The most cited articles published since 2009, extracted from Scopus
Volume 124, Issue 1, January 2010, Pages 80-89
Molecular tools have been developed to detect and differentiate Cryptosporidium at the species/genotype and subtype levels. These tools have been increasingly used in characterizing the transmission of Cryptosporidium spp. in humans and animals. Results of these molecular epidemiologic studies have led to better appreciation of the public health importance of Cryptosporidium species/genotypes in various animals and improved understanding of infection sources in humans. Geographic, seasonal and socioeconomic differences in the distribution of Cryptosporidium spp. in humans have been identified, and have been attributed to differences in infection sources and transmission routes. The transmission of C. parvum in humans is mostly anthroponotic in developing countries, with zoonotic infections play an important role in developed countries. Species of Cryptosporidium and subtype families of C. hominis have been shown to induce different clinical manifestations and have different potential to cause outbreaks. The wide use of a new generation of genotyping and subtyping tools in well designed epidemiologic studies should lead to a more in-depth understanding of the epidemiology of cryptosporidiosis in humans and animals.
Volume 124, Issue 1, January 2010, Pages 90-97
Amphibians, reptiles, birds and mammals serve as hosts for 19 species of Cryptosporidium. All 19 species have been confirmed by morphological, biological, and molecular data. Fish serve as hosts for three additional species, all of which lack supporting molecular data. In addition to the named species, gene sequence data from more than 40 isolates from various vertebrate hosts are reported in the scientific literature or are listed in GenBank. These isolates lack taxonomic status and are referred to as genotypes based on the host of origin. Undoubtedly, some will eventually be recognized as species. For them to receive taxonomic status sufficient morphological, biological, and molecular data are required and names must comply with the rules of the International Code for Zoological Nomenclature (ICZN). Because the ICZN rules may be interpreted differently by persons proposing names, original names might be improperly assigned, original literature might be overlooked, or new scientific methods might be applicable to determining taxonomic status, the names of species and higher taxa are not immutable. The rapidly evolving taxonomic status of Cryptosporidium sp. reflects these considerations.
Volume 124, Issue 1, January 2010, Pages 10-25
Jeffrey L. Jones | Jitender P. Dubey
Humans become infected with Toxoplasma gondii mainly by ingesting uncooked meat containing viable tissue cysts or by ingesting food or water contaminated with oocysts from the feces of infected cats. Circumstantial evidence suggests that oocyst-induced infections in humans are clinically more severe than tissue cyst-acquired infections. Until recently, waterborne transmission of T. gondii was considered uncommon, but a large human outbreak linked to contamination of a municipal water reservoir in Canada by wild felids and the widespread infection of marine mammals in the USA provided reasons to question this view. The present paper examines the possible importance of T. gondii transmission by water.
Volume 124, Issue 1, January 2010, Pages 138-146
Rachel Mary Chalmers | Angharad Puw Davies
Cryptosporidium has emerged as an important cause of diarrhoeal illness worldwide, especially amongst young children and patients with immune deficiencies. Usually presenting as a gastro-enteritis-like syndrome, disease ranges in seriousness from mild to severe and signs and symptoms depend on the site of infection, nutritional and immune status of the host, and parasite-related factors. Sources and routes of transmission are multiple, involving both zoonotic and anthroponotic spread, and facilitated by the resistance of the parasite to many commonly used disinfectants. Prevention and control measures are important for the protection of vulnerable groups since treatment options are limited. This review covers the life cycle, pathogenesis, clinical presentations, diagnosis, prevention and management of cryptosporidiosis in humans. Crown Copyright © 2009.
