Displaying publications 701 - 720 of 1902 in total

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  1. [Laboratory diagnosis and molecular tracing of dengue bordline cases in Henan Province, 2017]
    Du YH, Li Y, Wang RL, Wang HF, Su J, Xu BL, et al.
    Zhonghua Yu Fang Yi Xue Za Zhi, 2018 Nov 06;52(11):1164-1167.
    PMID: 30419702 DOI: 10.3760/cma.j.issn.0253-9624.2018.11.013
    Objective: To confirm the laboratory diagnosis of dengue bordline cases reported in Henan Province and trace its origin from molecular level in 2017. Methods: The study samples were blood samples (3-5 ml), which came from 8 suspected cases of dengue fever reported in the 2017 direct reporting system of Henan provincial infectious disease monitoring network. Meanwhile, case investigation was conducted according to National dengue fever surveillance programme. Serum were separated from blood samples and tested for Dengue NS1 antigen, IgM & IgG antibodies, and dengue RNA. According to dengue diagnosis criteria, confirmed cases were identified by testing results. Samples carried dengue RNA performed for real-time PCR genotyping and amplification of E gene. Then, the amplicons were sequenced and homological and phylogenetic analyses were constructed. Results: 8 serum samples of suspected dengue cases were collected in Henan Province, 2017. Six of them were diagnosed as dengue confirmed cases. All the dengue confirmed cases belonged to outside imported cases, 5 of them were positive by dengue RNA testing. Genotyping results showed there were 1 DENV1 case, 2 DENV2 cases and 2 DENV3 cases. A DENV2 case and a DENV3 case of this study were traced its origin successfully. The sequence of Pakistan imported DENV2 case belongs to cosmopolitan genotype, which was the most consistent with Pakistan's DENV2 KJ010186 in 2013 (identity 99.0%). The sequence of Malaysia imported DENV3 case belongs to genotype I, which was the most consistent with Singapore's DENV3 KX224276 in 2014(identity 99.0%). Conclusion: The laboratory diagnosis and molecular traceability of dengue cases in Henan Province in 2017 confirmed that all cases were imported and did not cause local epidemics.
    Matched MeSH terms: Phylogeny
  2. Review of the huntsman spider genus Rhitymna Simon, 1897 (Araneae: Sparassidae)
    Jäger P
    Zootaxa, 2019 Feb 26;4560(3):zootaxa.4560.3.2.
    PMID: 31716566 DOI: 10.11646/zootaxa.4560.3.2
    The genus Rhitymna Simon, 1897 is revised by means of new material. Four new species are described: R. gerdmangel spec. nov. (Thailand, Malaysia; male, female), R. merianae spec. nov. (Indonesia: Bali; male), R. flores spec. nov. (Indonesia: Flores; male, female), R. senckenbergi spec. nov. (Philippines; male). The male of R. plana Jäger, 2003 and the female of R. tangi Quan Liu, 2012 are described for the first time. Rhitymna simoni Jäger, 2003 is recognised as junior synonym of R. cursor (Thorell, 1894) comb. nov., the latter transferred from the genus Olios Walckenaer, 1837. New records are given for further Rhitymna species, among them new country or island records for R. verruca (Wang, 1991) (Thailand), R. tangi Quan Liu, 2012 (Laos), R. plana Jäger, 2003 (Cambodia), R. pinangensis (Thorell, 1891) (Thailand), R. deelemanae Jäger, 2003 (Bali). The number of cheliceral bristles close to the fang base is recognised as size dependent, therefore without true phylogenetic signal. Two main types of copulatory organs within the genus are recognised and discussed. R. gerdmangel spec. nov. has a special biology as it lives exclusively in bamboo. Holes made by beetles or woodpeckers are used to enter the bamboo stem. Spiders hide during the day and lay their eggs in bamboo internodes.
    Matched MeSH terms: Phylogeny
  3. First description of the tadpole of Theloderma ryabovi Orlov, Dutta, Ghate et Kent, 2006 (Anura: Rhacophoridae), an endemic mossy frog from Vietnam
    Kropachev II, Orlov NL, Ostroshabov AA, Nguyen TT
    Zootaxa, 2019 Aug 15;4657(1):zootaxa.4657.1.13.
