A moderately halophilic Vibrio from a Spanish saltern and its lytic bacteriophage

A number of bacteria and their phages were isolated from a saltern near Alicante, Spain. One isolate, Vibrio B1, a moderate halophile that is probably a strain of Vibrio costicola, was host to a lytic phage, UTAK. Studies of the host bacterium included the effects of salt concentrations on the action of a number of inhibitory agents. Phage UTAK has a head, a tail, and a baseplate. It contains 80 kbp of double-stranded DNA with no unusual bases. It was stable for long periods in the absence of high salt concentrations and even in distilled water. Salt concentrations had little effect on adsorption of UTAK to its host but resulted in considerable changes in burst size. It appears that phages of halophilic and salt-tolerant eubacteria, and also of some marine bacteria, have much lower salt requirements for stability than the phages of halophilic archaebacteria. Our results suggest that ionic controls of phage replication in these eubacteria may differ from those of growth.Key words: halophiles, Vibrio sp., bacteriophage, salt responses.

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A Novel Benthic Phage Infecting Shewanella with Strong Replication Ability

Viruses ◽

10.3390/v11111081 ◽

2019 ◽

Vol 11 (11) ◽

pp. 1081 ◽

Cited By ~ 3

Author(s):

Zengmeng Wang ◽

Jiulong Zhao ◽

Long Wang ◽

Chengcheng Li ◽

Jianhui Liu ◽

...

Keyword(s):

Burst Size ◽

Coastal Sediments ◽

The Yellow Sea ◽

Comparative Genomic ◽

Lytic Phage ◽

Host Interactions ◽

Metabolic Genes ◽

Double Stranded Dna ◽

Auxiliary Metabolic Genes ◽

Structure Assembly

The coastal sediments were considered to contain diverse phages playing important roles in driving biogeochemical cycles based on genetic analysis. However, till now, benthic phages in coastal sediments were very rarely isolated, which largely limits our understanding of their biological characteristics. Here, we describe a novel lytic phage (named Shewanella phage S0112) isolated from the coastal sediments of the Yellow Sea infecting a sediment bacterium of the genus Shewanella. The phage has a very high replication capability, with the burst size of ca. 1170 phage particles per infected cell, which is 5–10 times higher than that of most phages isolated before. Meanwhile, the latent period of this phage is relatively longer, which might ensure adequate time for phage replication. The phage has a double-stranded DNA genome comprising 62,286 bp with 102 ORFs, ca. 60% of which are functionally unknown. The expression products of 16 ORF genes, mainly structural proteins, were identified by LC-MS/MS analysis. Besides the general DNA metabolism and structure assembly genes in the phage genome, there is a cluster of auxiliary metabolic genes that may be involved in 7-cyano-7-deazaguanine (preQ0) biosynthesis. Meanwhile, a pyrophosphohydrolase (MazG) gene being considered as a regulator of programmed cell death or involving in host stringer responses is inserted in this gene cluster. Comparative genomic and phylogenetic analysis both revealed a great novelty of phage S0112. This study represents the first report of a benthic phage infecting Shewanella, which also sheds light on the phage–host interactions in coastal sediments.

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Isolation, Characterization, and Application in Poultry Product of a Specific Salmonella Bacteriophage S55

Journal of Food Protection ◽

10.4315/jfp-20-438 ◽

2021 ◽

Author(s):

Haojie Ge ◽

Yanping Xu ◽

Kai Zhang ◽

Shuxuan Zhang ◽

Maozhi Hu ◽

...

Keyword(s):

