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1.
Curr Microbiol ; 79(3): 89, 2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-35129700

RESUMO

Viruses that infect bacteria are emerging as attractive biocontrol agents and biopreservatives for foods. Since these bacteriophages kill the target pathogens by lysis and are also consumed along with food, it is essential to evaluate their collateral toxicity on the probiotic gut microbiota. In this study, we examined the acute oral toxicity of a Salmonella phage isolated from sewage in mice. Acute oral administration of the Salmonella phage for five consecutive days did not show any significant pathological changes in the vital organs like lung, kidneys, heart, liver, and intestine. In addition, growth of typical probiotic microbiota remained unaffected even after incubation up to 24 h with the Salmonella phage. The results of this study clearly showed that oral administration of the lytic Salmonella phage did not have any significant adverse effects on the animals, may not harm the probiotic gut microbiota, and are likely to be safe for use in food preservation.


Assuntos
Bacteriófagos , Microbioma Gastrointestinal , Probióticos , Salmonella/virologia , Animais , Camundongos , Camundongos Endogâmicos BALB C , Terapia por Fagos , Testes de Toxicidade
2.
PLoS Biol ; 19(11): e3001424, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34784345

RESUMO

Bacteriophages, the viruses infecting bacteria, hold great potential for the treatment of multidrug-resistant bacterial infections and other applications due to their unparalleled diversity and recent breakthroughs in their genetic engineering. However, fundamental knowledge of the molecular mechanisms underlying phage-host interactions is mostly confined to a few traditional model systems and did not keep pace with the recent massive expansion of the field. The true potential of molecular biology encoded by these viruses has therefore remained largely untapped, and phages for therapy or other applications are often still selected empirically. We therefore sought to promote a systematic exploration of phage-host interactions by composing a well-assorted library of 68 newly isolated phages infecting the model organism Escherichia coli that we share with the community as the BASEL (BActeriophage SElection for your Laboratory) collection. This collection is largely representative of natural E. coli phage diversity and was intensively characterized phenotypically and genomically alongside 10 well-studied traditional model phages. We experimentally determined essential host receptors of all phages, quantified their sensitivity to 11 defense systems across different layers of bacterial immunity, and matched these results to the phages' host range across a panel of pathogenic enterobacterial strains. Clear patterns in the distribution of phage phenotypes and genomic features highlighted systematic differences in the potency of different immunity systems and suggested the molecular basis of receptor specificity in several phage groups. Our results also indicate strong trade-offs between fitness traits like broad host recognition and resistance to bacterial immunity that might drive the divergent adaptation of different phage groups to specific ecological niches. We envision that the BASEL collection will inspire future work exploring the biology of bacteriophages and their hosts by facilitating the discovery of underlying molecular mechanisms as the basis for an effective translation into biotechnology or therapeutic applications.


Assuntos
Colífagos/fisiologia , Escherichia coli/virologia , Interações Hospedeiro-Patógeno/fisiologia , Escherichia coli/imunologia , Especificidade de Hospedeiro , Imunidade , Fenótipo , Filogenia , Polissacarídeos/metabolismo , Receptores de Superfície Celular/metabolismo , Salmonella/virologia , Proteínas Virais/metabolismo
3.
Viruses ; 13(11)2021 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-34834927

RESUMO

Bacteriophages are viruses that infect bacteria and are present in niches where bacteria thrive. In recent years, the suggested application areas of lytic bacteriophage have been expanded to include therapy, biocontrol, detection, sanitation, and remediation. However, phage application is constrained by the phage's host range-the range of bacterial hosts sensitive to the phage and the degree of infection. Even though phage isolation and enrichment techniques are straightforward protocols, the correlation between the enrichment technique and host range profile has not been evaluated. Agar-based methods such as spotting assay and efficiency of plaquing (EOP) are the most used methods to determine the phage host range. These methods, aside from being labor intensive, can lead to subjective and incomplete results as they rely on qualitative observations of the lysis/plaques, do not reflect the lytic activity in liquid culture, and can overestimate the host range. In this study, phages against three bacterial genera were isolated using three different enrichment methods. Host range profiles of the isolated phages were quantitatively determined using a high throughput turbidimetric protocol and the data were analyzed with an accessible analytic tool "PHIDA". Using this tool, the host ranges of 9 Listeria, 14 Salmonella, and 20 Pseudomonas phages isolated with different enrichment methods were quantitatively compared. A high variability in the host range index (HRi) ranging from 0.86-0.63, 0.07-0.24, and 0.00-0.67 for Listeria, Salmonella, and Pseudomonas phages, respectively, was observed. Overall, no direct correlation was found between the phage host range breadth and the enrichment method in any of the three target bacterial genera. The high throughput method and analytics tool developed in this study can be easily adapted to any phage study and can provide a consensus for phage host range determination.


