Macrolide-lincosamide-streptogramin B resistance phenotypes and their associated genotypes in Staphylococcus aureus isolates from a tertiary level public hospital of Uruguay / Fenotipos de resistencia a macrólidos lincosamidas-estreptograminas B y sus genotipos asociados en Staphylococcus aureus aislados en un hospital público de nivel terciario en Uruguay

Abstract This study was undertaken to investígate the resistance phenotypes to macrolide-lincosamide-streptogramin B (MLSb) antibiotics and their associated genotypes in isolates of Staphylococcus aureus. We analyzed one hundred, consecutive, non-duplicate isolates (methicillin-susceptible MSSA, n = 53 and methicillin-resistant MRSA, n =47) obtained from var-ious clinical samples between July 2012 to December 2013. The resistance profile to MLSb antibiotics was determined by phenotypic methods and the resistance genes were detected by PCR assays. All of the isolates were subjected to pulsed-field gel electrophoresis (SmaI-PFGE). The overall prevalence of resistance to MLSb antibiotics was 38% and the resistance phenotype distribution was as follows: cMLSb, 22%; iMLSB, 10%; MSb, 5% and L, 1%. We detected ermA, ermC, ermB and mrsA/B genes in these resistant isolates. The single ermA gene was commonly observed mainly in those with a cMLSb R phenotype, whereas the combination ermA and ermC was more commonly observed in isolates with inducible expression. The patterns of SmaI-PFGE suggest a great genetic diversity in both MRSA and MSSA resistant to MLSb antibiotics. The results demonstrate the local presence of S. aureus resistant to MLSb antibiotics and its most frequently described responsible genes. Some of these isolates, especially those with the iMLSB phenotype, may be associated with therapeutic failure. Therefore, efforts should be directed to the correct detection of all MLSb resistant isolates using appropriate laboratory tests. PFGE results reveal a wide spread of resistance genes rather than the circulation of S. aureus clones resistant to MLSb antibiotics.

Resumen Los objetivos de este estudio fueron investigar en Staphylococcus aureus la presencia de fenotipos resistentes a los antibióticos macrólidos, lincosamidas y estreptograminas tipoB (MLSb) y conocer sus genotipos responsables. Analizamos 100 aislamientos consecutivos, no duplicados (53 sensibles a meticilina [MSSA] y 47 resistentes a meticilina [MRSA]), obtenidos entre 2012 y 2013 a partir de diferentes muestras clínicas. El perfil de resistencia a los antibióticos MLSb fue determinado por métodos fenotípicos y los genes de resistencia se detectaron por PCR. Todos los aislamientos fueron comparados por SmaI-PFGE. La prevalencia global de resistencia a los antibióticos MLSB fue del 38% y la distribución de los fenotipos de resistencia fue la siguiente: cMLSB, 22%; iMLSB, 10%; MSB, 5%; L, 1%. Se detectaron los genes ermA, ermC y mrsA/B en los aislamientos resistentes. El gen ermA se observó, sobre todo, en aislamientos con fenotipo resistente constitutivo R (cMLSB), mientras que la combinación ermA y ermC se detectó principalmente en aislamientos con resistencia inducible (iMLSB). Los patrones de Smal-PFGE sugieren una gran diversidad genética en los aislamientos resistentes a los antibióticos MLSb, tanto MRSA como MSSA. Los resultados demuestran la presencia local de S. aureus resistentes a los antibióticos MLSB y de sus genes responsables más frecuentemente descritos. Estos cultivos, especialmente aquellos con fenotipo resistente iMLSB, pueden asociarse con fallas terapéuticas. Por lo tanto, los esfuerzos deben dirigirse a la correcta detección de todos los cultivos resistentes a MLSB utilizando pruebas de laboratorio adecuadas. Los resultados de Smal-PFGE sugieren una amplia diseminación de genes de resistencia, más que la circulación de clones resistentes a los antibióticos MLSB.

