RESUMO
Anthrax is an acute infectious zoonotic disease caused by Bacillus anthracis, a bacterium that is considered a potential biological warfare agent. Bacillus bacteriophages shape the composition and evolution of bacterial communities in nature and therefore have important roles in the ecosystem community. B. anthracis phages are not only used in etiological diagnostics but also have promising prospects in clinical therapeutics or for disinfection in anthrax outbreaks. In this study, two temperate B. anthracis phages, vB_BanS_A16R1 (A16R1) and vB_BanS_A16R4 (A16R4), were isolated and showed siphovirus-like morphological characteristics. Genome sequencing showed that the genomes of phages A16R1 and A16R4 are 36,569 bp and 40,059 bp in length, respectively. A16R1 belongs to the genus Wbetavirus, while A16R4 belongs to the genus Hubeivirus and is the first phage of that genus found to lyse B. anthracis. Because these two phages can comparatively specifically lyse B. anthracis, they could be used as alternative diagnostic tools for identification of B. anthracis infections.
Assuntos
Fagos Bacilares , Bacillus anthracis , Genoma Viral , Bacillus anthracis/virologia , Genoma Viral/genética , Fagos Bacilares/isolamento & purificação , Fagos Bacilares/genética , Fagos Bacilares/classificação , Siphoviridae/genética , Siphoviridae/isolamento & purificação , Siphoviridae/classificação , FilogeniaRESUMO
Bacillus cereus is a foodborne pathogen that induces vomiting and diarrhea in affected individuals. It exhibits resistance to traditional sterilization methods and has a high contamination rate in dairy products and rice. Therefore, the development of a new food safety controlling strategy is necessary. In this research, we isolated and identified a novel phage named vB_BceP_LY3, which belongs to a new genus of the subfamily Northropvirinae. This phage demonstrates a short latency period and remains stable over a wide range of temperatures (4-60 °C) and pH levels (4-11). The 28,124 bp genome of LY3 does not contain any antibiotic-resistance genes or virulence factors. With regards to its antibacterial properties, LY3 not only effectively inhibits the growth of B. cereus in TSB (tryptic soy broth), but also demonstrates significant inhibitory effects in various food matrices. Specifically, LY3 treatment at 4 °C with a high MOI (MOI = 10,000) can maintain B. cereus levels below the detection limit for up to 24 h in milk. LY3 represents a safe and promising biocontrol agent against B. cereus, possessing long-term antibacterial capabilities and stability.
Assuntos
Bacillus cereus , Microbiologia de Alimentos , Leite , Oryza , Oryza/microbiologia , Bacillus cereus/virologia , Leite/microbiologia , Animais , Genoma Viral , Contaminação de Alimentos/prevenção & controle , Contaminação de Alimentos/análise , Fagos Bacilares/genética , Fagos Bacilares/isolamento & purificação , Fagos Bacilares/classificação , Fagos Bacilares/fisiologia , Bacteriófagos/genética , Bacteriófagos/isolamento & purificação , Bacteriófagos/fisiologiaRESUMO
A new Bacillus cereus phage, SWEP1, was isolated from black soil. The host lysis activity of phage SWEP1 has a relatively short latent time (20 min) and a small burst size of 83 PFU. The genome of SWEP1 consists of 162,461 bp with 37.77% G+C content. The phage encodes 278 predicted proteins, 103 of which were assigned functionally. No tRNA genes were found. Comparative genomics analysis indicated that SWEP1 is related to Bacillus phage B4 (86.91% identity, 90% query coverage). Phenotypic and genotypic characterization suggested that SWEP1 is a new member of a new species in the genus Bequatrovirus, family Herelleviridae.
