Validação de conteúdo de tecnologia educacional para ensino de enfermagem em saúde ambiental

RESUMO O desenvolvimento e a validação de tecnologias educacionais são ainda incipientes na área de enfermagem em saúde ambiental. Objetivo: Validar o conteúdo da tecnologia educacional Ecosaúde para ensino em saúde ambiental com graduandos de enfermagem. Material e Método: Estudo metodológico e descritivo realizado com uma amostra intencional de 20 estudantes de enfermagem de uma universidade federal do estado do Rio de Janeiro, Brasil. A coleta de dados ocorreu em dois momentos: no mês de setembro de 2017 e no mês de maio de 2018, em sala de aula com duração média de 2 horas. Em cada encontro foi aplicada a tecnologia educacional (TE) Ecosaúde, e um instrumento de validação do conteúdo da TE, por meio de autopreenchimento pelos participantes. O estudo foi aprovado pelo comitê de ética em pesquisa dessa universidade (parecer de n°1.934.809). Resultados: A validação atingiu o valor proposto para a maioria das respostas (80%). Conclusão: A Ecosaúde mostrou-se uma metodologia inovadora e válida para ensino-aprendizagem em saúde ambiental na formação do enfermeiro.

ABSTRACT The development and validation of educational technologies are still emerging in the area of environmental health nursing. Objective: To validate the content of the Ecosaúde educational technology for teaching environmental health with nursing students. Materials and Methods: Methodological and descriptive study carried out with an intentional sample consisting of 20 nursing students from a federal university in the state of Rio de Janeiro, Brazil. Data collection took place in two moments: in the month of September 2017 and in the month of May 2018, in the classroom with an average duration of 2 hours. In each session, the educational technology (ET) Ecosaúde was applied, and a content validation instrument of the ET was filled out by the participants. The study was approved by the research ethics committee of the university under resolution n° 1,934,809. Results: The validation process reached the proposed value for most answers (80%). Conclusion: Ecosaúde proved to be an innovative and valid methodology for teaching-learning environmental health in nursing education.

RESUMEN El desarrollo y la validación de tecnologías educativas aún son incipientes en el área de enfermería de salud ambiental. Objetivo: Validar el contenido de la tecnología educativa Ecosaúde para la enseñanza de la salud ambiental con estudiantes de enfermería. Material y Métodos: Estudio metodológico y descriptivo realizado con una muestra intencional de 20 estudiantes de enfermería de una universidad federal del estado de Rio de Janeiro, Brasil. La recolección de datos tuvo lugar durante dos momentos: en el mes de septiembre de 2017 y en el mes de mayo de 2018, en una sala de clases con una duración promedio de dos horas. En cada sesión se aplicó la tecnología educacional (TE) Ecosáude y un instrumento de validación del contenido de la TE, el cual fue completado por los participantes. El estudio fue aprobado por el comité de ética en investigación de la universidad con el dictamen n° 1.934.809. Resultados: La validación alcanzó el valor propuesto para la mayoría de las respuestas (80%). Conclusión: Ecosaúde demostró ser una metodología innovadora y válida para la enseñanza-aprendizaje en salud ambiental en la formación de enfermeras.

Correção cirúrgica de pseudoaneurismas e fístula arteriovenosa complexa entre vasos poplíteos / Surgical repair of pseudoaneurysms and complex arteriovenous fistula between popliteal vessels

A fístula arteriovenosa (FAV) é uma comunicação anormal e permanente entre uma artéria e uma veia devido a traumas penetrantes e lesões iatrogênicas. O trauma penetrante na parede arterial pode levar à formação de pseudoaneurismas (PSA) e, se houver lesão venosa concomitante, à formação de uma FAV. Os autores apresentam o caso de um paciente portador de FAV complexa de vasos poplíteos associada a pseudoaneurisma de artéria poplítea, sugeridos a partir de exames clínicos e exames de imagem, e tratados por cirurgia convencional devido à indisponibilidade de um stent graft com diâmetro apropriado, além de a cirurgia endovascular não estar disponível no serviço em que o paciente foi operado

An arteriovenous fistula (AVF) is an abnormal and permanent communication between an artery and a vein caused by penetrating traumas or iatrogenic injuries. A penetrating trauma to the endothelial wall can lead to formation of pseudoaneurysms (PSA) and to formation of an AVF. Here, the authors present the case of a patient with a complex AVF of popliteal vessels, associated with popliteal artery pseudoaneurysm, suggested by clinical features and imaging exams, and treated with conventional surgery due to unavailability of a stent graft with appropriate diameter and because endovascular surgery isn't provided at the service where this patient was operated

