Chapare mammarenavirus - a new deadly virus outbreak: a review

In 2003 an emerging mammarenavirus (formerly arenaviruses) was discovered in Bolivia and named Chapare (CHAPV). It was related to severe and fatal haemorrhagic fever, being similar in clinical features to Machupo (MACV). In mid-2019, CHAPV was the explanation for a cluster of 5 cases, two of them laboratory confirmed, three of them fatal. Reverse transcription polymerase chain reaction (RT-PCR) analysis and subsequent analysis of the entire virus S and L ribonucleic acid (RNA) segment sequences identified the virus as a member of the New World Clade B arenaviruses, which includes all the pathogenic South American arenaviruses. The virus was shown to be most closely associated with Sabia´ virus, but with 26% and 30% nucleotide difference within the S and L segments, and 26%, 28%, 15% and 22% aminoalkanoic acid differences for the L, Z, N, and GP proteins. LUJV, CHAPV, GTOV, and SABV, which are geographically restricted, have been associated with only a few to a few dozen cases. They are, therefore, relatively unimportant to clinicians compared to many other viruses that are usually co-endemic. However, MACV, JUNV, and especially LASV have caused large outbreaks (LASV has caused hundreds of thousands of infections per year). Visitors to countries in which these viruses are endemic, or war-fighters that are deployed to these countries, need to be aware of how to prevent and suspect a mammarenavirus infection.

Gene exchange networks define species-like units in marine prokaryotes

SUMMARYAlthough horizontal gene transfer is recognized as a major evolutionary process in Bacteria and Archaea, its general patterns remain elusive, due to difficulties tracking genes at relevant resolution and scale within complex microbiomes. To circumvent these challenges, we analyzed a randomized sample of >12,000 genomes of individual cells of Bacteria and Archaea in the tropical and subtropical ocean - a well-mixed, global environment. We found that marine microorganisms form gene exchange networks (GENs) within which transfers of both flexible and core genes are frequent, including the rRNA operon that is commonly used as a conservative taxonomic marker. The data revealed efficient gene exchange among genomes with <28% nucleotide difference, indicating that GENs are much broader lineages than the nominal microbial species, which are currently delineated at 4-6% nucleotide difference. The 42 largest GENs accounted for 90% of cells in the tropical ocean microbiome. Frequent gene exchange within GENs helps explain how marine microorganisms maintain millions of rare genes and adapt to a dynamic environment despite extreme genome streamlining of their individual cells. Our study suggests that sharing of pangenomes through horizontal gene transfer is a defining feature of fundamental evolutionary units in marine planktonic microorganisms and, potentially, other microbiomes.

FILOGENI POPULASI Haliotis squamata REEVE, 1846 DARI PANTAI SELATAN PULAU JAWA DAN BALI BERDASARKAN SEKUEN CYTOCHROME B DNA MITOKONDRIA

Abalone Haliotis squamata Reeve 1846 is an abalone that has distribution on the southern coast of Java and Bali in Indonesia. The purpose of this study was to analyze the phylogenetic relationship of H. squamata from the southern coast of Java and Bali based on the cytochrome b (Cyt b) mitochondrial DNA sequence. A total of 38 samples were collected from Java (Binuangeun, Pangandaran, Banyuwangi, and Bali (Buleleng). Samples were extracted, applied using method PCR, and sequencing the method Sanger sequencing di 1st BASE Malaysia. Using primary sequences to applied namely forward primers forward AB-Cytb DivF (5'-TAAGCCAATTCGTAAGGTTC-3') dan primer reverse AB-Cytb DivR (5'-AAAATACCACTCTGGCTGAA-3'). Genetic distance was analyzed using the Kimura 2-parameter method and phylogenetic tree construction was carried out by Neighbor-Joining using the MEGA 7. The result showed that a specific nucleotide difference of 81 bp to 820 bp. The genetic distance between H. squamata intraspecies from the southern coast of Java and Bali is 0.96%-1.06%. This genetic distance is high enough to separate the two populations and form their clusters based on phylogenetic trees. The population of Bali seems to form new subpopulations. The data obtained in this study will be very useful for the management of H. squamata abalone genetic resources related to their sustainability and utilization.

Sequence variation among SARS-CoV-2 isolates in Taiwan

Taiwan experienced two waves of imported cases of coronavirus disease 2019 (COVID-19), first from China in January to late February, followed by those from other countries starting in early March. Additionally, several cases could not be traced to any imported cases and were suspected as sporadic local transmission. Twelve full viral genomes were determined in this study by Illumina sequencing either from virus isolates or directly from specimens, among which 5 originated from clustered infections. Phylogenetic tree analysis revealed that these sequences were in different clades, indicating that no major strain has been circulating in Taiwan. A deletion in open reading frame 8 was found in one isolate. Only a 4-nucleotide difference was observed among the 5 genomes from clustered infections.