Assuntos
Fagos Bacilares/fisiologia , Bacillus cereus/virologia , Genoma Viral , Fagos Bacilares/genética , Fagos Bacilares/isolamento & purificação , Bacillus cereus/isolamento & purificação , Composição de Bases , Replicação do DNA/genética , Genômica , Genótipo , Microscopia Eletrônica de Transmissão , Filogenia , RNA de Transferência/genética , Microbiologia do Solo , TemperaturaRESUMO
Bacillus is a highly diverse genus containing over 200 species that can be problematic in both industrial and medical settings. This is mainly attributed to Bacillus sp. being intrinsically resistant to an array of antimicrobial compounds, hence alternative treatment options are needed. In this study, two bacteriophages, PumA1 and PumA2 were isolated and characterized. Genome nucleotide analysis identified the two phages as novel at the DNA sequence level but contained proteins similar to phi29 and other related phages. Whole genome phylogenetic investigation of 34 phi29-like phages resulted in the formation of seven clusters that aligned with recent ICTV classifications. PumA1 and PumA2 share high genetic mosaicism and form a genus with another phage named WhyPhy, more recently isolated from the United States of America. The three phages within this cluster are the only candidates to infect B. pumilus. Sequence analysis of B. pumilus phage resistant mutants revealed that PumA1 and PumA2 require polymerized and peptidoglycan bound wall teichoic acid (WTA) for their infection. Bacteriophage classification is continuously evolving with the increasing phages' sequences in public databases. Understanding phage evolution by utilizing a combination of phylogenetic approaches provides invaluable information as phages become legitimate alternatives in both human health and industrial processes.
Assuntos
Fagos Bacilares/classificação , Fagos Bacilares/genética , Bacillus pumilus/virologia , Genoma Viral , Filogenia , Fagos Bacilares/isolamento & purificação , DNA Viral/genética , Evolução Molecular , Variação Genética , Mosaicismo , Análise de Sequência de DNARESUMO
Bacillus cereus is considered to be an important food poisoning agent causing diarrhea and vomiting. In this study, the occurrence of B. cereus bacteriophages in Thai fermented soybean products (Thua Nao) was studied using five B. cereus sensu lato indicator strains (four B. cereus strains and one B. thuringiensis strain). In a total of 26 Thua Nao samples, there were only two bacteriophages namely BaceFT01 and BaceCM02 exhibiting lytic activity against B. cereus. Morphological analysis revealed that these two bacteriophages belonged to the Myoviridae. Both phages were specific to B. cereus and not able to lyse other tested bacteria including B. licheniformis and B. subtilis. The two phages were able to survive in a pH range between 5 and 12. However, both phages were inactive either by treatment of 50°C for 2 h or exposure of UV for 2 h. It should be noted that both phages were chloroform-insensitive, however. This is the first report describing the presence of bacteriophages in Thua Nao products. The characterization of these two phages is expected to be useful in the food industry for an alternative strategy including the potential use of the phages as a biocontrol candidate against foodborne pathogenic bacteria.
Assuntos
Fagos Bacilares/isolamento & purificação , Bacillus cereus/virologia , Fermentação , Glycine max/química , Myoviridae/isolamento & purificação , Fagos Bacilares/fisiologia , Microbiologia de Alimentos , Humanos , Myoviridae/classificação , Myoviridae/genética , Myoviridae/crescimento & desenvolvimento , TailândiaRESUMO
One of the serious public health concerns is food contaminated with pathogens and their vital activity products such as toxins. Bacillus cereus group of bacteria includes well-known pathogenic species such as B. anthracis, B. cereus sensu stricto (ss), B. cytotoxicus and B. thuringiensis. In this report, we describe the Bacillus phages vB_BcM_Sam46 and vB_BcM_Sam112 infecting species of this group. Electron microscopic analyses indicated that phages Sam46 and Sam112 have the myovirus morphotype. The genomes of Sam46 and Sam112 comprise double-stranded DNA of 45,419 bp and 45,037 bp in length, respectively, and have the same GC-content. The genome identity of Sam46 and Sam112 is 96.0%, indicating that they belong to the same phage species. According to the phylogenetic analysis, these phages form a distinct clade and may be members of a new phage genus, for which we propose the name 'Samaravirus'. In addition, an interesting feature of the Sam46 and Sam112 phages is the unusual structure of their small terminase subunit containing N-terminal FtsK_gamma domain.
