The Experts below are selected from a list of 1071 Experts worldwide ranked by ideXlab platform
Eileen Devaney - One of the best experts on this subject based on the ideXlab platform.
-
diversity in parasitic nematode genomes the micrornas of Brugia Pahangi and haemonchus contortus are largely novel
BMC Genomics, 2012Co-Authors: Alan D Winter, Eileen Devaney, William Weir, Martin Hunt, Matthew Berriman, John S Gilleard, Collette BrittonAbstract:MicroRNAs (miRNAs) play key roles in regulating post-transcriptional gene expression and are essential for development in the free-living nematode Caenorhabditis elegans and in higher organisms. Whether microRNAs are involved in regulating developmental programs of parasitic nematodes is currently unknown. Here we describe the the miRNA repertoire of two important parasitic nematodes as an essential first step in addressing this question. The small RNAs from larval and adult stages of two parasitic species, Brugia Pahangi and Haemonchus contortus, were identified using deep-sequencing and bioinformatic approaches. Comparative analysis to known miRNA sequences reveals that the majority of these miRNAs are novel. Some novel miRNAs are abundantly expressed and display developmental regulation, suggesting important functional roles. Despite the lack of conservation in the miRNA repertoire, genomic positioning of certain miRNAs within or close to specific coding genes is remarkably conserved across diverse species, indicating selection for these associations. Endogenous small-interfering RNAs and Piwi-interacting (pi)RNAs, which regulate gene and transposon expression, were also identified. piRNAs are expressed in adult stage H. contortus, supporting a conserved role in germline maintenance in some parasitic nematodes. This in-depth comparative analysis of nematode miRNAs reveals the high level of divergence across species and identifies novel sequences potentially involved in development. Expression of novel miRNAs may reflect adaptations to different environments and lifestyles. Our findings provide a detailed foundation for further study of the evolution and function of miRNAs within nematodes and for identifying potential targets for intervention.
-
regulatory t cells modulate th2 responses induced by Brugia Pahangi third stage larvae
Infection and Immunity, 2005Co-Authors: Victoria Gillan, Eileen DevaneyAbstract:Infection of BALB/c mice with Brugia Pahangi third-stage larvae (L3) results in the production of interleukin-4 (IL-4), IL-5, and IL-10 with a resultant down-regulation in Th1 responses. Previously, this was thought to reflect a skewing of immune responses towards a Th2 phenotype by the infective stage of the parasite. In this study, we show that exposure to the L3 of Brugia also induces the expansion of a population of CD4 cells that express CD25 and cytotoxic-T-lymphocyte-associated antigen 4 in an IL-4-independent fashion. By quantitative reverse transcription-PCR, we show that the CD25+ population is highly enriched in mRNA for the Foxp3 transcription factor and that these cells express significantly more IL-10 mRNA than the CD25- population, suggesting a likely regulatory phenotype. The functional capacity of these cells was demonstrated using a neutralizing CD25 monoclonal antibody (MAb). Mice treated with this MAb demonstrated elevated levels of antigen (Ag)-specific proliferation in vitro, and levels of Ag-specific Th2 cytokines were significantly increased. These results suggest a complex network of regulation in L3-infected mice with Th2 cells limiting the Th1 response, while T-regulatory cells modulate Th2 responses.
-
hsp90 is essential in the filarial nematode Brugia Pahangi
International Journal for Parasitology, 2005Co-Authors: Eileen Devaney, Kerry Oneill, William Harnett, Luke Whitesell, Jane KinnairdAbstract:Abstract The development of a compound with activity against filarial nematodes (a ‘macrofilaricide’) has been a long-standing goal of the World Health Organization. However, adult filariae have proved remarkably difficult to kill. To some extent this reflects a lack of understanding of key pathways and processes in filarial nematodes that may be suitable targets for chemotherapy. In this paper we show that geldanamycin (GA), a specific inhibitor of the activity of the heat shock protein 90 (Hsp90) family, kills adult worms and microfilariae (Mf) of Brugia Pahangi at nanomolar concentrations. In addition, release of Mf from adult worms is inhibited within 24 h of exposure to GA and is not recoverable, demonstrating that GA effectively sterilises the worm. Similar results were obtained with a second filarial worm Acanthocheilonema viteae . In contrast GA has no effect on the free-living nematode Caenorhabditis elegans despite a high degree of conservation between the nematode Hsp90 sequences. In keeping with these findings, Brugia Hsp90 binds GA in a solid phase pull-down assay while the binding of C. elegans Hsp90 to immobilised GA is undetectable. In other eukaryotes, GA is known to bind in the N-terminal ATP pocket of Hsp90, disrupting its interactions with client proteins which are then targeted for degradation via the proteasome pathway. Thus, Hsp90 or some of its client proteins may provide novel targets for the chemotherapy of filarial infection.
