Green synthesis of silver nanoparticles using leaf extracts of Mentha arvensis Linn. and demonstration of their in vitro antibacterial activities

Abstract A study was carried out to synthesize silver nanoparticles (Ag-NPs) using plant extracts and to explore their pharmaceutical application as antibacterial agents. Dried leaves of Mentha arvensis Linn. were powdered and extracts were prepared using three different organic solvents. Preliminary screening on antibacterial activity by agar well diffusion method indicated that the methanolic extract possessed higher potential than the other two. Phytochemical analysis of the leaf extract revealed that it possesses tannins, steroids, terpenoids and flavonoids. Ag-NPs prepared using this extract were of spherical to cuboidal shape ranging in size from 40 to 70 nm. It retained essential chemical groups and had the required surface plasmon resonance. Further to the antimicrobial assay, the Ag-NPs, in contrast to the whole methanolic leaf extract, showed better (100% vs. 80%) bactericidal activity against the indicator organisms. The zones of growth inhibition for gram positive bacteria ranged between 14±0.6 and 23±0.3, while it was between 12±0.6 and 22±0.2 for gram negative bacteria. The Ag-NPs presented the minimum inhibitory concentration values of 250 µg/mL for gram positive bacteria and 250 - 500 µg/mL for gram negative bacteria. These findings suggest that the natural compounds present in M. arvensis L. possess the potency to facilitate the synthesis and antibacterial action of Ag-NPs.

Disparities in antimicrobial consumption and resistance within a country: the case of beta-lactams in Argentina / Disparidades en el consumo de antimicrobianos y la resistencia a estos dentro de un país: el caso de los betalactámicos en Argentina / Disparidades internas no consumo e na resistência aos antimicrobianos: o caso dos betalactâmicos na Argentina

ABSTRACT Objective. To describe bacterial resistance and antimicrobial consumption ratio at the subnational level in Argentina during 2018, considering beta-lactams group as a case-study. Methods. Antimicrobial consumption was expressed as defined daily doses (DDD)/1000 inhabitants. Resistance of Escherichia coli, Streptococcus pneumoniae, Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus to beta-lactams was recorded. Resistance/consumption ratio was estimated calculating "R" for each region of Argentina, and this data was compared with other countries. Results. The most widely consumed beta-lactams in Argentina were amoxicillin (3.64) for the penicillin sub-group, cephalexin (0.786) for first generation cephalosporins, cefuroxime (0.022) for second generation; cefixime (0.043) for third generation and cefepime (0.0001) for the fourth generation group. Comparison between beta-lactams consumption and bacterial resistance demonstrated great disparities between the six regions of the country. Conclusions. The case-study of Argentina shows that antimicrobial consumption and resistance of the most common pathogens differed among regions, reflecting different realities within the same country. Because this situation might also be occurring in other countries, this data should be taken into account to target local efforts towards better antimicrobial use, to improve antimicrobial stewardship programs and to propose more suitable sales strategies in order to prevent and control antimicrobial resistance.

RESUMEN Objetivo. Determinar la razón entre la resistencia bacteriana y el consumo de antimicrobianos a nivel subnacional en Argentina en el 2018, considerando el grupo de los betalactámicos como estudio de caso. Métodos. El consumo de antimicrobianos se expresó como una dosis diaria determinada (DDD) por 1000 habitantes. Se registró la resistencia de Escherichia coli, Streptococcus pneumoniae, Pseudomonas aeruginosa, Klebsiella pneumoniae y Staphylococcus aureus a los betalactámicos. Se determinó la razón entre la resistencia y el consumo calculando "R" para cada región de Argentina, y estos datos se compararon con los de otros países. Resultados. Los betalactámicos más consumidos en Argentina fueron la amoxicilina (3,64) para el subgrupo de la penicilina; la cefalexina (0,786) para las cefalosporinas de primera generación; la cefuroxima (0.022) para las de segunda generación; la cefixima (0.043) para las de tercera generación, y la cefepima (0.0001) para el grupo de la cuarta generación. La comparación entre el consumo de betalactámicos y la resistencia bacteriana demostró que había grandes disparidades entre las seis regiones del país. Conclusiones. El estudio de caso en Argentina indica que el consumo de antimicrobianos y la resistencia a los patógenos más comunes difería entre las regiones; esto demuestra que hay distintas realidades dentro del mismo país. Como esta situación también se puede dar en otros países, estos datos se deben tener en cuenta para definir las actividades locales destinadas a fomentar un mejor uso de los antimicrobianos, para mejorar los programas de manejo de los antimicrobianos y para proponer estrategias de venta más adecuadas con el fin de prevenir y controlar la resistencia a los antimicrobianos.

RESUMO Objetivo. Descrever a relação entre o consumo de antimicrobianos e a resistência bacteriana no nível subnacional na Argentina em 2018, considerando o grupo dos betalactâmicos no estudo de caso. Métodos. O consumo de antimicrobianos foi representado por doses diárias definidas (DDD) por 1.000 habitantes. Foi registrada a resistência de Escherichia coli, Streptococcus pneumoniae, Pseudomonas aeruginosa, Klebsiella pneumoniae e Staphylococcus aureus aos betalactâmicos. A relação entre consumo e resistência foi calculada com base no "R" para cada região do país e os dados da Argentina foram comparados aos de outros países. Resultados. Os betalactâmicos de maior consumo na Argentina foram amoxicilina (3,64) no grupo das penicilinas, cefalexina (0,786) no grupo das cefalosporinas de primeira geração, cefuroxima (0.022) no grupo das cefalosporinas de segunda geração, cefixima (0.043) no grupo das cefalosporinas de terceira geração e cefepima (0.0001) no grupo das cefalosporinas de quarta geração. Ao se comparar o consumo de betalactâmicos e a resistência bacteriana, observou-se grande disparidade entre as seis regiões do país. Conclusões. O estudo de caso revela diferenças no consumo de antimicrobianos e na resistência dos patógenos mais comuns entre as regiões da Argentina, refletindo realidades distintas dentro do mesmo país. Como esta mesma situação pode estar ocorrendo em outros países, estes achados devem servir para direcionar os esforços locais a uma melhor utilização dos antimicrobianos, aperfeiçoar os programas de gestão do uso destes medicamentos e propor estratégias de venda mais apropriadas, visando a prevenir e controlar a resistência aos antimicrobianos.

