Characterization of cultivable intestinal microbiota in Rhynchophorus palmarum Linnaeus (Coleoptera: Curculionidae) and determination of its cellulolytic activity.

Rhynchophorus palmarum Linnaeus is an agricultural pest that affects various palm crops, including coconut (Cocos nucifera) plantations which are prominent in the economy of Northeastern Brazil. Characterization of the intestinal microbiota of R. palmarum, as well as elucidation of aspects related to the biochemistry and physiology of the insect's digestion, is essential for intervention in specific metabolic processes as a form of pest control. Thus, this study aimed to characterize the intestinal microbiota of R. palmarum and investigate its ability to degrade cellulosic substrates, to explore new biological control measures. Intestinal dissection of eight adult R. palmarum insects was performed in a laminar flow chamber, and the intestines were homogenized in sterile phosphate-buffered saline solution. Subsequently, serial dilution aliquots of these solutions were spread on nutritive agar plates for the isolation of bacteria and fungi. The microorganisms were identified by matrix-assisted laser desorption/ionization with a time-of-flight mass spectrometry and evaluated for their ability to degrade cellulose. Fourteen bacterial genera (Acinetobacter, Alcaligenes, Arthrobacter, Bacillus, Citrobacter, Enterococcus, Kerstersia, Lactococcus, Micrococcus, Proteus, Providencia, Pseudomonas, Serratia, and Staphylococcus) and two fungal genera (Candida and Saccharomyces)-assigned to the Firmicutes, Actinobacteria, Proteobacteria, and Ascomycota phyla-were identified. The cellulolytic activity was exhibited by six bacterial and one fungal species; of these, Bacillus cereus demonstrated the highest enzyme synthesis (enzymatic index = 4.6). This is the first study characterizing the R. palmarum intestinal microbiota, opening new perspectives for the development of strategies for the biological control of this insect.

Proteus mirabilis resistant to carbapenems isolated from a patient with a venous leg ulcer: a case report.

OBJECTIVE: The aim of the study was to phenotypically investigate the expression of the enzyme Klebsiella pneumoniae carbapenemase (KPC) in a Proteus mirabilis sample resistant to carbapenems, isolated from the wound of a patient with a venous leg ulcer (VLU) treated at an outpatient referral service. METHOD: This was a case study conducted with a patient who had a VLU on the lower left limb. Samples were taken for the examination of microbiological material from the patient's wound, using an aseptic technique. The colonies extracted were submitted to Gram staining and biochemical tests to identify the strain. In addition, an antimicrobial susceptibility test, E-test and a modified Hodge test were performed. RESULTS: The identified microorganism was Proteus mirabilis, which showed resistance to cefuroxime and the carbapenems imipenem and meropenem. As well as the minimum inhibitory concentration (MIC) of 3.0µg/ml for imipenem, demonstrating resistance, there was no KPC production by the tested isolate, which presented a negative modified Hodge test. CONCLUSION: The results highlight the importance of microbiological surveillance, aimed at reducing morbidity and mortality rates associated with infection by multiresistant bacteria.

Antimicrobial Analysis of an Antiseptic Made from Ethanol Crude Extracts of P. granatum and E. uniflora in Wistar Rats against Staphylococcus aureus and Staphylococcus epidermidis.

INTRODUCTION: Surgical site infection remains a challenge for hospital infection control, especially when it relates to skin antisepsis in the surgical site. OBJECTIVE: To analyze the antimicrobial activity in vivo of an antiseptic from ethanol crude extracts of P. granatum and E. uniflora against Gram-positive and Gram-negative bacteria. METHODS: Agar drilling and minimal inhibitory tests were conducted for in vitro evaluation. In the in vivo bioassay were used Wistar rats and Staphylococcus aureus (ATCC 25923) and Staphylococcus epidermidis (ATCC 14990). Statistical analysis was performed through variance analysis and Scott-Knott cluster test at 5% probability and significance level. RESULTS: In the in vitro, ethanolic extracts of Punica granatum and Eugenia uniflora and their combination showed the best antimicrobial potential against S. epidermidis and S. aureus. In the in vivo bioassay against S. epidermidis, there was no statistically significant difference between the tested product and the patterns used after five minutes of applying the product. CONCLUSION: The results indicate that the originated product is an antiseptic alternative source against S. epidermidis compared to chlorhexidine gluconate. It is suggested that further researches are to be conducted in different concentrations of the test product, evaluating its effectiveness and operational costs.