-
b cells play a regulatory role in mice infected with the l3 of Brugia Pahangi
International Immunology, 2005Co-Authors: Victoria Gillan, Rachel A Lawrence, Eileen DevaneyAbstract:Mice infected with the L3 of the filarial nematode Brugia Pahangi make a strong T(h)2 response characterized by elevated levels of antigen-specific IL-4, IL-5 and IL-10. Here we show that B cells from these animals are the major proliferating population in vitro with depletion of B cells or infection of muMT mice, resulting in reduced levels of antigen-specific proliferation. B cells also act as antigen-presenting cells (APC) to CD4(+) cells as demonstrated by the switch in cytokine profiles upon B cell depletion. The efficiency of B cells in antigen presentation is attenuated by IL-10 which down-regulates the expression of B7-1 and B7-2 on the surface of B cells both in vitro and in vivo. Thus, IL-10 may modulate CD4 responses in L3-infected mice by suppressing the expression of B7 ligands on B cells. In support of this hypothesis, blockade of the IL-10R in vivo results in increased proliferation of CD4(+) cells. We propose that B cells participate in a negative feedback loop: IL-10 elicited by infection with L3 and produced by B cells (and CD4(+) cells) down-regulates the expression of B7 molecules on the B cell surface, attenuating their efficiency as APC to CD4(+) T cells and restricting their expansion.
-
mosquito transmission modulates the immune response in mice infected with the l3 of Brugia Pahangi
Parasite Immunology, 2004Co-Authors: Victoria Gillan, Eileen DevaneyAbstract:SUMMARY Mice infected by syringe inoculation with the L3 of the filarial nematode Brugia Pahangi generate a strong Th2 response. In this study we compared immune responses in mice infected via syringe with those infected by mosquito transmission of L3. Levels of antigen-specific IL-4, IL-5 and IL-10 were significantly reduced in mice infected via mosquito. A possible explanation of these results was that mice infected via mosquito received fewer L3 than those infected via syringe. To investigate this possibility, mice were infected with different numbers of L3 (50, 25 or 10). Howere there was no difference in responses in these animals, suggesting that the reduced immune reactivity in mice infected by mosquito cannot be solely ascribed to exposure to lower numbers of parasites. These results also demonstrate that the L3 is an extremely potent stimulus for Th2 differentiation, with 10 L3 sufficient to drive a strong Th2 response. The differences in immune reactivity between syringe and mosquito infected mice may relate to the presence of immuno-suppressive factors in mosquito saliva inoculated at the time of transmission or may reflect the interaction of L3 with different populations of antigen presenting cells in the two groups of mice. Further studies will be required to differentiate between these possibilities.
Sinnadurai Sivanandam - One of the best experts on this subject based on the ideXlab platform.
