Bacteriophage Formation Without Bacterial Growth

Price, Winston H.

doi:10.1085/jgp.31.2.119

Cited by 11 publications

(3 citation statements)

References 2 publications

(1 reference statement)

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“…A decrease in latency period shortens the amount of time for phage maturation, which can result in reduced burst size, but can also increase the phages’ rate of exponential growth [ 40 ]. Though most PAS studies that examine phage production typically see an increase in burst size or final phage titer [ 13 , 14 , 15 , 34 , 36 , 41 , 42 , 43 , 44 ], it is important to note that PAS has still been shown to occur in the absence of increased phage production [ 14 , 35 ]. This discrepancy in phage production highlights that PAS may be generated by many different aspects of the phage infection cycle, and as proposed previously [ 14 ], it is possible that many different molecular mechanisms are responsible for the total PAS effects observed for every different phage and antibiotic combination.…”

Section: Resultsmentioning

confidence: 99%

Aztreonam Lysine Increases the Activity of Phages E79 and phiKZ against Pseudomonas aeruginosa PA01

2021

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Pseudomonas aeruginosa is a pernicious bacterial pathogen that is difficult to treat because of high levels of antibiotic resistance. A promising alternative treatment option for such bacteria is the application of bacteriophages; the correct combination of phages plus antibiotics can produce synergistic inhibitory effects. In this study, we describe morphological changes induced by sub-MIC levels of the antibiotic aztreonam lysine (AzLys) on P. aeruginosa PA01, which may in part explain the observed phage–antibiotic synergy (PAS). One-step growth curves for phage E79 showed increased adsorption rates, decreased infection latency, accelerated time to lysis and a minor reduction in burst size. Phage E79 plus AzLys PAS was also able to significantly reduce P. aeruginosa biofilm growth over 3-fold as compared to phage treatment alone. Sub-inhibitory AzLys-induced filamentation of P. aeruginosa cells resulted in loss of twitching motility and a reduction in swimming motility, likely due to a reduction in the number of polar Type IV pili and flagella, respectively, on the filamented cell surfaces. Phage phiKZ, which uses Type IV pili as a receptor, did not exhibit increased activity with AzLys at lower sub-inhibitory levels, but still produced phage–antibiotic synergistic killing with sub-inhibitory AzLys. A one-step growth curve indicates that phiKZ in the presence of AzLys also exhibits a decreased infection latency and moderately undergoes accelerated time to lysis. In contrast to prior PAS studies demonstrating that phages undergo delayed time to lysis with cell filamentation, these PAS results show that phages undergo accelerated time to lysis, which therefore suggests that PAS is dependent upon multiple factors, including the type of phages and antibiotics used, and the bacterial host being tested.

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Section: Resultsmentioning

confidence: 99%

Aztreonam Lysine Increases the Activity of Phages E79 and phiKZ against Pseudomonas aeruginosa PA01

2021

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“…Subinhibitory concentrations of antibiotics have been shown to produce an increase in phage activity (26)(27)(28)(29)(30)(31)(32)(33)(34)(35), and recently, this was termed "phage-antibiotic synergy," or PAS (33). In this study, we have tested ciprofloxacin (a fluoroquinolone antibiotic), meropenem (a carbapenem, which is a modified ␤-lactam antibiotic), and tetracycline (a protein translation inhibitor).…”

Section: Discussionmentioning

confidence: 99%

“…It has been reported that more phages are produced from bacteria in the presence of penicillin than in its absence (27)(28)(29)(30). There have also been reports of the stimulation of phage development in Escherichia coli (31) and Staphylococcus aureus (32) by ␤-lactam antibiotics.…”

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Burkholderia cepacia Complex Phage-Antibiotic Synergy (PAS): Antibiotics Stimulate Lytic Phage Activity

Kamal

Dennis

2015

Appl Environ Microbiol

175

195

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The Burkholderia cepacia complex (Bcc) is a group of at least 18 species of Gram-negative opportunistic pathogens that can cause chronic lung infection in cystic fibrosis (CF) patients. Bcc organisms possess high levels of innate antimicrobial resistance, and alternative therapeutic strategies are urgently needed. One proposed alternative treatment is phage therapy, the therapeutic application of bacterial viruses (or bacteriophages). Recently, some phages have been observed to form larger plaques in the presence of sublethal concentrations of certain antibiotics; this effect has been termed phage-antibiotic synergy (PAS). Those reports suggest that some antibiotics stimulate increased production of phages under certain conditions. The aim of this study is to examine PAS in phages that infect Burkholderia cenocepacia strains C6433 and K56-2. Bcc phages KS12 and KS14 were tested for PAS, using 6 antibiotics representing 4 different drug classes. Of the antibiotics tested, the most pronounced effects were observed for meropenem, ciprofloxacin, and tetracycline. When grown with subinhibitory concentrations of these three antibiotics, cells developed a chain-like arrangement, an elongated morphology, and a clustered arrangement, respectively. When treated with progressively higher antibiotic concentrations, both the sizes of plaques and phage titers increased, up to a maximum. B. cenocepacia K56-2-infected Galleria mellonella larvae treated with phage KS12 and low-dose meropenem demonstrated increased survival over controls treated with KS12 or antibiotic alone. These results suggest that antibiotics can be combined with phages to stimulate increased phage production and/or activity and thus improve the efficacy of bacterial killing.

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Bacteriophages: Nature and Reproduction

Putnam

1953

Advances in Protein Chemistry

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Bacteriophage Formation Without Bacterial Growth

Abstract: Bacteriophage will increase 100,000 times in Staphylococcus muscae cultures whose multiplication has been completely inhibited by penicillin.

Cited by 11 publications

References 2 publications

Aztreonam Lysine Increases the Activity of Phages E79 and phiKZ against Pseudomonas aeruginosa PA01

Aztreonam Lysine Increases the Activity of Phages E79 and phiKZ against Pseudomonas aeruginosa PA01

Burkholderia cepacia Complex Phage-Antibiotic Synergy (PAS): Antibiotics Stimulate Lytic Phage Activity

Bacteriophages: Nature and Reproduction

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