Circulating tumor DNA association with residual cancer burden after neoadjuvant chemotherapy in triple-negative breast cancer in TBCRC 030.

BACKGROUND: We aimed to examine circulating tumor DNA (ctDNA) and its association with residual cancer burden (RCB) using an ultrasensitive assay in patients with triple-negative breast cancer (TNBC) receiving neoadjuvant chemotherapy. PATIENTS AND METHODS: We identified responders (RCB 0/1) and matched non-responders (RCB 2/3) from the phase II TBCRC 030 prospective study of neoadjuvant paclitaxel versus cisplatin in TNBC. We collected plasma samples at baseline, 3 weeks and 12 weeks (end of therapy). We created personalized ctDNA assays utilizing MAESTRO mutation enrichment sequencing. We explored associations between ctDNA and RCB status and disease recurrence. RESULTS: Of 139 patients, 68 had complete samples and no additional neoadjuvant chemotherapy. Twenty-two were responders and 19 of those had sufficient tissue for whole-genome sequencing. We identified an additional 19 non-responders for a matched case-control analysis of 38 patients using a MAESTRO ctDNA assay tracking 319-1000 variants (median 1000 variants) to 114 plasma samples from 3 timepoints. Overall, ctDNA positivity was 100% at baseline, 79% at week 3 and 55% at week 12. Median tumor fraction (TFx) was 3.7 × 10-4 (range 7.9 × 10-7-4.9 × 10-1). TFx decreased 285-fold from baseline to week 3 in responders and 24-fold in non-responders. Week 12 ctDNA clearance correlated with RCB: clearance was observed in 10 of 11 patients with RCB 0, 3 of 8 with RCB 1, 4 of 15 with RCB 2 and 0 of 4 with RCB 3. Among six patients with known recurrence, five had persistent ctDNA at week 12. CONCLUSIONS: Neoadjuvant chemotherapy for TNBC reduced ctDNA TFx by 285-fold in responders and 24-fold in non-responders. In 58% (22/38) of patients, ctDNA TFx dropped below the detection level of a commercially available test, emphasizing the need for sensitive tests. Additional studies will determine whether ctDNA-guided approaches can improve outcomes.

Microbiological, immunological, and histological changes in the gut of Salmonella Enteritidis-challenged rats fed goat cheese containing Lactobacillus rhamnosus EM1107.

Cheeses are able to serve as suitable matrices for supplying probiotics to consumers, enabling appropriate conditions for bacteria to survive gastric transit and reach the gut, where they are assumed to promote beneficial processes. The present study aimed to evaluate the microbiological, immunological, and histological changes in the gut of Salmonella Enteritidis-challenged rats fed goat cheese supplemented with the probiotic strain Lactobacillus rhamnosus EM1107. Thirty male albino Wistar rats were randomly distributed into 5 experimental groups with 6 animals each: negative (NC) and positive (PtC) control groups, control goat cheese (CCh), goat cheese added with L. rhamnosus EM1107 (LrCh), and L. rhamnosus EM1107 only (EM1107). All animals, except NC group were challenged with Salmonella Enteritidis (109 cfu in 1 mL of saline through oral gavage). Microbial composition was assessed with high-throughput 16S rRNA sequencing by means of Illumina MiSeq (Illumina, San Diego, CA). Nuclear factor kappa B (NF-κB) from the animal cecum tissue was determined by real-time PCR and interleukins (TNF-α, IL-1ß, IL-10, and IFN-γ) by means of ELISA. Myeloperoxidase and malondialdehyde levels were determined biochemically. The administration of the L. rhamnosus EM1107 probiotic strain, either as a pure culture or added to a cheese matrix, was able to reduce Salmonella colonization in the intestinal lumen and lessen tissue damage compared with rats from PtC group. In addition, the use of cheese for the probiotic strain delivery (LrCh) was associated with a marked shift in the gut microbiota composition toward the increase of beneficial organisms such as Blautia and Lactobacillus and a reduction in NF-κB expression. These findings support our hypothesis that cheeses might be explored as functional matrices for the efficacious delivery of probiotic strains to consumers.