-
Effect of Brugia Pahangi co-infection with Plasmodium berghei ANKA in gerbils (Meriones unguiculatus)
Parasitology Research, 2020Co-Authors: Olawale Quazim Junaid, Sinnadurai Sivanandam, Indra Vythilingam, Loke Tim Khaw, Rohela MahmudAbstract:Malaria and lymphatic filariasis (LF) are two leading and common mosquito-borne parasitic diseases worldwide. These two diseases are co-endemic in many tropical and sub-tropical regions and are known to share vectors. The interactions between malaria and filarial parasites are poorly understood. Thus, this study aimed at establishing the interactions that occur between Brugia Pahangi and Plasmodium berghei ANKA ( Pb A) co-infection in gerbils. Briefly, the gerbils were matched according to age, sex, and weight and grouped into filarial-only infection, Pb A-only infection, co-infection, and control group. The parasitemia, survival and clinical assessment of the gerbils were monitored for a period of 30 days post Plasmodium infection. The immune responses of gerbils to both mono and co-infection were monitored. Findings show that co-infected gerbils have higher survival rate than Pb A-infected gerbils. Food and water consumption were significantly reduced in both Pb A-infected and co-infected gerbils, although loss of body weight, hypothermia, and anemia were less severe in co-infected gerbils. Plasmodium -infected gerbils also suffered hypoglycemia, which was not observed in co-infected gerbils. Furthermore, gerbil cytokine responses to co-infection were significantly higher than Pb A-only-infected gerbils, which is being suggested as a factor for their increased longevity. Co-infected gerbils had significantly elicited interleukin-4, interferon-gamma, and tumor necrotic factor at early stage of infection than Pb A-infected gerbils. Findings from this study suggest that B. Pahangi infection protect against severe anemia and hypoglycemia, which are manifestations of Pb A infection.
-
observations of scrotal mass liver mass haemolytic jaundice and central vestibular disorder in Brugia Pahangi infected dogs
Tropical Biomedicine, 2019Co-Authors: Wei Yin Vinniesiow, Sinnadurai Sivanandam, Van Lun Low, Tiong Kai Tan, Y B Teoh, S Vellayan, Yvonne A L LimAbstract:Brugia Pahangi is known to infect humans and dogs. Its associated symptoms and complications, however, have not been fully understood in dogs. Herein, we reported the observations of B. Pahangi infections in dogs with scrotal mass, liver mass, haemolytic jaundice, and central vestibular disorder.
-
vector and reservoir host of a case of human Brugia Pahangi infection in selangor peninsular malaysia
Tropical Biomedicine, 2013Co-Authors: Azdayanti Muslim, Rohela Mahmud, Mun Yik Fong, Sinnadurai SivanandamAbstract:A case of human eye infection caused by Brugia Pahangi was reported in 2010 in a semi rural village in Selangor, peninsular Malaysia. Our report here reveals results of investigation on the vector and animal host for the transmission of the infection. We conducted entomological survey and cat blood examination in the vicinity of the patient's home. The mosquito species Armigeres subalbatus was incriminated as the vector, whereas cat served as the reservoir host.
-
armigeres subalbatus incriminated as a vector of zoonotic Brugia Pahangi filariasis in suburban kuala lumpur peninsular malaysia
Parasites & Vectors, 2013Co-Authors: Azdayanti Muslim, Rohela Mahmud, Mun Yik Fong, Yee Ling Lau, Sinnadurai SivanandamAbstract:Background: In 2011, we reported occurrence of natural human infections with Brugia Pahangi, a filarial worm of dogs and cats, in a surburb of Kuala Lumpur, the capital city of Malaysia. Our preliminary entomological survey at that time suggested the mosquito species Armigeres subalbatus as the vector of the zoonotic infections. In this present report, we provide biological evidence to confirm our preliminary finding. Findings: A total of 1798 adult female Ar. subalbatus mosquitoes was caught in the vicinity of the suburb, and 1599 were dissected for the presence of filarial larvae. Sixty-two mosquitoes were positive, and 27 of these were infected with L3 larvae. The L3 were inoculated into male gerbils. Microfilariae could be detected in the gerbils 92 days post-infection. Post-mortem on the gerbils recovered adult worms in the peritoneal cavity, heart, lungs, tail and testis. Male adult worms were confirmed to be B. Pahangi by the ratio length of their spicules (left spicule: right spicule). Female adult worms were confirmed by the absence of minute cuticular bosses in the tail region. The worms were further confirmed to be B. Pahangi by PCR. Conclusions: Our results showed that Ar. subalbatus was the vector for the zoonotic Brugia Pahangi infections. This mosquito species should now be categorised as a medically important mosquito species in Malaysia. Its role in the transmission of zoonotic B. Pahangi must therefore be considered in future studies on filarial infections.
-
Inferring the phylogenetic position of Brugia Pahangi using 18S ribosomal RNA (18S rRNA) gene sequence.
