Fungal endophytes from two orchid species pointer towards organ specificity

Fungal endophytes may influence plant communities by altering the host's fitness either positively or negatively. Little is known, however, about their host/organ specificity, life style and role in plantfungus symbiosis under varying environmental conditions. We compared the leaf and root endophyte assemblages of two orchids (Bulbophyllum neilgherrense and Pholidota pallida) from natural forests and greenhouse conditions. Xylariaceae species were consistently associated with leaf and root tissues, while Guignardia and Pestalotiopsis were found predominantly in the leaf tissues of both orchids. Correspondence analysis of the endophyte assemblages showed that the endophytes exhibited distinct organ but little host specificity. More endophytes were shared by the two different orchids growing in the same location when compared to endophyte assemblages of a single orchid from different locations. Considering the influence of endophytes in shaping the host's community, diverse habitats must be screened vigorously to address questions regarding the role of endophytes in hostendophyte interactions. Rostlinná společenstva mohou být ovlivněna působením houbových endofytů, které se odráží ve změnách fitness jejich hostitelů, ať už pozitivních či negativních. Avšak málo je známo o hostitelské či orgánové specificitě endofytů, jejich životním stylu a roli v symbiotickém vztahu s rostlinou při růz-ných podmínkách prostředí. Autoři srovnávali společenstva listových a kořenových endofytů dvou orchidejí (Bulbophyllum neilgherrense a Pholidota pallida), rostoucích v přirozených lesích a sklení-kových podmínkách. Druhy z čeledi Xylariaceae byly pevně spjaty s listovými i kořenovými pletivy, zatímco druhy rodů Guignardia a Pestalotiopsis jsou nacházeny převážně v listových pletivech obou orchidejí. Korespondenční analýza společenstev endofytů ukázala, že tyto houby vykazují zřetelnou orgánovou specificitu, ale nízkou specificitu hostitelskou. Vice společných endofytů měly dvě různé orchideje rostoucí na společné lokalitě ve srovnání se společenstvy endofytů jednotlivých rostlin z různých lokalit. Vzhledem k vlivu endofytů na utváření společenstev svých hostitelů bude ještě potřebný důsledný průzkum různých substrátů pro ozřejmení role endofytů v interakcích s jejich hostiteli

Genome Based Taxonomic Classification

Bacterial populations are routinely characterized based on the microscopic examination, colony formation and biochemical tests. However, in recent past, bacterial identification, classification and nomenclature have been strongly influenced by genome sequence information. Advances in bioinformatics and growth in genome databases has placed genome-based metadata analysis in the hands of researchers who will require taxonomic experience to resolve intricacies. To achieve this, different tools are now available to quantitatively measure genome relatedness within members of the same species and genome-wide average nucleotide identity (gANI) is one such reliable tool to measure genome similarity. A genome assembly showed gANI score ofThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Characteristics of microbial drug resistance and its correlates in chronic diabetic foot ulcer infections

Free to read While virulence factors and the biofilm-forming capabilities of microbes are the key regulators of the wound healing process, the host immune response may also contribute in the events following wound closure or exacerbation of non-closure. We examined samples from diabetic and non-diabetic foot ulcers/wounds for microbial association and tested the microbes for their antibiotic susceptibility and ability to produce biofilms. A total of 1074 bacterial strains were obtained with staphylococci, Pseudomonas, Citrobacter and enterococci as major colonizers in diabetic samples. Though non-diabetic samples had a similar assemblage, the frequency of occurrence of different groups of bacteria was different. Gram-negative bacteria were found to be more prevalent in the diabetic wound environment while Gram-positive bacteria were predominant in non-diabetic ulcers. A higher frequency of monomicrobial infection was observed in samples from non-diabetic individuals when compared to samples from diabetic patients. The prevalence of different groups of bacteria varied when the samples were stratified according to age and sex of the individuals. Several multidrug-resistant strains were observed among the samples tested and most of these strains produced moderate to high levels of biofilms. The weakened immune response in diabetic individuals and synergism among pathogenic micro-organisms may be the critical factors that determine the delicate balance of the wound healing process