Detection of icaA, icaD, and bap genes and biofilm production in Staphylococcus aureus and non-aureus staphylococci isolated from subclinical and clinical bovine mastitis / Detecção dos genes icaA, icaD e bap e produção de biofilme por Staphylococcus aureus e estafilococos não-aureus isolados de mastite clínica e subclínica bovina

Algumas espécies de Staphylococcus causam infecções crônicas intramamárias e podem levar à formação de biofilme. No presente estudo, levantou-se a hipótese de que as espécies de Staphylococcus isolados da mastite bovina são capazes de formar biofilme in vitro associado à presença dos genes icaA, icaD ou bap. Um total de 200 isolados de Staphylococcus, sendo 100 Staphylococcus aureus de casos de mastite subclínica e 100 estafilococos não aureus (ENA) de casos de mastite subclínica e clínica, obtidos em duas fazendas leiteiras, no estado de São Paulo, foram avaliados quanto à capacidade de produzir biofilmes in vitro. A presença de icaA, icaD e bap foi confirmada por PCR, e a produção de biofilme em ágar vermelho congo (Congo Red Agar - CRA) e em teste de microplaca (Microtiter Plate - MtP) foi avaliada nos isolados de S. aureus e ENA. Os resultados mostraram a presença dos genes icaA, icaD e bap em S. aureus, mas não em ENA. A produção de biofilme pode estar associada à presença de outros fatores ou genes que estimulam a produção de biofilme in vitro. O ensaio de MtP serve como um modelo quantitativo para o estudo da aderência de espécies de estafilococos associados à mastite bovina.(AU)

Antimicrobial activity of propolis and essential oils and synergism between these natural products

In the present study, Apis mellifera propolis and essential oils (EOs) obtained from aromatic plants were evaluated as alternative antimicrobials. We aimed to establish the antimicrobial activity of ethanolic extracts of propolis (EEP) from Apis mellifera and of EOs from Caryophyllus aromaticus, Zingiber officinale, Cinnamomum zeylanicum and Mentha piperita against 32 Staphylococcus aureus and Escherichia coli strains from human clinical specimens. The antimicrobials were diluted in agar and the minimal inhibitory concentrations (MIC) were found whereas MIC90 percent values were calculated. Time-kill curve assays using mixtures containing one quarter of MIC90 percent for EEP with all EOs as well cinnamon EO were performed. The cinnamon EO was found to be the most efficient, with MIC90 percent values of 1.22 and 0.96 mg x mL-1 respectively against S. aureus and E. coli, whereas MIC90 percent of EEP were 1.86 and 20.12 mg x mL-1 respectively against S. aureus and E. coli. The combinations of EEP with ginger and mint EOs, and cinnamon with ginger and clove EOs, showed synergistic effects. Consequently, further studies are necessary to confirm these activities in vivo and to evaluate the phytochemical characteristics of natural products.

Detection of enterotoxin genes of Staphylococcus sp isolated from nasal cavities and hands of food handlers

Food handlers, an important factor in food quality, may contain bacteria that are able to cause foodborne disease. The present study aimed to research coagulase-negative (CNS) and -positive staphylococci (CPS) in 82 food handlers, analyzing nasal and hand swabs, with identification of 62 CNS (75.6 percent) and 20 CPS strains (24.4 percent). Staphylococcal enterotoxins genes were investigated by PCR. In 20 CPS strains, 19 were positive for one or more genes. The percentage of CNS presenting genes for enterotoxins was high (46.8 percent). Despite of the staphylococcal species, the most common gene was sea (35.4 percent), followed by seh and sej (29.2 percent). The detection of new staphylococcal enterotoxins (SEs) genes showed a higher pathogenic potential in this genus. The presence of these gene points out the importance of CNS not only as contaminant bacteria but also as a pathogen.

Pulmonary, microbiological and hematological changes in Crotalus durissus terrificus (Serpentes, Viperidae) parasitized by nematodes of the genus Rhabdias (Nematoda, Rhabdiasidae) / Alterações Pulmonares, microbiológicas e hematológicas em Crotalus durissus terrificus (Serpentes, Viperidae) parasitadas pelos nematódeos do gênero Rhabdias (Nematoda, Rhabdiasidae)

This study reported the pulmonary, microbiological, and hematological alterations in Crotalus durissus terrificus parasitized by nematodes of the genus Rhabdias. Histological, microbiological, and hematological analysis were performed on parasitized (n=6) and non-parasitized (n=6) snakes. Granulocytic and mononuclear cell infiltrates in the pulmonary parenchyma and epithelium were also observed during the histological analysis of parasitized snakes. Microbiological analysis of parasitized animals revealed the following Gram-negative bacteria: Citrobacter divergens, Burkholderia cepacia, Stenotrophomonas maltophilia, Proteus vulgaris, Enterobacter sakazakii, Enterobacter ammnigenus, Pseudomonas aeruginosa, Pantoea sp. and Providencia rettgeri. In non-parasitized snakes, the following species were identified: B. cepacia, Pseudomonas fluorescens, and Acinetobacter baumanii. Increased levels of plasmatic protein, decreased lymphocyte counts, and normal red blood cell values were observed in parasitized animals.