Tropical Biomedicine, 2008Co-Authors: Mun Yik Fong, Asha Thanabalan, Azdayanti Muslim, Sinnadurai Sivanandam, Rohela MahmudAbstract:This paper presents the first reported use of 18S rRNA gene sequence to determine the phylogeny of Brugia Pahangi. The 18S rRNA nucleotide sequence of a Malaysian B. Pahangi isolate was obtained by PCR cloning and sequencing. The sequence was compared with 18S rRNA sequences of other nematodes, including those of some filarial nematodes. Multiple alignment and homology analysis suggest that B. Pahangi is closely related to B. malayi and Wuchereria bancrofti. Phylogenetic trees constructed using Neighbour Joining, Minimum Evolution and Maximum Parsimony methods correctly grouped B. Pahangi with other filarial nematodes, with closest relationship with B. malayi and W. bancrofti. The phylogeny of B. Pahangi obtained in this study is in concordance with those previously reported, in which the 5S rRNA gene spacer region and cytochrome oxidase subunit I (COI) sequences were used.
Thomas R. Klei - One of the best experts on this subject based on the ideXlab platform.
-
Brugia Pahangi in vivo tissue migration of early l3 alters gene expression
Experimental Parasitology, 2008Co-Authors: Sharon R Chirgwin, Sharon U Coleman, Thomas R. KleiAbstract:Events occurring during early filarial nematode migrations are central to parasite establishment but rarely studied. Brugia Pahangi larvae injected intradermal (ID) into the hind limb of the gerbil (Meriones unguiculatus) can be recovered from the popliteal lymph node (POP) at 3 days post-infection (DPI). They have been designated migrating larvae (IDL3). Alternatively, L3 recovered at 3 DPI from the peritoneal cavity (IPL3) do not migrate. Subtracted cDNA libraries using IDL3 and IPL3 revealed distinct gene profiles between IDL3 and IPL3. Troponin-c was significantly upregulated in IDL3, while Cathepsin L was significantly increased in IPL3. Differences in mRNA levels were also observed with these and other genes between IDL3, IPL3 and L3 isolated from mosquitoes (VL3). These data suggest that migratory activity, exposure to potentially different host environments and/or host location may be important external factors in influencing larval gene expression.
-
inflammatory responses to migrating Brugia Pahangi third stage larvae
Infection and Immunity, 2006Co-Authors: Kristina H Porthouse, Sharon R Chirgwin, Sharon U Coleman, Wayne H Taylor, Thomas R. KleiAbstract:Despite being central to parasite establishment and subsequent host pathological and immunologic responses, host-parasite interactions during early third-stage filarial larva (L3) migration are poorly understood. These studies aimed to define early tissue migration of Brugia Pahangi L3 in the gerbil (Meriones unguiculatus) and measure host cellular responses during this period. Gerbils were intradermally inoculated in the hind limb with 100 B. Pahangi L3, and necropsies were performed at various times. At 3 h, most L3 (96.3%) were recovered from tissues associated with the infection site, with marked L3 migration occurring by 24 h. Larvae were dispersed throughout the lymphatics at 7 days postinfection (dpi), and at 28 dpi, most parasites were recovered from the spermatic cord lymphatics. Parasites were identified histologically at all time points. Inflammatory cells, primarily neutrophils, were frequently observed around larvae in the dermis and muscle near the injection site at 3 h and 24 h. Levels of interleukin-6 (IL-6) and tumor necrosis factor-α mRNA peaked at 3 h in all tissues, with IL-6 levels also high in the spleen at 28 dpi. Levels of IL-4 mRNA were elevated in all tissues at 28 dpi. These observations demonstrate that L3 migrate quickly through various tissues and into lymph nodes in a predictable pattern. Migrating L3 induce an early acute inflammatory response that is modulated as parasites establish in the lymphatics. Polarization of the host response towards a dominant Th2-like profile is present at 7 dpi and is well established by 28 dpi in this permissive host.
-
cytokine profiles of filarial granulomas in jirds infected with Brugia Pahangi
Filaria Journal, 2006Co-Authors: Ramakrishna U Rao, Thomas R. KleiAbstract:Background A granulomatous inflammatory response develops in jirds infected subcutaneously or intraperitoneally with filarial nematodes namely Brugia Pahangi and B. malayi. Previous studies by light and electron microscopy have shown cellular inflammatory responses in and around these granulomas. Furthermore, the cellular inflammatory responses of granulomas found in the lymphatics and peritoneal cavity appear to be similar. The purpose of this study was to determine the cytokine profiles of granulomas in the peritoneal cavity of B. Pahangi-infected jirds and to determine whether the granulomas release any proinflammatory cytokines ex vivo.
