sequence typing. Eighteen of the 32 mastomys isolates (56%) were optochin resistant, all other isolates were optochin susceptible. All mastomys isolates were serotype 14, all guinea pig isolates serotype 19F, all horse isolates serotype 3. Rats had serotypes 14 or 19A, mice 33A or 33F. Dolphins had serotype 23F, the gorilla serotype 14. Cats and dogs had many different serotypes. Four isolates were resistant to macrolides, three isolates also to clindamycin and tetracyclin. Mastomys isolates were sequence type (ST) 15 (serotype 14), an ST/serotype combination commonly found in human isolates. Cats, dogs, pet rats, gorilla and dolphins showed various human ST/serotype combinations. Lab rats and lab mice showed single locus variants (SLV) of human STs, in human ST/serotype combinations. All guinea pig isolates showed the same completely new combination of known alleles. The horse isolates showed an unknown allele combination and three new alleles. Conclusions/Significance The isolates found in mastomys, mice, rats, cats, dogs, gorilla and dolphins are most likely identical to human

  6. Laboratory assessment of the molluscicidal and cercariacidal activities of Balanites aegyptiaca

    PubMed Central

    Molla, Eshetu; Giday, Mirutse; Erko, Berhanu

    2013-01-01

    Objective To assess the molluscicidal and cercariacidal activities of aqueous extracts of Balanites aegyptiaca (B. aegyptiaca) against Ethiopian Biomphalaria pfeifferi (B. pfeifferi), Lymnaea natalensis (L. natalensis) and Schistosoma mansoni (S. mansoni) cercariae. Methods Extracts of seeds, endocarp, mesocarp, and fruit of B. aegyptiaca were tested for their activities against adult B. pfeifferi and L. natalensis. The cercariacidal activity of the seeds of the plant was also evaluated against S. mansoni. Bioassays were carried out following the methods recommended by WHO. Snail mortalities were compared between each plant part and snail species, and LC50 and LC90 values for the plant parts tested were computed. The cercariacidal activity of the plant was assessed by exposing the mice to the cercariae pre-exposed to aqueous extract of B. aegyptiaca seeds. Results For the molluscicidal activities of seeds, endocarp, mesocarp and whole fruit, the LC50 values against B. pfeifferi were 56.32, 77.53, 65.51 and 66.63 mg/L, respectively, while the respective LC90 values were 77.70, 120.04, 89.50 and 97.55 mg/L. Similarly, the LC50 values for the seeds, endocarp, mesocarp and whole fruit against L. natalensis were 80.33, 92.61, 83.52 and 87.84 mg/L, respectively, while the respective LC90 values were 102.30, 138.21, 115.42 and 127.69 mg/L. B. pfeifferi were found to be more susceptible to B. aegyptiaca than L. natalensis. S. mansoni cercariae exposed to 15 mg/L of extract of seeds were incapable of infecting mice. The mean egg load of tissue was reduced in mice infected with the cercariae exposed to 5 and 10 mg/L of the extract. Conclusions The aqueous extracts of different parts of B. aegyptiaca exhibited reasonable molluscicidal activity against B. pfeifferi and L. natalensis, as well as cercariacidal activity against S. mansoni cercariae. However, comprehensive laboratory evaluation is recommended prior to field tests of the plant parts since their impact on other

  7. Morphologic and Genotypic Characterization of Psoroptes Mites from Water Buffaloes in Egypt.

    PubMed

    Amer, Said; Abd El Wahab, Taher; El Naby Metwaly, Abd; Feng, Yaoyu; Xiao, Lihua

    2015-01-01

    Species delimitation of Psoroptes spp. and identity of the parasite in water buffaloes remain poorly defined. In this study, Psoroptes infestation on three water buffalo farms in Egypt was examined based on morphometric characteristics, especially the opisthosomal setae of adult male mites. Clinical investigations showed that 28% (196/700) of the sampled animals had mange infestation. Microscopic examinations of 80 skin scrapings indicated the occurrence of Psoroptes mites in 17 (21.3%) samples, Sarcoptes mites in 27 (33.7%) samples, and the concurrence of both in 36 (45.0%) samples. Morphologically, the Psoroptes parasite was identified as Psoroptes natalensis. DNA sequence analysis of the second internal transcribed spacer (ITS2) in 11 representative samples confirmed the diagnosis and suggested the presence of a distinct variety of Psoroptes natalensis in Egypt.

  8. Morphologic and Genotypic Characterization of Psoroptes Mites from Water Buffaloes in Egypt

    PubMed Central

    Amer, Said; Abd El Wahab, Taher; El Naby Metwaly, Abd; Feng, Yaoyu; Xiao, Lihua

    2015-01-01

    Species delimitation of Psoroptes spp. and identity of the parasite in water buffaloes remain poorly defined. In this study, Psoroptes infestation on three water buffalo farms in Egypt was examined based on morphometric characteristics, especially the opisthosomal setae of adult male mites. Clinical investigations showed that 28% (196/700) of the sampled animals had mange infestation. Microscopic examinations of 80 skin scrapings indicated the occurrence of Psoroptes mites in 17 (21.3%) samples, Sarcoptes mites in 27 (33.7%) samples, and the concurrence of both in 36 (45.0%) samples. Morphologically, the Psoroptes parasite was identified as Psoroptes natalensis. DNA sequence analysis of the second internal transcribed spacer (ITS2) in 11 representative samples confirmed the diagnosis and suggested the presence of a distinct variety of Psoroptes natalensis in Egypt. PMID:26517834

  9. Aqueous extracts of Mozambican plants as alternative and environmentally safe acid-base indicators.

    PubMed

    Macuvele, Domingos Lusitaneo Pier; Sithole, Gerre Zebedias Samo; Cesca, Karina; Macuvele, Suzana Lília Pinare; Matsinhe, Jonas Valente

    2016-06-01

    Indicators are substances that change color as the pH of the medium. Many of these substances are dyes of synthetic origin. The mulala plant (Euclea natalensis), which roots are commonly used by rural communities for their oral hygiene, and roseira (Hibiscus rosa-sinensis), an ornamental plant, are abundant in Mozambique. Currently, synthetic acid-base indicators are most commonly used but have environmental implications and, on the other hand, are expensive products, so the demand for natural indicators started. This study investigated the applicability of aqueous extracts of H. rosa-sinensis and E. natalensis as acid-base indicators. Ground on this work, the extracts can be used as acid-base indicators. On the basis of the absorption spectroscopy in both the UV-Vis region and previous studies, it was possible to preliminarily pinpoint anthocyanins and naphthoquinones as responsible for the shifting of colors depending on the pH range of aqueous extracts of H. rosa-sinensis and E. natalensis. These natural indicators are easily accessible, inexpensive, easy to extract, environmentally safe, and locally available.

  10. Chemical constituents and antifilarial activity of Lantana camara against human lymphatic filariid Brugia malayi and rodent filariid Acanthocheilonema viteae maintained in rodent hosts.

    PubMed

    Misra, Namita; Sharma, Mithilesh; Raj, Kanwal; Dangi, Anil; Srivastava, Sudhir; Misra-Bhattacharya, Shailja

    2007-02-01

    Lymphatic filariasis continues to be a major health problem in tropical and subtropical countries. A macrofilaricidal agent capable of eliminating adult filarial parasites is urgently needed. In the present study, we report the antifilarial activity in the extract of stem portion of the plant Lantana camara. The crude extract at 1 g/kg for 5 days by oral route killed 43.05% of the adult Brugia malayi parasites and sterilized 76% of surviving female worms in the rodent model Mastomys coucha. A 34.5% adulticidal activity along with sterilization of 66% of female worms could be demonstrated in the chloroform fraction. Remarkable antifilarial activity was observed in the adult B. malayi transplanted gerbil model where up to 80% of the adult worms could be killed at the same dose and all the surviving female parasites were found sterilized. The extract was also found effective against a subcutaneous rodent filariid Acanthocheilonema viteae maintained in Mastomys coucha, where it exerted strong microfilaricidal (95.04%) and sterilization (60.66%) efficacy with mild macrofilaricidal action. Two compounds, oleanonic acid and oleanolic acid, isolated from hexane and chloroform fractions showed LC100 at 31.25 and 62.5 mug/ml, respectively, on B. malayi in vitro. This is the first ever report on the antifilarial efficacy of Lantana camara.

  11. Use of focussed beam reflectance measurement (FBRM) for monitoring changes in biomass concentration.

    PubMed

    Whelan, Jessica; Murphy, Eilis; Pearson, Alan; Jeffers, Paul; Kieran, Patricia; McDonnell, Susan; Raposo, Sara; Lima-Costa, Ma Emília; Glennon, Brian

    2012-08-01

    The potential of focussed beam reflectance measurement (FBRM) as a tool to monitor changes in biomass concentration was investigated in a number of biological systems. The measurement technique was applied to two morphologically dissimilar plant cell suspension cultures, Morinda citrifolia and Centaurea calcitrapa, to a filamentous bacteria, Streptomyces natalensis, to high density cultures of Escherichia coli and to a murine Sp2/0 hybridoma suspension cell line, 3-2.19. In all cases, the biomass concentration proved to be correlated with total FBRM counts. The nature of the correlation varied between systems and was influenced by the concentration, nature, size and morphology of the particle under investigation.

  12. A catalogue of the scaleworm genus Lepidonotus (Polynoidae, Polychaeta) from South America, with two new records for Brazilian waters

    PubMed Central

    De Assis, José Eriberto; de Brito, Rafael Justino; Christoffersen, Martin Lindsey; de Souza, José Roberto Botelho

    2015-01-01

    Abstract The genus Lepidonotus is the largest in number of species within the Polynoidae, with more than 70 described species and subspecies. A catalogue of 18 nominal species and subspecies of Lepidonotus from South America is provided, with valid names, synonyms and original citations. Redescriptions and illustrations of two species based on new specimens collected along the littoral of the State of Paraíba, northeastern Brazil are included. Lepidonotus carinulatus and Lepidonotus natalensis are reported for the first time for Brazilian waters. A comparative table of characters for all reported species and subspecies of Lepidonotus from South America is provided. PMID:26668541

  13. LINE-1 retrotransposons: from 'parasite' sequences to functional elements.

    PubMed

    Paço, Ana; Adega, Filomena; Chaves, Raquel

    2015-02-01

    Long interspersed nuclear elements-1 (LINE-1) are the most abundant and active retrotransposons in the mammalian genomes. Traditionally, the occurrence of LINE-1 sequences in the genome of mammals has been explained by the selfish DNA hypothesis. Nevertheless, recently, it has also been argued that these sequences could play important roles in these genomes, as in the regulation of gene expression, genome modelling and X-chromosome inactivation. The non-random chromosomal distribution is a striking feature of these retroelements that somehow reflects its functionality. In the present study, we have isolated and analysed a fraction of the open reading frame 2 (ORF2) LINE-1 sequence from three rodent species, Cricetus cricetus, Peromyscus eremicus and Praomys tullbergi. Physical mapping of the isolated sequences revealed an interspersed longitudinal AT pattern of distribution along all the chromosomes of the complement in the three genomes. A detailed analysis shows that these sequences are preferentially located in the euchromatic regions, although some signals could be detected in the heterochromatin. In addition, a coincidence between the location of imprinted gene regions (as Xist and Tsix gene regions) and the LINE-1 retroelements was also observed. According to these results, we propose an involvement of LINE-1 sequences in different genomic events as gene imprinting, X-chromosome inactivation and evolution of repetitive sequences located at the heterochromatic regions (e.g. satellite DNA sequences) of the rodents' genomes analysed.

  14. Spatial and temporal evolution of Lassa virus in the natural host population in Upper Guinea

    PubMed Central

    Fichet-Calvet, Elisabeth; Ölschläger, Stephan; Strecker, Thomas; Koivogui, Lamine; Becker-Ziaja, Beate; Camara, Amara Bongo; Soropogui, Barré; Magassouba, N’Faly; Günther, Stephan

    2016-01-01

    This study aimed at reconstructing the spatial and temporal evolution of Lassa virus (LASV) in the natural host population. To this end, we generated 132 partial nucleoprotein sequences of LASV from M. natalensis trapped in 12 villages around Faranah, Upper Guinea, over a period of 12 years. This study reveals two main features of LASV evolution in M. natalensis. First, the virus evolves in the reservoir with a molecular clock rate of 9 (7–11) × 10–4 position–1 year–1 implying that contemporary LASV lineages circulate in the Faranah area since less than 100 years. Second, viruses circulating in a specific village are diverse and polyphyletic. We observed, however, there are monophyletic clusters at village and sub-village level at specific points in time. In conclusion, our data indicate that the temporal and spatial pattern of LASV evolution in the natural reservoir is characterized by a combination of stationary circulation within a village and virus movement between villages. The latter feature is relevant for rodent control strategies, as it implies that recurrence of the virus from neighbouring villages may occur in villages where the virus has previously been eradicated. PMID:26911443

  15. Spatial and temporal evolution of Lassa virus in the natural host population in Upper Guinea.

    PubMed

    Fichet-Calvet, Elisabeth; Ölschläger, Stephan; Strecker, Thomas; Koivogui, Lamine; Becker-Ziaja, Beate; Camara, Amara Bongo; Soropogui, Barré; Magassouba, N'Faly; Günther, Stephan

    2016-02-25

    This study aimed at reconstructing the spatial and temporal evolution of Lassa virus (LASV) in the natural host population. To this end, we generated 132 partial nucleoprotein sequences of LASV from M. natalensis trapped in 12 villages around Faranah, Upper Guinea, over a period of 12 years. This study reveals two main features of LASV evolution in M. natalensis. First, the virus evolves in the reservoir with a molecular clock rate of 9 (7-11) × 10(-4) position(-1) year(-1) implying that contemporary LASV lineages circulate in the Faranah area since less than 100 years. Second, viruses circulating in a specific village are diverse and polyphyletic. We observed, however, there are monophyletic clusters at village and sub-village level at specific points in time. In conclusion, our data indicate that the temporal and spatial pattern of LASV evolution in the natural reservoir is characterized by a combination of stationary circulation within a village and virus movement between villages. The latter feature is relevant for rodent control strategies, as it implies that recurrence of the virus from neighbouring villages may occur in villages where the virus has previously been eradicated.

  16. Fasciola hepatica infections in cattle and the freshwater snail Galba truncatula from Dakhla Oasis, Egypt.

    PubMed

    Arafa, W M; Hassan, A I; Snousi, S A M; El-Dakhly, Kh M; Holman, P J; Craig, T M; Aboelhadid, S M

    2017-02-06

    Infection by Fasciola species was investigated in seven districts of Dakhla Oasis, Egypt, through abattoir inspection of cattle livers for adult worms and sedimentation of faecal samples from local cattle to detect Fasciola eggs. In addition, lymnaeid snails collected from the study area were examined microscopically for developmental stages of Fasciola spp. Abattoir inspection revealed that 51 out of 458 cattle livers (11.1%) contained adult flukes, which were identified morphologically as Fasciola hepatica. Examination of the cattle faecal samples revealed that 142 out of 503 (28.2%) contained Fasciola eggs. The collected snails, identified as Galba truncatula and Radix natalensis, showed larval stages of Fasciola in 71 out of 731 (9.7%) G. truncatula, while R. natalensis showed no infection. Specific duplex polymerase chain reaction (PCR) targeting the mitochondrial cox1 gene of F. hepatica and Fasciola gigantica was carried out on DNA extracted from pooled infected snails and adult worms. The F. hepatica size amplicon (1031 bp) was obtained from both the infected G. truncatula and the adult worms isolated from cattle livers from different districts. The amplicon sequences were identical to the published sequences of F. hepatica mitochondrial cox1 gene. In conclusion, the zoonotic importance of Fasciola infection and appropriate hygienic measures must be taken into consideration in Dakhla Oasis, Egypt.

