Genome sequence for "Candidatus Mycoplasma haemominutum," a low-pathogenicity hemoplasma species

We present the genome sequence of "Candidatus Mycoplasma haemominutum" strain Birmingham 1, a low-pathogenicity feline hemoplasma strain.     

鸡贫血病毒哈尔滨分离株全基因克隆和序列分析

通过PCR方法克隆了从哈尔滨分离的一株鸡贫血病毒(CAV)的全基因,并对其进行了测序,该病毒基因组为环状,全长2298bp,含有三个互相重叠的开放读码框和一个调控区。将克隆的基因与GenBank收录的CAV基因比较,同源性至少为97%,未发现与本次克隆的CAV基因完全一致的分离株。与德国分离株Cuxla、26p4和马来西亚分离株分别有42、42和72个核苷酸不同,同源性分别为98.2%、98.2%和96.9%。与德国分离株Cux1b相比,除在调控区内少一个类似增强子的重复序列外,尚有39处核苷酸不同。它与分离于欧洲的几株CAV的亲源性要比来自亚洲的马来西亚株近。对CAV哈尔滨分离株、26p4、Cux1b、Cux1a和马来西亚株的VP1、VP2和VP3蛋白比较,VP2的保守性最高。     

Insights into the gene expression profile of uncultivable hemotrophic Mycoplasma suis during acute infection, obtained using proteome analysis

Hemotrophic mycoplasmas, bacteria without cell walls whose niche is the erythrocytes of their hosts, have never been cultivated in vitro. Therefore, knowledge of their pathogenesis is fundamental. Mycoplasma suis infects pigs, causing either acute fatal hemolytic anemia or chronic low-grade anemia, growth retardation, and immune suppression. Recently, the complete genomes of two hemotrophic mycoplasma species, M. suis and M. haemofelis, were sequenced, offering new strategies for the analysis of their pathogenesis. In this study we implemented a proteomic approach to identify M. suis proteins during acute infection by using tandem mass spectrometry. Twenty-two percent of the predicted proteins encoded in M. suis strain KI_3806 were identified. These included nearly all encoded proteins of glycolysis and nucleotide metabolism. The proteins for lipid metabolism, however, were underrepresented. A high proportion of the detected proteins are involved in information storage and processing (72.6%). In addition, several proteins of different functionalities, i.e., posttranslational modification, membrane genesis, signal transduction, intracellular trafficking, inorganic ion transport, and defense mechanisms, were identified. In its reduced genome, M. suis harbors 65.3% (strain Illinois) and 65.9% (strain KI_3806) of the genes encode hypothetical proteins. Of these, only 6.3% were identified at the proteome level. All proteins identified in this study are present in both M. suis strains and are encoded in more highly conserved regions of the genome sequence. In conclusion, our proteome approach is a further step toward the elucidation of the pathogenesis and life cycle of M. suis as well as the establishment of an in vitro cultivation system.     

Hemolytic anemia and erythroleukemia, two distinct pathogenic effects of Friend MuLV: mapping of the effects to different regions of the viral genome

Two different pathogenic effects of the Friend ecotropic murine leukemia virus (F-MuLV) were distinguished by serial examinations of hematocrits and reticulocyte counts of IRW mice inoculated as newborns. F-MuLV induced hemolytic anemia with increased levels of erythropoiesis, which was detectable as early as 13 days of age, whereas blocked erythroid differentiation, associated with erythroleukemia, was apparent only after 30 days of age. Using strains of Friend-MuLV with different virulences, we constructed recombinant viruses that allowed us to map the hemolytic effect and the ability to induce rapid erythroleukemia to different regions of the viral genome. Moreover, the ability of the virus to induce rapid erythroleukemia appeared to be independent of the presence of severe early hemolytic anemia.     

Overexpression of complement receptor type I (CR1, CD35) on erythrocytes in patients with hemoplasma infection

In the present study, 12 patients with fever of undetermined origin, anemia and icterus were diagnosed with hemoplasma infection by light microscopy, transmission electron microscopy examination and PCR assay after being excluded from other usual febrile diseases. Complement receptor type I (CR1, CD35) expression on the surface of erythrocytes was assessed by flow cytometry using mouse anti‐human CD35 antibody. Compared with healthy volunteers, the level of CD35 was significantly elevated in patients with severe hemoplasma infection at diagnosis, and decreased sharply after treatment. However, in latent infection cases without clinical manifestations, CD35 expression showed an ascending trend but had no statistical difference compared to the healthy controls. The present study demonstrated that hemoplasma infection can induce high levels of expression of CR1 on the membrane of red blood cells, which may be a reaction to the immunity challenge.     