Monensin associated or not with virginiamycin or functional oil for feedlot beef cattle.

The objective of this study was to evaluate diets containing monensin (MON) associated or not with virginiamycin (VM) or functional oil based on cashew nut shell and castor beans (FOcc) for beef cattle in feedlots on nutritional (intake and digestibility) and productive parameters. A total of 1410 non-castrated Nellore cattle were selected, with an average age of 18 months and with an initial mean body weight (BW) of 305 ± 41.52 kg. The diet showed a roughage to concentrate ratio of 23:77, with the supply of corn silage as a source of roughage. The following additive inclusions in the diet were evaluated: (1) MON: 27 mg MON/kg dry matter (DM); (2) MON + VM: 22 mg MON/kg DM + 19 mg VM/kg DM; and (3) MON + FOcc: 22 mg MON/kg DM + 500 mg FOcc/kg DM. Statistical analyses were obtained through a linear model using initial BW and days of feedlot as covariables and comparisons between treatments using mutually orthogonal linear contrasts with a 5% significance level. The association or not of MON with VM or FOcc does not affect any of the nutritional and productive parameters evaluated. Animals that receive diets with MON + VM have higher average daily gain and feed efficiency (FE) than those that receive MON + FOcc without showing differences in nutritional parameters. The supply of MON associated with VM or FOcc does not increase intake and productive performance and, consequently, efficiency of feedlot beef cattle. However, in the case of use associated with MON, the VM provides greater performance than FOcc without changing food intake.

Immune response in nonspecific mastitis: What can it tell us?

We analyzed a large number of immune response parameters from quarter milk samples with distinct bacteriological and quarter somatic cell count (qSCC) statuses. Furthermore, we sought to explore and identify displayed immune response patterns in milk samples from mammary glands with nonspecific mastitis. Thus, 92 quarter milk samples from 28 cows were stratified into 4 groups, as follows: (1) 49 culture-negative control quarters with a low qSCC (<1 × 105 cells/mL) from 19 dairy cows (so-called healthy quarters); (2) 15 culture-negative quarters with high qSCC (>2 × 105 cells/mL; so-called quarters with nonspecific mastitis) from 10 dairy cows; (3) 8 culture-positive quarters with low qSCC (noninflammatory quarters with low qSCC) from 5 dairy cows; and (4) 20 culture-positive quarters with high qSCC (so-called truly infected quarters) from 8 dairy cows. Using flow cytometry, we evaluated the percentage of milk neutrophils and their viability, intracellular reactive oxygen species production, phagocytosis, and the expression of CD62L, CD11b, and CD44 for each of the 4 quarter strata. Furthermore, the percentage of monocyte/macrophages, B cells, and T lymphocyte subsets were evaluated by flow cytometry. Milk samples from bacteriologically negative quarters (both with a low and elevated qSCC) had a lower qSCC than those with bacteriologically positive outcomes (both with a low and elevated qSCC). As expected, the healthy quarters showed the lowest percentage of neutrophils and also showed a higher percentage of milk monocytes/macrophages and lower percentage of T lymphocytes than truly infected quarters. The most prominent result of the present study is that quarters with nonspecific mastitis showed the highest percentage of milk CD4+ T lymphocytes. The healthy quarters had a lower percentage of apoptotic neutrophils than noninflammatory and truly infected quarters, although it did not differ from those from the quarters with nonspecific mastitis. Our study supports the role of differential cell counting in the diagnosis of mastitis, as the milk leukocyte populations markedly fluctuate under healthy and inflammatory conditions. Furthermore, an increase in milk CD4+ T cells was associated with nonspecific mastitis, suggesting an increase in this leukocyte subpopulation is correlated with low bacterial shedding. Our study allows us to go further in our understanding of mammary gland immunity, providing further insights on potential protective mammary gland immunity, which we hypothesize can open new avenues for the development of novel targets that can promote bovine udder health.