  17. Experimental chemotherapy of mammalian coccidiosis with Bay g 7183.

    PubMed

    Haberkorn, A; Schulz, H P

    1981-01-01

    Bay g 7183, a substituted sym. triazintrione derivative has a known high efficacy against poultry coccidia. Experimental investigations using the mouse coccidia E. falciformis indicated an activity also against mammalian coccidia. Minimum effective daily doses range between 0.25 to 10 mg/kg. Eimeria species used: E. falciformis (mouse(, E. contorta (rat), E. chinchillae (Mastomys), E. irresidua, E. magna, E. media, E. perforans, E. stiedae (rabbit), E. ashata, E. arloingi, E. faurei, E. ninakohlyakimovi, E. parva (sheep). A very appropriate mode of treatment, e.g. for rabbits is the dermal one (pour on) beside the oral route by using a stomach tube or with medicated food. Bay g 7183 is active both on schizogonic stages and gamonts. This explains the high efficacy even of single doses. If given e.g. once weekly it prevents or stops development of even massive experimental infections and their clinical symptoms. The value of E. falciformis as a test model is discussed.

  18. The systematic position of some Ethiopian Nippostrongylinae (Nematoda, Trichostrongylina, Heligmosomoidea) from the National Collection of Animal Helminths, Onderstepoort, South Africa.

    PubMed

    Durette-Desset, M C; Digiani, M C

    2005-03-01

    The taxonomic status of some nippostrongyline nematodes deposited in the National Collection of Animal Helminths, Onderstepoort, is revised. Heligmonina boomkeri n. sp. is described from Aethomys chrysophilus from South Africa. The most closely related species by the body measurements and the pattern of the caudal bursa is Heligmonina bignonensis Diouf, Bâ & Durette-Desset, 1997, a parasite of Mastomys erythroleucus from Senegal. It differs from the new species mainly in the number of ventral cuticular ridges at mid-body (four versus five) and the left ala in the male is shorter than the body diameter. The systematic position of Heligmonina spira (Ortlepp, 1939) and Neoheligmonella capensis (Ortlepp, 1939) is confirmed here through their synlophe, which was not previously studied.

  19. Ectoparasites (sucking lice, fleas and ticks) of small mammals in southeastern Kenya

    PubMed Central

    OGUGE, N. O.; DURDEN, L. A.; KEIRANS, J. E.; BALAMI, H. D.; SCHWAN, T. G.

    2013-01-01

    During 1998–2000, at least 14 species (n = 309) of small mammals were live-trapped and examined for ectoparasites in moist forests of the Taita and Shimba Hills and drier savannah habitats of Nguruman, southeastern Kenya. Ectoparasites were recorded from 11 species of mammals. Five species of sucking lice [Hoplopleura inexpectans Johnson, H. intermedia Kellogg & Ferris, Polyplax reclinata (Nitzsch), P. waterstoni Bedford and Schizophthirus graphiuri Ferris], six species of fleas (Ctenophthalmus leptodactylous Hubbard, Dinopsyllus grypurus Jordan & Rothschild, D. lypusus Jordan & Rothschild, Hypsophthalmus campestris Jordan & Rothschild, Listropsylla basilewskyi Smit and Xiphiopsylla lippa Jordan) and at least six species of ticks (Amblyomma sp., Haemaphysalis sp., Ixodes sp., I. alluaudi Neumann, I. cumulatimpunctatus Schulze, I. muniensis Arthur & Burrow and Rhipicephalus sp.) were recorded from these hosts. Four of the five species of sucking lice were host specific whereas P. reclinata was recorded from two different species of white-toothed shrews, Crocidura spp. Although fleas and ticks were less host specific, C. leptodactylous, D. grypurus and I. cumulatimpunctatus were only recorded from the murid rodent Praomys delectorum (Thomas), Amblyomma sp. was only recorded from the nesomyid rodent Beamys hindei Thomas, Rhipicephalus sp. was only recorded from the murid Lemniscomys striatus (L.) and I. muniensis was only recorded from the dormouse Graphiurus microtis (Noack). More species of ectoparasites and significantly greater infestation prevalences were recorded from small mammals in moist habitats compared with those from the savannah habitat. At least one of the fleas recorded, D. lypusus, is a known vector of Yersinia pestis Lehmann & Neumann, the causative agent of plague, which is present in the region. PMID:19941604

  20. Screening of some Nigerian plants for molluscicidal activity.

    PubMed

    Kela, S L; Ogunsusi, R A; Ogbogu, V C; Nwude, N

    1989-01-01

    Methanolic (MEOH), evaporated crude water (ECW) and unevaporated crude water (UECW) extracts of 25 Nigerian plants, used for different medicinal and domestic purposes were screened for molluscacidal activity on laboratory-reared Lymnaea natalensis Krauss. Seven of the plants were not active; extracts from 18 (72 per cent) of the plants, some of which are renowned fish poisons, had molluscicidal activity. These were Acacia nilotica, Aristolochia albida, Balanites aegyptiaca, Blighia sapida, Boswellia dalzielii, Detarium microcarpum, Gnidia kraussiana, Kigelia africana, Nauclea latifolia, Opilia celtidefolia, Parkia clappertoniana, Polygonum limbatum, Pseudocedrela kotschyi, Sclerocarya birrea, Securidaca longipedunculata, Ximenia americana, Vetiveria nigritana and Ziziphus abyssinica. The LC50 of these extracts were determined. It is strongly recommended that the toxic effects of these extracts against fish, cercariae, snail eggs and mammals be further investigated so as to determine the right concentration, especially for use in fish ponds.

  1. Antineoplastic constituents of some Southern African plants.

    PubMed

    Charlson, A J

    1980-12-01

    Extracts of several Southern African plants which have been used in folk remedies have been prepared, and the extracts were tested in a variety of experimental tumour test-systems. Raphionacme hirsuta and Cheilanthes contracta have been used in African anticancer medicines. Extracts of these plants showed antitumor activity in some rodent test-systems, but the results were not confirmed. In the folk-lore, Haemanthus natalensis has been used in emetics and Urginea capitata preparations have been used to vaccinate African chiefs. Extracts of these plants showed significant cytotoxicity in the KB cell culture test-system. Infusions of Brunsvigia radulosa have been used as folk remedies for abdominal troubles. An extract of this Amaryllis plant increased the life span of P-388 leukaemic mice. Amaryllis bellandonna has also been investigated. Extracts of Amaryllis belladonna had to be fractionated in order to produce significant antitumour activity in the P-388 lymphocytic leukaemia test-system.

  2. A genomic comparison of two termites with different social complexity

    PubMed Central

    Korb, Judith; Poulsen, Michael; Hu, Haofu; Li, Cai; Boomsma, Jacobus J.; Zhang, Guojie; Liebig, Jürgen

    2015-01-01

    The termites evolved eusociality and complex societies before the ants, but have been studied much less. The recent publication of the first two termite genomes provides a unique comparative opportunity, particularly because the sequenced termites represent opposite ends of the social complexity spectrum. Zootermopsis nevadensis has simple colonies with totipotent workers that can develop into all castes (dispersing reproductives, nest-inheriting replacement reproductives, and soldiers). In contrast, the fungus-growing termite Macrotermes natalensis belongs to the higher termites and has very large and complex societies with morphologically distinct castes that are life-time sterile. Here we compare key characteristics of genomic architecture, focusing on genes involved in communication, immune defenses, mating biology and symbiosis that were likely important in termite social evolution. We discuss these in relation to what is known about these genes in the ants and outline hypothesis for further testing. PMID:25788900

  3. Habitat characteristics for different freshwater snail species as determined biologically through macroinvertebrate information.

    PubMed

    El-Khayat, Hanaa M M; Mahmoud, Kadria M A; Mostafa, Bayomy B; Tantawy, Ahmad A; El-Deeb, Fatma A; Ragb, Fawzy M; Ismail, Nahed M; El-Said, Kalil M; Taleb, Hoda M Abu

    2011-12-01

    Macro-invertebrates including freshwater snails collected from 643 sites over 8 successive seasons among the River Nile, branches, main canals and certain drains in eight Egyptian Governorates. Thirteen snail species and one bivalve species were identified. The most distributed were Lanistus carinatus and Physa acuta while the most abundant were Cleopatra bulimoides and Physa acuta during the whole study. The sites that harbored each snail species in all the examined water-courses were grouped seasonally and their biological assessment was determined by their minimum and maximum total point similarity percentage to that of the corresponded reference site and mean of the total points. Habitats for most snail species attained minimum total point's similarity percentage less than 21% (very poor habitat) during autumn and winter then spring while during summer very poor habitat was harbored by only few snail species. P. acuta was the only survived snails in habitat which attained 0 as a minimum total point's similarity percentage during two seasons and L. carinatus and Succinea cleopatra during one season. With respect to medically important snails very poor sites constituted 23% of Biomphalaria alexandrina sites, 14% of Lymnaea natalensis and 9.4% of Bulinus truncatus sites. The studied macroinvertebrate matrices, total number of organisms, taxa richness, the Ephemeroptera, Plecoptera, and Trichoptera (EPT) index, ratio of EPT index to chironomidae, ratio of scraper to filtering collector, contribution of dominant macroinvertebrate major group, comparison revealed descending tolerances from B. alexanrina followed by L. natalensis then B. truncates, but Hilsenhoff Biotic Index (HBI) showed the same tolerance to organic pollution.

  4. Stable Isotope Evidence for Dietary Overlap between Alien and Native Gastropods in Coastal Lakes of Northern KwaZulu-Natal, South Africa

    PubMed Central

    Miranda, Nelson A. F.; Perissinotto, Renzo

    2012-01-01

    Background Tarebia granifera (Lamarck, 1822) is originally from South-East Asia, but has been introduced and become invasive in many tropical and subtropical parts of the world. In South Africa, T. granifera is rapidly invading an increasing number of coastal lakes and estuaries, often reaching very high population densities and dominating shallow water benthic invertebrate assemblages. An assessment of the feeding dynamics of T. granifera has raised questions about potential ecological impacts, specifically in terms of its dietary overlap with native gastropods. Methodology/Principal Findings A stable isotope mixing model was used together with gut content analysis to estimate the diet of T. granifera and native gastropod populations in three different coastal lakes. Population density, available biomass of food and salinity were measured along transects placed over T. granifera patches. An index of isotopic (stable isotopes) dietary overlap (IDO, %) aided in interpreting interactions between gastropods. The diet of T. granifera was variable, including contributions from microphytobenthos, filamentous algae (Cladophora sp.), detritus and sedimentary organic matter. IDO was significant (>60%) between T. granifera and each of the following gastropods: Haminoea natalensis (Krauss, 1848), Bulinus natalensis (Küster, 1841) and Melanoides tuberculata (Müller, 1774). However, food did not appear to be limiting. Salinity influenced gastropod spatial overlap. Tarebia granifera may only displace native gastropods, such as Assiminea cf. ovata (Krauss, 1848), under salinity conditions below 20. Ecosystem-level impacts are also discussed. Conclusion/Significance The generalist diet of T. granifera may certainly contribute to its successful establishment. However, although competition for resources may take place under certain salinity conditions and if food is limiting, there appear to be other mechanisms at work, through which T. granifera displaces native gastropods

  5. Cryptosporidium proliferans n. sp. (Apicomplexa: Cryptosporidiidae): Molecular and Biological Evidence of Cryptic Species within Gastric Cryptosporidium of Mammals

    PubMed Central

    Kváč, Martin; Havrdová, Nikola; Hlásková, Lenka; Daňková, Tereza; Kanděra, Jiří; Ježková, Jana; Vítovec, Jiří; Sak, Bohumil; Ortega, Ynes; Xiao, Lihua; Modrý, David; Chelladurai, Jeba Rose Jennifer Jesudoss; Prantlová, Veronika; McEvoy, John

    2016-01-01

    The morphological, biological, and molecular characteristics of Cryptosporidium muris strain TS03 are described, and the species name Cryptosporidium proliferans n. sp. is proposed. Cryptosporidium proliferans obtained from a naturally infected East African mole rat (Tachyoryctes splendens) in Kenya was propagated under laboratory conditions in rodents (SCID mice and southern multimammate mice, Mastomys coucha) and used in experiments to examine oocyst morphology and transmission. DNA from the propagated C. proliferans isolate, and C. proliferans DNA isolated from the feces of an African buffalo (Syncerus caffer) in Central African Republic, a donkey (Equus africanus) in Algeria, and a domestic horse (Equus caballus) in the Czech Republic were used for phylogenetic analyses. Oocysts of C. proliferans are morphologically distinguishable from C. parvum and C. muris HZ206, measuring 6.8–8.8 (mean = 7.7 μm) × 4.8–6.2 μm (mean = 5.3) with a length to width ratio of 1.48 (n = 100). Experimental studies using an isolate originated from T. splendens have shown that the course of C. proliferans infection in rodent hosts differs from that of C. muris and C. andersoni. The prepatent period of 18–21 days post infection (DPI) for C. proliferans in southern multimammate mice (Mastomys coucha) was similar to that of C. andersoni and longer than the 6–8 DPI prepatent period for C. muris RN66 and HZ206 in the same host. Histopatologicaly, stomach glands of southern multimammate mice infected with C. proliferans were markedly dilated and filled with necrotic material, mucus, and numerous Cryptosporidium developmental stages. Epithelial cells of infected glands were atrophic, exhibited cuboidal or squamous metaplasia, and significantly proliferated into the lumen of the stomach, forming papillary structures. The epithelial height and stomach weight were six-fold greater than in non-infected controls. Phylogenetic analyses based on small subunit rRNA, Cryptosporidium oocyst

  6. Cryptosporidium proliferans n. sp. (Apicomplexa: Cryptosporidiidae): Molecular and Biological Evidence of Cryptic Species within Gastric Cryptosporidium of Mammals.

    PubMed

    Kváč, Martin; Havrdová, Nikola; Hlásková, Lenka; Daňková, Tereza; Kanděra, Jiří; Ježková, Jana; Vítovec, Jiří; Sak, Bohumil; Ortega, Ynes; Xiao, Lihua; Modrý, David; Chelladurai, Jeba Rose Jennifer Jesudoss; Prantlová, Veronika; McEvoy, John

    2016-01-01

    The morphological, biological, and molecular characteristics of Cryptosporidium muris strain TS03 are described, and the species name Cryptosporidium proliferans n. sp. is proposed. Cryptosporidium proliferans obtained from a naturally infected East African mole rat (Tachyoryctes splendens) in Kenya was propagated under laboratory conditions in rodents (SCID mice and southern multimammate mice, Mastomys coucha) and used in experiments to examine oocyst morphology and transmission. DNA from the propagated C. proliferans isolate, and C. proliferans DNA isolated from the feces of an African buffalo (Syncerus caffer) in Central African Republic, a donkey (Equus africanus) in Algeria, and a domestic horse (Equus caballus) in the Czech Republic were used for phylogenetic analyses. Oocysts of C. proliferans are morphologically distinguishable from C. parvum and C. muris HZ206, measuring 6.8-8.8 (mean = 7.7 μm) × 4.8-6.2 μm (mean = 5.3) with a length to width ratio of 1.48 (n = 100). Experimental studies using an isolate originated from T. splendens have shown that the course of C. proliferans infection in rodent hosts differs from that of C. muris and C. andersoni. The prepatent period of 18-21 days post infection (DPI) for C. proliferans in southern multimammate mice (Mastomys coucha) was similar to that of C. andersoni and longer than the 6-8 DPI prepatent period for C. muris RN66 and HZ206 in the same host. Histopatologicaly, stomach glands of southern multimammate mice infected with C. proliferans were markedly dilated and filled with necrotic material, mucus, and numerous Cryptosporidium developmental stages. Epithelial cells of infected glands were atrophic, exhibited cuboidal or squamous metaplasia, and significantly proliferated into the lumen of the stomach, forming papillary structures. The epithelial height and stomach weight were six-fold greater than in non-infected controls. Phylogenetic analyses based on small subunit rRNA, Cryptosporidium oocyst wall

  7. Dental microwear of sympatric rodent species sampled across habitats in southern Africa: Implications for environmental influence.