    PMID: 31716807 DOI: 10.11646/zootaxa.4657.1.13
    To date, 26 species of Theloderma have been described and all are distributed throughout Southeast Asia from Assam in northeastern India to Myanmar, Indochina, the Malay Peninsula, and the islands of the Greater Sundas: Sumatra and Borneo (Frost 2019). The tadpoles of only 12 species have been described and published: T. asperum (Boulenger); T. auratum Poyarkov, Kropachev, Gogoleva Orlov; T. bicolor (Bourret); T. corticale (Boulenger); T. gordoni Taylor; T. horridum (Boulenger); T. leave (Smith); T. moloch (Annandale); T. nebulosum Rowley, Le, Hoang, Dau Cao; T. palliatum Rowley, Le, Hoang, Dau Cao; T. stellatum Taylor; T. vietnamense Poyarkov, Orlov, Moiseeva, Pawangkhanant, Ruangsuwan, Vassilieva, Galoyan, Nguyen Gogoleva (Boulenger 1903; Annandale 1912; Wassersug et al. 1981; Inger et al. 1999; Leong Lim 2003; Inthara et al. 2005; Rowley et al. 2011; Gawor et al. 2012; Orlov et al. 2012; Poyarkov et al. 2015; Kropachev et al. 2018).
    Matched MeSH terms: Phylogeny
  4. Occurrence and molecular characterisation of Acanthamoeba isolated from recreational hot springs in Malaysia: evidence of pathogenic potential
    Mohd Hussain RH, Ishak AR, Abdul Ghani MK, Ahmed Khan N, Siddiqui R, Shahrul Anuar T
    J Water Health, 2019 Oct;17(5):813-825.
    PMID: 31638031 DOI: 10.2166/wh.2019.214
    This study aimed to identify the Acanthamoeba genotypes and their pathogenic potential in five recreational hot springs in Peninsular Malaysia. Fifty water samples were collected between April and September 2018. Physical parameters of water quality were measured in situ while chemical and microbiological analyses were performed in the laboratory. All samples were filtered through the nitrocellulose membrane and tested for Acanthamoeba using both cultivation and polymerase chain reaction (PCR) by targeting the 18S ribosomal RNA gene. The pathogenic potential of all positive isolates was identified using thermo- and osmotolerance tests. Thirty-eight (76.0%) samples were positive for Acanthamoeba. Water temperature (P = 0.035), chemical oxygen demand (P = 0.026), sulphate (P = 0.002) and Escherichia coli (P < 0.001) were found to be significantly correlated with the presence of Acanthamoeba. Phylogenetic analysis revealed that 24 samples belonged to genotype T4, nine (T15), two (T3) and one from each genotype T5, T11 and T17. Thermo- and osmotolerance tests showed that 6 (15.79%) of the Acanthamoeba strains were highly pathogenic. The existence of Acanthamoeba in recreational hot springs should be considered as a health threat among the public especially for high-risk people. Periodic surveillance of hot spring waters and posting warning signs by health authorities is recommended to prevent disease related to pathogenic Acanthamoeba.
    Matched MeSH terms: Phylogeny
  5. Fulltext Isolation and Characterization of a Novel Pathogenic Strain of Ehrlichia minasensis
    Moura de Aguiar D, Pessoa Araújo Junior J, Nakazato L, Bard E, Aguilar-Bultet L, Vorimore F, et al.
    Microorganisms, 2019 Nov 05;7(11).
    PMID: 31694172 DOI: 10.3390/microorganisms7110528
    The genus Ehrlichia is composed of tick-borne obligate intracellular gram-negative alphaproteobacteria of the family Anaplasmataceae. Ehrlichia includes important pathogens affecting canids (E. canis, E. chaffeensis, and E. ewingii), rodents (E. muris), and ruminants (E. ruminantium). Ehrlichiaminasensis, an Ehrlichia closely related to E. canis, was initially reported in Canada and Brazil. This bacterium has now been reported in Pakistan, Malaysia, China, Ethiopia, South Africa, and the Mediterranean island of Corsica, suggesting that E. minasensis has a wide geographical distribution. Previously, E. minasensis was found to cause clinical ehrlichiosis in an experimentally infected calf. The type strain E. minasensis UFMG-EV was successfully isolated from Rhipicephalus microplus ticks and propagated in the tick embryonic cell line of Ixodes scapularis (IDE8). However, the isolation and propagation of E. minasensis strains from cattle has remained elusive. In this study, the E. minasensis strain Cuiabá was isolated from an eight-month-old male calf of Holstein breed that was naturally infected with the bacterium. The calf presented clinical signs and hematological parameters of bovine ehrlichiosis. The in vitro culture of the agent was established in the canine cell line DH82. Ehrlichial morulae were observed using light and electron microscopy within DH82 cells. Total DNA was extracted, and the full genome of the E. minasensis strain Cuiabá was sequenced. A core-genome-based phylogenetic tree of Ehrlichia spp. and Anaplasma spp. confirmed that E. minasensis is a sister taxa of E. canis. A comparison of functional categories among Ehrlichia showed that E. minasensis has significantly less genes in the 'clustering-based subsystems' category, which includes functionally coupled genes for which the functional attributes are not well understood. Results strongly suggest that E. minasensis is a novel pathogen infecting cattle. The epidemiology of this Ehrlichia deserves further attention because these bacteria could be an overlooked cause of tick-borne bovine ehrlichiosis, with a wide distribution.