Assuntos
Bacteriófagos/isolamento & purificação , Bacteriófagos/fisiologia , Ciência de Dados/métodos , Ensaios de Triagem em Larga Escala/métodos , Especificidade de Hospedeiro , Listeria/virologia , Pseudomonas/virologia , Salmonella/virologia , Software
4.
Vet Res ; 52(1): 125, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34593043

RESUMO

Efficient in vivo delivery of a CRISPR/Cas9 plasmid is of paramount importance for effective therapy. Here, we investigated the usability of Salmonella as a plasmid carrier for in vivo therapy against virus-induced cancer using Marek's disease virus (MDV) as a model for study in chickens. A green fluorescent protein-expressing CRISPR/Cas9 plasmid encoding the virulence gene pp38 was constructed against Marek's disease virus. Therapeutic plasmids were transformed into Salmonella carrying lon and sifA gene deletions. The animals in 5 groups were intraperitoneally inoculated with phosphate-buffered saline, vector control, or Salmonella before or after MDV infection, or left uninfected as a naïve control. Therapeutic effectiveness was evaluated by observing disease outcomes and the viral copy number in peripheral blood mononuclear cells. The efficacy of plasmid delivery by Salmonella was 13 ± 1.7% in the spleen and 8.0 ± 1.8% in the liver on the 6th day post-infection. The Salmonella-treated groups showed significant resistance to MDV infection. The maximum effect was observed in the group treated with Salmonella before MDV infection. None of the chickens fully recovered; however, the results suggested that timely delivery of Salmonella could be effective for in vivo CRISPR/Cas9-mediated genetic interference against highly pathogenic MDV. The use of Salmonella in CRISPR systems provides a simpler and more efficient platform for in vivo therapy with CRISPR than the use of conventional in vivo gene delivery methods and warrants further development.


Assuntos
Sistemas CRISPR-Cas , Galinhas , Herpesvirus Galináceo 2/fisiologia , Doença de Marek/prevenção & controle , Plasmídeos/uso terapêutico , Doenças das Aves Domésticas/prevenção & controle , Salmonella/fisiologia , Animais , Feminino , Leucócitos Mononucleares/virologia , Doença de Marek/patologia , Doença de Marek/virologia , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/virologia , Salmonella/virologia
5.
Viruses ; 13(7)2021 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203492

RESUMO

Bacteriophages that lyse Salmonella enterica are potential tools to target and control Salmonella infections. Investigating the host range of Salmonella phages is a key to understand their impact on bacterial ecology, coevolution and inform their use in intervention strategies. Virus-host infection networks have been used to characterize the "predator-prey" interactions between phages and bacteria and provide insights into host range and specificity. Here, we characterize the target-range and infection profiles of 13 Salmonella phage clones against a diverse set of 141 Salmonella strains. The environmental source and taxonomy contributed to the observed infection profiles, and genetically proximal phages shared similar infection profiles. Using in vitro infection data, we analyzed the structure of the Salmonella phage-bacteria infection network. The network has a non-random nested organization and weak modularity suggesting a gradient of target-range from generalist to specialist species with nested subsets, which are also observed within and across the different phage infection profile groups. Our results have implications for our understanding of the coevolutionary mechanisms shaping the ecological interactions between Salmonella phages and their bacterial hosts and can inform strategies for targeting Salmonella enterica with specific phage preparations.