Volume 124, Issue 1, January 2010, Pages 31-39
Jonathan S. Yoder | Michael J. Beach
Surveillance for Cryptosporidium in the United States indicates that the reported incidence of infection has increased dramatically since 2004. The reasons for this increase are unclear but might be caused by an actual increase in incidence, improved surveillance, improved awareness about cryptosporidiosis, and/or increases in testing practices resulting from the licensing of the first-ever treatment for cryptosporidiosis. While regional differences remain, the incidence of cryptosporidiosis appears to be increasing across the United States. Onset of illness is most common during the summer, particularly among younger children. Cryptosporidiosis case reporting also influences outbreak detection and reporting; the recent rise in cases coincides with an increase in the number of reported cryptosporidiosis outbreaks, particularly in treated recreational water venues. Risk factors include ingesting contaminated recreational or drinking water, exposure to infected animals, having close contacts with cryptosporidiosis, travel to disease-endemic areas, and ingestion of contaminated food. Advances in molecular characterization of clinical specimens have improved our understanding of the changing epidemiology and risk factors. Prevention and control of cryptosporidiosis requires continued efforts to interrupt the transmission of Cryptosporidium through water, food, and contact with infected persons or animals. Of particular importance is continued improvement and monitoring of drinking water treatment and advances in the design, operation, and management of recreational water venues coupled with behavioral changes among the swimming public.
Volume 124, Issue 1, January 2010, Pages 61-79
Huw V. Smith | Rosely A B Nichols
Water and food are major environmental transmission routes for Cryptosporidium, but our ability to identify the spectrum of oocyst contributions in current performance-based methods is limited. Determining risks in water and foodstuffs, and the importance of zoonotic transmission, requires the use of molecular methods, which add value to performance-based morphologic methods. Multi-locus approaches increase the accuracy of identification, as many signatures detected in water originate from species/genotypes that are not infectious to humans. Method optimisation is necessary for detecting small numbers of oocysts in environmental samples consistently, and further work is required to (i) optimise IMS recovery efficiency, (ii) quality assure performance-based methods, (iii) maximise DNA extraction and purification, (iv) adopt standardised and validated loci and primers, (v) determine the species and subspecies range in samples containing mixtures, and standardising storage and transport matrices for validating genetic loci, primer sets and DNA sequences. © 2009 Elsevier Inc. All rights reserved.
Volume 124, Issue 1, January 2010, Pages 45-53
Jean François A Rossignol
Cryptosporidium species and Giardia intestinalis are the most common enteric protozoan pathogens affecting humans worldwide. In recent years, nitazoxanide has been licensed in the United States for the treatment of cryptosporidiosis in non-immunodeficient children and adults, becoming the first drug approved for treating this disease. There is a need for a highly effective treatment for cryptosporidiosis in immunodeficient patients, but the quest for such a drug has proven to be elusive. While not effective against Cryptosporidium, nitroimidazoles such as metronidazole or tinidazole are effective treatments for giardiasis and can be administered as a single dose. Albendazole and nitazoxanide are effective against giardiasis but require multiple doses. Nitazoxanide is the first new drug developed for treating giardiasis in more than 20 years. New potentially promising drug targets in Cryptosporidium and Giardia have been identified, but there appears to be little activity toward clinical development of new drugs. © 2009.
Volume 127, Issue 2, February 2011, Pages 357-364
Josué De Moraes | Carlos R M Nascimento | Priscilla O M V Lopes | Eliana Nakano | Lydia Yamaguchi | Massuo J. Kato | Toshie Kawano
Schistosomiasis is one of the world's greatly neglected tropical diseases, and its control is largely dependent on a single drug, praziquantel. Here, we report the in vitro effect of piplartine, an amide isolated from Piper tuberculatum (Piperaceae), on Schistosoma mansoni adult worms. A piplartine concentration of 15.8 μM reduced the motor activity of worms and caused their death within 24. h in a RPMI 1640 medium. Similarly, the highest sub-lethal concentration of piplartine (6.3 μM) caused a 75% reduction in egg production in spite of coupling. Additionally, piplartine induced morphological changes on the tegument, and a quantitative analysis carried out by confocal microscopy revealed an extensive tegumental destruction and damage in the tubercles. This damage was dose-dependent in the range of 15.8-630.2 μM. At doses higher than 157.6 μM, piplartine induced morphological changes in the oral and ventral sucker regions of the worms. It is the first time that the schistosomicidal activity has been reported for piplartine. © 2010.