Este trabalho relata as alterações pulmonares, microbiológicas e hematológicas em Crotalus durissus terrificus parasitadas pelo nematódeo do gênero Rhabdias. As análises histológicas, microbiológicas e hematológicas foram realizadas em serpentes parasitadas (n=6) e não parasitadas (n=6). Foram observados infiltrados de células granulocíticas e mononucleares no parênquima pulmonar durante a análise histopatológica das serpentes parasitadas. A análise microbiológica revelou as seguintes bactérias Gram-negativas; Citrobacter divergens, Burkholderia cepacia, Stenotrophomonas maltophilia, Proteus vulgaris, Enterobacter sakazakii, Enterobacter ammnigenus, Pseudomonas aeruginosa, Pantoea sp. e Providencia rettgeri. Nas serpentes não parasitadas foram identificadas: B. cepacia, Pseudomonas fluorescens e Acinetobacter baumanii. Nos animais parasitados observaram-se: aumento da concentração de proteína plasmática, diminuição da contagem de linfócitos, e valores normais de hematimetria.

Anti-coagulase-negative Staphylococcus activity of ethanolic extracts of propolis from two Brazilian regions and synergism with antimicrobial drugs by the E-test method

Propolis is a natural resinous substance collected by bees from vegetal sources and its therapeutic properties have been investigated. In this work, we evaluated the inhibitory activity of ethanolic extracts of propolis (EEP) from the Southeast and South of Brazil on coagulase-negative Staphylococcus (CNS) growth as well as the EEP in vitro synergism with antimicrobial drugs by using the diffusion method (E-test). The EEP chemical characteristics (dry weight, pH, flavonoid and phenolic compounds) were determined. Seven drugs were tested, and synergism was observed between three drugs and Southeast EEP, six drugs and South EEP, and one drug and ethanol control. Ethanolic extracts of propolis from the South of Brazil presented the greatest flavonoid content and synergism rate, while EEP from the Southeast presented the greatest anti-CNS activity and phenolic compound content. Results showed the correlation among anti-CNS activity, synergism rate and chemical characteristics of propolis.

Ballast water: a review of the impact on the world public health

Since the nineteenth century ships have been using ballast water (BW) for safety, stability, propulsion and maneuverability, as well as to redress loss of fuel weight and water consumption, and to maintain structural stress at acceptable levels. Ballast water has been spreading many non-native species around the globe, but little is known about the extent and potential significance of ship-mediated transfer of microorganisms. The global movements of ballast water by ships create a long-distance dispersal mechanism for human pathogens that may be important in the worldwide distribution of microorganisms, as well as for the epidemiology of waterborne diseases. Only a few studies have been carried out on this subject, most of them involving ballast water containing crustacean larvae and phytoplankton. Specialized microbiological studies on these waters are necessary to avoid a repeat of what happened in 1991, when epidemic cholera was reported in Peru and rapidly spread through Latin America and Mexico. In July of 1992, Vibrio cholerae was found in the USA and the Food and Drug Administration (FDA) determined that it came from ballast water of ships whose last port of call was in South America. In Brazil, just a few studies about the subject have been performed. An exploratory study by the Brazilian National Health Surveillance Agency (Agência Nacional de Vigilância Sanitária - ANVISA) found in ballast water different microorganisms, such as fecal coliforms, Escherichia coli, Enterococcus faecalis, Clostridium perfringens, coliphages, Vibrio cholerae O1 and Vibrio cholerae non-O1. Until now, Brazil has been focusing only on organisms transported to its territory from other countries by ballast water, to avoid their establishment and dissemination in Brazilian areas. Studies that can assess the probability that water ballast carries pathogenic microorganisms are extremely important, as is the examination of ships that arrive in the country. Treatment of the human...

Susceptibility profile of Salmonella against the antibacterial activity of propolis produced in two regions of Brazil

Propolis antibiotic action has been widely investigated. This assay was carried out in order to observe the in vitro antibacterial activity of propolis against Salmonella enteritidis isolated from food and Salmonella typhimurium isolated from human infections. Propolis was collected by Apis mellifera in two regions of Brazil (Mossoró, Rio Grande do Norte State; and Urubici, Santa Catarina State). Both strains survival percentage decreased with time of incubation in Ethanolic Extracts of Propolis (EEP), demonstrating bactericidal effect after 24 hours. It was also observed that EEP from Mossoró was more effective than that from Urubici. The control of the propolis solvent - 70 percent ethanol - was less effective than EEP, showing only a bacteriostatic effect. We can conclude that propolis shows an activity against Gram-negative bacteria that varies according to the geographical region where it was collected by bees.(AU)