Antibacterial and cytotoxicity activity in macroalgae extracts: perspectives for the use against pathogenic bacteria from shrimp farms (Litopenaeus vannamei) / Atividade antibacteriana e citotóxica em extratos de macroalgas: perspectivas de uso contra bactérias patogênicas de ambiente de cultivo de camarões (Litopenaeus vannamei)

Some infections caused by pathogenic microorganisms might shows high prevalence in farmed shrimp environments, compromising production and causing economic losses. Therefore, the search for compounds with antibiotic activity has become intensive, following the record of new antimicrobial-resistant bacteria. The study of those bioactive compounds in marine macroalgae has produced satisfactory results, such as the discovery of antibacterial activity against multiresistant strains. Accordingly, this study aims to research antibiotic activity in macroalgae extracts of Chlorophyta, Phaeophyta and Rhodophyta found in the coast of Ceará and also to evaluate the cytotoxicity activity against bacterial strains (Vibrio sp.) from shrimp farms (Litopenaeus vannamei). The extracts cytotoxicity was also evaluated. The results prove that there was antibacterial activity in ethanolic, acetonic, hexanic and methanolic extracts against bacterial strains of Vibrio with multiple resistance profile as well as displaying low cytotoxicity.

Algumas infecções causadas por micro-organismos patogênicos podem apresentar alta prevalência em ambientes de cultivo de camarões marinhos, comprometendo a produção e causando prejuízos econômicos aos aquicultores. Assim, tem-se tornado intensa a busca por compostos com atividade antibiótica pelo registro cada vez mais frequente de bactérias com perfil de resistência a antimicrobianos. A presença desses compostos com bioatividade em macroalgas marinhas tem revelado resultados satisfatórios, como a descoberta de ação antibacteriana contra cepas multirresistentes. Desta forma, decidiu-se pesquisar as propriedades antibióticas dos extratos de macroalgas das classes Chlorophyta, Phaeophyta e Rhodophyta, coletadas no litoral cearense, bem como avaliar a citotoxicidade destes extratos, frente a cepas bacterianas (Vibrio sp.) isoladas e provenientes de ambientes de cultivo de camarões marinhos (Litopenaeus vannamei). Os resultados comprovaram que houve atividade antibacteriana dos extratos etanólicos, acetônicos, hexânicos e metanólicos contra cepas bacterianas de Vibrio, além de apontar que os extratos de todas as espécies apresentaram baixa citotoxicidade.

Ecotypes and virulence factors of Salmonella spp. detected in shrimp farms in State of Ceara, Brazil / Ecotipos e fatores de virulência de Salmonella spp. detectadas em fazendas de carcinicultura do Ceará, Brasil

Our objective was to group in ecotypes 12 serovars of Salmonella isolated from shrimp farming environments in the State of Ceara (Northeast Brazil). Grouping was done based on genotypic virulence factors. Two groups based on the similarity of the Box-PCR were identified: a group consisting of three strains (01 S. ser. Madelia serovar and 02 S. ser. enterica subs. houtenae) and another group consisting of nine isolates (02 S. ser. Saintpaul serovars; 03 S. ser. Infantis; 02 S. ser. Panama; 01 S. enterica subs. enterica; and 01 S. enterica subs. houtenae). Distribution pattern of the serovars was not influenced by the origin matrices (water and sediment). Plasmid virulence genes pefA and invA were detected, unrelated to the serovar and environmental origin of the isolates. The presence of virulence genes in the isolates underlines the potential to trigger salmonellosis events via shrimp consumption. Biomonitoring of these sources of contamination should be encouraged as a protective measure, minimizing health risks and economic losses for the industry.

Nosso objetivo foi agrupar em ecotipos 12 sorovares de Salmonella isolados em ambientes de carcinicultura no Estado do Ceará. O agrupamento foi feito a partir da pesquisa de fatores genotípicos de virulência. Constatou-se a formação de dois grupos baseados na similaridade do Box-PCR: um grupo com três estirpes (01 sorovar S. ser. Madelia e 02 sorovares S. enterica subs. houtenae) e outro constituído por nove isolados (02 sorovares S. ser. Saintpaul, 03 sorovares S. ser. Infantis, 02 sorovares S. ser. Panama, 01 sorovar S. enterica subs. enterica e 01 sorovar S. enterica subs. houtenae). O padrão de distribuição dos sorovares não sofreu influência das matrizes de origem (água e sedimento). Os genes de virulência plasmidial pefA e invA foram detectados independente do sorovar e da origem ambiental dos isolados. A presença desses genes de virulência nos isolados de carcinicultura evidencia o potencial para desencadear eventos de salmonelose relacionados ao consumo de camarão. O biomonitoramento dessas fontes de contaminação deve ser incentivado como medida protetiva, minimizando os riscos do ponto de vista sanitário e das perdas econômicas para o setor da carcinicultura.