Volume 126, Issue 3, November 2010, Pages 366-380
Leanne Mortimer | Kris Chadee
Amebiasis is the disease caused by the enteric dwelling protozoan parasite Entamoeba histolytica. The WHO considers amebiasis as one of the major health problems in developing countries; it is surpassed by only malaria and schistosomiasis for death caused by parasitic infection. E. histolytica primarily lives in the colon as a harmless commensal, but is capable of causing devastating dysentery, colitis and liver abscess. What triggers the switch to a pathogenic phenotype and the onset of disease is unknown. We are becoming increasingly aware of the complexity of the host-parasite interaction. During chronic stages of amebiasis, the host develops an immune response that is incapable of eliminating tissue resident parasites, while the parasite actively immunosuppresses the host. However, most individuals with symptomatic infections succumb only to an episode of dysentery. Why most halt invasion and a minority progress to chronic disease remains poorly understood. This review presents a current understanding of the immune processes that shape the outcome of E. histolytica infections during its different stages. © 2010 Elsevier Inc.
Volume 121, Issue 3, March 2009, Pages 242-245
Maryam Niyyati | Jacob Lorenzo-Morales | Sasan Rezaie | Firoozeh Rahimi | Mehdi Mohebali | Amir Hossein Maghsood | Afsaneh Motevalli-Haghi | Carmen Ma Martín-Navarro | Shohreh H. Farnia | Basilio Valladares | Mostafa Rezaeian
In this study, 15 Acanthamoeba isolates from AK patients and 10 environmental samples (water, soil and animal-origin samples) were classified at the genotype level based on the sequence analysis of the Diagnostic Fragment 3 (DF3) of Acanthamoeba small subunit rRNA gene. The obtained results revealed that most of these Acanthamoeba strains belonged to genotype T4 both in clinical and environmental samples. The presence T11 genotype in clinical samples was also revealed after the genotyping analysis and to our knowledge this is the first report of T11 genotype in Iran. Moreover, the isolation of T4 genotype from cow faeces in this study highlights a possible transmission of Acanthamoeba through animal faeces in Iran. Overall, the widespread distribution of pathogenic Acanthamoeba T4 across the environmental sources and the increasing number of contact lens wearers in Iran, demands more awareness within the public and health professionals as this pathogen is emerging as a risk for human health in Iran and worldwide. © 2008 Elsevier Inc. All rights reserved.
Volume 122, Issue 1, May 2009, Pages 47-50
Houshuang Zhang | Oriel Matlhahane Molefi Thekisoe | Gabriel Oluga Aboge | Hisako Kyan | Junya Yamagishi | Noboru Inoue | Yoshifumi Nishikawa | Satoshi Zakimi | Xuenan Xuan
Loop-mediated isothermal amplification (LAMP) method amplifies DNA with high specificity, sensitivity and rapidity. In this study, we used a conserved sequence in the 200- to 300-fold repetitive 529 bp gene of Toxoplasma gondii to design primers for LAMP test. Detection limit of T. gondii LAMP assay with the primers is 1 pg/μL of T. gondii DNA, which was evaluated using 10-fold serially diluted DNA of cultured parasites. Furthermore, LAMP and conventional PCR methods were applied for amplification of the T. gondii DNA extracted from the lymph nodes taken from pigs which were suspected to be Toxoplasma infection. As a result, 76.9% (70/91) and 85.7% (78/91) of the samples were positive on PCR and LAMP analyzes, respectively. Therefore, the LAMP has a potential to be applied as an alternative molecular diagnostic tool for detection of T. gondii infection from veterinary samples. This is the first study, which applies the LAMP method to diagnose Toxoplasma from veterinary samples. © 2009 Elsevier Inc. All rights reserved.