    Matched MeSH terms: Phylogeny
  6. DNA polymorphism of D1S80 locus in modern Malay sample population of Sarawak
    Hairul Azman Roslan, Nur Hafizah Azizan, Rosmawati Saat
    Sains Malaysiana, 2009;38.
    The molecular genetic marker, minisatellite locus D1S80 (1p35-p36), is a highly polymorphic variable number of tandem repeats (VNTR). Its polymorphic nature allows for phylogenetic studies, forensic analysis, genetic maps construction and paternity testing to be performed. A study of the hypervariable locus D1S80 was conducted to determine the allele frequency and distribution of this locus in modern Malay in Sarawak population. The polymerase chain reaction technique was employed and results were analysed on polyacrylamide gel. A total of seventy-six DNA samples of unrelated Malay individuals in UNIMAS were collected and examined. The VNTR analysis of the D1S80 locus demonstrated the presence of 17 alleles in the Malay population. Allele with the size of 577 bp (27 repeats) was determined to be the most common in the sample population with the frequency of 0.1641, followed by allele with the size of 561 bp (26 repeats) and 529 bp (24 repeats) whose frequency is 0.1172 and 0.1094, respectively. The smallest allele is allele with the size of 465 bp (20 repeats) whereas the largest is allele with the size of 753 bp (38 repeats). The sample population exhibited 57.8% heterozygosity.
    Matched MeSH terms: Phylogeny
  7. Molecular phylogeny of holothuria (mertensiothuria) leucospilota (Brandt 1835) as inferred from cytochrome C oxidase I mitochondrial DNA gene sequences
    Hajar Fauzan Ahmad, Mohd Hanafi Anua, Mohd Yaman Idris, Aisyah Mohamed Rehan, Ridzwan Hashim, Usup G, et al.
    Sains Malaysiana, 2011;40.
    Holothuria (Mertensiothuria) leucospilota (Brandt 1835), white threads fish or locally known as bat puntil is currently considered as the most abundant sea cucumber species in Malaysia. This study aimed to generate the genetic profile of H. leucospilota from Malaysia and then to determine the phylogenetic relationship between H. leucospilota and other members of genus Holothuria using partial sequences of cytochrome c oxidase I (COI) mitochondrial DNA (mtDNA) gene. In this study, specimens of H. leucospilota were collected from Intan Besar Island, Langkawi, Kedah Darul Aman in the west coast of Peninsular Malaysia. Three main methods namely neighbour joining, maximum parsimony and maximum likelihood were used for the phylogenetic tree reconstruction. Tree topologies showed that H. leucospilota has its own monophyletic clade clearly distinct from the other species. The pairwise genetic distance calculated further supported these findings. In addition, the results also should that the COI mtDNA gene is capable to unravel the phylogenetic relationship of H. leucospilota.
    Matched MeSH terms: Phylogeny
  8. Revision of Acanthotaenia von Linstow, 1903 (Cestoda: Proteocephalidae), parasites of monitors (Varanus spp.), based on morphological and molecular data
    de Chambrier A, Brabec J, Tran BT, Scholz T
    Parasitol Res, 2019 Jun;118(6):1761-1783.
    PMID: 31065829 DOI: 10.1007/s00436-019-06326-6
    A morphological and molecular phylogenetic study of proteocephalid tapeworms of the genus Acanthotaenia von Linstow, 1903, parasites of monitors (Varanidae), was carried out. The type species, A. shipleyi von Linstow, 1903, which was originally described based on an immature specimen from Sri Lanka, is redescribed based on new material from the type host, Varanus salvator, in Sri Lanka, Malaysia, and Vietnam, and its neotype is designated. In addition, Acanthotaenia susanae n. sp. is described from Varanus nebulosus in Vietnam. The new species differs from congeners by the large size of the scolex, width of the rostellum and the number of testes. New molecular data (sequences of lsrDNA and cox1) revealed Acanthotaenia paraphyletic with the inclusion of Australotaenia bunthangi de Chambrier & Scholz, 2012, a parasite of Enhydris enhydris (Ophidia: Homalopsidae) in Cambodia. Molecular data confirm a wide distribution of A. shipleyi (isolates from Malaysia and Vietnam were almost identical) and indicate a strict host specificity (oioxeny) of individual species of the genus. Type specimens of four species made it possible to supplement their morphological descriptions. A survey of all species of Acanthotaenia recognised as valid is presented and the following taxonomic changes are proposed: Acanthotaenia pythonis Wahid, 1968 described from the green python, Morelia viridis, in a zoo, is transferred to Kapsulotaenia as Kapsulotaenia pythonis (Wahid, 1968) n. comb., because it possesses intrauterine eggs grouped in capsules. Acanthotaenia gracilis (Beddard, 1913) from Varanus varius in Australia is considered to be species inquirenda because its original descriptions did not contain sufficient data for adequate circumscription and differentiation from congeners and type material was not available. Generic diagnosis of Acanthotaenia is amended and a key to its seven species is provided.
