Publications

the efficacy of a mixture of trimethoprim and sulphaquinoxaline against plasmodium gallinaceum malaria in the domesticated fowl gallus gallus.	the apicomplexan parasite plasmodium gallinaceum has not been much studied from the veterinary standpoint. although it causes malaria in domesticated chickens, no effective drugs appear to be commercially available. a mixture of trimethoprim and sulphaquinoxaline (tmp/sqx, ratio 1:3), with a wide spectrum of activity against bacteria and coccidia, is here shown to be also efficacious against blood-induced p. gallinaceum malaria when administered therapeutically in the feed of chickens for 5-day ...	2005	15845274
avian malaria: clinical and chemical pathology of plasmodium gallinaceum in the domesticated fowl gallus gallus.	data on the effects of plasmodium gallinaceum on domesticated fowl are sparse, justifying a full investigation of its pathology. clinical signs following blood-induced infections with the wellcome line of strain 8a included depression, fever, anorexia, reduced weight gain, poor feed conversion, anaemia, green faeces and often death. after administration of 10(6) erythrocytic parasites, mortality 5 to 10 days after infection was 10% to 93% in chickens 7 to 84 days old. the older the birds, the lo ...	2005	15763737
plasmodium gallinaceum: clinical progression, recovery, and resistance to disease in chickens infected via mosquito bite.	historically, in vivo experiments of plasmodium gallinaceum in chickens have caused high mortality. perhaps because of this high mortality, it remains to be demonstrated whether recovered birds will resist a second episode of illness when re-exposed to infected mosquitoes. in the current study, groups of 10 chicks were infected with p. gallinaceum via mosquito bite. parasitemia and anemia were followed by recovery in all birds, although they had persisting, low levels of parasitized erythrocytes ...	2005	16354820
inhibition of malaria parasite blood stages by tyrocidines, membrane-active cyclic peptide antibiotics from bacillus brevis.	tyrothricin, a complex mixture of antibiotic peptides from bacillus brevis, was reported in 1944 to have antimalarial activity rivalling that of quinine in chickens infected with plasmodium gallinaceum. we have isolated the major components of tyrothricin, cyclic decapeptides collectively known as the tyrocidines, and tested them against the human malaria parasite plasmodium falciparum using standard in vitro assays. although the tyrocidines differ from each other by conservative amino acid subs ...	2007	17462586
correlation between serum transferrin receptor and percentage of parasitemia in malaria. a preliminary report.	the serum transferrin receptor (stfr) concentration is an individual reflects of the extent of erythropoietic activity, and is a useful marker for monitoring erythropoiesis. malaria is an important tropical disease with evidence of ineffective erythropoiesis. although there have been previous reports concerning stfr changes in malaria, these were descriptive studies of infected and non-infected case and there are no previous reports of correlation between stfr levels and parasitemia in malaria. ...	2007	17645190
change of serum transferrin receptor due to malarial infection, an experiment in plasmodium gallinaceum infected chicken model.	the serum transferrin receptor (stfr) concentration in an individual reflects the extent of erythropoietic activity and is considered as an useful marker of iron deficiency independent of concurrent inflammation or infection. however, data on the impact of malaria on this parameter are ambiguous.	2007	18092532
genetic control of malaria parasite transmission: threshold levels for infection in an avian model system.	genetic strategies for controlling malaria transmission based on engineering pathogen resistance in anopheles mosquitoes are being tested in a number of animal models. a key component is the effector molecule and the efficiency with which it reduces parasite transmission. single-chain antibodies (scfvs) that bind the circumsporozoite protein of the avian parasite, plasmodium gallinaceum, can reduce mean intensities of sporozoite infection of salivary glands by two to four orders of magnitude in ...	2007	17556613
laminin and a plasmodium ookinete surface protein inhibit melanotic encapsulation of sephadex beads in the hemocoel of mosquitoes.	in refractory mosquitoes, melanotic encapsulation of plasmodium ookinetes and oocysts is a commonly observed immune response. however, in susceptible mosquitoes, plasmodium oocysts develop extracellularly in the body cavity without being recognized by the immune system. like plasmodium gallinaceum oocysts, negatively charged carboxymethyl (cm)-sephadex beads implanted in the hemocoel of aedes aegypti female mosquitoes were not usually melanized, but were coated with mosquito-derived laminin. con ...	2007	17224290
exoerythrocytic development of plasmodium gallinaceum in the white leghorn chicken.	plasmodium gallinaceum typically causes sub-clinical disease with low mortality in its primary host, the indian jungle fowl gallus sonnerati. domestic chickens of european origin, however, are highly susceptible to this avian malaria parasite. here we describe the development of p. gallinaceum in young white leghorn chicks with emphasis on the primary exoerythrocytic phase of the infection. using various regimens for infection, we found that p. gallinaceum induced a transient primary exoerythroc ...	2008	18005972
