Leucocytozoon cariamae n. sp. and Haemoproteus pulcher coinfection in Cariama cristata (Aves: Cariamiformes): first mitochondrial genome analysis and morphological description of a leucocytozoid in Brazil.

The distribution of avian haemosporidians of the genus Leucocytozoon in the Neotropics remains poorly understood. Recent studies confirmed their presence in the region using molecular techniques alone, but evidence for gametocytes and data on putative competent hosts for Leucocytozoon are still lacking outside highland areas. We combined morphological and molecular data to characterize a new Leucocytozoon species infecting a non-migratory red-legged seriema (Cariama cristata), the first report of a competent host for Leucocytozoon in Brazil. Leucocytozoon cariamae n. sp. is distinguished from the Leucocytozoon fringillinarum group by its microgametocytes that are not strongly appressed to the host cell nucleus. The bird studied was coinfected with Haemoproteus pulcher, and we present a Bayesian phylogenetic analysis based on nearly complete mitochondrial genomes of these 2 parasites. Leucocytozoon cariamae n. sp. morphology is consistent with our phylogenetic analysis indicating that it does not share a recent common ancestor with the L. fringillinarum group. Haemoproteus pulcher and Haemoproteus catharti form a monophyletic group with Haemocystidium parasites of Reptilia, supporting the polyphyly of the genus Haemoproteus. We also discussed the hypothesis that H. pulcher and H. catharti may be avian Haemocystidium, highlighting the need to study non-passerine parasites to untangle the systematics of Haemosporida.

Plasmodium ouropretensis, n. sp., a new case of non-erythrocytic species within lizard malaria parasites.

Delimiting and describing Plasmodium species in reptiles remains a pressing problem in Haemosporida taxonomy. The few morphological characters used can overlap, and the significance of some life-history traits is not fully understood. Morphologically identical lizard Plasmodium forms have been reported infecting different cell types (red and white blood cells) in the same host and have been considered the same species. An example is Plasmodium tropiduri tropiduri, a species known to infect erythrocytes, thrombocytes and lymphocyte-like cells. Here, both forms of P. t. tropiduri were analysed using light microscope-based morphological characteristics and phylogenetic inferences based on almost complete mitochondrial genomes of parasites naturally infecting lizards in southeastern Brazil. Although morphologically similar, two distinct phylogenetic lineages infecting erythrocytes and non-erythrocytic cells were found. The lineage found in the erythrocytes forms a monophyletic group with species from Colombia. However, the non-erythrocytic lineage shares a recent common ancestor with Plasmodium leucocytica, which infects leucocytes in lizards from the Caribbean islands. Here, Plasmodium ouropretensis n. sp. is described as a species that infects thrombocytes and lymphocyte-like cells.

Cytochrome b as a more promising marker for analysing the distribution vector for Metagonimus suifunensis (Trematoda: Heterophyidae).

In this study of Metagonimus suifunensis (M. suifunensis) in the Russian Southern Far East, the variability of the full-length sequences of the cytochrome b (cytb) mtDNA gene was assessed for the first time. In addition, the cox1 mtDNA gene sequences were also obtained for this species from new localities. In total, 87 and 81 sequences of the cytb and cox1 genes, respectively, were used in the current study. The cytb gene proved more promising and revealed two haplogroups that are associated with the spatial distribution of the species: geographical isolation caused the fixation of differences between northern and southern populations. In addition, the results obtained for the cytb gene opened up new perspectives in the analysis of sequences of the cox1 gene, which was not sufficiently effective as a sole marker. Based on data for both mitochondrial genes, molecular processes influencing the formation of the modern population were analysed for M. suifunensis. The new data confirmed the previously expressed opinion that this species colonized the study territory from north to south and will form the basis for determining possible ways of its further expansion, which is important for predicting the emergence of new foci of metagonimosis.

Authentication of camel meat using species-specific PCR and PCR-RFLP.

