Effects of Gamma Interferon on Intestinal Epithelial Cells Stimulated with Salmonella Enterica serovar Typhimurium and Candida albicans.

Aims: The objective of this study was to determine the level of secretion of gammainterferon by interferon-primed and unprimed Caco-2 intestinal epithelial cells and their survival or growth following infection with Salmonella enterica subsp. enterica serovar Typhimurium (ATCC 14028), Salmonella enterica subsp. enterica serovar Typhimurium DT104 (ATCC 700408), and Candida albicans (Robin) Berkhout, anamorph (ATCC 10231) as well as the survival of the test microorganisms following infection. Study Design: Controlled laboratory experiments were performed using two different species of Salmonella and adenocarcinoma Caco-2 cells. Untreated/ unprimed Caco-2 cells served as control; Caco-2 cells’ growth and interferon production were then determined using, Enzyme Linked Immunosorbent Assay (ELISA) and flow cytometry. Place and Duration of Study: Department of Biological & Environmental Sciences Alabama A& M University and Center for Excellence in Post-Harvest Technologies, North Carolina A&T University USA April 2008 and February 2010. Methodology: Cell culture supernatants of Caco-2 intestinal epithelial cells, primed and unprimed with IFN-γ were infected with either wild-type Salmonella Typhimurium 14028, Candida albicans10231 or multi-drug resistant Salmonella Typhimurium DT104 were collected and analyzed. ELISA and flow cytometry were used to determine apoptosis, cell growth and interferon production. The Bioscreen-C Automated Growth Curve Analysis System was used under controlled environment to determine the growth of the microorganisms in the presence of different concentrations of IFN-γ. Results: Secretion of IFN-γ from Caco-2 cells that were previously treated with 50μg/ml, 20μg/ml, 10μg/ml, 5μg/ml, and 2.5 μg/ml of IFN-γ were not concentration dependent. However, the amount of IFN-γ released from Caco-2 cells was dependent on microbial stimulus type. Cells that were pretreated with 5 μg/ml and 2.5 μg/ml of IFN-γ and then infected with Salmonella Typhimurium DT104 showed an increase in the amount of IFN-γ in the culture medium after 5 minutes. IFN-y induced CaCo-2 cell death was dose-dependent for S.Typhimurium DT104 and Candida albicans. Results are reported as mean ± SEM fortriplicate values from three independent experiments at each time point and IFN-γ dose. Conclusion: These findings indicate that IFN-γ may serve as alternative antimicrobial compounds to reduce the persistence of multi-drug resistant microorganisms such as S. Typhimurium DT104. Induction of interferon-gamma production may be related to microbial virulence/pathogenicity. The potential of IFN-γ as a natural therapeutic for persistent infections in the immune-compromised populations still needs to be further investigated.

In Vitro effect of low-level laser therapy on typical oral microbial biofilms

The aim of this study was to evaluate the effect of specific parameters of low-level laser therapy (LLLT) on biofilms formed by Streptococcus mutans, Candida albicans or an association of both species. Single and dual-species biofilms - SSB and DSB - were exposed to laser doses of 5, 10 or 20 J/cm2 from a near infrared InGaAsP diode laser prototype (LASERTable; 780 ± 3 nm, 0.04 W). After irradiation, the analysis of biobilm viability (MTT assay), biofilm growth (cfu/mL) and cell morphology (SEM) showed that LLLT reduced cell viability as well as the growth of biofilms. The response of S. mutans (SSB) to irradiation was similar for all laser doses and the biofilm growth was dose dependent. However, when associated with C. albicans (DSB), S. mutans was resistant to LLLT. For C. albicans, the association with S. mutans (DSB) caused a significant decrease in biofilm growth in a dose-dependent fashion. The morphology of the microorganisms in the SSB was not altered by LLLT, while the association of microbial species (DSB) promoted a reduction in the formation of C. albicans hyphae. LLLT had an inhibitory effect on the microorganisms, and this capacity can be altered according to the interactions between different microbial species.