    Matched MeSH terms: Phylogeny
  9. Molecular Mitochondrial DNA and radiographic approaches for human archaeology identification
    Rus Dina Rus Din, Shahrul Hisham Zainal Ariffin, Sahidan Senafi, Rohaya Megat Abdul Wahab, Intan Zarina Zainol Abidin
    Sains Malaysiana, 2014;43:1523-1535.
    Ancient remains are considered very valuable artefacts, as they allow for the study of ancient cultures, phylogeny, evolution and the reconstruction of demographic history. To obtain all the information contained within remains, the investigation of such samples requires the expertise and various techniques from multiple fields of study. The present review focuses on the molecular biology and radiographic approaches used to identify ancient samples. Studies of ancient remains face various limitations; for example, the quality and quantity of the ancient samples can affect the difficulty of the investigations. Due to these limitations, new sophisticated techniques are being introduced to replace the earlier conventional techniques. A search was conducted using PubMed, Scopus, Science Direct and Science Finder to provide a new and timely review on the molecular mitochondrial DNA and radiographic analysis for human archaeology identification. The present review has determined that molecular biological approaches are very accurate and useful for the use in the ancestral determination of incomplete specimens, whereas observations of the dental pulp chamber are suitable for age at death estimations in both adults and children. However, these techniques are expensive and require expert personnel. Therefore, conventional approaches remain the favourite methods of most institutions, especially in Asia.
    Matched MeSH terms: Phylogeny
  10. Phylogenetic relationships within the genus holothuria inferred from 16S mitochondiral rRNA gene sequences
    Kamarul Rahim Kamarudin, ‘Aisyah Mohamed Rehan, Ridzwan Hashim, Usup G, Maryam Mohamed Rehan
    Sains Malaysiana, 2016;45:1079-1087.
    This study aimed to resolve the taxonomic status of a morphologically undetermined sea cucumber species of order Apodida
    from Malaysia (GenBank accession no.: FJ223867) using partial 16S mitochondrial rRNA gene sequences and subsequently
    to determine the validity of morphological taxonomy of Holothuria species into its current subgenera. The undetermined
    species clustered with all taxa of Holothuria in previous study. Phylogenetic analyses using maximum parsimony and
    Bayesian methods suggest that the undetermined species was genetically closer to Holothuria (Lessonothuria) pardalis and
    Holothuria (Acanthotrapeza) coluber; and its position in both phylogenetic trees further suggests its status as a Holothuria
    taxon. Subgenera of Holothuria, Merthensiothuria and Metriatyla are monophyletic with strong bootstrap supports and
    posterior probabilities of clades, thus strengthening their morphological taxonomies. Nonetheless, the non-monophyly of
    subgenera of Halodeima, Microthele and Platyperona suggests a requirement for their taxonomic revisions using integrative
    taxonomy. The status of Holothuria (Halodeima) edulis subgroups in the maximum parsimony and Bayesian trees is
    indistinct and further taxonomic revisions are necessary. In terms of sister relationship, both phylogenetic trees suggest
    that subgenus Holothuria is a sister taxon of subgenus Roweothuria while the other sister relationships were unclear due
    to the undetermined species, paraphyly and polyphyly of a number of subgenera. Further studies with more specimens of
    genus Holothuria from broader geographical locations and various mtDNA genes along with morphological approaches
    may facilitate to provide better insights into the molecular phylogeny of subgenera of Holothuria.
    Matched MeSH terms: Phylogeny
  11. Phylogeny of sea cucumber (Echinodermata: Holothuroidea) as inferred from 16S mitochondrial rRNa gene sequences
    Kamarul Rahim Kamarudin, Ridzwan Hashim, Usup G
    Sains Malaysiana, 2010;39:209-218.
    This study aimed to determine phylogenetic relationship between and among selected species of sea cucumbers (Echinodermata: Holothuroidea) using 16S mitochondrial ribosomal RNA (rRNA) gene. Phylogenetic analyses of 37 partial sequences of 16S mitochondrial rRNA gene using three main methods namely neighbour joining (NJ), maximum parsimony (MP) and maximum likelihood (ML) showed the presence of five main genera of sea cucumbers: Molpadia from order Molpadiida and four genera of order Aspidochirotida namely Holothuria, Stichopus, Bohadschia and Actinopyga. All of the 17 species obtained from Malaysia distributed among the main genera except within Actinopyga. Interestingly, Holothuria excellens was out of Holothuria group causing Holothuria to be paraphyletic. High bootstrap value and consistent clustering made Molpadia, Stichopus, Bohadschia and Actinopyga monophyletic. The relationship of Actinopyga with the other genera was unclarified and Stichopus was sister to Molpadia. The latter finding caused the resolution at order level unclear. The pairwise genetic distance calculated using Kimura 2-parameter model further supported and verified findings from the phylogenetic trees. Further studies with more samples and different mitochondrial DNA genes need to be done to get a better view and verification on the molecular phylogeny of sea cucumbers.