the avian malaria parasite plasmodium gallinaceum causes marked structural changes on the surface of its host erythrocyte.	using a combination of atomic force, scanning and transmission electron microscopy, we found that avian erythrocytes infected with the avian malaria parasite plasmodium gallinaceum develop approximately 60 nm wide and approximately 430 nm long furrow-like structures on the surface. furrows begin to appear during the early trophozoite stage of the parasite's development. they remain constant in size and density during the course of parasite maturation and are uniformly distributed in random orien ...	2008	18442920
expression of a mutated phospholipase a2 in transgenic aedes fluviatilis mosquitoes impacts plasmodium gallinaceum development.	the genetic manipulation of mosquito vectors is an alternative strategy in the fight against malaria. it was previously shown that bee venom phospholipase a2 (pla2) inhibits ookinete invasion of the mosquito midgut although mosquito fitness was reduced. to maintain the pla2 blocking ability without compromising mosquito biology, we mutated the protein-coding sequence to inactivate the enzyme while maintaining the protein's structure. dna encoding the mutated pla2 (mpla2) was placed downstream of ...	2008	18353106
ampelozyziphus amazonicus ducke (rhamnaceae), a medicinal plant used to prevent malaria in the amazon region, hampers the development of plasmodium berghei sporozoites.	most medicinal plants used against malaria in endemic areas aim to treat the acute symptoms of the disease such as high temperature fevers with periodicity and chills. in some endemic areas of the brazilian amazon region one medicinal plant seems to be an exception: ampelozyziphus amazonicus, locally named "indian beer" or "saracura-mira", used to prevent the disease when taken daily as a cold suspension of powdered dried roots. in previous work we found no activity of the plant extracts against ...	2008	18599059
proteomic analysis of zygote and ookinete stages of the avian malaria parasite plasmodium gallinaceum delineates the homologous proteomes of the lethal human malaria parasite plasmodium falciparum.	delineation of the complement of proteins comprising the zygote and ookinete, the early developmental stages of plasmodium within the mosquito midgut, is fundamental to understand initial molecular parasite-vector interactions. the published proteome of plasmodium falciparum does not include analysis of the zygote/ookinete stages, nor does that of p. berghei include the zygote stage or secreted proteins. p. gallinaceum zygote, ookinete, and ookinete-secreted/released protein samples were prepare ...	2008	18563747
pathogenic action of plasmodium gallinaceum in chickens: brain histology and nitric oxide production by blood monocyte-derived macrophages.	plasmodium infection causes major losses to animal and human populations. the characterization of experimental malaria models is needed for a better understanding of disease mechanisms and the development of new treatment protocols. chickens infected with plasmodium gallinaceum constitute an adequate malaria model due to the phylogenetic proximity of this parasite to human plasmodium as well as similarities in disease manifestation, such as cerebral malaria. the aim of the present study was to f ...	2010	20537466
blocking of plasmodium transmission by cooperative action of cecropin a and defensin a in transgenic aedes aegypti mosquitoes.	to overcome burden of mosquito-borne diseases, multiple control strategies are needed. population replacement with genetically modified mosquitoes carrying antipathogen effector genes is one of the possible approaches for controlling disease transmission. however, transgenic mosquitoes with antipathogen phenotypes based on overexpression of a single type effector molecule are not efficient in interrupting pathogen transmission. here, we show that co-overexpression of two antimicrobial peptides ( ...	2010	20385844
susceptibility of anopheles stephensi to plasmodium gallinaceum: a trait of the mosquito, the parasite, and the environment.	vector susceptibility to plasmodium infection is treated primarily as a vector trait, although it is a composite trait expressing the joint occurrence of the parasite and the vector with genetic contributions of both. a comprehensive approach to assess the specific contribution of genetic and environmental variation on "vector susceptibility" is lacking. here we developed and implemented a simple scheme to assess the specific contributions of the vector, the parasite, and the environment to "vec ...	2011	21694762
chickens treated with a nitric oxide inhibitor became more resistant to plasmodium gallinaceum infection due to reduced anemia, thrombocytopenia and inflammation.	malaria is a serious infectious disease caused by parasites of the plasmodium genus that affect different vertebrate hosts. severe malaria leads to host death and involves different pathophysiological phenomena such as anemia, thrombocytopenia and inflammation. nitric oxide (no) is an important effector molecule in this disease, but little is known about its role in avian malaria models. plasmodium gallinaceum-infected chickens were treated with aminoguanidine (ag), an inhibitor of inducible nit ...	2013	23398940
identification and expression of maebl, an erythrocyte-binding gene, in plasmodium gallinaceum.	avian malaria is of significant ecological importance and serves as a model system to study broad patterns of host switching and host specificity. the erythrocyte invasion mechanism of the malaria parasite plasmodium is mediated, in large part, by proteins of the erythrocyte-binding-like (ebl) family of genes. however, little is known about how these genes are conserved across different species of plasmodium, especially those that infect birds. using bioinformatical methods in conjunction with p ...	2013	23224610
