Isolation and characterization of new phage vB_CtuP_A24 and application to control Cronobacter spp. in infant milk formula and lettuce

Luo, Dong; Li, Chengsi; Wu, Qingping; Ding, Yu; Yang, Meiyan; Hu, Yongdan; Zeng, Haiyan; Zhang, Jumei

doi:10.1016/j.foodres.2021.110109

Cited by 24 publications

(8 citation statements)

References 40 publications

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“…Then, the supernatant was filtered using a 0.45-μm syringe filter. The double-layer agar method was performed to determine the phage titer, with the highest titer of infection being considered the optimal MOI ( Li et al, 2019 ; Luo et al, 2021 ). Each MOI test was performed based on three parallel experiments.…”

Section: Methodsmentioning

confidence: 99%

Isolation and Characterization of a Novel Salmonella Phage vB_SalP_TR2

et al. 2021

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Salmonella is a widely distributed foodborne pathogen. The use of Salmonella phages as biocontrol agents has recently gained significant interest. Because the Salmonella genus has high diversity, efforts are necessary to identify lytic Salmonella phages focusing on different serovars. Here, five Salmonella phages were isolated from soil samples, and vB_SalP_TR2 was selected as a novel phage with high lytic potential against the host Salmonella serovar Albany, as well as other tested serovars, including Corvallis, Newport, Kottbus, and Istanbul. Morphological analyses demonstrated that phage vB_SalP_TR2 belongs to the Podoviridae family, with an icosahedral head (62 ± 0.5 nm in diameter and 60 ± 1 nm in length) and a short tail (35 ± 1 nm in length). The latent period and burst size of phage vB_SalP_TR2 was 15 min and 211 PFU/cell, respectively. It contained a linear dsDNA of 71,453 bp, and G + C content was 40.64%. Among 96 putative open reading frames detected, only 35 gene products were found in database searches, with no virulence or antibiotic resistance genes being identified. As a biological control agent, phage vB_SalP_TR2 exhibited a high temperature and pH tolerance. In vitro, it lysed most S. Albany after 24 h at 37°C with multiplicities of infection of 0.0001, 0.001, 0.01, 0.1, 1, 10, and 100. In food matrices (milk and chicken meat), treatment with phage vB_SalP_TR2 also reduced the number of S. Albany compared with that in controls. These findings highlighted phage vB_SalP_TR2 as a potential antibacterial agent for the control of Salmonella in food samples.

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Section: Methodsmentioning

confidence: 99%

Isolation and Characterization of a Novel Salmonella Phage vB_SalP_TR2

et al. 2021

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“…The whole genome was compared with other nucleotide sequences using NCBI BLASTn (https://blast.ncbi.nlm.nih.gov/Blast.cgi, accessed on 20 October 2021). Subsequently, the average nucleotide identity was determined using the BLASTn alignment tool in the pyani package, and an interactive heatmap was constructed using heatmaply [37,38]. A genomic map was generated using CGview (http://cgview.ca/, accessed on 20 October 2021).…”

Section: Genome Sequencing and Bioinformatics Analysismentioning

confidence: 99%

Isolation of the Novel Phage PHB09 and Its Potential Use against the Plant Pathogen Pseudomonas syringae pv. actinidiae

Liu

et al. 2021

Viruses

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Bacteriophages are viruses that specifically infect target bacteria. Recently, bacteriophages have been considered potential biological control agents for bacterial pathogens due to their host specificity. Pseudomonas syringae pv. actinidiae (Psa) is a reemerging pathogen that causes bacterial canker of kiwifruit (Actinidia sp.). The economic impact of this pest and the development of resistance to antibiotics and copper sprays in Psa and other pathovars have led to investigation of alternative management strategies. Phage therapy may be a useful alternative to conventional treatments for controlling Psa infections. Although the efficacy of bacteriophage φ6 was evaluated for the control of Psa, the characteristics of other DNA bacteriophages infecting Psa remain unclear. In this study, the PHB09 lytic bacteriophage specific to Psa was isolated from kiwifruit orchard soil. Extensive host range testing using Psa isolated from kiwifruit orchards and other Pseudomonas strains showed PHB09 has a narrow host range. It remained stable over a wide range of temperatures (4–50 °C) and pH values (pH 3–11) and maintained stability for 50 min under ultraviolet irradiation. Complete genome sequence analysis indicated PHB09 might belong to a new myovirus genus in Caudoviricetes. Its genome contains a total of 94,844 bp and 186 predicted genes associated with phage structure, packaging, host lysis, DNA manipulation, transcription, and additional functions. The isolation and identification of PHB09 enrich the research on Pseudomonas phages and provide a promising biocontrol agent against kiwifruit bacterial canker.