Assuntos
Infecções Bacterianas/microbiologia , Interações entre Hospedeiro e Microrganismos , Especificidade de Hospedeiro , Fagos de Salmonella/genética , Salmonella/genética , Antibacterianos/farmacologia , Evolução Molecular , Salmonella/classificação , Salmonella/efeitos dos fármacos , Salmonella/virologia , Infecções por Salmonella/terapia , Fagos de Salmonella/patogenicidade
6.
Vet Microbiol ; 253: 108944, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33370618

RESUMO

The aim of this study was to explore the characteristics of blaCTX-M-27 carriage and mobilization in Salmonella and Escherichia coli isolates from food-producing animals in China. A total of 2280 E. coli and 229 Salmonella isolates collected from food animals from June 2003 to September 2014 were screened for the presence of blaCTX-M-27 gene. The blaCTX-M-27-positive isolates were typed and plasmid DNA sequenced to determine the genetic context of blaCTX-M-27 and plasmid types present. Bacterial fitness was evaluated by growth curve and plasmid stability in vitro. CTX-M-27-positive E. coli (18, 0.79 %) and Salmonella (34, 14.85 %) were detected. PFGE profiles of CTX-M-27-positive strains revealed a wide variety of genotypes and S. Indiana was the most prevalent serotype. Replicon typing, S1-PFGE and hybridization of CTX-M-27-carrying plasmids confirmed that blaCTX-M-27 gene was located on IncFII (12/18), IncN (4/18), and non-typeable (2/18) plasmids in E. coli and on P1-like bacteriophage (21/34), IncP (4/34), IncFIB (4/34), IncN (2/34), IncHI2 (2/34), and IncA/C (1/34) plasmids in Salmonella. Comparison and analysis of gene context of blaCTX-M-27 in P1-like bacteriophage and plasmids revealed they shared the same structure and contained an identical genetic context with the Tn1721-like structure ΔISEcp1B-blaCTX-M-27-IS903D-iroN-Δmap-Tn1721. In addition, plasmid stability tests indicated that the blaCTX-M-27 P1-like bacteriophage were more stable than plasmids in the absence of cefotaxime selective pressure. These results demonstrate that Tn1721-like transposons harboring CTX-M-27 could be mobilized between different plasmids in E. coli and P1-like bacteriophage disseminated among Salmonella.


Assuntos
Proteínas de Escherichia coli/genética , Escherichia coli/genética , Salmonella/virologia , beta-Lactamases/genética , Animais , Animais Domésticos/microbiologia , Antibacterianos/farmacologia , China , Farmacorresistência Bacteriana Múltipla , Escherichia coli/química , Escherichia coli/efeitos dos fármacos , Microbiologia de Alimentos , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Salmonella/química , Salmonella/efeitos dos fármacos , Salmonella/genética
7.
Viruses ; 12(12)2020 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-33321823

RESUMO

Non-typhoidal Salmonella present a major threat to animal and human health as food-borne infectious agents. We characterized 91 bacterial isolates from Armenia and Georgia in detail, using a suite of assays including conventional microbiological methods, determining antimicrobial susceptibility profiles, matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry, serotyping (using the White-Kauffmann-Le Minor scheme) and genotyping (repetitive element sequence-based PCR (rep-PCR)). No less than 61.5% of the isolates were shown to be multidrug-resistant. A new antimicrobial treatment strategy is urgently needed. Phage therapy, the therapeutic use of (bacterio-) phages, the bacterial viruses, to treat bacterial infections, is increasingly put forward as an additional tool for combatting antibiotic resistant infections. Therefore, we used this representative set of well-characterized Salmonella isolates to analyze the therapeutic potential of eleven single phages and selected phage cocktails from the bacteriophage collection of the Eliava Institute (Georgia). All isolates were shown to be susceptible to at least one of the tested phage clones or their combinations. In addition, genome sequencing of these phages revealed them as members of existing phage genera (Felixounavirus, Seunavirus, Viunavirus and Tequintavirus) and did not show genome-based counter indications towards their applicability against non-typhoidal Salmonella in a phage therapy or in an agro-food setting.


Assuntos
Bacteriófagos/fisiologia , Interações Hospedeiro-Patógeno , Infecções por Salmonella/epidemiologia , Infecções por Salmonella/microbiologia , Salmonella/virologia , Animais , Antibacterianos/farmacologia , Bacteriófagos/ultraestrutura , Doenças Transmitidas por Alimentos/microbiologia , Geografia Médica , República da Geórgia/epidemiologia , Humanos , Filogenia , Salmonella/classificação , Salmonella/efeitos dos fármacos , Salmonella/isolamento & purificação , Infecções por Salmonella/transmissão
8.
Viruses ; 13(1)2020 12 25.
Artigo em Inglês | MEDLINE | ID: mdl-33375688

