Draft genome sequences from 127 Legionella spp. strains isolated in water systems linked to legionellosis outbreaks.

Legionnaires' disease is a severe form of pneumonia caused by Legionella spp. bacteria. According to the European Centre for Disease Prevention and Control, problems related to this pathogen showed a significant surge in recent years, making its monitoring critical.

Organic vs. conventional: impact of cultivation treatments on the soil microbiota in the vineyard.

The aim of this study was to compare the effects of two vineyard management practices on the soil and its associated microbiota. The experiments were conducted in two adjacent plots, one completely organically managed and the other conventionally managed in terms of phytosanitary treatments but fertilized with organic amendments. The chemical soil analyses were correlated to the prokaryotic and fungal communities, which were studied using the metabarcoding technique. The main difference between the two treatments was a significantly higher amount of Cu in the organic managed vineyard soil, while conventional managed soil presented higher concentration of Na and Mg and was also associated with higher pH values. Despite these differences, no significant diversities were observed on soil biodiversity and microbial composition considering alpha and beta diversity metrics. However, the percentages of some phyla analyzed individually differed significantly between the two managements. Analyzing the metabolisms of these phyla, it was discovered an increment of species correlated to soils with higher organic matter content or land not used for agricultural purposes in the organic treated soil. The findings indicate that, despite the use of copper-based phytosanitary products, there was no degradation and loss of biodiversity in the organic soil microbial population compared to conventional management with the same type of fertilization, and the observed microbial population was more similar to that of natural soils.

Environmental surveillance and spatio-temporal analysis of Legionella spp. in a region of northeastern Italy (2002-2017).

Legionella spp. are considered an important cause of potentially preventable morbidity and mortality, making environmental surveillance a crucial component of risk assessment plans. In this work, 20,319 water samples were collected in 3,983 environmental surveys during a 16-year period by ARPA, the Regional Agency for Environmental Protection, Friuli Venezia Giulia, and the results were studied to better understand the diffusion mechanisms of Legionella. The data showed a strong seasonal signal, a prevalence of L. pneumophila serogroup 2-15 in most environments (63% of positive samples), a prevalence of L. pneumophila serogroup 1 in swimming pool-associated environments (82% of positive samples), a persistent presence of Legionella in hospitals and a recurrent presence of Legionella in other facilities such as hotels, possibly years after interventions, highlighting the difficulty of eradicating the bacteria. Retrospective spatio-temporal analyses on geocoded historical data were carried out with SaTScan using an ordinal model with risk as a covariate to identify potential clusters with an excess of cases in the higher-risk categories. Although no outbreaks occurred during the period of study, such analyses identified spatially restricted zones with unusual contamination, which sometimes were also areas in which several surveys triggered by notifications of clinical cases were performed. Simulations of periodic prospective analyses permitted the assessment of the efficacy of the method in early detection of such clusters. The proposed method may be a useful tool in environmental surveillance, prevention and control of Legionella.

Identification and characterization of bacteria isolated under selective pressure of volatile organic compounds.

Several bacterial strains tolerant to volatile organic compounds (VOCs) were isolated from the air emissions of a typical industrial wood painting plant. Four strains that grew vigorously on a mineral salt basal medium and VOC-saturated atmosphere were identified using BIOLOG and fatty acids analysis. A 16S rDNA sequence comparison was also performed on three of the four strains. Their phylogenetic positions were respectively: MC8M6 of the genus Arthrobacter MCEP3 of the genus Microbacterium, MCEPFL2 of the genus Rhodococcus. The fourth strain, C14, was identified as Pseudomonas aeruginosa. All the four strains showed multiple carbon sources among toluene, butyl acetate, ethoxy propyl acetate, isobutyl alcohol, ethyl acetate, diaceton alcohol, methyl ethyl ketone, methyl isobutyl ketone. By identifying a particular strain, an evaluation of its risk group can be made by comparing it to each strain type within important world-wide culture collections. This is the first step required to implement correct procedures using the strains and in implementing the appropriate biosafety containment in large scale applications.

Detection of aromatic catabolic gene expression in heterogeneous organic matter used for reduction of volatile organic compounds (VOC) by biofiltration.

A qualitative procedure of purified DNA/RNA co-extraction from complex organic matter, used as biofilter support for removing volatile organic compounds, was set up and applied to detect xylene monooxygenase gene expression by RT-PCR. A DNA/RNA extraction protocol based on a combination of sample lyophilization pre-treatment and CTAB--phenol/chloroform extraction procedure was optimized for the recovery of purified nucleic acids [100-500 ng DNA (10 kb) and 0.5-2 microg of rRNA 16S from 100 mg matrix]. PCR and RT-PCR protocols were established to detect xylene monooxygenase gene expression starting from differentially induced organic matrices obtained by biofiltration technology. This work allowed the microbial degradation activities in heterogeneous organic solid media to be studied and suggests a rapid method to follow specific biological activities during solid and/or semisolid organic substrates biotransformation.

Multiple microbial activities for volatile organic compounds reduction by biofiltration.

In the northeast of Italy, high volatile organic carbon (VOC) emissions originate from small-medium companies producing furniture. In these conditions it is difficult to propose a single, efficient, and economic system to reduce pollution. Among the various choices, the biofiltration method could be a good solution, because microbial populations possess multiple VOC degradation potentials used to oxidize these compounds to CO2. Starting from the air emissions of a typical industrial wood-painting plant, a series of experiments studied in vitro microbial degradation of each individual VOC. Isolated strains were then added to a laboratory-scale biofiltration apparatus filled with an organic matrix, and the different VOC behavior demonstrated the potential of single and/or synergic microbial removal actions. When a single substrate was fed, the removal efficiency of a Pseudomonas aeruginosa inoculated reactor was 1.1, 1.17, and 0.33 g m(-3) hr(-1), respectively, for xylene, toluene, and ethoxy propyl acetate. A VOC mixture composed of butyl acetate, ethyl acetate, diacetin alcohol, ethoxy propanol acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, and xylene was then fed into a 2-m(3) reactor treating 100 m3 hr(-1) of contaminated air. The reactor was filled with the same mixture of organic matrix, enriched with all of the isolated strains together. During reactor study, different VOC loading rates were used, and the behavior was evaluated continuously. After a short acclimation period, the removal efficiency was > 65% at VOC load of 150-200 g m(-3) hr(-1). Quantification of removal efficiencies and VOC speciation confirmed the relationship among removal efficiencies, compound biodegradability, and the dynamic transport of each mixture component within the organic matrix. Samples of the fixed bed were withdrawn at different intervals and the heterogeneous microbial community evaluated for both total and differential compound counts.