Monitoring non-carbonated (‘still’) mineral waters for aerobic colonization

Abstract

Fifty samples each of two leadmg brands of French, non-carbonated ('still') mineral waters, packed an plastic bottles, were stored in the dark for one month at approx~mateb. 200(. . to allot marked proliferation of their autotrophic microbial flora. Upon completion of th~s challenge test 1250 ml per bottle were filtered through five membranes. ~.h~ch were subsequently cultured on 1/10 strength nutrient agar for 48 h at a temperature favouring the growth of thermotrophtc orgam~ms only,, i.e 42 _+ 0 5°C. The numbers of colonies per one htre were below 10 ~ in all samples and did not exceed 200 in 56-80~. depending on the brand. Identification of the ~solates demonstrated strong inhibition of the psychrotrophic Gram-negative types, predominating m the association flora of stored stdl v, ater~ and preponderance of Gram-positive. catalase-posmve, facultatively anaerobic cfx:ci. Consequentl). a Reference Value for the thermotrophic autotrophic colony count per I ml m stdl, commercial mineral taters of the order m = I and M -5 seems justified. It is emphasized that. besides exammmg for these trl~.ial orgamsms, the usual tests for marker bacteria (Escherwht, coh and Lancefield group D .,treptoctv,,'cO and Pseud,monas aerugmosa should always be carried out

The microbiology of bottled natural mineral waters

“…Several workers have investigated the microbial flora of bottled waters (Schwaller and Schmidt-Lorenz 1980;Leclerc et al 1985;Quevedo-Sarmiento et al 1986;Hunter and Burge 1987;Gonzales et al 1987;Bischofberger et al 1990;Manaia et al 1990;Morais and da Costa 1990). Most of these studies have been concerned with only one or two sources or have not identified isolates to the species level.…”

Methods for the detection and isolation of Escherichia coli including pathogenic strains

“…The only water that is exported in considerable quantities is bottled mineral water. International standards for its quality and standardized methods to assess its microbiological status have been elaborated (Leclerc et al 1985).…”

A review of the microbiological quality of bottled water sold in Canada. Part 2. The need for more stringent standards and regulations

“…However, when determined at higher temperatures such as 35°C on a rich medium, the ACC is more likely to recover fecal microorganisms that have contaminated the waters (Spinedi and Gisin 1990;Stickler 1989), as such counts will be invariably low in waters of good sanitary quality (Leclerc et al 1985). Payment et al (1991) have shown that there is a strong correlation between water containing high ACC (obtained at 35OC) and gastrointestinal symptoms.…”

“…The examination of bottled water for indicators and some pathogens is essential (even up to a few weeks after bottling) (Leclerc et al 1985). Rather than examining water for the presence of all the possible pathogens, using a variety of technically difficult, insensitive, time-consuming, and expensive tests, it is better to utilize relatively simple and more rapid procedures for detecting and enumerating the Can.…”