Genetic data of 15 autosomal STR loci: an analysis of the Araraquara population colonization (São Paulo, Brazil)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Intestinal colonization of a human subject by vancomycin-resistant Enterococcus faecium

Objective: To study the ability of two strains of vancomycin-resistant Enterococcus faecium to colonize the human intestine. Methods: A single human subject ingested separately two strains of vancomycin-resistant E. faecium isolated from a pig and a chicken. The feces were cultured on selective medium. Prior to ingestion no vancomycin-resistant cocci were present in the feces. Ingestion of 10 4-10 5 CFU resulted in either no colonization or isolation only after enrichment. Ingestion of 10 7 CFU of one strain resulted in colonization for a period of nearly 3 weeks, with fecal counts at times in excess of 10 6 CFU/g. Ingestion of similar numbers of the other strain and reingestion of the first strain resulted in excretion in the feces for much shorter periods. When the fecal count of the ingested strains was greater than 10 4-10 5 CFU/g, the strains were isolated from swabs taken from perianal skin. Conclusions: Vancomycin-resistant E. faecium strains from pigs and poultry a re able to colonize the human gut and the perianal skin.

SEM evaluation of in situ early bacterial colonization on a Y-TZP ceramic: A pilot study

This study aimed to evaluate the effect of surface glazing and polishing of yttrium-stabilized tetragonal zirconia polycrystal ceramic on early dental biofilm formation, as well as the effect of brushing on the removal of adhered bacteria. Two subjects used oral appliances with polished and glazed samples fixed to the right and left sides. After 20 minutes, 1 hour, and 6 hours, the subjects manually brushed the samples on the right side. The samples were analyzed using scanning electron microscopy. Granular material was verified on the samples, especially on irregular surfaces. After 1 hour, there was no significant difference between glazed and polished surfaces in terms of bacterial presence. However, glazed surfaces tended to accumulate more biofilm, and brushing did not completely remove the biofilm. Polished surfaces seem to present a lower tendency for biofilm formation. Int J Prosthodont 2007;20:419-422.

SEM analysis of the in situ early bacterial colonization on two novel feldspathic ceramics submitted to different types of glazing

Aim: The aim of this study was to evaluate in situ, the early bacterial colonization on feldspar-ceramics submitted to different glazing. Methods and Materials: Fourteen standardized disc specimens (diameter: 5 mm, thickness: 1.5 mm) of each of two micro-particulate feldspathic ceramics (VM7 and VM13, Vita) were produced according to manufacturers' specifications for a total of 28 specimens (24 for the analysis of biofilm and 4 for topographic analysis analyzing the ceramic surfaces). Specimens from each type of ceramic were submitted to two different glazing methods composing four groups: VM7 glazed using glazing liquid Vita Akzent® 25 (G1) and glaze firing (G2), VM13 glazed using glazing liquid (G3) and glaze firing (G4). Six individuals (n=6) wore oral appliances with four ceramic specimens, fixed on the buccal face of the appliances. After 8 hours, each sample was evaluated for the presence (1) or absence (0) of bacterial colonization under a scanning electron microscope (SEM) on five randomly selected fields. The value for each sample was cumulative of the results observed in the fields. One sample from each group was evaluated under a SEM to verify the topographic pattern. Results: There was no difference with regard to bacterial colonization between the feldspar-ceramics and between the glazing types (Kruskal-Wallis non-parametric test). Conclusion: Feldspar-ceramics submitted to firing or glaze firing with Vita Akzent® 25 present a similar condition for in situ bacterial colonization. The similar topographic pattern of the ceramic surfaces seems to have influenced the bacterial colonization.

Candida species: Current epidemiology, pathogenicity, biofilm formation, natural antifungal products and new therapeutic options

The incidence of fungal infections has increased significantly, so contributing to morbidity and mortality. This is caused by an increase in antimicrobial resistance and the restricted number of antifungal drugs, which retain many side effects. Candida species are major human fungal pathogens that cause both mucosal and deep tissue infections. Recent evidence suggests that the majority of infections produced by this pathogen are associated with biofilm growth. Biofilms are biological communities with a high degree of organization, in which micro-organisms form structured, coordinated and functional communities. These biological communities are embedded in a self-created extracellular matrix. Biofilm production is also associated with a high level of antimicrobial resistance of the associated organisms. The ability of Candida species to form drugresistant biofilms is an important factor in their contribution to human disease. The study of plants as an alternative to other forms of drug discovery has attracted great attention because, according to the World Health Organization, these would be the best sources for obtaining a wide variety of drugs and could benefit a large population. Furthermore, silver nanoparticles, antibodies and photodynamic inactivation have also been used with good results. This article presents a brief review of the literature regarding the epidemiology of Candida species, as well as their pathogenicity and ability to form biofilms, the antifungal activity of natural products and other therapeutic options. © 2013 SGM.

