scholarly journals Characterization of a Unique Bordetella bronchiseptica vB_BbrP_BB8 Bacteriophage and Its Application as an Antibacterial Agent

2020 ◽  
Vol 21 (4) ◽  
pp. 1403 ◽  
Author(s):  
Mateusz Szymczak ◽  
Bartłomiej Grygorcewicz ◽  
Joanna Karczewska-Golec ◽  
Przemysław Decewicz ◽  
Jarosław Adam Pankowski ◽  
...  
Keyword(s):  
Galleria Mellonella ◽  
Therapeutic Potential ◽  
Burst Size ◽  
Genome Structure ◽  
Bacterial Biofilm ◽  
Bordetella Bronchiseptica ◽  
Atrophic Rhinitis ◽  
Lytic Bacteriophage ◽  
Safe Alternative ◽  
A Genome

Bordetella bronchiseptica, an emerging zoonotic pathogen, infects a broad range of mammalian hosts. B. bronchiseptica-associated atrophic rhinitis incurs substantial losses to the pig breeding industry. The true burden of human disease caused by B. bronchiseptica is unknown, but it has been postulated that some hypervirulent B. bronchiseptica isolates may be responsible for undiagnosed respiratory infections in humans. B. bronchiseptica was shown to acquire antibiotic resistance genes from other bacterial genera, especially Escherichia coli. Here, we present a new B. bronchiseptica lytic bacteriophage—vB_BbrP_BB8—of the Podoviridae family, which offers a safe alternative to antibiotic treatment of B. bronchiseptica infections. We explored the phage at the level of genome, physiology, morphology, and infection kinetics. Its therapeutic potential was investigated in biofilms and in an in vivo Galleria mellonella model, both of which mimic the natural environment of infection. The BB8 is a unique phage with a genome structure resembling that of T7-like phages. Its latent period is 75 ± 5 min and its burst size is 88 ± 10 phages. The BB8 infection causes complete lysis of B. bronchiseptica cultures irrespective of the MOI used. The phage efficiently removes bacterial biofilm and prevents the lethality induced by B. bronchiseptica in G. mellonella honeycomb moth larvae.

scholarly journals Previously Unknown Virus Infects Marine Diatom

2005 ◽  
Vol 71 (7) ◽  
pp. 3528-3535 ◽  
Author(s):  
Keizo Nagasaki ◽  
Yuji Tomaru ◽  
Yoshitake Takao ◽  
Kensho Nishida ◽  
Yoko Shirai ◽  
...  
Keyword(s):  
Single Molecule ◽  
Burst Size ◽  
Genome Structure ◽  
Marine Diatom ◽  
Linear Segment ◽  
Significant Similarity ◽  
New Host ◽  
A Genome ◽  
Marine System ◽  
Temperature Climate

ABSTRACT Diatoms are a major phytoplankton group that play important roles in maintaining oxygen levels in the atmosphere and sustaining the primary nutritional production of the aquatic environment. Among diatoms, the genus Chaetoceros is one of the most abundant and widespread. Temperature, climate, salinity, nutrients, and predators were regarded as important factors controlling the abundance and population dynamics of diatoms. Here we show that a viral infection can occur in the genus Chaetoceros and should therefore be considered as a potential mortality source. Chaetoceros salsugineum nuclear inclusion virus (CsNIV) is a 38-nm icosahedral virus that replicates within the nucleus of C. salsugineum. The latent period was estimated to be between 12 and 24 h, with a burst size of 325 infectious units per host cell. CsNIV has a genome structure unlike that of other viruses that have been described. It consists of a single molecule of covalently closed circular single-stranded DNA (ssDNA; 6,005 nucleotides), as well as a segment of linear ssDNA (997 nucleotides). The linear segment is complementary to a portion of the closed circle creating a partially double-stranded genome. Sequence analysis reveals a low but significant similarity to the replicase of circoviruses that have a covalently closed circular ssDNA genome. This new host-virus system will be useful for investigating the ecological relationships between bloom-forming diatoms and other viruses in the marine system. Our study supports the view that, given the diversity and abundance of plankton, the ocean is a treasury of undiscovered viruses.

scholarly journals Characterization of a Lytic Bacteriophage as an Antimicrobial Agent for Biocontrol of Shiga Toxin-Producing Escherichia coli O145 Strains

Antibiotics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 74 ◽  
Author(s):  
Yen-Te Liao ◽  
Alexandra Salvador ◽  
Leslie A. Harden ◽  
Fang Liu ◽  
Valerie M. Lavenburg ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Agent ◽  
Shiga Toxin ◽  
Burst Size ◽  
Lytic Bacteriophage ◽  
E Coli ◽  
A Genome ◽  
Wide Range ◽  
Foodborne Outbreaks

