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Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is a threat to the success of clinical treatment. Besides high antimicrobial resistance rates, the presence of heterogeneous vancomycin-intermediate S. aureus (hVISA) and heterogeneous daptomycin-non-susceptible S. aureus (hDNSSA) in the hospital environment is underestimated and is associated with treatment failure. The aim of this study was to investigate MRSA dissemination in a Brazilian hospital and to evaluate the efficacy of various treatment options in vitro., Methods: MRSA strains were typed by MLST, PFGE and SCCmec typing. Minimum inhibitory concentrations (MICs) to daptomycin, linezolid, quinupristin/dalfopristin, teicoplanin, tetracycline, tigecycline, vancomycin and tedizolid were determined by broth microdilution. The presence of a heterogeneous population was detected by population analysis profile (PAP). Regarding hVISA and hDNSSA strains, the sequences and expression levels of genes involved in resistance to daptomycin and vancomycin were determined as well as cell wall thickness and autolysis., Results: ST5/ST105-SCCmecII lineage was prevalent amongst 27 clinical MRSA characterised in this study. Two hDNSSA strains (one also hVISA) were detected and were confirmed by PAP. Isolate SCMSC29 (hVISA and hDNSSA) showed increased expression of genes involved in cell wall metabolism, slight cell wall thickening, reduction of autolysis, and single nucleotide polymorphisms (SNPs) in the rpoB and mprF genes compared with the susceptible strain SCMSC31. SCMSC35 (hDNSSA) presented SNPs in the rpoB and mprF genes as well as a thickened cell wall., Conclusions: Despite this worrying and hard to detect phenotype, treatment alternatives such as teicoplanin, linezolid, tetracycline, tigecycline, quinupristin/dalfopristin and tedizolid were all active against these isolates., (Copyright © 2018 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.)

Brazilian endemic fruit species have aroused attention due to their highly valuable, yet unexplored, agro-industrial, food and therapeutic potential. Herein, we describe the antifungal activity of four Eugenia spp. against Candida albicans biofilms, and further demonstrate insights into their potential mode(s) of action and toxicity in vitro and in vivo. Extracts from different parts (seeds, pulps, leaves) of E. leitonii (EL), E. brasiliensis (EB), E. myrcianthes (EM) and E. involucrata (EI) were obtained (S23°23',W45°39') and chemically characterized by GC/MS. The active extracts were tested against C. albicans biofilm viability and architecture, as well as mode of action, and toxicology using RAW 264.7 macrophages and Galleria mellonella larvae. The MIC values ranged from 15.62 to >2000 μg/mL. The most active extracts were EL (seed, 15.62 μg/mL) and EB (leaf and seeds, 31.25 and 15.62 μg/mL, respectively). Treatment with these extracts at 10xMIC reduced biofilm viability by 54-55% (P < 0.0001) as compared to 42% by nystatin. At 10xMIC, all extracts caused damages to biofilm architecture and integrity, and fewer hyphae remained attached to treated biofilms. None of them was found to interfere with cell wall biosynthesis or complexation with ergosterol. The extracts had low toxicity against macrophages in vitro (P > 0.05) and G. mellonella larvae, with mean in vivo LD 50 of 1500 mg/kg (EL, seeds); 2500 mg/kg (EB, seeds); and 1250 mg/kg (EB, leaf). The phenolic compounds epicatechin and gallic acid were the major constituents in the extracts. Our findings may open avenues for the application of these yet unexplored native fruits in the food and pharmaceutical industry., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Control of plant pathogen Sclerotinia sclerotiorum is an ongoing challenge because of its wide host range and the persistence of its sclerotia in soil. Fungicides are the most commonly used method to control this fungus but these can have ecotoxicity impacts. Chitinolytic Streptomyces strains isolated from Brazilian tropical soils were capable of inhibiting S. sclerotiorum growth in vitro, offering new possibilities for integrated pest management and biocontrol, with a new approach to dealing with an old problem. Strain Streptomyces sp. 80 was capable of irreversibly inhibiting fungal growth. Compared to other strains, its crude enzymes had the highest chitinolytic levels when measured at 25°C and strongly inhibited sclerotia from S. sclerotiorum. It produced four hydrolytic enzymes involved in fungal cell wall degradation when cultured in presence of the fungal mycelium. The best production, obtained after three days, was 0.75 U/ml for exochitinase, 0.9 U/ml for endochitinase, 0.16 U/ml for glucanase, and 1.78 U/ml for peptidase. Zymogram analysis confirmed two hydrolytic bands of chitinolytic activity with apparent molecular masses of 45.8 and 206.8 kDa. One glucanase activity with an apparent molecular mass of 55 kDa was also recorded, as well as seven bands of peptidase activity with apparent molecular masses ranging from 15.5 to 108.4 kDa. Differential interference contrast microscopy also showed alterations of hyphal morphology after co-culture. Streptomyces sp. 80 seems to be promising as a biocontrol agent against S. sclerotiorum, contributing to the development of new methods for controlling plant diseases and reducing the negative impact of using fungicides.