Volume 121, Issue 2, February 2009, Pages 144-150
Shinji Izumiyama | Mako Omura | Tomohiko Takasaki | Hiroshi Ohmae | Hiroko Asahi
Reliable analytical techniques to test growth-promoting and antimalarial efficacy on plasmodia are very important. Flow cytometry (FCM) offers the possibility to study developmental stages of intraerythrocytic growth of malaria parasites using nucleic acid staining. To analyze the growth of Plasmodium falciparum SYBR Green I was introduced as an intercalating dye with FCM for the 488 nm line of an argon laser. Procedures employing FCM, including fixatives, dye concentrations, dilution buffer, and staining period, were optimized to simplify the method. FCM as described here allows parasitemia and parasites of different stages to be quantified according to the DNA content. The proportion of parasitized erythrocytes estimated by FCM and the Giemsa method agreed with determination by parasite lactate dehydrogenase. The protocol was extended to merozoite counting as a sensitive assay of growth inhibition of the parasite. © 2008 Elsevier Inc. All rights reserved.
Volume 124, Issue 1, January 2010, Pages 113-120
Una M. Ryan
Whilst considerable information is available for avian cryptosporidiosis, scant information is available for Cryptosporidium infections in fish and amphibians. The present review details recent studies in avian cryptosporidiosis and our current knowledge of piscine and amphibian infections. © 2009 Elsevier Inc. All rights reserved.
Volume 121, Issue 2, February 2009, Pages 175-179
Chaoming Xia | Rong Rong | ZhengXian Lu | ChangJun Shi | Jing Xu | Huiqin Zhang | Wei Gong | Wei Luo
A specific PCR assay for the detection of Schistosoma japonicum DNA in rabbit fecal and serum samples was developed by amplifying a 230-bp fragment from the sequence information of the clone G55A of the highly repetitive retrotransposon SjR2. The minimum amount of DNA detectable using the PCR assay was 0.8 pg, and the expected PCR product was amplified when DNA equivalent of 1.1 egg from feces was used as template. In the meantime, serum anti-worm IgG was examined by ELISA. ELISA gave positive results at 4-6 weeks post-infection depending on the cercarial doses. The parasite eggs were detected in feces at 7 weeks post-infection. In contrast, S. japonicum DNA was detected in sera at first week post-infection, and it became negative at 10 weeks post-treatment, whereas the anti-worm IgG was still at high levels at 23 weeks post-treatment. These data demonstrated that the PCR assay established provides a potential tool for the early diagnosis and therapy evaluation for S. japonicum infection in humans. © 2008 Elsevier Inc. All rights reserved.
Volume 123, Issue 3, November 2009, Pages 218-225
Mohammad Ali Oshaghi | Naseh Maleki Ravasan | Mallorie Hide | Ezat Aldin Javadian | Y. Rassi | Javid Sadraei | Mehdi Mohebali | Mohammad Mehdi Mehdi Sedaghat | Homa Hajjaran | Zabiholah Zarei | Fatemeh Mohtarami
Leishmania infantum is the causative agent of infantile visceral leishmaniasis (IVL) in the Mediterranean Basin and, based on isoenzyme typing of the parasite isolated from dogs; this parasite was considered to predominate in the all foci of IVL in Iran. However, based on PCR detection and sequencing of parasite Cysteine Protease B (CPB), only one out of seven sandfly infections in Phlebotomus perfiliewi transcaucasicus was found to be L. infantum in the current investigation. The six other infections were haplotypes of Leishmania donovani, the causative agent of anthroponotic visceral leishmaniasis (AVL) in West Africa and India. The deduced amino acid of the L. donovani haplotype was found to be novel and the shortest CPB protein reported within the Leishmania spp. Circulation of both L. donovani and L. infantum by P. perfiliewi transcaucasicus, in addition to previous data indicating its ability to circulate L. tropica, suggests that this species, like other vectors of VL, is a permissive vector. Finding L. donovani infecting P. perfiliewi transcaucasicus in the area demands extensive and intensive typing of natural Leishmania infections in epidemiological investigations in Iran and the Mediterranean Basin in general. © 2009 Elsevier Inc. All rights reserved.