Thiocarbamates from Moringa oleifera Seeds Bioactive against Virulent and Multidrug-Resistant Vibrio Species.

Prospect of antibacterial agents may provide an alternative therapy for diseases caused by multidrug-resistant bacteria. This study aimed to evaluate the in vitro bioactivity of Moringa oleifera seed extracts against 100 vibrios isolated from the marine shrimp Litopenaeus vannamei. Ethanol extracts at low (MOS-E) and hot (MOS-ES) temperature are shown to be bioactive against 92% and 90% of the strains, respectively. The most efficient Minimum Inhibitory Concentration (MIC) levels of MOS-E and MOS-ES against a high percentage of strains were 32 µg mL-1. Bioguided screening of bioactive compounds showed that the ethyl acetate fraction from both extracts was the only one that showed antibacterial activity. Vibriocidal substances, niazirine and niazimicine, were isolated from the aforementioned fraction through chromatographic fractionation.

Multidrug-resistant Vibrio associated with an estuary affected by shrimp farming in Northeastern Brazil.

Bacteria of genus Vibrio with multidrug resistance in shrimp farm environment were recurrent. Thus, the aim of this study was to evaluate the antimicrobial resistance profile of 70 strains of Vibrio isolated from water and sediment of Acaraú estuary, Ceará, Brazil. In order to achieve this goal, disk diffusion technique was used with the following antimicrobial agents: ampicillin (Amp), aztreonam (Atm), cephalothin (Cef), cefotaxime (Ctx), ceftriaxone (Cro), ciprofloxacin (Cip), chloramphenicol (Clo), florfenicol (Flo), nitrofurantoin (Nit), gentamicin (Gen), oxytetracycline (Otc), tetracycline (Tet), streptomycin (Str), nalidixic acid (Nal), and sulfazotrim (Sut). All Vibrio strains were resistant to at least one antimicrobial agent, being verified as 17 multidrug-resistant profiles. All strains resistant to Otc and Tet were characterized to exhibit plasmidial resistance. Therefore, Vibrio strains from Acaraú estuary pose a risk to public health and aquatic culture.

RAW TROPICAL OYSTERS AS VEHICLES FOR MULTIDRUG-RESISTANT Vibrio parahaemolyticus.

The following study aimed to determine the antimicrobial susceptibility profile of Vibrio parahaemolyticus strains from fresh and frozen oysters Crassostrea rhizophorae sold in Fortaleza-Brazil. An antibiogram was performed on 87 isolates using nine antibiotics: gentamicin (Gen 10 µg), ampicillin (Amp 10 µg), penicillin G (Pen 10U), ciprofloxacin (Cip 5 µg), chloramphenicol (Chl 30 µg), nalidixic acid (Nal 30 µg), tetracycline (Tet 30 µg), vancomycin (Van 30 µg) and erythromycin (Ery 15 µg). All strains were resistant to at least one antibiotic, and 85 (97.7%) were multi-resistant, with predominance of the Van+ Pen+Amp resistance profile (n = 46). Plasmid resistance to Pen, Amp and Ery was detected. Thus, the risk that raw oyster consumption poses to the health of consumers is highlighted, due to the fact that these bivalves may host antibacterial-resistant microorganisms.

RAW TROPICAL OYSTERS AS VEHICLES FOR MULTIDRUG-RESISTANT Vibrio parahaemolyticus / Ostras tropicais cruas como fonte de Vibrio parahaemolyticus multirresistentes

The following study aimed to determine the antimicrobial susceptibility profile of Vibrio parahaemolyticus strains from fresh and frozen oysters Crassostrea rhizophorae sold in Fortaleza-Brazil. An antibiogram was performed on 87 isolates using nine antibiotics: gentamicin (Gen 10 µg), ampicillin (Amp 10 µg), penicillin G (Pen 10U), ciprofloxacin (Cip 5 µg), chloramphenicol (Chl 30 µg), nalidixic acid (Nal 30 µg), tetracycline (Tet 30 µg), vancomycin (Van 30 µg) and erythromycin (Ery 15 µg). All strains were resistant to at least one antibiotic, and 85 (97.7%) were multi-resistant, with predominance of the Van+ Pen+Amp resistance profile (n = 46). Plasmid resistance to Pen, Amp and Ery was detected. Thus, the risk that raw oyster consumption poses to the health of consumers is highlighted, due to the fact that these bivalves may host antibacterial-resistant microorganisms.