    PubMed

    Burgman, Jenny H E; Leichliter, Jennifer; Avenant, Nico L; Ungar, Peter S

    2016-03-01

    Dental microwear textures have proven to be a valuable tool for reconstructing the diets of a wide assortment of fossil vertebrates. Nevertheless, some studies have recently questioned the efficacy of this approach, suggesting that aspects of habitat unrelated to food preference, especially environmental grit load, might have a confounding effect on microwear patterning that obscures the diet signal. Here we evaluate this hypothesis by examining microwear textures of 3 extant sympatric rodent species that vary in diet breadth and are found in a variety of habitat types: Mastomys coucha, Micaelamys namaquensis and Rhabdomys pumilio. We sample each of these species from 3 distinct environmental settings in southern Africa that differ in rainfall and vegetative cover: Nama-Karoo shrublands (semi-desert) and Dry Highveld grasslands in the Free State Province of South Africa, and Afromontane (wet) grasslands in the highlands of Lesotho. While differences between habitat types are evident for some of the species, inconsistency in the pattern suggests that the microwear signal is driven by variation in foods eaten rather than grit-level per se. It is clear that, at least for species and habitats sampled in the current study, environmental grit load does not swamp diet-related microwear signatures.

  8. The rubber plantation environment and Lassa fever epidemics in Liberia, 2008-2012: a spatial regression.

    PubMed

    Olugasa, Babasola O; Dogba, John B; Ogunro, Bamidele; Odigie, Eugene A; Nykoi, Jomah; Ojo, Johnson F; Taiwo, Olalekan; Kamara, Abraham; Mulbah, Charles K; Fasunla, Ayotunde J

    2014-10-01

    As Lassa fever continues to be a public health challenge in West Africa, it is critical to produce good maps of its risk pattern for use in active surveillance and control intervention. We identified eight spatial features related to the rubber plantation environment and used them as explanatory variables for Lassa fever (LF) outbreaks on the Uniroyal Liberian Agricultural Company (LAC) rubber plantation environment in Grand Bassa County, Liberia. We computed classical and spatial lag regression models on all spatial features, including proximity of residential camp to rubber tree-edge, main road in the plantation, LAC hospital, rice farmland, household refuse dump, human population density, post-harvest storage density of rice and density of rodent deterrent on rice storage. We found significant (p=0.0024) spatial autocorrelation between LF cases and the spatial features we have considered. We concluded that the rubber plantation environment influenced Mastomys species' breeding and transmission of Lassa virus along spatial scale to humans. The risk factors identified in this study offered a baseline for more effective surveillance and control of LF in the post-civil conflict Liberia.

  9. [Characterization of contacts of the population of Guinea with synanthropic rodents as Lassa fever virus carriers].

    PubMed

    Inapogui, A P; Konstantinov, O K; Lapshov, V N; Comara, S K

    2007-01-01

    Questionnaire surveys made in 17 villages from 3 ecological zones of Guinea have provided evidence for the population's contact with synanthropic rodents as Lassa fever virus carriers. Over 100 rodents are quarterly captured in the houses of the traditional type in the villages located in the savanna woodland. Less than 10 specimens are captured at the food warehouses. There are more than 100 rodents in the majority of houses of the traditional type in the villages located in the secondary forest. In the villages of rainy tropical forests, the capture rate is low--10 to 100 rodents. The main rodent capturers are boys and young men (aged 7 to 20 years) who are principal rodent meat eaters; although almost the whole population, particularly in rural areas, consumes this meat in varying degrees. The proportion of captured rats of the genus Mastomys (the carrier of Lassa fever virus) in the town of Kindia is 11%. In the rural area, it is much higher (as high as 94%) in the villages located in the rainy tropical forests. It is estimated that one trapper quarterly catches 0.2 (in the savanna woodland) to 6.9 (in the secondary forests) infected rats, which agrees with the data of a serological survey of Guinea's population. By and large, the majority of the Guinean population may be referred to as a group at risk for Lassa fever due to their permanent contacts with rodents.

  10. Cofactor Independent Phosphoglycerate Mutase of Brugia malayi Induces a Mixed Th1/Th2 Type Immune Response and Inhibits Larval Development in the Host

    PubMed Central

    Singh, Prashant K.; Kushwaha, Susheela; Rana, Ajay K.; Misra-Bhattacharya, Shailja

    2014-01-01

    Lymphatic filariasis is a major debilitating disease, endemic in 72 countries putting more than 1.39 billion people at risk and 120 million are already infected. Despite the significant progress in chemotherapeutic advancements, there is still need for other measures like development of an effective vaccine or discovery of novel drug targets. In this study, structural and immunological characterization of independent phosphoglycerate mutase of filarial parasite Brugia malayi was carried out. Protein was found to be expressed in all major parasite life stages and as an excretory secretory product of adult parasites. Bm-iPGM also reacted to all the categories of human bancroftian patient's sera including endemic normals. In vivo immunological behaviour of protein was determined in immunized BALB/c mice followed by prophylactic analysis in BALB/c mice and Mastomys coucha. Immunization with Bm-iPGM led to generation of a mixed Th1/Th2 type immune response offering 58.2% protection against larval challenge in BALB/c and 65–68% protection in M. coucha. In vitro studies confirmed participation of anti-Bm-iPGM antibodies in killing of B. malayi infective larvae and microfilariae through ADCC mechanism. The present findings reveal potential immunoprotective nature of Bm-iPGM advocating its worth as an antifilarial vaccine candidate. PMID:25061608

  11. In vivo/ex vivo targeting of Langerhans cells after topical application of the immune response modifier TMX-202: confocal Raman microscopy and histology analysis

    NASA Astrophysics Data System (ADS)

    Darvin, Maxim E.; Thiede, Gisela; Ascencio, Saul Mujica; Schanzer, Sabine; Richter, Heike; Vinzón, Sabrina E.; Hasche, Daniel; Rösl, Frank; May, Roberto; Hazot, Yohan; Tamarkin, Dov; Lademann, Juergen

    2016-05-01

    The increased ability of TMX-202 (derivative of imiquimod) to penetrate the intact stratum corneum (SC) and the follicular orifices of porcine ear skin was shown ex vivo using confocal Raman microscopy and laser scanning microscopy. Moreover, to assess whether TMX-202 is able to reach the immune cells, Langerhans cells extracted from pretreated human skin were investigated ex vivo using confocal Raman microscopy combined with multivariate statistical methods. Tracking the Raman peak of dimethyl sulfoxide centered at 690 cm-1, the absorption of TMX-202 containing formulation by Langerhans cells was shown. To answer the question whether the TMX-202 active ingredient is able to reach Langerhans cells, the attraction of immune cells to TMX-202 containing formulation treated skin was measured in the in vivo rodent model Mastomys coucha. The results show that TMX-202 active ingredient is able to reach Langerhans cells after penetrating through the intact skin and subsequently attract immune cells. Both the intercellular/transcellular as well as the follicular pathways allow the penetration through the intact barrier of the SC.

  12. Parasites and invasions: changes in gastrointestinal helminth assemblages in invasive and native rodents in Senegal.

    PubMed

    Diagne, Christophe; Ribas, Alexis; Charbonnel, Nathalie; Dalecky, Ambroise; Tatard, Caroline; Gauthier, Philippe; Haukisalmi, Voitto; Fossati-Gaschignard, Odile; Bâ, Khalilou; Kane, Mamadou; Niang, Youssoupha; Diallo, Mamoudou; Sow, Aliou; Piry, Sylvain; Sembène, Mbacké; Brouat, Carine

    2016-12-01

    Understanding why some exotic species become widespread and abundant in their colonised range is a fundamental issue that still needs to be addressed. Among many hypotheses, newly established host populations may benefit from a parasite loss ("enemy release" hypothesis) through impoverishment of their original parasite communities or reduced infection levels. Moreover, the fitness of competing native hosts may be negatively affected by the acquisition of exotic taxa from invaders ("parasite spillover") and/or by an increased transmission risk of native parasites due to their amplification by invaders ("parasite spillback"). We focused on gastrointestinal helminth communities to determine whether these predictions could explain the ongoing invasion success of the commensal house mouse (Mus musculus domesticus) and black rat (Rattus rattus), as well as the associated decrease in native Mastomys spp., in Senegal. For both invasive species, our results were consistent with the predictions of the enemy release hypothesis. A decrease in overall gastrointestinal helminth prevalence and infracommunity species richness was observed along the invasion gradients as well as lower specific prevalence/abundance (Aspiculuris tetraptera in Mus musculus domesticus, Hymenolepis diminuta in Rattus rattus) on the invasion fronts. Conversely, we did not find strong evidence of GIH spillover or spillback in invasion fronts, where native and invasive rodents co-occurred. Further experimental research is needed to determine whether and how the loss of gastrointestinal helminths and reduced infection levels along invasion routes may result in any advantageous effects on invader fitness and competitive advantage.

  13. Anti-erosion stone bunds influence rodent dynamics and crop damage in Ethiopian highlands

    NASA Astrophysics Data System (ADS)

    Meheretu, Yonas; Welegerima, Kiros; Teferi, Mekonen; Yirga, Gidey; Haile, Mitiku; Sluydts, Vincent; Bauer, Hans; Nyssen, Jan; Deckers, Jozef; Leirs, Herwig

    2014-05-01

    In areas of subsistence agriculture, a variety of soil conservation methods have been implemented in the last few decades to improve crop yields, however these can have unintended consequences such as providing habitat for rodent pests. We studied rodent population dynamics and estimated crop damage in high and low stone bund density fields for four cropping seasons in Tigray highlands, northern Ethiopia. Stone bunds are physical structures for soil and water conservation, and potentially habitat for rodents. We used a general model to relate the proportion of crop damage to rodent abundance, stone bund density and crop stages. We found a positive correlation between rodent abundance and crop damage, and significant variation in rodent abundance and crop damage between high and low stone bund density fields. Furthermore, crop damage also varied significantly between crop stages. We concluded that Mastomys awashensis and Arvicanthis dembeensis were the two most important crop pests in the highlands causing significant damage. Fields with high stone bund density (~10 m average distance apart) harbor more rodents and endure a significantly higher proportion of crop damage compared to fields with lower stone bund density (~15 m average distance apart). The fact that rodent abundances peaked during the reproductive stage of the crop and around harvest implies the need for management intervention before these crop stages are attained.

  14. Preference of goats (Capra hircus L.) for tanniniferous browse species available in semi-arid areas in Ethiopia.

    PubMed

    Mengistu, G; Bezabih, M; Hendriks, W H; Pellikaan, W F

    2016-11-29

    The objectives were to determine browse species preference of goats using dry matter intake (DMI) as a proxy, to compare preference when offered in combination with polyethylene glycol (PEG) and to establish relationships between browse species intake and chemical compositional data. Air-dried leaves of Acacia etbaica, Cadaba farinosa, Capparis tomentosa, Dichrostachys cinerea, Dodonaea angustifolia, Euclea racemosa, Maerua angolensis, Maytenus senegalensis, Rhus natalensis and Senna singueana were used. Two cafeteria trials, each lasting 10 days, were conducted using four local mature male goats of 2-2.5 years receiving a daily ration of grass hay (4% of body weight) and 200 g wheat bran. In trial 1, goats were offered 25 g of each browse species for a total of 30 min with intake, time spent on consumption and the number of visits to specific browse species recorded at 10-min intervals. In trial 2, the same procedure was followed except that 25 g of PEG 4000 was added to the daily wheat bran ration. Crude protein and neutral detergent fibre in browse species ranged from 69.0-245.5 to 159.8-560.6 g/kg dry matter (DM) respectively. Total phenols and total tannins contents ranged between 3.7-70.6 and 2.5-68.1 mg tannic acid equivalent/g DM, respectively, and condensed tannins 1.7-18.4 Abs550 nm /g DM. Preference indicators measured in the first 10 min of browse species intake differed significantly among browse species and with PEG (p < 0.0001). Principal components explained 69.9% of the total variation in browse species DMI. Despite the high tannin levels, D. cinerea, R. natalensis and A. etbaica were the most preferred species regardless of PEG presence. Tannin levels at the observed browse species DMI did not determine preference, instead, preference appeared to be based on hemicellulose. Determining browse species preference is essential to exploit them to improve nutrient utilization and control parasites in goats.

  15. Mapping transmission risk of Lassa fever in West Africa: the importance of quality control, sampling bias, and error weighting.

    PubMed

    Peterson, A Townsend; Moses, Lina M; Bausch, Daniel G

    2014-01-01

    Lassa fever is a disease that has been reported from sites across West Africa; it is caused by an arenavirus that is hosted by the rodent M. natalensis. Although it is confined to West Africa, and has been documented in detail in some well-studied areas, the details of the distribution of risk of Lassa virus infection remain poorly known at the level of the broader region. In this paper, we explored the effects of certainty of diagnosis, oversampling in well-studied region, and error balance on results of mapping exercises. Each of the three factors assessed in this study had clear and consistent influences on model results, overestimating risk in southern, humid zones in West Africa, and underestimating risk in drier and more northern areas. The final, adjusted risk map indicates broad risk areas across much of West Africa. Although risk maps are increasingly easy to develop from disease occurrence data and raster data sets summarizing aspects of environments and landscapes, this process is highly sensitive to issues of data quality, sampling design, and design of analysis, with macrogeographic implications of each of these issues and the potential for misrepresenting real patterns of risk.

  16. Modular architecture of the conjugative plasmid pSVH1 from Streptomyces venezuelae.

    PubMed

    Reuther, Jens; Wohlleben, Wolfgang; Muth, Günther

    2006-05-01

    The conjugative rolling circle replication (RCR) type plasmid pSVH1 from the chloramphenicol producer Streptomyces venezuelae was characterized by DNA sequence analysis and insertion/deletion analysis. Nucleotide sequence of the 12,652 bp pSVH1 revealed 11 open reading frames with high coding probability for which putative functions could be assigned. Beside the replication initiator gene rep for RCR, pSVH1 contained only genes involved in conjugative transfer. The transfer gene traB encoding the septal DNA translocator TraB is regulated by the GntR-type transcriptional regulator TraR. Six spd genes involved in intra-mycelial plasmid spreading are organized in two operons, consisting of two and three translationally coupled genes. Subcloning experiments demonstrated that the transfer gene traB represents a kill function and localized the pSVH1 minimal replicon consisting of rep and the dso origin to a 2072-bp fragment. Plasmid pSVH1 showed a modular architecture. Its replication region resembled that of the Streptomyces natalensis plasmid pSNA1, while the transfer and spread regions involved in conjugative plasmid transfer were highly similar to the corresponding regions of the Streptomyces ghanaensis plasmid pSG5.