Assuntos
Fagos Bacilares/genética , Bacillus anthracis/virologia , Bacillus cereus/virologia , Bacillus thuringiensis/virologia , Endodesoxirribonucleases/química , Genoma Viral , Sequência de Aminoácidos , Fagos Bacilares/classificação , Fagos Bacilares/enzimologia , Fagos Bacilares/isolamento & purificação , Bacillus anthracis/crescimento & desenvolvimento , Bacillus cereus/crescimento & desenvolvimento , Bacillus thuringiensis/crescimento & desenvolvimento , Composição de Bases , Endodesoxirribonucleases/genética , Endodesoxirribonucleases/metabolismo , Filogenia , Homologia de Sequência , Ensaio de Placa ViralRESUMO
P59, a virulent phage of Bacillus oceanisediminis, was isolated from the sediment of Weiming Lake at Peking University (Beijing, China). P59 showed the typical morphology of myovirids. The complete genome sequence of P59 is 159,363 bp in length with a G+C content of 42.34%. The genome sequence has very low similarity to the other phage genome sequences in the GenBank database, suggesting that P59 is a new phage. A total of 261 open reading frames and 15 tRNA genes were predicted. Based on its morphological and genetic traits, we propose phage P59 to be a new member of the family Herelleviridae.
Assuntos
Fagos Bacilares/genética , Fagos Bacilares/isolamento & purificação , Bacillus/virologia , Genoma Viral , Filogenia , Fagos Bacilares/classificação , Composição de Bases , Sequência de Bases , China , Fases de Leitura Aberta , Sequenciamento Completo do GenomaRESUMO
As the most abundant biological entities, viruses are major players in marine ecosystems. However, our knowledge about virus-host interactions and viral ecology in the deep sea remains very limited. In this study, a novel bacteriophage (designated as phage BVE2) infecting Bacillus cereus group bacteria, was isolated from deep-sea sediments. Phage BVE2 caused host lysis within 1.5 h after infection. However, the presence of two integrase-encoding genes in the BVE2 genome suggested that BVE2 may also follow a temperate strategy. The genome of phage BVE2 is approximately 20 kb in length and is predicted to encode 28 proteins. Genomic and phylogenetic analysis suggested that BVE2 is a highly mosaic phage that has inherited genetic features from Wbeta-like viruses, B. cereus prophages, and its host, suggesting that frequent horizontal gene transfer events occurred during its evolution. This study will help to reveal the evolutionary history of Wbeta-like viruses and improve our understanding of viral diversity and virus-host interactions in the deep sea.
Assuntos
Fagos Bacilares/classificação , Fagos Bacilares/isolamento & purificação , Bacillus cereus/virologia , Genoma Viral , Água do Mar/virologia , Fagos Bacilares/genética , Fagos Bacilares/crescimento & desenvolvimento , Bacteriólise , Transferência Genética Horizontal , Genes Bacterianos , Lisogenia , Recombinação Genética , Análise de Sequência de DNARESUMO
vB_BmeM-Goe8 is a phage preying on Bacillus megaterium. Its genome has a GC content of 38.9%, is 161,583 bp in size, and has defined ends consisting of 7436-bp-long terminal repeats. It harbours 11 genes encoding tRNAs and 246 coding DNA sequences, 66 of which were annotated. The particle reveals Myoviridae morphology, and the formation of a double baseplate upon tail sheath contraction indicates morphological relatedness to the group of SPO1-like phages. BLASTn comparison against the NCBI non-redundant nucleotide database revealed that Bacillus phage Mater is the closest relative of vB_BmeM-Goe8.