Tannin-Rich Plants as Natural Manipulators of Rumen Fermentation in the Livestock Industry.

Condensed tannins (CTs) are plant anti-herbivore compounds with antimicrobial activity that can be used in ruminant diets as ruminal microbiome manipulators. However, not all CTs from fodder legumes are bioactive due to their wide structural diversity. The aim of our study was to investigate the effect of 10 CT-containing plants (Flemingia macrophylla, Leucaena leucocephala, Stylosanthes guianensis, Gliricidia sepium, Cratylia argentea, Cajanus cajan, Desmodium ovalifolium, Macrotiloma axilare, D. paniculatum, and Lespedeza procumbens) on in vitro fermentation kinetics of Nelore beef cattle. Polyethylene glycol (PEG), a specific CT-binding agent, was added to neutralize condensed tannin. Tifton and alfalfa hay were used as controls lacking CT. The experimental layout included a randomized complete block with factorial design and four blocks. The data were subjected to analysis of variance followed by Duncan's test to determine differences (p < 0.05) among treatment means. The addition of PEG in browse incubations resulted in increased gas production, fermentation rate, short-chain fatty acid (SCFA) and N-NH3 release. Within our study, Lespedeza procumbens, Desmodium paniculatum, Leucaena leucocephala, Desmodium ovalifolium, and Flemingia macrophylla showed superior bioactivity compared to other species evaluated, suggesting a natural alternative for replacing ionophores to modify ruminal fermentation. Condensed tannins from L. pocumbens, D. paniculatum, L. leucocephala, D. ovalifolium, and F. macrophylla have the potential to modify rumen fermentation in beef cattle.

Aeromonas caviae inhibits hepatic enzymes of the phosphotransfer network in experimentally infected silver catfish: Impairment on bioenergetics.

Several studies have been demonstrated that phosphotransfer network, through the adenylate kinase (AK) and pyruvate kinase (PK) activities, allows for new perspectives leading to understanding of disease conditions associated with disturbances in energy metabolism, metabolic monitoring and signalling. In this sense, the aim of this study was to evaluate whether experimental infection by Aeromonas caviae alters hepatic AK and PK activities of silver catfish Rhamdia quelen. Hepatic AK and PK activities decreased in infected animals compared to uninfected animals, as well as the hepatic adenosine triphosphate (ATP) levels. Also, a severe hepatic damage was observed in the infected animals due to the presence of dilation and congestion of vessels, degeneration of hepatocytes and loss of liver parenchyma architecture and sinusoidal structure. Therefore, we have demonstrated, for the first time, that experimental infection by A. caviae inhibits key enzymes linked to the communication between sites of ATP generation and ATP utilization. Moreover, the absence of a reciprocal compensatory mechanism between these enzymes contributes directly to hepatic damage and for a severe energetic imbalance, which may contribute to disease pathophysiology.

Molecular characteristics of granulosa and cumulus cells and oocyte competence in Nelore cows with low and high numbers of antral follicles.

The aims of this study were to investigate whether the number of antral follicles (AF) in the ovaries of Nelore cows is influenced with the developmental competence of oocytes to reach the blastocyst stage and to quantify the mRNA abundance of genes associated with folliculogenesis and oogenesis in granulosa and cumulus cells. A total of 168 cows were distributed into two experimental groups according to the number of AF, low (≤31) and high AF (≥92), which were determined based on the mean number of AF (61.14) ± SD (30.43). Granulosa and cumulus cells were used to assess the mRNA expression of 16 genes. Cumulus cells from cows with low AF had higher mRNA expression of genes involved in meiosis resumption (NPR-2, NPR-3) and cumulus cell expansion (FGF10), as well as a transcription factor involved in the regulation of oocyte maturation and cell proliferation (STAT3). Conversely, granulosa cells from females with high AF had higher expression of PGR and AMHR2a, which are involved in meiosis resumption and cumulus cell expansion. Cumulus-oocyte complexes (COCs) were collected from 356 cows with low and high AF populations to evaluate embryo development. Cleavage and blastocyst rates did not differ between the groups. In conclusion, our findings revealed that genes involved in folliculogenesis and oogenesis are differently expressed in cumulus and granulosa cells of cows having low and high numbers of AF. These molecular differences suggest that the regulation of oocyte maturation, meiotic resumption and cumulus expansion may be influenced by the number of AFs. However, the variations in gene expression were not associated with in vitro oocyte developmental competence to reach the blastocyst stage, which confirms that oocytes from Nelore cows with low and high numbers of AF are similarly able to mature, regulate the fertilization process and support pre-implantation embryo development.