In India and some of the African countries, one of the unconventional meats receiving the latest attention in meat adulteration is camel meat. So, the objective of this study was to develop a species-specific PCR based on mitochondrial cytochrome b (CYTB) gene and a PCR-RFLP assay of mitochondrial 12S rRNA to identify camel meat in suspected samples. Known sample of camel meat, samples suspected to be from illegally slaughtered camel and known samples of cattle, buffalo, sheep, goat, pork and chicken were used in the study. DNA were extracted from all samples following spin column method and PCR amplification were carried out using both CYTB and 12S rRNA gene primers. The CYTB gene amplification produced amplicon with a size of 435 bp without any non-specific spurious amplification towards other species studied. Further, the 12S rRNA PCR products were analysed both by sequencing and by RFLP using enzyme AluI. On BLAST analysis the 448 bp sequence obtained from suspected samples showed > 99% sequence homology to previously reported Camelus dromedaries (accession no: AM 9369251.1). On AluI digestion of the 448 bp product from both known and suspected camel samples, a specific RFLP pattern with three distinct products of 90, 148 and 210 bp size were evident, which were significantly different from the pattern of cattle, sheep, goat, chicken and buffalo. Further, after in-house validation, this cost effective and rapid method of camel meat identification is placed into practice for regular screening of vetero-legal samples in the lab.

Agrochemicals: Effect on genetic resistance in yeasts colonizing winter wheat kernels.

Crop protection agents are widely used in modern agriculture and exert direct effects on non-target microorganisms such as yeasts. Yeasts abundantly colonize wheat grain and affect its chemical composition. They can also limit pathogen growth. This study evaluated the sensitivity of yeast communities colonizing winter wheat kernels to benzimidazole, strobilurin, triazole and morpholine fungicides, trinexapac-ethyl, a commercial mixture of o-nitrophenol+p-nitrophenol+5-nitroguaiacol, and chitosan applied during the growing season of winter wheat and in vitro in a diffusion test. A molecular identification analysis of yeasts isolated from winter wheat kernels was performed, and nucleotide polymorphisms in the CYTb gene (G143A) conferring resistance to strobilurin fungicides in yeast cells were identified. The size of yeast communities increased during grain storage, and the total counts of endophytic yeasts were significantly (85%) reduced following intensive fungicide treatment (fenpropimorph, a commercial mixture of pyraclostrobin, epoxiconazole and thiophanate-methyl). This study demonstrated that agrochemical residues in wheat grain can drive selection of yeast communities for reduced sensitivity to xenobiotics. A mutation in the CYTb gene (G143A) was observed in all analyzed isolates of the following azoxystrobin-resistant species: Aureobasidium pullulans, Debaryomyces hansenii, Candida albicans and C. sake. Agrochemicals tested in vitro were divided into four classes of toxicity to yeasts: (1) tebuconazole and a commercial mixture of flusilazole and carbendazim - most toxic to yeasts; (2) fenpropimorph and a commercial mixture of pyraclostrobin and epoxyconazole; (3) propiconazole, chitosan, thiophanate-methyl and a commercial mixture of o-nitrophenol, p-nitrophenol and 5-nitroguaiacol; (4) trinexapac-ethyl and azoxystrobin - least toxic to yeasts. It was found that agrochemicals can have an adverse effect on yeast abundance and the composition of yeast communities, mostly due to differences in fungicide resistance between yeast species, including the clinically significant C. albicans.

Infection of Taenia asiatica in a Bai Person in Dali, China.

We report here a human case of Taenia asiatica infection which was confirmed by genetic analyses in Dali, China. A patient was found to have symptoms of taeniasis with discharge of tapeworm proglottids. By sequencing of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene, we observed nucleotide sequence identity of 99% with T. asiatica and 96% with T. saginata. Using the cytochrome b (cytb) gene, 99% identity with T. asiatica and 96% identity with T. saginata were found. Our findings suggest that taeniasis of people in Dali, China may be mainly caused by T. asiatica.

A somatic T15091C mutation in the Cytb gene of mouse mitochondrial DNA dominantly induces respiration defects.