Assuntos
Fagos Bacilares/classificação , Fagos Bacilares/isolamento & purificação , Bacillus megaterium/virologia , Genes Virais , Genoma Viral , Myoviridae/classificação , Myoviridae/isolamento & purificação , Fagos Bacilares/genética , Fagos Bacilares/ultraestrutura , Composição de Bases , Análise por Conglomerados , Myoviridae/genética , Myoviridae/ultraestrutura , Filogenia , Análise de Sequência de DNA , Homologia de Sequência , Sequências Repetidas Terminais , Vírion/ultraestruturaRESUMO
The phage vB_BthS-HD29phi infecting Bacillus thuringiensis strain HD29 was isolated and purified. The morphology of the phage showed that it belongs to the family Siphoviridae. The phage genome was 32,181 bp in length, comprised linear double-stranded DNA with an average G + C content of 34.9%, and exhibited low similarity to known phage genomes. Genomic and phylogenetic analysis revealed that vB_BthS-HD29phi is a novel phage. In total, 50 putative ORFs were predicted in the phage genome, and only 18 ORFs encoded proteins with known functions. This article reports the genome sequence of a new tailed phage and increases the known genetic diversity of tailed phages.
Assuntos
Fagos Bacilares/genética , Bacillus thuringiensis/virologia , Genoma Viral , Siphoviridae/genética , Fagos Bacilares/classificação , Fagos Bacilares/isolamento & purificação , Composição de Bases , Sequência de Bases , DNA Viral/genética , Variação Genética , Filogenia , Siphoviridae/classificação , Siphoviridae/isolamento & purificação , Sequenciamento Completo do GenomaRESUMO
The Bacillus cereus group of bacteria includes, inter alia, the species known to be associated with human diseases and food poisoning. Here, we describe the Bacillus phage vB_BtS_B83 (abbreviated as B83) infecting the species of this group. Transmission electron microscopy (TEM) micrographs indicate that B83 belongs to the Siphoviridae family. B83 is a temperate phage using an arbitrium system for the regulation of the lysis-lysogeny switch, and is probably capable of forming a circular plasmid prophage. Comparative analysis shows that it has been previously sequenced, but was mistaken for a plasmid. B83 shares common genome organization and >46% of proteins with other the Bacillus phage, BMBtp14. Phylograms constructed using large terminase subunits and a pan-genome presence-absence matrix show that these phages form a clade distinct from the closest viruses. Based on the above, we propose the creation of a new genus named Bembunaquatrovirus that includes B83 and BMBtp14.
Assuntos
Fagos Bacilares/classificação , Fagos Bacilares/genética , Filogenia , Plasmídeos , Siphoviridae/classificação , Siphoviridae/genética , Fagos Bacilares/isolamento & purificação , Fagos Bacilares/ultraestrutura , Bacillus thuringiensis/virologia , Sequência de Bases , DNA Viral/genética , Genes Virais/genética , Genoma Viral , Genômica , Especificidade de Hospedeiro , Microscopia Eletrônica de Transmissão , Prófagos/genética , Análise de Sequência de DNA , Siphoviridae/ultraestruturaRESUMO
Bacillus thuringiensis (Bt) is non-pathogenic for humans and serves as a biological control agent in agriculture. Understanding its phages will help to prevent industrial production loss of Bt products and will lead to a better understanding of phages in general. The complete genome of the new B. thuringiensis phage isolate vB_BthM-Goe5 (Goe5) was sequenced, revealing a linear 157,804-bp-long dsDNA chromosome flanked by 2579-bp-long terminal repeats. It contains two tRNAs and 272 protein coding regions, 69 of which could be assigned with an annotation. Morphological investigation, using transmission electron microscopy, revealed Myoviridae morphology. The formation of a double baseplate upon tail sheath contraction indicates a link to the group of SPO1-related phages. Comparative genomics with all Bacillus-related viral genomes available in the NCBI genome database during this investigation indicated that Goe5 was a unique isolate, with Bacillus phage Bastille as its closest relative.
