Strain specific motility patterns and surface adhesion of virulent and probiotic Escherichia coli

M M Abdulkadieva,S A Ermolaeva,O F Petrov,E V Vasilieva,Y M Stanishevskiy,E V Sysolyatina,A I Gusarov,P A Domnin,D A Slonova,M M Vasiliev

doi:10.1038/s41598-021-04592-y

Abstract

Bacterial motility provides the ability for bacterial dissemination and surface exploration, apart from a choice between surface colonisation and further motion. In this study, we characterised the movement trajectories of pathogenic and probiotic Escherichia coli strains (ATCC43890 and M17, respectively) at the landing stage (i.e., leaving the bulk and approaching the surface) and its correlation with adhesion patterns and efficiency. A poorly motile strain JM109 was used as a control. Using specially designed and manufactured microfluidic chambers, we found that the motion behaviour near surfaces drastically varied between the strains, correlating with adhesion patterns. We consider two bacterial strategies for effective surface colonisation: horizontal and vertical, based on the obtained results. The horizontal strategy demonstrated by the M17 strain is characterised by collective directed movements within the horizontal layer during a relatively long period and non-uniform adhesion patterns, suggesting co-dependence of bacteria in the course of adhesion. The vertical strategy demonstrated by the pathogenic ATCC43890 strain implies the individual movement of bacteria mainly in the vertical direction, a faster transition from bulk to near-surface swimming, and independent bacterial behaviour during adhesion, providing a uniform distribution over the surface.

Highlights

Bacterial motility provides the ability for bacterial dissemination and surface exploration, apart from a choice between surface colonisation and further motion
The bacteriological motility test in semi-liquid agar did not reveal differences between the motile strains M17 and ATCC43890 (Fig. 1). Both strains spread in semi-liquid agar with similar effectiveness, which was noticeably higher than that of the control non-motile strain JM109
The opacity areas showing bacterial spreading in the semi-liquid agar after 24 h of growth were 4 ± 0.5 mm for JM109, which could be regarded as a result of cell division (Fig. 1)

Summary

Introduction

Bacterial motility provides the ability for bacterial dissemination and surface exploration, apart from a choice between surface colonisation and further motion. We characterised the movement trajectories of pathogenic and probiotic Escherichia coli strains (ATCC43890 and M17, respectively) at the landing stage (i.e., leaving the bulk and approaching the surface) and its correlation with adhesion patterns and efficiency. The vertical strategy demonstrated by the pathogenic ATCC43890 strain implies the individual movement of bacteria mainly in the vertical direction, a faster transition from bulk to near-surface swimming, and independent bacterial behaviour during adhesion, providing a uniform distribution over the surface. To explain the biological sense of the ‘unproductive’ NSS circular motion demonstrated by the enterohemorrhagic E. coli O157:H7 strain, Ipina et al proposed a mathematical model based on short-term stops and attachment of bacteria at various points of the trajectory, important for effective surface colonisation. Medical Research Center of Pediatric Hematology, Oncology and Immunology, Russian Ministry of Health, Scientific Reports | (2022) 12:614

Methods

Results

Conclusion