Prevention And Control ◽

Burst Size ◽

Gc Content ◽

Skin Surface ◽

Open Reading Frames ◽

Lytic Phage ◽

Trna Genes ◽

Host Bacterium ◽

Salmonella Pullorum ◽

And Control

Salmonellosis occurs frequently worldwide, causing serious threats to public health safety. The abuse of antibiotics is increasing the antibiotic resistance in bacteria, thereby making the prevention and control of Salmonella more difficult. A phage can help control the spread of bacteria. In this study, S55, a lytic phage, was isolated from faecal samples obtained from poultry farms using Salmonella Pullorum ( S . Pullorum) as the host bacterium. This phage belongs to Siphoviridae and has a polyhedral head and a retraction-free tail. S55 showed a strong ability to lyse Salmonella serovars, such as S . Pullorum (58/60, 96.67%) and S . Enteritidis (97/104, 93.27%). One-step growth kinetics showed that the latent period was 10 min, burst period was 80 min and burst size was 40 pfu/cell. The optimal multiplicity of infection was 0.01, and the phage was able to survive at a pH of 4–11 and temperature of 40°C–60°C for 60 min. Complete genome sequence analysis revealed that the S55 genome length is 42,781 bp (GC content, 50.28%) and it contains 58 open reading frames (ORF), including 25 ORFs with known or assumed functions, without tRNA genes. Moreover, S55 does not carry genes that encode virulence or resistance factors. At different temperatures (4°C or 25°C), S55 was found to lower the populations of S . Pullorum and S . Enteritidis on chicken skin surface. Its bacteriostatic effect at 4°C was higher than that at 25°C. In conclusion, S55 can be considered a promising biological agent for the prevention and control of Salmonella .

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Effectiveness of a Lytic Phage SRG1 against Vancomycin-ResistantEnterococcus faecalisin Compost and Soil

BioMed Research International ◽

10.1155/2017/9351017 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Sidra Rahmat Ullah ◽

Saadia Andleeb ◽

Taskeen Raza ◽

Muhsin Jamal ◽

Khalid Mehmood

Keyword(s):

Soil Sample ◽

Burst Size ◽

Alternative Therapy ◽

Maximum Growth ◽

Sewage Water ◽

Infection Process ◽

Lytic Phage ◽

Lytic Bacteriophage ◽

Bacteriophage Therapy ◽

Tract Infections

Nosocomial infections caused by vancomycin-resistantEnterococcushave become a major problem. Bacteriophage therapy is proposed as a potential alternative therapy. Bacteriophages are viruses that infect bacteria and are ubiquitous in nature. Lytic bacteriophage was isolated from sewage water that infects VREF, the causative agent of endocarditis, bacteraemia, and urinary tract infections (UTIs). The phage produced clear plaques with unique clear morphology and well-defined boundaries. TEM results of phage revealed it to be108±0.2 nm long and90±0.5 nm wide. The characterization of bacteriophage revealed that infection process of phage was calcium and magnesium dependent and phage titers were highest under optimum conditions for VREF, with an optimal temperature range of 37–50°C. The maximum growth was observed at 37°C, hence having 100% viability. The latent period for phage was small with a burst size of 512 viral particles per bacterial cell. The phage was tested against various clinical strains and results proved it to be host specific. It can be used as a potential therapeutic agent for VREF infections. The phage efficiently eradicated VREF inoculated in cattle compost, poultry compost, and a soil sample which makes it a potential agent for clearing compost and soil sample.

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Modeling the probability distribution of the bacterial burst size via a game-theoretic approach

Journal of Bioinformatics and Computational Biology ◽

10.1142/s0219720018500129 ◽

2018 ◽

Vol 16 (04) ◽

pp. 1850012

Author(s):

Seyed Amir Malekpour ◽

Parsa Pakzad ◽

Mohammad-Hadi Foroughmand-Araabi ◽

Sama Goliaei ◽

Ruzbeh Tusserkani ◽

...

Keyword(s):

Probability Distribution ◽

Empirical Distribution ◽

Burst Size ◽

Size Variation ◽

Host Bacterium ◽

Theoretic Approach ◽

Lysis Time ◽

Game Theoretic ◽

Number Of Bacteria ◽

Game Theoretic Approach

Based on previous studies, empirical distribution of the bacterial burst size varies even in a population of isogenic bacteria. Since bacteriophage progenies increase linearly with time, it is the lysis time variation that results in the bacterial burst size variations.Here, the burst size variation is computationally modeled by considering the lysis time decisions as a game. Each player in the game is a bacteriophage that has initially infected and lysed its host bacterium. Also, the payoff of each burst size strategy is the average number of bacteria that are solely infected by the bacteriophage progenies after lysis. For calculating the payoffs, a new version of ball and bin model with time dependent occupation probabilities (TDOP) is proposed.We show that Nash equilibrium occurs for a range of mixed burst size strategies that are chosen and played by bacteriophages, stochastically. Moreover, it is concluded that the burst size variations arise from choosing mixed lysis strategies by each player. By choosing the lysis time and also the burst size stochastically, the released bacteriophage progenies infect a portion of host bacteria in environment and avoid extinction. The probability distribution of the mixed burst size strategies is also identified.