Tuning Biocompatibility and Bactericidal Efficacy as a Function of Doping of Gold in ZnO Nanocrystals.

Doping nanoparticles represents a strategy for modulating the energy levels and surface states of nanocrystals (NCs), thereby enhancing their efficiency and mitigating toxicity. Thus, we herein focus on the successful synthesis of pure and gold (Au)-doped zinc oxide (ZnO) nanocrystals (NCs), investigating their physical-chemical properties and evaluating their applicability and toxicity through in vitro and in vivo assessments. The optical, structural, and photocatalytic characteristics of these NCs were scrutinized by using optical absorption (OA), X-ray diffraction (XRD), and methylene blue degradation, respectively. The formation and doping of the NCs were corroborated by the XRD and OA results. While the introduction of Au as a dopant did induce changes in the phase and size of ZnO, a high concentration of Au ions in ZnO led to a reduction in their photocatalytic activity. This demonstrated a restricted antibacterial efficacy against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Remarkably, Au-doped counterparts exhibited enhanced biocompatibility in comparison to ZnO, as evidenced in both in vitro (murine macrophage cells) and in vivo (Drosophila melanogaster) studies. Furthermore, confocal microscopy images showed a high luminescence of Au-doped ZnO NCs in vivo. Thus, this study underscores the potential of Au doping of ZnO NCs as a promising technique to enhance material properties and increase biocompatibility.

Biogenic synthesis of silver nanoparticles using Brazilian propolis.

Biological methods have been used to synthesize silver nanoparticles through materials such as bacteria, fungi, plants, and propolis due to their reducing properties, stabilizer role and environmentally friendly characteristic. Considering the antimicrobial activity of propolis as well as the broad-spectrum antibacterial effects of silver nanoparticles, this study aim to describe the use of Brazilian propolis to synthesize silver nanoparticles (AgNP-P) and investigate its antimicrobial activity. The synthesis was optimized by factorial design, choosing the best conditions for smaller size particles. AgNP-P demonstrated a maximum absorbance at 412 nm in ultraviolet-visible spectra, which indicated a spherical format and its formation. Dynamic light scattering demonstrated a hydrodynamic size of 109 nm and polydispersity index less than 0.3, showing a good size distribution and stability. After its purification via centrifugation, microscopy analysis corroborates the format and showed the presence of propolis around silver nanoparticle. X-ray diffraction peaks were attributed to the main planes of the metallic silver crystalline structure; meanwhile infrared spectroscopy demonstrated the main groups responsible for silver reduction, represented by ∼22% of AgNP-P indicates by thermal analysis. Our product revealed an important antimicrobial activity indicating a synergism between propolis and silver nanoparticles as expected and promising to be an effective antimicrobial product to be used in infections.

Staphylococcal cassette chromosome mec elements from Staphylococcus intermedius group (SIG) isolates from dogs in a center for veterinary diagnostics in Brazil / Cassetes cromossômicos estafilocócicos mec de isolados do grupo Staphylococcus intermedius (GSI) de cães em um centro veterinário de diagnósticos no Brasil

ABSTRACT: Methicillin resistance in the Staphylococcus intermedius group (SIG) has emerged in small animal practice. Methicillin-resistant SIG (MRSIG) members have been implicated as causes of infections in both companion animals and humans. Staphylococcal cassette chromosome mec (SCCmec) elements carry the mecA/C genes, which encode for the transpeptidase PBP2a (PBP2') responsible for β-lactam antibiotic resistance in staphylococci. This study examined the SCCmec types of MRSIG isolates from different clinical specimens of dogs that exhibited methicillin MIC ≥ 0.5 μg/mL by an automated identification and susceptibility system in a Center for Veterinary Diagnostics in São Paulo, Brazil. Susceptibility to methicillin was determined by broth microdilution testing, and Oxoid® M.I.C.Evaluator® strips. PBP2a production was detected using a latex agglutination assay. SCCmec typing was performed according to the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG-SCC) guidelines. SCCmec type II (2A), SCCmec type III (3A), composite SCC structures consisting of a class A mec gene complex in addition to multiple ccr gene complexes, and non-typable SCCmec elements were reported in these MRSIG isolates. SCCmec type variants differing from those so far acknowledged by IWG-SCC were found, indicating new rearrangements in the genetic context of mecA in these canine MRSIG isolates.