    Matched MeSH terms: Phylogeny
  12. Molecular identification of Eimeria hestermani and Eimeria prionotemni from a red-necked wallaby (Macropodidae; Macropus rufogriseus) in Japan
    Ekawasti F, Kitagawa K, Domae H, Wardhana AH, Shibahara T, Uni S, et al.
    Parasitol Res, 2020 Apr;119(4):1271-1279.
    PMID: 32072327 DOI: 10.1007/s00436-020-06618-2
    To date, more than 50 Eimeria spp. have been isolated from marsupials of the family Macropodidae. Although 18 species of Eimeria have been previously detected from multiple animal species belonging to the genus Macropus of the family, limited genetic analyses of the parasites are available, and their pathogenicity remains unclear. Here, we report the isolation of Eimeria spp. from a zoo specimen of red-necked wallaby (Macropodidae; Macropus rufogriseus). Specifically, two distinct types of Eimeria oocysts were recovered, one from the feces before treatment with an anthelmintic and the second from the intestinal contents after death of the animal. The oocysts obtained from the two sources were morphologically identified as E. hestermani and E. prionotemni, respectively. We successfully determined partial gene sequences from the two isolates, including segments of the 18S rRNA genes, and for the first time have used phylogenetic analyses of these sequences to assign the species to distinct clades. In combination with further genetic data, these results are expected to help elucidate the pathogenicity and host ranges of Eimeria spp. within the respective family and genus.
    Matched MeSH terms: Phylogeny
  13. Characterization of Aquimarina hainanensis isolated from diseased mud crab Scylla serrata larvae in a hatchery
    Midorikawa Y, Shimizu T, Sanda T, Hamasaki K, Dan S, Lal MTBM, et al.
    J Fish Dis, 2020 May;43(5):541-549.
    PMID: 32147853 DOI: 10.1111/jfd.13151
    Mass mortality due to necrosis signs occurred in hatchery-reared zoea stage larvae of the mud crab Scylla serrata in Okinawa, Japan, and a causative bacterium was isolated. In this study, we identified and characterized the bacterium by genome analysis, biochemical properties and pathogenicity. The bacterium was a Gram-negative, non-motile, long rod, forming yellow colonies on a marine agar plate. It grew at 20-33°C (not at 37°C) and degraded chitin and gelatin. Phylogenetic analysis of the 16S rRNA gene sequence identified the bacterium as Aquimarina hainanensis. Genome sequence data obtained from Illumina MiSeq generated 29 contigs with 3.56 Mbp in total length and a G + C content of 32.5%. The predicted 16 chitinase genes, as putative virulence factors, had certain homologies with those of genus Aquimarina. Experimental infection with the bacterium conducted on larvae of four crustacean species, brine shrimp Artemia franciscana, freshwater shrimp Caridina multidentata, swimming crab Portunus trituberculatus and mud crab S. serrata, revealed that this bacterium was highly virulent to these species. The present study suggests that the bacterium caused mass mortality in mud crab seed production was A. hainanensis and can be widely pathogenic to crustaceans.
    Matched MeSH terms: Phylogeny
  14. Fulltext Population structure and genetic diversity of Aedes aegypti and Aedes albopictus in Penang as revealed by mitochondrial DNA cytochrome oxidase I
    Md Naim D, Kamal NZM, Mahboob S
    Saudi J Biol Sci, 2020 Mar;27(3):953-967.