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“…For food industry applications, phages with a broad host range, short latent period, and large burst size could be desirable candidates (Minh et al, 2020;Luo et al, 2021). Phage SQ17 has a large burst size of 71 PFU/infected cell and, a shorter latent period of 10 min compared with phages HY01, JN01, PS5, and PE37 (Heyn et al, 2016;Son et al, 2018;Minh et al, 2020;Li et al, 2021).…”

Section: Discussionmentioning

confidence: 99%

“…These data suggest that SQ17 has a high infection ability and fast replication rate. In fact, phages having prolonged persistence in variable environmental conditions are preferred for application in the food industry (Luo et al, 2021). In this study, we evaluated the performance of phage SQ17 to retain infectivity after incubation at different pHs and temperatures.…”

Section: Discussionmentioning

confidence: 99%

Application of a novel lytic phage vB_EcoM_SQ17 for the biocontrol of Enterohemorrhagic Escherichia coli O157:H7 and Enterotoxigenic E. coli in food matrices

et al. 2022

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Enterohemorrhagic Escherichia coli (EHEC) O157:H7 and Enterotoxigenic E. coli (ETEC) are important foodborne pathogens, causing serious food poisoning outbreaks worldwide. Bacteriophages, as novel antibacterial agents, have been increasingly exploited to control foodborne pathogens. In this study, a novel broad-host range lytic phage vB_EcoM_SQ17 (SQ17), was isolated, characterized, and evaluated for its potential to control bacterial counts in vitro and in three different food matrices (milk, raw beef, and fresh lettuce). Phage SQ17 was capable of infecting EHEC O157:H7, ETEC, and other E. coli strains. Morphology, one-step growth, and stability assay showed that phage SQ17 belongs to the Caudovirales order, Myoviridae family, and Mosigvirus genus. It has a short latent period of 10 min, a burst size of 71 PFU/infected cell, high stability between pH 4 to 12 as well as thermostability between 30°C and 60°C for 60 min. Genome sequencing analysis revealed that the genome of SQ17 does not contain any genes associated with antibiotic resistance, toxins, lysogeny, or virulence factors, indicating the potential safe application of phage SQ17 in the food industry. In Luria-Bertani (LB) medium, phage SQ17 significantly decreased the viable counts of EHEC O157:H7 by more than 2.40 log CFU/ml (p < 0.05) after 6 h of incubation at 37°C. Phage SQ17 showed great potential to be applied for biocontrol of EHEC O157:H7 in milk and raw beef. In fresh lettuce, treatment with SQ17 also resulted in significant reduction of viable cell counts of EHEC O157:H7 and ETEC at both 4°C and 25°C. Our results demonstrate that SQ17 is a good candidate for application as an EHEC O157:H7 and ETEC biocontrol agent in the processing stages of food production and food preservation.

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Isolation and characterization of new phage vB_CtuP_A24 and application to control Cronobacter spp. in infant milk formula and lettuce

Cited by 24 publications

References 40 publications

Isolation and Characterization of a Novel Salmonella Phage vB_SalP_TR2

Isolation and Characterization of a Novel Salmonella Phage vB_SalP_TR2

Isolation of the Novel Phage PHB09 and Its Potential Use against the Plant Pathogen Pseudomonas syringae pv. actinidiae

Application of a novel lytic phage vB_EcoM_SQ17 for the biocontrol of Enterohemorrhagic Escherichia coli O157:H7 and Enterotoxigenic E. coli in food matrices

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