RESUMO

The increasing emergence of antimicrobial resistance has become a global issue. Therefore, many researchers have attempted to develop alternative antibiotics. One promising alternative is bacteriophage. In this study, we focused on a jumbo-phage infecting Salmonella isolated from exotic pet markets. Using a Salmonella strain isolated from reptiles as a host, we isolated and characterized the novel jumbo-bacteriophage pSal-SNUABM-04. This phage was investigated in terms of its morphology, host infectivity, growth and lysis kinetics, and genome. The phage was classified as Myoviridae based on its morphological traits and showed a comparatively wide host range. The lysis efficacy test showed that the phage can inhibit bacterial growth in the planktonic state. Genetic analysis revealed that the phage possesses a 239,626-base pair genome with 280 putative open reading frames, 76 of which have a predicted function and 195 of which have none. By genome comparison with other jumbo phages, the phage was designated as a novel member of Machinavirus composed of Erwnina phages.


Assuntos
Fagos de Salmonella/isolamento & purificação , Fagos de Salmonella/fisiologia , Salmonella/virologia , Bacteriólise , Genoma Viral , Genômica , Concentração de Íons de Hidrogênio , Fases de Leitura Aberta , Fagos de Salmonella/ultraestrutura , Temperatura , Sequenciamento Completo do Genoma
9.
PLoS One ; 15(10): e0240579, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33057372

RESUMO

All Neisseria gonorrhoeae strains contain multiple copies of integrated filamentous phage genomes with undefined structures. In this study, we sought to characterize the capsid proteins of filamentous N. gonorrhoeae bacteriophage NgoΦ6 and phagemids propagated in different bacteria. The data demonstrate that purified phage contain phage-encoded structural proteins and bacterial host proteins; host proteins consistently copurified with the phage particles. The bacterial host proteins associated with the phage filament (as identified by mass spectrometry) tended to be one of the predominant outer membrane components of the host strain, plus minor additional host proteins. We were able to copurify a functional ß-lactamase, a phagemid-encoded protein, with phage filaments. We used protein modeling and immunological analysis to identify the major phage encoded structural proteins. The antigenic properties of these proteins depended on the bacterium where the phages were propagated. Polyclonal antibodies against N. gonorrhoeae phage NgoΦ6 recognized phage-encoded proteins if the phage was propagated in N. gonorrhoeae or H. influenzae cells but not if it was propagated in Salmonella or E. coli. We show that the phage filaments isolated from gonococci and Haemophilus are glycosylated, and this may explain the antigenic diversity seen. Taken en toto, the data demonstrate that while the neisserial filamentous phage are similar to other Inovirus with respect to overall genomic organization, their ability to closely associate with host proteins suggests that they have unique surface properties and are secreted by a here-to-fore unknown secretory pathway.


Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas do Capsídeo/metabolismo , Especificidade de Hospedeiro , Inovirus/metabolismo , Neisseria gonorrhoeae/virologia , Membrana Externa Bacteriana/metabolismo , Proteínas do Capsídeo/isolamento & purificação , Escherichia coli/virologia , Haemophilus influenzae/virologia , Inovirus/genética , Neisseria gonorrhoeae/citologia , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/metabolismo , Plasmídeos/genética , Salmonella/virologia
10.
Viruses ; 12(9)2020 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-32825132

RESUMO

"Giant" phages have genomes of >200 kbp, confined in correspondingly large capsids whose assembly and maturation are still poorly understood. Nevertheless, the first assembly product is likely to be, as in other tailed phages, a procapsid that subsequently matures and packages the DNA. The associated transformations include the cleavage of many proteins by the phage-encoded protease, as well as the thinning and angularization of the capsid. We exploited an amber mutation in the viral protease gene of the Salmonella giant phage SPN3US, which leads to the accumulation of a population of capsids with distinctive properties. Cryo-electron micrographs reveal patterns of internal density different from those of the DNA-filled heads of virions, leading us to call them "mottled capsids". Reconstructions show an outer shell with T = 27 symmetry, an embellishment of the HK97 prototype composed of the major capsid protein, gp75, which is similar to some other giant viruses. The mottled capsid has a T = 1 inner icosahedral shell that is a complex network of loosely connected densities composed mainly of the ejection proteins gp53 and gp54. Segmentation of this inner shell indicated that a number of densities (~12 per asymmetric unit) adopt a "twisted hook" conformation. Large patches of a proteinaceous tetragonal lattice with a 67 Å repeat were also present in the cell lysate. The unexpected nature of these novel inner shell and lattice structures poses questions as to their functions in virion assembly.