Assuntos
Fagos Bacilares/genética , Fagos Bacilares/isolamento & purificação , Bacillus thuringiensis/virologia , Genoma Viral/genética , Sequência de Bases , Agentes de Controle Biológico , DNA Viral/genética , Myoviridae/genética , Análise de Sequência de DNA , Sequenciamento Completo do GenomaRESUMO
AP631, a virulent bacteriophage of Bacillus anthracis, is widely used in China to identify anthrax bacteria. In this study, we report the complete AP631 phage genome sequence as well as comparative genomic analysis with other bacteriophages of B. cereus and related species. The double-stranded circular DNA genome of phage AP631 was 39,549 bp in length with 35.01% G + C content. The phage genome contained 56 putative protein-coding genes but no rRNA or tRNA genes. Comparative phylogenetic analysis of the phage major capsid proteins and terminase large subunits showed that phage AP631 belongs to the B. cereus sensu lato phage clade II. Comparative genomic analysis revealed a high degree of sequence similarity between phage AP631 and B. anthracis phages Wbeta, Gamma, Cherry, and Fah, as well as three AP631-specific genes bearing no significant similarity to those of other phages.
Assuntos
Fagos Bacilares/genética , Bacillus anthracis/virologia , Genoma Viral , Fagos Bacilares/classificação , Fagos Bacilares/isolamento & purificação , Composição de Bases , Sequência de Bases , China , Dados de Sequência Molecular , Fases de Leitura Aberta , Filogenia , Sequenciamento Completo do GenomaRESUMO
To control the spore-forming human pathogen Bacillus cereus, we isolated and characterized a novel endolysin, LysPBC2, from a newly isolated B. cereus phage, PBC2. Compared to the narrow host range of phage PBC2, LysPBC2 showed very broad lytic activity against all Bacillus, Listeria, and Clostridium species tested. In addition to a catalytic domain and a cell wall binding domain, LysPBC2 has a spore binding domain (SBD) partially overlapping its catalytic domain, which specifically binds to B. cereus spores but not to vegetative cells of B. cereus Both immunogold electron microscopy and a binding assay indicated that the SBD binds the external region of the spore cortex layer. Several amino acid residues required for catalytic or spore binding activity of LysPBC2 were determined by mutagenesis studies. Interestingly, LysPBC2 derivatives with impaired spore binding activity showed an increased lytic activity against vegetative cells of B. cereus compared with that of wild-type LysPBC2. Further biochemical studies revealed that these LysPBC2 derivatives have lower thermal stability, suggesting a stabilizing role of SBD in LysPBC2 structure.IMPORTANCE Bacteriophages produce highly evolved lytic enzymes, called endolysins, to lyse peptidoglycan and release their progeny from bacterial cells. Due to their potent lytic activity and specificity, the use of endolysins has gained increasing attention as a natural alternative to antibiotics. Since most endolysins from Gram-positive-bacterium-infecting phages have a modular structure, understanding the function of each domain is crucial to make effective endolysin-based therapeutics. Here, we report the functional and biochemical characterization of a Bacillus cereus phage endolysin, LysPBC2, which has an unusual spore binding domain and a cell wall binding domain. A single point mutation in the spore binding domain greatly enhanced the lytic activity of endolysin at the cost of reduced thermostability. This work contributes to the understanding of the role of each domain in LysPBC2 and will provide insight for the rational design of efficient antimicrobials or diagnostic tools for controlling B. cereus.
Assuntos
Fagos Bacilares/enzimologia , Bacillus cereus/virologia , Domínio Catalítico , Endopeptidases/metabolismo , Esporos Bacterianos/virologia , Anti-Infecciosos , Fagos Bacilares/genética , Fagos Bacilares/isolamento & purificação , Bacillus cereus/metabolismo , Parede Celular/metabolismo , Endopeptidases/química , Endopeptidases/genética , Especificidade de Hospedeiro , Modelos Moleculares , Peptidoglicano/metabolismo , Mutação Puntual , Conformação Proteica , Domínios Proteicos/genética , Alinhamento de Sequência , Esporos Bacterianos/metabolismoRESUMO
Bacillus subtilis-infecting phage BSP38 was isolated from a sewage sample. Morphologically, BSP38 was found to be similar to members of the subfamily Spounavirinae, family Myoviridae. Its genome is 153,268 bp long with 41.8% G+C content and 254 putative open reading frames (ORFs) as well as six tRNAs. A distinguishing feature for this phage among the reported B. subtilis-infecting phages is the presence of an encoding ORF, putative tRNAHis guanylyltransferase-like protein. Genomic comparisons with the other reported phages strongly suggest that BSP38 should be considered a member of a new genus in the subfamily Spounavirinae.
