Origanum vulgare L. essential oil inhibits the growth of carbapenem-resistant gram-negative bacteria

Abstract INTRODUCTION: Plant products are sources for drug development against multidrug resistant bacteria. METHODS The antimicrobial activity of Origanum vulgare L. essential oil (OVeo) against carbapenem-resistant strains was assessed by disk-diffusion, microdilution (REMA-Resazurin Microtiter Assay), and time kill assays. RESULTS Carbapenemase production was confirmed for all strains. OVeo exhibited a minimum inhibitory concentration of 0.059% v/v for Klebsiella pneumoniae and Serratia marcescens, and of 0.015 % v/v for Acinetobacter baumannii. A decrease in cell count was observed after a 4 h treatment. CONCLUSIONS OVeo antimicrobial effect was rapid and consistent, making it a candidate for developing alternative therapeutic options against carbapenem-resistant strains.

Contaminação microbiana em colírios de pacientes em tratamento de glaucoma / Microbial contamination in eye drops of patients in glaucoma treatment

Resumo Objetivos: Avaliar o grau de contaminação por fungos e bactérias e o modo de conservação destes colírios hipotensores por parte dos pacientes no ambulatório de Glaucoma da Santa Casa de Ribeirão Preto. Métodos: Foram selecionados aleatoriamente cinquenta e cinco pacientes, em seguimento no ambulatório, e após consentimento dos mesmos os colírios eram coletados e enviados via correio para análise por microbiologista e patologista em até 72 horas. Foi analisado 0,5ml aproximadamente das medicações e os pacientes respondiam a um questionário simples sobre o método de conservação e se consideravam estes adequados. Resultados: Dos 55 colírios analisados, cinco (9,01%) estavam com seu conteúdo líquido contaminado. Entre os microrganismos isolados haviam 4 bactérias Gram negativas, sendo 1 (1,8%) por Serratia marcescens, 1 (1,8%) Pseudomonas aeruginosa e 2 (3,6%) Stenotrophomas maltophilia. Um colírio estava contaminado pelo fungo Cândida ssp Todos pacientes do estudo julgam seus métodos de armazenamento e instilação adequados. Os pacientes que tiveram os colírios positivados eram convocados para exame clínico e passavam por novo questionário pelo investigador. Conclusão: O tempo de abertura dos frascos e os métodos de conservação influenciam na contaminação dos medicamentos, todos os colírios com crescimento de microrganismos no presente estudo estavam abertos entre 30 e 90 dias. O fato de que a maioria dos pacientes levam seus colírios em tarefas cotidianas, aumenta a exposição dos frascos e podem ser um fator relevante para determinar a contaminação destas medicações.

Abstract Objetives: To assess the degree of fungal and bacterial contamination of hypotensive eye drops and the way these are preserved by the patients at the Glaucoma outpatient clinic of Santa Casa Hospital in Ribeirão Preto. Methods: Fifty-five patients were randomly assigned to follow-up in the outpatient clinic and, after their consent, an eye drop was collected per patient and later sent by mail for analysis by microbiologist and pathologist in up to 72 hours. Approximately 0.5ml of the medications were analyzed and the patients were asked to answer a simple questionnaire on the method of drug conservation and whether they considered it adequate. Results: Of the 55 analysed eye drops, five (9.01%) had their liquid contents contaminated. Among the microorganisms isolated there were 4 Gram negative bacteria, 1 (1.8%) by Serratia marcenses, 1 (1.8%) Pseudomonas aeruginosa and 2 (3.6%) Stenotrophomas maltophilia. An eye drop was contaminated by the fungus Candida ssp. All the patients in the study judged their methods of storage and instillation appropriate. The patients who had the positive coliria were summoned for clinical examination and passed through a new questionnaire by the investigator. Conclusion: The time and methods of preservation influence the contamination of medicinal products. All the eye drops that presented growth of microorganisms in the present study were open between 30 and 90 days. The fact that most patients take their eye drops on daily tasks increases the exposure of the bottles and can be a relevant fact to determine the contamination of these medications.

Enhanced production of prodigiosin by Serratia marcescens MO-1 using ram horn peptone

This work addresses the production of prodigiosin from ram horn peptone (RHP) using MO-1, a local isolate in submerged culture. First, a novel gram-negative and rod-shaped bacterial strain, MO-1, was isolated from the body of the grasshopper (Poecilemon tauricola Ramme 1951), which was collected from pesticide-contaminated fields. Sequence analysis of 16S rDNA classified the microbe as Serratia marcescens. The substrate utilization potential (BIOLOG) and fatty acid methyl ester profile (FAME) of S. marcescens were also determined. The effect of RHP on the production of prodigiosin by S. marcescens MO-1 was investigated, and the results showed that RHP supplementation promoted the growth of MO-1 and increased the production of prodigiosin. A concentration of 0.4% (w/v) RHP resulted in the greatest yield of prodigiosin (277.74 mg/L) after 48 h when mannitol was used as the sole source of carbon. The pigment yield was also influenced by the types of carbon sources and peptones. As a result, RHP was demonstrated to be a suitable substrate for prodigiosin production. These results revealed that prodigiosin could be produced efficiently by S. marcescens using RHP.