Effects of dietary yeast cell wall on faecal bacteria and fermentation products in adult cats.

This study evaluated the effects of increasing concentrations of spray-dried yeast cell wall (YCW) in diets for healthy adult cats on apparent nutrient digestibility and on bacterial composition and fermentation products in the stool. Fourteen cats with an average weight of 4.40 ± 1.05 kg and an average age of 6.2 ± 0.54 years were used and assigned to treatments in an unbalanced randomized block design (by experimental period) with two blocks and three or four cats per diet in each block. Treatments included: control (0% YCW), 0.2% YCW, 0.4% YCW and 0.6% YCW, totalling seven animals per experimental diet. We found that YCW did not affect body weight, nutrient and food intake, faecal production, faecal score, faecal pH or urine output (p > .05). Regarding faecal bacteria, we observed a linear reduction in Clostridium perfringens, a quadratic reduction in Escherichia coli, and linear increases in Bifidobacterium spp. and Lactobacillus spp. (p < .05) with the inclusion of YCW. Regarding the faecal short-chain fatty acid profile, butyrate, valerate, total biogenic amines, putrescine, cadaverine and histamine increased linearly (p < .05) with the inclusion of YCW. It was concluded that in healthy adult cats, consumption of YCW modulates the faecal bacterial populations, with an increased presence of beneficial bacteria and a reduction in some potentially pathogenic bacteria. It was concluded that YCW modulated the levels of fermentation products. There was an increase in fermentation products coming from carbohydrate metabolism, an important effect that can potentially benefit the intestinal health of cats. The consumption of YCW also increased the fermentation of nitrogen compounds, which have not yet been defined as deleterious or beneficial. The fermentability of carbohydrates and nitrogen compounds may be associated. Therefore, YCW may cause rapid fermentation of both classes of compounds by enhancing the fermentability of one class.

Systemic therapies for recurrent or metastatic nasopharyngeal carcinoma: a systematic review.

BACKGROUND: The majority of published studies in recurrent or metastatic nasopharyngeal carcinoma (RM-NPC) are single-arm trials. Reliable modelling of progression-free survival (PFS) and overall survival (OS) outcomes, therefore, is difficult. This study aim to analyse existent literature to estimate the relative efficacy of available systemic regimens in RM-NPC, as well as provide estimates of aggregate OS and PFS. METHODS: We conducted a systematic search of MEDLINE, EMBASE and the Cochrane Library to March 2015. Clinical trials (in English only) investigating cytotoxic and molecularly targeted agents in adult patients with RM-NPC were included. All relevant studies were assessed for quality using Downs and Blacks (DB) checklist (maximum quality score of 27). Aggregate data analysis and Student's t-test were performed for all identified studies (model A). For studies that published analysable Kaplan-Meier curves, survival data were extracted and marginal proportional hazards models were constructed (model B). RESULTS: A total of 56 studies were identified and included in model A, 26 of which had analysable Kaplan-Meier curves and were included in model B. The 26 studies in model B had significantly higher mean DB scores than the remaining 30 (17.3 vs 13.7, P=0.002). For patients receiving first line chemotherapy, the estimated median OS was 15.7 months by model A (95% CI, 12.3-19.1), and 19.3 months by model B (95% CI, 17.6-21.1). For patients undergoing second line or higher therapies (2nd+), the estimated median OS was 11.5 months by model A (95% CI 10.1-12.9), and 12.5 months by model B (95% CI 11.9-13.4). PFS estimates for patients undergoing first-line chemotherapy by model A was 7.6 months (95% CI, 6.2-9.0), and 8.0 months by model B (95% CI, 7.6-8.8). For patients undergoing therapy in the 2nd+ setting, the estimated PFS by model A was 5.4 months (95% CI, 3.8-7.0), and 5.2 months by model B (95% CI, 4.7-5.6). CONCLUSIONS: We present the first aggregate estimates of OS and PFS for RM-NPC patients receiving first and second-line or higher treatment settings, which could inform the design of future clinical trials in this disease setting.