Potassium adsorption in soil cultivated with sugarcane

ABSTRACT Vinasse is a byproduct of the process of distillation of sugarcane juice for the manufacture of sugar and alcohol. Because it is rich in nutrients, mainly potassium (K), is used as fertilizer and applied via fertigation, without concerning for the fate of this compound in the soil. Thus, the objective of the study was to evaluate the interactions of the potassium ion (K+), applied via vinasse in a soil representative of the sugarcane zone of the State of Pernambuco using adsorption isotherms. The methodology was based on physical, chemical and soil mineralogical characterization, as well as equilibrium batch tests, where the experimental curves were fitted by Langmuir and Freundlich isotherm models. The results allowed to infer that the Freundlich model showed better fit of the curve in both forms: linear and non-linear (direct fit); the non-linear model was selected due to the values ​​of coefficient of determination (R²). The interaction between potassium and soil occurred mainly with organic matter and the presence of soil kaolinite, because they showed negative ions on the external surface, thereby promoting potassium adsorption. Soil potassium adsorption capacity was higher for the first layer (0-20 cm) and decreased along the depth profile.

Potassium adsorption in soil cultivated with sugarcane.

Vinasse is a byproduct of the process of distillation of sugarcane juice for the manufacture of sugar and alcohol. Because it is rich in nutrients, mainly potassium (K), is used as fertilizer and applied via fertigation, without concerning for the fate of this compound in the soil. Thus, the objective of the study was to evaluate the interactions of the potassium ion (K+), applied via vinasse in a soil representative of the sugarcane zone of the State of Pernambuco using adsorption isotherms. The methodology was based on physical, chemical and soil mineralogical characterization, as well as equilibrium batch tests, where the experimental curves were fitted by Langmuir and Freundlich isotherm models. The results allowed to infer that the Freundlich model showed better fit of the curve in both forms: linear and non-linear (direct fit); the non-linear model was selected due to the values ​​of coefficient of determination (R²). The interaction between potassium and soil occurred mainly with organic matter and the presence of soil kaolinite, because they showed negative ions on the external surface, thereby promoting potassium adsorption. Soil potassium adsorption capacity was higher for the first layer (0-20 cm) and decreased along the depth profile.

Surgical repair of pseudoaneurysms and complex arteriovenous fistula between popliteal vessels.

An arteriovenous fistula (AVF) is an abnormal and permanent communication between an artery and a vein caused by penetrating traumas or iatrogenic injuries. A penetrating trauma to the endothelial wall can lead to formation of pseudoaneurysms (PSA) and to formation of an AVF. Here, the authors present the case of a patient with a complex AVF of popliteal vessels, associated with popliteal artery pseudoaneurysm, suggested by clinical features and imaging exams, and treated with conventional surgery due to unavailability of a stent graft with appropriate diameter and because endovascular surgery isn't provided at the service where this patient was operated.

Força de preensão manual, nível de atividade física e qualidade de vida de competidores máster de judô / Handgrip strength, physical activity level and quality of life of Judo master competitors

Resumo O objetivo do presente estudo foi avaliar e testar a correlação entre força isométrica de preensão manual (FIPM), nível de atividade física (AF) e qualidade de vida (QV) de competidores máster de judô. A amostra foi composta por 44 homens (45 a 64 anos), participantes do Campeonato Panamericano Master de Judô de 2011. Para avaliar a força manual, utilizou-se teste de força isométrica de preensão manual. Empregaram-se os questionários WHOQOL-Breve e Questionário de Atividade Física Global (GPAQ). Na análise estatística, após a verificação da normalidade na distribuição dos dados, os mesmos são apresentados com média [Intervalo de confiança 95%]. Na comparação entre grupos etários, foi conduzida análise de variância (ANOVA), com pos-hoc de Tukey. Para correlações bivariadas, empregou-se o teste de Pearson. Os competidores de judô demonstraram: 1) quantidade elevada de AF (661 [513-810] min de AF moderada a vigorosa) quando se consideram as recomendações populacionais; 2) FIPM com valores moderados (soma bilateral de 87,1 [82,3-91,9] kgf) comparados com pessoas fisicamente ativas e idosos; e 3) escores de QV superiores aos registrados em outros estudos. Adicionalmente, destacam-se dois principais achados, ausência de diferenças significantes para percepção subjetiva de QV e de FIPM segundo grupos etários e correlação positiva entre quantidade semanal de AF moderada a vigorosa e escores de QV.(AU)