Our previous studies provided evidence that mammalian mitochondrial DNA (mtDNA) mutations that cause mitochondrial respiration defects behave in a recessive manner, because the induction of respiration defects could be prevented with the help of a small proportion (10%-20%) of mtDNA without the mutations. However, subsequent studies found the induction of respiration defects by the accelerated accumulation of a small proportion of mtDNA with various somatic mutations, indicating the presence of mtDNA mutations that behave in a dominant manner. Here, to provide the evidence for the presence of dominant mutations in mtDNA, we used mouse lung carcinoma P29 cells and examined whether some mtDNA molecules possess somatic mutations that dominantly induce respiration defects. Cloning and sequence analysis of 40-48 mtDNA molecules from P29 cells was carried out to screen for somatic mutations in protein-coding genes, because mutations in these genes could dominantly regulate respiration defects by formation of abnormal polypeptides. We found 108 missense mutations existing in one or more of 40-48 mtDNA molecules. Of these missense mutations, a T15091C mutation in the Cytb gene was expected to be pathogenic due to the presence of its orthologous mutation in mtDNA from a patient with cardiomyopathy. After isolation of many subclones from parental P29 cells, we obtained subclones with various proportions of T15091C mtDNA, and showed that the respiration defects were induced in a subclone with only 49% T15091C mtDNA. Because the induction of respiration defects could not be prevented with the help of the remaining 51% mtDNA without the T15091C mutation, the results indicate that the T15091C mutation in mtDNA dominantly induced the respiration defects.

Intraspecific diversity of Meriones persicus (Rodentia; Gerbillinae), the main plague reservoir in Iran, and its connection to enzootic plague in Iran.

Plague, a lethal zoonotic disease, primarily circulates within rodent populations and their fleas. In Iran, the widely distributed jird, Meriones persicus, serves as the principal reservoir for plague, with a belief in the existence of five out of its six recognized subspecies within the country. However, these subspecies are classified into four mitochondrial cytochrome b sub-lineages (IA, IB, IIA, IIB). This discrepancy, combined with the presence of an unnamed sub-lineage in central Iran awaiting taxonomic clarification, has left intraspecific taxonomy unsettled and obscured the true alignment between mtDNA sub-lineages and nominal subspecies. In this study, we investigated the intraspecific variation in the cytb gene across populations sampled throughout Iran, focusing on underexplored regions between the Zagros and Alborz Mountains and central Iran. While our genetic data generally support reported subspecies validity in Iran, we raise questions about M. p. baptistae, emphasizing the need for further data from its type territory in Pakistan. Two main lineages of M. persicus (I and II) exhibit geographical isolation, with limited overlap in the central Zagros Mts., where three subspecies (M. p. ambrosius, M. p. rossicus, and M. p. persicus) coexist. Superimposing infected rodents' geographic coordinates onto updated sub-lineages' distribution revealed a potential association between sub-lineage IA (M. p. rossicus) and all enzootic plague cases from 1946 to 2023. M. persicus rossicus extends into the Caucasus (where plague infections are common), Eastern Turkey, and Iraq. Consequently, interpreting this finding in the context of plague surveillance in Iran and neighboring areas requires caution.

High mitochondrial gene diversity of Pediculus humanus capitis among children in northern Iran.

BACKGROUND: The head louse, Pediculus humanus capitis, is an obligate ectoparasite and its infestation remains a major public health issue worldwide. Determining the genetic characteristics of the existing clades is essential to identify the population structure and to develop head lice-control programs. Hence, we aimed to investigate the genetic diversity of head lice among infested individuals in northern Iran. METHODS: Adult head lice were collected from 100 infested individuals referring to the health centers throughout five geographical regions in Mazandaran Province, Iran. Partial fragments of the mitochondrial cytb gene were amplified by PCR, then consequently sequenced. RESULTS: The results of the phylogenetic tree of collected head lice confirmed the existence of two clades, A and B, in the studied areas. Thirteen haplotypes were detected in the studied populations, of which 11 were novel haplotypes. Clade A was the dominant form and accounted for 75% of samples, while clade B included the rest. Haplotype and nucleotide diversity were 0.999 and 0.0411, respectively. CONCLUSIONS: Clade A and B of Pediculus humanus capitis exist among the human populations of northern Iran. We observed high genotypic diversity of this head lice.

Study of Local Black Iraqi Goats Genotypes for the Cytb Gene.