    PMID: 32127775 DOI: 10.1016/j.sjbs.2020.01.021
    The population genetics study is crucial as it helps in understanding the epidemiological aspects of dengue and help improving a vector control measures. This research aims to investigate the population genetics structure of two common species of Aedes mosquitoes in Penang; Aedes aegypti and Aedes albopictus using Cytochrome Oxidase I (COI) mitochondrial DNA (mtDNA) marker. Molecular investigations were derived from 440 bp and 418 bp mtDNA COI on 125 and 334 larvae of Aedes aegypti and Aedes albopictus respectively, from 32 locations in Penang. All samples were employed in the BLASTn for species identification. The haplotype diversity, nucleotide diversity, neutrality test and mismatch distribution analysis were conducted in DnaSP version 5.10.1. AMOVA analysis was conducted in ARLEQUIN version 3.5 and the phylogenetic reconstructions based on maximum likelihood (ML) and neighbor-joining (NJ) methods were implemented in MEGA X. The relationships among haplotypes were further tested by creating a minimum spanning tree using Network version 4.6.1. All samples were genetically identified and clustered into six distinct species. Among the species, Ae. albopictus was the most abundant (67.2%), followed by Ae. aegypti (25.2%) and the rest were counted for Culex sp. and Toxorhynchites sp. Both Ae. aegypti and Ae. albopictus show low nucleotide diversity (π) and high haplotype diversity (h), while the neutrality test shows a negative value in most of the population for both species. There are a total of 39 and 64 haplotypes recorded for Ae. aegypti and Ae. albopictus respectively. AMOVA analysis revealed that most of the variation occurred within population for both species. Mismatch distribution analysis showed bimodal characteristic of population differentiation for Ae. aegypti but Ae. albopictus showed unimodal characteristics of population differentiation. Genetic distance based on Tamura-Nei parameter showed low genetic divergent within population and high genetic divergent among population for both species. The maximum likelihood tree showed no obvious pattern of population genetic structure for both Ae. aegypti and Ae. albopictus from Penang and a moderate to high bootstrap values has supported this conclusion. The minimum spanning network for Ae. aegypti and Ae. albopictus showed five and three dominant haplotypes respectively, which indicates a mixture of haplotypes from the regions analysed. This study revealed that there is no population genetic structure exhibited by both Ae. aegypti and Ae. albopictus in Penang. Mutation has occurred rapidly in both species and this will be challenging in controlling the populations. However, further analysis needed to confirm this statement.
    Matched MeSH terms: Phylogeny
  15. Fulltext Complete Genome Sequence Analysis and Characterization of Selected Iron Regulation Genes of Pasteurella Multocida Serotype A Strain PMTB2.1
    Jabeen S, Yap HY, Abdullah FFJ, Zakaria Z, Isa NM, Tan YC, et al.
    Genes (Basel), 2019 01 25;10(2).
    PMID: 30691021 DOI: 10.3390/genes10020081
    Although more than 100 genome sequences of Pasteurella multocida are available, comprehensive and complete genome sequence analysis is limited. This study describes the analysis of complete genome sequence and pathogenomics of P. multocida strain PMTB2.1. The genome of PMTB2.1 has 2176 genes with more than 40 coding sequences associated with iron regulation and 140 virulence genes including the complete tad locus. The tad locus includes several previously uncharacterized genes such as flp2, rcpC and tadV genes. A transposable phage resembling to Mu phages was identified in P. multocida that has not been identified in any other serotype yet. The multi-locus sequence typing analysis assigned the PMTB2.1 genome sequence as type ST101, while the comparative genome analysis showed that PMTB2.1 is closely related to other P. multocida strains with the genomic distance of less than 0.13. The expression profiling of iron regulating-genes of PMTB2.1 was characterized under iron-limited environment. Results showed significant changes in the expression profiles of iron-regulating genes (p < 0.05) whereas the highest expression of fecE gene (281 fold) at 30 min suggests utilization of the outer-membrane proteins system in iron acquisition at an early stage of growth. This study showed the phylogenomic relatedness of P. multocida and improved annotation of important genes and functional characterization of iron-regulating genes of importance to the bacterial growth.
    Matched MeSH terms: Phylogeny
  16. First Report of Bark Dieback on Blueberry Caused by Botryosphaeria dothidea in Korea
    Choi IY
    Plant Dis, 2011 Feb;95(2):227.
