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Sample records for malayi infective larvae

  1. Characterization of a monoclonal antibody against infective larvae of Brugia malayi.

    PubMed Central

    Parab, P B; Rajasekariah, G R; Chandrashekar, R; Alkan, S S; Braun, D G; Subrahmanyam, D

    1988-01-01

    Monoclonal antibodies were produced following immunization of mice with live infective larvae of Brugia malayi. One of these, 46.08.76, is an antibody that promotes adherence of mouse peritoneal macrophages and human peripheral blood leucocytes to the infective larvae of B. malayi and Wuchereria bancrofti, respectively, and kills them. Fresh normal serum, as a source of complement, augments this effect. The same monoclonal antibody conferred 89% protection to jirds (Meriones unguiculatus) against challenge infection of B. malayi stage-three larvae. This monoclonal antibody recognizes antigens of 80,000, 67,000, 52,000 and 36,000 MW proteins present among the antigens of larvae, as detected by an immunoblotting technique. The antibody also reacts with antigens of infective larvae of Litomosoides carinii, Dipetalonema viteae and B. pahangi, but to a smaller extent. Images Figure 1 Figure 2 PMID:3384450

  2. Brugia malayi infective larvae fail to activate Langerhans cells and dermal dendritic cells in human skin.

    PubMed

    Cotton, R N; McDonald-Fleming, R; Boyd, A; Spates, K; Nutman, T B; Tolouei Semnani, R

    2015-02-01

    Filarial infection in humans is initiated when a mosquito deposits third-stage parasite larvae (L3) in the skin. Langerhans cells (LCs) and dermal dendritic cells (DDCs) are the first cells that the parasite encounters, and L3s must evade these highly effective antigen-presenting cells to establish infection. To assess LC and DDC responses to L3 in human skin, we employed three models of increasing physiologic relevance: in vitro-generated LCs, epidermal blister explants and full-thickness human skin sections. In vitro-generated LCs expressed TLR1-10 and robustly produced IL-6 and TNF-α in response to PolyI:C, but pre-exposure to L3s did not alter inflammatory cytokine production or TLR expression. L3s did not modulate expression of LC markers CDH1, CD207, or CD1a, or the regulatory products TSLP or IDO in epidermal explants or in vitro-generated LC. LC, CD14+ DDC, CD1c+ DC and CD141+ DC from human skin sections were analysed by flow cytometry. While PolyI:C potently induced CCL22 production in LC, CD1c+ DC, and CD141+ DC, and IL-10 production in LC, L3s did not modulate the numbers of or cytokine production by any skin DC subset. L3s broadly failed to activate or modulate LCs or DDCs, suggesting filarial larvae expertly evade APC detection in human skin.

  3. Vaccination with a genetically modified Brugia malayi cysteine protease inhibitor-2 reduces adult parasite numbers and affects the fertility of female worms following a subcutaneous challenge of Mongolian gerbils (Meriones unguiculatus) with B. malayi infective larvae.

    PubMed

    Arumugam, Sridhar; Wei, Junfei; Ward, Danielle; Abraham, David; Lustigman, Sara; Zhan, Bin; Klei, Thomas R

    2014-09-01

    Vaccination of Mongolian gerbils with Brugia malayi cysteine protease inhibitor-2 in which the amino acid Asn66 was mutated to Lys66 (Bm-CPI-2M) resulted in reduced parasite numbers of 48.6% and 48.0% at 42 and 90 days p.i. with B. malayi L3s. Fertility of female worms was also affected at 90 days p.i. In vitro killing of L3s observed in the presence of gerbil peritoneal exudate cells and anti-Bm-CPI-2M sera suggests antibody-dependent cell-mediated cytotoxicity as a putative protective mechanism. These observations suggest that Bm-CPI-2M is a promising prophylactic and anti-fecundity vaccine candidate.

  4. 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

  5. [Studies on filariasis in Korea: On the morphology and development of larvae of Brugia malayi in Aedes togoi

    PubMed

    Kim, Hee Kwan; Seo, Byong Seol

    1968-06-01

    muscles of the mosquitoes within 10 hours, after two moults in the mosquito host, the length of the developing 3rd stage larvae reached in size of 1.3~1.7 mm X 23~32 microns with anal ratio, 2.6 to 3.6. The first appearance of 3rd stage larvae in the mosquito host in this experiment was in 8th day after infection. The larvae were observed in the various cavities of mosquito, such as head, thoracic cavity, abdomen, halters, eye and legs. During the larval development in larval development in the host, the shortening of body length was first observed and then elnongation was followed until becoming 3rd stage larvae. 4)Aedes togoi was proved to be the most suitable host for this species of microfilaria malayi in the above endemic areas.

  6. Susceptibility of Mansonia uniformis to Brugia malayi microfilariae from infected domestic cat.

    PubMed

    Lek-Uthai, Usa; Tomoen, Wanachai

    2005-03-01

    Microfilariae of Brugia malayi is transmitted to man and other susceptible hosts via mosquito. The transmission of B. malayi from cat to man by Ma. uniformis bite has never been reported. The Ma. uniformis mosquito is the normal vector for Wuchereria bancrofti but has never been reported as a vector for B. malayi, or a susceptible host for the growth and development of the microfilariae of B. malayi. The purpose of this study was to examine the development of B. malayi in Mansonia uniformis after feeding on the blood of an infected cat in the laboratory. The B. malayi infected cat was identified using PCR with the primers Bm-1/Bm-2 on DNA (at 10 ng/50 microl) extracted from the WBC of the cat. W. bancrofti was employed as a negative control. The sensitivity of the B. malayi DNA detection by PCR was 0.0001 ng. Adult Ma. uniformis mosquitos at the ages of 5, 10, and 15 days, 100 mosquitos in each group, were fed on the infected cat blood. Recovery of third stage microfilariae was found to be the highest in the 5-day old mosquito group (48%), followed by the 10- and 15-day old mosquito groups (32% and 18%, respectively). The mean number of B. malayi microfilariae found in thorax, head, and abdomen of the mosquitos were composed. The 5-day old (40.3%) and 10-day old (41.9%) mosquitos were significantly more susceptible to microfilariae than the 15-day old mosquitos (17.8%) (p-values using the Scheffe method: 0.027 and 0.039, respectively). There was no significant difference in the mean number of microfilariae in the thorax (p = 0.482) by age, but the mean numbers of microfilariae in the heads, and abdomens were significantly different by age between the 5- and10-, and the 15-day old mosquitos (p < 0.001 and p = 0.004, respectively).

  7. Distribution of Brugia malayi larvae and DNA in vector and non-vector mosquitoes: implications for molecular diagnostics

    PubMed Central

    2009-01-01

    Background The purpose of this study was to extend prior studies of molecular detection of Brugia malayi DNA in vector (Aedes aegypti- Liverpool) and non-vector (Culex pipiens) mosquitoes at different times after ingestion of infected blood. Results Parasite DNA was detected over a two week time course in 96% of pooled thoraces of vector mosquitoes. In contrast, parasite DNA was detected in only 24% of thorax pools from non-vectors; parasite DNA was detected in 56% of midgut pools and 47% of abdomen pools from non-vectors. Parasite DNA was detected in vectors in the head immediately after the blood meal and after 14 days. Parasite DNA was also detected in feces and excreta of the vector and non-vector mosquitoes which could potentially confound results obtained with field samples. However, co-housing experiments failed to demonstrate transfer of parasite DNA from infected to non-infected mosquitoes. Parasites were also visualized in mosquito tissues by immunohistololgy using an antibody to the recombinant filarial antigen Bm14. Parasite larvae were detected consistently after mf ingestion in Ae. aegypti- Liverpool. Infectious L3s were seen in the head, thorax and abdomen of vector mosquitoes 14 days after Mf ingestion. In contrast, parasites were only detected by histology shortly after the blood meal in Cx. pipiens, and these were not labeled by the antibody. Conclusion This study provides new information on the distribution of filarial parasites and parasite DNA in vector and non-vector mosquitoes. This information should be useful for those involved in designing and interpreting molecular xenomonitoring studies. PMID:19922607

  8. 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.

  9. Transcriptomes and pathways associated with infectivity, survival and immunogenicity in Brugia malayi L3

    PubMed Central

    Li, Ben-Wen; Rush, Amy C; Mitreva, Makedonka; Yin, Yong; Spiro, David; Ghedin, Elodie; Weil, Gary J

    2009-01-01

    Background Filarial nematode parasites cause serious diseases such as elephantiasis and river blindness in humans, and heartworm infections in dogs. Third stage filarial larvae (L3) are a critical stage in the life cycle of filarial parasites, because this is the stage that is transmitted by arthropod vectors to initiate infections in mammals. Improved understanding of molecular mechanisms associated with this transition may provide important leads for development of new therapies and vaccines to prevent filarial infections. This study explores changes in gene expression associated with the transition of Brugia malayi third stage larvae (BmL3) from mosquitoes into mammalian hosts and how these changes are affected by radiation. Radiation effects are especially interesting because irradiated L3 induce partial immunity to filarial infections. The underlying molecular mechanisms responsible for the efficacy of such vaccines are unkown. Results Expression profiles were obtained using a new filarial microarray with 18, 104 64-mer elements. 771 genes were identified as differentially expressed in two-way comparative analyses of the three L3 types. 353 genes were up-regulated in mosquito L3 (L3i) relative to cultured L3 (L3c). These genes are important for establishment of filarial infections in mammalian hosts. Other genes were up-regulated in L3c relative to L3i (234) or irradiated L3 (L3ir) (22). These culture-induced transcripts include key molecules required for growth and development. 165 genes were up-regulated in L3ir relative to L3c; these genes encode highly immunogenic proteins and proteins involved in radiation repair. L3ir and L3i have similar transcription profiles for genes that encode highly immunogenic proteins, antioxidants and cuticle components. Conclusion Changes in gene expression that normally occur during culture under conditions that support L3 development and molting are prevented or delayed by radiation. This may explain the enhanced

  10. Molecular genetics analysis for co-infection of Brugia malayi and Brugia pahangi in cat reservoirs based on internal transcribed spacer region 1.

    PubMed

    Areekit, Supatra; Khuchareontaworn, Sintawee; Kanjanavas, Pornpimon; Sriyapai, Thayat; Pakpitchareon, Arda; Khawsak, Paisarn; Chansiri, Kosum

    2009-01-01

    This study described the diagnosis of a mixed infection of Brugia malayi and Brugia pahangi in a single domestic cat using the internal transcribed spacer 1 (ITS1) region. Following polymerase chain reaction amplification of the ITS1 region, the 580 bp amplicon was cloned, and 29 white colonies were randomly selected for DNA sequencing and phylogenetic tree construction. A DNA parsimony tree generated two groups of Brugia spp with one group containing 6 clones corresponding to B. pahangi and the other 23 clones corresponding to B. malayi. This indicated that mixed infection of the two Brugia spp, B. pahangi and B. malayi, had occurred in a single host.

  11. Vaccination of Gerbils with Bm-103 and Bm-RAL-2 Concurrently or as a Fusion Protein Confers Consistent and Improved Protection against Brugia malayi Infection

    PubMed Central

    Arumugam, Sridhar; Wei, Junfei; Liu, Zhuyun; Abraham, David; Bell, Aaron; Bottazzi, Maria Elena; Hotez, Peter J.; Zhan, Bin; Lustigman, Sara; Klei, Thomas R.

    2016-01-01

    Background The Brugia malayi Bm-103 and Bm-RAL-2 proteins are orthologous to Onchocerca volvulus Ov-103 and Ov-RAL-2, and which were selected as the best candidates for the development of an O. volvulus vaccine. The B. malayi gerbil model was used to confirm the efficacy of these Ov vaccine candidates on adult worms and to determine whether their combination is more efficacious. Methodology and Principle Findings Vaccine efficacy of recombinant Bm-103 and Bm-RAL-2 administered individually, concurrently or as a fusion protein were tested in gerbils using alum as adjuvant. Vaccination with Bm-103 resulted in worm reductions of 39%, 34% and 22% on 42, 120 and 150 days post infection (dpi), respectively, and vaccination with Bm-RAL-2 resulted in worm reductions of 42%, 22% and 46% on 42, 120 and 150 dpi, respectively. Vaccination with a fusion protein comprised of Bm-103 and Bm-RAL-2 resulted in improved efficacy with significant reduction of worm burden of 51% and 49% at 90 dpi, as did the concurrent vaccination with Bm-103 and Bm-RAL-2, with worm reduction of 61% and 56% at 90 dpi. Vaccination with Bm-103 and Bm-RAL-2 as a fusion protein or concurrently not only induced a significant worm reduction of 61% and 42%, respectively, at 150 dpi, but also significantly reduced the fecundity of female worms as determined by embryograms. Elevated levels of antigen-specific IgG were observed in all vaccinated gerbils. Serum from gerbils vaccinated with Bm-103 and Bm-RAL-2 individually, concurrently or as a fusion protein killed third stage larvae in vitro when combined with peritoneal exudate cells. Conclusion Although vaccination with Bm-103 and Bm-RAL-2 individually conferred protection against B. malayi infection in gerbils, a more consistent and enhanced protection was induced by vaccination with Bm-103 and Bm-RAL-2 fusion protein and when they were used concurrently. Further characterization and optimization of these filarial vaccines are warranted. PMID:27045170

  12. Real-time PCR detection of the HhaI tandem DNA repeat in pre- and post-patent Brugia malayi infections: a study in Indonesian transmigrants

    PubMed Central

    2014-01-01

    Background Lymphatic filariasis caused by Wuchereria bancrofti or Brugia spp. is a public health problem in developing countries. To monitor bancroftian filariasis infections, Circulating Filarial Antigen (CFA) test is commonly used, but for brugian infections only microfilariae (Mf) microscopy and indirect IgG4 antibody analyses are available. Improved diagnostics for detecting latent infections are required. Methods An optimized real-time PCR targeting the brugian HhaI repeat was validated with plasma from microfilariae negative Mongolian gerbils (jirds) infected with B. malayi. Plasma samples from microfilaremic patients infected with B. malayi or W. bancrofti were used as positive and negative controls, respectively. PCR results of plasma samples from a transmigrant population in a B. malayi endemic area were compared to those of life-long residents in the same endemic area; and to IgG4 serology results from the same population. To discriminate between active infections and larval exposure a threshold was determined by correlation and Receiver-Operating Characteristics (ROC) curve analyses. Results The PCR detected HhaI in pre-patent (56 dpi) B. malayi infected jirds and B. malayi Mf-positive patients from Central Sulawesi, Indonesia. HhaI was also detected in 9/9 elephantiasis patients. In South Sulawesi 87.4% of the transmigrants and life-long residents (94% Mf-negative) were HhaI PCR positive. Based on ROC-curve analysis a threshold for active infections was set to >53 HhaI copies/μl (AUC: 0.854). Conclusions The results demonstrate that the HhaI PCR detects brugian infections with greater sensitivity than the IgG4 test, most notably in Mf-negative patients (i.e. pre-patent or latent infections). PMID:24685183

  13. 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.

  14. 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).

  15. Transcriptional response of honey bee larvae infected with the bacterial pathogen Paenibacillus larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    American foulbrood disease of honey bees is caused by the bacterium Paenibacillus larvae. Infection occurs per os in larvae and systemic infection requires a breaching of the host peritrophic matrix and midgut epithelium. Genetic variation exists for both bacterial virulence and host resistance, and...

  16. Lethal infection thresholds of Paenibacillus larvae for honeybee drone and worker larvae (Apis mellifera).

    PubMed

    Behrens, Dieter; Forsgren, Eva; Fries, Ingemar; Moritz, Robin F A

    2010-10-01

    We compared the mortality of honeybee (Apis mellifera) drone and worker larvae from a single queen under controlled in vitro conditions following infection with Paenibacillus larvae, a bacterium causing the brood disease American Foulbrood (AFB). We also determined absolute P. larvae cell numbers and lethal titres in deceased individuals of both sexes up to 8 days post infection using quantitative real-time PCR (qPCR). Our results show that in drones the onset of infection induced mortality is delayed by 1 day, the cumulative mortality is reduced by 10% and P. larvae cell numbers are higher than in worker larvae. Since differences in bacterial cell titres between sexes can be explained by differences in body size, larval size appears to be a key parameter for a lethal threshold in AFB tolerance. Both means and variances for lethal thresholds are similar for drone and worker larvae suggesting that drone resistance phenotypes resemble those of related workers.

  17. 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

  18. Larva migrans in squirrel monkeys experimentally infected with Baylisascaris potosis.

    PubMed

    Tokiwa, Toshihiro; Tsugo, Kosuke; Nakamura, Shohei; Taira, Kensuke; Une, Yumi

    2015-10-01

    Roundworms of the genus Baylisascaris are natural parasites primarily of wild carnivores, and they can occasionally cause infection in humans and animals. Infection results in visceral larva migrans and/or neural larva migrans, which can be severe or fatal in some animals. Recently, Baylisascaris nematodes isolated from kinkajous (Potos flavus) and previously referred to as Baylisascaris procyonis were renamed as Baylisascaris potosis; however, data regarding the pathogenicity of B. potosis towards animals and humans are lacking. In the present study, we experimentally infected squirrel monkeys (Saimiri sciureus) with B. potosis to determine the suitability of the monkey as a primate model. We used embryonated eggs of B. potosis at two different doses (10,000 eggs and 100,000 eggs) and examined the animals at 30 days post-infection. Histopathological examination showed the presence of B. potosis larvae and infiltration of inflammatory cells around a central B. potosis larvae in the brain, intestines, and liver. Nevertheless, the monkeys showed no clinical signs associated with infection. Parasitological examination revealed the presence of B. potosis larvae in the intestines, liver, lung, muscles, brain, kidney, and diaphragm. Our findings extend the range of species that are susceptible to B. potosis and provide evidence for the zoonotic potential of larva migrans in high dose infections.

  19. Transcriptional Response of Honey Bee Larvae Infected with the Bacterial Pathogen Paenibacillus larvae

    PubMed Central

    Cornman, Robert Scott; Lopez, Dawn; Evans, Jay D.

    2013-01-01

    American foulbrood disease of honey bees is caused by the bacterium Paenibacillus larvae. Infection occurs per os in larvae and systemic infection requires a breaching of the host peritrophic matrix and midgut epithelium. Genetic variation exists for both bacterial virulence and host resistance, and a general immunity is achieved by larvae as they age, the basis of which has not been identified. To quickly identify a pool of candidate genes responsive to P. larvae infection, we sequenced transcripts from larvae inoculated with P. larvae at 12 hours post-emergence and incubated for 72 hours, and compared expression levels to a control cohort. We identified 75 genes with significantly higher expression and six genes with significantly lower expression. In addition to several antimicrobial peptides, two genes encoding peritrophic-matrix domains were also up-regulated. Extracellular matrix proteins, proteases/protease inhibitors, and members of the Osiris gene family were prevalent among differentially regulated genes. However, analysis of Drosophila homologs of differentially expressed genes revealed spatial and temporal patterns consistent with developmental asynchrony as a likely confounder of our results. We therefore used qPCR to measure the consistency of gene expression changes for a subset of differentially expressed genes. A replicate experiment sampled at both 48 and 72 hours post infection allowed further discrimination of genes likely to be involved in host response. The consistently responsive genes in our test set included a hymenopteran-specific protein tyrosine kinase, a hymenopteran specific serine endopeptidase, a cytochrome P450 (CYP9Q1), and a homolog of trynity, a zona pellucida domain protein. Of the known honey bee antimicrobial peptides, apidaecin was responsive at both time-points studied whereas hymenoptaecin was more consistent in its level of change between biological replicates and had the greatest increase in expression by RNA-seq analysis

  20. Lipid and fatty acid analysis of uninfected and granulosis virus-infected Plodia interpunctella larvae

    NASA Technical Reports Server (NTRS)

    Shastri-Bhalla, K.; Consigli, R. A.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    A comparative study on the lipid and fatty acid composition of the uninfected and GV-infected Plodia interpunctella larvae was performed. Higher levels of free fatty acids were found in GV-infected larvae compared to those of the uninfected larvae, while the latter had more triacylglycerol compared to the former. The known identified phospholipids were fewer in the GV-infected larvae compared to those in the uninfected larvae. However, an unidentified phospholipid was found to be approximately two times higher in GV-infected larvae. The total lipid of both larvae had palmitic, oleic, and linoleic as the major fatty acids. The fatty acid composition of the GV-infected larval phospholipid differed considerably compared to that of the uninfected larvae, in that the ratio of unsaturated fatty acid to saturated fatty acid was 3.5 times less in the GV-infected larvae.

  1. The migration of larvae of Toxascaris leonina (Linstow, 1909) in experimentally infected white mice.

    PubMed

    Prokopic, J; Figallová, V

    1982-01-01

    The migration of larvae of Toxascaris leonina was studied in 168 white mice. The larvae were found in lungs of 96% of infected mice on days 4-135, in genital organs (84%), intestinal mucosa (81%) and skeletal muscles (100%) on day 10 post infection. The maximum number of larvae were detected in intercostal muscles on day 105 post infection.

  2. Characterization of secreted proteases of Paenibacillus larvae, potential virulence factors in honeybee larval infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Paenibacillus larvae is the causative agent of American Foulbrood (AFB), the most severe bacterial disease that affects honeybee larvae. AFB causes a significant decrease in the honeybee population affecting the beekeeping industry and agricultural production. After infection of larvae, P. larvae se...

  3. Susceptibility of some vertebrate hosts to infection with early third-stage larvae of Gnathostoma hispidum.

    PubMed

    Sohn, W M; Lee, S H

    1997-09-01

    Susceptibility of some vertebrates was examined to the early third-stage larvae (EL3) of Gnathostoma hispidum. The larvae collected from the Chinese loaches were infected to 4 silk carps, 3 snake heads, 3 bullfrogs, 5 mice and 9 albino rats. No worms were detected in fish, silk carps and snake heads. In 3 bullfrogs fed 30 larvae, a total of 9 EL3 was recovered in the gastrointestinal tract (8 larvae) and liver (one). In 5 mice infected with 50 larvae, a total of 37 (74.0%) advanced third-stage larvae (AdL3) was recovered from the muscle (31 larvae), liver (5 larvae) and kidney at 4 weeks after infection. In 9 albino rats infected with 115 larvae, a total of 40 (34.8%) AdL3 was found in the muscle. The mammalian hosts were found susceptible to the EL3 of G. hispidum from Chinese loaches.

  4. High infectivity of Toxocara cati larvae from muscles of experimentally infected rats.

    PubMed

    Taira, Kensuke; Yanagida, Tomonori; Akazawa, Naoko; Saitoh, Yasuhide

    2013-09-23

    The organ distribution of Toxocara cati larvae in albino rats Rattus norvegicus (n=6/group) experimentally inoculated with 1000 embryonated eggs was examined 1, 2, 3, 7, 30, 90, and 180 days post inoculation (dpi), and the infectivity of recovered larvae was evaluated by bioassay in mice. The intestines, liver, lungs, muscles (carcass) and other organs (heart, brain, spleen, kidneys and genital organs) were digested for larval recovery. Larvae were recovered from all rats, with the mean number of recovered larvae ranging from 13.3 at 1 dpi to 135.6 at 90 dpi. Most of the larvae recovered were detected in the intestines (56.3%) and liver (43.8%) at 1 dpi; liver (21.6%) and lungs (69.6%) at 2 dpi; muscles (45.9%) and lungs (36.9%) at 3 dpi. Subsequently, most of larvae were recovered from muscles at 7 dpi (92.5%), 30 dpi (97.8%), 90 dpi (99.4%) and 180 dpi (99.1%). In the mouse bioassay, 43.8% of 90-day-old larvae and 43.0% of 180-day-old larvae recovered from rats established in mice. The present study demonstrated that T. cati larvae persist predominantly in rat muscles and nearly half of them retain infective for at least half a year. The results indicate that R. norvegicus may be a suitable paratenic host of T. cati under natural conditions.

  5. Comparative analysis of ITS1 nucleotide sequence reveals distinct genetic difference between Brugia malayi from Northeast Borneo and Thailand.

    PubMed

    Fong, Mun-Yik; Noordin, Rahmah; Lau, Yee-Ling; Cheong, Fei-Wen; Yunus, Muhammad Hafiznur; Idris, Zulkarnain Md

    2013-01-01

    Brugia malayi is one of the parasitic worms which causes lymphatic filariasis in humans. Its geographical distribution includes a large part of Asia. Despite its wide distribution, very little is known about the genetic variation and molecular epidemiology of this species. In this study, the internal transcribed spacer 1 (ITS1) nucleotide sequences of B. malayi from microfilaria-positive human blood samples in Northeast Borneo Island were determined, and compared with published ITS1 sequences of B. malayi isolated from cats and humans in Thailand. Multiple alignment analysis revealed that B. malayi ITS1 sequences from Northeast Borneo were more similar to each other than to those from Thailand. Phylogenetic trees inferred using Neighbour-Joining and Maximum Parsimony methods showed similar topology, with 2 distinct B. malayi clusters. The first cluster consisted of Northeast Borneo B. malayi isolates, whereas the second consisted of the Thailand isolates. The findings of this study suggest that B. malayi in Borneo Island has diverged significantly from those of mainland Asia, and this has implications for the diagnosis of B. malayi infection across the region using ITS1-based molecular techniques.

  6. Diversity and Expression of MicroRNAs in the Filarial Parasite, Brugia malayi

    PubMed Central

    Poole, Catherine B.; Gu, Weifeng; Kumar, Sanjay; Jin, Jingmin; Davis, Paul J.; Bauche, David; McReynolds, Larry A.

    2014-01-01

    Human filarial parasites infect an estimated 120 million people in 80 countries worldwide causing blindness and the gross disfigurement of limbs and genitals. An understanding of RNA-mediated regulatory pathways in these parasites may open new avenues for treatment. Toward this goal, small RNAs from Brugia malayi adult females, males and microfilariae were cloned for deep-sequencing. From ∼30 million sequencing reads, 145 miRNAs were identified in the B. malayi genome. Some microRNAs were validated using the p19 RNA binding protein and qPCR. B. malayi miRNAs segregate into 99 families each defined by a unique seed sequence. Sixty-one of the miRNA families are highly conserved with homologues in arthropods, vertebrates and helminths. Of those miRNAs not highly conserved, homologues of 20 B. malayi miRNA families were found in vertebrates. Nine B. malayi miRNA families appear to be filarial-specific as orthologues were not found in other organisms. The miR-2 family is the largest in B. malayi with 11 members. Analysis of the sequences shows that six members result from a recent expansion of the family. Library comparisons found that 1/3 of the B. malayi miRNAs are differentially expressed. For example, miR-71 is 5–7X more highly expressed in microfilariae than adults. Studies suggest that in C.elegans, miR-71 may enhance longevity by targeting the DAF-2 pathway. Characterization of B. malayi miRNAs and their targets will enhance our understanding of their regulatory pathways in filariads and aid in the search for novel therapeutics. PMID:24824352

  7. Larva Migration and Eosinophilia in Mice Experimentally Infected With Gnathostoma spinigerum

    PubMed Central

    Saksirisampant, W.; Choomchuay, N.; Kraivichian, K.; Thanomsub, B. Wongsatayanon

    2012-01-01

    Background Gnathostoma spinigerum causes larva migran in human which is endemic in Southeast Asia. Information regarding larva migration is limited. In this study, we investigated the parasite migration by recovery of worms from the whole body of mouse after oral infection with advanced third stage larvae (AL3). The percentage of blood eosinophils was examined in parallel. Methods Mice were orally infected with AL3 and histological study of organs was investigated in order to study the migration of AL3, along with blood eosinophilia. Results At 1 hr post infection (PI), the larvae remained in the stomach, thereafter at 3, 5, 7, 10 and 24 hr PI; they were recovered from various organs including liver, mesentery, esophagus, diaphragm, lung, heart and dorsal fat. At day 15 PI, they were mostly found in muscles (76.47%). The average worm recovery (5 months) was 78.03%. The worms were found in the liver at every time point. Larva encystment was detected. There was a significant difference in blood eosinophils between the 8 larvae- (average 9.33% + 6.25%) and the 15 larvae-infected groups (average 22.66% + 11.03%). Surprisingly, the blood eosinophils (average 19.00% + 2.92%) were not higher in the higher infective dose- group (25 larvae). Conclusion Liver was involved by G. spinigerum throughout the study. We detected larva encystment which had never been reported in human gnathostomiasis. The highest percentage of eosinophil occurred during the invasive stage. PMID:23109965

  8. Recombinant trehalose-6-phosphate phosphatase of Brugia malayi cross-reacts with human Wuchereria bancrofti immune sera and engenders a robust protective outcome in mice.

    PubMed

    Kushwaha, Susheela; Singh, Prashant Kumar; Gupta, Jyoti; Soni, Vishal Kumar; Misra-Bhattacharya, Shailja

    2012-11-01

    Trehalose-6-phosphate phosphatase of Brugia malayi (Bm-TPP) represents an attractive vaccine candidate because it is present in all the major life stages of parasite, but is absent in mammals. We have previously cloned, purified and biochemically characterized Bm-TPP. In the present study, we investigated the cross-reactivity of recombinant Bm-TPP (r-Bm-TPP) with the sera of human bancroftian patients belonging to different disease categories. In silico study using bioinformatics tool demonstrated that Bm-TPP is highly immunogenic in nature. BALB/c mice administered with r-Bm-TPP alone or in combination with Freund's complete adjuvant (FCA) generated a strong IgG response. Further investigations on the antibody isotypes showed generation of a mixed T helper cell response which was marginally biased towards Th1 phenotype. r-Bm-TPP with or without adjuvant lead to significantly increased accumulation of CD4+ and CD8+ T cells in the spleen of infected mice and increased the activation of peritoneal macrophages. Additionally, r-Bm-TPP enhanced the production of both proinflammatory (IL-2, IFN-γ) and anti-inflammatory (IL-4, IL-10) cytokines and mice immunized with r-Bm-TPP alone or in combination with FCA showed 54.5% and 67% protection respectively against B. malayi infective larvae challenge. Taken together, our findings suggest that Bm-TPP is protective in nature and might be a potential candidate for development of vaccine against lymphatic filarial infections.

  9. Brugia malayi Antigen (BmA) Inhibits HIV-1 Trans-Infection but Neither BmA nor ES-62 Alter HIV-1 Infectivity of DC Induced CD4+ Th-Cells

    PubMed Central

    Mouser, Emily E. I. M.; Pollakis, Georgios; Yazdanbakhsh, Maria; Harnett, William

    2016-01-01

    One of the hallmarks of HIV-1 disease is the association of heightened CD4+ T-cell activation with HIV-1 replication. Parasitic helminths including filarial nematodes have evolved numerous and complex mechanisms to skew, dampen and evade human immune responses suggesting that HIV-1 infection may be modulated in co-infected individuals. Here we studied the effects of two filarial nematode products, adult worm antigen from Brugia malayi (BmA) and excretory-secretory product 62 (ES-62) from Acanthocheilonema viteae on HIV-1 infection in vitro. Neither BmA nor ES-62 influenced HIV-1 replication in CD4+ enriched T-cells, with either a CCR5- or CXCR4-using virus. BmA, but not ES-62, had the capacity to bind the C-type lectin dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) thereby inhibiting HIV-1 trans-infection of CD4+ enriched T-cells. As for their effect on DCs, neither BmA nor ES-62 could enhance or inhibit DC maturation as determined by CD83, CD86 and HLA-DR expression, or the production of IL-6, IL-10, IL-12 and TNF-α. As expected, due to the unaltered DC phenotype, no differences were found in CD4+ T helper (Th) cell phenotypes induced by DCs treated with either BmA or ES-62. Moreover, the HIV-1 susceptibility of the Th-cell populations induced by BmA or ES-62 exposed DCs was unaffected for both CCR5- and CXCR4-using HIV-1 viruses. In conclusion, although BmA has the potential capacity to interfere with HIV-1 transmission or initial viral dissemination through preventing the virus from interacting with DCs, no differences in the Th-cell polarizing capacity of DCs exposed to BmA or ES-62 were observed. Neither antigenic source demonstrated beneficial or detrimental effects on the HIV-1 susceptibility of CD4+ Th-cells induced by exposed DCs. PMID:26808476

  10. Effects of irradiation on the biology of the infective larvae of Toxocara canis in the mouse

    SciTech Connect

    Barriga, O.O.; Myser, W.C.

    1987-02-01

    Mice were infected with either 2000 normal or irradiated embryonated eggs of Toxocara canis and the number of larvae in their livers, lungs, brains, and carcasses investigated at 5, 20, and 33 days of infection. Mortality of mice infected with normal eggs was 33% between day 4 and 8 postinfection but there was no mortality among mice infected with irradiated eggs. Irradiation with 60, 90, or 150 kr of X-rays inhibited the migration of larvae from the livers and lungs and their accumulation in brain and carcass in proportion to the irradiation dose. By day 33 of infection, the ratio of larvae in liver and lungs to larvae in brain and carcass was 0.16 in normal mice, 0.42 in 60-kr mice, 0.98 in 90-kr mice, and 23.3 in 150-kr mice. Irradiated larvae, particularly those migrating through the peritoneal cavity, died faster than normal larvae until day 20. Irradiation favored survival after day 20. By days 20 and 33 postinfection the total parasite load was 29% and 8%, respectively, of the administered dose in control mice, 18% and 12% in 60-kr mice, 8% and 4% in 90-kr mice, and 0.9% and 0.3% in 150-kr mice. Irradiation of infective T. canis larvae, then, reduces their pathogenicity, inhibits their migration from liver and lungs, kills some of the parasites during the first 3 weeks of infection, but favors their late survival in the host.

  11. Biological Control of the Nematode Infective larvae of Trichostrongylidae Family With Filamentous Fungi

    PubMed Central

    Zarrin, Majid; Rahdar, Mahmoud; Gholamian, Abbas

    2015-01-01

    Background: Biological control of parasitic nematodes by microorganisms is a promising approach to control such parasites. Microorganisms such as fungi, viruses and bacteria are recognized as biocontrol agents of nematodes. Objectives: The current study mainly aimed to evaluate the in vitro Potential of various saprophyte soil-fungi in reducing the infective larvae stage of parasitic nematode Trichostrongylidae family. Materials and Methods: Sheep feces were employed to provide the required third stage larvae source for the experiments. The nematode infective larvae of Trichostrongylidae family including three species of Ostertagia circumcincta, Marshalgia marshali and Heamonchos contortus were collected by Berman apparatus. Fifteen isolates of filamentous fungi were tested in the current study. One milliliter suspension containing 200 third stage larvae of Trichostrongylidae family was separately added to the fungal cultures in 2% water-agar medium Petri-dishes. Every day the live larvae were counted with light microscope (10X) and the number of captured larvae was recorded on different days. Results: Significant differences were observed in the results of co-culture of nematodes larva and fungi after seven days. The most effective fungi against the nematodes larvae were Cladosporium sp., Trichoderma sp., Fusarium equisetti, after seven days of incubation. Conclusions: The studies on fungi could be applied as suitable tools in biocontrol of nematode infections. However, additional surveys are required to select efficient with the ability to reduce the nematode larvae in the environment. PMID:25893084

  12. 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

  13. Nematode larvae infecting Priacanthus arenatus Cuvier, 1829 (Pisces: Teleostei) in Brazil.

    PubMed

    Kuraiem, Bianca P; Knoff, Marcelo; Felizardo, Nilza N; Gomes, Delir C; Clemente, Sérgio C São

    2016-05-31

    From July to December, 2013, thirty Priacanthus arenatus specimens commercialized in the cities of Niterói and Rio de Janeiro, State of Rio de Janeiro, were acquired. The fish were necropsied and filleted to investigate the presence of nematode larvae. Twenty fish (66.7%) out of the total were parasitized by nematode larvae. A total of 2024 larvae were collected; among them, 30 third-instar larvae of Anisakis sp. showed prevalence (P) = 20%, mean abundance (MA) = 1, and the mean intensity (MI) = 5, and infection sites (IS) = caecum, stomach, liver, and mesentery; and 1,994 third-instar larvae (1,757 encysted and 237 free) of Hysterothylacium deardorffoverstreetorum with P = 66.7%, MA = 66.5, and MI = 99.7, and IS = spleen, caecum, stomach, liver, mesentery, and abdominal muscle. This is the first study to report H. deardorffoverstreetorum and Anisakis sp. larvae parasitizing P. arenatus.

  14. Seasonal dynamics of cyathostomin (Nematoda - Cyathostominae) infective larvae in Brachiaria humidicola grass in tropical southeast Brazil.

    PubMed

    dos Santos, Claudia N; de Souza, Luciene S; Quinelato, Simone B; do Couto, Melissa C M; Pinheiro, Jairo; Rodrigues, M Lurdes de A

    2011-08-25

    The ecology of cyathostomin larvae was evaluated in different seasons, from July 2007 to June 2008, in the municipality of Seropédica, Rio de Janeiro state, southeastern Brazil. Samples of feces and grass were collected every 15 days at 8 AM and 5 PM and the infective larvae were recovered by the Baermann technique. Leaves of the grass Brachiaria humidicola were cut to 20 cm, which is the length containing most of the larvae. The highest number of larvae was recorded at 8 AM the winter (8300 L(3)kg(-1)dm) and spring (5300 L(3)kg(-1)dm). These results demonstrate that climate conditions can affect the recovery of larvae and that rain and temperature contributed to the migration and survival of the larvae, which were available throughout the year in the study area.

  15. A preliminary investigation on the infectivity of Trichinella larvae in traditional preparations of walrus meat.

    PubMed

    Leclair, Daniel; Forbes, Lorry B; Suppa, Sandy; Proulx, Jean-François; Gajadhar, Alvin A

    2004-08-01

    This study evaluated the infectivity of Trichinella nativa in freshly frozen walrus meat and traditionally aged walrus meat (igunaq) associated with two human outbreaks of trichinellosis in the Canadian Arctic. Trichinella larvae recovered from walrus meat stored at -20 degrees C for up to 20 months remained infective for guinea pigs inoculated with 135 or 716 larval doses. However, none of the 4-5 and 10-month-old igunaq preparations contained infective T. nativa larvae as measured by bioassays using mice and guinea pigs at inoculation doses ranging from 6 to 500 larvae. This indicates that the degradation process that occurred in the field can be sufficient to either kill Trichinella larvae or render them non-infective for mice and guinea pigs. Further research is needed to evaluate the food safety risk of traditional walrus igunaq aged under different field conditions and storage times.

  16. Phage therapy as an approach to prevent Vibrio anguillarum infections in fish larvae production.

    PubMed

    Silva, Yolanda J; Costa, Liliana; Pereira, Carla; Mateus, Cristiana; Cunha, Angela; Calado, Ricardo; Gomes, Newton C M; Pardo, Miguel A; Hernandez, Igor; Almeida, Adelaide

    2014-01-01

    Fish larvae in aquaculture have high mortality rates due to pathogenic bacteria, especially the Vibrio species, and ineffective prophylactic strategies. Vaccination is not feasible in larvae and antibiotics have reduced efficacy against multidrug resistant bacteria. A novel approach to controlling Vibrio infections in aquaculture is needed. The potential of phage therapy to combat vibriosis in fish larvae production has not yet been examined. We describe the isolation and characterization of two bacteriophages capable of infecting pathogenic Vibrio and their application to prevent bacterial infection in fish larvae. Two groups of zebrafish larvae were infected with V. anguillarum (∼106 CFU mL-1) and one was later treated with a phage lysate (∼108 PFU mL-1). A third group was only added with phages. A fourth group received neither bacteria nor phages (fish control). Larvae mortality, after 72 h, in the infected and treated group was similar to normal levels and significantly lower than that of the infected but not treated group, indicating that phage treatment was effective. Thus, directly supplying phages to the culture water could be an effective and inexpensive approach toward reducing the negative impact of vibriosis in larviculture.

  17. Phage Therapy as an Approach to Prevent Vibrio anguillarum Infections in Fish Larvae Production

    PubMed Central

    Silva, Yolanda J.; Costa, Liliana; Pereira, Carla; Mateus, Cristiana; Cunha, Ângela; Calado, Ricardo; Gomes, Newton C. M.; Pardo, Miguel A.; Hernandez, Igor; Almeida, Adelaide

    2014-01-01

    Fish larvae in aquaculture have high mortality rates due to pathogenic bacteria, especially the Vibrio species, and ineffective prophylactic strategies. Vaccination is not feasible in larvae and antibiotics have reduced efficacy against multidrug resistant bacteria. A novel approach to controlling Vibrio infections in aquaculture is needed. The potential of phage therapy to combat vibriosis in fish larvae production has not yet been examined. We describe the isolation and characterization of two bacteriophages capable of infecting pathogenic Vibrio and their application to prevent bacterial infection in fish larvae. Two groups of zebrafish larvae were infected with V. anguillarum (∼106 CFU mL−1) and one was later treated with a phage lysate (∼108 PFU mL−1). A third group was only added with phages. A fourth group received neither bacteria nor phages (fish control). Larvae mortality, after 72 h, in the infected and treated group was similar to normal levels and significantly lower than that of the infected but not treated group, indicating that phage treatment was effective. Thus, directly supplying phages to the culture water could be an effective and inexpensive approach toward reducing the negative impact of vibriosis in larviculture. PMID:25464504

  18. Detailed investigation of the sequential pathological changes in silkworm larvae infected with Bombyx densovirus type 1.

    PubMed

    Ito, Katsuhiko; Kidokoro, Kurako; Shimura, Sachiko; Katsuma, Susumu; Kadono-Okuda, Keiko

    2013-03-01

    Bombyx mori densovirus type 1 (BmDNV-1) is a pathogen causing flacherie disease in silkworms. BmDNV-1 multiplies only in the nuclei of the columnar cells of larval midgut epithelium. Although several immunohistochemical studies using anti-BmDNV-1 antibody have been reported to date, sequential pathological changes in BmDNV-1-infected larvae have not been completely elucidated. In this paper, sequential investigations were performed on the pathological features of BmDNV-1-infected larvae and BmDNV-1 propagation. Oral infection experiments using newly ecdysed 4th instar larvae revealed that the larvae began to die 9 days post infection (dpi), and the remaining died 10 dpi. Histological observations revealed phenotypic alterations in the midgut cells from 4 dpi, and complete disruption of the midgut structure at 9 dpi. Quantitative RT-PCR of two BmDNV-1 genes indicated that BmDNV-1 began to propagate from 4 dpi, and gradually increased until the larvae died. These expression patterns revealed marked correlation with the histological changes observed in the virus-infected midgut cells. Moreover, bioassays using larvae at various developmental stages clearly indicated that the pathogenicity of this virus is not dependent on the larval stage or the molting process.

  19. Costs of Three Wolbachia Infections on the Survival of Aedes aegypti Larvae under Starvation Conditions.

    PubMed

    Ross, Perran A; Endersby, Nancy M; Hoffmann, Ary A

    2016-01-01

    The mosquito Aedes aegypti, the principal vector of dengue virus, has recently been infected experimentally with Wolbachia: intracellular bacteria that possess potential as dengue biological control agents. Wolbachia depend on their hosts for nutrients they are unable to synthesize themselves. Consequently, competition between Wolbachia and their host for resources could reduce host fitness under the competitive conditions commonly experienced by larvae of Ae. aegypti in the field, hampering the invasion of Wolbachia into natural mosquito populations. We assess the survival and development of Ae. aegypti larvae under starvation conditions when infected with each of three experimentally-generated Wolbachia strains: wMel, wMelPop and wAlbB, and compare their fitness to wild-type uninfected larvae. We find that all three Wolbachia infections reduce the survival of larvae relative to those that are uninfected, and the severity of the effect is concordant with previously characterized fitness costs to other life stages. We also investigate the ability of larvae to recover from extended food deprivation and find no effect of Wolbachia on this trait. Aedes aegypti larvae of all infection types were able to resume their development after one month of no food, pupate rapidly, emerge at a large size, and exhibit complete cytoplasmic incompatibility and maternal transmission. A lowered ability of Wolbachia-infected larvae to survive under starvation conditions will increase the threshold infection frequency required for Wolbachia to establish in highly competitive natural Ae. aegypti populations and will also reduce the speed of invasion. This study also provides insights into survival strategies of larvae when developing in stressful environments.

  20. Costs of Three Wolbachia Infections on the Survival of Aedes aegypti Larvae under Starvation Conditions

    PubMed Central

    Ross, Perran A.; Endersby, Nancy M.; Hoffmann, Ary A.

    2016-01-01

    The mosquito Aedes aegypti, the principal vector of dengue virus, has recently been infected experimentally with Wolbachia: intracellular bacteria that possess potential as dengue biological control agents. Wolbachia depend on their hosts for nutrients they are unable to synthesize themselves. Consequently, competition between Wolbachia and their host for resources could reduce host fitness under the competitive conditions commonly experienced by larvae of Ae. aegypti in the field, hampering the invasion of Wolbachia into natural mosquito populations. We assess the survival and development of Ae. aegypti larvae under starvation conditions when infected with each of three experimentally-generated Wolbachia strains: wMel, wMelPop and wAlbB, and compare their fitness to wild-type uninfected larvae. We find that all three Wolbachia infections reduce the survival of larvae relative to those that are uninfected, and the severity of the effect is concordant with previously characterized fitness costs to other life stages. We also investigate the ability of larvae to recover from extended food deprivation and find no effect of Wolbachia on this trait. Aedes aegypti larvae of all infection types were able to resume their development after one month of no food, pupate rapidly, emerge at a large size, and exhibit complete cytoplasmic incompatibility and maternal transmission. A lowered ability of Wolbachia-infected larvae to survive under starvation conditions will increase the threshold infection frequency required for Wolbachia to establish in highly competitive natural Ae. aegypti populations and will also reduce the speed of invasion. This study also provides insights into survival strategies of larvae when developing in stressful environments. PMID:26745630

  1. Nosema ceranae Can Infect Honey Bee Larvae and Reduces Subsequent Adult Longevity

    PubMed Central

    Eiri, Daren M.; Suwannapong, Guntima; Endler, Matthew; Nieh, James C.

    2015-01-01

    Nosema ceranae causes a widespread disease that reduces honey bee health but is only thought to infect adult honey bees, not larvae, a critical life stage. We reared honey bee (Apis mellifera) larvae in vitro and provide the first demonstration that N. ceranae can infect larvae and decrease subsequent adult longevity. We exposed three-day-old larvae to a single dose of 40,000 (40K), 10,000 (10K), zero (control), or 40K autoclaved (control) N. ceranae spores in larval food. Spores developed intracellularly in midgut cells at the pre-pupal stage (8 days after egg hatching) of 41% of bees exposed as larvae. We counted the number of N. ceranae spores in dissected bee midguts of pre-pupae and, in a separate group, upon adult death. Pre-pupae exposed to the 10K or 40K spore treatments as larvae had significantly elevated spore counts as compared to controls. Adults exposed as larvae had significantly elevated spore counts as compared to controls. Larval spore exposure decreased longevity: a 40K treatment decreased the age by which 75% of adult bees died by 28%. Unexpectedly, the low dose (10K) led to significantly greater infection (1.3 fold more spores and 1.5 fold more infected bees) than the high dose (40K) upon adult death. Differential immune activation may be involved if the higher dose triggered a stronger larval immune response that resulted in fewer adult spores but imposed a cost, reducing lifespan. The impact of N. ceranae on honey bee larval development and the larvae of naturally infected colonies therefore deserve further study. PMID:26018139

  2. Nosema ceranae Can Infect Honey Bee Larvae and Reduces Subsequent Adult Longevity.

    PubMed

    Eiri, Daren M; Suwannapong, Guntima; Endler, Matthew; Nieh, James C

    2015-01-01

    Nosema ceranae causes a widespread disease that reduces honey bee health but is only thought to infect adult honey bees, not larvae, a critical life stage. We reared honey bee (Apis mellifera) larvae in vitro and provide the first demonstration that N. ceranae can infect larvae and decrease subsequent adult longevity. We exposed three-day-old larvae to a single dose of 40,000 (40K), 10,000 (10K), zero (control), or 40K autoclaved (control) N. ceranae spores in larval food. Spores developed intracellularly in midgut cells at the pre-pupal stage (8 days after egg hatching) of 41% of bees exposed as larvae. We counted the number of N. ceranae spores in dissected bee midguts of pre-pupae and, in a separate group, upon adult death. Pre-pupae exposed to the 10K or 40K spore treatments as larvae had significantly elevated spore counts as compared to controls. Adults exposed as larvae had significantly elevated spore counts as compared to controls. Larval spore exposure decreased longevity: a 40K treatment decreased the age by which 75% of adult bees died by 28%. Unexpectedly, the low dose (10K) led to significantly greater infection (1.3 fold more spores and 1.5 fold more infected bees) than the high dose (40K) upon adult death. Differential immune activation may be involved if the higher dose triggered a stronger larval immune response that resulted in fewer adult spores but imposed a cost, reducing lifespan. The impact of N. ceranae on honey bee larval development and the larvae of naturally infected colonies therefore deserve further study.

  3. Radiolabeling of infective third-stage larvae of Strongyloides stercoralis by feeding ( sup 75 Se)selenomethionine-labeled Escherichia coli to first- and second-stage larvae

    SciTech Connect

    Aikens, L.M.; Schad, G.A. )

    1989-10-01

    A technique is described for radiolabeling Strongyloides stercoralis larvae with ({sup 75}Se)selenomethionine. Cultures of an auxotrophic methionine-dependent stain of Escherichia coli were grown in a medium containing Dulbecco's modified Eagle's medium supplemented with 5% nutrient broth, amino acids, and ({sup 75}Se)selenomethionine. When the {sup 75}Se-labeled bacterial populations were in the stationary phase of growth, cultures were harvested and the bacteria dispersed on agar plates to serve as food for S. stercoralis larvae. Use of nondividing bacteria is important for successful labeling because the isotope is not diluted by cell division and death of larvae attributable to overgrowth by bacteria is prevented. First-stage S. stercoralis larvae were recovered from feces of infected dogs and reared in humid air at 30 C on agar plates seeded with bacteria. After 7 days, infective third-stage larvae were harvested. The mean specific activity of 6 different batches of larvae ranged from 75 to 330 counts per min/larva with 91.8 +/- 9.5% of the population labeled sufficiently to produce an autoradiographic focus during a practicable, 6-wk period of exposure. Labeled infective larvae penetrated the skin of 10-day-old puppies and migrated to the small intestine, where the developed to adulthood.

  4. [Experimental infection of 2 species of laboratory rodents with invasive larvae of Elaphostrongylus cervi (Nematoda, Metastrongyloidea)].

    PubMed

    Demiaszkiewicz, A W

    1989-01-01

    Single doses (from 300 to 1000 larvi per an animal) of invasive larvae E. cervi Cameron, 1931, obtained from experimentally infected snails Helix pomatia L. were given to 17 guinea pigs and 17 golden hamsters. Clinical nervous symptoms in the form of paresis and paralysis of limbs occurred only in the guinea pigs which were given a dose of 1000 larvi. These animals died in the period from the 75th to 117th day of infection. From their central nervous system single adult males and females of E. cervi were isolated. In the lungs and mesenteries of 2 dead pigs live larvae of E. cervi were found. This fact proves that the guinea pig can fulfil the role of a final and a paratenic host of E. cervi. No clinical symptoms were noticed in any hamster. In hamsters dissected on the 7th day of infection live larvae of E. cervi were found in the mesentery and in the fleshy part of the diaphgram. After 14 days the larvae found both in the mesentery and in the diaphragm were dead and surrounded by cellular infiltration. A strong tissue reaction of the hamster after the administration of E. cervi larvae is responsible for the larvae destruction and resorption.

  5. Distribution patterns and predilection muscles of Trichinella zimbabwensis larvae in experimentally infected Nile crocodiles (Crocodylus niloticus Laurenti).

    PubMed

    La Grange, Louis J; Mukaratirwa, Samson

    2014-02-21

    No controlled studies have been conducted to determine the predilection muscles of Trichinella zimbabwensis larvae in Nile crocodiles (Crocodylus niloticus) or the influence of infection intensity on the distribution of the larvae in crocodiles. The distribution of larvae in muscles of naturally infected Nile crocodiles and experimentally infected caimans (Caiman crocodilus) and varans (Varanus exanthematicus) have been reported in literature. To determine the distribution patterns of T. zimbabwensis larvae and predilection muscles, 15 crocodiles were randomly divided into three cohorts of five animals each, representing high infection (642 larvae/kg of bodyweight average), medium infection (414 larvae/kg of bodyweight average) and low infection (134 larvae/kg of bodyweight average) cohorts. In the high infection cohort, high percentages of larvae were observed in the triceps muscles (26%) and hind limb muscles (13%). In the medium infection cohort, high percentages of larvae were found in the triceps muscles (50%), sternomastoid (18%) and hind limb muscles (13%). In the low infection cohort, larvae were mainly found in the intercostal muscles (36%), longissimus complex (27%), forelimb muscles (20%) and hind limb muscles (10%). Predilection muscles in the high and medium infection cohorts were similar to those reported in naturally infected crocodiles despite changes in infection intensity. The high infection cohort had significantly higher numbers of larvae in the sternomastoid, triceps, intercostal, longissimus complex, external tibial flexor, longissimus caudalis and caudal femoral muscles (p < 0.05) compared with the medium infection cohort. In comparison with the low infection cohort, the high infection cohort harboured significantly higher numbers of larvae in all muscles (p < 0.05) except for the tongue. The high infection cohort harboured significantly higher numbers of larvae (p < 0.05) in the sternomastoid, triceps, intercostal, longissimus complex

  6. Integrative Study of Physiological Changes Associated with Bacterial Infection in Pacific Oyster Larvae

    PubMed Central

    Genard, Bertrand; Miner, Philippe; Nicolas, Jean-Louis; Moraga, Dario; Boudry, Pierre; Pernet, Fabrice; Tremblay, Réjean

    2013-01-01

    Background Bacterial infections are common in bivalve larvae and can lead to significant mortality, notably in hatcheries. Numerous studies have identified the pathogenic bacteria involved in such mortalities, but physiological changes associated with pathogen exposure at larval stage are still poorly understood. In the present study, we used an integrative approach including physiological, enzymatic, biochemical, and molecular analyses to investigate changes in energy metabolism, lipid remodelling, cellular stress, and immune status of Crassostrea gigas larvae subjected to experimental infection with the pathogenic bacteria Vibrio coralliilyticus. Findings Our results showed that V. coralliilyticus exposure induced (1) limited but significant increase of larvae mortality compared with controls, (2) declined feeding activity, which resulted in energy status changes (i.e. reserve consumption, β-oxidation, decline of metabolic rate), (3) fatty acid remodeling of polar lipids (changes in phosphatidylinositol and lysophosphatidylcholine composition`, non-methylene–interrupted fatty acids accumulation, lower content of major C20 polyunsaturated fatty acids as well as activation of desaturases, phospholipase and lipoxygenase), (4) activation of antioxidant defenses (catalase, superoxide dismutase, peroxiredoxin) and cytoprotective processes (heat shock protein 70, pernin), and (5) activation of the immune response (non-self recognition, NF-κκ signaling pathway, haematopoiesis, eiconosoids and lysophosphatidyl acid synthesis, inhibitor of metalloproteinase and antimicrobial peptides). Conclusion Overall, our results allowed us to propose an integrative view of changes induced by a bacterial infection in Pacific oyster larvae, opening new perspectives on the response of marine bivalve larvae to infections. PMID:23704993

  7. Prolonged pre-incubation increases the susceptibility of Galleria mellonella larvae to bacterial and fungal infection.

    PubMed

    Browne, Niall; Surlis, Carla; Maher, Amie; Gallagher, Clair; Carolan, James C; Clynes, Martin; Kavanagh, Kevin

    2015-01-01

    Galleria mellonella larvae are widely used for assessing the virulence of microbial pathogens and for measuring the in vivo activity of antimicrobial agents and produce results comparable to those that can be obtained using mammals. The aim of the work described here was to ascertain the effect of pre-incubation at 15°C for 1, 3, 6 or 10 weeks on the susceptibility of larvae to infection with Candida albicans and Staphylococcus aureus. Larvae infected with C. albicans after 1 week pre-incubation at 15°C showed 73.3 ± 3.3% survival at 24 hours post-infection while those infected after 10 weeks pre-incubation showed 30 ± 3.3% survival (P < 0.01). Larvae infected with S. aureus after 1 week pre-incubation showed 65.5 ± 3.3% survival after 24 hours while those infected after 10 weeks pre-incubation showed 13.3 ± 3.3% (P < 0.001). Analysis of the haemocyte density in larvae pre-incubated for 3-10 weeks showed a reduction in haemocytes over time but a proportionate increase in the density of granular haemocytes in the population as determined by FACS analysis. Proteomic analysis revealed decreased abundance of proteins associated with metabolic pathways (e.g. malate dehydrogenase, fructose-1,6-bisphosphatase, glyceraldehyde-3-phosphate dehydrogenase) and prophenoloxidase. G. mellonella larvae are a useful in vivo model system but the duration of the pre-incubation stage significantly affects their susceptibility to microbial pathogens possibly as a result of altered metabolism.

  8. Tetracycline treatment targeting Wolbachia affects expression of an array of proteins in Brugia malayi parasite.

    PubMed

    Dangi, Anil; Vedi, Satish; Nag, Jeetendra Kumar; Paithankar, Sameer; Singh, Mahendra Pratap; Kar, Santosh Kumar; Dube, Anuradha; Misra-Bhattacharya, Shailja

    2009-09-01

    Wolbachia is an intracellular endosymbiont of Brugia malayi parasite whose presence is essential for the survival of the parasite. Treatment of B. malayi-infected jirds with tetracycline eliminates Wolbachia, which affects parasite survival and fitness. In the present study we have tried to identify parasite proteins that are affected when Wolbachia is targeted by tetracycline. For this Wolbachia depleted parasites (B. malayi) were obtained by tetracycline treatment of infected Mongolian jirds (Meriones unguiculatus) and their protein profile after 2-DE separation was compared with that of untreated parasites harboring Wolbachia. Approximately 100 protein spots could be visualized followed by CBB staining of 2-D gel and included for comparative analysis. Of these, 54 showed differential expressions, while two new protein spots emerged (of 90.3 and 64.4 kDa). These proteins were subjected to further analysis by MALDI-TOF for their identification using Brugia coding sequence database composed of both genomic and EST sequences. Our study unravels two crucial findings: (i) the parasite or Wolbachia proteins, which disappeared/down-regulated appear be essential for parasite survival and may be used as drug targets and (ii) tetracycline treatment interferes with the regulatory machinery vital for parasites cellular integrity and defense and thus could possibly be a molecular mechanism for the killing of filarial parasite. This is the first proteomic study substantiating the wolbachial genome integrity with its nematode host and providing functional genomic data of human lymphatic filarial parasite B. malayi.

  9. Wolbachia endosymbiont of Brugia malayi elicits a T helper type 17-mediated pro-inflammatory immune response through Wolbachia surface protein.

    PubMed

    Pathak, Manisha; Verma, Meenakshi; Srivastava, Mrigank; Misra-Bhattacharya, Shailja

    2015-02-01

    Wolbachia is an endosymbiotic bacterium of the filarial nematode Brugia malayi. The symbiotic relationship between Wolbachia and its filarial host is dependent on interactions between the proteins of both organisms. However, little is known about Wolbachia proteins that are involved in the inflammatory pathology of the host during lymphatic filariasis. In the present study, we cloned, expressed and purified Wolbachia surface protein (r-wsp) from Wolbachia and administered it to mice, either alone or in combination with infective larvae of B. malayi (Bm-L3) and monitored the developing immune response in infected animals. Our results show that spleens and mesenteric lymph nodes of mice immunized with either r-wsp or infected with Bm-L3 show increased percentages of CD4(+) T helper type 17 (Th17) cells and Th1 cytokines like interferon-γ and interleukin-2 (IL-2) along with decreased percentages of regulatory T cells, Th2 cytokines like IL-4 and IL-10 and transforming growth factor β (TGF-β) levels in culture supernatants of splenocytes. These observations were stronger in mice immunized with r-wsp alone. Interestingly, when mice were first immunized with r-wsp and subsequently infected with Bm-L3, percentages of CD4(+) Th17 cells and Th1 cytokines increased even further while that of regulatory T cells, Th2 cytokines and TGF-β levels decreased. These results for the first time show that r-wsp acts synergistically with Bm-L3 in promoting a pro-inflammatory response by increasing Th17 cells and at the same time diminishes host immunological tolerance by decreasing regulatory T cells and TGF-β secretion.

  10. Complete Genome Sequences of Nine Phages Capable of Infecting Paenibacillus larvae, the Causative Agent of American Foulbrood Disease in Honeybees

    PubMed Central

    Yost, Diane G.; Krohn, Andrew; LeBlanc, Lucy; Zhang, Anna; Stamereilers, Casey; Amy, Penny S.

    2015-01-01

    We present here the complete genome sequences of nine phages that infect Paenibacillus larvae, the causative agent of American foulbrood disease in honeybees. The phages were isolated from soil, propolis, and infected bees from three U.S. states. This is the largest number of P. larvae phage genomes sequenced in a single publication to date. PMID:26472825

  11. Identification of Ecdysone Hormone Receptor Agonists as a Therapeutic Approach for Treating Filarial Infections

    PubMed Central

    Mhashilkar, Amruta S.; Vankayala, Sai L.; Liu, Canhui; Kearns, Fiona; Mehrotra, Priyanka; Tzertzinis, George; Palli, Subba R.; Woodcock, H. Lee; Unnasch, Thomas R.

    2016-01-01

    Background A homologue of the ecdysone receptor has previously been identified in human filarial parasites. As the ecdysone receptor is not found in vertebrates, it and the regulatory pathways it controls represent attractive potential chemotherapeutic targets. Methodology/ Principal Findings Administration of 20-hydroxyecdysone to gerbils infected with B. malayi infective larvae disrupted their development to adult stage parasites. A stable mammalian cell line was created incorporating the B. malayi ecdysone receptor ligand-binding domain, its heterodimer partner and a secreted luciferase reporter in HEK293 cells. This was employed to screen a series of ecdysone agonist, identifying seven agonists active at sub-micromolar concentrations. A B. malayi ecdysone receptor ligand-binding domain was developed and used to study the ligand-receptor interactions of these agonists. An excellent correlation between the virtual screening results and the screening assay was observed. Based on both of these approaches, steroidal ecdysone agonists and the diacylhydrazine family of compounds were identified as a fruitful source of potential receptor agonists. In further confirmation of the modeling and screening results, Ponasterone A and Muristerone A, two compounds predicted to be strong ecdysone agonists stimulated expulsion of microfilaria and immature stages from adult parasites. Conclusions The studies validate the potential of the B. malayi ecdysone receptor as a drug target and provide a means to rapidly evaluate compounds for development of a new class of drugs against the human filarial parasites. PMID:27300294

  12. In situ localization of heat-shock and histone proteins in honey-bee (Apis mellifera l.) larvae infected with Paenibacillus larvae.

    PubMed

    Gregorc, A; Bowen, I D

    1999-01-01

    The immunohistochemical localization of the heat shock proteins (Hsp70 and Hsp90) and histone protein in healthy and Paenibacillus larvae infected honeybee (Apis mellifera L.) larvae has been studied. Hsp70 was found in the nuclei and the cytoplasm of infected midgut, salivary gland cells and haemocytes, but not in uninfected larvae. Hsp90 was localized in both infected and uninfected cells. Exposed histone proteins were localized in the nuclei of dying uninfected cells undergoing programmed cell death. The distribution of histone protein in uninfected cells of midgut, salivary gland, and other tissues was nuclear and indicative of normal programmed cell death at levels between 1 and 5%. After applying histone protein antibodies to P. larvae infected honeybee larvae, the DAB based reaction product was located in the nuclei or immediate surroundings of all larval cells. The Hsp70, Hsp90 and histone protein distribution patterns are discussed in relation to the morphological, cytochemical and immunocytochemical characteristics of programmed cell death and pathological necrosis. Results produced by methyl green-pyronin staining confirm an elevation of RNA levels in normal programmed cell death and a reduced staining for RNA in necrotic infected cells.

  13. The ultrastructure of infective larvae (L3) of Wuchereria bancrofti after treatment with diethylcarbamazine.

    PubMed

    Alves, L C; Brayner, F A S; Silva, L F; Peixoto, C A

    2005-01-01

    Although the large use of diethylcarbamazine (DEC), as the major anti-filaricide drug, its mechanism of action remains a matter of controversy. Several authors defend the hypothesis that DEC has no direct effect on nematodes. This study demonstrated that infective larvae (L3) of Wuchereria bancrofti treated in vitro with DEC presented several behaviour and morphological changes. The first alteration produced by treatment for 2 h with 3, 5, 10 microg/ml of DEC was the reduction of motility. Larvae treated with 5, 10 microg/ml DEC showed severely affected organelles, formation of several vacuoles, mainly in neurocytes and in the muscle cells, and dissolution of cytoplasm. Some larvae showed extreme cellular disorganization with abundance of large and dense mitochondria and numerous large vacuoles containing residual organelles. Lamellar bodies, probably related to an assembly of hipodermal membranes, were also observed in some damaged larvae. Thus, undoubtedly in vitro treatment with concentrations of DEC similar to therapeutic conditions, which are 1-5 microg/ml (Hawking, 1979), had a direct effect on infective larvae of W. bancrofti by causing, primarily neuromuscular alterations with subsequent damage to organelles.

  14. Viability and infectivity of Trichinella spiralis muscle larvae in frozen horse tissue.

    PubMed

    Hill, D E; Forbes, L; Gajadhar, A A; Gamble, H R

    2007-05-15

    Many aspects of the biology and epidemiology of Trichinella infection in the horse are poorly understood, including survival of Trichinella spp in horse muscle. In this study, we have assessed the freeze tolerance of T. spiralis in horse meat stored at 5, -5, and -18 degrees C for 1 day to 24 weeks. Results demonstrate a steady reduction in the number of live ML recovered from the cold stored meat samples. On Day 1, recovery of live larvae had been reduced by 18.6%, 50.1%, and 37.2%, and by 4 weeks, recovery of larvae had been reduced by 65.4%, 66.5%, and 96.2% in samples stored at 5, -5, and -18 degrees C, respectively. Infectivity results (measured as reproductive capacity index (RCI)) from mice inoculated with larvae recovered from non-frozen meat samples at day 0 was 23.5. Following storage at -18 degrees C for one and two days, the RCIs were 2.09 and 0.99, respectively. Small numbers of infective larvae were still present in meat samples stored at -18 degrees C for 4 weeks. The RCI of ML recovered from meat samples stored at -5 degrees C was 14.99 and 6.36 at 2 weeks and 4 weeks respectively; the RCI of samples stored at 5 degrees C was 23.1 at 8 weeks, and fell rapidly thereafter (12 week RCI 1.33; 0 at 24 weeks). These data demonstrate that infective T. spiralis, a non-freeze tolerant species, can survive for at least 4 weeks in horse tissue frozen at -5 or -18 degrees C, and that the numbers of infective larvae decrease substantially by day 2 at -18 degrees C and by week 4 at -5 degrees C.

  15. DNA hybridization assay for detection of gypsy moth nuclear polyhedrosis virus in infected gypsy moth (Lymantria dispar L. ) larvae

    SciTech Connect

    Keating, S.T.; Burand, J.P.; Elkinton, J.S. )

    1989-11-01

    Radiolabeled Lymantria dispar nuclear polyhedrosis virus DNA probes were used in a DNA hybridization assay to detect the presence of viral DNA in extracts from infected larvae. Total DNA was extracted from larvae, bound to nitrocellulose filters, and assayed for the presence of viral DNA by two methods: slot-blot vacuum filtration and whole-larval squashes. The hybridization results were closely correlated with mortality observed in reared larvae. Hybridization of squashes of larvae frozen 4 days after receiving the above virus treatments also produced accurate measures of the incidence of virus infection.

  16. Field study on the survival, migration and overwintering of infective larvae of horse strongyles on pasture in central Ukraine.

    PubMed

    Kuzmina, T A; Kuzmin, Y I; Kharchenko, V A

    2006-11-05

    Experimental studies on the survival of infective stage larvae of horse strongyles and their ability to overwinter on pasture were carried out in central Ukraine (Poltavska oblast). Faecal pats (1.5 kg each) of naturally infected horses were placed on pasture, and samples of faeces and surrounding vegetation (10 g each) were collected each month, excluding the winter months, from November 2002 until April 2004. The number of infective third stage larvae was calculated in each sample and compared with that from the control faecal samples cultivated in the laboratory. In the control samples, the ratio of infective third stage larvae to the initial number of eggs was from 54.7% in June up to 84.2% in November. This ratio depended on the presence of nematophagous fungi growing in the faeces. On pasture, the development of larvae to the infective third stage took approximately 4 weeks in the warm season, from April until September. In October, a percentage of the eggs (25% to EPG value) did not hatch. No larval development was observed in faeces in November. A minute quantity of larvae, about 0.03% of their initial number, was observed to survive on pasture for the 12 months. Migration of infective larvae from the faeces to vegetation was not intensive, between 71% and 89% of larvae remained in the faeces 4 weeks after deposition of the faecal pats, the percentage related to soil humidity in each month. The proportion of larvae successfully surviving during winter appeared to be maximal in faecal pats deposited on pasture in September of the previous year (up to 42.0% of the initial number of larvae). Some larvae were observed surviving winter in soil beneath the faecal pats. The results of the study demonstrated that horse pastures in the central part of Ukraine are never free from the infective third stage larvae of strongyles.

  17. Establishment of Infection Models in Zebrafish Larvae (Danio rerio) to Study the Pathogenesis of Aeromonas hydrophila

    PubMed Central

    Saraceni, Paolo R.; Romero, Alejandro; Figueras, Antonio; Novoa, Beatriz

    2016-01-01

    Aeromonas hydrophila is a Gram-negative opportunistic pathogen of fish and terrestrial animals. In humans, A. hydrophila mainly causes gastroenteritis, septicaemia, and tissue infections. The mechanisms of infection, the main virulence factors and the host immune response triggered by A. hydrophila have been studied in detail using murine models and adult fish. However, the great limitation of studying adult animals is that the animal must be sacrificed and its tissues/organs extracted, which prevents the study of the infectious processes in the whole living animal. Zebrafish larvae are being used for the analysis of several infectious diseases, but their use for studying the pathogenesis of A. hydrophila has never been explored. The great advantage of zebrafish larvae is their transparency during the first week after fertilization, which allows detailed descriptions of the infectious processes using in vivo imaging techniques such as differential interferential contrast (DIC) and fluorescence microscopy. Moreover, the availability of fluorescent pathogens and transgenic reporter zebrafish lines expressing fluorescent immune cells, immune marker genes or cytokines/chemokines allows the host–pathogen interactions to be characterized. The present study explores the suitability of zebrafish larvae to study the pathogenesis of A. hydrophila and the interaction mechanisms between the bacterium and the innate immune responses through an infection model using different routes for infection. We used an early-embryo infection model at 3 days post-fertilization (dpf) through the microinjection of A. hydrophila into the duct of Cuvier, caudal vein, notochord, or muscle and two bath infection models using 4 dpf healthy and injured larvae. The latter resembled the natural conditions under which A. hydrophila produces infectious diseases in animals. We compared the cellular processes after infection in each anatomical site by confocal fluorescence imaging and determined the

  18. Insecticidal activity of two proteases against Spodoptera frugiperda larvae infected with recombinant baculoviruses

    PubMed Central

    2010-01-01

    Background Baculovirus comprise the largest group of insect viruses most studied worldwide, mainly because they efficiently kill agricutural insect pests. In this study, two recombinant baculoviruses containing the ScathL gene from Sarcophaga peregrina (vSynScathL), and the Keratinase gene from the fungus Aspergillus fumigatus (vSynKerat), were constructed. and their insecticidal properties analysed against Spodoptera frugiperda larvae. Results Bioassays of third-instar and neonate S. frugiperda larvae with vSynScathL and vSynKerat showed a decrease in the time needed to kill the infected insects when compared to the wild type virus. We have also shown that both recombinants were able to increase phenoloxidase activity in the hemolymph of S. frugiperda larvae. The expression of proteases in infected larvae resulted in destruction of internal tissues late in infection, which could be the reason for the increased viral speed of kill. Conclusions Baculoviruses and their recombinant forms constitute viable alternatives to chemical insecticides. Recombinant baculoviruses containing protease genes can be added to the list of engineered baculoviruses with great potential to be used in integrated pest management programs. PMID:20587066

  19. Effects of Doxycycline on gene expression in Wolbachia and Brugia malayi adult female worms in vivo

    PubMed Central

    2012-01-01

    Background Most filarial nematodes contain Wolbachia symbionts. The purpose of this study was to examine the effects of doxycycline on gene expression in Wolbachia and adult female Brugia malayi. Methods Brugia malayi infected gerbils were treated with doxycycline for 6-weeks. This treatment largely cleared Wolbachia and arrested worm reproduction. RNA recovered from treated and control female worms was labeled by random priming and hybridized to the Version 2- filarial microarray to obtain expression profiles. Results and discussion Results showed significant changes in expression for 200 Wolbachia (29% of Wolbachia genes with expression signals in untreated worms) and 546 B. malayi array elements after treatment. These elements correspond to known genes and also to novel genes with unknown biological functions. Most differentially expressed Wolbachia genes were down-regulated after treatment (98.5%). In contrast, doxycycline had a mixed effect on B. malayi gene expression with many more genes being significantly up-regulated after treatment (85% of differentially expressed genes). Genes and processes involved in reproduction (gender-regulated genes, collagen, amino acid metabolism, ribosomal processes, and cytoskeleton) were down-regulated after doxycycline while up-regulated genes and pathways suggest adaptations for survival in response to stress (energy metabolism, electron transport, anti-oxidants, nutrient transport, bacterial signaling pathways, and immune evasion). Conclusions Doxycycline reduced Wolbachia and significantly decreased bacterial gene expression. Wolbachia ribosomes are believed to be the primary biological target for doxycycline in filarial worms. B. malayi genes essential for reproduction, growth and development were also down-regulated; these changes are consistent with doxycycline effects on embryo development and reproduction. On the other hand, many B. malayi genes involved in energy production, electron-transport, metabolism, anti

  20. Susceptibility of Anopheles quadrimaculatus (Diptera: Culicidae) to subperiodic Brugia malayi and Brugia pahangi (Nematoda: Filarioidea) adapted to nude mice and jirds.

    PubMed

    Nayar, J K; Knight, J W; Vickery, A C

    1990-05-01

    Anopheles quadrimaculatus and Aedes aegypti (Black-eyed Liverpool strain) were fed on jirds and nude mice (jird-jird infection, jird-mouse infection, and mouse-jird infection) infected with subperiodic Brugia malayi and B. pahangi. Microfilariae of B. malayi from jird-mouse and mouse-jird infections developed normally in An. quadrimaculatus, whereas those from jird-jird infections did not develop. Microfilariae of both species from jirds and nude mice developed normally in Ae. aegypti and those of B. pahangi developed normally in An. quadrimaculatus. It is suggested that microfilariae from nude mice are modified physiologically, immunologically, or both so that they can develop in refractory An. quadrimaculatus, thus indicating that susceptibility and refractoriness of An. quadrimaculatus to B. malayi also is influenced by factors relating to the vertebrate host in addition to mosquito genetic factors.