RESUMO: A resistência à meticilina no grupo Staphylococcus intermedius (GSI) tem aumentado na clínica de pequenos animais. Membros GSI resistentes à meticilina (GSIRM) têm sido causas de infecções tanto em animais de companhia e humanos. Cassetes cromossômicos estafilocócicos mec (SCCmec) carregam os genes mecA/C, que codificam a transpeptidase PBP2a (PBP2') responsável pela resistência aos antibióticos β-lactâmicos em estafilococos. Nosso objetivo foi investigar os elementos SCCmec de GSIRM isolados de diferentes amostras clínicas de cães que exibiram CIM de meticilina ≥ 0,5 μg/mL por meio de um sistema automatizado em um Centro Veterinário de Diagnósticos em São Paulo, Brasil. A sensibilidade à meticilina foi determinada por meio do teste de microdiluição em caldo e fitas Oxoid® M.I.C.Evaluator®. A produção de PBP2a foi detectada usando um ensaio de aglutinação de látex. A tipagem dos elementos SCCmec foi realizada de acordo com as diretrizes do International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG-SCC). SCCmec tipo II (2A), SCCmec tipo III (3A), SCC compostos de um complexo mec de classe A com múltiplos complexos ccr, e elementos SCCmec não tipáveis foram encontrados nesses isolados GSIRM. Variantes que diferem dos elementos SCCmec reconhecidos até o momento pelo IWG-SCC foram encontradas, indicando novos rearranjos no contexto genético de mecA nesses isolados GSIRM caninos.

Atividade antimicrobiana de frações da própolis vermelha de Alagoas, Brasil / Antimicrobial activity of fractions of red propolis from Alagoas, Brazil

A própolis vermelha, como é conhecida popularmente, é uma própolis recentemente encontrada no Brasil e tem potente ação biológica. O presente trabalho avaliou a atividade antimicrobiana do extrato etanólico e das frações hexânica, clorofórmica e acetanólica da própolis proveniente de apiário do estado de Alagoas. As linhagens microbianas utilizadas foram: Shigella flexneri, Proteus vulgaris, Staphylococcus, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli e Candida albicans. O extrato etanólico apresentou atividade antimicrobiana frente a cepas gram-positivas (100%), gram-negativas (62,5%) e fúngicas (100%), com eficiência em 76,9% em todas as espécies testadas. A fração hexânica mostrou eficiência em 76,9% das espécies, semelhante ao extrato bruto; já a fração clorofórmica mostrou atividade frente a 92,3% das espécies analisadas, sendo Klebsiella pneumoniae a única espécie resistente. A fração acetanólica foi a fração que apresentou melhor atividade antimicrobiana com eficiência em 100% das espécies analisadas. Perante Candida albicans, observamos excelentes resultados, principalmente para a fração acetanólica, na qual a concentração inibitória mínima (CIM) se compara aos valores encontrados para as bactérias gram-positivas. Assim, as frações de própolis vermelha apresentaram excelente atividade antimicrobiana, principalmente frente a microrganismos gram-positivos e Candida albicans. Além disso, observamos que a fração acetanólica destacou-se como um promissor produto biotecnológico.

The red propolis is a new type of propolis founded in Brazil with large biological action. This study evaluated the antimicrobial activity of ethanol extract and fractions of hexane, chloroform and acetanolica of propolis from the apiary of the state of Alagoas. The microbial strains used were: Shigella flexneri, Proteus vulgaris, Staphylococcus, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Candida albicans. The ethanolic extract showed activity against Gram-positive strains (100%), Gram-negative (62.5%) and fungi (100%) with efficiency against 76.9% of all the analyzed strains. The hexanic fraction showed efficiency against 76.9% as observed with the ethanolic extract, though the chloroform fraction showed activity against 92.3% of the strains analyzed. Klebsiella pneumoniae was the only resistant species. The ethyl acetate was the fraction that showed the best antimicrobial activity with efficiency against 100% of all strains analized. Excellent results were observed to Candida albicans mainly with ethyl acetate fraction with the value of minimum inhibitory concentration (MIC) similar to those observed to Gram-positives bacteria. We concluded that the partitions of red propolis showed excellent antimicrobial activity mainly against Gram-positive microorganisms and Candida albicans. Furthermore, we observed the ethyl acetate fraction stood out as a promissory biotechnological product.

