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1.
J Appl Microbiol ; 131(3): 1344-1359, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33555060

RESUMO

AIMS: Sulphate-reducing bacteria (SRB) are ecologically important group of anaerobic micro-organisms that can reduce sulphate to form hydrogen sulphide-a toxic gas causing iron corrosion on metal surfaces. In this work, SRB strains were isolated from aquatic environments in the country of Georgia to determine their lysogenicity and the role of temperate phages in host metabolism. METHODS AND RESULTS: SRB strains were isolated in samples from the Black Sea coast of Georgia. Based on their genetic, cytological and physiological properties of bacteria, 10 Georgian isolates were assigned to the genus Desulfovibrio. Temperate bacteriophages were induced from three out of ten strains by UV-exposure. Comparison of metal (Fe and Cr) reduction and utilization of various carbon sources by the wild-type (lysogenic) bacterial strains and their UV-irradiated counterparts was done. CONCLUSIONS: Temperate phage in the cells of SRB could alter significant functions of bacteria and may have a contribution in the acquisition of different traits by SRB. SIGNIFICANCE AND IMPACT OF THE STUDY: This article pointed to a significant role for temperate bacteriophages in the metabolism and metabolic potential of host strains of SRB, which were first isolated from the aquatic environment of Georgia.


Assuntos
Bacteriófagos , Desulfovibrio , Lisogenia , Organismos Aquáticos , Bacteriófagos/genética , Desulfovibrio/metabolismo , Desulfovibrio/virologia , Georgia , Água do Mar , Sulfatos , Microbiologia da Água
2.
Phage (New Rochelle) ; 1(3): 158-165, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36147826

RESUMO

To investigate the potential role of bacteriophages in the treatment of surgical infections, we conducted a retrospective analysis of four surgical patients who have sought treatment at the Eliava Phage Therapy Center, Tbilisi, Georgia. Two patients had chronic osteomyelitis, one presented with a diabetic foot ulcer, and the fourth patient had developed a severe infectious complication after skin grafting surgery. Patients were treated with different combinations of bacteriophage preparations, based on the sensitivity of the isolated bacterial strain toward commercially available bacteriophages. The treatment lasted on average for 1 month, and positive results were obtained in all four cases: the wounds have healed, the general health status of the patients has improved. No allergic or adverse reactions have been observed throughout the treatment.

3.
BMC Genomics ; 19(1): 685, 2018 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-30227847

RESUMO

BACKGROUND: In the present study, we sequenced the complete genomes of three novel bacteriophages v_B-Bak1, v_B-Bak6, v_B-Bak10 previously isolated from historical anthrax burial sites in the South Caucasus country of Georgia. We report here major trends in the molecular evolution of these phages, which we designate as "Basilisk-Like-Phages" (BLPs), and illustrate patterns in their evolution, genomic plasticity and core genome architecture. RESULTS: Comparative whole genome sequence analysis revealed a close evolutionary relationship between our phages and two unclassified Bacillus cereus group phages, phage Basilisk, a broad host range phage (Grose JH et al., J Vir. 2014;88(20):11846-11860) and phage PBC4, a highly host-restricted phage and close relative of Basilisk (Na H. et al. FEMS Microbiol. letters. 2016;363(12)). Genome comparisons of phages v_B-Bak1, v_B-Bak6, and v_B-Bak10 revealed significant similarity in sequence, gene content, and synteny with both Basilisk and PBC4. Transmission electron microscopy (TEM) confirmed the three phages belong to the Siphoviridae family. In contrast to the broad host range of phage Basilisk and the single-strain specificity of PBC4, our three phages displayed host specificity for Bacillus anthracis. Bacillus species including Bacillus cereus, Bacillus subtilis, Bacillus anthracoides, and Bacillus megaterium were refractory to infection. CONCLUSIONS: Data reported here provide further insight into the shared genomic architecture, host range specificity, and molecular evolution of these rare B. cereus group phages. To date, the three phages represent the only known close relatives of the Basilisk and PBC4 phages and their shared genetic attributes and unique host specificity for B. anthracis provides additional insight into candidate host range determinants.