Abstract The aim of this study was to evaluate and test the correlation between isometric handgrip (IH), physical activity level (PA) and quality of life (QOL) of master judo competitors. The sample was composed by 44 men (45-64 years) participating in the Pan-American Master Judo Championships, 2011. To evaluate the handgrip strength was used isometric handgrip test. Additionally, were employed WHOQOL-Bref questionnaire and Global Physical Activity Questionnaire (GPAQ). In the statistical analysis, after checking the normal distribution of the data, they are presented as mean [95% confidence interval]. In the comparison between age groups, we conducted analysis of variance (ANOVA) with Tukey post-hoc. For bivariate correlations, we used the Pearson test. The judo athletes showed: 1) high amount of PA (661 [513-810] min of moderate to vigorous PA) when considering the population recommendations; 2) moderate values of FIPM (bilateral sum equal to 87.1 [82.3 -91.9] kgf) compared with physically active people and the elderly; and 3) QOL scores higher than in other studies. Additionally, we highlight two main findings, no significant differences in subjective perception of QOL and FIPM by age groups and positive correlation between weekly amount of moderate to vigorous PA and QoL scores.(AU)

Anterior cruciate ligament reconstruction: how do we perform it? Brazilian orthopedic surgeons' preference.

PURPOSE: We evaluated current trends and common practice of Brazilian orthopedic surgeons while selecting approaches for anterior cruciate ligament (ACL) reconstruction surgery. METHODS: Orthopedic surgeons (n = 191) completed a survey consisting of seven questions regarding their profiles and preference for ACL reconstruction techniques. RESULTS: Most surgeons were from Southeast Brazil (56.6%) and had specialized in knee surgery (79.5%); most participants (55.1%) had worked in this field for > five years, and 46.8% had performed >50 ACL reconstructions. Further, 93.1% respondents preferred the hamstring graft. Analysis of preference for the femoral tunnel approach in terms of years of experience showed that surgeons with ten to 15 years' experience preferred the transtibial approach; those with < five years of experience, the transportal technique; those with >15 years' experience, the two-incision technique. CONCLUSIONS: Surgeons' preferences for ACL reconstruction are variable, and are influenced by learning time and availability of tools rather than research evidence.

Quantification of platelets obtained by different centrifugation protocols in SHR rats / Quantificação do número de plaquetas a partir de diferentes métodos de centrifugação em ratos da linhagem SHR

To quantify the platelet concentration in the blood of SHR rats, by means of different centrifugation protocols, and to evaluate what the most effective method for obtaining platelets is. METHODS: We used 40 male rats of the isogenic SHR lineage. The animals were divided into three groups: control, using whole blood without centrifugation; single centrifugation, using whole blood subjected to a single centrifugation at 200 × gand 400 × g; and double centrifugation, using whole blood subjected one centrifugation at different rotations, followed by collection of whole plasma subjected to another centrifugation at different rotations: 200 × g+ 200 ×g; 200 × g+ 400 × g; 200 × g+ 800 × g; 400 ×g+ 400 × g; 400 × g+ 800 × g. Samples of 3 ml of blood were drawn from each animal by means of cardiac puncture. The blood was stored in Vacutainer collection tubes containing 3.2% sodium citrate. The blood from the control group animals was analyzed without being subjected to centrifugation. After the blood from the other groups of animals had been subjected to centrifugation, the whole plasma was collected and subjected to platelet counting in the lower third of the sample. RESULTS: We obtained greatest platelet enrichment in the subgroup with two centrifugations comprising 400 × gfor 10 min + 400 ×gfor 10 min, in which the mean platelet concentration was 11.30 times higher than that of the control group. CONCLUSION: It was possible to obtain a high platelet concentration using viable simple techniques, by means of centrifugation of whole blood and use of commonly used materials. The most effective method for obtaining platelet concentrate was found in samples subjected to two centrifugations.