-
kinetics of t cell cytokine gene expression in gerbils after a primary subcutaneous Brugia Pahangi infection
Journal of Parasitology, 2005Co-Authors: Sharon R Chirgwin, Sharon U Coleman, U R Rao, Z Mai, Jena M Nowling, Thomas R. KleiAbstract:The majority of patients infected with lymphatic filariae are microfilaremic but tend to manifest little obvious pathology because of the infections. Data collected from the Mongolian gerbil–Brugia spp. model for human lymphatic filariasis suggest this experimental animal model system most closely represents this patient group and will be useful in studying immunological parameters associated with chronic infections. This article reports the quantitation of interleukin (IL)-4, IL-5, IL-10, IL-13, and interferon (IFN)-γ messenger RNA (mRNA) in gerbils after a primary subcutaneous infection with Brugia Pahangi. Chronically infected gerbils showed elevated IL-4 in all tissues, compared with earlier time points, linking this Th2 cytokine to the downregulation of responsiveness, which develops in gerbils and humans. Both IL-5 and IL-13 mRNA expression were transient in all tissues. The peak in IL-5 at 14–28 days postinfection reflects the peak of peripheral eosinophilia observed in B. Pahangi–infected gerbils....
-
Brugia Pahangi and wolbachia the kinetics of bacteria elimination worm viability and host responses following tetracycline treatment
Experimental Parasitology, 2003Co-Authors: Sharon R Chirgwin, Sharon U Coleman, Jena M Nowling, Thomas R. KleiAbstract:Wolbachia spp., first reported from filariae nearly 30 years ago, have been suggested to contribute to the pathogenesis associated with human filarial infection. Tetracycline has been used to cure filariae of Wolbachia, as a novel means of chemotherapeutic treatment for both ocular and lymphatic filariasis. Tetracycline treatment of L4 or adult Brugia Pahangi in vivo resulted in Wolbachia clearance. Less tetracycline was required to clear Wolbachia when treatment began at the L4 stage, compared with adults. Female worms died earlier than male worms when tetracycline was administered at the L4 stage. In all cases, Wolbachia clearance was closely associated with worm death. Worm recoveries decreased following the L4-L5 molt, suggesting tetracycline does not interrupt molting in this model system. Despite worm death and the assumed release of both bacterial- and worm-derived molecules, differences in inflammatory cell population and T cell cytokine mRNA profiles were negligible between tetracycline-treated and non-treated B. Pahangi infected gerbils. These data suggest the contribution of Wolbachia to the in vivo induction of the gerbil immune response to B. Pahangi may be small.
Rohela Mahmud - One of the best experts on this subject based on the ideXlab platform.
-
Effect of Brugia Pahangi co-infection with Plasmodium berghei ANKA in gerbils (Meriones unguiculatus)
Parasitology Research, 2020Co-Authors: Olawale Quazim Junaid, Sinnadurai Sivanandam, Indra Vythilingam, Loke Tim Khaw, Rohela MahmudAbstract:Malaria and lymphatic filariasis (LF) are two leading and common mosquito-borne parasitic diseases worldwide. These two diseases are co-endemic in many tropical and sub-tropical regions and are known to share vectors. The interactions between malaria and filarial parasites are poorly understood. Thus, this study aimed at establishing the interactions that occur between Brugia Pahangi and Plasmodium berghei ANKA ( Pb A) co-infection in gerbils. Briefly, the gerbils were matched according to age, sex, and weight and grouped into filarial-only infection, Pb A-only infection, co-infection, and control group. The parasitemia, survival and clinical assessment of the gerbils were monitored for a period of 30 days post Plasmodium infection. The immune responses of gerbils to both mono and co-infection were monitored. Findings show that co-infected gerbils have higher survival rate than Pb A-infected gerbils. Food and water consumption were significantly reduced in both Pb A-infected and co-infected gerbils, although loss of body weight, hypothermia, and anemia were less severe in co-infected gerbils. Plasmodium -infected gerbils also suffered hypoglycemia, which was not observed in co-infected gerbils. Furthermore, gerbil cytokine responses to co-infection were significantly higher than Pb A-only-infected gerbils, which is being suggested as a factor for their increased longevity. Co-infected gerbils had significantly elicited interleukin-4, interferon-gamma, and tumor necrotic factor at early stage of infection than Pb A-infected gerbils. Findings from this study suggest that B. Pahangi infection protect against severe anemia and hypoglycemia, which are manifestations of Pb A infection.