Assuntos
Fagos Bacilares/genética , Bacillus anthracis/virologia , Genoma Viral , Genômica/métodos , Sequenciamento Completo do Genoma/métodos , Fagos Bacilares/classificação , Evolução Molecular , Especificidade de Hospedeiro , Filogenia , Análise de Sequência de DNA , Sintenia , Proteínas Virais/genética
4.
BMC Genomics ; 19(1): 713, 2018 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-30261838

RESUMO

Following the publication of this article [1], the authors noted two typographical errors: one in Table 1 with regard to the location of the Basilisk Phage, which was incorrectly captured as "Kutaisis, country of Georgia Utah, USA" but should be "Utah, USA".

5.
Res Microbiol ; 169(9): 540-542, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29777836

RESUMO

Respiratory infections can lead to serious complications in CF patients, especially when infected with antibiotic resistant bacteria. Alternative treatments for these infections are being sought out to help address this problem. We present a clinical case of a cystic fibrosis (CF) patient, with multi-drug resistant (MDR) Achromobacter xylosoxidans chronic lung infection who was successfully managed with bacteriophage therapy.


Assuntos
Achromobacter denitrificans/efeitos dos fármacos , Antibacterianos/farmacologia , Fibrose Cística/complicações , Infecções por Bactérias Gram-Negativas/terapia , Terapia por Fagos , Pneumonia Bacteriana/terapia , Adolescente , Fibrose Cística/microbiologia , Fibrose Cística/terapia , Farmacorresistência Bacteriana , Feminino , Humanos , Pulmão/efeitos dos fármacos , Pulmão/microbiologia
6.
Georgian Med News ; (274): 19-24, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29461221

RESUMO

Adrenocortical carcinoma is a very rare and aggressive endocrinological malignancy arising from the adrenal cortex. The estimated incidence is 1 per million people, with an estimated 5-year survival rate of 16-47%. It can be bilateral in roughly 2-10% of cases, but the data is scarce and there is no conclusive evidence whether the contralateral mass is an independent tumor or a metastasis from the other adrenal gland cancer. Radical surgical excision is the only curative treatment. Therefore, careful pre- and intraoperative surgical planning is critically important. Open adrenalectomy has historically been the gold standard approach for surgical treatment of adrenocortical carcinoma. Laparoscopic adrenalectomy has emerged as a minimally invasive alternative, but its oncological safety and effectiveness has long been under debate. Current evidence suggests that in experienced hands laparoscopic adrenalectomy is as safe and effective as its open counterpart in the treatment of localized adrenocortical carcinoma and the adrenal masses ≤10 cm. Urologists have been tempted to apply laparoscopy also to bilateral disease, although the need to reposition the patient and a longer operative time can be limitations. Given the rarity of adrenocortical carcinoma and the lack of quality evidence for the bilateral disease, we used the conventional narrative strategy to review the available literature. We also report a case of nonfunctioning bilateral adrenocortical carcinoma in a 65-year old man, who was operated on with simultaneous bilateral laparoscopic adrenalectomy for suspected localized (stage 2) disease, which proved to be bilateral locally advanced carcinoma (stage 3). Postoperatively, the disease rapidly progressed to the fatal outcome. The case once again highlights the importance of detailed operative planning and the need of imaging studies as close as possible to the date of planned surgery.


Assuntos
Neoplasias do Córtex Suprarrenal/cirurgia , Córtex Suprarrenal/cirurgia , Adrenalectomia/métodos , Carcinoma Adrenocortical/cirurgia , Dor nas Costas/patologia , Compressão da Medula Espinal/patologia , Córtex Suprarrenal/diagnóstico por imagem , Córtex Suprarrenal/patologia , Neoplasias do Córtex Suprarrenal/diagnóstico por imagem , Neoplasias do Córtex Suprarrenal/patologia , Carcinoma Adrenocortical/diagnóstico por imagem , Carcinoma Adrenocortical/patologia , Idoso , Dor nas Costas/diagnóstico por imagem , Evolução Fatal , Humanos , Imageamento por Ressonância Magnética , Masculino , Duração da Cirurgia , Compressão da Medula Espinal/diagnóstico por imagem , Tomografia Computadorizada por Raios X
7.
Georgian Med News ; (261): 31-36, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28132039

