Bacterial Genomics and Epidemiology.

Innovative technologies for Whole-Genome Sequencing (WGS) help to improve our understanding of the epidemiology and pathogenesis of bacterial infectious diseases and are becoming affordable for most microbiological laboratories [...

A Practical Bioinformatics Workflow for Routine Analysis of Bacterial WGS Data.

The use of whole-genome sequencing (WGS) for bacterial characterisation has increased substantially in the last decade. Its high throughput and decreasing cost have led to significant changes in outbreak investigations and surveillance of a wide variety of microbial pathogens. Despite the innumerable advantages of WGS, several drawbacks concerning data analysis and management, as well as a general lack of standardisation, hinder its integration in routine use.

Fungal Diversity and Composition of the Continental Solar Saltern in Añana Salt Valley (Spain).

The Añana Salt Valley in Spain is an active continental solar saltern formed 220 million years ago. To date, no fungal genomic studies of continental salterns have been published, although DNA metabarcoding has recently expanded researchers' ability to study microbial community structures. Accordingly, the aim of this present study was to evaluate fungal diversity using the internal transcribed spacer (ITS) metabarcoding at different locations along the saltern (springs, ponds, and groundwater) to describe the fungal community of this saline environment.

Molecular Epidemiology, Antimicrobial Surveillance, and PK/PD Analysis to Guide the Treatment of Infections.

The aim of this study was to apply molecular epidemiology, antimicrobial surveillance, and PK/PD analysis to guide the antimicrobial treatment of gonococci infections in a region of the north of Spain. Antibiotic susceptibility testing was performed on all isolates (2017 to 2019, = 202). A subset of 35 isolates intermediate or resistant to at least two antimicrobials were selected to search for resistance genes and genotyping through WGS.

sp. nov., isolated from hypersaline Añana Salt Valley spring water, a continental thalassohaline-type solar saltern.

A novel salt-tolerant alpha-proteobacterium, designated SALINAS58, was isolated from Santa Engracia hypersaline spring water in the Añana Salt Valley, Álava, Spain. The isolate was Gram-negative, aerobic, non-motile, catalase-positive, oxidase-negative, rod-shaped and formed orange colonies on marine agar. Optimal growth was observed at pH 6.

Genotyping Study of 4,[5],12:i:- Monophasic Variant of Serovar Typhimurium and Characterization of the Second-Phase Flagellar Deletion by Whole Genome Sequencing.

After Enteritidis and Typhimurium, 4,[5],12:i:- is the most reported serovar in human clinical cases. During the past 20 years, many tools have been used for its typing and second-phase flagellar deletion characterization. Currently, whole genome sequencing (WGS) and different bioinformatic programs have shown the potential to be more accurate than earlier tools.

Virulotyping of Salmonella enterica serovar Typhi isolates from Pakistan: Absence of complete SPI-10 in Vi negative isolates.

The pathogenesis of Salmonella enterica serovar Typhi (S. Typhi), the cause of typhoid fever in humans, is mainly attributed to the acquisition of horizontally acquired DNA elements. Salmonella pathogenicity islands (SPIs) are indubitably the most important form of horizontally acquired DNA with respect to pathogenesis of this bacterium.

Antimicrobial susceptibility and MLVA analysis of S. Typhimurium strains isolated from human and poultry samples in Tunisia.

Introduction: Salmonella enterica infections are a significant public health concern worldwide, being Salmonella Typhimurium one of the most prevalent serovars. Human salmonellosis is typically associated with the consumption of contaminated foods, such as poultry, eggs and processed meat. The extensive use of antimicrobials in humans and animals has led to an increase in multidrug resistance among Salmonella strains, becoming multidrug-resistant (MDR) strains a major public health concern.

Draft Genome Sequence of an Oceanobacillus sp. Strain Isolated from Soil in a Burial Crypt.

We present the draft genome of an Oceanobacillus sp. strain isolated from spores found in soil samples from a burial crypt of the Cathedral of Sant'Antonio Abate in Castelsardo, Italy. The data obtained indicated the closest relation of the strain with Oceanobacillus caeni.

Aspergillus fumigatus transcriptome response to a higher temperature during the earliest steps of germination monitored using a new customized expression microarray.

Aspergillus fumigatus is considered to be the most prevalent airborne pathogenic fungus and can cause invasive diseases in immunocompromised patients. It is known that its virulence is multifactorial, although the mechanisms of pathogenicity remain unclear. With the aim of improving our understanding of these mechanisms, we designed a new expression microarray covering the entire genome of A.

Reprint of "Identification of staphylococcal species based on variations in protein sequences (mass spectrometry) and DNA sequence (sodA microarray)".

This report is among the first using sequence variation in newly discovered protein markers for staphylococcal (or indeed any other bacterial) speciation. Variation, at the DNA sequence level, in the sodA gene (commonly used for staphylococcal speciation) provided excellent correlation. Relatedness among strains was also assessed using protein profiling using microcapillary electrophoresis and pulsed field electrophoresis.

Online exercise for the design and simulation of PCR and PCR-RFLP experiments.

Background: Polymerase Chain Reaction (PCR) and Restriction Fragment Length Polymorphism of PCR products (PCR-RFLP) are extensively used molecular biology techniques. An exercise for the design and simulation of PCR and PCR-RFLP experiments will be a useful educational tool.

