Plasmids profiles, antibiotic and heavy metal resistance incidence of endophytic bacteria isolated from grapevine (Vitis vinifera L.)

Little is known about the bacterial communities associated with the plant inhabiting desert ecosystem. In this study, the bacterial population associated with grapevine (Vitis vinifera L.) plant, growing desertsoil was analyzed using the culture dependent approach. A total of 111 bacterial isolates were isolated from stems and leaves samples, collected from different locations and subjected to further analyses. Based on the identification methods, the bacterial isolates were grouped into 14 genera. The main genera are Acetobacter, Acinetobacter, Citrobacter, Enterobacter, Erwinia, Escherichia, Methylococcus, Xanthomonas, Vibrio, Bacillus, Micrococcus, Planococcus, Staphylococcus and Streptomyces.Significant differences in the endophytic communities were observed between plants collected from different sites and also between plant stems and leaves. All the isolates were examined for plasmid DNA content and resistance to antibiotics (Ampicillin, Kanamycin, Tetracyclin) and heavy metals. Minimum inhibitory concentrations (MICs) of Cu, Cd, Hg, Mn, Ni and Zn for isolates were also determined. Resistance was most frequent to Ampicillin (57%), followed by Kanamycin (53%) and Tetracycline (26%). The highest MICs observed were 10 ìg/ml for mercury, 50 ìg/ml for Cu and Cd and 200 ìg/ml for other metals. On a percentage basis, 18.48% of total strains from leaves were found to harbour plasmids, whereas, 11.83% of the roots isolates contained plasmids

β-Lactamase Production in Key Gram-Negative Pathogen Isolates from the Arabian Peninsula

Infections due to Gram-negative bacilli (GNB) are a leading cause of morbidity and mortality worldwide. The extent of antibiotic resistance in GNB in countries of the Gulf Cooperation Council (GCC), namely, Saudi Arabia, United Arab Emirates, Kuwait, Qatar, Oman, and Bahrain, has not been previously reviewed. These countries share a high prevalence of extended-spectrum-β-lactamase (ESBL)- and carbapenemase-producing GNB, most of which are associated with nosocomial infections. Well-known and widespread β-lactamases genes (such as those for CTX-M-15, OXA-48, and NDM-1) have found their way into isolates from the GCCstates. However, less common and unique enzymes have also been identified. These include PER-7, GES-11, and PME-1. Several potential risk factors unique to the GCC states may have contributed to the emergence and spread of β-lactamases, including the unnecessary use of antibiotics and the large population of migrant workers, particularly from the Indian subcontinent. It is clear that active surveillance of antimicrobial resistance in the GCC states is urgently needed to address regional interventions that can contain the antimicrobial resistance issue