RESUMO

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and one of the major reasons for performing percutaneous endovascular procedures or liver surgery. Hepatic arterial anatomy is of major importance in performing these procedures on the liver. The aim of our study was to estimate the prevalence of various hepatic arterial variants in HCC patients. 78 patients were included in the study. Abdominal multiphase Computed Tomography scans of all patients have been assessed for presence of the hepatic arterial supply anatomical variations. Prevalent variant of arterial anatomy in each group and subgroup has been determined. Standard anatomy was seen in 38 patients. The rest 40 patients had anatomical variations. Among those 7 patients had left hepatic artery (LHA) replaced to the left gastric artery (LGA). 14 patients were found to have replaced right hepatic artery (RHA) from the superior mesenteric artery (SMA). Replaced LHA and RHA were found in 1 patient. Accessory LHA originating from the left gastric artery was found in 5 patients. Accessory RHA arising from the SMA was seen in 5 patients. Simultaneous existence of the replaced RHA and accessory LHA was encountered in 6 cases. Preoperative knowledge of the range of hepatic arterial anomalies and their specific frequencies is of great importance in planning and performance of endovascular interventional procedures. High prevalence of the hepatic arterial anatomy variations favors performing pre-embolization and pre-surgical CTA for the mapping of the hepatic arteries and is in consensus with other authors.


Assuntos
Carcinoma Hepatocelular/patologia , Artéria Hepática/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Adulto , Idoso , Angiografia por Tomografia Computadorizada , Artéria Hepática/patologia , Humanos , Pessoa de Meia-Idade
8.
Artigo em Russo | MEDLINE | ID: mdl-26950992

RESUMO

AIM: Evaluate role of gene polymorphisms of surfactant proteins in susceptibility and severity of influenza infection course in representatives of Moscow population. MATERIALS AND METHODS; 320 influenza patients, infected with various influenza virus strains, and 115 healthy individuals (control group),, were included into the study. Human DNA samples genotyping for determination of SFTPA2 gene rs1965708 and rs1059046, SFTPB gene rs1130866 polymorphisms was carried out using a modified method of "adjacent samples". RESULTS: Most of the individuals of the control group and influenza patients are carries of alleles and genotypes rs1965708 and rs1059046 of SFTPA2 gene, rs1130866 of SFTPB gene, that have, based on scientific literature data, shown association with severe course of influenza A(H1N1) pdm09 and other inflammatory diseases of the respiratory tract. Generally, significant differences in frequency of occurrence of unfavorable genotypes CC rs1965708, AA rs1059046 of SFTPA2 gene and CC rs1130866 of SFTPB gene in influenza patients in comparison with individuals of the control group were not detected, that gives evidence on a high (from 19 to 51%) prevalence of these genotypes in the studied population. Allele C and genotype CC rs1965708 of SFTPA2 gene, allele A and genotype AA rs1059046 of SFTPA2 gene, allele C and genotype CC rs1130866 of SFTPB gene did not shown an association with severe course of A(H1N1) pdm09 influenza. The following pathology registered in most (88%) of the patients with severe course of influenza A (H1N1)pdm09: diseases of cardiovascilar (44%), endocrine (36%) and respiratory (12%) systems. CONCLUSION: Because in most of the deceased patients due to severe course of A (H1N1)pdm09 influenza, diseases of cardiovascular, respiratory and endocrine system were detected, and an association of unfavorable disease outcome with the studied genetic markers was not detected, dominating risk factor of development of severe course and lethal outcome for A(H1N1)pdm09 influenza in the studied cohort was comorbidity.


Assuntos
Doenças Cardiovasculares/epidemiologia , Doenças do Sistema Endócrino/epidemiologia , Influenza Humana/epidemiologia , Pneumopatias/epidemiologia , Proteína A Associada a Surfactante Pulmonar/genética , Proteína B Associada a Surfactante Pulmonar/genética , Adulto , Doenças Cardiovasculares/mortalidade , Estudos de Casos e Controles , Comorbidade , Doenças do Sistema Endócrino/mortalidade , Feminino , Expressão Gênica , Estudos de Associação Genética , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/imunologia , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Influenza Humana/mortalidade , Pneumopatias/mortalidade , Masculino , Polimorfismo de Nucleotídeo Único , Federação Russa/epidemiologia
9.
Prikl Biokhim Mikrobiol ; 51(6): 600-9, 2015.
Artigo em Russo | MEDLINE | ID: mdl-26859962

RESUMO

The sensitivity of 512 newly isolated Pseudomonas aeruginosa clinical strains to six classes of anti-microbial preparations has been studied. Antibiotic-resistant strains were selected and genotyped. Three new virulent bacteriophages of the families Myoviridae and Podoviridae were isolated against these strains. The parameters of the intracellular phage development cycle were established, and the influence of inactivating factors (temperature, pH, and UV exposure) on phage viability was studied. The molecular weight of the phage genome was determined. Phage DNA restriction analysis and polyacrylamide gel electrophoresis in the presence of envelope protein SDS were carried out. The plating efficacy of phages on 28 genetically distant antibiotic-resistant P. aeruginosa strains was studied. It was established that 26 of them were lysed by phages with a high efficacy. The range of antibacterial action of the studied phages and their mixtures on 427 multi-drug-resistant clinical isolates was assessed. It is shown that including these phages in one multicomponent preparation enhanced their lytic activity.


