Chronic lymphocytic leukaemia in a pot-bellied pig

An 11‐year‐old, neutered male, Vietnamese pot‐bellied pig was admitted for routine dental and foot care. As a part of routine geriatric evaluation, blood was submitted for a complete blood count and serum biochemical analysis. The blood count revealed a marked leucocytosis due to lymphocytosis. Further diagnostic evaluation, including abdominal and thoracic radiography, abdominal ultrasonography and blood lymphocyte immunophenotyping confirmed a diagnosis of chronic lymphocytic leukaemia of T‐cell origin. Treatment was initiated with oral prednisone and cyclophosphamide. The pig did well on treatment for about 1 month after discharge but was then euthanized.     

Pathogenicity and molecular phylogenetic analysis reveal a distinct position of the banana fingertip rot pathogen among the Burkholderia cenocepacia genomovars

Banana (Musa spp.) is one of the most widely cultivated subtropical fruits around the globe. Banana cultivation has been extensively increased in southeastern Iran over the last two decades. Recently, banana fruits possessing rotten and blackened fingertip symptoms were observed in Sistan-Baluchestan, Iran. Isolation and characterization of the causal agent showed that the pathogen belongs to the multifaceted bacterial species Burkholderia cenocepacia. Pathogenicity tests and host range assays showed that the strains were pathogenic on banana, as well as carrot, onion and potato. All the strains were resistant to 50 mg L⁻¹ rifampicin and 200 mg L⁻¹ copper sulphate. Phylogenetic analysis of 16S rRNA and recA gene sequences showed that the strains belong to two different genomovars of B. cenocepacia (III-A and III-B), which also include environmental and cystic fibrosis associated strains of the species. The results obtained from recA phylogeny were confirmed using multilocus sequence analysis (MLSA), although MLSA showed that the banana strains were clustered as a novel phylogroup among the members of both genomovars. Banana-pathogenic B. cenocepacia strains isolated in Iran were different from the strains isolated in Taiwan, as the ‘B. cepacia epidemic strain marker’ reported in the Taiwanese strains was absent from Iranian strains. To the authors’ knowledge, this is the first MLSA-based study on the banana-pathogenic strains of B. cenocepacia. However, further in-depth molecular studies are needed to decipher the relationships between the banana fingertip rot pathogen and the clinical strains of B. cenocepacia.     

Multilocus sequence typing reveals the presence of three distinct flavescence dorée phytoplasma genetic clusters in Croatian vineyards

Flavescence dorée phytoplasma (FDp) is a quarantine pathogen associated with a severe and epidemic grapevine yellows disease representing a great threat for grapevine cultivation in Europe. An increase in disease spread prompted efforts to identify FDp strains in Croatia. Over 800 samples of grapevine together with presumed reservoir plants and almost 400 samples of Scaphoideus titanus and other potential vectors were collected countrywide and analysed. FDp isolates were characterized by multilocus sequence typing (MLST) of map, secY and uvrB-degV genes in order to determine genetic diversity and structure of FDp populations, and to trace transmission pathways. FD-related phytoplasmas were found in Croatia for the first time in alder, the invasive tree species Ailanthus altissima and leafhopper Phlogotettix cyclops. Phylogenetic analysis revealed the presence of three mapFD strain clusters: mapFD1, mapFD2 and mapFD3, and for the first time in Croatia a case of Palatinate grapevine yellows strain A (PGY-A). In total, 7 different map, 10 secY and 11 uvrB-degV genotypes were detected. The identification of 15 comprehensive FDp genotypes based on MLST suggests separate routes for disease introduction and propagation origins in Croatia. Moreover, high genetic variability of Croatian isolates indicates a complex ecological cycle of FDp involving various hosts.     

Application of RAPD and SI-typing techniques to confirm genetic integrity of radish (Raphanus sativus L.) varieties

The random amplified polymorphic DNA (RAPD) and self-incompatibility (SI) typing techniques were applied to settle a lawsuit between a Seed Company and a farmer concerning seed impurity in radish (Raphanus sativus L.). After sowing “Halra Woldong” (HW) a winter radish variety, two morphologically different radish plants grew. Genomic DNA from each of the two types were prepared and analyzed using ninety-six RAPD markers and four variety-specific markers were found. The polymorphic RAPD band patterns were compared with those of the twenty Korean radish varieties. The genetic integrity of the two varieties in question was identified and further confirmed by SI-typing of S-locus glycoprotein (SLG) and S-locus receptor kinase (SRK) genes.     

Clonal structure in Ichthyobacterium seriolicida,the causative agent of bacterial haemolytic jaundice in yellowtail,Seriola quinqueradiata,inferred from molecular epidemiological analysis

Bacterial haemolytic jaundice caused by Ichthyobacterium seriolicida has been responsible for mortality in farmed yellowtail, Seriola quinqueradiata, in western Japan since the 1980s. In this study, polymorphic analysis of I. seriolicida was performed using three molecular methods: amplified fragment length polymorphism (AFLP) analysis, multilocus sequence typing (MLST) and multiple‐locus variable‐number tandem repeat analysis (MLVA). Twenty‐eight isolates were analysed using AFLP, while 31 isolates were examined by MLST and MLVA. No polymorphisms were identified by AFLP analysis using EcoRI and MseI, or by MLST of internal fragments of eight housekeeping genes. However, MLVA revealed variation in repeat numbers of three elements, allowing separation of the isolates into 16 sequence types. The unweighted pair group method using arithmetic averages cluster analysis of the MLVA data identified four major clusters, and all isolates belonged to clonal complexes. It is likely that I. seriolicida populations share a common ancestor, which may be a recently introduced strain.     