    PMID: 30743439 DOI: 10.1094/PDIS-05-10-0371
    This study was conducted to identify the causal organism of bark dieback disease of highbush blueberry (Vaccinium corymbosum L.) observed in Korea. Blueberry, a woody plant that is native to North America, belongs to the family Ericaceae and genus Vaccinium. Of the 400 species of blueberry in the world, most are distributed in the tropics of Malaysia and Southeast Asia. Highbush blueberry is abundantly grown in Canada and the United States and has become a popular commercial crop in Korea for products such as jam, wine, and sauce. Bark dieback disease of blueberry was found in Sunchang (<5% incidence), Jeollabuk-do, Korea in July 2009. Typical symptoms of the disease were blight and dieback on the stems with lesions extending along entire branches. Morphological examination revealed that the perithecia were of the globose type with a nipple, 155 to 490 (374.6) μm, and brown on the dead bark. Asci were bitunicate and clavate or cylindrical with dimensions of 63 to 125 × 16 to 20 μm and containing eight ascospores. Ascospores were of the long ovoid type with dimensions of 13.2 to 23.7 (17.98) × 25.4 to 41.1 (33.21) μm. From extracted genomic DNA, the internal transcribed spacer (ITS)-5.8S ribosomal DNA region was amplified with universal primers ITS1 (5'-TCCGTAGGTGAACCTGCGG-3') and ITS4 (5'-TCCTCCGCTTATTGATATGC-3'). A BLAST search of GenBank with the ITS sequence revealed that the Sunchang isolate (GenBank Accession No. HQ384217) had 99 to 100% sequence identity with the following Botryosphaeria dothidea accessions: FJ517657, AJ938005, FJ478129, FJ171723, and AJ938004. Phylogenetic analysis with the Sunchang isolate, B. dothidea strains, and related species revealed that the B. dothidea isolate and strains comprised a monophyletic group distinguished from other Botryosphaeria spp. including B. ribis, B. parva, B. protearum, B. lutea, B. australis, B. rhodina, B. obtuse, and B. stevensii (2). On the basis of morphological and molecular results, the isolate was identified as B. dothidea (Moug.) Ces. & De Not. A culture of B. dothidea isolate was grown on potato dextrose agar (PDA) for 10 days. A 5-mm plug was inoculated into stem wounds created with a No. 2 cork borer in 20 2-year-old disease-free blueberry plants grown in a greenhouse. Six plants inoculated with only PDA plugs served as noninoculated controls. The wounds were covered with Parafilm. After 3 months, the Parafilm was removed and black lesions were observed at the fungal inoculation sites, while no lesion was observed on the control plants. To complete Koch's postulates, the fungus was reisolated from the lesions and confirmed to be B. Dothidea (1). There is an urgent need to determine the spread of this disease in Korea, estimate the losses, and develop methods for reducing damage through biological and eco-friendly cultural control methods. References: (1) D. Jurc et al. Plant Pathol. 55:299, 2006. (2) B. Slippers et al. Mycologia 96:83, 2004.
    Matched MeSH terms: Phylogeny
  17. Two reads to rule them all: Nanopore long read-guided assembly of the iconic Christmas Island red crab, Gecarcoidea natalis (Pocock, 1888), mitochondrial genome and the challenges of AT-rich mitogenomes
    Gan HM, Linton SM, Austin CM
    Mar Genomics, 2019 Jun;45:64-71.
    PMID: 30928201 DOI: 10.1016/j.margen.2019.02.002
    Despite recent advances in sequencing technology, a complete mitogenome assembly is still unavailable for the gecarcinid land crabs that include the iconic Christmas Island red crab (Gecarcoidea natalis) which is known for its high population density, annual mass breeding migration and ecological significance in maintaining rainforest structure. Using sequences generated from Nanopore and Illumina platforms, we assembled the complete mitogenome for G. natalis, the first for the genus and only second for the family Gecarcinidae. Nine Nanopore long reads representing 0.15% of the sequencing output from an overnight MinION Nanopore run were aligned to the mitogenome. Two of them were >10 kb and combined are sufficient to span the entire G. natalis mitogenome. The use of Illumina genome skimming data only resulted in a fragmented assembly that can be attributed to low to zero sequencing coverage in multiple high AT-regions including the mitochondrial protein-coding genes (NAD4 and NAD5), 16S ribosomal rRNA and non-coding control region. Supplementing the mitogenome assembly with previously acquired transcriptome dataset containing high abundance of mitochondrial transcripts improved mitogenome sequence coverage and assembly reliability. We then inferred the phylogeny of the Eubrachyura using Maximum Likelihood and Bayesian approaches, confirming the phylogenetic placement of G. natalis within the family Gecarcinidae based on whole mitogenome alignment. Given the substantial impact of AT-content on mitogenome assembly and the value of complete mitogenomes in phylogenetic and comparative studies, we recommend that future mitogenome sequencing projects consider generating a modest amount of Nanopore long reads to facilitate the closing of problematic and fragmented mitogenome assemblies.
    Matched MeSH terms: Phylogeny
  18. Identification, pathogenicity and histopathology of Colletotrichum sansevieriae causing anthracnose of Sansevieria trifasciata in Malaysia
    Kee YJ, Zakaria L, Mohd MH
    J Appl Microbiol, 2020 Sep;129(3):626-636.
    PMID: 32167647 DOI: 10.1111/jam.14640
    AIMS: To characterize causal pathogen of Sansevieria trifasciata anthracnose through morphology and molecular analysis; to evaluate the host range of the pathogen; and to explicate the infection process by the pathogen histopathologically.

    METHODS AND RESULTS: Symptomatic leaves of S. trifasciata were collected from five states in Malaysia. The causal pathogen was isolated and identified for the first time in Malaysia as C. sansevieriae based on morphological and multi-gene phylogenetic analyses using ITS, TUB2 and GAPDH sequences. Pathogenicity tests were conducted on different hosts. Colletotrichum sansevieriae was not pathogenic towards S. cylindrica, S. masoniana, Furcraea foetida, Chlorophytum comosum, Aloe vera and Gasteria carinata, confirming the exceptionally high host specificity for a species of Colletotrichum. Histopathology was performed using light microscope and scanning electron microscopy to study the infection process of C. sansevieriae on S. trifasciata. Colonization of host leaves by the pathogen was observed 2 days after inoculation.