Assuntos
Genoma Viral , Myoviridae/patogenicidade , Podoviridae/patogenicidade , Fagos de Pseudomonas/patogenicidade , Pseudomonas aeruginosa/virologia , Farmacorresistência Bacteriana Múltipla , Genótipo , Humanos , Concentração de Íons de Hidrogênio , Lisogenia , Tipagem Molecular , Peso Molecular , Myoviridae/classificação , Myoviridae/genética , Myoviridae/isolamento & purificação , Filogenia , Podoviridae/classificação , Podoviridae/genética , Podoviridae/isolamento & purificação , Infecções por Pseudomonas/microbiologia , Fagos de Pseudomonas/classificação , Fagos de Pseudomonas/genética , Fagos de Pseudomonas/isolamento & purificação , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/isolamento & purificação , Temperatura , Raios Ultravioleta , Virulência
10.
Med Mal Infect ; 38(8): 426-30, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18687542

RESUMO

The rapid spread of multidrug resistant bacterial strains limits the effectiveness of antibiotic treatments and induces intense research for alternatives. Today, the use of phage preparations as alternative approach is gaining attention, particularly for treating a wide variety of diseases which are difficult to control by chemotherapeutic agents. This article relates the phage therapy experience of the Eliava Institute of Bacteriophage, Microbiology and Virology.


Assuntos
Bacteriófagos/fisiologia , Doenças Transmissíveis/terapia , Lisogenia , Fibrose Cística/terapia , Fibrose Cística/virologia , República da Geórgia , Humanos , Infecções Estafilocócicas/terapia , Staphylococcus/virologia
11.
Georgian Med News ; (133): 56-8, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16705229

RESUMO

The study was aimed to assess influence of nebivolol (nebilet) on endothelial factors (NO and endothelin1) during treatment of salt-sensitive hypertensive patients. A total of 40 patients (18 females and 22 males, mean age 53,1+/-1,58 yrs) with mild (I stage) arterial hypertension (with diastolic pressure 90-99 mm Hg and/or systolic pressure 140-159 mm Hg) were studied. Twelve age matched healthy subjects (4 women and 8 males) composed control group. Salt sensitivity was detected by M. Weir (1993) method. Patients were divided in two groups: salt sensitive hypertension (group I, 16 patients) and salt-resistant hypertension (group II, 24 patients). Nebivolol (Nebilet, Berlin-Chemie, Germany) was administered to 25 patients in dosage of 5 mg once a day during two weeks. Our studies have showed that ET-1 plasma levels were significantly elevated in patients with essential hypertension, while NO was markedly reduced compared to control group. NO levels were slightly lower in salt-sensitive hypertensives than in salt-resistant patients (p>0,05). ET-1 levels expressed opposite changes: in patients with salt-sensitive hypertension ET-1 levels almost twice exceeded those of salt-resistant patients (p<0,01). After treatment with nebivolol NO plasma level in salt-sensitive hypertensives significantly increased in Group I and did not change significantly in salt-resistant patients. Only slight decrease in ET-1 levels was detected in both groups after taking nebilet. Nebilet (nebivolol) treatment has an influence only on NO levels and appears to be the most effective in salt-sensitive hypertension.


Assuntos
Benzopiranos/farmacologia , Endotélio Vascular/efeitos dos fármacos , Etanolaminas/farmacologia , Hipertensão , Sódio/metabolismo , Vasodilatadores/farmacologia , Benzopiranos/uso terapêutico , Etanolaminas/uso terapêutico , Feminino , Humanos , Hipertensão/tratamento farmacológico , Hipertensão/epidemiologia , Hipertensão/metabolismo , Masculino , Pessoa de Meia-Idade , Nebivolol , Óxido Nítrico/sangue , Vasodilatadores/uso terapêutico
12.
Eur Biophys J ; 35(3): 231-8, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16341727