Colonization pressure and risk factors for acquisition of imipenem-resistant Acinetobacter baumannii in a medical surgical intensive care unit in Brazil

We studied a nonconcurrent cohort of 582 patients admitted to a medical-surgical intensive care unit. Use of antimicrobials (imipenem and metronidazole) was a risk factor for acquisition of imipenem-resistant Acinetobacter baumannii only for the subcohort of patients admitted in months in which colonization pressure was lower than the median value. © 2013 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Protective effect of mannan oligosaccharides against early colonization by Salmonella Enteritidis in chicks is improved by higher dietary threonine levels

Aims: To evaluate mannan oligosaccharide (MOS) and threonine effects on performance, small intestine morphology and Salmonella spp. counts in Salmonella Enteritidis-challenged birds. Methods and Results: One-day-old chicks (1d) were distributed into five treatments: nonchallenged animals fed basal diet (RB-0), animals fed basal diet and infected with Salmonella Enteritidis (RB-I), animals fed high level of threonine and infected (HT-I), birds fed basal diet with MOS and infected (MOS-I), birds fed high level of threonine and MOS and infected (HT+MOS-I). Birds were inoculated at 2d with Salmonella Enteritidis, except RB-0 birds. Chicks fed higher dietary threonine and MOS showed performance similar to RB-0 and intestinal morphology recovery at 8 dpi. Salmonella counts and the number of Salmonella-positive animals were lower in HT+MOS-I compared with other challenged groups. Conclusion: Mannan oligosaccharides and threonine act synergistically, resulting in improved intestinal environment and recovery after Salmonella inoculation. Significance and Impact of the Study: Nutritional approaches may be useful to prevent Salmonella infection in the first week and putative carcass contamination at slaughter. This is the first report on the possible synergistic effect of mannan oligosaccharides and threonine, and further studies should be performed including performance, microbiota evaluation, composition of intestinal mucins and immune assessment. © 2012 The Society for Applied Microbiology.

Recent mouse and rat methods for the study of experimental oral candidiasis

The Candida genus expresses virulence factors that, when combined with immunosuppression and other risk factors, can cause different manifestations of oral candidiasis. The treatment of mucosal infections caused by Candida and the elucidation of the disease process have proven challenging. Therefore, the study of experimentally induced oral candidiasis in rats and mice is useful to clarify the etiopathology of this condition, improve diagnosis, and search for new therapeutic options because the disease process in these animals is similar to that of human candidiasis lesions. Here, we describe and discuss new studies involving rat and mouse models of oral candidiasis with respect to methods for inducing experimental infection, methods for evaluating the development of experimental candidiasis, and new treatment strategies for oral candidiasis. © 2013 Landes Bioscience.

Hydroxyurea therapy in sickle cell anemia patients aids to maintain oral fungal colonization balance

Background: The aim of this study was to evaluate the frequency of Candida species and presence of lesions in the oral cavity of patients with sickle cell anemia (SS). Methods: The study included 30 patients diagnosed with sickle cell anemia and taking hydroxyurea for at least 90 days (SS/HU+); and 39 patients with sickle cell anemia and without hydroxyurea therapy (SS/HU-). Two control groups were constituted by healthy individuals matched to the test groups in age, gender, and oral conditions (C/HU+ for SS/HU+ and C/HU- for SS/HU-). Oral clinical examination and anamnesis were performed. Yeasts were collected by oral rinses and identified by API system. Antifungal susceptibility evaluation was performed according to the CLSI methodology. Data obtained for microorganisms counts were compared by Student's t test (SS/HU+ vs. C/HU+ and SS/HU- vs. C/HU-) using MINITAB for Windows 1.4. Significance level was set at 5%. Results: No oral candidosis lesions were detected. Significant differences in yeasts counts were observed between SS/HU- group and the respective control, but there were no differences between SS/HU+ and C/HU+. Candida albicans was the most prevalent species in all groups. Candida famata was observed both in SS and control groups. Candida dubliniensis, Candida glabrata, Candida krusei, Candida tropicalis, Candida pelliculosa, and Candida parapsilosis were observed only in SS groups. Most strains were susceptible to all antifungal agents. Conclusion: Hydroxyurea therapy seems to decrease candidal counts and resistance rate in sickle cell anemia patients. However, further studies should be conducted in the future to confirm this finding. Hydroxyurea therapy in sickle cell anemia patients maintains fungal species balance in oral cavity. © 2013 John Wiley & Sons A/S.