What Are the Roles of Carbapenems in an Institution-specific Epidemiological Antibiogram in East Trinidad?

ABSTRACT Objective: To provide an overview of the development of an institution-specific epidemiological antibiogram. Emphasis was on last-line antibiotics, such as carbapenems. Methods: In 2013, the antibiograms of various organisms were retrieved from the computerized database of the Microscan (Siemens Healthcare) at the Microbiology Laboratory of the Sangre Grande Hospital in East Trinidad, West Indies. These were divided into blood and urine specimen antibiograms. All the wards and hospital clinics were included. A 20% cut-off was used to determine that a particular antibiotic or antibiotic class could be used for empiric therapy. All the organisms were not chosen. Only the most common and clinically relevant organisms were chosen. Results: Blood: Escherichia coli, Klebsiella pneumonia, Proteus mirabilis: Imipenem, mero- penem, ertapenem showed greater than 80% sensitivity, respectively. Pseudomonas aeruginosa: ceftazidime, ciprofloxacin, gentamicin, levofloxacin and tazobactam/piperacillin showed 100%, 80%, 80%, 100% and 100% sensitivity, respectively. Urines: E. coli, Klebsiella pneumonia, Proteus mirabilis: Imipenem, meropenem, ertapenem, were greater than 80% sensitive. Enterobacter cloacae: Imipenem, meropenem were 92%, 100% sensitive. Pseudomonas aeruginosa: tazobactam-piperacillin and amikacin were both 85% susceptible. Acinetobacter baumanii/haemolyticus: All the antibiotics were above the 20% resistance threshold. Conclusion: Patient-specific antibiograms and unit-specific trends (eg, ICU, surgical wards and outpatient clinic) can be used as a guide in patients with less severe infections. Carbapenems can still be used empirically, in East Trinidad, for sepsis.

A vancomicina administrada na dose empírica garante a cobertura de pacientes pediátricos contra patógenos Gram-positivos? / Does vancomycin administered at an empirical dose ensure coverage of pediatric patients against gram-positive pathogens?

RESUMO Objetivo: Investigar a efetividade da vancomicina contra Gram-positivos com concentração inibitória mínima de 1mg/L em pacientes pediátricos com base na razão entre área sob a curva e concentração inibitória mínima > 400. Métodos: População de 22 pacientes pediátricos (13 meninos) internados no centro de terapia intensiva pediátrica, com função renal preservada, que foram distribuídos em dois grupos (G1 < 7 anos e G2 ≥ 7 anos). Após a quarta dose de vancomicina (10 - 15mg/kg a cada 6 horas), duas amostras de sangue foram colhidas (terceira e quinta horas), seguidas da dosagem sérica por imunoensaios para investigação da farmacocinética e da cobertura do antimicrobiano. Resultados: Não se registrou diferença entre os grupos com relação à dose, ao nível de vale ou ainda na área sob a curva. A cobertura contra Gram-positivos com concentração inibitória mínima de 1mg/L ocorreu em apenas 46% dos pacientes em ambos os grupos. A farmacocinética se mostrou alterada nos dois grupos diante dos valores de referência, mas a diferença entre grupos foi registrada pelo aumento da depuração total corporal e pelo encurtamento da meia-vida biológica, mais pronunciados nos pacientes mais novos. Conclusão: A dose empírica mínima de 60mg/kg ao dia deve ser prescrita ao paciente pediátrico de unidade de terapia intensiva com função renal preservada. A utilização da razão entre área sob a curva e concentração inibitória mínima na avaliação da cobertura da vancomicina é recomendada para se atingir o desfecho desejado, uma vez que a farmacocinética está alterada nesses pacientes, podendo impactar na efetividade do antimicrobiano.

Abstract Objective: To investigate the vancomycin effectiveness against gram-positive pathogens with the minimum inhibitory concentration of 1mg/L in pediatric patients based on the area under the curve and the minimum inhibitory concentration ratio > 400. Methods: A population of 22 pediatric patients (13 boys) admitted to the pediatric intensive care unit with preserved renal function was stratified in two groups (G1 < 7 years and G2 ≥ 7 years). After the fourth dose administered of vancomycin (10 - 15mg/kg every 6 hours) was administered, two blood samples were collected (third and fifth hours), followed by serum measurement by immunoassays to investigate the pharmacokinetics and antimicrobial coverage. Results: There was no difference between the groups regarding dose, trough level or area under the curve. Coverage against gram-positive pathogens with a minimum inhibitory concentration of 1mg/L occurred in only 46% of patients in both groups. The pharmacokinetics in both groups were altered relative to the reference values, and the groups differed in regard to increased total body clearance and shortening of the biological half-life, which were more pronounced in younger patients. Conclusion: A minimum empirical dose of 60mg/kg per day should be prescribed for pediatric patients in intensive care units with preserved renal function. The use of the ratio between the area under the curve and minimum inhibitory concentration in the evaluation of vancomycin coverage is recommended to achieve the desired outcome, since the pharmacokinetics are altered in these patients, which may impact the effectiveness of the antimicrobial.

Anatomical, Histochemical and Biological Studies of Clusia grandiflora Splitg. (Clusiaceae)

Abstract Clusia grandiflora belongs to an important botanical family which is known for its medicinal value, however there are few reports in literature about the species, highlighting the relevance of this study. Anatomical studies with leaves and stems were performed using traditional techniques. In this investigation it was identified particularities of the species such as the presence of vascular system arranged in an opened arc-shaped with the flexed ends towards the inside of the arch with accessory bundles in the petiole. In histochemical studies, performed with different reagents, alkaloids, phenols substances, carbohydrates and lipids were located. The cytotoxic activity of the extracts was performed by tetrazole salt and showed promising results for ethanolic extracts of stems (IC50 human colon cells of 24.30 μg/ mL) and leaves (IC50 ascites gastric cells of 44.15 μg/ mL), without cell membrane disruption of erythrocytes. The antibacterial activity was evaluated by tryptic soy agar and minimal inhibitory concentration assays and showed positive results for Pseudomonas aeruginosa and Escherichia coli, with better result for adventitious roots (32 μg/ mL and 16 μg/ mL, respectively), stems (64 μg/ mL and 32 μg/ mL, respectively) and leaves (64 μg/ mL and 32 μg/ mL, respectively) ethanolic extracts. Thus, these studies were able to characterize the species and show its potential as promising source of active substances.