RESUMO

In spite of the similarities in a structural organization of T5 and IRA phages their thermal and hydrodynamical peculiarities are completely different. One of the significant differences is observed in temperature value at which thermally induced DNA ejection starts. If in the case of physiological conditions this difference equals to 30 degrees capital ES, Cyrillic, then it decreases as ionic strength of the solvent decreases. Also, from our experimental results follows that in the opening of phage tail channel for T5 phage (at pH7) significant role-play electrostatic forces. In spite of that both of these phages grow on the same Escherichia coli strain, we have shown that these phages need different receptors to penetrate into the bacterial cell precisely FhuA serves as receptor only for T5 phage. The higher FhuA concentration in T5 phage suspension is, the more intensive DNA ejection in environment is. The minimal FhuA/T5 ratio, which is 300/1, correspondingly, necessary for effective DNA ejection from the phage head was experimentally determined. For the first time the ejection of T5 phage DNA induced by FhuA was observed in an incessant regime. The deconvolution of calorimetric curve of FhuA's denaturation has been shown that in a chosen condition there are four thermodynamically independent domains in the structure of FhuA.


Assuntos
Proteínas da Membrana Bacteriana Externa , Bacteriófagos , DNA Viral/fisiologia , Proteínas de Escherichia coli , Fagos T , Ligação Viral , Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas da Membrana Bacteriana Externa/fisiologia , Bacteriófagos/fisiologia , Calorimetria , DNA Viral/análise , Escherichia coli/fisiologia , Escherichia coli/virologia , Proteínas de Escherichia coli/metabolismo , Proteínas de Escherichia coli/fisiologia , Análise Numérica Assistida por Computador , Concentração Osmolar , Ligação Proteica , Estrutura Terciária de Proteína , Espectrofotometria Ultravioleta , Suspensões , Fagos T/fisiologia , Temperatura , Viscosidade
13.
Georgian Med News ; (122): 69-72, 2005 May.
Artigo em Russo | MEDLINE | ID: mdl-15988089

RESUMO

Using original experimental method (partial, different extent emptying of stomach from contents in various parts of time after satiety condition--denying the food intake) the mechanosensoric, homeostatic function of the stomach was revealed while performing the chronic experiments on adult male dogs, while on puppies the ageing peculiarities of its formation was shown. On polyfistuled (stomach, proximal and distal parts of duodenum) adult dogs, it was demonstrated that duodenum participates in maintenance and formation of satiety only while complex irritation by chime of the interoreceptors of gastrointestinal tract in natural succession of digestion takes place together with the sensoric processes in stomach.


Assuntos
Ingestão de Alimentos/psicologia , Resposta de Saciedade/fisiologia , Estômago/fisiologia , Animais , Cães , Duodeno/fisiologia , Ingestão de Alimentos/fisiologia , Esvaziamento Gástrico , Motilidade Gastrointestinal , Homeostase , Fome/fisiologia , Masculino
14.
Georgian Med News ; (121): 78-81, 2005 Apr.
Artigo em Russo | MEDLINE | ID: mdl-15908733

RESUMO

We have investigated the modulation of satiety in chronic experiments by stretching (different intensity and duration) stomach and duodenum with elastic intragastric balloon, filled with warm water on polifistuled (esophagus, gaster, duodenum) dogs. Estimation of periodical gastric motor activity was done by multiple determination of glucose concentration level in blood flow portions (blood tap method) towards and out of the brain, as well as liver. It appears that the signal conditioned by gastric stretching occurs to be the constant factor of formation and maintenance satiety condition for prolonged time.


Assuntos
Mecanorreceptores/fisiologia , Saciação/fisiologia , Estômago/inervação , Animais , Cães , Esvaziamento Gástrico/fisiologia , Masculino , Estimulação Física
15.
J Bacteriol ; 183(1): 358-66, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11114936

