Bacterial dominance is due to effective utilisation of secondary metabolites produced by competitors

Abstract

Interactions between bacteria govern the progression of respiratory infections; however, the mechanisms underpinning these interactions are still unclear. Understanding how a bacterial species comes to dominate infectious communities associated with respiratory infections has direct relevance to treatment. In this study, Burkholderia, Pseudomonas, and Staphylococcus species were isolated from the sputum of an individual with Cystic Fibrosis and assembled in a fully factorial design to create simple microcosms. Measurements of growth and habitat modification were recorded over time, the later using proton Nuclear Magnetic Resonance spectra. The results showed interactions between the bacteria became increasingly neutral over time. Concurrently, the bacteria significantly altered their ability to modify the environment, with Pseudomonas able to utilise secondary metabolites produced by the other two isolates, whereas the reverse was not observed. This study indicates the importance of including data about the habitat modification of a community, to better elucidate the mechanisms of bacterial interactions.

High Occurrence of Bacterial Competition Among Clinically Documented Opportunistic Pathogens Including Achromobacter xylosoxidans in Cystic Fibrosis

“…When clinical CF strains are studied, with a few exceptions, there is usually no information given on the colonization history or profile of patients and these are major factors in the competitive traits of bacterial isolates. Indeed, isolates from early and later stages of infection have previously been shown to have distinct competitiveness ( Michelsen et al, 2014 ; Ghoul et al, 2015 ; Morgan et al, 2020 ) or differences in gene expression that may influence the strains’ competitive ability ( Nielsen et al, 2017 ). Finally, little information on the genotypes of clinical strains is usually available in these studies.…”

Application of Lactobacillus helveticus CNRZ 32 to Control the Microbial Contaminants in Cheese by Addition of Bacterial Extracts or by In Situ Production of Bioactive Metabolites

“…The great activity of this bacteriocin; Nisin was recorded by many researchers [27][28][29][30][31]. The arising count of gram negative bacteria and mycotic growth may be organized by the nutritional competition among microbial populations [32]. In contrary to Talaga cheese, the inefficient role of Diethyl ether extract, in either in free or loaded states, in Karish cheese can be elucidated by the inclusion of Talaga in salting solution along storage period that enables effective exposure to the treatments.…”

Efflux, Signaling and Warfare in a Polymicrobial World

“…A role for the MexAB-OprM efflux pump has been proposed in growth antagonism of P. aeruginosa by Enterococcus faecalis , though the NalC-iron related mechanism of this modulation remains to be fully determined [ 123 ]. The recent finding that utilization of secondary metabolites produced by co-colonizing competitors underpins bacterial dominance suggests that efflux systems and metabolic flux will play an important role in shaping the dynamics of these communities [ 124 ]. Disrupting balance through off-target effects or unintended metabolic shifts could have consequences for the diversity and stability of the ‘healthy’ community in the ecosystem or niche in which the target pathogen resides.…”