Assuntos
Fagos Bacilares/genética , Bacillus subtilis/virologia , Genoma Viral , Myoviridae/genética , Fagos Bacilares/classificação , Fagos Bacilares/isolamento & purificação , Composição de Bases , Sequência de Bases , Dados de Sequência Molecular , Myoviridae/classificação , Myoviridae/isolamento & purificação , Filogenia , Análise de Sequência de DNA , Esgotos/virologiaRESUMO
Phages, the parasites of bacteria, are considered as a new kind of antimicrobial agent due to their ability to lyse pathogenic bacteria. Due to the increase of available phage isolates, the newly isolated phage showed increasing genomic similarities with previously isolated phages. In this study, the novel phage vB_BthS_BMBphi, infecting the Bacillus thuringiensis strain BMB171, is isolated and characterized together with its endolysin. This phage is the first tadpole-like phage infecting the Bacillus strains. Genomic analysis shows that the phage genome is dissimilar to all those of previously characterized phages, only exhibiting low similarities with partial regions of the B. thuringiensis prophages. Phylogenetic analysis revealed that the phage was distant from the other Bacillus phages in terms of evolution. The novel genome sequence, the distant evolutionary relationship, and the special virion morphology together suggest that the phage vB_BthS_BMBphi could be classified as a new phage lineage. The genome of the phage is found to contain a restriction modification system, which might endow the phage with immunity to the restriction modification system of the host bacterium. The function of the endolysin PlyBMB encoded by the phage vB_BthS_BMBphi was analyzed, and the endolysin could lyse all the tested Bacillus cereus group strains, suggesting that the endolysin might be used in controlling pathogenic B. cereus group strains. The findings of this study enrich the understanding of phage diversity and provide a resource for controlling the B. cereus group pathogenic bacteria.
Assuntos
Fagos Bacilares/isolamento & purificação , Fagos Bacilares/fisiologia , Bacillus thuringiensis/virologia , Endopeptidases/genética , Fagos Bacilares/classificação , Fagos Bacilares/ultraestrutura , Bacteriólise , Biologia Computacional/métodos , Genoma Viral , Filogenia , Ensaio de Placa Viral , Sequenciamento Completo do GenomaRESUMO
We present the recently isolated virus vB_BthP-Goe4 infecting Bacillus thuringiensis HD1. Morphological investigation via transmission electron microscopy revealed key characteristics of the genus Phi29virus, but with an elongated head resulting in larger virion particles of approximately 50 nm width and 120 nm height. Genome sequencing and analysis resulted in a linear phage chromosome of approximately 26 kb, harbouring 40 protein-encoding genes and a packaging RNA. Sequence comparison confirmed the relation to the Phi29virus genus and genomes of other related strains. A global average nucleotide identity analysis of all identified φ29-like viruses revealed the formation of several new groups previously not observed. The largest group includes Goe4 and may significantly expand the genus Phi29virus (Salasvirus) or the Picovirinae subfamily.
Assuntos
Fagos Bacilares/classificação , Fagos Bacilares/genética , Genoma Viral , Genômica , Fagos Bacilares/isolamento & purificação , Fagos Bacilares/ultraestrutura , Biologia Computacional/métodos , Evolução Molecular , Ordem dos Genes , Genômica/métodos , FilogeniaRESUMO
While the harmful effects of lactic acid bacterial bacteriophages in the dairy industry are well-established, the importance of Bacillus subtilis-infecting bacteriophages on soybean fermentation is poorly-studied. In this study, we isolated a B. subtilis-infecting bacteriophage BSP10 from Meju (a brick of dried fermented soybean) and further characterized it. This Myoviridae family bacteriophage exhibited a narrow host range against B. subtilis strains (17/52, 32.7%). The genome of bacteriophage BSP10 is 153,767 bp long with 236 open reading frames and 5 tRNAs. Comparative genomics (using dot plot, progressiveMauve alignment, heat-plot, and BLASTN) and phylogenetic analysis strongly suggest its incorporation as a new species in the Nit1virus genus. Furthermore, bacteriophage BSP10 was efficient in the growth inhibition of B. subtilis ATCC 15245 in liquid culture and in Cheonggukjang (a soybean fermented food) fermentation. Artificial contamination of as low as 10² PFU/g of bacteriophage BSP10 during Cheonggukjang fermentation significantly reduced bacterial numbers by up to 112 fold in comparison to the control (no bacteriophage). Moreover, for the first time, we experimentally proved that B. subtilis-infecting bacteriophage greatly enhanced poly-γ-glutamic acid degradation during soybean fermentation, which is likely to negatively affect the functionalities of Cheonggukjang.