  1. New Paenibacillus larvae bacterial isolates from honey bee colonies infected with American foulbrood disease in Egypt

    PubMed Central

    Masry, Saad Hamdy Daif; Kabeil, Sanaa Soliman; Hafez, Elsayed Elsayed

    2014-01-01

    The American foulbrood disease is widely distributed all over the world and causes a serious problem for the honeybee industry. Different infected larvae were collected from different apiaries, ground in phosphate saline buffer (PSB) and bacterial isolation was carried out on nutrient agar medium. Different colonies were observed and were characterized biologically. Two bacterial isolates (SH11 and SH33) were subjected to molecular identification using 16S rRNA gene and the sequence analysis revealed that the two isolates are Paenibacillus larvae with identity not exceeding 83%. The DNA sequence alignment between the other P. larvae bacterial strains and the two identified bacterial isolates showed that all the examined bacterial strains have the same ancestor, i.e. they have the same origin. The SH33 isolate was closely related to the P. larvae isolated from Germany, whereas the isolate SH11 was close to the P. larvae isolated from India. The phylogenetic tree constructed for 20 different Bacillus sp. and the two isolates SH11 and SH33 demonstrated that the two isolates are Bacillus sp. and they are new isolates. The bacterial isolates will be subjected to more tests for more confirmations. PMID:26740757

  2. Following the infection process of vibriosis in Manila clam (Ruditapes philippinarum) larvae through GFP-tagged pathogenic Vibrio species.

    PubMed

    Dubert, Javier; Nelson, David R; Spinard, Edward J; Kessner, Linda; Gomez-Chiarri, Marta; da Costa, Fiz; Prado, Susana; Barja, Juan L

    2016-01-01

    Vibriosis represents the main bottleneck for the larval production process in shellfish aquaculture. While the signs of this disease in bivalve larvae are well known, the infection process by pathogenic Vibrio spp. during episodes of vibriosis has not been elucidated. To investigate the infection process in bivalves, the pathogens of larvae as V. tubiashii subsp. europaensis, V. neptunius and V. bivalvicida were tagged with green fluorescent protein (GFP). Larvae of Manila clam (Ruditapes philippinarum) were inoculated with the GFP-labeled pathogens in different infection assays and monitored by microscopy. Manila clam larvae infected by distinct GFP-tagged Vibrio spp. in different challenges showed the same progression in the infection process, defining three infection stages. GFP-tagged Vibrio spp. were filtered by the larvae through the vellum and entered in the digestive system through the esophagus and stomach and colonized the digestive gland and particularly the intestine, where they proliferated during the first 2h of contact (Stage I), suggesting a chemotactic response. Then, GFP-tagged Vibrio spp. expanded rapidly to the surrounding organs in the body cavity from the dorsal to ventral region (Stage II; 6-8h), colonizing the larvae completely at the peak of infection (Stage III) (14-24h). Results demonstrated for the first time that the vibriosis is asymptomatic in Manila clam larvae during the early infection stages. Thus, the early colonization and the rapid proliferation of Vibrio pathogens within the body cavity supported the sudden and fatal effect of the vibriosis, since the larvae exhibited the first signs of disease when the infection process is advanced. As a first step in the elucidation of the potential mechanisms of bacterial pathogenesis in bivalve larvae the enzymatic activities of the extracellular products released from the wild type V. neptunius, V. tubiashii subsp. europaensis and V. bivalvicida were determined and their cytotoxicity was

  3. Experimental bacteriophage treatment of honeybees (Apis mellifera) infected with Paenibacillus larvae, the causative agent of American Foulbrood Disease.

    PubMed

    Yost, Diane G; Tsourkas, Philippos; Amy, Penny S

    2016-01-01

    American Foulbrood Disease (AFB) is an infection of honeybees caused by the bacterium Paenibacillus larvae. One potential remedy involves using biocontrol, such as bacteriophages (phages) to lyse P. larvae. Therefore, bacteriophages specific for P. larvae were isolated to determine their efficacy in lysing P. larvae cells. Samples from soil, beehive materials, cosmetics, and lysogenized P. larvae strains were screened; of 157 total samples, 28 were positive for at least one P. larvae bacteriophage, with a total of 30. Newly isolated bacteriophages were tested for the ability to lyse each of 11 P. larvae strains. Electron microscopy demonstrated that the phage isolates were from the family Siphoviridae. Seven phages with the broadest host ranges were combined into a cocktail for use in experimental treatments of infected bee larvae; both prophylactic and post-infection treatments were conducted. Results indicated that although both pre- and post-treatments were effective, prophylactic administration of the phages increased the survival of larvae more than post-treatment experiments. These preliminary experiments demonstrate the likelihood that phage therapy could be an effective method to control AFB.

  4. Experimental bacteriophage treatment of honeybees (Apis mellifera) infected with Paenibacillus larvae, the causative agent of American Foulbrood Disease

    PubMed Central

    Yost, Diane G.; Tsourkas, Philippos; Amy, Penny S.

    2016-01-01

    ABSTRACT American Foulbrood Disease (AFB) is an infection of honeybees caused by the bacterium Paenibacillus larvae. One potential remedy involves using biocontrol, such as bacteriophages (phages) to lyse P. larvae. Therefore, bacteriophages specific for P. larvae were isolated to determine their efficacy in lysing P. larvae cells. Samples from soil, beehive materials, cosmetics, and lysogenized P. larvae strains were screened; of 157 total samples, 28 were positive for at least one P. larvae bacteriophage, with a total of 30. Newly isolated bacteriophages were tested for the ability to lyse each of 11 P. larvae strains. Electron microscopy demonstrated that the phage isolates were from the family Siphoviridae. Seven phages with the broadest host ranges were combined into a cocktail for use in experimental treatments of infected bee larvae; both prophylactic and post-infection treatments were conducted. Results indicated that although both pre- and post-treatments were effective, prophylactic administration of the phages increased the survival of larvae more than post-treatment experiments. These preliminary experiments demonstrate the likelihood that phage therapy could be an effective method to control AFB. PMID:27144085

  5. Tick-borne flavivirus infection in Ixodes scapularis larvae: development of a novel method for synchronous viral infection of ticks

    PubMed Central

    Mitzel, Dana N.; Wolfinbarger, James B.; Daniel Long, R.; Masnick, Max; Best, Sonja M.; Bloom, Marshall E.

    2007-01-01

    Following a bite from an infected tick, tick-borne flaviviruses cause encephalitis, meningitis and hemorrhagic fever in humans. Although these viruses spend most of their time in the tick, little is known regarding the virus-vector interactions. We developed a simple method for synchronously infecting Ixodes scapularis larvae with Langat virus (LGTV) by immersion in media containing the virus. This technique resulted in approximately 96% of ticks becoming infected. LGTV infection and replication were demonstrated by both viral antigen expression and the accumulation of viral RNA. Furthermore, ticks transmitted LGTV to 100% of the mice and maintained the virus through molting into the next life stage. This technique circumvents limitations present in the current methods by mimicking the natural route of infection and by using attenuated virus strains to infect ticks; thereby, making this technique a powerful tool to study both virus and tick determinants of replication, pathogenesis and transmission. PMID:17490700

  6. Tick-borne flavivirus infection in Ixodes scapularis larvae: development of a novel method for synchronous viral infection of ticks.

    PubMed

    Mitzel, Dana N; Wolfinbarger, James B; Long, R Daniel; Masnick, Max; Best, Sonja M; Bloom, Marshall E

    2007-09-01

    Following a bite from an infected tick, tick-borne flaviviruses cause encephalitis, meningitis and hemorrhagic fever in humans. Although these viruses spend most of their time in the tick, little is known regarding the virus-vector interactions. We developed a simple method for synchronously infecting Ixodes scapularis larvae with Langat virus (LGTV) by immersion in media containing the virus. This technique resulted in approximately 96% of ticks becoming infected. LGTV infection and replication were demonstrated by both viral antigen expression and the accumulation of viral RNA. Furthermore, ticks transmitted LGTV to 100% of the mice and maintained the virus through molting into the next life stage. This technique circumvents limitations present in the current methods by mimicking the natural route of infection and by using attenuated virus strains to infect ticks, thereby making this technique a powerful tool to study both virus and tick determinants of replication, pathogenesis and transmission.

  7. Physical stress primes the immune response of Galleria mellonella larvae to infection by Candida albicans.

    PubMed

    Mowlds, Peter; Barron, Aoife; Kavanagh, Kevin

    2008-05-01

    Larvae of the greater wax moth (Galleria mellonella) that had been subjected to physical stress by shaking in cupped hands for 2 min showed reduced susceptibility to infection by Candida albicans when infected 24 h after the stress event. Physically stressed larvae demonstrated an increase in haemocyte density and elevated mRNA levels of galiomicin and an inducible metalloproteinase inhibitor (IMPI) but not transferrin or gallerimycin. In contrast, previous work has demonstrated that microbial priming of larvae resulted in the induction of all four genes. Examination of the expression of proteins in the insect haemolymph using 2D electrophoresis and MALDI TOF analysis revealed an increase in the intensity of a number of peptides showing some similarities with proteins associated with the insect immune response to infection. This study demonstrates that non-lethal physical stress primes the immune response of G. mellonella and this is mediated by elevated haemocyte numbers, increased mRNA levels of genes coding for two antimicrobial peptides and the appearance of novel peptides in the haemolymph. This work demonstrates that physical priming increases the insect immune response but the mechanism of this priming is different to that induced by low level exposure to microbial pathogens.

  8. CHARACTERIZATION OF THE GLYCOSYLATED ECDYSTEROIDS IN THE HEMOLYMPH OF BACULOVIRUS-INFECTED GYPSY MOTH LARVAE AND CELLS IN CULTURE

    EPA Science Inventory

    Fourth-instar gypsy moth (Lymantria dispar; Lepidoptera: Lymantriidae) larvae, infected with the gypsy moth baculovirus (LdNPV), show an elevated and prolonged extension of the hemolymph ecdysteroid titer peak associated with molting. The ecdysteroid immunoreactivity associated w...

  9. Monitoring of Vibrio harveyi quorum sensing activity in real time during infection of brine shrimp larvae.

    PubMed

    Defoirdt, Tom; Sorgeloos, Patrick

    2012-12-01

    Quorum sensing, bacterial cell-to-cell communication, has been linked to the virulence of pathogenic bacteria. Indeed, in vitro experiments have shown that many bacterial pathogens regulate the expression of virulence genes by this cell-to-cell communication process. Moreover, signal molecules have been detected in samples retrieved from infected hosts and quorum sensing disruption has been reported to result in reduced virulence in different host-pathogen systems. However, data on in vivo quorum sensing activity of pathogens during infection of a host are currently lacking. We previously reported that quorum sensing regulates the virulence of Vibrio harveyi in a standardised model system with gnotobiotic brine shrimp (Artemia franciscana) larvae. Here, we monitored quorum sensing activity in Vibrio harveyi during infection of the shrimp, using bioluminescence as a read-out. We found that wild-type Vibrio harveyi shows a strong increase in quorum sensing activity early during infection. In this respect, the bacteria behave remarkably similar in different larvae, despite the fact that only half of them survive the infection. Interestingly, when expressed per bacterial cell, Vibrio harveyi showed around 200-fold higher maximal quorum sensing-regulated bioluminescence when associated with larvae than in the culture water. Finally, the in vivo quorum sensing activity of mutants defective in the production of one of the three signal molecules is consistent with their virulence, with no detectable in vivo quorum sensing activity in AI-2- and CAI-1-deficient mutants. These results indicate that AI-2 and CAI-1 are the dominant signals during infection of brine shrimp.

  10. Diversity and genetic population structure of fungal pathogens infecting white grub larvae in agricultural soils.

    PubMed

    Carrillo-Benítez, María G; Guzmán-Franco, Ariel W; Alatorre-Rosas, Raquel; Enríquez-Vara, Jhony N

    2013-02-01

    White grub larvae are important soil-dwelling pests in many regions of Mexico as they attack many important crops such as maize. The use of synthetic chemicals is currently the main control strategy, but they are not always effective; thus, other alternatives are needed. Microbial control using entomopathogenic fungi represents an important alternative strategy, and species within the genera Beauveria and Metarhizium are considered amongst the most promising candidates. Seventeen Beauveria spp. and two Metarhizium spp. isolates were obtained in surveys of white grub larvae from different regions of Guanajuato, Mexico. All isolates were capable of infecting healthy larvae of the white grub Phyllophaga polyphilla in laboratory assays, but mortality never exceeded 50 %. Isolates were identified using morphological and molecular methods. Based on elongation factor1-α and ITS partial gene sequence data, all Beauveria isolates were identified as Beauveria pseudobassiana. Elongation factor1-α and β-tubulin sequence data identified the Metarhizium isolates to be Metarhizium pingshaense. In contrast, three additional Metarhizium isolates obtained the previous year in the same region were identified as M. pingshaense, Metarhizium anisopliae and Metarhizium robertsii. Microsatellite genotyping showed that all B. pseudobassiana isolates were the same haplotype. Enterobacterial Repetitive Intergenic Consensus fingerprinting information confirmed no significant variation amongst the B. pseudobassiana isolates. The ecological role of these isolates and their impact on white grub larvae populations are discussed.

  11. Sublethal pesticide doses negatively affect survival and the cellular responses in American foulbrood-infected honeybee larvae

    NASA Astrophysics Data System (ADS)

    López, Javier Hernández; Krainer, Sophie; Engert, Antonia; Schuehly, Wolfgang; Riessberger-Gallé, Ulrike; Crailsheim, Karl

    2017-02-01

    Disclosing interactions between pesticides and bee infections is of most interest to understand challenges that pollinators are facing and to which extent bee health is compromised. Here, we address the individual and combined effect that three different pesticides (dimethoate, clothianidin and fluvalinate) and an American foulbrood (AFB) infection have on mortality and the cellular immune response of honeybee larvae. We demonstrate for the first time a synergistic interaction when larvae are exposed to sublethal doses of dimethoate or clothianidin in combination with Paenibacillus larvae, the causative agent of AFB. A significantly higher mortality than the expected sum of the effects of each individual stressor was observed in co-exposed larvae, which was in parallel with a drastic reduction of the total and differential hemocyte counts. Our results underline that characterizing the cellular response of larvae to individual and combined stressors allows unmasking previously undetected sublethal effects of pesticides in colony health.

  12. Sublethal pesticide doses negatively affect survival and the cellular responses in American foulbrood-infected honeybee larvae

    PubMed Central

    López, Javier Hernández; Krainer, Sophie; Engert, Antonia; Schuehly, Wolfgang; Riessberger-Gallé, Ulrike; Crailsheim, Karl

    2017-01-01

    Disclosing interactions between pesticides and bee infections is of most interest to understand challenges that pollinators are facing and to which extent bee health is compromised. Here, we address the individual and combined effect that three different pesticides (dimethoate, clothianidin and fluvalinate) and an American foulbrood (AFB) infection have on mortality and the cellular immune response of honeybee larvae. We demonstrate for the first time a synergistic interaction when larvae are exposed to sublethal doses of dimethoate or clothianidin in combination with Paenibacillus larvae, the causative agent of AFB. A significantly higher mortality than the expected sum of the effects of each individual stressor was observed in co-exposed larvae, which was in parallel with a drastic reduction of the total and differential hemocyte counts. Our results underline that characterizing the cellular response of larvae to individual and combined stressors allows unmasking previously undetected sublethal effects of pesticides in colony health. PMID:28145462

  13. Sublethal pesticide doses negatively affect survival and the cellular responses in American foulbrood-infected honeybee larvae.

    PubMed

    López, Javier Hernández; Krainer, Sophie; Engert, Antonia; Schuehly, Wolfgang; Riessberger-Gallé, Ulrike; Crailsheim, Karl

    2017-02-01

    Disclosing interactions between pesticides and bee infections is of most interest to understand challenges that pollinators are facing and to which extent bee health is compromised. Here, we address the individual and combined effect that three different pesticides (dimethoate, clothianidin and fluvalinate) and an American foulbrood (AFB) infection have on mortality and the cellular immune response of honeybee larvae. We demonstrate for the first time a synergistic interaction when larvae are exposed to sublethal doses of dimethoate or clothianidin in combination with Paenibacillus larvae, the causative agent of AFB. A significantly higher mortality than the expected sum of the effects of each individual stressor was observed in co-exposed larvae, which was in parallel with a drastic reduction of the total and differential hemocyte counts. Our results underline that characterizing the cellular response of larvae to individual and combined stressors allows unmasking previously undetected sublethal effects of pesticides in colony health.

  14. Freeze-tolerance of Trichinella muscle larvae in experimentally infected wild boars.

    PubMed

    Lacour, Sandrine A; Heckmann, Aurélie; Macé, Pauline; Grasset-Chevillot, Aurélie; Zanella, Gina; Vallée, Isabelle; Kapel, Christian M O; Boireau, Pascal

    2013-05-20

    Freeze-tolerance of encapsulated Trichinella muscle larvae (ML) is mainly determined by Trichinella species, but is also influenced by host species, the age of the infection and the storage time and temperature of the infected meat. Moreover, the freeze-tolerance of the encapsulated species appears to be correlated to the development of thick capsule walls which increases with age. An extended infection period and the muscle composition in some hosts (e.g. herbivores) may provide freeze-avoiding matrices due to high carbohydrate contents. The present experiment compares freeze-tolerance of Trichinella spiralis and Trichinella britovi ML in wild boar meat 24 weeks post inoculation (wpi). Three groups of four wild boars were infected with 200, 2000 or 20,000 ML of T. britovi (ISS 1575), respectively. Additionally, three wild boars were inoculated with 20,000 ML of T. spiralis (ISS 004) and two animals served as negative controls. All wild boars were sacrificed 24 wpi. Muscle samples of 70 g were stored at -21°C for 19, 30 and 56 h, and for 1-8 weeks. Larvae were recovered by artificial digestion. Their mobilities were recorded using Saisam(®) image analysis software and their infectivities were evaluated using mouse bioassays. Samples frozen for 19, 30 and 56 h allowed recovery of mobile ML, but samples frozen for 1 or 2 weeks did not. Correspondingly, only T. spiralis and T. britovi larvae isolated from wild boar meat frozen for 19, 30 and 56 h established in mice. This study showed that freezing at -21°C for 1 week inactivated T. spiralis and T. britovi ML encapsulated in wild boar meat for 24 weeks.

  15. Distribution of infective gastrointestinal helminth larvae in tropical erect grass under different feeding systems for lambs.

    PubMed

    Tontini, Jalise Fabíola; Poli, Cesar Henrique Espírito Candal; Bremm, Carolina; de Castro, Juliane Machado; Fajardo, Neuza Maria; Sarout, Bruna Nunes Marsiglio; Castilhos, Zélia Maria de Souza

    2015-08-01

    This study examined tropical pasture contamination dynamics under different feeding systems for finishing lambs. The experiment aimed to evaluate the vertical distribution of gastrointestinal helminth infective larvae (L3) in erect grass subjected to grazing and to assess the parasite load and its impact on lamb performance in three production systems. Three treatments based on Aruana grass (Panicum maximum cv. IZ-5) were as follows: T1, grass only; T2, grass with 1.5% of body weight (BW) nutrient concentrate supplementation; and T3, grass with 2.5% BW concentrate supplementation. The randomized block design had three replicates of three treatments, with six lambs per replicate. L3 were recovered from three pasture strata (upper, middle, and bottom), each representing one third of the sward height, and correlated with microclimatic data. Significant differences (P < 0.05) were observed among treatments in the L3 recovery. Despite different grass heights between treatments and microclimates within the sward, the L3 concentration generally did not differ significantly among the three strata within a treatment (P > 0.05). Pasture microclimate did not correlate with larval recovery. At the end of the experiment, the animal fecal egg count was similar among treatments (P > 0.05). The results indicated that different lamb feeding systems in a tropical erect grassland caused differences in grass height but did not affect the distribution of infective larvae among strata. Larvae were found from the base to the top of the grass sward.

  16. Predatory activity of Butlerius nematodes and nematophagous fungi against Haemonchus contortus infective larvae.

    PubMed

    Silva, Manoel Eduardo da; Uriostegui, Miguel Angel Mercado; Millán-Orozco, Jair; Gives, Pedro Mendoza de; Hernández, Enrique Liébano; Braga, Fabio Ribeiro; Araújo, Jackson Victor de

    2017-01-26

    The purpose of this study was to evaluate the predatory activity of the nematode Butlerius spp. and fungal isolates of Duddingtonia flagrans, Clonostachys rosea, Arthrobotrys musiformis and Trichoderma esau against H. contortus infective larvae (L3) in grass pots. Forty-eight plastic gardening pots containing 140 g of sterile soil were used. Panicum spp. grass seeds (200 mg) were sown into each pot and individually watered with 10 mL of tap water. Twelve days after seeding, the pots were randomly divided into 6 groups (n=8). Two thousand H. contortus infective larvae (L3) were added to each group. Additionally, the following treatments were established: Group 1 - 2000 Butlerius spp. larvae; group 2 - A. musiformis (1x107 conidia); group 3 - T. esau (1x107 conidia); group 4 - C. rosea (1x107 conidia), group 5 - D. flagrans (1x107conidia) and Group 6 - no biological controller (control group). The larval population of H. contortus exposed to Butlerius spp. was reduced by 61.9%. Population reductions of 90.4, 66.7, 61.9 and 85.7% were recorded in the pots containing A. musiformis, T. esau, C. rosea and D. flagrans, respectively. The results of this study indicate that the predatory nematode Butlerius spp. and the assessed fungi display an important predatory activity can be considered suitable potential biological control agents.

  17. Immunogenicity and Protective Efficacy of Brugia malayi Heavy Chain Myosin as Homologous DNA, Protein and Heterologous DNA/Protein Prime Boost Vaccine in Rodent Model

    PubMed Central

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

    2015-01-01

    We earlier demonstrated the immunoprophylactic efficacy of recombinant heavy chain myosin (Bm-Myo) of Brugia malayi (B. malayi) in rodent models. In the current study, further attempts have been made to improve this efficacy by employing alternate approaches such as homologous DNA (pcD-Myo) and heterologous DNA/protein prime boost (pcD-Myo+Bm-Myo) in BALB/c mouse model. The gene bm-myo was cloned in a mammalian expression vector pcDNA 3.1(+) and protein expression was confirmed in mammalian Vero cell line. A significant degree of protection (79.2%±2.32) against L3 challenge in pcD-Myo+Bm-Myo immunized group was observed which was much higher than that exerted by Bm-Myo (66.6%±2.23) and pcD-Myo (41.6%±2.45). In the heterologous immunized group, the percentage of peritoneal leukocytes such as macrophages, neutrophils, B cells and T cells marginally increased and their population augmented further significantly following L3 challenge. pcD-Myo+Bm-Myo immunization elicited robust cellular and humoral immune responses as compared to pcD-Myo and Bm-Myo groups as evidenced by an increased accumulation of CD4+, CD8+ T cells and CD19+ B cells in the mouse spleen and activation of peritoneal macrophages. Though immunized animals produced antigen-specific IgG antibodies and isotypes, sera of mice receiving pcD-Myo+Bm-Myo or Bm-Myo developed much higher antibody levels than other groups and there was profound antibody-dependent cellular adhesion and cytotoxicity (ADCC) to B. malayi infective larvae (L3). pcD-Myo+Bm-Myo as well as Bm-Myo mice generated a mixed T helper cell phenotype as evidenced by the production of both pro-inflammatory (IL-2, IFN-γ) and anti-inflammatory (IL-4, IL-10) cytokines. Mice receiving pcD-Myo on contrary displayed a polarized pro-inflammatory immune response. The findings suggest that the priming of animals with DNA followed by protein booster generates heightened and mixed pro- and anti-inflammatory immune responses that are capable of providing

  18. Efficacy of albendazole against Taenia multiceps larvae in experimentally infected goats.

    PubMed

    Afonso, Sónia M S; Neves, Luis; Pondja, Alberto; Macuamule, Cristiano; Mukaratirwa, Samson; Arboix, Margarita; Cristòfol, Carles; Capece, Bettencourt P S

    2014-12-15

    A controlled trial was conducted to evaluate the efficacy of three therapeutics regimes of albendazole (ABZ) against Taenia multiceps larvae in experimental infected goats. Forty-nine goats experimentally infected with 3000 T. multiceps eggs were selected and randomly divided into treatment or control groups. Treatment with 10mg/kg for 3 days for group 1 (G1), 10mg/kg for group 2 (G2) and 20mg/kg/day for group 3 (G3) was applied 2 months after infection; group 4 (G4) served as a control group. A treatment with doses of 10mg/kg/day for 3 days on group 5 (G5) and group 6 (G6) was used as control, 5 months after the infection. The efficacy of ABZ was assessed as percentage of non-viable cysts which were determined by morphologic characteristics, movement and methyl blue staining technique. The efficacy of ABZ against 2 months old cysts was significantly different from the control and were 90.3% (28/31), 72.7% (8/11) and 73.9% (14/19) for G1, G2 and G3, respectively. No differences were observed in cyst viability between treated and control groups for 5-month old cysts. The results in this study indicate that ABZ is effective in goats against 2-month-old cysts of T. multiceps larva located in tissues outside the brain.

  19. Wolbachia-mediated antiviral protection in Drosophila larvae and adults following oral infection.

    PubMed

    Stevanovic, Aleksej L; Arnold, Pieter A; Johnson, Karyn N

    2015-12-01

    Understanding viral dynamics in arthropods is of great importance when designing models to describe how viral spread can influence arthropod populations. The endosymbiotic bacterium Wolbachia spp., which is present in up to 40% of all insect species, has the ability to alter viral dynamics in both Drosophila spp. and mosquitoes, a feature that in mosquitoes may be utilized to limit spread of important arboviruses. To understand the potential effect of Wolbachia on viral dynamics in nature, it is important to consider the impact of natural routes of virus infection on Wolbachia antiviral effects. Using adult Drosophila strains, we show here that Drosophila-Wolbachia associations that have previously been shown to confer antiviral protection following systemic viral infection also confer protection against virus-induced mortality following oral exposure to Drosophila C virus in adults. Interestingly, a different pattern was observed when the same fly lines were challenged with the virus when still larvae. Analysis of the four Drosophila-Wolbachia associations that were protective in adults indicated that only the w1118-wMelPop association conferred protection in larvae following oral delivery of the virus. Analysis of Wolbachia density using quantitative PCR (qPCR) showed that a high Wolbachia density was congruent with antiviral protection in both adults and larvae. This study indicates that Wolbachia-mediated protection may vary between larval and adult stages of a given Wolbachia-host combination and that the variations in susceptibility by life stage correspond with Wolbachia density. The differences in the outcome of virus infection are likely to influence viral dynamics in Wolbachia-infected insect populations in nature and could also have important implications for the transmission of arboviruses in mosquito populations.

  20. Wolbachia-Mediated Antiviral Protection in Drosophila Larvae and Adults following Oral Infection

    PubMed Central

    Stevanovic, Aleksej L.; Arnold, Pieter A.

    2015-01-01

    Understanding viral dynamics in arthropods is of great importance when designing models to describe how viral spread can influence arthropod populations. The endosymbiotic bacterium Wolbachia spp., which is present in up to 40% of all insect species, has the ability to alter viral dynamics in both Drosophila spp. and mosquitoes, a feature that in mosquitoes may be utilized to limit spread of important arboviruses. To understand the potential effect of Wolbachia on viral dynamics in nature, it is important to consider the impact of natural routes of virus infection on Wolbachia antiviral effects. Using adult Drosophila strains, we show here that Drosophila-Wolbachia associations that have previously been shown to confer antiviral protection following systemic viral infection also confer protection against virus-induced mortality following oral exposure to Drosophila C virus in adults. Interestingly, a different pattern was observed when the same fly lines were challenged with the virus when still larvae. Analysis of the four Drosophila-Wolbachia associations that were protective in adults indicated that only the w1118-wMelPop association conferred protection in larvae following oral delivery of the virus. Analysis of Wolbachia density using quantitative PCR (qPCR) showed that a high Wolbachia density was congruent with antiviral protection in both adults and larvae. This study indicates that Wolbachia-mediated protection may vary between larval and adult stages of a given Wolbachia-host combination and that the variations in susceptibility by life stage correspond with Wolbachia density. The differences in the outcome of virus infection are likely to influence viral dynamics in Wolbachia-infected insect populations in nature and could also have important implications for the transmission of arboviruses in mosquito populations. PMID:26407882

  1. Defining Brugia malayi and Wolbachia symbiosis by stage-specific dual RNA-seq

    PubMed Central

    Voronin, Denis; Ding, Tao; Twaddle, Alan; Unnasch, Thomas R.; Lustigman, Sara; Ghedin, Elodie

    2017-01-01

    Background Filarial nematodes currently infect up to 54 million people worldwide, with millions more at risk for infection, representing the leading cause of disability in the developing world. Brugia malayi is one of the causative agents of lymphatic filariasis and remains the only human filarial parasite that can be maintained in small laboratory animals. Many filarial nematode species, including B. malayi, carry an obligate endosymbiont, the alpha-proteobacteria Wolbachia, which can be eliminated through antibiotic treatment. Elimination of the endosymbiont interferes with development, reproduction, and survival of the worms within the mamalian host, a clear indicator that the Wolbachia are crucial for survival of the parasite. Little is understood about the mechanism underlying this symbiosis. Methodology/ Principle findings To better understand the molecular interplay between these two organisms we profiled the transcriptomes of B. malayi and Wolbachia by dual RNA-seq across the life cycle of the parasite. This helped identify functional pathways involved in this essential symbiotic relationship provided by the co-expression of nematode and bacterial genes. We have identified significant stage-specific and gender-specific differential expression in Wolbachia during the nematode’s development. For example, during female worm development we find that Wolbachia upregulate genes involved in ATP production and purine biosynthesis, as well as genes involved in the oxidative stress response. Conclusions/ Significance This global transcriptional analysis has highlighted specific pathways to which both Wolbachia and B. malayi contribute concurrently over the life cycle of the parasite, paving the way for the development of novel intervention strategies. PMID:28358880

  2. Infective larvae of Cercopithifilaria spp. (Nematoda: Onchocercidae) from hard ticks (Ixodidae) recovered from the Japanese serow (Bovidae)

    PubMed Central

    Uni, Shigehiko; Bain, Odile; Fujita, Hiromi; Matsubayashi, Makoto; Fukuda, Masako; Takaoka, Hiroyuki

    2013-01-01

    Hard ticks taken from the Japanese serow, Capricornis crispus, in Yamagata Prefecture, Honshu, harboured infective larvae of onchocercid filariae after incubation from the 22nd to the 158th day. Haemaphysalis flava and H. japonica contained one to eight filarial larvae; females, males and a nymph of the ticks were infected. The 44 infective larvae recovered were 612–1,370 μm long, and 11 of them, 930–1,340 μm long, were studied in detail. The larvae possessed the morphologic characteristics of the larvae of the genus Cercopithifilaria, namely an oesophagus with a posterior glandular part, no buccal capsule and a long tail with three terminal lappets. Five types (A to E) of infective larvae were identified based on the morphologic characteristics. While to date five species of Cercopithifilaria have been described from the Japanese serow, a specific identification of the larvae found in this study was generally not possible. Only type E larvae could be tentatively assigned to Cercopithifilaria tumidicervicata, as they had a cervical swelling similar to that of the adults of this species. A key for the identification of the five larval types is presented. The study presents circumstantial evidences indicating that H. flava and H. japonica may transmit Cercopithifilaria spp. to Japanese serows. It also suggests the possibility that such filarial larvae will be found in hard ticks anywhere, because Cercopithifilaria is distributed worldwide, though this genus generally goes unnoticed, as its microfilariae occur in the skin, not in the blood, of host animals. PMID:23340227

  3. Identification and methods for prevention of Enterococcus mundtii infection in silkworm larvae, Bombyx mori, reared on artificial diet.

    PubMed

    Nwibo, Don Daniel; Matsumoto, Yasuhiko; Sekimizu, Kazuhisa

    2015-06-01

    Previously, it was reported that Enterococcus mundtii (E. mundtii) was associated with flacherie disease of silkworm larvae reared on artificial diet. In this study, we report that E. mundtii was isolated from diseased silkworm larvae, and validated as a pathogenic bacterium of the animal. When silkworm larva was infected with 1.04 × 10⁶ colony-forming units of E. mundtii via oral administration of diet, half population died within six days, indicating that the bacterium is pathogenic to silkworm. Less severe infection was found to cause anorexia and hamper the development of larvae. This pathogen was found to proliferate in both time- and dose-dependent manner in the gastrointestinal tract of the animal. The bacterium was isolated from powder of artificial diet made from mulberry leaves, and from mulberry leaves growing at a field. Minimum inhibitory concentration determination revealed that this bacterium was susceptible to tested antibiotics. Vancomycin treatment of diet significantly decreased the number of E. mundtii in intestine of silkworm larvae infected with the bacteria, compared to control. Furthermore, autoclaving or gamma ray irradiation of diet was also effective for exclusion of E. mundtii from the diet without the loss of its nutrient capacities. These results suggest that mulberry leaves used in making artificial diet for silkworm larvae is one of the sources of E. mundtii infection; and that antibiotic treatment, autoclaving or gamma ray irradiation of artificial diet can exclude the bacteria.

  4. Histopathology and ultrastructure of Platichthys flesus naturally infected with Anisakis simplex s.l. larvae (Nematoda: Anisakidae).

    PubMed

    Dezfuli, Bahram S; Pironi, Flavio; Shinn, Andrew P; Manera, Maurizio; Giari, Luisa

    2007-12-01

    The histopathology, ultrastructure, and immunohistochemistry of the alimentary canal of flounder Platichthys flesus (L.), naturally infected with the nematode Anisakis simplex s.l. (Rudolphi 1809) from the River Forth (Scotland), were investigated and described. Eight of the 16 flounders were infected with A. simplex s.l. larvae (L3); parasites were encapsulated by serosa on the external surface of the host's digestive tract (intensity of infection 1-8 parasites per host), although nematode larvae were found encysted under the peritoneal visceral serosa of the host spleen and liver and, occasionally, in the liver parenchyma (intensity of infection 3-10 parasites per host). In all sites, different structural elements were recognized within the capsule surrounding larvae. Among the epithelial cells of the intestine of 5 flounders with larvae encysted on external surface of the gut, the presence of several rodlet cells (RCs) was observed. Furthermore, often the occurrence of macrophage aggregates (MAs) was noticed in infected liver and spleen, mainly around the parasite larvae. Eight neuropeptide antisera were tested with immunohistochemistry methods on gut sections of 4 P. flesus infected with extraintestinal nematodes. Sections from the gut of 5 uninfected flounder were used for comparative purposes. In the tunica mucosa of parasitized P. flesus, several endocrine epithelial cells were immunoreactive to anti-CCK-39 (cholecystokinin 39) and -NPY (neuropeptide Y) sera; furthermore, in the myenteric plexus, a high number of neurons were immunoreactive to antibombesin, -galanin, and several to -NPY and -PHI (peptide histidine isoleucine) sera.

  5. Ingestion of bacteria overproducing DnaK attenuates Vibrio infection of Artemia franciscana larvae.

    PubMed

    Sung, Yeong Yik; Dhaene, Till; Defoirdt, Tom; Boon, Nico; MacRae, Thomas H; Sorgeloos, Patrick; Bossier, Peter

    2009-11-01

    Feeding of bacterially encapsulated heat shock proteins (Hsps) to invertebrates is a novel way to limit Vibrio infection. As an example, ingestion of Escherichia coli overproducing prokaryotic Hsps significantly improves survival of gnotobiotically cultured Artemia larvae upon challenge with pathogenic Vibrio campbellii. The relationship between Hsp accumulation and enhanced resistance to infection may involve DnaK, the prokaryotic equivalent to Hsp70, a major molecular chaperone in eukaryotic cells. In support of this proposal, heat-stressed bacterial strains LVS 2 (Bacillus sp.), LVS 3 (Aeromonas hydrophila), LVS 8 (Vibrio sp.), GR 8 (Cytophaga sp.), and GR 10 (Roseobacter sp.) were shown in this work to be more effective than nonheated bacteria in protecting gnotobiotic Artemia larvae against V. campbellii challenge. Immunoprobing of Western blots and quantification by enzyme-linked immunosorbent assay revealed that the amount of DnaK in bacteria and their ability to enhance larval resistance to infection by V. campbellii are correlated. Although the function of DnaK is uncertain, it may improve tolerance to V. campbellii via immune stimulation, a possibility of significance from a fundamental perspective and also because it could be applied in aquaculture, a major method of food production.

  6. Infection by the microsporidium Vairimorpha necatrix (Microspora: Microsporidia) elevates juvenile hormone titres in larvae of the tomato moth, Lacanobia oleracea (Lepidoptera: Noctuidae).

    PubMed

    Down, Rachel E; Bell, Howard A; Bryning, Gareth; Kirkbride-Smith, Anne E; Edwards, John P; Weaver, Robert J

    2008-03-01

    The effects of infection by a microsporidium, Vairimorpha necatrix (Kramer), on the endogenous levels of juvenile hormones in tomato moth (Lacanobia oleracea L.) larvae were investigated. Levels of juvenile hormone II (JH II) were 10-fold greater in the infected larvae on day two of the sixth stadium but no significant difference was observed on day seven. Juvenile hormone I (JH I) was also detected in day two and day seven sixth instar infected larvae but was not detected in non-infected larvae. The duration of the fifth and sixth stadia was significantly longer for infected larvae when compared with non-infected larvae. No evidence was found to suggest that supernumerary moults are a feature of infection by V. necatrix in L. oleracea larvae. Experiments were performed to determine whether the elevation in JH levels, which probably prevents pupation, is an adaptive mechanism of the microsporidium for extending the growth phase of the host, thereby allowing increased spore production. A proportion of infected larvae were collected on days 9 and 24 of the sixth stadium and spore extracts prepared from each larva. These days represent the average duration of the sixth stadium required for uninfected larvae to reach pupation, and the average number of days that V. necatrix-infected larvae survive in the sixth stadium before dying from infection. The mean spore yields from infected larvae 24 days into the sixth stadium were significantly higher than the spore yields obtained from day nine sixth instar larvae. The hypothesis that V. necatrix manipulates host endocrinology (i.e. prolong the host larval state to maximise spore yield) is discussed in context with the results obtained.

  7. The Effect of In Vitro Cultivation on the Transcriptome of Adult Brugia malayi

    PubMed Central

    O’Neill, Maeghan; Burkman, Erica; Zaky, Weam I.; Xia, Jianguo; Moorhead, Andrew; Williams, Steven A.; Geary, Timothy G.

    2016-01-01

    Background Filarial nematodes cause serious and debilitating infections in human populations of tropical countries, contributing to an entrenched cycle of poverty. Only one human filarial parasite, Brugia malayi, can be maintained in rodents in the laboratory setting. It has been a widely used model organism in experiments that employ culture systems, the impact of which on the worms is unknown. Methodology/Principal Findings Using Illumina RNA sequencing, we characterized changes in gene expression upon in vitro maintenance of adult B. malayi female worms at four time points: immediately upon removal from the host, immediately after receipt following shipment, and after 48 h and 5 days in liquid culture media. The dramatic environmental change and the 24 h time lapse between removal from the host and establishment in culture caused a globally dysregulated gene expression profile. We found a maximum of 562 differentially expressed genes based on pairwise comparison between time points. After an initial shock upon removal from the host and shipping, a few stress fingerprints remained after 48 h in culture and until the experiment was stopped. This was best illustrated by a strong and persistent up-regulation of several genes encoding cuticle collagens, as well as serpins. Conclusions/Significance These findings suggest that B. malayi can be maintained in culture as a valid system for pharmacological and biological studies, at least for several days after removal from the host and adaptation to the new environment. However, genes encoding several stress indicators remained dysregulated until the experiment was stopped. PMID:26727204

  8. Evaluation of Galleria mellonella larvae for measuring the efficacy and pharmacokinetics of antibiotic therapies against Pseudomonas aeruginosa infection.

    PubMed

    Hill, Lucy; Veli, Neyme; Coote, Peter J

    2014-03-01

    The aim of this study was to determine whether Galleria mellonella larvae can be used (i) as an in vivo infection model for Pseudomonas aeruginosa and (ii) for evaluating the pharmacokinetics and efficacy of antipseudomonal antibiotics. Two strains of P. aeruginosa were employed, NCTC 10662 (antibiotic-susceptible) and NCTC 13437 (multidrug-resistant). Larvae were infected with increasing doses of either P. aeruginosa strain to investigate the effect of inoculum size on survival. Subsequently, infected larvae were treated with a range of antibiotics to examine whether these agents were effective against P. aeruginosa infection in vivo and whether the efficacy of these drugs matched the known susceptibilities of each bacterial strain. Larval burden of P. aeruginosa was also determined after infection and treatment with cefotaxime. Pharmacokinetic properties of the antibiotics tested were measured using a well diffusion assay to determine the concentration of antibiotics in larval haemolymph over time. Galleria mellonella larvae were sensitive to P. aeruginosa infection, and increasing inoculum doses of live cells resulted in greater larval mortality. Heat-killed bacteria had no detrimental effect on survival. Antibiotic efficacy against P. aeruginosa-infected G. mellonella correlated with the measured in vitro sensitivities of the two strains tested. The therapeutic benefit arising from administration of cefotaxime correlated with a reduced burden of bacteria present in the haemolymph. There was a clear correlation between measured antibiotic pharmacokinetics and the therapeutic effect. This study strongly supports future application of the G. mellonella infection model to initial studies of novel antipseudomonal treatments.

  9. Induction of an IAP antagonist in Culex quinquefasciatus larvae in response to infection by the baculovirus CuniNPV

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CuniNPV is a member of the Dipteran–specific baculoviruses in the genus Deltabaculovirus that specifically infects mosquito larvae within the genus Culex while species of Aedes and Anopheles are refractory. Infections are restricted to the nuclei of larval midgut epithelial cells with transmission...

  10. Heme acquisition in the parasitic filarial nematode Brugia malayi

    PubMed Central

    Luck, Ashley N.; Yuan, Xiaojing; Voronin, Denis; Slatko, Barton E.; Hamza, Iqbal; Foster, Jeremy M.

    2016-01-01

    Nematodes lack a heme biosynthetic pathway and must acquire heme from exogenous sources. Given the indispensable role of heme, this auxotrophy may be exploited to develop drugs that interfere with heme uptake in parasites. Although multiple heme-responsive genes (HRGs) have been characterized within the free-living nematode Caenorhabditis elegans, we have undertaken the first study of heme transport in Brugia malayi, a causative agent of lymphatic filariasis. Through functional assays in yeast, as well as heme analog, RNAi, and transcriptomic experiments, we have shown that the heme transporter B. malayi HRG-1 (BmHRG-1) is indeed functional in B. malayi. In addition, BmHRG-1 localizes both to the endocytic compartments and cell membrane when expressed in yeast cells. Transcriptomic sequencing revealed that BmHRG-1, BmHRG-2, and BmMRP-5 (all orthologs of HRGs in C. elegans) are down-regulated in heme-treated B. malayi, as compared to non–heme-treated control worms. Likely because of short gene lengths, multiple exons, other HRGs in B. malayi (BmHRG-3–6) remain unidentified. Although the precise mechanisms of heme homeostasis in a nematode with the ability to acquire heme remains unknown, this study clearly demonstrates that the filarial nematode B. malayi is capable of transporting exogenous heme.—Luck, A. N., Yuan, X., Voronin, D., Slatko, B. E., Hamza, I., Foster, J. M. Heme acquisition in the parasitic filarial nematode Brugia malayi. PMID:27363426

  11. Microarray-Based Analysis of Differential Gene Expression between Infective and Noninfective Larvae of Strongyloides stercoralis

    PubMed Central

    Ramanathan, Roshan; Varma, Sudhir; Ribeiro, José M. C.; Myers, Timothy G.; Nolan, Thomas J.; Abraham, David; Lok, James B.; Nutman, Thomas B.

    2011-01-01

    Background Differences between noninfective first-stage (L1) and infective third-stage (L3i) larvae of parasitic nematode Strongyloides stercoralis at the molecular level are relatively uncharacterized. DNA microarrays were developed and utilized for this purpose. Methods and Findings Oligonucleotide hybridization probes for the array were designed to bind 3,571 putative mRNA transcripts predicted by analysis of 11,335 expressed sequence tags (ESTs) obtained as part of the Nematode EST project. RNA obtained from S. stercoralis L3i and L1 was co-hybridized to each array after labeling the individual samples with different fluorescent tags. Bioinformatic predictions of gene function were developed using a novel cDNA Annotation System software. We identified 935 differentially expressed genes (469 L3i-biased; 466 L1-biased) having two-fold expression differences or greater and microarray signals with a p value<0.01. Based on a functional analysis, L1 larvae have a larger number of genes putatively involved in transcription (p = 0.004), and L3i larvae have biased expression of putative heat shock proteins (such as hsp-90). Genes with products known to be immunoreactive in S. stercoralis-infected humans (such as SsIR and NIE) had L3i biased expression. Abundantly expressed L3i contigs of interest included S. stercoralis orthologs of cytochrome oxidase ucr 2.1 and hsp-90, which may be potential chemotherapeutic targets. The S. stercoralis ortholog of fatty acid and retinol binding protein-1, successfully used in a vaccine against Ancylostoma ceylanicum, was identified among the 25 most highly expressed L3i genes. The sperm-containing glycoprotein domain, utilized in a vaccine against the nematode Cooperia punctata, was exclusively found in L3i biased genes and may be a valuable S. stercoralis target of interest. Conclusions A new DNA microarray tool for the examination of S. stercoralis biology has been developed and provides new and valuable insights regarding

  12. Litomosoides sigmodontis: a simple method to infect mice with L3 larvae obtained from the pleural space of recently infected jirds (Meriones unguiculatus).

    PubMed

    Hübner, Marc P; Torrero, Marina N; McCall, John W; Mitre, Edward

    2009-09-01

    Litomosoides sigmodontis is a filarial nematode that is used as a mouse model for human filarial infections. The life cycle of L. sigmodontis comprises rodents as definitive hosts and tropical rat mites as alternate hosts. Here, we describe a method of infecting mice with third stage larvae (L3) extracted from the pleural space of recently infected jirds (Meriones unguiculatus). This method enables infection of mice with a known number of L3 larvae without the time-consuming dissection of L3 larvae from mites and results in higher worm recovery and patency rates than conventional methods. Additionally, this method allows for geographical separation of the facility maintaining the L. sigmodontis life cycle from the institution at which mice are infected.

  13. Efficacy of Clonostachys rosea and Duddingtonia flagrans in Reducing the Haemonchus contortus Infective Larvae

    PubMed Central

    da Silva, Manoel Eduardo; Braga, Fabio Ribeiro; de Gives, Pedro Mendoza; Uriostegui, Miguel Angel Mercado; Reyes, Manuela; Soares, Filippe Elias de Freitas; de Carvalho, Lorendane Millena; Rodrigues, Francielle Bosi; de Araújo, Jackson Victor

    2015-01-01

    The biocontrol is proven effective in reducing in vitro and in situ free-living stages of major gastrointestinal helminths, allowing progress in reducing losses by parasitism, maximizing production, and productivity. This study aimed at evaluating the predatory activity of fungal isolates of Duddingtonia flagrans and Clonostachys rosea species and its association on infective larvae (L3) of H. contortus in microplots formed by grasses and maintained in a protected environment. All groups were added with 10 mL of an aqueous suspension with 618 H. contortus L3 approximately. Group 1 was used as control and only received the infective larvae. Groups 2 and 3 received D. flagrans chlamydospores and C. rosea conidia at doses of 5 × 106. Group 4 received the combination of 5 × 106 D. flagrans chlamydospores + 5 × 106 C. rosea conidia. D. flagrans and C. rosea showed nematicidal effectiveness reducing by 91.5 and 88.9%, respectively, the population of H. contortus L3. However, when used in combination efficiency decreased to 74.5% predation of H. contortus L3. These results demonstrate the need for further studies to determine the existence of additive effects, synergistic or antagonistic, between these species. PMID:26504809

  14. Brugia malayi microfilariae transport alphaviruses across the mosquito midgut.

    PubMed

    Vaughan, Jefferson A; Turell, Michael J

    2017-01-01

    Concurrent ingestion of microfilariae (MF) and arboviruses by mosquitoes can enhance mosquito transmission of virus compared to when virus is ingested alone. Within hours of being ingested, MF penetrate the mosquito midgut and introduce virus into mosquito hemocoel, creating a disseminated viral infection much sooner than normal. How virus is actually introduced is not known. In this report, we present experimental evidence that suggests that certain alphaviruses may adhere or otherwise associate with sheathed Brugia malayi MF in the blood of a dually-infected host and that the virus is carried into the mosquito hemocoel by the MF during their penetration of the mosquito midgut. The mechanism of MF enhancement may be more complex than simple leakage of viremic blood into the hemocoel during MF penetration. The affinity of arboviruses to adhere to or otherwise associate with MF may depend on the specific combination of the virus and MF involved in a dual host infection. This in turn may determine the relative importance that MF enhancement has within an arbovirus transmission system.

  15. Brugia malayi microfilariae transport alphaviruses across the mosquito midgut

    PubMed Central

    Turell, Michael J.

    2017-01-01

    Concurrent ingestion of microfilariae (MF) and arboviruses by mosquitoes can enhance mosquito transmission of virus compared to when virus is ingested alone. Within hours of being ingested, MF penetrate the mosquito midgut and introduce virus into mosquito hemocoel, creating a disseminated viral infection much sooner than normal. How virus is actually introduced is not known. In this report, we present experimental evidence that suggests that certain alphaviruses may adhere or otherwise associate with sheathed Brugia malayi MF in the blood of a dually-infected host and that the virus is carried into the mosquito hemocoel by the MF during their penetration of the mosquito midgut. The mechanism of MF enhancement may be more complex than simple leakage of viremic blood into the hemocoel during MF penetration. The affinity of arboviruses to adhere to or otherwise associate with MF may depend on the specific combination of the virus and MF involved in a dual host infection. This in turn may determine the relative importance that MF enhancement has within an arbovirus transmission system. PMID:28222120

  16. Characterization of a 14,000 dalton antigen of Dirofilaria immitis infective third stage larvae

    SciTech Connect

    Fuller, S.A.; Cachia, P.J.; Wong, M.M.; Hurrell, J.G.R.

    1986-05-01

    Immunogenic proteins of Dirofilaria immitis (canine heartworm) were identified by probing extracts of adult worms or their excretory-secretory proteins (ESP) blotted to nitrocellulose following SDS-PAGE with control or infected dog sera. A 14,000 dalton antigen (a prominent component of ESP by protein staining) was consistently recognized both in extracts and ESP by dog sera as early as three months post infection. This indicates a larval origin for the antigen since no adult worms are present until approximately five months post infection. Monoclonal antibodies (MAbs) prepared against the 14,000 dalton antigen confirmed by immunoblotting that this antigen is expressed by infective third stage larvae, adults and microfilariae and is present intact in the sera of infected dogs. Surface-labelling of whole adult D. immitis with Na/sup 125/I produced radiolabelled antigens closely corresponding to those of ESP. An anti-14,000 dalton MAb was able to immunoprecipitate radiolabelled antigen which strongly suggest a surface or membrane location in the intact organism. Gel filtration data suggests that the protein is a native monomer. A MAb-affinity column has been used to purify the 14,000 dalton antigen to at least 98% homogeneity in one step from crude worm extracts. Further fractionation by HPLC yields a homogeneous preparation. Amino acid analysis and the N-terminal amino acid sequence data will be presented.

  17. High-level expression, purification and production of the fungal immunomodulatory protein-gts in baculovirus-infected insect larva.

    PubMed

    Wu, Tzong-Yuan; Chen, Hsin-An; Li, Feng-Yin; Lin, Ching-Ting; Wu, Chi-Ming; Hsieh, Feng-Chia; Tzen, Jason Tze-Cheng; Hsieh, Sheng-Kuo; Ko, Jiunn-Liang; Jinn, Tzyy-Rong

    2013-02-01

    Fip-gts, a fungal immunomodulatory protein (Fip) isolated from Ganoderma tsugae (gts), has been reported to possess therapeutic effects in the treatment of cancer and autoimmune disease. To cost-effectively produce Fip-gts and bypass the bottleneck involved in its time-consuming purification from G. tsugae, in this study, we incorporated the SP(bbx) secretion signal into recombinant baculovirus for expressing glycosylated and bioactive rFip-gts in baculovirus-infected insect cells and Trichoplusia ni larva. This is the first study to employ the aerosol infecting T. ni larva with recombinant baculovirus for economical and high-level production of foreign proteins. In this study, one purification could yield 10 mg of rFip-gts protein merely from ∼100 infected T. ni larvae by aerosol inoculation, corresponding to 5 L (5 × 10⁹ cells) of the infected Sf21 culture. In addition, the rFip-gts purified from T. ni larvae could induce the expression of interleukin-2 in murine splenocytes with an immunoresponsive level similar to that induced by LZ-8 (a known potent immunomodulatory protein purified from Ling zhi, Ganoderma lucidum). Thus, our results demonstrated that the larva-based baculovirus expression system can successfully express rFip-gts with the assembling capability required for maintaining immunomodulatory and anticancer activity. Our approach will open a new avenue for the production of rFip-gts and facilitate the immunoregulatory activity of rFip-gts available in the future.

  18. Survival of infective Ostertagia ostertagi larvae on pasture plots under different simulated grazing conditions.

    PubMed

    Fernández, S; Sarkunas, M; Roepstorff, A

    2001-04-19

    This study was carried out to examine the survival of infective Ostertagia ostertagi larvae (L(3)) on pasture under different simulated conditions of grazing, i.e. mixed grazing of cattle and nose-ringed sows, or grazing by cattle alone. Standardised pats of cattle faeces containing O. ostertagi eggs were deposited on three types of herbage plots, which were divided into zone 1: faecal pat; zone 2: a circle extending 25cm from the edge of the faecal pat; zone 3: a circle extending 25cm from the edge of zone 2. For "tall herbage" (TH) plots, the herbage in zone 2 was allowed to grow naturally, while the herbage in zone 3 was cut down to 5-7cm fortnightly, imitating a cattle-only pasture. For "short herbage" (SH) plots, the herbage in both zones 2 and 3 were cut down to 5-7cm fortnightly, imitating mixed grazing of cattle and sows. The grass in the "short herbage and scattered faeces" (SH/SF) plots were cut as for SH plots, and the faeces were broken down 3 weeks after deposition and scattered within zone 2, imitating the rooting behaviour of co-grazing sows. Five faecal pats from each plot group were collected on monthly basis, along with the herbage from zones 2 and 3 cut down to the ground. Infective larvae were then recovered from both faeces and herbage. The numbers of L(3) recovered from zone 1 were higher in the TH plots than in the other two groups and, furthermore, the larval counts from SH plots were always higher than from SH/SF plots. The three groups followed a similar pattern during the season regarding numbers of L(3) in zone 2, and no clear patterns between plot types were obtained. The presence of L(3) in zone 3 was almost negligible. Important differences were seen throughout the study from the biological point of view; more L(3) were able to survive in faeces on the TH plots, presumably reflecting a better protection from heat and desiccation compared to those in the other plots. The overall results support the idea that mixed grazing of cattle and

  19. Ascaridia galli in chickens: intestinal localization and comparison of methods to isolate the larvae within the first week of infection.

    PubMed

    Ferdushy, Tania; Nejsum, Peter; Roepstorff, Allan; Thamsborg, Stig M; Kyvsgaard, Niels C

    2012-12-01

    This study was conducted to observe the localization and to compare methods for isolation of minute Ascaridia galli larvae in chicken intestine. Firstly, six 7-week-old layer pullets were orally infected with 2,000 embryonated A. galli eggs and necropsied either at 3, 5 or 7 days post infection (dpi). More than 95 % of the recovered larvae were obtained from the anterior half of the jejunoileum, suggesting this part as the initial predilection site for A. galli larvae. Secondly, the intestinal wall of one layer pullet infected with 20,000 A. galli eggs 3 days earlier was digested in pepsin-HCl for 90 min. The initial 10 min of digestion released 51 % of the totally recovered larvae and the last 30 min of continuous digestion yielded only 5 %. This indicates that the majority of larvae were located superficially in the intestinal mucosa. Thirdly, 48 7-week-old layer pullets were infected with 500 A. galli eggs and necropsied at 3 dpi to compare three different larval isolation methods from the intestinal wall, viz., EDTA incubation, agar-gel incubation and pepsin-HCl digestion, resulting in mean percentages of the recovered larvae: 14.4, 18.2 and 20.0 %, respectively (P = 0.15). As conclusion, we recommended Pepsin-HCl digestion as the method of choice for larval recovery from the intestinal wall in future population dynamics study due to high efficiency and quick and simple detection. The agar-gel method was considered to be a prerequisite for molecular and immunological investigations as the larvae were more active and fully intact.

  20. In-situ Hybridization for the Detection of Sacbrood Virus in Infected Larvae of the Honey Bee (Apis cerana).

    PubMed

    Park, C; Kang, H S; Jeong, J; Kang, I; Choi, K; Yoo, M-S; Kim, Y-H; Kang, S-W; Lim, H-Y; Yoon, B-S; Chae, C

    2016-01-01

    The aim of this study was to develop and use in-situ hybridization (ISH) for the detection and localization of the sacbrood virus (SBV) in Korean honey bee (Apis cerana) larvae that were infected naturally with SBV. A 258 base pair cDNA probe for SBV was generated by polymerase chain reaction. Cells positive for viral genome typically showed a dark brown reaction in the cytoplasm. SBV was detected consistently in trophocytes and urocytes. The ISH was successfully applied to routinely fixed and processed tissues and thus should prove helpful in the diagnosis and characterization of viral distribution in infected larvae.

  1. Anisakis simplex larvae: infection status in marine fish and cephalopods purchased from the Cooperative Fish Market in Busan, Korea.

    PubMed

    Choi, Seon Hee; Kim, Jung; Jo, Jin Ok; Cho, Min Kyung; Yu, Hak Sun; Cha, Hee Jae; Ock, Mee Sun

    2011-03-01

    The infection status of marine fish and cephalopods with Anisakis simplex third stage larva (L3) was studied over a period of 1 year. A total of 2,537 specimens, which consisted of 40 species of fish and 3 species of cephalopods, were purchased from the Cooperative Fish Market in Busan, Korea, from August 2006 to July 2007. They were examined for A. simplex L3 from the whole body cavity, viscera, and muscles. A. simplex L3 were confirmed by light microscopy. The overall infection rate reached 34.3%, and average 17.1 larvae were parasitized per infected fish. Fish that recorded the highest infection rate was Lophiomus setigerus (100%), followed by Liparis tessellates (90%), Pleurogrammus azonus (90%), and Scomber japonicus (88.7%). The intensity of infection was the highest in Gadus macrocephalus (117.7 larvae per fish), followed by S. japonicus (103.9 larvae) and L. setigerus (54.2 larvae). Although abundance of A. simplex L3 was not seasonal in most of the fish species, 10 of the 16 selected species showed the highest abundance in February and April. A positive correlation between the intensity of L3 infection and the fish length was obvious in S. japonicus and G. macrocephalus. It was likely that A. simplex L3 are more frequently infected during the spring season in some species of fish. Our study revealed that eating raw or undercooked fish or cephalopods could still be a source of human infection with A. simplex L3 in Korea.

  2. Establishment of multi-site infection model in zebrafish larvae for studying Staphylococcus aureus infectious disease.

    PubMed

    Li, Ya-juan; Hu, Bing

    2012-09-20

    Zebrafish (Danio rerio) is an ideal model for studying the mechanism of infectious disease and the interaction between host and pathogen. As a teleost, zebrafish has developed a complete immune system which is similar to mammals. Moreover, the easy acquirement of large amounts of transparent embryos makes it a good candidate for gene manipulation and drug screening. In a zebrafish infection model, all of the site, timing, and dose of the bacteria microinjection into the embryo are important factors that determine the bacterial infection of host. Here, we established a multi-site infection model in zebrafish larvae of 36 hours post-fertilization (hpf) by microinjecting wild-type or GFP-expressing Staphylococcus aereus (S. aureus) with gradient burdens into different embryo sites including the pericardial cavity (PC), eye, the fourth hindbrain ventricle (4V), yolk circulation valley (YCV), caudal vein (CV), yolk body (YB), and Duct of Cuvier (DC) to resemble human infectious disease. With the combination of GFP-expressing S. aureus and transgenic zebrafish Tg (coro1a: eGFP; lyz: Dsred) and Tg (lyz: Dsred) lines whose macrophages or neutrophils are fluorescent labeled, we observed the dynamic process of bacterial infection by in vivo multicolored confocal fluorescence imaging. Analyses of zebrafish embryo survival, bacterial proliferation and myeloid cells phagocytosis show that the site- and dose-dependent differences exist in infection of different bacterial entry routes. This work provides a consideration for the future study of pathogenesis and host resistance through selection of multi-site infection model. More interaction mechanisms between pathogenic bacteria virulence factors and the immune responses of zebrafish could be determined through zebrafish multi-site infection model.

  3. Mortality of Cutworm Larvae Is Not Enhanced by Agrotis segetum Granulovirus and Agrotis segetum Nucleopolyhedrovirus B Coinfection Relative to Single Infection by Either Virus

    PubMed Central

    Wennmann, Jörg T.; Köhler, Tim; Gueli Alletti, Gianpiero

    2015-01-01

    Mixed infections of insect larvae with different baculoviruses are occasionally found. They are of interest from an evolutionary as well as from a practical point of view when baculoviruses are applied as biocontrol agents. Here, we report mixed-infection studies of neonate larvae of the common cutworm, Agrotis segetum, with two baculoviruses, Agrotis segetum nucleopolyhedrovirus B (AgseNPV-B) and Agrotis segetum granulovirus (AgseGV). By applying quantitative PCR (qPCR) analysis, coinfections of individual larvae were demonstrated, and occlusion body (OB) production within singly infected and coinfected larvae was determined in individual larvae. Mixtures of viruses did not lead to changes in mortality rates compared with rates of single-virus treatments, indicating an independent action within host larvae under our experimental conditions. AgseNPV-B-infected larvae showed an increase in OB production during 2 weeks of infection, whereas the number of AgseGV OBs did not change from the first week to the second week. Fewer OBs of both viruses were produced in coinfections than in singly infected larvae, suggesting a competition of the two viruses for larval resources. Hence, no functional or economic advantage could be inferred from larval mortality and OB production from mixed infections of A. segetum larvae with AgseNPV-B and AgseGV. PMID:25681187

  4. Transdifferentiation and Proliferation in Two Distinct Hemocyte Lineages in Drosophila melanogaster Larvae after Wasp Infection

    PubMed Central

    Ihalainen, Teemu O.; Vanha-aho, Leena-Maija; Andó, István; Rämet, Mika

    2016-01-01

    Cellular immune responses require the generation and recruitment of diverse blood cell types that recognize and kill pathogens. In Drosophila melanogaster larvae, immune-inducible lamellocytes participate in recognizing and killing parasitoid wasp eggs. However, the sequence of events required for lamellocyte generation remains controversial. To study the cellular immune system, we developed a flow cytometry approach using in vivo reporters for lamellocytes as well as for plasmatocytes, the main hemocyte type in healthy larvae. We found that two different blood cell lineages, the plasmatocyte and lamellocyte lineages, contribute to the generation of lamellocytes in a demand-adapted hematopoietic process. Plasmatocytes transdifferentiate into lamellocyte-like cells in situ directly on the wasp egg. In parallel, a novel population of infection-induced cells, which we named lamelloblasts, appears in the circulation. Lamelloblasts proliferate vigorously and develop into the major class of circulating lamellocytes. Our data indicate that lamellocyte differentiation upon wasp parasitism is a plastic and dynamic process. Flow cytometry with in vivo hemocyte reporters can be used to study this phenomenon in detail. PMID:27414410

  5. Neurotropic mesomycetozoean-like infection in larvae of the southern toad Anaxyrus terrestris in Florida, USA.

    PubMed

    Kiryu, Yasunari; Landsberg, Jan H

    2015-03-09

    As part of a state-wide multispecies survey of amphibian diseases, sampling was conducted at Archbold Biological Station, Venus, Florida, USA, on 15 April 2011. Gross examination of southern toad (Anaxyrus terrestris) larvae was unremarkable, but infections by a mesomycetozoean-like organism were observed in longitudinally sectioned routine haematoxylin and eosin-stained histologic slides. In 100% of the sectioned specimens examined (n = 5), a high density of the organism, representing several developmental stages, was found in the central nervous system, mainly in the spinal cord, brain, retina and optic nerve. No host inflammatory responses were found to be associated with the parasitic infection. Free, mature schizonts were occasionally found in the gill chamber and, more commonly, in the dorsal roof area. No organisms were found in other organs examined histologically, i.e. liver, kidney, heart, alimentary tract, exocrine pancreas and skeletal muscles. Presumptive mesomycetozoean ichthyophonids in anurans are usually reported to be pathogenic, especially affecting skeletal muscle tissue and causing death. To our knowledge, this is the first report of a similar organism infecting primarily the central nervous system in an amphibian.

  6. A Deep Sequencing Approach to Comparatively Analyze the Transcriptome of Lifecycle Stages of the Filarial Worm, Brugia malayi

    PubMed Central

    Choi, Young-Jun; Ghedin, Elodie; Berriman, Matthew; McQuillan, Jacqueline; Holroyd, Nancy; Mayhew, George F.; Christensen, Bruce M.; Michalski, Michelle L.

    2011-01-01

    Background Developing intervention strategies for the control of parasitic nematodes continues to be a significant challenge. Genomic and post-genomic approaches play an increasingly important role for providing fundamental molecular information about these parasites, thus enhancing basic as well as translational research. Here we report a comprehensive genome-wide survey of the developmental transcriptome of the human filarial parasite Brugia malayi. Methodology/Principal Findings Using deep sequencing, we profiled the transcriptome of eggs and embryos, immature (≤3 days of age) and mature microfilariae (MF), third- and fourth-stage larvae (L3 and L4), and adult male and female worms. Comparative analysis across these stages provided a detailed overview of the molecular repertoires that define and differentiate distinct lifecycle stages of the parasite. Genome-wide assessment of the overall transcriptional variability indicated that the cuticle collagen family and those implicated in molting exhibit noticeably dynamic stage-dependent patterns. Of particular interest was the identification of genes displaying sex-biased or germline-enriched profiles due to their potential involvement in reproductive processes. The study also revealed discrete transcriptional changes during larval development, namely those accompanying the maturation of MF and the L3 to L4 transition that are vital in establishing successful infection in mosquito vectors and vertebrate hosts, respectively. Conclusions/Significance Characterization of the transcriptional program of the parasite's lifecycle is an important step toward understanding the developmental processes required for the infectious cycle. We find that the transcriptional program has a number of stage-specific pathways activated during worm development. In addition to advancing our understanding of transcriptome dynamics, these data will aid in the study of genome structure and organization by facilitating the identification of

  7. Kinetics of capture and infection of infective larvae of trichostrongylides and free-living nematodes Panagrellus sp. by Duddingtonia flagrans.

    PubMed

    da Cruz, Daniela Guedes; Araújo, Flávia Biasoli; Molento, Marcelo Beltrão; Damatta, Renato Augusto; de Paula Santos, Clóvis

    2011-10-01

    Duddingtonia flagrans, a nematode-trapping fungus, has been investigated as an agent for biological control against infective larvae of gastrointestinal nematode parasites of production animals. The initial process of nematode-trapping fungi infection is based on an interaction between the trap structure of the fungus and the surface of the nematode cuticle. This report investigates by light and scanning electron microscopy the kinetics of capture and infection during the interaction of D. flagrans with the infective larvae (L(3)) of trichostrongylides and the free-living nematode Panagrellus sp. D. flagrans was cultivated for 7 days in a Petri dish containing agar-water. L(3) and Panagrellus sp. were inoculated in the Petri dishes and the samples consisting of agar-L(3)-fungi and agar-Panagrellus sp.-fungi were collected after 10, 20, 30, 40, 50, 60, and 70 min and 3, 4, 5, 10, 15, 20, and 25 h of interaction. All samples were observed by light microscopy. The samples with 1, 5, 15, and 25 h of interaction were also analyzed by scanning electron microscopy. The interaction was monitored up to 25 h. An initial differentiation of predation structures was observed after 30 min of interaction. The presence of traps and of captured L(3) or Panagrellus sp. occurred after 70 min. The live captured nematodes were observed up to 3 h of interaction. However, after 4 h, all Panagrellus sp. were dead. It took 15 h of interaction for the fungus to invade the L(3), and the presence of hyphae inside the nematode near the region of penetration was evident. At this time, the hyphae had filled the whole body of Panagrellus sp. The complete occupation of the body of L(3) occurred at 20 h of interaction and with 25 h the nematode was completely damaged except for the cuticle. Although the double cuticle of L(3) slows the penetration of D. flagrans, it was possible to verify that the process of trap formation and capture occurs quickly when both nematodes were tested, suggesting that

  8. Human Leukocytes Kill Brugia malayi Microfilariae Independently of DNA-Based Extracellular Trap Release

    PubMed Central

    McCoy, Ciaran J.; Reaves, Barbara J.; Giguère, Steeve; Coates, Ruby; Rada, Balázs

    2017-01-01

    Background Wuchereria bancrofti, Brugia malayi and Brugia timori infect over 100 million people worldwide and are the causative agents of lymphatic filariasis. Some parasite carriers are amicrofilaremic whilst others facilitate mosquito-based disease transmission through blood-circulating microfilariae (Mf). Recent findings, obtained largely from animal model systems, suggest that polymorphonuclear leukocytes (PMNs) contribute to parasitic nematode-directed type 2 immune responses. When exposed to certain pathogens PMNs release extracellular traps (NETs) in the form of chromatin loaded with various antimicrobial molecules and proteases. Principal findings In vitro, PMNs expel large amounts of NETs that capture but do not kill B. malayi Mf. NET morphology was confirmed by fluorescence imaging of worm-NET aggregates labelled with DAPI and antibodies to human neutrophil elastase, myeloperoxidase and citrullinated histone H4. A fluorescent, extracellular DNA release assay was used to quantify and observe Mf induced NETosis over time. Blinded video analyses of PMN-to-worm attachment and worm survival during Mf-leukocyte co-culture demonstrated that DNase treatment eliminates PMN attachment in the absence of serum, autologous serum bolsters both PMN attachment and PMN plus peripheral blood mononuclear cell (PBMC) mediated Mf killing, and serum heat inactivation inhibits both PMN attachment and Mf killing. Despite the effects of heat inactivation, the complement inhibitor compstatin did not impede Mf killing and had little effect on PMN attachment. Both human PMNs and monocytes, but not lymphocytes, are able to kill B. malayi Mf in vitro and NETosis does not significantly contribute to this killing. Leukocytes derived from presumably parasite-naïve U.S. resident donors vary in their ability to kill Mf in vitro, which may reflect the pathological heterogeneity associated with filarial parasitic infections. Conclusions/Significance Human innate immune cells are able to

  9. Radiation inactivation of Paenibacillus larvae and sterilization of American Foul Brood (AFB) infected hives using Co-60 gamma rays.

    PubMed

    De Guzman, Zenaida M; Cervancia, Cleofas R; Dimasuay, Kris Genelyn B; Tolentino, Mitos M; Abrera, Gina B; Cobar, Ma Lucia C; Fajardo, Alejandro C; Sabino, Noel G; Manila-Fajardo, Analinda C; Feliciano, Chitho P

    2011-10-01

    The effectiveness of gamma radiation in inactivating the Philippine isolate of Paenibacillus larvae was investigated. Spores of P. larvae were irradiated at incremental doses (0.1, 0.2, 0.4, 0.8 and 1.6 kGy) of gamma radiation emitted by a ⁶⁰Co source. Surviving spores were counted and used to estimate the decimal reduction (D₁₀) value. A dose of 0.2 kGy was sufficient to inactivate 90% of the total recoverable spores from an initial count of 10⁵- 9 × 10³ spores per glass plate. The sterilizing effect of high doses of gamma radiation on the spores of P. larvae in infected hives was determined. In this study, a minimum dose (D(min)) of 15 kGy was tested. Beehives with sub-clinical infections of AFB were irradiated and examined for sterility. All the materials were found to be free of P. larvae indicating its susceptibility to γ-rays. After irradiation, there were no visible changes in the physical appearance of the hives' body, wax and frames. Thus, a dose of 15 kGy is effective enough for sterilization of AFB-infected materials.

  10. Control of infective larvae of gastrointestinal nematodes in heifers using different isolates of nematophagous fungi.

    PubMed

    Silva, Manoel Eduardo da; Araújo, Jackson Victor de; Braga, Fabio Ribeiro; Freitas Soares, Filippe Elias de; Rodrigues, Daniel Sobreira

    2013-01-01

    The effect of different nematophagous fungi [Duddingtonia flagrans (AC001 and CG722) and Monacrosporium thaumasium (NF34)] with regard to controlling infective larvae (L3) of nematodes after gastrointestinal transit in female cattle (3/4 Holstein × Zebu) was evaluated. A total of 24 pubescent female cattle were used, weighing approximately 320 kg each one. There were three treatment groups, each contained six animals that received 150 g of pellets (0.2 g of mycelium), orally in a single dose, in a sodium alginate matrix containing mycelial mass of the fungus D. flagrans (AC001 or CG722) or M. thaumasium (NF34); and one control group (without fungi). Fecal samples were collected from the animals at intervals of 12, 15, 18, 21, 24, 48, and 72 hours. At the end of 17 days, the L3 not subjected to predation were recovered by means of the Baermann method. The fungal isolates tested were capable of destroying the L3 after gastrointestinal transit. It was observed that within 72 hours, the isolates AC001, CG722, and NF34 showed a higher predatory activity (81.2%, 97.3%, and 98.3%, respectively). The results justify the need for studies in the field, and over longer intervals, in order to observe the efficiency of the fungus D. flagrans, or even M. thaumasium, for environmental control over nematodes in naturally infected cattle.

  11. Bacterial Infection and Immune Responses in Lutzomyia longipalpis Sand Fly Larvae Midgut

    PubMed Central

    Heerman, Matthew; Weng, Ju-Lin; Hurwitz, Ivy; Durvasula, Ravi; Ramalho-Ortigao, Marcelo

    2015-01-01

    The midgut microbial community in insect vectors of disease is crucial for an effective immune response against infection with various human and animal pathogens. Depending on the aspects of their development, insects can acquire microbes present in soil, water, and plants. Sand flies are major vectors of leishmaniasis, and shown to harbor a wide variety of Gram-negative and Gram-positive bacteria. Sand fly larval stages acquire microorganisms from the soil, and the abundance and distribution of these microorganisms may vary depending on the sand fly species or the breeding site. Here, we assess the distribution of two bacteria commonly found within the gut of sand flies, Pantoea agglomerans and Bacillus subtilis. We demonstrate that these bacteria are able to differentially infect the larval digestive tract, and regulate the immune response in sand fly larvae. Moreover, bacterial distribution, and likely the ability to colonize the gut, is driven, at least in part, by a gradient of pH present in the gut. PMID:26154607

  12. [Larva migrans].

