CssRS is a two-component system that plays a pivotal role in mediating the secretion stress response in Bacillus subtilis. This system upregulates the synthesis of membrane-bound HtrA family ...proteases that cope with misfolded proteins that accumulate within the cell envelope as a result of overexpression or heat shock. Recent studies have shown the induction of CssRS-regulated genes in response to cell envelope stress. We investigated the induction of the CssRS-regulated htrA promoter in the presence of different cell wall- and membrane-active substances and observed induction of the CssRS-controlled genes by glycopeptides (vancomycin and teicoplanin), polymyxins B and E, certain β-lactams, and detergents. Teicoplanin was shown to elicit remarkably stronger induction than vancomycin and polymyxin B. Teicoplanin and polymyxin B induced the spxO gene expression in a CssRS-dependent fashion, resulting in increased activity of Spx, a master regulator of disulfide stress in Bacillus subtilis. The CssRS signaling pathway and Spx activity were demonstrated to be involved in Bacillus subtilis resistance to teicoplanin and polymyxin B.CssRS is a two-component system that plays a pivotal role in mediating the secretion stress response in Bacillus subtilis. This system upregulates the synthesis of membrane-bound HtrA family proteases that cope with misfolded proteins that accumulate within the cell envelope as a result of overexpression or heat shock. Recent studies have shown the induction of CssRS-regulated genes in response to cell envelope stress. We investigated the induction of the CssRS-regulated htrA promoter in the presence of different cell wall- and membrane-active substances and observed induction of the CssRS-controlled genes by glycopeptides (vancomycin and teicoplanin), polymyxins B and E, certain β-lactams, and detergents. Teicoplanin was shown to elicit remarkably stronger induction than vancomycin and polymyxin B. Teicoplanin and polymyxin B induced the spxO gene expression in a CssRS-dependent fashion, resulting in increased activity of Spx, a master regulator of disulfide stress in Bacillus subtilis. The CssRS signaling pathway and Spx activity were demonstrated to be involved in Bacillus subtilis resistance to teicoplanin and polymyxin B.
The complete genomes of the new
Erwinia amylovora
bacteriophages Loshitsa2 and Micant are 43,092 bp and 43,028 bp long, respectively, encode 51 putative proteins, and have two tRNA genes. Comparative ...analysis with representatives of the class
Caudoviricetes
suggests that bacteriophages Loshitsa2 and Micant are related to LIMElight bacteriophage belonging to the family
Autographiviridae
and could be proposed to be members of a novel subfamily.
Bacteriophages are often considered as possible agents of biological control of unwanted bacterial populations in medicine, agriculture and food industry. Although the virulent phages can efficiently ...kill the infected host cells but at the population level phage attack not always leads to the host population collapse but may result in establishment of a more or less stable co-existence. The mechanism of the long-term stabilization of the mixed phage-host cultures is poorly understood. Here we describe bacteriophages VyarbaL and Hena2, the members of the
Molineuxvirinae
and the
Ounavirinae
subfamilies, respectively, that are able to form the pseudolysogenic associations (PA) with their host
Erwinia amylovora
1/79Sm on solid media. These PAs were stable through multiple passages. The phenomenon of the PA formation between a bacterial culture and bacteriophages decreases the effectiveness of bacteriophage-mediated biological control agents based on lytic bacteriophages.
ABSTRACT
Fire blight, caused by plant pathogenic bacterium Erwinia amylovora, is one of the most important diseases of Rosaceae plants. Due to the lack of effective control measures, fire blight ...infections pose a recurrent threat on agricultural production worldwide. Recently, bacterial viruses, or bacteriophages, have been proposed as environmentally friendly natural antimicrobial agents for fire blight control. Here, we isolated a novel bacteriophage Hena1 with activity against E. amylovora. Further analysis revealed that Hena1 is a narrow-host-range lytic phage belonging to Myoviridae family. Its genome consists of a linear 148,842 bp dsDNA (48.42% GC content) encoding 240 ORFs and 23 tRNA genes. Based on virion structure and genomic composition, Hena1 was classified as a new species of bacteriophage subfamily Vequintavirinae. The comprehensive analysis of Hena1 genome may provide further insights into evolution of bacteriophages infecting plant pathogenic bacteria.