Assuntos
Capsídeo/metabolismo , Vírus Gigantes/fisiologia , Fagos de Salmonella/fisiologia , Montagem de Vírus , Capsídeo/ultraestrutura , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Microscopia Crioeletrônica , Empacotamento do DNA , Genoma Viral , Vírus Gigantes/genética , Vírus Gigantes/ultraestrutura , Salmonella/virologia , Fagos de Salmonella/genética , Fagos de Salmonella/ultraestrutura , Vírion/genética , Vírion/fisiologia , Vírion/ultraestrutura
11.
Vet Microbiol ; 246: 108725, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32605745

RESUMO

Viet Nam is the world's fifth largest producer of pork meat. Salmonella is frequently found at farm level; however, risk factors for Salmonella infection in pigs have not been thoroughly investigated in the production system. In the current study, 123 commercial feed samples were obtained from 103 small, medium and large-scale pig farms in Viet Nam and investigated for the presence of Salmonella in 25 g of feed using the ISO 6579:2002/Cor 1:2004 method. Salmonella was detected in five samples (4.1%; 95% CI 1.75-9.16%). All five samples were found to contain S. Weltevreden as the only serovar. The isolates were subjected to phenotypic and whole genome sequencing analysis for further characterization. They all belonged to ST365 and were sensitive to the 14 antimicrobials tested. Four strains were found to belong to the continental lineage of S. Weltevreden, while one isolate was of the island type. This isolate, contrary to the remaining four isolates contained a prophage homolog to the Vibrio prophage X-29. The findings of only S. Weltevreden, which is often isolated from fish and aquatic samples, suggests that fishmeal used in the feed preparation was a likely source of contamination.


Assuntos
Ração Animal/microbiologia , Genoma Bacteriano , Filogenia , Salmonelose Animal/epidemiologia , Salmonella/classificação , Doenças dos Suínos/epidemiologia , Ração Animal/análise , Animais , Antibacterianos/farmacologia , Fazendas , Microbiologia de Alimentos , Testes de Sensibilidade Microbiana , Prevalência , Prófagos/genética , Salmonella/virologia , Sorogrupo , Suínos , Doenças dos Suínos/microbiologia , Vietnã/epidemiologia , Sequenciamento Completo do Genoma
12.
Viruses ; 12(7)2020 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-32635654

RESUMO

The head of Salmonella virus SPN3US is composed of ~50 different proteins and is unusual because within its packaged genome there is a mass (>40 MDa) of ejection or E proteins that enter the Salmonella cell. The assembly mechanisms of this complex structure are poorly understood. Previous studies showed that eight proteins in the mature SPN3US head had been cleaved by the prohead protease. In this study, we present the characterization of SPN3US prohead protease mutants using transmission electron microscopy and mass spectrometry. In the absence of the prohead protease, SPN3US head formation was severely impeded and proheads accumulated on the Salmonella inner membrane. This impediment is indicative of proteolysis being necessary for the release and subsequent DNA packaging of proheads in the wild-type phage. Proteomic analyses of gp245- proheads that the normal proteolytic processing of head proteins had not occurred. Assays of a recombinant, truncated form of the protease found it was active, leading us to hypothesize that the C-terminal propeptide has a role in targeting the protease into the prohead core. Our findings provide new evidence regarding the essential role of proteolysis for correct head assembly in this remarkable parasite.


Assuntos
Proteínas do Capsídeo/metabolismo , Capsídeo/metabolismo , Fagos de Salmonella/metabolismo , Montagem de Vírus , Capsídeo/ultraestrutura , Genoma Viral/genética , Espectrometria de Massas , Microscopia Eletrônica de Transmissão , Salmonella/virologia , Fagos de Salmonella/genética , Fagos de Salmonella/ultraestrutura , Análise de Sequência de DNA , Internalização do Vírus
13.
Poult Sci ; 99(7): 3643-3654, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32616261

