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Lin YH, Dharmaraj T, Chen Q, Echterhof A, Manasherob R, Zhang LJ, de Leeuw C, Peterson NA, Stannard W, Li Z, Hajfathalian M, Hargil A, Martinez HA, Pourtois J, Chang THW, Blankenberg FG, Amanatullah D, Chaudhuri O, Bollyky PL. Optimized Dosing and Delivery of Bacteriophage Therapy for Wound Infections. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.07.593005. [PMID: 38766200 PMCID: PMC11100690 DOI: 10.1101/2024.05.07.593005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Lytic bacteriophages, viruses that lyse (kill) bacteria, hold great promise for treating infections, including wound infections caused by antimicrobial-resistant Pseudomonas aeruginosa. However, the optimal dosing and delivery strategies for phage therapy remain unclear. In a mouse wound infection model, we investigated the impact of dose, frequency, and administration route on the efficacy of phage therapy. We find that topical but not intravenous delivery is effective in this model. High-doses of phage reduces bacterial burden more effectively than low-doses, and repeated dosing achieves the highest eradication rates. Building on these insights, we developed HydroPhage, a hyaluronan-based hydrogel system that uses dynamic covalent crosslinking to deliver high-titre phages over one week. HydroPhage eradicates infections five times more effectively than intravenous injection. We conclude that hydrogel-based sustained phage delivery enhances the efficacy of phage therapy and offers a practical, well-tolerated option for topical application.
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Affiliation(s)
- Yung-Hao Lin
- Department of Chemical Engineering, Stanford University, Stanford, CA, USA
| | - Tejas Dharmaraj
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Qingquan Chen
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Arne Echterhof
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
- Institute of Medical Microbiology, University Hospital of Muenster, Muenster, Germany
| | - Robert Manasherob
- Department of Orthopaedic Surgery, Stanford Hospital and Clinics, Redwood City, CA, USA
| | - Lucy J. Zhang
- Department of Material Science and Engineering, Stanford University, Stanford, CA, USA
| | - Cas de Leeuw
- Institute for Molecules and Materials, Radboud University, Nijmegen, Netherlands
| | - Nana A. Peterson
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Whitney Stannard
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Zhiwei Li
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Maryam Hajfathalian
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
- Department of Biomedical Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ
| | - Aviv Hargil
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Hunter A. Martinez
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Julie Pourtois
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Tony H. W. Chang
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Francis G. Blankenberg
- Division of Pediatric Radiology and Nuclear Medicine, Department of Radiology, Lucile Packard Children’s Hospital, Stanford, CA, USA
| | - Derek Amanatullah
- Department of Orthopaedic Surgery, Stanford Hospital and Clinics, Redwood City, CA, USA
| | - Ovijit Chaudhuri
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
| | - Paul L. Bollyky
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
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Parmar K, Fackler JR, Rivas Z, Mandrekar J, Greenwood-Quaintance KE, Patel R. A comparison of phage susceptibility testing with two liquid high-throughput methods. Front Microbiol 2024; 15:1386245. [PMID: 39171268 PMCID: PMC11335653 DOI: 10.3389/fmicb.2024.1386245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 07/09/2024] [Indexed: 08/23/2024] Open
Abstract
Phage therapy is a promising antibacterial strategy, especially given that drug-resistant bacterial infections are escalating worldwide. Because phages are not active against all strains of a given species, phages being considered for therapeutic use would ideally be tested against bacterial isolates from individual patients prior to administration. Standardized, clinically validated phage susceptibility testing (PST) methods are needed for assessing in vitro phage activity. This study compared two high-throughput liquid-based PST assays. The first, using the Biolog Omnilog™, assessed changes in microbial respiration leading to color changes based on a tetrazolium dye. The second, Agilent BioTek Cytation 7, assessed changes in optical density. Both used 96-well microtiter plate formats. A total of 55 diverse phages with activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, or Enterococcus faecalis were studied against their respective susceptible bacterial hosts and non-susceptible controls, with susceptibility defined based on plaque assay. PST was performed by both assays in replicates, with results compared in terms of hold times (time through which bacterial growth is inhibited by phage compared to controls). Coefficients of variance and interclass correlation coefficients were used to assess inter- and intra-assay reproducibility. Based on a ≤50% coefficient of variance cutpoint, 87% of Biolog and 84% of Agilent assays were considered valid for susceptible bacteria, with 100% considered valid for non-susceptible bacteria by both systems. Using a 8 h hold time cutpoint, 100% of the results matched between the two assays. The interclass correlation coefficient showed 26% excellent agreement, 35% good agreement, and 17% moderate agreement between the two assays for susceptible isolates and 100% excellent agreement for non-susceptible isolates. Overall, the assays compared provided good/fair statistical reproducibility for the assessment of phage susceptibility.