四川鲟源海豚链球菌的毒力基因谱及分子分型

【目的】明确四川鲟源海豚链球菌Streptococcus iniae的毒力谱及分子流行病学特点,为鲟海豚链球菌病的防控提供参考。【方法】对四川地区17株鲟源海豚链球菌以及海豚链球菌ATCC29178进行毒力基因多重PCR检测,并通过随机扩增多态性DNA(RAPD)和重复序列PCR(REP-PCR)分析进行分子分型。【结果】所有菌株的7个主要毒力基因pgm、 scpI、 simA、 cpsD、 sagA、 pdi和cfi均为阳性,部分菌株的simA基因发生了变异。基于RAPD分析,18株菌分为Ⅰ、Ⅱ2个基因型;基于REP-PCR分析,18株菌分为A、B、C、D 4个基因型。【结论】四川地区17株鲟源海豚链球菌分离株均为强毒株,毒力谱为pgm/scpI/simA/cpsD/sagA/pdi/cfi,并且同时存在多种基因型的菌株,其中D型为优势流行型。     

细菌分型的分子生物学技术研究进展

回顾了传统细菌分型方法的重要作用,并重点介绍了近年发展得比较成熟的脉冲凝胶电泳（PF-GE）、低频限制性切割位点聚合酶链式反应（IRS-PCR）、随意扩增多态性DNA（RAPD）、扩增片段长度多态性（AFLP）、多位点酶电泳（MLEE）和多位点测序分型（MLST）等6种用于细菌分型的分子生物学技术的原理、特点以及应用情况,指出了其他细菌分型技术,如ARDRA、SSCP、DGGE、TGGEI、S等的不足,对基因芯片技术和实时PCR在细菌分型上的应用潜力进行了展望。     

Random amplified polymorphic DNA (RAPD) analysis of Mycobacterium tuberculosis strains in India

The usefulness of random amplification of polymorphic DNA (RAPD) analysis for typing Indian strains of M. tuberculosis was investigated. M. tuberculosis H37Rv, M. tuberculosis DT and 42 clinical isolates of M. tuberculosis were subjected to RAPD-PCR using 7 random decamer primers. All 7 primers were found to be differentiated and produced specific RAPD profiles. The polymorphic amplicons served as RAPD markers for M. tuberculosis. The dendrograms, obtained by different primers, showed the discriminatory ability of the primers. RAPD analysis provided a rapid and easy means of identifying polymorphism in M. tuberculosis isolates, and it was found to be a valuable alternative epidemiological tool. In addition, the results of the present study showed heterogeneity in the M. tuberculosis strains in the population studied.     

中国部分地区犬源伪中间葡萄球菌的流行特征分析

旨在调查犬源伪中间葡萄球菌的耐药性和分子特征，本研究自2017年11月—2019年4月收集601份送检至中国农业大学动物医院检验科和第三方检测机构的犬源临床样本，分离鉴定伪中间葡萄球菌；采用琼脂稀释法检测伪中间葡萄球菌对14种抗菌药物的敏感性；所有分离菌株均进行全基因组测序（WGS），并从WGS结果中获取耐药基因、多位点序列分型（ST）和葡萄球菌染色体基因盒（SCCmec）分型。结果显示，共分离到75株伪中间葡萄球菌（分离率为12.5%），其中包括42株（56%）耐甲氧西林伪中间葡萄球菌（MRSP）和33株（44%）甲氧西林敏感伪中间葡萄球菌（MSSP）；所有菌株均对青霉素、阿奇霉素、克林霉素、多西环素、环丙沙星、恩诺沙星、苯唑西林和氯霉素高度耐药，对利奈唑胺、万古霉素、阿米卡星和利福平敏感，多重耐药率达90.7%；所有MRSP均具有多重耐药性；75株伪中间葡萄球菌中检测到19种耐药基因，blaZ和aac（6'）-aph（2″）检出率最高，均为92%（69/75）；共发现70种ST型，54种为新ST型，无优势ST型；23株（54.7%） MRSP为SCCmec V型。综上表明，犬源伪中间葡萄球菌存在严重的多重耐药性；MRSP和MSSP均具有较大的遗传多样性。     

Method comparison of targeted influenza A virus typing and whole-genome sequencing from respiratory specimens of companion animals

Epidemics of H3N8 and H3N2 influenza A viruses (IAVs) in dogs, along with recognition of spillover infections from IAV strains typically found in humans or other animals, have emphasized the importance of efficient laboratory testing. Given the lack of active IAV surveillance or immunization requirements for dogs, cats, or horses imported into the United States, serotype prediction and whole-genome sequencing of positive specimens detected at veterinary diagnostic laboratories are also needed. The conserved sequences at the ends of the viral genome segments facilitate universal amplification of all segments of viral genomes directly from respiratory specimens. Although several methods for genomic analysis have been reported, no optimization focusing on companion animal strains has been described, to our knowledge. We compared 2 sets of published universal amplification primers using 26 IAV-positive specimens from dogs, horses, and a cat. Libraries prepared from the resulting amplicons were sequenced using Illumina chemistry, and reference-based assemblies were generated from the data produced by both methods. Although both methods produced high-quality data, coverage profiles and base calling differed between the 2 methods. The sequence data were also used to identify the subtype of the IAV strains sequenced and then compared to standard PCR assays for neuraminidase types N2 and N8.