Shiga toxin-producing Escherichia coli (STEC) O145 is one of the most prevalent non-O157 serogroups associated with foodborne outbreaks. Lytic phages are a potential alternative to antibiotics in combatting bacterial pathogens. In this study, we characterized a Siphoviridae phage lytic against STEC O145 strains as a novel antimicrobial agent. Escherichia phage vB_EcoS-Ro145clw (Ro145clw) was isolated and purified prior to physiological and genomic characterization. Then, in vitro antimicrobial activity against an outbreak strain, E. coli O145:H28, was evaluated. Ro145clw is a double-stranded DNA phage with a genome 42,031 bp in length. Of the 67 genes identified in the genome, 21 were annotated with functional proteins, none of which were stx genes. Ro145clw had a latent period of 21 min and a burst size of 192 phages per infected cell. The phage could sustain a wide range of pH (pH 3 to pH 10) and temperatures (−80 °C to −73 °C). Ro145clw was able to reduce E. coli O145:H28 in lysogeny broth by approximately 5 log at 37 °C in four hours. These findings indicate that the Ro145clw phage is a promising antimicrobial agent that can be used to control E. coli O145 in adverse pH and temperature conditions.

scholarly journals Molecular Characterization of Ahp2, a Lytic Bacteriophage of Aeromonas hydrophila

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 477
Author(s):  
Jian-Bin Wang ◽  
Mei-Shiuan Yu ◽  
Tsai-Tien Tseng ◽  
Ling-Chun Lin
Keyword(s):  
Aeromonas Hydrophila ◽  
Burst Size ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gc Content ◽  
Opportunistic Pathogen ◽  
Aeromonas Salmonicida ◽  
Lytic Bacteriophage ◽  
Protein Sequence Analysis ◽  
Double Stranded Dna ◽  
A Genome

Aeromonas hydrophila is an opportunistic pathogen that infects fish, amphibians, mammals, and humans. This study isolated a myophage, vB_AhyM_Ahp2 (Ahp2), that lytically infects A. hydrophila. We observed that 96% of the Ahp2 particles adsorbed to A. hydrophila within 18 min. Ahp2 also showed a latent period of 15 min with a burst size of 142 PFU/cell. This phage has a linear double-stranded DNA genome of 47,331 bp with a GC content of 57%. At least 20 Ahp2 proteins were detected by SDS-polyacrylamide gel electrophoresis; among them, a 40-kDa protein was predicted as the major capsid protein. Sequence analysis showed that Ahp2 has a genome organization closely related to a group of Aeromonas phages (13AhydR10RR, 14AhydR10RR, 85AhydR10RR, phage 3, 32 Asp37, 59.1), which infect Aeromonas hydrophila and Aeromonas salmonicida. The tail module encompassing ORF27-29 in the Ahp2 genome was present in all Aeromonas phages analyzed in this study and likely determines the host range of the virus. This study found that Ahp2 completely lyses A. hydrophila AH300206 in 3.5 h at a MOI of 0.0001 and does not lysogenize its host. Altogether, these findings show that Ahp2 is a lytic Aeromonas phage and could be a candidate for therapeutic phage cocktails.

Dysregulation of HOX as a Potential Therapeutic Target in Breast Cancer

2020 ◽  
Vol 27 ◽  
Author(s):  
Ji-Yeon Lee ◽  
Myoung Hee Kim
Keyword(s):  
Breast Cancer ◽  
Hox Genes ◽  
Therapeutic Potential ◽  
Expression Patterns ◽  
Genome Structure ◽  
Control Cell ◽  
Three Dimensional ◽  
Cellular Processes ◽  
Hox Protein

: HOX genes belong to the highly conserved homeobox superfamily, responsible for the regulation of various cellular processes that control cell homeostasis, from embryogenesis to carcinogenesis. The abnormal expression of HOX genes is observed in various cancers, including breast cancer; they act as oncogenes or as suppressors of cancer, according to context. In this review, we analyze HOX gene expression patterns in breast cancer and examine their relationship, based on the three-dimensional genome structure of the HOX locus. The presence of non-coding RNAs, embedded within the HOX cluster, and the role of these molecules in breast cancer have been reviewed. We further evaluate the characteristic activity of HOX protein in breast cancer and its therapeutic potential.