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Affiliation(s)
- Krupa Parmar
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Joseph R. Fackler
- Adaptive Phage Therapeutics, Inc. (APT), Gaithersburg, MD, United States
| | - Zuriel Rivas
- Adaptive Phage Therapeutics, Inc. (APT), Gaithersburg, MD, United States
| | - Jay Mandrekar
- Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, MN, United States
| | - Kerryl E. Greenwood-Quaintance
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Robin Patel
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
- Division of Public Health, Infectious Diseases, and Occupational Medicine, Department of Medicine, Mayo Clinic, Rochester, MN, United States
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Lyytinen OL, Dapuliga C, Wallinger D, Patpatia S, Audu BJ, Kiljunen SJ. Three novel Enterobacter cloacae bacteriophages for therapeutic use from Ghanaian natural waters. Arch Virol 2024; 169:156. [PMID: 38967872 PMCID: PMC11226500 DOI: 10.1007/s00705-024-06081-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 05/15/2024] [Indexed: 07/06/2024]
Abstract
Infections caused by multidrug-resistant (MDR) bacteria are a growing global concern. Enterobacter cloacae complex (ECC) species are particularly adept at developing antibiotic resistance. Phage therapy is proposed as an alternative treatment for pathogens that no longer respond to antibiotics. Unfortunately, ECC phages are understudied when compared to phages of many other bacterial species. In this Ghanaian-Finnish study, we isolated two ECC strains from ready-to-eat food samples and three novel phages from natural waters against these strains. We sequenced the genomic DNA of the novel Enterobacter phages, fGh-Ecl01, fGh-Ecl02, and fGh-Ecl04, and assessed their therapeutic potential. All of the phages were found to be lytic, easy to propagate, and lacking any toxic, integrase, or antibiotic resistance genes and were thus considered suitable for therapy purposes. They all were found to be related to T4-type viruses: fGh-Ecl01 and fGh-Ecl04 to karamviruses and fGh-Ecl02 to agtreviruses. Testing of Finnish clinical ECC strains showed promising susceptibility to these novel phages. As many as 61.1% of the strains were susceptible to fGh-Ecl01 and fGh-Ecl04, and 7.4% were susceptible to fGh-Ecl02. Finally, we investigated the susceptibility of the newly isolated ECC strains to three antibiotics - meropenem, ciprofloxacin, and cefepime - in combination with the novel phages. The use of phages and antibiotics together had synergistic effects. When using an antibiotic-phage combination, even low concentrations of antibiotics fully inhibited the growth of bacteria.
