In vitro antileishmanial, antiplasmodial and cytotoxic activities of phenolics and triterpenoids from Baccharis dracunculifolia D. C. (Asteraceae)

Baccharis dracunculifolia (Asteraceae), the most important plant source of the Brazilian green propolis (GPE), displayed in vitro activity against Leishmania donovani. with an IC(50) value of 45 mu g/mL. while GPE presented an IC(50) value of 49 mu g/mL Among the isolated compounds of B. dracunculifolia, ursolic acid, and hautriwaic acid lactone showed IC(50) values of 3.7 mu g/mL and 7.0 mu g/mL, respectively. Uvaol, acacetin, and ermanin displayed moderate antileishmanial activity. Regarding the antiplasmodial assay against Plasmodium falciparum, BdE and GPE gave similar IC(50) values (about 20 mu g/mL), while Hautriwaic acid lactone led to an IC(50) value of 0.8 mu g/mL (D6 clone). (C) 2009 Elsevier B.V. All rights reserved.

Staphylococcus hominis subsp novobiosepticus strains causing nosocomial bloodstream infection in Brazil

To report the isolation of six Staphylococcus hominis subsp. novobiosepticus (SHN) strains from hospitalized patients with bloodstream infections in two Brazilian hospitals and to characterize their susceptibility profile to several antimicrobials. Species identification was performed by biochemical methods and sodA gene sequencing. The MICs of antimicrobials were determined by broth and agar dilution methods and by Etest. Isolates were typed by PFGE and PCR amplification was used to detect the ccr gene complex and the mec class. Morphometric evaluation of cell wall was performed by transmission electron microscopy (TEM). Susceptibility profiles indicated that the majority of isolates (five) were multidrug-resistant. Overlapping and multiplex PCR showed that five out of the six strains harboured SCCmec type III with class A mec and type 3 ccr. The initial vancomycin MIC value of 4 mg/L for these strains increased to 16-32 mg/L after growth for 10 days in BHI broth supplemented with this antimicrobial. TEM indicated that vancomycin resistance was associated with cell wall thickening and to another mechanism not fully elucidated. Only one SHN strain was oxacillin- and vancomycin-susceptible. The nosocomial infections in at least five of the patients from both hospitals were caused by a single clone of SHN. It is very important to consider SHN strains as the cause of nosocomial infections. The clinical implications resulting from the pattern of multidrug resistance in these strains may be complicated by the emergence of vancomycin resistance.

Prevalence and characterization of Enterococcus spp. isolated from Brazilian foods

Enterococci can be used in the food industry as starter or probiotic cultures. However, enterococci are also implicated in severe multi-resistant nosocomial infections. In this study, the prevalence of enterococci in selected Brazilian foodstuffs (raw and pasteurized milk, meat products, cheeses and vegetables) was evaluated. Phenotypic and PCR protocols were used for species identification. Tests for production of gelatinase, haemolysin, bacteriocin and bile salt hydrolysis were done with all enterococci isolates, whereas molecular determination of virulence markers (genes esp, gel, ace, as, efaA, hyl and cylA) and antibiotic resistance was checked only for Enterococcus faecium and Enterococcus faecalis isolates. The antibiotic-resistant isolates were assayed for biofilm formation and adhesion to mammalian cells. From the 120 food samples analyzed, 52.5% were positive for enterococci, meat and cheese being the most contaminated. E. faecium was the predominant species, followed by E. faecalis, E. casseliflavus and Enterococcus gallinarum. Phenotypic tests indicated that 67.7% of isolates hydrolyzed bile salts, 15.2% produced bacteriocin, 12.0% were beta-hemolytic and 18.2% produced gelatinase. Antibiotic resistance (gentamicin, tetracycline and erythromycin) and genes encoding for virulence traits were more frequent in E. faecalis than in E. faecium. Three E. faecium isolates were resistant to vancomycin. Among antibiotic-resistant isolates, 72.4% of E. faecalis were able to form biofilm and 13.8% to adhere to Caco-2 cells. Antibiotic-resistant E. faecalis and E. faecium isolates were grouped by RAPD-PCR and a scattered distribution was noted, indicating that resistance was not related to a particular clone. The spread of virulence/resistance traits in isolates of the two species and different RAPD-types suggest the pathogenic potential of both species. By contrast, the recovery of bacteriocinogenic E. faecium isolates with no virulence traits suggests their potential for biotechnological applications. In conclusion, our results showed that enterococci from Brazilian foods present important dualist aspects for food safety. (C) 2008 Elsevier Ltd. All rights reserved.