Infections and antimicrobial resistance in an adult intensive care unit in a Brazilian hospital and the influence of drug resistance on the thirty-day mortality among patients with bloodstream infections

Abstract INTRODUCTION: The present study aimed to determine the incidence of health care-associated infections (HCAIs) and identify the main resistant microorganisms in intensive care unit (ICU) patients in a Brazilian university hospital. METHODS: A retrospective cohort study was conducted in a Brazilian teaching hospital between 2012 and 2014. RESULTS: Overall, 81.2% of the infections were acquired in the ICU. The most common resistant pathogenic phenotypes in all-site and bloodstream infections were oxacillin-resistant coagulase-negative staphylococci and carbapenem-resistant Acinetobacter spp. (89.9% and 87.4%; 80.6% and 70.0%), respectively. CONCLUSIONS: There is an urgent need to focus on HCAIs in ICUs in Brazil.

Microbiologic characteristics and antibiotic resistance rates of diabetic foot infections / Perfil microbiológico e de resistência bacteriana no pé diabético infectado

ABSTRACT Purpose: the purpose of this research was to identify the sociodemographic and microbiological characteristics and antibiotic resistance rates of patients with diabetic foot infections, hospitalized in an emergency reference center. Methods: it was an observational and transversal study. The sociodemographic data were collected by direct interview with the patients. During the surgical procedures, specimens of tissue of the infected foot lesions were biopsied to be cultured, and for bacterial resistance analysis. Results: the sample consisted of 105 patients. The majority of patierns were men, over 50 years of age, married and with low educational level. There was bacterial growth in 95 of the 105 tissue cultures. In each positive culture only one germ was isolated. There was a high prevalence of germs of the Enterobacteriaceae family (51,5%). Gram-negative germs were isolated in 60% of cultures and the most individually isolated germs were the Gram-positive cocci, Staphylococcus aureus (20%) and Enterococcus faecalis (17,9%). Regarding antibiotic resistance rates, a high frequency of Staphylococcus aureus resistant to methicillin (63,0%) and to ciprofloxacin (55,5%) was found; additionally, 43,5% of the Gram-negative isolated germs were resistant to ciprofloxacin. Conclusions: the majority of patients were men, over 50 years of age, married and with low educational level. The most prevalent isolated germs from the infected foot lesions were Gram-negative bacteria, resistant to ciprofloxacin, and the individually most isolated germ was the methicillin resistant Staphylococcus aureus.

RESUMO Objetivo: identificar o perfil sociodemográfico, microbiológico e de resistência bacteriana em pacientes com pé diabético infectado. Métodos: tratou-se de estudo observacional, transversal que avaliou os perfis sóciodemográfico e microbiológico de pacientes portadores de pé diabético infectado internados em Pronto Socorro de referência. Os dados sociodemográficos foram coletados por meio de entrevista. Foram colhidos, durante os procedimentos cirúrgicos, fragmentos de tecidos das lesões podais infectadas para realização de cultura/antibiograma. Resultados: a amostra foi composta por 105 pacientes. O perfil sociodemográfico mais prevalente foi o de pacientes do sexo masculino, acima dos 50 anos, casados e com baixa escolaridade. Das 105 amostras de fragmentos de tecidos colhidos para realização de cultura e antibiograma, 95 foram positivas, com crescimento de um único germe em cada um dos exames. Houve predomínio de germes da família Enterobacteriaceae (51,5%). Germes Gram-negativos foram isolados em 60,0% das culturas e os espécimes mais isolados individualmente foram os cocos Gram-positivos, Staphylococcus aureus (20,0%) e Enterococcus faecalis (17,9%). Considerando-se os perfis de resistência bacteriana, verificou-se alta taxa de Staphylococcus aureus resistente à meticilina (63,0%) e à ciprofloxacino (55,5%); verificou-se, também, que 43,5% dos germes Gram-negativos eram resistentes à ciprofloxacino. Conclusões: o perfil sociodemográfico majoritário, foi o de homens, com mais de 50 anos e com baixa escolaridade. Concluímos que os germes mais prevalentes nas lesões podais dos pacientes diabéticos foram os Gram-negativos, resistentes ao ciprofloxacino e que o germe mais isolado individualmente foi o Staphylococcus aureus resistente à meticilina.

Evaluación del potencial antioxidante de algunas tinturas madre homeopáticas / Evaluation of the antioxidant potential of some homeopathic mother tinctures

Objetivos: en sistemas homeopáticos de medicina, las tinturas madre se prescriben para varias enfermedades y especialmente para condiciones sépticas y la cura de muchos padecimientos. Este estudio se llevó a cabo para evaluar el potencial antioxidante y antibacterial de las diez tinturas madre homeopáticas que se utilizan con mayor frecuencia. Materiales y métodos: diez tinturas madre fueron preparadas y puestas a prueba contra cinco bacterias de importancia clínica patogénica en los humanos (Sal­ monella typhi [ST], Escherichia coli [EC], Bacillus subtilis [BS], Straphylococus aureus [SA], y Pseudomonas aeruiginosa [PA]) mediante el método de microdilución con ciprofloxacina como control positivo. La actividad antioxidante se estimó con un ensayo de inhibición 2,2-difenil-1-picrilhidrazilo (DPPH). El ácido ascórbico se tomó como estándar positivo en actividad antioxidante. Resultados: todas las tinturas madre mostraron cierto nivel de actividad antibacterial. Chinchona officinalis tuvo la actividad máxima (inhibición del 89%) contra Salmonella typhi que las demás tinturas madre en el estudio. Pulsatilla nigricans mostró la inhibición más alta de DPPH (85%) entre las demás tinturas madre de origen vegetal. Conclusión: este estudio revela que las tinturas madre ya mencionadas tienen potencial antibacteriano y antioxidante contra el microorganismo particular y 2,2-difenil-1-picrilidracil (DPPH), respectivamente. (AU)

Antibacterial and Antifungal Activities of Compounds Isolated from Gymnosporia Royleana (Celastraceae) / Actividades antibacterianas y antifúngicas de compuestos aislados de Gymnosporia Royleana (Celastraceae)

