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 on the first floor and on the last floor, while the potable water quality was analysed in three cold water samples collected at the inlet from the aqueduct network, at the exit from the autoclave, and at the most remote tap. Legionella pneumophila sg1, Legionella pneumophila sg2–16, and non-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 and/or 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 °C 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.

Invasive alien species are a major cause of biodiversity loss. Nevertheless, non-native species can also contribute to conservation objectives. In 1673, the red-legged partridge (Alectoris rufa), a galliform native to southwest Europe, was introduced from France (A. r. rufa) into the UK for hunting purposes. Nowadays, hunters constantly supplement natural populations of A. rufa in its native range with stocks of captive-bred individuals. Such birds are usually genetically unscreened, and human-mediated hybridization with the exotic chukar (Alectoris chukar) has undermined genomic integrity of the species. Alectoris rufa in the UK has never been genetically investigated, and birds from East Anglian estates with no modern history of supplementation offer a potential genomic backup for the highly polluted native-range A. r. rufa. We genotyped modern and ancient birds at the mitochondrial DNA (mtDNA) level to determine present and past kinship between East Anglian and native-range A. rufa. We used Short Tandem Repeats (STR) and Random Amplified Polymorphic DNA (RAPD) markers to identify A. rufa 9 A. chukar hybrids. The kinship of East Anglian birds with A. r. rufa was confirmed. No A. chukar introgression was found in ancient East Anglian A. rufa. Among modern partridges, we found birds with A. chukar mtDNA, and both STRs and RAPDs disclosed many A. rufa 9 A. chukar hybrids. While the genetic analysis pointed to the increase of diversity and decline of disparity over time within and among A. rufa populations, respectively, the conservation value of the resource historically introduced to the UK proved to have been quashed by three decades of recent releases of A. chukar and its A. rufa hybrids.

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. Preprints (www.preprints.org) | NOT PEER-REVIEWED |