Limits...
Cryptic prophages help bacteria cope with adverse environments.

Wang X, Kim Y, Ma Q, Hong SH, Pokusaeva K, Sturino JM, Wood TK - Nat Commun (2010)

Bottom Line: We find that cryptic prophages contribute significantly to resistance to sub-lethal concentrations of quinolone and β-lactam antibiotics primarily through proteins that inhibit cell division (for example, KilR of rac and DicB of Qin).Moreover, the prophages are beneficial for withstanding osmotic, oxidative and acid stresses, for increasing growth, and for influencing biofilm formation.Therefore, cryptic prophages provide multiple benefits to the host for surviving adverse environmental conditions.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Engineering, Texas A & M University, 220 Jack E. Brown Building, College Station, Texas 77843-3122, USA.

ABSTRACT
Phages are the most abundant entity in the biosphere and outnumber bacteria by a factor of 10. Phage DNA may also constitute 20% of bacterial genomes; however, its role is ill defined. Here, we explore the impact of cryptic prophages on cell physiology by precisely deleting all nine prophage elements (166 kbp) using Escherichia coli. We find that cryptic prophages contribute significantly to resistance to sub-lethal concentrations of quinolone and β-lactam antibiotics primarily through proteins that inhibit cell division (for example, KilR of rac and DicB of Qin). Moreover, the prophages are beneficial for withstanding osmotic, oxidative and acid stresses, for increasing growth, and for influencing biofilm formation. Prophage CPS-53 proteins YfdK, YfdO and YfdS enhanced resistance to oxidative stress, prophages e14, CPS-53 and CP4-57 increased resistance to acid, and e14 and rac proteins increased early biofilm formation. Therefore, cryptic prophages provide multiple benefits to the host for surviving adverse environmental conditions.

Show MeSH

Related in: MedlinePlus

Prophage excised at different frequencies.Proportion of wild-type cells that have the indicated prophage excised without mitomycin C (open bar), with the addition of 1 μg ml−1 of mitomycin C (grey bar) and 10 μg ml−1 of mitomycin C (black bar). Mitomycin C was added to exponential-phase cells (turbidity /1.0) in LB medium at 37 °C for 4 h. Error bars indicate s.d. values (n=3).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3105296&req=5

f5: Prophage excised at different frequencies.Proportion of wild-type cells that have the indicated prophage excised without mitomycin C (open bar), with the addition of 1 μg ml−1 of mitomycin C (grey bar) and 10 μg ml−1 of mitomycin C (black bar). Mitomycin C was added to exponential-phase cells (turbidity /1.0) in LB medium at 37 °C for 4 h. Error bars indicate s.d. values (n=3).

Mentions: To test the stability and excision proficiency of each of the nine prophages, the fraction of cells that undergoes excision was quantified by quantitative PCR in a total of /1010 cells. The size and the position of each prophage is shown in Figure 1 and Table 1. In exponentially growing cells, seven of the nine prophages excised (Fig. 5). Prophage e14 had the highest excision rate (1–5 per 10,000 cells), and CP4-6 and rac had an excision frequency of tenfold lower (1–27 per 100,000 cells). DLP12, CPS-53, CPZ-55 and CP4-57 also excised, but with very low frequencies (<1 per 100,000 cells). In contrast, excision of Qin and CP4-44 was not detected. This is expected because the integrase for Qin (intQ) is inactive34, and CP4-44 lacks an integrase35. These results indicate these prophages are stable under exponential growth.


Cryptic prophages help bacteria cope with adverse environments.

Wang X, Kim Y, Ma Q, Hong SH, Pokusaeva K, Sturino JM, Wood TK - Nat Commun (2010)

Prophage excised at different frequencies.Proportion of wild-type cells that have the indicated prophage excised without mitomycin C (open bar), with the addition of 1 μg ml−1 of mitomycin C (grey bar) and 10 μg ml−1 of mitomycin C (black bar). Mitomycin C was added to exponential-phase cells (turbidity /1.0) in LB medium at 37 °C for 4 h. Error bars indicate s.d. values (n=3).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3105296&req=5

f5: Prophage excised at different frequencies.Proportion of wild-type cells that have the indicated prophage excised without mitomycin C (open bar), with the addition of 1 μg ml−1 of mitomycin C (grey bar) and 10 μg ml−1 of mitomycin C (black bar). Mitomycin C was added to exponential-phase cells (turbidity /1.0) in LB medium at 37 °C for 4 h. Error bars indicate s.d. values (n=3).
Mentions: To test the stability and excision proficiency of each of the nine prophages, the fraction of cells that undergoes excision was quantified by quantitative PCR in a total of /1010 cells. The size and the position of each prophage is shown in Figure 1 and Table 1. In exponentially growing cells, seven of the nine prophages excised (Fig. 5). Prophage e14 had the highest excision rate (1–5 per 10,000 cells), and CP4-6 and rac had an excision frequency of tenfold lower (1–27 per 100,000 cells). DLP12, CPS-53, CPZ-55 and CP4-57 also excised, but with very low frequencies (<1 per 100,000 cells). In contrast, excision of Qin and CP4-44 was not detected. This is expected because the integrase for Qin (intQ) is inactive34, and CP4-44 lacks an integrase35. These results indicate these prophages are stable under exponential growth.

Bottom Line: We find that cryptic prophages contribute significantly to resistance to sub-lethal concentrations of quinolone and β-lactam antibiotics primarily through proteins that inhibit cell division (for example, KilR of rac and DicB of Qin).Moreover, the prophages are beneficial for withstanding osmotic, oxidative and acid stresses, for increasing growth, and for influencing biofilm formation.Therefore, cryptic prophages provide multiple benefits to the host for surviving adverse environmental conditions.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Engineering, Texas A & M University, 220 Jack E. Brown Building, College Station, Texas 77843-3122, USA.

ABSTRACT
Phages are the most abundant entity in the biosphere and outnumber bacteria by a factor of 10. Phage DNA may also constitute 20% of bacterial genomes; however, its role is ill defined. Here, we explore the impact of cryptic prophages on cell physiology by precisely deleting all nine prophage elements (166 kbp) using Escherichia coli. We find that cryptic prophages contribute significantly to resistance to sub-lethal concentrations of quinolone and β-lactam antibiotics primarily through proteins that inhibit cell division (for example, KilR of rac and DicB of Qin). Moreover, the prophages are beneficial for withstanding osmotic, oxidative and acid stresses, for increasing growth, and for influencing biofilm formation. Prophage CPS-53 proteins YfdK, YfdO and YfdS enhanced resistance to oxidative stress, prophages e14, CPS-53 and CP4-57 increased resistance to acid, and e14 and rac proteins increased early biofilm formation. Therefore, cryptic prophages provide multiple benefits to the host for surviving adverse environmental conditions.

Show MeSH
Related in: MedlinePlus