ABSTRACT Objective: In the present study, five new source compounds isolated from aerial parts of Gymnosporia royleana (G royleana) were screened for antibacterial and antifungal activities. Methods: Extraction from plant material was carried out using cold maceration technique. Isolation of pure compounds was accomplished through repeated column chromatography of different fractions obtained from crude extract and using silica gel as stationary phase. Their structures were established via advanced spectroscopic techniques along with the spectral data previously reported for these compounds. Dilution method was used for the evaluation of antimicrobial potential of the compounds against various microbial strains. Results: Among the tested compounds, Gymnosporin B displayed moderate antimicrobial activity against Escherichia Coli (E coli), Staphylococcus aureus (S aureus), Candida albicans (C albicans) and Aspergillus flavus (A flavus) [minimum inhibitory concentration (MIC) range; 32-64 μg/mL]. Similarly, Gymnosporin C also showed moderate activity against E coli and S aureus (MIC; 32 μg/mL each) as well as weak activity against C albicans and A flavus (MIC; 64 μg/mL each). However, Royaflavone showed moderate antibacterial activity against S aureus only (MIC; 32 μg/mL). Antimicrobial activity of the rest of the compounds was weak and negligible. Conclusion: The present study has provided fascinating results of antimicrobial activities of the isolated compounds. However, the broad antimicrobial spectrum of Gymnosporin B and Gymnosporin C demands for further exploration of these triterpenes, both on the basis of mechanism and quantitative structure-activity relationship.

RESUMEN Objetivo: En el presente estudio, cinco nuevos compuestos de origen aislados de partes aéreas de Gymnosporia royleana (G royleana) fueron tamizados en sus actividades antibacterianas y antifúngicas. Métodos: La extracción de material vegetal se realizó mediante la técnica de maceración en frío. El aislamiento de compuestos puros se logró a través de la cromatografía en columna repetida de diversas fracciones obtenidas del extracto crudo y usando gel de silicona como fase estacionaria. Sus estructuras fueron establecidas mediante técnicas espectroscópicas avanzadas junto con los datos espectrales previamente reportados para estos compuestos. El método de dilución fue usado para evaluar el potencial antimicrobiano de los compuestos contra diversas cepas microbianas. Resultados: Entre los compuestos sometidos a prueba, Gymnosporina B mostró una actividad antimicrobiana moderada contra Escherichia Coli (E coli), Staphylococcus aureus (S aureus), Candida Albicans (C albicans) y Aspergillus flavus (A flavus) [rango de concentración inhibitoria mínima (CIM); 32 - 64 μg/mL]. De manera similar, Gymnosporina C también mostró actividad moderada contra E coli y S aureus (CIM; 32 μg/mL cada uno) así como débil actividad frente a C albicans y A flavus (CIM; 64 μg/mL cada uno). Sin embargo, Royaflavone mostró actividad antibacteriana moderada sólo frente a S aureus (CIM; 32 μg/mL). La actividad antimicrobiana del resto de los compuestos fue débil e insignificante. Conclusión: El presente estudio ha proporcionado resultados interesantes acerca de las actividades antimicrobianas de los compuestos aislados. Sin embargo, el amplio espectro antimicrobiano de la Gymnosporina B y la Gymnosporina C exige una mayor exploración de estos triterpenos, tanto sobre la base del mecanismo como a partir de la relación cuantitativa estructura-actividad.

Antibacterial Activity of Glycyrrhiza Glabra Roots against food-borne bacterial pathogens / Actividad Antibacteriana de la Raíz de Glycyrrhiza glabra Contra las Bacterias Patógenas Transmitidas por los Alimentos

ABSTRACT Objective: The antibacterial activity of Glycyrrhiza glabra (Liquorice) roots was evaluated against several food-borne bacterial pathogens. Methods: The in vitro anti-bacterial activity was evaluated by determining the zone diameter of inhibition (ZDI), minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) using the aqueous. Ethanolic and methanolic extracts of the roots of Glycyrrhiza glabra. Results: Therefore, significant increase in inhibitory feature was observed because of increase in extracts concentration. In addition, the aqueous extract was more effective than the others; while, among the tested bacteria, Staphylococcus aureus and Pseudomonas aeruginosa were the most sensitive and the most resistant, respectively. Conclusion: Extracts of Glycyrrhiza glabra roots can potentially be used in the pharmaceutical and food industries as preservatives or antimicrobial agents.

RESUMEN Objetivo: La actividad antibacteriana del extracto de raíces de Glycyrrhiza glabra (regaliz) fue evaluada frente a varias bacterias patógenas trasmitidas por los alimentos. Métodos: La actividad antimicrobiana se evalúa determinando el diámetro de la zona de inhibición (DZI), y la concentración bactericida mínima (CBM). Extractos acuosos, etanólicos y metanólicos de la raíz de Glycyrrhiza glabra fueron analizados en su actividad antibacteriana in vitro. Resultados: Por lo tanto, se observó un aumento significativo en la característica inhibitoria debido al aumento en la concentración de extractos. Además, el extracto acuoso fue más eficaz que los otros, en tanto que, entre las bacterias probadas, Staphylococcus aureus y Pseudomonas aeruginosa fueron las más sensibles y las más resistentes, respectivamente. Conclusión: Los resultados sugieren que los extractos de raíz de Glycyrrhiza glabra tienen un uso potencial en la industria farmacéutica y alimentaria, y pueden ser útiles como conservantes o agentes antimicrobianos.