Goats are the earliest domesticated ruminants. The local goat, Capra hircus, is considered one of the most important animals globally to provide good livestock production under harsh environmental conditions. This study aimed to detect the genetic structures of the local Iraqi goats bred in the central and southern regions of the country and investigate the possibility of benefiting from their genetic structures to construct improvement programs for increasing the productivity of these animals. To this end, blood samples were taken from 15 domestic black goats. A total of 10 ml of each animal's blood was placed in plastic containers of 10 ml. The DNA was extracted and sent to the laboratories of Juan Ju University, People's Republic of China, to analyze the sequences of the nitrogenous bases of the Cytochrome b (Cytb) gene. The results showed the presence of a genetic morphology for a segment of 670 base pairs for all the studied samples, and 15 sequences of this strain were recorded in the gene bank under the following accession numbers (LC496353.1:1-LC496367.1:1). The sequences of the nitrogenous bases of this segment of the gene, which were registered in the gene bank of some international goat breeds, were used for comparison with the sequences of black Iraqi goats to analyze the phylogenetic tree, calculate the genetic distance, study haplotypes, and calculate neutrality. The results showed the presence of one mutation in the studied segment of the Cytb gene, with a size of 670 bp. The mutation in base 46 of the studied gene converted from the purine group to the pyrimidine group (the shift from the nitrogen leaders A

Cutaneous protothecosis in a dog successfully treated with oral itraconazole in pulse dosing.

BACKGROUND: Protothecosis is a rare infectious disease caused by unicellular, achlorophyllous, microalgae of the genus Prototheca, ubiquitously distributed in nature. The algae are emerging pathogens, whose incidence is increasing in both human and animal populations and serious systemic infections related to this pathogen have been increasingly described in humans in recent years. After mastitis in dairy cows, canine protothecosis is the second most prevalent form of the protothecal disease in animals. Here, we report the first case of chronic cutaneous protothecosis due to P. wickerhamii in a dog in Brazil, successfully treated with a long-term therapy with itraconazole in pulse. CASE PRESENTATION: Upon clinical examination, exudative nasolabial plaque, ulcered, and painful lesions in central and digital pads and lymphadenitis were observed in a 2-year-old mixed-breed dog, with a 4-month history of cutaneous lesions and contact with sewage water. Histopathological examination revealed intense inflammatory reaction, with numerous spherical to oval, encapsulated structures stained with Periodic Acid Schiff, compatible with Prototheca morphology. Tissue culture on Sabouraud agar revealed yeast-like, greyish-white colonies after 48 h of incubation. The isolate was subjected to mass spectrometry profiling and PCR-sequencing of the mitochondrial cytochrome b (CYTB) gene marker, leading to identification of the pathogen as P. wickerhamii. The dog was initially treated with oral itraconazole at a dosage of 10 mg/kg once daily. After six months, the lesions resolved completely, yet recurred shortly after cessation of therapy. The dog was then treated with terbinafine at a dose of 30 mg/kg, once daily for 3 months, with no success. The resolution of clinical signs, with no recurrence over a 36-months follow-up period, was achieved after 3 months of treatment with itraconazole (20 mg/kg) in pulse intermittently on two consecutive days a week. CONCLUSIONS: This report highlights the refractoriness of skin infections by Prototheca wickerhamii with therapies proposed in the literature and suggests a new treatment option with oral itraconazole in pulse dosing for long-term disease control successfully performed in a dog with skin lesions.

Rapid detection of duck ingredient in adulterated foods by isothermal recombinase polymerase amplification assays.

Duck is often used in meat fraud as a substitute for more expensive meats. Rapid detection of duck ingredient in meat products is of great significance for combating meat fraud and safeguarding the interests of consumers. Therefore, we aim to develop duck-specific recombinase polymerase amplification (RPA)-based assays for the rapid detection of duck ingredient in animal-derived foods. Using Cytb gene as target, the real-time RPA and RPA combined with lateral flow strips (LFS RPA) were developed successfully for the rapid detection of ducks in 20 min at 39 °C and 40 °C, respectively. The assays did not show cross-reactions with 6 other livestock and poultry. The developed RPA assays could detect 10 pg duck genomic DNA per reaction and 0.1 % (w/w) duck ingredient in duck and mutton mixed powder within 30 min, including a rapid nucleic acid extraction. Furthermore, duck ingredient could be detected in 30 different actual foods including heat-processed meats and blood products. Therefore, duck-specific real-time RPA and LFS RPA assays were successfully developed with good specificity and sensitivity, which could enable rapid detection of duck ingredient in the field and provide technical support for combating the meat fraud.