  17. New records of marine algae in Vietnam

    NASA Astrophysics Data System (ADS)

    Le Hau, Nhu; Ly, Bui Minh; Van Huynh, Tran; Trung, Vo Thanh

    2015-06-01

    In May, 2013, a scientific expedition was organized by the Vietnam Academy of Science and Technology (VAST) and the Far Eastern Branch of the Russian Academy of Sciences (FEBRAS) through the frame of the VAST-FEBRAS International Collaboration Program. The expedition went along the coast of Vietnam from Quang Ninh to Kien Giang. The objective was to collect natural resources to investigate the biological and biochemical diversity of the territorial waters of Vietnam. Among the collected algae, six taxa are new records for the Vietnam algal flora. They are the red algae Titanophora pikeana (Dickie) Feldmann from Cu Lao Xanh Island, Laurencia natalensis Kylin from Tho Chu Island, Coelothrix irregularis (Harvey) Børgesen from Con Dao Island, the green algae Caulerpa oligophylla Montagne, Caulerpa andamanensis (W.R. Taylor) Draisma, Prudhomme et Sauvage from Phu Quy Island, and Caulerpa falcifolia Harvey & Bailey from Ly Son Island. The seaweed flora of Vietnam now counts 833 marine algal taxa, including 415 Rhodophyta, 147 Phaeophyceae, 183 Chlorophyta, and 88 Cyanobacteria.

  18. Exposing the illegal trade in cycad species (Cycadophyta: Encephalartos) at two traditional medicine markets in South Africa using DNA barcoding.

    PubMed

    Williamson, J; Maurin, O; Shiba, S N S; van der Bank, H; Pfab, M; Pilusa, M; Kabongo, R M; van der Bank, M

    2016-09-01

    Species in the cycad genus Encephalartos are listed in CITES Appendix I and as Threatened or Protected Species in terms of South Africa's National Environmental Management: Biodiversity Act (NEM:BA) of 2004. Despite regulations, illegal plant harvesting for medicinal trade has continued in South Africa and resulted in declines in cycad populations and even complete loss of sub-populations. Encephalartos is traded at traditional medicine markets in South Africa in the form of bark strips and stem sections; thus, determining the species traded presents a major challenge due to a lack of characteristic plant parts. Here, a case study is presented on the use of DNA barcoding to identify cycads sold at the Faraday and Warwick traditional medicine markets in Johannesburg and Durban, respectively. Market samples were sequenced for the core DNA barcodes (rbcLa and matK) as well as two additional regions: nrITS and trnH-psbA. The barcoding database for cycads at the University of Johannesburg was utilized to assign query samples to known species. Three approaches were followed: tree-based, similarity-based, and character-based (BRONX) methods. Market samples identified were Encephalartos ferox (Near Threatened), Encephalartos lebomboensis (Endangered), Encephalartos natalensis (Near Threatened), Encephalartos senticosus (Vulnerable), and Encephalartos villosus (Least Concern). Results from this study are crucial for making appropriate assessments and decisions on how to manage these markets.

  19. Transcriptomic and epigenomic characterization of the developing bat wing

    PubMed Central

    Eckalbar, Walter L.; Schlebusch, Stephen A.; Mason, Mandy K.; Gill, Zoe; Parker, Ash V.; Booker, Betty M.; Nishizaki, Sierra; Muswamba-Nday, Christiane; Terhune, Elizabeth; Nevonen, Kimberly; Makki, Nadja; Friedrich, Tara; VanderMeer, Julia E.; Pollard, Katherine S.; Carbone, Lucia; Wall, Jeff D.; Illing, Nicola; Ahituv, Nadav

    2016-01-01

    Bats are the only mammals capable of powered flight, but little is known about the genetic determinants that shape their wings. Here, we generated a genome for Miniopterus natalensis and performed RNA-seq and ChIP-seq (H3K27ac, H3K27me3) on its developing forelimb and hindlimb autopods at sequential embryonic stages to decipher the molecular events that underlie bat wing development. Over 7,000 genes and several lncRNAs, including Tbx5-as1 and Hottip, were differentially expressed between forelimb, hindlimb and different stages. ChIP-seq identified thousands of regions that are differentially modified in forelimb versus hindlimb. Comparative genomics found 2,796 bat-accelerated regions within H3K27ac peaks, several of which cluster near limb-associated genes. Pathway analyses revealed multiple ribosomal proteins and known limb patterning signaling pathways as differentially regulated, and implicated increased forelimb mesenchymal condensations with differential growth. Combined, our work outlines multiple genetic components that contribute to bat wing formation, providing a genomic blueprint for this morphological innovation. PMID:27019111

  20. Indels ascertain the phylogenetic position of Coleodactylus elizae Gonçalves, Torquato, Skuk & Sena, 2012 (Gekkota: Sphaerodactylidae).

    PubMed

    Correia, Larissa Lima; Gamble, Tony; Landell, Melissa Fontes; Mott, Tamí

    2016-02-24

    The Neotropical gecko genus Coleodactylus Parker 1926 was, until recently, composed of five species: C. amazonicus (Andersson 1918), C. brachystoma (Amaral 1935), C. meridionalis (Boulenger 1888), C. natalensis Freire 1999, and C. septentrionalis Vanzolini 1980 (Geurgas et al. 2008). However, several phylogenetic analyses recovered a polyphyletic Coleodactylus (Geurgas et al. 2008; Gamble et al. 2011a) leading Gamble et al. (2011b) to recognize a new genus, Chatogekko, for C. amazonicus. Coleodactylus and Chatogekko differ in both morphological and molecular characters. Coleodactylus has smooth dorsal scales and five scales forming the ungual sheath, while Chatogekko has keeled dorsal scales and four scales forming the ungual sheath (Gamble et al. 2011b). Furthermore, all Coleodactylus species have two deletions in the protein coding recombination-activating gene 1 (RAG1), one of six base pairs (bp) and another of 18 bp (Gamble et al. 2008a; Geurgas et al. 2008), while Chatogekko has a unique three bp deletion in the RBMX gene and a three bp deletion in the protein tyrosine phosphatase nonreceptor type 12 gene (PTPN12) (Gamble et al. 2011b). In addition, Chatogekko is differentiated from all others geckos by a unique set of 10 craniofacial features (Gamble et al. 2011b).

  1. Role of the lymnaeid snail Pseudosuccinea columella in the transmission of the liver fluke Fasciola hepatica in Egypt.

    PubMed

    Dar, Y; Vignoles, P; Rondelaud, D; Dreyfuss, G

    2015-11-01

    Experimental infections of three Egyptian Pseudosuccinea columella populations with sympatric miracidia of Fasciola sp., coming from cattle- or sheep-collected eggs, were carried out to determine the capacity of this lymnaeid to support larval development of the parasite. Using microsatellite markers, the isolates of Egyptian miracidia were identified as Fasciola hepatica. Apart from being independent of snail origin, prevalences ranging from 60.4 to 75.5% in snails infected with five miracidia of F. hepatica were significantly higher than values of 30.4 to 42.2% in snails with bi-miracidial infections. The number of metacercariae ranged from 243 to 472 per cercarial-shedding snail and was independent of snail origin, parasite origin and miracidial dose used for infection. If P. columella was subjected to two successive bi-miracidial infections with F. hepatica, prevalence of infection was 63.3%, with a mean of 311 metacercariae per snail. These values were clearly greater than those already reported for Radix natalensis infected with the same parasite and the same protocol. Successful experimental infection of P. columella with F. hepatica suggests that this lymnaeid snail is an important intermediate host for the transmission of fascioliasis in Egypt.

  2. Farming termites determine the genetic population structure of Termitomyces fungal symbionts.

    PubMed

    Nobre, Tânia; Fernandes, Cecília; Boomsma, Jacobus J; Korb, Judith; Aanen, Duur K

    2011-05-01

    Symbiotic interactions between macrotermitine termites and their fungal symbionts have a moderate degree of specificity. Consistent with horizontal symbiont transmission, host switching has been frequent over evolutionary time so that single termite species can often be associated with several fungal symbionts. However, even in the few termite lineages that secondarily adopted vertical symbiont transmission, the fungal symbionts are not monophyletic. We addressed this paradox by studying differential transmission of fungal symbionts by alate male and female reproductives, and the genetic population structure of Termitomyces fungus gardens across 74 colonies of Macrotermes bellicosus in four west and central African countries. We confirm earlier, more limited, studies showing that the Termitomyces symbionts of M. bellicosus are normally transmitted vertically and clonally by dispersing males. We also document that the symbionts associated with this termite species belong to three main lineages that do not constitute a monophyletic group. The most common lineage occurs over the entire geographical region that we studied, including west, central and southern Africa, where it is also associated with the alternative termite hosts Macrotermes subhyalinus and Macrotermes natalensis. While Termitomyces associated with these alternative hosts are horizontally transmitted and recombine freely, the genetic population structure of the same Termitomyces associated with M. bellicosus is consistent with predominantly clonal reproduction and only occasional recombination. This implies that the genetic population structure of Termitomyces is controlled by the termite host and not by the Termitomyces symbiont.

  3. Reduced growth of Listeria monocytogenes in two model cheese microcosms is not associated with individual microbial strains.

    PubMed

    Imran, Muhammad; Bré, Jean-Michel; Guéguen, Marielle; Vernoux, Jean-Paul; Desmasures, Nathalie

    2013-02-01

    Two model antilisterial microbial communities consisting of two yeasts, two Gram positive and two Gram negative bacteria, and originating from Livarot cheese smear were previously designed. They were used in the present study to analyse the impact of microbial population dynamics on growth of Listeria monocytogenes in cheese microcosm. Specific culture media and PCR primers were developed for simultaneous culture-dependent and real-time PCR quantification of strains belonging to Marinomonas sp., Paenibacillus sp., Staphylococcus equorum, Arthrobacter arilaitensis, Pseudomonas putida, Serratia liquefaciens, Candida natalensis, and Geotrichum candidum, in cheese microcosms. All strains were enumerated after 3, 5, 8 and 14 days at 15 °C. They established well at high counts in all cheese microcosms. Growth dynamics for all strains in presence of L. monocytogenes WSLC 1685 were compared to those of microbial communities obtained by omitting in turn one of the six members of the initial community. The growth of the microbial strains was neither markedly disturbed by Listeria presence nor by the removal of each strain in turn. Furthermore, these communities had a significant reducing effect on growth of L. monocytogenes independently of pH, as confirmed by mathematical modelling. A barrier effect was observed, that could be explained by specific competition for nutrients.

  4. Predicting the influence of multiple components on microbial inhibition using a logistic response model - a novel approach

    PubMed Central

    2014-01-01

    Background There are several synergistic methods available. However, there is a vast discrepancy in the interpretation of the synergistic results. Also, these synergistic methods do not assess the influence the tested components (drugs, plant and natural extracts), have upon one another, when more than two components are combined. Methods A modified checkerboard method was used to evaluate the synergistic potential of Heteropyxis natalensis, Melaleuca alternifolia, Mentha piperita and the green tea extract known as TEAVIGO™. The synergistic combination was tested against the oral pathogens, Streptococcus mutans, Prevotella intermedia and Candida albicans. Inhibition data obtained from the checkerboard method, in the form of binary code, was used to compute a logistic response model with statistically significant results (p < 0.05). This information was used to construct a novel predictive inhibition model. Results Based on the predictive inhibition model for each microorganism, the oral pathogens tested were successfully inhibited (at 100% probability) with their respective synergistic combinations. The predictive inhibition model also provided information on the influence that different components have upon one another, and on the overall probability of inhibition. Conclusions Using the logistic response model negates the need to ‘calculate’ synergism as the results are statistically significant. In successfully determining the influence multiple components have upon one another and their effect on microbial inhibition, a novel predictive model was established. This ability to screen multiple components may have far reaching effects in ethnopharmacology, agriculture and pharmaceuticals. PMID:24928297

  5. Trials with N-tritylmorpholine (Shell WL 8008) as a molluscicide in Southern Rhodesia

    PubMed Central

    Shiff, C. J.

    1966-01-01

    In the course of research into the effectiveness of new molluscicides for bilharziasis control, a recently developed compound, Shell WL 8008 (N-tritylmorpholine), has been tested in Southern Rhodesia, both in the laboratory and in the field. It is highly toxic to Bulinus (Physopsis) globosus, Biomphalaria pfeifferi and Lymnaea natalensis, all of which succumbed to the compound at a concentration of 1.0 ppm in a contact time of only 15 minutes. In experiments in reservoirs and natural watercourses, a concentrated aqueous suspension was sprayed on or just under the water surface, forming a white ”blanket” that sank at a rate depending on temperature, amount of vegetation, and so on. The period of contact with snails is sufficiently long for the molluscicide to kill them as it sinks; this characteristic is of great importance in the economic treatment of large stagnant water bodies or slow-moving streams. The compound is highly piscicidal, but has little effect on a wide range of microfauna. PMID:5297004

  6. Associations between trematode infections in cattle and freshwater snails in highland and lowland areas of Iringa Rural District, Tanzania.

    PubMed

    Nzalawahe, Jahashi; Kassuku, Ayub A; Stothard, J Russell; Coles, Gerald C; Eisler, Mark C

    2015-09-01

    The epidemiology of trematode infections in cattle was investigated within highland and lowland areas of Iringa Rural District, in southern Tanzania. Fecal samples were collected from 450 cattle in 15 villages at altitudes ranging from 696 to 1800 m above the sea level. Freshwater snails were collected from selected water bodies and screened for emergence of cercariae. The infection rates in cattle were Fasciola gigantica 28·2%, paramphistomes 62·8% and Schistosoma bovis 4·8%. Notably, prevalence of trematode infections in cattle was much higher in highland (altitude > 1500 m) as compared with lowland (altitude < 1500 m) areas and was statistically significant (P-value = 0·000) for F. gigantica and paramphistomes but not for S. bovis. The snails collected included Lymnaea natalensis, Bulinus africanus, Bulinus tropicus, Bulinus forskali, Biomphalaria pfeifferi, Melanoides tuberculata and Bellamya constricta with a greater proportion of highland (75%) than lowland (36%) water bodies harbouring snails. Altitude is a major factor shaping the epidemiology of F. gigantica and paramphistomes infections in cattle in Iringa Rural District with greater emphasis upon control needed in highland areas.