Impacto das mudanças da microbiologia na peritonite bacteriana espontânea em três diferentes períodos ao longo de 17 anos / Impact of microbiological changes on spontaneous bacterial peritonitis in three different periods over 17 years

ABSTRACT BACKGROUND: Spontaneous bacterial peritonitis is a serious complication in cirrhotic patients, and changes in the microbiological characteristics reported in the last years are impacting the choice of antibiotic used for treatment. OBJECTIVE: The aim of the present study is to evaluate the changes in the epidemiology and bacterial resistance of the germs causing spontaneous bacterial peritonitis over three different periods over 17 years. METHODS: All cirrhotic patients with spontaneous bacterial peritonitis and positive culture of ascites fluid were retrospectively studied in a reference Hospital in Southern Brazil. Three periods were ramdomly evaluated: 1997-1998, 2002-2003 and 2014-2015. The most frequent infecting organisms and the sensitivity in vitro to antibiotics were registered. RESULTS: In the first period (1997-1998) there were 33 cases, the most common were: E. coli in 13 (36.11%), Staphylococcus coagulase-negative in 6 (16.66%), K. pneumoniae in 5 (13.88%), S. aureus in 4 (11.11%) and S. faecalis in 3 (8.33%). In the second period (2002-2003), there were 43 cases, the most frequent were: Staphylococus coagulase-negative in 16 (35.55%), S. aureus in 8 (17.77%), E. coli in 7 (15.55%) and K. pneumoniae in 3 (6.66%). In the third period (2014-2015) there were 58 cases (seven with two bacteria), the most frequent were: E. coli in 15 (23.1%), S. viridans in 12 (18.5%), K. pneumoniae in 10 (15.4%) and E. faecium 5 (7.7%). No one was using antibiotic prophylaxis. Considering all staphylococci, the prevalence increased to rates of the order of 50% in the second period, with a reduction in the third period evaluated. Likewise, the prevalence of resistant E. coli increased, reaching 14%. CONCLUSION: There was a modification of the bacterial population causing spontaneous bacterial peritonitis, with high frequency of gram-positive organisms, as well as an increase in the resistance to the traditionally recommended antibiotics. This study suggests a probable imminent inclusion of a drug against gram-positive organisms in the empiric treatment of spontaneous bacterial peritonitis.

RESUMO CONTEXTO: A peritonite bacteriana espontânea é uma complicação séria em pacientes cirróticos e as alterações nas características microbiológicas relatadas nos últimos anos podem afetar a escolha do antibiótico utilizado no tratamento. OBJETIVO: Os objetivos do presente estudo são avaliar as mudanças na epidemiologia e perfil de resistência bacteriana dos germes causadores de peritonite bacteriana espontânea em três períodos diferentes ao longo de 17 anos. MÉTODOS: Todos os pacientes cirróticos com peritonite bacteriana espontânea e cultura positiva de fluido ascítico foram estudados retrospectivamente em um hospital de referência no Sul do Brasil. Foram avaliados três diferentes períodos selecionados de forma randômica: 1997-1998, 2002-2003 e 2014-2015. Os organismos infecciosos mais frequentes e a sensibilidade in vitro a antibióticos foram registados. RESULTADOS: No primeiro período (1997-1998) houve 33 casos; os mais comuns foram: E. coli em 13 (36,1%), Staphylococcus coagulase-negativo em 6 (16,7%), K. pneumoniae em 5 (13,9%), S. aureus em 4 (11,1%) e S. faecalis em 3 (8,3%). No segundo período (2002-2003), houve 43 casos, os mais frequentes foram: Staphylococus coagulase-negativo em 16 (35,5%), S. aureus em 8 (17,8%), E. coli em 7 (15,5%) e K. pneumoniae em 3 (6,7%). No terceiro período (2014-2015), houve 58 casos (sete com duas bactérias), os mais frequentes foram: E. coli em 15 (23,1%), S. viridans em 12 (18,5%), K. pneumoniae em 10 (15,4%) e E. faecium 5 (7,7%). Nenhum paciente estava usando profilaxia antibiótica. Quando considerados todos os estafilococos, a prevalência aumentou para taxas da ordem de 50% no segundo período, apresentando redução no terceiro período avaliado. Do mesmo modo, a prevalência de E coli resistente aumentou, chegando a 14%. CONCLUSÃO: Houve modificação da população bacteriana causadora de peritonite bacteriana espontânea, com alta frequência de organismos gram-positivos, bem como aumento da resistência aos antibióticos tradicionalmente recomendados. Este estudo sugere uma provável inclusão iminente de um medicamento contra organismos gram-positivos no tratamento empírico da peritonite bacteriana espontânea.

Tissue reaction to Aroeira (Myracrodruon urundeuva) extracts associated with microorganisms: an in vivo study

Abstract: Based on aroeira's (Myracrodruon urundeuva) antimicrobial activity and a future trend to compose intracanal medication, the aim of this study was to assess in vivo inflamatory tissue response to the extracts by edemogenic and histological analysis containing inactivated facultative and anaerobic microorganisms. For edema quantification, eighteen animals were divided into three groups (n = 3, periods: 3 and 6 hours) and 0.2 mL of 1% Evans blue per 100 g of body weight was injected into the penile vein under general anesthesia. After 30 min the animals received a subcutaneous injection in the dorsal region of aqueous or ethanolic extract of aroeira or saline (control) containing inactivated bacteria. Samples were collected, immersed in formamide for 72h, and evaluated by spectrophotometry (630 m). For histological analysis, polyethylene tubes with the extracts were implanted in the dorsal of 30 male rats. Analysis of the fibrous capsule and inflammatory infiltrate were performed after 7 and 30 days. The aqueous extract group induced less edema in both postoperative periods compared to the other groups, but the differences were not significant (p > 0.05). Tissue repair was significantly better after 30 days than after 7 days (p < 0.01). The aqueous solution showed less inflammatory response than the ethanolic solution (p < 0.05), with tendency for better results than control after 7 days. After 30 days, the response to both extracts was similar to control. The aqueous and ethanolic aroeira extracts containing inactivated microorganisms showed a trend for better results than saline, even when associated with microorganisms, and facilitated the tissue repair process.

Nuevas cefalosporinas / New cephalosporins

Resumen La resistencia bacteriana se ha incrementado en América Latina y el mundo, por lo que se requiere investigación y creación de nuevos antimicrobianos capaces de erradicar a los microorganismos resistentes. Se realizó una revisión acerca de nuevas cefalosporinas y sus combinaciones con un inhibidor de β-lactamasas, recopilando información de espectro, farmacocinética, farmacodinamia y estudios clínicos de las indicaciones actuales para ceftarolina, ceftazidima/avibactam y ceftolozano/tazobactam. La primera, con actividad frente a Staphylococcus aureus y Staphylococcus coagulasa negativa sensibles y resistentes a meticilina, y contra Streptococcus pneumoniae resistente a penicilina; por lo tanto, aprobada para uso en neumonía bacteriana adquirida en comunidad e infecciones bacterianas de piel y tejidos blandos. Entre las nuevas combinaciones, ceftazidima, una cefalosporina de tercera generación con actividad anti-pseudomonas, asociada a avibactam, un inhibidor de β-lactamasas, ha demostrado efectividad en el tratamiento de infecciones abdominales e infecciones urinarias complicadas. Por último, la combinación ceftolozano y el conocido tazobactam presenta acción comparable a la combinación de ceftazidima y avibactam por su actividad contra bacilos gramnegativos y, en combinación con metronidazol no presenta inferioridad a meropenem en infecciones intra-abdominales. Se presentan los estudios clínicos y las potenciales indicaciones y escenarios de uso de estas cefalosporinas.