    PubMed

    Chabasse, D; Le Clec'h, C; de Gentile, L; Verret, J L

    1995-01-01

    Larbish, cutaneous larva migrans or creeping eruption, is a serpiginous cutaneous eruption caused by skin penetration of infective larva from various animal nematodes. Hookworms (Ancylostoma brasiliense, A. caninum) are the most common causative parasites. They live in the intestines of dogs and cats where their ova are deposited in the animal feces. In sandy and shady soil, when temperature and moisture are elevated, the ova hatch and mature into infective larva. Infection occurs when humans have contact with the infected soil. Infective larva penetrate the exposed skin of the body, commonly around the feet, hands and buttocks. In humans, the larva are not able to complete their natural cycle and remain trapped in the upper dermis of the skin. The disease is widespread in tropical or subtropical regions, especially along the coast on sandy beaches. The diagnosis is easy for the patient who is returning from a tropical or subtropical climate and gives a history of beach exposure. The characteristic skin lesion is a fissure or erythematous cord which is displaced a few millimeters each day in a serpiginous track. Scabies, the larva currens syndrome due to Strongyloides stercoralis, must be distinguished from other creeping eruptions and subcutaneous swelling lesions caused by other nematodes or myiasis. Medical treatments are justified because it shortens the duration of the natural evolution of the disease. Topical tiabendazole is safe for localized invasions, but prolonged treatment may be necessary. Oral thiabendazole treatment for three days is effective, but sometimes is associated with adverse effects. Trials using albendazole for one or four consecutive days appear more efficacious. More recent trials using ivermectine showed that a single oral dose can cure 100% of the patients; thus, this drug looks very promising as a new form of therapy. Individual prophylaxis consists of avoiding skin contact with soil which has been contaminated with dog or cat feces

  13. Tissue and Stage-Specific Distribution of Wolbachia in Brugia malayi

    PubMed Central

    Fischer, Kerstin; Beatty, Wandy L.; Jiang, Daojun; Weil, Gary J.; Fischer, Peter U.

    2011-01-01

    Background Most filarial parasite species contain Wolbachia, obligatory bacterial endosymbionts that are crucial for filarial development and reproduction. They are targets for alternative chemotherapy, but their role in the biology of filarial nematodes is not well understood. Light microscopy provides important information on morphology, localization and potential function of these bacteria. Surprisingly, immunohistology and in situ hybridization techniques have not been widely used to monitor Wolbachia distribution during the filarial life cycle. Methods/Principal Findings A monoclonal antibody directed against Wolbachia surface protein and in situ hybridization targeting Wolbachia 16S rRNA were used to monitor Wolbachia during the life cycle of B. malayi. In microfilariae and vector stage larvae only a few cells contain Wolbachia. In contrast, large numbers of Wolbachia were detected in the lateral chords of L4 larvae, but no endobacteria were detected in the genital primordium. In young adult worms (5 weeks p.i.), a massive expansion of Wolbachia was observed in the lateral chords adjacent to ovaries or testis, but no endobacteria were detected in the growth zone of the ovaries, uterus, the growth zone of the testis or the vas deferens. Confocal laser scanning and transmission electron microscopy showed that numerous Wolbachia are aligned towards the developing ovaries and single endobacteria were detected in the germline. In inseminated females (8 weeks p.i.) Wolbachia were observed in the ovaries, embryos and in decreasing numbers in the lateral chords. In young males Wolbachia were found in distinct zones of the testis and in large numbers in the lateral chords in the vicinity of testicular tissue but never in mature spermatids or spermatozoa. Conclusions Immunohistology and in situ hybridization show distinct tissue and stage specific distribution patterns for Wolbachia in B. malayi. Extensive multiplication of Wolbachia occurs in the lateral chords of L4

  14. Effect of plant trichomes on the vertical migration of Haemonchus contortus infective larvae on five tropical forages.

    PubMed

    Oliveira, Aruaque L F; Costa, Ciniro; Rodella, Roberto A; Silva, Bruna F; Amarante, Alessandro F T

    2009-06-01

    The influence of trichomes on vertical migration and survival of Haemonchus contortus infective larvae (L3) on different forages was investigated. Four different forages showing different distributions of trichomes (Brachiaria brizantha cv. Marandu, Brachiaria brizantha cv. Xaraes, Andropogon gayanus, and Stylosanthes spp.), and one forage species without trichomes (Panicum maximum cv. Tanzania), were used. Forages cut at the post-grazing height were contaminated with faeces containing L3. Samples of different grass strata (0-10, 10-20, >20 cm) and faeces were collected for L3 quantification once per week over four weeks. In all forages studied, the highest L3 recovery occurred seven days after contamination, with the lowest recovery on A. gayanus. In general, larvae were found on all forages' strata. However, most of the larvae were at the lower stratum. There was no influence of trichomes on migration and survival of H. contortus L3 on the forages.

  15. Metarhizium pingshaense applied as a seed treatment induces fungal infection in larvae of the white grub Anomala cincta.

    PubMed

    Peña-Peña, A J; Santillán-Galicia, M T; Hernández-López, J; Guzmán-Franco, A W

    2015-09-01

    Metarhizium pingshaense has potential as a control agent of the white grub Anomala cincta. We compared its ability to cause infection when applied as a seed treatment or directly to the compost around the plant roots. Although the greatest infection (93%) occured in the direct inoculation treatment, 50% of larvae still became infected by M. pingshaense applied as a seed treatment. The fungus persisted in the compost and also colonised the roots of the developing maize plants endophytically. More research is required but seed treatments with M. pingshaense have potential as cost-effective control options for A. cincta.

  16. Chitinase is stored and secreted from the inner body of microfilariae and has a role in exsheathment in the parasitic nematode Brugia malayi

    PubMed Central

    Wu, Yang; Preston, Gillian; Bianco, Albert E.

    2008-01-01

    Chitinase expression in microfilariae of the parasitic nematode Brugia malayi (B. malayi, Bm) is coincidental with the onset of their infectivity to mosquitoes. An antibody raised to Onchocerca volvulus (O. volvulus, Ov) infective-stage larval chitinase (Ov-CHI-1) was specifically reactive against B. malayi microfilarial chitinase and was used to study the localization of chitinase in B. malayi during microfilarial development and transmission to the insect vector. Immuno-electron microscopy (IEM) was used to demonstrate that the chitinase was confined to the inner body of the microfilariae and furthermore that chitinase was only present in sheathed microfilarial species, although the inner body is present in all species. Observation using the IEM implicates two distinct routes of chitinase secretion from the inner body, via either the pharyngeal thread, or during transmission of the microfilariae to the vector, contained in vesicle-like structures. Many morphological studies have described the structure of the inner body, but no function has been assigned to it as of yet. Although it has been commented that the cells surrounding the inner body and pharyngeal thread are those destined to become the intestine and pharynx and that the inner body represents a store of material. Our studies suggest that chitinase is one such product stored in the inner body and that it is secreted during the exsheathment of the microfilaria in the mosquito. PMID:18611418

  17. Live Brugia malayi microfilariae inhibit transendothelial migration of neutrophils and monocytes.

    PubMed

    Schroeder, Jan-Hendrik; Simbi, Bigboy H; Ford, Louise; Cole, Sara R; Taylor, Mark J; Lawson, Charlotte; Lawrence, Rachel A

    2012-01-01

    Lymphatic filariasis is a major tropical disease caused by the parasite Brugia malayi. Microfilariae (Mf) circulate in the peripheral blood for 2-3 hours in synchronisation with maximal feeding of the mosquito vector. When absent from the peripheral blood, Mf sequester in the capillaries of the lungs. Mf are therefore in close contact with vascular endothelial cells (EC) and may induce EC immune function and/or wound repair mechanisms such as angiogenesis. In this study, Mf were co-cultured with human umbilical vein EC (HUVEC) or human lung microvascular EC (HLMVEC) and the transendothelial migration of leukocyte subsets was analysed. In addition, the protein and/or mRNA expression of chemokine, cytokine and angiogenic mediators in endothelial cells in the presence of live microfilariae were measured by a combination of cDNA arrays, protein arrays, ELISA and fluorescence antibody tests.Surprisingly, our findings indicate that Mf presence partially blocked transendothelial migration of monocytes and neutrophils, but not lymphocytes. However, Mf exposure did not result in altered vascular EC expression of key mediators of the tethering stage of extravasation, such as ICAM-1, VCAM-1 and various chemokines. To further analyse the immunological function of vascular EC in the presence of Mf, we measured the mRNA and/or protein expression of a number of pro-inflammatory mediators. We found that expression levels of the mediators tested were predominantly unaltered upon B. malayi Mf exposure. In addition, a comparison of angiogenic mediators induced by intact Mf and Wolbachia-depleted Mf revealed that even intact Mf induce the expression of remarkably few angiogenic mediators in vascular EC. Our study suggests that live microfilariae are remarkably inert in their induction and/or activation of vascular cells in their immediate local environment. Overall, this work presents important insights into the immunological function of the vascular endothelium during an infection

  18. Comparison of artificial digestion and Baermann's methods for detection of Trichinella spiralis pre-encapsulated larvae in muscles with low-level infections.

    PubMed

    Jiang, Peng; Wang, Zhong-Quan; Cui, Jing; Zhang, Xi

    2012-01-01

    Artificial digestion method is widely used for the detection of Trichinella larvae (mainly the mature larvae, e.g., encapsulated larvae in encapsulated Trichinella) in meat. The previous studies demonstrated that Trichinella spiralis pre-encapsulated larvae (PEL) at 14-18 days postinfection (dpi) had the infectivity to new hosts. However, to our knowledge, there is no report on the detection methods of PEL in meat. The purpose of this study was to compare the efficiency of artificial digestion and Baermann's methods for detection of T. spiralis PEL in meat, and to test the factors affecting the sensitivity of the two methods. Forty-five male Kunming mice were randomly divided into 3 groups (15 mice per group), and each group of mice was orally inoculated with 20, 10, or 5 muscle larvae of T. spiralis, respectively. All infected mice were slaughtered at 18 dpi, and the muscles were minced. The digestion method that was recommended by International Commission on Trichinellosis and Baermann's method were used to detect the PEL in the infected mice. The detection rate of PEL in both mice infected with 20 muscle larvae by digestion and Baermann's method was 100% (15/15); the detection rates of PEL in mice infected with 10 larvae by the two methods just mentioned were 93.33% (14/15) and 100% (15/15), respectively; when the mice infected with 5 larvae were tested, the different detection rate of PEL was achieved by using digestion method (63.33%) and Baermann's method (100%). Additionally, the number of PEL collected from the mice infected with 20, 10, or 5 larvae by Baermann's method was greater than that by digestion methods. The mortality of PEL increased along with the prolongation of digestion duration, because the PEL were not resistant to enzymatic digestion. The results revealed that the Baermann's method is superior to the digestion methods for detection of T. spiralis PEL in muscle samples with low-level infections.

  19. EVALUATION OF THE THERAPEUTIC EFFICACY OF LEVAMISOLE HYDROCHLORIDE ON THIRD-STAGE LARVAE OF Lagochilascaris minor IN EXPERIMENTALLY INFECTED MICE

    PubMed Central

    CAMPOS, Dulcinéa Maria Barbosa; BARBOSA, Alverne Passos; OLIVEIRA, Jayrson Araújo; BARBOSA, Carlos Augusto Lopes; LOBO, Tamara Flavia Correa; SILVA, Luana Gabriella; THOMAZ, Douglas Vieira; PEIXOTO, Josana de Castro

    2016-01-01

    Lagochilascariosis, a disease caused by Lagochilascaris minor, affects the neck, sinuses, tonsils, lungs, the sacral region, dental alveoli, eyeballs and the central nervous system of humans. A cycle of autoinfection may occur in human host tissues characterized by the presence of eggs, larvae and adult worms. This peculiarity of the cycle hinders therapy, since there are no drugs that exhibit ovicidal, larvicidal and vermicidal activity. Given these facts, we studied the action of levamisole hydrochloride on third-stage larvae in the migration phase (G1) and on encysted larvae (G3) of L. minor. To this end, 87 inbred mice of the C57BL/6 strain were divided into test groups comprising 67 animals (G1-37; G3-30) and a control group (G2-10; G4-10) with 20 animals. Each animal was inoculated orally with 2,000 infective eggs of the parasite. The animals of the test groups were treated individually with a single oral dose of levamisole hydrochloride at a concentration of 0.075 mg. The drug was administered either 30 minutes prior to the parasite inoculation (G1 animals) or 120 days after the inoculation (G3 animals). The mice in the control groups were not treated with the drug. After the time required for the migration and the encysting of L. minor larvae, all the animals were euthanized and their tissues examined. The data were analyzed using the Student's unpaired t-test and the Levene test. The groups showed no statistically significant difference. Levamisole hydrochloride was ineffective on third-stage larvae of L. minor. These findings explain the massive expulsion of live adult worms, as well as the use of long treatment schemes, owing to the persistence of larvae and eggs in human parasitic lesions. PMID:27253745

  20. Efficient, low-cost protein factories: expression of human adenosine deaminase in baculovirus-infected insect larvae.

    PubMed Central

    Medin, J A; Hunt, L; Gathy, K; Evans, R K; Coleman, M S

    1990-01-01

    Human adenosine deaminase (EC 3.5.4.4), a key purine salvage enzyme essential for immune competence, has been overproduced in Spodoptera frugiperda cells and in Trichoplusia ni (cabbage looper) larvae infected with recombinant baculovirus. The coding sequence of human adenosine deaminase was recombined into a baculovirus immediately downstream from the strong polyhedrin gene promoter. Approximately 60 hr after infection of insect cells with the recombinant virus, maximal levels of intracellular adenosine deaminase mRNA, protein, and enzymatic activity were detected. The recombinant human adenosine deaminase represented 10% of the total cellular protein and exhibited a specific activity of 70 units/mg of protein in crude homogenate. This specific activity is 70-350 times greater than that exhibited by the enzyme in homogenates of the two most abundant natural sources of human adenosine deaminase, thymus and leukemic cells. When the recombinant virus was injected into insect larvae, the maximum recombinant enzyme was produced 4 days postinfection and represented about 2% of the total insect protein with a specific activity of 10-25 units/mg of protein. The recombinant human adenosine deaminase was purified to homogeneity from both insect cells and larvae and demonstrated to be identical to native adenosine deaminase purified from human cells with respect to molecular weight, interaction with polyclonal anti-adenosine deaminase antibody, and enzymatic properties. A pilot purification yielded 8-9 mg of homogeneous enzyme from 22 larvae. The production of large quantities of recombinant human adenosine deaminase in insect larvae is inexpensive and rapid and eliminates the need for specialized facilities for tissue culture. This method should be applicable to large-scale production of many recombinant proteins. Images PMID:2181448

  1. Proteolytic activity of extracellular products from Arthrobotrys musiformis and their effect in vitro against Haemonchus contortus infective larvae

    PubMed Central

    Acevedo-Ramírez, Perla María del Carmen; Figueroa-Castillo, Juan Antonio; Ulloa-Arvizú, Raúl; Martínez-García, Luz Gisela; Guevara-Flores, Alberto; Rendón, Juan Luis; Valero-Coss, Rosa Ofelia; Mendoza-de Gives, Pedro; Quiroz-Romero, Héctor

    2015-01-01

    Arthrobotrys musiformis is a nematophagous fungus with potential for the biological control of Haemonchus contortus larvae. This study aimed to identify and demonstrate the proteolytic activity of extracellular products from A musiformis cultured in a liquid medium against H contortus infective larvae. A musiformis was cultured on a solid medium and further grown in a liquid medium, which was then processed through ion exchange and hydrophobic interaction chromatography. The proteolytic activity of the purified fraction was assayed with either gelatin or bovine serum albumin as substrate. Optimum proteolytic activity was observed at pH 8 and a temperature of 37°C. Results obtained with specific inhibitors suggest the enzyme belongs to the serine-dependent protease family. The purified fraction concentrate from A musiformis was tested against H contortus infective larvae. A time-dependent effect was observed with 77 per cent immobility after 48 hours incubation, with alteration of the sheath. It is concluded that A musiformis is a potential candidate for biological control because of its resistant structures and also because of its excretion of extracellular products such as proteases. The present study contributes to the identification of one of the in vitro mechanisms of action of Amusiformis, namely the extracellular production of proteases against H contortus infective larvae. More investigations should be undertaken into how these products could be used to decrease the nematode population in sheep flocks under field conditions, thereby improving animal health while simultaneously diminishing the human and environmental impact of chemical-based drugs. PMID:26392902

  2. Description, microhabitat selection and infection patterns of sealworm larvae (Pseudoterranova decipiens species complex, nematoda: ascaridoidea) in fishes from Patagonia, Argentina

    PubMed Central

    2013-01-01

    Background Third-stage larvae of the Pseudoterranova decipiens species complex (also known as sealworms) have been reported in at least 40 marine fish species belonging to 21 families and 10 orders along the South American coast. Sealworms are a cause for concern because they can infect humans who consume raw or undercooked fish. However, despite their economic and zoonotic importance, morphological and molecular characterization of species of Pseudoterranova in South America is still scarce. Methods A total of 542 individual fish from 20 species from the Patagonian coast of Argentina were examined for sealworms. The body cavity, the muscles, internal organs, and the mesenteries were examined to detect nematodes. Sealworm larvae were removed from their capsules and fixed in 70% ethanol. For molecular identification, partial fragments of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) were amplified for 10 isolates from 4 fish species. Morphological and morphometric data of sealworms were also obtained. Results A total of 635 larvae were collected from 12 fish species. The most infected fish was Prionotus nudigula, followed by Percophis brasiliensis, Acanthistius patachonicus, Paralichthys isosceles, and Pseudopercis semifasciata. Sequences obtained for the cox1 of sealworms from A. patachonicus, P. isosceles, P. brasiliensis and P. nudigula formed a reciprocally monophyletic lineage with published sequences of adult specimens of Pseudoterranova cattani from the South American sea lion Otaria flavescens, and distinct from the remaining 5 species of Pseudoterranova. A morphological description, including drawings and scanning electron microscopy photomicrographs of these larvae is provided. Sealworms collected from Argentinean fishes did not differ in their diagnostic traits from the previously described larvae of P. cattani. However a discriminant analysis suggests that specimens from P. nudigula were significantly larger than those from other fishes

  3. Larva migrans syndrome caused by Toxocara and Ascaris roundworm infections in Japanese patients.

    PubMed

    Yoshida, A; Hombu, A; Wang, Z; Maruyama, H

    2016-09-01

    Larva migrans syndrome (LMS) caused by Toxocara and Ascaris roundworms is generally believed to be more common in children, while a report from Japan suggests that it is more common in adults. We conducted a large-scale retrospective study to confirm these findings and to clarify what caused the difference between Japan and other countries, to reveal overlooked aspects of this disease. The clinical information of 911 cases which we diagnosed as Toxocara or Ascaris LMS during 2001 and 2015 was analysed. Information used included age, sex, address (city or county), chief complaint, present history, dietary history, overseas travelling history, medical imaging findings and laboratory data (white blood cell count, peripheral blood eosinophil number and total IgE). The sex ratio of the disease was 2.37 (male/female = 641/270). The number of patients not younger than 20 years old were 97.8 and 95.1 % among males and females, respectively. Major disease types were visceral, ocular, neural and asymptomatic. The visceral type was more prevalent in older patients, while younger patients were more vulnerable to ocular symptoms. More than two-thirds of the patients whose dietary habits were recorded had a history of ingesting raw or undercooked animal meat. LMS caused by Toxocara or Ascaris is primarily a disease of adult males in Japan, who probably acquired infections by eating raw or undercooked animal meat/liver. Healthcare specialists should draw public attention to the risk of raw or undercooked animal meat in Europe as well.

  4. Genetic and Biochemical Diversity of Paenibacillus larvae Isolated from Tunisian Infected Honey Bee Broods

    PubMed Central

    Hamdi, Chadlia; Essanaa, Jihène; Sansonno, Luigi; Crotti, Elena; Abdi, Khaoula; Barbouche, Naima; Balloi, Annalisa; Gonella, Elena; Alma, Alberto; Daffonchio, Daniele; Boudabous, Abdellatif; Cherif, Ameur

    2013-01-01

    Paenibacillus larvae is the causative agent of American foulbrood (AFB), a virulent disease of honeybee (Apis mellifera) larvae. In Tunisia, AFB has been detected in many beekeeping areas, where it causes important economic losses, but nothing is known about the diversity of the causing agent. Seventy-five isolates of P. larvae, identified by biochemical tests and 16S rRNA gene sequencing, were obtained from fifteen contaminated broods showing typical AFB symptoms, collected in different locations in the northern part of the country. Using BOX-PCR, a distinct profile of P. larvae with respect to related Paenibacillus species was detected which may be useful for its identification. Some P. larvae-specific bands represented novel potential molecular markers for the species. BOX-PCR fingerprints indicated a relatively high intraspecific diversity among the isolates not described previously with several molecular polymorphisms identifying six genotypes on polyacrylamide gel. Polymorphisms were also detected in several biochemical characters (indol production, nitrate reduction, and methyl red and oxidase tests). Contrary to the relatively high intraspecies molecular and phenotypic diversity, the in vivo virulence of three selected P. larvae genotypes did not differ significantly, suggesting that the genotypic/phenotypic differences are neutral or related to ecological aspects other than virulence. PMID:24073406

  5. Rotavirus A-specific single-domain antibodies produced in baculovirus-infected insect larvae are protective in vivo

    PubMed Central

    2012-01-01

    Background Single-domain antibodies (sdAbs), also known as nanobodies or VHHs, are characterized by high stability and solubility, thus maintaining the affinity and therapeutic value provided by conventional antibodies. Given these properties, VHHs offer a novel alternative to classical antibody approaches. To date, VHHs have been produced mainly in E. coli, yeast, plants and mammalian cells. To apply the single-domain antibodies as a preventive or therapeutic strategy to control rotavirus infections in developing countries (444,000 deaths in children under 5 years of age) has to be minimized their production costs. Results Here we describe the highly efficient expression of functional VHHs by the Improved Baculovirus Expression System (IBES® technology), which uses a baculovirus expression vector in combination with Trichoplusia ni larvae as living biofactories. Two VHHs, named 3B2 and 2KD1, specific for the inner capsid protein VP6 of Group A rotavirus, were expressed in insect larvae. The IBES® technology achieved very high expression of 3B2 and 2KD1, reaching 2.62% and 3.63% of the total soluble protein obtained from larvae, respectively. These expression levels represent up to 257 mg/L of protein extract after insect processing (1 L extract represents about 125 g of insect biomass or about 375 insect larvae). Larva-derived antibodies were fully functional when tested in vitro and in vivo, neutralizing Group A rotaviruses and protecting offspring mice against rotavirus-induced diarrhea. Conclusions Our results open up the possibility of using insects as living biofactories (IBES® technology) for the cost-efficient production of these and other fully functional VHHs to be used for diagnostic or therapeutic purposes, thereby eliminating concerns regarding the use of bacterial or mammalian cells. To the best of our knowledge, this is the first time that insects have been used as living biofactories to produce a VHH molecule. PMID:22953695

  6. Taurine drinking attenuates the burden of intestinal adult worms and muscle larvae in mice with Trichinella spiralis infection.

    PubMed

    Yu, Yan-Rong; Liu, Xi-Cheng; Zhang, Jin-Sheng; Ji, Chao-Yue; Qi, Yong-Fen

    2013-10-01

    The parasitic nematode Trichinella spiralis can cause trichinellosis, which leads to pathological processes in the intestine and muscle. The intestinal invasion determines the development, subsequent course, and consequences of the disease. Gastrointestinal nematode infection, including with T. spiralis, is accompanied by a rapid and reversible expansion of mucosal mast cell and goblet cell in the intestinal epithelium, which play important roles in the host immune response to parasite and worm expulsion from the intestine. Taurine and its derivatives have anti-infection and anti-inflammatory properties. We investigated whether taurine supplementation in mice could influence the development and pathological processes of infection with T. spiralis. Supplementing 1% taurine in drinking water in mice infected with T. spiralis could alleviate the burden of intestinal adult worms on days 7 and 10 postinfection (all p < 0.01) and the formation of infective muscle larvae in striated muscle during T. spiralis infection (p < 0.01). As compared with T. spiralis infection alone, taurine treatment increased the number of goblet cells on days 7, 10, and 15 (p < 0.01 and p < 0.05) and alleviated intestinal mucosal mast cell hyperplasia on days 10 and 15 (all p < 0.01). So taurine supplementation in drinking water increased infection-induced intestinal goblet cell hyperplasia and ameliorated mucosal mastocytosis. Thus, taurine can ameliorate the pathological processes of trichinellosis and may be of great value for the treatment and prevention of infection with T. spiralis and other gastrointestinal nematodes.

  7. Temperature and water quality effects in simulated woodland pools on the infection of Culex mosquito larvae by Lagenidium giganteum (Oomycetes: Lagenidiales) in North Carolina

    SciTech Connect

    Guzman, D.R.; Axtell, R.C.

    1987-06-01

    Asexual stages of the California (CA) isolate of Lagenidium giganteum cultured on sunflower seed extract (SFE)-agar, were applied to outdoor pools containing Culex larvae near Raleigh, NC in August and September 1984. Infection rates among the larvae ranged from 19 to 74% at 2-4 days posttreatment and subsequent epizootics eliminated most of the newly hatched larvae for at least 10 days posttreatment. Substantial reductions in numbers of larvae and adult emergence were achieved from a single application of the fungus. Water quality and temperature data are presented. From laboratory assays of organically polluted water, the percent infection of Culex quinquefasciatus by the fungus was correlated with water quality and temperature. A logistic model of water quality (COD and NH/sub 3/-N) effects on infectivity rates by the CA isolate is described.

  8. Effective immunosuppression with dexamethasone phosphate in the Galleria mellonella larva infection model resulting in enhanced virulence of Escherichia coli and Klebsiella pneumoniae.

    PubMed

    Torres, Miquel Perez; Entwistle, Frances; Coote, Peter J

    2016-08-01

    The aim was to evaluate whether immunosuppression with dexamethasone 21-phosphate could be applied to the Galleria mellonella in vivo infection model. Characterised clinical isolates of Escherichia coli or Klebsiella pneumoniae were employed, and G. mellonella larvae were infected with increasing doses of each strain to investigate virulence in vivo. Virulence was then compared with larvae exposed to increasing doses of dexamethasone 21-phosphate. The effect of dexamethasone 21-phosphate on larval haemocyte phagocytosis in vitro was determined via fluorescence microscopy and a burden assay measured the growth of infecting bacteria inside the larvae. Finally, the effect of dexamethasone 21-phosphate treatment on the efficacy of ceftazidime after infection was also noted. The pathogenicity of K. pneumoniae or E. coli in G. mellonella larvae was dependent on high inoculum numbers such that virulence could not be attributed specifically to infection by live bacteria but also to factors associated with dead cells. Thus, for these strains, G. mellonella larvae do not constitute an ideal infection model. Treatment of larvae with dexamethasone 21-phosphate enhanced the lethality induced by infection with E. coli or K. pneumoniae in a dose- and inoculum size-dependent manner. This correlated with proliferation of bacteria in the larvae that could be attributed to dexamethasone inhibiting haemocyte phagocytosis and acting as an immunosuppressant. Notably, prior exposure to dexamethasone 21-phosphate reduced the efficacy of ceftazidime in vivo. In conclusion, demonstration of an effective immunosuppressant regimen can improve the specificity and broaden the applications of the G. mellonella model to address key questions regarding infection.

  9. New diagnostic antigens for early trichinellosis: the excretory-secretory antigens of Trichinella spiralis intestinal infective larvae.

    PubMed

    Sun, Ge Ge; Liu, Ruo Dan; Wang, Zhong Quan; Jiang, Peng; Wang, Li; Liu, Xiao Lin; Liu, Chun Yin; Zhang, Xi; Cui, Jing

    2015-12-01

    The excretory-secretory (ES) antigens from Trichinella spiralis muscle larvae (ML) are the most commonly used diagnostic antigens for trichinellosis, but anti-Trichinella IgG antibodies cannot be detected until 2-3 weeks after infection; there is an obvious window period between Trichinella infection and antibody positivity. Intestinal infective larvae (IIL) are the first invasive stage during Trichinella infection, and their ES antigens are firstly exposed to the immune system and might be the early diagnostic markers of trichinellosis. The aim of this study was to evaluate the early diagnostic values of IIL ES antigens for trichinellosis. The IIL were collected from intestines of infected mice at 6 h postinfection (hpi), and IIL ES antigens were prepared by incubation for 18 h. Anti-Trichinella IgG antibodies in mice infected with 100 ML were detectable by ELISA with IIL ES antigens as soon as 10 days postinfection (dpi), but ELISA with ML ES antigens did not permit detection of infected mice before 12 dpi. When the sera of patients with trichinellosis at 19 dpi were assayed, the sensitivity (100 %) of ELISA with IIL ES antigens was evidently higher than 75 % of ELISA with ML ES antigens (P < 0.05) The specificity (96.86 %) of ELISA with IIL ES antigens was also higher than 89.31 % of ELISA with ML ES antigens (P < 0.05). The IIL ES antigens provided a new source of diagnostic antigens and could be considered as a potential early diagnostic antigen for trichinellosis.

  10. Yeast-Based High-Throughput Screens to Identify Novel Compounds Active against Brugia malayi

    PubMed Central

    Bilsland, Elizabeth; Bean, Daniel M.; Devaney, Eileen; Oliver, Stephen G.

    2016-01-01

    Background Lymphatic filariasis is caused by the parasitic worms Wuchereria bancrofti, Brugia malayi or B. timori, which are transmitted via the bites from infected mosquitoes. Once in the human body, the parasites develop into adult worms in the lymphatic vessels, causing severe damage and swelling of the affected tissues. According to the World Health Organization, over 1.2 billion people in 58 countries are at risk of contracting lymphatic filariasis. Very few drugs are available to treat patients infected with these parasites, and these have low efficacy against the adult stages of the worms, which can live for 7–15 years in the human body. The requirement for annual treatment increases the risk of drug-resistant worms emerging, making it imperative to develop new drugs against these devastating diseases. Methodology/Principal Findings We have developed a yeast-based, high-throughput screening system whereby essential yeast genes are replaced with their filarial or human counterparts. These strains are labeled with different fluorescent proteins to allow the simultaneous monitoring of strains with parasite or human genes in competition, and hence the identification of compounds that inhibit the parasite target without affecting its human ortholog. We constructed yeast strains expressing eight different Brugia malayi drug targets (as well as seven of their human counterparts), and performed medium-throughput drug screens for compounds that specifically inhibit the parasite enzymes. Using the Malaria Box collection (400 compounds), we identified nine filarial specific inhibitors and confirmed the antifilarial activity of five of these using in vitro assays against Brugia pahangi. Conclusions/Significance We were able to functionally complement yeast deletions with eight different Brugia malayi enzymes that represent potential drug targets. We demonstrated that our yeast-based screening platform is efficient in identifying compounds that can discriminate between

  11. Analysis of Babesia bovis infection-induced gene expression changes in larvae from the cattle tick, Rhipicephalus (Boophilus) microplus

    PubMed Central

    2012-01-01

    Background Cattle babesiosis is a tick-borne disease of cattle that has severe economic impact on cattle producers throughout the world’s tropical and subtropical countries. The most severe form of the disease is caused by the apicomplexan, Babesia bovis, and transmitted to cattle through the bite of infected cattle ticks of the genus Rhipicephalus, with the most prevalent species being Rhipicephalus (Boophilus) microplus. We studied the reaction of the R. microplus larval transcriptome in response to infection by B. bovis. Methods Total RNA was isolated for both uninfected and Babesia bovis-infected larval samples. Subtracted libraries were prepared by subtracting the B. bovis-infected material with the uninfected material, thus enriching for expressed genes in the B. bovis-infected sample. Expressed sequence tags from the subtracted library were generated, assembled, and sequenced. To complement the subtracted library method, differential transcript expression between samples was also measured using custom high-density microarrays. The microarray probes were fabricated using oligonucleotides derived from the Bmi Gene Index database (Version 2). Array results were verified for three target genes by real-time PCR. Results Ticks were allowed to feed on a B. bovis-infected splenectomized calf and on an uninfected control calf. RNA was purified in duplicate from whole larvae and subtracted cDNA libraries were synthesized from Babesia-infected larval RNA, subtracting with the corresponding uninfected larval RNA. One thousand ESTs were sequenced from the larval library and the transcripts were annotated. We used a R. microplus microarray designed from a R. microplus gene index, BmiGI Version 2, to look for changes in gene expression that were associated with infection of R. microplus larvae. We found 24 transcripts were expressed at a statistically significant higher level in ticks feeding upon a B. bovis-infected calf contrasted to ticks feeding on an uninfected calf

  12. [New case of human infection by a Pseudoterranova decipiens larva (Nematode, Anisakidae) in Peru].

    PubMed

    Cabrera, Rufino; Luna-Pineda, Miguel Angel; Suárez-Ognio, Luis

    2003-01-01

    The purpose of this report is to divulge a new case of human anisakidosis in Peru, caused by a larva of the Pseudoterranova decipiens nematode found in a 17 year old female patient from Lima, who had ingested "cebiche" in a restaurant in the city of Ica, in the central coast of Peru. Approximately 4 hours after having ingested the food, the patient reported a feeling of uneasiness, with a nauseous sensation in the epigastric region, which intensified 5 hours later when she vomited. In the vomit content a live nematode was found, which was identified as larva L3 of P. decipiens. This is one of the etiologic agents of anisakidosis.

  13. Positivity and intensity of Gnathostoma spinigerum infective larvae in farmed and wild-caught swamp eels in Thailand.

    PubMed

    Saksirisampant, Wilai; Thanomsub, Benjamas Wongsatayanon

    2012-06-01

    From July 2008 to June 2009, livers of the swamp eels (Monopterus alba) were investigated for advanced third-stage larvae (AL3) of Gnathostoma spinigerum. Results revealed that 10.2% (106/1,037) and 20.4% (78/383) of farmed eels from Aranyaprathet District, Sa Kaeo Province and those of wild-caught eels obtained from a market in Min Buri District of Bangkok, Thailand were infected, respectively. The prevalence was high during the rainy and winter seasons. The infection rate abruptly decreased in the beginning of summer. The highest infection rate (13.7%) was observed in September and absence of infection (0%) in March-April in the farmed eels. Whereas, in the wild-caught eels, the highest rate (30.7%) was observed in November, and the rate decreased to the lowest at 6.3% in March. The average no. (mean±SE) of AL3 per investigated liver in farmed eels (1.1±0.2) was significantly lower (P=0.040) than those in the caught eels (0.2±0.03). In addition, the intensity of AL3 recovered from each infected liver varied from 1 to 18 (2.3±0.3) in the farmed eels and from 1 to 47 (6.3±1.2) in the caught eels, respectively. The AL3 intensity showed significant difference (P=0.011) between these 2 different sources of eels. This is the first observation that farmed eels showed positive findings of G. spinigerum infective larvae. This may affect the standard farming of the culture farm and also present a risk of consuming undercooked eels from the wild-caught and farmed eels.

  14. Positivity and Intensity of Gnathostoma spinigerum Infective Larvae in Farmed and Wild-Caught Swamp Eels in Thailand

    PubMed Central

    Saksirisampant, Wilai

    2012-01-01

    From July 2008 to June 2009, livers of the swamp eels (Monopterus alba) were investigated for advanced third-stage larvae (AL3) of Gnathostoma spinigerum. Results revealed that 10.2% (106/1,037) and 20.4% (78/383) of farmed eels from Aranyaprathet District, Sa Kaeo Province and those of wild-caught eels obtained from a market in Min Buri District of Bangkok, Thailand were infected, respectively. The prevalence was high during the rainy and winter seasons. The infection rate abruptly decreased in the beginning of summer. The highest infection rate (13.7%) was observed in September and absence of infection (0%) in March-April in the farmed eels. Whereas, in the wild-caught eels, the highest rate (30.7%) was observed in November, and the rate decreased to the lowest at 6.3% in March. The average no. (mean±SE) of AL3 per investigated liver in farmed eels (1.1±0.2) was significantly lower (P=0.040) than those in the caught eels (0.2±0.03). In addition, the intensity of AL3 recovered from each infected liver varied from 1 to 18 (2.3±0.3) in the farmed eels and from 1 to 47 (6.3±1.2) in the caught eels, respectively. The AL3 intensity showed significant difference (P=0.011) between these 2 different sources of eels. This is the first observation that farmed eels showed positive findings of G. spinigerum infective larvae. This may affect the standard farming of the culture farm and also present a risk of consuming undercooked eels from the wild-caught and farmed eels. PMID:22711921

  15. Comparison of isolates and species of Toxocara and Toxascaris by biosynthetic labelling of somatic and ES proteins from infective larvae.

    PubMed

    Page, A P; Richards, D T; Lewis, J W; Omar, H M; Maizels, R M

    1991-12-01

    Infective-stage larvae of three different isolates of Toxocara canis were intrinsically ([35S]methionine) labelled in culture, to determine the presence of similarities or differences in the somatic and ES antigens expressed between larvae derived from different hosts and different geographical regions. Two other closely related ascaridids, Toxascaris leonina which infects cats and dogs, and Toxocara vitulorum (Neoascaris vitulorum) which infects cattle, were also compared to T. canis larvae by this method. Overall comparisons were made by 1- and 2-dimensional electrophoresis, while immunological cross-reactivities between the different species were analysed by radio-immunoprecipitation. Our results show that extensive physicochemical characteristics are shared between T. canis isolates, both from different hosts and different geographical locations. A substantial overlap was revealed when T. canis and T. vitulorum antigens were compared, whereas Toxascaris was found to produce a distinct antigen profile: this result was independent of whether methionine- or Iodogen-labelled products were being considered. Antigen recognition by polyclonal antibodies raised to all three species and to the cat ascaridid Toxocara cati, revealed considerable cross-reactivities. The cross-reactions were especially prominent between the Toxocara species, a fact further substantiated when reactivity of T. canis ES-specific monoclonal antibodies were tested against T. leonina and T. vitulorum antigens. The ES antigens of T. leonina were not recognized by the T. canis monoclonals, whereas the majority of these antibodies precipitated antigens of T. vitulorum. One which did not react with T. vitulorum was monoclonal antibody Tcn 2, indicating its species-specific reactivity and therefore its potential for the specific diagnosis of human toxocariasis.

  16. Pentastomid infections in cichlid fishes in the Kruger National Park and the description of the infective larva of Subtriquetra rileyi n. sp.

    PubMed

    Junker, K; Boomker, J; Booyse, D G

    1998-09-01

    During 1995, studies were conducted on the pentastome fauna of the cichlid fishes Tilapia rendalli and Oreochromis mossambicus in the Kruger National Park. The prevalence of infective pentastome larvae was 40.5% in T. rendalli and 9.2% in O. mossambicus. Encapsulated nymphs of Leiperia cincinnalis were taken from the mesentery, while Sebekia wedli was either encapsulated or free-living in the swim bladder. The subtriquetrids moved about freely in the swim bladder. L. cincinnalis was present in 0.5% of T. rendalli and 0.8% of O. mossambicus and additional descriptions and measurements of the nymphs are presented. S. wedli was present in 2.5% of O. mossambicus and a new Subtriquetra species, for which the name Subtriquetra riley n. sp. is proposed, in 7.5%. This ratio in T. rendalli was 40.5% and 2.2%, respectively. Of the infected T. rendalli, 89% harboured one or two sebekiid larvae, while a single fish harboured eight. Fish infected with S. rileyi contained only one larva each. The condition factor of infected T. rendalli was compared statistically to that of uninfected fish and no significant difference found. However, infected fish were significantly shorter and lighter than uninfected ones. S. rileyi differs from the other three known Subtriquetra spp., Subtriquetra subtriquetra, Subtriquetra megacephala and Subtriquetra shipleyi in both hook size and annulus counts. Furthermore, S. subtriquetra occurs in South American crocodilians (Riley 1986), and S. megacephala and S. shipleyi in crocodilians in India (Fain 1961). This is the first record of the genus occurring in Africa and although adult specimens of S. rileyi n. sp. were not obtained, we assume that the new species is specific to Nile crocodiles.

  17. Comparative infectivity of homologous and heterologous nucleopolyhedroviruses against beet armyworm larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Homologous and heterologous nucleopolyhedroviruses (NPVs) were assayed to determine the most effective NPV against beet armyworm larvae, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae)(SeMNPV). Included were three isolates from S. exigua, one isolate each from S. littoralis Boisduval, S. litura...

  18. Tyramine functions as a toxin in honey bee larvae during Varroa-transmitted infection by Melissococcus pluton.

    PubMed

    Kanbar, G; Engels, W; Nicholson, G J; Hertle, R; Winkelmann, G

    2004-05-01

    From wounds of honey bee pupae, caused by the mite Varroa destructor, coccoid bacteria were isolated and identified as Melissococcus pluton. The bacterial isolate was grown anaerobically in sorbitol medium to produce a toxic compound that was purified on XAD columns, gelfiltration and preparative HPLC. The toxic agent was identified by GC-MS and FTICR-MS as tyramine. The toxicity of the isolated tyramine was tested by a novel mobility test using the protozoon Stylonychia lemnae. A concentration of 0.2 mg/ml led to immediate inhibition of mobility. In addition the toxicity was studied on honey bee larvae by feeding tyramine/water mixtures added to the larval jelly. The lethal dosis of tyramine on 4-5 days old bee larvae was determined as 0.3 mg/larvae when added as a volume of 20 microl to the larval food in brood cells. Several other biogenic amines, such as phenylethylamine, histamine, spermine, cadaverine, putrescine and trimethylamine, were tested as their hydrochloric salts for comparison and were found to be inhibitory in the Stylonychia mobility test at similar concentrations. A quantitative hemolysis test with human red blood cells revealed that tyramine and histamine showed the highest membranolytic activity, followed by the phenylethylamine, trimethylamine and spermine, while the linear diamines, cadaverine and putrescine, showed a significantly lower hemolysis when calculated on a molar amine basis. The results indicate that tyramine which is a characteristic amine produced by M. pluton in culture, is the causative agent of the observed toxic symptoms in bee larvae. Thus this disease, known as European foulbrood, is possibly an infection transmitted by the Varroa destructor mite.

  19. DEPENDENCE OF ECDYSTEROID METABOLISM AND DEVELOPMENT IN HOST LARVAE ON THE TIME OF BACULOVIRUS INFECTION AND THE ACTIVITY OF THE UDP-GLUCOSYL TRANSFERASE GENE.

    EPA Science Inventory

    Infection of fourth-instar gypsy moth (Lymantria dispar, Lepidoptera: Lymantriidae) larvae with the wild-type (Wt) gypsy moth baculovirus, LdNPV on the first day post-molt, or infection of fifth instars on the fifth day post-molt, results in elevated ecdysteroid levels in both he...

  20. Toxocara canis: monoclonal antibodies to larval excretory-secretory antigens that bind with genus and species specificity to the cuticular surface of infective larvae.

    PubMed

    Bowman, D D; Mika-Grieve, M; Grieve, R B

    1987-12-01

    When maintained in culture, the infective-stage larvae of Toxocara canis produce a group of excretory-secretory antigens. Monoclonal antibodies to these antigens have been produced and partially characterized. Hybridomas were made using spleens from mice that had been given 250 embryonated eggs of T. canis followed by immunization with excretory-secretory antigens. Monoclonal antibodies were first screened against excretory-secretory antigens using an indirect enzyme-linked immunosorbent assay. Those antibodies positive in this assay were then screened against the surfaces of formalin-fixed, infective-stage larvae using an indirect fluorescent antibody assay. The two monoclonal antibodies showing fluorescence were also tested against the surfaces of infective-stage larvae of Toxocara cati, Baylisascaris procyonis, Toxascaris leonina, Ascaris suum, a Porrocaecum sp., and Dirofilaria immitis. One of these two antibodies bound to the surface of T. canis and T. cati while the other bound only to the surface of T. canis; neither were reactive with the other ascaridoid larvae or the larvae of D. immitis. Enzyme-linked immunoelectrotransfer blotting techniques were used to demonstrate that the cross-reactive antibody recognized antigens with molecular weights of about 200 kDa while the more specific monoclonal antibody recognized antigens with approximate molecular weights of 80 kDa. The specificity of these two antibodies for T. canis and T. cati should prove helpful in the development of more specific assays for the diagnosis of visceral and ocular larva migrans.

  1. Haemonchus contortus egg excretion and female length reduction in sheep previously infected with Oestrus ovis (Diptera: Oestridae) larvae.

    PubMed

    Terefe, G; Yacob, H T; Grisez, C; Prevot, F; Dumas, E; Bergeaud, J P; Dorchies, Ph; Hoste, H; Jacquiet, P

    2005-03-31

    Mixed parasitic infection of animals is a common phenomenon in nature. The existence of one species often positively or negatively influences the survival of the other. Our experimental study was started with the objectives to demonstrate the interaction of Haemonchus contortus and Oestrus ovis in relation to cellular and humoral immune responses in sheep. Twenty-two sheep of Tarasconnais breed (France) were divided into four groups (O, OH, H and C) of five or six animals. Group O and OH received 5 weekly consecutive inoculations with O. ovis L1 larvae (total = 82 L1) in the first phase of the experiment between days 0 and 28. On the second phase, groups OH and H received 5000 L3 of H. contortus on day 48 while group C served as our control throughout the experimental period. Parasitological, haematological, serological and histopathological examinations were made according to standard procedures and all animals were slaughtered at day 95. There was no significant variation in the number and degree of development of O. ovis larvae between the two infected groups. Furthermore, in tissues examined in the upper respiratory tract (nasal septum, turbinate, ethmoide and sinus), group O and OH has responded similarly on the basis of cellular inflammatory responses (blood and tissue eosinophils, mast cells and globule leucocytes (GL)) and serum antibody responses against the nasal bots. This may indicate that the presence of H. contortus in the abomasa of group OH had no marked influence over the development of O. ovis larvae in the upper respiratory tract. On the other hand, we have observed a significantly lower H. contortus female worm length, fecal egg count (FEC) and in utero egg count in animals harbouring the nasal bot (OH) than in the mono-infected group (H). This was significantly associated with higher blood eosinophilia, higher packed cell volume (PCV) and increased number of tissue eosinophils and globule leucocytes. We conclude that, the establishment of O

  2. Vertical migration of Haemonchus contortus infective larvae on Cynodon dactylon and Paspalum notatum pastures in response to climatic conditions.

    PubMed

    Amaradasa, Bimal S; Lane, Robert A; Manage, Ananda

    2010-05-28

    Observations were made on vertical migration patterns of Haemonchus contortus infective larvae on Cynodon dactylon (bermudagrass) and Paspalum notatum (bahiagrass) pastures under summer climatic conditions typical of East Texas. Ten thousand H. contortus infective larvae (L3) were introduced to 100 cm(2) subplots of each pasture species within a plot area of 1m(2). Subplots were inoculated with larvae by applying them in an aqueous medium to the soil or mat beneath the vegetation. Herbage from the inoculated areas was harvested on 5 sampling days over a span of 21 days. L3 recoveries were observed and recorded each day on four herbage strata viz. 0-5, 5-10, 10-20 and >20 cm from ground level. The log transformed larval recovery data were analyzed for effect of day, stratum, and day x stratum interaction for each grass species during two separate experimental periods. Precipitation, relative humidity and temperature during the study were subjected to correlation and multiple regression analyses with the larval counts. Significant (Por=0.93) between rainfall and total average daily larval counts was apparent. The multiple regression analysis did not show significant results for any of the climatic factors tested. This study showed that the H. contortus infective larvae can survive beyond 21 days in the soil and infest pasture grasses when the climatic conditions are favorable. Avoiding use of H. contortus contaminated pasturelands in summer at the onset of rainfall following a dry spell may effectively reduce nematode loads in susceptible farm animals. Additional studies should focus on factors affecting long term L3 survivability, migrational pattern on these and other plant species and the

  3. Draft genome of the filarial nematode parasite Brugia malayi.

    PubMed

    Ghedin, Elodie; Wang, Shiliang; Spiro, David; Caler, Elisabet; Zhao, Qi; Crabtree, Jonathan; Allen, Jonathan E; Delcher, Arthur L; Guiliano, David B; Miranda-Saavedra, Diego; Angiuoli, Samuel V; Creasy, Todd; Amedeo, Paolo; Haas, Brian; El-Sayed, Najib M; Wortman, Jennifer R; Feldblyum, Tamara; Tallon, Luke; Schatz, Michael; Shumway, Martin; Koo, Hean; Salzberg, Steven L; Schobel, Seth; Pertea, Mihaela; Pop, Mihai; White, Owen; Barton, Geoffrey J; Carlow, Clotilde K S; Crawford, Michael J; Daub, Jennifer; Dimmic, Matthew W; Estes, Chris F; Foster, Jeremy M; Ganatra, Mehul; Gregory, William F; Johnson, Nicholas M; Jin, Jinming; Komuniecki, Richard; Korf, Ian; Kumar, Sanjay; Laney, Sandra; Li, Ben-Wen; Li, Wen; Lindblom, Tim H; Lustigman, Sara; Ma, Dong; Maina, Claude V; Martin, David M A; McCarter, James P; McReynolds, Larry; Mitreva, Makedonka; Nutman, Thomas B; Parkinson, John; Peregrín-Alvarez, José M; Poole, Catherine; Ren, Qinghu; Saunders, Lori; Sluder, Ann E; Smith, Katherine; Stanke, Mario; Unnasch, Thomas R; Ware, Jenna; Wei, Aguan D; Weil, Gary; Williams, Deryck J; Zhang, Yinhua; Williams, Steven A; Fraser-Liggett, Claire; Slatko, Barton; Blaxter, Mark L; Scott, Alan L

    2007-09-21

    Parasitic nematodes that cause elephantiasis and river blindness threaten hundreds of millions of people in the developing world. We have sequenced the approximately 90 megabase (Mb) genome of the human filarial parasite Brugia malayi and predict approximately 11,500 protein coding genes in 71 Mb of robustly assembled sequence. Comparative analysis with the free-living, model nematode Caenorhabditis elegans revealed that, despite these genes having maintained little conservation of local synteny during approximately 350 million years of evolution, they largely remain in linkage on chromosomal units. More than 100 conserved operons were identified. Analysis of the predicted proteome provides evidence for adaptations of B. malayi to niches in its human and vector hosts and insights into the molecular basis of a mutualistic relationship with its Wolbachia endosymbiont. These findings offer a foundation for rational drug design.

  4. The predatory capability of three nematophagous fungi in the control of Haemonchus contortus infective larvae in ovine faeces.

    PubMed

    Flores-Crespo, J; Herrera-Rodríguez, D; Mendoza de Gives, P; Liébano-Hernández, E; Vázquez-Prats, V M; López-Arellano, M E

    2003-12-01

    The effect of oral administration of three different nematode-trapping fungi, in aqueous suspension containing either Dactylaria sp. or Arthrobotrys oligospora conidia or Duddingtonia flagrans chlamydospores, on the number of Haemonchus contortus infective larvae in sheep faeces, was evaluated. The three selected species of fungi produce three-dimensional adhesive nets in the presence of nematodes. Sixteen Creole sheep were divided into four groups of four animals each. Groups 1 and 2 were orally drenched with a suspension containing 2x10(7) conidia of either A. oligospora or Dactylaria sp. Group 3, received a similar treatment, with D. flagrans chlamydospores, instead of conidia, being administered, at the same dose. Group 4 acted as control, without any fungi. Faecal samples were collected directly from the rectum of each sheep and faecal cultures were prepared and incubated at 15 and 21 days. Larvae were recovered from faecal cultures and counted. The highest reduction of the nematode population occurred in the D. flagrans group, reaching reductions of 96.3% and 91.4% in individual samplings in plates incubated for 15 and 21 days, respectively. Arthrobotrys oligospora showed moderate reductions in the faecal larval population, ranging between 25-64% at 15 days incubation. In general, Dactylaria sp., was less efficient in its trapping ability. Despite the inconsistent results with Dactylaria sp., reduction percentages of 73.4% and 80.7% were recorded in individual samplings during the first and second days, in plates incubated for 15 days. Duddingtonia flagrans, was shown to be a potential biological control agent of H. contortus infective larvae.

  5. Ancylostoma caninum MTP-1, an astacin-like metalloprotease secreted by infective hookworm larvae, is involved in tissue migration.

    PubMed

    Williamson, Angela L; Lustigman, Sara; Oksov, Yelena; Deumic, Vehid; Plieskatt, Jordan; Mendez, Susana; Zhan, Bin; Bottazzi, Maria Elena; Hotez, Peter J; Loukas, Alex

    2006-02-01

    Infective larvae (L3) of nematodes secrete macromolecules that are critical to infection and establishment of the parasite in the host. The dog hookworm Ancylostoma caninum secretes an astacin-like metalloprotease, Ac-MTP-1, upon activation in vitro with host serum. Recombinant Ac-MTP-1 was expressed in the baculovirus/insect cell system as a secreted protein and was purified from culture medium by two separate methods, cation-exchange fast-performance liquid chromatography and gelatin-affinity chromatography. Recombinant MTP-1 was catalytically active and digested a range of native and denatured connective tissue substrates, including gelatin, collagen, laminin, and fibronectin. A dog was immunized with recombinant Ac-MTP-1 formulated with AS03 adjuvant, and the antiserum was used to immunolocalize the anatomic sites of expression within A. caninum L3 to secretory granules in the glandular esophagus and the channels that connect the esophagus to the L3 surface and to the cuticle. Antiserum inhibited the ability of recombinant MTP-1 to digest collagen by 85% and inhibited larval migration through tissue in vitro by 70 to 75%, in contrast to just 5 to 10% inhibition obtained with preimmunization serum. The metalloprotease inhibitors EDTA and 1,10-phenanthroline also reduced the penetration of L3 through skin in vitro by 43 to 61%. The data strongly suggest that Ac-MTP-1 is critical for the invasion process of hookworm larvae, and moreover, that antibodies against the enzyme can neutralize its function and inhibit migration.

  6. Og4C3 circulating antigen, anti-Brugia malayi IgG and IgG4 titers in Wuchereria bancrofti infected patients, according to their parasitological status.

    PubMed

    Chanteau, S; Glaziou, P; Luquiaud, P; Plichart, C; Moulia-Pelat, J P; Cartel, J L

    1994-09-01

    This study involved 221 microfilaremic (Mf+), 302 amicrofilaremic (Mf-) antigen positive (AG+) and 1454 Mf-antigen negative (AG-) individuals living in endemic villages. Whatever the group considered, antigen and antibody titers were widely distributed. Og4C3 antigen, detected both in Mf- and Mf+ patients, was significantly higher in Mf+ patients. The Mf parasitological status did not significantly influence the antifilarial antibodies levels in the infected AG+ individuals, although IgG4 was more discriminant. In the supposedly uninfected individuals (Mf-AG-), anti-filarial IgG and IgG4 could be detected in a large proportion of the group. Og4C3 circulating antigen test was confirmed to be a good marker of active Wuchereria bancrofti infection.

  7. Hyperplasia of gastric mucosa in donor rats orally infected with Taenia taeniaeformis eggs and in recipient rats surgically implanted with the larvae in the abdominal cavity.

    PubMed

    Konno, K; Oku, Y; Nonaka, N; Kamiya, M

    1999-06-01

    Rats heavily infected with Taenia taeniaeformis larvae in the liver show a remarkable increase in their stomach weight, hyperplasia, and hypergastrinemia. However, it is unknown what causes these phenomena. Hence, as a preliminary study to investigate the importance of larval parasitism in the liver, two experiments were done. In the first experiment, 14 donor rats were orally inoculated with 3,000 T. taeniaeformis eggs. In the second experiment, 136-300 of the larvae obtained from the rats were surgically implanted into the abdominal cavity of 7 recipient rats. Gastrin levels and histopathological changes in the gastric mucosa were investigated. In all, 11 donor rats showed hypergastrinemia and hyperplasia, 5 recipient rats showed gastric mucosal hyperplasia accompanied by excessive mucous cell proliferation, and 2 recipient rats showed hypergastrinemia. These results suggest that parasitism of the liver by the larvae is not essential for the development of hyperplasia and that factors from the larvae might cause these phenomena.

  8. Cellular Visualization of Macrophage Pyroptosis and Interleukin-1β Release in a Viral Hemorrhagic Infection in Zebrafish Larvae

    PubMed Central

    Varela, Mónica; Romero, Alejandro; Dios, Sonia; van der Vaart, Michiel; Figueras, Antonio; Meijer, Annemarie H.

    2014-01-01

    ABSTRACT Hemorrhagic viral diseases are distributed worldwide with important pathogens, such as dengue virus or hantaviruses. The lack of adequate in vivo infection models has limited the research on viral pathogenesis and the current understanding of the underlying infection mechanisms. Although hemorrhages have been associated with the infection of endothelial cells, other cellular types could be the main targets for hemorrhagic viruses. Our objective was to take advantage of the use of zebrafish larvae in the study of viral hemorrhagic diseases, focusing on the interaction between viruses and host cells. Cellular processes, such as transendothelial migration of leukocytes, virus-induced pyroptosis of macrophages. and interleukin-1β (Il-1β) release, could be observed in individual cells, providing a deeper knowledge of the immune mechanisms implicated in the disease. Furthermore, the application of these techniques to other pathogens will improve the current knowledge of host-pathogen interactions and increase the potential for the discovery of new therapeutic targets. IMPORTANCE Pathogenic mechanisms of hemorrhagic viruses are diverse, and most of the research regarding interactions between viruses and host cells has been performed in cell lines that might not be major targets during natural infections. Thus, viral pathogenesis research has been limited because of the lack of adequate in vivo infection models. The understanding of the relative pathogenic roles of the viral agent and the host response to the infection is crucial. This will be facilitated by the establishment of in vivo infection models using organisms such as zebrafish, which allows the study of the diseases in the context of a complete individual. The use of this animal model with other pathogens could improve the current knowledge on host-pathogen interactions and increase the potential for the discovery of new therapeutic targets against diverse viral diseases. PMID:25100833

  9. Cellular visualization of macrophage pyroptosis and interleukin-1β release in a viral hemorrhagic infection in zebrafish larvae.

    PubMed

    Varela, Mónica; Romero, Alejandro; Dios, Sonia; van der Vaart, Michiel; Figueras, Antonio; Meijer, Annemarie H; Novoa, Beatriz

    2014-10-01

    Hemorrhagic viral diseases are distributed worldwide with important pathogens, such as dengue virus or hantaviruses. The lack of adequate in vivo infection models has limited the research on viral pathogenesis and the current understanding of the underlying infection mechanisms. Although hemorrhages have been associated with the infection of endothelial cells, other cellular types could be the main targets for hemorrhagic viruses. Our objective was to take advantage of the use of zebrafish larvae in the study of viral hemorrhagic diseases, focusing on the interaction between viruses and host cells. Cellular processes, such as transendothelial migration of leukocytes, virus-induced pyroptosis of macrophages. and interleukin-1β (Il-1β) release, could be observed in individual cells, providing a deeper knowledge of the immune mechanisms implicated in the disease. Furthermore, the application of these techniques to other pathogens will improve the current knowledge of host-pathogen interactions and increase the potential for the discovery of new therapeutic targets. Importance: Pathogenic mechanisms of hemorrhagic viruses are diverse, and most of the research regarding interactions between viruses and host cells has been performed in cell lines that might not be major targets during natural infections. Thus, viral pathogenesis research has been limited because of the lack of adequate in vivo infection models. The understanding of the relative pathogenic roles of the viral agent and the host response to the infection is crucial. This will be facilitated by the establishment of in vivo infection models using organisms such as zebrafish, which allows the study of the diseases in the context of a complete individual. The use of this animal model with other pathogens could improve the current knowledge on host-pathogen interactions and increase the potential for the discovery of new therapeutic targets against diverse viral diseases.

  10. Trypanosoma rangeli: effects of physalin B on the immune reactions of the infected larvae of Rhodnius prolixus.

    PubMed

    Garcia, Eloi S; Castro, Daniele P; Ribeiro, Ivone M; Tomassini, Therezinha C B; Azambuja, Patrícia

    2006-01-01

    Physalins are seco-steroids obtained from plants of the family Solanaceae. Herein, we tested Physalis angulata L purified physalin B as an immunomodulatory compound in 5th-instar larvae of Rhodnius prolixus, which were systemically infected with the H14 Trypanosoma rangeli strain protozoan. In uninfected insects, the effective concentration of physalin B, which inhibited 50% of the blood ingested (ED(50)) volume, was 15.2+/-1.6 microg/ml of the meal. Ecdysis processes and mortality in uninfected larvae, treated orally with physalin B in concentrations ranging from 1 to 10 microg/ml, was similar to that observed in insects not treated with physalin B. However, R. prolixus larvae previously fed on blood containing 1.0, 0.1, and 0.01 microg of physalin B/ml exhibited mortality rates of 78.1, 54.3, and 12.7%, respectively, 6 days after inoculation of T. rangeli (1 x 10(3) parasites/insect), whereas only 7.2% mortality was observed in the control group, injected with sterile culture medium. The insects treated with physalin B (0.1 microg/ml) and inoculated with T. rangeli did not modify the phenoloxidase (PO) activity and total hemocyte count in the hemolymph. However, physalin B treatment caused a reduction in hemocyte micro-aggregation and nitric oxide production and enhanced the parasitemia in the hemolymph. These results demonstrate that physalin B from P. angulata is a potent immunomodulatory substance for the bloodsucking insect, R. prolixus.

  11. Radiolabeling of infective larvae of Haemonchus contortus (Nematoda: Trichostrongyloidea) with /sup 75/Se-methionine and their performance as tracers in sheep

    SciTech Connect

    Georgi, J.R.; Le Jambre, L.F.

    1983-10-01

    Haemonchus contortus infective larvae incorporated between 5 and 12 pCi/larva for each muCi of /sup 75/Se-methionine added per gram of fecal sediment. Thorough admixture of /sup 75/Se-methionine and fecal sediment was necessary to obtain approximately normal distribution and low variance of individual larval radioactivities. Ecdysis induced by treatment with 0.025% HClO in vitro resulted in loss of approximately 40% of the /sup 75/Se label of infective larvae. Loss of /sup 75/Se by parasitic larvae and adult H. contortus in vivo conformed to a two-component negative exponential function with half lives of 3.1 and 56 days acting on compartments representing 90% and 10%, respectively, of the /sup 75/Se label remaining after ecdysis. Labeled and unlabeled worms were readily distinguished by autoradiography 37 days after infection. No effect of gamma radiation arising from decay of /sup 75/Se in the range 130 to 1,300 pCi/larva could be measured in terms of survival or sex ratio of worms recovered at 17 days PI.

  12. Pineapple juice for digestion of swamp eel viscera for harvesting infective-stage larva of Gnathostoma spp.

    PubMed

    Soogarun, Suphan; Suwansaksri, Jamsai; Wiwanitkit, Viroj

    2004-06-01

    Third-stage larvae were used as antigen in the diagnosis of gnathostomiasis in Western blot analysis. Normally, the larvae were obtained from digestion of eel's liver (Fluta alba) by the enzyme pepsin. We used pineapple juice (Ananus comosus) instead of enzyme pepsin in harvesting Gnathostoma spinigerum third-stage larvae. The difference in recovered larvae numbers, between pineapple juice and pepsin, were not statistically significantly different (p>0.05). The larvae from pepsin and pineapple juice digestion were cultivated on BME for 7 days; the survival rates were not significantly different (p>0.05). Thus, pineapple juice is another enzyme of choice for recovering Gnathostoma spinigerum third-stage larvae.

  13. Early Detection of Baculovirus Expression and Infection in Lepidopteran Larvae Fed Occlusion Bodies of an AcMNPV Recombinant Carrying a Red Fluorescent Protein Gene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A method has been devised utilizing a baculovirus recombinant (AcMNPV hsp70Red) carrying a red fluorescent protein (RFP) gene under the early heat shock promoter (hsp70) to assess potential infectivity of larvae fed occlusion bodies. A time study was employed whereby first and third instars of Trich...

  14. Morphological and morphometric differentiation of dorsal-spined first stage larvae of lungworms, (Nematoda: Protostrongylidae) infecting muskoxen (Ovibos moschatus) in the Central Canadian Arctic

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Umingmakstrongylus pallikuukensis and Varestrongylus eleguneniensis are the two most common protostrongylid nematodes infecting muskoxen in the North American Arctic and Subarctic. First stage larvae (L1) of both these lungworms have a characteristic dorsal spine originating at the level of proxima...

  15. Characterization and experimental infection of Flexibacter maritimus (Wakabayashi et al. 1986) in hatcheries of post-larvae of Litopenaeus vannamei Boone, 1931.

    PubMed

    Mouriño, J L P; Vinatea, L; Buglione-Neto, C; Ramirez, C T; Vieira, F N; Pedrotti, F; Martins, M L; Derner, R B; Aguilar, M A; Beltrame, E

    2008-02-01

    A preliminary study to characterize filamentous bacteria, whose presence is related to high mortality of Litopenaeus vannamei larvae cultured in Santa Catarina State, Brazil, is reported. The extract of infected larvae was diluted in different concentrations, cultured in marine agar (Difco, Marine Agar 2216) and incubated at 30 degrees C for 48 hours. The biochemical characterization included hydrolytic reactions of starch, gelatin and tyrosine, growth in TCBS agar, growth in 0 and 37 per thousand salinity, pigment production in tyrosine agar, production of H2S, nitrate reduction, congo red reaction, oxidase and catalase. The isolated bacteria belong to the species Flexibacter maritimus, Gram-negative bacilli of 0.4-0.5 microm width and 15 microm length. Experiments were carried out on pathogenicity of F. maritimus in post-larvae of L. vannamei. Survival and symptoms in L. vannamei post-larvae 24 hours after inoculation with F. maritimus and its growth in marine agar were evaluated. Mortality was detected around 92,5% as well as symptoms like melanized lesions in several parts of body, discolouration of gills, bad formation of appendages and of the last abdominal segment, low motility and feeding reduction. The experimental infection results suggested that isolated bacteria of the genus Flexibacter are pathogenic to the shrimp Litopenaeus vannamei post-larvae.

  16. Increase in Gut Microbiota after Immune Suppression in Baculovirus-infected Larvae

    PubMed Central

    Jakubowska, Agata K.; Vogel, Heiko; Herrero, Salvador

    2013-01-01

    Spodoptera exigua microarray was used to determine genes differentially expressed in S. exigua cells challenged with the species-specific baculovirus SeMNPV as well as with a generalist baculovirus, AcMNPV. Microarray results revealed that, in contrast to the host transcriptional shut-off that is expected during baculovirus infection, S. exigua cells showed a balanced number of up- and down-regulated genes during the first 36 hours following the infection. Many immune-related genes, including pattern recognition proteins, genes involved in signalling and immune pathways as well as immune effectors and genes coding for proteins involved in the melanization cascade were found to be down-regulated after baculovirus infection. The down-regulation of immune-related genes was confirmed in the larval gut. The expression of immune-related genes in the gut is known to affect the status of gut microorganisms, many of which are responsible for growth and development functions. We therefore asked whether the down-regulation that occurs after baculovirus infection affects the amount of gut microbiota. An increase in the gut bacterial load was observed and we hypothesize this to be as a consequence of viral infection. Subsequent experiments on virus performance in the presence and absence of gut microbiota revealed that gut bacteria enhanced baculovirus virulence, pathogenicity and dispersion. We discuss the host immune response processes and pathways affected by baculoviruses, as well as the role of gut microbiota in viral infection. PMID:23717206

  17. Predatory activity of the fungus Duddingtonia flagrans in equine strongyle infective larvae on natural pasture in the Southern Region of Brazil.

    PubMed

    de Almeida, Gisane Lanes; Santurio, Janio Morais; Filho, José Osvaldo Jardim; Zanette, Régis Adriel; Camillo, Giovana; Flores, Alexandra Geyer; da Silva, José Henrique Souza; de la Rue, Mário Luiz

    2012-02-01

    Biological control is an alternative method to reduce the population of parasites through natural predators. A promising option of biological control in the reduction of infective larvae on pasture is the use of nematophagous fungi. In this study, the efficacy of the nematophagous fungus Duddingtonia flagrans in controlling gastrointestinal nematode parasites in field-raised horses was tested. Ten foals with an average age of 12 months were divided in two groups: five males constituted the treated group and five females constituted the control group. Each group was introduced in a field of mixed pasture with approximately 5 ha. The treated group received the fungus D. flagrans at a concentration of 10(6) chlamydospores per kilogramme of animal body weight daily, mixed with horse food for 5 months. The control group did not receive the fungus. Samples were collected to perform eggs per gramme (EPG) counts weekly. Coproculture and collection of pasture were done monthly for larvae counting. No significant difference was observed in the EPG counting and in the number of larvae recovered from coprocultures, where cyathostomines, Strongylus and Trichostrongylus spp. were found after monthly larvae counting. No significant difference was observed in the EPG counts, and Trichostrongylus sp. was identified. The number of recovered larvae on pasture was significantly lower in the treated group in the last month of treatment, showing a reduction of 73.5% (p < 0.05). As such, the fungus was able to reduce the number of infective larvae in the pasture. Nevertheless, this did not reflect in a decrease of parasitic infection during the 5-month study period.

  18. The efficacy of a single-oral-dose administration of ivermectin and diethylcarbamazine on the treatment of feline Brugia malayi.

    PubMed

    Chansiri, Gaysorn; Khawsak, Phaisan; Phantana, Sirichai; Sarataphan, Nopporn; Chansiri, Kosum

    2005-09-01

    The combination of ivermectin and diethylcarbamazine (DEC) have been shown to be superior to either drug alone for the suppression of Brugia malayi in humans, but their efficacy against infection with B. malayi in cats has never been investigated. Fourteen asymptomatic microfilaremic (1-200 microfilariae/20 microl blood) cats received oral doses of ivermectin (400 microg/kg body weight) and DEC (6 mg/kg body weight) as a single treatment. A two-month post-treatment examination revealed that 87-100% of the microfilariae in each subject had been cleared, with two of the subjects being amicrofilaremic. A further reduction in microfilarial levels was observed until the final follow-up, at 8 months post-treatment, when the mean clearance rate was 99% and 12 out of the 14 subjects (86%) were amicrofilaremic. The combination of ivermectin and DEC demonstrated a microfilaricidal effect superior to that of either drug used alone, both in the initial rapid clearance of microfilariae, and in sustaining the effect for 8 months. This finding has important implications for the control of brugian lymphatic filariasis in the cat reservoir.

  19. Trichinella spiralis: strong antibody response to a 49 kDa newborn larva antigen in infected rats.

    PubMed

    Salinas-Tobon, Maria Del Rosario; Navarrete-Leon, Anaid; Mendez-Loredo, Blanca Esther; Esquivel-Aguirre, Dalia; Martínez-Abrajan, Dulce Maria; Hernandez-Sanchez, Javier

    2007-02-01

    In this work, we analyzed the kinetics of anti-Trichinella spiralis newborn larva (NBL) antibodies (Ab) and the antigenic recognition pattern of NBL proteins and its dose effects. Wistar rats were infected with 0, 700, 2000, 4000 and 8000 muscle larvae (ML) and bled at different time intervals up to day 31 post infection (p.i.). Ab production was higher with 2000 ML dose and decreased with 8000, 4000 and 700 ML. Abs were not detected until day 10, peaked on day 14 for the 2000 ML dose and on day 19 for the other doses and thereafter declined slowly from 19 to 31 days p.i. In contrast, Abs to ML increased from day 10, peaked on day 19 and remained high until the end of the study. Abs bound strongly at least to three NBL components of 188, 205 and 49 kDa. NBL antigen of 188 and 205 kDa were recognized 10-26 days p.i. and that of 49 kDa from day 10 to day 31 p.i. A weak recognition towards antigens of 52, 54, 62 and 83 kDa was also observed during the infection. An early recognition of 31, 43, 45, 55, 68 and 85 kDa ML antigens was observed whereas the response to those of 43, 45, 48, 60, 64 and 97 kDa (described previously as TSL-1 antigens) occurred late in the infection. A follow-up of antigen recognition up to day 61 with the optimal immunization dose (2000 ML) evidenced a decline of Ab production to the 49 kDa NBL antigen 42 days p.i., which suggested antigenic differences with the previously reported 43 kDa ML antigen strongly recognized late in the infection. To analyze the stage-specificity of the 49 kDa NBL antigen, polyclonal antibodies (PoAb) were obtained in rats immunized with 49 kDa NBL antigen. PoAb reacted strongly with the 49 kDa NBL component in NBL total soluble extract but no reactivity was observed with soluble antigen of the other T. spiralis stages. Albeit with less intensity, the 49 kDa component was also recognized by PoAb together with other antigens of 53, 97 and 107 kDa, in NBL excretory-secretory products (NBL-ESP). Thus, our results reveal

  20. In vivo expression of genes in the entomopathogenic fungus Beauveria bassiana during infection of lepidopteran larvae.

    PubMed

    Galidevara, Sandhya; Reineke, Annette; Koduru, Uma Devi

    2016-05-01

    The entomopathogenic fungus Beauveria bassiana (Bals.) Vuillemin is commercially available as a bio insecticide. The expression of three genes previously identified to have a role in pathogenicity in in vitro studies was validated in vivo in three lepidopteran insects infected with B. bassiana. Expression of all three genes was observed in all the tested insects starting from 48 or 72h to 10d post infection corroborating their role in pathogenicity. We suggest that it is essential to test the expression of putative pathogenicity genes both in vitro and in vivo to understand their role in different insect species.

  1. A novel small heat shock protein 12.6 (HSP12.6) from Brugia malayi functions as a human IL-10 receptor binding protein.

    PubMed

    Gnanasekar, Munirathinam; Anandharaman, Veerapathran; Anand, Setty Balakrishnan; Nutman, Thomas B; Ramaswamy, Kalyanasundaram

    2008-06-01

    Phage display cDNA expression library of the third stage larvae (L3) of Brugia malayi was screened for identifying target(s) that bound to the human interleukin-10 receptor (huIL10R). This iterative screening identified an insert that showed significant homology to Caenorhabditis elegans HSP12.6. The gene was designated B. malayi HSP12.6 (BmHSP12.6) and has orthologues in several gastrointestinal nematode genome (Ancylostoma caninum, Ascaris lumbricoides and Ascaris suum) but the gene or gene product has not been studied further in these parasites. Structural analyses of BmHSP12.6 showed that it has a highly conserved alpha-crystallin central domain that is characteristic of other small heat shock proteins (HSPs). BmHSP12.6 has a short N-terminal domain and an unusually small C-terminal domain flanking the crystallin domain suggesting that this protein belongs to a novel class of small HSPs. BmHSP12.6 appears to be differentially transcribed with highest expression in the vertebrate stages of the parasite (L4, adult and mf) compared to its mosquito vector stage (L3). More importantly recombinant BmHSP12.6 bound to huIL10R in a dose dependent fashion and inhibited the binding of human IL-10 (huIL10) to huIL10R in vitro. rBmHSP12.6 also enhanced the growth and proliferation of MC/9 mast cells in vitro similar to huIL10. This study thus describes a novel small HSP from B. malayi that has the capacity to bind to huIL10R, block binding of huIL10 to huIL10R and function similar to huIL10.

  2. Filarial infection influences mosquito behaviour and fecundity

    PubMed Central

    Gleave, Katherine; Cook, Darren; Taylor, Mark J.; Reimer, Lisa J.