New method for quantification of Trypanosoma cruzi in animal`s tissue in the chronic phase of experimental Chagas` disease

We developed a new method for the quantification of parasites in tissue. Trypanosoma cruzi strain CL parasites were genetically engineered to express the Escherichia coli beta-galactosidase gene, lacZ and this enzyme is able to catalyze a colorimetric reaction with chlorophenol red beta-d galactopyranoside (CPRG) as the substrate. The animals were infected with clone CL Brener strain B5 of T. cruzi and treated with benznidazole in order to verify the reduction in the number of parasites in tissue study by quantifying the enzyme beta-galactosidase. The assay demonstrates a reduction in the number of parasites in the groups treated. Thus, this test can be used to test other substances with the aim of verifying the effectiveness in the chronic phase of experimental Chagas` disease.

Nosocomial outbreak by imipenem-resistant metallo-beta-lactamase-producing Pseudomonas aeruginosa in an adult intensive care unit in a Brazilian teaching hospital

Objective: To describe an outbreak of imipenem-resistant metallo-beta-lactamase-producing Pseudomonas aeruginosa, enzyme type bla, by horizontal transmission in patients admitted to a mixed adult ICU. Methods: A case-control study was carried out, including 47 patients (cases) and 122 patients (control) admitted to the mixed ICU of a university hospital in Minas Gerais. Brazil from November 2003 to July 2005. The infection site, risk factors, mortality, antibiotic susceptibility, metallo-beta-lactamase (MBL) production, enzyme type, and clonal diversity were analyzed, Results: A temporal/spatial relationship was detected in most patients (94%), overall mortality was 55.3%, and pneumonia was the predominant infection (85%). The majority of isolates (95%) were resistant to imipenem and other antibiotics, except for polymyxin, and showed MBL production (76.7%). Only bla SPM-1 (33%) was identified in the 15 specimens analyzed. In addition, 4 clones were identified, with a predominance of clone A (61.5%) and B (23.1%). On multivariate analysis, advanced age, mechanical ventilation, tracheostomy, and previous imipenem use were significant risk factors for imipenem-resistant P. aeruginosa infection. Conclusions: Clonal dissemination of MBL-producing P. aeruginosa strains with a spatial/temporal relationship disclosed problems in the practice of hospital infection control, low adherence to hand hygiene, and empirical antibiotic use. (C) 2008 Elsevier Espana, S.L. All rights reserved.

Differences Between ""Classical"" Risk Factors for Infections Caused by Methicillin-Resistant Staphylococcus aureus (MRSA) and Risk Factors for Nosocomial Bloodstream Infections Caused by Multiple Clones of the Staphylococcal Cassette Chromosome mec Type IV MRSA Strain