-
vector and reservoir host of a case of human Brugia Pahangi infection in selangor peninsular malaysia
Tropical Biomedicine, 2013Co-Authors: Azdayanti Muslim, Rohela Mahmud, Mun Yik Fong, Sinnadurai SivanandamAbstract:A case of human eye infection caused by Brugia Pahangi was reported in 2010 in a semi rural village in Selangor, peninsular Malaysia. Our report here reveals results of investigation on the vector and animal host for the transmission of the infection. We conducted entomological survey and cat blood examination in the vicinity of the patient's home. The mosquito species Armigeres subalbatus was incriminated as the vector, whereas cat served as the reservoir host.
-
armigeres subalbatus incriminated as a vector of zoonotic Brugia Pahangi filariasis in suburban kuala lumpur peninsular malaysia
Parasites & Vectors, 2013Co-Authors: Azdayanti Muslim, Rohela Mahmud, Mun Yik Fong, Yee Ling Lau, Sinnadurai SivanandamAbstract:Background: In 2011, we reported occurrence of natural human infections with Brugia Pahangi, a filarial worm of dogs and cats, in a surburb of Kuala Lumpur, the capital city of Malaysia. Our preliminary entomological survey at that time suggested the mosquito species Armigeres subalbatus as the vector of the zoonotic infections. In this present report, we provide biological evidence to confirm our preliminary finding. Findings: A total of 1798 adult female Ar. subalbatus mosquitoes was caught in the vicinity of the suburb, and 1599 were dissected for the presence of filarial larvae. Sixty-two mosquitoes were positive, and 27 of these were infected with L3 larvae. The L3 were inoculated into male gerbils. Microfilariae could be detected in the gerbils 92 days post-infection. Post-mortem on the gerbils recovered adult worms in the peritoneal cavity, heart, lungs, tail and testis. Male adult worms were confirmed to be B. Pahangi by the ratio length of their spicules (left spicule: right spicule). Female adult worms were confirmed by the absence of minute cuticular bosses in the tail region. The worms were further confirmed to be B. Pahangi by PCR. Conclusions: Our results showed that Ar. subalbatus was the vector for the zoonotic Brugia Pahangi infections. This mosquito species should now be categorised as a medically important mosquito species in Malaysia. Its role in the transmission of zoonotic B. Pahangi must therefore be considered in future studies on filarial infections.
-
zoonotic Brugia Pahangi filariasis in a suburbia of kuala lumpur city malaysia
Parasitology International, 2011Co-Authors: Lian Huat Tan, Azdayanti Muslim, Rohela Mahmud, Mun Yik Fong, Yee Ling Lau, Adeeba KamarulzamanAbstract:Five local Malaysian patients with clinical manifestations consistent with lymphatic filariasis were referred to our medical centre between 2003 and 2006. Although no microfilariae (mf) were detected in their nocturnal blood samples, all were diagnosed to have lymphatic filariasis on the basis of clinical findings and positive serology results. PCR on their blood samples revealed that two of the patients were infected with Brugia Pahangi, an animal filarial worm hitherto not known to cause human disease in the natural environment. All the patients were successfully treated with anti-filarial drugs: four patients were treated with a combination of diethylcarbamazine (DEC) and albendazole, and one with doxycycline. Four of them were residents of Petaling Jaya, a residential suburbia located 10 km southwest of Kuala Lumpur city, Malaysia. The fifth patient was a frequent visitor of the suburbia. This suburbia has no history or record of B. malayi infection. The most likely vector of the worm was Armigeres subalbatus as extensive entomological surveys within the suburbia revealed only adult females of this mosquito species were infected with B. Pahangi larvae. Wild monkeys caught in the suburbia were free from B. Pahangi mf, but domestic cats were mf positive. This suggests that infected cats might be the source of the zoonotic infection in the suburbia.