RESUMO

Salmonella is regarded as the predominant cause of foodborne illnesses worldwide, and the increase of these antimicrobial-resistant strains makes it more difficult to prevent. On this occasion, bacteriophages (phages) stand out as an alternative biocontrol agent with high efficiency and low mutation rates. Salmonella phages have confronted challenges to counteract with more than 2,500 serovars of Salmonella spp. and overcome the universality of antibiotics to different species, and thus, broad-host-range phages infecting Salmonella spp. are urgently required to realize precise poultry treatment or clinical therapy. First, phage STP4-a was screened to have a broad host range through bioinformatics analysis, and then the host range assay proved that phage STP4-a could inhibit 88 out of 91 Salmonella strains. Then, in silico analysis excluded the possibility of phage STP4-a possessing any known lysogeny factors, toxins, pathogen-related genes, or foodborne allergens, and oral toxicity studies further ensured the safety of unknown factors or suspected risks. In addition, strong inhibition effects of phage STP4-a were seen on both single Salmonella strain and multiple Salmonella strains in vitro, reducing 3-5 log in 30 min. Phage STP4-a could survive and keep more than 50% activity in simulated stomach or intestine environments in vitro. In terms of antimicrobial activities in chickens, pretreatment with phage STP4-a was the most efficient approach to Salmonella biocontrol, non-detectable in feces during the 14-day experimental period. Therefore, phage STP4-a was an extremely broad-host-range and safe biocontrol agent, performing its potential as a food additive or therapeutic drug in poultry industry.


Assuntos
Especificidade de Hospedeiro , Doenças das Aves Domésticas/prevenção & controle , Salmonelose Animal/prevenção & controle , Fagos de Salmonella/fisiologia , Salmonella/virologia , Proteínas Virais/genética , Animais , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Proteínas Virais/metabolismo
14.
Int J Mol Sci ; 21(15)2020 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-32707941

RESUMO

Phages are generally considered species- or even strain-specific, yet polyvalent phages are able to infect bacteria from different genera. Here, we characterize the novel polyvalent phage S144, a member of the Loughboroughvirus genus. By screening 211 Enterobacteriaceae strains, we found that phage S144 forms plaques on specific serovars of Salmonella enterica subsp. enterica and on Cronobacter sakazakii. Analysis of phage resistant mutants suggests that the O-antigen of lipopolysaccharide is the phage receptor in both bacterial genera. The S144 genome consists of 53,628 bp and encodes 80 open reading frames (ORFs), but no tRNA genes. In total, 32 ORFs coding for structural proteins were confirmed by ESI-MS/MS analysis, whereas 45 gene products were functionally annotated within DNA metabolism, packaging, nucleotide biosynthesis and phage morphogenesis. Transmission electron microscopy showed that phage S144 is a myovirus, with a prolate head and short tail fibers. The putative S144 tail fiber structure is, overall, similar to the tail fiber of phage Mu and the C-terminus shows amino acid similarity to tail fibers of otherwise unrelated phages infecting Cronobacter. Since all phages in the Loughboroughvirus genus encode tail fibers similar to S144, we suggest that phages in this genus infect Cronobacter sakazakii and are polyvalent.


Assuntos
Bacteriófagos/genética , Corticoviridae/genética , Cronobacter sakazakii/genética , DNA Viral/genética , Antígenos O/metabolismo , Fagos de Salmonella/genética , Salmonella/genética , Bacteriófagos/química , Bacteriófagos/metabolismo , Bacteriófagos/ultraestrutura , Classificação , Cronobacter sakazakii/virologia , Genoma Viral , Especificidade de Hospedeiro , Microscopia Eletrônica de Transmissão , Antígenos O/genética , Fases de Leitura Aberta , Proteômica , Salmonella/virologia , Análise de Sequência de DNA , Espectrometria de Massas em Tandem
15.
Viruses ; 12(7)2020 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-32664206

RESUMO

Bacteriophages are bacterial predators, which are garnering much interest nowadays vis-à-vis the global phenomenon of antimicrobial resistance. Bacteriophage preparations seem to be an alternative to antibiotics, which can be used at all levels of the food production chain. Their safety and efficacy, however, are of public concern. In this study, a detailed evaluation of BAFASAL® preparation was performed. BAFASAL® is a bacteriophage cocktail that reduces Salmonella in poultry farming. In vivo acute and sub-chronic toxicity studies on rats and tolerance study on targeted animals (chicken broiler) conducted according to GLP and OECD guidelines did not reveal any signs of toxicity, which could be associated with BAFASAL® administration. In addition, no evidences of genotoxicity were observed. The tolerance study with 100-times concentrated dose also did not show any statistically significant differences in the assessed parameters. The in vitro crop assay, mimicking normal feed storage and feed application conditions showed that BAFASAL® reduced the number of Salmonella bacteria in experimentally contaminated feed. Moreover, reductions were observed for all examined forms (liquid, powder, spray). Furthermore, the in vivo efficacy study showed that treatment with BAFASAL® significantly decreased Salmonella content in caeca of birds infected with Salmonella Enteritidis. Detailed examination of BAFASAL® in terms of safety and efficacy, adds to the body of evidence that bacteriophages are harmless to animals and effective in the struggle against bacteria.