OBJECTIVE. To identify risk factors associated with nosocomial bloodstream infections caused by multiple clones of the staphylococcal cassette chromosome mec (SCCmec) type IV strain of methicillin-resistant Staphylococcus aureus (MRSA). DESIGN. An unmatched case-control study (at a ratio of 1 : 2) performed during the period from October 2002 through September 2003. SETTING. A 2,000-bed tertiary care teaching hospital affiliated with the University of Sao Paulo in Sao Paulo, Brazil. METHODS. Case patients (n = 30) were defined either as patients who had a bloodstream infection due to SCCmec type IV strains of MRSA diagnosed at least 48 hours after hospital admission or as neonates with the infection who were born in the hospital. Control patients (n = 60) were defined as patients with SCCmec type III MRSA infection diagnosed at least 48 hours after hospital admission. Genes n = 60 encoding virulence factors were studied in the isolates recovered from case patients, and molecular typing of the SCCmec type IV MRSA isolates was also done by pulsed-field gel electrophoresis and multilocus sequence typing. RESULTS. In multivariate analysis, the following 3 variables were significantly associated with having a nosocomial bloodstream infection caused by SCCmec type IV strains of MRSA: an age of less than 1 year, less frequent use of a central venous catheter (odds ratio [OR], 0.07 [95% confidence interval {CI}, 0.02-0.28]; P = .001), and female sex. A second analysis was performed that excluded the case and Pp. 001 control patients from the neonatal unit, and, in multivariate analysis, the following variables were significantly associated with having a nosocomial bloodstream infection caused by SCCmec type IV strains of MRSA: less frequent use of a central venous catheter (OR, 0.12 [95% CI, 0.03-0.55]; P = .007), lower Acute Physiology and Chronic Health Evaluation II score on admission (OR, 0.14 [95% CI, 0.03-0.61];), less frequent surgery (OR, 0.21 [95% CI, 0.06-0.83];), and female sex (OR, 5.70 [95% CI, 1.32-24.66]; P =.020). P = .009 Pp. 025 Pp). Of the 29 SCCmec type IV MRSA isolates recovered from case patients, none contained the Panton-Valentine leukocidin, gamma-hemolysin, enterotoxin B or C, or toxic shock syndrome toxin-1. All of the isolates contained genes for the LukE-LukD leukocidin and alpha-hemolysin. Genes for enterotoxin A were present in 1 isolate, and genes for beta-hemolysin were present in 3 isolates. CONCLUSIONS. ""Classical"" risk factors do not apply to patients infected with the SCCmec type IV strain of MRSA, which is an important cause of nosocomial bacteremia. This strain infects a patient population that is less ill and has had less frequent invasive procedures than a patient population infected with the multidrug-resistant strain of SCCmec type III MRSA. We found that virulence factors were rare and that Panton-Valentine leukocidin was absent. There were multiple clones of the SCCmec type IV strain in our hospital. Children under 1 year of age were at a higher risk. There was a predominant clone ( sequence type 5) in this patient population.

Controlling the clonal spread of Pseudomonas aeruginosa infection

To evaluate nosocomial infections due to imipenem-resistant and imipenem-susceptible Pseudomonas aeruginosa, a case-control study that included genotyping was performed. Hospitalization for more than 15 days was independently associated with infection with an imipenem-resistant organism. Sixty-seven percent of the imipenem-resistant isolates analyzed and 23% of the imipenem-susceptible isolates analyzed belonged to a single clone. Intervention led to a decrease in the number of infections due to imipenem-resistant and imipenem-susceptible P. aeruginosa.

Salvage of long-term central venous catheters during an outbreak of Pseudomonas putida and Stenotrophomonas maltophilia infections associated with contaminated heparin catheter-lock solution

objective. To describe the management of patients with long-term central venous catheters (CVCs) during an outbreak of infection due to Pseudomonas putida and Stenotrophomonas maltophilia associated with contaminated heparin catheter-lock solution. design. Descriptive study. setting. Private, 250-bed tertiary-care hospital. methods. In March 2003, we identified 2 febrile cancer patients with P. putida bacteremia. Over 2 days, 7 cases of bacteremia were identified; lots of syringes prefilled with heparin catheter-lock solution, supplied by a compounding pharmacy, were recalled and samples were cultured. More cases of bacteremia appeared during the following days, and any patient who had had a catheter lock infused with the suspect solution was asked to provide blood samples for culture, even if the patient was asymptomatic. Isolates that were recovered from culture were typed by pulsed-field gel electrophoresis. Antimicrobial salvage treatment of long-term CVCs was attempted. results. A total of 154 patients had had their catheter lock infused with solution from the lots that were suspected of being contaminated. Only 48 of these patients had CVCs. By day 7 of the outbreak, 18 of these patients had become symptomatic. Twenty-six of the remaining 30 asymptomatic patients then also provided blood samples for culture, 10 of whom developed fever shortly after samples were collected. Thirty-two patients were identified who had P. putida bacteremia; 9 also had infection due to S. maltophilia. Samples from 1 of the 3 lots of prefilled syringes in use at the time of the outbreak also grew P. putida on culture. Molecular typing identified 3 different clones of P. putida from patients and heparin catheter-lock solution, and 1 clone of S. maltophilia. A total of 27 patients received antimicrobial therapy regimens, some of which included decontamination of the catheter lock with anti- infective lock solution. Of 27 patients, 19 (70%) retained their long-term CVC during the 6-month follow-up period. conclusions. To our knowledge, this is one of the largest prospective experiences in the management of bloodstream infection associated with long-term CVCs. The infections were caused by gram-negative bacilli and were managed without catheter removal, with a high response rate. We emphasize the risks of using intravenous formulations of medications supplied by compounding pharmacies that produce large quantities of drugs.