Bacterial resistance has increased in Latin America and the world, making research and creation of new antimicrobials capable of eradicating resistant microorganisms essential. A review of new cephalosporins and their combinations with a beta-lactamase inhibitor was conducted, collecting data on the spectrum, pharmacokinetic and pharmacodynamic profile and clinical studies of the current indications for ceftaroline, and the combinations ceftazidime with avibactam and ceftolozane with tazobactam. The first one has activity against methicillin-resistant Staphylococcus aureus and coagulase negative Staphylococcus (SCoN) and against penicillin-resistant Streptococcus pneumoniae, therefore approved for use in community-acquired pneumonia and acute bacterial skin and skin structure infections. Among the new combinations, ceftazidime, a third generation cephalosporin with antipseudomonal activity, associated with avibactam, a betalactamase inhibitor, has been shown to be effective in the treatment of abdominal infections and complicated urinary infections. Finally, the combination of ceftolozane with tazobactam has comparable action to ceftazidime with avibactam due to its activity against Gram negative rods, and in combination with metronidazole they do not present inferiority to meropenem in intra-abdominal infections. The clinical studies are presented, as well as the potential indications and clinical scenarios for their use of this cephalosporins.

Sepsis neonatal tardía nosocomial en una unidad de terapia intensiva: agentes etiológicos y localización más frecuente / Late onset neonatal sepsis in an intensive care neonatal unit: etiological agents and most frequent location

Resumen Introducción: La sepsis neonatal nosocomial (SNN) es una entidad frecuente en las unidades de cuidados intensivos, donde causa una gran morbimortalidad. La ubicación más frecuente es bacteriemia, seguido de neumonía asociada a ventilador mecánico y vía urinaria. Objetivo: Conocer la etiología y localización más frecuente de la infección en el SNN. Población, Material y Métodos: Estudio retrospectivo, de prevalencias de enero a diciembre de 2015, realizado en la Unidad de Cuidados Intensivos Neonatal de un hospital de alta complejidad. Fueron incluidos todos los neonatos. Resultados: Se incluyeron 70 pacientes, se analizaron 88 episodios de SNN. La localización más frecuente fue sangre 40% de los casos, seguido de orina y aspirado traqueal en 25% respectivamente. Los microorganismos más frecuentemente aislados fueron Staphylococcus de diferentes tipos, seguido de Acinetobacter baumannii multi-resistente. La afectación del SNC fue de 32%. La mortalidad fue de 34%, elevándose a 50% ante un segundo episodio de SNN. La terapia empírica de elección fue vancomicina y carbapenem, ajustándose a antibiograma. Conclusiones: La infección más frecuente fue la bacteremia, principalmente por Staphylococcus resistentes a meticilina. La afectación del SNC fue elevada, lo mismo que la mortalidad.

Introduction: Nosocomial neonatal sepsis (NNS) is a frequent entity in intensive care units, causing great morbidity and mortality. The most frequent site is blood, followed by lungs and urine. Objective: To know the etiology and most frequent localization of infection in the NNS. Population, Material and Methods: Cross sectional study, from January to December 2015, performed in a teaching hospital. All newborns infants were included. Results: 70 patients were included, 88 episodes of NNS were analyzed. The most frequent localization was bacteremia in 40% of cases, followed by urinary tract infection and VAP in 25% respectively. The bacteria most frequently isolated were staphylococci of different types, followed by multiresistant Acinetobacter. The CNS involvement was 32%. Mortality was 34%, rising up to 50% with a second episode of NNS. The empirical therapy of choice was vancomycin and carbapenem, adjusting to antibiogram. Conclusions: The most frequent infection was bacteremia, mainly by staphylococci resistant to methicillin. CNS involvement was elevated, as well as mortality.

Epidemiología de las infecciones urinarias asociadas a catéter y no asociadas a catéter en un hospital universitario de tercer nivel / Nosocomial urinary tract infection: an analysis beyond urinary catheterization

Resumen Introducción: Las infecciones urinarias asociadas a la atención de la salud (ITU-AAS) representan un importante problema sanitario, siendo poco conocidas sus características cuando no están asociadas a cateterización urinaria u ocurren fuera de unidades de cuidados intensivos (UCI). Objetivos: Determinar las características de los pacientes con ITU-AAS, etiología y susceptibilidad antimicrobiana de las mismas, tanto asociadas a catéter (ITU-C) como no asociadas a catéter (ITU-noC), en UCI y en sala general. Materiales y Métodos: Se realizó un estudio analítico retrospectivo de corte transversal entre 2009 y 2013 en un hospital universitario de tercer nivel. Se identificaron todos los episodios de ITU-AAS, diferenciándolas en ITU-C e ITU-noC. Resultados: Se incluyeron 253 episodios de ITU-AAS, siendo más frecuentes las ITU-C (60,9%) respecto a ITU-noC. Un 37,4% de ITU-noC y 59,7% de ITU-C ocurrieron en UCI. Los microorganismos aislados más frecuentemente fueron Escherichia coli, Klebsiella pneumoniae y Enterococcus sp. El 19% de los bacilos gramnegativos fueron productores de β-lactamasa de espectro extendido, siendo su frecuencia similar en ambos grupos. Conclusión: Las co-morbilidades de los pacientes con ITU-AAS, los agentes etiológicos responsables y sus correspondientes espectros de sensibilidad, fueron similares en los grupos de ITU-C e ITU-noC, tanto en sala general como en UCI.

