Reconstruction of the parental origins of cultivated plants from wild relatives, especially after long periods of domestication, is not a trivial task. However, recent advances in molecular phylogenetics, among other approaches, have proved to be very informative in analyses of the origin and evolution of polyploid genomes. An established minor garden crop, triploid onion Allium x cornutum (Clementi ex Visiani, 1842) (2n = 3x = 24), is widespread in southeastern Asia and Europe. Our previous cytogenetic analyses confirmed its highly heterozygous karyotype and indicated its possible complex triparental genome origin. Allium cepa L. and Allium roylei Stearn were suggested as two putative parental species of A. x cornutum, whereas the third parental species remained hitherto unknown.
During an environmental study of bacterial resistance to antibiotics in coastal waters of the Kaštela Bay, Adriatic Sea, Croatia, 47 Burkholderia cepacia complex (Bcc) isolates were recovered from seawater and mussel (Mytilus galloprovincialis) samples. All isolates showed multiple antibiotic resistance. Among the isolates, two Burkholderia cenocepacia isolates produced chromosomally encoded TEM-116 extended-spectrum β-lactamase (ESBL). Analysis of outer membrane proteins revealed that decreased expression of a 36-kDa protein could be associated with a high level of β-lactam resistance in both isolates. Phenotypic study of efflux system also indicated an over-expression of Resistance-Nodulation-Cell Division (RND) efflux-mediated mechanism in one of the isolates. This study demonstrated the presence of Bcc inseawater and M. galloprovincialis, which gives evidence that coastal marine environment, including mussels, could be considered as a reservoir for Bcc species. Detection of ESBL-encoding genes indicates the potential role of these bacteria in the maintenance and dispersion of antibiotic resistance genes.
The role of marine environments in the global spread of antibiotic resistance still remains poorly understood, leaving gaps in the One Health-based research framework. Antibiotic resistance genes (ARGs) encoding resistance to five major antibiotic classes, including sulfonamides (sul1, sul2), tetracyclines (tetA, tetB), β-lactams (blaCTX-M, blaTEMblaVIM), macrolides (ermB, mphA), aminoglycosides (aac3-2), and integrase gene (intl1) were quantified by RT-qPCR, and their distribution was investigated in relation to environmental parameters and the total bacterial community in bottom layer and surface waters of the central Adriatic (Mediterranean), over a 68 km line from the wastewater-impacted estuary to coastal and pristine open sea. Seasonal changes (higher in winter) were observed for antibiotic resistance frequency and the relative abundances of ARGs, which were generally higher in eutrophic coastal areas. In particular, intl1, followed by blaTEM and blaVIM, were strongly associated with anthropogenic influence and Gammaproteobacteria as their predominant carriers. Water column stratification and geographic location had a significant influence on ARGs distribution in the oligotrophic zone, where the bacterial community exhibited a seasonal shift from Gammaproteobacteria in winter to Marine group II in summer.