Evaluation of the genotoxicity of treated urban sludge in the Tradescantia micronucleus assay

The sludge produced in sewage treatment plants can contain toxic substances. Among these, the genotoxic substances are of great concern. The present paper aimed at evaluating the genotoxicity of treated sludge samples collected at four different sewage treatment plants (STP) located in the State of Sao Paulo Brazil, using the Trad-MN assay. Another objective of the study was to compare the responses of the Clone #4430 with the Tradescantia pallida. Sludge samples mixed with reference soil in concentrations of 10, 25 and 50% (v/v) were tested in experiments with 3 months exposure in the field. Negative and positive controls (arsenic trioxide) were also tested with both plants. In Clone #4430 two sludge samples induced genotoxicity while in T pallida three were positive, although no clear dose-response were observed for both plants. Results with the negative and positive controls suggest that T pallida presented similar results when compared to the Clone #4430. The protocol using plants chronically exposed to sludge mixed with soil seems to be a promising tool to assess the genotoxicity of sludge although time consuming. (C) 2008 Elsevier B.V. All rights reserved.

PLUNC protein expression in major salivary glands of HIV-infected patients

Objective: To analyse and compare the expression of Palate, Lung, and Nasal Epithelium Clone (PLUNC) proteins in salivary glands from patients with and without AIDS (control group) using autopsy material. Methods: We analysed the expression of PLUNCs using immunohistochemistry in parotid (n = 45), submandibular (n = 47) and sublingual gland (n = 37) samples of AIDS patients [30 with normal histology, 21 with mycobacteriosis, 14 with cytomegalovirus (CMV) infection, 30 with chronic non-specific sialadenitis, and 30 HIV-negative controls. In situ hybridization (ISH) for SPLUNC 2 in the HIV-negative group was performed. Results: SPLUNC 1 expression was detected in the mucous acini of submandibular and sublingual glands, and SPLUNC 2 were seen in the serous cells. LPLUNC 1 expression was only positive in the salivary ducts. There was a higher expression of SPLUNC 2 in AIDS patients with CMV infection and mycobacteriosis when compared with all other groups. The intensity of staining for SPLUNC 2 was greater around the lesions than the peripheral ones. ISH for SPLUNC 2 showed perinuclear positivity in the serous cells in all HIV-negative cases. Conclusions: SPLUNC 1 and LPLUNC 1 proteins were similarly expressed in the salivary glands of AIDS patients and non-HIV patients. CMV infection and mycobacteriosis increase SPLUNC 2 expression in serous cells in the salivary gland of AIDS patients.

Application of recombinant antibody library for screening specific antigens in a bovine sperm cell subpopulation

Antibody phage display libraries are a useful tool in proteomic analyses. This study evaluated an antibody recombinant library for identification of sex-specific proteins on the sperm cell surface. The Griffin.1 library was used to produce phage antibodies capable of recognizing membrane proteins from Nelore sperm cells. After producing soluble monoclonal scFv, clones were screened on Simental sperm cells by flow cytometry and those that bound to 40-60% of cells were selected. These clones were re-analyzed using Nelore sperm cells and all clones bound to 40-60% of cells. Positive clones were submitted to a binding assay against male and female bovine leukocytes by flow cytometry and one clone preferentially bound to male cells. The results indicate that phage display antibodies are an alternative method for identification of molecules markers on sperm cells. (C) 2007 Elsevier B.V. All rights reserved.