Findings: An online PCR and PCR-RFLP exercise has been create that requires users to find the target genes, compare them, design primers, search for restriction endonucleases, and finally to simulate the experiment.

Identification of staphylococcal species based on variations in protein sequences (mass spectrometry) and DNA sequence (sodA microarray).

This report is among the first using sequence variation in newly discovered protein markers for staphylococcal (or indeed any other bacterial) speciation. Variation, at the DNA sequence level, in the sodA gene (commonly used for staphylococcal speciation) provided excellent correlation. Relatedness among strains was also assessed using protein profiling using microcapillary electrophoresis and pulsed field electrophoresis.

The aspHS gene as a new target for detecting Aspergillus fumigatus during infections by quantitative real-time PCR.

Invasive aspergillosis (IA) is a serious nosocomial infection caused by Aspergillus spp. which has a high mortality rate due to the fact, among other factors, that it is difficult to diagnose. Within the Aspergillus genus, A.

Intra- and inter-laboratory evaluation of an improved multiplex-PCR method for detection and typing of Salmonella.

Introduction: We developed and evaluated a multiplex-PCR method for rapid detection of the most common Salmonella serovars in both developed and developing countries. Additionally, the stability of the premixed reagents at high room temperature was studied.

Methodology: Fifty-two Salmonella strains belonging to the collections of the University of Sassari, Italy, and to the University of the Basque Country, Spain, and a collection of a hundred blinded strains, were used to evaluate the multiplex-PCR.

What makes Aspergillus fumigatus a successful pathogen? Genes and molecules involved in invasive aspergillosis.

Aspergillus fumigatus is an opportunistic pathogen that causes 90% of invasive aspergillosis (IA) due to Aspergillus genus, with a 50-95% mortality rate. It has been postulated that certain virulence factors are characteristic of A. fumigatus, but the "non-classical" virulence factors seem to be highly variable.

Genetic evolution of the Spanish multidrug-resistant Salmonella enterica 4,5,12:i:- monophasic variant.

We analyzed a collection of 60 Salmonella enterica 4,5,12:i:- phage type U302 multidrug-resistant monophasic variant strains, isolated in Spain between 2000 and 2007. Most strains showed resistance to ampicillin (A), chloramphenicol (C), sulfamethoxazole (Su), gentamicin (G), streptomycin (S), tetracycline (T), and co-trimoxazole (SxT) (an ACSuGSTSxT resistance pattern). Only one pulsed-field gel electrophoresis (PFGE) type was detected, with 19 subtypes (Simpson's index of diversity [SID]=0.

Validation of double digest selective label database for sequenced prokaryotic genomes.

Summary: A database for simulation of double digest selective label (DDSL) typing technique has been created and validated against a sequenced strain (Salmonella enterica serovar Typhimurium strain LT2). In silico bands were in agreement with experimental, and the technique was able to discriminate among strains belonging to the same species. When compared with other strain discrimination techniques, DDSL showed a higher discriminatory power.

Evaluation of molecular typing methods in characterizing a European collection of epidemic methicillin-resistant Staphylococcus aureus strains: the HARMONY collection.

We analyzed a representative sample of methicillin-resistant Staphylococcus aureus (MRSA) from 11 European countries (referred to as the HARMONY collection) using three molecular typing methods used within the HARMONY group to examine their usefulness for large, multicenter MRSA surveillance networks that use these different laboratory methodologies. MRSA isolates were collected based on their prevalence in each center and their genetic diversity, assessed by pulsed-field gel electrophoresis (PFGE). PFGE groupings (< or = 3 bands difference between patterns) were compared to those made by sequencing of the variable repeats in the protein A gene spa and clonal designations based on multilocus sequence typing (MLST), combined with PCR analysis of the staphylococcal chromosome cassette containing the mec genes involved in methicillin resistance (SCCmec).

Use of DNA microarray technology and gene expression profiles to investigate the pathogenesis, cell biology, antifungal susceptibility and diagnosis of Candida albicans.

The use of DNA microarrays is becoming the method of choice for assaying gene expression, particularly as costs and complexity are being reduced as the technology becomes more widespread and better standardized. A DNA array is nothing but a collection of probes fixed on a solid support. The probes can be PCR products of ORFs or short intragenic oligonucleotides deposited or synthesized in situ by photolithographic methods.

Kefir: a symbiotic yeasts-bacteria community with alleged healthy capabilities.

Kefir is a fermented milk beverage. The milk fermentation is achieved by the of kefir grains, a cluster of microorganisms held together by a polysaccharide matrix named kefiran. Kefir grains are an example of symbiosis between yeast and bacteria.

DNA microarray technology: a new tool for the epidemiological typing of bacterial pathogens?

Genomic hybridization on whole genome arrays detects the presence or absence of similar DNA regions in sufficiently related microorganisms, allowing genome-wide comparison of their genetic contents. A whole genome array is based on a sequenced bacterial isolate, and is a collection of DNA probes fixed on a solid support. In a single hybridization experiment, the absence/presence status of all genes of the sequenced microbe in the queried isolate can be examined.

In silico simulation of fingerprinting techniques based on double endonuclease digestion of genomic DNA.

Unlabelled: We have developed an online generic tool for simulation of fingerprinting techniques based on the double endonuclease digestion of DNA. This tool allows modelling and modifications of already existing techniques, as well as new theoretical approaches not yet tried in the lab. It allows the use of any combination of recognition patterns and discrimination of end types yielded by restriction with non palindromic recognition sizes.