    CONCLUSIONS: Colletotrichum sansevieriae caused anthracnose of S. trifasciata in Malaysia. It is a host-specific pathogen and colonized the host intracellularly.

    SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report of C. sansevieriae causing anthracnose of S. trifasciata in Malaysia. The host range test and understanding of the infection process will provide better understanding of the host-pathogen relationship and beneficial for effective disease management.

    Matched MeSH terms: Phylogeny
  19. Fulltext The efficiency of universal mitochondrial DNA barcodes for species discrimination of Pomacea canaliculata and Pomacea maculata
    Kannan A, Rama Rao S, Ratnayeke S, Yow YY
    PeerJ, 2020;8:e8755.
    PMID: 32274263 DOI: 10.7717/peerj.8755
    Invasive apple snails, Pomacea canaliculata and P. maculata, have a widespread distribution globally and are regarded as devastating pests of agricultural wetlands. The two species are morphologically similar, which hinders species identification via morphological approaches and species-specific management efforts. Advances in molecular genetics may contribute effective diagnostic tools to potentially resolve morphological ambiguity. DNA barcoding has revolutionized the field of taxonomy by providing an alternative, simple approach for species discrimination, where short sections of DNA, the cytochrome c oxidase subunit I (COI) gene in particular, are used as 'barcodes' to delineate species boundaries. In our study, we aimed to assess the effectiveness of two mitochondrial markers, the COI and 16S ribosomal deoxyribonucleic acid (16S rDNA) markers for DNA barcoding of P. canaliculata and P. maculata. The COI and 16S rDNA sequences of 40 Pomacea specimens collected from six localities in Peninsular Malaysia were analyzed to assess their barcoding performance using phylogenetic methods and distance-based assessments. The results confirmed both markers were suitable for barcoding P. canaliculata and P. maculata. The phylogenies of the COI and 16S rDNA markers demonstrated species-specific monophyly and were largely congruent with the exception of one individual. The COI marker exhibited a larger barcoding gap (6.06-6.58%) than the 16S rDNA marker (1.54%); however, the magnitude of barcoding gap generated within the barcoding region of the 16S rDNA marker (12-fold) was bigger than the COI counterpart (approximately 9-fold). Both markers were generally successful in identifying P. canaliculata and P. maculata in the similarity-based DNA identifications. The COI + 16S rDNA concatenated dataset successfully recovered monophylies of P. canaliculata and P. maculata but concatenation did not improve individual datasets in distance-based analyses. Overall, although both markers were successful for the identification of apple snails, the COI molecular marker is a better barcoding marker and could be utilized in various population genetic studies of P. canaliculata and P. maculata.
    Matched MeSH terms: Phylogeny
  20. Mitogenome of gymnothorax minor and phylogenetic relationship with its congeners and related genera (anguilliformes: muraenidae)
    Sze-Looi Song, Kar-Hoe Loh, Phaik-Eem Lim, Amy Yee-Hui Then, Hoi-Sen Yong, Praphathip Eamsobhana
    Sains Malaysiana, 2018;47:2519-2531.
    Gymnothorax minor is a moray eel of the family Muraenidae found in the Western Pacific Ocean. We report here
    its complete mitogenome as determined by Illumina next-generation sequencing and the phylogenetic relationship
    with its congeners and other taxa of the family Muraenidae. The whole mitogenome of G. minor had a total length
    of 16,574 bp, comprising 37 genes - 13 protein-coding genes (PCGs), two ribosomal ribonucleic acid (rRNA) and 22
    transfer ribonucleic acid (tRNA) genes - and a control region. Excepting cox1 with GTG, the other 12 PCGs had ATG
    start codon. Seven of its PCGs had incomplete stop codon - five (nad2; cox1; cox2; nad3 and nad4) with T and two
    (atp6 and cox3) with TA. Molecular phylogeny based on 13 PCGs was concordant with 15 mitochondrial genes (13 PCGs
    and 2 rRNA genes). The subfamily Muraeninae as well as the subfamily Uropterygiinae were monophyletic. However,
    the genus Gymnothorax was paraphyletic, with G. minor forming a sister group with Rhinomuraena quaesita in the
    lineage containing also G. kidako and G. formosus forming a sister group with Enchelynassa canina. The phylogenetic
    relationship of the genus Gymnothorax and related taxa of the family Muraenidae, based on the mitochondrial cob
    gene, was in general similar to that based on 15 mt-genes. The mitogenome is useful for future studies on phylogenetics
    and systematics of eels of the family Muraenidae and other taxa of the order Anguilliformes.
    Matched MeSH terms: Phylogeny
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