Quantificar a concentração de plaquetas do sangue de ratos SHR, por meio de diferentes protocolos de centrifugação, e avaliar qual o método mais eficaz de obtenção de plaquetas. MÉTODOS: Usamos 40 ratos machos da linhagem isogênica SHR. Os animais foram divididos em três grupos: Controle (GCT) - sangue total sem centrifugação; Única Centrifugação (GUC) - sangue total submetido a uma única centrifugação: 200 g e 400 g; Dupla Centrifugação (GDC) - sangue total submetido a uma centrifugação, seguido de coleta do plasma total, e realizado uma centrifugação, em diferentes rotações: 200 g + 200 g; 200 g + 400 g; 200 g + 800 g; 400 g + 400 g; 400 g + 800 g. Foram retirados 3 ml de sangue de cada animal por meio de punção cardíaca. O sangue foi acondicionado em tubo de coleta vacutainer com citrato de sódio 3,2%. O sangue dos animais do grupo controle não foi submetido à centrifugação e foi analisado. Após a centrifugação do sangue dos animais, submetido à centrifugação, o plasma total foi coletado e submetido à contagem de plaquetas no terço inferior da amostra. RESULTADOS: Obtivemos maior enriquecimento de plaquetas no subgrupo de duas centrifugações (400 g por 10 minutos + 400 g por 10 minutos), no qual ocorreu uma concentração média de plaquetas 11,30 vezes superior em relação ao grupo controle. CONCLUSÃO: Foi possível obter uma alta concentração plaquetária, com técnica simples e viável, por meio de centrifugação do sangue total e uso de materiais de uso corriqueiro; e método mais eficaz de obtenção de concentrado de plaquetas ocorreu nas amostras submetidas a duas centrifugações.

Quantification of platelets obtained by different centrifugation protocols in SHR rats.

OBJECTIVE: To quantify the platelet concentration in the blood of SHR rats, by means of different centrifugation protocols, and to evaluate what the most effective method for obtaining platelets is. METHODS: We used 40 male rats of the isogenic SHR lineage. The animals were divided into three groups: control, using whole blood without centrifugation; single centrifugation, using whole blood subjected to a single centrifugation at 200 × g and 400 × g; and double centrifugation, using whole blood subjected one centrifugation at different rotations, followed by collection of whole plasma subjected to another centrifugation at different rotations: 200 × g + 200 × g; 200 × g + 400 × g; 200 × g + 800 × g; 400 × g + 400 × g; 400 × g + 800 × g. Samples of 3 ml of blood were drawn from each animal by means of cardiac puncture. The blood was stored in Vacutainer collection tubes containing 3.2% sodium citrate. The blood from the control group animals was analyzed without being subjected to centrifugation. After the blood from the other groups of animals had been subjected to centrifugation, the whole plasma was collected and subjected to platelet counting in the lower third of the sample. RESULTS: We obtained greatest platelet enrichment in the subgroup with two centrifugations comprising 400 × g for 10 min + 400 × g for 10 min, in which the mean platelet concentration was 11.30 times higher than that of the control group. CONCLUSION: It was possible to obtain a high platelet concentration using viable simple techniques, by means of centrifugation of whole blood and use of commonly used materials. The most effective method for obtaining platelet concentrate was found in samples subjected to two centrifugations.

OBJETIVO: Quantificar a concentração de plaquetas do sangue de ratos SHR, por meio de diferentes protocolos de centrifugação, e avaliar qual o método mais eficaz de obtenção de plaquetas. MÉTODOS: Usamos 40 ratos machos da linhagem isogênica SHR. Os animais foram divididos em três grupos: Controle (GCT) - sangue total sem centrifugação; Única Centrifugação (GUC) - sangue total submetido a uma única centrifugação: 200 g e 400 g; Dupla Centrifugação (GDC) - sangue total submetido a uma centrifugação, seguido de coleta do plasma total, e realizado uma centrifugação, em diferentes rotações: 200 g + 200 g; 200 g + 400 g; 200 g + 800 g; 400 g + 400 g; 400 g + 800 g. Foram retirados 3 ml de sangue de cada animal por meio de punção cardíaca. O sangue foi acondicionado em tubo de coleta vacutainer com citrato de sódio 3,2%. O sangue dos animais do grupo controle não foi submetido à centrifugação e foi analisado. Após a centrifugação do sangue dos animais, submetido à centrifugação, o plasma total foi coletado e submetido à contagem de plaquetas no terço inferior da amostra. RESULTADOS: Obtivemos maior enriquecimento de plaquetas no subgrupo de duas centrifugações (400 g por 10 minutos + 400 g por 10 minutos), no qual ocorreu uma concentração média de plaquetas 11,30 vezes superior em relação ao grupo controle. CONCLUSÃO: Foi possível obter uma alta concentração plaquetária, com técnica simples e viável, por meio de centrifugação do sangue total e uso de materiais de uso corriqueiro; e método mais eficaz de obtenção de concentrado de plaquetas ocorreu nas amostras submetidas a duas centrifugações.