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Affiliation(s)
- O L Lyytinen
- Human Microbiome Research Program (HUMI), Faculty of Medicine, University of Helsinki, Helsinki, Finland.
| | - C Dapuliga
- Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana
| | - D Wallinger
- Human Microbiome Research Program (HUMI), Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - S Patpatia
- Human Microbiome Research Program (HUMI), Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - B J Audu
- National Veterinary Research Institute, Vom, Nigeria
| | - S J Kiljunen
- Human Microbiome Research Program (HUMI), Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Division of Clinical Microbiology, HUSLAB, Helsinki University Hospital, Helsinki, Finland
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Ranta K, Skurnik M, Kiljunen S. fENko-Kae01 is a flagellum-specific jumbo phage infecting Klebsiella aerogenes. BMC Microbiol 2024; 24:234. [PMID: 38951769 PMCID: PMC11218385 DOI: 10.1186/s12866-024-03387-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 06/19/2024] [Indexed: 07/03/2024] Open
Abstract
BACKGROUND Klebsiella aerogenes is an opportunistic pathogen that causes a wide variety of infections. Due to the rising problem of antibiotic resistance, novel antibiotics and strategies to combat bacterial infections are needed. Host-specific bacteriophages are natural enemies of bacteria and can be used in phage therapy as an alternative form of treatment against bacterial infections. Jumbo phages are defined as phages with genomes larger than 200 kb. Relatively few studies have been done on jumbo phages compared to smaller phages. RESULTS A novel phage, fENko-Kae01, was isolated from a commercial phage cocktail. Genomic analysis revealed that fENko-Kae01 is a lytic jumbo phage with a 360 kb genome encoding 578 predicted genes. No highly similar phage genomes were identified and fENko-Kae01 may be a completely new genus representative. No known genes associated with lysogenic life cycle, bacterial virulence, or antibiotic resistance were identified. The phage had myovirus morphology and a narrow host range. Phage resistant bacterial mutants emerged under phage selection. Whole genome sequencing revealed that the biogenesis of the flagellum was affected in four mutants and the lack of functional flagellum was confirmed in motility assays. Furthermore, phage fENKo-Kae01 failed to adsorb on the non-motile mutants indicating that the bacterial flagellum is the phage-binding receptor. CONCLUSIONS fENko-Kae01 is a novel jumbo bacteriophage that is considered safe for phage therapy. fENko-Kae01 uses the flagellum as the phage-binding receptor and may represent a completely novel genus.
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Affiliation(s)
- Kira Ranta
- HUS Diagnostic Center, Clinical Microbiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Human Microbiome Research Program, Research Program Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Mikael Skurnik
- Human Microbiome Research Program, Research Program Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Saija Kiljunen
- Human Microbiome Research Program, Research Program Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
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Yerushalmy O, Braunstein R, Alkalay-Oren S, Rimon A, Coppenhagn-Glazer S, Onallah H, Nir-Paz R, Hazan R. Towards Standardization of Phage Susceptibility Testing: The Israeli Phage Therapy Center "Clinical Phage Microbiology"-A Pipeline Proposal. Clin Infect Dis 2023; 77:S337-S351. [PMID: 37932122 DOI: 10.1093/cid/ciad514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023] Open
Abstract
Using phages as salvage therapy for nonhealing infections is gaining recognition as a viable solution for patients with such infections. The escalating issue of antibiotic resistance further emphasizes the significance of using phages in treating bacterial infections, encompassing compassionate-use scenarios and clinical trials. Given the high specificity of phages, selecting the suitable phage(s) targeting the causative bacteria becomes critical for achieving treatment success. However, in contrast to conventional antibiotics, where susceptibility-testing procedures were well established for phage therapy, there is a lack of standard frameworks for matching phages from a panel to target bacterial strains and assessing their interactions with antibiotics or other agents. This review discusses and compares published methods for clinical phage microbiology, also known as phage susceptibility testing, and proposes guidelines for establishing a standard pipeline based on our findings over the past 5 years of phage therapy at the Israeli Phage Therapy Center.
