Antimicrobial susceptibility of cinnamon and red and common thyme essential oils and their main constituent compounds against Streptococcus suis.

Streptococcus suis is an emerging zoonotic pathogen causing different diseases, in both humans and pigs. Generally, the control of this pathogen is based on antimicrobial therapy, but the development of bacterial resistance has led one to look for new options. In this sense, the essential oils (EOs) constitute a promising alternative. The activity of cinnamon, common thyme and red thyme EOs and their main active compounds (cinnamaldehyde and thymol) against S. suis isolates from pigs (n = 50) and humans (n = 6) was determined by the broth microdilution method. MIC50-90, MBC50-90 and the bactericidal index (BI) (minimal bactericidal concentration (MBC)/minimal inhibitory concentration (MIC)) were calculated. Also, the time-kill curve of each product against the S. suis P1/7 European reference strain was determined. No differences in the MIC or MBC values were observed between all the tested products, which suggest a homogeneous behaviour of S. suis, independently of their origin, organ of isolation or resistance profile. All the products showed a concentration-dependent and time-dependent killing activity and achieved the virtual eradication of S. suis at supra-inhibitory concentrations within the first 5 min of exposure, except cinnamaldehyde that showed only bacteriostatic effect. It suggests that these products could be utilized as antimicrobials in veterinary medicine for the control of this zoonotic pathogen.

Combined effect of conventional antimicrobials with essential oils and their main components against resistant Streptococcus suis strains.

Streptococcus suis is a major swine pathogen. Different strategies to reduce the antimicrobial resistance to conventional antimicrobials (AMBs) have been proposed, including the combined use with essential oils (EOs). The objective of this work was to evaluate the effectiveness of the combination of cinnamon, oregano, common thyme and red thyme EOs and their main components (cinnamaldehyde, carvacrol and thymol) with conventional AMBs (oxytetracycline, trimethoprim-sulfamethoxazole, gentamicin and penicillin) against field resistant S. suis strains. The checkerboard method was used to assess the interaction, by the fractional inhibitory concentration index (FICindex ) determination. All the AMBs showed synergistic (FICindex  ≤ 0·5) or additive (0·5 < FICindex  ≤ 1) effect with at least one of the four essential oils. In general, the combination of the AMBs with the EOs showed better results than combination the AMBs with the main components, although no antagonist effects were detected in any case. The results obtained would support the combined use of AMBs agents with EOs for the treatment of S. suis. SIGNIFICANCE AND IMPACT OF THE STUDY: Streptococcus suis is an important pig pathogen and a zoonosis. Control is based on antimicrobials; however, there is pressure to reduce the use of antimicrobials and new products or combination therapies are of considerable interest. We have evaluated the combined interaction of four essential oils or their main components with conventional antimicrobials against resistant S. suis strains. A positive interaction between gentamicin and oxytetracycline with cinnamon, oregano or thyme was observed, suggesting that a combination of conventional antimicrobials with EOs is a promising alternative for the control of S. suis infections.

Philometra saltatrix (Nematoda: Philometridae) in the ovary of the bluefish, Pomatomus saltatrix (Linnaeus, 1766), off the coast of the state of Rio de Janeiro, Brazil.

The aims of the present study were to identify and describe the occurrence of nematode parasites in the gonads of bluefish Pomatomus saltatrix from off the coast of the state of Rio de Janeiro, Brazil. Only females were found to be parasitized by the nematodes, which were identified as P. saltatrix using morphological, morphometric and molecular data. Infection of female bluefish by this nematode had the following values: prevalence, 48.7%; mean intensity, 2.6; mean abundance, 1.3; and range of infection, 1-10 specimens. Histopathological examination of transverse and longitudinal sections of the parasitized ovaries showed nematodes at different stages of development among oocytes, but no indication of any associated inflammatory reaction. The presence of nematodes in the ovaries of bluefish is an important indication of fish hygiene, and parasitized fish are usually rejected by consumers because of their repugnant appearance.

Comparability of river quality assessment using macrophytes: a multi-step procedure to overcome biogeographical differences.