O objetivo deste estudo foi avaliar o efeito de parâmetros específicos de irradiação com laser de baixa intensidade sobre biofilmes formados por Streptococcus mutans (S. mutans), Candida albicans (C. albicans) ou associação de ambas as espécies. Biofilmes isolados ou associados destes microrganismos foram irradiados com um dispositivo laser infra-vermelho próximo de diodos InGaAsP (LaserTABLE 780 ±3 nm, 0,04W), utilizando-se para isto o dispositivo LASERTable. Quinze horas após a irradiação, foi demonstrado, por meio da avaliação da viabilidade celular (Teste de MTT), da morfologia das células (MEV) e do crescimento do biofilme (UFC/mL), que esta terapia foi capaz de reduzir o metabolismo celular, número de microrganismos presentes no biofilme, bem como seu crescimento no local. Quanto à viabilidade celular, a resposta à irradiação do biofilme de S. mutans (SSB) foi semelhante para todas as doses de energia, sendo que o crescimento do biofilme foi dose dependente. Porém, quando associado à C. albicans, este microrganismo apresentou resistência à fototerapia. Já a C. albicans associada ao S. mutans apresentou redução de crescimento significativa, sendo este resultado também foi dose dependente. A morfologia dos microrganismos não foi alterada pelas irradiações realizadas quando em biofilmes isolados. A associação entre os microrganismos promoveu redução na formação de hifas pela C. albicans. A laserterapia de baixa intensidade apresentou efeito inibitório sobre microrganismos, sendo que esta capacidade pode ser alterada de acordo com a interação entre diferentes microrganismos.

Depression of efficiency of neutrophils for candida albicans phagocytosis in personnel working in radiation field

The neutrophil functions, chemotaxis, phagocytosis using Candida albicans, phagocytosis by NBT and adherence were studied on 55 persons working in radiation field [group I] and 40 persons as controls [group II]. The effect of radiation on blood picture of persons working in this field with special references to leucocytic counts and neutrophil functions was studied. White and red cells counts were 6.275 +/- 1.723 and 5.475 +/- 1.039 [group I] and 6.440 +/- 1.556, 4.704 +/- 0.734 for group II, respectively, with no significant difference; while in neutrophil function, there was a statistically significant difference in all functions between the two groups which indicated the importance of neutrophil functions in following up persons working in radiation field

Mutagenesis of candida albicans by N-Methyl N-Nitro-N-Nitroso guanidine, ultraviolet and acriflavine

N-methyl-N-nitro N-nitroso guanidine [MNNG], Acriflavine [A C] and Ultraviolet [UV] have been used to induce mutation in 4 clinical isolates of C. albicans. Sixteen stable mutants were isolated with MNNG, 11 with AC and 4 mutants with UV. The most lethal effect was recorded, with MNNG [99.48%] and the least lethal action was with UV [77.70%]. UV gives the highest percentage of revertant [73.3%]. The results showed marked differences between the 4 strains to the mutagenic effects of MNNG, AC and UV. These differences could be attributed to differences in the genetic background of the four strains

Aspectos dos quadros clínico, citológico e da microbiota fúngica da mucosa bucal de pacientes com carcinoma da boca, antes e durante a radioterapia / Aspects of the clinical diagnosis, cytological and of oral mucosa of patients with oral cancer, before and during the radiotherapy

Os autores estudaram clinicamente as lesöes e alteraçöes observadas na mucosa bucal de pacientes com carcinoma da boca, independente da neoplasia presente, antes e durante o tratamento radioterapico, por meio de citologia esfoliativa (papanicolau e PAS) e esfregaços corados pelo Gram. Comprovou-se um aumento de leveduras durante o tratamento, predominando as formas filamentosas consideradas mais patogênicas. Podem-se detectar áreas bem definidas de candidose, quer do tipo atrófica ou pseudomembranosa, além de áreas de radiomucosite, embora a associaçäo de lesöes brancas e eritematosas predominassem levando a um mascaramento do quadro clínico presente. Aumento significativo de sintomas desde a xerostomia, entre outros, foi observado durante o tratamento.