Protective effects of exogenous and endogenous hydrogen sulfide in mast cell-mediated pruritus and cutaneous acute inflammation in mice.

The recently described 'gasomediator' hydrogen sulfide (H2S) has been involved in pain mechanisms, but its effect on pruritus, a sensory modality that similarly to pain acts as a protective mechanism, is poorly known and controversial. The effects of the slow-releasing (GYY4137) and spontaneous H2S donors (Na2S and Lawesson's reagent, LR) were evaluated in histamine and compound 48/80 (C48/80)-dependent dorsal skin pruritus and inflammation in male BALB/c mice. Animals were intradermally (i.d.) injected with C48/80 (3µg/site) or histamine (1µmol/site) alone or co-injected with Na2S, LR or GYY4137 (within the 0.3-100nmol range). The involvement of endogenous H2S and KATP channel-dependent mechanism were also evaluated. Pruritus was assessed by the number of scratching bouts, whilst skin inflammation was evaluated by the extravascular accumulation of intravenously injected 125I-albumin (plasma extravasation) and myeloperoxidase (MPO) activity (neutrophil recruitment). Histamine or C48/80 significantly evoked itching behavior paralleled by plasma extravasation and increased MPO activity. Na2S and LR significantly ameliorated histamine or C48/80-induced pruritus and inflammation, although these effects were less pronounced or absent with GYY4137. Inhibition of endogenous H2S synthesis increased both Tyrode and C48/80-induced responses in the skin, whereas the blockade of KATP channels by glibenclamide did not. H2S-releasing donors significantly attenuate C48/80-induced mast cell degranulation either in vivo or in vitro. We provide first evidences that H2S donors confer protective effect against histamine-mediated acute pruritus and cutaneous inflammation. These effects can be mediated, at least in part, by stabilizing mast cells, known to contain multiple mediators and to be primary initiators of allergic processes, thus making of H2S donors a potential alternative/complementary therapy for treating inflammatory allergic skin diseases and related pruritus.

Antioxidant activity and chemical composition of oleoresin from leaves and flowers of Brunfelsia uniflora.

In this study, the temperature and pressure of supercritical CO2 extraction were evaluated to obtain oleoresin of Brunfelsia uniflora leaves and flowers. The oleoresin compounds were identified by gas chromatography-mass spectrometry. The antioxidant activity was evaluated by three different methods. The highest oleoresin yields were 3.32% at 40°C and 200 bar for the leaves, and 1.03% at 60°C and 200 bar for the flowers. The main extracted compounds from leaves were phytol varying from 11.95 to 36.42% and α-tocopherol from 15.53 to 43.10%, and from flowers were geranyl linalool from 11.05 to 21.42% and α-amyrin from 9.66 to 22.12%. Oleoresin obtained at 60°C and 150 bar from leaves presented high antioxidant activity by DPPH (IC50 1.90 mg/mL) and by FRAP (1.8 µmol Fe2+/mg). ß-carotene/linoleic acid co-oxidation oleoresin from leaves at 0.25 mg/mL presented higher antioxidant activity than Trolox. The total phenolic content of the oleoresin from leaves ranged from 66.20 to 83.33 µg/mg and from flowers it was just up to 12.46 µg/mg. The extraction conditions affected yield, chemical composition, and antioxidant activity of oleoresin from leaves and flowers. This is the first report on the antioxidant activity of B. uniflora oleoresin from leaves and flowers and provides subsidies for potential applications in chemical, pharmaceutical, and food industries.

