Molecular approach to characterize ectomycorrhizae fungi from Mediterranean pine stands in Portugal

Abstract

Stone pine (Pinus pinea L.), like other conifers, forms ectomycorrhizas (ECM), which have beneficial impact on plant growth in natural environments and forest ecosystems. An in vitro co-culture of stone pine microshoots with pure mycelia of isolated ECM sporocarps was used to overcome the root growth cessation not only in vitro but also to improve root development during acclimation phase. Pisolithus arhizus (Scop.) Rauschert and Lactarius deliciosus (L. ex Fr.) S.F. Gray fungi, were collected, pure cultured and used in in vitro co-culture with stone pine microshoots. Samples of P. arhizus and L. deliciosus for the in vitro co-cultures were collected from the pine stands southwest Portugal. The in situ characterization was based on their morphotypes. To confirm the identity of the collected material, ITS amplification was applied using the pure cultures derived from the sporocarps. Additionally, a molecular profile using PCR based genomic fingerprinting comparison was executed with other genera of Basidiomycetes and Ascomycetes. Our results showed the effectiveness of the techniques used to amplify DNA polymorphic sequences, which enhances the characterization of the genetic profile of ECM fungi and also provides an option to verify the fungus identity at any stage of plant mycorrhization.

Prevalence, serotyping and antimicrobials resistance mechanism of Salmonella enterica isolated from clinical and environmental samples in Saudi Arabia

“…There are several evidences underpin that the antibiotics resistance among Salmonella strains is attributed to intensive use of antibiotics as growth promoters in animals feeding 8 . Moreover, the intensive use of antimicrobial agents to treat both animal and human infections led to flourish the horizontal resistance genes transfer between bacterial communities 9 .…”

Tolerance response of multidrug-resistant Salmonella enterica strains to habituation to Origanum vulgare L. essential oil

“…Salmonella enterica presents a dynamic interaction with host and environment and has a high genetic variability related to the development of different antimicrobial resistance mechanisms ( Ferrari et al, 2013a ; Du et al, 2014 ). The serovars S. Enteritidis and S. Typhimurium are frequently cited as more tolerant to many antimicrobials agents when compared to other Salmonella serovars ( Souza et al, 2011 ; Ferrari et al, 2013b ; Ballesté-Delpierre et al, 2014 ).…”

“…However, in the present study MIC values of OVEO and CIP were higher against S. Corvallis 297 when compared to the values against S. Enteritidis 209 and S. Typhimurium 149. The presence of qnr B19 gene in S. Corvalis 297 ( Ferrari et al, 2013a ), a well-known mechanism of resistance to quinolone in Salmonella , could be related to the higher tolerance of the strains to the substances that were tested.…”

“…The strains were resistant to aminoglycosides (gentamicin and streptomycin); β-lactams (ampicillin and cefotaxime); quinolones (norfloxacin and nalidixic acid), and sulphametoxazole-trimethoprim. The strains were characterized according to their quinolone resistance mechanism(s) as described in Table 1 ( Souza et al, 2011 ; Ferrari et al, 2013a , b ). Stock cultures were kept at 4 C before use.…”

“…Ciprofloxacin (CIP) is a 2 nd generation quinolone, is one of the first-choice agents used to treat salmonellosis. However, a significant rise in the number of Salmonella strains with reduced susceptibility to this antibiotic has been observed in humans and food involved outbreaks ( Ferrari et al, 2013a ; Rushdy et al, 2013 ; Ballesté-Delpierre et al, 2014 ).…”