Amamentação: conhecimentos e experiências de gestantes / Breastfeeding: pregnant women knowledge and experience

INTRODUCTION: Breastfeeding, among its many benefits, provides health care to the newborn and strengthens the mother and son bond. Objective: The present study aims to identify knowledge and practices of pregnant women about breastfeeding in a health care unit in the city of Fortaleza, Ceará. METHODS: It is a cross-sectional study, involving 60 pregnant women seen during prenatal from November 2013 to January 2014. A previously tested instrument for data collection was applied. Women younger than 19 years old were excluded from the study. RESULTS: Most pregnant women reported having received some orientation about breastfeeding. The most commonly reported was breastfeeding on demand. All participants agreed that the baby must be fed for the first time immediately after the delivery while 80% knew that the baby must be exclusively breastfed in the first six months of life. However, introducing water, juice or tea in this period was a practice mentioned by 43.3% of them. "Losing weight" and "avoiding diseases" were mentioned as the main advantages of breastfeeding for the mothers. The breastfeeding experience was characterized as "tiring", "tiresome", "hurting" and "stressful". Some of them tried cross-breastfeeding. CONCLUSIONS: These pregnant women's knowledge about exclusively-maternal breastfeeding doesn't seem to be turning into practice. They showed little satisfaction with the breastfeeding and cross-breastfeeding practices, being the latter not recommended but still practiced by some women. In the health care unit where this study was conducted it becomes a necessity not only to orientate, but also support, breastfeeding

INTRODUÇÃO: O aleitamento materno, entre suas inúmeras vantagens, propicia saúde ao recém-nascido e fortalece o vínculo mãe e filho. Objetivo: O objetivo do presente estudo é identificar conhecimentos e práticas sobre aleitamento materno de gestantes em uma unidade de saúde no município de Fortaleza, Ceará. MÉTODOS: Trata-se de estudo transversal, envolvendo 60 gestantes atendidas em pré-natal de novembro de 2013 a janeiro de 2014. Foi aplicado um instrumento de coleta de dados previamente testado. Foram excluídas do estudo mulheres com menos de 19 anos. RESULTADOS: A maioria das gestantes relatou ter recebido alguma orientação sobre aleitamento sendo a mais citada a amamentação em livre demanda. Todas as participantes souberam informar que o bebê deve ser amamentado pela primeira vez imediatamente após o parto e 80% afirmaram que ele deveria mamar exclusivamente até seis meses. Porém, a introdução de água, suco ou chá, nesse período foi uma prática citada por 43,3% delas. "Perda de peso" e "evitar doenças" foram citadas como as principais vantagens do aleitamento materno para as mães. A experiência com amamentação foi citada como "cansativa", "dá trabalho", "dói" e "estressante". Algumas gestantes praticaram a amamentação cruzada. CONCLUSÕES: Os conhecimentos das gestantes sobre aleitamento materno exclusivo não parecem estar se transformando em prática. As gestantes demonstraram pouca satisfação com o ato de amamentar e com a amamentação cruzada, prática não recomendada, mas ainda praticada por algumas mulheres. No ambiente de saúde onde o estudo foi realizado percebe-se que é necessário não apenas orientar, mas também dar apoio à prática da amamentação

A atuação da educação física nas residências multiprofissionais em saúde / Performance of physical education in multiprofessional health residency / La actuación de la educación física en las residências multiprofesionales en salud

Objetivo: Apresentar as atividades de competência e atuação da Educação Física nas residências multiprofissionais em saúde e as dificuldades dessa experiência. Síntese dos dados: Apresentam-se as atividades de competência e atuação no Sistema Único de Saúde (SUS) da Residência Integrada Multiprofissional Hospitalar com Ênfase na Atenção à Saúde Cardiometabólica do Adulto (RIMHAS) e da Residência Multiprofissional em Saúde da Família (RMSF), supervisionadas pela Comissão das Residências Multiprofissionais (COREMU), ambas com atenção à saúde dos usuários do SUS e duração de dois anos. No que diz respeito à atuação dos residentes, no primeiro ano na RIMHAS, as atividades são desenvolvidas no Hospital Universitário da Universidade Federal do Rio Grande (FURG), no Serviço de Pronto Atendimento, Clínica Médica e Clínica Cirúrgica; no segundo, ocorrem no Centro Integrado de Diabetes e Centro de Reabilitação Física. Na RMSF, há uma imersão em uma equipe de Estratégia de Saúde da Família, com atuação em uma Unidade Básica de Saúde, além da realização de estágios em outros serviços. Conclusão: O estudo mostra que experiências que articulam a formação acadêmica do núcleo da Educação Física e o SUS contribuem para a construção de um canal de diálogo entre indivíduos atuantes nas residências multiprofissionais.

