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.
ARTICLE | doi:10.20944/preprints201801.0105.v1
Subject: Behavioral Sciences, Other Keywords: energy drinks; adolescent lifestyle; alcohol; caffeine; sports
Online: 12 January 2018 (05:12:03 CET)
The European Food Safety Authority (EFSA) has identified some risk factors for the occurrence of side effects linked to energy drinks (EDs) consumption by young people. Tachycardia, sleeplessness, caffeine addiction may be caused by excessive consumption of EDs during parties, sport matches, ect. EDs consumption has been evaluated in a sample of students in Italy together with some aspects of their lifestyle. The survey was performed in two high schools from September 2014 to June 2015. 583 students between 14 to 18 years were recruited and a standard questionnaire (EFSA checklist) was used to collect information on responders characteristics, beverages consumption, EDs with alcohol, and EDs and sports. 350 out of 583 responders (60%) consumed EDs and 146 out of 583 responders (25%) reported an occasional alcohol consumption. Despite 82 out of 146 alcoholic drinkers (56%) were EDs-alcohol consumers, only 70 out of 583 adolescents (12%) reported habitual EDs consumption. Moreover, 38 out of 379 (10%) of all physically active adolescents reported frequent EDs consumption before sportive trainings. Study results highlight the need for primary prevention measures in communication campaigns and training delivered by school to limit potential health threats related to excess of EDs consumption.
ARTICLE | doi:10.20944/preprints201710.0058.v1
Subject: Life Sciences, Microbiology Keywords: Legionella; residential buildings; water risk; community-acquired Legionnaire’s disease cases
Online: 10 October 2017 (03:33:02 CEST)
Although the European reports highlight an increase in community-acquired Legionnaires’ disease cases, the risk of Legionella spp. in private houses is underestimated. In Pisa (Italy) we performed a three-year survey on Legionella presence in 121 buildings with an independent hot water production (IB); 64 buildings with a central hot water production (CB); and 35 buildings with a solar thermal system for hot water production (TB). From all the 220 buildings Legionella spp. was researched in two hot water samples collected either at the recirculation point or at on the first floor and on the last floor, while the potable water quality was analyzed in three cold water samples collected at the inlet from the aqueduct network, at the exit from the autoclave, and at the most remove remote? tap. Legionella pneumophila sg1, Legionella pneumophila sg2-16 and not-pneumophila Legionella species were detected in 26% of the hot water networks, mostly in CB and TB. In these buildings we detected correlations between the presence of Legionella and the total chlorine concentration decrease or/and the increase of the temperature. Cold water resulted free from microbiological hazards, with the exception of Serratia liquefaciens and Enterobacter cloacae isolated at the exit from two different autoclaves. We observed an increase in total microbial counts at 22 and 37°C between the samples collected at the most remote taps compared to the ones collected at the inlet from the aqueduct. The study highlights a condition of potential risk for susceptible categories of population and supports the need for measures of risk assessment and control.
ARTICLE | doi:10.20944/preprints201905.0186.v1
Subject: Life Sciences, Other Keywords: Legionella spp.; residential buildings; waterborne pathogens, water safety plan.
Online: 15 May 2019 (10:36:57 CEST)
Literature data on Legionella spp. presence in houses water networks have been increasing during the last years, but epidemiological reports assert a high incidence of Legionnaires’ disease infection in Italy. Updating our previously published data, we report a five-year survey on Legionella spp. colonization in 235 buildings with an independent hot water production (IB); 82 buildings with a central hot water production (CB); and 58 buildings with a solar thermal system for hot water production (TB). In all the 375 buildings Legionella spp. was researched in hot and cold water samples and microbiological potability standards of cold water were evaluated. Legionella spp. was detected in 27% of the water networks, mostly in CB and TB. We detected correlations between the presence of bacteria and some physical-chemical parameters (low chlorine level and optimal temperature for Legionella spp. growth). Cold water resulted free from microbiological hazards, except for coliform bacteria isolated in three separate cases, and Legionella spp., detected when cold water temperature was about 20°C. After a five-year survey we confirm the presence of a Legionnaires’ disease risk and the need of training programs for all the workers involved in residential water systems management.
ARTICLE | doi:10.20944/preprints201812.0057.v1
Online: 4 December 2018 (10:56:33 CET)
International literature data report that the increase of infectious risk may be due to heating, ventilation and air conditioning (HVAC) systems contaminated by airborne pathogens. Moreover, the presence of complex rotating dehumidification wheels (RDWs) may complicate the cleaning and disinfection procedures of the HVAC systems. We evaluated the efficacy of a disinfection strategy applied to the RDW of two hospitals HVAC systems. Hospitals have 4 RDW systems related to the surgical areas (SA1 and SA2) and to the intensive and sub-intensive cares (IC and sIC). Microbiological air and surfaces analysis were performed in HVAC systems, before and after the disinfection treatment. Hydrogen peroxide (12%) with silver ions (10 mg/L) was aerosolized in all the air sampling points, located close to the RDW device. After the air disinfection procedure, reductions of total microbial counts at 22°C and fungi were achieved in SA2 and IC HVAC systems. An Aspergillus fumigatus contamination (6 CFU/500L), detected in one air sample collected in the IC HVAC system, was eradicated after the disinfection. Surface samples proved a good microbiological quality. Results suggest the need of a disinfection procedure aimed to improve the microbiological quality of the complex HVAC systems, mostly in surgical and intensive care areas.
ARTICLE | doi:10.20944/preprints201702.0063.v1
Subject: Life Sciences, Microbiology Keywords: Hydrogen Peroxide; Legionella; Hospital; Disinfection
Online: 16 February 2017 (18:48:27 CET)
Objectives: To evaluate the effectiveness of hydrogen peroxide (HP) use in the hospital water network disinfection to control Legionella spp. colonization. Methods: Following the detection of high levels of Legionella contamination in a 136-bed general hospital water network, an HP treatment of the hot water (25 mg/L) was adopted. During a period of 34 months, the effectiveness of HP on Legionella colonization was assessed. Legionella was isolated in accordance with ISO-11731 and identification was carried out by sequencing of the mip gene. Results: Before HP treatment L.pneumophila sg 2-15 was isolated in all sites with a mean count of 9950±8279 CFU/L. After one month of HP-treatment, we observed the disappearance of L. pneumophila 2-15, however other Legionella species never cultured before appeared; Legionella pneumophila 1 was isolated in 1 out of 4 sampling sites (2,000 CFU/L) and other non-pneumophila species in all sites (mean load 3,000 ±2887 CFU/L). Starting from September 2013, HP-treatment was modified adding food-grade polyphosphates and in the following months we observed a progressive reduction of the mean load of all species (p<0.05), until to a substantial disappearing of Legionella colonization. Conclusion: Hydrogen peroxide demonstrated a good efficacy in controlling Legionella. Although in the initial phases of treatment it seemed unable to eliminate all the species, by keeping HP levels to 25 mg/L and adding food-grade polyphosphates, a progressive and complete control of colonisation was obtained.