Detection of Listeria spp. in cattle and environment of pasture-based dairy farms / Detecção de Listeria spp. em gados leiteiros no meio ambiente com base na pastagem

The aim of the study was to detect Listeria spp., particularly Listeria monocytogenes, in cattle and environment of pasture based dairy farms in Paysandú, Uruguay. A two-stage sampling was conducted, 10 farms were selected by probability proportional to size. A single visit was made to each farm. Samples from bovine faeces, feedstuffs, bulk tank milk, drinking water and soil from the entry and exit pens of the milking parlour were collected for bacteriological studies. PCR assays were used to confirm species and determine the serotype profile of L. monocytogenes isolates. AscI-pulsed-field gel electrophoresis was done to genetically compare them. Listeria spp. were isolated from eight of ten dairy farms, whereas L. monocytogenes in three of them. Serotype distribution in L. monocytogenes was as follows: 1/2a, three isolates; 4b, one isolate. L. monocytogenes or L. innocua excreted from clinically healthy milking cows was detected via faeces. In feedstuffs, only one L. monocytogenes 1/2a isolate from a pasture was obtained. The strain was identical by PFGE to an isolate 1/2a obtained from a pool of milking cow feces that grazed on this farm. No isolation of Listeria spp. was retrieved from the bulk tank milk or drinking water from any of the farms. Listeria innocua was detected in 13 feedstuffs and seven samples of soil from the entry and exit pens of the milking parlour. This is a first local study that confirms the presence of Listeria spp. including L. monocytogenes in healthy cattle and environment of pasture-based dairy farms. These results suggest the potential role that healthy cattle and their sub-products would play as a source of these agents for humans and/or others animals. More detailed studies that include genetic comparison of human and animal isolates are required in order to clearly establish the epidemiological relationship.(AU)

O objetivo deste trabalho foi detectar a presença de bactérias do gênero Listeria e particularmente Listeria monocytogenes, em bovinos leiteiros no ambiente de Paysandú, Uruguai. Foi realizada uma amostragem em duas etapas, dez estabelecimentos foram selecionados por probabilidade proporcional ao tamanho. Foi realizada uma única visita a cada propriedade. Foram coletadas amostras para cultura bacteriológica de matéria fecal bovina, além de alimentos, leite do tanque de resfriamento, água e solo na entrada e saída da sala de ordenha. Com os isolados de L. monocytogenes foi realizado PCR para a confirmação da espécie e determinação do perfil do serotipo. AscI-elctroforese em gel de campo pulsado foi realizado para compará-los geneticamente. Listeria spp. foram isoladas de oito de dez estabelecimentos, enquanto L. monocytogenes foram detectadas em três deles. A distribuição dos serotipos nos isolados de L. monocytogenes recuperados foi: 1/2a três isolados, 4b um isolado. Foram detectadas vacas leiteras clinicamente sadias ​​que excretaram L. monocytogenes ou L. innocua nas fezes. Dos alimentos do gado houve só um isolamento de L. monocytogenes 1/2a em uma pastagem. Esta estirpe foi idêntica no PFGE a um isolado 1/2a obtido de uma "piscina" de fezes de vacas leiteiras do mesmo estabelecimento. Não houve isolamento de Listeria no leite do tanque de resfriamento ou na água de nenhum dos estabelecimentos. Listeria innocua foi detectada em 13 alimentos para o gado e sete amostras de solo na entrada e saída da sala de ordenha. Este parece ser o primeiro estudo local que confirma a presença de Listeria spp. incluindo L. monocytogenes em vacas leiteiras sadias e no meio ambiente de propriedades leiteiras com base alimentícia na pastagem. Esses resultados sugerem o potencial de vacas sadias e seus subprodutos como possível fonte desses agentes para humanos e/ou outros animais. São necessários estudos mais detalhados que incluem a comparação genética de isolados humanos e de animais para estabelecer claramente seu relacionamento epidemiológico.(AU)

Prevalence and serotype distribution of Listeria monocytogenes isolated from foods in Montevideo-Uruguay

