Disseminated Clonal Complex 5 (CC5) methicillin-resistant Staphylococcus aureus SCCmec type II in a tertiary hospital of Southern Brazil

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of human infections worldwide, with major dominant lineage circulating in particular geographical regions. The Brazilian Epidemic Clone (BEC, SCCmec III, ST 239) has been predominant in most Brazilian hospitals. Here, we report the prevalence of MRSA SCCmec type II exhibiting different STs, most of them belonging to CC5 in a tertiary hospital in Southern Brazil

Secondary metabolite from Pseudomonas aeruginosa LV strain exhibits antibacterial activity against Staphylococcus aureus: Metabólito secundário de Pseudomonas aeruginosa cepa LV exibe atividade antibacteriana em Staphylococcus aureus

This study aimed to evaluate the antibacterial activity of the dichloromethane/ethyl acetate fraction (named F4a), obtained from the culture of Pseudomonas aeruginosa LV strain in presence of copper chloride, against planktonic and sessile cells of Staphylococcus aureus, including those presenting multidrug resistance. First, the minimal inhibitory concentrations (MIC) of F4a for twenty-six clinical isolates were determined and the values ranged from 1.56 to 6.25 µg/mL. Minimal bactericidal concentration (MBC) of 3.13 µg/mL was detected in 84.6% of the isolates. The time-kill curve analysis revealed a significant decreased in colony-forming unit counts after 4 h of treatment with the MIC/MBC of F4a. Moreover, the MIC/MBC of the fluopsin C, a copper-containing compound present in F4a, were 1.56/3.13 µg/mL, indicating that this compound seems to be one of the active components related to the antibacterial activity against S. aureus. Images of transmission electron microscopy showed significant ultrastructural alterations in planktonic cells treated with the MIC/MBC of F4a. A significant reduction in the metabolic activity of established biofilms of all S. aureus isolates was observed after treatment with F4a. No hemolytic activity to human erythrocytes was detected for F4a, and the cytotoxic concentration to LLC-MK2 cells was 3.44 µg/mL. In conclusion, F4a exhibited a bactericidal activity against planktonic cells and inhibited the metabolic activity of biofilms of S. aureus. F4a can be promising for the development of new strategies for the treatment of infections caused by S. aureus

Biofilm - forming characteristics of vancomycin - resistant Enterococcus faecium vanA of the epidemic clonal complex 17 isolated in a university hospital of southern Brazil: Características dos biofilmes formados por Enterococcus faecium resistente à vancomicina vanA do complexo clonal epidêmico 17 isolado em um hospital universitário do sul do Brasil

Vancomycin-resistant Enterococcus faecium (VREfm) is an important etiologic agent of healthcare-associated infections worldwide. The present study aimed to characterize the vanA-carrying VREfm isolates according to their genetic relatedness, multilocus sequence typing (MLST), biofilm-forming characteristics, and the occurrence of putative genes involved in adhesion, biofilm formation, and pili assembly. High genetic diversity among the ten vanA VREfm isolated from inpatients was observed using the rep-PCR analysis. According to the MLST analyses, four different STs were detected among the vanA VREfm isolates, with ST 412 being the most prevalent. Most of the STs detected in this study belong to Clonal Complex 17 (CC 17), a high-risk clone adapted to the hospital environment. All VREfm were capable of forming biofilm on a polystyrene surface. However, significant differences in biofilm biomass were observed among the different isolates, including those with the same ST. Scanning electron microscopy analyses of the 24-h biofilms revealed the presence of sessile cells surrounded by an extracellular polymeric substance. All VREfm harbored the atlA gene, and nine were positive for the ecbA gene. The acm, scm, and ebpC genes were detected in six isolates. Finally, the fms21/pilA gene was detected in seven isolates