O presente estudo objetivou determinar o perfil de suscetibilidade a antimicrobianos de cepas de Vibrio parahaemolyticus oriundas de ostras “in natura” e congeladas comercializadas em Fortaleza-Brasil. Oitenta e sete (87) cepas foram submetidas ao antibiograma com emprego de nove antibióticos: gentamicina (Gen 10 µg), ampicilina (Amp 10 µg), penicilina G (Pen 10U), ciprofloxacin (Cip 5 µg), cloranfenicol (Clo 30 µg), ácido nalidíxico (Nal 30 µg), tetraciclina (Tet 30 µg), vancomicina (Van 30 µg) e eritromicina (Eri 15 µg). Todas as cepas mostram-se resistentes a pelo menos um antibiótico, e 85 (97,7%) apresentaram multirresistência, com predomínio do perfil Van+ Pen+Amp (n = 46). Foi detectada resistência plasmidial a Pen, Amp e Eri. Dessa forma, o risco que o consumo de ostras cruas representa para a saúde dos consumidores merece ser destacado, uma vez que esses bivalves podem ser veículos de transmissão de micro organismos multirresistentes a fármacos antibacterianos.

Antibiotic-resistant vibrios in farmed shrimp.

Antimicrobial susceptibility pattern was determined in 100 strains of Vibrio isolated from the Litopenaeus vannamei shrimp and identified phenotypically. A high antibiotic-resistance index (75%) was observed, with the following phenotypic profiles: monoresistance (n = 42), cross-resistance to ß-lactams (n = 20) and multiple resistance (n = 13). Plasmid resistance was characterized for penicillin (n = 11), penicillin + ampicillin (n = 1), penicillin + aztreonam (n = 1), and ampicillin (n = 1). Resistance to antimicrobial drugs by the other strains (n = 86) was possibly mediated by chromosomal genes. The findings of this study support the conclusion that the cultured shrimps can be vehicles of vibrios resistant to ß-lactam and tetracycline.

Population dynamics and antimicrobial susceptibility of Aeromonas spp. along a salinity gradient in an urban estuary in Northeastern Brazil.

The main objective of this study was to quantify population and identify culturable species of Aeromonas in sediment and surface water collected along a salinity gradient in an urban estuary in Northeastern Brazil. Thirty sediment samples and 30 water samples were collected from 3 sampling locations (A, B and C) between October 2007 and April 2008. The Aeromonas count was 10-7050CFU/mL (A), 25-38,500CFU/mL (B) and<10CFU/mL (C) for water samples, and ∼100-37,500CFU/g (A), 1200-43,500CFU/g (B) and<10CFU/g (C) for sediment samples. Five species (Aeromonas caviae, A. sobria, A. trota, A. salmonicida and A. allosaccharophila) were identified among 41 isolates. All strains were sensitive to chloramphenicol and ceftriaxone, whereas 33 (80, 4%) strains were resistant to at least 2 of the 9 antibiotics tested. Resistance to erythromycin was mostly plasmidial. In conclusion, due to pollution, the Cocó River is contaminated by pathogenic strains of Aeromonas spp. with a high incidence of antibacterial resistance, posing a serious risk to human health.

Detection of virulence genes in environmental strains of Vibrio cholerae from estuaries in northeastern Brazil.

The objectives of this study were to detect the presence of Vibrio cholerae in tropical estuaries (Northeastern Brazil) and to search for virulence factors in the environmental isolates. Water and sediment samples were inoculated onto a vibrio-selective medium (TCBS), and colonies with morphological resemblance to V. cholerae were isolated. The cultures were identified phenotypically using a dichotomous key based on biochemical characteristics. The total DNA extracted was amplified by PCR to detect ompW and by multiplex PCR to detect the virulence genes ctx, tcp, zot and rfbO1. The results of the phenotypic and genotypic identification were compared. Nine strains of V. cholerae were identified phenotypically, five of which were confirmed by detection of the species-specific gene ompW. The dichotomous key was efficient at differentiating environmental strains of V. cholerae. Strains of V. cholerae were found in all four estuaries, but none possessed virulence genes.