Introduction: Nosocomially acquired urinary tract infections (NAUTI) represent an important public health issue, but its characteristics when they are not catheter associated (CA-UTI) or when they take place outside intensive care units (ICU) are poorly understood. Objectives: To determine the patients' characteristics, etiology and antimicrobial susceptibility of NAUTI, both CA-UTI and no CA-UTI, in general ward and ICU. Methods: We conducted a retrospective analytic cross-sectional study, between 2009 and 2013, in a third level universitary hospital. All NAUTI episodes were identified, classifying them as CA-UTI and no CA-UTI. Results: We included 253 episodes of NAUTI, being CA-UTI (60,9%) more frequent than no CA-UTI. A 37,4% of no CA-UTI and 59,7% of CA-UTI were identified in ICU. The most frequently isolated microorganisms were Escherichia coli, Klebsiella pneumoniae and Enterococcus sp. A 19% of extended spectrum betalactamase producing gram negative bacilli were found, without differences between groups. Conclusion: Patients's comorbidities, microorganisms associated to NAUTI and its antimicrobial susceptibility were similar in CA-UTI and no CA-UTI, as in general ward and ICU.

Antimycobacterial and antimalarial activities of endophytic fungi associated with the ancient and narrowly endemic neotropical plant Vellozia gigantea from Brazil

BACKGROUND Endophytic fungi, present mainly in the Ascomycota and Basidiomycota phyla, are associated with different plants and represent important producers of bioactive natural products. Brazil has a rich biodiversity of plant species, including those reported as being endemic. Among the endemic Brazilian plant species, Vellozia gigantea (Velloziaceae) is threatened by extinction and is a promising target to recover endophytic fungi. OBJECTIVE The present study focused on bioprospecting of bioactive compounds of the endophytic fungi associated with V. gigantea, an endemic, ancient, and endangered plant species that occurs only in the rupestrian grasslands of Brazil. METHODS The capability of 285 fungal isolates to produce antimicrobial and antimalarial activities was examined. Fungi were grown at solid-state fermentation to recover their crude extracts in dichloromethane. Bioactive extracts were analysed by chromatographic fractionation and NMR and displayed compounds with antimicrobial, antimycobacterial, and antimalarial activities. FINDINGS Five fungi produced antimicrobial and antimalarial compounds. Extracts of Diaporthe miriciae showed antifungal, antibacterial, and antimalarial activities; Trichoderma effusum displayed selective antibacterial activity against methicillin-resistant Staphylococcus aureus and Mycobacterium intracellulare; and three Penicillium species showed antibacterial activity. D. miriciae extract contained highly functionalised secondary metabolites, yielding the compound epoxycytochalasin H with high antimalarial activity against the chloroquine-resistant strain of Plasmodium falciparum, with an IC50 approximately 3.5-fold lower than that with chloroquine. MAIN CONCLUSION Our results indicate that V. gigantea may represent a microhabitat repository hotspot of potential fungi producers of bioactive compounds and suggest that endophytic fungal communities might be an important biological component contributing to the fitness of the plants living in the rupestrian grassland.

Etiología y resistencia a antimicrobianos de la infección no complicada del tracto urinario / Etiology and antimicrobial resistance of uncomplicated urinary tract infections

La infección urinaria no complicada en mujeres es un motivo frecuente de consulta e indicación de antimicrobianos. El objetivo de este estudio fue definir etiología y resistencia a antimicrobianos en episodios de infección urinaria no complicada. Este estudio prospectivo incluyó mujeres premenopáusicas no embarazadas, con infección urinaria no complicada, que consultaron en un hospital público y tres centros privados de las ciudades de Buenos Aires y La Plata (2011-2013). La edad media de 138 pacientes con infección confirmada por urocultivo fue 28 años. El diagnóstico fue cistitis en 97 (70%) y pielonefritis en 41 (30%). Las frecuencias de los microorganismos aislados fueron: Escherichia coli 97 (70%), Staphylococcus saprophyticus 24 (17%), Proteus spp. 10 (7%), Klebsiella spp. 5 (4%), Enterococcus spp. 1 (0.7%) y Pseudomonas aeruginosa 1 (0.7%). Las frecuencias de resistencia a antimicrobianos fueron: ampicilina-sulbactam 51 (37%), cefalexina 39 (28%), trimetoprima/sulfametoxazol 31 (22%), nitrofurantoína 17 (12%), gentamicina 10 (7%) y ciprofloxacina 7 (5%). La frecuencia de resistencia a ampicilina-sulbactam, trimetoprima/sulfametoxazol y cefalexina es mayor que las previamente publicadas en Argentina, lo que limita su recomendación para el tratamiento empírico. Una mejor comprensión de la etiología y la susceptibilidad antimicrobiana local permite el diseño de pautas más adecuadas para el tratamiento empírico.

Uncomplicated urinary tract infections rank among the most frequent bacterial infections in women in the outpatient setting and represent a major cause of antimicrobial prescription. The aims of this study were to assess frequencies and antimicrobial resistance of current uropathogens causing uncomplicated urinary tract infection. In a prospective multicenter study, patients were recruited in ambulatory settings of four participating hospitals between June 2011 and December 2013. We analyzed 138 patients that met clinical and bacteriological diagnostic criteria. The mean age was 28 years. Cystitis was defined in 70% (n: 97) and pyelonephritis in 30% (n: 41). Frequencies of isolated microorganisms were: Escherichia coli 70% (n: 97), Staphylococcus saprophyticus 17% (n: 24), Proteus spp. 7% (n: 10), Klebsiella spp. 4% (n: 5), Enterococcus spp. and Pseudomonas aeruginosa 1 (0.7%) each. The antimicrobial resistance was: ampicillin-sulbactam 37% (n: 51) cephalexin 28% (n: 39), trimethoprim/sulfamethoxazole 22% (n: 31), nitrofurantoin 12% (n: 17), gentamicin 7% (n: 10) and ciprofloxacin 5% (n: 7). The levels of resistance found for ampicillin-sulbactam, trimethoprim/sulfamethoxazole and cephalexin were higher than those previously reported in Argentina. A better knowledge of the etiology and local antimicrobial susceptibility allows the design of more adequate guidelines for empirical treatment.

