Influence of salinity upon the phenotypic expression of antibiotic resistance in nonhalophilic and halophilic vibrios.

The purpose of the present work is to demonstrate the influence of different NaCI concentrations included in the Mueller Hinton medium, upon the antibiotic susceptibility of 10 non-halophilic and 28 halophilic Vibrio strains. The highest number of resistance aspects were recorded at 1% NaCl concentration for V. cholerae O1/non O1 strains and at 3% for V.

[Trends of antimicrobial resistance in microbial strains isolated from invasive infections in Romania. Experience of participation in EARSS (European Antimicrobial Resistance Surveillance System), 2002-2008].

EARSS (European Antimicrobial Resistance Surveillance System) is the biggest antimicrobial resistance surveillance project in the world financed from public finds, aiming to provide validated and comparable official data on antimicrobial resistance of invasive microbial strains (isolated from blood and CSF), belonging to 6 indicator bacterial species, i.e.: S.

Cytokine profiles of HeLa and human diploid cells induced by different fractions of Vibrio parahaemolyticus cultures exposed to stress conditions.

Vibrio (V.) parahaemolyticus is an aquatic halophilic bacteria which produces gastroenteritis and in rare cases septicaemia after the consumption of raw or under-cooked contaminated seafood.The severity of diarrheal illness caused by this bacterium is closely related to the presence of two types of hemolysins (the thermostable direct hemolysin-TDH and TDH related hemolysin-TRH) and also of type III secretion system (TTSS) proteins.

Antimicrobial activity of some new of 2-(4-ethyl-phenoximethyl) benzoic acid thioureides against planktonic cells.

The aim of the present study was to evaluate the antimicrobial activity of new 2-(4-ethyl-phenoxymethyl) benzoic acid thioureides. The synthesis of the new compounds was done in three steps starting with the synthesis of 2-(4-ethyl-phenoxymethyl) benzoic acid. In the second stage, the 2-(4-ethyl-phenoxymethyl)-benzoyl chloride was prepared and the new thioureides were synthesized in the third step by the reaction of 2-(4-ethyl-phenoxymethyl) benzoyl isothiocyanate with various primary aromatic amines.

Subinhibitory concentrations of phenyl lactic acid interfere with the expression of virulence factors in Staphylococcus aureus and Pseudomonas aeruginosa clinical strains.

The discovery of intra- and intercellular communication systems (quorum sensing systems) regulating bacterial virulence has afforded a novel opportunity to control infectious bacteria, without interfering with their growth. In this study, we investigated the ability of subinhibitory concentrations (sIC) of phenyl lactic acid (PLA), known to be produced by Lactobacillus probiotic strains, to attenuate the virulence and pathogenicity of Pseudomonas aeruginosa (as experimental model of intercellular bacterial communication in Gram-negative bacteria) and Staphylococcus aureus (as experimental model of intercellular bacterial communication in Gram-positive bacteria) by interfering with the coordinated expression of different virulence factors implicated in the pathogenicity of these opportunistic strains. Our results showed that sIC of PLA decreased the ability of the tested strains to adhere both to the cellular and inert substrata and induced changes in the adherence patterns as well as in the cell morphology.

New thioureides of 2-(4-methylphenoxymethyl) benzoic acid with antimicrobial activity.

The purpose of this study was to evaluate in vitro, by means of qualitative and quantative methods, the antimicrobial activity of some new synthesized chemical compounds previously solubilized in DMF (Dimethyl formamide). The qualitative screening of the susceptibility spectra of different microbial strains versus these compounds was performed by three adaptated diffusion methods: paper filter disk impregnation with the tested substances solutions, the disposal of tested solutions in agar wells and the spotting of tested solutions on solid medium previously inoculated with microbial suspension. The quantitative assay of the antimicrobial activity was performed by broth microdilution method in 96-well microplates in order to establish the minimal inhibitory concentration (MIC).

The role of proteins expressed under the stress condition in virulence of some Vibrio strains.

In order to survive in changing environments, bacteria possess enormous adaptive capabilities that allow them to modulate their behavior and reprogram gene expression in response to environmental cues. Vibrios are inhabitants of estuarine and fresh waters and some species are pathogenic to humans, and marine vertebrates and invertebrates. Surface attachment is believed to be essential for colonization of all of these natural environments.

Virulence and resistance markers in clinical and environmental Aeromonas strains isolated in Romania.

The virulence and resistance (R) features of 37 Aeromonas strains from diarrheal cases and 150 from the aquatic environment (isolated during cold and warm season) were tested at different incubation temperatures (4 degrees C, 28 degrees C and 37 degrees C). When incubated at 4 degrees C temperature, the Aeromonasstrains isolated during the cold season expressed the highest number of virulence factors by comparison with the strains isolated during warm season and from diarrhoeal cases, the virulence spectrum increasing simultaneously with the incubation temperature (i.e.

[Effect of transferrin on the expression of virulence factors in Listeria monocytogenes strains].

Iron is an essential element for the great majority of microorganisms, which developed transport systems for iron acquisition, because during the colonization and invasion processes the microorganisms encounter iron-limiting conditions. The bacterial genes implicated in the iron transport and those codifying for other virulence factors are simultaneously depressed. The purpose of this study was to investigate the role of transferrin on the virulence factors expression in food isolated Listeria monocytogenes strains.

[Comparative study of classical and commercial microtest API galleries in the diagnosis of cholera infection].

Cholera still remains in the top of causes generating global mortality and morbidity, as revealed by the latest WHO reports. In 2000, on CDC/Atlanta website, the cholera agent was mentioned as potential biological weapon for bioterrorism actions in 9460 publications. Considering these aspects, a correct and rapid diagnosis is necessary in order to take appropriate epidemiological measures and to prevent the secondary transmission.

[Discordancies between classical and API 20E microtest biochemical identification of Vibrio and Aeromonas strains].

The present study reveals some discordancies of diagnosis considering Vibrionaceae strains when tested by comparison with API 20E (BioMerieux) system and classical biochemical reactions, aspects already mentioned in the literature by other authors. If any misidentification has not an important impact (e.g.

[Study of antibiotic influence on adherence capacity of gram positive and gram negative bacteria to the cellular substrate].

Bacterial adherence to the cellular substrate (skin and mucosa) represents a precondition of infectious pathology. It was demonstrated that bacteria which adhere and form biofilms on catheters and other inert materials used in medicine are resistant to the therapeutic antibiotic concentrations being protected by the biofilm mathrix and generating severe and hard to treat infections. There are only few studies on the influence of antibiotics on the bacterial adhesins synthesis and bacterial adherence to the cellular substrate.

[ Study of exo-enzymatic profile and cytotoxic effect of bacterial culture supernatants in different growth phase].

Bacterial quorum-sensing represents an ubiquitary regulating system in which the pheromones (small molecules with different chemical structures, i.e. homoserin-lactones, octapeptides, aminoacids) act as extracellular mediators of signaling and intercellular communication.

[Factors influencing the capacity of cellular substrate adherence of vibrio cholerae O1 and non O1 strains].

Bacterial adherence to eukariotic cells represents an important step of tissue colonization and is mediated by specific molecules called adhesins. Bacterial adherence to cellular substrate is a very complex process consisting in specific interactions between the surface of host cell and bacterial cell surface respectively. Adherence to cellular substrate confers selective advantages to bacterial cells, as: rapid growth rate by shorter lag period and protection against antibodies and lysozime.