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Molecular Characterization of Ahp2, a Lytic Bacteriophage of Aeromonas hydrophila

Viruses ◽

10.3390/v13030477 ◽

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.

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Genome sequence analysis of Vibrio parahaemolyticus lytic phage vP_VpaS_VP-RY-9

10.21203/rs.3.rs-355458/v1 ◽

2021 ◽

Author(s):

Yuan Ren ◽

Renjie Chen ◽

Yongping Xu ◽

Xiaoyu Li ◽

Cong Cong ◽

...

Keyword(s):

Phylogenetic Analysis ◽

Sequence Analysis ◽

Genome Sequence ◽

Vibrio Parahaemolyticus ◽

Therapeutic Agent ◽

Lytic Phage ◽

Lytic Bacteriophage ◽

Genome Sequence Analysis ◽

Genomic Features ◽

Double Stranded Dna

Abstract A lytic bacteriophage Vp-9, designated vP_VpaS_VP-RY-9, was isolated from sewage collected in Dalian, China. The double-stranded DNA genome of phage vP_VpaS_VP-RY-9 is 81.604 kb long, which has a mol% G + C content of 45.75, containing 117 ORFs, but any tRNA was found. Comparison of its genomic features and phylogenetic analysis revealed that phage vP_VpaS_VP-RY-9 is a novel member of the order Caudovirales, family Siphoviridae, genus Vibrio. The present results suggest that phage vP_VpaS_VP-RY-9 may represent a potential therapeutic agent against Vibrio parahaemolyticus.

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Lytic Myophage Abp53 Encodes Several Proteins Similar to Those Encoded by Host Acinetobacter baumannii and Phage phiKO2

Applied and Environmental Microbiology ◽

10.1128/aem.05116-11 ◽

2011 ◽

Vol 77 (19) ◽

pp. 6755-6762 ◽

Cited By ~ 14

Author(s):

Chia-Ni Lee ◽

Tsai-Tien Tseng ◽

Juey-Wen Lin ◽

Yung-Chieh Fu ◽

Shu-Fen Weng ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

Burst Size ◽

Sputum Sample ◽

Polyacrylamide Gel Electrophoresis ◽

Multiple Drug ◽

Lytic Phage ◽

Tail Fiber ◽

Drug Resistant ◽

Content Type ◽

Multiple Drug Resistant

ABSTRACTAcinetobacter baumanniiis an important Gram-negative opportunistic pathogen causing nosocomial infections. The emergence of multiple-drug-resistantA. baumanniiisolates has increased in recent years. Directed toward phage therapy, a lytic phage ofA. baumannii, designated Abp53, was isolated from a sputum sample in this study. Abp53 has an isometric head and a contractile tail with tail fibers (belonging toMyoviridae), a latent period of about 10 min, and a burst size of approximately 150 PFU per infected cell. Abp53 could completely lyse 27% of theA. baumanniiisolates tested, which were all multiple drug resistant, but not other bacteria. Mg2+enhanced the adsorption and productivity of, and host lysis by, Abp53. Twenty Abp53 virion proteins were visualized in SDS-polyacrylamide gel electrophoresis, with a 47-kDa protein being the predicted major capsid protein. Abp53 has a double-stranded DNA genome of 95 kb. Sequence analyses of a 10-kb region revealed 8 open reading frames. Five of the encoded proteins, including 3 tail components and 2 hypothetical proteins, were similar to proteins encoded byA. baumanniistrain ACICU. ORF1176 (one of the tail components, 1,176 amino acids [aa]), which is also similar to tail protein gp21 ofKlebsiellaphage phiKO2, contained repeated domains similar to those within the ACICU_02717 protein ofA. baumanniiACICU and gp21. These findings suggest a common ancestry and horizontal gene transfer during evolution. As phages can expand the host range by domain duplication in tail fiber proteins, repeated domains in ORF1176 might have a similar significance in Abp53.