Safety and efficacy of a novel drug elores (ceftriaxone + sulbactam + disodium edetate) in the management of multi-drug resistant bacterial infections in tertiary care centers: a post-marketing surveillance study

Abstract Objective: In India, Elores (CSE-1034: ceftriaxone + sulbactam + disodium edetate) was approved as a broad spectrum antibiotic in year 2011 and is used for management of Extended Spectrum Beta Lactamases/Metallo Beta lactamases infections in tertiary care centers. The objective of this study was to investigate the efficacy of this drug in patients with Extended Spectrum Beta Lactamases/Metallo Beta lactamases infections and identify the incidence of adverse events in real clinical settings. Methods: This Post Marketing Surveillance study was conducted at 17 centers across India and included 2500 patients of all age groups suffering from various bacterial infections and treated with Elores (CSE1034). Information regarding demographic, clinical and microbiological parameters, dosage and treatment duration, efficacy and adverse events (AEs) associated with the treatment were recorded. Results: A total of 2500 patients were included in the study and efficacy was evaluated in 2487 patients. In total, 409 AEs were reported in 211 (8.4%) patients. The major AEs reported were vomiting (3.0%), pain at injection site (2.5%), nausea (2.3%), redness at site (1.96%), thrombophlebitis (1.4%). Of total reported AEs, 40 (5.3%) AEs were reported in pediatric, 310 (20.6%) in adult, and 59 (23.6%) in geriatric group. No AE belonging to grade IV or V was reported in any patient. In terms of efficacy, 1977 (79.4%) patients were cured, 501 (20.1%) patients showed clinical improvement and 5 (0.2%) patients were complete failure. The treatment duration varied from 5 to 7 days in different patients depending on the infection type. Conclusion: In this post-marketing surveillance study, CSE-1034 was found to be an effective and safe option against Pip tazo and meropenem in management of patients with multi-drug resistant (MDR) bacterial infections under routine ward settings.

Biosynthesized silver nanoparticles: are they effective antimicrobials?

BACKGROUND Silver nanoparticles (AgNPs) are increasingly being used in medical applications. Therefore, cost effective and green methods for generating AgNPs are required. OBJECTIVES This study aimed towards the biosynthesis, characterisation, and determination of antimicrobial activity of AgNPs produced using Pseudomonas aeruginosa ATCC 27853. METHODS Culture conditions (AgNO3 concentration, pH, and incubation temperature and time) were optimized to achieve maximum AgNP production. The characterisation of AgNPs and their stability were evaluated by UV-visible spectrophotometry and scanning electron microscopy. FINDINGS The characteristic UV-visible absorbance peak was observed in the 420-430 nm range. Most of the particles were spherical in shape within a size range of 33-300 nm. The biosynthesized AgNPs exhibited higher stability than that exhibited by chemically synthesized AgNPs in the presence of electrolytes. The biosynthesized AgNPs exhibited antimicrobial activity against Escherichia coli, P. aeruginosa, Salmonella typhimurium, Staphylococcus aureus, methicillin-resistant S. aureus, Acinetobacter baumannii, and Candida albicans. MAIN CONCLUSION As compared to the tested Gram-negative bacteria, Gram-positive bacteria required higher contact time to achieve 100% reduction of colony forming units when treated with biosynthesized AgNPs produced using P. aeruginosa.

Etiología aerobia de apendicitis aguda en adultos: Estudio multicéntrico de la sepsis abdominal en Argentina / Aerobic etiology of acute appendicitis in adults. Multicenter study of abdominal sepsis in Argentina

El tratamiento antibiótico de las apendicitis agudas se decide empíricamente basándose en la información epidemiológica. Las resistencias son variables entre regiones y los datos de Argentina son escasos. En el contexto de un estudio multicéntrico, observacional, de infecciones abdominales, se efectuó el análisis de los pacientes adultos con diagnóstico de apendicitis, incorporados al estudio entre enero 2014 y junio 2015, en 16 centros de 5 provincias argentinas. El objetivo fue analizar los gérmenes aeróbicos prevalentes, su resistencia a antibióticos y el patrón de prescripción antimicrobiana. Se estudiaron 131 apendicitis. Se aislaron 184 bacterias aerobias (1.4 bacterias/episodio): Escherichia coli 106 (57.6%), Klebsiella spp 16 (8.7%), Pseudomonas aeruginosa 19 (10.3%), Enterobacter spp. 2 (1%), otros bacilos Gram negativos 5 (2.7%). Enterococcus spp. 16 (8.7%) y otros cocos Gram positivos 20 (10.9%). La resistencia de E. coli y enterobacterias a ampicilina/sulbactam fue mayor a 34% y a ciprofloxacina mayor a 31%. En cambio, la resistencia de enterobacterias a piperacilina/tazobactam fue 4.8%, a ceftriaxona 9.5% y no se halló resistencia a carbapenemes. Respecto a amikacina fue 3.6% y a gentamicina 8.2%. En función de los resultados, el uso de quinolonas o de ampicilina/sulbactam para el tratamiento de las apendicitis debiera ser desaconsejado. Los esquemas basados en aminoglucósidos debieran ser jerarquizados en función de la sensibilidad hallada y su bajo impacto en la inducción de resistencias.

Antibiotic treatment for acute appendicitis is empirically chosen, based on epidemiological information. Resistance rates are different between regions and there are limited data on the situation in Argentina. As a part of a multicenter, observational study of abdominal infections, we performed the analysis of adult patients diagnosed with appendicitis, enrolled in 16 centers of 5 provinces, between Jan/01/2014 and Jun/30/2015. The aim was to analyze the prevalent aerobic pathogens, their resistance rates and the antimicrobial prescription pattern. On a total of 131 appendicitis cases analyzed, we found 184 aerobic pathogens (1.4 bacteria/episode): Escherichia coli 106 (57.6%), Klebsiella spp 16 (8.7%), Pseudomonas aeruginosa 19 (10.3%), Enterobacter spp. 2 (1%), other Gram negative bacilli 5 (2.7%); Enterococcus spp. 16 (8.7%) and other Gram positive cocci 20 (10.9%). The resistance rate of E. coli and enterobacteria to ampicillin/sulbactam was greater than 34% and greater than 31% to ciprofloxacin. However, the resistance of enterobacteria to piperacillin/tazobactam was 4.8%, to ceftriaxone 9.5%, to amikacin 3.6% and 8.2% to gentamicin. No resistance to carbapenems was found. The choice of quinolones or ampicillin/sulbactam for the treatment of appendicitis should be discouraged in our context, due to the high rates of resistance found in this prevalent etiology. Aminoglycoside-based treatments should be considered, given the findings of high antibiotic susceptibility and their low impact on the induction of resistance.