This study reports a novel lytic E. amylovora bacteriophage Hena1, that could be classified as a member of Myoviridae subfamily Vequintavirinae.
Erwinia amylovora is a Gram-negative plant pathogenic bacteria causing fire blight disease in many Rosaceae species.A novel E. amylovora bacteriophage, phiEa2809, was isolated from symptomless apple ...leaf sample collected in Belarus. This phage was also able to infect Pantoea agglomerans strains. The genome of phiEa2809 is a double-stranded linear DNA 162 160 bp in length, including 145 ORFs and one tRNA gene. The phiEa2809 genomic sequence is similar to the genomes of the Serratia plymutica phage MAM1, Shigella phage AG-3, Dickeya phage vB DsoM LIMEstone1 and Salmonella phage ViI and lacks similarity to described E. amylovora phage genomes. Based on virion morphology (an icosahedral head, long contractile tail) and genome structure, phiEa2809 was classified as a member of Myoviridae, ViI-like bacteriophages group. PhiEa2809 is the firstly characterized ViI-like bacteriophage able to lyse E. amylovora.
In this study, we investigated morphologic and genomic features of the new Erwinia amylovora bacteriophage phiEa2809 isolated from plant sample collected in Belarus.
Fire blight, caused by plant pathogenic bacterium Erwinia amylovora, is one of the most important diseases of Rosaceae plants. Due to the lack of effective control measures, fire blight infections ...pose a recurrent threat on agricultural production worldwide. Recently, bacterial viruses, or bacteriophages, have been proposed as environmentally friendly natural antimicrobial agents for fire blight control. Here, we isolated a novel bacteriophage Hena1 with activity against E. amylovora. Further analysis revealed that Hena1 is a narrow-host-range lytic phage belonging to Myoviridae family. Its genome consists of a linear 148,842 bp dsDNA (48.42% GC content) encoding 240 ORFs and 23 tRNA genes. Based on virion structure and genomic composition, Hena1 was classified as a new species of bacteriophage subfamily Vequintavirinae.The comprehensive analysis of Hena1 genome may provide further insights into evolution of bacteriophages infecting plant pathogenic bacteria.
The article is dedicated to the centenary of Belarusian State University and the centenary of biological university education in Belarus. The history of the faculty of biology is described, a ...retrospective of the development of its units since 1921 is presented. The most significant personalities and events are highlighted. The inseparable connection between the life of the faculty and the university as a whole is demonstrated.
Erwinia chrysanthemi ENA49 structural and regulatory ptl genes, coding for pectate lyase (Ptl) were cloned in Escherichia coli cells. Phage vector lambda L47.1 and phasmid vector lambda pMYF131 were ...used for constructing libraries of BamHI and EcoRI fragments, respectively, of Er. chrysanthemi chromosomal DNA. Among the 1,100 hybrid clones containing BamHI Er. chrysanthemi DNA fragments and 11,000 hybrid clones containing EcoRI fragments, six and 45 clones, respectively, were identified as having pectolytic activity. Two different structural genes, designated ptlA and ptlB, have been subcloned on multi-copy plasmids. Genes ptlA and ptlB are located side by side on the chromosome of Er. chrysanthemi and transcribe in the same direction. Each of the genes has its own promoter. Southern-blot hybridization analysis showed that the cloned ptl genes shared practically no homology and each of the genes was represented by a single copy on the Er. chrysanthemi chromosome. Other ptl genes capable of expression in E. coli cells were not found in the gene libraries. Negative regulation of the ptlA gene expression by a cloned gene called ptlR was shown. To screen the gene library for the ptlR gene, a specific genetic system was devised. The genes studied are located within an EcoRI chromosomal DNA fragment of 7.3 kb in the order: ptlA-ptlB-ptlR.
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