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Affiliation(s)
- Ortal Yerushalmy
- The Israeli Phage Therapy Center (IPTC) of Hadassah Medical Center and the Hebrew University, Jerusalem, Israel
- Faculty of Dental Medicine, Institute of Biomedical and Oral Research (IBOR), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ron Braunstein
- The Israeli Phage Therapy Center (IPTC) of Hadassah Medical Center and the Hebrew University, Jerusalem, Israel
- Faculty of Dental Medicine, Institute of Biomedical and Oral Research (IBOR), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Sivan Alkalay-Oren
- The Israeli Phage Therapy Center (IPTC) of Hadassah Medical Center and the Hebrew University, Jerusalem, Israel
- Faculty of Dental Medicine, Institute of Biomedical and Oral Research (IBOR), The Hebrew University of Jerusalem, Jerusalem, Israel
- The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Amit Rimon
- The Israeli Phage Therapy Center (IPTC) of Hadassah Medical Center and the Hebrew University, Jerusalem, Israel
- Faculty of Dental Medicine, Institute of Biomedical and Oral Research (IBOR), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Shunit Coppenhagn-Glazer
- The Israeli Phage Therapy Center (IPTC) of Hadassah Medical Center and the Hebrew University, Jerusalem, Israel
- Faculty of Dental Medicine, Institute of Biomedical and Oral Research (IBOR), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Hadil Onallah
- The Israeli Phage Therapy Center (IPTC) of Hadassah Medical Center and the Hebrew University, Jerusalem, Israel
- Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Ran Nir-Paz
- The Israeli Phage Therapy Center (IPTC) of Hadassah Medical Center and the Hebrew University, Jerusalem, Israel
- The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
- Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Ronen Hazan
- The Israeli Phage Therapy Center (IPTC) of Hadassah Medical Center and the Hebrew University, Jerusalem, Israel
- Faculty of Dental Medicine, Institute of Biomedical and Oral Research (IBOR), The Hebrew University of Jerusalem, Jerusalem, Israel
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Kolsi A, Haukka K, Dougnon V, Agbankpè AJ, Fabiyi K, Virta M, Skurnik M, Kantele A, Kiljunen S. Isolation and characterization of three novel Acinetobacter baumannii phages from Beninese hospital wastewater. Arch Virol 2023; 168:228. [PMID: 37574509 PMCID: PMC10423700 DOI: 10.1007/s00705-023-05845-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/19/2023] [Indexed: 08/15/2023]
Abstract
Acinetobacter baumannii is an opportunistic pathogen that is mostly associated with hospital-acquired infections. The rapid emergence of multi- and pan-drug-resistant Acinetobacter strains poses an increasing challenge in hospitals. Phage therapy offers one treatment option for infections caused by A. baumannii. We isolated three phages from Beninese hospital wastewater - fBenAci001, fBenAci002, and fBenAci003 - that infected clinical A. baumannii strains from Finnish patients. Phylogenetic analysis showed that these phages resemble phages of the genus Friunavirus, family Autographiviridae. The isolated phages meet the requirements set for phages used for phage therapy. However, they were found to have a narrow host range, which may limit their therapeutic use.
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Affiliation(s)
- Anna Kolsi
- Human Microbiome Research Program, Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Department of Microbiology, University of Helsinki, Helsinki, Finland
| | - Kaisa Haukka
- Human Microbiome Research Program, Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Department of Microbiology, University of Helsinki, Helsinki, Finland
| | - Victorien Dougnon
- Research Unit in Applied Microbiology and Pharmacology of natural substances, Polytechnic School of Abomey-Calavi, University of Abomey-Calavi, Abomey Calavi, Benin
| | - Alidehou Jerrold Agbankpè
- Research Unit in Applied Microbiology and Pharmacology of natural substances, Polytechnic School of Abomey-Calavi, University of Abomey-Calavi, Abomey Calavi, Benin
| | - Kafayath Fabiyi
- Research Unit in Applied Microbiology and Pharmacology of natural substances, Polytechnic School of Abomey-Calavi, University of Abomey-Calavi, Abomey Calavi, Benin
| | - Marko Virta
- Department of Microbiology, University of Helsinki, Helsinki, Finland
| | - Mikael Skurnik
- Human Microbiome Research Program, Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Division of Clinical Microbiology, HUS Diagnostic Center, Hospital District of Helsinki and Uusimaa, Helsinki, Finland
| | - Anu Kantele
- Human Microbiome Research Program, Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Meilahti Vaccine Research Center MeVac, Infectious Diseases, Helsinki University, Hospital District of Helsinki and Uusimaa, Helsinki, Finland
| | - Saija Kiljunen
- Human Microbiome Research Program, Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
- Division of Clinical Microbiology, HUS Diagnostic Center, Hospital District of Helsinki and Uusimaa, Helsinki, Finland.
