Genomic characterization and assessment of pathogenic potential of Legionella spp. isolates from environmental monitoring

Several species in the genus Legionella are known to cause an acute pneumonia when the aerosols containing the bacteria from man-made water systems are inhaled. The disease is usually caused by Legionella pneumophila, but other species have been implicated in the infection. The disease is frequently manifested as an outbreak, which means several people are affected when exposed to the common source of Legionella contamination. Therefor environmental surveillance which includes isolation and identification of Legionella is performed routinely. However, usually no molecular or genome-based methods are employed in further characterization of the isolates during routine environmental monitoring. During several years of such monitoring, isolates from different geographical locations were collected and 39 of them were sequenced by hybrid de novo approach utilizing short and long sequencing reads. In addition, the isolates were typed by standard culture and MALDI-TOF method. The sequencing reads were assembled and annotated to produce high-quality genomes. By employing discriminatory genome typing, four potential new species in the Legionella genus were identified, which are yet to be biochemically and morphologically characterized. Moreover, functional annotations concerning virulence and antimicrobial resistance were performed on the sequenced genomes. The study contributes to the knowledge on little-known non-pneumophila species present in man-made water systems and establishes support for future genetic relatedness studies as well as understanding of their pathogenic potential

Magnetska rezonancija - novi pristup u istraživanju ugroženih morskih školjkaša

Magnetic Resonance Imaging (MRI) is increasingly used in biology and the appearance of such imaging and structural findings devoted to endangered marine bivalves shows the recent keen interest in these research techniques. New imaging techniques are ideal for understanding the normal form of soft structures (e.g. gonad, stomach, digestive gland, muscle, gills), and identifying anatomical positions and landmarks of structures in vivo. Because of its biological importance, endangered bivalve mollusks are the subject of much research in physiology. In terms of protection of species, it seemed necessary to perform a preliminary technological evaluation of the MRI possibilities. Aim of this research was to make a preliminary exploration of the possibilities and limits of MRI for assessing anatomical structures and gonad development of the date mussel, Lithophaga lithophaga L., an endangered bivalve from Adriatic sea. This paper presents a new imaging technique used in comparative morphology, with examples of recent applications, and will present original research demonstrating a use of this technique to investigate morphological structures in endangered species. This report therefore presents the preliminary results on MR imaging of the date mussel. From the obtained images, variations in the volumes of the flesh, digestive gland, gonad and adductor muscle, and the surface of the gills could be measured during growth. Gonad measurement by MRI presents a non-destructive method and therefore makes it possible to assess live individual development as well as to compare live individuals.Magnetska rezonancija (MR) sve se više koristi u istraživanjima na području biologije. Upotreba i implementiranje ove metode u svrhu nedestruktivnog proučavanja anatomije i fiziologije ugroženih vrsta morskih školjkaša daje veliki značaj ovakvim istraživačkim tehnikama. Nove moderne tehnologije omogućavaju bolje razumijevanje građe i oblika mekih struktura (npr. gonade, želudac, probavna žlijezda, mišići, škrge), te prepoznavanje anatomskih odlika i međusobni odnos organa kod živih školjkaša. Zbog svoje biološke važnosti, ugrožene vrste školjkaša predmet su mnogih istraživanja. U okviru zaštite vrsta, potrebno je izvršiti preliminarnu procjenu tehnoloških mogućnosti MR. Cilj ovog istraživanja je napraviti prikaz mogućnosti i ograničenja primjene MR u procjeni anatomskih struktura i razvoju gonada kod prstaca, Lithophaga lithophaga L., zaštićenog školjkaša iz Jadranskog mora. Ovaj rad predstavlja primjenu moderne tehnologije u svrhu istraživanja komparativne anatomije te je, uz dosadašnja saznanja, predstavljen originalan način kako bi se istražile morfološke osobitosti ugroženih vrsta. Ovo izvješće obuhvaća preliminarne MR snimke prstaca. Na dobivenim fotografijama moguće je razlučiti i izračunati indekse mase mišića, funkciju probavne žlijezde, gonada i aduktornih mišića te škrga u različitom razdoblju razvoja školjkaša. Primjenom ove nedestruktivne metode u svrhu mjerenja rasta gonada i spolnog sazrijevanja prstaca moguće je procijeniti individualni razvoj, kao i usporediti pojedine žive jedinke