  7. Identification of an antifungal metabolite produced by a potential biocontrol Actinomyces strain A01

    PubMed Central

    Lu, Cai Ge; Liu, Wei Cheng; Qiu, Ji Yan; Wang, Hui Min; Liu, Ting; De Liu, Wen

    2008-01-01

    Actinomyces strain A01 was isolated from soil of a vegetable field in the suburb of Beijing, China. According to the morphological, cultural, physiological and biochemical characteristics, and 16S rDNA sequence analysis, strain A01 was identified as Streptomyces lydicus. In the antimicrobial spectrum test strain A01 presented a stable and strong inhibitory activity against several plant pathogenic fungi such as Fusarium oxysporum, Botrytis cinerea, Monilinia laxa, etc. However, no antibacterial activity was found. In pot experiments in greenhouse, the development of tomato gray mold was markedly suppressed by treatment with the fermentation broth of the strain A01, and the control efficacy was higher than those of Pyrimethanil and Polyoxin. A main antifungal compound (purity 99.503%) was obtained from the fermentation broth of strain A01 using column chromatography and HPLC. The chemical structural analysis with U V, IR, MS, and NMR confirmed that the compound produced by the strain A01 is natamycin, a polyene antibiotic produced by S. chattanovgensis, S. natalensis, and S. gilvosporeus, widely used as a natural biological preservative for food according to previous reports. The present study revealed a new producing strain of natamycin and its potential application as a biological control agent for fungal plant diseases. PMID:24031293

  8. Complementary symbiont contributions to plant decomposition in a fungus-farming termite

    PubMed Central

    Hu, Haofu; Li, Cai; Chen, Zhensheng; Otani, Saria; Nygaard, Sanne; Nobre, Tania; Klaubauf, Sylvia; Schindler, Philipp M.; Hauser, Frank; Pan, Hailin; Yang, Zhikai; Sonnenberg, Anton S. M.; de Beer, Z. Wilhelm; Zhang, Yong; Wingfield, Michael J.; Grimmelikhuijzen, Cornelis J. P.; de Vries, Ronald P.; Korb, Judith; Aanen, Duur K.; Wang, Jun; Boomsma, Jacobus J.; Zhang, Guojie

    2014-01-01

    Termites normally rely on gut symbionts to decompose organic matter but the Macrotermitinae domesticated Termitomyces fungi to produce their own food. This transition was accompanied by a shift in the composition of the gut microbiota, but the complementary roles of these bacteria in the symbiosis have remained enigmatic. We obtained high-quality annotated draft genomes of the termite Macrotermes natalensis, its Termitomyces symbiont, and gut metagenomes from workers, soldiers, and a queen. We show that members from 111 of the 128 known glycoside hydrolase families are represented in the symbiosis, that Termitomyces has the genomic capacity to handle complex carbohydrates, and that worker gut microbes primarily contribute enzymes for final digestion of oligosaccharides. This apparent division of labor is consistent with the Macrotermes gut microbes being most important during the second passage of comb material through the termite gut, after a first gut passage where the crude plant substrate is inoculated with Termitomyces asexual spores so that initial fungal growth and polysaccharide decomposition can proceed with high efficiency. Complex conversion of biomass in termite mounds thus appears to be mainly accomplished by complementary cooperation between a domesticated fungal monoculture and a specialized bacterial community. In sharp contrast, the gut microbiota of the queen had highly reduced plant decomposition potential, suggesting that mature reproductives digest fungal material provided by workers rather than plant substrate. PMID:25246537

  9. Generic Delimitations in Tuberous Periplocoideae (Apocynaceae) from Africa and Madagascar

    PubMed Central

    MEVE, ULRICH; LIEDE, SIGRID

    2004-01-01

    • Background and Aims The number of genera included in Apocynaceae subfamily Periplocoideae is a matter of debate. DNA sequences are used here as an independent dataset to clarify generic relationships and classification of the tuberous periplocoid genera and to address the question of the phylogenetic interpretation of pollinia formation in Schlechterella. • Methods Representatives of nearly all African and Malagasy genera of Periplocoideae possessing root tubers were analysed using ITS and plastid DNA sequence characters. • Key Results Sequence data from non‐coding molecular markers (ITS of nrDNA and the trnT‐L and trnL‐F spacers as well as the trnL intron of plastid DNA) give support for a broad taxonomic concept of Raphionacme including Pentagonanthus. Together with Schlechterella, which is sister to Raphionacme, all Raphionacme‐like taxa form a derived monophyletic group of somewhat diverse species. Sister to the Schlechterella/Raphionacme clade is a clade comprising Stomatostemma and the not truly tuberous vine Mondia. In the combined analysis, sister to these two clades combined is a clade formed by Petopentia natalensis and Periploca. • Conclusions The recent inclusion of the monotypic South African Petopentia in the monotypic Malagasy endemic Ischnolepis is to be rejected. The Malagasy Camptocarpus is sister to the remainder of Periplocoideae in the ITS and combined analyses, and a Malagasy origin for the subfamily is discussed. PMID:14980976

  10. Comparative sperm ultrastructure of twelve leptodactylid frog species with insights into their phylogenetic relationships.

    PubMed

    Santos, Julio Sérgio; Introíni, Gisele Orlandi; Veiga-Menoncello, Ana Cristina Prado; Blasco, Ailin; Rivera, Miryan; Recco-Pimentel, Shirlei Maria

    2016-12-01

    The spermatozoa of representatives of three Neotropical frog subfamilies, Leiuperinae, Leptodactylinae and Paratelmatobiinae, were observed using Transmission Electron Microscopy, with the aim of identifying ultrastructural traits that provide insights into the phylogenetic relationships among these anurans, which are currently unclear. In the leiuperines, spermatozoa of Physalaemus albifrons, P. cicada, P. deimaticus and P. feioi were characterized by an acrosomal vesicle covering the subacrosomal cone that was not observed in the spermatozoa of Physalaemus centralis and P. cuvieri. The tail of the spermatozoa of P. albifrons, P. centralis, P. cicada, P. cuvieri, P. deimaticus, and P. feioi presented a long undulating membrane, whereas Engystomops petersi and E. freibergi, which form a sister clade to Physalaemus, had an axial fiber, which were absent in Physalaemus. Other leiuperine, E. puyango had an abaxonemal bulb-like swelling distally to the paraxonemal rod, which were also absent in Physalaemus. These differences support the revalidation of Engystomops as a true taxon, distinct from Physalaemus. The tail of the spermatozoa of E. petersi and E. freibergi was similar to that of Paratelmatobius poecilogaster (Paratelmatobiinae). The spermatozoa of Leptodactylus natalenis (Leptodactylinae) had undulating membrane and axial fiber, in contrast with Adenomera marmorata, which lacked these structures. Morphological differences between A. marmorata and L. natalensis sperm cells appeared to validate the allocation of A. marmorata into a genus distinct from Leptodactylus. Overall, dissimilarities in the spermatozoa of the leptodactylids provided an important phylogenetic signal for the understanding of their taxonomic relationships.

  11. The n-hexane and chloroform fractions of Piper betle L. trigger different arms of immune responses in BALB/c mice and exhibit antifilarial activity against human lymphatic filarid Brugia malayi.

    PubMed

    Singh, Meghna; Shakya, Shilpy; Soni, Vishal Kumar; Dangi, Anil; Kumar, Nikhil; Bhattacharya, Shailja-Misra

    2009-06-01

    Modulation of immune functions by using herbal plants and their products has become fundamental regime of therapeutic approach. Piper betle Linn. (Piperaceae) is a widely distributed plant in the tropical and subtropical regions of the world and has been attributed as traditional herbal remedy for many diseases. We have recently reported the antifilarial and antileishmanial efficacy in the leaf extract of Bangla Mahoba landrace of P. betle which is a female plant. The present report describes the in vivo immunomodulatory efficacy of the crude methanolic extract and its n-hexane, chloroform, n-butanol fractions of the female plant at various dose levels ranging between 0.3 and 500 mg/kg in BALB/c. Attempts were also made to observe antifilarial activity of the active extracts and correlate it with the antigen specific immune responses in another rodent Mastomys coucha infected with human lymphatic filarial parasite Brugia malayi. The crude methanol extract and n-hexane fraction were found to potentiate significant (p<0.001) enhancement of both humoral (plaque forming cells, hemagglutination titre) as well as cell-mediated (lymphoproliferation, macrophage activation, delayed type hypersensitivity) immune responses in mice. The flow cytometric analysis of splenocytes of treated mice indicated enhanced population of T-cells (CD4(+), CD8(+)) and B-cells (CD19(+)). The n-hexane fraction (3 mg/kg) was found to induce biased type 2 cytokine response as revealed by increased IL-4(+) and decreased IFN-gamma(+) T-cell population while the chloroform fraction (10 mg/kg) produced a predominant type 1 cytokines. Crude methanolic extract (100 mg/kg) demonstrated a mixed type 1 and type 2 cytokine responses thus suggesting a remarkable immunomodulatory property in this plant. The induction of differential T-helper cell immune response appears ideal to overcome immunosuppression as observed in case of lymphatic, filarial Brugia malayi infection which may also be extended to other

  12. Homology modeling of NAD+-dependent DNA ligase of the Wolbachia endosymbiont of Brugia malayi and its drug target potential using dispiro-cycloalkanones.

    PubMed

    Shrivastava, Nidhi; Nag, Jeetendra K; Pandey, Jyoti; Tripathi, Rama Pati; Shah, Priyanka; Siddiqi, Mohammad Imran; Misra-Bhattacharya, Shailja

    2015-07-01

    Lymphatic filarial nematodes maintain a mutualistic relationship with the endosymbiont Wolbachia. Depletion of Wolbachia produces profound defects in nematode development, fertility, and viability and thus has great promise as a novel approach for treating filarial diseases. NAD(+)-dependent DNA ligase is an essential enzyme of DNA replication, repair, and recombination. Therefore, in the present study, the antifilarial drug target potential of the NAD(+)-dependent DNA ligase of the Wolbachia symbiont of Brugia malayi (wBm-LigA) was investigated using dispiro-cycloalkanone compounds. Dispiro-cycloalkanone specifically inhibited the nick-closing and cohesive-end ligation activities of the enzyme without inhibiting human or T4 DNA ligase. The mode of inhibition was competitive with the NAD(+) cofactor. Docking studies also revealed the interaction of these compounds with the active site of the target enzyme. The adverse effects of these inhibitors were observed on adult and microfilarial stages of B. malayi in vitro, and the most active compounds were further monitored in vivo in jirds and mastomys rodent models. Compounds 1, 2, and 5 had severe adverse effects in vitro on the motility of both adult worms and microfilariae at low concentrations. Compound 2 was the best inhibitor, with the lowest 50% inhibitory concentration (IC50) (1.02 μM), followed by compound 5 (IC50, 2.3 μM) and compound 1 (IC50, 2.9 μM). These compounds also exhibited the same adverse effect on adult worms and microfilariae in vivo (P < 0.05). These compounds also tremendously reduced the wolbachial load, as evident by quantitative real-time PCR (P < 0.05). wBm-LigA thus shows great promise as an antifilarial drug target, and dispiro-cycloalkanone compounds show great promise as antifilarial lead candidates.

  13. Identification of Two Novel Members of the Tentative Genus Wukipolyomavirus in Wild Rodents

    PubMed Central

    Nainys, Juozas; Timinskas, Albertas; Schneider, Julia; Ulrich, Rainer G.; Gedvilaite, Alma

    2015-01-01

    Two novel polyomaviruses (PyVs) were identified in kidney and chest-cavity fluid samples of wild bank voles (Myodes glareolus) and common voles (Microtus arvalis) collected in Germany. All cloned and sequenced genomes had the typical PyV genome organization, including putative open reading frames for early regulatory proteins large T antigen and small T antigen on one strand and for structural late proteins (VP1, VP2 and VP3) on the other strand. Virus-like particles (VLPs) were generated by yeast expression of the VP1 protein of both PyVs. VLP-based ELISA and large T-antigen sequence-targeted polymerase-chain reaction investigations demonstrated signs of infection of these novel PyVs in about 42% of bank voles and 18% of common voles. In most cases only viral DNA, but not VP1-specific antibodies were detected. In additional animals exclusively VP1-specific antibodies, but no viral DNA was detected, indicative for virus clearance. Phylogenetic and clustering analysis including all known PyV genomes placed novel bank vole and common vole PyVs amongst members of the tentative Wukipolymavirus genus. The other known four rodent PyVs, Murine PyV and Hamster PyV, and Murine pneumotropic virus and Mastomys PyV belong to different phylogenetic clades, tentatively named Orthopolyomavirus I and Orthopolyomavirus II, respectively. In conclusion, the finding of novel vole-borne PyVs may suggest an evolutionary origin of ancient wukipolyomaviruses in rodents and may offer the possibility to develop a vole-based animal model for human wukipolyomaviruses. PMID:26474048

  14. Homology Modeling of NAD+-Dependent DNA Ligase of the Wolbachia Endosymbiont of Brugia malayi and Its Drug Target Potential Using Dispiro-Cycloalkanones

    PubMed Central

    Shrivastava, Nidhi; Nag, Jeetendra K.; Pandey, Jyoti; Tripathi, Rama Pati; Shah, Priyanka; Siddiqi, Mohammad Imran

    2015-01-01

    Lymphatic filarial nematodes maintain a mutualistic relationship with the endosymbiont Wolbachia. Depletion of Wolbachia produces profound defects in nematode development, fertility, and viability and thus has great promise as a novel approach for treating filarial diseases. NAD+-dependent DNA ligase is an essential enzyme of DNA replication, repair, and recombination. Therefore, in the present study, the antifilarial drug target potential of the NAD+-dependent DNA ligase of the Wolbachia symbiont of Brugia malayi (wBm-LigA) was investigated using dispiro-cycloalkanone compounds. Dispiro-cycloalkanone specifically inhibited the nick-closing and cohesive-end ligation activities of the enzyme without inhibiting human or T4 DNA ligase. The mode of inhibition was competitive with the NAD+ cofactor. Docking studies also revealed the interaction of these compounds with the active site of the target enzyme. The adverse effects of these inhibitors were observed on adult and microfilarial stages of B. malayi in vitro, and the most active compounds were further monitored in vivo in jirds and mastomys rodent models. Compounds 1, 2, and 5 had severe adverse effects in vitro on the motility of both adult worms and microfilariae at low concentrations. Compound 2 was the best inhibitor, with the lowest 50% inhibitory concentration (IC50) (1.02 μM), followed by compound 5 (IC50, 2.3 μM) and compound 1 (IC50, 2.9 μM). These compounds also exhibited the same adverse effect on adult worms and microfilariae in vivo (P < 0.05). These compounds also tremendously reduced the wolbachial load, as evident by quantitative real-time PCR (P < 0.05). wBm-LigA thus shows great promise as an antifilarial drug target, and dispiro-cycloalkanone compounds show great promise as antifilarial lead candidates. PMID:25845868

  15. Moxidectin causes adult worm mortality of human lymphatic filarial parasite Brugia malayi in rodent models.

    PubMed

    Verma, Meenakshi; Pathak, Manisha; Shahab, Mohd; Singh, Kavita; Mitra, Kalyan; Misra-Bhattacharya, Shailja

    2014-12-01

    Moxidectin is a macrocyclic lactone belonging to milbemycin family closely related to ivermectin and is currently progressing towards Phase III clinical trial against human infection with the filaria Onchocerca volvulus (Leuckart, 1894). There is a single report on the microfilaricidal and embryostatic activity of moxidectin in case of the human lymphatic filarial parasite Brugia malayi (Brug, 1927) in Mastomys coucha (Smith) but without any adulticidal action. In the present study, the in vitro and in vivo antifilarial efficacy of moxidectin was evaluated on, B. malayi. In vitro moxidectin showed 100% reduction in adult female worm motility at 0.6 μM concentration within 7 days with 68% inhibition in the reduction of MTT (3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide dye) (which is used to detect viability of worms). A 50% inhibitory concentration (IC50) of moxidectin for adult female parasite was 0.242 μM, for male worm 0.186 μM and for microfilaria IC50 was 0.813 μM. In adult B. malayi-transplanted primary screening model (Meriones unguiculatus Milne-Edwards), moxidectin at a single optimal dose of 20 mg/kg by oral and subcutaneous route was found effective on both adult parasites and microfilariae. In secondary screening (M coucha, subcutaneously inoculated with infective larvae), moxidectin at the same dose by subcutaneous route brought about death of 49% of adult worms besides causing sterilisation in 54% of the recovered live female worms. The treated animals exhibited a continuous and sustained reduction in peripheral blood microfilaraemia throughout the observation period of 90 days. The mechanism of action of moxidectin is suggested to be similar to avermectins. The in silico studies were also designed to explore the interaction of moxidectin with glutamate-gated chloride channels of B. malayi. The docking results revealed a close interaction of moxidectin with various GluCl ligand sites of B. malayi.