Volume 126, Issue 3, November 2010, Pages 283-291
Conrad L. Epting | Bria M. Coates | David M. Engman
The protozoan parasite Trypanosoma cruzi, the etiologic agent of Chagas disease, is an obligate intracellular protozoan pathogen. Overlapping mechanisms ensure successful infection, yet the relationship between these cellular events and clinical disease remains obscure. This review explores the process of cell invasion from the perspective of cell surface interactions, intracellular signaling, modulation of the host cytoskeleton and endosomal compartment, and the intracellular innate immune response to infection. © 2010 Elsevier Inc.
Volume 121, Issue 2, February 2009, Pages 151-156
Hyeongkyu Jeon | Jongyil Chai | Yoon Kong | Jitra Waikagul | Bounnaloth Insisiengmay | Hanjong Rim | Keeseon Eom
Taenia asiatica and T. saginata are frequently confused tapeworms due to their morphological similarities and sympatric distribution in Asian regions. To resolve this problem, a high-resolution multiplex PCR assay was developed to distinguish T. asiatica infections from infection with other human Taenia tapeworms. For molecular characterization, the species specificity of all materials used was confirmed by sequencing of the cox1 gene. Fifty-two samples were analyzed in this study, comprising 20 samples of T. asiatica genomic DNA from China, Korea, and the Philippines; 24 samples of T. saginata from Belgium, Chile, China, Ethiopia, France, Indonesia, Korea, Laos, the Philippines, Poland, Taiwan, Thailand, and Switzerland; and 10 samples of T. solium from Cape Verde, China, Honduras, and Korea. The diagnostic quality of the results obtained using PCR and species-specific primers designed from valine tRNA and NADH genes was equal to that based on the nucleotide sequencing of the cox1 gene. Using oligonucleotide primers Ta4978F, Ts5058F, Tso7421F, and Rev7915, the multiplex PCR assay was useful for the differentially diagnosing T. asiatica, T. saginata, and T. solium based on 706-, 629-, and 474-bp bands. © 2008.
Volume 124, Issue 1, January 2010, Pages 98-106
Thomas Geurden | Jozef Vercruysse | Edwin Claerebout
Although Giardia duodenalis is recognised worldwide as the most important parasitic cause of gastro-intestinal disorder in human patients, the relevance of infection in production animals is prone to debate. Since the 1980s, clinical disease has been associated with giardiasis in production animals, both in natural conditions and in experimental studies. However, most Giardia research is focussed on the relevance of production animals as a reservoir for zoonotic transmission. In this study, the current knowledge on clinical relevance of giardiasis in production animals is reviewed, along with the diagnosis, treatment and control of infection. Furthermore, future research objectives are discussed. © 2009 Elsevier Inc. All rights reserved.
Volume 121, Issue 4, April 2009, Pages 352-361
Yutaka Asato | Minoru Oshiro | Chomar Kaung Myint | Yuichi Yamamoto | Hirotomo Kato | Jorge Diego Marco | Tatsuyuki Mimori | Eduardo A L Gómez | Yoshihisa Hashiguchi | Hiroshi Uezato
In a previous report (Luyo-Acero et al., 2004), we demonstrated that cytochrome b (Cyt b) gene analysis is an effective method for classifying several isolates of the genus Leishmania; hence, we have further applied this method to other Leishmania species in an effort to enhance the accuracy of the procedure and to construct a new phylogenic tree. In this study, a total of 30 Leishmania and Endotrypanum WHO reference strains, clinical isolates from our patients assigned to 28 strains (human and non-human pathogenic species) and two species of the genus Endotrypanum were analyzed. The Cyt b gene in each sample was amplified by PCR, and was then sequenced by several primers, as reported previously. The phylogenic tree was constructed based on the results obtained by the computer software MEGA v3.1 and PAUP* v4.0 Beta. The present phylogenic tree was almost identical to the traditional method of classification proposed by Lainson and Shaw (1987). However, it produces the following suggestions: (1) exclusion of L. (Leishmania) major from the L. (L.) tropica complex; (2) placement of L. tarentolae in the genus Sauroleishmania; (3) L. (L.) hertigi complex and L. (V.) equatorensis close to the genus Endotrypanum; (4) L. (L.) enrietti, defined as L. (L.) mexicana complex, placed in another position; and (5) L. (L.) turanica and L. (L.) arabica are located in an area far from human pathogenic Leishmania strains. Cyt b gene analysis is thus applicable to the analyzing phylogeny of the genus Leishmania and may be useful for separating non-human pathogenic species from human pathogenic species. © 2008 Elsevier Inc. All rights reserved.
