Lars Sundstrom

Background

About Lars Sundstrom

Mobile DNA elements are organized into well-branched networks that allow fast and horizontal spreading of a broad variation of genes through microbial communities. The transfer and recombination of antibiotic resistance genes set them free to relocate and meet antibiotic selection. Furthermore, in recent years it has been demonstrated that gene transfer is stimulated in bacteria exposed to antimicrobial agents or irradiation. Drug promotion of horizontal transfer is due to induction of physiological stress systems that are triggered by a primary antibiotic effect often connected to formation of minor lesions in the DNA. The final display is a whole panel of stress effects on a common theme of DNA-rescuing activity and survival, among the exposed bacteria. Stress-induced capacities include genetic communication and recombination. To stress inducing antibiotics belong synthetic antimicrobial agents e.g. quinolones, antifolates and sulfonamide that have been used globally for more than 50 years in large quantities. Because degradation of xenobiotic agents as those mentioned, is slow, upregulated gene shedding may be prevalent in the antibiotic-exposed, environmental microflora. Contamination of the environment with antibiotics may hence increase the prevalence of resistance genes in a strategic depony from which further transfer of resistance to pathogenic bacteria is likely to occur for instance via the food chain. Resistance to antibiotic drugs is now widespread and we are on the threshold of a situation when we will lack remedies, in worst case stand defenceless, to a growing list of common bacterial infections. Efficient antimicrobial drugs is a fundament of modern health care, not least in surgery. The best we can do is consume less drugs, handle those we have properly, find new drugs and augmenting our knowledge of gene transfer, recombination and stress induction.