    2016-01-01

    Understanding vector-parasite interactions is increasingly important as we move towards the endpoint goals set by the Global Programme for the Elimination of Lymphatic Filariasis (GPELF), as interaction dynamics may change with reduced transmission pressure. Elimination models used to predict programmatic endpoints include parameters for vector-specific transmission dynamics, despite the fact that our knowledge of the host-seeking behaviour of filariasis infected mosquitoes is lacking. We observed a dynamic, stage-specific and density dependent change in Aedes aegypti behaviour towards host cues when exposed to Brugia malayi filarial parasites. Infected mosquitoes exhibited reduced activation and flight towards a host during the period of larval development (L1/L2), transitioning to a 5 fold increase in activation and flight towards a host when infective stage larvae (L3) were present (p < 0.001). In uninfected control mosquitoes, we observed a reduction in convergence towards a host during the same period. Furthermore, this behaviour was density dependent with non-activated mosquitoes harbouring a greater burden of L1 and L2 larvae while activated mosquitoes harboured a greater number of L3 (p < 0.001). Reductions in fecundity were also density-dependent, and extended to mosquitoes that were exposed to microfilariae but did not support larval development. PMID:27796352

  3. Pre-exposure to yeast protects larvae of Galleria mellonella from a subsequent lethal infection by Candida albicans and is mediated by the increased expression of antimicrobial peptides.

    PubMed

    Bergin, David; Murphy, Lisa; Keenan, Joanne; Clynes, Martin; Kavanagh, Kevin

    2006-07-01

    Pre-exposure of the larvae of Galleria mellonella to Candida albicans or Saccharomyces cerevisiae protects against a subsequent infection with 10(6) C. albicans cells. This protection can also be induced by exposing larvae to glucan or laminarin prior to the administration of the potentially lethal inoculum. Analysis of the genes coding for galiomicin, a defensin in G. mellonella, a cysteine-rich antifungal peptide gallerimycin, an iron-binding protein transferrin and an inducible metalloproteinase inhibitor (IMPI) from G. mellonella demonstrated increased expression, which is at its highest after 24 h of the initial inoculum. Examination of the expression of proteins in the insect haemolymph using 2D electrophoresis and MALDI TOF analysis revealed an increased expression of a number of proteins associated with the insect immune response to infection 24 h after the initial exposure. This study demonstrates that the larvae of G. mellonella can withstand a lethal inoculum of C. albicans if pre-exposed to a non-lethal dose of yeast or polysaccharide 24 h previously which is mediated by increased expression of a number of antimicrobial peptides and the appearance of a number of peptides in the challenged larvae.

  4. Integration of insecticidal protein Vip3Aa1 into Beauveria bassiana enhances fungal virulence to Spodoptera litura larvae by cuticle and per Os infection.

    PubMed

    Qin, Yi; Ying, Sheng-Hua; Chen, Ying; Shen, Zhi-Cheng; Feng, Ming-Guang

    2010-07-01

    The entomopathogenic fungus Beauveria bassiana acts slowly on insect pests through cuticle infection. Vegetative insecticidal proteins (Vip3A) of Bacillus thuringiensis kill lepidopteran pests rapidly, via per os infection, but their use for pest control is restricted to integration into transgenic plants. A transgenic B. bassiana strain (BbV28) expressing Vip3Aa1 (a Vip3A toxin) was thus created to infect the larvae of the oriental leafworm moth Spodoptera litura through conidial ingestion and cuticle adhesion. Vip3Aa1 ( approximately 88 kDa) was highly expressed in the conidial cytoplasm of BbV28 and was detected as a digested form ( approximately 62 kDa) in the larval midgut 18 and 36 h after conidial ingestion. The median lethal concentration (LC(50)) of BbV28 against the second-instar larvae feeding on cabbage leaves sprayed with conidial suspensions was 26.2-fold lower than that of the wild-type strain on day 3 and 1.1-fold lower on day 7. The same sprays applied to both larvae and leaves for their feeding reduced the LC(50) of the transformant 17.2- and 1.3-fold on days 3 and 7, respectively. Median lethal times (LT(50)s) of BbV28 were shortened by 23 to 35%, declining with conidial concentrations. The larvae infected by ingestion of BbV28 conidia showed typical symptoms of Vip3A action, i.e., shrinkage and palsy. However, neither LC(50) nor LT(50) trends differed between BbV28 and its parental strain if the infection occurred through the cuticle only. Our findings indicate that fungal conidia can be used as vectors for spreading the highly insecticidal Vip3A protein for control of foliage feeders such as S. litura.

  5. Whole-cell patch-clamp recording of nicotinic acetylcholine receptors in adult Brugia malayi muscle

    PubMed Central

    Robertson, A. P.; Buxton, S. K.; Martin, R. J.

    2013-01-01

    Lymphatic filariasis is a debilitating disease caused by clade III parasites like Brugia malayi and Wuchereria bancrofti. Current recommended treatment regimen for this disease relies on albendazole, ivermectin and diethylcarbamazine, none of which targets the nicotinic acetylcholine receptors in these parasitic nematodes. Our aim therefore has been to develop adult B. malayi for electrophysiological recordings to aid in characterizing the ion channels in this parasite as anthelmintic target sites. In that regard, we recently demonstrated the amenability of adult B. malayi to patch-clamp recordings and presented results on the single-channel properties of nAChR in this nematode. We have built on this by recording whole-cell nAChR currents from adult B. malayi muscle. Acetylcholine, levamisole, pyrantel, bephenium and tribendimidine activated the receptors on B. malayi muscle, producing robust currents ranging from > 200 pA to ~1.5 nA. Levamisole completely inhibited motility of the adult B. malayi within 10 min and after 60 min, motility had recovered back to control values. PMID:23562945

  6. In vitro anthelmintic activity of five tropical legumes on the exsheathment and motility of Haemonchus contortus infective larvae.

    PubMed

    von Son-de Fernex, Elke; Alonso-Díaz, Miguel Angel; Valles-de la Mora, Braulio; Capetillo-Leal, Concepción M

    2012-08-01

    This study investigated the in vitro anthelmintic (AH) activity of five tropical legume plants [Arachis pintoi CIAT 22160 (A.p. 22160), Gliricidia sepium, Cratylia argentea (C.a. Yacapani), C. argentea CIAT 22386 (C.a. 22386), C. argentea Veranera (C.a. Veranera)] against Haemonchus contortus infective larvae and the role of tannins/polyphenolic compounds in the AH effect. Lyophilized leaf extracts of each plant were evaluated using the Larval Exsheathment Inhibition Assay (LEIA) and the larval migration inhibition assay (LMIA). The role of tannins/polyphenolic compounds in the AH effect was evaluated in both assays using polyethylene glycol (PEG) to remove tannins from the solutions. At the highest concentration (1200μg of extract/ml), A. pintoi 22160, C.a. Yacapani, C.a. Veranera and C.a. 22386 completely inhibited the exsheathment process of H. contortus (P<0.01). At the same concentration (1200μg of extract/ml), the inhibition of larval migration for C.a. 22386, C.a. Veranera and G. sepium was 66.0%, 35.9% and 39.2% (relative to the PBS control), respectively. In both bioassays (LEIA and LMIA), the AH effect shown by each plant was blocked after the addition of polyethylene glycol (PEG), corroborating the role of tannins/polyphenolic compounds.

  7. Fungal Antagonism Assessment of Predatory Species and Producers Metabolites and Their Effectiveness on Haemonchus contortus Infective Larvae

    PubMed Central

    Silva, Manoel Eduardo; Braga, Fabio Ribeiro; de Gives, Pedro Mendoza; Millán-Orozco, Jair; Uriostegui, Miguel Angel Mercado; Marcelino, Liliana Aguilar; Soares, Filippe Elias de Freitas; Araújo, Andréia Luiza; Vargas, Thainá Souza; Aguiar, Anderson Rocha; Senna, Thiago; Rodrigues, Maria Gorete; Froes, Frederico Vieira; de Araújo, Jackson Victor

    2015-01-01

    The objective of this study was to assess antagonism of nematophagous fungi and species producers metabolites and their effectiveness on Haemonchus contortus infective larvae (L3). Assay A assesses the synergistic, additive, or antagonistic effect on the production of spores of fungal isolates of the species Duddingtonia flagrans, Clonostachys rosea, Trichoderma esau, and Arthrobotrys musiformis; Assay B evaluates in vitro the effect of intercropping of these isolates grown in 2% water-agar (2% WA) on L3 of H. contortus. D. flagrans (Assay A) produced 5.3 × 106 spores and associated with T. esau, A. musiformis, or C. rosea reduced its production by 60.37, 45.28, and 49.05%, respectively. T. esau produced 7.9 × 107 conidia and associated with D. flagrans, A. musiformis, or C. rosea reduced its production by 39.24, 82.27, and 96.96%, respectively. A. musiformis produced 7.3 × 109 spores and associated with D. flagrans, T. esau, or C. rosea reduced its production by 99.98, 99.99, and 99.98%, respectively. C. rosea produced 7.3 × 108 conidia and associated with D. flagrans, T. esau, or A. musiformis reduced its production by 95.20, 96.84, and 93.56%, respectively. These results show evidence of antagonism in the production of spores between predators fungi. PMID:26504791

  8. Candida parapsilosis Resistance to Fluconazole: Molecular Mechanisms and In Vivo Impact in Infected Galleria mellonella Larvae.

    PubMed

    Souza, Ana Carolina R; Fuchs, Beth Burgwyn; Pinhati, Henrique M S; Siqueira, Ricardo A; Hagen, Ferry; Meis, Jacques F; Mylonakis, Eleftherios; Colombo, Arnaldo L

    2015-10-01

    Candida parapsilosis is the main non-albicans Candida species isolated from patients in Latin America. Mutations in the ERG11 gene and overexpression of membrane transporter proteins have been linked to fluconazole resistance. The aim of this study was to evaluate the molecular mechanisms in fluconazole-resistant strains of C. parapsilosis isolated from critically ill patients. The identities of the nine collected C. parapsilosis isolates at the species level were confirmed through molecular identification with a TaqMan qPCR assay. The clonal origin of the strains was checked by microsatellite typing. The Galleria mellonella infection model was used to confirm in vitro resistance. We assessed the presence of ERG11 mutations, as well as the expression of ERG11 and two additional genes that contribute to antifungal resistance (CDR1 and MDR1), by using real-time quantitative PCR. All of the C. parapsilosis (sensu stricto) isolates tested exhibited fluconazole MICs between 8 and 16 μg/ml. The in vitro data were confirmed by the failure of fluconazole in the treatment of G. mellonella infected with fluconazole-resistant strains of C. parapsilosis. Sequencing of the ERG11 gene revealed a common mutation leading to a Y132F amino acid substitution in all of the isolates, a finding consistent with their clonal origin. After fluconazole exposure, overexpression was noted for ERG11, CDR1, and MDR1 in 9/9, 9/9, and 2/9 strains, respectively. We demonstrated that a combination of molecular mechanisms, including the presence of point mutations in the ERG11 gene, overexpression of ERG11, and genes encoding efflux pumps, are involved in fluconazole resistance in C. parapsilosis.

  9. Candida parapsilosis Resistance to Fluconazole: Molecular Mechanisms and In Vivo Impact in Infected Galleria mellonella Larvae

    PubMed Central

    Souza, Ana Carolina R.; Fuchs, Beth Burgwyn; Pinhati, Henrique M. S.; Siqueira, Ricardo A.; Hagen, Ferry; Meis, Jacques F.

    2015-01-01

    Candida parapsilosis is the main non-albicans Candida species isolated from patients in Latin America. Mutations in the ERG11 gene and overexpression of membrane transporter proteins have been linked to fluconazole resistance. The aim of this study was to evaluate the molecular mechanisms in fluconazole-resistant strains of C. parapsilosis isolated from critically ill patients. The identities of the nine collected C. parapsilosis isolates at the species level were confirmed through molecular identification with a TaqMan qPCR assay. The clonal origin of the strains was checked by microsatellite typing. The Galleria mellonella infection model was used to confirm in vitro resistance. We assessed the presence of ERG11 mutations, as well as the expression of ERG11 and two additional genes that contribute to antifungal resistance (CDR1 and MDR1), by using real-time quantitative PCR. All of the C. parapsilosis (sensu stricto) isolates tested exhibited fluconazole MICs between 8 and 16 μg/ml. The in vitro data were confirmed by the failure of fluconazole in the treatment of G. mellonella infected with fluconazole-resistant strains of C. parapsilosis. Sequencing of the ERG11 gene revealed a common mutation leading to a Y132F amino acid substitution in all of the isolates, a finding consistent with their clonal origin. After fluconazole exposure, overexpression was noted for ERG11, CDR1, and MDR1 in 9/9, 9/9, and 2/9 strains, respectively. We demonstrated that a combination of molecular mechanisms, including the presence of point mutations in the ERG11 gene, overexpression of ERG11, and genes encoding efflux pumps, are involved in fluconazole resistance in C. parapsilosis. PMID:26259795

  10. Baylisascaris Larva Migrans

    USGS Publications Warehouse

    Kazacos, Kevin R.; Abbott, Rachel C.; Van Riper, Charles

    2016-05-26

    SummaryBaylisascaris procyonis, the common raccoon roundworm, is the most commonly recognized cause of clinical larva migrans (LM) in animals, a condition in which an immature parasitic worm or larva migrates in a host animal’s tissues, causing obvious disease. Infection with B. procyonis is best known as a cause of fatal or severe neurologic disease that results when the larvae invade the brain, the spinal cord, or both; this condition is known as neural larva migrans (NLM). Baylisascariasis is a zoonotic disease, that is, one that is transmissible from animals to humans. In humans, B. procyonis can cause damaging visceral (VLM), ocular (OLM), and neural larva migrans. Due to the ubiquity of infected raccoons around humans, there is considerable human exposure and risk of infection with this parasite. The remarkable disease-producing capability of B. procyonis in animals and humans is one of the most significant aspects of the biology of ascarids (large roundworms) to come to light in recent years. Infection with B. procyonis has important health implications for a wide variety of free-ranging and captive wildlife, zoo animals, domestic animals, as well as human beings, on both an individual and population level. This report, eighth in the series of U.S. Geological Survey Circulars on zoonotic diseases, will help us to better understand the routes of Baylisascaris procyonis infections and how best to adequately monitor this zoonotic disease.

  11. Release of Small RNA-containing Exosome-like Vesicles from the Human Filarial Parasite Brugia malayi

    PubMed Central

    Agbedanu, Prince N; Harischandra, Hiruni; Moorhead, Andrew R; Day, Tim A; Bartholomay, Lyric C; Kimber, Michael J

    2015-01-01

    Lymphatic filariasis (LF) is a socio-economically devastating mosquito-borne Neglected Tropical Disease caused by parasitic filarial nematodes. The interaction between the parasite and host, both mosquito and human, during infection, development and persistence is dynamic and delicately balanced. Manipulation of this interface to the detriment of the parasite is a promising potential avenue to develop disease therapies but is prevented by our very limited understanding of the host-parasite relationship. Exosomes are bioactive small vesicles (30–120 nm) secreted by a wide range of cell types and involved in a wide range of physiological processes. Here, we report the identification and partial characterization of exosome-like vesicles (ELVs) released from the infective L3 stage of the human filarial parasite Brugia malayi. Exosome-like vesicles were isolated from parasites in culture media and electron microscopy and nanoparticle tracking analysis were used to confirm that vesicles produced by juvenile B. malayi are exosome-like based on size and morphology. We show that loss of parasite viability correlates with a time-dependent decay in vesicle size specificity and rate of release. The protein cargo of these vesicles is shown to include common exosomal protein markers and putative effector proteins. These Brugia-derived vesicles contain small RNA species that include microRNAs with host homology, suggesting a potential role in host manipulation. Confocal microscopy shows J774A.1, a murine macrophage cell line, internalize purified ELVs, and we demonstrate that these ELVs effectively stimulate a classically activated macrophage phenotype in J774A.1. To our knowledge, this is the first report of exosome-like vesicle release by a human parasitic nematode and our data suggest a novel mechanism by which human parasitic nematodes may actively direct the host responses to infection. Further interrogation of the makeup and function of these bioactive vesicles could seed

  12. Biological control of Haemonchus contortus infective larvae in ovine faeces by administering an oral suspension of Duddingtonia flagrans chlamydospores to sheep.

    PubMed

    Mendoza de Gives, P; Flores Crespo, J; Herrera Rodriguez, D; Vazquez Prats, V; Liebano Hernandez, E; Ontiveros Fernandez, G E

    1998-12-01

    A single oral dose of an aqueous suspension containing 11,350,000 chlamydospores of a Mexican isolate of Duddingtonia flagrans (FTHO-8) given to sheep, resulted in a maximum reduction of 88% (range 86.7-90.4%) of the population of Haemonchus contortus infective larvae in the faeces. The effect of this treatment continued for 4-5 days after administration of the suspension. The possible use of this treatment as a method of control of ovine haemonchosis is discussed.

  13. Taenia taeniaeformis: fate and proliferation of mucosal cells during gastric hyperplasia in larvae infected rats.

    PubMed

    Lagapa, J T; Oku, Y; Nonaka, N; Kamiya, M

    2008-04-01

    Fate and proliferation of gastric mucosal cells during hyperplasia of Taenia taeniaeformis eggs inoculated Wistar rats were investigated using PCNA immunohistochemistry, BrdU labeling and other histopathologic staining techniques. Results revealed marked cell proliferation in gastric corpus and antral mucosa of infected rats as evidenced by increased lengths of proliferative zones and indices of BrdU labeling. The gastropathy in corpus was characterized by massive accumulation of precursors, neck and intermediate cells following significant decreases in numbers of parietal and zymogenic cells. Gastropathy in antrum was described with significant increases in precursors and mucous cells. Our results suggested that T. taeniaeformis-induced gastric hyperplasia was initiated by depletion of parietal cells presumably due to the cestode's ES products. As a result, there was inhibition of zymogenic cell differentiation due to the disruption of normal development pathways of gastric mucosal lineages. These sequences of events were considered to cause the increase in cell proliferation and accumulation of intermediate cells resulting to the hyperplastic lesions.

  14. Molecular cloning, purification and characterization of Brugia malayi phosphoglycerate kinase.

    PubMed

    Kumar, Ranjeet; Doharey, Pawan Kumar; Saxena, Jitendra Kumar; Rathaur, Sushma

    2017-04-01

    Phosphoglycerate kinase (PGK) is a glycolytic enzyme present in many parasites. It has been reported as a candidate molecule for drug and vaccine developments. In the present study, a full-length cDNA encoding the Brugia malayi 3-phosphoglycerate kinase (BmPGK) with an open reading frame of 1.3 kb was isolated and PCR amplified and cloned. The exact size of the BmPGK's ORF is 1377 bps. The BmPGK gene was subcloned into pET-28a (+) expression vector, the expressed enzyme was purified by affinity column and characterized. The SDS-PAGE analysis revealed native molecular weight of recombinant Brugia malayi 3-phosphoglycerate kinase (rBmPGK) to be ∼45 kDa. The enzyme was found sensitive to temperature and pH, it showed maximum activity at 25 °C and pH 8.5. The Km values for PGA and ATP were 1.77 and 0.967 mM, respectively. The PGK inhibitor, clorsulon and antifilarial drugs albendazole and ivermectin inhibited the enzyme. The specific inhibitor of PGK, clorsulon, competitively inhibited enzyme with Ki value 1.88 μM. Albendazole also inhibited PGK competitively with Ki value 35.39 μM. Further these inhibitory studies were confirmed by docking and molecular simulation of drugs with enzyme. Clorsulon interacted with substrate binding site with glutamine 37 as well as in hinge regions with aspartic acid 385 and valine 387 at ADP binding site. On the other hand albendazole interacted with asparagine 335 residues. These effects were in good association with binding interactions. Thus current study might help in designing and synthesis of effective inhibitors for this novel drug target and understanding their mode of interaction with the potent anthelmintic drugs.

  15. Differential transcript expression between the microfilariae of the filarial nematodes, Brugia malayi and B. pahangi

    PubMed Central

    2010-01-01

    Background Brugia malayi and B. pahangi are two closely related nematodes that cause filariasis in humans and animals. However, B. pahangi microfilariae are able to develop in and be transmitted by the mosquito, Armigeres subalbatus, whereas most B. malayi are rapidly melanized and destroyed within the mosquito hemocoel. A cross-species microarray analysis employing the B. malayi V2 array was carried out to determine the transcriptional differences between B. malayi and B. pahangi microfilariae with similar age distribution. Results Following microarray data analysis, a list of preferentially expressed genes in both microfilariae species was generated with a false discovery rate estimate of 5% and a signal intensity ratio of 2 or higher in either species. A total of 308 probes were preferentially expressed in both species with 149 probes, representing 123 genes, in B. pahangi microfilariae and 159 probes, representing 107 genes, in B. malayi microfilariae. In B. pahangi, there were 76 (62%) up-regulated transcripts that coded for known proteins that mapped into the KEGG pathway compared to 61 (57%) transcripts in B. malayi microfilariae. The remaining 47 (38%) transcripts in B. pahangi and 46 (43%) transcripts in B. malayi microfilariae were comprised almost entirely of hypothetical genes of unknown function. Twenty-seven of the transcripts in B. pahangi microfilariae coded for proteins that associate with the secretory pathway compared to thirty-nine in B. malayi microfilariae. The data obtained from real-time PCR analysis of ten genes selected from the microarray list of preferentially expressed genes showed good concordance with the microarray data, indicating that the microarray data were reproducible. Conclusion In this study, we identified gene transcripts that were preferentially expressed in the microfilariae of B. pahangi and B. malayi, some of which coded for known immunomodulatory proteins. These comparative transcriptome data will be of interest to

  16. Larvae of chigger mites Neotrombicula spp. (Acari: Trombiculidae) exhibited Borrelia but no Anaplasma infections: a field study including birds from the Czech Carpathians as hosts of chiggers.

    PubMed

    Literak, Ivan; Stekolnikov, Alexandr A; Sychra, Oldrich; Dubska, Lenka; Taragelova, Veronika

    2008-04-01

    Chigger mites were collected from 1,080 wild birds of 37 species at Certak (Czech Republic), in the western Carpathian Mountains, from 29 July to 24 September 2005. The prevalence of infestation with chigger larvae was 7%. A total of 325 chigger specimens from 10 bird species was identified and three chigger species were found: Neotrombicula autumnalis, N. carpathica, and N. inopinata, the latter two species being reported on new hosts. Neotrombicula carpathica is reported in the Czech Republic for the first time. A total of 509 chigger larvae found on 79 host specimens were examined by polymerase chain reaction (PCR) for the presence of Borrelia burgdorferi s.l. DNA (fragments of the rrf (5S)--rrl (23S) intergenic spacer), and Anaplasma phagocytophilum DNA (epank1 gene). A fragment of specific Borrelia DNA was amplified through PCR in one sample, and the PCR product was further analyzed by reverse line blotting assay, whereby both genospecies of B. garinii and B. valaisiana were proved. This sample pooled five chigger larvae collected from one Sylvia atricapilla on 11 August 2005. No A. phagocytophilum DNA was amplified. We conclude that larvae of the genus Neotrombicula can be infected with Borrelia genospecies originated from their present or former hosts.

  17. [Effects of aqueous extracts of Mentha piperita L. and Chenopodium ambrosioides L. leaves in infective larvae cultures of gastrointestinal nematodes of goats].

    PubMed

    De Almeida, Maria Angela O; Domingues, Luciana F; Almeida, Gisele N; Simas, Mônica Mattos Dos S; Botura, Mariana B; Da Cruz, Ana Carla Ferreira G; Da Silva, Ana Valéria Araújo F; Menezes, Taise P; Batatinha, Maria José M

    2007-01-01

    Phitotherapy has been frequently utilized in parasitism control for numerous animal species. The aim of this experiment was to evaluate the in vitro effects of aqueous extracts of Mentha piperita L. and Chenopodium ambrosioides L. leaves in larvae cultures of gastrointestinal nematodes of goats. Six different concentrations of M. piperita extracts (196; 150.7; 115.9; 89.1; 68.5 e 52.7 mg/mL) and C. ambrosioides extracts (110,6; 85; 65,3; 50,2; 38,6 e 29,6 mg/mL) were used for the treatment of larvae cultures, in triple assays. Distilled water and doramectin were used in larvae cultures as negative and positive controls, respectively. The results revealed a reduction of more than 95% of the infective larvae when M. piperita extracts were used in the concentrations of 115.9 and 196 mg/mL, and C. ambrosioides extract in the concentration of 110.6 mg/mL, supporting the effect of these extracts in the in vitro treatment of gastrointestinal nematodes of goats.

  18. Brugia malayi Asparaginyl - tRNA Synthetase Stimulates Endothelial Cell Proliferation, Vasodilation and Angiogenesis

    PubMed Central

    D, Jeeva Jothi; Dhanraj, Muthu; Solaiappan, Shanmugam; Sivanesan, Sanjana; Kron, Michael; Dhanasekaran, Anuradha

    2016-01-01

    A hallmark of chronic infection with lymphatic filarial parasites is the development of lymphatic disease which often results in permanent vasodilation and lymphedema, but all of the mechanisms by which filarial parasites induce pathology are not known. Prior work showed that the asparaginyl-tRNA synthetase (BmAsnRS) of Brugia malayi, an etiological agent of lymphatic filariasis, acts as a physiocrine that binds specifically to interleukin-8 (IL-8) chemokine receptors. Endothelial cells are one of the many cell types that express IL-8 receptors. IL-8 also has been reported previously to induce angiogenesis and vasodilation, however, the effect of BmAsnRS on endothelial cells has not been reported. Therefore, we tested the hypothesis that BmAsnRS might produce physiological changes in endothelial by studying the in vitro effects of BmAsnRS using a human umbilical vein cell line EA.hy926 and six different endothelial cell assays. Our results demonstrated that BmAsnRS produces consistent and statistically significant effects on endothelial cells that are identical to the effects of VEGF, vascular endothelial growth factor. This study supports the idea that new drugs or immunotherapies that counteract the adverse effects of parasite-derived physiocrines may prevent or ameliorate the vascular pathology observed in patients with lymphatic filariasis. PMID:26751209

  19. Glucose and Glycogen Metabolism in Brugia malayi Is Associated with Wolbachia Symbiont Fitness

    PubMed Central

    Voronin, Denis; Bachu, Saheed; Shlossman, Michael; Unnasch, Thomas R.; Ghedin, Elodie; Lustigman, Sara

    2016-01-01

    Wolbachia are endosymbiotic bacteria found in the majority of arthropods and filarial nematodes of medical and veterinary importance. They have evolved a wide range of symbiotic associations. In filarial nematodes that cause human lymphatic filariasis (Wuchereria bancrofti, Brugia malayi) or onchocerciasis (Onchocerca volvulus), Wolbachia are important for parasite development, reproduction and survival. The symbiotic bacteria rely in part on nutrients and energy sources provided by the host. Genomic analyses suggest that the strain of Wolbachia found in B. malayi (wBm) lacks the genes for two glycolytic enzymes—6-phosphofructokinase and pyruvate kinase—and is thus potentially unable to convert glucose into pyruvate, an important substrate for energy generation. The Wolbachia surface protein, wBm00432, is complexed to six B. malayi glycolytic enzymes, including aldolase. In this study we characterized two B. malayi aldolase isozymes and found that their expression is dependent on Wolbachia fitness and number. We confirmed by immuno-transmission electron microscopy that aldolase is associated with the Wolbachia surface. RNAi experiments suggested that aldolase-2 plays a significant role in both Wolbachia survival and embryogenesis in B. malayi. Treatment with doxycycline reduced Wolbachia fitness and increased the amount of both glucose and glycogen detected in the filarial parasite, indicating that glucose metabolism and glycogen storage in B. malayi are associated with Wolbachia fitness. This metabolic co-dependency between Wolbachia and its filarial nematode indicates that glycolysis could be a shared metabolic pathway between the bacteria and B. malayi, and thus a potential new target for anti-filarial therapy. PMID:27078260

  20. Glucose and Glycogen Metabolism in Brugia malayi Is Associated with Wolbachia Symbiont Fitness.

    PubMed

    Voronin, Denis; Bachu, Saheed; Shlossman, Michael; Unnasch, Thomas R; Ghedin, Elodie; Lustigman, Sara

    2016-01-01

    Wolbachia are endosymbiotic bacteria found in the majority of arthropods and filarial nematodes of medical and veterinary importance. They have evolved a wide range of symbiotic associations. In filarial nematodes that cause human lymphatic filariasis (Wuchereria bancrofti, Brugia malayi) or onchocerciasis (Onchocerca volvulus), Wolbachia are important for parasite development, reproduction and survival. The symbiotic bacteria rely in part on nutrients and energy sources provided by the host. Genomic analyses suggest that the strain of Wolbachia found in B. malayi (wBm) lacks the genes for two glycolytic enzymes--6-phosphofructokinase and pyruvate kinase--and is thus potentially unable to convert glucose into pyruvate, an important substrate for energy generation. The Wolbachia surface protein, wBm00432, is complexed to six B. malayi glycolytic enzymes, including aldolase. In this study we characterized two B. malayi aldolase isozymes and found that their expression is dependent on Wolbachia fitness and number. We confirmed by immuno-transmission electron microscopy that aldolase is associated with the Wolbachia surface. RNAi experiments suggested that aldolase-2 plays a significant role in both Wolbachia survival and embryogenesis in B. malayi. Treatment with doxycycline reduced Wolbachia fitness and increased the amount of both glucose and glycogen detected in the filarial parasite, indicating that glucose metabolism and glycogen storage in B. malayi are associated with Wolbachia fitness. This metabolic co-dependency between Wolbachia and its filarial nematode indicates that glycolysis could be a shared metabolic pathway between the bacteria and B. malayi, and thus a potential new target for anti-filarial therapy.

  1. Identification and characterization of nematode specific protective epitopes of Brugia malayi TRX towards development of synthetic vaccine construct for lymphatic filariasis.

    PubMed

    Madhumathi, Jayaprakasam; Prince, Prabhu Rajaiah; Anugraha, Gandhirajan; Kiran, Pote; Rao, Donthamsetty Nageswara; Reddy, Maryada Venkata Rami; Kaliraj, Perumal

    2010-07-12

    Although multi-epitope vaccines have been evaluated for various diseases, they have not yet been investigated for lymphatic filariasis. Here, we report for the first time identification of two immunodominant B epitopes (TRXP1 and TRXP2) from the antioxidant Brugia malayi thioredoxin by studying their immune responses in mice model and human subjects. TRXP1 was also found to harbor a T epitope recognized by human PBMCs and mice splenocytes. Further, the epitopic peptides were synthesized as a single peptide conjugate (PC1) and their prophylactic efficacy was tested in a murine model of filariasis with L3 larvae. PC1 conferred a significantly high protection (75.14%) (P < 0.0001) compared to control (3.7%) and recombinant TRX (63.03%) (P < 0.018) in experimental filariasis. Our results suggest that multi-epitope vaccines could be a promising strategy in the control of lymphatic filariasis.

  2. Diethylcarbamazine activity against Brugia malayi microfilariae is dependent on inducible nitric-oxide synthase and the cyclooxygenase pathway

    PubMed Central

    McGarry, Helen F; Plant, Leigh D; Taylor, Mark J

    2005-01-01

    Background Diethylcarbamazine (DEC) has been used for many years in the treatment of human lymphatic filariasis. Its mode of action is not well understood, but it is known to interact with the arachidonic acid pathway. Here we have investigated the contribution of the nitric oxide and cyclooxygenase (COX) pathways to the activity of DEC against B. malayi microfilariae in mice. Methods B. malayi microfilariae were injected intravenously into mice and parasitaemia was measured 24 hours later. DEC was then administered to BALB/c mice with and without pre-treatment with indomethacin or dexamethasone and the parasitaemia monitored. To investigate a role for inducible nitric oxide in DEC's activity, DEC and ivermectin were administered to microfilaraemic iNOS-/- mice and their background strain (129/SV). Western blot analysis was used to determine any effect of DEC on the production of COX and inducible nitric-oxide synthase (iNOS) proteins. Results DEC administered alone to BALB/c mice resulted in a rapid and profound reduction in circulating microfilariae within five minutes of treatment. Microfilarial levels began to recover after 24 hours and returned to near pre-treatment levels two weeks later, suggesting that the sequestration of microfilariae occurs independently of parasite killing. Pre-treatment of animals with dexamethasone or indomethacin reduced DEC's efficacy by almost 90% or 56%, respectively, supporting a role for the arachidonic acid and cyclooxygenase pathways in vivo. Furthermore, experiments showed that treatment with DEC results in a reduction in the amount of COX-1 protein in peritoneal exudate cells. Additionally, in iNOS-/- mice infected with B. malayi microfilariae, DEC showed no activity, whereas the efficacy of another antifilarial drug, ivermectin, was unaffected. Conclusion These results confirm the important role of the arachidonic acid metabolic pathway in DEC's mechanism of action in vivo and show that in addition to its effects on the 5

  3. First record of the insect pathogenic alga Helicosporidium sp. (Chlorophyta: Trebouxiophyceae) infection in larvae and pupae of Rhizophagusgrandis Gyll. (Coleoptera, Rhizophaginae) from Turkey.

    PubMed

    Yaman, Mustafa; Radek, Renate; Aydin, Ciçek; Tosun, Onur; Ertürk, Omer

    2009-10-01

    The predator beetle Rhizophagus grandis Gyll. (Coleoptera, Rhizophaginae) is one of the most important biological control agents, mass-bred and used to suppress populations of an important pest: the great spruce bark beetle, Dendroctonus micans. The achlorophyllous alga Helicosporidium sp. was first discovered in the pest. Later it was also found in the predator, but only in the adults. In this study, the pathogenic alga Helicosporidium sp. was discovered in larvae and early pupae of R. grandis for the first time. The morphological characteristics of the pathogenic alga were revealed by light and electron microscopy. Infection rates of Helicosporidium sp. in the larvae and pupae of R. grandis were 23.5% and 6.25%, respectively.

  4. Physicochemical properties of the modeled structure of astacin metalloprotease moulting enzyme NAS-36 and mapping the druggable allosteric space of Heamonchus contortus, Brugia malayi and Ceanorhabditis elegans via molecular dynamics simulation.

    PubMed

    Sharma, Om Prakash; Agrawal, Sonali; Kumar, M Suresh

    2013-12-01

    Nematodes represent the second largest phylum in the animal kingdom. It is the most abundant species (500,000) in the planet. It causes chronic, debilitating infections worldwide such as ascariasis, trichuriasis, hookworm, enterobiasis, strongyloidiasis, filariasis and trichinosis, among others. Molecular modeling tools can play an important role in the identification and structural investigation of molecular targets that can act as a vital candidate against filariasis. In this study, sequence analysis of NAS-36 from H. contortus (Heamonchus contortus), B. malayi (Brugia malayi) and C. elegans (Ceanorhabditis elegans) has been performed, in order to identify the conserved residues. Tertiary structure was developed for an insight into the molecular structure of the enzyme. Molecular Dynamics Simulation (MDS) studies have been carried out to analyze the stability and the physical properties of the proposed enzyme models in the H. contortus, B. malayi and C. elegans. Moreover, the drug binding sites have been mapped for inhibiting the function of NAS-36 enzyme. The molecular identity of this protease could eventually demonstrate how ex-sheathment is regulated, as well as provide a potential target of anthelmintics for the prevention of nematode infections.

  5. 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

  6. The effect of previous cold storage on the subsequent recovery of infective third stage nematode larvae from sheep faeces.

    PubMed

    McKenna, P B

    1998-12-31

    An investigation undertaken to determine the effect of previous cold storage on the recovery of third stage larvae of gastrointestinal nematodes of sheep, showed that increasing periods of exposure of faeces to 4 degrees C resulted in decreasing numbers of larvae subsequently recovered from them. Differences in the abilities of the eggs of the various genera, to survive such treatment, were found to lead to significant changes in the percentage generic compositions of their third stage larvae--in some cases following the prior refrigeration of faecal samples for as little as 24 h. These results suggest that where larval cultures are intended to provide estimates of the proportions of the various worm eggs in the faeces of sheep harboring mixed gastrointestinal nematode burdens, they should be performed only on freshly collected samples.

  7. Neutropenic Mice Provide Insight into the Role of Skin-Infiltrating Neutrophils in the Host Protective Immunity against Filarial Infective Larvae

    PubMed Central

    Pionnier, Nicolas; Brotin, Emilie; Karadjian, Gregory; Hemon, Patrice; Gaudin-Nomé, Françoise; Vallarino-Lhermitte, Nathaly; Nieguitsila, Adélaïde; Fercoq, Frédéric; Aknin, Marie-Laure; Marin-Esteban, Viviana; Chollet-Martin, Sylvie; Schlecht-Louf, Géraldine

    2016-01-01

    Our knowledge and control of the pathogenesis induced by the filariae remain limited due to experimental obstacles presented by parasitic nematode biology and the lack of selective prophylactic or curative drugs. Here we thought to investigate the role of neutrophils in the host innate immune response to the infection caused by the Litomosoides sigmodontis murine model of human filariasis using mice harboring a gain-of-function mutation of the chemokine receptor CXCR4 and characterized by a profound blood neutropenia (Cxcr4+/1013). We provided manifold evidence emphasizing the major role of neutrophils in the control of the early stages of infection occurring in the skin. Firstly, we uncovered that the filarial parasitic success was dramatically decreased in Cxcr4+/1013 mice upon subcutaneous delivery of the infective stages of filariae (infective larvae, L3). This protection was linked to a larger number of neutrophils constitutively present in the skin of the mutant mice herein characterized as compared to wild type (wt) mice. Indeed, the parasitic success in Cxcr4+/1013 mice was normalized either upon depleting neutrophils, including the pool in the skin, or bypassing the skin via the intravenous infection of L3. Second, extending these observations to wt mice we found that subcutaneous delivery of L3 elicited an increase of neutrophils in the skin. Finally, living L3 larvae were able to promote in both wt and mutant mice, an oxidative burst response and the release of neutrophil extracellular traps (NET). This response of neutrophils, which is adapted to the large size of the L3 infective stages, likely directly contributes to the anti-parasitic strategies implemented by the host. Collectively, our results are demonstrating the contribution of neutrophils in early anti-filarial host responses through their capacity to undertake different anti-filarial strategies such as oxidative burst, degranulation and NETosis. PMID:27111140

  8. Evaluation of follow-up of therapy with fenbendazole incorporated into stabilized liposomes and immunomodulator glucan in mice infected with Toxocara canis larvae.

    PubMed

    Hrckova, G; Velebný, S; Obwaller, A; Auer, H; Kogan, G

    2007-01-01

    Anthelmintic activity of benzimidazole carbamate anthelmintics is low against dormant Toxocara canis larvae during late infections in paratenic hosts. The present study was conducted to examine the efficacy of pure fenbendazole, or drug incorporated into sterically stabilized liposomes (SL-FBZ) administered to T. canis-infected mice alone and after its co-administration with the immunomodulator (1-->3)-beta-D-glucan against larvae localized in muscles and brains. Therapy with either drug forms (in total 250 mg/kg in 10 doses) commenced on day 28 post-infection (p.i.) and the efficacy of treatment, examined on day 30 after the last dose of drug, was the highest in groups of mice treated with SL-FBZ in combination with glucan (89.5+/-5.8% in the muscles, 66.1+/-8.1% in brains). During 56 days of follow-up after termination of therapy, serum levels of anti-TES IgG antibodies, circulating IgG-TES immune complexes (CIC) as well as IgG antibodies to the most immunogenic part of recombinant myosin antigen of T. canis larvae were investigated. In contrast to anti-TES IgG antibodies, levels of CIC and anti-myosin antibodies were in the linear correlation with the efficacy of treatments beginning from day 38 post-therapy. We also showed that the serum levels of CIC as well as anti-myosin IgG antibodies seem to be the suitable serological markers for the monitoring of progress in larval destruction and TES resorption from the tissues.

  9. Investigating the Effect of Different Treatments with Lactic Acid Bacteria on the Fate of Listeria monocytogenes and Staphylococcus aureus Infection in Galleria mellonella Larvae

    PubMed Central

    Grounta, Athena; Harizanis, Paschalis; Mylonakis, Eleftherios; Nychas, George-John E.; Panagou, Efstathios Z.

    2016-01-01

    The use of Galleria mellonella as a model host to elucidate microbial pathogenesis and search for novel drugs and therapies has been well appreciated over the past years. However, the effect of microorganisms with functional appeal in the specific host remains scarce. The present study investigates the effect of treatment with selected lactic acid bacteria (LAB) with probiotic potential, as potential protective agents by using live or heat-killed cells at 6 and 24 h prior to infection with Listeria monocytogenes and Staphylococcus aureus or as potential therapeutic agents by using cell-free supernatants (CFS) after infection with the same pathogens. The employed LAB strains were Lactobacillus pentosus B281 and Lactobacillus plantarum B282 (isolated from table olive fermentations) along with Lactobacillus rhamnosus GG (inhabitant of human intestinal tract). Kaplan-Meier survival curves were plotted while the pathogen’s persistence in the larval hemolymph was determined by microbiological analysis. It was observed that the time (6 or 24 h) and type (live or heat-killed cells) of challenge period with LAB prior to infection greatly affected the survival of infected larvae. The highest decrease of L. monocytogenes population in the hemolymph was observed in groups challenged for 6 h with heat-killed cells by an average of 1.8 log units compared to non challenged larvae for strains B281 (p 0.0322), B282 (p 0.0325), and LGG (p 0.0356). In the case of S. aureus infection, the population of the pathogen decreased in the hemolymph by 1 log units at 8 h post infection in the groups challenged for 6 h with heat-killed cells of strains B281 (p 0.0161) and B282 (p 0.0096) and by 1.8 log units in groups challenged with heat-killed cells of LGG strain (p 0.0175). Further use of CFS of each LAB strain did not result in any significant prolonged survival but interestingly it resulted in pronounced decrease of L. monocytogenes in the hemolymph at 24 h and 48 h after infection by

  10. The usefulness of DNA derived from third stage larvae in the detection of Ashworthius sidemi infection in European bison, by a simple polymerase chain reaction

    PubMed Central

    2014-01-01

    Background Ashworthius sidemi, a blood-sucking nematode, is a primary parasite of Asiatic cervides, primarily sika deer (Cervus nippon). As A. sidemi infections are common in bison, red and roe deer, and gastrointestinal nematodes are often exchanged between animals, it is possible that other farm animals such as cows and sheep that may use the same pastures can be infected. Hence, histopathological changes observed in the walls of the abomasa and duodena of infected wildlife caused by a strong parasite presence may become an important health problem also for farm animals. Methods In the present study, a simple PCR test for the detection of A. sidemi infection in European bison based on DNA from third stage infective larvae (L3) has been optimized. Results The species-specific primers generated a 406 bp fragment, and A. sidemi DNA could be detected at concentrations of 0.1 pg/μl. The specificity of PCR was confirmed by the use of the genomic DNA of adult Ostertagia ostertagi, Haemonchus contortus, Cooperiaoncophora as negative controls. Conclusion It is possible to detect A. sidemi infection in European bison using DNA from L3. If this nematode infection is transmitted to cows this method may be effective to diagnose invasion in breeding animals in vivo. PMID:24886355

  11. Evaluation of histological techniques for the detection of fungal infections caused by Leptolegnia chapmanii (Oomycetes: Saprolegniales) in Aedes aegypti (Diptera: Culicidae) larvae.

    PubMed

    Dikgolz, V E; Toledo, A V; Topa, P E; López Lastra, C C

    2005-01-01

    We evaluated which of the fixatives and stains most frequently used for observation of insect tissues were the most appropriate for histopathological visualization of entomopathogenic fungal infections with Leptolegnia chapmanii in larvae of Aedes aegypti. The best contrast between the host tissues and the fungal structures was obtained when using a combination of Camoy fixative with Grocott staining contrasted with light green. Masson trichromic stain combined with 10% formaldehyde-phosphate buffer also provided satisfactory results--a good contrast and clearly distinguishable host tissues and fungal structures.

  12. A parvo-like virus persistently infecting a C6/36 clone of Aedes albopictus mosquito cell line and pathogenic for Aedes aegypti larvae.

    PubMed

    Jousset, F X; Barreau, C; Boublik, Y; Cornet, M

    1993-08-01

    We have isolated and partially characterized from an apparently healthy C6/36 subclone of Aedes albopictus cell line a small icosahedral non-enveloped DNA virus, designated AaPV. This virus proved to be highly pathogenic for Aedes aegypti neonate larvae. Viral infection persisted for over 4 years in the cell culture without any cytopathic effect. Attempts to infect suckling mice, Drosophila melanogaster adults and Spodoptera littoralis larvae with AaPV were unsuccessful. Similarly, the AaPV failed to replicate in vertebrate and Drosophila cell lines. Virions, about 22 nm in diameter, had a buoyant density of 1.43 g/cm3 and contained three capsid polypeptides with molecular weights of 53, 41 and 40 kDa. A preliminary study of the viral genome indicated the presence of single-stranded DNA. By its biophysical and biochemical properties, this virus appears to be related to the genus Densovirus within the family Parvoviridae, but lacks serological relationships with the other members of this genus.

  13. Stage- and Gender-Specific Proteomic Analysis of Brugia malayi Excretory-Secretory Products

    PubMed Central

    Moreno, Yovany; Geary, Timothy G.

    2008-01-01

    Introduction While we lack a complete understanding of the molecular mechanisms by which parasites establish and achieve protection from host immune responses, it is accepted that many of these processes are mediated by products, primarily proteins, released from the parasite. Parasitic nematodes occur in different life stages and anatomical compartments within the host. Little is known about the composition and variability of products released at different developmental stages and their contribution to parasite survival and progression of the infection. Methodology/Principal Findings To gain a deeper understanding on these aspects, we collected and analyzed through 1D-SDS PAGE and LC-MS/MS the Excretory-Secretory Products (ESP) of adult female, adult male and microfilariae of the filarial nematode Brugia malayi, one of the etiological agents of human lymphatic filariasis. This proteomic analysis led to the identification of 228 proteins. The list includes 76 proteins with unknown function as well as also proteins with potential immunoregulatory properties, such as protease inhibitors, cytokine homologues and carbohydrate-binding proteins. Larval and adult ESP differed in composition. Only 32 proteins were shared between all three stages/genders. Consistent with this observation, different gene ontology profiles were associated with the different ESP. Conclusions/Significance A comparative analysis of the proteins released in vitro by different forms of a parasitic nematode dwelling in the same host is presented. The catalog of secreted proteins reflects different stage- and gender-specific related processes and different strategies of immune evasion, providing valuable insights on the contribution of each form of the parasite for establishing the host–parasite interaction. PMID:18958170

  14. Characterization of innate immunity genes in the parasitic nematode Brugia malayi.

    PubMed

    Libro, Silvia; Slatko, Barton E; Foster, Jeremy M

    The filarial nematode Brugia malayi is one of the causative agents of lymphatic filariasis, a neglected tropical disease that affects 120 million people worldwide. The limited effectiveness of available anthelmintics and the absence of a vaccine have prompted extensive research on the interaction between Brugia and its obligate bacterial endosymbiont, Wolbachia. Recent studies suggest that Wolbachia is able to manipulate its nematode host immunity but relatively little is known about the immune system of filarial nematodes. Therefore, elucidation of the mechanisms underlying the immune system of B. malayi may be useful for understanding how the symbiotic relationship is maintained and help in the identification of new drug targets. In order to characterize the main genetic pathways involved in B. malayi immunity, we exposed adult female worms to two bacterial lysates (Escherichia coli and Bacillus amyloliquefaciens), dsRNA and dsDNA. We performed transcriptome sequencing of worms exposed to each immune elicitor at two different timepoints. Gene expression analysis of untreated and immune-challenged worms was performed to characterize gene expression patterns associated with each type of immune stimulation. Our results indicate that different immune elicitors produced distinct expression patterns in B. malayi, with changes in the expression of orthologs of well-characterized C. elegans immune pathways such as insulin, TGF-β, and p38 MAPK pathways, as well as C-type lectins and several stress-response genes.

  15. Identification of tgh-2, a Filarial Nematode Homolog of Caenorhabditis elegans daf-7 and Human Transforming Growth Factor β, Expressed in Microfilarial and Adult Stages of Brugia malayi

    PubMed Central

    Gomez-Escobar, Natalia; Gregory, William F.; Maizels, Rick M.

    2000-01-01

    A novel member of the transforming growth factor β (TGF-β) family has been identified in the filarial nematode parasite Brugia malayi by searching the recently developed Expressed Sequence Tag (EST) database produced by the Filarial Genome Project. Designated tgh-2, this new gene shows most similarity to a key product regulating dauer larva formation in Caenorhabditis elegans (DAF-7) and to the human down-modulatory cytokine TGF-β. Homology to DAF-7 extends throughout the length of the 349-amino-acid (aa) protein, which is divided into an N-terminal 237 aa, including a putative signal sequence, a 4-aa basic cleavage site, and a 108-aa C-terminal active domain. Similarity to human TGF-β is restricted to the C-terminal domain, over which there is a 32% identity between TGH-2 and TGF-β1, including every cysteine residue. Expression of tgh-2 mRNA has been measured over the filarial life cycle. It is maximal in the microfilarial stage, with lower levels of activity around the time of molting within the mammal, but continues to be expressed by mature adult male and female parasites. Expression in both the microfilaria, which is in a state of arrested development, and the adult, which is terminally differentiated, indicates that tgh-2 may play a role other than purely developmental. This is consistent with our observation that TGH-2 is secreted by adult worms in vitro. Recombinant TGH-2 expressed in baculovirus shows a low level of binding to TGF-β-receptor bearing mink lung epithelial cells (MELCs), which is partially inhibited (16 to 39%) with human TGF-β, and activates plasminogen activator inhibitor-1 transcription in MELCs, a marker for TGF-β-mediated transduction. Further tests will be required to establish whether the major role of B. malayi TGH-2 (Bm-TGH-2) is to modulate the host immune response via the TGF-β pathway. PMID:11035752

  16. A Phosphorylcholine-Containing Glycolipid-like Antigen Present on the Surface of Infective Stage Larvae of Ascaris spp. Is a Major Antibody Target in Infected Pigs and Humans

    PubMed Central

    Masure, Dries; Wang, Tao; Nejsum, Peter; Hokke, Cornelis H.; Geldhof, Peter

    2016-01-01

    Background The pig parasite Ascaris suum plays and important role in veterinary medicine and represents a suitable model for A. lumbricoides, which infects over 800 million people. In pigs, continued exposure to Ascaris induces immunity at the level of the gut, protecting the host against migrating larvae. The objective of this study was to identify and characterize parasite antigens targeted by this local immune response that may be crucial for parasite invasion and establishment and to evaluate their protective and diagnostic potential. Methodology/Principal Findings Pigs were immunized by trickle infection for 30 weeks, challenged with 2,000 eggs at week 32 and euthanized two weeks after challenge. At necropsy, there was a 100% reduction in worms recovered from the intestine and a 97.2% reduction in liver white spots in comparison with challenged non-immune control animals. Antibodies purified from the intestinal mucus or from the supernatant of cultured antibody secreting cells from mesenteric lymph nodes of immune pigs were used to probe L3 extracts to identify antibody targets. This resulted in the recognition of a 12kDa antigen (As12) that is actively shed from infective Ascaris L3. As12 was characterized as a phosphorylcholine-containing glycolipid-like antigen that is highly resistant to different enzymatic and chemical treatments. Vaccinating pigs with an As12 fraction did not induce protective immunity to challenge infection. However, serological analysis using sera or plasma from experimentally infected pigs or naturally infected humans demonstrated that the As12 ELISA was able to detect long-term exposure to Ascaris with a high diagnostic sensitivity (98.4% and 92%, respectively) and specificity (95.5% and 90.0%) in pigs and humans, respectively. Conclusions/Significance These findings show the presence of a highly stage specific, glycolipid-like component (As12) that is actively secreted by infectious Ascaris larvae and which acts as a major antibody

  17. Regulation of Life Cycle Checkpoints and Developmental Activation of Infective Larvae in Strongyloides stercoralis by Dafachronic Acid

    PubMed Central

    Pilgrim, Adeiye A.; Nolan, Thomas J.; Wang, Zhu; Kliewer, Steven A.; Mangelsdorf, David J.; Lok, James B.

    2016-01-01

    The complex life cycle of the parasitic nematode Strongyloides stercoralis leads to either developmental arrest of infectious third-stage larvae (iL3) or growth to reproductive adults. In the free-living nematode Caenorhabditis elegans, analogous determination between dauer arrest and reproductive growth is governed by dafachronic acids (DAs), a class of steroid hormones that are ligands for the nuclear hormone receptor DAF-12. Biosynthesis of DAs requires the cytochrome P450 (CYP) DAF-9. We tested the hypothesis that DAs also regulate S. stercoralis development via DAF-12 signaling at three points. First, we found that 1 μM Δ7-DA stimulated 100% of post-parasitic first-stage larvae (L1s) to develop to free-living adults instead of iL3 at 37°C, while 69.4±12.0% (SD) of post-parasitic L1s developed to iL3 in controls. Second, we found that 1 μM Δ7-DA prevented post-free-living iL3 arrest and stimulated 85.2±16.9% of larvae to develop to free-living rhabditiform third- and fourth-stages, compared to 0% in the control. This induction required 24–48 hours of Δ7-DA exposure. Third, we found that the CYP inhibitor ketoconazole prevented iL3 feeding in host-like conditions, with only 5.6±2.9% of iL3 feeding in 40 μM ketoconazole, compared to 98.8±0.4% in the positive control. This inhibition was partially rescued by Δ7-DA, with 71.2±16.4% of iL3 feeding in 400 nM Δ7-DA and 35 μM ketoconazole, providing the first evidence of endogenous DA production in S. stercoralis. We then characterized the 26 CYP-encoding genes in S. stercoralis and identified a homolog with sequence and developmental regulation similar to DAF-9. Overall, these data demonstrate that DAF-12 signaling regulates S. stercoralis development, showing that in the post-parasitic generation, loss of DAF-12 signaling favors iL3 arrest, while increased DAF-12 signaling favors reproductive development; that in the post-free-living generation, absence of DAF-12 signaling is crucial for iL3 arrest

  18. An In Vitro/In Vivo Model to Analyze the Effects of Flubendazole Exposure on Adult Female Brugia malayi

    PubMed Central

    O’Neill, Maeghan; Mansour, Abdelmoneim; DiCosty, Utami; Geary, James; Dzimianski, Michael; McCall, Scott D.; McCall, John W.; Mackenzie, Charles D.; Geary, Timothy G.

    2016-01-01

    Current control strategies for onchocerciasis and lymphatic filariasis (LF) rely on prolonged yearly or twice-yearly mass administration of microfilaricidal drugs. Prospects for near-term elimination or eradication of these diseases would be improved by availability of a macrofilaricide that is highly effective in a short regimen. Flubendazole (FLBZ), a benzimidazole anthelmintic registered for control of human gastrointestinal nematode infections, is a potential candidate for this role. FLBZ has profound and potent macrofilaricidal effects in many experimental animal models of filariases and in one human trial for onchocerciasis after parental administration. Unfortunately, the marketed formulation of FLBZ provides very limited oral bioavailability and parenteral administration is required for macrofilaricidal efficacy. A new formulation that provided sufficient oral bioavailability could advance FLBZ as an effective treatment for onchocerciasis and LF. Short-term in vitro culture experiments in adult filariae have shown that FLBZ damages tissues required for reproduction and survival at pharmacologically relevant concentrations. The current study characterized the long-term effects of FLBZ on adult Brugia malayi by maintaining parasites in jirds for up to eight weeks following brief drug exposure (6–24 hr) to pharmacologically relevant concentrations (100 nM—10 μM) in culture. Morphological damage following exposure to FLBZ was observed prominently in developing embryos and was accompanied by a decrease in microfilarial output at 4 weeks post-exposure. Although FLBZ exposure clearly damaged the parasites, exposed worms recovered and were viable 8 weeks after treatment. PMID:27145083

  19. Incidence of ascaridoid larvae in Kuwaiti food fishes.

    PubMed

    Sey, O; Petter, A J

    1997-01-01

    Three hundred and six fish of 83 species were carefully examined in Kuwait during the period from October 1992 to September 1995 for ascaridoid larvae. Thirty-nine fishes (12.7%) belonging to 23 species were infected with 9 types of ascaridoid third-stage larvae: Anisakis simplex, Terranva spp, Contracaecum spp and 6 different types of Hysterothylacium spp (KA-KF). Hysterothylacium larvae (including all types) were found in all the infected fish except one (94.6%); Terranova larvae were found in 12 fishes (10 species, 56.1%); Anisakis simplex larvae occurred in 2 fishes (2 species, 8.6%) and Contracaecum spp larvae in one fish only.

  20. 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.

  1. Recognition of Trichinella spiralis muscle larvae antigens by sera from human infected with this parasite and its potential use in diagnosis.

    PubMed

    Chapa-Ruiz, M R; Salinas-Tobón, M R; Aguilar-Alvarez, D J; Martínez-Marañón, R

    1992-01-01

    Human antibody response to total soluble extract of Trichinella spiralis muscle larvae (TSE) was analyzed by Western blot. The most frequently recognized antigens had molecular weights of 96, 67, 63, 60, 55 and 47 kDa. An antigenic fraction containing two peptides with M.W. of 43, 47 kDa from the parasite (p43, 47 Ts L1) was isolated by elution from polyacrylamide gel slabs. It was used as antigen in an ELISA test and compared to that of TSE. Serum samples from 51 symptomatic trichinellosis patients--43 with high antibody levels to TSE, 5 of them with positive biopsy and 8 with low levels of these antibodies--as well as 38 from asymptomatic individuals from the area where the trichinellosis outbreaks had occurred and 43 from apparently healthy individuals from a non-endemic area, 37 from patients with intestinal parasitic infections caused by helminth and protozoan parasites--11 from recurrent and 26 from non-recurrent disease--were analyzed by ELISA using both antigens. The ELISA using p43, 47 Ts L1 detected all trichinellosis patients with high antibody levels as well as 6 out of 8 of those with low antibody levels. All control groups were negative. Therefore, this purified fraction allowed the ELISA to be more specific and sensitive for human trichinellosis diagnosis.

  2. A Proteomic Analysis of the Body Wall, Digestive Tract, and Reproductive Tract of Brugia malayi.

    PubMed

    Morris, C Paul; Bennuru, Sasisekhar; Kropp, Laura E; Zweben, Jesse A; Meng, Zhaojing; Taylor, Rebekah T; Chan, King; Veenstra, Timothy D; Nutman, Thomas B; Mitre, Edward

    2015-01-01

    Filarial worms are parasitic nematodes that cause devastating diseases such as lymphatic filariasis (LF) and onchocerciasis. Filariae are nematodes with complex anatomy including fully developed digestive tracts and reproductive organs. To better understand the basic biology of filarial parasites and to provide insights into drug targets and vaccine design, we conducted a proteomic analysis of different anatomic fractions of Brugia malayi, a causative agent of LF. Approximately 500 adult female B. malayi worms were dissected, and three anatomical fractions (body wall, digestive tract, and reproductive tract) were obtained. Proteins from each anatomical fraction were extracted, desalted, trypsinized, and analyzed by microcapillary reverse-phase liquid chromatography-tandem-mass spectrometry. In total, we identified 4,785 B. malayi proteins. While 1,894 were identified in all three anatomic fractions, 396 were positively identified only within the digestive tract, 114 only within the body wall, and 1,011 only within the reproductive tract. Gene set enrichment analysis revealed a bias for transporters to be present within the digestive tract, suggesting that the intestine of adult filariae is functional and important for nutrient uptake or waste removal. As expected, the body wall exhibited increased frequencies of cytoskeletal proteins, and the reproductive tract had increased frequencies of proteins involved in nuclear regulation and transcription. In assessing for possible vaccine candidates, we focused on proteins sequestered within the digestive tract, as these could possibly represent "hidden antigens" with low risk of prior allergic sensitization. We identified 106 proteins that are enriched in the digestive tract and are predicted to localize to the surface of cells in the the digestive tract. It is possible that some of these proteins are on the luminal surface and may be accessible by antibodies ingested by the worm. A subset of 27 of these proteins appear

  3. Complete Genome Sequence of Paenibacillus larvae MEX14, Isolated from Honey Bee Larvae from the Xochimilco Quarter in Mexico City

    PubMed Central

    Peréz de la Rosa, D.; Pérez de la Rosa, J. J.; Cossio-Bayugar, R.; Miranda-Miranda, E.; Lozano, L.; Bravo-Díaz, M. A.; Rocha-Martínez, M. K.

    2015-01-01

    Paenibacillus larvae strain MEX14 is a facultative anaerobic endospore-forming bacterium that infects Apis mellifera larvae. Strain MEX14 was isolated from domestic bee larvae collected in a backyard in Mexico City. The estimated genome size was determined to be 4.18 Mb, and it harbors 4,806 protein coding genes (CDSs). PMID:26316636

  4. Complete Genome Sequence of Paenibacillus larvae MEX14, Isolated from Honey Bee Larvae from the Xochimilco Quarter in Mexico City.

    PubMed

    Peréz de la Rosa, D; Pérez de la Rosa, J J; Cossio-Bayugar, R; Miranda-Miranda, E; Lozano, L; Bravo-Díaz, M A; Rocha-Martínez, M K; Sachman-Ruiz, B

    2015-08-27

    Paenibacillus larvae strain MEX14 is a facultative anaerobic endospore-forming bacterium that infects Apis mellifera larvae. Strain MEX14 was isolated from domestic bee larvae collected in a backyard in Mexico City. The estimated genome size was determined to be 4.18 Mb, and it harbors 4,806 protein coding genes (CDSs).

  5. In vitro radioisotopic labeling of the L-3 stage of Brugia malayi.

    PubMed

    Lengemann, F W; Marchell, T F; Chmielewicz, M; Georgi, J R

    1986-07-01

    Ten radioisotopes (133Ba, 207Bi, 109Cd, 51Cr, 59Fe, 203Hg, 54Mn, 125Sb and 75Se) were used to label the L-3 stage of Brugia malayi. The in vitro uptake at 4 hours in a buffered salt solution was greatest for 207Bi and exceeded that of 203Hg, by a factor of 6 and the rest of the radionuclides by factors of 26 or more. Dimethylsulfoxide (DMSO) (1%) in the medium only slightly enhanced the uptake of 207Bi but increased 203Hg uptake by a factor of 2.5. After incubation in non-radioactive medium only 2% of the 207Bi was retained; for 203Hg the retention was 70% or better. Increasing the labeling time increased total uptake and retention of the radionuclides. The retention of the 203Hg injected intraperitoneally into jirds (Meriones unguiculatus) in the form of labeled L-3s was followed over a 16 day period by counting the jirds in a whole animal NaI crystal detector. One L-4 stage of B malayi was recovered at the end of this period.

  6. In vitro radioisotopic labeling of the L-3 stage of Brugia malayi

    SciTech Connect

    Lengemann, F.W.; Marchell, T.F.; Chmielewicz, M.; Georgi, J.R.

    1986-07-01

    Ten radioisotopes (/sup 133/Ba, /sup 207/Bi, /sup 109/Cd, /sup 51/Cr, /sup 59/Fe, /sup 203/Hg, /sup 54/Mn, /sup 125/Sb and /sup 75/Se) were used to label the L-3 stage of Brugia malayi. The in vitro uptake at 4 hours in a buffered salt solution was greatest for /sup 207/Bi and exceeded that of /sup 203/Hg, by a factor of 6 and the rest of the radionuclides by factors of 26 or more. Dimethylsulfoxide (DMSO) (1%) in the medium only slightly enhanced the uptake of /sup 207/Bi but increased /sup 203/Hg uptake by a factor of 2.5. After incubation in non-radioactive medium only 2% of the /sup 207/Bi was retained; for /sup 203/Hg the retention was 70% or better. Increasing the labeling time increased total uptake and retention of the radionuclides. The retention of the /sup 203/Hg injected intraperitoneally into jirds (Meriones unguiculatus) in the form of labeled L-3s was followed over a 16 day period by counting the jirds in a whole animal NaI crystal detector. One L-4 stage of B malayi was recovered at the end of this period.

  7. Cloning, expression, purification and kinetics of trehalose-6-phosphate phosphatase of filarial parasite Brugia malayi.

    PubMed

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

    2011-08-01

    The pleiotropic functions of disaccharide trehalose in the biology of nematodes and its absence from mammalian cells suggest that its biosynthesis may provide a useful target for developing novel nematicidal drugs. The trehalose-6-phosphate phosphatase (TPP), one of the enzymes of trehalose metabolism has not been characterized so far in nematodes except the free living nematode Caenorhabditis elegans where it's silencing results into lethal outcomes. This prompted us to clone and characterize Brugia malayi TPP in order to discover novel antifilarial drug target. The recombinant protein (Bm-TPP) was purified with apparent homogeneity on a metal ion column and it was found to possess high phosphatase activity with robust specificity for the substrate trehalose-6-phosphate. Bm-TPP was found to be a member of the HAD-like hydrolase super family II based on the conserved motifs required for catalytic reaction. The K(m) for substrate trehalose-6-phosphate was around 0.42 mM with pH optimum ∼7.0 and the enzyme showed an almost absolute requirement for Mg(2+) as a metal ion. Bm-TPP was expressed in all the life-stages of B. malayi. In the absence of an effective macrofilaricidal agent and validated antifilarial drug target, Bm-TPP bodes well as a rational drug target against lymphatic filariasis.

  8. Midgut Barrier Imparts Selective Resistance to Filarial Worm Infection in Culex pipiens pipiens

    PubMed Central

    Michalski, Michelle L.; Erickson, Sara M.; Bartholomay, Lyric C.; Christensen, Bruce M.

    2010-01-01

    Mosquitoes in the Culex pipiens complex thrive in temperate and tropical regions worldwide, and serve as efficient vectors of Bancroftian lymphatic filariasis (LF) caused by Wuchereria bancrofti in Asia, Africa, the West Indies, South America, and Micronesia. However, members of this mosquito complex do not act as natural vectors for Brugian LF caused by Brugia malayi, or for the cat parasite B. pahangi, despite their presence in South Asia where these parasites are endemic. Previous work with the Iowa strain of Culex pipiens pipiens demonstrates that it is equally susceptible to W. bancrofti as is the natural Cx. p. pipiens vector in the Nile Delta, however it is refractory to infection with Brugia spp. Here we report that the infectivity barrier for Brugia spp. in Cx. p. pipiens is the mosquito midgut, which inflicts internal and lethal damage to ingested microfilariae. Following per os Brugia exposures, the prevalence of infection is significantly lower in Cx. p. pipiens compared to susceptible mosquito controls, and differs between parasite species with <50% and <5% of Cx. p. pipiens becoming infected with B. pahangi and B. malayi, respectively. When Brugia spp. mf were inoculated intrathoracically to bypass the midgut, larvae developed equally well as in controls, indicating that, beyond the midgut, Cx. p. pipiens is physiologically compatible with Brugia spp. Mf isolated from Cx. p. pipiens midguts exhibited compromised motility, and unlike mf derived from blood or isolated from the midguts of Ae. aegypti, failed to develop when inoculated intrathoracically into susceptible mosquitoes. Together these data strongly support the role of the midgut as the primary infection barrier for Brugia spp. in Cx. p. pipiens. Examination of parasites recovered from the Cx. p. pipiens midgut by vital staining, and those exsheathed with papain, suggest that the damage inflicted by the midgut is subcuticular and disrupts internal tissues. Microscopic studies of these worms

  9. Behavioural fever in zebrafish larvae.

    PubMed

    Rey, Sonia; Moiche, Visila; Boltaña, Sebastian; Teles, Mariana; MacKenzie, Simon

    2017-02-01

    Behavioural fever has been reported in different species of mobile ectotherms including the zebrafish, Danio rerio, in response to exogenous pyrogens. In this study we report, to our knowledge for the first time, upon the ontogenic onset of behavioural fever in zebrafish (Danio rerio) larvae. For this, zebrafish larvae (from first feeding to juveniles) were placed in a continuous thermal gradient providing the opportunity to select their preferred temperature. The novel thermal preference aquarium was based upon a continuous vertical column system and allows for non-invasive observation of larvae vertical distribution under isothermal (TR at 28 °C) and thermal gradient conditions (TCH: 28-32 °C). Larval thermal preference was assessed under both conditions with or without an immersion challenge, in order to detect the onset of the behavioural fever response. Our results defined the onset of the dsRNA induced behavioural fever at 18-20 days post fertilization (dpf). Significant differences were observed in dsRNA challenged larvae, which prefer higher temperatures (1-4 °C increase) throughout the experimental period as compared to non-challenged larvae. In parallel we measured the abundance of antiviral transcripts; viperin, gig2, irf7, trim25 and Mxb mRNAs in dsRNA challenged larvae under both thermal regimes: TR and TCh. Significant increases in the abundance of all measured transcripts were recorded under thermal choice conditions signifying that thermo-coupling and the resultant enhancement of the immune response to dsRNA challenge occurs from 18 dpf onwards in the zebrafish. The results are of importance as they identify a key developmental stage where the neuro-immune interface matures in the zebrafish likely providing increased resistance to viral infection.

  10. Phage Therapy is Effective in Protecting Honeybee Larvae from American Foulbrood Disease.

    PubMed

    Ghorbani-Nezami, Sara; LeBlanc, Lucy; Yost, Diane G; Amy, Penny S

    2015-01-01

    American foulbrood disease has a major impact on honeybees (Apis melifera) worldwide. It is caused by a Gram-positive, spore-forming bacterium, Paenibacillus larvae. The disease can only affect larval honeybees, and the bacterial endospores are the infective unit of the disease. Antibiotics are not sufficient to combat the disease due to increasing resistance among P. larvae strains. Because of the durability and virulence of P. larvae endospores, infections spread rapidly, and beekeepers are often forced to burn beehives and equipment. To date, very little information is available on the use of bacteriophage therapy in rescuing and preventing American foulbrood disease, therefore the goal of this study was to test the efficacy of phage therapy against P. larvae infection. Out of 32 previously isolated P. larvae phages, three designated F, WA, and XIII were tested on artificially reared honeybee larvae infected with P. larvae strain NRRL B-3650 spores. The presence of P. larvae DNA in dead larvae was confirmed by 16S rRNA gene-specific polymerase chain reaction amplification. Survival rates for phage-treated larvae were approximately the same as for larvae never infected with spores (84%), i.e., the phages had no deleterious effect on the larvae. Additionally, prophylactic treatment of larvae with phages before spore infection was more effective than administering phages after infection, although survival in both cases was higher than spores alone (45%). Further testing to determine the optimal combination and concentration of phages, and testing in actual hive conditions are needed.

  11. Phage Therapy is Effective in Protecting Honeybee Larvae from American Foulbrood Disease

    PubMed Central

    Ghorbani-Nezami, Sara; LeBlanc, Lucy; Yost, Diane G.; Amy, Penny S.

    2015-01-01

    American foulbrood disease has a major impact on honeybees (Apis melifera) worldwide. It is caused by a Gram-positive, spore-forming bacterium, Paenibacillus larvae. The disease can only affect larval honeybees, and the bacterial endospores are the infective unit of the disease. Antibiotics are not sufficient to combat the disease due to increasing resistance among P. larvae strains. Because of the durability and virulence of P. larvae endospores, infections spread rapidly, and beekeepers are often forced to burn beehives and equipment. To date, very little information is available on the use of bacteriophage therapy in rescuing and preventing American foulbrood disease, therefore the goal of this study was to test the efficacy of phage therapy against P. larvae infection. Out of 32 previously isolated P. larvae phages, three designated F, WA, and XIII were tested on artificially reared honeybee larvae infected with P. larvae strain NRRL B-3650 spores. The presence of P. larvae DNA in dead larvae was confirmed by 16S rRNA gene-specific polymerase chain reaction amplification. Survival rates for phage-treated larvae were approximately the same as for larvae never infected with spores (84%), i.e., the phages had no deleterious effect on the larvae. Additionally, prophylactic treatment of larvae with phages before spore infection was more effective than administering phages after infection, although survival in both cases was higher than spores alone (45%). Further testing to determine the optimal combination and concentration of phages, and testing in actual hive conditions are needed. PMID:26136497

  12. 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

  13. Brugia pahangi in nude mice: protective immunity to infective larvae is Thy 1.2+ cell dependent and cyclosporin A resistant.

    PubMed

    Vickery, A C; Nayar, J K

    1987-03-01

    Mechanisms of protective immunity to larvae of Brugia pahangi were studied in congenitally athymic nude C3H/HeN mice and their syngeneic heterozygous littermates. An average 11% of subcutaneous larval inocula was recovered from control nudes 28 days after inoculation. No worms were recovered from nude recipients of viable splenic Thy 1.2+ T lymphocytes from heterozygotes which had killed a priming dose of B. pahangi larvae. Primed T lymphocytes, depleted of either Lyt 1.1+ or Lyt 2.1+ cells or incubated with anti-Thy 1.2 monoclonal antibody and complement, failed to protect nude mice against a larval challenge. Nor were primed B lymphocytes depleted by Thy 1.2+ T cell contaminants protective. Treatment with cyclosporin A (CsA) did not increase the numbers of worms recovered from heterozygotes nor did CsA treatment of heterozygous cell donors abolish the ability of primed Thy 1.2+ T lymphocytes to transfer protection to nude mice. IgG but not IgM antibody titres to B. pahangi antigens were depressed in all CsA-treated mice. CsA treatment of nude mice had no direct effect upon development of B. pahangi larvae. These results show that protective immunity to larvae of B. pahangi in mice depends upon small numbers of Thy 1.2+ T cells which are CsA-resistant.

  14. Infectivity of Steinernema carpocapsae and S. feltiae to Larvae and Adults of the Hazelnut Weevil, Curculio nucum: Differential Virulence and Entry Routes

    PubMed Central

    Batalla-Carrera, Laia; Morton, Ana; Shapiro-Ilan, David; Strand, Michael R.; García-del-Pino, Fernando

    2014-01-01

    We investigated the existing susceptibility differences of the hazelnut weevil, Curculio nucum L. (Coleoptera:, Curculionidae) to entomopathogenic nematodes by assessing the main route of entry of the nematodes, Steinernema carpocapsae strain B14 and S. feltiae strain D114, into larvae and adult insects, as well as host immune response. Our results suggested that S. carpocapsae B14 and S. feltiae D114 primarily entered adult insects and larvae through the anus. Larvae were more susceptible to S. feltiae D114 than S. carpocapsae B14 and adults were highly susceptible to S. carpocapsae B14 but displayed low susceptibility to S. feltiae D114. Penetration rate correlated with nematode virulence. We observed little evidence that hazelnut weevils mounted any cellular immune response toward S. carpocapsae B14 or S. feltiae D114. We conclude the differential susceptibility of hazelnut weevil larvae and adults to S. carpocapsae B14 and S. feltiae D114 primarily reflected differences in the ability of these two nematodes to penetrate the host. PMID:25276002

  15. Molecular Characterization of NAD+-Dependent DNA Ligase from Wolbachia Endosymbiont of Lymphatic Filarial Parasite Brugia malayi

    PubMed Central

    Shrivastava, Nidhi; Nag, Jeetendra Kumar; Misra-Bhattacharya, Shailja

    2012-01-01

    The lymphatic filarial parasite, Brugia malayi contains Wolbachia endobacteria that are essential for development, viability and fertility of the parasite. Therefore, wolbachial proteins have been currently seen as the potential antifilarial drug targets. NAD+-dependent DNA ligase is characterized as a promising drug target in several organisms due to its crucial, indispensable role in DNA replication, recombination and DNA repair. We report here the cloning, expression and purification of NAD+-dependent DNA ligase of Wolbachia endosymbiont of B. malayi (wBm-LigA) for its molecular characterization. wBm-LigA has all the domains that are present in nearly all the eubacterial NAD+-dependent DNA ligases such as N-terminal adenylation domain, OB fold, helix-hairpin-helix (HhH) and BRCT domain except zinc-binding tetracysteine domain. The purified recombinant protein (683-amino acid) was found to be biochemically active and was present in its native form as revealed by the circular dichroism and fluorescence spectra. The purified recombinant enzyme was able to catalyze intramolecular strand joining on a nicked DNA as well as intermolecular joining of the cohesive ends of BstEII restricted lamda DNA in an in vitro assay. The enzyme was localized in the various life-stages of B. malayi parasites by immunoblotting and high enzyme expression was observed in Wolbachia within B. malayi microfilariae and female adult parasites along the hypodermal chords and in the gravid portion as evident by the confocal microscopy. Ours is the first report on this enzyme of Wolbachia and these findings would assist in validating the antifilarial drug target potential of wBm-LigA in future studies. PMID:22815933

  16. Discovery of mammalian hosts to Gnathostoma nipponicum larvae and prevalence of the larvae in rodents and insectivores.

