Search results for "Bacterial typing"
showing 10 items of 125 documents
Pheno-genotyping of Salmonella enterica serotype Enteritidis isolates identified in Sicily during a reemergence period.
2005
After an upward trend paralleling that occurring in most European countries, including Italy, since October 2002 Salmonella enterica serotype Enteritidis (S. Enteritidis) has again gained the first position among outbreak and sporadic human isolates of Salmonella in Sicily. Because phage typing of S. Enteritidis has many technical and epidemiological limitations and molecular methods have proved to be poorly discriminative for this organism, multiple typing, using phage typing together with pulsed field gel electrophoresis (PFGE) and plasmid profiling on a sample of fifty human and poultry isolates identified during the period October 2002 to May 2003 in Sicily, was chosen as the most valua…
Use of TaqMan® real-time PCR for rapid detection of Salmonella enterica serovar Typhi
2014
We evaluated the performances of a newly designed real-time polymerase chain reaction (PCR) assay using TaqMan® probes to detectSalmonellaTyphi. TaqMan® real-time PCR assays were performed by designed primers and probe based on thestaGgene for detectingS.Typhi. The specificity of the assay was evaluated on 15Salmonellaserovars. The analytical specificity was evaluated on 20 non-Salmonellamicroorganisms. The analytical sensitivity was assessed using decreasing DNA quantities ofS.Typhi ATCC 19430. Finally the detection capability of the TaqMan® real-time PCR assay on isolates recovered from patients withSalmonellainfections was compared to the conventional PCR assay. OnlyS.Typhi strain had po…
Evaluation of a modified single-enzyme amplified fragment length polymorphism (SE-AFLP) technique for subtyping Salmonella enterica serotype Enteriti…
2006
Salmonella enterica subsp. enterica serotype Enteritidis is not readily subtyped beyond the level of phage type (PT). Pulsed field gel electrophoresis (PFGE) is generally acknowledged to be the most discriminating typing method for Salmonella, but only a restricted variety of PFGE types has been described for S. enterica serotype Enteritidis. In the present study, a modification of the SE-AFLP typing method was used to investigate both outbreak and apparently sporadic isolates of S. enterica serotype Enteritidis belonging to different PTs and/or PFGE types. The method proved to be as discriminatory as PFGE when combined with phage typing, and provided subtyping data consistent with epidemio…
Distribution and characteristics of Listeria monocytogenes isolates from surface waters of the South Nation River Watershed, Ontario, Canada
2007
ABSTRACT Listeria monocytogenes is a facultative intracellular pathogen thought to be widely distributed in the environment. We investigated the prevalence and characteristics of L. monocytogenes isolates from surface waters derived from catchments within the South Nation River watershed (Ontario, Canada). This watershed is dominated by urban and rural development, livestock and crop production, and wildlife habitats. From June to November 2005, a total of 314 surface water samples were collected biweekly from 22 discrete sampling sites characterized by various upstream land uses. Presumptive Listeria spp. were isolated using a selective enrichment and isolation procedure, and 75 L. monocyt…
Molecular Typing Reveals Frequent Clustering among Human Isolates of Listeria monocytogenes in Italy
2009
In Italy, the annual incidence of reported cases of listeriosis amounts in recent years (2004 to 2006) to 0.8 cases per million inhabitants. Our study is a subtyping analysis by serotyping, ribotyping, and pulsed-field gel electrophoresis analysis of 44 human isolates from apparently sporadic cases of infection in the Lombardy region and in the Province of Florence, Italy, in the years 1996 to 2007. Based on the results of the different subtyping methods, 10 occasions were detected when strains of L. monocytogenes with the same subtype were isolated from more than one listeriosis case. A total of 28 (66.7%) out of 44 isolates were attributed to molecular subtype clusters. Our data support t…
Molecular Epidemiological Survey ofCitrobacter freundiiMisidentified asCronobacterspp. (Enterobacter sakazakii) andEnterobacter hormaecheiIsolated fr…
2011
A total of 75 powdered infant milk formula (PIF) samples collected from pharmacies and drugstores in Western Sicily, Italy, and representative of 12 different brands were analyzed in this study to evaluate their microbiological quality. According to the U.S. Food and Drug Administration protocol, 32 samples out of 75 were contaminated by enterobacteria. Commercial biochemical API(r) 20E-system identification method indicated that six PIF samples were presumptively contaminated by Cronobacter spp., but further characterization by alpha-glucosidase based polymerase chain reaction (PCR) assay identification strongly suggested that these strains did not belong to the genus Cronobacter. Phylogen…
PFGE: importance in food quality.
2010
In late 19 century, great interest has arisen for food quality. This is referred as absence of pathogens in food (safety for consumers) and as nutritional quality of food (organoleptic characteristics). Pulsed-field gel electrophoresis (PFGE) is, among the molecular techniques developed in the last years, one of the most reliable, discriminative and reproducible technique. It can be used in clinical field for the identification of pathogens and the origin of outbreaks, and in food microbiology for the identification of pathogens (food borne disease surveillance) or of microorganisms responsible for the organoleptic characteristics of food. The present article shows some useful patents relat…
THE FINGERPRINT OF THE HUMAN GASTROINTESTINAL TRACT MICROBIOTA: A HYPOTHESIS OF MOLECULAR MAPPING
2017
The precise etiology of Inflammatory Bowel Disease (IDB) remains unclear and several factors are believed to play a role in its development and progression, including the composition of microbial communities resident in the gastrointestinal tract. Human intestinal microbiota are extensive with at least 15,000-36,000 bacterial species. However, thanks to the new development in sequencing and molecular taxonomic methodologies, our understanding of the microbiota population composition, dynamics, and ecology has greatly increased. Intestinal microbiota play a critical role in the maintenance of the host intestinal barrier homeostasis, while dysbiosis, which involves reduction in the microbiome…
Shigella sonnei biotype g carrying class 2 integrons in southern Italy: a retrospective typing study by pulsed field gel electrophoresis
2006
Abstract Background Emergence and global dissemination of multiresistant strains of enteric pathogens is a very concerning problem from both epidemiological and Public Health points of view. Shigella sonnei is the serogroup of Shigella most frequently responsible for sporadic and epidemic enteritis in developed countries. The dissemination is associated most often to human to human transmission, but foodborne episodes have also been described. In recent years the circulation of multiresistant strains of S. sonnei biotype g carrying a class 2 integron has been reported in many countries worldwide. In southern Italy a strain with similar properties has been responsible for a large community o…
Marinifilum flexuosum sp. nov., a new Bacteroidetes isolated from coastal Mediterranean Sea water and emended description of the genus Marinifilum Na…
2012
Abstract A facultatively anaerobe, moderately halophilic, Gram-negative, filamentous, non motile and unpigmented bacterium, designated M30 T , was isolated from coastal Mediterranean Sea water in Valencia, Spain. Phylogenetic analysis based on 16S rRNA sequences placed this strain in the phylum “ Bacteroidetes ” with Marinifilum fragile JC2469 T as its closest relative with 97% sequence similarity. Average nucleotide identity (ANI) values between both strains were far below the 95% threshold value for species delineation (about 89% using BLAST and about 90% using MUMmer). A comprehensive polyphasic study, including morphological, biochemical, physiological, chemotaxonomic and phylogenetic d…