Assuntos
Fagos Bacilares/genética , Bacillus subtilis/virologia , Genoma Viral , Ácido Poliglutâmico/análogos & derivados , Fagos Bacilares/classificação , Fagos Bacilares/isolamento & purificação , Fermentação , Alimentos Fermentados/microbiologia , Alimentos Fermentados/virologia , Microbiologia de Alimentos , Especificidade de Hospedeiro , Myoviridae/classificação , Myoviridae/genética , Myoviridae/isolamento & purificação , Filogenia , Ácido Poliglutâmico/metabolismo , Análise de Sequência de DNA , Glycine maxRESUMO
Bacteriophage Deep-Purple, isolated from an agricultural soil in Belgium, lyses the emetic Bacillus weihenstephanensis strain LH002 and exhibits a lytic activity against 55% of emetic Bacillus cereus and B. weihenstephanensis strains. Deep-Purple is able to complete its lytic cycle within 45 min and is stable to a large range of pHs and temperatures below 60 °C. It possesses an icosahedral head of about 63 nm in diameter and a non-contractile tail of approximately 165 nm in length. The genome of this newly classifiable Siphoviridae family member is 36,278 bp long, with a G+C content of 38.36% and 40 putative CDSs. Most CDSs do not display similarity with other B. cereus group phages supporting the idea that Deep-Purple belongs to a new and currently uncharacterised Siphoviridae subfamily.
Assuntos
Fagos Bacilares/genética , Fagos Bacilares/isolamento & purificação , Bacillus cereus/virologia , Genoma Viral , Siphoviridae/genética , Siphoviridae/isolamento & purificação , Fagos Bacilares/classificação , Composição de Bases , Bélgica , Filogenia , Siphoviridae/classificação , Microbiologia do Solo , Sequenciamento Completo do GenomaRESUMO
Drug-resistant Gram-positive pathogens have been a rising risk in hospitals and food industries from the last decades. Here in, the potential of endolysin production in Dasht Desert Bacterial Culture Collection (DDBCC), against indicator bacteria, was investigated. DDBCC was screened against autoclaved-indicator bacteria; Streptococcus faecalis, Streptococcus pyogenes, Bacillus sp, Bacillus subtilis and Staphylococcus aureus as the substrates for the endolysin enzymes. The endolysins were produced in BHI medium followed by ammonium sulfate purification. Peptidoglycan hydrolytic activity was tested by zymogram method. Lysogenic bacteria were induced by 0.1⯵g/ml mitomycin C for bacteriophages extraction. The lysogenic bacteria inhibited S. pyogenes, S. faecalis, Bacillus sp. and B. subtilis. The strain DDBCC10 was selected for further experiments on its higher and specific activity against the cell wall of S. faecalis. The highest activity for the endolysin was obtained at 50-60% ammonium sulfate saturation as 8 U/ml. Lys10, a 22â¯kDa enzyme, digested the cell wall of S. faecalis in 15â¯min while the whole phage from DDBCC10 could form plaque on S. faecalis and S. pyogenes. In a Transmission Electron Microscopy assay (TEM), the phage was distinguished as a member of Siphoviridae. Here; Lys10 is introduced as a new biocontrol agent against S. faecalis for therapeutics, disinfection, and food preservatives purposes at a much lower expense than recombinant endolysins.