    PubMed

    Oyamada, T; Kobayashi, H; Kindou, T; Kudo, N; Yoshikawa, H; Yoshikawa, T

    1996-09-01

    From September 1993 to November 1995, to clarify the natural infection of Gnathostoma nipponicum (G.n.) larvae in small wild mammals, a total of 313 animals consisted of three species of rodents and two species of insectivores, collected from an endemic area of this nematode in Aomori Prefecture, were investigated. Two species, Rattus norvegicus (R.n.) and Chimarrogale himalayica (C.h.) were infected with G.n. larvae, and the infection rate was extremely high with 27.2% and 72.7% in the former and latter. The infected animals harbored the larvae of 2-10 (mean: 6.0) in R.N. and 2-40 (10.6) in C.h., and a total of 273 larvae was recovered. The all larvae (18) from R.n. and the vast majority of the larvae (216/255: 82.4%) from C.h. were recovered from the musculature, and many encapsulated larvae were found in these portions of C.h. Taxonomically, all the larvae were identified as the advance third-stage larvae (AdL3) of G.n. The body length was 1,056-2,110 microns, and was larger than those of the naturally-infected AdL3 reported from cold-blooded animals. No morphological alterations or death of the larva was observed. From these results, it would seem that R.n. and C.h. are highly susceptible to G.n. larvae, and has very suitable characteristics as the hosts. Furthermore, a hypothesis is advanced that these mammals serves as the plausible paratenic hosts in the life cycle of G.n. This report is the first record of R.n. (Rodentia) and C.h. (Insectivora) naturally-infected with AdL3 of G.n.

  17. A Madurella mycetomatis Grain Model in Galleria mellonella Larvae.

    PubMed

    Kloezen, Wendy; van Helvert-van Poppel, Marilyn; Fahal, Ahmed H; van de Sande, Wendy W J

    2015-01-01

    Eumycetoma is a chronic granulomatous subcutaneous infectious disease, endemic in tropical and subtropical regions and most commonly caused by the fungus Madurella mycetomatis. Interestingly, although grain formation is key in mycetoma, its formation process and its susceptibility towards antifungal agents are not well understood. This is because grain formation cannot be induced in vitro; a mammalian host is necessary to induce its formation. Until now, invertebrate hosts were never used to study grain formation in M. mycetomatis. In this study we determined if larvae of the greater wax moth Galleria mellonella could be used to induce grain formation when infected with M. mycetomatis. Three different M. mycetomatis strains were selected and three different inocula for each strain were used to infect G. mellonella larvae, ranging from 0.04 mg/larvae to 4 mg/larvae. Larvae were monitored for 10 days. It appeared that most larvae survived the lowest inoculum, but at the highest inoculum all larvae died within the 10 day observation period. At all inocula tested, grains were formed within 4 hours after infection. The grains produced in the larvae resembled those formed in human and in mammalian hosts. In conclusion, the M. mycetomatis grain model in G. mellonella larvae described here could serve as a useful model to study the grain formation and therapeutic responses towards antifungal agents in the future.

  18. Working with dauer larvae.

    PubMed

    Karp, Xantha

    2016-07-14

    Dauer diapause is a stress-resistant, developmentally quiescent, and long-lived larval stage adopted by Caenorhabditis elegans when conditions are unfavorable for growth and reproduction. This chapter contains methods to induce dauer larva formation, to isolate dauer larvae, and to study pre- and post-dauer stages.

  19. [Discrimination of geographic strains of periodic Brugia malayi by the cuticular ornamentation of the male].

    PubMed

    Bain, O; Chandrasekharan, S A; Partono, F; Mak, J W; Zheng, H J; Seo, B S; Wu, S H

    1988-01-01

    A comparative study of five periodic human strains of Brugia malayi, originating from India, China, Korea, Malaysia and Indonesia, is given. This morphological analysis is based on males; the "standard" characters (oesophagus, papillae, spicules...) appear identical. On the contrary, the cuticular ornamentation of the posterior region--which is composed of the area rugosa and of a system of bosses and constitutes a secondary non-skid copulatory apparatus--differs following the geographical origin of the strain. A key is given, based on this character. 1(2) At 800-1,200 micron from the tip of tail, numerous cuticular bosses present on the right side of the body (fig. 2 and 8 B). 2(1) At 800-1,200 micron from the tip of tail, cuticular bosses absent or scarce on the right side of the body (fig. 8 D). 3(4) At 1,800-1,200 micron from the tip of tail (fig. 4), scarce and slightly projecting cuticular bosses on the dorsal side of the body contrasting with well projecting lateral cuticular bosses (fig. 9 E and F). Anterior extremity of the area rugosa made by a few stripes of tiny bosses linked transversally (fig. 9 A). 4(3) At 1,800-2,200 micron, numerous cuticular bosses on the dorsal side of the body (figs. 5, 6 and 7). Anterior extremity of the area rugosa made by the stripes of longitudinal rods (fig. 9C). 5(6) Oblong transversally stretched cuticular bosses on the dorsal and left sides of the body, anteriorly to the area rugosa (fig. 5); big oblong bosses on the left side (fig. 9 B). Transversal wrinkles and stripes of rods absent on the dorsal side of the body. 6(5) Round cuticular bosses on the dorsal and left sides of the body anteriorly to the area rugosa (figs. 6 and 7): no big oblong bosses on the left side. Transversal wrinkles or stripes of rods present on the dorsal side of the body (fig. 9 D). Nomenclaturally, such differences could be used in defining different taxa, but it could be useful to perform "blind determination" (material without labelling), to

  20. Expression of five acetylcholine receptor subunit genes in Brugia malayi adult worms

    PubMed Central

    Li, Ben-Wen; Rush, Amy C.; Weil, Gary J.

    2015-01-01

    Acetylcholine receptors (AChRs) are required for body movement in parasitic nematodes and are targets of “classical” anthelmintic drugs such as levamisole and pyrantel and of newer drugs such as tribendimidine and derquantel. While neurotransmission explains the effects of these drugs on nematode movement, their effects on parasite reproduction are unexplained. The levamisole AChR type (L-AChRs) in Caenorhabditis elegans is comprised of five subunits: Cel-UNC-29, Cel-UNC-38, Cel-UNC-63, Cel-LEV-1 and Cel-LEV-8. The genome of the filarial parasite Brugia malayi contains nine AChRs subunits including orthologues of Cel-unc-29, Cel-unc-38, and Cel-unc-63. We performed in situ hybridization with RNA probes to localize the expression of five AChR genes (Bm1_35890-Bma-unc-29, Bm1_20330-Bma-unc-38, Bm1_38195-Bma-unc-63, Bm1_48815-Bma-acr-26 and Bm1_40515-Bma-acr-12) in B. malayi adult worms. Four of these genes had similar expression patterns with signals in body muscle, developing embryos, spermatogonia, uterine wall adjacent to stretched microfilariae, wall of Vas deferens, and lateral cord. Three L-AChR subunit genes (Bma-unc-29, Bma-unc-38 and Bma-unc-63) were expressed in body muscle, which is a known target of levamisole. Bma-acr-12 was co-expressed with these levamisole subunit genes in muscle, and this suggests that its protein product may form receptors with other alpha subunits. Bma-acr-26 was expressed in male muscle but not in female muscle. Strong expression signals of these genes in early embryos and gametes in uterus and testis suggest that AChRs may have a role in nervous system development of embryogenesis and spermatogenesis. This would be consistent with embryotoxic effects of drugs that target these receptors in filarial worms. Our data show that the expression of these receptor genes is tightly regulated with regard to localization in adult worms and developmental stage in embryos and gametes. These results may help to explain the broad effects

  1. cGMP and NHR Signaling Co-regulate Expression of Insulin-Like Peptides and Developmental Activation of Infective Larvae in Strongyloides stercoralis

    PubMed Central

    Stoltzfus, Jonathan D.; Bart, Stephen M.; Lok, James B.

    2014-01-01

    The infectious form of the parasitic nematode Strongyloides stercoralis is a developmentally arrested third-stage larva (L3i), which is morphologically similar to the developmentally arrested dauer larva in the free-living nematode Caenorhabditis elegans. We hypothesize that the molecular pathways regulating C. elegans dauer development also control L3i arrest and activation in S. stercoralis. This study aimed to determine the factors that regulate L3i activation, with a focus on G protein-coupled receptor-mediated regulation of cyclic guanosine monophosphate (cGMP) pathway signaling, including its modulation of the insulin/IGF-1-like signaling (IIS) pathway. We found that application of the membrane-permeable cGMP analog 8-bromo-cGMP potently activated development of S. stercoralis L3i, as measured by resumption of feeding, with 85.1±2.2% of L3i feeding in 200 µM 8-bromo-cGMP in comparison to 0.6±0.3% in the buffer diluent. Utilizing RNAseq, we examined L3i stimulated with DMEM, 8-bromo-cGMP, or the DAF-12 nuclear hormone receptor (NHR) ligand Δ7-dafachronic acid (DA)—a signaling pathway downstream of IIS in C. elegans. L3i stimulated with 8-bromo-cGMP up-regulated transcripts of the putative agonistic insulin-like peptide (ILP) -encoding genes Ss-ilp-1 (20-fold) and Ss-ilp-6 (11-fold) in comparison to controls without stimulation. Surprisingly, we found that Δ7-DA similarly modulated transcript levels of ILP-encoding genes. Using the phosphatidylinositol-4,5-bisphosphate 3-kinase inhibitor LY294002, we demonstrated that 400 nM Δ7-DA-mediated activation (93.3±1.1% L3i feeding) can be blocked using this IIS inhibitor at 100 µM (7.6±1.6% L3i feeding). To determine the tissues where promoters of ILP-encoding genes are active, we expressed promoter::egfp reporter constructs in transgenic S. stercoralis post-free-living larvae. Ss-ilp-1 and Ss-ilp-6 promoters are active in the hypodermis and neurons and the Ss-ilp-7 promoter is active in the intestine and a

  2. Comparative analysis of Wolbachia surface protein in D. melanoagster, A. tabida and B. malayi

    PubMed Central

    Uday, Jayaramaiah; Puttaraju, Hosagavi Puttegowda

    2012-01-01

    Wolbachia surface protein (WSP) is an eight beta-barrel transmembrane structure which participates in host immune response, cell proliferation, pathogenicity and controlled cell death program. The protein has four extracellular loops containing hyper variable regions separated by conserved regions. The WSP structure is homologous to Neisseria surface protein (Nsp A) which has about 34% similarity including antigenic variation and hydrophilicity. Recombination has a large impact on diversity of this protein including positive selection which is major constraint on protein evolution. The molecular mechanism through which Wolbachia induces various reproductive anomalies is unclear; a key feature observed for such anomalies might be because of Wolbachia undergoing extensive recombination. In Wolbachia, increased recombination is observed in ankyrin proteins, surface proteins and in some hypothetical proteins. Genetic divergence is extensive in the WSP gene, WSP is known to be a chimeric protein involved in host-symbiont interactions. Here we predicted the structural and functional variations in WSP sequences of Wolbachia present in D. melanogaster, A. tabida and in B. malayi. PMID:23055615

  3. Visceral larva migrans

    MedlinePlus

    ... with certain parasites found in the intestines of dogs and cats. Causes Visceral larva migrans (VLM) is ... parasites) that are found in the intestines of dogs and cats. Eggs produced by these worms are ...

  4. [Effect of wound to growth of larva of host to Ophiocordyceps sinensis during artificial breeding].

    PubMed

    Liu, Fei; Zhang, De-li; Zeng, Wei; Li, Li; Luo, Qing-ming; Tu, Yong-qin; Chen, Shi-jiang; Yin, Ding-hua

    2015-01-01

    To clear the effect of the wound to the growth of the larva of the host to the Ophiocordyceps sinensis, the wounds of same severity at the same position were made artificially to the larva and which were artificial fed at the same environment and condition. The results indicated that, over the winter, the survival rate of the wounded of the infection larva was lower than that of the healthy larva, but the weight had no significant difference between the wounded and the healthy larva. The survival rate of the wounded of the no infection larva was lower than that of the healthy larva, but except with black skin, the wounded larva with offwhite and dusty red had no influence on the variety of the weight. In summery, wound had no advantage to the survival rate, but had no influence to the weight. The result had provided theoretical basis to the reforming of the system of the artificial culture O. sinensis.

  5. The Effects of Ivermectin on Brugia malayi Females In Vitro: A Transcriptomic Approach

    PubMed Central

    O’Neill, Maeghan; Burkman, Erica; Zaky, Weam I.; Xia, Jianguo; Moorhead, Andrew; Williams, Steven A.; Geary, Timothy G.

    2016-01-01

    Background Lymphatic filariasis and onchocerciasis are disabling and disfiguring neglected tropical diseases of major importance in developing countries. Ivermectin is the drug of choice for mass drug administration programs for the control of onchocerciasis and lymphatic filariasis in areas where the diseases are co-endemic. Although ivermectin paralyzes somatic and pharyngeal muscles in many nematodes, these actions are poorly characterized in adult filariae. We hypothesize that paralysis of pharyngeal pumping by ivermectin in filariae could result in deprivation of essential nutrients, especially iron, inducing a wide range of responses evidenced by altered gene expression, changes in metabolic pathways, and altered developmental states in embryos. Previous studies have shown that ivermectin treatment significantly reduces microfilariae release from females within four days of exposure in vivo, while not markedly affecting adult worms. However, the mechanisms responsible for reduced production of microfilariae are poorly understood. Methodology/Principal Findings We analyzed transcriptomic profiles from Brugia malayi adult females, an important model for other filariae, using RNAseq technology after exposure in culture to ivermectin at various concentrations (100 nM, 300 nM and 1 μM) and time points (24, 48, 72 h, and 5 days). Our analysis revealed drug-related changes in expression of genes involved in meiosis, as well as oxidative phosphorylation, which were significantly down-regulated as early as 24 h post-exposure. RNA interference phenotypes of the orthologs of these down-regulated genes in C. elegans include “maternal sterile”, “embryonic lethal”, “larval arrest”, “larval lethal” and “sick”. Conclusion/Significance These changes provide insight into the mechanisms involved in ivermectin-induced reduction in microfilaria output and impaired fertility, embryogenesis, and larval development. PMID:27529747

  6. Low-Molecular-Weight Metabolites Secreted by Paenibacillus larvae as Potential Virulence Factors of American Foulbrood

    PubMed Central

    Schild, Hedwig-Annabell; Fuchs, Sebastian W.

    2014-01-01

    The spore-forming bacterium Paenibacillus larvae causes a severe and highly infective bee disease, American foulbrood (AFB). Despite the large economic losses induced by AFB, the virulence factors produced by P. larvae are as yet unknown. To identify such virulence factors, we experimentally infected young, susceptible larvae of the honeybee, Apis mellifera carnica, with different P. larvae isolates. Honeybee larvae were reared in vitro in 24-well plates in the laboratory after isolation from the brood comb. We identified genotype-specific differences in the etiopathology of AFB between the tested isolates of P. larvae, which were revealed by differences in the median lethal times. Furthermore, we confirmed that extracts of P. larvae cultures contain low-molecular-weight compounds, which are toxic to honeybee larvae. Our data indicate that P. larvae secretes metabolites into the medium with a potent honeybee toxic activity pointing to a novel pathogenic factor(s) of P. larvae. Genome mining of P. larvae subsp. larvae BRL-230010 led to the identification of several biosynthesis gene clusters putatively involved in natural product biosynthesis, highlighting the potential of P. larvae to produce such compounds. PMID:24509920

  7. Efficacy of mealworm and super mealworm larvae probiotics as an alternative to antibiotics challenged orally with Salmonella and E. coli infection in broiler chicks.

    PubMed

    Islam, Md Manirul; Yang, Chul-Ju

    2017-01-01

    This study was conducted to evaluate dry mealworm (Tenebrio molitor) (DMLP) and super mealworm (Zophobas morio) (DSMLP) larvae probiotics as alternatives to antibiotics in broiler chicks. A total of 240 one-day old Ross 308 male broiler chicks were randomly assigned to three dietary treatments consisting of ten replications with eight birds each in a completely randomized design. The dietary treatments were, (i) control (basal diet), (ii) 0.4% DMLP (basal diet + 0.4% DMLP, DM basis), and (iii) 0.4% DSMLP (basal diet + 0.4% DSMLP, DM basis). On day one, 1 mL of mixed broth agar consisting of 2.4 × 10(7) cfu Salmonella enteritidis KCTC 2021 and 3.7 × 10(7) cfu Escherichia coli KCTC 2571 was injected orally into each chick. After one week, growth performance, immunity, mortality, internal organ weight, and cecal and fecal microbiota were investigated. Average daily gain ( ADG: ) and average daily feed intake (ADFI) increased, while feed conversion ratio (FCR) (g intake/g gain per bird) decreased in response to DMLP and DSMLP supplementation (P < 0.05). Additionally, mortality decreased (P < 0.05), while IgG and IgA levels increased following DMLP and DSMLP supplementation (P < 0.05). Internal organs remained unaffected, except for a reduced bursa of Fabricius weight in DSMLP supplementation (P < 0.05). Cecal E. coli and Salmonella contents were reduced in DMLP and DSMLP supplementation (P < 0.05), while fecal microbiota contents and pH of cecal and fecal digesta remained unaffected. In conclusion, dietary supplementation with DMLP and DSMLP increased ADG and IgG and IgA levels, while reducing FCR, mortality and cecal E. coli and Salmonella spp.

  8. The effect of electron transport (ET) inhibitors and thiabendazole on the fumarate reductase (FR) and succinate dehydrogenase (SDH) of Strongyloides ratti infective (L3) larvae.

    PubMed

    Armson, A; Grubb, W B; Mendis, A H

    1995-02-01

    The fumarate reductase (FR) and succinate dehydrogenase (SDH) activities of isolated submitochondrial particles (SMPs) prepared from axenised L3 larvae of S. ratti were characterised with respect to their response to a selected range of inhibitors. Rotenone (a specific inhibitor of electron transport Complex I) inhibited the S. ratti FR (EC50 = 3.0 x 10(-7) M) but not SDH. This strongly suggests that the S. ratti FR is functionally linked with the S. ratti ET-Complex I. 2-Thenoyltrifluoroacetone (TTFA, an inhibitor of ET-Complex II) inhibited FR (EC50 = 2.6 x 10(-5) M) and SDH (EC50 = 2.8 x 10(-5) M) with similar effectiveness. Sodium malonate (substrate analogue of succinate) had a greater affinity for SDH (EC50 = 6.8 x 10(-4) M), than FR (EC50 = 1.9 x 10(-2) M). Sodium fumarate was ca. 8-fold more effective in inhibiting the S. ratti FR (EC50 = 6.0 x 10(-4) M) than SDH (EC50 = 4.8 x 10(-3) M). The S. ratti FR was more sensitive to inhibition by thiabendazole (TBZ; EC50 = 4.6 x 10(-4) M) than SDH (EC50 > 1.0 x 10(-3) M), suggesting that one of the sites-of-action of TBZ to be the FR of S. ratti mitochondria. More potent inhibitors of S. ratti FR, if developed, may prove to be effective chemotherapeutic agents in the management of human strongloidiasis.

  9. Inhibition of the activation of Hageman factor (factor XII) and of platelet aggregation by extracts of Brugia malayi microfilariae.

    PubMed

    Foster, C B; Flanigan, T P; Kazura, J W; Dumenco, L L; Ratnoff, O D

    1991-05-01

    In human filariasis, large numbers of blood-borne microfilariae circulate unimpeded through the blood stream. How intravascular filarial parasites avoid precipitating thrombosis has not been studied in detail. We hypothesized that extracts of Brugia malayi microfilariae would contain factors that inhibit activation of hemostatic mechanisms. Initial studies demonstrated an inhibitor specific for the intrinsic coagulation cascade. The addition of microfilarial extracts to human plasma prolonged the activated partial thromboplastin time in a dose-dependent fashion but did not prolong the prothrombin, thrombin, or Russell's viper venom times. Microfilarial extracts (0.1 mg/ml) completely inhibited activation of Hageman factor (factor XII, at 0.05 U/ml) as measured in an amidolytic assay. Hageman factor previously activated by ellagic acid (factor XIIa) retained full enzymatic activity in the presence of microfilarial extract (0.1 mg/ml). The presence of inhibitory activity in the culture medium of live parasites raises the possibility that microfilariae secrete an inhibitory protein into their local environment. Microfilarial extracts at a final concentration of 0.1 mg/ml also inhibited collagen- and adenosine diphosphate-induced platelet aggregation. Arachidonic acid-induced platelet aggregation was inhibited by microfilarial extracts at a final concentration of 0.6 mg/ml. These results suggest that microfilariae of Brugia malayi, a human filarial parasite, may avoid initiating thrombosis through inhibition of the intrinsic coagulation pathway and platelet aggregation.

  10. Immunological evaluation of an rsmD-like rRNA methyltransferase from Wolbachia endosymbiont of Brugia malayi.

    PubMed

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

    2016-02-01

    Wolbachia is a wonderful anti-filarial target with many of its enzymes and surface proteins (WSPs) representing potential drug targets and vaccine candidates. Here we report on the immunologic response of a drug target, rsmD-like rRNA methyltransferase from Wolbachia endosymbiont of Brugia malayi. The recombinant protein generated both humoral and cell-mediated response in BALB/c mice but compromised its immunity. The humoral response was transient and endured barely for six months in mice with or without B. Malayi challenge. In splenocytes of mice, the key humoral immunity mediating cytokine IL4 was lowered (IL4↓) while IFNγ, the major cytokine mediating cellular immunity was decreased along with upregulation of IL10 cytokine (IFNγ↓, IL10↑). The finding here indicates that the enzyme has low immunogenicity and triggers lowering of cytokine level in BALB/c mice. Interestingly the overall immune profile can be summed up with equivalent response generated by WSP or whole Wolbachia.

  11. Effects of low temperatures on larvae of the genus Trichinella.

    PubMed

    Hulínská, D; Figallová, V; Shaikenov, B

    1985-01-01

    We examined the effect of an exposure to -25 degrees C (for 8 days) on the histochemistry and the fine structure of 30-day-old Trichinella larvae from muscle fibres of the diaphragm. The larvae of T. pseudospiralis and T. nelsoni were either destroyed in the muscle fibres, dead, eosinophile, or were not found. The structureless mass of a degenerating, changed sarcoplasm was highly AIP-active, and gave a weak positive reaction for SS-groups of proteins. The wall of the deformed capsule around T. nelsoni, and the cuticle of the larva, stained diffusely; it did not contain AM. In a few muscle fibres exposed to -25 degrees C, histochemical reactions of the capsule surrounding larvae of T. nativa and sometimes of larvae of T. spiralis, and reaction of the changed sarcoplasm, were similar to those of the controls. A few mobile larvae were isolated by digestion only from a diaphragm infected with T. nativa. Deterrent to a prolonged survival of larvae were the formation of ice crystals and a denaturation of proteins by which the sarcoplasm of the infected muscle fibre was changed gradually into both a plasmolytically and karyolytically altered mass. Degenerative changes in the fine structure of infected muscle fibres were demonstrated by the presence of "spheromembranous bodies" in the sarcoplasm resembling myeline formations observed after exposure to poisonous substances, e.g., colchicine.

  12. A potential role for the interaction of Wolbachia surface proteins with the Brugia malayi glycolytic enzymes and cytoskeleton in maintenance of endosymbiosis.

    PubMed

    Melnikow, Elena; Xu, Shulin; Liu, Jing; Bell, Aaron J; Ghedin, Elodie; Unnasch, Thomas R; Lustigman, Sara

    2013-01-01

    The human filarial parasite Brugia malayi harbors an endosymbiotic bacterium of the genus Wolbachia. The Wolbachia represent an attractive target for the control of filarial induced disease as elimination of the bacteria affects molting, reproduction and survival of the worms. The molecular basis for the symbiotic relationship between Wolbachia and their filarial hosts has yet to be elucidated. To identify proteins involved in this process, we focused on the Wolbachia surface proteins (WSPs), which are known to be involved in bacteria-host interactions in other bacterial systems. Two WSP-like proteins (wBm0152 and wBm0432) were localized to various host tissues of the B. malayi female adult worms and are present in the excretory/secretory products of the worms. We provide evidence that both of these proteins bind specifically to B. malayi crude protein extracts and to individual filarial proteins to create functional complexes. The wBm0432 interacts with several key enzymes involved in the host glycolytic pathway, including aldolase and enolase. The wBm0152 interacts with the host cytoskeletal proteins actin and tubulin. We also show these interactions in vitro and have verified that wBm0432 and B. malayi aldolase, as well as wBm0152 and B. malayi actin, co-localize to the vacuole surrounding Wolbachia. We propose that both WSP protein complexes interact with each other via the aldolase-actin link and/or via the possible interaction between the host's enolase and the cytoskeleton, and play a role in Wolbachia distribution during worm growth and embryogenesis.

  13. A Potential Role for the Interaction of Wolbachia Surface Proteins with the Brugia malayi Glycolytic Enzymes and Cytoskeleton in Maintenance of Endosymbiosis

    PubMed Central

    Melnikow, Elena; Xu, Shulin; Liu, Jing; Bell, Aaron J.; Ghedin, Elodie; Unnasch, Thomas R.; Lustigman, Sara

    2013-01-01

    The human filarial parasite Brugia malayi harbors an endosymbiotic bacterium of the genus Wolbachia. The Wolbachia represent an attractive target for the control of filarial induced disease as elimination of the bacteria affects molting, reproduction and survival of the worms. The molecular basis for the symbiotic relationship between Wolbachia and their filarial hosts has yet to be elucidated. To identify proteins involved in this process, we focused on the Wolbachia surface proteins (WSPs), which are known to be involved in bacteria-host interactions in other bacterial systems. Two WSP-like proteins (wBm0152 and wBm0432) were localized to various host tissues of the B. malayi female adult worms and are present in the excretory/secretory products of the worms. We provide evidence that both of these proteins bind specifically to B. malayi crude protein extracts and to individual filarial proteins to create functional complexes. The wBm0432 interacts with several key enzymes involved in the host glycolytic pathway, including aldolase and enolase. The wBm0152 interacts with the host cytoskeletal proteins actin and tubulin. We also show these interactions in vitro and have verified that wBm0432 and B. malayi aldolase, as well as wBm0152 and B. malayi actin, co-localize to the vacuole surrounding Wolbachia. We propose that both WSP protein complexes interact with each other via the aldolase-actin link and/or via the possible interaction between the host's enolase and the cytoskeleton, and play a role in Wolbachia distribution during worm growth and embryogenesis. PMID:23593519

  14. Examination of the migration of first instar larvae of the parasite OEstrus ovis (Linne 1761) [Diptera: OEstridae] in the upper respiratory tract of artificially infected lambs and daily measurements of the kinetics of blood eosinophilia and mucosal inflammatory response associated with repeated infection.

    PubMed

    Yacob, H T; Jacquiet, Ph; Prevot, F; Bergeaud, J P; Bleuart, C; Dorchies, Ph; Hoste, H

    2004-12-15

    Twelve lambs were divided into two groups: Group C control, non-infected, and Group O infected once a week for 5 weeks with OEstrus ovis L1 through the same nostril. The first objective of this experiment was to check whether larvae moving through a given nostril remain in the same side nasal cavity or might to spread in both nasal cavities. It has been observed that larvae invade and spread through the entire nasal cavities. The only possible passage way between both sides is via the choanae and velum palatinum. The second objective was to follow the kinetics of blood eosinophilia. A primary peak in eosinophil numbers was noted 4 days following infection, with a higher peak following the second infection. After that, no major changes were seen. Nevertheless, the numbers of eosinophils were always higher than in control animals until the end of the follow-up. The third objective of the study was an enumeration of reactive cells (mast cells, globule leucocytes, and eosinophils) in the mucosae of the upper and lower respiratory tract after necropsy of the animals of the two groups. As observed in previous experiments, there was a large accumulation of these cells in mucosae of the upper respiratory tract. It was also worth noting a significant accumulation of eosinophils in the tissues of the trachea, bronchae and lungs even though OE. ovis was not present there. This "distant" eosinophilic reaction may have important consequences on patho-physiology of other parasites living in these locations: eosinophils have the potential to kill them even though these cells are not activated by their specific antigens.

  15. [Eosinophilic pneumonia in response to cutaneous larva migrans syndrome--a case report].

    PubMed

    Darocha, Szymon; Wawrzyńska, Liliana; Oniszh, Karina; Dziewulska, Barbara

    2011-01-01

    Cutaneous larva migrans is a parasitic dermatosis imported by travelers returning from tropical and subtropical regions. In cutaneous larva migrans syndrome humans are incidental hosts and the larvae are unable to complete their natural cycle. Adult hookworms live in the intestines of dogs and cats, shedding eggs in feces that hatch and mature into larvae that can remain infective for months in the soil. Larvae penetrate the skin after contact with infected soil and cause an itchy creeping eruption. Cutaneous larva migrans is not usually associated with systemic symptoms and is rarely accompanied by peripheral blood eosinophilia. We report a patient who had both cutaneous larva migrans syndrome caused by Ancylostoma brasiliense and eosinophilic pneumonia after returning from Sri Lanka. The patient has been applied intravenous corticosteroids and local treatment with albendazole ointment with a very good clinical response.

  16. Biological Role of Paenilarvins, Iturin-Like Lipopeptide Secondary Metabolites Produced by the Honey Bee Pathogen Paenibacillus larvae.

    PubMed

    Hertlein, Gillian; Seiffert, Marlene; Gensel, Sebastian; Garcia-Gonzalez, Eva; Ebeling, Julia; Skobalj, Ranko; Kuthning, Anja; Süssmuth, Roderich D; Genersch, Elke

    2016-01-01

    The Gram-positive bacterium Paenibacillus larvae (P. larvae) is the causative agent of a deadly honey bee brood disease called American Foulbrood (AFB). AFB is a notifiable epizootic in most countries and, hence, P. larvae is of considerable relevance for veterinarians and apiculturists alike. Over the last decade, much progress has been made in the understanding of the (patho)biology of P. larvae. Recently, several non-ribosomally produced peptides (NRP) and peptide/polyketide (NRP/PK) hybrids produced by P. larvae were identified. Among these NRPs were iturin-like lipopeptides, the paenilarvins A-C. Iturins are known to exhibit strong anti-fungal activity; for some iturins, cytotoxic activity towards mammalian erythrocytes and human cancer cell lines are described. We here present our results on the analysis of the natural function of the paenilarvins during pathogenesis of P. larvae infections. We demonstrated production of paenilarvins in infected larvae. However, we could neither demonstrate cytotoxicity of paenilarvins towards cultured insect cells nor towards larvae in feeding assays. Accordingly, exposure bioassays performed with larvae infected by wild-type P. larvae and a knockout mutant of P. larvae lacking production of paenilarvins did not substantiate a role for the paenilarvins as virulence factor. Further experiments are necessary to analyze the relevance of the paenilarvins' anti-fungal activity for P. larvae infections in the presence of fungal competitors in the larval midgut or cadaver.

  17. Biological Role of Paenilarvins, Iturin-Like Lipopeptide Secondary Metabolites Produced by the Honey Bee Pathogen Paenibacillus larvae

    PubMed Central

    Gensel, Sebastian; Garcia-Gonzalez, Eva; Ebeling, Julia; Skobalj, Ranko; Kuthning, Anja; Süssmuth, Roderich D.

    2016-01-01

    The Gram-positive bacterium Paenibacillus larvae (P. larvae) is the causative agent of a deadly honey bee brood disease called American Foulbrood (AFB). AFB is a notifiable epizootic in most countries and, hence, P. larvae is of considerable relevance for veterinarians and apiculturists alike. Over the last decade, much progress has been made in the understanding of the (patho)biology of P. larvae. Recently, several non-ribosomally produced peptides (NRP) and peptide/polyketide (NRP/PK) hybrids produced by P. larvae were identified. Among these NRPs were iturin-like lipopeptides, the paenilarvins A-C. Iturins are known to exhibit strong anti-fungal activity; for some iturins, cytotoxic activity towards mammalian erythrocytes and human cancer cell lines are described. We here present our results on the analysis of the natural function of the paenilarvins during pathogenesis of P. larvae infections. We demonstrated production of paenilarvins in infected larvae. However, we could neither demonstrate cytotoxicity of paenilarvins towards cultured insect cells nor towards larvae in feeding assays. Accordingly, exposure bioassays performed with larvae infected by wild-type P. larvae and a knockout mutant of P. larvae lacking production of paenilarvins did not substantiate a role for the paenilarvins as virulence factor. Further experiments are necessary to analyze the relevance of the paenilarvins’ anti-fungal activity for P. larvae infections in the presence of fungal competitors in the larval midgut or cadaver. PMID:27760211

  18. Structure of the Trehalose-6-phosphate Phosphatase from Brugia malayi Reveals Key Design Principles for Anthelmintic Drugs

    PubMed Central

    Farelli, Jeremiah D.; Galvin, Brendan D.; Li, Zhiru; Liu, Chunliang; Aono, Miyuki; Garland, Megan; Hallett, Olivia E.; Causey, Thomas B.; Ali-Reynolds, Alana; Saltzberg, Daniel J.; Carlow, Clotilde K. S.; Dunaway-Mariano, Debra; Allen, Karen N.

    2014-01-01

    Parasitic nematodes are responsible for devastating illnesses that plague many of the world's poorest populations indigenous to the tropical areas of developing nations. Among these diseases is lymphatic filariasis, a major cause of permanent and long-term disability. Proteins essential to nematodes that do not have mammalian counterparts represent targets for therapeutic inhibitor discovery. One promising target is trehalose-6-phosphate phosphatase (T6PP) from Brugia malayi. In the model nematode Caenorhabditis elegans, T6PP is essential for survival due to the toxic effect(s) of the accumulation of trehalose 6-phosphate. T6PP has also been shown to be essential in Mycobacterium tuberculosis. We determined the X-ray crystal structure of T6PP from B. malayi. The protein structure revealed a stabilizing N-terminal MIT-like domain and a catalytic C-terminal C2B-type HAD phosphatase fold. Structure-guided mutagenesis, combined with kinetic analyses using a designed competitive inhibitor, trehalose 6-sulfate, identified five residues important for binding and catalysis. This structure-function analysis along with computational mapping provided the basis for the proposed model of the T6PP-trehalose 6-phosphate complex. The model indicates a substrate-binding mode wherein shape complementarity and van der Waals interactions drive recognition. The mode of binding is in sharp contrast to the homolog sucrose-6-phosphate phosphatase where extensive hydrogen-bond interactions are made to the substrate. Together these results suggest that high-affinity inhibitors will be bi-dentate, taking advantage of substrate-like binding to the phosphoryl-binding pocket while simultaneously utilizing non-native binding to the trehalose pocket. The conservation of the key residues that enforce the shape of the substrate pocket in T6PP enzymes suggest that development of broad-range anthelmintic and antibacterial therapeutics employing this platform may be possible. PMID:24992307

  19. Development of an In Vivo RNAi Protocol to Investigate Gene Function in the Filarial Nematode, Brugia malayi

    PubMed Central

    Song, Chuanzhe; Gallup, Jack M.; Day, Tim A.

    2010-01-01

    Our ability to control diseases caused by parasitic nematodes is constrained by a limited portfolio of effective drugs and a paucity of robust tools to investigate parasitic nematode biology. RNA interference (RNAi) is a reverse-genetics tool with great potential to identify novel drug targets and interrogate parasite gene function, but present RNAi protocols for parasitic nematodes, which remove the parasite from the host and execute RNAi in vitro, are unreliable and inconsistent. We have established an alternative in vivo RNAi protocol targeting the filarial nematode Brugia malayi as it develops in an intermediate host, the mosquito Aedes aegypti. Injection of worm-derived short interfering RNA (siRNA) and double stranded RNA (dsRNA) into parasitized mosquitoes elicits suppression of B. malayi target gene transcript abundance in a concentration-dependent fashion. The suppression of this gene, a cathepsin L-like cysteine protease (Bm-cpl-1) is specific and profound, both injection of siRNA and dsRNA reduce transcript abundance by 83%. In vivo Bm-cpl-1 suppression results in multiple aberrant phenotypes; worm motility is inhibited by up to 69% and parasites exhibit slow-moving, kinked and partial-paralysis postures. Bm-cpl-1 suppression also retards worm growth by 48%. Bm-cpl-1 suppression ultimately prevents parasite development within the mosquito and effectively abolishes transmission potential because parasites do not migrate to the head and proboscis. Finally, Bm-cpl-1 suppression decreases parasite burden and increases mosquito survival. This is the first demonstration of in vivo RNAi in animal parasitic nematodes and results indicate this protocol is more effective than existing in vitro RNAi methods. The potential of this new protocol to investigate parasitic nematode biology and to identify and validate novel anthelmintic drug targets is discussed. PMID:21203489

  20. Consumption of nutritional pellets with Duddingtonia flagrans fungal chlamydospores reduces infective nematode larvae of Haemonchus contortus in faeces of Saint Croix lambs.

    PubMed

    Aguilar-Marcelino, L; Mendoza-de-Gives, P; Torres-Hernández, G; López-Arellano, M E; Becerril-Pérez, C M; Orihuela-Trujillo, A; Torres-Acosta, J F J; Olmedo-Juárez, A

    2016-11-21

    Two groups of six Haemonchus contortus infected Saint Croix lambs each received different diets for 11 weeks: control group, commercial food, molasses and lucerne hay; and treated group, nutritional pellets (NPs) containing Duddingtonia flagrans at 2 × 106 chlamydospores/kg body weight (BW), sorghum and lucerne hay. Mean BW gain (BWG), body condition score (BCS) and packed cell volume (PCV) and also eggs/g of faeces (EPG) and recovered L3 were compared using a repeated measures across time model. Groups had similar BWG (control 139.7 ± 0.035 g/day and treated 167.7 ± 0.041 g/day), BCS (control 3.6 ± 0.39 and treated 3.4 ± 0.46) and PCV (control 32.5 ± 1.68% and treated 30.0 ± 1.68%). The mean EPG of the control group was 1215 ± 1040 and in the treated group it was 2097.91 ± 2050. No reduction in larval population was observed during weeks 2 and 3. The greatest larval population reduction in the faeces of treated lambs was observed during the first week (70.5%) and from weeks 6 to 11, with a mean value close to 70% (P < 0.05). In general, both experimental groups showed a similar feed conversion. It was concluded that both diets resulted in similar lamb growth, PCV, BCS and H. contortus EPG. However, NP consumption significantly reduced the H. contortus L3 population in lamb faeces.

  1. First detection of Paenibacillus larvae the causative agent of American Foulbrood in a Ugandan honeybee colony.

    PubMed

    Chemurot, Moses; Brunain, Marleen; Akol, Anne M; Descamps, Tine; de Graaf, Dirk C

    2016-01-01

    Paenibacillus larvae is a highly contagious and often lethal widely distributed pathogen of honeybees, Apis mellifera but has not been reported in eastern Africa to date. We investigated the presence of P. larvae in the eastern and western highland agro-ecological zones of Uganda by collecting brood and honey samples from 67 honeybee colonies in two sampling occasions and cultivated them for P. larvae. Also, 8 honeys imported and locally retailed in Uganda were sampled and cultivated for P. larvae. Our aim was to establish the presence and distribution of P. larvae in honeybee populations in the two highland agro-ecological zones of Uganda and to determine if honeys that were locally retailed contained this lethal pathogen. One honeybee colony without clinical symptoms for P. larvae in an apiary located in a protected area of the western highlands of Uganda was found positive for P. larvae. The strain of this P. larvae was genotyped and found to be ERIC I. In order to compare its virulence with P. larvae reference strains, in vitro infection experiments were conducted with carniolan honeybee larvae from the research laboratory at Ghent University, Belgium. The results show that the virulence of the P. larvae strain found in Uganda was at least equally high. The epidemiological implication of the presence of P. larvae in a protected area is discussed.

  2. 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.

  3. Production of the Catechol Type Siderophore Bacillibactin by the Honey Bee Pathogen Paenibacillus larvae

    PubMed Central

    Garcia-Gonzalez, Eva; Poppinga, Lena; Süssmuth, Roderich D.; Genersch, Elke

    2014-01-01

    The Gram-positive bacterium Paenibacillus larvae is the etiological agent of American Foulbrood. This bacterial infection of honey bee brood is a notifiable epizootic posing a serious threat to global honey bee health because not only individual larvae but also entire colonies succumb to the disease. In the recent past considerable progress has been made in elucidating molecular aspects of host pathogen interactions during pathogenesis of P. larvae infections. Especially the sequencing and annotation of the complete genome of P. larvae was a major step forward and revealed the existence of several giant gene clusters coding for non-ribosomal peptide synthetases which might act as putative virulence factors. We here present the detailed analysis of one of these clusters which we demonstrated to be responsible for the biosynthesis of bacillibactin, a P. larvae siderophore. We first established culture conditions allowing the growth of P. larvae under iron-limited conditions and triggering siderophore production by P. larvae. Using a gene disruption strategy we linked siderophore production to the expression of an uninterrupted bacillibactin gene cluster. In silico analysis predicted the structure of a trimeric trithreonyl lactone (DHB-Gly-Thr)3 similar to the structure of bacillibactin produced by several Bacillus species. Mass spectrometric analysis unambiguously confirmed that the siderophore produced by P. larvae is identical to bacillibactin. Exposure bioassays demonstrated that P. larvae bacillibactin is not required for full virulence of P. larvae in laboratory exposure bioassays. This observation is consistent with results obtained for bacillibactin in other pathogenic bacteria. PMID:25237888

  4. Production of the catechol type siderophore bacillibactin by the honey bee pathogen Paenibacillus larvae.

    PubMed

    Hertlein, Gillian; Müller, Sebastian; Garcia-Gonzalez, Eva; Poppinga, Lena; Süssmuth, Roderich D; Genersch, Elke

    2014-01-01

    The Gram-positive bacterium Paenibacillus larvae is the etiological agent of American Foulbrood. This bacterial infection of honey bee brood is a notifiable epizootic posing a serious threat to global honey bee health because not only individual larvae but also entire colonies succumb to the disease. In the recent past considerable progress has been made in elucidating molecular aspects of host pathogen interactions during pathogenesis of P. larvae infections. Especially the sequencing and annotation of the complete genome of P. larvae was a major step forward and revealed the existence of several giant gene clusters coding for non-ribosomal peptide synthetases which might act as putative virulence factors. We here present the detailed analysis of one of these clusters which we demonstrated to be responsible for the biosynthesis of bacillibactin, a P. larvae siderophore. We first established culture conditions allowing the growth of P. larvae under iron-limited conditions and triggering siderophore production by P. larvae. Using a gene disruption strategy we linked siderophore production to the expression of an uninterrupted bacillibactin gene cluster. In silico analysis predicted the structure of a trimeric trithreonyl lactone (DHB-Gly-Thr)3 similar to the structure of bacillibactin produced by several Bacillus species. Mass spectrometric analysis unambiguously confirmed that the siderophore produced by P. larvae is identical to bacillibactin. Exposure bioassays demonstrated that P. larvae bacillibactin is not required for full virulence of P. larvae in laboratory exposure bioassays. This observation is consistent with results obtained for bacillibactin in other pathogenic bacteria.

  5. Comparative genomics of 9 novel Paenibacillus larvae bacteriophages

    PubMed Central

    Stamereilers, Casey; LeBlanc, Lucy; Yost, Diane; Amy, Penny S.; Tsourkas, Philippos K.

    2016-01-01

    ABSTRACT American Foulbrood Disease, caused by the bacterium Paenibacillus larvae, is one of the most destructive diseases of the honeybee, Apis mellifera. Our group recently published the sequences of 9 new phages with the ability to infect and lyse P. larvae. Here, we characterize the genomes of these P. larvae phages, compare them to each other and to other sequenced P. larvae phages, and putatively identify protein function. The phage genomes are 38–45 kb in size and contain 68–86 genes, most of which appear to be unique to P. larvae phages. We classify P. larvae phages into 2 main clusters and one singleton based on nucleotide sequence identity. Three of the new phages show sequence similarity to other sequenced P. larvae phages, while the remaining 6 do not. We identified functions for roughly half of the P. larvae phage proteins, including structural, assembly, host lysis, DNA replication/metabolism, regulatory, and host-related functions. Structural and assembly proteins are highly conserved among our phages and are located at the start of the genome. DNA replication/metabolism, regulatory, and host-related proteins are located in the middle and end of the genome, and are not conserved, with many of these genes found in some of our phages but not others. All nine phages code for a conserved N-acetylmuramoyl-L-alanine amidase. Comparative analysis showed the phages use the “cohesive ends with 3′ overhang” DNA packaging strategy. This work is the first in-depth study of P. larvae phage genomics, and serves as a marker for future work in this area. PMID:27738559

  6. Visceral and Neural Larva Migrans in Rhesus Macaques

    PubMed Central

    Gozalo, Alfonso S; Maximova, Olga A; StClaire, Marisa C; Montali, Richard J; Ward, Jerrold M; Cheng, Lily I; Elkins, William R; Kazacos, Kevin R

    2008-01-01

    Large ascarid larvae within granulomas were noted histologically in the mesenteric and pancreatic lymph nodes of 13 of 21 rhesus macaques (Macaca mulatta) euthanized as part of an experimental viral pathogenesis study. In addition, 7 of the 13 monkeys had cerebral granulomas, which in 4 animals contained nematode larvae similar to those within the lymph nodes. Despite the lesions, the animals did not show clinical signs associated with the parasitic infections. Characteristics of the larvae included, on cross-section, a midbody diameter of approximately 60 to 80 µm, a centrally located and slightly compressed intestine flanked on either side by large triangular excretory columns, and prominent single lateral cuticular alae. The morphology of the larvae was compatible with Baylisascaris spp. Baylisascariasis is a well-described infection of animals and humans that is caused by migrating larvae of the raccoon roundworm, Baylisascaris procyonis. A similar species, B. columnaris, is found in skunks and can cause cerebrospinal nematodiasis, but most reported cases of baylisascariasis have been due to B. procyonis. Our macaques were born free-ranging on an island in the southeastern United States where raccoons, but not skunks, were found to be common inhabitants, indicating that B. procyonis was the most likely parasite involved. These cases are similar to the low-level or covert cases of Baylisascaris infection described to occur in humans and provide further evidence of the existence of this parasite in the southeastern United States. PMID:18702454

  7. TIME management by medicinal larvae.

    PubMed

    Pritchard, David I; Čeřovský, Václav; Nigam, Yamni; Pickles, Samantha F; Cazander, Gwendolyn; Nibbering, Peter H; Bültemann, Anke; Jung, Wilhelm

    2016-08-01

    Wound bed preparation (WBP) is an integral part of the care programme for chronic wounds. The acronym TIME is used in the context of WBP and describes four barriers to healing in chronic wounds; namely, dead Tissue, Infection and inflammation, Moisture imbalance and a non-migrating Edge. Larval debridement therapy (LDT) stems from observations that larvae of the blowfly Lucilia sericata clean wounds of debris. Subsequent clinical studies have proven debriding efficacy, which is likely to occur as a result of enzymatically active alimentary products released by the insect. The antimicrobial, anti-inflammatory and wound healing activities of LDT have also been investigated, predominantly in a pre-clinical context. This review summarises the findings of investigations into the molecular mechanisms of LDT and places these in context with the clinical concept of WBP and TIME. It is clear from these findings that biotherapy with L. sericata conforms with TIME, through the enzymatic removal of dead tissue and its associated biofilm, coupled with the secretion of defined antimicrobial peptides. This biotherapeutic impact on the wound serves to reduce inflammation, with an associated capacity for an indirect effect on moisture imbalance. Furthermore, larval serine proteinases have the capacity to alter fibroblast behaviour in a manner conducive to the formation of granulation tissue.

  8. Infection

    DTIC Science & Technology

    2010-09-01

    standing, diagnosis, and treatment of musculoskeletal infections. Key Words: musculoskeletal infection, biofilm , bacteria, biomaterial (J Orthop Trauma...form a biofilm , or slime layer.1 The recurrence of infections is often the result of microbial biofilm formation on the implant, enabling the persistence...Klebsiella pneumoniae). Staphylococcus species is by far the most studied pathogen in musculoskeletal infections and can produce a multilayered biofilm

  9. Zoonotic aspects of filarial infections in man

    PubMed Central

    Dissanaike, A. S.

    1979-01-01

    This article gives an account of the filarial parasites found in man and their potential transmissibility to and from other vertebrate animals under natural and experimental conditions. Those species that are regarded as being primarily parasites of other vertebrates, but which also infect man, are then dealt with in greater detail. These include the subperiodic strain of Brugia malayi and perhaps also B. pahangi, both of which are found in wild and domestic carnivores and monkeys, and Dirofilaria species of dogs and racoons. The Brugia parasites develop to maturity with the production of microfilaraemia and clinical manifestations in man similar to those caused by periodic B. malayi in man. Human dirofilariasis, on the other hand, represents a transmission cul-de-sac for the parasite. Clinical manifestations are mild or absent and generally the worms do not mature and, even if they do, they rarely give rise to microfilaraemia. D. immitis causes pulmonary dirofilariasis, and D. repens and D. tenuis give rise to subcutaneous nodules in man. The diagnosis of dirofilariasis depends on an awareness of the infection in the animal reservoirs and of the possibility of man being exposed to bites of infected vectors. ImagesFig. 2Fig. 3Fig. 4Fig. 5Fig. 6 PMID:314349

  10. Transmission of a Gammabaculovirus within Cohorts of Balsam Fir Sawfly (Neodiprion abietis) Larvae

    PubMed Central

    Graves, Roger; Quiring, Dan T.; Lucarotti, Christopher J.

    2012-01-01

    Nucleopolyhedroviruses (NPV: Gammabaculovirus: Baculoviridae) of diprionid sawflies (Diprionidae: Hymenoptera) are highly host specific and only infect the midgut epithelium. While still alive, infected sawfly larvae excrete NPV-laden diarrhea that contaminates food sources. The diarrhea can then be consumed by conspecific larvae, resulting in rapid horizontal transmission of the virus. To better understand the efficacy of Gammabaculovirus-based biological control products, the horizontal spread of such a virus (NeabNPV) within cohorts of balsam fir sawfly (Neodiprion abietis) larvae was studied by introducing NeabNPV-treated larvae into single-cohort groups at densities similar to those observed during the increasing (field study) and peak (laboratory study) phases of an outbreak. In field studies (~200 N. abietis larvae/m2 of balsam fir (Abies balsamea) foliage), NeabNPV-induced mortality increased positively in a density-dependent manner, from 23% (in control groups) to 51% with the addition of one first-instar NeabNPV-treated larva, to 84% with 10 first–instar-treated larvae. Mortality was 60% and 63% when one or 10 NeabNPV-treated third-instar larva(e), respectively, were introduced into groups. Slightly higher levels of NeabNPV-induced mortality occurring when NeabNPV-treated larvae were introduced into first- rather than third-instar cohorts suggests that early instars are more susceptible to the virus. In the laboratory (~1330 N. abietis larvae/ m2 of foliage), NeabNPV-caused mortality increased from 20% in control groups to over 80% with the introduction of one, five or 10 NeabNPV-treated larvae into treatment groups of first-instar larvae. PMID:26466722

  11. Brugia malayi soluble and excretory-secretory proteins attenuate development of streptozotocin-induced type 1 diabetes in mice.

    PubMed

    Amdare, N; Khatri, V; Yadav, R S P; Tarnekar, A; Goswami, K; Reddy, M V R

    2015-12-01

    Understanding the modulation of the host-immune system by pathogens-like filarial parasites offers an alternate approach to prevent autoimmune diseases. In this study, we have shown that treatment with filarial proteins prior to or after the clinical onset of streptozotocin-induced type-1 diabetes (T1D) can ameliorate the severity of disease in BALB/c mice. Pre-treatment with Brugia malayi adult soluble (Bm A S) or microfilarial excretory-secretory (Bm mf ES) or microfilarial soluble (Bm mf S) antigens followed by induction of diabetes led to lowering of fasting blood glucose levels with as many as 57.5-62.5% of mice remaining nondiabetic. These proteins were more effective when they were used to treat the mice with established T1D as 62.5-71.5% of the mice turned to be nondiabetic. Histopathological examination of pancreas of treated mice showed minor inflammatory changes in pancreatic islet cell architecture. The therapeutic effect was found to be associated with the decreased production of cytokines TNF-α & IFN-γ and increased production of IL-10 in the culture supernatants of splenocytes of treated mice. A switch in the production of anti-insulin antibodies from IgG2a to IgG1 isotype was also seen. Together these results provide a proof towards utilizing the filarial derived proteins as novel anti-diabetic therapeutics.

  12. Use of Iodogen and sulfosuccinimidobiotin to identify and isolate cuticular proteins of the filarial parasite Brugia malayi.

    PubMed

    Alvarez, R M; Henry, R W; Weil, G J

    1989-03-01

    The cuticle of filarial nematodes is a dynamic structure which may be an important target for protective host immune responses. Prior studies have employed radioiodination of intact parasites to demonstrate that the collagenous cuticle of filariids contains relatively few exposed proteins, some of which are stage and/or species-specific. In the present study, we have used sulfo-NHS-biotin to label and affinity purify cuticular components of living adult Brugia malayi. Results obtained by this method were compared with the widely used Iodogen method of surface radioiodination by SDS-PAGE analysis of detergent-solubilized worms and by ultrastructural analysis. Both labeling methods produced very similar electrophoretic patterns with major doublets at 70 and 100 kDa, a major band at 25 kDa, and minor bands between 60-200 kDa. Ultrastructural analysis showed that both methods labeled components throughout all levels of the parasite cuticle; underlying somatic tissues were not labeled. The biotinylated components were isolated from the total parasite extract by affinity chromatography on an avidin matrix. Further characterization of these surface-associated proteins may lead to improved methods for the control of filariasis.

  13. Microgavage of Zebrafish Larvae

    PubMed Central

    Cocchiaro, Jordan L.; Rawls, John F.

    2013-01-01

    The zebrafish has emerged as a powerful model organism for studying intestinal development1-5, physiology6-11, disease12-16, and host-microbe interactions17-25. Experimental approaches for studying intestinal biology often require the in vivo introduction of selected materials into the lumen of the intestine. In the larval zebrafish model, this is typically accomplished by immersing fish in a solution of the selected material, or by injection through the abdominal wall. Using the immersion method, it is difficult to accurately monitor or control the route or timing of material delivery to the intestine. For this reason, immersion exposure can cause unintended toxicity and other effects on extraintestinal tissues, limiting the potential range of material amounts that can be delivered into the intestine. Also, the amount of material ingested during immersion exposure can vary significantly between individual larvae26. Although these problems are not encountered during direct injection through the abdominal wall, proper injection is difficult and causes tissue damage which could influence experimental results.We introduce a method for microgavage of zebrafish larvae. The goal of this method is to provide a safe, effective, and consistent way to deliver material directly to the lumen of the anterior intestine in larval zebrafish with controlled timing. Microgavage utilizes standard embryo microinjection and stereomicroscopy equipment common to most laboratories that perform zebrafish research. Once fish are properly positioned in methylcellulose, gavage can be performed quickly at a rate of approximately 7-10 fish/ min, and post-gavage survival approaches 100% depending on the gavaged material. We also show that microgavage can permit loading of the intestinal lumen with high concentrations of materials that are lethal to fish when exposed by immersion. To demonstrate the utility of this method, we present a fluorescent dextran microgavage assay that can be used to

  14. Ultrastructural characteristics of nurse cell-larva complex of four species of Trichinella in several hosts.

    PubMed

    Sacchi, L; Corona, S; Gajadhar, A A; Pozio, E

    2001-06-01

    The nurse cell-larva complex of nematodes of the genus Trichinella plays an important role in the survival of the larva in decaying muscles, frequently favouring the transmission of the parasite in extreme environmental conditions. The ultrastructure of the nurse cell-larva complex in muscles from different hosts infected with T. nativa (a walrus and a polar bear), T. spiralis (horses and humans), T. pseudospiralis (a laboratory mouse) and T. papuae (a laboratory mouse) were examined. Analysis with transmission electron microscope showed that the typical nurse cell structure was present in all examined samples, irrespective of the species of larva, of the presence of a collagen capsule, of the age of infection and of the host species, suggesting that there exists a molecular mechanism that in the first stage of larva invasion is similar for encapsulated and non-encapsulated species.

  15. Infection

    MedlinePlus

    ... 23(4):251-69. Association for Professionals in Infection Control and Epidemiology (APIC) guideline. Back to Top Administration ... : Hospital Scope | Glossary | References | Site Map | Credits Freedom of ...

  16. Hookworm-related cutaneous larva migrans acquired in the UK.

    PubMed

    Baple, Katy; Clayton, James

    2015-11-13

    Hookworm-related cutaneous larva migrans (HrCLM) is a skin disease caused by infection with the larvae of animal hookworms. With conditions for infection more favourable in tropical climates, HrCLM in the UK is classically diagnosed in the returning traveller. We present two cases of clinically diagnosed UK-acquired HrCLM from a district general hospital in the south of England. A 68-year-old woman presented with a pruritic serpiginous tract on the right hand. She was a keen gardener and had been handling compost. A 50-year-old man, a long distance runner, presented with a similar lesion on the dorsum of his foot. Both patients were treated with a single dose of albendazole. These cases may represent an emerging infection in the UK. In the absence of a suggestive travel history, early recognition followed by efficient access to therapy is vital for treating HrCLM transmitted in the UK.

  17. Homologs of the Caenorhabditis elegans masculinizing gene her-1 in C. briggsae and the filarial parasite Brugia malayi.

    PubMed Central

    Streit, A; Li, W; Robertson, B; Schein, J; Kamal, I H; Marra, M; Wood, W B

    1999-01-01

    The masculinizing gene her-1 in Caenorhabditis elegans (Ce-her-1) encodes a novel protein, HER-1A, which is required for male development. To identify conserved elements in her-1 we have cloned and characterized two homologous nematode genes: one by synteny from the closely related free-living species C. briggsae (Cb-her-1) and the other, starting with a fortuitously identified expressed sequence tag, from the distantly related parasite Brugia malayi (Bm-her-1). The overall sequence identities of the predicted gene products with Ce-HER-1A are only 57% for Cb-HER-1, which is considerably lower than has been found for most homologous briggsae genes, and 35% for Bm-HER-1. However, conserved residues are found throughout both proteins, and like Ce-HER-1A, both have putative N-terminal signal sequences. Ce-her-1 produces a larger masculinizing transcript (her-1a) and a smaller transcript of unknown function (her-1b); both are present essentially only in males. By contrast, Cb-her-1 appears to produce only one transcript, corresponding to her-1a; it is enriched in males but present also in hermaphrodites. Injection of dsRNA transcribed from Cb-her-1 into C. briggsae hermaphrodites (RNA interference) caused XO animals to develop into partially fertile hermaphrodites. Introducing a Cb-her-1 construct as a transgene under control of the C. elegans unc-54 myosin heavy chain promoter caused strong masculinization of both C. briggsae and C. elegans hermaphrodites. Introduction of a similar Bm-her-1 construct into C. elegans caused only very weak, if any, masculinization. We conclude that in spite of considerable divergence the Cb gene is likely to be a functional ortholog of Ce-her-1, while the function of the distantly related Bm gene remains uncertain. PMID:10430584

  18. Filarial Worms Reduce Plasmodium Infectivity in Mosquitoes

    PubMed Central

    Aliota, Matthew T.; Chen, Cheng-Chen; Dagoro, Henry; Fuchs, Jeremy F.; Christensen, Bruce M.

    2011-01-01

    Background Co-occurrence of malaria and filarial worm parasites has been reported, but little is known about the interaction between filarial worm and malaria parasites with the same Anopheles vector. Herein, we present data evaluating the interaction between Wuchereria bancrofti and Anopheles punctulatus in Papua New Guinea (PNG). Our field studies in PNG demonstrated that An. punctulatus utilizes the melanization immune response as a natural mechanism of filarial worm resistance against invading W. bancrofti microfilariae. We then conducted laboratory studies utilizing the mosquitoes Armigeres subalbatus and Aedes aegypti and the parasites Brugia malayi, Brugia pahangi, Dirofilaria immitis, and Plasmodium gallinaceum to evaluate the hypothesis that immune activation and/or development by filarial worms negatively impact Plasmodium development in co-infected mosquitoes. Ar. subalbatus used in this study are natural vectors of P. gallinaceum and B. pahangi and they are naturally refractory to B. malayi (melanization-based refractoriness). Methodology/Principal Findings Mosquitoes were dissected and Plasmodium development was analyzed six days after blood feeding on either P. gallinaceum alone or after taking a bloodmeal containing both P. gallinaceum and B. malayi or a bloodmeal containing both P. gallinaceum and B. pahangi. There was a significant reduction in the prevalence and mean intensity of Plasmodium infections in two species of mosquito that had dual infections as compared to those mosquitoes that were infected with Plasmodium alone, and was independent of whether the mosquito had a melanization immune response to the filarial worm or not. However, there was no reduction in Plasmodium development when filarial worms were present in the bloodmeal (D. immitis) but midgut penetration was absent, suggesting that factors associated with penetration of the midgut by filarial worms likely are responsible for the observed reduction in malaria parasite infections

  19. Radiolabeling and autoradiographic tracing of Toxocara canis larvae in male mice

    SciTech Connect

    Wade, S.E.; Georgi, J.R.

    1987-02-01

    Artificially hatched infective larvae of Toxocara canis were labeled with /sup 75/Se in Medium 199 (Gibco) containing /sup 75/Se-methionine. Male CD-1 mice were infected with radiolabeled larvae by intragastric intubation or by intraperitoneal injection. At intervals of 3-56 days mice were killed and the organs prepared for compressed organ autoradiography. Radioactivity of parasitic larvae showed an exponential decrease with time, reflecting catabolism of label with a biological half life of 26 days (effective half life of 21 days) making possible experiments lasting several months. Total body larva counts, estimated by total body autoradiography, displayed an overall downward trend, but the rate of reduction was probably not constant because no significant positive or negative trends were noted from day 14 onward in the numbers of larvae. The carcass accumulated the greatest number of larvae followed by the central nervous system, liver, and lung in that order. When the numbers of larvae were considered in relationship to the mass of tissue, there were 4 groupings: central nervous system, liver, lung, carcass, and kidney, and genito-urinary organ, pelt, and intestine. No significant difference between intragastric and intraperitoneal administration was observed in the larval distribution after the larvae had left the initial site of deposition.

  20. Differentiation of larva migrans caused by Baylisascaris procyonis and Toxocara species by Western blotting.

    PubMed

    Dangoudoubiyam, Sriveny; Kazacos, Kevin R

    2009-11-01

    Baylisascaris procyonis and Toxocara species are two important causes of larva migrans in humans. Larva migrans caused by Toxocara spp. is well known and is diagnosed serologically by enzyme immunoassay. Over a dozen cases of larva migrans and associated eosinophilic encephalitis caused by B. procyonis have also been reported, and at least a dozen additional cases are known. An enzyme-linked immunosorbent assay (ELISA) using the excretory-secretory (ES) antigen of B. procyonis larvae is currently being used in our laboratory as an aid in the diagnosis of this infection in humans. Clinically affected individuals show very high reactivity (measured as the optical density) on this ELISA; however, a one-way cross-reactivity with Toxocara spp. has been observed. As an approach to differentiate these two infections based on serology, we performed Western blots, wherein the B. procyonis ES antigen was reacted with serum samples from individuals known to be positive for either Toxocara spp. or B. procyonis larva migrans. Western blot results showed that B. procyonis antigens of between 30 and 45 kDa were specifically identified only by the sera from individuals with Baylisascaris larva migrans, thus allowing for differentiation between the two infections. This included human patient serum samples submitted for serologic testing, as well as sera from rabbits experimentally infected with B. procyonis. When used in conjunction with the ELISA, Western blotting could be an efficient tool for diagnosis of this infection in humans.

  1. Passive vectoring of entomopathogenic fungus Beauveria bassiana among the wax moth Galleria mellonella larvae by the ectoparasitoid Habrobracon hebetor females.

    PubMed

    Kryukov, Vadim Yu; Kryukova, Natalia A; Tyurin, Maksim V; Yaroslavtseva, Olga N; Glupov, Viktor V

    2017-03-15

    Females of the ectoparasitoid Habrobracon hebetor attack and envenomate numerous host individuals during oviposition. The vectoring of the entomopathogenic fungus Beauveria bassiana during the adhesion stage by ectoparasitoid females among the wax moth larvae Galleria mellonella was explored under laboratory conditions. Vectoring occurred both from infected parasitoids to wax moth larvae and from infected to healthy wax moth larvae by parasitoids. The efficacy of vectoring in both cases was dose dependent. Parasitoid females were unable to recognize infected larvae in a labyrinth test. In addition, the presence of H. hebetor females significantly (1.5-13 fold) increased the mycoses level in clusters of G. mellonella, with 40 % of the larvae infected with fungal conidia. Envenomation by H. hebetor increased conidia germination on the cuticles of the wax moth larvae by 4.4-fold. An enhanced germination rate (2-fold) was registered in the n-hexane epicuticular extract of envenomated larvae compared to that of healthy larvae. Both envenomation and mycoses enhanced the phenoloxidase (PO) activity in the integument of G. mellonella and, in contrast, decreased the encapsulation rate in hemolymphs. We hypothesize that changes in the integument property and inhibition of cellular immunity provide the highest infection efficacy of entomopathogenic fungi with H. hebetor. This article is protected by copyright. All rights reserved.

  2. Rapid detection and identification of Wuchereria bancrofti, Brugia malayi, B. pahangi, and Dirofilaria immitis in mosquito vectors and blood samples by high resolution melting real-time PCR.

    PubMed

    Thanchomnang, Tongjit; Intapan, Pewpan M; Tantrawatpan, Chairat; Lulitanond, Viraphong; Chungpivat, Sudchit; Taweethavonsawat, Piyanan; Kaewkong, Worasak; Sanpool, Oranuch; Janwan, Penchom; Choochote, Wej; Maleewong, Wanchai

    2013-12-01

    A simple, rapid, and high-throughput method for detection and identification of Wuchereria bancrofti, Brugia malayi, Brugia pahangi, and Dirofilaria immitis in mosquito vectors and blood samples was developed using a real-time PCR combined with high-resolution melting (HRM) analysis. Amplicons of the 4 filarial species were generated from 5S rRNA and spliced leader sequences by the real-time PCR and their melting temperatures were determined by the HRM method. Melting of amplicons from W. bancrofti, B. malayi, D. immitis, and B. pahangi peaked at 81.5±0.2℃, 79.0±0.3℃, 76.8±0.1℃, and 79.9±0.1℃, respectively. This assay is relatively cheap since it does not require synthesis of hybridization probes. Its sensitivity and specificity were 100%. It is a rapid and technically simple approach, and an important tool for population surveys as well as molecular xenomonitoring of parasites in vectors.

  3. Rapid Detection and Identification of Wuchereria bancrofti, Brugia malayi, B. pahangi, and Dirofilaria immitis in Mosquito Vectors and Blood Samples by High Resolution Melting Real-Time PCR

    PubMed Central

    Thanchomnang, Tongjit; Intapan, Pewpan M.; Tantrawatpan, Chairat; Lulitanond, Viraphong; Chungpivat, Sudchit; Taweethavonsawat, Piyanan; Kaewkong, Worasak; Sanpool, Oranuch; Janwan, Penchom; Choochote, Wej

    2013-01-01

    A simple, rapid, and high-throughput method for detection and identification of Wuchereria bancrofti, Brugia malayi, Brugia pahangi, and Dirofilaria immitis in mosquito vectors and blood samples was developed using a real-time PCR combined with high-resolution melting (HRM) analysis. Amplicons of the 4 filarial species were generated from 5S rRNA and spliced leader sequences by the real-time PCR and their melting temperatures were determined by the HRM method. Melting of amplicons from W. bancrofti, B. malayi, D. immitis, and B. pahangi peaked at 81.5±0.2℃, 79.0±0.3℃, 76.8±0.1℃, and 79.9±0.1℃, respectively. This assay is relatively cheap since it does not require synthesis of hybridization probes. Its sensitivity and specificity were 100%. It is a rapid and technically simple approach, and an important tool for population surveys as well as molecular xenomonitoring of parasites in vectors. PMID:24516268

  4. Paenibacillus larvae-Directed Bacteriophage HB10c2 and Its Application in American Foulbrood-Affected Honey Bee Larvae.

    PubMed

    Beims, Hannes; Wittmann, Johannes; Bunk, Boyke; Spröer, Cathrin; Rohde, Christine; Günther, Gabi; Rohde, Manfred; von der Ohe, Werner; Steinert, Michael

    2015-08-15

    Paenibacillus larvae is the causative agent of American foulbrood (AFB), the most serious honey bee brood bacterial disease. We isolated and characterized P. larvae-directed bacteriophages and developed criteria for safe phage therapy. Whole-genome analysis of a highly lytic virus of the family Siphoviridae (HB10c2) provided a detailed safety profile and uncovered its lysogenic nature and a putative beta-lactamase-like protein. To rate its antagonistic activity against the pathogens targeted and to specify potentially harmful effects on the bee population and the environment, P. larvae genotypes ERIC I to IV, representatives of the bee gut microbiota, and a broad panel of members of the order Bacillales were analyzed for phage HB10c2-induced lysis. Breeding assays with infected bee larvae revealed that the in vitro phage activity observed was not predictive of the real-life scenario and therapeutic efficacy. On the basis of the disclosed P. larvae-bacteriophage coevolution, we discuss the future prospects of AFB phage therapy.

  5. Paenibacillus larvae-Directed Bacteriophage HB10c2 and Its Application in American Foulbrood-Affected Honey Bee Larvae

    PubMed Central

    Beims, Hannes; Wittmann, Johannes; Bunk, Boyke; Spröer, Cathrin; Rohde, Christine; Günther, Gabi; Rohde, Manfred; von der Ohe, Werner

    2015-01-01

    Paenibacillus larvae is the causative agent of American foulbrood (AFB), the most serious honey bee brood bacterial disease. We isolated and characterized P. larvae-directed bacteriophages and developed criteria for safe phage therapy. Whole-genome analysis of a highly lytic virus of the family Siphoviridae (HB10c2) provided a detailed safety profile and uncovered its lysogenic nature and a putative beta-lactamase-like protein. To rate its antagonistic activity against the pathogens targeted and to specify potentially harmful effects on the bee population and the environment, P. larvae genotypes ERIC I to IV, representatives of the bee gut microbiota, and a broad panel of members of the order Bacillales were analyzed for phage HB10c2-induced lysis. Breeding assays with infected bee larvae revealed that the in vitro phage activity observed was not predictive of the real-life scenario and therapeutic efficacy. On the basis of the disclosed P. larvae-bacteriophage coevolution, we discuss the future prospects of AFB phage therapy. PMID:26048941

  6. Infection,

    DTIC Science & Technology

    1980-10-16

    inapparent infection. A refeeding program may thus become complicated by the sudden appearance of a life-threatening infectious illness (3). (3) The...Beisel, W. R. 23 Unusually low serum concentrations of inorganic phosphate have been reported in patients with gram-negative sepsis and in Reye’s syndrome ...infection should be corrected by a well-managed program of convalescent-period refeeding . This aspect of nutritional support is too often ignored. On the

  7. First Record of Anisakis simplex Third-Stage Larvae (Nematoda, Anisakidae) in European Hake Merluccius merluccius lessepsianus in Egyptian Water

    PubMed Central

    Abou-Rahma, Yasmin; Abdel-Gaber, Rewaida; Kamal Ahmed, Amira

    2016-01-01

    The prevalence of infection and the identification of anisakid larvae in European hake Merluccius merluccius lessepsianus from Hurghada City, Red Sea Governorate, Egypt, were investigated. Fish samples were collected during the period of February and November 2014. Twenty-two (36.66%) out of sixty examined fish specimens were found to be naturally infected with Anisakis type I larvae mostly found as encapsulated larvae in visceral organs. There was a positive relationship between host length/weight and prevalence of infection. Based on morphological, morphometric, and molecular analyses, these nematodes were identified as third-stage larvae of Anisakis simplex. The present study was considered as the first report of anisakid larvae from European hake in the Egyptian water. PMID:26925257

  8. Uncommon Human Urinary Tract Myiasis Due to Psychoda Sp. Larvae, Kashan, Iran: A Case Report

    PubMed Central

    RASTI, Sima; DEHGHANI, Rouhullah; KHALEDI, Hassan NAEIMI; TAKHTFIROOZEH, Sayed Mahdi; CHIMEHI, Elahe

    2016-01-01

    Contamination of human and animal body tissues with flies’ larvae and diptera cause myiasis. A 26 yr old female patient refers to Kashan Shahid Beheshti Hospital, central Iran because of urogenital infection, pain in the right part of stomach, smelly and reddish vaginal discharge and frequent urination. In the first checking, urine sample was taken. In the sample, active and alive larvae were seen. The live samples were taken to the Environmental Health Department Lab of Kashan University of Medical Sciences in clean glass jars. In the morphological survey, Psychoda sp larvae were identified. In Iran, this study is the first report of this species of larva that causes urinary myiasis. This fly larva is not carnivore or bloodsucker and feeds on bacterial agents. Observance of personal hygiene especially during defecation and urination is essential to prevent contamination of this type of myiasis. PMID:28127350

  9. Coral larvae exhibit few measurable transcriptional changes during the onset of coral-dinoflagellate endosymbiosis.

    PubMed

    Schnitzler, Christine E; Weis, Virginia M

    2010-06-01

    The cellular mechanisms controlling the successful establishment of a stable mutualism between cnidarians and their dinoflagellate partners are largely unknown. The planula larva of the solitary Hawaiian scleractinian coral Fungia scutaria and its dinoflagellate symbiont Symbiodinium sp. type C1f represents an ideal model for studying the onset of cnidarian-dinoflagellate endosymbiosis due to the predictable availability of gametes, the ability to raise non-symbiotic larvae and establish the symbiosis experimentally, and the ability to precisely quantify infection success. The goal of this study was to identify genes differentially expressed in F. scutaria larvae during the initiation of endosymbiosis with Symbiodinium sp. C1f. Newly symbiotic larvae were compared to non-symbiotic larvae using a custom cDNA microarray. The 5184-feature array was constructed with cDNA libraries from newly symbiotic and non-symbiotic F. scutaria larvae, including 3072 features (60%) that were enriched for either state by subtractive hybridization. Our analyses revealed very few changes in the F. scutaria transcriptome as a result of infection with Symbiodinium sp. C1f, similar to other studies focused on the early stages of this symbiotic interaction. We suggest that these results may be due, in part, to an inability to detect the transcriptional signal from the small percentage of infected cells compared to uninfected cells. We discuss several other potential explanations for this result, including suggesting that certain types of Symbiodinium sp. may have evolved mechanisms to suppress or circumvent cnidarian host responses to infection.