A Pilot Mitochondrial Genome-Wide Association on Migraine Among Saudi Arabians.

Background: Mitochondrial DNA (mtDNA) mutations have been reported in multiple neurological diseases and helped to explain the pathophysiology of these diseases. Similarly, variations in mtDNA might exist in migraine and can explain the effect of low ATP production in the neurons on the initiation of migraine attack. Therefore, in the current study we aim to explore the association of mtDNA mutations on migraine in the Saudi population. Subjects and Methods: Over 1950 young Saudi female students were screened for migraine, among that a total of 103 satisfied the ICHD-3 criteria. However,  20 migraine cases confirmed in the neurology clinic and gave consent to participate in the study. Another 20 age-matched healthy controls were also recruited. Mitochondrial sequence variations were filtered from exome sequencing using NCBI GenBank Reference Sequence: NC_012920.1 and analysed using MITOMAP. Genes with significant single nucleotide polymorphisms (SNPs) were investigated by the gene functional classification tool DAVID and functional enrichment analysis of protein-protein interaction networks through STRING 11.5 for the most significant associated genes. Results: Genome wide analysis of the mitochondrial sequence variations between the patients with migraine and control revealed the association of 30 SNPs (p < 0.05) in the mitochondrial genome. The highest significance (p = 0.001033) was observed in a coding SNP (rs1603225278) in the CYTB gene and rs386829281 in the region of origin of replication. Twenty-four significant SNPs were in the coding region of nine (ND5, ND4, COX2, COX1, ND3, CYTB, COX3, ND2 and ND1) genes. Conclusion: This is the first study to demonstrate the association of mtDNA variations with migraine in the Saudi population. The current findings will help to highlight the significance of mtDNA mutations to migraine pathophysiology and will serve as a reference data for larger national and international studies.

First Report of Anuran Trypanosoma DNA in Flat-Tailed House Geckos (Reptilia: Gekkonidae) Collected from Southern Thailand: No Evidence as a Reservoir for Human Trypanosomatids.

Over the years, cases of autochthonous leishmaniasis have been dramatically increasing in Thailand. Recently, several publications have claimed certain species of the phlebotomine sand flies and biting midges potentially serve as natural vectors of Leishmania and Trypanosoma species in this country. However, more information regarding the vector-parasite relationships, as well as their natural reservoirs in the country, still needs to be explored. Herein, we hypothesized that synanthropic reptiles in the leishmaniasis-affected area might be a natural reservoir for these parasites. In this present study, a total of nineteen flat-tailed house geckos were collected from the house of a leishmaniasis patient in Songkhla province, southern Thailand, and then dissected for their visceral organs for parasite detection. Small subunit ribosomal RNA (SSU rRNA) gene and internal transcribed spacer 1 (ITS-1)-specific amplifications were conducted to verify the presence of Trypanosoma and Leishmania parasites, respectively. Only Trypanosoma DNA was screened positive in eight gecko individuals by SSU rRNA-PCR in at least one visceral organ (4, 4, and 6 of the heart, liver, and spleen, respectively) and phylogenetically related to the anuran Trypanosoma spp. (An04/Frog1 clade) previously detected in three Asian sand fly species (Phlebotomus kazeruni, Sergentomyia indica, and Se. khawi). Hence, our data indicate the first detection of anuran Trypanosoma sp. in the flat-tailed house geckos from southern Thailand. Essentially, it can be inferred that there is no evidence for the flat-tailed house gecko (Hemidactylus platyurus) as a natural reservoir of human pathogenic trypanosomatids in the leishmaniasis-affected area of southern Thailand.

Cryptic Diversity of the European Blind Mole Rat Nannospalax leucodon Species Complex: Implications for Conservation.

