TY - JOUR

T1 - Screening for Highly Transduced Genes in Staphylococcus aureus Revealed Both Lateral and Specialized Transduction

AU - Bowring, Janine Zara

AU - Su, Yue

AU - Alsaadi, Ahlam

AU - Svenningsen, Sine L.

AU - Parkhill, Julian

AU - Ingmer, Hanne

N1 - Publisher Copyright: © 2022 Bowring et al.

PY - 2022

Y1 - 2022

N2 - Bacteriophage-mediated transduction of bacterial DNA is a major route of horizontal gene transfer in the human pathogen, Staphylococcus aureus. Transduction involves the packaging of bacterial DNA by viruses and enables the transmission of virulence and resistance genes between cells. To learn more about transduction in S. aureus, we searched a transposon mutant library for genes and mutations that enhanced transfer mediated by the temperate phage, f 11. Using a novel screening strategy, we performed multiple rounds of transduction of transposon mutant pools selecting for an antibiotic resistance marker within the transposon element. When determining the locations of transferred mutations, we found that the screen had selected for just 1 or 2 transposon mutant(s) within each pool of 96 mutants. Subsequent analysis showed that the position of the transposon, rather than the inactivation of bacterial genes, was responsible for the phenotype. Interestingly, from multiple rounds, we identified a pattern of transduction that encompassed mobile genetic elements as well as chromosomal regions both upstream and downstream of the phage integration site. The latter was confirmed by DNA sequencing of purified phage lysates. Importantly, transduction frequencies were lower for phage lysates obtained by phage infection rather than induction. Our results confirmed previous reports of lateral transduction of bacterial DNA downstream of the integrated phage but also indicated a novel form of specialized transduction of DNA upstream of the phage. These findings illustrated the complexity of transduction processes and increased our understanding of the mechanisms by which phages transfer bacterial DNA.

AB - Bacteriophage-mediated transduction of bacterial DNA is a major route of horizontal gene transfer in the human pathogen, Staphylococcus aureus. Transduction involves the packaging of bacterial DNA by viruses and enables the transmission of virulence and resistance genes between cells. To learn more about transduction in S. aureus, we searched a transposon mutant library for genes and mutations that enhanced transfer mediated by the temperate phage, f 11. Using a novel screening strategy, we performed multiple rounds of transduction of transposon mutant pools selecting for an antibiotic resistance marker within the transposon element. When determining the locations of transferred mutations, we found that the screen had selected for just 1 or 2 transposon mutant(s) within each pool of 96 mutants. Subsequent analysis showed that the position of the transposon, rather than the inactivation of bacterial genes, was responsible for the phenotype. Interestingly, from multiple rounds, we identified a pattern of transduction that encompassed mobile genetic elements as well as chromosomal regions both upstream and downstream of the phage integration site. The latter was confirmed by DNA sequencing of purified phage lysates. Importantly, transduction frequencies were lower for phage lysates obtained by phage infection rather than induction. Our results confirmed previous reports of lateral transduction of bacterial DNA downstream of the integrated phage but also indicated a novel form of specialized transduction of DNA upstream of the phage. These findings illustrated the complexity of transduction processes and increased our understanding of the mechanisms by which phages transfer bacterial DNA.

KW - Bacteriophages

KW - Gene transfer

KW - Mobile genetic elements

KW - Phages

KW - Staphylococcus aureus

KW - Transducing particles

KW - Transduction

KW - Transposons

U2 - 10.1128/spectrum.02423-21

DO - 10.1128/spectrum.02423-21

M3 - Journal article

C2 - 35138167

AN - SCOPUS:85124315320

VL - 10

JO - Microbiology spectrum

JF - Microbiology spectrum

SN - 2165-0497

IS - 1

M1 - e02423-21

ER -