  10. Sediment bioassays with oyster larvae

    SciTech Connect

    Chapman, P.M.; Morgan, J.D.

    1983-10-01

    Tests with naturally-occurring sediments are rare and sediment testing methodology is not standardized. The authors present a simple methodology for undertaking sediment bioassays with oyster larvae, and present data from a recent study to prove the utility of this method.

  11. How the pilidium larva feeds

    PubMed Central

    2013-01-01

    Introduction The nemertean pilidium is a long-lived feeding larva unique to the life cycle of a single monophyletic group, the Pilidiophora, which is characterized by this innovation. That the pilidium feeds on small planktonic unicells seems clear; how it does so is unknown and not readily inferred, because it shares little morphological similarity with other planktotrophic larvae. Results Using high-speed video of trapped lab-reared pilidia of Micrura alaskensis, we documented a multi-stage feeding mechanism. First, the external ciliation of the pilidium creates a swimming and feeding current which carries suspended prey past the primary ciliated band spanning the posterior margins of the larval body. Next, the larva detects prey that pass within reach, then conducts rapid and coordinated deformations of the larval body to re-direct passing cells and surrounding water into a vestibular space between the lappets, isolated from external currents but not quite inside the larva. Once a prey cell is thus captured, internal ciliary bands arranged within this vestibule prevent prey escape. Finally, captured cells are transported by currents within a buccal funnel toward the stomach entrance. Remarkably, we observed that the prey of choice – various cultured cryptomonads – attempt to escape their fate. Conclusions The feeding mechanism deployed by the pilidium larva coordinates local control of cilia-driven water transport with sensorimotor behavior, in a manner clearly distinct from any other well-studied larval feeding mechanisms. We hypothesize that the pilidium’s feeding strategy may be adapted to counter escape responses such as those deployed by cryptomonads, and speculate that similar needs may underlie convergences among disparate planktotrophic larval forms. PMID:23927417

  12. Analysis of somatic and salivary gland antigens of third stage larvae of Rhinoestrus spp. (Diptera, Oestridae).

    PubMed

    Milillo, Piermarino; Traversa, Donato; Elia, Gabriella; Otranto, Domenico

    2010-04-01

    Larvae of Rhinoestrus spp. (Diptera, Oestridae) infect nasal and sinus cavities of horses, causing a nasal myiasis characterized by severe respiratory distress. Presently, the diagnosis of horse nasal botfly relies on the observation of clinical signs, on the post mortem retrieval of larvae or on molecular assays performed using pharyngeal swabs. The present study was carried out to characterize larval somatic proteins and salivary glands of Rhinoestrus spp. in a preliminary assessment towards the immunodiagnosis of equine rhinoestrosis. Out of the 212 necropsied horses 13 were positive for the presence of Rhinoestrus spp. larvae. The analysis of the sera from the infected animals by Western blotting assay showed the presence of a specific host humoral immune response against Rhinoestrus spp. larvae and proved that the salivary glands are the major immunogens in horse nasal botflies.

  13. Workbook on the Identification of Mosquito Larvae.

    ERIC Educational Resources Information Center

    Pratt, Harry D.; And Others

    This self-instructional booklet is designed to enable public health workers identify larvae of some important North American mosquito species. The morphological features of larvae of the various genera and species are illustrated in a programed booklet, which also contains illustrated taxonomic keys to the larvae of 11 North American genera and to…

  14. Gene expression in honey bee (Apis mellifera) larvae exposed to pesticides and Varroa mites (Varroa destructor).

    PubMed

    Gregorc, Aleš; Evans, Jay D; Scharf, Mike; Ellis, James D

    2012-08-01

    Honey bee (Apis mellifera) larvae reared in vitro were exposed to one of nine pesticides and/or were challenged with the parasitic mite, Varroa destructor. Total RNA was extracted from individual larvae and first strand cDNAs were generated. Gene-expression changes in larvae were measured using quantitative PCR (qPCR) targeting transcripts for pathogens and genes involved in physiological processes, bee health, immunity, and/or xenobiotic detoxification. Transcript levels for Peptidoglycan Recognition Protein (PGRPSC), a pathogen recognition gene, increased in larvae exposed to Varroa mites (P<0.001) and were not changed in pesticide treated larvae. As expected, Varroa-parasitized brood had higher transcripts of Deformed Wing Virus than did control larvae (P<0.001). Varroa parasitism, arguably coupled with virus infection, resulted in significantly higher transcript abundances for the antimicrobial peptides abaecin, hymenoptaecin, and defensin1. Transcript levels for Prophenoloxidase-activating enzyme (PPOact), an immune end product, were elevated in larvae treated with myclobutanil and chlorothalonil (both are fungicides) (P<0.001). Transcript levels for Hexameric storage protein (Hsp70) were significantly upregulated in imidacloprid, fluvalinate, coumaphos, myclobutanil, and amitraz treated larvae. Definitive impacts of pesticides and Varroa parasitism on honey bee larval gene expression were demonstrated. Interactions between larval treatments and gene expression for the targeted genes are discussed.

  15. Simultaneous Larva Migrans and Larva Currens Caused by Strongyloides stercoralis: A Case Report

    PubMed Central

    Corte, Liliam Dalla; da Silva, Mariana Vale Scribel; Souza, Paulo Ricardo Martins

    2013-01-01

    Strongyloidiasis is an infectious disease caused by the Strongyloides stercoralis larvae, which penetrate the skin, go through the lymphatic circulation, and migrate to the lungs before reaching the intestines. They mature and may cause cutaneous strongyloidiasis, known as larva currens because of the quick migratory rate of the larva. The authors describe a case in which the larvae did not follow their natural lymph route, and after penetrating into the intertriginous area, they migrated to the dermis, developing larva migrans in the early phase, and later associated with the typical lesions of larva currens. The diagnosis was confirmed by the presence of larva in the skin biopsy. PMID:23476820

  16. Strain- and Genotype-Specific Differences in Virulence of Paenibacillus larvae subsp. larvae, a Bacterial Pathogen Causing American Foulbrood Disease in Honeybees

    PubMed Central

    Genersch, Elke; Ashiralieva, Ainura; Fries, Ingemar

    2005-01-01

    Virulence variations of Paenibacillus larvae subsp. larvae, the causative agent of American foulbrood disease of honeybees, were investigated by analysis of 16 field isolates of this pathogen, belonging to three previously characterized genotypes, as well as the type strain (ATCC 9545) of P. larvae subsp. larvae, with exposure bioassays. We demonstrated that the strain-specific 50% lethal concentrations varied within an order of magnitude and that differences in amount of time for the pathogen to kill 100% of the infected hosts (LT100) correlated with genotype. One genotype killed rather quickly, with a mean LT100 of 7.8 ± 1.7 days postinfection, while the other genotypes acted more slowly, with mean LT100s of 11.2 ± 0.8 and 11.6 ± 0.6 days postinfection. PMID:16269801

  17. Cyathostomin larvae: presence on Brachiaria humidicola grass during the rainy and dry seasons of Brazil.

    PubMed

    dos Santos, Claudia Navarro; de Souza, Luciene Soares; Vieira, Vivian Suane de Freitas; Pinheiro, Jairo; Rodrigues, Maria de Lurdes de Azevedo

    2012-01-01

    The presence of cyathostomin larvae is directly associated to climatic conditions of each region. This study aimed to evaluate the ecology of infective larvae on Brachiaria humidicola during the dry and rainy seasons from October 2007 to September 2008 in a tropical region, Rio de Janeiro state, southeastern Brazil. Stools were collected from the rectum of horses naturally infected with cyathostomins at the beginning of the rainy season (October to March) and dry season (April to September). They were divided into four samples of 500 g and deposited on a grass patch of B. humidicola. Seven days later and every 15 days thereafter samples of feces and grass were collected and processed by the Baermann technique. The mean number of larvae recovered from the grass varied according to the season, with greater recovery of larvae during the peak of the dry season (14,700 L3.kg-¹ DM). There was a statistically significant difference between L3 recovered from feces and grass, but not between L3 recovered from the grass base and apex. These results show that the region's climate favors the development and survival of infective cyathostomin larvae throughout the year, with a greater number of larvae during the dry season.

  18. Designing, synthesis of selective and high-affinity chalcone-benzothiazole hybrids as Brugia malayi thymidylate kinase inhibitors: In vitro validation and docking studies.

    PubMed

    Sashidhara, Koneni V; Avula, Srinivasa Rao; Doharey, Pawan Kumar; Singh, L Ravithej; Balaramnavar, Vishal M; Gupta, Jyoti; Misra-Bhattacharya, Shailja; Rathaur, Sushma; Saxena, Anil K; Saxena, Jitendra Kumar

    2015-10-20

    In our continuing search for safe and efficacious antifilarials, a series of novel chalcone-benzothiazole hybrids have been synthesized and evaluated for their Brugia malayi thymidylate kinase (BmTMK) enzyme inhibition activity. Their selectivity towards BmTMK was studied and compared to the human TMK (HsTMK) by an in silico method. Out of seventeen derivatives, compounds 34 and 42 showed higher interactions with the BmTMK active site. MolDock docking model revealed the interactions of these two derivatives and the results corroborated well with their in vitro antifilarial activities. Our studies suggest that these hybrids are selective towards the BmTMK enzyme and may serve as potential therapeutic agents against filariasis.

  19. Low positive predictive value of anti-Brugia malayi IgG and IgG4 serology for the diagnosis of Wuchereria bancrofti.

    PubMed

    Chanteau, S; Glaziou, P; Moulia-Pelat, J P; Plichart, C; Luquiaud, P; Cartel, J L

    1994-01-01

    Enzyme-linked immunosorbent assays (ELISAs) for anti-Brugia malayi immunoglobulin (Ig) G and IgG4 were evaluated on sera from 1561 subjects in French Polynesia for the serodiagnosis of Wuchereria bancrofti filariasis, compared with the test for Onchocerca gibsoni circulating antigen (Og4C3) as a 'gold standard'. The sensitivity of the ELISA-IgG and ELISA-IgG4 assays was 90.8% and 94.5%, and the specificity was 45.9% and 50.7%. The positive predictive values were 41% and 45% respectively for an antigen prevalence rate of 30%. Thus antibody prevalences exceeded by two-fold the antigen prevalence, which itself exceeded by two-fold the prevalence of microfilaraemia.

  20. 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.

  1. 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

  2. Cloning, expression and characterization of UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) from Wolbachia endosymbiont of human lymphatic filarial parasite Brugia malayi.

    PubMed

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

    2014-01-01

    Wolbachia, an endosymbiont of filarial nematode, is considered a promising target for treatment of lymphatic filariasis. Although functional characterization of the Wolbachia peptidoglycan assembly has not been fully explored, the Wolbachia genome provides evidence for coding all of the genes involved in lipid II biosynthesis, a part of peptidoglycan biosynthesis pathway. UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) is one of the lipid II biosynthesis pathway enzymes and it has inevitably been recognized as an antibiotic target. In view of the vital role of MurA in bacterial viability and survival, MurA ortholog from Wolbachia endosymbiont of Brugia malayi (wBm-MurA) was cloned, expressed and purified for further molecular characterization. The enzyme kinetics and inhibition studies were undertaken using fosfomycin. wBm-MurA was found to be expressed in all the major life stages of B. malayi and was immunolocalized in Wolbachia within the microfilariae and female adults by the confocal microscopy. Sequence analysis suggests that the amino acids crucial for enzymatic activity are conserved. The purified wBm-MurA was shown to possess the EPSP synthase (3-phosphoshikimate 1-carboxyvinyltransferase) like activity at a broad pH range with optimal activity at pH 7.5 and 37°C temperature. The apparent affinity constant (Km) for the substrate UDP-N-acetylglucosamine was found to be 0.03149 mM and for phosphoenolpyruvate 0.009198 mM. The relative enzymatic activity was inhibited ∼2 fold in presence of fosfomycin. Superimposition of the wBm-MurA homology model with the structural model of Haemophilus influenzae (Hi-MurA) suggests binding of fosfomycin at the same active site. The findings suggest wBm-MurA to be a putative antifilarial drug target for screening of novel compounds.

  3. Validation studies of the latex agglutination test for the detection of Trichinella larvae in meat products.

    PubMed

    Gayda, Jennifer; Reckinger, Sabine; Thaben, Nora; Nöckler, Karsten; Mayer-Scholl, Anne

    2016-11-15

    Human trichinellosis is a foodborne disease caused by ingestion of meat infected with Trichinella muscle larvae. To control Trichinella spp. infection in the European Union, all slaughtered pigs from holdings that are not officially recognized as applying controlled housing conditions and other animals susceptible to Trichinella infection and intended for human consumption should be examined by one of the approved digestion methods described in Regulation (EU) No. 2015/1375. In the past, Trichinella outbreaks due to the consumption of cured wild boar or pork products have been described in several European countries, making the identification of the larvae from these products relevant for Trichinella control. Therefore, this study aimed to validate the newly approved latex agglutination test (Trichin-L) for routine testing of cured meat products. The test was validated based on the OIE Guidelines using pork products spiked with Trichinella larvae. The sensitivity of the method varied greatly depending on the investigated meat product and was usually lower than for the gold standard, the magnetic stirrer method. The detection rate reached 80% for three larvae and 60% for one larva in cured pork sausages. A detection rate of 100% for three larvae and 50% for one larva was found in bacon. For frozen samples (-20°C) the Trichin-L kit is similarly sensitive as for cured samples. Further, to determine the performance of the test under field conditions, pork products from regions with known high Trichinella prevalences confiscated by customs authorities at two German international airports were analyzed. Problems associated with the Trichin-L test were incomplete digestion due to fatty ingredients, spices and very dry meat products, resulting in data which could not be evaluated. Therefore, the test is currently not suitable for the detection of Trichinella larvae in cured meat products and needs further adaptation steps to increase both usability and sensitivity.

  4. Kinetics of plasmid transfer among Bacillus cereus group strains within lepidopteran larvae.

    PubMed

    Yuan, Y M; Hu, X M; Liu, H Z; Hansen, Bjarne Munk; Yan, J P; Yuan, Z M

    2007-06-01

    The cry toxin encoding plasmid pHT73 was transferred from Bacillus thuringiensis subspecies kurstaki KT0 to six B. cereus group strains in three lepidopteran (Spodoptera exigua, Plutella xyllostella and Helicoverpa armigera) larvae by conjugation. The conjugation kinetics of the plasmid was precisely studied during the larval infection using a new protocol. The infections were performed with both vegetative and sporulated strains. However, larval death only occurred when infections were made with spore and toxin preparations. Likewise, spore germinations of both donor and recipient strains were only observed in killed larvae, 44-56 h post-infection. Accordingly, kinetics showed that gene transfer between B. thuringiensis strain KT0 and other B. cereus strains only took place in dead larvae among vegetatively growing bacteria. The conjugational transfer ratios varied among different strain combinations and different larvae. The highest transfer ratio reached 5.83 x 10(-6) CFU/donor between the KT0 and the AW05R recipient in Helicoverpa armigera, and all transconjugants gained the ability to produce the insecticidal crystal. These results indicated that horizontal gene transfer among B. cereus group strains might play a key role for the acquisition of extra plasmids and evolution of these strains in toxin susceptible insect larvae.

  5. Toxocara cati larva migrans in domestic pigs--detected at slaughterhouse control in Norway.

    PubMed

    Davidson, Rebecca K; Mermer, Anna; Øines, Øivind

    2012-11-21

    Routine Trichinella meat inspection at the slaughterhouse detected one larva in a pooled batch of 100 pig samples. The larva was sent to the Norwegian Veterinary Institute (NVI) for species identification.Morphological examination revealed that the larva was not Trichinella spp. Molecular analysis was performed. PCR and sequencing of 5S/ITS identified the larva as Toxocara cati. A second round of digests was carried out at the meat inspection laboratory, in smaller batches to try to identify the infected animal. No further larvae were detected and it was not possible to identify which of the 100 animals the larva had come from. This is the first time that Toxocara cati has been reported in slaughterhouse pigs in Norway.Although the infected individual could not be identified, the meat originated from one of six potential farms. A small survey regarding rodent control and cats was sent to each of these farms. Cats had restricted access to food storage areas (two farms reported that cats had access) whilst none of the farms allowed cats into the production housing. Cats were, however, present on all the farms (mostly stray cats of unknown health status). Half of the farms also reported seeing rodents in the pig housing during the previous six months and half reported finding rodents in the feed and straw storage areas. We were unable to narrow down the source of infection - however contamination of food or bedding material, with cat faeces or infected rodents, in addition to the presence of infected rodents in pig housing remain potential routes of infection.

  6. Molecular identification of larvae of a tetraphyllidean tapeworm (Platyhelminthes: Eucestoda) in a razor clam as an alternative intermediate host in the life cycle of Acanthobothrium brevissime.

    PubMed

    Holland, Nicholas D; Wilson, Nerida G

    2009-10-01

    Dwarf razor clams (Ensis minor) in the Gulf of Mexico are known to be infected with plerocercoid larvae of a tetraphyllidean tapeworm. Here, we show that these larvae live unencysted in the intestinal lumen of the clam. Morphologically, the larvae are similar to (although significantly larger than) tapeworm larvae previously described living in the gut of amphioxus (Branchiostoma floridae) from the same habitat. Sequence data from the D2 region of the 28S rDNA from clam-infecting larvae were identical to the sequence of Acanthobothrium brevissime isolated as larvae from amphioxus and as adults from a stingray (Dasyatis say). The sequence data leave little doubt that the dwarf razor clam and the amphioxus are alternative intermediate hosts in the life cycle of A. brevissime.

  7. Identification of Nanopillars on the Cuticle of the Aquatic Larvae of the Drone Fly (Diptera: Syrphidae).

    PubMed

    Hayes, Matthew J; Levine, Timothy P; Wilson, Roger H

    2016-01-01

    Here, we describe a nano-scale surface structure on the rat-tailed maggot, the aquatic larva of the Drone fly Eristalis tenax(L.). Larvae of this syrphid hover fly live in stagnant, anaerobic water-courses that are rich in organic matter. The larvae burrow into fetid slurry and feed on microorganisms which they filter out from the organic material. This environment is rich in bacteria, fungi and algae with the capacity to form biofilms that might develop on the larval surface and harm them. Using transmission and scanning electron microscopy we have identified an array of slender (typically < 100 nm in diameter) nanopillars that cover the surface of the larvae. The high density and dimensions of these spine-like projections appear to make it difficult for bacteria to colonize the surface of the animal. This may interfere with the formation of biofilms and potentially act as a defence against bacterial infection.

  8. Identification of Nanopillars on the Cuticle of the Aquatic Larvae of the Drone Fly (Diptera: Syrphidae)

    PubMed Central

    Hayes, Matthew J.; Levine, Timothy P.; Wilson, Roger H.

    2016-01-01

    Here, we describe a nano-scale surface structure on the rat-tailed maggot, the aquatic larva of the Drone fly Eristalis tenax (L.). Larvae of this syrphid hover fly live in stagnant, anaerobic water-courses that are rich in organic matter. The larvae burrow into fetid slurry and feed on microorganisms which they filter out from the organic material. This environment is rich in bacteria, fungi and algae with the capacity to form biofilms that might develop on the larval surface and harm them. Using transmission and scanning electron microscopy we have identified an array of slender (typically < 100 nm in diameter) nanopillars that cover the surface of the larvae. The high density and dimensions of these spine-like projections appear to make it difficult for bacteria to colonize the surface of the animal. This may interfere with the formation of biofilms and potentially act as a defence against bacterial infection. PMID:27030395

  9. Experimental Susceptibility of Gilthead Sea Bream, Sparus aurata, via Challenge with Anisakis pegreffii Larvae

    PubMed Central

    Marino, Fabio; Lanteri, Giovanni; De Stefano, Carmelo; Costa, Antonella; Gaglio, Gabriella; Macrì, Francesco

    2013-01-01

    The endoscopic and histopathological findings detected in Sparus aurata experimentally infected with third-stage Anisakis larvae without intermediate host are evaluated and discussed. In six fish, live nematode larvae were introduced by gastroscopy into the stomach. The first observation by endoscope, 15 days after challenge, showed the presence of some larvae at the level of gastric mucosa. An explorative celioscopy, performed 60 days after challenge, showed haemorrhages and/or nodules on the gut of two fishes. Necropsy and histology demonstrated parasites in the context of the tissue changes. The finding of live nematode larvae as well as the evidence of tissue change confirm the experimental susceptibility of gilthead sea bream towards Anisakis. PMID:23957000

  10. Experimental Trichinella infection in seals.

    PubMed

    Kapel, C M O; Measures, L; Møller, L N; Forbes, L; Gajadhar, A

    2003-11-01

    The susceptibility of seals to infection with Trichinella nativa and the cold tolerant characteristics of muscle larvae in seal meat were evaluated. Two grey seals, Halichoerus grypus, were inoculated with 5000 (100 larvae/kg) T. nativa larvae and two grey seals with 50000 (1000 larvae/kg). One seal from each dose group and two control seals were killed at 5 and 10 weeks post-inoculation (p.i.). At 5 weeks p.i., infection was established in both low and high dose seals with mean larval densities of 68 and 472 larvae per gram (lpg), respectively, using eight different muscles for analyses. At 10 weeks p.i., mean larval densities were 531 and 2649 lpg, respectively, suggesting an extended persistence of intestinal worms. In seals with high larval density infections, the distribution of larvae in various muscles was uniform, but in one seal with a low larval density infection, predilection sites of larvae included muscle groups with a relative high blood flow, i.e. diaphragm, intercostal and rear flipper muscles. Trichinella-specific antibody levels, as measured by ELISA, increased during the 10 week experimental period. Infected seal muscle was stored at 5, -5 and -18 degrees C for 1, 4 and 8 weeks. Muscle larvae released from stored seal muscle by artificial digestion were inoculated into mice to assess viability and infectivity. Larvae from seal muscle 10 weeks p.i. tolerated -18 degrees C for 8 weeks but larvae from seal muscle 5 weeks p.i. tolerated only 1 week at -18 degrees C, supporting the hypothesis that freeze tolerance increases with the age of the host-parasite tissue complex. The expressed susceptibility to infection, extended production of larvae, antibody response and freeze tolerance of T. nativa in seals are new findings from the first experimental Trichinella infection in any marine mammal and suggest that pinnipeds (phocids, otariiids or walrus) may acquire Trichinella infection by scavenging even small amounts of infected tissue left by hunters or

  11. Biology of Paenibacillus larvae, a deadly pathogen of honey bee larvae.

    PubMed

    Ebeling, Julia; Knispel, Henriette; Hertlein, Gillian; Fünfhaus, Anne; Genersch, Elke

    2016-09-01

    The gram-positive bacterium Paenibacillus larvae is the etiological agent of American Foulbrood of honey bees, a notifiable disease in many countries. Hence, P. larvae can be considered as an entomopathogen of considerable relevance in veterinary medicine. P. larvae is a highly specialized pathogen with only one established host, the honey bee larva. No other natural environment supporting germination and proliferation of P. larvae is known. Over the last decade, tremendous progress in the understanding of P. larvae and its interactions with honey bee larvae at a molecular level has been made. In this review, we will present the recent highlights and developments in P. larvae research and discuss the impact of some of the findings in a broader context to demonstrate what we can learn from studying "exotic" pathogens.

  12. Single stimulus learning in zebrafish larvae

    PubMed Central

    O’Neale, Ashley; Ellis, Joseph; Creton, Robbert; Colwill, Ruth M.

    2014-01-01

    Learning about a moving visual stimulus was examined in zebrafish larvae using an automated imaging system and a t1-t2 design. In three experiments, zebrafish larvae were exposed to one of two inputs at t1 (either a gray bouncing disk or an identical but stationary disk) followed by a common test at t2 (the gray bouncing disk). Using 7 days post-fertilization (dpf) larvae and 12 stimulus exposures, Experiment 1 established that these different treatments produced differential responding to the moving disk during testing. Larvae familiar with the moving test stimulus were significantly less likely to be still in its presence than larvae that had been exposed to the identical but stationary stimulus. Experiment 2 confirmed this result in 7 dpf larvae and extended the finding to 5 and 6 dpf larvae. Experiment 3 found differential responding to the moving test stimulus with 4 or 8 stimulus exposures but not with just one exposure in 7 dpf larvae. These results provide evidence for learning in very young zebrafish larvae. The merits and challenges of the t1-t2 framework to study learning are discussed. PMID:24012906

  13. Diagnostic morphology of four larval ascaridoid nematodes that may cause visceral larva migrans: Toxascaris leonina, Baylisascaris procyonis, Lagochilascaris sprenti, and Hexametra leidyi.

    PubMed

    Bowman, D D

    1987-12-01

    The gross and histological morphology of the larvae of 4 ascaridoid nematodes, Toxascaris leonina, Baylisascaris procyonis, Lagochilascaris sprenti, and Hexametra leidyi, are described. The larvae of T. leonina, B. procyonis, and L. sprenti were recovered from experimentally infected mice at 32, 14, and 75 days of infection, respectively. Hexametra leidyi larvae used for morphological study were collected on day 159 postinfection from a rhesus monkey, Macaca mulatta, while H. leidyi larvae used for histological study were collected from mice when they had reached the same size as those found in the monkey, i.e., at 23 days postinfection. Larvae for morphological study were collected by pepsin digestion, fixed in glacial acetic acid, and cleared in glycerin. Tissues for histological study were fixed in 10% formalin or Bouin's fixative. All sections were stained with hematoxylin and eosin. The differences in the morphology of the larvae of these 4 species were found to be length of the body, shape of the anterior end, and shape of the tail. The major differences in the histological anatomy of these larvae were found to be the body diameter, form of lateral alae when present, presence or absence of internal cuticular bars, shape and internal patterns of the excretory columns, and size and number of intestinal cells. These 4 larvae are differentiated from other described species of ascaridoid larvae that may cause visceral larva migrans, and keys have been devised to aid in the making of a diagnosis.

  14. Relationship between red vent syndrome and anisakid larvae burden in wild atlantic salmon (salmo salar).

    PubMed

    Larrat, Sylvain; Bouchard, Francis; Séguin, Guylaine; Lair, Stéphane

    2013-04-01

    The pathogenesis of the recently recognized "red vent syndrome" in wild Atlantic salmon (Salmo salar) is not fully understood. Pathologic observations indicate that this syndrome is associated with the presence of nonencapsulated larvae of the nematode Anisakis simplex in the body wall, the lower intestinal wall, and the visceral cavity surrounding the vent region. We evaluated the relationship between the occurrence of red vent syndrome and intensity of infection with Anisakis sp. larvae in naturally infected fish. Salmon caught by sport anglers were opportunistically evaluated to detect red vent syndrome. We included 106 salmon with red vent syndrome and 98 without red vent syndrome in this study. Intensity of infection was established by counting the total number of perivisceral larvae and by determining the number of larvae per gram in 10 g of pepsin-digested perianal tissue. The severity of inflammatory changes was also evaluated in standard histologic sections of the perianal area using a semiquantitative scale. Salmon with red vent syndrome had significantly higher intensity of inflammation than salmon without red vent syndrome (P=0.008). The odds of having red vent syndrome increased with the number of perianal larvae per gram of perianal tissue (P=0.002; odds ratio [OR]=1.12; 95% confidence interval: [1.05; 1.22]) but not with the number of perivisceral larvae, fish length, or gender. Although these results support the association between this syndrome and intensity of infection by A. simplex, the relationship is not strong (OR near 1), suggesting that the clinical expression of red vent syndrome at an individual level, and the emergence of this disease on a global scale, must be determined by other factors, such as timing of infection.

  15. Molecular identification of anisakid nematodes third stage larvae isolated from common squid ( Todarodes pacificus) in Korea

    NASA Astrophysics Data System (ADS)

    Setyobudi, Eko; Jeon, Chan-Hyeok; Choi, Kwangho; Lee, Sung Il; Lee, Chung Il; Kim, Jeong-Ho

    2013-06-01

    The occurrence of Genus Anisakis nematode larvae in marine fishes and cephalopods is epidemiologically important because Anisakis simplex larval stage can cause a clinical disease in humans when infected hosts are consumed raw. Common squid ( Todarodes pacificus) from Korean waters were investigated for anisakid nematodes infection during 2009˜2011. In total, 1,556 larvae were collected from 615 common squids and 732 of them were subsequently identified by PCR-RFLP analysis of ITS rDNA. Depending on the sampling locations, the nematode larvae from common squid showed different prevalence, intensity and species distribution. A high prevalence (P) and mean intensity (MI) of infection were observed in the Yellow Sea (n = 250, P = 86.0%, MI = 5.99 larvae/host) and the southern sea of Korea (n = 126, P = 57.1%, MI = 3.36 larvae/host). Anisakis pegreffii was dominantly found in common squid from the southern sea (127/ 140, 90.7%) and the Yellow Sea (561/565, 98.9%). In contrast, the P and MI of infection were relatively low in the East Sea (n = 239, P = 8.37%, MI = 1.25 larvae/host). A. pegreffii was not found from the East Sea and 52.0% (13/25) of the nematodes were identified as A. simplex. Most of them were found in the body cavity or digestive tract of common squid, which are rarely consumed raw by humans. Considering the differenences in anisakid nematode species distribution and their microhabitat in common squid, it remains unclear whether common squid plays an important role in the epidemiology of human anisakis infection in Korea. Further extensive identification of anisakid nematodes in common squid, with geographical and seasonal information will be necessary.

  16. In vitro development of cyathostomin larvae from the third stage larvae to the fourth stage: morphologic characterization, effects of refrigeration, and species-specific patterns.

    PubMed

    Brianti, Emanuele; Giannetto, Salvatore; Traversa, Donato; Chirgwin, Sharon R; Shakya, Krishna; Klei, Thomas R

    2009-08-26

    A mixed population of equine cyathostomin (Nematoda, Strongyloidea) infective third stage larvae (L3) was cultured in vitro using a cell-free medium. Some L3 were cultured immediately after Baermann collection from fecal cultures, while others were kept in water at 4 degrees C for 7 days before initiating the in vitro cultures. Cultures were examined daily for viability. At days 2, 7, 14 and 21 larvae were collected for identification of developmental stage and morphological changes, using both light and scanning electron microscopy. Larvae were classified as early L3 (EL3), developing L3 (DL3), late L3 (LL3) and fourth stage larvae (L4) on the basis of morphological features. Viability remained high throughout the entire study period in cultures of both non-refrigerated (84.7%) and refrigerated (77.4%) larvae. However, viability of the non-refrigerated was significantly greater from 7 through 21 days of culture. Significant differences were also observed in the percentage of DL3 between the non-refrigerated and refrigerated larval cultures by day 7. The highest percentage of DL3 larvae (22.5%) was reached at the end of study in those larvae that were not previously refrigerated. The data suggests that prior refrigeration decreases viability and slows L3 development. At day 21 LL3 larvae were only a small percentage of the DL3: 6.9 and 5% in non-refrigerated and refrigerated cultures, respectively. Few of these larvae freed themselves from the L3 cuticle and moulted to L4 stage. Characteristics of individual species in vitro developmental patterns were determined by the molecular identification of individual larvae in pools of larvae randomly collected at days 0 and 21. Seven species (Coronocyclus coronatus, Cylicostephanus goldi, Cylicostephanus longibursatus, Cyathostomum catinatum, Cylicocyclus nassatus, Cylicocyclus ashworthi, Petrovinema poculatum) were identified in the day 0 pool. The greatest tendency to develop in vitro was shown by the genus

  17. Workbook on Identification of Aedes Aegypti Larvae.

    ERIC Educational Resources Information Center

    Pratt, Harry D.; And Others

    This self-instructional booklet is designed to enable yellow fever control workers to identify the larvae of "Aedes aegypti." The morphological features of mosquito larvae are illustrated in this partially programed text, and the distinguishing features of "A. aegypti" indicated. A glossary is included. (AL)

  18. A PCR Detection Method for Rapid Identification of Melissococcus pluton in Honeybee Larvae

    PubMed Central

    Govan, V. A.; Brözel, V.; Allsopp, M. H.; Davison, S.

    1998-01-01

    Melissococcus pluton is the causative agent of European foulbrood, a disease of honeybee larvae. This bacterium is particularly difficult to isolate because of its stringent growth requirements and competition from other bacteria. PCR was used selectively to amplify specific rRNA gene sequences of M. pluton from pure culture, from crude cell lysates, and directly from infected bee larvae. The PCR primers were designed from M. pluton 16S rRNA sequence data. The PCR products were visualized by agarose gel electrophoresis and confirmed as originating from M. pluton by sequencing in both directions. Detection was highly specific, and the probes did not hybridize with DNA from other bacterial species tested. This method enabled the rapid and specific detection and identification of M. pluton from pure cultures and infected bee larvae. PMID:9572987

  19. Taenia taeniaeformis: immunoprecipitation analysis of the protein antigens of oncospheres and larvae.

    PubMed

    Bowtell, D D; Mitchell, G F; Anders, R F; Lightowlers, M W; Rickard, M D

    1983-12-01

    Biosynthetically or exogenously labeled proteins and immunoprecipitated protein antigens of established 28-day-old larvae of Taenia taeniaeformis were compared with proteins and antigens of infective oncospheres using single and two-dimensional gel electrophoresis. Immunoprecipitation was carried out using sera from infected mice and mouse antisera raised to larvae or oncospheres, and emphasis was placed on identifying antigens common to both oncospheres and larvae. Two major larval antigens of Mr 40,000 and 200,000, designated Tt40 and Tt200, are common to somatic larval preparations and oncospheres. Additionally, two major oncosphere antigens of Mr 55,000 and 60,000, designated Tt55 and Tt60, are also present in larval excretory and secretory (i.e., ES or exoantigen) products. Information obtained from these immunoprecipitation analyses will facilitate isolation and production of common as well as stage-specific protein antigens in the development of defined-antigen vaccines in this model system of cysticercosis.

  20. Cross-reactivity of Toxocariasis with Crude Antigen of Toxascaris leonina Larvae by ELISA.

    PubMed

    Jin, Yan; Shen, Chenghua; Huh, Sun; Choi, Min-Ho; Hong, Sung-Tae

    2015-05-01

    Roundworms of Toxocara canis and Toxascaris leonina are common gastrointestinal helminths of canids over the world. Humans are infected with T. canis larvae through ingestion of infective eggs in contaminated environments or larvae by consumption of raw or uncooked meat or livers. Recently, patients of clinically diagnosed toxocariasis are increasing and require correct diagnosis in Korea. The present study investigated serological cross-reactivity between crude antigens of T. canis (TCLA) and T. leonina (TLLA) larvae. We collected serum specimens from 177 toxocariasis patients who were clinically suspected in the Seoul National University Hospital and 115 healthy controls. An ELISA method for toxocariasis was used to evaluate diagnostic efficacy of TLLA for serodiagnosis of human toxocariasis. The IgG ELISA using TLLA gave 14 (14.3%) positives of 98 TCLA positive specimens among 177 suspected toxocariasis patients. Most of them showed high absorbances with TCLA. In conclusion, there is a partial cross reaction between serum specimens of toxocariasis and TLLA.

  1. Assessment of toxicity test endpoints for freshwater mussel larvae (glochidia).

    PubMed

    Fritts, Andrea K; Barnhart, M Christopher; Bradley, Megan; Liu, Na; Cope, W Gregory; Hammer, Edward; Bringolf, Robert B

    2014-01-01

    The objectives of the present study were to determine if the viability of freshwater mussel larvae (glochidia) is an ecologically relevant endpoint for toxicity tests and to define the appropriate duration of those tests. The authors assessed 1) how viability (the shell closure response to sodium chloride) compares with infectivity (ability to attach to a host fish and successfully metamorphose to the juvenile stage), and 2) the decline of viability and infectivity over time after glochidia were released from female mussels. Glochidia of 7 mussel species were isolated from females, placed in water, and subsampled daily for 2 d to 5 d. Viability, when ≥90%, was generally a good predictor of infectivity; however, when viability was <90%, infectivity was often disproportionately low, especially for glochidia collected near the end of the brooding period. Viability and infectivity declined more rapidly in natural water and sediment compared to reconstituted water. Following 24-h exposure to a toxicant (sodium chloride or copper), infectivity of the viable glochidia did not differ among concentrations of toxicants. The results indicate that viability is a valid proxy for infectivity and an ecologically relevant endpoint for standard toxicity tests with freshwater mussels for any test duration with control viability >90%.

  2. Lobesia botrana larvae develop faster in the presence of parasitoids.

    PubMed

    Vogelweith, Fanny; Moret, Yannick; Thiery, Denis; Moreau, Jérôme

    2013-01-01

    To combat parasitism hosts often rely on their immune system, which is the last line of defense. However, the immune system may not always be effective, and other non-immunological defenses might be favored to reduce the cost of parasite infection. Here we report that larvae of the moth Lobesia botrana can rapidly accelerate their development and reach maturity earlier in response to cues perceived at a distance from parasitoids. Such a phenotypically plastic life history shift, induced by the perception of deadly enemies in the environment, is likely to be an adaptive defensive strategy to prevent parasitoid attack, and has important implications in host-parasite dynamics.

  3. Lobesia botrana Larvae Develop Faster in the Presence of Parasitoids

    PubMed Central

    Vogelweith, Fanny; Moret, Yannick; Thiery, Denis; Moreau, Jérôme

    2013-01-01

    To combat parasitism hosts often rely on their immune system, which is the last line of defense. However, the immune system may not always be effective, and other non-immunological defenses might be favored to reduce the cost of parasite infection. Here we report that larvae of the moth Lobesia botrana can rapidly accelerate their development and reach maturity earlier in response to cues perceived at a distance from parasitoids. Such a phenotypically plastic life history shift, induced by the perception of deadly enemies in the environment, is likely to be an adaptive defensive strategy to prevent parasitoid attack, and has important implications in host–parasite dynamics. PMID:24015260

  4. Transmission of lymphocystis disease virus to cultured gilthead seabream, Sparus aurata L., larvae.

    PubMed

    Cano, I; Valverde, E J; Garcia-Rosado, E; Alonso, M C; Lopez-Jimena, B; Ortiz-Delgado, J B; Borrego, J J; Sarasquete, C; Castro, D

    2013-06-01

    The transmission of lymphocystis disease virus (LCDV) to gilthead seabream, Sparus aurata L., larvae was investigated using fertilized eggs from a farm with previous reports of lymphocystis disease. LCDV genome was detected by PCR-hybridization in blood samples from 17.5% of the asymptomatic gilthead seabream broodstock analysed. Using the same methodology, eggs spawned from these animals were LCDV positive, as well as larvae hatched from them. The presence of infective viral particles was confirmed by cytopathic effects development on SAF-1 cells. Whole-mount in situ hybridization (ISH) and immunohistochemistry (IHC) showed the presence of LCDV in the epidermis of larvae hatched from LCDV-positive eggs. When fertilized eggs were disinfected with iodine, no viral DNA was detected either in eggs (analysed by PCR-hybridization) or in larvae (PCR-hybridization and ISH). These results suggest the vertical transmission of LCDV, the virus being transmitted on the egg surface. Larvae hatched from disinfected eggs remain LCDV negative during the endotrophic phase, as showed by PCR-hybridization, ISH and IHC. After feeding on LCDV-positive rotifers, viral antigens were observed in the digestive tract, which suggests that viral entry could be achieved via the alimentary canal, and that rotifers can act as a vector in LCDV transmission to gilthead seabream larvae.

  5. Recirculating elutriator for extracting gastrointestinal nematode larvae from pasture herbage samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gastrointestinal nematode parasites present an important limitation to ruminant production worldwide. Methods for quantifying infective larvae of GIN on pastures are generally tedious, time-consuming, and require bulky equipment set-ups. This limitation to expedient data collection is a bottleneck...

  6. Occurrence of viral pathogens in Penaeus monodon post-larvae from aquaculture hatcheries.

    PubMed

    Joseph, Toms C; James, Roswin; Anbu Rajan, L; Surendran, P K; Lalitha, K V

    2015-09-01

    Viral pathogens appear to exert the most significant constraints on the growth and survival of crustaceans under culture conditions. The prevalence of viral pathogens White Spot Syndrome Virus (WSSV), Hepatopancreatic Parvo Virus (HPV), Monodon Baculo Virus (MBV) and Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) in Penaeus monodon post-larvae was studied. Samples collected from different hatcheries and also samples submitted by farmers from Kerala were analyzed. Out of 104 samples collected, WSSV was detected in 12.5% of the post-larvae samples. Prevalence of concurrent infections by HPV, MBV and WSSV (either dual or triple infection) was present in 60.6% of the total post-larvae tested. Out of the 51 double positives, 98% showed either HPV or IHHNV infection. HPV or IHHNV was detected in 11 post-larval samples showing triple viral infection. This is the first report of IHHNV from India. Result of this study reveals the lack of efficient screening strategies to eradicate viruses in hatchery reared post-larvae.

  7. Occurrence of viral pathogens in Penaeus monodon post-larvae from aquaculture hatcheries

    PubMed Central

    Joseph, Toms C.; James, Roswin; Anbu Rajan, L.; Surendran, P.K.; Lalitha, K.V.

    2015-01-01

    Viral pathogens appear to exert the most significant constraints on the growth and survival of crustaceans under culture conditions. The prevalence of viral pathogens White Spot Syndrome Virus (WSSV), Hepatopancreatic Parvo Virus (HPV), Monodon Baculo Virus (MBV) and Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) in Penaeus monodon post-larvae was studied. Samples collected from different hatcheries and also samples submitted by farmers from Kerala were analyzed. Out of 104 samples collected, WSSV was detected in 12.5% of the post-larvae samples. Prevalence of concurrent infections by HPV, MBV and WSSV (either dual or triple infection) was present in 60.6% of the total post-larvae tested. Out of the 51 double positives, 98% showed either HPV or IHHNV infection. HPV or IHHNV was detected in 11 post-larval samples showing triple viral infection. This is the first report of IHHNV from India. Result of this study reveals the lack of efficient screening strategies to eradicate viruses in hatchery reared post-larvae. PMID:26217783

  8. First Case Report of Canthariasis in an Infant Caused by the Larvae of Lasioderma serricorne (Coleoptera: Anobiidae)

    PubMed Central

    Mokhtar, Aida Syafinaz; Sridhar, Ganiga Srinivasaiah; Mahmud, Rohela; Jeffery, John; Lau, Yee Ling; Wilson, John-James; Abdul-Aziz, Noraishah Mydin

    2016-01-01

    We report an unusual cause of gastrointestinal infection occurring in a 1-year-old infant patient who was brought to a public hospital in Kuala Lumpur, Malaysia. Larvae passed out in the patient’s feces were confirmed by DNA barcoding as belonging to the species, Lasioderma serricorne (F.), known as the cigarette beetle. We postulate that the larvae were acquired from contaminated food and were responsible for gastrointestinal symptoms in the patient. To our knowledge, this the first report of human canthariasis caused by larvae of L. serricorne. PMID:27208008

  9. Live-cell imaging of Salmonella Typhimurium interaction with zebrafish larvae after injection and immersion delivery methods.

    PubMed

    Varas, Macarena; Fariña, Alonso; Díaz-Pascual, Francisco; Ortíz-Severín, Javiera; Marcoleta, Andrés E; Allende, Miguel L; Santiviago, Carlos A; Chávez, Francisco P

    2017-04-01

    The zebrafish model has been used to determine the role of vertebrate innate immunity during bacterial infections. Here, we compare the in vivo immune response induced by GFP-tagged Salmonella Typhimurium inoculated by immersion and microinjection in transgenic zebrafish larvae. Our novel infection protocols in zebrafish allow live-cell imaging of Salmonella colonization.

  10. Molecular Identification of Zoonotic Tissue-Invasive Tapeworm Larvae Other than Taenia solium in Suspected Human Cysticercosis Cases

    PubMed Central

    Tappe, Dennis; Berkholz, Jörg; Mahlke, Uwe; Lobeck, Hartmut; Nagel, Thomas; Haeupler, Alexandra; Muntau, Birgit; Racz, Paul

    2015-01-01

    Rarely, zoonotic Taenia species other than Taenia solium cause human cysticercosis. The larval stages are morphologically often indistinguishable. We therefore investigated 12 samples of suspected human cysticercosis cases at the molecular level and surprisingly identified one Taenia crassiceps and one Taenia serialis (coenurosis) infection, which were caused by tapeworm larvae normally infecting rodents and sheep via eggs released from foxes and dogs. PMID:26491175

  11. Molecular Identification of Zoonotic Tissue-Invasive Tapeworm Larvae Other than Taenia solium in Suspected Human Cysticercosis Cases.

    PubMed

    Tappe, Dennis; Berkholz, Jörg; Mahlke, Uwe; Lobeck, Hartmut; Nagel, Thomas; Haeupler, Alexandra; Muntau, Birgit; Racz, Paul; Poppert, Sven

    2016-01-01

    Rarely, zoonotic Taenia species other than Taenia solium cause human cysticercosis. The larval stages are morphologically often indistinguishable. We therefore investigated 12 samples of suspected human cysticercosis cases at the molecular level and surprisingly identified one Taenia crassiceps and one Taenia serialis (coenurosis) infection, which were caused by tapeworm larvae normally infecting rodents and sheep via eggs released from foxes and dogs.

  12. Mass Death of Predatory Carp, Chanodichthys erythropterus, Induced by Plerocercoid Larvae of Ligula intestinalis (Cestoda: Diphyllobothriidae)

    PubMed Central

    Sohn, Woon-Mok; Na, Byoung-Kuk; Jung, Soo Gun; Kim, Koo Hwan

    2016-01-01

    We describe here the mass death of predatory carp, Chanodichthys erythropterus, in Korea induced by plerocercoid larvae of Ligula intestinalis as a result of host manipulation. The carcasses of fish with ligulid larvae were first found in the river-edge areas of Chilgok-bo in Nakdong-gang (River), Korea at early February 2016. This ecological phenomena also occurred in the adjacent areas of 3 dams of Nakdong-gang, i.e., Gangjeong-bo, Dalseong-bo, and Hapcheon-Changnyeong-bo. Total 1,173 fish carcasses were collected from the 4 regions. To examine the cause of death, we captured 10 wondering carp in the river-edge areas of Hapcheon-Changnyeong-bo with a landing net. They were 24.0-28.5 cm in length and 147-257 g in weight, and had 2-11 plerocercoid larvae in the abdominal cavity. Their digestive organs were slender and empty, and reproductive organs were not observed at all. The plerocercoid larvae occupied almost all spaces of the abdominal cavity under the air bladders. The proportion of larvae per fish was 14.6-32.1% of body weight. The larvae were ivory-white, 21.5-63.0 cm long, and 6.0-13.8 g in weight. We suggest that the preference for the river-edge in infected fish during winter is a modified behavioral response by host manipulation of the tapeworm larvae. The life cycle of this tapeworm seems to be successfully continued as the infected fish can be easily eaten by avian definitive hosts. PMID:27417095

  13. The Galleria mellonella larvae as an in vivo model for evaluation of Shigella virulence.

    PubMed

    Barnoy, Shoshana; Gancz, Hanan; Zhu, Yuewei; Honnold, Cary L; Zurawski, Daniel V; Venkatesan, Malabi M

    2017-02-13

    Shigella spp. causing bacterial diarrhea and dysentery are human enteroinvasive bacterial pathogens that are orally transmitted through contaminated food and water and cause bacillary dysentery. Although natural Shigella infections are restricted to humans and primates, several smaller animal models are used to analyze individual steps in pathogenesis. No animal model fully duplicates the human response and sustaining the models requires expensive animals, costly maintenance of animal facilities, veterinary services and approved animal protocols. This study proposes the development of the caterpillar larvae of Galleria mellonella as a simple, inexpensive, informative, and rapid in-vivo model for evaluating virulence and the interaction of Shigella with cells of the insect innate immunity. Virulent Shigella injected through the forelegs causes larvae death. The mortality rates were dependent on the Shigella strain, the infectious dose, and the presence of the virulence plasmid. Wild-type S. flexneri 2a, persisted and replicated within the larvae, resulting in haemocyte cell death, whereas plasmid-cured mutants were rapidly cleared. Histology of the infected larvae in conjunction with fluorescence, immunofluorescence, and transmission electron microscopy indicate that S. flexneri reside within a vacuole of the insect haemocytes that ultrastructurally resembles vacuoles described in studies with mouse and human macrophage cell lines. Some of these bacteria-laden vacuoles had double-membranes characteristic of autophagosomes. These results suggest that G. mellonella larvae can be used as an easy-to-use animal model to understand Shigella pathogenesis that requires none of the time and labor-consuming procedures typical of other systems.

  14. Isolation and characterization of a novel phage lysin active against Paenibacillus larvae, a honeybee pathogen

    PubMed Central

    LeBlanc, Lucy; Nezami, Sara; Yost, Diane; Tsourkas, Philippos; Amy, Penny S

    2015-01-01

    Paenibacillus larvae is the causative agent of American foulbrood (AFB) disease which affects early larval stages during honeybee development. Due to its virulence, transmissibility, capacity to develop antibiotic resistance, and the inherent resilience of its endospores, Paenibacillus larvae is extremely difficult to eradicate from infected hives which often must be burned. AFB contributes to the worldwide decline of honeybee populations, which are crucial for pollination and the food supply. We have isolated a novel bacteriophage lysin, PlyPalA, from the genome of a novel Paenibacillus larvae bacteriophage originally extracted from an environmental sample. PlyPalA has an N-terminal N-acetylmuramoyl-L-alanine amidase catalytic domain and possesses lytic activity against infectious strains of Paenibacillus larvae without harming commensal bacteria known to compose the honeybee larval microbiota. A single dose of PlyPalA rescued 75% of larvae infected with endospores, showing that it represents a powerful tool for future treatment of AFB. This represents the first time that lysins have been tested for therapeutic use in invertebrates. PMID:26904379

  15. Behavior of Settling Marine Larvae in Flow

    NASA Astrophysics Data System (ADS)

    Hernandez, J.; Koehl, M. A.

    2012-12-01

    Many bottom-dwelling marine animals produce microscopic larvae that are dispersed by ambient water currents. These larvae can only recruit to habitats on which they have landed if they can resist being washed away by ambient water flow. We found that larvae on marine surfaces do not experience steady water flow, but rather are exposed to brief pulses of water movement as turbulent eddies sweep across them. We made video recordings of larvae of the tube worm, Hydroides elegans, (important members of the community of organisms growing on docks and ships) on surfaces subjected to measured realistic flow pulses to study factors that might affect their dislodgement from surfaces in nature. We found that the response of a larva of H. elegans to a realistic pulse of water flow depended on its behavior at the time of the pulse and on its recent history of exposure to flow pulses, and that stationary larvae were less likely than locomoting larvae to be blown away when hit by the first pulse of water flow.; ;

  16. Hyperparasitism of mosquitoes by water mite larvae.

    PubMed

    Werblow, Antje; Martin, Peter; Dörge, Dorian D; Koch, Lisa K; Mehlhorn, Heinz; Melaun, Christian; Klimpel, Sven

    2015-07-01

    Hyperparasitism of ectoparasitic water mite larvae on mosquitoes is still a neglected relationship and was investigated only in a few studies. We analysed 2313 female mosquitoes from six different sampling localities with regard to their degree of parasitism with water mite larvae. In total, we found 38 mosquito individuals parasitized by 93 water mite larvae, ranging from 1 to 12 larvae per mosquito. Water mite larvae detected are members of the two species Parathyas cf. barbigera (n = 92) and Arrenurus cf. globator (n = 1). Out of the analysed mosquitoes, individuals out of the species Aedes vexans, Anopheles claviger, Ochlerotatus communis, the Ochlerotatus cantans/annulipes group, Ochlerotatus cataphylla and Ochlerotatus sticticus were tested to be parasitized by water mite larvae. The highest prevalence was found within the species Oc. cataphylla (28.6 %) and Oc. cantans/annulipes (21.7 %). No water mite larvae were found, e.g. on individuals of Aedes cinereus, Coquillettidia richiardii, the Culex pipiens/torrentium group, Ochlerotatus caspius, Ochlerotatus dorsalis or Ochlerotatus punctor. All of the attachment sites were located between the neck and abdomen with the ventral thorax site being the most frequent one.

  17. Cutaneous Larva Migrans in Early Infancy

    PubMed Central

    Siddalingappa, Karjigi; Murthy, Sambasiviah Chidambara; Herakal, Kallappa; Kusuma, Marganahalli Ramachandra

    2015-01-01

    Cutaneous larva migrans or creeping eruptions is a cutaneous dermatosis caused by hookworm larvae, Ancylostoma braziliense. A 2-month-old female child presented with a progressive rash over the left buttock of 4 days duration. Cutaneous examination showed an urticarial papule progressing to erythematous, tortuous, thread-like tract extending a few centimeters from papule over the left gluteal region. A clinical diagnosis of cutaneous larva migrans was considered. Treatment with albendazole led to complete resolution, confirming the diagnosis. This is to the best of our knowledge, the youngest age at which this condition is being reported. PMID:26538729

  18. ELEVATED TRANS-MAMMARY TRANSMISSION OF Toxocara canis LARVAE IN BALB/c MICE

    PubMed Central

    Telmo, Paula de Lima; de Avila, Luciana Farias da Costa; dos Santos, Cristina Araújo; de Aguiar, Patrícia de Souza; Martins, Lourdes Helena Rodrigues; Berne, Maria Elisabeth Aires; Scaini, Carlos James

    2015-01-01

    Toxocariasis is a widespread zoonosis and is considered an important worldwide public health problem. The aim of this study was to investigate the frequency of trans-mammary Toxocara canis infection in newborn BALB/c mice nursed by females experimentally infected with 1,200 eggs after delivery. After 50 days of age, the presence of larvae in different organs of the offspring was investigated. Trans-mammary infection was confirmed in 73.9% of the mice that had been nursed by infected females. These data show a high trans-mammary transmission of T. canis and confirm the significance of this transmission route in paratenic hosts. PMID:25651332

  19. Efficiency of bacteriophage therapy against Cronobacter sakazakii in Galleria mellonella (greater wax moth) larvae.

    PubMed

    Abbasifar, Reza; Kropinski, Andrew M; Sabour, Parviz M; Chambers, James R; MacKinnon, Joanne; Malig, Thomas; Griffiths, Mansel W

    2014-09-01

    Cronobacter sakazakii, an opportunistic pathogen found in milk-based powdered infant formulae, has been linked to meningitis in infants, with high fatality rates. A set of phages from various environments were purified and tested in vitro against strains of C. sakazakii. Based on host range and lytic activity, the T4-like phage vB_CsaM_GAP161, which belongs to the family Myoviridae, was selected for evaluation of its efficacy against C. sakazakii. Galleria mellonella larvae were used as a whole-animal model for pre-clinical testing of phage efficiency. Twenty-one Cronobacter strains were evaluated for lethality in G. mellonella larvae. Different strains of C. sakazakii caused 0 to 98% mortality. C. sakazakii 3253, with an LD50 dose of ~2.0×10(5) CFU/larva (24 h, 37 °C) was selected for this study. Larvae infected with a dose of 5×LD50 were treated with phage GAP161 (MOI=8) at various time intervals. The mortality rates were as high as 100% in the groups injected with bacteria only, compared to 16.6% in the group infected with bacteria and treated with phage. Phage GAP161 showed the best protective activity against C. sakazakii when the larvae were treated prior to or immediately after infection. The results obtained with heat-inactivated phage proved that the survival of the larvae is not due to host immune stimulation. These results suggest that phage GAP161 is potentially a useful control agent against C. sakazakii. In addition, G. mellonella may be a useful whole-animal model for pre-screening phages for efficacy and safety prior to clinical evaluation in mammalian models.

  20. Molecular characterisation of Anisakidae larvae from fish in Adriatic Sea.

    PubMed

    Vardić Smrzlić, I; Valić, D; Kapetanović, D; Kurtović, B; Teskeredžić, E

    2012-12-01

    In the present study, anisakids from: tuna (Thunnus thynnus) fattened in the Croatian farm in middle Adriatic Sea, three different feral fish species caught near tuna farm (Trachurus trachurus, Scomber japonicus and Oblada melanura) and fish marketed in Croatia (T. trachurus) were analysed by morphology and molecular methods. Larvae were identified to the species level by PCR restriction fragment length polymorphism and characterised by sequencing of nuclear (internal transcribed spacer) and mitochondrial (cytochrome c oxidase subunit 2) markers. The results revealed diverse Anisakidae community consisting of: Anisakis pegreffi, Anisakis simplex (s.s.), Anisakis typica and Hysterothylacium aduncum. This is the first report of A. typica in Adriatic Sea, and also the first record of this species in T. thynnus as host in Mediterranean Sea. Molecular identification of H. aduncum found in co-infection with Anisakis larvae type I expands our knowledge of the occurrence of these taxa in the Adriatic Sea. Zoonotic Anisakidae worms found in fish from the Adriatic Sea could represent a risk to acquire parasitic infection/allergies in Croatia.

  1. Mortality Caused by Bath Exposure of Zebrafish (Danio rerio) Larvae to Nervous Necrosis Virus Is Limited to the Fourth Day Postfertilization

    PubMed Central

    Morick, Danny; Faigenbaum, Or; Smirnov, Margarita; Fellig, Yakov; Inbal, Adi

    2015-01-01

    Nervous necrosis virus (NNV) is a member of the Betanodavirus genus that causes fatal diseases in over 40 species of fish worldwide. Mortality among NNV-infected fish larvae is almost 100%. In order to elucidate the mechanisms responsible for the susceptibility of fish larvae to NNV, we exposed zebrafish larvae to NNV by bath immersion at 2, 4, 6, and 8 days postfertilization (dpf). Here, we demonstrate that developing zebrafish embryos are resistant to NNV at 2 dpf due to the protection afforded by the egg chorion and, to a lesser extent, by the perivitelline fluid. The zebrafish larvae succumbed to NNV infection during a narrow time window around the 4th dpf, while 6- and 8-day-old larvae were much less sensitive, with mortalities of 24% and 28%, respectively. PMID:25746990

  2. Dispersal strategies in sponge larvae: integrating the life history of larvae and the hydrologic component.

    PubMed

    Mariani, Simone; Uriz, María-J; Turon, Xavier; Alcoverro, Teresa

    2006-08-01

    While known to be uniformly non-feeding, short-lived, and potentially short dispersing, sponge larvae display different behaviours (swimming ability and taxis). Our aim was to show whether sponge larvae with different behaviours exhibit different dispersal strategies under variable intensity of water movements. We first assessed the distribution of larvae of six taxa: Dictyoceratida spp., Dysidea avara, Crambe crambe, Phorbas tenacior, Scopalina lophyropoda, and Cliona viridis, collected through plankton sampling, and the abundance of the corresponding adult sponges across three hard bottom communities and a sandy bottom from a north-west Mediterranean rocky shore. We then tested adult-larvae couplings (abundance of larvae vs abundance of adults) under increasing levels of water movements (surge) to assess the importance of this environmental factor in driving differences in dispersal strategies. Adults of Dictyoceratida spp., D. avara, and P. tenacior were most abundant in semi-dark caves (SDC), C. crambe and C. viridis in communities of sciaphilic algae (SA), whereas the distribution of S. lophyropoda was extremely patchy, being present almost only in the SA community of one of the five stations studied. Larvae of Dictyoceratida spp. and P. tenacior were more abundant in the SDC, whereas D. avara and C. crambe were homogeneously distributed across the communities. The larvae of C. viridis were more abundant in the SA communities and the S. lophyropoda larvae were mostly present in one station and one community (SA). Increased water movement did not modify the adult-larvae coupling for Dictyoceratida spp., D. avara, and C. crambe, whereas it broke up the positive association for P. tenacior and to some extent S. lophyropoda. For C. viridis, possible variability in adult-larvae coupling was not tested because the larvae were collected on only one day under calm sea conditions. We confirm that efficient-swimming larvae with some cue response can actively counteract

  3. Rearing Chrysoperla externa Larvae on Artificial Diets.

    PubMed

    Bezerra, C E S; Amaral, B B; Souza, B

    2017-02-01

    We tested three artificial diets for rearing larvae of Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae), aiming at reducing the production costs of this predator. Two of the diets come from studies with other species of lacewings, and the third is a modification described in this paper. All diets were based on animal protein and were supplied to 2nd and 3rd instar larvae, whereas 1st instar larvae received eggs of Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae). We evaluated the preimaginal duration and survival, adult size, longevity and fecundity, egg hatchability, and predatory capacity of larvae produced. The performance of the diets was followed for seven generations. The diet we describe showed to be the best among the artificial diets tested. Our results show that C. externa can be successfully reared on artificial diets during second and third instars, reducing in 90% the dependency on eggs of A. kuehniella.

  4. Comparison of two techniques used for the recovery of third-stage strongylid nematode larvae from herbage.

    PubMed

    Krecek, R C; Maingi, N

    2004-07-14

    A laboratory trial to determine the efficacy of two methods in recovering known numbers of third-stage (L3) strongylid nematode larvae from herbage was carried out. Herbage samples consisting almost entirely of star grass (Cynodon aethiopicus) that had no L3 nematode parasitic larvae were collected at Onderstepoort, South Africa. Two hundred grams samples were placed in fibreglass fly gauze bags and seeded with third-stage strongylid nematode larvae at 11 different levels of herbage infectivity ranging from 50 to 8000 L3/kg. Eight replicates were prepared for each of the 11 levels of herbage infectivity. Four of these were processed using a modified automatic Speed Queen heavy-duty washing machine at a regular normal cycle, followed by isolation of larvae through centrifugation-flotation in saturated sugar solution. Larvae in the other four samples were recovered after soaking the herbage in water overnight and the larvae isolated with the Baermann technique of the washing. There was a strong correlation between the number of larvae recovered using both methods and the number of larvae in the seeded samples, indicating that the two methods give a good indication of changes in the numbers of larvae on pasture if applied in epidemiological studies. The washing machine method recovered higher numbers of larvae than the soaking and Baermann method at all levels of pasture seeding, probably because the machine washed the samples more thoroughly and a sugar centrifugation-flotation step was used. Larval suspensions obtained using the washing machine method were therefore cleaner and thus easier to examine under the microscope. In contrast, the soaking and Baermann method may be more suitable in field-work, especially in places where resources and equipment are scarce, as it is less costly in equipment and less labour intensive. Neither method recovered all the larvae from the seeded samples. The recovery rates for the washing machine method ranged from 18 to 41% while

  5. Activity of R(+) Limonene Against Anisakis Larvae

    PubMed Central

    Muscolino, Daniele; Panebianco, Felice; Patania, Andrea; Benianti, Chiara; Ziino, Graziella; Giuffrida, Alessandro

    2015-01-01

    The aim of this work is to evaluate the activity of R(+) limonene of against Anisakidae larvae. Its effectiveness was tested in vitro. The results obtained showed a significant activity of the compound against Anisakis larvae, suggesting further investigation on its potential use in the industrial marinating process. In this regard, the use of R(+) limonene in seafood products could be interesting, also due the sensory attributes resulting from its use and its relatively safe status. PMID:27800423

  6. Efficacy of maslinic acid and fenbendazole on muscle larvae of Trichinella zimbabwensis in laboratory rats.

    PubMed

    Mukaratirwa, S; Gcanga, L; Kamau, J

    2016-01-01

    Trichinellosis is a zoonotic disease caused by nematode species of the genus Trichinella. Anthelmintics targeting the intestinal adults and muscle-dwelling larvae of Trichinella spp. have been tested, with limited success. This study was aimed at determining the efficacy of maslinic acid and fenbendazole on muscle larvae of Trichinella zimbabwensis in laboratory rats. Forty-two Sprague-Dawley rats, with an average weight of 270 g and 180 g for males and females respectively, were infected with T. zimbabwensis larvae. Infected rats were randomly assigned to three groups which were subjected to single treatments with each of maslinic acid, fenbendazole and a combination of both on day 25 post-infection (pi), and three groups which were subjected to double treatments with each of these drugs and a combination on days 25 and 32 pi. The untreated control group received a placebo. In single-treatment groups, the efficacy of each treatment, measured by rate of reduction in muscle larvae, was significant (P0.05). We conclude that the efficacy of maslinic acid against larval stages of T. zimbabwensis in rats was comparable to that of fenbendazole, with no side-effects observed, making maslinic acid a promising anthelmintic against larval stages of Trichinella species.

  7. [Galleria mellonella larva model in evaluating the effects of biofilm in Candida albicans].

    PubMed

    Karaman, Meral; Alvandian, Ali; Bahar, I Hakkı

    2017-01-01

    Biofilm-related infections are chronic infections that cause serious increase in morbidity and mortality as well as significant economic loss. Galleria mellonella larva is shown as a reliable animal model for in vivo toxicology and pathogenicity tests due to its large size, ease of practice, ability to survive at 15-37°C and its similarity to mammals' natural immune system. The aim of this study was to evaluate the effects biofilm activity of Candida albicans in a G.mellonella larva model. Two C.albicans strains isolated as a disease agent were used for the model, where one was positive (BP), and the other one was negative (BN) for biofilm production. Eighty healthy G.mellonella larvae, all in the last larval stage and 2-2.5 cm long, were divided into 4 groups of equal size. Group 1 was set as the control group. Group 2 was injected with sterile phosphate buffer (PBS) group. Group 3 was injected with BP C.albicans strain and group 4 with BN C.albicans strain. A 5 μL volume of C.albicans prepared at 5 × 10(5) cfu/ml concentration with PBS was injected into the last left rear-legs of the larvae. The larvae were kept in sterile petri dishes at 37°C. They were observed for a total of 96 hours, for 4 hours in the first 24 hours, then in 12 hours intervals. Melanization, survival, total hemocyte count and fungal burden were evaluated as infection indicators. Melanization and death were not observed throughout the study period in group 1. One larva died in group 2. Small melanization spots (dark spots) and subsequent progressive melanization were observed from 3rd hour in the larvae infected with C.albicans. When compared with the BN C.albicans infected group, survival rate was 20% for BP C.albicans infected larvae at the end of 24 hours. Total hemocyte count was very low in the infected groups compared to groups 1 and 2, also significantly lower in group 3 than in group 4. In quantitative cultures, growth of C.albicans was detected in groups 3 and 4 while not in

  8. Pilot project to investigate over-wintering of free-living gastrointestinal nematode larvae of sheep in Ontario, Canada.

    PubMed

    Falzon, Laura C; Menzies, Paula I; VanLeeuwen, John; Shakya, Krishna P; Jones-Bitton, Andria; Avula, Jacob; Jansen, Jocelyn T; Peregrine, Andrew S

    2014-08-01

    This study investigated the overwintering survival and infectivity of free-living gastrointestinal nematode (GIN) stages on pasture. The presence of GIN larvae was assessed on 3 sheep farms in Ontario with a reported history of clinical haemonchosis, by collecting monthly pasture samples over the winter months of 2009/2010. The infectivity of GIN larvae on spring pastures was evaluated using 16 tracer lambs. Air and soil temperature and moisture were recorded hourly. Free-living stages of Trichostrongylus spp. and Nematodirus spp. were isolated from herbage samples. Gastrointestinal nematodes were recovered from all tracer lambs on all farms; Teladorsagia sp. was the predominant species. Very low levels of Haemonchus contortus were recovered from 1 animal on 1 farm. The results suggest that Haemonchus larvae do not survive well on pasture, while Teladorsagia sp., Trichostrongylus spp. and Nematodirus spp. are able to overwinter on pasture in Ontario and are still infective for sheep in the spring.

  9. Galleria mellonella larvae are capable of sensing the extent of priming agent and mounting proportionatal cellular and humoral immune responses.

    PubMed

    Wu, Gongqing; Xu, Li; Yi, Yunhong

    2016-06-01

    Larvae of Galleria mellonella are useful models for studying the innate immunity of invertebrates or for evaluating the virulence of microbial pathogens. In this work, we demonstrated that prior exposure of G. mellonella larvae to high doses (1×10(4), 1×10(5) or 1×10(6) cells/larva) of heat-killed Photorhabdus luminescens TT01 increases the resistance of larvae to a lethal dose (50 cells/larva) of viable P. luminescens TT01 infection administered 48h later. We also found that the changes in immune protection level were highly correlated to the changes in levels of cellular and humoral immune parameters when priming the larvae with different doses of heat-killed P. luminescens TT01. Priming the larvae with high doses of heat-killed P. luminescens TT01 resulted in significant increases in the hemocytes activities of phagocytosis and encapsulation. High doses of heat-killed P. luminescens TT01 also induced an increase in total hemocyte count and a reduction in bacterial density within the larval hemocoel. Quantitative real-time PCR analysis showed that genes coding for cecropin and gallerimycin and galiomycin increased in expression after priming G. mellonella with heat-killed P. luminescens TT01. All the immune parameters changed in a dose-dependent manner. These results indicate that the insect immune system is capable of sensing the extent of priming agent and mounting a proportionate immune response.

  10. Virulence Differences among Melissococcus plutonius Strains with Different Genetic Backgrounds in Apis mellifera Larvae under an Improved Experimental Condition

    PubMed Central

    Nakamura, Keiko; Yamazaki, Yuko; Shiraishi, Akiyo; Kobayashi, Sota; Harada, Mariko; Yoshiyama, Mikio; Osaki, Makoto; Okura, Masatoshi; Takamatsu, Daisuke

    2016-01-01

    European foulbrood (EFB) caused by Melissococcus plutonius is an important bacterial disease of honeybee larvae. M. plutonius strains can be grouped into three genetically distinct groups (CC3, CC12 and CC13). Because EFB could not be reproduced in artificially reared honeybee larvae by fastidious strains of CC3 and CC13 previously, we investigated a method to improve experimental conditions using a CC3 strain and found that infection with a potassium-rich diet enhanced proliferation of the fastidious strain in larvae at the early stage of infection, leading to the appearance of clear clinical symptoms. Further comparison of M. plutonius virulence under the conditions revealed that the representative strain of CC12 was extremely virulent and killed all tested bees before pupation, whereas the CC3 strain was less virulent than the CC12 strain, and a part of the infected larvae pupated. In contrast, the tested CC13 strain was avirulent, and as with the non-infected control group, most of the infected brood became adult bees, suggesting differences in the insect-level virulence among M. plutonius strains with different genetic backgrounds. These strains and the improved experimental infection method to evaluate their virulence will be useful tools for further elucidation of the pathogenic mechanisms of EFB. PMID:27625313

  11. Molecular analysis of Anisakis type I larvae in marine fish from three different sea areas in Korea.

    PubMed

    Sohn, Woon-Mok; Kang, Jung-Mi; Na, Byoung-Kuk

    2014-08-01

    Anisakiasis, a human infection of Anisakis L3 larvae, is one of the common foodborne parasitic diseases in Korea. Studies on the identification of anisakid larvae have been performed in the country, but most of them have been focused on morphological identification of the larvae. In this study, we analyzed the molecular characteristics of 174 Anisakis type I larvae collected from 10 species of fish caught in 3 different sea areas in Korea. PCR-RFLP and sequence analyses of rDNA ITS and mtDNA cox1 revealed that the larvae showed interesting distribution patterns depending on fish species and geographical locations. Anisakis pegreffii was predominant in fish from the Yellow Sea and the South Sea. Meanwhile, both A. pegreffii and A. simplex sensu stricto (A. simplex s.str.) larvae were identified in fish from the East Sea, depending on fish species infected. These results suggested that A. pegreffii was primarily distributed in a diverse species of fish in 3 sea areas around Korea, but A. simplex s.str. was dominantly identified in Oncorhynchus spp. in the East Sea.

  12. Fascioliasis Control: In Vivo and In Vitro Phytotherapy of Vector Snail to Kill Fasciola Larva

    PubMed Central

    Sunita, Kumari; Singh, D. K.

    2011-01-01

    Snail is one of the important components of an aquatic ecosystem, it acts as intermediate host of Fasciola species. Control of snail population below a certain threshold level is one of the important methods in the campaign to reduce the incidence of fascioliasis. Life cycle of the parasite can be interrupted by killing the snail or Fasciola larva redia and cercaria in the snail body. In vivo and in vitro toxicity of the plant products and their active component such as citral, ferulic acid, umbelliferone, azadirachtin, and allicin against larva of Fasciola in infected snail Lymnaea acuminata were tested. Mortality of larvae were observed at 2 h, 4 h, 6 h, and 8 h, of treatment. In in vivo treatment, azadirachtin caused highest mortality in redia and cercaria larva (8 h, LC50 0.11, and 0.05 mg/L) whereas in in vitro condition allicin was highly toxic against redia and cercaria (8 h, LC50 0.01, and 0.009 mg/L). Toxicity of citral was lowest against redia and cercaria larva. PMID:22132306

  13. Pathogenicity of Isolates of Serratia Marcescens towards Larvae of the Scarab Phyllophaga Blanchardi (Coleoptera)

    PubMed Central

    Pineda-Castellanos, Mónica L.; Rodríguez-Segura, Zitlhally; Villalobos, Francisco J.; Hernández, Luciano; Lina, Laura; Nuñez-Valdez, M. Eugenia

    2015-01-01

    Serratia marcescens is a Gram negative bacterium (Enterobacteriaceae) often associated with infection of insects. In order to find pathogenic bacteria with the potential to control scarab larvae, several bacterial strains were isolated from the hemocoel of diseased Phyllophaga spp (Coleoptera:Scarabaeidae) larvae collected from cornfields in Mexico. Five isolates were identified as Serratia marcescens by 16S rRNA gene sequencing and biochemical tests. Oral and injection bioassays using healthy Phyllophaga blanchardi larvae fed with the S. marcescens isolates showed different degrees of antifeeding effect and mortality. No insecticidal activity was observed for Spodoptera frugiperda larvae (Lepidoptera: Noctuidae) by oral inoculation. S. marcescens (Sm81) cell-free culture supernatant caused significant antifeeding effect and mortality to P. blanchardi larvae by oral bioassay and also mortality by injection bioassay. Heat treated culture broths lost the ability to cause disease symptoms, suggesting the involvement of proteins in the toxic activity. A protein of 50.2 kDa was purified from the cell-free broth and showed insecticidal activity by injection bioassay towards P. blanchardi. Analysis of the insecticidal protein by tandem- mass spectrometry (LC-MS/MS) showed similarity to a Serralysin-like protein from S. marcescens spp. This insecticidal protein could have applications in agricultural biotechnology. PMID:25984910

  14. A novel mode of induction of the humoral innate immune response in Drosophila larvae

    PubMed Central

    Kenmoku, Hiroyuki

    2017-01-01

    ABSTRACT Drosophila adults have been utilized as a genetically tractable model organism to decipher the molecular mechanisms of humoral innate immune responses. In an effort to promote the utility of Drosophila larvae as an additional model system, in this study, we describe a novel aspect of an induction mechanism for innate immunity in these larvae. By using a fine tungsten needle created for manipulating semi-conductor devices, larvae were subjected to septic injury. However, although Toll pathway mutants were susceptible to infection with Gram-positive bacteria as had been shown for Drosophila adults, microbe clearance was not affected in the mutants. In addition, Drosophila larvae were found to be sensitive to mechanical stimuli with respect to the activation of a sterile humoral response. In particular, pinching with forceps to a degree that might cause minor damage to larval tissues could induce the expression of the antifungal peptide gene Drosomycin; notably, this induction was partially independent of the Toll and immune deficiency pathways. We therefore propose that Drosophila larvae might serve as a useful model to analyze the infectious and non-infectious inflammation that underlies various inflammatory diseases such as ischemia, atherosclerosis and cancer. PMID:28250052

  15. Paenilamicin: structure and biosynthesis of a hybrid nonribosomal peptide/polyketide antibiotic from the bee pathogen Paenibacillus larvae.

