Eradication of a Mature Methicillin-Resistant Staphylococcus aureus (MRSA) Biofilm From Acrylic Surfaces

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Community-associated methicillin-resistant Staphylococcus aureus in non-outbreak skin infections

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Small hospitals matter: insights from the emergence and spread of vancomycin-resistant enterococci in 2 public hospitals in inner Brazil

Although vancomycin-resistant enterococci (VRE) are reported in Brazil since 1996, data on their impact over settings of different complexity are scarce. We performed a study aimed at identifying determinants ofVRE emergence and spread in a public hospital consortium (comprising 2 hospitals, with 318 and 57 beds) in inner Brazil. Molecular typing and case-control studies (addressing predictors of acquisition or clonality) were performed. Among 122 authocthonous isolates, 106 were Enterococcus faecium (22 clones), and 16, Enterococcus faecalis (5 clones). Incidence was greater in the small-sized hospital, and a previous admission to this hospital was associated with greater risk of VRE colonization or infection during admission to the larger one. Overall risk factors included comorbidities, procedures, and antimicrobials (piperacillin-tazobactam, cefepime, and imipenem). Risk factors varied among different hospitals, species, and clones. Our findings demonstrate that VRE can spread within low-complexity facilities and from these to larger hospitals. (C) 2015 Elsevier Inc. All rights reserved.

Dynamics of biofilm formation and the interaction between candida albicans and methicillin-susceptible (MSSA) and -resistant staphylococcus aureus (MRSA)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

In vitro antibacterial and chemical properties of essential oils including native plants from Brazil against pathogenic and resistant bacteria

The antimicrobials products from plants have increased in importance due to the therapeutic potential in the treatment of infectious diseases. Therefore, we aimed to examine the chemical characterisation (GC-MS) of essential oils (EO) from seven plants and measure antibacterial activities against bacterial strains isolated from clinical human specimens (methicillin-resistant Staphylococcus aureus (MRSA) and sensitive (MSSA), Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium) and foods (Salmonella Enteritidis). Assays were performed using the minimal inhibitory concentration (MIC and MIC90%) (mg/mL) by agar dilution and time kill curve methods (log CFU/mL) to aiming synergism between EO. EO chemical analysis showed a predominance of terpenes and its derivatives. The highest antibacterial activities were with Cinnamomun zeylanicum (0.25 mg/mL on almost bacteria tested) and Caryophyllus aronzaticus EO (2.40 mg/mL on Salmonella Enteritidis), and the lowest activity was with Eugenia uniflora (from 50.80 mg/mL against MSSA to 92.40 mg/mL against both Salmonella sources and P aeruginosa) EO. The time kill curve assays revealed the occurrence of bactericide synergism in combinations of C. aromaticus and C. zeylanicum with Rosmarinus. officinalis. Thus, the antibacterial activities of the EO were large and this can also be explained by complex chemical composition of the oils tested in this study and the synergistic effect of these EO, yet requires further investigation because these interactions between the various chemical compounds can increase or reduce (antagonism effect) the inhibitory effect of essential oils against bacterial strains.

Microbiological Profile Resistant to Different Intracanal Medications in Primary Endodontic Infections

Introduction: This clinical study aimed to determine the microbiological profile resistant to different intracanal medications in primary endodontic infections by using both microbiological culture and the checkerboard DNA-DNA hybridization technique. Methods: Twenty primarily infected root canals were selected and then instrumented before being randomly divided into 2 groups according to the intracanal medications: calcium hydroxide (Ca[OH](2)) or Ca(OH)(2) + chlorhexidine (CHX). Samples were collected before and after root canal procedures, which consisted in submitting them to microbiological culture and processing them for checkerboard DNA-DNA hybridization. Results: No differences were found between the Ca(OH)(2) (99.98%) and Ca(OH)(2) + CHX groups (99.76%) regarding the median percentage values for the reduction of cultivable bacteria. The most frequently detected species were Capnocytophaga ochracea (70%) and Fusobacterium nucleatum ssp. vincentii (70%) in the initial samples. After instrumentation, the most frequently detected species were E. faecium (60%). After root canal treatments using either Ca(OH)(2) or Ca(OH)(2) + CHX as intracanal medications, the most frequently detected species were E nucleatum ssp. vincentii (90%) and Enterococcus faecium (40%), respectively. Both treatments significantly decreased the number of bacterial species compared with the initial sample. However, this reduction was significantly greater in the Ca(OH)(2) + CHX group (P < .05). This difference was also observed when evaluating the total bacterial load (P < .05). Conclusions: The use of Ca(OH)(2) associated with CHX as an intracanal medication showed better results by acting on gram-positive and gram-negative microorganisms although such an action to eradicate enterococci should also be sought.