  16. Coevolution of Cryptosporidium tyzzeri and the house mouse (Mus musculus).

    PubMed

    Kváč, Martin; McEvoy, John; Loudová, Martina; Stenger, Brianna; Sak, Bohumil; Květoňová, Dana; Ditrich, Oleg; Rašková, Veronika; Moriarty, Elaine; Rost, Michael; Macholán, Miloš; Piálek, Jaroslav

    2013-09-01

    Two house mouse subspecies occur in Europe, eastern and northern Mus musculus musculus (Mmm) and western and southern Mus musculus domesticus (Mmd). A secondary hybrid zone occurs where their ranges meet, running from Scandinavia to the Black Sea. In this paper, we tested a hypothesis that the apicomplexan protozoan species Cryptosporidium tyzzeri has coevolved with the house mouse. More specifically, we assessed to what extent the evolution of this parasite mirrors divergence of the two subspecies. In order to test this hypothesis, we analysed sequence variation at five genes (ssrRNA, Cryptosporidium oocyst wall protein (COWP), thrombospondin-related adhesive protein of Cryptosporidium 1 (TRAP-C1), actin and gp60) in C. tyzzeri isolates from Mmd and Mmm sampled along a transect across the hybrid zone from the Czech Republic to Germany. Mmd samples were supplemented with mice from New Zealand. We found two distinct isolates of C. tyzzeri, each occurring exclusively in one of the mouse subspecies (C. tyzzeri-Mmm and C. tyzzeri-Mmd). In addition to genetic differentiation, oocysts of the C. tyzzeri-Mmd subtype (mean: 4.24×3.69μm) were significantly smaller than oocysts of C. tyzzeri-Mmm (mean: 4.49×3.90 μm). Mmm and Mmd were susceptible to experimental infection with both C. tyzzeri subtypes; however, the subtypes were not infective for the rodent species Meriones unguiculatus, Mastomys coucha, Apodemus flavicollis or Cavia porcellus. Overall, our results support the hypothesis that C. tyzzeri is coevolving with Mmm and Mmd.

  17. Coevolution of Cryptosporidium tyzzeri and the house mouse (Mus musculus)✯

    PubMed Central

    Kváč, Martin; McEvoy, John; Loudová, Martina; Stenger, Brianna; Sak, Bohumil; Květoňová, Dana; Ditrich, Oleg; Rašková, Veronika; Moriarty, Elaine; Rost, Michael; Macholán, Miloš; Piálek, Jaroslav

    2013-01-01

    Two house mouse subspecies occur in Europe, eastern and northern Mus musculus musculus (Mmm) and western and southern Mus musculus domesticus (Mmd). A secondary hybrid zone occurs where their ranges meet, running from Scandinavia to the Black Sea. In this paper, we tested a hypothesis that the apicomplexan protozoan species Cryptosporidium tyzzeri has coevolved with the house mouse. More specifically, we assessed to what extent the evolution of this parasite mirrors divergence of the two subspecies. In order to test this hypothesis, we analyzed sequence variation at five genes (ssrRNA, Cryptosporidium oocyst wall protein (COWP), thrombospondin-related adhesive protein of Cryptosporidium 1 (TRAP-C1), actin and gp60) in C. tyzzeri isolates from Mmd and Mmm sampled along a transect across the hybrid zone from the Czech Republic to Germany. Mmd samples were supplemented with mice from New Zealand. We found two distinct isolates of C. tyzzeri, each occurring exclusively in one of the mouse subspecies (C. tyzzeri-Mmm and C. tyzzeri-Mmd). In addition to genetic differentiation, oocysts of the C. tyzzeri-Mmd subtype (mean: 4.24 × 3.69 μm) were significantly smaller than oocysts of C. tyzzeri-Mmm (mean: 4.49 × 3.90 μm). Mmm and Mmd were susceptible to experimental infection with both C. tyzzeri subtypes; however, the subtypes were not infective for the rodent species Meriones unguiculatus, Mastomys coucha, Apodemus flavicollis or Cavia porcellus. Overall, our results support the hypothesis that C. tyzzeri is coevolving with Mmm and Mmd. PMID:23791796

  18. Prior killing of intracellular bacteria Wolbachia reduces inflammatory reactions and improves antifilarial efficacy of diethylcarbamazine in rodent model of Brugia malayi.

    PubMed

    Shakya, Shilpy; Bajpai, Preeti; Sharma, Sharad; Misra-Bhattacharya, Shailja

    2008-04-01

    The discovery of the endosymbiont Wolbachia, which has a mutualistic relationship with filarial nematodes, and its importance in filarial parasite biology has provided a lead for developing novel chemotherapeutic agents against human filariasis. Wolbachia also appears to be involved in immunopathological responses as well as adverse reactions after antifilarial therapy. The aim of the present study was to explore the potential of administering anti-Wolbachial therapy before antifilarial treatment to improve the filaricidal efficacy of the present-day filaricide diethylcarbamazine. An additional objective was to minimize host inflammatory reactions using a rodent model Mastomys coucha and Meriones unguiculatus infected with human lymphatic filariid Brugia malayi. We observed: (1) a 40-day treatment schedule of tetracycline alone resulted in delayed reduction in microfilaraemia and a low degree of macrofilaricidal efficacy; (2) tetracycline therapy followed by 100 mg/kg diethylcarbamazine (DEC) x5 days led to marked reduction in microfilaraemia from day 48 onward after initiation of treatment. The combination treatment also brought about approximately 70% death of adult B. malayi and sterilization of 82.3% of the surviving female worms, thus exhibiting remarkable enhancement in the antifilarial activity of DEC; (3) tissue inflammatory reactions and pathogenesis were significantly reduced as observed by histopathology, and peritoneal macrophage mediated oxidative burst shown by fluorescence-activated cell sorting (FACS) analysis using dichlorofluorescein diacetate (DCF-DA); and (4) the characteristic filarial antigen-specific and mitogen-specific cellular unresponsiveness was significantly reversed, possibly due to marked clearance of microfilaraemia. It is therefore advisable to give an anti-Wolbachial antibiotic trial before starting antifilarial therapy to achieve maximum benefits.

  19. Ecological filtering by a dominant herb selects for shade tolerance in the tree seedling community of coastal dune forest.

    PubMed

    Tsvuura, Zivanai; Griffiths, Megan E; Gunton, Richard M; Franks, Peter J; Lawes, Michael J

    2010-12-01

    The regeneration niche is commonly partitioned along a gradient from shade-tolerant to shade-intolerant species to explain plant community assembly in forests. We examined the shade tolerance of tree seedlings in a subtropical coastal forest to determine whether the ecological filtering effect of a dominant, synchronously monocarpic herb (Isoglossa woodii) selects for species at either end of the light response continuum during the herb's vegetative and reproductive phases. Photosynthetic characteristics of seedlings of 20 common tree species and the herb were measured. Seedlings were grown in the greenhouse at 12-14% irradiance, and their light compensation points measured using an open-flow gas exchange system. The light compensation points for the tree species were low, falling within a narrow range from 2.1 ± 0.8 μmol m(-2) s(-1) in Celtis africana to 6.4 ± 0.7 μmol m(-2) s(-1) in Allophylus natalensis, indicating general shade tolerance, consistent with a high and narrow range of apparent quantum yield among species (0.078 ± 0.002 mol CO(2) mol(-1) photon). Rates of dark respiration were significantly lower in a generalist pioneer species (Acacia karroo) than in a forest pioneer (C. africana), or in late successional phase forest species. We argue that the general shade tolerance, and phenotypic clustering of shade tolerance, in many tree species from several families in this system, is a result of ecological filtering by the prevailing low light levels beneath the I. woodii understorey, which excludes most light-demanding species from the seedling community.

  20. Studies on the effect of pollution on Lake Manzala ecosystem in Port-Said, Damietta and Dakahlia Governorates Egypt.

    PubMed

    El-Khayat, Hanaa M M; Mahmoud, Kadria M A; Gaber, Hanan S; Abdel-Hamid, Hoda; Abu Taleb, Hoda M A

    2015-04-01

    This work studied how pollution impacts the ecosystem of Lake Manzala by determination of physicochemical parameters, studying biodiversity of aquatic plants and macroinvertebrates, and determining bioaccumulation of Pb, Cu, Cd & Zn in some major organisms, Biomphalaria alexandrina and Melanoides tuberculata snails and Oreochromis niloticus fish. The more near to Mediterranean Sea and to the industrial area, Port-Said and Damietta sites showed higher dissolved oxygen and conductivity than Dakahlia sites. Distribution percentage of Eichhornia crassipes is high among Port-Said and Dakahlia sites of 100 and 88%, respectively, while Lemna giba is the most abundant among Damietta sites of 60%. The maximum macroinvertebrate taxa richness was obtained at Gammalya, Dakahlia of 16 species while the maximum abundance was registered at Annanya, Damietta of 591 organisms. Gastropoda are the most distributed organisms in Lake Manzala followed by Hemiptera and Plecoptera then shrimps and scud. All the medically important snails, B. alexandrina, B. truncatus and L. natalensis were recorded in Dakahlia, but only B. alexandrina was in Damietta and Port-Said sites. The collected water samples from Damietta sites showed the highest significant Cu & Cd concentration while Port-Said samples showed the highest Pb concentration and Dakahlia showed the highest Zn concentration. The metals concentrations were higher in snail tissue and in fish liver, kidney and most of muscle samples as compared in surface water. The higher metal bioaccumulation was determined in snails collected from sites showed higher water metals concentrations. Fish muscle showed the least residues than liver and kidney for all the measured metals. Pb and Cd were more accumulated in kidneys, Cu was more accumulated in liver and Zn was accumulated in all examined fish parts in descending order as follows Kidney > liver > muscle.

  1. Synergistic Antimycobacterial Actions of Knowltonia vesicatoria (L.f) Sims

    PubMed Central

    Labuschagné, Antoinette; Hussein, Ahmed A.; Rodríguez, Benjamín; Lall, Namrita

    2012-01-01

    Euclea natalensis A.DC., Knowltonia vesicatoria (L.f) Sims, and Pelargonium sidoides DC. are South African plants traditionally used to treat tuberculosis. Extracts from these plants were used in combination with isoniazid (INH) to investigate the possibility of synergy with respect to antimycobacterial activity. The ethanol extract of K. vesicatoria was subjected to fractionation to identify the active compounds. The activity of the Knowltonia extract remained superior to the fractions with a minimum inhibitory concentration (MIC) of 625.0 μg/mL against Mycobacterium smegmatis and an MIC of 50.00 μg/mL against M. tuberculosis. The K. vesicatoria extract was tested against two different drug-resistant strains of M. tuberculosis, which resulted in an MIC of 50.00 μg/mL on both strains. The combination of K. vesicatoria with INH exhibited the best synergistic antimycobacterial activity with a fractional inhibitory concentration index of 0.25 (a combined concentration of 6.28 μg/mL). A fifty percent inhibitory concentration of this combination against U937 cells was 121.0 μg/mL. Two compounds, stigmasta-5,23-dien-3-ol (1) and 5-(hydroxymethyl)furan-2(5H)-one (2), were isolated from K. vesicatoria as the first report of isolation for both compounds from this plant and the first report of antimycobacterial activity. Compound (1) was active against drug-sensitive M. tuberculosis with an MIC of 50.00 μg/mL. PMID:22611433

  2. Data for giant constrictors - Biological management profiles and an establishment risk assessment for nine large species of pythons, anacondas, and the boa constrictor

    USGS Publications Warehouse

    Jarnevich, C.S.; Rodda, G.H.; Reed, R.N.

    2011-01-01

    Giant Constrictors' Climate Space The giant constrictors' climate space data set represents the information needed to recreate the climate space and climate matching analyses in Reed and Rodda (2009). A detailed methodology and results are included in that report. The data include locations for nine species of large constrictors including Python molurus, Broghammerus reticulatus, P. sebae, P. natalensis, Boa constrictor, Eunectes notaeus, E. deschauenseei, E. beniensis, and E. murinus. The locations are from published sources. Climate data are included for monthly precipitation and average monthly temperature along with the species locations. The individual spreadsheets of location data match the figures in the Reed and Rodda (2009) report, illustrating areas of the mainland United States that match the climate envelope of the native range. The precipitation and temperature data at each location were used to determine the climate space for each species. Graphs of climate space formed the basis for the algorithms in the data set, and more details can be found in Reed and Rodda (2009). These algorithms were used in ArcGIS to generate maps of areas in the United States that matched the climate space of locations of the snakes in their native range. We discovered a rounding error in ArcGIS in the implementation of the algorithms, which has been corrected here. Therefore the shapefiles are slightly different than those appearing in the risk assessment figures illustrating areas of the United States that match the climate envelope of the species in their native ranges. However, the suitable localities are not different at the scale of intended use for these maps, although there are more noticeable differences between areas classified as 'too cold' and 'too hot'.

  3. Distribution and abundance of schistosomiasis and fascioliasis host snails along the Mara River in Kenya and Tanzania.

    PubMed

    Dida, Gabriel O; Gelder, Frank B; Anyona, Douglas N; Matano, Ally-Said; Abuom, Paul O; Adoka, Samson O; Ouma, Collins; Kanangire, Canisius K; Owuor, Phillip O; Ofulla, Ayub V O

    2014-01-01

    We purposively selected 39 sampling sites along the Mara River and its two perennial tributaries of Amala and Nyangores and sampled snails. In addition, water physicochemical parameters (temperature, turbidity, dissolved oxygen, conductivity, alkalinity, salinity and pH) were taken to establish their influence on the snail abundance and habitat preference. Out of the 39 sites sampled, 10 (25.6%) had snails. The snail species encountered included Biomphalaria pfeifferi Krauss - the intermediate host of Schistosoma mansoni Sambon, Bulinus africanus - the intermediate host of Schistosoma haematobium, and Lymnaea natalensis Krauss - the intermediate host of both Fasciola gigantica and F. hepatica Cobbold. Ceratophallus spp., a non-vector snail was also encountered. Most (61.0%) of the snails were encountered in streamside pools. Schistosomiasis-transmitting host snails, B. pfeifferi and B. africanus, were fewer than fascioliasis-transmitting Lymnaea species. All the four different snail species were found to be attached to different aquatic weeds, with B. pfeifferi accounting for over half (61.1%) of the snails attached to the sedge, followed by B. africanus and Lymnaea spp., accounting for 22.2 and 16.7%, respectively. Ceratophallus spp. were non-existent in sedge. The results from this preliminary study show that snails intermediate hosts of schistosomiasis and fascioliasis exists in different habitats, in few areas along the Mara River, though their densities are still low to have any noticeable impacts on disease transmission in case they are infected. The mere presence of the vector snails in these focal regions calls for their immediate control and institution of proper regulations, management, and education among the locals that can help curtail the spread of the snails and also schistosomiasis and fascioliasis within the Mara River basin.

  4. Molecular Control of Polyene Macrolide Biosynthesis

    PubMed Central

    Santos-Aberturas, Javier; Vicente, Cláudia M.; Guerra, Susana M.; Payero, Tamara D.; Martín, Juan F.; Aparicio, Jesús F.

    2011-01-01

    Control of polyene macrolide production in Streptomyces natalensis is mediated by the transcriptional activator PimM. This regulator, which combines an N-terminal PAS domain with a C-terminal helix-turn-helix motif, is highly conserved among polyene biosynthetic gene clusters. PimM, truncated forms of the protein without the PAS domain (PimMΔPAS), and forms containing just the DNA-binding domain (DBD) (PimMDBD) were overexpressed in Escherichia coli as GST-fused proteins. GST-PimM binds directly to eight promoters of the pimaricin cluster, as demonstrated by electrophoretic mobility shift assays. Assays with truncated forms of the protein revealed that the PAS domain does not mediate specificity or the distinct recognition of target genes, which rely on the DBD domain, but significantly reduces binding affinity up to 500-fold. Transcription start points were identified by 5′-rapid amplification of cDNA ends, and the binding regions of PimMDBD were investigated by DNase I protection studies. In all cases, binding took place covering the −35 hexamer box of each promoter, suggesting an interaction of PimM and RNA polymerase to cause transcription activation. Information content analysis of the 16 sequences protected in target promoters was used to deduce the structure of the PimM-binding site. This site displays dyad symmetry, spans 14 nucleotides, and adjusts to the consensus TVGGGAWWTCCCBA. Experimental validation of this binding site was performed by using synthetic DNA duplexes. Binding of PimM to the promoter region of one of the polyketide synthase genes from the Streptomyces nodosus amphotericin cluster containing the consensus binding site was also observed, thus proving the applicability of the findings reported here to other antifungal polyketides. PMID:21187288

  5. Hierarchical Control on Polyene Macrolide Biosynthesis: PimR Modulates Pimaricin Production via the PAS-LuxR Transcriptional Activator PimM

    PubMed Central

    Santos-Aberturas, Javier; Vicente, Cláudia M.; Payero, Tamara D.; Martín-Sánchez, Lara; Cañibano, Carmen; Martín, Juan F.; Aparicio, Jesús F.

