In the last decade many studies have been performed on the virulence of Newcastle disease virus (NDV). This is mainly due to the development of reverse genetics systems which made it possible to genetically modify NDV and to investigate the contribution of individual genes and genome regions to its virulence. However, the available information is scattered and a comprehensive overview of the fa...

The aim of this study was to examine virulence factors and the ability of S. aureus and CNS species isolated from milk of cows with mastitis to form biofilm, and to compare them with virulence factors of staphylococci from milk of cows without mastitis and cowshed environment. Most of S. aureus strains from cows with mastitis showed haemolytic activity (93.9%), among them 72.7% and 21.2% produc...

Objectives: In Iran as well as throughout the world Enterococci have been rated as the important cause of urinary tract and nosocomial infections. The aim of this study was to evaluate the relationship between high antimicrobial resistance activity and harboring the virulence factors among clinical Enterococcus isolates. Materials and Methods: Clinical strains were isolated from hospitalized pa...

Tests of eight Dutch Meloidogyne chitwoodi isolates to the differential set for host races 1 and 2 in M. chitwoodi provided no evidence for the existence of host race 2 in the Netherlands. The data showed deviations from expected reactions on the differential hosts, which raised doubts of the usefulness of the host race classification in M. chitwoodi. The term ''pathotype'' is proposed for grou...

Aspergillus fumigatus causes serious, life-threatening human infection, and is one of the most important pathogenic fungi. Little is known, however, about its mechanism of infection or its virulence factors. To learn about its virulence factors, the effect of the culture filtrate of A. fumigatus on macrophages was studied. When cocultured with A. fumigatus in 96-well microplates, murine periton...

Natural competence for genetic transformation is the best-characterized feature of the major human pathogen Streptococcus pneumoniae. Recent studies have shown the virulence of competence-deficient mutants to be attenuated, but the nature of the connection between competence and virulence remained unknown. Here we document the release, triggered by competent cells, of virulence factors (e.g., t...

1 To whom correspondence should be addressed: Sudhir Paul, Chemical Immunology Research Center, Department of Pathology and Laboratory Medicine, University of Texas–Houston Medical School, 6431 Fannin, Houston, Texas 77030, USA, Tel.: 713-500-5347; Fax: 713-500-0574; E-mail: [email protected]; Or Eric L. Brown, Center for Infectious Diseases, University of Texas School of Public Health, 1...

The type III secretion system (T3SS) is a multiprotein complex that plays a central role in the virulence of many Gram-negative bacterial pathogens. To ensure that effector proteins are efficiently translocated into the host cell, bacteria must be able to sense their contact with the host cell. In this study, we found that EscP, which was previously shown to function as the ruler protein of the...

Cytolytic colonies were found in 57% of tap water samples, and up to 6% of samples were found to contain bacteria having three or more virulence factors. The factors evaluated were cytotoxicity, hemolysis, cell adherence, and cell invasiveness. Overall, 17% of the samples contained cytolytic colonies that were adherent and hemolytic. Among the media tested, tryptic soy agar with sheep blood (in...

Porcine enterotoxigenic Escherichia coli (ETEC) continues to result in major morbidity and mortality in the swine industry via postweaning diarrhea. The key virulence factors of ETEC strains, their serotypes, and their fimbrial components have been well studied. However, most studies to date have focused on plasmid-encoded traits related to colonization and toxin production, and the chromosomal...