Quality of life in patients with allergic rhinitis: a clinical trial comparing the use of bilastine versus loratadine.

OBJECTIVES: The aim of this study was to determine whether there were differences in health-related quality of life of patients with allergic rhinitis treated with bilastine 20 mg compared to those treated with loratadine 10 mg. DESIGN: This was a prospective randomised double-blinded study. SETTING: Otolaryngology outpatient clinics in Criciúma, state of Santa Catarina, Brazil. PARTICIPANTS: Seventy-three patients, aged between 18 and 63 years, of whom 36 were treated with loratadine 10 mg and 37 with bilastine 20 mg with medication administered once a day for 10 days. MAIN OUTCOME MEASURES: The outcome was quality of life as assessed by the modified Rhinoconjunctivitis Quality of Life Questionnaire (RQLQm), which was applied at baseline and after 10 days of treatment. RESULTS: The use of bilastine 20 mg or loratadine 10 mg significantly reduced RQLQm scores after 10 days of treatment (P < 0.001); however, there was no statistically significant difference between the two treatment groups (P > 0.05). CONCLUSIONS: Health-related quality of life in patients with allergic rhinitis improved significantly after 10 days of treatment with loratadine and bilastine, and the effectiveness of both was equivalent.

Subgingival bacterial community profiles in HIV-infected Brazilian adults with chronic periodontitis.

BACKGROUND AND OBJECTIVE: To compare the subgingival microbial diversity between non-HIV-infected and HIV-infected individuals with chronic periodontitis using denaturing gradient gel electrophoresis (DGGE). MATERIAL AND METHODS: Thirty-two patients were selected: 11 were HIV-infected and 21 were non-HIV-infected, and all had chronic periodontitis. Periodontal measurements included probing depth, clinical attachment level, visible supragingival biofilm and bleeding on probing. Subgingival biofilm samples were collected from periodontal sites (50% with probing depth ≤ 4 mm and 50% with probing depth ≥ 5 mm) and whole-genomic-amplified DNA was obtained. The DNA samples were subjected to amplification of a 16S rRNA gene fragment using universal bacterial primers, followed by DGGE analysis of the amplified gene sequences. RESULTS: The non-HIV-infected group presented higher mean full-mouth visible supragingival biofilm (p = 0.004), bleeding on probing (p = 0.006), probing depth (p < 0.001) and clinical attachment level (p = 0.001) in comparison with the HIV-infected group. DGGE analysis revealed 81 distinct bands from all 33 individuals. Banding profiles revealed a higher diversity of the bacterial communities in the subgingival biofilm of HIV-infected patients with chronic periodontitis. Moreover, cluster and principal component analyses demonstrated that the bacterial community profiles differed between these two conditions. High interindividual and intra-individual variability in banding profiles were observed for both groups. CONCLUSION: HIV-infected patients with chronic periodontitis present greater subgingival microbial diversity. In addition, the bacterial communities associated with HIV-infected and non-HIV-infected individuals are different in structure.

Mapping the spatio-temporal distribution of threatened batoids to improve conservation in a subtropical estuary.

The spatio-temporal distributions of four batoid species were examined in a subtropical estuary. Fluvial gradient was the most important factor explaining abundances, reflecting positive relationships with either salinity or distance from urbanised areas that were consistent across seasons and depths. The results support existing protected areas.

Worldwide HLA-E nucleotide and haplotype variability reveals a conserved gene for coding and 3' untranslated regions.