Atividade antimicrobiana de extratos hidroalcoólicos de Lafoensia pacari A. St.-Hil., Lythraceae, frente a bactérias multirresistentes de origem hospitalar / Antibacterial activity of the hydro-alcoholic extracts of Lafoensia pacari Saint Hil. against multiresistant bacterial strains from hospital source

Os microrganismos patogênicos multirresistentes apresentam-se como grandes responsáveis por milhões de mortes em todo o mundo, principalmente Pseudomonas aeruginosa e Staphylococcus aureus, responsáveis por grande parte das infecções hospitalares. A preocupação com estas espécies faz com que novas pesquisas busquem alternativas para controlar estes microrganismos de uma forma mais eficiente e também mais econômica. Os extratos fitoterápicos são alternativas promissoras para este fim, visto que são uma imensa fonte de compostos de ação biológica. O objetivo do trabalho foi a elucidação da atividade antimicrobiana do extrato de Lafoensia pacari A. St.-Hil., Lythraceae, frente a linhagens de bactérias multirresistentes (P. aeruginosa, S. aureus) isoladas de pacientes com múltiplas infecções internados na Unidade de Emergência de Maceió. Os testes de atividade antibacteriana foram avaliados pelo método de difusão em meio sólido (Kirby-Bauer) modificado. De acordo com os ensaios in vitro, foi constatado que 96,4 por cento das linhagens de bactérias utilizadas na pesquisa apresentaram-se sensíveis ao extrato da folha da planta, demonstrando atividade antibacteriana. Halos de inibição de crescimento de até 26 mm foram encontrados. Dessa forma, conclui-se que o extrato de Lafoensia pacari apresenta possibilidades de se encontrar substâncias úteis no combate a bactérias multirresistentes.

Multiresistant pathogenic microorganisms are responsible for million of death all the world, mainly Pseudomonas aeruginosa and Staphylococcus aureus that are responsible for great part of hospital infections. The concern with this species does new researches to find out alternatives to control these microorganisms in the way more efficient and more economic. The phytoterapic extracts are promissory alternatives for that purpose because they are an immense source of biological action. The objective of this study was to evaluate the antimicrobial activity of Lafoensia pacari A. St.-Hil., Lythraceae, extract on multiresistant bacterial strains (P. aeruginosa, S. aureus) that have been isolated from patients with multiple infections occupying an Emergency Unit from Maceió in Brazil. The antibacterial activity experiments were evaluated by agar diffusion tests. Agreeable us experiments in vitro, ascertain that 96,4 percent of bacterial strains utilized in this research have showed susceptible to the plant's leaf extract, it means an excellent antibacterial activity. Halos of bacterial inhibition until 26 mm were observed. Thus, it can be concluded that the Lafoensia pacari extract has showed as an excellent product to combat multiresistant bacterial.

Ação toxicológica da lidocaína na motilidade espermática e na fecundação do ouriço-do-mar / Toxicological action of lidocaine in the sperm motility and fertilization of sea urchin

Objetivo: o objetivo do presente estudo foi analisar a ação toxicológica para a lidocaína, usando como modelo os gametas de ouriço-do-mar. Material e métodos: os ouriços da espécie Arbacia lixula foram coletados e levados ao laboratório, onde foram extraídos os espermatozóides e os óvulos. Foram adicionadas dosagens de 5, 10, 20, 30, 40 e 50% de lidocaína aos espermatozóides ativados e monitorou-se a motilidade. Os óvulos foram colocados em contato com a solução de lidocaína nas concentrações de 10, 30 e 50% e em seguida foram postos juntos aos espermatozóides ativados. Resultados: a lidocaína paralisou os espermatozóides imediatamente depois de adicionada em doses iguais e acima de 20%, e ainda mostrou-se gametotóxica para os óvulos de ouriço- do-mar na dose de 50%. Conclusões: a dosagem de lidocaína esteve diretamente relacionada com a toxicidade, e tanto os espermatozóides quanto os óvulos sofreram influência dessa toxicidade.