Chemical control of different digitaria insularis populations and management of a glyphosate-resistant population

This study aimed to control different populations of Digitaria insularis by glyphosate herbicide, isolated and mixed, besides the combination of methods (chemical and mechanical) to manage resistant adult plants. Three experiments were conducted, one in pots which were maintained under non-controlled conditions and two under field conditions. In the experiment in pots, twelve populations of D. insularis were sprayed with isolated glyphosate (1.44 and 2.16 kg a.e. ha(-1)) and mixed (1.44 and 2.16 kg a.e. ha(-1)) with quizalofop-p tefuryl (0.12 kg i.a. ha(-1)). The treatment of 1.44 kg a.e. ha(-1) of glyphosate plus 0.12 kg a.i. ha(-1) of quizalofop was sufficient for adequate control (>95%) of all populations. Population 11 (area of grain production in Itumbiara, GO) was considered sensitive to glyphosate. Others populations were moderately sensitive or tolerant to the herbicide. In the field, the plants of D. insularis of one of the experiments were mowed and, in the other, there were not. Eight treatments with herbicides [isolated glyphosate (1.44 and 2.16 kg a.e. ha(-1)) and mixed (1.44 and 2.16 kg a.e. ha(-1)) with quizalofop-p-tefuryl at 0.12 kg a.i. ha(-1)), clethodim at 0.108 kg a.i. ha(-1)) or nicosulfuron at 0.06 kg a.i. ha(-1))] were assessed, in combination with or without sequential application of the standard treatment, sprayed 15 days after the first application. The combination of the mechanic control with the application of glyphosate (2.16 and 1.44 kg a.e. ha(-1)) plus quizalofop-p-tefuryl (0.12 kg a.i. ha(-1)) or clethodim (0.108 kg a.i. ha(-1)), associated to the sequential application, was the most effective strategy for the management of adult plants of resistant D. insularis.

Clinical and epidemiological profiles of individuals with drug-resistant tuberculosis

Drug-resistant tuberculosis (TB) is a growing global threat. Approximately 450,000 people developed multidrugresistant TB worldwide in 2012 and an estimated 170,000 people died from the disease. This paper describes the sociodemographic, clinical-epidemiological and bacteriological aspects of TB and correlates these features with the distribution of anti-TB drug resistance. Mycobacterium tuberculosis (MT) cultures and drug susceptibility testing were performed according to the BACTEC MGIT 960 method. The results demonstrated that MT strains from individuals who received treatment for TB and people who were infected with human immunodeficiency virus were more resistant to TB drugs compared to other individuals (p < 0.05). Approximately half of the individuals received supervised treatment, but most drug-resistant cases were positive for pulmonary TB and exhibited positive acid-fast bacilli smears, which are complicating factors for TB control programs. Primary healthcare is the ideal level for early disease detection, but tertiary healthcare is the most common entry point for patients into the system. These factors require special attention from healthcare managers and professionals to effectively control and monitor the spread of TB drug-resistant cases.

Community-associated methicillin-resistant Staphylococcus aureus in non-outbreak skin infections

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Gallus gallus domesticus are resistant to infection with Neospora caninum tachyzoites of the NC-1 strain

The aim of this study was to experimentally evaluate infection in Gallus gallus domesticus with Neospora caninum tachyzoites of the NC-1 strain. Experimental infection was conducted in 90-day-old chickens, embryonated eggs and bioassays in dogs. In the first experiment, poults were randomly divided into four groups. Groups I and II were provided feed with coccidiostat, whereas groups III and IV received feed without coccidiostat. When the poults from groups I and III reached 90 days of age, they received a subcutaneous inoculation of N. caninum. Once the hens entered their egg-laying period, during the following 30 days, the eggs were collected, identified, weighed and placed in an incubator. On the 70th day after inoculation, all animals, including the chicks, were euthanized. Tissue samples from the adult poultry and chicks were collected for histopathology, immunohistochemistry (IHC) and PCR. Brain tissue and pectoral muscle samples from infected birds were fed to two dogs. Notably, the average weight of the group III eggs was lower than that of the group IV eggs (p <0.05). No changes consistent with infection in adult poultry or chicks were detected by histopathology or IHC; moreover, no amplified parasite DNA was detected in the birds'tissues or dogs'feces. No dog eliminated oocysts. In the second experiment, the embryonated chicken eggs were inoculated with 1 x 10(2) N. caninum tachyzoites, on the 10th day of incubation, and chicks born from these eggs were housed in boxes suitable for the species and received commercial feed and distilled water ad libitum. On the 30th day after infection (DAI), the poultry were euthanized, and their organs were processed as described in experiment I. The amplification of parasite DNA was observed in the spleen and pectoral muscles of one of the birds. The ingestion of bird tissues by dogs did not result in oocyst elimination. These results indicate that the parasite may have been eliminated by the host and that the use of tachyzoites to induce chronic disease might be a poor source for hens. (C) 2014 Elsevier B.V. All rights reserved.

