Antimicrobial resistance of marine heterotrophic bacteria to different antimicrobials agents were evaluated in seawater, dry and wet sands from three marine recreational beaches with different pollution levels. In all studied beaches, the greatest frequencies of resistance were found in relation to penicillin. On Gonzaguinha, the most polluted beach, 72.3% of all isolated strains showed simple resistance, whilst 8.33% had multiple resistance. The values found on Ilha Porchat beach, were 70.8% and 6.9% for simple and multiple resistances, respectively. On Guaraú, the less polluted beach, only 35.3% of isolated strains had simple resistance. Multiple resistance was not observed. While samples from Gonzaguinha and Ilha Porchat beach showed isolated strains resistant to seven and six different antimicrobial agents, respectively, samples from Guaraú beach were resistant only to penicillin and erytromicin. The positive correlations obtained between the degree of seawater contamination and frequency and variability of bacterial resistance indicate that polluted marine recreational waters and sands are sources of resistant bacteria contributing thus, to the dissemination of bacterial resistance.
Heavy metals influence the population size, diversity, and metabolic activity of bacteria. In turn, bacteria can develop heavy metal resistance mechanisms, and this can be used in bioremediation of contaminated areas. The purpose of the present study was to understand how heavy metals concentration influence on diversity and distribution of heavy metal-resistant bacteria in Araça Bay, São Sebastião, on the São Paulo coast of Brazil. The hypothesis is that activities that contribute for heavy metal disposal and the increase of metals concentrations in environment can influence in density, diversity, and distribution of heavy metal-resistant bacteria. Only 12 % of the isolated bacteria were sensitive to all of the metals tested. We observed that the highest percentage of resistant strains were in areas closest to the São Sebastião channel, where port activity occurs and have bigger heavy metals concentrations. Bacterial isolated were most resistant to Cr, followed by Zn, Cd, and Cu. Few strains resisted to Cd levels greater than 200 mg L(-1). In respect to Cr, 36 % of the strains were able to grow in the presence of as much as 3200 mg L(-1). Few strains were able to grow at concentrations of Zn and Cu as high as 1600 mg L(-1), and none grew at the highest concentration of 3200 mg L(-1). Bacillus sp. was most frequently isolated and may be the dominant genus in heavy metal-polluted areas. Staphylococcus sp., Planococcus maritimus, and Vibrio aginolyticus were also isolated, suggesting their potential in bioremediation of contaminated sites.
Diversidade de microrganismos indicadores utilizados na avaliação da contaminação fecal de areias de praias recreacionais marinhas:estado atual do conhecimento e perspectivas Diversity of indicator microorganisms in the evaluation of sea recreational beach sand fecal contamination: current knowledge and perspectives Diversidad de los microorganismos indicadores utilizados en la evaluación de la contaminación fecal de las arenas de playas marinas recreacionales: conocimiento actual y perspectivas Aline Bartelochi Pinto* Ana Julia Fernandes Cardoso de Oliveira** ReSumo: Embora a qualidade de águas recreacionais marinhas já seja monitorada por programas implantados em vários estados brasileiros, incluindo o Estado de São Paulo, pouca atenção tem sido dada às areias de praias, as quais têm sido desconsideradas do ponto de vista da saúde pública. Entretanto, esse panorama vem mudando nos últimos anos devido ao aumento dos casos de micoses e infecções bacterianas contraídas por pessoas que frequentam as praias e utilizam suas areias como local de recreação. Isso tem ocasionado maiores preocupações com a contaminação desse ambiente, também mensurável pelo aumento do número de trabalhos científicos sobre a microbiota de sedimentos e areias de praias recreacionais. Atualmente, sabe-se que, de maneira geral, esses sedimentos contêm mais microrganismos do que a própria coluna de água, sendo, portanto, fontes potenciais de contaminação de humanos por microrganismos patogênicos. Os resultados de trabalhos realizados em vários países são preocupantes e têm demonstrado a necessidade da determinação de padrões e limites para que sejam implantados programas de monitoramento da qualidade microbiológica das areias de praias. Tal preocupação é especialmente destacada no Brasil, país de clima tropical onde milhares de praias, utilizadas para recreação, se estendem por quase oito mil quilômetros de litoral. No contexto da Baixada Santista, estudos realizados têm mostrado que, em determinadas situações, as areias de praias podem conter mais microrganismos de que suas águas, o pode oferecer riscos à saúde de seus usuários. PalavRaS-chave:Areia. Microrganismos -indicadores de contaminação. Escherichia coli.abStRact: Although the quality of sea recreational waters is already monitored by programs implanted in some Brazilian states, including the State São Paulo, little attention has been given to beach sands, which have been disregarded from the point of view of public health. However, this panorama is changing in recent years due to an increasing number of cases of mycoses and bacterial infections affecting people who frequent beaches and use sands as recreation places. This has caused greater concerns with the contamination of this environment, also measurable by the increase of the number of scientific works on sediments and recreational beach sands microbiota. Currently one knows that in general these sediments contain more microorganisms than the water and are therefore potential sources of contamination of human beings by pathogeni...
Bacterial resistance is a rising problem all over the world. Many studies have showed that beach sands can contain higher concentration of microorganisms and represent a risk to public health. This paper aims to evaluate the densities and resistance to antimicrobials of Escherichia coli strains, isolated from seawater and samples. The hypothesis is that microorganisms show higher densities in contaminated beach sands and more antimicrobial resistance than the water column. Density, distribution, and antimicrobial resistance of bacteria E. coli were evaluate in seawater and sands from two recreational beaches with different levels of pollution. At the beach with higher degree of pollution (Gonzaguinha), water samples presented the highest densities of E. coli; however, higher frequency of resistant strains was observe in wet sand (71.9 %). Resistance to a larger number of antimicrobial groups was observe in water (betalactamics, aminoglycosides, macrolides, rifampicins, and tetracyclines) and sand (betagalactamics and aminoglycosids). In water samples, highest frequencies of resistance were obtain against ampicilin (22.5 %), streptomycin (15.0 %), and rifampicin (15.0 %), while in sand, the highest frequencies were observe in relation to ampicilin (36.25 %) and streptomycin (23.52 %). At the less polluted beach, Ilha Porchat, highest densities of E. coli and higher frequency of resistance were obtain in wet and dry sand (53.7 and 53.8 %, respectively) compared to water (50 %). Antimicrobial resistance in strains isolated from water and sand only occurred against betalactamics (ampicilin and amoxicilin plus clavulanic acid). The frequency and variability of bacterial resistance to antimicrobials in marine recreational waters and sands were related to the degree of fecal contamination in this environment. These results show that water and sands from beaches with a high index of fecal contamination of human origin may be potential sources of contamination by pathogens and contribute to the dissemination of bacterial resistance.
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