Search results for "microbiology"

In vitro enterococcus faecalis biofilm formation on five adhesive systems

2011

Objective: To determine the E. faecalis biofilm formation on the surface of five adhesive systems (AS) and its relationship with roughness. Study Design: The formation of E. faecalis biofilms was tested on the surface of four dual-cure AS: AdheSE DC, Clearfil DC Bond, Futurabond DC and Excite DSC and one light-cure antimicrobial AS, Clearfil Protect Bond, after 24 hours of incubation, using the MBEC high-throughput device. Results: E. faecalis biofilms grew on all the adhesives. The least growth of biofilm was on Excite DSC, Clearfil Protect Bond, and the control. Futurabond DC resulted in the greatest roughness and biofilm amount. There was a close relationship between the quantity of biof…

T cell specificity and cross reactivity towards enterobacteria,Bacteroides,Bifidobacterium, and antigens from resident intestinal flora in humans

1999

BACKGROUNDT cell responses to normal intestinal bacteria or their products may be important in the immunopathogenesis of chronic enterocolitis.AIMSTo investigate the T cell specificity and cross reactivity towards intestinal bacteria.PATIENTS/METHODST cell clones were isolated with phytohaemagglutinin from peripheral blood and biopsy specimens of inflamed and non-inflamed colon from five patients with inflammatory bowel disease (IBD) and two controls. T cell clones were restimulated with anaerobicBacteroides andBifidobacteria species, enterobacteria, and direct isolates of aerobic intestinal flora. T cell phenotype was analysed by single-cell immunocyte assay.RESULTSAnalysis of 96 T cell cl…

Biochemical and toxigenic properties of Vibrio furnissii isolated from a European eel farm

1995

Abstract The present study describes for the first time the isolation of Vibrio furnissii strains from a European eel culture system which are pathogenic for eels ( Anguilla anguilla ) (LD 50 dose, 10 6 cfu/fish). Biochemical characterization of the isolates was performed by API 20E system and by classical numerical taxonomy. Growth at 4 °C, and with 6–8% (w/v) NaCl in a broth medium were necessary to differentiate Vibrio furnissii from Aeromonas species when the API 20E system was used. Virulence for eels of V. furnissii isolates was demonstrated by intraperitoneal injection of living cells. The extracellular products (ECPs) produced by V. furnissii were lethal to elvers and induced some o…

Toxicity of the extracellular products ofVibrio damsela isolated from diseased fish

1993

In this work we analyzed the pathogenic in vivo and in vitro activities for both fish and mammals of extracellular products (ECP) of several isolates of Vibrio damsela implicated in disease problems in marine culture. The ECP from all the strains were strongly lethal for fish (LD50 ranging from 0.06 to 3.7 μg protein/g fish) and mice (LD50 ranging from 0.02 to 0.43 μg protein/g mouse), causing death between 4 and 72 h after inoculation. These ECP samples possessed low proteolytic activity without production of caseinase, gelatinase, or elastase. However, most of them showed remarkable phospholipase and hemolytic activity for sheep, human, and turbot red blood cells. In addition, all the ECP…

Neo-clerodane diterpenoids from Conyza pyrrhopappa Sch.Bip. ex A.Rich

2019

Two hitherto unknown neo-clerodane-type diterpenoids along with twelve known compounds have been isolated from Conyza pyrrhopappa Sch.Bip. ex A.Rich, a medicinal plant traditionally used across tropical Africa to relieve fever. The structures of isolates have been elucidated by a combination of spectroscopic techniques. The crude extract and the isolated compounds were evaluated in the Hela-S3 cell line and in a panel of microorganisms (bacteria and fungi) at concentrations up to 50 µg/mL. The new compounds were inactive while the pentamethylated flavonoids showed low to significant activity against the cancer cell line used. However, none of the samples showed any activity against the test…

Evaluation of the API 20E system for identification and discrimination of Vibrio vulnificus biotypes 1 and 2

1993

Vibrios isolated from the cultured manila clam (Ruditapes philippinarum): numerical taxonomy and antibacterial activities.

2002

Aims: A numerical taxonomic study of halophilic Vibrio isolated from healthy and brown ring disease (BRD) affected manila clams (Ruditapes philippinarum), harvested from the Atlantic coast of south-western Spain, was performed. Methods and Results: Characterization of 123 presumptive Vibrio spp. was carried out using 94 phenotypic tests. Simple matching and Jaccard similarity coefficients were used for numerical analysis. Cluster analysis by the unweighted pair group method with arithmetic averages yielded 15 phena defined at 0.81 similarity. Large phena corresponded to Vibrio tubiashii, V. splendidus biotype I and V. harveyi (phena 1, 5 and 9, respectively). The species V. splendidus bioty…

Pathophysiology of Campylobacter jejuni infections of humans.

2000

Campylobacter jejuni and closely related organisms are major causes of human bacterial enteritis. These infections can lead to extraintestinal disease and severe long-term complications. Of these, neurological damage, apparently due to the immune response of the host, is the most striking. This review examines current knowledge of the pathophysiology of the organism. Diversity of C. jejuni isolates in genotypic and phenotypic characteristics now is recognized and clinically relevant examples are presented. Expected future directions are outlined.

Distributions of the growth rate of the germ tubes and germination time of Penicillium chrysogenum conidia depend on water activity

2008

The effects of water activities for sporulation (a(wsp)) and germination (a(wge)) on the distributions of the growth rate of the germ tubes (mu) and the germination time (t(G)) of Penicillium chrysogenum conidia were determined by monitoring the length of the same germ tubes throughout the experiments automatically. No relationship between the individual t(G)'s and mu's could be established. Irrespective of the water activity for germination, mu was greater and t(G) was less for conidia produced at 0.95a(wsp) than that at 0.99a(wsp). At 0.99 a(wge) the mean and the standard deviation of t(G) were smaller than those obtained at 0.95a(wge). At 0.99a(wge), normal distributions for mu and t(G) …

Gut microbiota changes in rainbow trout, Oncorhynchus mykiss (Walbaum), during organic acid feed supplementation and Yersinia ruckeri infection

2013

Gut microbiota (GM) composition of vertebrates are considered to influence health parameters including immunological parameters in the host but knowledge of these issues in fish are sparse. We have performed a 45 day experimental study elucidating effects of dietary supplementation of organic acids (Mera Cid) and immunostimulants on the GM composition of rainbow trout Oncorhynchus mykiss (Walbaum) and investigated its association with blood parameters and disease resistance (against enteric red mouth disease (ERM) caused the bacterium Yersinia ruckeri). A total of 640 fish received either 1) basic fish feed without organic acids or immunostimulants, 2) fish feed with immunostimulants (β6glu…