Molecular typing of Aeromonas isolates in natural mineral waters.

P Villari,P Montuori,M Crispino,S Boccia

doi:10.1128/aem.69.1.697-701.2003

Abstract

A total of 103 isolates of Aeromonas spp. were obtained over a 3-year period from a natural mineral water and from surface streams located within the boundaries of the watershed of the natural mineral water wells and were typed by macrorestriction analysis of genomic DNA with XbaI and by pulsed-field gel electrophoresis. All Aeromonas caviae isolates from the natural mineral water belonged to the same clone, and an analogous clonal identity was found among Aeromonas hydrophila isolates. These two clones expressed no hemolytic or cytotoxic activities. Aeromonas isolates from surface waters showed high molecular heterogeneity and were not related to the clones found in the natural mineral water. The presence of aeromonads chronically found in the natural mineral water was a likely consequence of a localized development of a biofilm, with no exogenous contamination of the aquifer. Molecular fingerprinting of drinking water isolates is a useful tool in explaining possible reasons for bacterial occurrences.

Highlights

The health consequences of the presence of motile species of the genus Aeromonas in drinking water are the subject of much debate [7, 11, 12, 20, 25]
A total of 103 isolates of Aeromonas spp. were obtained over a 3-year period from a natural mineral water and from surface streams located within the boundaries of the watershed of the natural mineral water wells and were typed by macrorestriction analysis of genomic DNA with XbaI and by pulsed-field gel electrophoresis
In this paper we show how macrorestriction analysis of genomic DNAs of Aeromonas isolates with pulsed-field gel electrophoresis (PFGE) was useful in clarifying the reasons for the chronic occurrence of Aeromonas spp. in an Italian brand of bottled natural mineral water and the reasons these organisms are not presumed to be a hazard to human health

Summary

Introduction

The health consequences of the presence of motile species of the genus Aeromonas in drinking water are the subject of much debate [7, 11, 12, 20, 25]. Aeromonas isolates from surface waters showed high molecular heterogeneity and were not related to the clones found in the natural mineral water.

Results

Conclusion