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Characterization and Full Genome Sequence of Novel KPP-5 Lytic Phage against Klebsiella pneumoniae Responsible for Recalcitrant Infection

Biomedicines ◽

10.3390/biomedicines9040342 ◽

2021 ◽

Vol 9 (4) ◽

pp. 342

Author(s):

Ahmed R. Sofy ◽

Noha K. El-Dougdoug ◽

Ehab E. Refaey ◽

Rehab A. Dawoud ◽

Ahmed A. Hmed

Keyword(s):

Klebsiella Pneumoniae ◽

Burst Size ◽

Phylogenetic Analyses ◽

Foodborne Pathogen ◽

Gc Content ◽

Full Genome Sequence ◽

Multiple Drug ◽

Lytic Phage ◽

Trna Genes ◽

Bacteriophage Therapy

Klebsiella pneumoniae is a hazardous opportunistic pathogen that is involved in many serious human diseases and is considered to be an important foodborne pathogen found in many food types. Multidrug resistance (MDR) K. pneumoniae strains have recently spread and increased, making bacteriophage therapy an effective alternative to multiple drug-resistant pathogens. As a consequence, this research was conducted to describe the genome and basic biological characteristics of a novel phage capable of lysing MDR K. pneumoniae isolated from food samples in Egypt. The host range revealed that KPP-5 phage had potent lytic activity and was able to infect all selected MDR K. pneumoniae strains from different sources. Electron microscopy images showed that KPP-5 lytic phage was a podovirus morphology. The one-step growth curve exhibited that KPP-5 phage had a relatively short latent period of 25 min, and the burst size was about 236 PFU/infected cells. In addition, KPP-5 phage showed high stability at different temperatures and pH levels. KPP-5 phage has a linear dsDNA genome with a length of 38,245 bp with a GC content of 50.8% and 40 predicted open reading frames (ORFs). Comparative genomics and phylogenetic analyses showed that KPP-5 is most closely associated with the Teetrevirus genus in the Autographviridae family. No tRNA genes have been identified in the KPP-5 phage genome. In addition, phage-borne virulence genes or drug resistance genes were not present, suggesting that KPP-5 could be used safely as a phage biocontrol agent.

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

BioMed Research International ◽

10.1155/2015/752930 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 41

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.

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Characterization of a New and Efficient Polyvalent Phage Infecting E. coli O157:H7, Salmonella spp., and Shigella sonnei

Microorganisms ◽

10.3390/microorganisms9102105 ◽

2021 ◽

Vol 9 (10) ◽

pp. 2105

Author(s):

Su-Hyeon Kim ◽

Damilare Adeyemi ◽

Mi-Kyung Park

Keyword(s):

Burst Size ◽

Genomic Analysis ◽

Cesium Chloride ◽

Shigella Sonnei ◽

Health Concern ◽

Lytic Phage ◽

Salmonella Spp ◽

E Coli ◽

Significant Public Health ◽

Ph Range

Ongoing outbreaks of foodborne diseases remain a significant public health concern. Lytic phages provide promising attributes as biocontrol agents. This study characterized KFS-EC3, a polyvalent and lytic phage, which was isolated from slaughterhouse sewage and purified by cesium chloride density centrifugation. Host range and efficiency of plating analyses revealed that KFS-EC3 is polyvalent and can efficiently infect E. coli O157:H7, Salmonella spp., and Shigella sonnei. KFS-EC3 had a latent time of 20 min and burst size of ~71 phages/infected cell. KFS-EC3 was stable and infectious following storage at a pH range of 3 to 11 and a temperature range of −70°C to 60°C. KFS-EC3 could inhibit E. coli O157:H7 growth by 2 logs up to 52 h even at the lowest MOI of 0.001. Genomic analysis of KFS-EC3 revealed that it consisted of 167,440 bp and 273 ORFs identified as functional genes, without any genes associated with antibiotic resistance, virulence, allergenicity, and lysogenicity. This phage was finally classified into the Tequatrovirus genus of the Myoviridae family. In conclusion, KFS-EC3 could simultaneously infect E. coli O157:H7, S. sonnei, and Salmonella spp. with the lowest MOI values over long periods, suggesting its suitability for simultaneous pathogen control in foods.

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