scholarly journals Occurrence ofBordetellaInfection in Pigs in Northern India

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Sandeep Kumar ◽  
Bhoj R. Singh ◽  
Monika Bhardwaj ◽  
Vidya Singh
Keyword(s):  
Plasmid Profile ◽  
Antigen Detection ◽  
Bordetella Bronchiseptica ◽  
Atrophic Rhinitis ◽  
Serum Samples ◽  
Northern India ◽  
Antimicrobial Sensitivity ◽  
Nasal Swabs ◽  
Species Specific ◽  
Almost All

Bordetella bronchisepticainfection causing atrophic rhinitis in pigs is reported from almost all countries. In the present study, occurrence ofBordetellainfection in apparently healthy pigs was determined in 392 pigs sampled to collect 358 serum samples and 316 nasal swabs from Northern India by conventional bacterioscopy, detection of antigen with multiplex polymerase chain reaction (mPCR), and detection of antibodies with microagglutination test (MAT) and enzyme linked immune-sorbent assay (ELISA).Bordetella bronchisepticacould be isolated from six (1.92%) nasal swabs. Although isolates varied significantly in their antimicrobial sensitivity, they had similar plasmid profile. The genus specific and species specific amplicons were detected from 8.2% and 4.4% nasal swabs using mPCR withalcgene (genus specific) andflagene andfim2 gene (species specific) primers, respectively. Observations revealed that there may be other bordetellae infecting pigs because about 50% of the samples positive using mPCR for genus specific amplicons failed to confirm presence ofB. bronchiseptica. Of the pig sera tested with MAT and ELISA forBordetellaantibodies, 67.6% and 86.3% samples, respectively, were positive. For antigen detection mPCR was more sensitive than conventional bacterioscopy while for detection of antibodies neither of the two tests (MAT and ELISA) had specificity in relation to antigen detection. Study indicated high prevalence of infection in swine herds in Northern India.

scholarly journals Occurrence of Genes Encoding Virulence Factors in Bordetella Bronchiseptica Strains Isolated from Infected and Healthy Pigs

2012 ◽  
Vol 56 (4) ◽  
pp. 483-487 ◽  
Author(s):  
Katarzyna Stępniewska ◽  
Iwona Markowska-Daniel
Keyword(s):  
Health Status ◽  
Virulence Factors ◽  
Bordetella Bronchiseptica ◽  
Atrophic Rhinitis ◽  
Genes Encoding ◽  
Progressive Atrophic Rhinitis ◽  
Swine Herds ◽  
Clinical Cases

Abstract The objective of the study was to determine genotypic profiles of Bordetella bronchiseptica (Bbr) strains, based on the occurrence of genes encoding virulence factors, such as flagella (fla), dermonecrotoxin (dnt), and exogenous ferric siderophore receptor (bfrZ), using PCR. 209 tested Bbr strains were obtained from Polish swine herds with different health status (with progressive atrophic rhinitis - PAR, suspected for PAR, and unknown). In total, seven different Bbr genotypes were determined. In 39.2% of Bbr isolates all three genes were present. In 41.1% of the isolates only two genes were detected. The most common genotype dnt+bfrZ-fla+ was present in 60 (28.5%) Bbr strains, 65% of them were obtained from farms with PAR. Twenty five (12%) Bbr isolates were identified as dnt-bfrZ+fla+ genotype and, as above, they were more frequently isolated from clinical cases of disease (84%). Among 31 (14.8%) strains only fla gene was evident, and in nine (4.3%) only dnt gene was present. There were no Bbr strains with bfrZ gene only. These results confirm the heterogenicity among Bbr strains.

scholarly journals Evaluation of the Efficacy of a Bacteriophage in the Treatment of Pneumonia Induced by Multidrug ResistanceKlebsiella pneumoniaein Mice

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Fang Cao ◽  
Xitao Wang ◽  
Linhui Wang ◽  
Zhen Li ◽  
Jian Che ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Burst Size ◽  
Multidrug Resistant ◽  
Lung Lesion ◽  
Lytic Bacteriophage ◽  
Short Latent Period ◽  
Dose Dependent ◽  
Antibiotic Control