ANTIFUNGAL POTENTIAL OF PLANT SPECIES FROM BRAZILIAN CAATINGA AGAINST DERMATOPHYTES

Trichophyton rubrum and Trichophyton mentagrophytes complex, or Trichophyton spp. are the main etiologic agents of dermatophytosis, whose treatment is limited by the high cost of antifungal treatments, their various side effects, and the emergence of resistance amongst these species. This study evaluated the in vitro antidermatophytic activity of 23 crude extracts from nine plant species of semiarid vegetation (caatinga) found in Brazil. The extracts were tested at concentrations ranging from 1.95 to 1,000.0 mg/mL by broth microdilution assay against the reference strains T. rubrum ATCC 28189 and T. mentagrophytesATCC 11481, and 33 clinical isolates of dermatophytes. All plants showed a fungicidal effect against both fungal species, with MIC/MFC values of the active extracts ranging from 15.6 to 250.0 µg/mL. Selected extracts of Eugenia uniflora (AcE), Libidibia ferrea (AE), and Persea americana (AcE) also exhibited a fungicidal effect against all clinical isolates of T. rubrum and T. mentagrophytes complex. This is the first report of the antifungal activity of Schinus terebinthifolius, Piptadenia colubrina, Parapiptadenia rigida, Mimosa ophthalmocentra, and Persea americana against both dermatophyte species

Antifungal Combination of Ethyl Acetate Extract of Poincianella pluviosa (DC.) L. P. Queiros Stem Bark With Amphotericin B in Cryptococcus neoformans

Cryptococcus neoformans is the leading cause of cryptococcosis, an invasive and potentially fatal infectious disease. Therapeutic failures are due to the increase in antifungal resistance, the adverse effects of drugs, and the unavailability of therapeutic regimens in low-income countries, which limit the treatment of cryptococcosis, increasing the morbidity and mortality associated with these infections. Thus, new antifungal drugs and innovative strategies for the cryptococcosis treatment are urgently needed. The aim of the present study was to evaluate the effect of ethyl acetate fraction (EAF) of Poincianella pluviosa stem bark on planktonic and biofilm mode of growth of C. neoformans. Furthermore, the interaction between the EAF and amphotericin B (AmB) was evaluated in vitro and in Galleria mellonella infection model. Minimal inhibitory concentrations (MICs) of EAF ranged from 125.0 to >1,000.0 μg/ml and >1,000.0 μg/ml for planktonic and sessile cells, respectively. The combination between EAF and AmB exhibited a synergistic fungicidal activity toward C. neoformans, with a fractional inhibitory concentration index (FICI) ranging from 0.03 to 0.06 and 0.08 to 0.28 for planktonic and sessile cells, respectively. Microscopy analyses of planktonic C. neoformans cells treated with EAF, alone or combined with AmB, revealed morphological and ultrastructural alterations, including loss of integrity of the cell wall and cell membrane detachment, suggesting leakage of intracellular content, reduction of capsule size, and presence of vacuoles. Moreover, EAF alone or combined with AmB prolonged the survival rate of C. neoformans-infected G. mellonella larvae. These findings indicate that P. pluviosa may be an important source of new compounds that can be used as a fungus-specific adjuvant for the treatment of cryptococcosis

Bacteremia causada por Staphylococcus aureus: Uma análise de quinze anos da sensibilidade a antimicrobianos em um hospital terciário do Brasil

Justificativa e Objetivo: Infecções da corrente sanguínea por Staphylococcus aureus constituem uma das principais causas de morbidade e mortalidade em todo mundo. O tratamento de infecções por S. aureus é complicado pela elevada prevalência de resistência a antimicrobianos. Compreender a epidemiologia e os padrões de resistência deste microrganismo é um ponto crítico para a prescrição empírica adequada de antimicrobianos. Desta maneira, este estudo teve por objetivo avaliar a evolução de resistência antimicrobiana de S. aureus num período de quinze anos. Metodologia: Foram analisados os testes de sensibilidade aos antimicrobianos de 720 S. aureus isolados de hemoculturas de um hospital terciário do sul do Brasil. Os dados foram obtidos do Sistema de Informação AGTA Healthcare, módulo LABHOS®. Resultados: A frequência média de S. aureus resistentes a meticilina foi de 43,74%. Com exceção de penicilina, ocorreu variação significativa da resistência para todos os antimicrobianos no período avaliado (< 0,001). Ciprofloxacina, Eritromicina e Clindamicina apresentaram os maiores índices de resistência com tendência de aumento. Surpreendentemente, Gentamicina e Sulfametoxazol-Trimetoprim apresentaram queda significativa nos percentuais de resistência. Analisando-se vancomicina do ano 2011 a 2015 pode-se evidenciar um aumento das concentrações inibitórias mínimas. Conclusão: Embora a resistência a antimicrobianos tenha aumentado nos quinze anos para a maioria dos antimicrobianos, para Sulfametoxazol-Trimetoprim e Gentamicina ocorreu redução significativa, indicando uma possível alteração clonal. Este estudo evidenciou, ainda, a emergência do fenótipo S. aureus intermediário a vancomicina