The human leukocyte antigen-E (HLA-E) locus is a human major histocompatibility complex (MHC) gene associated with immune-modulation and suppression of the immune response by the interaction with specific natural killer (NK) and T cell receptors (TCRs). It is considered one of the most conserved genes of the human MHC; however, this low nucleotide variability seems to be a consequence of the scarce number of studies focusing on this subject. In this manuscript we assessed the nucleotide variability at the HLA-E coding and 3' untranslated regions (3'UTRs) in Brazil and in the populations from the 1000Genomes Consortium. Twenty-eight variable sites arranged into 33 haplotypes were detected and most of these haplotypes (98.2%) are encoding one of the two HLA-E molecules found worldwide, E*01:01 and E*01:03. Moreover, three worldwide spread haplotypes, associated with the coding alleles E*01:01:01, E*01:03:01 and E*01:03:02, account for 85% of all HLA-E haplotypes, suggesting that they arose early before human speciation. In addition, the low nucleotide diversity found for the HLA-E coding and 3'UTR in worldwide populations suggests that the HLA-E gene is in fact a conserved gene, which might be a consequence of its key role in the modulation of the immune system.

Reliability of the MicroScan WalkAway PC21 panel in identifying and detecting oxacillin resistance in clinical coagulase-negative staphylococci strains.

The purpose of this study was to determine the reliability of the MicroScan WalkAway PosCombo21 (PC21) system for the identification of coagulase-negative staphylococci (CNS) strains and the detection of oxacillin resistance. Using molecular and phenotypic methods, 196 clinical strains were evaluated. The automated system demonstrated 100 % reliability for the identification of the clinical strains Staphylococcus haemolyticus, Staphylococcus hominis and Staphylococcus cohnii; 98.03 % reliability for the identification of Staphylococcus epidermidis; 70 % reliability for the identification of Staphylococcus lugdunensis; 40 % reliability for the identification of Staphylococcus warneri; and 28.57 % reliability for the identification of Staphylococcus capitis, but no reliability for the identification of Staphylococcus auricularis, Staphylococcus simulans and Staphylococcus xylosus. We concluded that the automated system provides accurate results for the more common CNS species but often fails to accurately identify less prevalent species. For the detection of oxacillin resistance, the automated system showed 100 % specificity and 90.22 % sensitivity. Thus, the PC21 panel detects oxacillin-resistant strains, but is limited by the heteroresistance that is observed when using most phenotypic methods.

Infective endocarditis in Rio de Janeiro, Brazil: a 5-year experience at two teaching hospitals.

INTRODUCTION: Despite the recent advances in diagnosis and treatment, mortality rates due to infective endocarditis (IE) remain high if not aggressively treated with antibiotics, whether or not associated with surgery. Data on the prevalence, epidemiology and etiology of IE from developing countries remain scarce. The aim of this observational, prospective cohort study was to report a 5-year experience of IE at two teaching hospitals in Rio de Janeiro, Brazil. MATERIAL AND METHODS: Demographical, anamnestic and microbiological characteristics of 71 IE patients were evaluated during the period of January 2009 to March 2013. RESULTS: The mean age of the IE patients was 49.8 ± 2.4 years, of which 41 (57.7%) were males. The median time between the onset of symptoms and diagnosis of IE was 35.8 ± 4.8 days. A total of 31 (43.6%) cases of community-acquired infective endocarditis (CAIE) and 40 (56.3%) cases of healthcare-acquired infective endocarditis (HAIE) were observed. Staphylococcus aureus (30%) was the predominant cause of IE. Streptococcus spp. (45.1 %) was the predominant cause of the CAIE while S. aureus (32.5%) and Enterococcus spp. (27.2 %) were the main etiological agents of HAIE. For 64 (90.1 %) patients with native valve endocarditis, the mitral valve was the most commonly affected (48.3%). The main source of IE in this cohort was intravascular catheter. The tricuspid valve and renal chronic insufficiency were more frequent in patients with HAIE than CAIE (p = 0.001). The risk factors associated with in-hospital mortality rate (46.4%) in IE patients were: age over 45 (OR 3.4; 95% CI 1.03-11.24; p = 0.04) and chronic renal insufficiency (OR 38.3; 95% CI 3.2-449.4; p = 0.004). CONCLUSIONS: At two main teaching hospitals in Brazil, Streptococcus spp. was the principal pathogen of CAIE while S. aureus and Enterococcus spp. were the most frequent causes of HAIE. IE remains a serious disease associated with high in-hospital mortality rate (46.6%); especially, in individuals over 45 years of age and with renal failure. Data suggest that early surgery may improve the outcome of IE patients.