This paper exposes a new methodological approach to solve the problem of intercalibrating river quality national methods when a common metric is lacking and most of the countries share the same Water Framework Directive (WFD) assessment method. We provide recommendations for similar works in future concerning the assessment of ecological accuracy and highlight the importance of a good common ground to make feasible the scientific work beyond the intercalibration. The approach herein presented was applied to highly seasonal rivers of the Mediterranean Geographical Intercalibration Group for the Biological Quality Element Macrophytes. The Mediterranean Group of river macrophytes involved seven countries and two assessment methods with similar acquisition data and assessment concept: the Macrophyte Biological Index for Rivers (IBMR) for Cyprus, France, Greece, Italy, Portugal and Spain, and the River Macrophyte Index (RMI) for Slovenia. Database included 318 sites of which 78 were considered as benchmarks. The boundary harmonization was performed for common WFD-assessment methods (all countries except Slovenia) using the median of the Good/Moderate and High/Good boundaries of all countries. Then, whenever possible, the Slovenian method, RMI was computed for the entire database. The IBMR was also computed for the Slovenian sites and was regressed against RMI in order to check the relatedness of methods (R(2)=0.45; p<0.00001) and to convert RMI boundaries into the IBMR scale. The boundary bias of RMI was computed using direct comparison of classification and the median boundary values following boundary harmonization. The average absolute class differences after harmonization is 26% and the percentage of classifications differing by half of a quality class is also small (16.4%). This multi-step approach to the intercalibration was endorsed by the WFD Regulatory Committee.

Least Disturbed Condition for European Mediterranean rivers.

The present report describes a three-step approach that was used to characterize and define thresholds for the Least Disturbed Condition in Mediterranean streams of four different types, regarding organic pollution and nutrients, hydrological and morphological alterations, and land use. For this purpose, a common database composed of national reference sites (929 records) from seven countries, sampled for invertebrates, diatoms and macrophytes was used. The analyses of reference sites showed that small (catchment <100 km(2)) siliceous and non-siliceous streams were mainly affected by channelization, bank alteration and hydropeaking. Medium-sized siliceous rivers were the most affected by stressors: 25-43% of the samples showed at least slight alterations regarding channelization, connectivity, upstream dam influence, hydropeaking and degradation of riparian vegetation. Temporary streams were the least affected by hydromorphological changes, but they were nevertheless affected by alterations in riparian vegetation. There were no major differences between all permanent stream types regarding water quality, but temporary streams showed lower values for oxygenation (DO) and wider ranges for other variables, such as nitrates. A lower threshold value for DO (60%) was determined for this stream type and can be attributed to the streams' natural characteristics. For all other river types, common limits were found for the remaining variables (ammonium, nitrate, phosphate, total P, % of artificial areas, % of intensive and extensive agriculture, % of semi-natural areas in the catchment). These values were then used to select the list of reference sites. The biological communities were characterized, revealing the existence of nine groups of Mediterranean invertebrate communities, six for diatoms and five for macrophytes: each group was characterized by specific indicator taxa that highlighted the differences between groups.

FAS and ErbB2 expression in early local recurrent oral cancer.

BACKGROUND: Local failure occurs in 13.9-62.6% and it is a well known indicator of poor prognosis in patients with oral squamous cell carcinoma (OSCC), despite aggressive treatments. The purpose of this study was to investigate the value of histopathology and molecular biomarkers in predicting the development of early local recurrence. METHODS: This study included a total of 69 patients. There were 23 patients with early recurrent OSCC and 46 patients without local recurrence with the same clinical stage and tumor site, in a pair-matched study design. Their charts were retrospectively analyzed. All surgical specimens of the primary tumors were evaluated according to the system proposed by Anneroth et al. and immunohistochemical for ErbB2 and FAS were performed. RESULTS: A significant correlation of early local recurrence with grade of histological malignancy (more than 15 points) was observed (Fisher's exact test, P = 0.03). Early local recurrence was also significantly associated with weak FAS expression and strong intracytoplasmic ErbB2 staining (Mantel-Haenszal chi-square, P = 0.0038 and P = 0.0068, respectively). Histological grade of malignancy (more than 15 points) was also correlated with reduced survival (log-rank, P = 0.06). Among the histopathological parameters, keratinization, pattern of invasion and inflammation were important for overall survival (log-rank, P < 0.0001). Regarding the biomarkers, only FAS was significantly associated with overall survival (log-rank, P = 0.0002). Moreover, a positive correlation of FAS and membrane ErbB2 expression with keratinization was noticed. CONCLUSION: Histopathological characteristics and the expression of FAS and ErbB2 carry prognosis importance in local recurrence and overall survival in OSCC.