Multidrug-resistantKlebsiella pneumoniae(MRKP) has steadily grown beyond antibiotic control. However, a bacteriophage is considered to be a potential antibiotic alternative for treating bacterial infections. In this study, a lytic bacteriophage, phage 1513, was isolated using a clinical MRKP isolate KP 1513 as the host and was characterized. It produced a clear plaque with a halo and was classified as Siphoviridae. It had a short latent period of 30 min, a burst size of 264 and could inhibit KP 1513 growthin vitrowith a dose-dependent pattern. Intranasal administration of a single dose of 2 × 109 PFU/mouse 2 h after KP 1513 inoculation was able to protect mice against lethal pneumonia. In a sublethal pneumonia model, phage-treated mice exhibited a lower level ofK. pneumoniaeburden in the lungs as compared to the untreated control. These mice lost less body weight and exhibited lower levels of inflammatory cytokines in their lungs. Lung lesion conditions were obviously improved by phage therapy. Therefore, phage 1513 has a great effectin vitroandin vivo, which has potential to be used as an alternative to an antibiotic treatment of pneumonia that is caused by the multidrug-resistantK. pneumoniae.

scholarly journals In VitroandIn VivoAntimicrobial Activities of Gallium Nitrate against Multidrug-Resistant Acinetobacter baumannii

2012 ◽  
Vol 56 (11) ◽  
pp. 5961-5970 ◽  
Author(s):  
Luísa C. S. Antunes ◽  
Francesco Imperi ◽  
Fabrizia Minandri ◽  
Paolo Visca
Keyword(s):  
Human Serum ◽  
Acinetobacter Baumannii ◽  
Galleria Mellonella ◽  
Therapeutic Potential ◽  
Survival Rates ◽  
Bloodstream Infections ◽  
Multidrug Resistant ◽  
Gallium Nitrate ◽  
Content Type ◽  
Bacterial Physiology

ABSTRACTMultidrug-resistantAcinetobacter baumanniiposes a tremendous challenge to traditional antibiotic therapy. Due to the crucial role of iron in bacterial physiology and pathogenicity, we investigated iron metabolism as a possible target for anti-A. baumanniichemotherapy using gallium as an iron mimetic. Due to chemical similarity, gallium competes with iron for binding to several redox enzymes, thereby interfering with a number of essential biological reactions. We found that Ga(NO3)3, the active component of an FDA-approved drug (Ganite), inhibits the growth of a collection of 58A. baumanniistrains in both chemically defined medium and human serum, at concentrations ranging from 2 to 80 μM and from 4 to 64 μM, respectively. Ga(NO3)3delayed the entry ofA. baumanniiinto the exponential phase and drastically reduced bacterial growth rates. Ga(NO3)3activity was strongly dependent on iron availability in the culture medium, though the mechanism of growth inhibition was independent of dysregulation of gene expression controlled by the ferric uptake regulator Fur. Ga(NO3)3also protectedGalleria mellonellalarvae from lethalA. baumanniiinfection, with survival rates of ≥75%. At therapeutic concentrations for humans (28 μM plasma levels), Ga(NO3)3inhibited the growth in human serum of 76% of the multidrug-resistantA. baumanniiisolates tested by ≥90%, raising expectations on the therapeutic potential of gallium for the treatment ofA. baumanniibloodstream infections. Ga(NO3)3also showed strong synergism with colistin, suggesting that a colistin-gallium combination holds promise as a last-resort therapy for infections caused by pan-resistantA. baumannii.

scholarly journals A target expression threshold dictates invader defense and autoimmunity by CRISPR-Cas13

2021 ◽  
Author(s):  
Elena Vialetto ◽  
Yanying Yu ◽  
Scott P. Collins ◽  
Katharina G. Wandera ◽  
Lars Barquist ◽  
...  
Keyword(s):  
Immune Activation ◽  
Rna Degradation ◽  
Lytic Bacteriophage ◽  
Immune Systems ◽  
Expression Levels ◽  
Additional Requirement ◽  
Genome Wide ◽  
A Genome ◽  
Rna Targeting ◽  
Target Transcript

Immune systems must recognize and clear foreign invaders without eliciting autoimmunity. CRISPR-Cas immune systems in prokaryotes manage this task by following two criteria: extensive guide:target complementarity and a defined target-flanking motif. Here we report an additional requirement for RNA-targeting CRISPR-Cas13 systems: expression of the target transcript exceeding a threshold. This finding is based on targeting endogenous non-essential transcripts, which rarely elicited dormancy through collateral RNA degradation. Instead, eliciting dormancy required over-expressing targeted transcripts above a threshold. A genome-wide screen confirmed target expression levels as the principal determinant of cytotoxic autoimmunity and revealed that the threshold shifts with the guide:target pair. This expression threshold ensured defense against a lytic bacteriophage yet allowed tolerance of a targeted beneficial gene expressed from an invading plasmid. These findings establish target expression levels as a third criterion for immune activation by RNA-targeting CRISPR-Cas systems, buffering against autoimmunity and distinguishing pathogenic and benign invaders.

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