ARTICLE | doi:10.20944/preprints201708.0007.v1
Subject: Life Sciences, Microbiology Keywords: natural mineral water; free living protozoa; Nontuberculous mycobacteria; Legionella; qPCR
Online: 3 August 2017 (09:11:03 CEST)
Italian Directives recommends the good quality of natural mineral waters but literature data assert a potential risk from several microorganisms colonizing wellsprings and mineral water bottling plants. Aim of study is the identification of microorganisms from spring waters (SW) and bottled mineral waters (BMW) samples. Methods: Routine microbiological indicators, Legionella spp., Nontuberculous mycobacteria (NTM), protozoa (FLA) and physical-chemical parameters were assessed in 24 SW and 10 BMW samples performing culture methods and molecular tests as PCR and qPCR. Results: In 33 out of 34 samples no cultivable bacteria were isolated with the exception of 83 CFU/L of Mycobacterium gilvum, detected in one warm rich-mineralized SW. qPCR showed the presence of Legionella genomic units in 24% of samples (mean 2,9x102±1,7x102 GU/L) and NTM genomic units in 18% of samples (mean 5,7x103±4,1x103 GU/L). Vermamoeba vermiformis and Acanthamoeba polyphaga were recovered respectively in 70% of BMW samples (counts from 1,3x103 to 1,2x105) and 42% of SW samples (counts from 1,1x103 to 1,3x104). Vahlkampfia spp. was detected in 42% of SW and 70% of BMW samples (mean 1,3x104 ±2,9x103 GU/L). Conclusion: The study highlights a low rate of microbial risk and the importance of risk assessment in natural mineral waters.
REVIEW | doi:10.20944/preprints201612.0097.v2
Subject: Life Sciences, Microbiology Keywords: pathogens; Legionella; amoeba; protozoa; biofilm; antibacterial; antimicrobial; cooling towers; biocides; polyvalent metals
Online: 20 December 2016 (10:26:22 CET)
Application of toxic antibacterial agents is considered necessary to control prevalent fresh water microorganisms in evaporative cooling water systems, but these agents can adversely affect the environment and human health. Alternatively, natural antibacterial water chemistry has been applied in industrial cooling water systems for over 10 years with excellent results. The tower water chemistry method concentrates natural salts in highly-softened water to produce elevated pH and dissolved solids, with low calcium and magnesium. This practice conserves water while generating only a small volume of non-toxic natural salt concentrate for cost efficient separation and disposal if required. This review presents a novel perspective of natural antimicrobial chemistry for inhibiting parasitic microbiome functional relationships within the bio-triad of Legionella outbreaks, "Trojan Protozoans" and biofilms. The review further examines practical application and function of polyvalent metal ions in the inhibition of biofilms. Reducing global dependence on toxic antibacterial agents discharged to the environment is an emerging concern due to their impact on the natural microbiome, plants, animals and humans. Discharge of antibacterial agents also contributes to development of pathogen resistance. Use of natural antibacterial chemistry can play a key role in managing the cooling water environment in a more ecologically sustainable manner.