Cytotoxicity and enterotoxicity of the thermostable direct hemolysin-deletion mutants of Vibrio parahaemolyticus

The thermostable direct hemolysin (TDH) has been proposed to be a major virulence factor of Vibrio parahaemolyticus. We have recently completed the genome sequence of a TDH-producing V. parahaemolyticus strain, RIMD2210633. In this study, we constructed tdh-deletion mutants from the sequenced strain by homologous recombination and analyzed their phenotypes. Although the deletion of both copies of tdh completely abolished the hemolytic activity of the wild-type strain, the deletion did not affect the cytotoxicity to HeLa cells. Enterotoxicity, assayed by the rabbit ileal loop test, was lowered by tdh deletion, but the mutant still showed partial fluid accumulation in rabbit intestine. These results indicate that the cytotoxicity and enterotoxicity of TDH-producing V. parahaemolyticus are not explained by TDH alone, and suggest that an unknown virulence factor(s) could be involved in these pathogenic activities.     

Prevalence and molecular characterization of Mycoplasma ovis in selected free-ranging Brazilian deer populations

Mycoplasma ovis is a hemoplasma that may cause anemia and mortality in small ruminants. Our aim was to determine whether M. ovis infects populations of free-ranging deer in Brazil. Buffy coat samples from 64 Blastocerus dichotomus from Porto Primavera, 18 Ozotocerus bezoarticus from Pantanal, and 21 O. bezoarticus from Emas National Park were tested. Using a M. ovis PCR protocol to amplify extracted DNA, 46/64 (72%) of deer from Porto Primavera, 10/18 (56%) from Pantanal, and 4/21 (19%) from Emas National Park were positive, giving an overall positive rate of 58% for hemoplasma in these wild deer. Sequencing and phylogenetic analysis of the 16S rRNA gene revealed 3 genetically distinct hemoplasmas including M. ovis, 'Candidatus Mycoplasma erythrocervae', and a hemoplasma most closely related to M. ovis. Phylogenetic analysis of the 23S rRNA gene from selected sequences confirmed these relationships.     

Human mutations in glucose 6-phosphate dehydrogenase reflect evolutionary history.

Glucose 6-phosphate dehydrogenase (G6PD) is a cytosolic enzyme encoded by a housekeeping X-linked gene whose main function is to produce NADPH, a key electron donor in the defense against oxidizing agents and in reductive biosynthetic reactions. Inherited G6PD deficiency is associated with either episodic hemolytic anemia (triggered by fava beans or other agents) or life-long hemolytic anemia. We show here that an evolutionary analysis is a key to understanding the biology of a housekeeping gene. From the alignment of the amino acid (aa) sequence of 52 glucose 6-phosphate dehydrogenase (G6PD) species from 42 different organisms, we found a striking correlation between the aa replacements that cause G6PD deficiency in humans and the sequence conservation of G6PD: two-thirds of such replacements are in highly and moderately conserved (50-99%) aa; relatively few are in fully conserved aa (where they might be lethal) or in poorly conserved aa, where presumably they simply would not cause G6PD deficiency. This is consistent with the notion that all human mutants have residual enzyme activity and that null mutations are lethal at some stage of development. Comparing the distribution of mutations in a human housekeeping gene with evolutionary conservation is a useful tool for pinpointing amino acid residues important for the stability or the function of the corresponding protein. In view of the current explosive increase in full genome sequencing projects, this tool will become rapidly available for numerous other genes.     

Complete genome sequence of Mycoplasma hyopneumoniae strain 168

Mycoplasma hyopneumoniae strain 168, a pathogenic strain prevalent in China, was isolated in 1974. Although this strain has been widespread for a long time, the genome sequence had not been determined. Here, we announce the complete genome sequence of M. hyopneumoniae strain 168.     