-
Inferring the phylogenetic position of Brugia Pahangi using 18S ribosomal RNA (18S rRNA) gene sequence.
Tropical Biomedicine, 2008Co-Authors: Mun Yik Fong, Asha Thanabalan, Azdayanti Muslim, Sinnadurai Sivanandam, Rohela MahmudAbstract:This paper presents the first reported use of 18S rRNA gene sequence to determine the phylogeny of Brugia Pahangi. The 18S rRNA nucleotide sequence of a Malaysian B. Pahangi isolate was obtained by PCR cloning and sequencing. The sequence was compared with 18S rRNA sequences of other nematodes, including those of some filarial nematodes. Multiple alignment and homology analysis suggest that B. Pahangi is closely related to B. malayi and Wuchereria bancrofti. Phylogenetic trees constructed using Neighbour Joining, Minimum Evolution and Maximum Parsimony methods correctly grouped B. Pahangi with other filarial nematodes, with closest relationship with B. malayi and W. bancrofti. The phylogeny of B. Pahangi obtained in this study is in concordance with those previously reported, in which the 5S rRNA gene spacer region and cytochrome oxidase subunit I (COI) sequences were used.
Yoshiki Aoki - One of the best experts on this subject based on the ideXlab platform.
-
chemoattractant activity of tris hydroxymethyl aminomethane for Brugia Pahangi infective third stage larvae
Journal of Helminthology, 2017Co-Authors: Yoshinori Mitsui, K E Urenatatis, Yoshiki AokiAbstract:Urocanic acid (UCA) is known as a major chemoattractant for Strongyloides stercoralis infective third-stage larvae (L3). Since Brugia Pahangi is a skin-penetrating parasitic nematode similar to S. stercoralis, UCA was expected to be a chemoattractant for B. Pahangi L3. Thus, the chemoattractant activity of UCA for B. Pahangi L3 was assessed. The chemotactic responses of B. Pahangi L3 to UCA or acetic acid (CH3COOH) dissolved in amine solutions were assessed using an agar-plate assay. A test solution of 200 mm UCA dissolved in aqueous 270 mm tris(hydroxymethyl)aminomethane (Tris) significantly attracted B. Pahangi L3 compared with deionized water (DW), while neither a solution of 200 mm UCA dissolved in aqueous 230 mm ammonia (NH3) nor 290 mm triethylamine (TEA) significantly attracted L3. Similarly, a test solution of 200 mm CH3COOH dissolved with 200 mm Tris significantly attracted L3, but neither a test solution of 200 mm CH3COOH plus 200 mm NH3 nor 200 mm TEA attracted L3. Furthermore, L3 were significantly attracted to 200 mm Tris alone, compared with DW, but avoided 200 mm NH3 and 200 mm TEA. Moreover, the chemoattractant activity of Tris for L3 was observed even at a low concentration of 25 mm, and it was observed in a mild alkaline condition but not in an acidic condition. The present study reveals that Tris is a potential chemoattractant for B. Pahangi L3 while UCA is not. This finding will contribute to an understanding of the mechanisms of skin-penetrating infection of filarial L3.
