Specific Strains (specific + strain)

Distribution by Scientific Domains


Selected Abstracts


INFLUENCE OF ACID ADAPTATION ON THE SURVIVAL OF SALMONELLA ENTERITIDIS AND SALMONELLA TYPHIMURIUM IN SIMULATED GASTRIC FLUID AND IN RATTUS NORVEGICUS INTESTINE INFECTION

JOURNAL OF FOOD SAFETY, Issue 2 2010
KARLA JOSEANE PEREZ
ABSTRACT The aim of this study was to investigate the influence of acid adaptation in the survival of Salmonella Enteritidis (SE86) and Salmonella Typhimurium (ST99) during exposure to simulated gastric fluid (SGF) and in intestinal infection of Rattus norvegicus. Acid-adapted and nonadapted Salmonella strains were exposed to SGF (pH 1.5) and were inoculated by gavage in adult rats. Results indicated that acid-adapted SE86 survived significantly better (P < 0.05) than nonadapted SE86, nonadapted ST99 and acid-adapted ST99 in SGF. Nonadapted microorganisms were observed in higher counts in feces than acid-adapted strains, while acid-adapted microorganisms demonstrated higher counts in intestine samples, suggesting intestinal invasion capacity. Acid-adapted SE86 was recovered in higher counts from ileum-cecum junction than the other microorganisms. PRACTICAL APPLICATIONS Salmonella Enteritidis has been identified as the most frequent serovar involved with the foodborne outbreaks in Brazil. In Southern Brazil, a specific strain of Salmonella Enteritidis (SE86) has been involved with more than 90% of the salmonellosis occurring in the last years, and the main food vehicle is home-made mayonnaise frequently added with different quantities of vinegar, which can cause acid adaptation in Salmonella cells. The results of this work indicate that SE86 presented higher acid adaptation, which contributed to higher survival rates in simulated gastric fluid and better intestinal colonization. These results could be related to human virulence and the frequent involvement of this strain with foodborne outbreaks in southern Brazil. [source]


Molecular epidemiological studies show that hepatitis A virus is endemic among active homosexual men in Europe

JOURNAL OF MEDICAL VIROLOGY, Issue 4 2007
Kathrine Stene-Johansen
Abstract Large outbreaks of hepatitis A have occurred in Denmark, Germany, the Netherlands, Norway, Spain, Sweden, and the United Kingdom during the period 1997,2005 affecting homosexual men. A collaborative study was undertaken between these countries to determine if the strains involved in these hepatitis A outbreaks were related genetically. The N-terminal region of VP1 and the VP1/P2A region of the strains were sequenced and compared. The majority of the strains found among homosexual men from the different European countries formed a closely related cluster, named MSM1, belonging to genotype IA. Different HAV strains circulated among other risk groups in these countries during the same period, indicating that specific strains were circulating among homosexual men exclusively. Similar strains found among homosexual men from 1997 to 2005 indicate that these HAV strains have been circulating among homosexual men for a long time. The homosexual communities are probably too small within the individual countries to maintain HAV in their population over time, whereas the homosexual communities across Europe are probably sufficiently large to sustain continued circulation of homologous HAV strains for years resulting in an endemic situation among homosexual men. J. Med. Virol. 79:356,365, 2007. © 2007 Wiley-Liss, Inc. [source]


Probiotics: Considerations for Human Health

NUTRITION REVIEWS, Issue 3 2003
Mary Ellen Sanders PhD
Evidence for the role of probiotics in maintenance of health or prevention of disease is mounting and is supported in some cases by blinded, placebo-controlled human trials. Today, in an era of antibiotic-resistant pathogens and other looming microbial threats, the value of prevention of infection is recognized. Probiotics may play an important role in helping the body protect itself from infection, especially along the colonized mucosal surfaces of the gastrointestinal tract. Probiotic products are available in many different forms worldwide, including pills, powders, foods, and infant formula. In some cases, general health claims are made that cannot be substantiated for the specific strains and levels being used and consumers must therefore beware. [source]


Probiotics for the treatment of women with bacterial vaginosis

CLINICAL MICROBIOLOGY AND INFECTION, Issue 7 2007
M. E. Falagas
Abstract This review considers whether probiotics are effective agents for the treatment and/or prevention of bacterial vaginosis (BV). There seems to be an association between the absence of, or low concentrations of, vaginal lactobacilli and the development of BV. Many studies have suggested that the presence of H2O2 -producing vaginal lactobacilli may protect against BV, although some studies do not support this hypothesis. In-vitro studies have suggested that certain specific strains of lactobacilli are able to inhibit the adherence of Gardnerella vaginalis to the vaginal epithelium and/or produce H2O2, lactic acid and/or bacteriocins, which inhibit the growth of bacteria causing BV. Clinical trials showed that intra-vaginal administration of Lactobacillus acidophilus for 6,12 days, or oral administration of L. acidophilus or Lactobacillus rhamnosus GR-1 and Lactobacillus fermentum RC-14 for 2 months, resulted in the cure of BV (defined as a 0,1 positive score according to Amsel's criteria), and/or reduced the recurrences of BV, and/or caused an increase in vaginal lactobacilli and restoration of a normal vaginal microbiota, significantly more frequently than did a placebo, acetic acid or no treatment. However, several trials have found no significant difference in the cure rate of BV and in the number of vaginal lactobacilli after intra-vaginal instillation of lactobacilli when compared with the effect of a placebo or oestrogen. Thus, although the available results concerning the effectiveness of the administration of lactobacilli for the treatment of BV are mostly positive, it cannot yet be concluded definitively that probiotics are useful for this purpose. [source]