Assuntos
Antibacterianos/administração & dosagem , Cadeia Alimentar , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos/métodos , Fagos de Salmonella/fisiologia , Salmonella/virologia , Animais , Ceco/microbiologia , Galinhas , Feminino , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/prevenção & controle , Ratos , Ratos Wistar , Salmonella/classificação , Fagos de Salmonella/isolamento & purificação
16.
Food Res Int ; 132: 109011, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32331668

RESUMO

Salmonella is a foodborne pathogen constantly threating public health. The widespread use of antibiotics and globalization of the food industry result in rapid growth of drug-resistance. Eggs contaminated by multidrug-resistant (MDR) Salmonella are one of the riskiest factors of salmonellosis, which are frequently associated with outbreaks worldwide. Thus, there are increasing needs for the development of new technologies in controlling MDR pathogens and for the confirmation of their practical efficiency in target food matrices. In this study, 43 Salmonella phages were isolated from environmental resources and among them, phage D1-2 was selected since it exhibited the most potent lytic ability and the broadest host spectrum against tested Salmonella strains. Further study demonstrated that D1-2 shows high pH and thermal tolerances and a short latent period, together with a low frequency of emergence of phage resistance. D1-2 effectively inhibited the growth of two MDR Salmonella strains in liquid egg white and egg yolk at both 4 °C and 25 °C. Morphology and phylogeny indicated that D1-2 belongs to the Myoviridae family. Genome analysis of D1-2 revealed a linear dsDNA sequence with no homology to virulence or antibiotic-resistance associated genes, presenting D1-2 is a promising candidate for the biocontrol of MDR Salmonella in highly risky foods.


Assuntos
Ovos/microbiologia , Microbiologia de Alimentos , Intoxicação Alimentar por Salmonella/prevenção & controle , Fagos de Salmonella/fisiologia , Salmonella/virologia , Farmacorresistência Bacteriana Múltipla , Inocuidade dos Alimentos , Genoma Viral , Especificidade de Hospedeiro , Concentração de Íons de Hidrogênio , Infecções por Salmonella/prevenção & controle , Fagos de Salmonella/genética , Fagos de Salmonella/isolamento & purificação , Temperatura , Virulência
17.
Curr Microbiol ; 77(7): 1308-1315, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32086533

RESUMO

Salmonella is a significant food-borne pathogen that infects a large number of people worldwide. In this study, a lytic bacteriophage vB_SenS_SE1 capable of infecting Salmonella is isolated from municipal wastewater in Beijing, and its biological and genomic features are analyzed. Transmission electron micrograph shows that vB_SenS_SE1 is likely a Siphoviridae virus, with an icosahedral head and a long non-contracted tail. The stability test in vitro reveals that it is stable at 4-50 °C and pH 4-12. Based on the one-step growth curve, vB_SenS_SE1 has a 60-min exponential phase and a low burst size (19 PFU per cell). Bioinformatics analysis reveals that vB_SenS_SE1 consists of a circular, double-stranded DNA molecule of 40,987 bp with a GC content of 51.2%. Its genome carries 63 predicted open reading frames (orfs), with 22 orfs encoding known proteins. Phylogenetic analysis of the large terminase subunit shows that vB_SenS_SE1 exhibits strong homology to Salmonella phage St161, St162, VSiP, and FSL SP-031. The CoreGenes analysis shows that it is a member of the virus genus Cornellvirus. The features of phage vB_SenS_SE1 suggest that it has the potential to be an agent to control Salmonella.