Molecular characterisation of Mycoplasma gallisepticum isolates from Iran in the period 2012–2017

Mycoplasma gallisepticum (MG) causes chronic non-fatal diseases in the poultry industry with a remarkable decrease in feed consumption, egg production and other production indices. To study the genetic characteristics of MG isolates in commercial and backyard poultry flocks, 21 positive samples from different regions of Iran were analysed in the period 2012–2017. Typical macroscopic and histopathological lesions of the upper respiratory tract and lungs were found, similar to those reported by other researchers. A 298–361 bp part of the mgc2 gene was sequenced and analysed. Based on the phylogenetic analysis, the Iranian MG isolates fell into four distinct subgroups. The nucleotide difference between subgroups 1 and 4 was remarkable (91.6–94.9%). A 22-amino-acid insertion was present in two of the studied MG isolates, not observed in other vaccine and standard MG strains. The Iranian Veterinary Organisation (IVO) should consider the observed diversity of prevalent MG isolates from both commercial and backyard flocks in designing the strategy for controlling MG. More studies are needed to understand modifications in MG antigenicity and pathogenicity because of the observed genetic variations.

Ultrasensitive SERS detection of highly homologous miRNAs by generating 3D organic-nanoclusters and a functionalized chip with locked nucleic acid probes

Herein, a new finding is reported that 3D organic-nanoclusters (3DONs) with superior SERS properties as an original reporter could accurately and sensitively distinguish microRNAs (miRNAs) with highly similar sequences, even with a single-nucleotide difference.

Variasi Gen matK dan Filogenetik Tumbuhan Kantong Semar (Nepenthes sp.) dari Gunung Mahawu dan Gunung Soputan di Sulawesi Utara (The Variation of matK Gene and the Phylogeny of Nepenthes sp. Obtained from Mount Mahawu and Mount Soputan in North Sulawesi)

Abstrak Kantong semar (Nepenthes sp.) merupakan salah satu tumbuhan langka yang dilindungi. Eksploitasi yang berlebihan, serta alih fungsi hutan menjadi ancaman bagi kehidupan Nepenthes sp. Penelitian ini bertujuan untuk menentukan variasi gen matK dari tumbuhan Nepenthes sp. di Gunung Mahawu (JTM) dan Gunung Soputan (JTS) di Sulawesi Utara dan membandingkannya dengan kerabat terdekat di GenBank, serta membuat pohon filogenetiknya. Hasil penelitian menunjukkan bahwa hanya terdapat satu perbedaan nukleotida sekuens gen matK antara Nepenthes sp. dari Gunung Mahawu dan Gunung Soputan. Selain itu, variasi juga ditunjukan pada Nepenthes sp. yang diperoleh dari basis data GenBank dengan adanya perbedaan 1-7 basa nukleotida dengan sampel penelitian ini. Hasil analisis menggunakan ABGD (Automatic Barcode Gap Discovery) menunjukkan bahwa variasi intraspesies untuk Nepenthes sp. berada dalam rentang 0,000 – 0,004. Apabila mempertimbangkan barcode gap tersebut sebagai pembatas spesies, maka diasumsikan bahwa JTM, JTS, N. fusca, N. pilosa, N. maxima, N. faizaliana, dan N. clipeata merupakan spesies yang sama. Hal ini ditunjang oleh rekonstruksi pohon filogenetik menggunakan gen matK.Kata Kunci: ABGD, barcode gap, gen matK, Nepenthes sp., pohon filogenetik, variasi sekuens. Abstract Tropical pitcher plant (Nepenthes sp.) is listed as one of the endangered and protected plants. Excessive exploitation and forest conversion threaten the life of this Nepenthes sp. This research was aimed to determine variation in matK gene of Nepenthes sp. obtained from Mount Mahawu (JTM) and Mount Soputan (JTS) North Sulawesi, and compare the matK sequences with their allied taxa in public domain data base. Analysis of matK gene showed that there was only one nucleotide difference of matK gene sequence between Mahawu and Soputan samples. There were 1-7 different nucleotides between those samples and their allied taxa. Analysis of barcode gap using ABGD (Automatic Barcode Gap Discovery) showed that the range of intraspecies variation of Nepenthes sp. was 0,000 – 0,004. Considering this barcode gap generated from ABGD as species delimination, it could be assumed that JTM, JTS, N. fusca, N. pilosa, N. maxima, N. faizaliana, dan N. clipeata were the same species. These results were also supported by the reconstruction of phylogenetic tree using matK gene.Keywords: ABGD, barcode gap, matK gene, Nepenthes sp., phylogeneteic tree, sequence variation.