Resistant starch in cassava products

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A study of multidrug-resistant tuberculosis in risk groups in the city of Santos, Sao Paulo, Brazil

Monitoring the extent of and trends in multidrug-resistant tuberculosis (MDR-TB) is a priority of the Brazilian National Tuberculosis Control Programme. The current study aimed to estimate the incidence of MDR-TB, describe the profile of TB drug resistance in risk groups and examine whether screening for MDR-TB adhered to the recommended guidelines. A descriptive study that examined diagnosed cases of pulmonary TB was conducted in the city of Santos, Brazil, between 2000-2004. Of the 2,176 pulmonary TB cases studied, 671 (30.8%) met the criteria for drug sensitivity testing and, of these cases, 31.7% (213/671) were tested. Among the tested cases, 9.4% were resistant to one anti-TB drug and 15% were MDR. MDR was observed in 11.6% of 86 new TB cases and 17.3% of 127 previously treated cases. The average annual incidence of MDR-TB was 1.9 per 100,000 inhabitants-years. The extent of known MDR-TB in the city of Santos is high, though likely to be underestimated. Our study therefore indicates an inadequate adherence to the guidelines for MDR-TB screening and suggests the necessity of alternative strategies of MDR-TB surveillance.

Anti-CD25 Treatment Depletes Treg Cells and Decreases Disease Severity in Susceptible and Resistant Mice Infected with Paracoccidioides brasiliensis

Regulatory T (Treg) cells are fundamental in the control of immunity and excessive tissue pathology. In paracoccidioidomycosis, an endemic mycosis of Latin America, the immunoregulatory mechanisms that control the progressive and regressive forms of this infection are poorly known. Due to its modulatory activity on Treg cells, we investigated the effects of anti-CD25 treatment over the course of pulmonary infection in resistant (A/J) and susceptible (B10.A) mice infected with Paracoccidioides brasiliensis. We verified that the resistant A/J mice developed higher numbers and more potent Treg cells than susceptible B10.A mice. Compared to B10.A cells, the CD4(+)CD25(+)Foxp3(+) Treg cells of A/J mice expressed higher levels of CD25, CTLA4, GITR, Foxp3, LAP and intracellular IL-10 and TGF-beta. In both resistant and susceptible mice, anti-CD25 treatment decreased the CD4(+)CD25(+)Foxp3(+) Treg cell number, impaired indoleamine 2,3-dioxygenase expression and resulted in decreased fungal loads in the lungs, liver and spleen. In A/J mice, anti-CD25 treatment led to an early increase in T cell immunity, demonstrated by the augmented influx of activated CD4(+) and CD8(+) T cells, macrophages and dendritic cells to the lungs. At a later phase, the mild infection was associated with decreased inflammatory reactions and increased Th1/Th2/Th17 cytokine production. In B10.A mice, anti-CD25 treatment did not alter the inflammatory reactions but increased the fungicidal mechanisms and late secretion of Th1/Th2/Th17 cytokines. Importantly, in both mouse strains, the early depletion of CD25(+) cells resulted in less severe tissue pathology and abolished the enhanced mortality observed in susceptible mice. In conclusion, this study is the first to demonstrate that anti-CD25 treatment is beneficial to the progressive and regressive forms of paracoccidioidomycosis, potentially due to the anti-CD25-mediated reduction of Treg cells, as these cells have suppressive effects on the early T cell response in resistant mice and the clearance mechanisms of fungal cells in susceptible mice.

Ultraviolet-radiation-resistant isolates revealed cellulose-degrading species of Cellulosimicrobium cellulans (UVP1) and Bacillus pumilus (UVP4)

Among extremophiles, microorganisms resistant to ultraviolet radiation (UVR) have been known to produce a variety of metabolites (i.e., extremolytes). We hypothesized that natural microbial flora on elevated land (hills) would reveal a variety of UVR-resistant extremophiles and polyextremophiles with modulated proteins and enzymes that had biotechnological implications. Microorganisms Cellulosimicrobium cellulans UVP1 and Bacillus pumilus UVP4 were isolated and identified using 16S rRNA sequencing, and showed extreme UV resistance (1.03 x 106 and 1.71 x 105 similar to J/m2, respectively) from elevated land soil samples along with unique patterns of protein expression under UVR and non-UVR. A broad range of cellulolytic activity on carboxymethyl cellulose agar plates in C. cellulans UVP1 and B. pumilus UVP4 was revealed at varying pH, temperature, and inorganic salt concentration. Further, the microbial strain B. pumilus UVP4 showed the basic characteristics of a novel group: polyextremophiles with significance in bioenergy.