    2012-01-01

    Control of polyene macrolide production in Streptomyces natalensis is mediated by the transcriptional activator PimR. This regulator combines an N-terminal domain corresponding to the Streptomyces antibiotic regulatory protein (SARP) family of transcriptional activators with a C-terminal half homologous to guanylate cyclases and large ATP-binding regulators of the LuxR family. The PimR SARP domain (PimRSARP) was expressed in Escherichia coli as a glutathione S-transferase (GST)–fused protein. Electrophoretic mobility shift assays showed that GST-PimRSARP binds a single target, the intergenic region between the regulatory genes pimR and pimMs in the pimaricin cluster. The PimRSARP-binding site was investigated by DNaseI protection studies, revealing that it contains three heptameric direct repeats adjusting to the consensus 5′-CGGCAAG-3′. Transcription start points of pimM and pimR promoters were identified by 5′-RACE, revealing that unlike other SARPs, PimRSARP does not interact with the -35 region of its target promoter. Quantitative transcriptional analysis of these regulatory genes on mutants on each of them has allowed the identification of the pimM promoter as the transcriptional target for PimR. Furthermore, the constitutive expression of pimM restored pimaricin production in a pimaricin-deficient strain carrying a deletion mutant of pimR. These results reveal that PimR exerts its positive effect on pimaricin production by controlling pimM expression level, a regulator whose gene product activates transcription from eight different promoters of pimaricin structural genes directly. PMID:22693644

  6. Active edible coating and γ-irradiation as cold combined treatments to assure the safety of broccoli florets (Brassica oleracea L.).

    PubMed

    Ben-Fadhel, Yosra; Saltaji, Sabrina; Khlifi, Mohamed Ali; Salmieri, Stephane; Dang Vu, Khanh; Lacroix, Monique

    2017-01-16

    The antimicrobial activity of essential oils (EOs), organic acid (OA) salts and natamycin, a natural antifungal produced during fermentation by the bacterium Streptomyces natalensis, was assessed against four pathogens (Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium and Aspergillus niger). The Minimum Inhibitory Concentration (MIC) of each antimicrobial (AM) was assessed to determine their efficiency on tested microbial species in order to select the most efficient. Then, the interactions between different antimicrobial compounds showing the lowest MIC were determined by the checkerboard method. The most effective antimicrobial formulation showing synergistic or additive effects was then encapsulated in an alginate matrix to protect the antimicrobial efficiency during storage. The effectiveness of the formulation was then evaluated in situ using broccoli as a food model. A combined treatment of active coating and γ-irradiation (0.4 and 0.8kGy) was also done in order to evaluate the possible synergistic effect between treatments. The results of this study allowed the selection of 4 EOs, one OA salt and the natamycin as an antifungal agent exhibiting lower MIC values. The interactive antimicrobial effects between them showed that an antimicrobial formulation composed of 300ppm of lemongrass EO, 5000ppm of sodium diacetate and 80ppm of natamycin resulted in an additive effect against A. niger, E. coli and S. Typhimurium and showing synergistic effect against L. monocytogenes. Finally, in situ analyses showed a synergistic antimicrobial activity between active coating and γ-irradiation and allowed the extension of the shelf-life of ready-to-eat (RTE) broccoli during storage at 4°C.

  7. Zooplankton community structure during a transition from dry to wet state in a shallow, subtropical estuarine lake

    NASA Astrophysics Data System (ADS)

    Carrasco, Nicola K.; Perissinotto, Renzo

    2015-12-01

    Lake St Lucia is among the most important shallow ecosystems globally and Africa's largest estuarine lake. It has long been regarded as a resilient system, oscillating through periods of hypersalinity and freshwater conditions, depending on the prevailing climate. The alteration of the system's catchment involving the diversion of the Mfolozi River away from Lake St Lucia, however, challenged the resilience of the system, particularly during the most recent drought (2002-2011), sacrificing much of its biodiversity. This study reports on the transition of the St Lucia zooplankton community from a dry hypersaline state to a new wet phase. Sampling was undertaken during routine quarterly surveys at five representative stations along the lake system from February 2011 to November 2013. A total of 54 taxa were recorded during the study period. The zooplankton community was numerically dominated by the calanoid copepods Acartiella natalensis and Pseudodiaptomus stuhlmanni and the cyclopoid copepod Oithona brevicornis. While the mysid Mesopodopsis africana was still present in the system during the wet phase, it was not found in the swarming densities that were recorded during the previous dry phase, possibly due to increased predation pressure, competition with other taxa and or the reconnection with the Mfolozi River via a beach spillway. The increase in zooplankton species richness recorded during the present study shows that the system has undergone a transition to wet state, with the zooplankton community structure reflecting that recorded during the past. It is likely, though, that only a full restoration of natural mouth functioning will result in further diversity increases.

  8. Echolocation in the bat, Rhinolophus capensis: the influence of clutter, conspecifics and prey on call design and intensity

    PubMed Central

    Fawcett, Kayleigh; Jacobs, David S.; Surlykke, Annemarie; Ratcliffe, John M.

    2015-01-01

    Echolocating bats are exposed not only to the echoes of their own calls, but often the signals of conspecifics and other bats. For species emitting short, frequency modulated signals e.g. vespertilionoids, adjustments in both the frequency and time domain have been observed in such situations. However, bats using long duration, constant frequency calls may confront special challenges, since these bats should be less able to avoid temporal and frequency overlap. Here we investigated echolocation call design in the highduty cycle bat, Rhinolophus capensis, as bats flew with either a conspecific or heterospecific in a large outdoor flight-room. We compared these recordings to those made of bats flying alone in the same flight-room, and in a smaller flight room, alone, and hunting tethered moths. We found no differences in duty cycle or peak frequency of the calls of R. capensis across conditions. However, in the presence of a conspecific or the vespertilionoid, Miniopterus natalensis, R. capensis produced longer frequency-modulated downward sweeps at the terminus of their calls with lower minimum frequencies than when flying alone. In the presence of the larger high-duty cycle bat, R. clivosus, R. capensis produced shorter calls than when flying alone or with a conspecific. These changes are similar to those of vespertilionoids when flying from open to more cluttered environments. They are not similar to those differences observed in vespertilionoids when flying with other bats. Also unlike vespertilinoids, R. capensis used calls 15 dB less intense in conspecific pairs than when alone. PMID:25987587

  9. Urban Market Gardening and Rodent-Borne Pathogenic Leptospira in Arid Zones: A Case Study in Niamey, Niger.

    PubMed

    Dobigny, Gauthier; Garba, Madougou; Tatard, Caroline; Loiseau, Anne; Galan, Max; Kadaouré, Ibrahima; Rossi, Jean-Pierre; Picardeau, Mathieu; Bertherat, Eric

    2015-01-01

    Leptospirosis essentially affects human following contact with rodent urine-contaminated water. As such, it was mainly found associated with rice culture, recreational activities and flooding. This is also the reason why it has mainly been investigated in temperate as well as warm and humid regions, while arid zones have been only very occasionally monitored for this disease. In particular, data for West African countries are extremely scarce. Here, we took advantage of an extensive survey of urban rodents in Niamey, Niger, in order to look for rodent-borne pathogenic Leptospira species presence and distribution across the city. To do so, we used high throughput bacterial 16S-based metabarcoding, lipL32 gene-targeting RT-PCR, rrs gene sequencing and VNTR typing as well as GIS-based multivariate spatial analysis. Our results show that leptospires seem absent from the core city where usual Leptospira reservoir rodent species (namely R. rattus and M. natalensis) are yet abundant. On the contrary, L. kirschneri was detected in Arvicanthis niloticus and Cricetomys gambianus, two rodent species that are restricted to irrigated cultures within the city. Moreover, the VNTR profiles showed that rodent-borne leptospires in Niamey belong to previously undescribed serovars. Altogether, our study points towards the importance of market gardening in maintain and circulation of leptospirosis within Sahelian cities. In Africa, irrigated urban agriculture constitutes a pivotal source of food supply, especially in the context of the ongoing extensive urbanization of the continent. With this in mind, we speculate that leptospirosis may represent a zoonotic disease of concern also in arid regions that would deserve to be more rigorously surveyed, especially in urban agricultural settings.

  10. Specific Paucity of Unmyelinated C-Fibers in Cutaneous Peripheral Nerves of the African Naked-Mole Rat: Comparative Analysis Using Six Species of Bathyergidae

    PubMed Central

    Smith, Ewan S; Purfürst, Bettina; Grigoryan, Tamara; Park, Thomas J; Bennett, Nigel C; Lewin, Gary R

    2012-01-01

    In mammalian peripheral nerves, unmyelinated C-fibers usually outnumber myelinated A-fibers. By using transmission electron microscopy, we recently showed that the saphenous nerve of the naked mole-rat (Heterocephalus glaber) has a C-fiber deficit manifested as a substantially lower C:A-fiber ratio compared with other mammals. Here we determined the uniqueness of this C-fiber deficit by performing a quantitative anatomical analysis of several peripheral nerves in five further members of the Bathyergidae mole-rat family: silvery (Heliophobius argenteocinereus), giant (Fukomys mechowii), Damaraland (Fukomys damarensis), Mashona (Fukomys darlingi), and Natal (Cryptomys hottentotus natalensis) mole-rats. In the largely cutaneous saphenous and sural nerves, the naked mole-rat had the lowest C:A-fiber ratio (∼1.5:1 compared with ∼3:1), whereas, in nerves innervating both skin and muscle (common peroneal and tibial) or just muscle (lateral/medial gastrocnemius), this pattern was mostly absent. We asked whether lack of hair follicles alone accounts for the C-fiber paucity by using as a model a mouse that loses virtually all its hair as a consequence of conditional deletion of the β-catenin gene in the skin. These β-catenin loss-of function mice (β-cat LOF mice) displayed only a mild decrease in C:A-fiber ratio compared with wild-type mice (4.42 compared with 3.81). We suggest that the selective cutaneous C-fiber deficit in the cutaneous nerves of naked mole-rats is unlikely to be due primarily to lack of skin hair follicles. Possible mechanisms contributing to this unique peripheral nerve anatomy are discussed. J. Comp. Neurol. 520:2785–2803, 2012. © 2012 Wiley Periodicals, Inc. PMID:22528859

  11. Identification of five phytosterols from Aloe vera gel as anti-diabetic compounds.

    PubMed

    Tanaka, Miyuki; Misawa, Eriko; Ito, Yousuke; Habara, Noriko; Nomaguchi, Kouji; Yamada, Muneo; Toida, Tomohiro; Hayasawa, Hirotoshi; Takase, Mitunori; Inagaki, Masanori; Higuchi, Ryuuichi

    2006-07-01

    The genus Aloe in the family Liliaceae is a group of plants including Aloe vera (Aloe barbadensis MILLER) and Aloe arborescens (Aloe arborescens MILLER var. natalensis BERGER) that are empirically known to have various medical efficacies. In the present study, we evaluated the anti-hyperglycemic effect of Aloe vera gel and isolated a number of compounds from the gel. On the basis of spectroscopic data, these compounds were identified as lophenol, 24-methyl-lophenol, 24-ethyl-lophenol, cycloartanol, and 24-methylene-cycloartanol. These five phytosterols were evaluated for their anti-hyperglycemic effects in type 2 diabetic BKS.Cg-m(+/+)Lepr(db/J) (db/db) mice. In comparison with the hemoglobin A1c (HbA1c) levels of vehicle-treated mice, statistically significant decreases of 15 to 18% in HbA1c levels were observed in mice treated with 1 mug of the five phytosterols. Considering the ability to reduce blood glucose in vivo, there were no differences between the five phytosterols. Administration of beta-sitosterol did not reduce the blood glucose levels in db/db mice. After administration of the five phytosterols for 28 d, fasting blood glucose levels decreased to approximately 64%, 28%, 47%, 51%, and 55% of control levels, respectively. Severe diabetic mice treated with phytosterols derived from Aloe vera gel did not suffer weight reduction due to glucose loss in the urine. These findings suggest that Aloe vera gel and phytosterols derived from Aloe vera gel have a long-term blood glucose level control effect and would be useful for the treatment of type 2 diabetes mellitus.

  12. Urban Market Gardening and Rodent-Borne Pathogenic Leptospira in Arid Zones: A Case Study in Niamey, Niger

    PubMed Central

    Dobigny, Gauthier; Garba, Madougou; Tatard, Caroline; Loiseau, Anne; Galan, Max; Kadaouré, Ibrahima; Rossi, Jean-Pierre; Picardeau, Mathieu; Bertherat, Eric

    2015-01-01

    Leptospirosis essentially affects human following contact with rodent urine-contaminated water. As such, it was mainly found associated with rice culture, recreational activities and flooding. This is also the reason why it has mainly been investigated in temperate as well as warm and humid regions, while arid zones have been only very occasionally monitored for this disease. In particular, data for West African countries are extremely scarce. Here, we took advantage of an extensive survey of urban rodents in Niamey, Niger, in order to look for rodent-borne pathogenic Leptospira species presence and distribution across the city. To do so, we used high throughput bacterial 16S-based metabarcoding, lipL32 gene-targeting RT-PCR, rrs gene sequencing and VNTR typing as well as GIS-based multivariate spatial analysis. Our results show that leptospires seem absent from the core city where usual Leptospira reservoir rodent species (namely R. rattus and M. natalensis) are yet abundant. On the contrary, L. kirschneri was detected in Arvicanthis niloticus and Cricetomys gambianus, two rodent species that are restricted to irrigated cultures within the city. Moreover, the VNTR profiles showed that rodent-borne leptospires in Niamey belong to previously undescribed serovars. Altogether, our study points towards the importance of market gardening in maintain and circulation of leptospirosis within Sahelian cities. In Africa, irrigated urban agriculture constitutes a pivotal source of food supply, especially in the context of the ongoing extensive urbanization of the continent. With this in mind, we speculate that leptospirosis may represent a zoonotic disease of concern also in arid regions that would deserve to be more rigorously surveyed, especially in urban agricultural settings. PMID:26437456

  13. Subcutaneously Administered Ultrafine PLGA Nanoparticles Containing Doxycycline Hydrochloride Target Lymphatic Filarial Parasites.