Objetive: To present the activities under the competence of physical education and its performance in the multidisciplinary residences in health and the difficulties involved in this experience. Data synthesis: The study presented the activities of competence and the performance in the Unified Health System (Serviço Único de Saúde - SUS) of the Hospital Multiprofessional Integrated Residency Program with emphasis on Adults? CardiometabolicHealthcare (Residência Integrada Multiprofissional Hospitalar - RIHMAS) and the Multiprofessional Residency Program in Family Health (Residência Multiprofissional em Saúde da Família - RMSF), supervised by the Commission of Multidisciplinary Residences (Comissão das Residências Multiprofissionais - COREMU), both with two-year duration, aiming healthcare for SUS users. As regards the actions of residents, all activities take place at the University Hospital of the Federal University of Rio Grande (FURG); in their first year in RIMHAS, the activities are developed in the Emergency room, Medical and Surgical Clinic; in the second one, they occur in the Integrated Center for Diabetes and Physical Rehabilitation Centre. In RMSF there is a dip in the Family Health Strategy, carrying out activities in a Basic Health Unit, in addition to internships in other health services. Conclusion: The study shows that experiences that link the academic training of the Physical Education core and the SUS contribute to open a channel of dialogue between individuals acting in multiprofessional residency programs.

Objetivo: Presentar las actividades de competencia y actuación de la Educación Física en las residencias multiprofesionales en salud y las dificultades de esa experiencia. Síntesis de los datos: Se presentan las actividades de competencia y actuación en el Sistema de Salud (SUS) de la Residencia Integrada Multiprofesional Hospitalario con Énfasis en la Atención a La Salud Cardiometabólica del Adulto (RIMHAS) y de la Residencia Multiprofesional en Salud de la Familia (RMSF), supervisionadas por la Comisión de las Residencias Multiprofesionales (COREMU), ambas con atención a la salud de los usuarios del SUS y duración de dos años. Respecto la actuación de los residentes, en el primer año de la RIMHAS, las actividades son desarrolladas en el Hospital Universitario de la Universidad Federal de Rio Grande (FURG),en el Servicio de Pronta Asistencia, Clínica Médica y Clínica Quirúrgica. En el segundo año las actividades se dan en el Centro Integrado de Diabetes y Centro de Rehabilitación Física. En La RMSF hay una inmersión en un equipo de Estrategia de Salud de la Familia con actuación en una Unidad Básica de Salud, además de la realización de prácticas en otros servicios. Conclusión: El estudio muestra que las experiencias que involucran la formación académica del núcleo de Educación Física y el SUS contribuyen para la construcción del dialogo entre los individuos de las residencias multiprofesionales.

Identification and characterization of psychrotolerant sporeformers associated with fluid milk production and processing.

Psychrotolerant spore-forming bacteria represent a major challenge to the goal of extending the shelf life of pasteurized dairy products. The objective of this study was to identify prominent phylogenetic groups of dairy-associated aerobic sporeformers and to characterize representative isolates for phenotypes relevant to growth in milk. Analysis of sequence data for a 632-nucleotide fragment of rpoB showed that 1,288 dairy-associated isolates (obtained from raw and pasteurized milk and from dairy farm environments) clustered into two major divisions representing (i) the genus Paenibacillus (737 isolates, including the species Paenibacillus odorifer, Paenibacillus graminis, and Paenibacillus amylolyticus sensu lato) and (ii) Bacillus (n = 467) (e.g., Bacillus licheniformis sensu lato, Bacillus pumilus, Bacillus weihenstephanensis) and genera formerly classified as Bacillus (n = 84) (e.g., Viridibacillus spp.). When isolates representing the most common rpoB allelic types (ATs) were tested for growth in skim milk broth at 6°C, 6/9 Paenibacillus isolates, but only 2/8 isolates representing Bacillus subtypes, grew >5 log CFU/ml over 21 days. In addition, 38/40 Paenibacillus isolates but only 3/47 Bacillus isolates tested were positive for ß-galactosidase activity (including some isolates representing Bacillus licheniformis sensu lato, a common dairy-associated clade). Our study confirms that Paenibacillus spp. are the predominant psychrotolerant sporeformers in fluid milk and provides 16S rRNA gene and rpoB subtype data and phenotypic characteristics facilitating the identification of aerobic spore-forming spoilage organisms of concern. These data will be critical for the development of detection methods and control strategies that will reduce the introduction of psychrotolerant sporeformers and extend the shelf life of dairy products.