An Essential Nuclear Protein in Trypanosomes Is a Component of mRNA Transcription/Export Pathway

In eukaryotic cells, different RNA species are exported from the nucleus via specialized pathways. The mRNA export machinery is highly integrated with mRNA processing, and includes a different set of nuclear transport adaptors as well as other mRNA binding proteins, RNA helicases, and NPC-associated proteins. The protozoan parasite Trypanosoma cruzi is the causative agent of Chagas disease, a widespread and neglected human disease which is endemic to Latin America. Gene expression in Trypanosoma has unique characteristics, such as constitutive polycistronic transcription of protein-encoding genes and mRNA processing by trans-splicing. In general, post-transcriptional events are the major points for regulation of gene expression in these parasites. However, the export pathway of mRNA from the nucleus is poorly understood. The present study investigated the function of TcSub2, which is a highly conserved protein ortholog to Sub2/ UAP56, a component of the Transcription/Export (TREX) multiprotein complex connecting transcription with mRNA export in yeast/human. Similar to its orthologs, TcSub2 is a nuclear protein, localized in dispersed foci all over the nuclei —except the fibrillar center of nucleolus— and at the interface between dense and non-dense chromatin areas, proposing the association of TcSub2 with transcription/processing sites. These findings were analyzed further by BrUTP incorporation assays and confirmed that TcSub2 is physically associated with active RNA polymerase II (RNA pol II), but not RNA polymerase I (RNA pol I) or Spliced Leader (SL) transcription, demonstrating participation particularly in nuclear mRNA metabolism in T. cruzi. The double knockout of the TcSub2 gene is lethal in T. cruzi, suggesting it has an essential function. Alternatively, RNA interference assays were performed in Trypanosoma brucei. It allowed demonstrating that besides being an essential protein, its knockdown causes mRNA accumulation in the nucleus and decrease of translation levels, reinforcing that Trypanosoma-Sub2 (Tryp-Sub2) is a component of mRNA transcription/export pathway in trypanosomes

Effect of Eugenol against Streptococcus agalactiae

Streptococcus agalactiae (group B streptococci (GBS)) is an important infections agent in newborns associated with maternal vaginal colonization. Intrapartum antibiotic prophylaxis in GBS-colonized pregnant women has led to a significant reduction in the incidence of early neonatal infection in various geographic regions. However, this strategy may lead to resistance selecting among GBS, indicating the need for new alternatives to prevent bacterial transmission and even to treat GBS infections. This study reported for the first time the effect of eugenol on GBS isolated from colonized women, alone and in combination with silver nanoparticles produced by Fusarium oxysporum (AgNPbio). Eugenol showed a bactericidal effect against planktonic cells of all GBS strains, and this effect appeared to be time-dependent as judged by the time-kill curves and viability analysis. Combination of eugenol with AgNPbio resulted in a strong synergistic activity, significantly reducing the minimum inhibitory concentration values of both compounds. Scanning and transmission electron microscopy revealed fragmented cells and changes in bacterial morphology after incubation with eugenol. In addition, eugenol inhibited the viability of sessile cells during biofilm formation and in mature biofilms. These results indicate the potential of eugenol as an alternative for controlling GBS infections

Bacteremia causada por Staphylococcus aureus: Uma análise de quinze anos da sensibilidade a antimicrobianos em um hospital terciário do Brasil