Volume 124, Issue 4, April 2010, Pages 373-379
Mitra Sharbatkhori | Hossein Mirhendi | Majid Fasihi Harandi | Mostafa Rezaeian | Mehdi Mohebali | Mohammad Reza Eshraghian | Hamidreza Reza Rahimi | Eshrat Beigom Kia
In this study, 112 Echinococcus granulosus isolates from different livestock of Iran were genotyped by PCR amplification of ribosomal DNA-internal transcribed spacer 1 (rDNA-ITS1) region followed by restriction fragment length polymorphism (RFLP) with the enzyme RsaI. The possibility of intra-genotype variation was also investigated using randomly amplified polymorphic DNA (RAPD) analysis. Isolates from sheep, goats, cattle and the majority of camels (12 of 18; 66.7%) were identified as the G1 genotype and a few camel isolates (6 of 18; 33.3%) belonged to the G6 genotype. Overall G1 and G6 genotypes were identified in 94.6% (106 of 112) and 5.3% (6 of 112) of all isolates, respectively. RAPD analysis based on 15 separate primers showed 7-14 bands of 200-3000 bp for strain G1. Considering each individual primer, no differences observed among isolates from different hosts and between livers and lungs. This study confirmed the existence of G1 and G6 genotypes in Iran. Moreover, G1 is much more prevalent even in camels, indicating the importance of sheep-dog cycle in public health. Studying intra-genotypic variation of E. granulosus warrants more research using other primers and methods. © 2009 Elsevier Inc.
Volume 122, Issue 2, June 2009, Pages 124-127
Liette S. Waldron | Belinda C. Ferrari | Michelle L. Power
Management and control of cryptosporidiosis in human requires knowledge of Cryptosporidium species contributing to human disease. Markers that are able to provide information below the species level have become important tools for source tracking. Using the hypervariable surface antigen, glycoprotein 60 (GP60), C. hominis (n = 37) and C. parvum (n = 32) isolates from cryptosporidiosis cases in New South Wales, Australia, were characterised. Extensive variation was observed within this locus and the isolates could be divided into 8 families and 24 different subtypes. The subtypes identified have global distributions and indicate that anthroponotic and zoonotic transmission routes contribute to sporadic human cryptosporidiosis in NSW. © 2009 Elsevier Inc. All rights reserved.
Volume 122, Issue 3, July 2009, Pages 182-191
Upasna Gaur | Melissa Showalter | Suzanne M. Hickerson | Rahul P. Dalvi | Salvatore Joseph Turco | Mary Elizabeth Wilson | Stephen M. Beverley
Surface phosophoglycans such as lipophosphoglycan (LPG) or proteophosphoglycan (PPG) and glycosylinositol phospholipids (GIPLs) modulate essential interactions between Leishmania and mammalian macrophages. Phosphoglycan synthesis depends on the Golgi GDP-mannose transporter encoded by LPG2. LPG2-null (lpg2-) Leishmania major cannot establish macrophage infections or induce acute pathology, whereas lpg2- Leishmania mexicana retain virulence. lpg2- Leishmania donovani has been reported to survive poorly in cultured macrophages but in vivo survival has not been explored. Herein we discovered that, similar to lpg2- L. major, lpg2- L. donovani promastigotes exhibited diminished virulence in mice, but persisted at consistently low levels. lpg2- L. donovani promastigotes could not establish infection in macrophages and could not transiently inhibit phagolysosomal fusion. Furthermore, lpg2- promastigotes of L. major, L. donovani and L. mexicana were highly susceptible to complement-mediated lysis. We conclude that phosphoglycan assembly and expression mediated by L. donovani LPG2 are important for promastigote and amastigote virulence, unlike L. mexicana but similar to L. major.