-
Comparison of the Methods Available for Purification of Brugia Pahangi Microfilariae in the Peritoneal Lavage of
2015Co-Authors: Jirds Unguiculatus, Yasunori Fujimaki, M. Galal, Masaaki Shimada, Yoshiki AokiAbstract:Abstract: The pros and cons of the methods available for the separation and purifica-tion of Brugia Pahangi microfilariae in jirds peritoneal lavage was studied. The methods examined in the present study were agar-enclosing method described by Nogami et al. (1982) and Sephadex PD-10 column method described by Rathaur et al. (1987). Both methods allowed us to recover live microfilariae alone. The purity of microfilarial suspen-sion was satisfactory in both methods; no peritoneal cells, dead microfilariae nor ovum. The PD-10 column method was superior in the percent recovery of microfilariae; 77-89 % of microfilariae loaded were recovered by passage on PD-10 column, while 53-74 % of microfilariae embedded were recovered by agar-enclosing method. Agar pads used for separation of microfilariae were fragile and frequently disrupted, resulting in the contamination of peritoneal cells in microfilarial suspension. In addition, the PD-10 method was superior in less time consuming and less laborious procedure. PD-10 column can be used repeatedly. Thus the PD-10 column method is, at present, the best available one for separation and purification of microfilariae from peritoneal lavage
-
in vitro chemotactic responses of Brugia Pahangi infective larvae to sodium ions
Journal of Helminthology, 2012Co-Authors: Yoshinori Mitsui, Mitsumasa Miura, D A Bome, Yoshiki AokiAbstract:In vitro chemotactic responses of infective third-stage larvae (L3) of Brugia Pahangi to NaCl, Na2HPO4, KCl, K2HPO4, MgCl2 and CaCl2 were assessed. Compared to deionized water as a control, 200 mm NaCl and 100 mm Na2HPO4 significantly attracted L3 (P < 0.01 and P < 0.01), whereas L3 were likely to avoid 200 mm KCl and 100 mm K2HPO4 (P < 0.05 and P < 0.05). L3 showed no significant tendency to avoid or to be attracted to 200 mm CaCl2 and 200 mm MgCl2. Furthermore, NaCl exhibited a significant chemoattractant activity for L3 at a low concentration of 100 mm.
-
in vitro chemotaxis of Brugia Pahangi infective larvae to the sera and hemolymph of mammals and lower animals
Parasitology International, 2008Co-Authors: Teruyo Kusaba, Yasunori Fujimaki, Albert L Vincent, Yoshiki AokiAbstract:The jird (Mongolian gerbil) is a highly susceptible experimental host for the lymphatic filarial nematode, Brugia Pahangi. The chemotactic activity of serum from this host for B. Pahangi infective larvae was compared in vitro to that of sera or hemolymph of a wide variety of other organisms including mammals, reptiles, fishes and invertebrates. The range of the Chemotactic Index (CI) was from 96.0 for the jird to 56.2 for a snail. An average of CI of saline control was 4.5. Significant chemotactic activity was present in many organisms, especially mammals, but was not closely related to either the phylogenetic position of the organism and to its known susceptibility as definitive host for B. Pahangi. Migratory response was diminished in a consistent way by serial dilution of sera of humans, jirds and fetal bovine serum. Pre-incubation of larvae in fetal bovine serum inhibited migration, especially towards the sera of humans. Inhibition could be reversed by rinsing larvae in saline, longer rinse periods resulting in greater recovery of CI. These results are the first to suggest the activity of the specific amphid chemoreceptors in the chemotaxis of the infective larvae of B. Pahangi.
-
macrofilaricidal and microfilaricidal effects of neurolaena lobata a guatemalan medicinal plant on Brugia Pahangi
Journal of Helminthology, 2005Co-Authors: Yasunori Fujimaki, T Kamachi, T Yanagi, Armando Caceres, Jun Maki, Yoshiki AokiAbstract:Twelve extracts of 11 Guatemalan medicinal plants were initially screened in vitro for potential macrofilaricidal activity against Brugia Pahangi, a lymphatic dwelling filarial worm, using concentrations from 125 to 1000 μg ml−1 of each extract that could be dissolved in the culture medium. Of 12 extracts used, the ethanol extract of leaves of Neurolaena lobata showed the strongest activity against the motility of adult worms. Subsequently, the extract of N. lobata was extensively examined in vitro for macro- and micro-filaricidal effects using a series of concentrations of 500, 250, 100, 50 and 10 μg ml−1. The effects were assessed by worm motility, microfilarial release by female worms and a MTT assay. The effect on the motility of adult worms was observed in a concentration- and time-dependent manner. The time required to stop motility of both sexes of adult worms was 6 h at 500 μg ml−1, 24 h at 250 μg ml−1, and 3 days for females and 4 days for males at 100 μg ml−1. The movement of females ceased at 4 days at a concentration of 50 μg ml−1 whereas the motility of males was only reduced. The loss of worm's viability was confirmed by the MTT assay and was similar to the motility results. These concentrations, including 10 μg ml−1, prevented microfilarial release by females in a concentration- and time-dependent manner. Concentrations higher than 100 μg ml−1 even induced mortality of the microfilariae. The present study suggested that the ethanol extract of Neurolaena lobata has potential macro- and micro-filaricidal activities.