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Suh GA, Patel R. Clinical phage microbiology: a narrative summary. Clin Microbiol Infect 2023:S1198-743X(23)00059-9. [PMID: 36805835 DOI: 10.1016/j.cmi.2023.02.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 02/17/2023]
Abstract
BACKGROUND Although phage therapy has been in existence for a century, a recent resurgence in interest has occurred because of the continued emergence of antimicrobial resistance and the rising use of indwelling medical devices, resulting in biofilm-associated infections, for which conventional antibiotics are of limited use. Despite this, the clinical successes have been inconsistent because of multiple reasons, including (1) the narrow host range of phages, (2) challenges with concentrating phages at the site of infection, (3) development of resistance of bacteria to phages and (4) immune neutralization. Microbiologic assays have the potential to help guide the course of clinical therapy and improve outcomes. Methods developed decades ago remain the mainstay of phage diagnostics and recently, newer diagnostics are closing the gap needed to further advance clinical phage therapy. OBJECTIVES To review the current state of clinical phage microbiology and identify gaps. SOURCES A PubMed search was performed using the terms "phage microbiology", "phage susceptibility test", "phage host range", "phage biofilm", and "phage therapeutic monitoring". CONTENT Phage susceptibility testing, biofilm assays, phage-antibiotic combination testing, therapeutic drug monitoring, and immune monitoring assays are the current foundation for clinical phage diagnostics. Standardization of these assays and better understanding as to if and how they should be used in terms of clinical management of patients receiving phage therapy is needed. IMPLICATIONS A substantial gap between in vitro studies and in vivo outcomes indicates that further work is needed in phage pharmacokinetics to accurately assay phage particles at the site of infection; recapitulate in vivo biofilm; capture the complex interactions between phages and antibiotics, phages and their target bacteria, among phages in a cocktail, and with the superhost immune system.
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Affiliation(s)
- Gina A Suh
- Division of Public Health, Infectious Diseases, and Occupational Medicine, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
| | - Robin Patel
- Division of Public Health, Infectious Diseases, and Occupational Medicine, Department of Medicine, Mayo Clinic, Rochester, MN, USA; Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
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Wójcicki M, Świder O, Gientka I, Błażejak S, Średnicka P, Shymialevich D, Cieślak H, Wardaszka A, Emanowicz P, Sokołowska B, Juszczuk-Kubiak E. Effectiveness of a Phage Cocktail as a Potential Biocontrol Agent against Saprophytic Bacteria in Ready-To-Eat Plant-Based Food. Viruses 2023; 15:172. [PMID: 36680211 PMCID: PMC9860863 DOI: 10.3390/v15010172] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/01/2023] [Accepted: 01/05/2023] [Indexed: 01/11/2023] Open
Abstract
This study aimed to evaluate the effectiveness of the phage cocktail to improve the microbiological quality of five different mixed-leaf salads: rucola, mixed-leaf salad with carrot, mixed-leaf salad with beetroot, washed and unwashed spinach, during storage in refrigerated conditions. Enterobacterales rods constituted a significant group of bacteria in the tested products. Selected bacteria were tested for antibiotic resistance profiles and then used to search for specific bacteriophages. Forty-three phages targeting bacteria dominant in mixed-leaf salads were isolated from sewage. Their titer was determined, and lytic activity was assessed using the Bioscreen C Pro automated growth analyzer. Two methods of phage cocktail application including spraying, and an absorption pad were effective for rucola, mixed leaf salad with carrot, and mixed leaf salad with beetroot. The maximum reduction level after 48 h of incubation reached 99.9% compared to the control sample. In washed and unwashed spinach, attempts to reduce the number of microorganisms did not bring the desired effect. The decrease in bacteria count in the lettuce mixes depended on the composition of the autochthonous saprophytic bacteria species. Both phage cocktail application methods effectively improved the microbiological quality of minimally processed products. Whole-spectral phage cocktail application may constitute an alternative food microbiological quality improvement method without affecting food properties.
