Search results for "virulence"
showing 10 items of 457 documents
Differentiation of Candida parapsilosis, C. orthopsilosis, and C. metapsilosis by specific PCR amplification of the RPS0 intron
2011
Although Candida parapsilosis is the most prevalent among the 3 species of the *psilosis group, studies applying DNA-based diagnostic techniques with isolates previously identified as C. parapsilosis have revealed that both C. orthopsilosis and C. metapsilosis account for 0-10% of all these isolates, depending on the geographical area. Differences in the degrees of antifungal susceptibility and virulence have been found, so a more precise identification is required. In a first approach, we reidentified 38 randomly chosen clinical isolates, previously identified as C. parapsilosis, using the RPO2 (CA2) RAPD marker. Among them, we reclassified 4 as C. metapsilosis and 5 as C. orthopsilosis. W…
Candida and Candidiasis: The Cell Wall as a Potential Molecular Target for Antifungal Therapy
2004
The fungal species Candida albicans is an opportunistic pathogen, which causes serious infections in humans, particularly in immunocompromised patients. Depending on the underlying host defect, C. albicans causes a variety of infections, ranging from superficial mucocutaneous candidiasis to life-threatening disseminated infections. Both the limited spectrum of antifungal drugs currently in clinical use and the emergence of resistances make necessary the development of new effective antifungal drugs with minimal side effects; however, such a research is limited by the small number of specific target sites identified to date. The cell wall is a fungal specific dynamic structure essential to a…
Anti-adhesion agents against Gram-positive pathogens
2014
The rise of antibiotic-resistance as well as the deficiency of investments by pharmaceutical companies in the development of new antibiotics, have stimulated the investigation of alternative strategies to conventional antibiotics for counteracting the pathogens. A fundamental step of Gram positive pathogenesis is the bacterial adhesion to the host tissue involving a direct and a specific interaction between bacterial surface molecules and host ligands. Targeting the adhesion is a good strategy to design novel anti-infective drugs agents useful to interfere with the pathogenic process and with a virulence mechanism as biofilm formation. This review is focused on anti-virulence compounds whic…
Mixed vaginal infections of Balb/c mice with low virulent herpes simplex type 1 strains result in restoration of virulence properties: vaginitis/vulv…
1997
Vaginal infections of BALB/c Ann mice with herpes simplex virus type 1 (HSV-1) were studied. Mice were inoculated with virulent strains ANG path and 17 syn+ or low-virulent recombinant strains 27/III and 17-syn3 that differ from parental strains in their glycoprotein B (gB) gene sequences. When low-virulent strains were inoculated separately, no vaginitis/vulvitis was produced despite replication in the vagina. In contrast, after coinfection of mice with the two low-virulent strains, vaginitis/vulvitis was produced and virus could be recovered from the central nervous system (CNS). Two of the CNS isolates produced vaginitis/vulvitis, neuroinvasiveness and death of mice after vaginal infecti…
The Fish Pathogen Vibrio vulnificus Biotype 2: Epidemiology, Phylogeny, and Virulence Factors Involved in Warm-Water Vibriosis
2015
ABSTRACT Vibrio vulnificus biotype 2 is the etiological agent of warm-water vibriosis, a disease that affects eels and other teleosts, especially in fish farms. Biotype 2 is polyphyletic and probably emerged from aquatic bacteria by acquisition of a transferable virulence plasmid that encodes resistance to innate immunity of eels and other teleosts. Interestingly, biotype 2 comprises a zoonotic clonal complex designated as serovar E that has extended worldwide. One of the most interesting virulence factors produced by serovar E is RtxA1 3 , a multifunctional protein that acts as a lethal factor for fish, an invasion factor for mice, and a survival factor outside the host. Two practically id…
Method for Specific Identification of the Emerging Zoonotic Pathogen Vibrio vulnificus Lineage 3 (Formerly Biotype 3).
2020
ABSTRACT Vibrio vulnificus is a zoonotic pathogen that is spreading worldwide due to global warming. Lineage 3 (L3; formerly biotype 3) includes the strains of the species with the unique ability to cause fish farm-linked outbreaks of septicemia. The L3 strains emerged recently and are particularly virulent and difficult to identify. Here, we describe a newly developed PCR method based on a comparative genomic study useful for both rapid identification and epidemiological studies of this interesting emerging group. The comparative genomic analysis also revealed the presence of a genetic duplication in the L3 strains that could be related to the unique ability of this lineage to produce sept…
Drug Resistance in Salmonella enterica ser. Typhimurium Bloodstream Infection, Malawi
2014
To the Editor: Salmonella enterica serotype Typhimurium is one of the most common causes of bloodstream infection in sub-Saharan Africa (1). Among adults, the principal risk factor for invasive nontyphoidal Salmonella (iNTS) disease is advanced HIV infection; up to 44% of HIV-infected patients experience bacteremic recurrence through recrudescence of the original infection (2,3). Epidemics of iNTS disease in sub-Saharan Africa have been associated with a novel genotype of S. enterica ser. Typhimurium of multilocus sequence type (ST) 313 that is rarely seen outside the region and is associated with multidrug resistance (MDR) to chloramphenicol, cotrimoxazole, and ampicillin (4,5). As a conse…
Identification of a polyketide synthase gene (pksP) of Aspergillus fumigatus involved in conidial pigment biosynthesis and virulence.
1998
Aspergillus fumigatus is an important pathogen of the immunocompromised host causing pneumonia and invasive disseminated disease with high mortality. Previously, we identified a mutant strain (white, W) lacking conidial pigmentation and, in addition, the conidia showed a smooth surface morphology, whereas wild-type (WT) conidia are grey-green and have a typical ornamentation. W conidia appeared to be less protected against killing by the host defence, e.g., were more susceptible to oxidants in vitro and more efficiently damaged by human monocytes in vitro than WT conidia. When compared to the WT, the W mutant strain showed reduced virulence in a murine animal model. Genetic analysis suggest…
Comparison of Delivery Methods in Phage Therapy against Flavobacterium columnare Infections in Rainbow Trout
2021
Viruses of bacteria, bacteriophages, specifically infect their bacterial hosts with minimal effects on the surrounding microbiota. They have the potential to be used in the prevention and treatment of bacterial infections, including in the field of food production. In aquaculture settings, disease-causing bacteria are often transmitted through the water body, providing several applications for phage-based targeting of pathogens, in the rearing environment, and in the fish. We tested delivery of phages by different methods (via baths, in phage-coated material, and via oral delivery in feed) to prevent and treat Flavobacterium columnare infections in rainbow trout fry using three phages (FCOV…
Denitrification in pathogenic bacteria : for better or worst ?
2005
A large variety of physiological and taxonomic groups have the ability to use nitrogen oxides as alternative electron acceptors. Brucella spp. is an alpha-proteobacteriaceae that induces a persistent disease in some mammals. Recent work has revealed that a denitrifying gene cluster is important in the interaction of Brucella neotomoae with its host.