Efeitos benéficos de probióticos no intestino de juvenis de tilápia-do-nilo

The aim of this study was to evaluate the survival rate, the intestinal microbiota, the mucosal integrity, and the carcass quality of juvenile Nile Tilapia, Oreochromis niloticus, after 80 days being fed on a diet containing probiotic additive (Bacillus cereus 4.0×108 CFUg-1 and Bacillus subtilis 4.0×108 CFUg-1), at the ratio of 4g/kg of pelleted feed. The completely randomized design with two treatments was used: one control group and one group fed on the mentioned diet. The evaluation of survival rate, the intestinal microbiota analysis by microbiological culture, histomorphometrical analysis of intestinal mucosa and chemical analysis of carcass was performed. The results showed that tilapias from the treated group had higher relative survival rate (P<0.05) than the control group, higher number of colony-forming units (P<0.05) regarding intestinal colonization by B. cereus and B. subtilis, and higher rates of intestinal mucosal integrity (P<0.05), evaluated by histomorphometry. As for the latter, the group being fed on feed with probiotic additive was observed to have higher and larger villi, besides having a higher number of goblet cells than the control group. Concerning the carcass quality, the results showed that there was positive interference (P<0.05) of the probiotic on the treated group in comparison to the control group as in regard to levels of protein and ether extract. These results allow the inference that the supplementation with probiotic, as tested in this experiment, led to the intestinal colonization by beneficial bacteria and resulted in higher relative survival rate, decreased the mucosal desquamation and helped in the increase of the number of goblet cells.

Implant-abutment gap versus microbial colonization: Clinical significance based on a literature review

Microorganisms from the oral cavity may settle at the implant-abutment interface (IAI). As a result, tissue inflammation could occur around these structures. The databases MEDLINE/PubMed and PubMed Central were used to identify articles published from 1981 through 2012 related to the microbial colonization in the implant-abutment gap and its consequence in terms of crest bone loss and osseointegration. The following considerations could be put forward, with respect to the clinical importance of IAI: (a) the space present at the IAI seems to allow bacterial leakage to occur, in spite of the size of this space; (b) bacterial leakage seems to occur at the IAI, irrespective of the type of connection. More studies are necessary to clarify the relationship between leakage at IAI and abutment connection designs; (c) losses at the peri-implant bone crests cannot be related to the IAI size, since few studies have shown no relationship. Also, the microbial leakage at the IAI cannot be related to the bone crest loss, since there are no articles reporting this relationship; remains controversial the influence of the IAI position on the bone crest losses. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 101B: 1321-1328, 2013. Copyright © 2013 Wiley Periodicals, Inc.

Bacillus cereus e Bacillus subtilis na suplementação dietária de juvenis de Tilápias-do-Nilo (Oreochromis niloticus) e seu efeito probiótico

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

From west to east: Environmental influences on the rate and pathways of Polynesian colonization

The prime movers behind the prehistoric colonization of Remote Oceania, and in particular the large c. 2000-year temporal gap (i.e. long pause') seen between West and East Polynesia, has long been major point of interest in the Pacific. To address these events and the processes that may have led to the known chronological disparity of these diasporas, we present results from two different, but equally powerful, analytical tools which are used to examine Polynesian seafaring capabilities and trajectories. The first is a statistical model known as Seascape, which simulates voyages, while the second uses ease of eastward travel estimates based on land distribution and wind pattern analysis. These analyses were done with the goal of determining the potential role of environmental factors in the colonization process, particularly as they relate to the long pause. We show that the eastern boundary of West Polynesia, the limit of the initial colonization pulse, is marked by a discontinuity in land distribution, where the distances travelers would have to cross in order to reach islands further to the east become significantly larger. At the same time, in West Polynesia, the frequency and intensity of winds favorable to eastward displacement decrease continuously from west to east. As far as winds are concerned, eastward travel in West Polynesia is favored in the northern and southern areas and much more difficult across the central portion. Favorable winds have a clear seasonality, and eastward displacement along the northern area is much easier under El Nino conditions. Voyaging simulations show that intentional eastward voyages departing from Tonga and Samoa, when undertaken with vessels capable of sailing efficiently against the wind, afford a viable route toward several island groups in East Polynesia, with trips starting in Samoa having a higher probability of success.

Oral microbial colonization in children with sickle cell anaemia under long-term prophylaxis with penicillin

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Risk factors for the acquisition of imipenem-resistant Acinetobacter baumannii in a burn unit: An appraisal of the effect of colonization pressure

Imipenem-resistant Acinetobacter baumannii (IRAB) is a major threat for critically ill patients, including those admitted to burn units. Recent studies have suggested that colonization pressure (the proportion of patients or patient-days harbouring the pathogen of interest) is an important driver of the risk for acquisition of multidrug-resistant organisms. With that in mind, we conducted a cohort study, enrolling 208 patients admitted to a burn unit from November 2008 through December 2009. The outcome of interest was the acquisition of IRAB. In addition to the usual risk factors, we assessed the impact of colonization pressure. The number of wound excisions (odds ratio (OR) 12.06, 95% confidence interval (CI) 2.82-51.64) and the number of antimicrobials used (OR 22.82, 95% CI 5.15-101.19) were significant risk factors for the outcome of interest. On the other hand, colonization pressure (measured for whole time of exposure or up to the last 14, 7, or 3 days) was not associated with the risk for IRAB acquisition.