Inhibition of Snake Venoms and Phospholipases A(2) by Extracts from Native and Genetically Modified Eclipta alba: Isolation of Active Coumestans

We genetically modified Eclipta alba using Agrobacterium rhizogenes LBA 9402, with the aim of producing secondary metabolites with pharmacological properties against phospholipase A(2) and the myotoxic activities of snake venom. Extracts from in natura aerial parts and roots, both native and genetically modified (in vitro), were prepared and analysed by high-performance liquid chromatography. In natura materials showed the coumestan wedelolactone at higher concentration in the aerial parts, while demethylwedelolactone appeared at higher concentration in roots. Among the modified roots, clone 19 showed higher concentrations of these coumestans. Our results show that the in natura extracts of plants collected from Botucatu and Ribeirao Preto were efficient in inhibiting snake venom phospholipase A(2) activity. Regarding in vitro material, the best effect against Crotalus durissus terrificus venom was that of clone 19. Clone 19 and isolated coumestans (wedelolactone and demethylwedelolactone) inhibited the myotoxic activity induced by basic phospholipases A(2) isolated from the venoms of Crotalus durissus terrificus (CB) and Bothrops jararacussu (BthTX-I and II). The search for antivenom is justified by the need of finding active principles that are more efficient in neutralizing snake venoms and also as an attempt to complement serum therapy.

Molecular characteristics of extended-spectrum beta-lactamase-producing Escherichia coli from Rio de Janeiro, Brazil

Twenty-five extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli clinical isolates from Rio de Janeiro, Brazil were characterized by isoelectric focusing, PCR and sequencing of bla(ESBL) genes, plasmid-mediated quinolone resistance determinants, phylogenetic groups, replicon typing, pulsed-field electrophoresis, and multilocus sequencing typing. Twenty-three (92%) ESBL-producing E. coli isolates were positive for bla(CTX-M) genes, aac(6`)-lb-cr, and qnrB. Genetic relatedness of ESBL producers clustered seven (28%) CTX-M-15-producing isolates as sequence type (ST) 410, clonal complex (CC) 23, and two (8%) as clone O25-ST131. Our results illustrate the predominance of phylo-group A (52%), ST410 (CC 23) and CTX-M-15 among ESBL-producing E. coli isolates from hospitals in Rio de Janeiro.

A DNA vaccine candidate encoding the structural prM/E proteins elicits a strong immune response and protects mice against dengue-4 virus infection

A DNA vaccine expressing dengue-4 virus premembrane (prM) and envelope (E) genes was produced by inserting these genes into a mammalian expression plasmid (pCI). Following a thorough screening, including confirmation of protein expression in vitro, a recombinant clone expressing these genes was selected and used to immunize BALB/c mice. After 3 immunizations all the animals produced detectable levels of neutralizing antibodies against dengue-4 virus. The cytokines levels and T cell proliferation, detected ex vivo from the spleen of the immunized mice, showed that our construction induced substantial immune stimulation after three doses. Even though the antibody levels, induced by our DNA vaccine, were lower than those obtained in mice immunized with dengue-4 virus the levels of protection were high with this vaccine. This observation is further supported by the fact that 80% of the vaccine immunized group was protected against lethal challenge. In conclusion, we developed a DNA vaccine employing the genes of the prM and E proteins from dengue-4 virus that protects mice against this virus. (C) 2010 Elsevier Ltd. All rights reserved.

Serum Starvation and Full Confluency for Cell Cycle Synchronization of Domestic Cat (Felis catus) Foetal Fibroblasts

Nuclear transfer of domestic cat can be used as a tool to develop reproductive biotechnologies in wild felids. The importance of cell cycle phase during the nuclear transfer has been a matter of debate since the first mammalian clone was produced. The cell cycle phase of donor cells interferes on maintenance of correct ploidy and genetic reprogramming of the reconstructed embryo. The use of G0/G1 arrested donor cells has been shown to improve nuclear transfer efficiency. The present study was conducted to test the hypothesis that domestic cat foetal fibroblasts cultured up to the fifth passage and submitted to full confluency provide a higher percentage of cells at G0/G1 stage than fibroblasts cultured in serum starved media. Results demonstrated that serum starvation increased (p < 0.05) the percentage of G0/G1 fibroblasts when compared with control. Moreover, the combined protocol using confluency and serum starvation was more efficient (p < 0.05) synchronizing cells at G0/G1 stage than serum starvation or confluency alone for the first 3 days of treatment. In conclusion, serum starvation and full confluency act in a synergistic manner to improve domestic cat foetal fibroblast cell cycle synchronization at the G0/G1 stage.