Identification of a new hemolysin from diarrheal isolate SSU of Aeromonas hydrophila

A clinical strain SSU of Aeromonas hydrophila produces a potent cytotoxic enterotoxin (Act) with cytotoxic, enterotoxic, and hemolytic activities. A new gene, which encoded a hemolysin of 439-amino acid residues with a molecular mass of 49 kDa, was identified. This hemolysin (HlyA) was detected based on the observation that the act gene minus mutant of A. hydrophila SSU still had residual hemolytic activity. The new hemolysin gene (hlyA) was cloned, sequenced, and overexpressed in Escherichia coli. The hlyA gene exhibited 96% identity with its homolog found in a recently annotated genome sequence of an environmental isolate, namely the type strain ATCC 7966 of A. hydrophila subspecies hydrophila. The hlyA gene did not exhibit any homology with other known hemolysins and aerolysin genes detected in Aeromonas isolates. However, this hemolysin exhibited significant homology with hemolysin of Vibrio vulnificus as well as with the cystathionine beta synthase domain protein of Shewanella oneidensis. The HlyA protein was activated only after treatment with trypsin and the resulting hemolytic activity was not neutralizable with antibodies to Act. The presence of the hlyA gene in clinical and water Aeromonas isolates was investigated and DNA fingerprint analysis was performed to demonstrate its possible role in Aeromonas virulence.     

Complete genome sequence of Bifidobacterium bifidum S17

Here, we report on the first completely annotated genome sequence of a Bifidobacterium bifidum strain. B. bifidum S17, isolated from feces of a breast-fed infant, was shown to strongly adhere to intestinal epithelial cells and has potent anti-inflammatory activity in vitro and in vivo. The genome sequence will provide new insights into the biology of this potential probiotic organism and allow for the characterization of the molecular mechanisms underlying its beneficial properties.     

乙型脑炎病毒减毒中间株SA14—12—1—7基因组全序列的测定

本研究通过对乙型脑炎活疫苗减毒过程中间株SA14 12 1 7株进行全序列测定和分析 ,进一步了解乙脑活疫苗减毒及其稳定性的分子机制。根据已发表的SA14 14 2株及SA14 株的序列 ,设计 6对重叠引物 ,涵括整个乙脑病毒的基因组 ,通过RT PCR扩增出SA14 12 1 7株的各cDNA片段 ,分别克隆到pGEM T载体 ,转化至TG1受体菌中 ,挑取阳性克隆进行鉴定后测序。结果表明SA14 12 1 7株基因组全序列长 10 976个核苷酸 ,从 96到 10 394为一个长开放读码框 ,编码 3432个氨基酸。与野毒株SA14 和疫苗株SA14 14 2的核苷酸序列和氨基酸序列相比 ,同源性均在 99%以上 ,突变位点分散于各个区域 ,E区有 5个位点与疫苗株一致而与野毒株不同 ,3个位点与野毒株一致而与疫苗株不同 ,推测与其容易产生回复突变、恢复毒力有关。此外 ,NS3、NS5和 3′NTR的几个位点可能与病毒毒力稳定性相关。综上所述 ,乙脑病毒减毒中间株的基因组全序列基本类似于已发表的序列 ,若干突变位点影响病毒的弱毒性及毒力的稳定性。全序列的测定对于研究疫苗株的减毒机理具有重要意义     

一株辛德毕斯病毒的基因组序列测定及分析

目的：对引进的一株辛德毕斯病毒的基因组序列进行测定,阐明其与已报道毒株序列的关系。方法：对辛德毕斯病毒基因组编码区进行分段RT-PCR扩增,对非编码区采用RACE法进行扩增,将扩增产物直接进行测序,应用DNAStar软件将测序结果拼接得到基因组序列,采用MEGA3.1软件对9株辛德毕斯病毒基因组序列进行系统进化发生树的构建。结果与结论：此株辛德毕斯病毒基因组共11663nt,编码3745个氨基酸残基,其中5＇端的2/3基因组编码4种非结构蛋白NSp1、NSp2、NSp3和NSp4,3＇端的1/3基因组编码5种结构蛋白E1、E2、E3、6K和C;结构基因和非结构基因之间有48nt的连接区为非翻译区;病毒基因组5＇末端和3＇末端分别有59、318nt的非编码区;序列同源性分析结果表明,此株病毒与S.A.AR86株的同源性最高,两者核苷酸序列的同源性为99.7%,氨基酸序列的同源性为99.6%,而与本室保存的另一辛德毕斯病毒MEI株的遗传进化关系稍远,系统进化发生树处于不同分支上。     

HEMOLYTIC ANEMIAS,Recent Advances in Diagnosis and Treatment

The hemolytic anemias of unknown cause can be separated into two main groups: (1) those produced by a defect in cell structure, which is usually hereditary, and (2) those due to a hemolysin of immune-body type.The hemolytic anemias associated with hypersensitivity to drugs and disease processes such as leukemia are less well understood and need further investigation.Splenectomy is the only effective treatment in congenital hemolytic jaundice and in acquired hemolytic anemia; the operation should be carried out promptly in most cases. Transfusion may be used in all varieties of hemolytic disease and is the only effective form of therapy in sickle-cell anemia and paroxysmal nocturnal hemoglobinuria.     