RESUMO

We examined a number of bacteriophages with T4-type morphology that propagate in different genera of enterobacteria, Aeromonas, Burkholderia, and Vibrio. Most of these phages had a prolate icosahedral head, a contractile tail, and a genome size that was similar to that of T4. A few of them had more elongated heads and larger genomes. All these phages are phylogenetically related, since they each had sequences homologous to the capsid gene (gene 23), tail sheath gene (gene 18), and tail tube gene (gene 19) of T4. On the basis of the sequence comparison of their virion genes, the T4-type phages can be classified into three subgroups with increasing divergence from T4: the T-evens, pseudoT-evens, and schizoT-evens. In general, the phages that infect closely related host species have virion genes that are phylogenetically closer to each other than those of phages that infect distantly related hosts. However, some of the phages appear to be chimeras, indicating that, at least occasionally, some genetic shuffling has occurred between the different T4-type subgroups. The compilation of a number of gene 23 sequences reveals a pattern of conserved motifs separated by sequences that differ in the T4-type subgroups. Such variable patches in the gene 23 sequences may determine the size of the virion head and consequently the viral genome length. This sequence analysis provides molecular evidence that phages related to T4 are widespread in the biosphere and diverged from a common ancestor in acquiring the ability to infect different host bacteria and to occupy new ecological niches.


Assuntos
Bacteriófago T4/classificação , Bacteriófago T4/genética , Genes Virais , Filogenia , Proteínas Virais/genética , Proteínas da Cauda Viral/genética , Sequência de Aminoácidos , Capsídeo/química , Capsídeo/genética , Eletroforese em Gel de Campo Pulsado , Genoma Viral , Bactérias Gram-Negativas/virologia , Microscopia Eletrônica , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Alinhamento de Sequência , Análise de Sequência de DNA , Proteínas Virais/química , Proteínas da Cauda Viral/química
16.
J Mol Biol ; 267(2): 237-49, 1997 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-9096222

RESUMO

Polymerase chain reaction analysis of a large collection of bacteriophages with T-even morphology revealed four phages that are distantly related to all the others. The genomes of these pseudo T-even phages hybridized under stringent conditions to only a limited portion of the T4 genome that encodes virus head, head-to-tail joining and contractile tail genes. Except for this region, no extensive hybridization was detected between most pairs of the different pseudo T-even genomes. Sequencing of this conserved region of the pseudo T-even phage RB49 revealed substantial nucleotide sequence divergence from T4 (approximately 30% to 40%), and random genomic sequencing of this phage indicated that more than a third of its sequences had no detectable homology to T4. Among those sequences related to the T-even genes were virion structural components including the constituents of the phage base plate. Only a few sequences had homology to T4 early functions; these included ribonucleotide diphosphatase reductase, DNA ligase and the large subunit of DNA topoisomerase. The genomes of the pseudo T-even phage were digested by restriction enzymes that are unable to digest the T-even DNAs which contain glucosylated hydroxymethyl-cytosine residues. This suggests that only limited nucleotide modifications must be present in the pseudo T-even genomes. Conservation of much of the morphogenetic region of these diverse phage genomes may reflect particularly strong sequence constraints on these gene products. However, other explanations are considered, including the possibility that the various morphogenetic segments were acquired by the pseudo T-even genomes by modular evolution. These results support the notion that phage evolution may proceed within a network of both closely and distantly related genomes.


Assuntos
Genoma Viral , Fagos T/genética , Sequência de Aminoácidos , Bacteriófago T4/genética , Southern Blotting , Western Blotting , Clonagem Molecular , Sequência Conservada/genética , Enzimas de Restrição do DNA/metabolismo , DNA Viral/genética , Evolução Molecular , Microscopia Eletrônica , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Reação em Cadeia da Polimerase , Mapeamento por Restrição , Homologia de Sequência de Aminoácidos , Proteínas Virais/química , Proteínas Virais/genética
17.
J Basic Microbiol ; 30(10): 707-16, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2090804

RESUMO

Morphological and biological properties of Salmonella typhimurium phage IRA were studied. The phage is a member of the Styloviridae family and exhibits a very wide spectrum of lytic activity. Molecular cloning of phage genes whose expression is lethal for the host cell has been performed and consequences of gene expression have been investigated. Expression of recombinant plasmid pKI71 causes structural changes of the cell wall and also degradation of host DNA while plasmid DNA remains intact. Expression of pKI72 blocks normal cell division. The possibility of applying such recombinant clones in marking pathways of microbial contamination in water areas is proposed.


Assuntos
DNA Viral/análise , Regulação Viral da Expressão Gênica , Fagos de Salmonella/genética , Salmonella typhimurium/ultraestrutura , Bacteriólise , Parede Celular/metabolismo , Clonagem Molecular , DNA Bacteriano/metabolismo , Hidrólise , Microscopia Eletrônica , Plasmídeos , Mapeamento por Restrição , Fagos de Salmonella/fisiologia , Fagos de Salmonella/ultraestrutura , Salmonella typhimurium/genética
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