Antimicrobial synergism against different lineages of methicillin-resistant Staphylococcus aureus carrying SCCmec IV.

AIM: To evaluate the synergistic activity of antimicrobial drugs against lineages of methicillin-resistant Staphylococcus aureus (MRSA) carrying SCCmec IV. The biofilm production and related genes were also detected. METHODS AND RESULTS: Forty two MRSA isolates were tested for biofilm production and related genes. Biofilm/biomass susceptibility to gentamicin (G), linezolid (L), rifampicin (R) and vancomycin (V) was determined for six isolates from three lineages prevalent in Rio de Janeiro hospitals in concentrations ranging from 0·25 to 64 µg ml(-1). Biomass was evaluated by microtitre plate test and number of viable cells (CFU cm(-2)) and inspected by epifluorescence microscopy. All isolates presented the icaA and sasG genes, but only 38% were biofilm producers. There were 50 and 45% biomass reductions when concentrations ≥4 µg ml(-1) of R or L and ≥16 µg ml(-1) of G or V, respectively, were used. Synergism tests produced a 55% biomass reduction with R(2µgml-1) + G(16µgml-1), R(2µgml-1) + L(2µgml-1), R(2µgml-1) + V(4µgml-1), and L(2µgml-1) + V(4µgml-1). Number of viable cells was reduced from 2 to 3 logs with R(2µgml-1) + L(2µgml-1) and R(2µgml-1) + V(4µgml-1). CONCLUSIONS: Synergisms involving R plus L and R plus V caused important reductions in biofilm/biomass and the number of viable cells. Drug combinations should be considered in the chemotherapies of MRSA-SCCmec IV infections. SIGNIFICANCE AND IMPACT OF THE STUDY: Biofilms in MRSA infections restrict the clinical choice of antimicrobials. Thus, knowledge of the best options for monotherapy and drug synergisms could improve clinical results.

Antibacterial effect of coffee: calcium concentration in a culture containing teeth/biofilm exposed to Coffea Canephora aqueous extract.

UNLABELLED: This study determined the changes of calcium concentration in a medium containing teeth/biofilm exposed to Coffea canephora extract (CCE). Enamel fragments were randomly fixed into two 24-well polystyrene plates containing BHI. Pooled human saliva was added to form biofilm on fragments. Specimens were divided into treatment groups (G, n = 8 per group) and treated with 50 µl daily for 1 min per week, as follows: G1, 20% CCE; G2, Milli-Q water (negative control); G3, antibiotic (positive control). Six fragments represented the blank control (G4). The calcium content was observed at baseline, 4 and 7 days of treatment by atomic-absorption spectrophotometry. Cross-sectional hardness of enamel was a demineralization indicator. Calcium increased in the medium after 4 and 7 days of treatment in G1 (3·80 ± 1·3 mg l(-1) and 4·93 ± 2·1 mg l(-1) , respectively) and G3 (4th day = 5·7 ± 1·8 mg l(-1) ; 7th day = 6·7 ± 3·5 mg l(-1) ) (P > 0·05). Calcium from G2 decreased after 7 days, which was different from G3 (P < 0·05). The lower calcium content, at the end of the experiment, was represented by G4, 2·16 ± 0·2 mg l(-1) . The increase in calcium after treatment with CCE is probably due to its antibacterial effect, which caused the bacterial lysis and consequent release of calcium in the medium. SIGNIFICANCE AND IMPACT OF THE STUDY: This study revealed an inhibitory action of Coffea canephora against dental biofilm. This coffee species caused bacterial lysis and consequent release of calcium into the medium. Furthermore, the advantage of coffee as an antibacterial beverage is that it is consumed in a concentrated form (6-10%) as opposed to various medicinal infusions that have shown such effect in vitro and are usually consumed at 1-2%. Therefore, a light roasted C. canephora aqueous extract can be considered as a potential anticariogenic substance.