Background and Objective: Bloodstream infections caused by Staphylococcus aureus are a major cause of morbidity and mortality worldwide. Treatment of S. aureus infections is complex, in part, due to the high prevalence of antimicrobial resistance. Understanding the epidemiology and resistance patterns of this microorganism is a critical point for the proper empirical prescription of antimicrobials. Thus, this study aimed to evaluate the evolution of antimicrobial resistance of S. aureus in a period of fifteen years. Methods: Antimicrobial susceptibility profiles was determined for cefoxitin (30μg), penicillin (10 U), erythromycin (15 μg), clindamycin (2 μg), gentamycin (10 μg),ciprofloxacin (5μg), sulfamethoxazole-trimethoprim (23.75/1.25 μg), rifampicin (5 μg), and tetracycline (30μg) in 720 S. aureus isolated from blood cultures in a tertiary hospital in southern Brazil were analyzed. Sensiblity values was determined according to Clinical Laboratory Standards Institute (CLSI, 2018).The data were obtained from the AGTA Healthcare Information System, LABHOS ® module. Results: The mean frequency of methicillin-resistant S. aureus was 43.74%. Except for penicillin, there was a significant variation of resistance for all antimicrobials in the period evaluated (ρJustificación y Objetivo: Infecciones del flujo sanguíneo por Staphylococcus aureus constituyen una de las principales causas de morbilidad y mortalidad en todo el mundo. El tratamiento de las infecciones por S. aureus es complejo, en parte debido a la elevada prevalencia de resistencia a los antimicrobianos. Comprender la epidemiología y los patrones de resistencia de este microorganismo es un punto crítico para la prescripción empírica adecuada de antimicrobianos. Así, este estudio tuvo por objetivo evaluar la evolución de resistencia antimicrobiana de S. aureus en un período de quince años. Metodología: Se analizaron los perfiles de sensibilidad a los antimicrobianos ciprofloxacino (5μg); clindamicina (2μg); eritromicina (15μg); gentamicina (10μg); oxacilina (30μg); penicilina (10U); rifampicina (5μg); sulfametoxazol-trimetoprima (23.75 / 1.25 μg) y tetraciclina (30μg) de 720 S. aureus aislados de hemocultivos de un hospital terciario del sur de Brasil. Losvalores de sensibilidad adoptados fueron aquellos contenidos en el Clinical Laboratory Standards Institute (CLSI, 2018). Los datos fueron obtenidos del Sistema de Información AGTA Healthcare, módulo LABHOS ® . Resultados: La frecuencia media de S. aureus resistente a meticilina fue de 43,74%. Con excepción de la penicilina, hubo variación significativa de la resistencia para todos los antimicrobianos en el período evaluado (Justificativa e Objetivo: Infecções da corrente sanguínea por Staphylococcus aureus constituem uma das principais causas de morbidade e mortalidade em todo mundo. O tratamento de infecções por S. aureus é complicado pela elevada prevalência de resistência a antimicrobianos. Compreender a epidemiologia e os padrões de resistência deste microrganismo é um ponto crítico para a prescrição empírica adequada de antimicrobianos. Desta maneira, este estudo teve por objetivo avaliar a evolução de resistência antimicrobiana de S. aureus num período de quinze anos. Metodologia: Foram analisados os testes de sensibilidade aos antimicrobianos de 720 S. aureus isolados de hemoculturas de um hospital terciário do sul do Brasil. Os dados foram obtidos do Sistema de Informação AGTA Healthcare, módulo LABHOS®. Resultados: A frequência média de S. aureus resistentes a meticilina foi de 43,74%. Com exceção de penicilina, ocorreu variação significativa da resistência para todos os antimicrobianos no período avaliado (< 0,001). Ciprofloxacina, Eritromicina e Clindamicina apresentaram os maiores índices de resistência com tendência de aumento. Surpreendentemente, Gentamicina e Sulfametoxazol-Trimetoprim apresentaram queda significativa nos percentuais de resistência. Analisando-se vancomicina do ano 2011 a 2015 pode-se evidenciar um aumento das concentrações inibitórias mínimas. Conclusão: Embora a resistência a antimicrobianos tenha aumentado nos quinze anos para a maioria dos antimicrobianos, para Sulfametoxazol-Trimetoprim e Gentamicina ocorreu redução significativa, indicando uma possível alteração clonal. Este estudo evidenciou, ainda, a emergência do fenótipo S. aureus intermediário a vancomicina