Assuntos
Genoma Viral/genética , Fagos de Salmonella , Composição de Bases/genética , Pequim , DNA Viral/química , DNA Viral/genética , Filogenia , Salmonella/virologia , Fagos de Salmonella/química , Fagos de Salmonella/classificação , Fagos de Salmonella/genética , Siphoviridae/química , Siphoviridae/classificação , Siphoviridae/genética , Águas Residuárias
18.
Microb Genom ; 6(2)2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32022660

RESUMO

Prophages are integrated phage elements that are a pervasive feature of bacterial genomes. The fitness of bacteria is enhanced by prophages that confer beneficial functions such as virulence, stress tolerance or phage resistance, and these functions are encoded by 'accessory' or 'moron' loci. Whilst the majority of phage-encoded genes are repressed during lysogeny, accessory loci are often highly expressed. However, it is challenging to identify novel prophage accessory loci from DNA sequence data alone. Here, we use bacterial RNA-seq data to examine the transcriptional landscapes of five Salmonella prophages. We show that transcriptomic data can be used to heuristically enrich for prophage features that are highly expressed within bacterial cells and represent functionally important accessory loci. Using this approach, we identify a novel antisense RNA species in prophage BTP1, STnc6030, which mediates superinfection exclusion of phage BTP1. Bacterial transcriptomic datasets are a powerful tool to explore the molecular biology of temperate phages.


Assuntos
Bacteriófagos/fisiologia , Lisogenia , Transcriptoma , Bacteriófagos/genética , Prófagos/genética , Prófagos/fisiologia , Salmonella/virologia , Proteínas Virais/genética , Proteínas Virais/metabolismo
19.
Virol J ; 17(1): 3, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31910855

RESUMO

A previously isolated a bacteriophage, vB_EcoS_AKFV33 of T5virus, demonstrated great potential in biocontrol of Shiga toxigenic Escherichia coli (STEC) O157. This study further evaluated its potential as a biocontrol agent in broth culture against other important non-O157 serogroups of STEC and Salmonella. AKFV33 was capable of lysing isolates of STEC serogroups O26 (n = 1), O145 (n = 1) and Salmonella enterica serovars (n = 6). In a broth culture microplate system, efficacy of AKFV33 for killing STEC O26:H11, O145:NM and Salmonella was improved (P < 0.05) at a lower multiplicity of infection and sampling time (6-10 h), when STEC O157:H7 was also included in the culture. This phage was able to simultaneously reduce numbers of STEC and Salmonella in mixtures with enhanced activity (P < 0.05) against O157:H7 and O26:H11, offering great promise for control of multiple zoonotic pathogens at both pre and post-harvest.


Assuntos
Salmonella/crescimento & desenvolvimento , Salmonella/virologia , Escherichia coli Shiga Toxigênica/crescimento & desenvolvimento , Escherichia coli Shiga Toxigênica/virologia , Siphoviridae/fisiologia , Técnicas Bacteriológicas , Agentes de Controle Biológico , Salmonella/classificação , Sorogrupo
20.
Comp Immunol Microbiol Infect Dis ; 68: 101405, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31887484

RESUMO

Salmonellosis represents an important public health concern. Several authors point out the inefficiency of the cleaning and disinfection protocols to remove the bacteria from the field. For this reason, innovative techniques, as bacteriophages, could be implemented to control the bacteria. The main objectives of this study were to assess the effect of bacteriophages against Salmonella Infantis and Salmonella Enteritidis on farm surfaces, and to evaluate bacteriophage procedure application as sanitiser against Salmonella in field conditions. Thus, most prevalent serovars in poultry production were selected (Salmonella Infantis and Salmonella Enteritidis) to contaminate farm facilities. Then, two specific bacteriophages isolated from poultry faeces were applied against them. Results showed Salmonella Infantis and Salmonella Enteritidis decreased of 4.55 log10CFU/mL and 3.85 log10CFU/mL, respectively; the maximum reduction in Salmonella was the 5th day, after 108 PFU/mL and 103 PFU/mL bacteriophage application. These results highlight bacteriophages as a promising tool together with cleaning and disinfection.


Assuntos
Desinfecção/métodos , Fazendas , Fezes/virologia , Salmonelose Animal/prevenção & controle , Fagos de Salmonella/patogenicidade , Salmonella enteritidis/virologia , Salmonella/virologia , Animais , Pisos e Cobertura de Pisos , Abrigo para Animais , Aves Domésticas/microbiologia , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/prevenção & controle , Fagos de Salmonella/isolamento & purificação
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