    PubMed

    Müller, Sebastian; Garcia-Gonzalez, Eva; Mainz, Andi; Hertlein, Gillian; Heid, Nina C; Mösker, Eva; van den Elst, Hans; Overkleeft, Herman S; Genersch, Elke; Süssmuth, Roderich D

    2014-09-26

    The spore-forming bacterium Paenibacillus larvae is the causative agent of American Foulbrood (AFB), a fatal disease of honey bees that occurs worldwide. Previously, we identified a complex hybrid nonribosomal peptide/polyketide synthesis (NRPS/PKS) gene cluster in the genome of P. larvae. Herein, we present the isolation and structure elucidation of the antibacterial and antifungal products of this gene cluster, termed paenilamicins. The unique structures of the paenilamicins give deep insight into the underlying complex hybrid NRPS/PKS biosynthetic machinery. Bee larval co-infection assays reveal that the paenilamicins are employed by P. larvae in fighting ecological niche competitors and are not directly involved in killing the bee larvae. Their antibacterial and antifungal activities qualify the paenilamicins as attractive candidates for drug development.

  16. Chironomidae bloodworms larvae as aquatic amphibian food.

    PubMed

    Fard, Mojdeh Sharifian; Pasmans, Frank; Adriaensen, Connie; Laing, Gijs Du; Janssens, Geert Paul Jules; Martel, An

    2014-01-01

    Different species of chironomids larvae (Diptera: Chironomidae) so-called bloodworms are widely distributed in the sediments of all types of freshwater habitats and considered as an important food source for amphibians. In our study, three species of Chironomidae (Baeotendipes noctivagus, Benthalia dissidens, and Chironomus riparius) were identified in 23 samples of larvae from Belgium, Poland, Russia, and Ukraine provided by a distributor in Belgium. We evaluated the suitability of these samples as amphibian food based on four different aspects: the likelihood of amphibian pathogens spreading, risk of heavy metal accumulation in amphibians, nutritive value, and risk of spreading of zoonotic bacteria (Salmonella, Campylobacter, and ESBL producing Enterobacteriaceae). We found neither zoonotic bacteria nor the amphibian pathogens Ranavirus and Batrachochytrium dendrobatidis in these samples. Our data showed that among the five heavy metals tested (Hg, Cu, Cd, Pb, and Zn), the excess level of Pb in two samples and low content of Zn in four samples implicated potential risk of Pb accumulation and Zn inadequacy. Proximate nutritional analysis revealed that, chironomidae larvae are consistently high in protein but more variable in lipid content. Accordingly, variations in the lipid: protein ratio can affect the amount and pathway of energy supply to the amphibians. Our study indicated although environmentally-collected chironomids larvae may not be vectors of specific pathogens, they can be associated with nutritional imbalances and may also result in Pb bioaccumulation and Zn inadequacy in amphibians. Chironomidae larvae may thus not be recommended as single diet item for amphibians.

  17. Ventral nerve cord in Phoronopsis harmeri larvae.

    PubMed

    Temereva, Elena N

    2012-01-15

    The nervous system organization is considered a phylogenetically important character among metazoans. The phylum Phoronida is included in a supraphyletic taxon known as Lophotrochozoa. Many lophotrochozoans possess a metameric ventral nerve cord as adults or larvae. Phoronids do not exhibit external metamery either as larvae or as adults. The current study describes the ventral nerve cord in the young larva of Phoronopsis harmeri. This structure is apparent both in the serotonergic and FMRF-amidergic nervous system in young larvae. The ventral nerve cord extends from the mouth to the tentacular ridge. Both serotonergic and FMRF-amidergic components consist of two ventrolateral nerves, each with several unipolar neurons. The ventrolateral nerves connect to each other by means of thin repetitive transversal nerves ("commissures"). The abundance of neurons and nerves in the epidermis of the oral field of actinotrocha larva likely reflects the importance of this area in collection of food particles. The ventral nerve cords of the actinotrocha and the metatrochophore differ in their positions with respect to ciliated bands: the cord is located between the preoral and postoral ciliated bands in the actinotrocha but between the postoral ciliated band and telotroch in the metatrochophore. The presence of the ventral nerve cord, which contains repetitive elements (neurons and "commissures"), in the early development of P. harmeri may recapitulate some stages of nervous system development during phoronid phylogeny. The larval nervous system does not contain nervous centers under the tentacular ridge that can correlate with the catastrophic metamorphosis and unique body plan of phoronids.

  18. Development of a bacterial challenge test for gnotobiotic Nile tilapia Oreochromis niloticus larvae.

    PubMed

    Situmorang, Magdalena Lenny; Dierckens, Kristof; Mlingi, Frank Thomas; Van Delsen, Bart; Bossier, Peter

    2014-04-23

    Gastrointestinal microbiota have an important impact on fish health and disease, stimulating interest in a better understanding of how these gastrointestinal microbial communities are composed and consequently affect host fitness. In this respect, probiotic microorganisms have been extensively used in recent aquaculture production. To study the use of probiotics in the treatment of infectious diseases, the establishment of a method of experimental infection to obtain consistent results for mortality and infection in challenge tests is important. In pathogen-screening tests, 4 candidate pathogenic bacteria strains (Edwardsiella ictaluri gly09, E. ictaluri gly10, E. tarda LMG2793 and Streptococcus agalactiae LMG15977) were individually tested on xenic Nile tilapia larvae. Only Edwardsiella strains delivered via Artemia nauplii, with or without additional pathogen delivery via the culture water, led to increased mortality in fish larvae. A gnotobiotic Nile tilapia larvae model system was developed to provide a research tool to investigate the effects and modes-of-action of probiotics under controlled conditions. A double disinfection procedure using hydrogen peroxide and sodium hypochlorite solution was applied to the fish eggs, which were subsequently incubated in a cocktail of antibiotic and antifungal agents. In the gnotobiotic challenge test, E. ictaluri gly09R was added to the model system via Artemia nauplii and culture water, resulting in a significant mortality of the gnotobiotic fish larvae. The developed gnotobiotic Nile tilapia model can be used as a tool to extend understanding of the mechanisms involved in host-microbe interactions and to evaluate new methods of disease control.

  19. Metarhizium anisopliae Pathogenesis of Mosquito Larvae: A Verdict of Accidental Death

    PubMed Central

    Butt, Tariq M.; Greenfield, Bethany P. J.; Greig, Carolyn; Maffeis, Thierry G. G.; Taylor, James W. D.; Piasecka, Justyna; Dudley, Ed; Abdulla, Ahmed; Dubovskiy, Ivan M.; Garrido-Jurado, Inmaculada; Quesada-Moraga, Enrique; Penny, Mark W.; Eastwood, Daniel C.

    2013-01-01

    Metarhizium anisopliae, a fungal pathogen of terrestrial arthropods, kills the aquatic larvae of Aedes aegypti, the vector of dengue and yellow fever. The fungus kills without adhering to the host cuticle. Ingested conidia also fail to germinate and are expelled in fecal pellets. This study investigates the mechanism by which this fungus adapted to terrestrial hosts kills aquatic mosquito larvae. Genes associated with the M. anisopliae early pathogenic response (proteinases Pr1 and Pr2, and adhesins, Mad1 and Mad2) are upregulated in the presence of larvae, but the established infection process observed in terrestrial hosts does not progress and insecticidal destruxins were not detected. Protease inhibitors reduce larval mortality indicating the importance of proteases in the host interaction. The Ae. aegypti immune response to M. anisopliae appears limited, whilst the oxidative stress response gene encoding for thiol peroxidase is upregulated. Cecropin and Hsp70 genes are downregulated as larval death occurs, and insect mortality appears to be linked to autolysis through caspase activity regulated by Hsp70 and inhibited, in infected larvae, by protease inhibitors. Evidence is presented that a traditional host-pathogen response does not occur as the species have not evolved to interact. M. anisopliae retains pre-formed pathogenic determinants which mediate host mortality, but unlike true aquatic fungal pathogens, does not recognise and colonise the larval host. PMID:24349111

  20. Quantifying and predicting Drosophila larvae crawling phenotypes

    PubMed Central

    Günther, Maximilian N.; Nettesheim, Guilherme; Shubeita, George T.

    2016-01-01

    The fruit fly Drosophila melanogaster is a widely used model for cell biology, development, disease, and neuroscience. The fly’s power as a genetic model for disease and neuroscience can be augmented by a quantitative description of its behavior. Here we show that we can accurately account for the complex and unique crawling patterns exhibited by individual Drosophila larvae using a small set of four parameters obtained from the trajectories of a few crawling larvae. The values of these parameters change for larvae from different genetic mutants, as we demonstrate for fly models of Alzheimer’s disease and the Fragile X syndrome, allowing applications such as genetic or drug screens. Using the quantitative model of larval crawling developed here we use the mutant-specific parameters to robustly simulate larval crawling, which allows estimating the feasibility of laborious experimental assays and aids in their design. PMID:27323901

  1. Sensorimotor structure of Drosophila larva phototaxis.

    PubMed

    Kane, Elizabeth A; Gershow, Marc; Afonso, Bruno; Larderet, Ivan; Klein, Mason; Carter, Ashley R; de Bivort, Benjamin L; Sprecher, Simon G; Samuel, Aravinthan D T

    2013-10-01

    The avoidance of light by fly larvae is a classic paradigm for sensorimotor behavior. Here, we use behavioral assays and video microscopy to quantify the sensorimotor structure of phototaxis using the Drosophila larva. Larval locomotion is composed of sequences of runs (periods of forward movement) that are interrupted by abrupt turns, during which the larva pauses and sweeps its head back and forth, probing local light information to determine the direction of the successive run. All phototactic responses are mediated by the same set of sensorimotor transformations that require temporal processing of sensory inputs. Through functional imaging and genetic inactivation of specific neurons downstream of the sensory periphery, we have begun to map these sensorimotor circuits into the larval central brain. We find that specific sensorimotor pathways that govern distinct light-evoked responses begin to segregate at the first relay after the photosensory neurons.

  2. Sensorimotor structure of Drosophila larva phototaxis

    PubMed Central

    Kane, Elizabeth A.; Gershow, Marc; Afonso, Bruno; Larderet, Ivan; Klein, Mason; Carter, Ashley R.; de Bivort, Benjamin L.; Sprecher, Simon G.; Samuel, Aravinthan D. T.

    2013-01-01

    The avoidance of light by fly larvae is a classic paradigm for sensorimotor behavior. Here, we use behavioral assays and video microscopy to quantify the sensorimotor structure of phototaxis using the Drosophila larva. Larval locomotion is composed of sequences of runs (periods of forward movement) that are interrupted by abrupt turns, during which the larva pauses and sweeps its head back and forth, probing local light information to determine the direction of the successive run. All phototactic responses are mediated by the same set of sensorimotor transformations that require temporal processing of sensory inputs. Through functional imaging and genetic inactivation of specific neurons downstream of the sensory periphery, we have begun to map these sensorimotor circuits into the larval central brain. We find that specific sensorimotor pathways that govern distinct light-evoked responses begin to segregate at the first relay after the photosensory neurons. PMID:24043822

  3. Quantifying and predicting Drosophila larvae crawling phenotypes.

    PubMed

    Günther, Maximilian N; Nettesheim, Guilherme; Shubeita, George T

    2016-06-21

    The fruit fly Drosophila melanogaster is a widely used model for cell biology, development, disease, and neuroscience. The fly's power as a genetic model for disease and neuroscience can be augmented by a quantitative description of its behavior. Here we show that we can accurately account for the complex and unique crawling patterns exhibited by individual Drosophila larvae using a small set of four parameters obtained from the trajectories of a few crawling larvae. The values of these parameters change for larvae from different genetic mutants, as we demonstrate for fly models of Alzheimer's disease and the Fragile X syndrome, allowing applications such as genetic or drug screens. Using the quantitative model of larval crawling developed here we use the mutant-specific parameters to robustly simulate larval crawling, which allows estimating the feasibility of laborious experimental assays and aids in their design.

  4. Quantifying and predicting Drosophila larvae crawling phenotypes

    NASA Astrophysics Data System (ADS)

    Günther, Maximilian N.; Nettesheim, Guilherme; Shubeita, George T.

    2016-06-01

    The fruit fly Drosophila melanogaster is a widely used model for cell biology, development, disease, and neuroscience. The fly’s power as a genetic model for disease and neuroscience can be augmented by a quantitative description of its behavior. Here we show that we can accurately account for the complex and unique crawling patterns exhibited by individual Drosophila larvae using a small set of four parameters obtained from the trajectories of a few crawling larvae. The values of these parameters change for larvae from different genetic mutants, as we demonstrate for fly models of Alzheimer’s disease and the Fragile X syndrome, allowing applications such as genetic or drug screens. Using the quantitative model of larval crawling developed here we use the mutant-specific parameters to robustly simulate larval crawling, which allows estimating the feasibility of laborious experimental assays and aids in their design.

  5. Transstadial transmission of Hepatozoon canis from larvae to nymphs of Rhipicephalus sanguineus.

    PubMed

    Giannelli, Alessio; Ramos, Rafael Antonio Nascimento; Di Paola, Giancarlo; Mencke, Norbert; Dantas-Torres, Filipe; Baneth, Gad; Otranto, Domenico

    2013-09-01

    Hepatozoon canis is an apicomplexan parasite of dogs, which is known to become infected by ingesting Rhipicephalus sanguineus adult ticks. To investigate the possibility of H. canis transovarial and transstadial transmission from larvae to nymphs, engorged adult female ticks were collected from a private animal shelter in southern Italy, where H. canis infection is highly prevalent. Female ticks (n=35) and egg batches were tested by PCR for H. canis. All eggs examined were PCR-negative whereas 88.6% of females from the environment tested positive. Additionally, fed larvae (n=120) from a dog naturally infected by H. canis were dissected at different time points post collection (i.e. 0, 10, 20 and 30 days). Molted nymphs dissected at 20 days post collection revealed immature oocysts displaying an amorphous central structure in 50% of the specimens, and oocysts containing sporocysts with sporozoites were found in 53.3% of the nymphs dissected at 30 days post collection. This study demonstrates that H. canis is not transmitted transovarially, but it is transmitted transstadially from larvae to nymphs of R. sanguineus and develops sporozoites in oocysts that may infect dogs.

  6. Liver histopathology in the cane toad, Rhinella marina (Amphibia: Bufonidae), induced by Ortleppascaris sp. larvae (Nematoda: Ascarididae).

    PubMed

    Silva, Jefferson P E; da Silva, Djane C B; Melo, Francisco T V; Giese, Elane G; Furtado, Adriano P; Santos, Jeannie N

    2013-04-01

    Exposure to parasites is considered to be an important factor in the development of many diseases and histopathologies which are the result of the parasite-host interaction. The present study evaluated the impact of natural infection by larvae of Ortleppascaris sp. (Nematoda: Ascaridida) in the liver of the cane toad Rhinella marina (Linnaeus, 1758). Larvae were encysted in nodules delimited by collagenous fibers and fibroblasts or freely within the hepatic parenchyma, provoking a clear response from the host. The histological examination of the liver revealed viable larvae in a number of different developmental stages, as well as cysts filled with amorphous material and cell residues and surrounded by dense fibrotic tissue. The infection of the liver by these larvae induces a significant increase in the area occupied by melanomacrophages and a reduction or deficit in the vascularization of the liver, hypertrophy of the hepatocytes, vacuolar bodies, and cytoplasmatic granules. Focal concentrations of inflammatory infiltrates were observed enclosing the unencapsulated early-stage larvae. These results indicate that infection by Ortleppascaris sp. induces severe physiological problems and histopathological lesions in the liver of R. marina .

  7. Transcriptional responses in honey bee larvae infected with chalkbrood fungus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diseases and other stress factors working synergistically weaken honey bee health and may play a major role in the losses of bee populations in recent years. Among a large number of bee diseases, chalkbrood has been on the rise. We present here the experimental identification of honey bee genes that...

  8. Predators induce cloning in echinoderm larvae.

    PubMed

    Vaughn, Dawn; Strathmann, Richard R

    2008-03-14

    Asexual propagation (cloning) is a widespread reproductive strategy of plants and animals. Although larval cloning is well documented in echinoderms, identified stimuli for cloning are limited to those associated with conditions favorable for growth and reproduction. Our research shows that larvae of the sand dollar Dendraster excentricus also clone in response to cues from predators. Predator-induced clones were smaller than uncloned larvae, suggesting an advantage against visual predators. Our results offer another ecological context for asexual reproduction: rapid size reduction as a defense.

  9. Entomopathogenic nematodes, root weevil larvae, and dynamic interactions among soil texture, plant growth, herbivory, and predation.

    PubMed

    El-Borai, Fahiem E; Stuart, Robin J; Campos-Herrera, Raquel; Pathak, Ekta; Duncan, Larry W

    2012-01-01

    Greenhouse experiments were conducted to assess the influence of soil texture on the persistence, efficacy and plant protection ability of entomopathogenic nematodes (EPNs) applied to control larvae of the Diaprepes root weevil (DRW), Diaprepes abbreviatus, infesting potted citrus seedlings. Seedlings were grown in pots containing either coarse sand, fine sand, or sandy loam. Three DRW larvae were added to each of 80 pots of each soil type. 24 h later, 20 pots of each soil type that had received weevil larvae were inoculated with EPN infective juveniles (IJs) of one of the following species: Steinernema diaprepesi, Steinernema riobrave and Heterorhabditis indica. Pots of each soil without EPNs were established as controls with DRW and controls without DRWs. Subsequently, pots with larvae received three additional larvae monthly, and the experiment continued for 9 months. Plant root and top weights at the end of the experiment were affected by both soil (P≤0.0001) and nematodes (P≤0.0001), and nematode species protected plants differently in different soils (interaction P≤0.0001). Soil porosity was inversely related to plant damage by DRW, whether or not EPNs were present; and porosity was directly related to the level of plant protection by EPNs. Mortality of caged sentinel weevil larvae placed in pots near the end of the experiment was highest in pots treated with S. diaprepesi. In a second, similar experiment that included an additional undescribed steinernematid of the Steinernema glaseri-group, soil type affected root damage by DRW and root protection by EPNs in the same manner as in the first experiment. Final numbers of S. diaprepesi and Steinernema sp. as measured by real-time PCR were much greater than those of S. riobrave or H. indica in all soils. Across all treatments, the number of weevil larvae in soil at the end the experiment was inversely related to soil porosity. In all soils, fewer weevil larvae survived in soil treated with S. diaprepesi or

  10. Pathogenesis of Helicosporidium sp. (Chlorophyta: Trebouxiophyceae) in susceptible noctuid larvae.

    PubMed

    Bläske-Lietze, Verena-Ulrike; Boucias, Drion G

    2005-11-01

    Helicosporidium sp. is a unique, achlorophyllous green alga that has been reported to infect various insect orders, including Lepidoptera, Diptera, and Coleoptera. The infectious cyst stage is ingested by the host, ruptures in the midgut lumen, and releases a filamentous cell. Histopathological examinations using larvae of a susceptible noctuid host, Spodoptera exigua, showed both cysts and filamentous cells affiliated with the microvillar lining of the midgut epithelium. A considerable proportion of the ingested cysts (22-39%) were recovered in feces collected 24 h after ingestion. A small number of filamentous cells passed the midgut epithelium and entered the hemocoel within 4-24 h after cyst ingestion. After 48 h, vegetative cell stages were detected in the hemolymph, followed by a 4- to 5-day period of increasing multiplication. Cyst differentiation in the colonized hemolymph began 6-7 days after the treatment.

  11. Attraction to and learning from social cues in fruitfly larvae.

    PubMed

    Durisko, Zachary; Dukas, Reuven

    2013-09-22

    We examined the use of social information in fruitfly larvae, which represent an ideal model system owing to their robust learning abilities, small number of neurons and well-studied neurogenetics. Focal larvae showed attraction to the distinct odour emanating from food occupied by other larvae. In controlled learning experiments, focal larvae preferred novel odours previously paired with food occupied by other larvae over novel odours previously paired with unoccupied food. When we gave groups of larvae a choice between food patches differing in quality, more larvae aggregated on the higher-quality food, suggesting that attraction to and learning about cues associated with other larvae can be beneficial. Furthermore, larvae were more likely to find the best available food patch in trials when that food patch was occupied by other larvae than in trials when that food patch was unoccupied. Our data suggest, however, that the benefits from joining others may be at least partially offset by the fitness costs of increased competition, because larvae reared in isolation did as well as or better than larvae reared in groups on three key fitness parameters: developmental rate, survival rate and adult dry body mass. Our work establishes fruitfly larvae as a highly tractable model species for further research on the mechanisms that modulate behaviour and learning in a social context.

  12. The Effect of an Eextremely Low Frequency Magnetic Field on Larvae Production in the Parasite-Host System: Fasciola hepatica-Galba truncatula: a Preliminary Study.

    PubMed

    Kołodziejczyk, Lidia; Podraza, Wojciech; Gonet, Bolesław; Dzika, Ewa; Kosik-Bogacka, Danuta I

    2016-01-01

    The aim of this study was to determine the effect of an extremely low-frequency magnetic field (ELFMF) on the production of liver fluke larvae in a parasite-host system: Fasciola hepatica--Galba truncatula. Both F. hepatica eggs and F. hepatica-infected snails were exposed to an ELFMF (50 Hz, 2.0 mT) for 14 days and 36 days, respectively. F. hepatica-infected snails were divided into 4 groups, 10 specimens each. The snails of groups I and II were infected with F. hepatica larvae--miracidia obtained from control cultures, while the snails of groups III and IV were infected with miracidia reared from eggs that had been incubated in an ELFMF. After infection, the snails of groups II and IV were placed in an ELFMF, while those of groups I (control) and III were housed outside the ELFMF. At 36 days post-infection (dpi) there were no statistically significant differences between the number of F. hepatica larvae--cercariae and metacercariae, obtained from G. truncatula snails in the control group (group I) and the snail groups exposed to ELFMF (groups II, III and IV). However, a statistically significant difference between the average number of F. hepatica larvae in snail groups III and IV may indicate that the duration of exposure to ELFMF, i.e. embryogenesis period vs. the entire larval development, played a role in the production of F. hepatica larvae, and resulted in a reduction of their number.

  13. Suppressing bullfrog larvae with carbon dioxide

    USGS Publications Warehouse

    Gross, Jackson A.; Ray, Andrew; Sepulveda, Adam J.; Watten, Barnaby J.; Densmore, Christine L.; Layhee, Megan J.; Mark Abbey-Lambert,; ,

    2014-01-01

    Current management strategies for the control and suppression of the American Bullfrog (Lithobates catesbeianus = Rana catesbeiana Shaw) and other invasive amphibians have had minimal effect on their abundance and distribution. This study evaluates the effects of carbon dioxide (CO2) on pre- and prometamorphic Bullfrog larvae. Bullfrogs are a model organism for evaluating potential suppression agents because they are a successful invader worldwide. From experimental trials we estimated that the 24-h 50% and 99% lethal concentration (LC50 and LC99) values for Bullfrog larvae were 371 and 549 mg CO2/L, respectively. Overall, larvae that succumbed to experimental conditions had a lower body condition index than those that survived. We also documented sublethal changes in blood chemistry during prolonged exposure to elevated CO2. Specifically, blood pH decreased by more than 0.5 pH units after 9 h of exposure and both blood partial pressure of CO2 (pCO2) and blood glucose increased. These findings suggest that CO2 treatments can be lethal to Bullfrog larvae under controlled laboratory conditions. We believe this work represents the necessary foundation for further consideration of CO2 as a potential suppression agent for one of the most harmful invaders to freshwater ecosystems.

  14. Evolution of foraging behavior in Drosophilid larvae

    NASA Astrophysics Data System (ADS)

    Rivera-Alba, Marta; Kabra, Mayank; Branson, Kristin; Mirth, Christen

    2015-03-01

    Drosophilids, like other insects, go through a larval phase before metamorphosing into adults. Larvae increase their body weight by several orders of magnitude in a few days. We therefore hypothesized that foraging behavior is under strong evolutionary pressure to best fit the larval environment. To test our hypothesis we used a multidisciplinary approach to analyze foraging behavior across species and larval stages. First, we recorded several videos of larvae foraging for each of 47 Drosophilid species. Then, using a supervised machine learning approach, we automatically annotated the video collection for the foraging sub-behaviors, including crawling, turning, head casting or burrowing. We also computed over 100 features to describe the posture and dynamics of each animal in each video frame. From these data, we fit models to the behavior of each species. The models each had the same parametric form, but differed in the exact parameters. By simulating larva behavior in virtual arenas we can infer which properties of the environments are better for each species. Comparisons between these inferred environments and the actual environments where these animals live will give us a deeper understanding about the evolution of foraging behavior in Drosophilid larvae.

  15. Helminth and leech community structure in tadpoles and caudatan larvae of two amphibian species from Western Nebraska.

    PubMed

    Rhoden, Heather R; Bolek, Matthew G

    2012-04-01

    Currently no comparative studies exist on helminth and leech community structure among sympatric anuran tadpoles and salamander larvae. During June-August 2007-2009, we examined 50 bullfrog tadpoles, Rana catesbeiana , 50 barred tiger salamander larvae, Ambystoma mavortium , and 3 species of snails from Nevens Pond, Keith County, Nebraska for helminth and leech infections. The helminth and leech compound community of this larval amphibian assemblage consisted of at least 7 species, 4 in bullfrog tadpoles and 4 in barred tiger salamander larvae. Bullfrog tadpoles were infected with 2 species of nematodes ( Gyrinicola batrachiensis and Spiroxys sp.) and 2 types of metacercariae ( Telorchis sp. and echinostomatids), whereas barred tiger salamander larva were infected with 1 species of leech ( Placobdella picta ), 2 species of adult trematodes ( Telorchis corti and Halipegus sp.), and 1 species of an unidentified metacercaria. The component community of bullfrog tadpoles was dominated by helminths acquired through active penetration, or incidentally ingested through respiratory currents, or both, whereas the component community of larval salamanders was dominated by helminths acquired through ingestion of intermediate hosts (χ²  =  3,455.00, P < 0.00001). Differences in amphibian larval developmental time (2-3 yr for bullfrog tadpoles versus 2-5 mo for salamander larvae), the ephemeral nature of intermediate hosts in Nevens Pond, and the ability of bullfrog tadpole to eliminate echinostome infections had significant effects on mean helminth species richness among amphibian species and years (t  =  12.31, P < 0.0001; t  =  2.09, P  =  0.04). Differences in herbivorous and carnivorous diet and time to metamorphosis among bullfrog tadpoles and barred tiger salamander larvae were important factors in structuring helminth communities among the larval stages of these 2 sympatric amphibian species, whereas size was important in structuring helminth and leech

  16. Survival of Campylobacter spp. in darkling beetles (Alphitobius diaperinus) and their larvae in Australia.

    PubMed

    Templeton, Jillian M; De Jong, Amanda J; Blackall, P J; Miflin, Jeanette K

    2006-12-01

    Campylobacter infection is the most frequently reported notifiable food-borne disease in humans in Australia. Our studies investigated the persistence of Campylobacter spp. in or on darkling beetles (Alphitobius diaperinus) and their larvae. Our results in analyses with chickens confirm that, unless very short turnaround times are used (<72 h), beetles colonized in one production cycle (i.e., one batch of chickens) are most unlikely to still be colonized during the next cycle of chickens.

  17. Survival of Campylobacter spp. in Darkling Beetles (Alphitobius diaperinus) and Their Larvae in Australia▿

    PubMed Central

    Templeton, Jillian M.; De Jong, Amanda J.; Blackall, P. J.; Miflin, Jeanette K.

    2006-01-01

    Campylobacter infection is the most frequently reported notifiable food-borne disease in humans in Australia. Our studies investigated the persistence of Campylobacter spp. in or on darkling beetles (Alphitobius diaperinus) and their larvae. Our results in analyses with chickens confirm that, unless very short turnaround times are used (<72 h), beetles colonized in one production cycle (i.e., one batch of chickens) are most unlikely to still be colonized during the next cycle of chickens. PMID:17012593

  18. Appetitive associative olfactory learning in Drosophila larvae.

    PubMed

    Apostolopoulou, Anthi A; Widmann, Annekathrin; Rohwedder, Astrid; Pfitzenmaier, Johanna E; Thum, Andreas S

    2013-02-18

    In the following we describe the methodological details of appetitive associative olfactory learning in Drosophila larvae. The setup, in combination with genetic interference, provides a handle to analyze the neuronal and molecular fundamentals of specifically associative learning in a simple larval brain. Organisms can use past experience to adjust present behavior. Such acquisition of behavioral potential can be defined as learning, and the physical bases of these potentials as memory traces. Neuroscientists try to understand how these processes are organized in terms of molecular and neuronal changes in the brain by using a variety of methods in model organisms ranging from insects to vertebrates. For such endeavors it is helpful to use model systems that are simple and experimentally accessible. The Drosophila larva has turned out to satisfy these demands based on the availability of robust behavioral assays, the existence of a variety of transgenic techniques and the elementary organization of the nervous system comprising only about 10,000 neurons (albeit with some concessions: cognitive limitations, few behavioral options, and richness of experience questionable). Drosophila larvae can form associations between odors and appetitive gustatory reinforcement like sugar. In a standard assay, established in the lab of B. Gerber, animals receive a two-odor reciprocal training: A first group of larvae is exposed to an odor A together with a gustatory reinforcer (sugar reward) and is subsequently exposed to an odor B without reinforcement. Meanwhile a second group of larvae receives reciprocal training while experiencing odor A without reinforcement and subsequently being exposed to odor B with reinforcement (sugar reward). In the following both groups are tested for their preference between the two odors. Relatively higher preferences for the rewarded odor reflect associative learning--presented as a performance index (PI). The conclusion regarding the associative

  19. Carabid larvae as predators of weed seeds: granivory in larvae of Amara eurynota (Coleoptera: Carabidae).

    PubMed

    Saska, Pavel

    2004-01-01

    Up to date we do not have much information about predation on seeds by larvae of ground beetles. One of the reasons why such knowledge is important is that granivorous larvae contribute to predation of weed seeds. In this study, the food requirements of larvae of autumn breeding carabid species Amara eurynota (Panzer) were investigated in the laboratory and a hypothesis, that they are granivorous was tested. Insect diet (Tenebrio molitor larvae), three seed diets (seeds of Artemisia vulgaris, Tripleurospermum inodorum or Urtica dioica or a mixed diet (T. molitor + A. uulgaris) were used as food. For larvae of A. eurynota, seeds are essential for successful completion of development, because all those fed pure insect diet died before pupation. However, differences in suitability were observed between pure seed diets. Larvae fed seeds of A. vulgaris had the lowest mortality and fastest development of the seed diets. Those fed seeds of T. inodorum had also low mortality, but the development was prolonged in the third instar. In contrast, development of larvae reared on seeds of U. dioica was slowest of the tested diets and could not be completed, as all individuals died before pupation. When insects were included to seed diet of A. vulgaris (mixed diet), the duration of development shortened, but mortality remained the same when compared to seed diet of A. vulgaris. According to the results it was concluded that larvae of A. eurynota are granivorous. A mixed diet and seed diets of A. uulgaris and T. inodorum were suitable and insect diet and seeds of U. dioica were unsuitable diets in this experiment.

  20. Molecular typing of Paenibacillus larvae strains isolated from Bulgarian apiaries based on repetitive element polymerase chain reaction (Rep-PCR).

    PubMed

    Rusenova, Nikolina; Parvanov, Parvan; Stanilova, Spaska

    2013-06-01

    The aim of the present study was to perform molecular typing of Paenibacillus larvae (P. larvae) isolates from Bulgarian apiaries with repetitive element polymerase chain reaction (rep-PCR) using BOX A1R, MBO REP1, and ERIC primers. A total of 96 isolates collected from brood combs with clinical symptoms of American foulbrood originating from apiaries located in different geographical regions of Bulgaria, a reference strain P. larvae NBIMCC 8478 and 30 commercial honey samples with Bulgarian origin were included in the study. Rep-PCR fingerprinting analysis revealed two genotypes ab and AB of P. larvae isolates from brood combs and honey samples. A combination of genotypes ab/AB was detected in one apiary and honey sample. The prevailing genotype ab was found in 78.1 % of brood combs isolates as well as in the reference strain whereas genotype AB was determined in 21.9 % of isolates. The examination of honey samples confirmed the preponderance of ab genotype which was demonstrated in 20 of 30 samples analyzed. In conclusion, the genetic epidemiology of P. larvae revealed two genotypes--ab and AB for Bulgarian strains. Developed protocols for molecular typing of P. larvae are reliable and may be used to trace the source of infection.

  1. A Systems Biology Approach to the Characterization of Stress Response in Dermacentor reticulatus Tick Unfed Larvae

    PubMed Central

    Villar, Margarita; Popara, Marina; Ayllón, Nieves; Fernández de Mera, Isabel G.; Mateos-Hernández, Lourdes; Galindo, Ruth C.; Manrique, Marina; Tobes, Raquel; de la Fuente, José

    2014-01-01

    Background Dermacentor reticulatus (Fabricius, 1794) is distributed in Europe and Asia where it infests and transmits disease-causing pathogens to humans, pets and other domestic and wild animals. However, despite its role as a vector of emerging or re-emerging diseases, very little information is available on the genome, transcriptome and proteome of D. reticulatus. Tick larvae are the first developmental stage to infest hosts, acquire infection and transmit pathogens that are transovarially transmitted and are exposed to extremely stressing conditions. In this study, we used a systems biology approach to get an insight into the mechanisms active in D. reticulatus unfed larvae, with special emphasis on stress response. Principal Findings The results support the use of paired end RNA sequencing and proteomics informed by transcriptomics (PIT) for the analysis of transcriptomics and proteomics data, particularly for organisms such as D. reticulatus with little sequence information available. The results showed that metabolic and cellular processes involved in protein synthesis were the most active in D. reticulatus unfed larvae, suggesting that ticks are very active during this life stage. The stress response was activated in D. reticulatus unfed larvae and a Rickettsia sp. similar to R. raoultii was identified in these ticks. Significance The activation of stress responses in D. reticulatus unfed larvae likely counteracts the negative effect of temperature and other stress conditions such as Rickettsia infection and favors tick adaptation to environmental conditions to increase tick survival. These results show mechanisms that have evolved in D. reticulatus ticks to survive under stress conditions and suggest that these mechanisms are conserved across hard tick species. Targeting some of these proteins by vaccination may increase tick susceptibility to natural stress conditions, which in turn reduce tick survival and reproduction, thus reducing tick populations and

  2. Experimental exposure of Artemia to hepatopancreatic parvo-like virus and subsequent transmission to post-larvae of Penaeus monodon.

    PubMed

    Sivakumar, V K; Sarathi, M; Venkatesan, C; Sivaraj, A; Hameed, A S Sahul

    2009-11-01

    The different life stages of Artemia franciscana were experimentally exposed to Hepatopancreatic parvo-like virus (HPV), in order to evaluate the possibility of Artemia acting as reservoir or carrier for HPV. All the five developmental stages of Artemia were challenged with HPV both by immersion and oral infection routes. The viral infectivity to Artemia was studied by PCR but not much difference in mortality between control and challenge groups were observed. To confirm the vector status of Artemia for HPV, the HPV exposed Artemia were fed to postlarval forms of Penaeus monodon. Post-larvae of P. monodon were fed with HPV exposed Artemia and could get infected upon feeding on them. Mortality was observed in the post-larvae, which were fed with HPV exposed Artemia, and whereas no mortality was observed in post-larvae fed with Artemia not exposed to HPV and these post-larvae were PCR negative for HPV, as well. Results of this experiment suggest that Artemia might be a possible horizontal transmission pathway for HPV. Further research however is required with histology, immunohistochemistry and transmission electron microcopy to determine whether the Artemia are actually infected with this virus or whether they are simply mechanical carriers. This will enable us to understand better whether Artemia is a carrier of this virus and if so the mechanism involved.

  3. [Larvae of barnacles (Cirripedia: Thoracica) in the White sea plankton].

    PubMed

    Poltarukha, O P

    2003-01-01

    The barnacle fauna in the White Sea is briefly described. The morphology of barnacle larvae in this water body is comparatively analyzed. The characters important for the larvae identification are given particular attention. A classification key was developed for the nauplius and cyprid larvae of barnacles in the White Sea.

  4. Workbook on the Identification of Anopheles Larvae. Preliminary Issue.

    ERIC Educational Resources Information Center

    Pratt, Harry D.; Stojanovich, Chester J.

    This self-instructional booklet is designed to enable malarial control workers to identify the larvae of "Anopheles" species that are important malaria vectors. The morphological features of the larvae are illustrated in a programed booklet, which also contains an illustrated taxonomic key to 25 species of anopheline larvae. A glossary and a short…

  5. An Introduction to the Identification of Chironomid Larvae.

    ERIC Educational Resources Information Center

    Mason, William T., Jr.

    This publication is an introductory guide to the identification of Chironomid (Midge) larvae. The larvae of these small flies are an important link in the food chain between algae and microinvertebrates. As a family, the larvae exhibit a wide range of tolerance to environmental factors such as amounts and types of pollutants. Much of this…

  6. Release of Lungworm Larvae from Snails in the Environment: Potential for Alternative Transmission Pathways

    PubMed Central

    Giannelli, Alessio; Colella, Vito; Abramo, Francesca; do Nascimento Ramos, Rafael Antonio; Falsone, Luigi; Brianti, Emanuele; Varcasia, Antonio; Dantas-Torres, Filipe; Knaus, Martin; Fox, Mark T.; Otranto, Domenico

    2015-01-01

    Background Gastropod-borne parasites may cause debilitating clinical conditions in animals and humans following the consumption of infected intermediate or paratenic hosts. However, the ingestion of fresh vegetables contaminated by snail mucus and/or water has also been proposed as a source of the infection for some zoonotic metastrongyloids (e.g., Angiostrongylus cantonensis). In the meantime, the feline lungworms Aelurostrongylus abstrusus and Troglostrongylus brevior are increasingly spreading among cat populations, along with their gastropod intermediate hosts. The aim of this study was to assess the potential of alternative transmission pathways for A. abstrusus and T. brevior L3 via the mucus of infected Helix aspersa snails and the water where gastropods died. In addition, the histological examination of snail specimens provided information on the larval localization and inflammatory reactions in the intermediate host. Methodology/Principal Findings Twenty-four specimens of H. aspersa received ~500 L1 of A. abstrusus and T. brevior, and were assigned to six study groups. Snails were subjected to different mechanical and chemical stimuli throughout 20 days in order to elicit the production of mucus. At the end of the study, gastropods were submerged in tap water and the sediment was observed for lungworm larvae for three consecutive days. Finally, snails were artificially digested and recovered larvae were counted and morphologically and molecularly identified. The anatomical localization of A. abstrusus and T. brevior larvae within snail tissues was investigated by histology. L3 were detected in the snail mucus (i.e., 37 A. abstrusus and 19 T. brevior) and in the sediment of submerged specimens (172 A. abstrusus and 39 T. brevior). Following the artificial digestion of H. aspersa snails, a mean number of 127.8 A. abstrusus and 60.3 T. brevior larvae were recovered. The number of snail sections positive for A. abstrusus was higher than those for T. brevior

  7. Paenibacillus larvae chitin-degrading protein PlCBP49 is a key virulence factor in American Foulbrood of honey bees.

    PubMed

    Garcia-Gonzalez, Eva; Poppinga, Lena; Fünfhaus, Anne; Hertlein, Gillian; Hedtke, Kati; Jakubowska, Agata; Genersch, Elke

    2014-07-01

    Paenibacillus larvae, the etiological agent of the globally occurring epizootic American Foulbrood (AFB) of honey bees, causes intestinal infections in honey bee larvae which develop into systemic infections inevitably leading to larval death. Massive brood mortality might eventually lead to collapse of the entire colony. Molecular mechanisms of host-microbe interactions in this system and of differences in virulence between P. larvae genotypes are poorly understood. Recently, it was demonstrated that the degradation of the peritrophic matrix lining the midgut epithelium is a key step in pathogenesis of P. larvae infections. Here, we present the isolation and identification of PlCBP49, a modular, chitin-degrading protein of P. larvae and demonstrate that this enzyme is crucial for the degradation of the larval peritrophic matrix during infection. PlCBP49 contains a module belonging to the auxiliary activity 10 (AA10, formerly CBM33) family of lytic polysaccharide monooxygenases (LPMOs) which are able to degrade recalcitrant polysaccharides. Using chitin-affinity purified PlCBP49, we provide evidence that PlCBP49 degrades chitin via a metal ion-dependent, oxidative mechanism, as already described for members of the AA10 family. Using P. larvae mutants lacking PlCBP49 expression, we analyzed in vivo biological functions of PlCBP49. In the absence of PlCBP49 expression, peritrophic matrix degradation was markedly reduced and P. larvae virulence was nearly abolished. This indicated that PlCBP49 is a key virulence factor for the species P. larvae. The identification of the functional role of PlCBP49 in AFB pathogenesis broadens our understanding of this important family of chitin-binding and -degrading proteins, especially in those bacteria that can also act as entomopathogens.

  8. Paenibacillus larvae Chitin-Degrading Protein PlCBP49 Is a Key Virulence Factor in American Foulbrood of Honey Bees

    PubMed Central

    Garcia-Gonzalez, Eva; Poppinga, Lena; Fünfhaus, Anne; Hertlein, Gillian; Hedtke, Kati; Jakubowska, Agata; Genersch, Elke

    2014-01-01

    Paenibacillus larvae, the etiological agent of the globally occurring epizootic American Foulbrood (AFB) of honey bees, causes intestinal infections in honey bee larvae which develop into systemic infections inevitably leading to larval death. Massive brood mortality might eventually lead to collapse of the entire colony. Molecular mechanisms of host-microbe interactions in this system and of differences in virulence between P. larvae genotypes are poorly understood. Recently, it was demonstrated that the degradation of the peritrophic matrix lining the midgut epithelium is a key step in pathogenesis of P. larvae infections. Here, we present the isolation and identification of PlCBP49, a modular, chitin-degrading protein of P. larvae and demonstrate that this enzyme is crucial for the degradation of the larval peritrophic matrix during infection. PlCBP49 contains a module belonging to the auxiliary activity 10 (AA10, formerly CBM33) family of lytic polysaccharide monooxygenases (LPMOs) which are able to degrade recalcitrant polysaccharides. Using chitin-affinity purified PlCBP49, we provide evidence that PlCBP49 degrades chitin via a metal ion-dependent, oxidative mechanism, as already described for members of the AA10 family. Using P. larvae mutants lacking PlCBP49 expression, we analyzed in vivo biological functions of PlCBP49. In the absence of PlCBP49 expression, peritrophic matrix degradation was markedly reduced and P. larvae virulence was nearly abolished. This indicated that PlCBP49 is a key virulence factor for the species P. larvae. The identification of the functional role of PlCBP49 in AFB pathogenesis broadens our understanding of this important family of chitin-binding and -degrading proteins, especially in those bacteria that can also act as entomopathogens. PMID:25080221

  9. Larva of Palaemnema brasiliensis Machado (Odonata: Platystictidae), from Amazonas, Brazil.

    PubMed

    Neiss, Ulisses Gaspar; Hamada, Neusa

    2016-02-09

    The larva of Palaemnema brasiliensis Machado, 2009 is described and illustrated based on last-instar larvae and exuviae of reared larvae collected in a blackwater stream in Barcelos and Presidente Figueiredo municipalities, Amazonas state, Brazil. The larva of P. brasiliensis can be distinguished from the two South American species of the genus with described larvae (P. clementia Selys and P. mutans Calvert), mainly by presence of a single obtuse cusp on the labial palp, the presence and configuration of setae in the caudal lamellae, and the proportional length of terminal filaments of the caudal lamellae. The family is recorded here for the first time in Brazilian state of Amazonas.

  10. Gram-Negative Bacterial Wound Infections

    DTIC Science & Technology

    2014-05-01

    Infections PRINCIPAL INVESTIGATOR: Luis A. Actis CONTRACTING ORGANIZATION: Miami University, Oxford, OH 45056 REPORT DATE: May 2014...SUBTITLE Gram-negative bacterial wound infections 5a. CONTRACT NUMBER W81XWH-12-2-0035 5b. GRANT NUMBER W81XWH-12-2-0035 5c. PROGRAM...laboratory conditions as well as to infect and kill G. mellonella larvae and BALB/c mice in experimental infection assays. These results validate

  11. Novel circular DNA viruses identified in Procordulia grayi and Xanthocnemis zealandica larvae using metagenomic approaches.

    PubMed

    Dayaram, Anisha; Galatowitsch, Mark; Harding, Jon S; Argüello-Astorga, Gerardo R; Varsani, Arvind

    2014-03-01

    Recent advances in sequencing and metagenomics have enabled the discovery of many novel single stranded DNA (ssDNA) viruses from various environments. We have previously demonstrated that adult dragonflies, as predatory insects, are useful indicators of ssDNA viruses in terrestrial ecosystems. Here we recover and characterise 13 viral genomes which represent 10 novel and diverse circular replication associated protein (Rep)-encoding single stranded (CRESS) DNA viruses (1628-2668nt) from Procordulia grayi and Xanthocnemis zealandica dragonfly larvae collected from four high-country lakes in the South Island of New Zealand. The dragonfly larvae associated CRESS DNA viruses have different genome architectures, however, they all encode two major open reading frames (ORFs) which either have bidirectional or unidirectional arrangement. The 13 viral genomes have a conserved NAGTATTAC nonanucleotide motif and in their predicted Rep proteins we identified the rolling circle replication (RCR) motif 1, 2 and 3, as well as superfamily 3 (SF3) helicase motifs. Maximum likelihood phylogenetic and pairwise identity analysis of the Rep amino acid sequences reveal that the dragonfly larvae novel CRESS DNA viruses share <63% pairwise amino acid identity to the Reps of other CRESS DNA viruses whose complete genomes have been determined and available in public databases and that these viruses are novel. CRESS DNA viruses are circulating in larval dragonfly populations; however, we are unable to ascertain whether these viruses are infecting the larvae directly or are transient within dragonflies via their diet.

  12. Occurrence and Intensity of Anisakid Nematode Larvae in Some Commercially Important Fish Species in Persian Gulf

    PubMed Central

    DADAR, Maryam; ALBORZI, Alireza; PEYGHAN, Rahim; ADEL, Milad

    2016-01-01

    Background: Anisakid nematodes are common parasites of fish, mammals, fish-eating birds, and reptiles with a worldwide distribution, causing diseases in human, fish and important economic losses. Methods: A preliminary epidemiological study was carried out on Anisakid nematodes larvae in some commercially important fish species to evaluate the anisakid nematode larvae from greater lizardfish, (Saurida tumbil), Japanese thread fin bream (Nemipterus japonicus), crocodile longtom (Tylosurus crocodilus crocodiles) and longfin trevally (Carangoides armatus) from the Persian Gulf of Iran. Results: The collected larvae were identified mainly as the third larval stage (L3) of Hysterothylacium larval type A, B and C, Anisakis sp., Raphidascaris sp., Pseudoterranova sp. and Philometra sp. (Nematoda: Philometridae). The prevalence of Anisakid larvae infection of examined fishes was 97.2% in N. japonicus, 90.3% in S. tumbil, 20.5% in crocodile longtom and 5.5% in longfin trevally. Anisakis type III for the first time was different from Anisakis type I and Anisakis type II. Discussion: Zoonotic anisakids by high prevalence in edible fish could be a health hazard for people. So health practices should be considered in these areas. PMID:28096859

  13. Growth and development of Brugia pahangi larvae under various in vitro conditions.

    PubMed

    Wisnewski, N; Weinstein, P P

    1993-06-01

    In vitro culture methods were utilized to investigate specific nutritional requirements of Brugia pahangi larvae. Infective third-stage larvae (L3) isolated from Aedes aegypti (Liverpool) mosquitoes were cultured in NCTC 135:IMDM (NI) medium plus various types of serum under 5% CO2/air and 5% CO2/N2 atmospheres. Larvae grew, developed, and molted to the fourth stage (L4); however, further growth and differentiation beyond the mid-L4 were minimal. Serum supplementation was necessary to induce molting of B. pahangi L3s. Iron-supplemented calf serum (FeCS) consistently promoted higher percentages of molting than the other 4 types of serum tested. Specific nutritional requirements for B. pahangi larvae were assessed through testing of supplements known to be important for growth of mammalian cells or other parasites in vitro. Addition of various concentrations and combinations of hemoglobin, insulin, transferrin, selenium, albumin, cholesterol, or a cell feeder layer did not improve larval growth, molting, or survival compared to that obtained with FeCS alone. The L4s derived from in vitro culture, when injected intraperitoneally into jirds, developed to sexually mature, microfilarial-producing adults in a normal in vivo time frame. Developing L4s isolated from jirds molted to young adults in vitro in NI medium plus serum.

  14. Predatory cannibalism in Drosophila melanogaster larvae.

    PubMed

    Vijendravarma, Roshan K; Narasimha, Sunitha; Kawecki, Tadeusz J

    2013-01-01

    Hunting live prey is risky and thought to require specialized adaptations. Therefore, observations of predatory cannibalism in otherwise non-carnivorous animals raise questions about its function, adaptive significance and evolutionary potential. Here we document predatory cannibalism on larger conspecifics in Drosophila melanogaster larvae and address its evolutionary significance. We found that under crowded laboratory conditions younger larvae regularly attack and consume 'wandering-stage' conspecifics, forming aggregations mediated by chemical cues from the attacked victim. Nutrition gained this way can be significant: an exclusively cannibalistic diet was sufficient for normal development from eggs to fertile adults. Cannibalistic diet also induced plasticity of larval mouth parts. Finally, during 118 generations of experimental evolution, replicated populations maintained under larval malnutrition evolved enhanced propensity towards cannibalism. These results suggest that, at least under laboratory conditions, predation on conspecifics in Drosophila is a functional, adaptive behaviour, which can rapidly evolve in response to nutritional conditions.

  15. Infectivity and egg production of Nematospiroides dubius as affected by space flight and ultraviolet irradiation

    NASA Technical Reports Server (NTRS)

    Long, R. A.; Ellis, W. L.; Taylor, G. R.

    1973-01-01

    Nematospiroides dubius was tested to determine the infective potential of the third stage larvae and the egg-production and egg-viability rates of the resulting adults after they are exposed to space flight and solar ultraviolet irradiation. The results are indicative that space-flown larvae exposed to solar ultraviolet irradiation were rendered noninfective in C57 mice, whereas flight control larvae that received no solar ultraviolet irradiation matured at the same rate as the ground control larvae. However, depressed egg viability was evident in the flight control larvae.

  16. Undescribed Setae in Larvae of Culicidae (Diptera)

    DTIC Science & Technology

    1974-03-01

    ABSTRACT. An unnamed pair of setae (two pairs in some species groups) on the larval cervical membrane in all genera of Culicidae examined is des- cribed...ventrolat- era1 seta was noted on the cervical membrane by the senior author. Further research confirmed its presence in all culicid genera for...referred to them as cervical hairs and recorded their length and branching in third and fourth stage larvae of the four Aedes species he studied

  17. Metarhizium brunneum Blastospore Pathogenesis in Aedes aegypti Larvae: Attack on Several Fronts Accelerates Mortality

    PubMed Central

    Alkhaibari, Abeer M.; Carolino, Aline T.; Yavasoglu, Sare I.; Maffeis, Thierry; Mattoso, Thalles C.; Bull, James C.; Samuels, Richard I.; Butt, Tariq M.

    2016-01-01

    Aedes aegypti is the vector of a wide range of diseases (e.g. yellow fever, dengue, Chikungunya and Zika) which impact on over half the world’s population. Entomopathogenic fungi such as Metarhizium anisopliae and Beauveria bassiana have been found to be highly efficacious in killing mosquito larvae but only now are the underlying mechanisms for pathogenesis being elucidated. Recently it was shown that conidia of M. anisopliae caused stress induced mortality in Ae. aegypti larvae, a different mode of pathogenicity to that normally seen in terrestrial hosts. Blastospores constitute a different form of inoculum produced by this fungus when cultured in liquid media and although blastospores are generally considered to be more virulent than conidia no evidence has been presented to explain why. In our study, using a range of biochemical, molecular and microscopy methods, the infection process of Metarhizium brunneum (formerly M. anisopliae) ARSEF 4556 blastospores was investigated. It appears that the blastospores, unlike conidia, readily adhere to and penetrate mosquito larval cuticle. The blastospores are readily ingested by the larvae but unlike the conidia are able infect the insect through the gut and rapidly invade the haemocoel. The fact that pathogenicity related genes were upregulated in blastospores exposed to larvae prior to invasion, suggests the fungus was detecting host derived cues. Similarly, immune and defence genes were upregulated in the host prior to infection suggesting mosquitoes were also able to detect pathogen-derived cues. The hydrophilic blastospores produce copious mucilage, which probably facilitates adhesion to the host but do not appear to depend on production of Pr1, a cuticle degrading subtilisin protease, for penetration since protease inhibitors did not significantly alter blastospore virulence. The fact the blastospores have multiple routes of entry (cuticle and gut) may explain why this form of the inoculum killed Ae. aegypti

  18. Alteration of cytokine production during visceral larva migrans by Toxascaris leonina in mice.

    PubMed

    Kang, Shin Ae; Park, Mi-Kyung; Cho, Min Kyoung; Yu, Hak Sun

    2013-10-01

    To determine alteration of immune responses during visceral larva migrans (VLM) caused by Toxascaris leonina at several time points, we experimentally infected mice with embryonated eggs of T. leonina and measured T-helper (Th) cell-related serial cytokine production after infection. At day 5 post infection (PI), most larvae were detected from the lungs, spleen, intestine, and muscle. Expression of thymic stromal lymphopoietin (TSLP) and CCL11 (eotaxin) showed a significant increase in most infected organs, except the intestine. However, expression of the CXCL1 (Gro-α) gene was most highly enhanced in the intestine at day 14 PI. Th1-related cytokine secretion of splenocytes showed increases at day 28 PI, and the level showed a decrease at day 42 PI. Th2-related cytokine secretion of splenocytes also showed an increase after infection; in particular, IL-5 level showed a significant increase at day 14 PI, and the level showed a decrease at day 28 PI. However, levels of Th17-related cytokines, IL-6 and IL-17A, showed gradual increases until day 42 PI. In conclusion, Th1, Th2, and Th17-related cytokine production might be important in immune responses against T. leonina VLM in experimental mice.

  19. Alteration of Cytokine Production during Visceral Larva Migrans by Toxascaris leonina in Mice

    PubMed Central

    Kang, Shin Ae; Park, Mi-Kyung; Cho, Min Kyoung

    2013-01-01

    To determine alteration of immune responses during visceral larva migrans (VLM) caused by Toxascaris leonina at several time points, we experimentally infected mice with embryonated eggs of T. leonina and measured T-helper (Th) cell-related serial cytokine production after infection. At day 5 post infection (PI), most larvae were detected from the lungs, spleen, intestine, and muscle. Expression of thymic stromal lymphopoietin (TSLP) and CCL11 (eotaxin) showed a significant increase in most infected organs, except the intestine. However, expression of the CXCL1 (Gro-α) gene was most highly enhanced in the intestine at day 14 PI. Th1-related cytokine secretion of splenocytes showed increases at day 28 PI, and the level showed a decrease at day 42 PI. Th2-related cytokine secretion of splenocytes also showed an increase after infection; in particular, IL-5 level showed a significant increase at day 14 PI, and the level showed a decrease at day 28 PI. However, levels of Th17-related cytokines, IL-6 and IL-17A, showed gradual increases until day 42 PI. In conclusion, Th1, Th2, and Th17-related cytokine production might be important in immune responses against T. leonina VLM in experimental mice. PMID:24327787

  20. Visual learning in individually assayed Drosophila larvae.

    PubMed

    Gerber, B; Scherer, S; Neuser, K; Michels, B; Hendel, T; Stocker, R F; Heisenberg, M

    2004-01-01

    An understanding of associative learning is facilitated if it can be analyzed in a simple animal like the fruit fly Drosophila. Here, we introduce the first visual associative learning paradigm for larval Drosophila; this is remarkable as larvae have an order of magnitude fewer neurons than adult flies. Larvae were subjected to either of two reciprocal training regimes: Light+/Dark- or Light-/Dark+. Subsequently, all larvae were individually tested for their preference between Light versus Dark. The difference between training regimes was therefore exclusively which visual situation was associated with which reinforcer; differences observed during the test thus reflected exclusively associative learning. For positive reinforcement (+) we used fructose (FRU), and for negative reinforcement (-) either quinine or sodium chloride (QUI, NaCl). Under these conditions, associative learning could be reproducibly observed in both wild-type strains tested. We then compared the effectiveness of training using differential conditioning, with both positive and negative reinforcement, to that using only positive or only negative reinforcement. We found that FRU only, but neither QUI nor NaCl, was in itself effective as a reinforcer. This is the first demonstration of appetitive learning in larval Drosophila. It is now possible to investigate the behavioral and neuronal organization of appetitive visual learning in this simple and genetically easy-to-manipulate experimental system.

  1. Caffeine Taste Signaling in Drosophila Larvae

    PubMed Central

    Apostolopoulou, Anthi A.; Köhn, Saskia; Stehle, Bernhard; Lutz, Michael; Wüst, Alexander; Mazija, Lorena; Rist, Anna; Galizia, C. Giovanni; Lüdke, Alja; Thum, Andreas S.

    2016-01-01

    The Drosophila larva has a simple peripheral nervous system with a comparably small number of sensory neurons located externally at the head or internally along the pharynx to assess its chemical environment. It is assumed that larval taste coding occurs mainly via external organs (the dorsal, terminal, and ventral organ). However, the contribution of the internal pharyngeal sensory organs has not been explored. Here we find that larvae require a single pharyngeal gustatory receptor neuron pair called D1, which is located in the dorsal pharyngeal sensilla, in order to avoid caffeine and to associate an odor with caffeine punishment. In contrast, caffeine-driven reduction in feeding in non-choice situations does not require D1. Hence, this work provides data on taste coding via different receptor neurons, depending on the behavioral context. Furthermore, we show that the larval pharyngeal system is involved in bitter tasting. Using ectopic expressions, we show that the caffeine receptor in neuron D1 requires the function of at least four receptor genes: the putative co-receptors Gr33a, Gr66a, the putative caffeine-specific receptor Gr93a, and yet unknown additional molecular component(s). This suggests that larval taste perception is more complex than previously assumed already at the sensory level. Taste information from different sensory organs located outside at the head or inside along the pharynx of the larva is assembled to trigger taste guided behaviors. PMID:27555807

  2. Toxocara canis: potential activity of natural products against second-stage larvae in vitro and in vivo.

    PubMed

    Reis, Mariana; Trinca, Alcione; Ferreira, Maria José U; Monsalve-Puello, Ana R; Grácio, Maria Amélia A

    2010-10-01

    The anthelmintic activity of extracts from Chenopodiumambrosioides, Pycnanthusangolensis and Nutridesintox was in vitro and in vivo investigated, against Toxocaracanis larvae. The in vitro assays results showed that the aqueous extract of Nutridesintox was the most effective, followed by C. ambrosioides extracts, hexane, dichloromethane and the infusion. P. angolensis extracts showed a lower anthelmintic activity compared to the other natural products. For the in vivo assays, Nutridesintox, the hexane extract and the infusion of C. ambrosioides were administered orally to T. canis-infected mice, in single doses, during three consecutive days. The efficacy was evaluated on the 17th day post-infection, not only by counting T. canis larvae in the tissues but also by ELISA detection of IgM and IgG antibodies and histological analysis of liver and lungs. The different treatments did not reduce the larvae burden and had no influence on the antibodies dynamic. Interestingly, a reduction on the inflammatory infiltrates was observed in the liver and lung sections of the group treated with the hexane extract of C. ambrosioides. In conclusion, the hexane extract of C. ambrosioides is of further research interest, as it showed an anthelmintic activity in vitro and a reduction on the inflammatory reaction produced by the infection of T. canis larvae in vivo.

  3. Drosophila larvae: Thermal ecology in changing environments

    NASA Astrophysics Data System (ADS)

    Wang, George

    Temperature affects almost all aspects of life. Although much work has been done to assess the impact of temperature on organismal performance, relatively little is known about how organisms behaviorally regulate temperature, how these behaviors effect population fitness, or how changing climate may interact with these behaviors. I explore these questions with the model system Drosophila larvae. Larvae are small, with a low thermal mass and limited capacity for physiological thermoregulation. Mortality is generally high in larvae, with large potential impacts on population growth rate. Thus behavioral thermoregulation in larvae should be of critical selective importance. I present a review of the current knowledge of Drosophila thermal preference. I describe quantifiable thermoregulatory behaviors ( TMV and TW) unique to larvae. I show interspecific variation of these behaviors in Drosophila melanogaster and several close relatives, and intraspecific variation between populations collected from different environments. I also investigate these behaviors in two mutant lines, ssa and biz, to investigate the genetic basis of these behaviors. I show that larval thermoregulatory systems are independent of those of adults. Further these thermoregulatory behaviors differ between two sister species, D. yakuba and D. santomea. Although these two species readily hybridize in laboratory conditions, very few hybrids are observed in the field. The surprising result that hybrids of D. yakuba and D. santomea seem to inherit TMV from D. yakuba suggests a novel extrinsic isolation mechanism between the two species. I explore how fitness is the result of the interaction between genetics and the environment. I utilize Monte Carlo simulation to show how non-linear norms of reaction generate variation in populations even in the absence of behavior or epigenetic evolutionary mechanisms. Finally I investigate the global distribution of temperatures in which these organisms exist using

  4. Exposure of gnotobiotic Artemia franciscana larvae to abiotic stress promotes heat shock protein 70 synthesis and enhances resistance to pathogenic Vibrio campbellii

    PubMed Central

    Pineda, Carlos; MacRae, Thomas H.; Sorgeloos, Patrick; Bossier, Peter

    2008-01-01

    Larvae of the brine shrimp Artemia franciscana serve as important feed in fish and shellfish larviculture; however, they are subject to bacterial diseases that devastate entire populations and consequently hinder their use in aquaculture. Exposure to abiotic stress was shown previously to shield Artemia larvae against infection by pathogenic Vibrio, with the results suggesting a mechanistic role for heat shock protein 70. In the current report, combined hypothermic/hyperthermic shock followed by recovery at ambient temperature induced Hsp70 synthesis in Artemia larvae. Thermotolerance was also increased as was protection against infection by Vibrio campbellii, the latter indicated by reduced mortality and lower bacterial load in challenge tests. Resistance to Vibrio improved in the face of declining body mass as demonstrated by measurement of ash-free dry weight. Hypothermic stress only and acute osmotic insult did not promote Hsp70 expression and thermotolerance in Artemia larvae nor was resistance to Vibrio challenge augmented. The data support a causal link between Hsp70 accumulation induced by abiotic stress and enhanced resistance to infection by V. campbellii, perhaps via stimulation of the Artemia immune system. This possibility is now under investigation, and the work may reveal fundamental properties of crustacean immunity. Additionally, the findings are important in aquaculture where development of procedures to prevent bacterial infection of feed stock such as Artemia larvae is a priority. PMID:18347942

  5. Interactions among Drosophila larvae before and during collision

    PubMed Central

    Otto, Nils; Risse, Benjamin; Berh, Dimitri; Bittern, Jonas; Jiang, Xiaoyi; Klämbt, Christian

    2016-01-01

    In populations of Drosophila larvae, both, an aggregation and a dispersal behavior can be observed. However, the mechanisms coordinating larval locomotion in respect to other animals, especially in close proximity and during/after physical contacts are currently only little understood. Here we test whether relevant information is perceived before or during larva-larva contacts, analyze its influence on behavior and ask whether larvae avoid or pursue collisions. Employing frustrated total internal reflection-based imaging (FIM) we first found that larvae visually detect other moving larvae in a narrow perceptive field and respond with characteristic escape reactions. To decipher larval locomotion not only before but also during the collision we utilized a two color FIM approach (FIM2c), which allowed to faithfully extract the posture and motion of colliding animals. We show that during collision, larval locomotion freezes and sensory information is sampled during a KISS phase (german: Kollisions Induziertes Stopp Syndrom or english: collision induced stop syndrome). Interestingly, larvae react differently to living, dead or artificial larvae, discriminate other Drosophila species and have an increased bending probability for a short period after the collision terminates. Thus, Drosophila larvae evolved means to specify behaviors in response to other larvae. PMID:27511760

  6. The Identification of Congeners and Aliens by Drosophila Larvae.

    PubMed

    Del Pino, Francisco; Jara, Claudia; Pino, Luis; Medina-Muñoz, María Cristina; Alvarez, Eduardo; Godoy-Herrera, Raúl

    2015-01-01

    We investigated the role of Drosophila larva olfactory system in identification of congeners and aliens. We discuss the importance of these activities in larva navigation across substrates, and the implications for allocation of space and food among species of similar ecologies. Wild type larvae of cosmopolitan D. melanogaster and endemic D. pavani, which cohabit the same breeding sites, used species-specific volatiles to identify conspecifics and aliens moving toward larvae of their species. D. gaucha larvae, a sibling species of D. pavani that is ecologically isolated from D. melanogaster, did not respond to melanogaster odor cues. Similar to D. pavani larvae, the navigation of pavani female x gaucha male hybrids was influenced by conspecific and alien odors, whereas gaucha female x pavani male hybrid larvae exhibited behavior similar to the D. gaucha parent. The two sibling species exhibited substantial evolutionary divergence in processing the odor inputs necessary to identify conspecifics. Orco (Or83b) mutant larvae of D. melanogaster, which exhibit a loss of sense of smell, did not distinguish conspecific from alien larvae, instead moving across the substrate. Syn97CS and rut larvae of D. melanogaster, which are unable to learn but can smell, moved across the substrate as well. The Orco (Or83b), Syn97CS and rut loci are necessary to orient navigation by D. melanogaster larvae. Individuals of the Trana strain of D. melanogaster did not respond to conspecific and alien larval volatiles and therefore navigated randomly across the substrate. By contrast, larvae of the Til-Til strain used larval volatiles to orient their movement. Natural populations of D. melanogaster may exhibit differences in identification of conspecific and alien larvae. Larval locomotion was not affected by the volatiles.

  7. The Identification of Congeners and Aliens by Drosophila Larvae

    PubMed Central

    Del Pino, Francisco; Jara, Claudia; Pino, Luis; Medina-Muñoz, María Cristina; Alvarez, Eduardo; Godoy-Herrera, Raúl

    2015-01-01

    We investigated the role of Drosophila larva olfactory system in identification of congeners and aliens. We discuss the importance of these activities in larva navigation across substrates, and the implications for allocation of space and food among species of similar ecologies. Wild type larvae of cosmopolitan D. melanogaster and endemic D. pavani, which cohabit the same breeding sites, used species-specific volatiles to identify conspecifics and aliens moving toward larvae of their species. D. gaucha larvae, a sibling species of D. pavani that is ecologically isolated from D. melanogaster, did not respond to melanogaster odor cues. Similar to D. pavani larvae, the navigation of pavani female x gaucha male hybrids was influenced by conspecific and alien odors, whereas gaucha female x pavani male hybrid larvae exhibited behavior similar to the D. gaucha parent. The two sibling species exhibited substantial evolutionary divergence in processing the odor inputs necessary to identify conspecifics. Orco (Or83b) mutant larvae of D. melanogaster, which exhibit a loss of sense of smell, did not distinguish conspecific from alien larvae, instead moving across the substrate. Syn97CS and rut larvae of D. melanogaster, which are unable to learn but can smell, moved across the substrate as well. The Orco (Or83b), Syn97CS and rut loci are necessary to orient navigation by D. melanogaster larvae. Individuals of the Trana strain of D. melanogaster did not respond to conspecific and alien larval volatiles and therefore navigated randomly across the substrate. By contrast, larvae of the Til-Til strain used larval volatiles to orient their movement. Natural populations of D. melanogaster may exhibit differences in identification of conspecific and alien larvae. Larval locomotion was not affected by the volatiles. PMID:26313007

  8. Philornis sp. bot fly larvae in free living scarlet macaw nestlings and a new technique for their extraction.

    PubMed

    Olah, George; Vigo, Gabriela; Ortiz, Lizzie; Rozsa, Lajos; Brightsmith, Donald J

    2013-09-01

    Bot fly larvae (Philornis genus) are obligate subcutaneous blood-feeding parasites of Neotropical birds including psittacines. We analyze twelve years of data on scarlet macaw (Ara macao) nestlings in natural and artificial nests in the lowland forests of southeastern Peru and report prevalence and intensity of Philornis parasitism. Bot fly prevalence was 28.9% while mean intensity was 5.0 larvae per infected chick. Prevalence in natural nests (11%, N=90 nestlings) was lower than in wooden nest-boxes (39%, N=57) and PVC boxes (39%, N=109). We describe a new technique of removing Philornis larvae using a reverse syringe design snake bite extractor. We compare this new technique to two other methods for removing bots from macaw chicks and find the new method the most suitable.

  9. Antihelmintic effects of nutmeg (Myristica fragans) on Anisakis simplex L3 larvae obtained from Micromesistius potassou.

    PubMed

    López, Víctor; Gerique, Javier; Langa, Elisa; Berzosa, César; Valero, Marta Sofía; Gómez-Rincón, Carlota

    2015-06-01

    Anisakis simplex is a foodborne pathogen that can produce human infections and allergic reactions due to the high consumption of raw fish. The seeds of Myristica fragans (Myristicaceae), popularly known as nutmeg, are worldwide used as a culinary spice due to its flavour and properties in food preservation. A nutmeg extract was prepared, analyzed, screened for cytotoxicity and tested against Anisakis simplex L3 larvae. In order to detect the biologically active constituents of the extract, myristicin was tested on the larvae. An acetylcholinesterase inhibition bioassay was also carried out to investigate the antihelmintic mechanism of action. Our results demonstrate that nutmeg exerts antihelmintic effects on Anisakis simplex, being myristicin one of the active compounds. The extract induced a high rate of dead anisakis at concentrations between 0.5 and 0.7 mg/ml without being considered cytotoxic; however, an inhibition of acetylcholinesterase was discarded as the molecular mechanism involved in the activity.

  10. Protective Yeasts Control V. anguillarum Pathogenicity and Modulate the Innate Immune Response of Challenged Zebrafish (Danio rerio) Larvae.

    PubMed

    Caruffo, Mario; Navarrete, Natalie C; Salgado, Oscar A; Faúndez, Nelly B; Gajardo, Miguel C; Feijóo, Carmen G; Reyes-Jara, Angélica; García, Katherine; Navarrete, Paola

    2016-01-01

    We investigated mechanisms involved in the protection of zebrafish (Danio rerio) larvae by two probiotic candidate yeasts, Debaryomyces hansenii 97 (Dh97) and Yarrowia lypolitica 242 (Yl242), against a Vibrio anguillarum challenge. We determined the effect of different yeast concentrations (10(4)-10(7) CFU/mL) to: (i) protect larvae from the challenge, (ii) reduce the in vivo pathogen concentration and (iii) modulate the innate immune response of the host. To evaluate the role of zebrafish microbiota in protection, the experiments were performed in conventionally raised and germ-free larvae. In vitro co-aggregation assays were performed to determine a direct yeast-pathogen interaction. Results showed that both yeasts significantly increased the survival rate of conventionally raised larvae challenged with V. anguillarum. The concentration of yeasts in larvae tended to increase with yeast inoculum, which was more pronounced for Dh97. Better protection was observed with Dh97 at a concentration of 10(6) CFU/mL compared to 10(4) CFU/mL. In germ-free conditions V. anguillarum reached higher concentrations in larvae and provoked significantly more mortality than in conventional conditions, revealing the protective role of the host microbiota. Interestingly, yeasts were equally (Dh97) or more effective (Yl242) in protecting germ-free than conventionally-raised larvae, showing that protection can be exerted only by yeasts and is not necessarily related to modulation of the host microbiota. Although none of the yeasts co-aggregated with V. anguillarum, they were able to reduce its proliferation in conventionally raised larvae, reduce initial pathogen concentration in germ-free larvae and prevent the upregulation of key components of the inflammatory/anti-inflammatory response (il1b, tnfa, c3, mpx, and il10, respectively). These results show that protection by yeasts of zebrafish larvae challenged with V. anguillarum relates to an in vivo anti-pathogen effect, the modulation

  11. Protective Yeasts Control V. anguillarum Pathogenicity and Modulate the Innate Immune Response of Challenged Zebrafish (Danio rerio) Larvae

    PubMed Central

    Caruffo, Mario; Navarrete, Natalie C.; Salgado, Oscar A.; Faúndez, Nelly B.; Gajardo, Miguel C.; Feijóo, Carmen G.; Reyes-Jara, Angélica; García, Katherine; Navarrete, Paola

    2016-01-01

    We investigated mechanisms involved in the protection of zebrafish (Danio rerio) larvae by two probiotic candidate yeasts, Debaryomyces hansenii 97 (Dh97) and Yarrowia lypolitica 242 (Yl242), against a Vibrio anguillarum challenge. We determined the effect of different yeast concentrations (104–107 CFU/mL) to: (i) protect larvae from the challenge, (ii) reduce the in vivo pathogen concentration and (iii) modulate the innate immune response of the host. To evaluate the role of zebrafish microbiota in protection, the experiments were performed in conventionally raised and germ-free larvae. In vitro co-aggregation assays were performed to determine a direct yeast-pathogen interaction. Results showed that both yeasts significantly increased the survival rate of conventionally raised larvae challenged with V. anguillarum. The concentration of yeasts in larvae tended to increase with yeast inoculum, which was more pronounced for Dh97. Better protection was observed with Dh97 at a concentration of 106 CFU/mL compared to 104 CFU/mL. In germ-free conditions V. anguillarum reached higher concentrations in larvae and provoked significantly more mortality than in conventional conditions, revealing the protective role of the host microbiota. Interestingly, yeasts were equally (Dh97) or more effective (Yl242) in protecting germ-free than conventionally-raised larvae, showing that protection can be exerted only by yeasts and is not necessarily related to modulation of the host microbiota. Although none of the yeasts co-aggregated with V. anguillarum, they were able to reduce its proliferation in conventionally raised larvae, reduce initial pathogen concentration in germ-free larvae and prevent the upregulation of key components of the inflammatory/anti-inflammatory response (il1b, tnfa, c3, mpx, and il10, respectively). These results show that protection by yeasts of zebrafish larvae challenged with V. anguillarum relates to an in vivo anti-pathogen effect, the modulation of

  12. In vitro culture of Parascaris equorum larvae and initial investigation of parasite excretory-secretory products.

    PubMed

    Burk, Steffanie V; Dangoudoubiyam, Sriveny; Brewster-Barnes, Tammy; Bryant, Uneeda K; Howe, Daniel K; Carter, Craig N; Vanzant, Eric S; Harmon, Robert J; Kazacos, Kevin R; Rossano, Mary G

    2014-11-01

    Currently, diagnosis of Parascaris equorum infection in equids is limited to patent infections. The goals of this study were to culture P. equorum larvae in vitro and identify excretory-secretory (ES) products for prepatent diagnostic testing. Parascaris equorum L2/L3 larvae were hatched and cultured for up to 3 weeks for ES product collection. Fifth stage (L5) P. equorum were also cultured for ES product collection. Examination of ES fractions by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and silver stain revealed L2/L3 products ranging from 12-94 kDa and L5 products ranging from 12-189 kDa. Western blot analyses were conducted using polyclonal antibodies produced against P. equorum or Baylisascaris procyonis L2/L3 ES products, sera from rabbits inoculated with B. procyonis or Toxocara canis eggs, and sera from animals naturally infected with P. equorum or T. canis. Western blot results indicated parasite antigens migrating at 19 and 34 kDa may be useful for specifically detecting P. equorum infections.