    PubMed

    Singh, Yuvraj; Srinivas, Adepu; Gangwar, Mamta; Meher, Jaya Gopal; Misra-Bhattacharya, Shailja; Chourasia, Manish K

    2016-06-06

    Systemic chemotherapeutic targeting of filarial parasites is unfocused due to their deep seated location in lymphatic vessels. This warrants a prolonged dosing regimen in high doses for an anthelmintic like doxycycline hydrochloride (DOX). In order to provide an alternative, we have constructed ultrafine PLGA nanoparticles of DOX (DPNPs), so as to exploit the peculiarity of lymphatic vasculature underneath the subcutaneous layer of skin, which preferentially allows entry of only 10-100 nm sized particles. DPNPs were constructed using a novel solvent diffusion method aided by probe sonication, which resulted in an average size 95.43 ± 0.8 nm as per DLS, PDI 0.168 ± 0.03, zeta potential -7.38 ± 0.32, entrapment efficiency 75.58 ± 1.94%, and refrigerator stability of 7 days with respect to size in the optimized batch. TEM further substantiated the spherical shape of DPNPs along with their actual nonhydrated size as being well below 100 nm. FTIR analysis of DOX, dummy nanoparticles, and freeze-dried DPNPs revealed that the formulation step did not induce prominent changes in the chemical nature of DOX. The drug release was significantly altered (p < 0.05) with 64.6 ± 1.67% release in 48 h from DPNPs and was dictated by Fickian diffusion. Pharmacokinetic studies in Wistar rats further revealed that DPNPs caused a 16-fold prolongation in attainment of plasma Tmax and a 2-fold extension of elimination half-life (28.569 ± 1.27 h) at a dose of 5 mg/kg when compared to native drug (DOX solution) of the same strength. Contrastingly the trend was reversed in regional lymph nodes where Cmax for DPNPs (820 ± 84 ng/mg) was 4-fold greater, and lymphatic Tmax was attained in one-fourth of what was required for DOX solution. This size based preferential lymphatic targeting resulted in significantly greater in vivo antifilarial activity of DPNPs when compared to DOX solution as gauged by several parameters in Brugia malayi infected Mastomys coucha. Interestingly, the

  14. A multi-locus species phylogeny of African forest duikers in the subfamily Cephalophinae: evidence for a recent radiation in the Pleistocene

    PubMed Central

    2012-01-01

    Background Duikers in the subfamily Cephalophinae are a group of tropical forest mammals believed to have first originated during the late Miocene. However, knowledge of phylogenetic relationships, pattern and timing of their subsequent radiation is poorly understood. Here we present the first multi-locus phylogeny of this threatened group of tropical artiodactyls and use a Bayesian uncorrelated molecular clock to estimate divergence times. Results A total of 4152 bp of sequence data was obtained from two mitochondrial genes and four nuclear introns. Phylogenies were estimated using maximum parsimony, maximum likelihood, and Bayesian analysis of concatenated mitochondrial, nuclear and combined datasets. A relaxed molecular clock with two fossil calibration points was used to estimate divergence times. The first was based on the age of the split between the two oldest subfamilies within the Bovidae whereas the second was based on the earliest known fossil appearance of the Cephalophinae and molecular divergence time estimates for the oldest lineages within this group. Findings indicate strong support for four major lineages within the subfamily, all of which date to the late Miocene/early Pliocene. The first of these to diverge was the dwarf duiker genus Philantomba, followed by the giant, eastern and western red duiker lineages, all within the genus Cephalophus. While these results uphold the recognition of Philantomba, they do not support the monotypic savanna-specialist genus Sylvicapra, which as sister to the giant duikers leaves Cephalophus paraphyletic. BEAST analyses indicate that most sister species pairs originated during the Pleistocene, suggesting that repeated glacial cycling may have played an important role in the recent diversification of this group. Furthermore, several red duiker sister species pairs appear to be either paraphyletic (C.callipygus/C. ogilbyi and C. harveyi/C. natalensis) or exhibit evidence of mitochondrial admixture (C. nigrifrons

  15. Giant Constrictors: Biological and Management Profiles and an Establishment Risk Assessment for Nine Large Species of Pythons, Anacondas, and the Boa Constrictor

    USGS Publications Warehouse

    Reed, Robert N.; Rodda, Gordon H.

    2009-01-01

    Giant Constrictors: Biological and Management Profiles and an Establishment Risk Assessment for Nine Large Species of Pythons, Anacondas, and the Boa Constrictor, estimates the ecological risks associated with colonization of the United States by nine large constrictors. The nine include the world's four largest snake species (Green Anaconda, Eunectes murinus; Indian or Burmese Python, Python molurus; Northern African Python, Python sebae; and Reticulated Python, Broghammerus reticulatus), the Boa Constrictor (Boa constrictor), and four species that are ecologically or visually similar to one of the above (Southern African Python, Python natalensis; Yellow Anaconda, Eunectes notaeus; DeSchauensee's Anaconda, Eunectes deschauenseei; and Beni Anaconda, Eunectes beniensis). At present, the only probable pathway by which these species would become established in the United States is the pet trade. Although importation for the pet trade involves some risk that these animals could become established as exotic or invasive species, it does not guarantee such establishment. Federal regulators have the task of appraising the importation risks and balancing those risks against economic, social, and ecological benefits associated with the importation. The risk assessment quantifies only the ecological risks, recognizing that ecosystem processes are complex and only poorly understood. The risk assessment enumerates the types of economic impacts that may be experienced, but leaves quantification of economic costs to subsequent studies. Primary factors considered in judging the risk of establishment were: (1) history of establishment in other countries, (2) number of each species in commerce, (3) suitability of U.S. climates for each species, and (4) natural history traits, such as reproductive rate and dispersal ability, that influence the probability of establishment, spread, and impact. In addition, the risk assessment reviews all management tools for control of invasive giant

  16. Biodiversity census of Lake St Lucia, iSimangaliso Wetland Park (South Africa): Gastropod molluscs.

    PubMed

    Perissinotto, Renzo; Miranda, Nelson A F; Raw, Jacqueline L; Peer, Nasreen

    2014-01-01

    The recent dry phase experienced by the St Lucia estuarine system has led to unprecedented desiccation and hypersaline conditions through most of its surface area. This has changed only recently, at the end of 2011, with the onset of a new wet phase that has already caused a major shift to oligo- and mesohaline conditions. The estuary mouth, however, remains closed to the ocean, making the weak connection recently established between the St Lucia and the Mfolozi estuaries the only conveyance for marine recruitment. As a result, only 10 indigenous and two alien aquatic gastropod species are currently found living in the St Lucia estuarine lake. This is out of a total of 37 species recorded within the system since the earliest survey undertaken in 1924, half of which have not been reported in the literature before. The tick shell, Nassarius kraussianus, which was consistently found in large abundance prior to the recent dry phase, appears to have temporarily disappeared from the system, probably as a result of the extinction of Zostera marine grasses inside the lake. Population explosions of the bubble shell Haminoea natalensis, with its distinct egg masses, were recorded seasonally until 2009, but the species has subsequently not been observed again. A molecular DNA analysis of the various populations previously reported as belonging to the same assimineid species, variably referred to as Assiminea capensis, A. ovata, or A. bifasciata, has revealed that the St Lucia assemblage actually comprises two very distinct taxa, A. cf. capensis and a species provisionally referred to here as "A." aff. capensis or simply Assimineidae sp. In the mangroves, the climbing whelk Cerithidea decollata is still found in numbers, while ellobiids such as Cassidula labrella, Melampus semiaratus and M. parvulus are present in low abundances and all previously recorded littorinids have disappeared. A number of alien freshwater species have colonized areas of the system that have remained

  17. Biodiversity census of Lake St Lucia, iSimangaliso Wetland Park (South Africa): Gastropod molluscs

    PubMed Central

    Perissinotto, Renzo; Miranda, Nelson A.F.; Raw, Jacqueline L.; Peer, Nasreen

    2014-01-01

    Abstract The recent dry phase experienced by the St Lucia estuarine system has led to unprecedented desiccation and hypersaline conditions through most of its surface area. This has changed only recently, at the end of 2011, with the onset of a new wet phase that has already caused a major shift to oligo- and mesohaline conditions. The estuary mouth, however, remains closed to the ocean, making the weak connection recently established between the St Lucia and the Mfolozi estuaries the only conveyance for marine recruitment. As a result, only 10 indigenous and two alien aquatic gastropod species are currently found living in the St Lucia estuarine lake. This is out of a total of 37 species recorded within the system since the earliest survey undertaken in 1924, half of which have not been reported in the literature before. The tick shell, Nassarius kraussianus, which was consistently found in large abundance prior to the recent dry phase, appears to have temporarily disappeared from the system, probably as a result of the extinction of Zostera marine grasses inside the lake. Population explosions of the bubble shell Haminoea natalensis, with its distinct egg masses, were recorded seasonally until 2009, but the species has subsequently not been observed again. A molecular DNA analysis of the various populations previously reported as belonging to the same assimineid species, variably referred to as Assiminea capensis, A. ovata, or A. bifasciata, has revealed that the St Lucia assemblage actually comprises two very distinct taxa, A. cf. capensis and a species provisionally referred to here as “A.” aff. capensis or simply Assimineidae sp. In the mangroves, the climbing whelk Cerithidea decollata is still found in numbers, while ellobiids such as Cassidula labrella, Melampus semiaratus and M. parvulus are present in low abundances and all previously recorded littorinids have disappeared. A number of alien freshwater species have colonized areas of the system that

  18. IgG subclass responses to proinflammatory fraction of Brugia malayi in human filariasis

    PubMed Central

    Joseph, S.K.; Verma, S.K.; Sahoo, M.K.; Sharma, A.; Srivastava, M.; Reddy, M.V.R.; Murthy, P.K.

    2012-01-01

    Background & objectives: Earlier we demonstrated that immunization with F6, a proinflammatory molecular fraction isolated from the human filarial parasite Brugia malayi, protected the host and eliminated the infection in Mastomys coucha by a Th1/Th2 response including IgG2a antibody response. Whether F6 molecules become accessible to human host during natural course of infection and elicit similar response is not known. The present study was undertaken to determine the profile of IgG subclasses specifically reactive to F6 in different categories of bancroftian filariasis cases to infer any relationship between the levels of a particular F6-specific IgG subclass and the infection or disease status. Methods: Serum samples of normal individuals from filariasis non-endemic regions of India like Jammu & Kashmir, Uttarakhand, and Chandigarh [(NEN-W; n=10), healthy subjects from USA (NEN-U; n=10) and three categories of bancroftian filariasis cases from endemic areas: endemic normals (EN; n=10) with no symptoms and no microfilariae, asymptomatic microfilaremics (ASM; n=10) and chronic symptomatic amicrofilaremics (CL; n=10) were assayed for F6-specific IgG1, IgG2, IgG3 and IgG4 by ELISA using SDS-PAGE-isolated F6 fraction of B. malayi adult worms. Results: Significantly high levels of F6-specific IgG1, IgG2 and IgG3 were found in CL (P<0.001) and EN (P<0.01-0.001) bancroftian filariasis cases compared to NEN-U. Significant levels of F6-specific IgG1 (P<0.01) and IgG2 (P<0.01) but not IgG3 were found in ASM cases compared to NEN-U. The most abundant was IgG2 which when compared to NEN-U, was significantly high in CL (P<0.001) and EN cases (P<0.001), followed by ASM (P<0.01). F6-specific IgG4 response in EN, ASM and CL subjects was not significantly different from the levels of NEN-U. Among the non-endemic normals, the NEN-W subjects showed significant reactivity with IgG2 (P<0.001) but not with IgG1, IgG3 and IgG4 as compared to NEN-U subjects. IgG subclass levels were

  19. Evaluation of the inhibition of carbohydrate hydrolysing enzymes, antioxidant activity and polyphenolic content of extracts of ten African Ficus species (Moraceae) used traditionally to treat diabetes

    PubMed Central

    2013-01-01

    Background Some Ficus species have been used in traditional African medicine in the treatment of diabetes. The antidiabetic potential of certain species has been confirmed in vivo but the mechanism of activity remains uncertain. The aim of this study was to determine the activity and to investigate the mechanism of antidiabetic activity of ten selected Ficus species through inhibition of α-amylase and α-glucosidase activity, and the possible relationship between these activities, the total polyphenolic content and the antioxidant activity. Methods Dried acetone leaf extracts were reconstituted with appropriate solvents and used to determine total polyphenolic content antioxidant activity, α-amylase and α-glucosidase inhibitory activity. Results The crude acetone extract of F. lutea had the highest polyphenolic content (56.85 ± 1.82 mg GAE/g of dry material) and the strongest antioxidant activity with a TEAC value of 4.80 ± 0.90. The antioxidant activity of the acetone extracts of the Ficus species may not be ascribed to total polyphenolic content alone. The crude extract at a concentration of 0.5 mg/ml of F. lutea (64.3 ± 3.6%) had the best α-glucosidase (sucrase) inhibitory activity. The EC50 of F. lutea (290 ± 111 μg/ml) was not significantly different from that of F. sycomorus (217 ± 69 μg/ml). The α-amylase inhibitory activity of F. lutea (95.4 ± 1.2%) at a concentration of 1 mg/ml was the highest among the Ficus species screened. The EC50 for F. lutea (9.42 ± 2.01 μ g/ml), though the highest, was not significantly different (p < 0.05) from that of F. craterostoma and F. natalensis. It was apparent that the crude acetone extract of F. lutea is a partially non-competitive inhibitor of α-amylase and α-glucosidase. Based on correlation coefficients polyphenolics may be responsible for α-glucosidase activity but probably not for α-amylase activity. Conclusion Antidiabetic activity potential via inhibition

  20. Skeletons in confusion: a review of astrophorid sponges with (dicho–)calthrops as structural megascleres (Porifera, Demospongiae, Astrophorida)

    PubMed Central

    Van Soest, Rob W.M.; Beglinger, Elly J.; De Voogd, Nicole J.

    2010-01-01

    , Pachastrella geodioides, is barely distinct from the type species of Calthropella, Calthropella simplex. Two species previously assigned to Dercitus or Stoeba (Dercitus loricatus and Stoeba natalensis) are excluded from the genus Dercitus as they do not fit with the emended and improved definition of the genus. One species assigned to Calthropella, Calthropella digitata, is excluded from that genus and assigned to the ancorinid genus Stelletta. Based on the similarity of the megascleres and their structure-less arrangement, we predict that the two reviewed genera will be found to be closely related and eventually will need to be accomodated in a single family, but independent molecular evidence is awaited before changes in the family classification, including a verdict on the validity of the family Calthropellidae, will be proposed. Our review included 38 valid species among which fourteen species and one subspecies appear to be new to science. Four of these were represented by insufficient material for a proper description, but the remaining ten are described as new species: Dercitus (Stoeba) senegalensis sp. n., Dercitus (Stoeba) verdensis sp. n., Dercitus (Stoeba) fijiensis sp. n., Dercitus (Stoeba) bahamensis sp. n., Dercitus (Halinastra) berau sp. n., Dercitus (Halinastra) japonensis sp. n., Dercitus (Halinastra) arubensis sp. n., Dercitus (Halinastra) sibogae sp. n., Calthropella (Calthropella) xavierae sp. n., and Calthropella (Pachataxa) pyrifera sp. n. The new subspecies, Dercitus (Dercitus) bucklandi lusitanicus ssp. n. is described for southern East Atlantic populations of the nominal species. Several specimens assigned to existing species were found to be deviating to the extent that they are likely members of further undescribed species. These are briefly discussed to facilitate further studies of the diversity of the two genera. Species of both genera and the six subgenera, including deviating or insufficiently characterized specimens belonging to species not yet

  1. Water-use dynamics of a peat swamp forest and a dune forest in Maputaland, South Africa

    NASA Astrophysics Data System (ADS)

    Clulow, A. D.; Everson, C. S.; Price, J. S.; Jewitt, G. P. W.; Scott-Shaw, B. C.

    2013-05-01

    in the same way in the dune forest and the water use found to be highly seasonal. Over the entire measurement period, the water use was highest for an emergent Mimusops caffra (5 to 45 L d-1), whereas the water use of the Eugenia natalitia (2 to 28 L d-1) and Drypetes natalensis (1 to 4 L d-1) was lower. At the dune forest, the water use was highest in the wetter summer due to the reliance of the trees on rainfall to recharge the soil water. A split-line regression showed that on average, soil water limited tree water use 64% of the time over the measurement period at the dune forest. For modelling tree water use at the dune forest, it was concluded that a two-stage model, taking soil water content into account (from multiple sampling points), would be necessary.