We explored the cryptic speciation of the Nannospalax leucodon species complex, characterised by intense karyotype evolution and reduced phenotypic variability that has produced different lineages, out of which 25 are described as chromosomal forms (CFs), so many cryptic species remain unnoticed. Although some of them should be classified as threatened, they lack the official nomenclature necessary to be involved in conservation strategies. Reproductive isolation between seven CFs has previously been demonstrated. To investigate the amount and dynamics of genetic discrepancy that follows chromosomal changes, infer speciation levels, and obtain phylogenetic patterns, we analysed mitochondrial 16S rRNA and MT-CYTB nucleotide polymorphism among 17 CFs-the highest number studied so far. Phylogenetic trees delineated 11 CFs as separate clades. Evolutionary divergence values overlapped with acknowledged higher taxonomic categories, or sometimes exceeded them. The fact that CFs with higher 2n are evolutionary older corresponds to the fusion hypothesis of Nannospalax karyotype evolution. To participate in conservation strategies, N. leucodon classification should follow the biological species concept, and proposed cryptic species should be formally named, despite a lack of classical morphometric discrepancy. We draw attention towards the syrmiensis and montanosyrmiensis CFs, estimated to be endangered/critically endangered, and emphasise the need for detailed monitoring and population survey for other cryptic species.

Better Resolution for Cytochrome b than Cytochrome c Oxidase Subunit I to Identify Schizothorax Species (Teleostei: Cyprinidae) from the Tibetan Plateau and Its Adjacent Area.

The genus Schizothorax is one of the most diverse groups of schizothoracine fish. Many species within this genus possess highly similar morphological characters and are very difficult to be identified accurately only based on morphology. The present study aims to test the effectiveness of mitochondrial cytochrome c oxidase subunit I (COI) gene and cytochrome b (Cytb) gene for discriminating the Schizothorax fish. A total of 185 individuals of 11 species for COI gene and 264 individuals of 23 species for Cytb gene were used for analyzing, respectively. According to the genetic distances, only one species based on COI gene and five species based on Cytb gene had "barcoding gaps," respectively. The tree-based analysis displayed that four species based on COI gene and six species based on Cytb gene clustered monophyletic group with strong support, respectively. The optimal threshold value of Schizothorax is 0.005 based on COI gene and 0.008 based on Cytb gene. The results of genetic similarity tests performed through online BLAST showed that 108 of 185 similarity searches succeeded in identifying conspecific sequences based on COI gene and 199 of 264 succeeded in identifying conspecific sequences based on Cytb gene. Considering greater interspecific genetic distance in Kimura 2-parameter (K2P) analysis and many clades with higher supporting values in tree-based analysis, we suggest that Cytb gene has better resolution in discrimination of Schizothorax species than COI gene. However, there are still many confused clustering relationships based on molecular data currently available. Incomplete lineage sorting, the existence of possible cryptic species and problematic morphological identification, etc. might have greatly weakened the resolution of Cytb gene in discrimination of Schizothorax species.

Diversity of mitochondrial genes and predominance of Clade B in different head lice populations in the northwest of Iran.

BACKGROUND: The head louse, Pediculus humanus capitis, is the most important ectoparasite causing many health problems. Several linkages are presented for this parasite, each representing a particular geographical distribution, prevalence rate, vector competence, susceptibility to pediculicides, and infestation rate. Determining the genetic nature of these linkages is necessary to identify the population structure and also to develop and monitor control programmes against head lice. This study was designed to analyse cox1 and cytb genes and determine the mitochondrial clades in head lice populations in the northwest of Iran. METHODS: Adult head lice were collected from infested females of Ardabil, East and West Azerbaijan, and Zanjan Provinces from 2016 to 2018. Partial fragments of the mitochondrial genes cox1 and cytb were amplified by PCR and some of the amplicons were sequenced. All confirmed sequences were analysed, and the frequency of each mitochondrial clade was determined in the studied areas. RESULTS: A total of 6410 females were clinically examined, and 897 adult head lice were collected from 562 infested cases. Genomic DNA was extracted from 417 samples, and fragments of cox1 and cytb genes were amplified in 348 individuals. Analysis of the 116 sequences showed the 632-bp and 495-bp fragments for cox1 and cytb genes, respectively. The nucleotide and haplotype diversities of cytb and cox1 genes were 0.02261 and 0.589 and 0.01443 and 0.424, respectively. Sequence analysis indicated 6 haplotypes clustered in two clades, A and B. The relative prevalence of clade B was 73% for cytb and 82% for cox1 gene. Haplotypes of clade B were found in all the studied areas, while those of clade A were observed only in rural and suburban areas. CONCLUSIONS: To our knowledge, this is the first study investigated deeply the field populations of Pediculus and documented two clades in the Middle East. The considerable prevalence of pediculosis in the studied areas requires authorities' attention to establish effective control and preventive measures. Given the role of cytb in monitoring population groups, application of this marker is suggested for future epigenetic studies to evaluate the factors affecting the abundance of these clades.