ABSTRACT The aim of this work was to study the prevalence of Listeria monocytogenes in foods obtained in retail shops and food industries located in Montevideo-Uruguay, and to identify the serogroups of the obtained isolates. Three-thousand one-hundred and seventy-five food samples (frozen, deli meats, ready-to-eat and cheese) were analyzed. The obtained isolates were serogrouped by multiplex PCR and serotyped by conventional procedure. Genetic comparisons were performed using pulsed-field gel electrophoresis on a sub-set of isolates belonging to the same serotype successively recovered from the same establishment. L. monocytogenes was isolated from 11.2% of samples. The highest prevalence was observed in frozen foods (38%), followed by cheese (10%). 1/2b and 4b were the most frequently identified serotypes. In six of 236 analyzed establishments we successively recovered L. monocytogenes isolates belonging to the same serotype. Most of them corresponded to serotype 1/2b. Pulsed-field gel electrophoresis profiles suggest that at least 33% of L. monocytogenes 1/2b isolates are genetically related and that may remain viable for prolonged periods. The observed prevalence of L. monocytogenes was lower than reported in neighboring countries. Our findings highlight the role that frozen foods may play in the spread of this pathogen, and the relevance of serotypes 1/2b and 4b.

Experiencia de importacao de equipamentos para pesquisa no ELSA-Brasil / La experiencia de importacion de equipos para investigacion en el ELSA-Brasil / Experience of importation of equipment for research in the ELSA-Brasil

OBJETIVO: Políticas de fomento à pesquisa em saúde foram estabelecidas na última década, avançando a produção científica nacional. Tal movimento não foi acompanhado do aperfeiçoamento do arcabouço legal-institucional, dificultando o desenvolvimento dos projetos de pesquisa. Isso inclusive no que tange às atividades de importação de equipamentos. O objetivo deste artigo foi analisar o processo de importação de equipamentos para o Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil). MÉTODOS: Trata-se de estudo de caso, com dados coletados em documentos internos do ELSA-Brasil em cinco Centros de Investigação e respectivas fundações de apoio. Foram analisados documentos de importação de: velocidade de onda de pulso, bioimagem e retinografia. Adicionalmente, foram realizadas entrevistas não estruturadas com pesquisadores e informantes chave nas fundações. Os dados foram tratados e organizados em três etapas: administrativa-operacional, cambial e fiscal. Foram calculados os intervalos de duração dessas etapas de modo comparativo entre os centros. RESULTADOS: A necessidade de padronização dos equipamentos em estudo multicêntrico exigiu atuação conjunta de instituições executoras e fundações. Dos equipamentos analisados, a primeira etapa, a administrativa-operacional, teve duração variada (mínimo 8 e máximo de 101, com média de 55 dias), sendo mais demorada quando incluía pareceres jurídicos. A segunda etapa, a cambial, mais longa que a primeira, não apresentou entraves ao processo (mínimo 11 e máximo 381, média de 196 dias). A terceira etapa, a fiscal, foi a mais longa (mínimo 43 e máximo 388 dias, média de 215,5 dias), ...

OBJECTIVE: Policies that promote research in health were established in the last decade, developing the Brazilian scientific production. This development has not been accompanied by an improvement in the legal-institutional framework, thus hindering the development of research projects, including equipment importation activities. The present study aimed to analyze the equipment importation process for the Brazilian Longitudinal Study for Adult Health (ELSA-Brasil). METHODS: A case study was performed with data collected from internal ELSA-Brasil documents in five Investigation Centers and their respective supporting foundations. The following importation documents were analyzed: pulse wave velocity, bioimaging and retinography. Additionally, non-structured interviews with researchers and key informers were conducted in the foundations. Data were treated and organized into three stages: administrative-operational, exchange rate, and fiscal. Lengths of duration of these stages were calculated comparatively among centers. RESULTS: The need to standardize equipment in a multicenter study required a joint action of implementing institutions and foundations. Of all pieces of equipment analyzed, the first stage was administrative-operational, with a varying duration (minimum of eight, maximum of 101, and mean of 55 days) which was longer when legal opinions were included. The second stage was the exchange rate, which was longer than the former and did not pose any obstacles to the process (minimum of 11, maximum of 381, and mean of 196 days). The third stage was fiscal, which was the longest one (minimum of 43, maximum of 388, and mean of 215.5 days), due to the release of equipment without registration into the country. There were other factors that posed obstacles: inexperience of investigation centers and institutions in networking; inadequacy of the national legislation on scientific ...

Propriedades e mecanismo de ação do hidróxido de cálcio / Propertiens and action mechanism of calcium hydroxide

O objetivo deste trabalho é estudar o mecanismo de ação do hidróxido de cálcio, substância muito importante na terapêutica endodôntica, além de explorar algumas de suas propriedades essenciais como antimicrobiana, pH e solubilidade