Volume 126, Issue 2, October 2010, Pages 209-213
Jan R. Šlapeta | Simon Craig | Denise McDonell | David L. Emery
The genetic relationship amongst Tritrichomonas foetus isolated from domestic cats and cattle was investigated by DNA sequencing of the internal transcribed region of the ribosomal DNA unit and the TR7/TR8 variable-length repeat. The results reject the hypothesis that T. foetus from domestic cats is genetically identical to T. foetus in cattle. We suggest recognition of a 'cat genotype' and a 'cattle genotype' of T. foetus. Review of public nucleotide repositories revealed that the 'cat genotype' has not been isolated from cattle nor the 'cattle genotype' recovered from cats. However, at least one cat isolate has been shown to induce disease in experimentally infected cattle. We conclude that these genotypes fall within the single species T. foetus. © 2010 Elsevier Inc.
Volume 122, Issue 1, May 2009, Pages 61-65
Mohammad Ali Oshaghi | Naseh Maleki Ravasan | Mallorie Hide | Ezat Aldin Javadian | Y. Rassi | Mohammad Mehdi Mehdi Sedaghat | Mehdi Mohebali | Homa Hajjaran
Discrimination of Leishmania infantum and L. donovani, the members of the L. (L.) donovani complex, is important for diagnosis and epidemiological studies of visceral leishmaniasis (VL). We have developed two molecular tools including a restriction fragment length polymorphisms of amplified DNA (PCR-RFLP) and a PCR that are capable to discriminate L. donovani from L. infantum. Typing of the complex was performed by a simple PCR of cysteine protease B (cpb) gene followed by digestion with DraIII. The enzyme cuts the 741-bp amplicon of L. donovani into 400 and 341 bp fragments whereas the 702 bp of L. infantum remains intact. The designed PCR species-specific primer pair is specific for L. donovani and is capable of amplifying a 317 bp of 3' end of cpb gene of L. donovani whereas it does not generate an amplicon for L. infantum. The species-specific primers and the restriction enzyme were designed based on a 39 bp insertion/deletion (indel) in the middle of the cpb gene. Both assays could differentiate correctly the two species and are reliable and high-throughput alternatives for molecular diagnosis and epidemiological studies of VL in various foci. © 2009 Elsevier Inc. All rights reserved.
Volume 127, Issue 2, February 2011, Pages 527-533
Vaidas Palinauskas | Gediminas Valkiūnas | Casimir V. Bolshakov | Staffan Bensch
The effects of avian malaria parasites of the genus Plasmodium on their hosts are insufficiently understood. This is particularly true for malarial co-infections, which predominant in many bird populations. We investigated effects of primary co-infection of Plasmodium relictum (lineage SGS1) and Plasmodium ashfordi (GRW2) on experimentally infected naive juveniles of siskin Spinus spinus, crossbill Loxia curvirostra and starling Sturnus vulgaris. All siskins and crossbills were susceptible but starlings resistant to both these infections. A general pattern of the co-infections was that heavy parasitemia (over 35% during peaks) of both parasites developed in both susceptible host species. There were no significant effects of the co-infections on mean body mass of the majority of infected birds. Mean haematocrit value decreased approximately 1.5 and 3 times in siskins and crossbills at the peak of parasitemia, respectively. Mortality was recorded among infected crossbills. We conclude that co-infections of P. relictum and P. ashfordi are highly virulent and act synergetically during primary infections in some but not all passerine birds. © 2010 Elsevier Inc.