The ability of non-bacteriocin producing Streptococcus bovis strains to bind and transfer bovicin HC5 to other sensitive bacteria.

Streptococcus bovis HC5 produces a broad spectrum lantibiotic (bovicin HC5), but S. bovis JB1 does not have antimicrobial activity. Preliminary experiments revealed an anomaly. When S. bovis JB1 cells were washed in stationary phase S. bovis HC5 cell-free culture supernatant, the S. bovis JB1 cells were subsequently able to inhibit hyper-ammonia producing ruminal bacteria (Clostridium sticklandii, Clostridium aminophilum and Peptostreptococcus anaerobius). Other non-bacteriocin producing S. bovis strains also had the ability to bind and transfer semi-purified bovicin HC5. Bovicin HC5 that was bound to S. bovis JB1 was much more resistant to Pronase E than cell-free bovicin HC5, but it could be inactivated if the incubation period was 24 h. Acidic NaCl treatment (100 mM, pH 2.0) liberates half of the bovicin HC5 from S. bovis HC5, but it did not prevent bovicin HC5 from binding to S. bovis JB1. Acidic NaCl liberated some bovicin HC5 from S. bovis JB1, but the decrease in activity was only 2-fold. Bovicin HC5 is a positively charged peptide, and the ability of S. bovis JB1 to bind bovicin HC5 could be inhibited by either calcium or magnesium (100 mM). Acidic NaCl-treated S. bovis JB1 cells were unable to accumulate potassium, but they were still able to bind bovicin HC5 and prevent potassium accumulation by untreated S. bovis JB1 cells. Based on these results, bovicin HC5 bound to S. bovis JB1 cells still acts as a pore-forming lantibiotic.

The activity and stability of cell-associated activity of bovicin HC5, a bacteriocin from Streptococcus bovis HC5.

Streptococcus bovis HC5 cultures released a broad spectrum lantibiotic, bovicin HC5, into the cell-fee culture supernatant after they reached stationary phase, but most of the antibacterial activity remained cell-associated. Cell-associated bovicin HC5 was more resistant to degradation by Pronase E than the cell-free activity. Acidic NaCl (pH 2.0, 100 mM) did not release all of the cell-associated activity, and cells that were sequentially treated with acidic NaCl and Pronase E still had antibacterial activity. Cell-associated activity retained after acidic NaCl treatment was still able to catalyze potassium efflux from S. bovis JB1, a sensitive strain. These results indicate that cell-associated bovicin HC5 is more active and stable than cell-free bovicin HC5.

Bacterial competition between a bacteriocin-producing and a bacteriocin-negative strain of Streptococcus bovis in batch and continuous culture.

A bacteriocin-producing Streptococcus bovis strain (HC5) outcompeted a sensitive strain (JB1) before it reached stationary phase (pH 6.4), even though it grew 10% slower and cell-free bovicin HC5 could not yet be detected. The success of bacteriocin-negative S. bovis isolates was enhanced by the presence of another sensitive bacterium (Clostridium sticklandii SR). PCR based on repetitive DNA sequences indicated that S. bovis HC5 was not simply transferring bacteriocin genes to S. bovis JB1. When the two S. bovis strains were coinoculated into minimal medium, bacteriocin-negative isolates predominated, and this effect could be explained by the longer lag time (0.5 vs. 1.5 h) of S. bovis HC5. If the glucose concentration of the minimal medium was increased from 2 to 7 mg mL(-1), the effect of lag time was diminished and bacteriocin-producing isolates once again dominated the coculture. When the competition was examined in continuous culture, it became apparent that batch culture inocula were never able to displace a strain that had already reached steady state, even if the inoculum was large. This result indicated that bacterial selection for substrate affinity was even more important than bacteriocin production.