Scoping the effectiveness and evolutionary obstacles in using plasmid-dependent phages to fight antibiotic resistance.

Aim: To investigate the potential evolutionary obstacles in the sustainable therapeutic use of plasmid-dependent phages to control the clinically important conjugative plasmid-mediated dissemination of antibiotic resistance genes to pathogenic bacteria.

Materials & Methods: The lytic plasmid-dependent phage PRD1 and the multiresistance conferring plasmid RP4 in an Escherichia coli host were utilized to assess the genetic and phenotypic changes induced by combined phage and antibiotic selection.

Results & Conclusions: Resistance to PRD1 was always coupled with either completely lost or greatly reduced conjugation ability.

Conjugation is necessary for a bacterial plasmid to survive under protozoan predation.

Horizontal gene transfer by conjugative plasmids plays a critical role in the evolution of antibiotic resistance. Interactions between bacteria and other organisms can affect the persistence and spread of conjugative plasmids. Here we show that protozoan predation increased the persistence and spread of the antibiotic resistance plasmid RP4 in populations of the opportunist bacterial pathogen Serratia marcescens.

Protist predation can select for bacteria with lowered susceptibility to infection by lytic phages.

Background: Consumer-resource interactions constitute one of the most common types of interspecific antagonistic interaction. In natural communities, complex species interactions are likely to affect the outcomes of reciprocal co-evolution between consumers and their resource species. Individuals face multiple enemies simultaneously, and consequently they need to adapt to several different types of enemy pressures.

Evolutionary rescue of bacteria via horizontal gene transfer under a lethal β-lactam concentration.

β-Lactams are a commonly used class of bactericidal antibiotics. The number of β-lactam-resistant pathogens is constantly increasing in hospitals around the world. Interestingly, most of the β-lactam-resistant bacteria carry mobile genetic elements, such as conjugative plasmids, that render the pathogen resistant.

Fight evolution with evolution: plasmid-dependent phages with a wide host range prevent the spread of antibiotic resistance.

The emergence of pathogenic bacteria resistant to multiple antibiotics is a serious worldwide public health concern. Whenever antibiotics are applied, the genes encoding for antibiotic resistance are selected for within bacterial populations. This has led to the prevalence of conjugative plasmids that carry resistance genes and can transfer themselves between diverse bacterial groups.