Complete genome sequence analysis of a recent chicken anemia virus isolate and comparison with a chicken anemia virus isolate from human fecal samples in china

A new isolate of chicken anemia virus (CAV) was designated GD-1-12. GD-1-12 was isolated from a 12-day-old commercial broiler in Guangdong province, China, in 2012. The GD-1-12 CAV caused high mortality, severe anemia, thymic atrophy, and subcutaneous hemorrhage in commercial broilers. Here, we report the complete genome sequence of GD-1-12 CAV and comparison with the complete genome sequence of another CAV that was isolated from human fecal samples in China (GenBank accession no. JQ690762). The genomes of the two CAV isolates shared high homology, although a deletion was identified by comparison. The findings from this study provide additional insights into the molecular characteristics of the CAV genomes and should advance knowledge for continuous monitoring and, perhaps, preventing the spread of the virus in chickens as well as in humans.     

An Imported Case of Severe Falciparum Malaria with Prolonged Hemolytic Anemia Clinically Mimicking a Coinfection with Babesiosis

While imported falciparum malaria has been increasingly reported in recent years in Korea, clinicians have difficulties in making a clinical diagnosis as well as in having accessibility to effective anti-malarial agents. Here we describe an unusual case of imported falciparum malaria with severe hemolytic anemia lasting over 2 weeks, clinically mimicking a coinfection with babesiosis. A 48-year old Korean man was diagnosed with severe falciparum malaria in France after traveling to the Republic of Benin, West Africa. He received a 1-day course of intravenous artesunate and a 7-day course of Malarone (atovaquone/proguanil) with supportive hemodialysis. Coming back to Korea 5 days after discharge, he was readmitted due to recurrent fever, and further treated with Malarone for 3 days. Both the peripheral blood smears and PCR test were positive for Plasmodium falciparum. However, he had prolonged severe hemolytic anemia (Hb 5.6 g/dl). Therefore, 10 days after the hospitalization, Babesia was considered to be potentially coinfected. A 7-day course of Malarone and azithromycin was empirically started. He became afebrile within 3 days of this babesiosis treatment, and hemolytic anemia profiles began to improve at the completion of the treatment. He has remained stable since his discharge. Unexpectedly, the PCR assays failed to detect DNA of Babesia spp. from blood. In addition, during the retrospective review of the case, the artesunate-induced delayed hemolytic anemia was considered as an alternative cause of the unexplained hemolytic anemia.     

Draft genome sequence of salt-tolerant yeast Debaryomyces hansenii var. hansenii MTCC 234

Debaryomyces hansenii is one of the most halotolerant species of yeast, and the genome sequence of D. hansenii strain CBS767 is already available. Here we report the 11.46-Mb draft genome of D. hansenii strain MTCC 234, which is even more halotolerant than strain CBS767. Comparative analysis of these sequences would definitely provide further insight into the halotolerance of this yeast.     

Genome sequence of Rhodococcus sp. strain R04, a polychlorinated-biphenyl biodegrader

The genus Rhodococcus has proved to be a promising option for the cleanup of polluted sites and application of a microbial biocatalyst. Rhodococcus sp. strain R04, isolated from oil-contaminated soil, can biodegrade polychlorinated biphenyls. Here we report the draft genome sequence of Rhodococcus sp. strain R04, which could be used to predict genes for xenobiotic biodegradation and provide important insights into the applications of this strain.     

Draft genome sequence of Thermus sp. strain RL, isolated from a hot water spring located atop the Himalayan ranges at Manikaran, India

Thermus sp. strain RL was isolated from a hot water spring (90°C to 98°C) at Manikaran, Himachal Pradesh, India. Here we report the draft genome sequence (20,36,600 bp) of this strain. The draft genome sequence consists of 17 contigs and 1,986 protein-coding sequences and has an average G+C content of 68.77%.     

Draft genome sequence of the nontoxigenic Clostridium difficile strain CD37

Here we report the draft genome sequence of Clostridium difficile strain CD37, the first nontoxigenic strain sequenced. Every sequenced strain of Clostridium difficile has been shown to contain multiple different mobile genetic elements. The draft genome sequence of strain CD37 reveals the presence of two putative conjugative transposons.