loop-mediated isothermal amplification assay for detection of histomonas meleagridis infection in chickens targeting the 18s rrna sequences.	histomonas meleagridis is the causative agent of histomonosis, a disease of gallinaceous fowl characterized by necrotic typhlitis, hepatitis, and high mortality. to develop a rapid and sensitive method for specific detection of h. meleagridis, an assay based on loop-mediated isothermal amplification (lamp) targeting the 18s rrna gene was established. the detection limit of the lamp assay was 10 copies for standard plasmids containing an 18s rrna gene fragment, which was superior to that of a cla ...	2013	24325302
in vivo transmission blocking activities of artesunate on the avian malaria parasite plasmodium gallinaceum.	infection and transmission of the avian malaria parasite plasmodium gallinaceum in domestic chickens is associated with high economic burden and presents a major challenge to poultry industry in south east asia. development of drugs targeting both asexual blood stage parasites and sexual stages of the avian malarias will be beneficial for malaria treatment and eradication. however, current drugs recommended for treatment of the avian malaria parasites target specifically the asexual blood stage ...	2013	23937960
transcriptome sequencing and analysis of plasmodium gallinaceum reveals polymorphisms and selection on the apical membrane antigen-1.	plasmodium erythrocyte invasion genes play a key role in malaria parasite transmission, host-specificity and immuno-evasion. however, the evolution of the genes responsible remains understudied. investigating these genes in avian malaria parasites, where diversity is particularly high, offers new insights into the processes that confer malaria pathogenesis. these parasites can pose a significant threat to birds and since birds play crucial ecological roles they serve as important models for dise ...	2014	25261185
loop-mediated isothermal amplification assay for detection of histomonas meleagridis infection in chickens targeting the 18s rrna sequences.	histomonas meleagridis is the causative agent of histomonosis, a disease of gallinaceous fowl characterized by necrotic typhlitis, hepatitis, and high mortality. to develop a rapid and sensitive method for specific detection of h. meleagridis, an assay based on loop-mediated isothermal amplification (lamp) targeting the 18s rrna gene was established. the detection limit of the lamp assay was 10 copies for standard plasmids containing an 18s rrna gene fragment, which was superior to that of a cla ...	2014	24320623
effects of artesunate treatment on plasmodium gallinaceum transmission in the vectors aedes aegypti and culex quinquefasciatus.	in the absence of vaccines, chemotherapy is an effective and economical way for controlling malaria. development of anti-malarial drugs that target pathogenic blood stage parasites and gametocytes is preferable for the treatment as it can alleviate the host's morbidity and mortality and block transmission of the plasmodium parasite. recently, our laboratory has developed an in vivo transmission blocking assay that involves administration of 7 consecutive daily doses of a test compound into domes ...	2015	25466617
development of malaria transmission-blocking vaccines: from concept to product.	despite decades of effort battling against malaria, the disease is still a major cause of morbidity and mortality. transmission-blocking vaccines (tbvs) that target sexual stage parasite development could be an integral part of measures for malaria elimination. in the 1950s, huff et al. first demonstrated the induction of transmission-blocking immunity in chickens by repeated immunizations with plasmodium gallinaceum-infected red blood cells. since then, significant progress has been made in ide ...	2015	26003037
molecular detection of the avian malaria parasite plasmodium gallinaceum in thailand.	avian malaria is one of the most common veterinary problems in southeast asia. the standard molecular method for detection of the avian malaria parasite involves the phenol-chloroform extraction of parasite genomic (g)dna followed by the amplification of parasite gdna using polymerase chain reaction (pcr). however, the phenol-chloroform extraction method is time-consuming and requires large amounts of samples and toxic organic solvents, thereby limiting its applications for parasite detection in ...	2015	25868848
vector competence of aedes albopictus (skuse) and aedes aegypti (linnaeus) for plasmodium gallinaceum infection and transmission.	avian malaria caused by plasmodium gallinaceum is an important mosquito-borne disease. eradication of this disease remains problematic since its competent vectors are diverse and widely distributed across the globe. several mosquito species were implicated as competent vectors for this parasite. however, studies on vector competence for p. gallinaceum remain limited. in this study, vector competence in the two most predominant mosquito vectors in tropical countries, aedes albopictus and ae. aegy ...	2017	28579025
artesunate-tafenoquine combination therapy promotes clearance and abrogates transmission of the avian malaria parasite plasmodium gallinaceum.	clinical manifestations of malaria infection in vertebrate hosts arise from the multiplication of the asexual stage parasites in the blood, while the gametocytes are responsible for the transmission of the disease. antimalarial drugs that target the blood stage parasites and transmissible gametocytes are rare, but are essentially needed for the effective control of malaria and for limiting the spread of resistance. artemisinin and its derivatives are the current first-line antimalarials that are ...	2017	28043395