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Affiliation(s)
- Michał Wójcicki
- Laboratory of Biotechnology and Molecular Engineering, Department of Microbiology, Prof. Waclaw Dabrowski Institute of Agricultural and Food Biotechnology—State Research Institute, Rakowiecka 36 Street, 02-532 Warsaw, Poland
| | - Olga Świder
- Department of Food Safety and Chemical Analysis, Prof. Waclaw Dabrowski Institute of Agricultural and Food Biotechnology—State Research Institute, Rakowiecka 36 Street, 02-532 Warsaw, Poland
| | - Iwona Gientka
- Department of Biotechnology and Food Microbiology, Institute of Food Sciences, Warsaw University of Life Sciences (WULS-SGGW), Nowoursynowska 166 Street, 02-776 Warsaw, Poland
| | - Stanisław Błażejak
- Department of Biotechnology and Food Microbiology, Institute of Food Sciences, Warsaw University of Life Sciences (WULS-SGGW), Nowoursynowska 166 Street, 02-776 Warsaw, Poland
| | - Paulina Średnicka
- Laboratory of Biotechnology and Molecular Engineering, Department of Microbiology, Prof. Waclaw Dabrowski Institute of Agricultural and Food Biotechnology—State Research Institute, Rakowiecka 36 Street, 02-532 Warsaw, Poland
| | - Dziyana Shymialevich
- Culture Collection of Industrial Microorganisms—Microbiological Resources Center, Department of Microbiology, Prof. Waclaw Dabrowski Institute of Agricultural and Food Biotechnology—State Research Institute, Rakowiecka 36 Street, 02-532 Warsaw, Poland
| | - Hanna Cieślak
- Culture Collection of Industrial Microorganisms—Microbiological Resources Center, Department of Microbiology, Prof. Waclaw Dabrowski Institute of Agricultural and Food Biotechnology—State Research Institute, Rakowiecka 36 Street, 02-532 Warsaw, Poland
| | - Artur Wardaszka
- Laboratory of Biotechnology and Molecular Engineering, Department of Microbiology, Prof. Waclaw Dabrowski Institute of Agricultural and Food Biotechnology—State Research Institute, Rakowiecka 36 Street, 02-532 Warsaw, Poland
| | - Paulina Emanowicz
- Laboratory of Biotechnology and Molecular Engineering, Department of Microbiology, Prof. Waclaw Dabrowski Institute of Agricultural and Food Biotechnology—State Research Institute, Rakowiecka 36 Street, 02-532 Warsaw, Poland
| | - Barbara Sokołowska
- Department of Microbiology, Prof. Waclaw Dabrowski Institute of Agricultural and Food Biotechnology—State Research Institute, Rakowiecka 36 Street, 02-532 Warsaw, Poland
| | - Edyta Juszczuk-Kubiak
- Laboratory of Biotechnology and Molecular Engineering, Department of Microbiology, Prof. Waclaw Dabrowski Institute of Agricultural and Food Biotechnology—State Research Institute, Rakowiecka 36 Street, 02-532 Warsaw, Poland
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