Hurdles in the evolutionary epidemiology of Angiostrongylus cantonensis: Pseudogenes, incongruence between taxonomy and DNA sequence variants, and cryptic lineages.

Angiostrongylus cantonensis, the rat lungworm, is a zoonotic pathogen that is one of the leading causes of eosinophilic meningitis worldwide. This parasite is regarded as an emerging pathogen with a global range expansion out of southeastern Asia post-WWII. To date, molecular systematic/phylogeographic studies on A. cantonensis have mainly used two mitochondrial (mtDNA) markers, cytochrome c oxidase 1 (CO1) and cytochrome b (CYTB), where the focus has largely been descriptive in terms of reporting local patterns of haplotype variants. In order to look for more global evolutionary patterns, we herein provide a collective phylogenetic assessment using the six available whole mtDNA genome samples that have been tagged as A. cantonensis, A. malaysiensis, or A. mackerrasae along with all other GenBank CO1 and CYTB partial sequences that carry these species identifiers. The results reveal three important complications that researchers will need to be aware of, or will need to resolve, prior to conducting future molecular evolutionary studies on A. cantonensis. These three problems are (i) incongruence between taxonomic identifications and mtDNA variants (haplotypes or whole mtDNA genome samples), (ii) the presence of a CYTB mtDNA pseudogene, and (iii) the need to verify A. mackerrasae as a species along with other possible cryptic lineages, of which there is suggestive evidence (i.e., A. cantonensis could be a species complex). We provided a discussion of how these complications are hurdles to our understanding of the global epidemiology of angiostrongyliasis. We call for future studies to be more explicit in morphological traits used for identifications (e.g., provide measurements). Moreover, it will be necessary to repeat prior morphological and life-history studies while simultaneously using sequence data in order to assess possible associations between critical epidemiological data (e.g., biogeography, virulence/pathology, host species use) and specific lineages.

The first report of human-derived G10 genotype of Echinococcus canadensis in China and possible sources and routes of transmission.

Cystic echinococcosis (CE) is one of the most important parasitic zoonoses. 10 distinct genotypes, designated G1-G10 genotypes of Echinococcus granulosus sensu lato (s.l.), have been split into 4 species: Echinococcus granulosus sensu stricto (s.s.) (G1-G3), Echinococcus equinus (G4), Echinococcus ortleppi (G5) and Echinococcus canadensis (G6-G10); Echinococcus felidis has also been suggested as a sister taxon of E. granulosus s.s. recently. Four genotypes belonging to two species (G1 and G3 genotypes of E. granulosus s.s., and G6 and G7 genotypes of E. canadensis) have been identified in humans and animals in China. In the present study, a human-derived hydatid cyst from a patient in northeastern China's Heilongjiang Province was identified as G10 genotype of E. canadensis based on mitochondrial cytochrome c oxidase subunit I (cox1), cytochrome b (cytb) and NADH dehydrogenase subunit 1 (nad1) genes. Homology analysis showed the cox1 gene sequence of G10 genotype of E. canadensis had 100% homology with those from wolves in Mongolia and from a moose in Russia. The cytb and nad1 gene sequences of G10 genotype of E. canadensis had 100% homology with the complete sequence from a moose in Finland at an amino acid level. The infection source of the CE patient here might be primarily attributable to wolves. This is the first report of G10 genotype of E. canadensis in a human in China. The finding of G10 genotype of E. canadensis in China shows that this genotype possibly has a more wide geographical distribution than previously considered.

Infection of Taenia asiatica in a Bai Person in Dali, China

We report here a human case of Taenia asiatica infection which was confirmed by genetic analyses in Dali, China. A patient was found to have symptoms of taeniasis with discharge of tapeworm proglottids. By sequencing of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene, we observed nucleotide sequence identity of 99% with T. asiatica and 96% with T. saginata. Using the cytochrome b (cytb) gene, 99% identity with T. asiatica and 96% identity with T. saginata were found. Our findings suggest that taeniasis of people in Dali, China may be mainly caused by T. asiatica.