  13. Self-mixing of fly larvae during feeding

    NASA Astrophysics Data System (ADS)

    Shishkov, Olga; Johnson, Christopher; Zhang, Bryan; Hu, David

    2016-11-01

    How do we sustainably feed a growing world population? One solution of increasing interest is the use of black solider fly larvae, pea-sized grubs envisioned to transform hundreds of tons of food waste into a sustainable protein source. Although startups across the world are raising these larvae, a physical understanding of how they should be raised and fed remains missing. In this study, we present experiments measuring their feeding rate as a function of number of larvae. We show that larger groups of larvae have greater mixing which entrains hungry larvae around the food, increasing feeding rate. Feeding of larvae thus differs from feeding of cattle or other livestock which exhibit less self-mixing.

  14. Equipment for transporting live black fly larvae (Diptera: Simuliiae)

    USGS Publications Warehouse

    Tarshis, I.B.; Adkins, T.R.

    1971-01-01

    In studies relating to the biology and ecology of black flies, live larvae of at least 70 species of Simuliidae have been collected from their natural breeding sites and transported in containers with nonagitated water for short distances to the laboratory. One of us (Tarshis 1966) found, however, that even small numbers of simuliid larvae cannot survive in containers with nonagitated water for more than 6 hr. Additionally, when massive numbers of larvae are introduced into transport containers in which the water is not agitated, the larvae perish because they become entangled within the masses of silken threads they emit whenever disturbed (Tarshis and Neil 1970). Therefore, when transporting larvae long distances or when transporting large numbers of larvae any distance, it is essential to agitate the water in the transport containers.

  15. Fate of pharmaceuticals and pesticides in fly larvae composting.

    PubMed

    Lalander, C; Senecal, J; Gros Calvo, M; Ahrens, L; Josefsson, S; Wiberg, K; Vinnerås, B

    2016-09-15

    A novel and efficient organic waste management strategy currently gaining great attention is fly larvae composting. High resource recovery efficiency can be achieved in this closed-looped system, but pharmaceuticals and pesticides in waste could potentially accumulate in every loop of the treatment system and spread to the environment. This study evaluated the fate of three pharmaceuticals (carbamazepine, roxithromycin, trimethoprim) and two pesticides (azoxystrobin, propiconazole) in a fly larvae composting system and in a control treatment with no larvae. It was found that the half-life of all five substances was shorter in the fly larvae compost (<10% of control) and no bioaccumulation was detected in the larvae. Fly larvae composting could thus impede the spread of pharmaceuticals and pesticides into the environment.

  16. Learning and memory in zebrafish larvae.

    PubMed

    Roberts, Adam C; Bill, Brent R; Glanzman, David L

    2013-01-01

    Larval zebrafish possess several experimental advantages for investigating the molecular and neural bases of learning and memory. Despite this, neuroscientists have only recently begun to use these animals to study memory. However, in a relatively short period of time a number of forms of learning have been described in zebrafish larvae, and significant progress has been made toward their understanding. Here we provide a comprehensive review of this progress; we also describe several promising new experimental technologies currently being used in larval zebrafish that are likely to contribute major insights into the processes that underlie learning and memory.

  17. Learning and memory in zebrafish larvae

    PubMed Central

    Roberts, Adam C.; Bill, Brent R.; Glanzman, David L.

    2013-01-01

    Larval zebrafish possess several experimental advantages for investigating the molecular and neural bases of learning and memory. Despite this, neuroscientists have only recently begun to use these animals to study memory. However, in a relatively short period of time a number of forms of learning have been described in zebrafish larvae, and significant progress has been made toward their understanding. Here we provide a comprehensive review of this progress; we also describe several promising new experimental technologies currently being used in larval zebrafish that are likely to contribute major insights into the processes that underlie learning and memory. PMID:23935566

  18. Toxicity of phenol on Macrobrachium rosenbergii (de Man) eggs, larvae, and post-larvae

    SciTech Connect

    Law, A.T.; Yeo, M.E.

    1997-03-01

    Literature on the toxicities of phenol on aquatic organisms is very limited. USEPA reported that the acute and chronic toxicities of phenol to freshwater aquatic life occur at concentrations as low as 10.2 mg/L and 2.56 mg/L, respectively. While for the saltwater aquatic life the acute toxicity occurs at concentrations as low as 5.8 mg/L. No data are available for the chronic toxicity of phenol to saltwater aquatic life. Sublethal concentrations of phenol have significant effects on the physiological and histological processes of the aquatic organisms: such as gill necrosis; destruction of erythrocyte cells; inhibition of sexual activities; suppression on growth and reduction of resistance to diseases. Macrobrachium rosenbergii(de Man) is the sole freshwater prawn cultured in Malaysia. Occasionally, the hatcheries are unable to produce the post-larvae because of undefined pollutants present in the water supplies. It has been observed that the use of cracked fiberglass tanks for larvae rearing is correlated with high mortality. This high mortality is probably due to the toxicity of the phenolic compounds which are leached out from the fiber glass tank into the water. This study was undertaken to evaluate the toxicity of phenol on eggs, larvae and post-larvae of M. rosenbergii and to set the water quality criteria of phenol for the said species. 16 refs., 3 tabs.

  19. Structure and occurrence of cyphonautes larvae (bryozoa, ectoprocta).

    PubMed

    Nielsen, Claus; Worsaae, Katrine

    2010-09-01

    We have studied larvae of the freshwater ctenostome Hislopia malayensis with scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and LM of serial sections. Some additional observations on larvae of M. membranacea using SEM and CLSM are also reported. The overall configuration of muscles, nerves, and cilia of the two larvae are identical. However, the larva of H. malayensis is much smaller than that of M. membranacea, which may explain most of the differences observed. Although all major nerves and muscle strands are present in H. malayensis, they are generally composed of fewer fibers. The H. malayensis larva lacks the anterior and posterior intervalve cilia. Its pyriform organ is unciliated with only a small central depression. The adhesive epithelium is not invaginated as an adhesive sac and lacks the large muscles interpreted as adhesive sac muscles in the M. membranacea larva. The velum carries two rows of ciliated cells, though the lower "row" consists of only one or two cells. Both rows of ciliated cells are innervated by nerves, which have not been detected in the M. membranacea larva. The ciliated ridge of H. malayensis lacks the frontal cilia. The planktotrophic cyphonautes larvae in a number of ctenostome clades and in the "basal" cheilostome clade Malacostega (and probably in the earliest cheilostomes) support the idea that the cyphonautes larva is the ancestral larval type of the Eurystomata. It may even represent the ancestral larval type of the bryozoans (= ectoprocts).

  20. Effects of Volatiles from Maruca vitrata Larvae and Caterpillar-Infested Flowers of Their Host Plant Vigna unguiculata on the Foraging Behavior of the Parasitoid Apanteles taragamae

    PubMed Central

    Dannon, Elie A.; Tamò, Manuele; Van Huis, Arnold

    2010-01-01

    The parasitoid wasp Apanteles taragamae is a promising candidate for the biological control of the legume pod borer Maruca vitrata, which recently has been introduced into Benin. The effects of volatiles from cowpea and peabush flowers and Maruca vitrata larvae on host selection behavior of the parasitoid Apanteles taragamae were investigated under laboratory conditions by using a Y-tube olfactometer. Naïve and oviposition-experienced female wasps were given a choice between several odor sources that included (1) uninfested, (2) Maruca vitrata-infested, and (3) mechanically damaged cowpea flowers, as well as (4) stem portions of peabush plants carrying leaves and flowers, (5) healthy M. vitrata larvae, and moribund (6), and live (7) virus-infected M. vitrata larvae. Responses of naïve and oviposition-experienced female wasps did not differ for any of the odor source combinations. Wasps were significantly attracted to floral volatiles produced by cowpea flowers that had been infested with M. vitrata larvae and from which the larvae had been removed. Apanteles taragamae females also were attracted to Maruca vitrata-infested flowers after removal of both the larvae and their feces. Female wasps discriminated between volatiles from previously infested flowers and mechanically damaged flowers. Uninfested cowpea flowers attracted only oviposition-experienced wasps that had received a rewarding experience (i.e. the parasitization of two M. vitrata larvae feeding on cowpea flowers) before the olfactometer test. Wasps also were attracted to uninfested leaves and flowers of peabush. Moreover, they were also attracted to healthy and live virus-infected M. vitrata larvae, but not when the latter were moribund. Our data show that, similarly to what has been extensively been reported for foliar volatiles, flowers of plants also emit parasitoid-attracting volatiles in response to being infested with an herbivore. PMID:20842412

  1. A Model of Drosophila Larva Chemotaxis.

    PubMed

    Davies, Alex; Louis, Matthieu; Webb, Barbara

    2015-11-01

    Detailed observations of larval Drosophila chemotaxis have characterised the relationship between the odour gradient and the runs, head casts and turns made by the animal. We use a computational model to test whether hypothesised sensorimotor control mechanisms are sufficient to account for larval behaviour. The model combines three mechanisms based on simple transformations of the recent history of odour intensity at the head location. The first is an increased probability of terminating runs in response to gradually decreasing concentration, the second an increased probability of terminating head casts in response to rapidly increasing concentration, and the third a biasing of run directions up concentration gradients through modulation of small head casts. We show that this model can be tuned to produce behavioural statistics comparable to those reported for the larva, and that this tuning results in similar chemotaxis performance to the larva. We demonstrate that each mechanism can enable odour approach but the combination of mechanisms is most effective, and investigate how these low-level control mechanisms relate to behavioural measures such as the preference indices used to investigate larval learning behaviour in group assays.

  2. Metamorphosis of cinctoblastula larvae (Homoscleromorpha, porifera).

    PubMed

    Ereskovsky, Alexander V; Tokina, Daria B; Bézac, Chantal; Boury-Esnault, Nicole

    2007-06-01

    The metamorphosis of the cinctoblastula of Homoscleromorpha is studied in five species belonging to three genera. The different steps of metamorphosis are similar in all species. The metamorphosis occurs by the invagination and involution of either the anterior epithelium or the posterior epithelium of the larva. During metamorphosis, morphogenetic polymorphism was observed, which has an individual character and does not depend on either external or species specific factors. In the rhagon, the development of the aquiferous system occurs only by epithelial morphogenesis and subsequent differentiation of cells. Mesohylar cells derive from flagellated cells after ingression. The formation of pinacoderm and choanoderm occurs by the differentiation of the larval flagellated epithelium. This is possibly due to the conservation of cell junctions in the external surface of the larval flagellated cells and of the basement membrane in their internal surface. The main difference in homoscleromorph metamorphosis compared with Demospongiae is the persistence of the flagellated epithelium throughout this process and even in the adult since exo- and endopinacoderm remain flagellated. The antero-posterior axis of the larva corresponds to the baso-apical axis of the adult in Homoscleromorpha.

  3. Olfactory Learning in Individually Assayed Drosophila Larvae

    PubMed Central

    Scherer, Sabine; Stocker, Reinhard F.; Gerber, Bertram

    2003-01-01

    Insect and mammalian olfactory systems are strikingly similar. Therefore, Drosophila can be used as a simple model for olfaction and olfactory learning. The brain of adult Drosophila, however, is still complex. We therefore chose to work on the larva with its yet simpler but adult-like olfactory system and provide evidence for olfactory learning in individually assayed Drosophila larvae. We developed a differential conditioning paradigm in which odorants are paired with positive (“+” fructose) or negative (“-” quinine or sodium chloride) gustatory reinforcers. Test performance of individuals from two treatment conditions is compared—one received odorant A with the positive reinforcer and odorant B with a negative reinforcer (A+/B-); animals from the other treatment condition were trained reciprocally (A-/B+). During test, differences in choice between A and B of individuals having undergone either A+/B- or A-/B+ training therefore indicate associative learning. We provide such evidence for both combinations of reinforcers; this was replicable across repetitions, laboratories, and experimenters. We further show that breaks improve performance, in accord with basic principles of associative learning. The present individual assay will facilitate electrophysiological studies, which necessarily use individuals. As such approaches are established for the larval neuromuscular synapse, but not in adults, an individual larval learning paradigm will serve to link behavioral levels of analysis to synaptic physiology. PMID:12773586

  4. Avian hosts of Ixodes pacificus (Acari: Ixodidae) and the detection of Borrelia burgdorferi in larvae feeding on the Oregon junco.

    PubMed

    Wright, S A; Tucker, J R; Donohue, A M; Castro, M B; Kelley, K L; Novak, M G; Macedo, P A

    2011-07-01

    Larval and nymphal western blacklegged tick, Ixodes pacificus Cooley & Kohls (Acari: Ixodidae), were collected from birds, rodents, and lizards at Quail Ridge Reserve located in Napa County in northwestern California. Species from three vertebrate classes were sampled simultaneously from two transects during two consecutive spring seasons. Feeding larval and nymphal ticks were removed and preserved for counting, examination and testing for the presence of Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner. Mean infestations with I. pacificus subadults on lizards were 10.0, on birds 2.9, and on rodents 1.3. I. pacificus larvae (204) collected from 10 avian species and (215) collected from two rodent species were tested for the presence of B. burgdorferi s.s. via real-time polymerase chain reaction. Three B. burgdorferi-infected larvae were taken from two Junco hyemalis and two infected larvae from one Neotoma fuscipes Baird. This is the detection of B. burgdorferi ss in an Ixodes pacificus larvae feeding on a Junco hyemalis L., [corrected] in western North America.

  5. Ascaris and hookworm transmission in preschool children from rural Panama: role of yard environment, soil eggs/larvae and hygiene and play behaviours.

    PubMed

    Krause, Rachel J; Koski, Kristine G; Pons, Emérita; Sandoval, Nidia; Sinisterra, Odalis; Scott, Marilyn E

    2015-10-01

    This study explored whether the yard environment and child hygiene and play behaviours were associated with presence and intensity of Ascaris and hookworm in preschool children and with eggs and larvae in soil. Data were collected using questionnaires, a visual survey of the yard, soil samples and fecal samples collected at baseline and following re-infection. The presence of eggs/larvae in soil was associated negatively with water storage (eggs) but positively with dogs (eggs) and distance from home to latrine (larvae). Baseline and re-infection prevalences were: hookworm (28.0%, 3.4%); Ascaris (16.9%, 9.5%); Trichuris (0.9%, 0.7%). Zero-inflated negative binomial regression models revealed a higher baseline hookworm infection if yards had eggs or larvae, more vegetation or garbage, and if the child played with soil. Baseline Ascaris was associated with dirt floor, dogs, exposed soil in yard, open defecation and with less time playing outdoors, whereas Ascaris re-infection was associated with water storage, vegetation cover and garbage near the home and not playing with animals. Our results show complex interactions between infection, the yard environment and child behaviours, and indicate that transmission would be reduced if latrines were closer to the home, and if open defecation and water spillage were reduced.

  6. [Ectoparasites. Part 2: Bed bugs, Demodex, sand fleas and cutaneous larva migrans].

    PubMed

    Nenoff, P; Handrick, W; Krüger, C; Herrmann, J; Schmoranzer, B; Paasch, U

    2009-09-01

    Ectoparasites or epidermal parasites include a very heterogenous group of infections of the outer layers of the skin. Worldwide the most common are scabies, lice, tungiasis, and hookworm-induced cutaneous larva migrans. In recent years, bed bug infestations in hotels or vacation homes seem to have become more frequent. Demodex folliculorum and Demodex brevis are found in the facial and scalp hair follicles in 95% of individuals. Classic Demodex folliculitis is often overlooked in differential diagnostic considerations. This inflammatory sebaceous gland disease as well as Demodex blepharitis both provide a diagnostic and therapeutic challenge. Permethrin can be used topically against demodicosis. Vacationers who go barefoot on beaches in tropical Africa, South America and subtropical Asia risk infestations from female sand fleas. The lesions can be curetted or removed with a punch biopsy, then treated with antiseptics or even systemic antibiotics if a secondary infection develops. Cutaneous larva migrans is one of the most common imported ectoparasite infections from the tropics. Topical treatment measures include thiabendazole or cryotherapy. If the infestation is severe, systemic antihelminthics or ivermectin can be employed.

  7. Active downward propulsion by oyster larvae in turbulence.

    PubMed

    Fuchs, Heidi L; Hunter, Elias J; Schmitt, Erika L; Guazzo, Regina A

    2013-04-15

    Oyster larvae (Crassostrea virginica) could enhance their settlement success by moving toward the seafloor in the strong turbulence associated with coastal habitats. We characterized the behavior of individual oyster larvae in grid-generated turbulence by measuring larval velocities and flow velocities simultaneously using infrared particle image velocimetry. We estimated larval behavioral velocities and propulsive forces as functions of the kinetic energy dissipation rate ε, strain rate γ, vorticity ξ and acceleration α. In calm water most larvae had near-zero vertical velocities despite propelling themselves upward (swimming). In stronger turbulence all larvae used more propulsive force, but relative to the larval axis, larvae propelled themselves downward (diving) instead of upward more frequently and more forcefully. Vertical velocity magnitudes of both swimmers and divers increased with turbulence, but the swimming velocity leveled off as larvae were rotated away from their stable, velum-up orientation in strong turbulence. Diving speeds rose steadily with turbulence intensity to several times the terminal fall velocity in still water. Rapid dives may require a switch from ciliary swimming to another propulsive mode such as flapping the velum, which would become energetically efficient at the intermediate Reynolds numbers attained by larvae in strong turbulence. We expected larvae to respond to spatial or temporal velocity gradients, but although the diving frequency changed abruptly at a threshold acceleration, the variation in propulsive force and behavioral velocity was best explained by the dissipation rate. Downward propulsion could enhance oyster larval settlement by raising the probability of larval contact with oyster reef patches.

  8. Complete Genome Sequences of Five Paenibacillus larvae Bacteriophages.

    PubMed

    Sheflo, Michael A; Gardner, Adam V; Merrill, Bryan D; Fisher, Joshua N B; Lunt, Bryce L; Breakwell, Donald P; Grose, Julianne H; Burnett, Sandra H

    2013-11-14

    Paenibacillus larvae is a pathogen of honeybees that causes American foulbrood (AFB). We isolated bacteriophages from soil containing bee debris collected near beehives in Utah. We announce five high-quality complete genome sequences, which represent the first completed genome sequences submitted to GenBank for any P. larvae bacteriophage.

  9. Selenium impacts on razorback sucker, Colorado: Colorado River: III. Larvae

    USGS Publications Warehouse

    Hamilton, S.J.; Holley, K.M.; Buhl, K.J.; Bullard, F.A.

    2005-01-01

    Razorback sucker (Xyrauchen texanus) larvae from adults exposed to selenium at three sites near Grand Junction, Colorado, for 9 months were used in a 30-day waterborne and dietary selenium study. Selenium concentrations in water averaged <1.6 ??g/L from 24-Road, 0.9 ??g/L from Horsethief, 5.5 ??g/L from Adobe Creek, and 10.7 ??g/L from the North Pond. Selenium in dietary items averaged 2.7 ??g/g in brine shrimp, 5.6 ??g/g in zooplankton from Horsethief east wetland, 20 ??g/g in zooplankton from Adobe Creek, and 39 ??g/g in zooplankton from North Pond. The lowest survival occurred in larvae fed zooplankton rather than brine shrimp. Survival of larvae at Adobe Creek and North Pond was lower in site water than in reference water. Survival of brood stock larvae was higher than Horsethief larvae even though they received the same water and dietary treatments. Arsenic concentrations in brine shrimp may have resulted in an antagonistic interaction with selenium and reduced adverse effects in larvae. Deformities in larvae from North Pond were similar to those reported for selenium-induced teratogenic deformities in other fish species. Selenium concentrations of ???4.6 ??g/g in food resulted in rapid mortality of larvae from Horsethief, Adobe Creek, and North Pond, and suggested that selenium toxicity in the Colorado River could limit recovery of this endangered fish.

  10. Prey capture of pike Esox lucius larvae in turbid water.

    PubMed

    Salonen, M; Engström-Ost, J

    2010-06-01

    Pike Esox lucius larvae captured fewer calanoid and cyclopoid copepods in turbid than in clear water, whereas no differences were detected in feeding rates on Daphnia longispina. Decreased capture of copepods may lead to lower growth and survival of E. lucius larvae in turbid areas, in particular, if cladocerans are scarce.

  11. The effects of dissolved gas supersaturation on white sturgeon larvae

    USGS Publications Warehouse

    Counihan, T.D.; Miller, A.I.; Mesa, M.G.; Parsley, M.J.

    2000-01-01

    Spill at dams has caused supersaturation of atmospheric gas in waters of the Columbia and Snake rivers and raised concerns about the effects of dissolved gas supersaturation (DGS) on white sturgeons Acipenser transmontanus. The timing and location of white sturgeon spawning and the dispersal of white sturgeon larvae from incubation areas makes the larval stage potentially vulnerable to the effects of DGS. To assess the effects of DGS on white sturgeon larvae, we exposed larvae to mean total dissolved gas (TDG) levels of 118% and 131% saturation in laboratory bioassay tests. Gas bubble trauma (GBT) was manifested as a gas bubble in the buccal cavity, nares, or both and it first occurred at developmental stages characterized by the formation of the mouth and gills. Exposure times of 15 min were sufficient to elicit these signs in larvae in various stages of development. No mortality was observed in larvae exposed to 118% TDG for 10 d, but 50% mortality occurred after a 13-d exposure to 131% TDG. The signs of GBT we observed resulted in positive buoyancy and alterations in behavior that may affect the dispersal and predation vulnerability of white sturgeon larvae. The exact depth distribution of dispersing white sturgeon larvae in the Columbia River currently is unknown. Thus, our results may represent a worst-case scenario if white sturgeon larvae are dispersed at depths with insufficient hydrostatic pressure to compensate for high TDG levels.

  12. Rapid bioassay to screen potential biopesticides in Tenebrio molitor larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A simplified assay was devised to evaluate the response of Tenebrio molitor larvae to potential insect control products. The assay incorporates punched disks of flattened whole-grain bread placed in 96-well plates, with treatments applied topically, and neonate larvae added to each well. To evalua...

  13. Selenium impacts on razorback sucker, Colorado: Colorado River III. Larvae.

    PubMed

    Hamilton, Steven J; Holley, Kathy M; Buhl, Kevin J; Bullard, Fern A

    2005-06-01

    Razorback sucker (Xyrauchen texanus) larvae from adults exposed to selenium at three sites near Grand Junction, Colorado, for 9 months were used in a 30-day waterborne and dietary selenium study. Selenium concentrations in water averaged <1.6 microg/L from 24-Road, 0.9 microg/L from Horsethief, 5.5 microg/L from Adobe Creek, and 10.7 microg/L from the North Pond. Selenium in dietary items averaged 2.7 microg/g in brine shrimp, 5.6 microg/g in zooplankton from Horsethief east wetland, 20 microg/g in zooplankton from Adobe Creek, and 39 microg/g in zooplankton from North Pond. The lowest survival occurred in larvae fed zooplankton rather than brine shrimp. Survival of larvae at Adobe Creek and North Pond was lower in site water than in reference water. Survival of brood stock larvae was higher than Horsethief larvae even though they received the same water and dietary treatments. Arsenic concentrations in brine shrimp may have resulted in an antagonistic interaction with selenium and reduced adverse effects in larvae. Deformities in larvae from North Pond were similar to those reported for selenium-induced teratogenic deformities in other fish species. Selenium concentrations of 4.6 microg/g in food resulted in rapid mortality of larvae from Horsethief, Adobe Creek, and North Pond, and suggested that selenium toxicity in the Colorado River could limit recovery of this endangered fish.

  14. Trail marking by larvae of the eastern tent caterpillar.

    PubMed

    Fitzgerald, T D

    1976-11-26

    Eastern tent caterpillars that are successful foragers deposit trails as they return to the tent that are more attractive than the exploratory trails of the unfed larvae. The trails of these fed returning larvae attract unfed tentmates to food finds anre chemical factors account for the attractiveness of these trails.

  15. Early detection of non-native fishes using fish larvae

    EPA Science Inventory

    Our objective was to evaluate the use of fish larvae for early detection of non-native fishes, comparing traditional and molecular taxonomy approaches to investigate potential efficiencies. Fish larvae present an interesting opportunity for non-native fish early detection. First,...

  16. Loeffler's Syndrome Following Cutaneous Larva Migrans: An Uncommon Sequel

    PubMed Central

    Podder, Indrashis; Chandra, Somodyuti; Gharami, Ramesh Chandra

    2016-01-01

    Cutaneous larva migrans (CLM) is characterized by the formation of distinctive, tortuous, and serpentine skin lesions occurring as a result of epidermal burrowing by certain helminthic larvae. Although this condition is usually uneventful, rarely it may result in patchy pulmonary infiltration with peripheral eosinophilia, also called Loeffler's syndrome. This association is fairly uncommon and is thus being reported. PMID:27057020

  17. Gnathostome infection in swamp eels, Fluta alba, in central Thailand.

    PubMed

    Nuamtanong, S; Waikagul, J; Anantaphruti, M T

    1998-03-01

    To investigate the distribution of gnathostome worms in central Thailand, the infective larvae of Gnathostoma spp were examined from the flesh and liver of swamp eels, Fluta alba. Seven hundred and eighty-eight eels were purchased from markets in 11 provinces; Ang Thong (30), Ayutthaya (36), Chachoengsao (30), Lop Buri (30), Nakhon Nayok (437), Pathum Thani (30), Prachin Buri (48), Ratchaburi (53), Saraburi (30), Samut Prakan (30) and Suphan Buri (34). The highest rate of gnathostome infection was observed in swamp eels from Nakhon Nayok (68.7%). The infection rates in Ayutthaya, Ang Thong, Prachin Buri, Ratchaburi, Saraburi and Lop Buri were 33.3%, 26.7%, 25.0%, 18.9%, 13.3% and 10.0% respectively. Gnathostome larvae were not found in swamp eels from Chachoengsao, Pathum Thani, Samut Prakan and Suphan Buri. Among the 9,573 larvae recovered, almost all were the advanced third stage larvae of G. spinigerum, except one larva from Nakhon Nayok and two larvae from Ratchaburi which were identified as the advanced third stage larvae of G. vietnamicum and G. hispidum respectively. This study is the first report of swamp eels as natural intermediate hosts of G. vietnamicum and G. hispidum.

  18. Vertical transmission of Nosema fumiferanae (Microsporidia: Nosematidae) and consequences for distribution, post-diapause emergence and dispersal of second-instar larvae of the spruce budworm, Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae).

    PubMed

    van Frankenhuyzen, Kees; Nystrom, Carl; Liu, Y

    2007-10-01

    We examined vertical transmission of Nosema fumiferanae in the eastern spruce budworm, Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae), and how it affects overwintering distribution and survival and spring emergence and dispersal of second-instar larvae in outbreak populations. Females containing 5.0 x 10(5) spores or more consistently produced 100% infected progeny. Transmission efficiency was still 50% at burdens as low as 0.2 x 10(5) spores per moth. Infection intensity in offspring increased with maternal spore load but became highly variable above 25 x 10(5) spores per female. Nosema multiplied in second instars for at least 1 month after they entered dormancy, regardless of temperature (2 degrees C versus 21 degrees C). Infection did not affect the distribution of overwintering larvae in a white spruce canopy. Dormancy survival between late-summer and the following spring was lower in families from infected females and was negatively correlated with larval infection intensity. Infection delayed larval emergence from hibernacula in the spring and resulted in delayed dispersal of emerged larvae, at least when parasite prevalence and infection intensities were high. Infected larvae were less successful in establishing feeding sites after dispersal. Our results underscore the potential of Nosema infection to negatively affect processes early in the budworm life cycle.

  19. Application of Giemsa stain for easy detection of Trichinella spiralis muscle larvae

    PubMed Central

    Ramírez-Melgar, Carmen; Gómez-Priego, Alberto

    2007-01-01

    The application of Giemsa technique to stain compressed diaphragm samples obtained from rodents experimentally infected with Trichinella spiralis is described. Diaphragm samples from rats heavily infected with 20 muscle larvae per gram of body weight (20 ML/gbw) were cut into several pieces and stained with Giemsa; on the other hand, whole diaphragms from slightly infected mice (1 ML/gbw) were also stained with Giemsa. Besides, muscle samples were also stained with Giemsa. Observation at 10 × magnification revealed that both ML and nurse cells (NC) look as bluish structures clearly contrasting with the pinkish color of the non-infected muscle fibers. NC in the diaphragms of mice could be easily observed at naked eye as blue points contrasting with the pink surrounding areas formed by the non-infected muscle fibers. Among NC observed in the diaphragms of rats infected with 20 ML/gbw, 4.4% was multiple infection. These findings were confirmed in sectioned and hematoxylin-eosin stained specimens. This data could be usefulness for a rapid diagnosis of trichinellosis in post-mortem mammals without magnification procedures. PMID:17374981

  20. Application of Giemsa stain for easy detection of Trichinella spiralis muscle larvae.

    PubMed

    Ramírez-Melgar, Carmen; Gómez-Priego, Alberto; De-la-Rosa, Jorge-Luis

    2007-03-01

    The application of Giemsa technique to stain compressed diaphragm samples obtained from rodents experimentally infected with Trichinella spiralis is described. Diaphragm samples from rats heavily infected with 20 muscle larvae per gram of body weight (20 ML/gbw) were cut into several pieces and stained with Giemsa; on the other hand, whole diaphragms from slightly infected mice (1 ML/gbw) were also stained with Giemsa. Besides, muscle samples were also stained with Giemsa. Observation at 10 x magnification revealed that both ML and nurse cells (NC) look as bluish structures clearly contrasting with the pinkish color of the non-infected muscle fibers. NC in the diaphragms of mice could be easily observed at naked eye as blue points contrasting with the pink surrounding areas formed by the non-infected muscle fibers. Among NC observed in the diaphragms of rats infected with 20 ML/gbw, 4.4% was multiple infection. These findings were confirmed in sectioned and hematoxylin-eosin stained specimens. This data could be usefulness for a rapid diagnosis of trichinellosis in post-mortem mammals without magnification procedures.

  1. Survival of model helminth eggs and larvae (Ascaris suum, Oesophagostomum sp.) in the ensilaging process.

    PubMed

    Juris, P; Rataj, D; Ilavská, I; Ziláková, J; Knotek, S; Vasilková, Z

    1997-06-01

    Ascaris suum nonembryonated eggs remained viable for the most part even after 42 days of ensilaging. At the end of the anaerobic fermentation, mean of damaged eggs was 15.2 +/- 4.02 (min. 11, max. 21), 32.9%. Conversely, the viability of Oesophagostomum sp. nonembryonated eggs and infective L3 larvae was reduced-eggs: mean number 23.6 +/- 3.64 (min. 20. max. 28) specimens (93.3%), L3 larvae: mean number 24.2 +/- 4.38 (min. 19, max. 28) specimens (96.7%), during the period of study (42 days). Control group of the same helminth propagative stages, was kept under optimum aerobic conditions. After 42 days of exposition, 9.0 +/- 3.46 (min. 5, max. 11) nonembryonated Ascaris suum eggs (12.9%), 17.33 +/- 2.51 (min. 15, max. 20) Oesophagostomum sp. eggs (36.4%) and 3.66 +/- 1.15 (min. 3, max. 5) Oesophagostomum sp. larvae L3 (6.3%) were damaged on average. Helminth eggs, thick-walled and more resistant to the environment in particular, are able to survive the anaerobic process of ensilaging. To protect animals against parasitic diseases, it is necessary to consider the epidemiological hazard of silages and silage juices, which are potentially contaminated by helminth propagative stages. Silages and silage juices under certain conditions may become harmful to polygastric animals.

  2. ANTHELMINTIC ACTIVITY OF LAPACHOL, β-LAPACHONE AND ITS DERIVATIVES AGAINST Toxocara canis LARVAE

    PubMed Central

    MATA-SANTOS, Taís; PINTO, Nitza França; MATA-SANTOS, Hilton Antônio; DE MOURA, Kelly Gallan; CARNEIRO, Paula Fernandes; CARVALHO, Tatiane dos Santos; DEL RIO, Karina Pena; PINTO, Maria do Carmo Freire Ribeiro; MARTINS, Lourdes Rodrigues; FENALTI, Juliana Montelli; DA SILVA, Pedro Eduardo Almeida; SCAINI, Carlos James

    2015-01-01

    Anthelmintics used for intestinal helminthiasis treatment are generally effective; however, their effectiveness in tissue parasitosis (i.e. visceral toxocariasis) is moderate. The aim of this study was to evaluate the in vitroactivity of lapachol, β-lapachone and phenazines in relation to the viability of Toxocara canis larvae. A concentration of 2 mg/mL (in duplicate) of the compounds was tested using microculture plates containing Toxocara canis larvae in an RPMI-1640 environment, incubated at 37 °C in 5% CO2 tension for 48 hours. In the 2 mg/mL concentration, four phenazines, lapachol and three of its derivatives presented a larvicide/larvistatic activity of 100%. Then, the minimum larvicide/larvistatic concentration (MLC) test was conducted. The compounds that presented the best results were nor-lapachol (MLC, 1 mg/mL), lapachol (MLC 0.5 mg/mL), β-lapachone, and β-C-allyl-lawsone (MLC, 0.25 mg/mL). The larvae exposed to the compounds, at best MLC with 100% in vitro activity larvicide, were inoculated into healthy BALB/c mice and were not capable of causing infection, confirming the larvicide potential in vitro of these compounds. PMID:26200958

  3. Larvicidal Activity of Nerium oleander against Larvae West Nile Vector Mosquito Culex pipiens (Diptera: Culicidae)

    PubMed Central

    El-Akhal, Fouad; Guemmouh, Raja; Ez Zoubi, Yassine; El Ouali Lalami, Abdelhakim

    2015-01-01

    Background. Outbreaks of the West Nile virus infection were reported in Morocco in 1996, 2003, and 2010. Culex pipiens was strongly suspected as the vector responsible for transmission. In the North center of Morocco, this species has developed resistance to synthetic insecticides. There is an urgent need to find alternatives to the insecticides as natural biocides. Objective. In this work, the insecticidal activity of the extract of the local plant Nerium oleander, which has never been tested before in the North center of Morocco, was studied on larval stages 3 and 4 of Culex pipiens. Methods. Biological tests were realized according to a methodology inspired from standard World Health Organization protocol. The mortality values were determined after 24 h of exposure and LC50 and LC90 values were calculated. Results. The extract had toxic effects on the larvae of culicid mosquitoes. The ethanolic extract of Nerium oleander applied against the larvae of Culex pipiens has given the lethal concentrations LC50 and LC90 in the order of 57.57 mg/mL and 166.35 mg/mL, respectively. Conclusion. This investigation indicates that N. oleander could serve as a potential larvicidal, effective natural biocide against mosquito larvae, particularly Culex pipiens. PMID:26640701

  4. Observations on house fly larvae midgut ultrastructure after Brevibacillus laterosporus ingestion.

    PubMed

    Ruiu, Luca; Satta, Alberto; Floris, Ignazio

    2012-11-01

    The pathological and histopathological course caused by Brevibacillus laterosporus on house fly larvae has been investigated conducting observations on insect behavior and midgut ultrastructure. After dissection and fixation, gut tissues were analyzed under transmission electron microscopy (TEM) in order to compare in vivo-treated and non-treated (control) fly specimens. Treated larvae showed extensively reduced feeding and growth rate, then became sluggish and died within 72 h. A progressive midgut epithelium deterioration was observed in treated larvae, compared to the control. Ultrastructural changes consisted of microvilli disruption, cytoplasm vacuolization and general disorganization, endoplasmic reticulum deformation, mitochondria alteration. Deterioration became progressively more dramatic until the infected cells released their content into the gut lumen. Disruption was associated also with midgut muscular sheath and connective tissue. These ultrastructural changes are similar to those widely described for other entomopathogenic bacteria, such as Bacillus thuringiensis, against different insect species. The rapid disruption of cellular fine structure supports a hypothesis based on an interaction of toxins with the epithelial cell membranes reminiscent of the specific B. thuringiensis δ-endotoxins mechanism of action on other insect targets.

  5. Eosinophils mediate protective immunity against secondary nematode infection.

    PubMed

    Huang, Lu; Gebreselassie, Nebiat G; Gagliardo, Lucille F; Ruyechan, Maura C; Luber, Kierstin L; Lee, Nancy A; Lee, James J; Appleton, Judith A

    2015-01-01

    Eosinophils are versatile cells that regulate innate and adaptive immunity, influence metabolism and tissue repair, and contribute to allergic lung disease. Within the context of immunity to parasitic worm infections, eosinophils are prominent yet highly varied in function. We have shown previously that when mice undergo primary infection with the parasitic nematode Trichinella spiralis, eosinophils play an important immune regulatory role that promotes larval growth and survival in skeletal muscle. In this study, we aimed to address the function of eosinophils in secondary infection with T. spiralis. By infecting eosinophil-ablated mice, we found that eosinophils are dispensable for immunity that clears adult worms or controls fecundity in secondary infection. In contrast, eosinophil ablation had a pronounced effect on secondary infection of skeletal muscle by migratory newborn larvae. Restoring eosinophils to previously infected, ablated mice caused them to limit muscle larvae burdens. Passive immunization of naive, ablated mice with sera or Ig from infected donors, together with transfer of eosinophils, served to limit the number of newborn larvae that migrated in tissue and colonized skeletal muscle. Results from these in vivo studies are consistent with earlier findings that eosinophils bind to larvae in the presence of Abs in vitro. Although our previous findings showed that eosinophils protect the parasite in primary infection, these new data show that eosinophils protect the host in secondary infection.

  6. Bacteria Present in Comadia redtenbacheri Larvae (Lepidoptera: Cossidae).

    PubMed

    Hernández-Flores, L; Llanderal-Cázares, C; Guzmán-Franco, A W; Aranda-Ocampo, S

    2015-09-01

    The external and internal culturable bacterial community present in the larvae of Comadia redtenbacheri Hammerschmidt, an edible insect, was studied. Characterization of the isolates determined the existence of 18 morphotypes and phylogenetic analysis of the 16S rRNA gene revealed the existence of Paenibacillus sp., Bacillus safensis, Pseudomonas sp., Bacillus pseudomycoides, Corynebacterium variabile, Enterococcus sp., Gordonia sp., Acinetobacter calcoaceticus, Arthrobacter sp., Micrococcus sp., and Bacillus cereus. Greater diversity of bacteria was found in those larvae obtained from vendors than in those directly taken from Agave plants in nature. Many of the larvae obtained from vendors presented signs of potential disease, and after the analysis, results showed a greater bacterial community compared with the larvae with a healthy appearance. This indicates that bacterial flora can vary in accordance with how the larvae are handled during extraction, collection, and transport.

  7. Mechanical recovery of inhibited cyathostomin larvae from equine intestinal tissue.

    PubMed

    Glover, I D; Henry, G M; Townsend, N B; Coles, G C

    2009-08-01

    The Stomacher is very widely used in food and medical research for extracting tissues. To determine whether nematode larvae were disrupted by the Stomacher, L3 larvae of Haemonchus contortus were homogenised for up to 40 min at full power but no larval disruption occurred. Therefore, tissue from the mucosa and submucosa of the caecum of horses collected from a licenced abattoir was treated to determine whether inhibited cyathostomin larvae could be extracted. The optimum time on full power for a 10-g sample was 20 min, and in three out of five caecal samples from different horses, significantly more larvae were recovered than with 6 h pepsin HCl digestion. It is concluded that the Stomacher provides a simple fast method of extracting inhibited nematode larvae from gastrointestinal tissues in the horse that could replace digestion with pepsin HCl.

  8. Habitat selection by marine larvae in changing chemical environments.

    PubMed

    Lecchini, D; Dixson, D L; Lecellier, G; Roux, N; Frédérich, B; Besson, M; Tanaka, Y; Banaigs, B; Nakamura, Y

    2017-01-15

    The replenishment and persistence of marine species is contingent on dispersing larvae locating suitable habitat and surviving to a reproductive stage. Pelagic larvae rely on environmental cues to make behavioural decisions with chemical information being important for habitat selection at settlement. We explored the sensory world of crustaceans and fishes focusing on the impact anthropogenic alterations (ocean acidification, red soil, pesticide) have on conspecific chemical signals used by larvae for habitat selection. Crustacean (Stenopus hispidus) and fish (Chromis viridis) larvae recognized their conspecifics via chemical signals under control conditions. In the presence of acidified water, red soil or pesticide, the ability of larvae to chemically recognize conspecific cues was altered. Our study highlights that recruitment potential on coral reefs may decrease due to anthropogenic stressors. If so, populations of fishes and crustaceans will continue their rapid decline; larval recruitment will not replace and sustain the adult populations on degraded reefs.

  9. Chemical spying in coral reef fish larvae at recruitment.

    PubMed

    Roux, Natacha; Brooker, Rohan M; Lecellier, Gaël; Berthe, Cécile; Frédérich, Bruno; Banaigs, Bernard; Lecchini, David

    2015-10-01

    When fish larvae recruit back to a reef, chemical cues are often used to find suitable habitat or to find juvenile or adult conspecifics. We tested if the chemical information used by larvae was intentionally produced by juvenile and adult conspecifics already on the reef (communication process) or whether the cues used result from normal biochemical processes with no active involvement by conspecifics ("spying" behavior by larvae). Conspecific chemical cues attracted the majority of larvae (four out of the seven species tested); although while some species were equally attracted to cues from adults and juveniles (Chromis viridis, Apogon novemfasciatus), two exhibited greater sensitivity to adult cues (Pomacentrus pavo, Dascyllus aruanus). Our results indicate also that spying cues are those most commonly used by settling fishes (C. viridis, P. pavo, A. novemfasciatus). Only one species (D. aruanus) preferred the odour of conspecifics that had had visual contact with larvae (communication).

  10. External Ophthalmomyiasis Caused by a Rare Infesting Larva, Sarcophaga argyrostoma

    PubMed Central

    Graffi, Shmuel; Peretz, Avi; Wilamowski, Amos; Schnur, Heather; Akad, Fouad; Naftali, Modi

    2013-01-01

    Purpose. External ophthalmomyiasis (EO) is caused by infesting larvae belonging to various species of flies. Most documented cases result from sheep (Oestrus ovis) and Russian (Rhinoestrus purpureus) botfly larvae, but we recently discovered a rare case of EO caused by flesh fly (Sarcophaga argyrostoma) larvae. Here, we report the case of a patient with EO who had been hospitalized and sedated for 1 week because of unrelated pneumonia. Methods. Case report. Results. A total of 32 larvae were removed from the adnexae of both eyes. Larvae identification was confirmed through DNA analysis. Treatment with topical tobramycin resulted in complete resolution of EO. Conclusion. EO can be caused by S. argyrostoma, and the elderly and debilitated may require extra ocular protection against flies during sedation. PMID:24455366

  11. Neuromechanics of crawling in D. melanogaster larvae

    NASA Astrophysics Data System (ADS)

    Pehlevan, Cengiz; Paoletti, Paolo; Mahadevan, L.

    2015-03-01

    Nervous system, body and environment interact in non-trivial ways to generate locomotion and thence behavior in an organism. Here we present a minimal integrative mathematical model to describe the simple behavior of forward crawling in Drosophila larvae. Our model couples the excitation-inhibition circuits in the nervous system to force production in the muscles and body movement in a frictional environment, which in turn leads to a proprioceptive signal that feeds back to the nervous system. Our results explain the basic observed phenomenology of crawling with or without proprioception, and elucidate the stabilizing role of proprioception in crawling with respect to external and internal perturbations. Our integrated approach allows us to make testable predictions on the effect of changing body-environment interactions on crawling, and serves as a substrate for the development of hierarchical models linking cellular processes to behavior.

  12. Antibacterial properties of grapefruit seed extract against Paenibacillus larvae subsp. larvae.

    PubMed

    Semprini, P; Langella, V; Pasini, B; Falda, M T; Calvarese, S

    2004-01-01

    Twenty-one samples of grapefruit seed extract (GSE) either from marketed products or provided by an apiculturist were analysed to verify their inhibition activity, in particular against Paenibacillus larvae subsp. larvae, responsible for American foulbrood. The bactericide capacity of GSE has been measured in Bacillus subtilis BGA, Bacillus cereus 11778, Bacillus cereus K250 and Micrococcus luteus 9341a; these bacteria are normally used in the laboratory to study inhibitors. The results showed that not all GSE have the same inhibitory activity and two of those analysed do not inhibit the five bacteria used. Considering that 19 samples inhibited American foulbrood bacillus, the authors conclude that the use of a natural product (such as GSE) to control this important disease of bees, can be used as a substitute for chemotherapeutic products, after appropriate expedients.

  13. Iodine nutrition and toxicity in Atlantic cod (Gadus morhua) larvae.

    PubMed

    Penglase, S; Harboe, T; Sæle, O; Helland, S; Nordgreen, A; Hamre, K

    2013-01-01

    Copepods as feed promote better growth and development in marine fish larvae than rotifers. However, unlike rotifers, copepods contain several minerals such as iodine (I), at potentially toxic levels. Iodine is an essential trace element and both under and over supply of I can inhibit the production of the I containing thyroid hormones. It is unknown whether marine fish larvae require copepod levels of I or if mechanisms are present that prevent I toxicity. In this study, larval Atlantic cod (Gadus morhua) were fed rotifers enriched to intermediate (26 mg I kg(-1) dry weight; MI group) or copepod (129 mg I kg(-1) DW; HI group) I levels and compared to cod larvae fed control rotifers (0.6 mg I kg(-1) DW). Larval I concentrations were increased by 3 (MI) and 7 (HI) fold compared to controls during the rotifer feeding period. No differences in growth were observed, but the HI diet increased thyroid follicle colloid to epithelium ratios, and affected the essential element concentrations of larvae compared to the other groups. The thyroid follicle morphology in the HI larvae is typical of colloid goitre, a condition resulting from excessive I intake, even though whole body I levels were below those found previously in copepod fed cod larvae. This is the first observation of dietary induced I toxicity in fish, and suggests I toxicity may be determined to a greater extent by bioavailability and nutrient interactions than by total body I concentrations in fish larvae. Rotifers with 0.6 mg I kg(-1) DW appeared sufficient to prevent gross signs of I deficiency in cod larvae reared with continuous water exchange, while modelling of cod larvae versus rotifer I levels suggests that optimum I levels in rotifers for cod larvae is 3.5 mg I kg(-1) DW.

  14. Iodine nutrition and toxicity in Atlantic cod (Gadus morhua) larvae

    PubMed Central

    Penglase, S; Harboe, T; Sæle, Ø; Helland, S; Nordgreen, A

    2013-01-01

    Copepods as feed promote better growth and development in marine fish larvae than rotifers. However, unlike rotifers, copepods contain several minerals such as iodine (I), at potentially toxic levels. Iodine is an essential trace element and both under and over supply of I can inhibit the production of the I containing thyroid hormones. It is unknown whether marine fish larvae require copepod levels of I or if mechanisms are present that prevent I toxicity. In this study, larval Atlantic cod (Gadus morhua) were fed rotifers enriched to intermediate (26 mg I kg-1 dry weight; MI group) or copepod (129 mg I kg-1 DW; HI group) I levels and compared to cod larvae fed control rotifers (0.6 mg I kg-1 DW). Larval I concentrations were increased by 3 (MI) and 7 (HI) fold compared to controls during the rotifer feeding period. No differences in growth were observed, but the HI diet increased thyroid follicle colloid to epithelium ratios, and affected the essential element concentrations of larvae compared to the other groups. The thyroid follicle morphology in the HI larvae is typical of colloid goitre, a condition resulting from excessive I intake, even though whole body I levels were below those found previously in copepod fed cod larvae. This is the first observation of dietary induced I toxicity in fish, and suggests I toxicity may be determined to a greater extent by bioavailability and nutrient interactions than by total body I concentrations in fish larvae. Rotifers with 0.6 mg I kg-1 DW appeared sufficient to prevent gross signs of I deficiency in cod larvae reared with continuous water exchange, while modelling of cod larvae versus rotifer I levels suggests that optimum I levels in rotifers for cod larvae is 3.5 mg I kg-1 DW. PMID:23638355

  15. How to Kill the Honey Bee Larva: Genomic Potential and Virulence Mechanisms of Paenibacillus larvae

    PubMed Central

    Fünfhaus, Anne; Voss, Jörn; Gollnow, Kathleen; Poppinga, Lena; Liesegang, Heiko; Garcia-Gonzalez, Eva; Genersch, Elke; Daniel, Rolf

    2014-01-01

    Paenibacillus larvae, a Gram positive bacterial pathogen, causes American Foulbrood (AFB), which is the most serious infectious disease of honey bees. In order to investigate the genomic potential of P. larvae, two strains belonging to two different genotypes were sequenced and used for comparative genome analysis. The complete genome sequence of P. larvae strain DSM 25430 (genotype ERIC II) consisted of 4,056,006 bp and harbored 3,928 predicted protein-encoding genes. The draft genome sequence of P. larvae strain DSM 25719 (genotype ERIC I) comprised 4,579,589 bp and contained 4,868 protein-encoding genes. Both strains harbored a 9.7 kb plasmid and encoded a large number of virulence-associated proteins such as toxins and collagenases. In addition, genes encoding large multimodular enzymes producing nonribosomally peptides or polyketides were identified. In the genome of strain DSM 25719 seven toxin associated loci were identified and analyzed. Five of them encoded putatively functional toxins. The genome of strain DSM 25430 harbored several toxin loci that showed similarity to corresponding loci in the genome of strain DSM 25719, but were non-functional due to point mutations or disruption by transposases. Although both strains cause AFB, significant differences between the genomes were observed including genome size, number and composition of transposases, insertion elements, predicted phage regions, and strain-specific island-like regions. Transposases, integrases and recombinases are important drivers for genome plasticity. A total of 390 and 273 mobile elements were found in strain DSM 25430 and strain DSM 25719, respectively. Comparative genomics of both strains revealed acquisition of virulence factors by horizontal gene transfer and provided insights into evolution and pathogenicity. PMID:24599066

  16. NOD2 dependent neutrophil recruitment is required for early protective immune responses against infectious Litomosoides sigmodontis L3 larvae

    PubMed Central

    Ajendra, Jesuthas; Specht, Sabine; Ziewer, Sebastian; Schiefer, Andrea; Pfarr, Kenneth; Parčina, Marijo; Kufer, Thomas A.; Hoerauf, Achim; Hübner, Marc P.

    2016-01-01

    Nucleotide-binding oligomerization domain-containing protein 2 (NOD2) recognizes muramyl dipeptide (MDP) of bacterial cell walls, triggering NFκB-induced pro-inflammation. As most human pathogenic filariae contain Wolbachia endobacteria that synthesize the MDP-containing cell wall precursor lipid II, NOD2’s role during infection with the rodent filaria Litomosoides sigmodontis was investigated. In NFκB reporter-cells, worm-extract containing Wolbachia induced NOD2 and NOD1. NOD2-deficient mice infected with L. sigmodontis had significantly more worms than wildtype controls early in infection. Increased worm burden was not observed after subcutaneous infection, suggesting that protective NOD2-dependent immune responses occur within the skin. Flow cytometry demonstrated that neutrophil recruitment to the skin was impaired in NOD2−/− mice after intradermal injection of third stage larvae (L3), and blood neutrophil numbers were reduced after L. sigmodontis infection. PCR array supported the requirement of NOD2 for recruitment of neutrophils to the skin, as genes associated with neutrophil recruitment and activation were downregulated in NOD2−/− mice after intradermal L3 injection. Neutrophil depletion before L. sigmodontis infection increased worm recovery in wildtype mice, confirming that neutrophils are essential against invading L3 larvae. This study indicates that NOD-like receptors are implemented in first-line protective immune responses against filarial nematodes. PMID:28004792

  17. Effects of various diets on the calcium and phosphorus composition of mealworms (Tenebrio molitor larvae) and superworms (Zophobas morio larvae).

    PubMed

    Latney, La'Toya V; Toddes, Barbara D; Wyre, Nicole R; Brown, Dorothy C; Michel, Kathryn E; Briscoe, Johanna A

    2017-02-01

    OBJECTIVE To evaluate whether the nutritive quality of Tenebrio molitor larvae and Zophobas morio larvae, which are commonly cultured as live food sources, is influenced by 4 commercially available diets used as nutritional substrates; identify which diet best improved calcium content of larvae; and identify the feeding time interval that assured the highest calcium intake by larvae. ANIMALS 2,000 Zophobas morio larvae (ie, superworms) and 7,500 Tenebrio molitor larvae (ie, mealworms). PROCEDURES Larvae were placed in control and diet treatment groups for 2-, 7-, and 10-day intervals. Treatment diets were as follows: wheat millings, avian hand feeding formula, organic avian mash diet, and a high-calcium cricket feed. Control groups received water only. After treatment, larvae were flash-frozen live with liquid nitrogen in preparation for complete proximate and mineral analyses. Analyses for the 2-day treatment group were performed in triplicate. RESULTS The nutrient composition of the high-calcium cricket feed groups had significant changes in calcium content, phosphorus content, and metabolizable energy at the 2-day interval, compared with other treatment groups, for both mealworms and superworms. Calcium content and calcium-to-phosphorus ratios for larvae in the high-calcium cricket feed group were the highest among the diet treatments for all treatment intervals and for both larval species. CONCLUSIONS AND CLINICAL RELEVANCE A 2-day interval with the high-calcium cricket feed achieved a larval nutrient composition sufficient to meet National Research Council dietary calcium recommendations for nonlactating rats. Mealworm calcium composition reached 2,420 g/1,000 kcal at 48 hours, and superworm calcium composition reached 2,070g/1,000 kcal at 48 hours. These findings may enable pet owners, veterinarians, insect breeders, and zoo curators to optimize nutritive content of larvae fed to insectivorous animals.

  18. Evaluation of a digestion assay and determination of sample size and tissue for the reliable detection of Trichinella larvae in walrus meat.

    PubMed

    Leclair, Daniel; Forbes, Lorry B; Suppa, Sandy; Gajadhar, Alvin A

    2003-03-01

    A digestion assay was validated for the detection of Trichinella larvae in walrus (Odobenus rosmarus) meat, and appropriate samples for testing were determined using tissues from infected walruses harvested for food. Examination of muscles from 3 walruses showed that the tongue consistently contained approximately 2-6 times more larvae than the pectoral and intercostal muscles. Comparison of numbers of larvae in the root, body, and apex of the tongue from 3 walruses failed to identify a predilection site within the tongue, but the apex was considered an optimal tissue because of the high larval density within the tongue and the ease of collection. All 31 spiked samples weighing 50 g each and containing between 0.1 and 0.4 larvae per gram (lpg) were correctly identified as infected, indicating that the sensitivity of this procedure is adequate for diagnostic use. A sample size of 10 g consistently detected larvae in 2 walrus tongues containing > or = 0.3 lpg (n = 40), and until additional data are available, sample sizes from individual walrus tongues should be a minimum of 10 g. This study provides the preliminary data that were used for the development of a food safety analytical protocol for the detection of Trichinella in walrus meat in arctic communities.

  19. Proteomic analysis of the urine of Dirofilaria immitis infected dogs.

    PubMed

    Hormaeche, Marta; Carretón, Elena; González-Miguel, Javier; Gussoni, Stefania; Montoya-Alonso, José Alberto; Simón, Fernando; Morchón, Rodrigo

    2014-06-16

    Canine cardiopulmonary dirofilariosis caused by Dirofilaria immitis habitually develops as a chronic disease affecting pulmonary arteries, lung parenchyma and heart. Other organs like kidneys can also be involved. Renal pathology is a consequence of glomerulonephritis whose main sign is proteinuria. The aim of the present work is to identify proteins excreted in the urine of D. immitis infected dogs showing proteinuria, and the possible contribution of their loss to heartworm disease. Proteinuria is higher in microfilaremic (mf+) than in amicrofilaremic (mf-) dogs. Using bidimensional electrophoresis and mass spectrometry 9 different proteins from Canis lupus familiaris in the urine of both mf- and mf+ dogs were identified (serotransferrin isoform 6, serum albumin precursor, albumin, immunoglobulin gamma heavy chain D, apolipoprotein A-I, immunoglobulin lambda-like polypeptide 5-like, arginine esterase precursor, inmunoglobulin gamma heavy chain B and hemoglobin subunit alpha). Furthermore, 3 additional proteins were identified only in the urine of mf+ dogs, corresponding to dog fibrinogen alpha chain and immunoglobulin gamma heavy chain A and actin 2 homologous to a protein of Brugia malayi. The loss of these proteins and other in the urine of D. immitis infected dogs could affect the general condition of parasitized dogs through the interference in the cholesterol metabolism and O₂ transport, among other mechanisms.

  20. [Effect of temperature on the viability of Trichinella spiralis larvae].

    PubMed

    Randazzo, Viviana R; La Sala, Luciano F; Costamagna, Sixto R

    2011-01-01

    The aim of this work was to study the effect of temperature on the viability of free and encysted larvae of Trichinella spiralis from southwest Buenos Aires province, Argentina. Larvae were treated at variable temperatures (-30 °C, -20 °C, 4 °C, 20 °C, gradual heating between 0-100 °C). The time necessary to kill 100 % of larvae was calculated. During the first days of freezing, larval mortality significantly increased as a function of time. Regardless of temperature, encysted larvae survived longer than the free ones. At -30 °C, -20 °C, and 20 °C there were no significant differences between the survival curves for each larval stage. At 4 °C, mortality was less severe for encysted larvae. All free and encysted larvae died at 61 days and 95 days (-30 °C), 160 days and 180 days (-20 °C), 280 days and 330 days (4 °C) and 460 days and 590 days (20 °C), respectively. Cooking at 90 °C and 100 °C during 15 minutes killed 100 % of free and encysted larvae, respectively. Our results suggest that temperatures and exposure times traditionally used to treat meat products with a potential to transmit T. spiralis are not entirely efficient.

  1. Effect of fungal colonization of wheat grains with Fusarium spp. on food choice, weight gain and mortality of meal beetle larvae (Tenebrio molitor).

    PubMed

    Guo, Zhiqing; Döll, Katharina; Dastjerdi, Raana; Karlovsky, Petr; Dehne, Heinz-Wilhelm; Altincicek, Boran

    2014-01-01

    Species of Fusarium have significant agro-economical and human health-related impact by infecting diverse crop plants and synthesizing diverse mycotoxins. Here, we investigated interactions of grain-feeding Tenebrio molitor larvae with four grain-colonizing Fusarium species on wheat kernels. Since numerous metabolites produced by Fusarium spp. are toxic to insects, we tested the hypothesis that the insect senses and avoids Fusarium-colonized grains. We found that only kernels colonized with F. avenaceum or Beauveria bassiana (an insect-pathogenic fungal control) were avoided by the larvae as expected. Kernels colonized with F. proliferatum, F. poae or F. culmorum attracted T. molitor larvae significantly more than control kernels. The avoidance/preference correlated with larval feeding behaviors and weight gain. Interestingly, larvae that had consumed F. proliferatum- or F. poae-colonized kernels had similar survival rates as control. Larvae fed on F. culmorum-, F. avenaceum- or B. bassiana-colonized kernels had elevated mortality rates. HPLC analyses confirmed the following mycotoxins produced by the fungal strains on the kernels: fumonisins, enniatins and beauvericin by F. proliferatum, enniatins and beauvericin by F. poae, enniatins by F. avenaceum, and deoxynivalenol and zearalenone by F. culmorum. Our results indicate that T. molitor larvae have the ability to sense potential survival threats of kernels colonized with F. avenaceum or B. bassiana, but not with F. culmorum. Volatiles potentially along with gustatory cues produced by these fungi may represent survival threat signals for the larvae resulting in their avoidance. Although F. proliferatum or F. poae produced fumonisins, enniatins and beauvericin during kernel colonization, the larvae were able to use those kernels as diet without exhibiting increased mortality. Consumption of F. avenaceum-colonized kernels, however, increased larval mortality; these kernels had higher enniatin levels than F

  2. Effect of Fungal Colonization of Wheat Grains with Fusarium spp. on Food Choice, Weight Gain and Mortality of Meal Beetle Larvae (Tenebrio molitor)

    PubMed Central

    Guo, Zhiqing; Döll, Katharina; Dastjerdi, Raana; Karlovsky, Petr; Dehne, Heinz-Wilhelm; Altincicek, Boran

    2014-01-01

    Species of Fusarium have significant agro-economical and human health-related impact by infecting diverse crop plants and synthesizing diverse mycotoxins. Here, we investigated interactions of grain-feeding Tenebrio molitor larvae with four grain-colonizing Fusarium species on wheat kernels. Since numerous metabolites produced by Fusarium spp. are toxic to insects, we tested the hypothesis that the insect senses and avoids Fusarium-colonized grains. We found that only kernels colonized with F. avenaceum or Beauveria bassiana (an insect-pathogenic fungal control) were avoided by the larvae as expected. Kernels colonized with F. proliferatum, F. poae or F. culmorum attracted T. molitor larvae significantly more than control kernels. The avoidance/preference correlated with larval feeding behaviors and weight gain. Interestingly, larvae that had consumed F. proliferatum- or F. poae-colonized kernels had similar survival rates as control. Larvae fed on F. culmorum-, F. avenaceum- or B. bassiana-colonized kernels had elevated mortality rates. HPLC analyses confirmed the following mycotoxins produced by the fungal strains on the kernels: fumonisins, enniatins and beauvericin by F. proliferatum, enniatins and beauvericin by F. poae, enniatins by F. avenaceum, and deoxynivalenol and zearalenone by F. culmorum. Our results indicate that T. molitor larvae have the ability to sense potential survival threats of kernels colonized with F. avenaceum or B. bassiana, but not with F. culmorum. Volatiles potentially along with gustatory cues produced by these fungi may represent survival threat signals for the larvae resulting in their avoidance. Although F. proliferatum or F. poae produced fumonisins, enniatins and beauvericin during kernel colonization, the larvae were able to use those kernels as diet without exhibiting increased mortality. Consumption of F. avenaceum-colonized kernels, however, increased larval mortality; these kernels had higher enniatin levels than F

  3. The phylogenetic significance of colour patterns in marine teleost larvae

    PubMed Central

    Baldwin, Carole C

    2013-01-01

    Ichthyologists, natural-history artists, and tropical-fish aquarists have described, illustrated, or photographed colour patterns in adult marine fishes for centuries, but colour patterns in marine fish larvae have largely been neglected. Yet the pelagic larval stages of many marine fishes exhibit subtle to striking, ephemeral patterns of chromatophores that warrant investigation into their potential taxonomic and phylogenetic significance. Colour patterns in larvae of over 200 species of marine teleosts, primarily from the western Caribbean, were examined from digital colour photographs, and their potential utility in elucidating evolutionary relationships at various taxonomic levels was assessed. Larvae of relatively few basal marine teleosts exhibit erythrophores, xanthophores, or iridophores (i.e. nonmelanistic chromatophores), but one or more of those types of chromatophores are visible in larvae of many basal marine neoteleosts and nearly all marine percomorphs. Whether or not the presence of nonmelanistic chromatophores in pelagic marine larvae diagnoses any major teleost taxonomic group cannot be determined based on the preliminary survey conducted, but there is a trend toward increased colour from elopomorphs to percomorphs. Within percomorphs, patterns of nonmelanistic chromatophores may help resolve or contribute evidence to existing hypotheses of relationships at multiple levels of classification. Mugilid and some beloniform larvae share a unique ontogenetic transformation of colour pattern that lends support to the hypothesis of a close relationship between them. Larvae of some tetraodontiforms and lophiiforms are strikingly similar in having the trunk enclosed in an inflated sac covered with xanthophores, a character that may help resolve the relationships of these enigmatic taxa. Colour patterns in percomorph larvae also appear to diagnose certain groups at the interfamilial, familial, intergeneric, and generic levels. Slight differences in generic

  4. Anguilliform larvae collected off North Carolina

    USGS Publications Warehouse

    Ross, S.W.; Casazza, T.L.; Quattrini, A.M.; Sulak, K.J.

    2007-01-01

    The distinctive larval stage of eels (leptocephalus) facilitates dispersal through prolonged life in the open ocean. Leptocephali are abundant and diverse off North Carolina, yet data on distributions and biology are lacking. The water column (from surface to 1,293 m) was sampled in or near the Gulf Stream off Cape Hatteras, Cape Lookout, and Cape Fear, North Carolina during summer through fall of 1999-2005, and leptocephali were collected by neuston net, plankton net, Tucker trawl, and dip net. Additional samples were collected nearly monthly from a transect across southern Onslow Bay, North Carolina (from surface to 91 m) from April 2000 to December 2001 by bongo and neuston nets, Methot frame trawl, and Tucker trawl. Overall, 584 tows were completed, and 224 of these yielded larval eels. The 1,295 eel leptocephali collected (combining all methods and areas) represented at least 63 species (nine families). Thirteen species were not known previously from the area. Dominant families for all areas were Congridae (44% of individuals, 11 species), Ophichthidae (30% of individuals, 27 species), and Muraenidae (22% of individuals, ten species). Nine taxa accounted for 70% of the overall leptocephalus catches (in order of decreasing abundance): Paraconger caudilimbatus (Poey), Gymnothorax ocellatus Agassiz complex, Ariosoma balearicum (Delaroche), Ophichthus gomesii (Castelnau), Callechelys muraena Jordan and Evermann, Letharchus aliculatus McCosker, Rhynchoconger flavus (Goode and Bean), Ophichthus cruentifer (Goode and Bean), Rhynchoconger gracilior (Ginsburg). The top three species represented 52% of the total eel larvae collected. Most leptocephali were collected at night (79%) and at depths > 45 m. Eighty percent of the eels collected in discrete depth Tucker trawls at night ranged from mean depths of 59-353 m. A substantial number (38% of discrete depth sample total) of larval eels were also collected at the surface (neuston net) at night. Daytime leptocephalus

  5. Accelerated larvae development of Ascaris lumbricoides eggs with ultraviolet radiation

    NASA Astrophysics Data System (ADS)

    Aladawi, M. A.; Albarodi, H.; Hammoudeh, A.; Shamma, M.; Sharabi, N.

    2006-01-01

    In order to investigate the effect of UV radiation on the development of Ascaris lumbricoides larvae, eggs were exposed to increasing UV doses. Filtered wastewater from the secondary effluent taken from the Damascus wastewater treatment plant (DWTP) was used as irradiation and incubation medium. The progressive and accelerated embryonation stages were microscopically observed and the percentages of completely developed larvae were determined weekly. Results indicated that the UV radiation accelerated the development of larvae with increasing UV dose. Preliminary information about the relationship between the UV radiation dose and rate of embryonation is also presented.

  6. Fatal Baylisascaris larva migrans in a colony of Japanese macaques kept by a safari-style zoo in Japan.

    PubMed

    Sato, Hiroshi; Une, Yumi; Kawakami, Shigehisa; Saito, Eriko; Kamiya, Haruo; Akao, Nobuaki; Furuoka, Hidefumi

    2005-06-01

    A colony of Japanese macaques (Macaca fuscata fuscata) kept by a safari-style zoo in Japan experienced 9 sporadic cases of fatal neurological diseases, such as epilepsy and posterior paralysis, during the 12 yr from 1989 to 2001. This macaque colony consisted of approximately 30 animals, on average, during this period, and the macaques shared their living space with II American black bears (Ursus americanus) harboring zoonotic roundworms (Baylisascaris transfuga). Close to this enclosure, a cote for 2-3 raccoons (Procyon lotor) was placed, and raw sewage from this cote ran into a shallow drain in the area for macaques and bears. However, fecal examinations in recent years did not detect the infection of raccoons with zoonotic roundworms (Baylisascaris procyonis). Postmortem histological examination of the latest 2 ill macaques detected multifocal malacia in the brain; 2 ascarid larvae of 60 microm maximum width were encapsulated in the cerebrum and lungs of 1 of the animals. To determine the causative ascarid species of the fatal larva migrans, we analyzed 2 additional encapsulated Baylisascaris larvae collected from formalin-fixed lungs by morphological and molecular approaches. This sporadic outbreak is the second record of Baylisascaris larva migrans in animals in Japan.

  7. Caspofungin primes the immune response of the larvae of Galleria mellonella and induces a non-specific antimicrobial response.

    PubMed

    Kelly, Judy; Kavanagh, Kevin

    2011-02-01

    The echinocandins (e.g. caspofungin) function by inhibiting the synthesis of 1,3-β-glucan in the fungal cell wall. While the potent antifungal activity of caspofungin has been well characterized in mammals, this study investigated the in vivo antifungal effect of caspofungin using larvae of the insect Galleria mellonella. Caspofungin was successful in increasing the survival of larvae that were inoculated with Candida albicans 1 h before the drug was administered, particularly when a concentration of 0.19 μg ml(-1) was used. Pre-injecting larvae with caspofungin also increased their survival when they were inoculated with either Staphylococcus aureus or C. albicans. Caspofungin administration resulted in an increase in the number of circulating immune cells (haemocytes), an increase in the expression of the genes encoding IMPI and transferrin, and an increase in the expression of a number of proteins (identified by liquid chromatography-mass spectrometry) some of which have immune functions. This work indicates that administration of caspofungin can increase the survival of infected G. mellonella larvae, and this is due to the antifungal properties of caspofungin and also to the ability of caspofungin to prime the insect's immune response.

  8. Inducible costimulator is required for type 2 antibody isotype switching but not T helper cell type 2 responses in chronic nematode infection

    PubMed Central

    Loke, P'ng; Zang, Xingxing; Hsuan, Lisa; Waitz, Rebecca; Locksley, Richard M.; Allen, Judith E.; Allison, James P.

    2005-01-01

    Inducible costimulator (ICOS) has been suggested to perform an important role in T helper cell type 2 (Th2) responses, germinal center formation, and isotype switching. The role of ICOS in chronic Th2 responses was studied in a nematode model with the filarial parasite, Brugia malayi. Contrary to expectations, we did not observe a significant defect in IL-4-producing Th2 cells in ICOS–/– mice or in eosinophil recruitment. We also found that ICOS was not required for the differentiation of alternatively activated macrophages (AAMΦ) that express Ym1 and Fizz1. Although the production of IgE was slightly reduced in ICOS–/– mice, this was not as significant as in CD28–/– mice. In contrast to live infection, the primary response of ICOS–/– mice immunized with soluble B. malayi antigen and complete Freund's adjuvant resulted in significantly fewer IL-4-producing cells in the lymph nodes. As previously reported, we observed a defect in antibody isotype switching toward the IgG1 isotype in ICOS–/– mice during live infection. Interestingly, there was a significant enhancement of parasite-specific IgG3 isotype antibodies. CD28–/– and MHC class II–/– mice also had enhanced parasite-specific IgG3 isotype antibodies. Our results suggest that ICOS is not required to maintain a chronic cellular Th2 response. The primary role of ICOS in a chronic helminth infection could be to drive antibodies toward type 2 isotypes. T-independent antibody response to the parasite could be enhanced in the absence of costimulation and T cell help. PMID:15994233

  9. Using parasitic trematode larvae to quantify an elusive vertebrate host.

    PubMed

    Byers, James E; Altman, Irit; Grosse, Andrew M; Huspeni, Todd C; Maerz, John C

    2011-02-01

    Digenean trematode parasites require multiple host species to complete their life cycles, and their abundance can often be strongly correlated with the abundance of their host species. Species richness and abundance of parasites in easily sampled host species may yield an accurate estimate of the species richness and abundance of other hosts in a parasite's life cycle that are difficult to survey directly. Accordingly, we investigated whether prevalence and mean abundance of trematodes could be used to estimate the abundance of one of their host species, diamondback terrapins (Malaclemys terrapin), which are difficult to sample and are designated as near threatened (by the International Union for Conservation of Nature [IUCN Red List]) along some U.S. coasts. As an adult the trematode Pleurogonius malaclemys is specific to terrapins. Its larval stages live first inside mud snails (Ilyanassa obsoleta) and are subsequently shed into the environment where they form external metacercarial cysts on hard surfaces such as snail opercula. The life cycle of P. malaclemys is completed when terrapins ingest these cysts. At 12 sites along the coast of Georgia (U.S.A.), we determined the prevalence of internal P. malaclemys larvae in mud snails (proportion of infected snails in a population) and the prevalence and mean abundance of external trematode cysts. We examined whether these data were correlated with terrapin abundance, which we estimated with mark-recapture methods. The abundance of external cysts and salinity explained ≥59% of the variability in terrapin abundance. We suggest that dependent linkages between the life stages of multihost parasites make them reliable predictors of host species' abundance, including hosts with abundances that are challenging to quantify directly.

  10. Simple clearing technique as species determination tool in blowfly larvae.

    PubMed

    Niederegger, Senta; Wartenberg, Nelly; Spiess, Roland; Mall, Gita

    2011-03-20

    A simple clearing technique is presented by which species specific structures and organs of blowfly larvae can easily be visualized and displayed without any danger of mechanical damages or dislocations of delicate formations and without fixation of the object.

  11. [Community features of Sacrabaeoida larvae in Stipa grandis steppe].

    PubMed

    Xinmin, Liu; Ning, Wu

    2004-09-01

    The study showed that in the Stipa grandis steppe of Inner Mongolia, there were 4 families and 9 species of Scarabaeoidea larvae, among which, the numbers of species and individuals of Melolonthidae were more than those of other families. The important value of the dominant species in Scarabaeoidea larvae community were Trematodes tenebrioides > Serica orientalis > Amphimallon solstitialis > Cyriopertha arcuata. Based on the features of their seasonal dynamics, they could be classified into three kinds. The first kind was that their density peak occurred in spring and autumn, such as Serica orientalis. Cyriopertha arcuata belonged to the second kind, and its density had no obvious fluctuation through all the year. Trematodes tenebrioides and Amphimallon solstitialis could be classified into the third kind, and their density peak all occurred in autumn. The biodiversity index of Scarabaeoidea larvae community was relatively higher in autumn than in spring and summer. Although the richness of Scarabaeoidea larvae populations was not lower in spring, their composition was very simple.

  12. Lead levels of Culex mosquito larvae inhabiting lead utilizing factory

    PubMed Central

    Kitvatanachai, S; Apiwathnasorn, C; Leemingsawat, S; Wongwit, W; Overgaard, HJ

    2011-01-01

    Objective To determine lead level primarily in Culex quinquefasciatus (Cx. quinquefasciatus), and Culex gelidus (Cx. gelidus) larvae inhabiting lead consuming factories, and to putatively estimate eco-toxicological impact of effluents from the firms. Methods Third instars larvae were sampled by standard dipping method and lead concentrations in the larvae and their respective surrounding factory aquatic environments were determined through standard atomic absorption spectrophotometry (AAS). Results Cx. quinquefasciatus was the most abundant species followed by Cx. gelidus. The levels of lead were higher in the Cx. quinquefasci