DETECTION OF VIRULENCE GENES IN ENVIRONMENTAL STRAINS OF Vibrio cholerae FROM ESTUARIES IN NORTHEASTERN BRAZIL / Detecção de genes de virulência em estirpes de Vibrio cholerae isolados de estuários no Nordeste do Brasil

The objectives of this study were to detect the presence of Vibrio cholerae in tropical estuaries (Northeastern Brazil) and to search for virulence factors in the environmental isolates. Water and sediment samples were inoculated onto a vibrio-selective medium (TCBS), and colonies with morphological resemblance to V. cholerae were isolated. The cultures were identified phenotypically using a dichotomous key based on biochemical characteristics. The total DNA extracted was amplified by PCR to detect ompW and by multiplex PCR to detect the virulence genes ctx, tcp, zot and rfbO1. The results of the phenotypic and genotypic identification were compared. Nine strains of V. cholerae were identified phenotypically, five of which were confirmed by detection of the species-specific gene ompW. The dichotomous key was efficient at differentiating environmental strains of V. cholerae. Strains of V. cholerae were found in all four estuaries, but none possessed virulence genes.

O objetivo deste estudo foi detectar a presença potencial virulência de Vibrio cholerae isolado de estuários do Nordeste do Brasil. Amostras de água e sedimento foram coletadas e inoculadas sobre meio seletivo para víbrios (TCBS) e colônias com características morfológicas de V. cholerae foram isoladas. A identificação fenotípica seguiu chave dicotômica baseada em caraterísticas bioquímicas. Foram empregadas as técnicas de amplificação da polimerase em cadeia (PCR) utilizando o gene ompW e a de multiplex PCR para detecção de genes de virulência (ctx, tcp, zot e rfbO1). Os resultados da identificação das diferentes abordagens foram comparados. Nove cepas de V. cholerae foram identificadas fenotipicamente e cinco confirmadas através da detecção do gene ompW. A chave dicotômica utilizada foi eficiente para a confirmação da espécie. Os quatro estuários analisados apresentaram estirpes de V. cholerae, e nenhuma das cepas isoladas apresentaram genes de virulência.

Antimicrobial Susceptibility of Escherichia coli Isolated from Fresh-Marketed Nile Tilapia (Oreochromis niloticus).

The contamination of seafood by bacteria of fecal origin, especially Escherichia coli, is a widely documented sanitary problem. The objective of the present study was to isolate E. coli strains from the gills, muscle, and body surface of farmed Nile tilapias (Oreochromis niloticus) fresh-marketed in supermarkets in Fortaleza (Ceará, Brazil), to determine their susceptibility to antibiotics of different families (amikacin, gentamicin, imipenem, cephalothin, cefotaxime, ciprofloxacin, aztreonam, ampicillin, nalidixic acid, tetracycline, and sulfametoxazol-trimetoprim), and to determine the nature of resistance by plasmid curing. Forty-four strains (body surface = 25, gills = 15, muscle = 4) were isolated, all of which were susceptible to amikacin, aztreonam, cefotaxime, ciprofloxacin, gentamicin, and imipenem. Gill and body surface samples yielded 11 isolates resistant to ampicillin, tetracycline, and sulfametoxazol-trimetoprim, 4 of which of plasmidial nature. The multiple antibiotic resistance index was higher for strains isolated from body surface than from gills. The overall high antibiotic susceptibility of E. coli strains isolated from fresh-marketed tilapia was satisfactory, although the occasional finding of plasmidial resistance points to the need for close microbiological surveillance of the farming, handling, and marketing conditions of aquaculture products.

Hemolytic and urease activities in vibrios isolated from fresh and frozen oysters.

INTRODUCTION: The present study aimed to survey the Vibrio microbiota of oysters (Crassostrea rhizophorae) obtained from restaurants in Fortaleza, State of Ceará, Brazil, and to identify virulence factors. METHODS: The isolated vibrios were submitted to biochemical identification and were tested for hemolytic and urease activities. RESULTS: The isolated strains belonged to 13 species, with predominance of Vibrio mimicus. Of the strain isolates only from fresh samples, 20.5% and 2.8% showed hemolytic and urease activities, respectively. CONCLUSIONS: The findings support the little-publicized claim that Vibrio species other than V. parahaemolyticus and V. vulnificus can represent a health risk to public health.

Hemolytic and urease activities in vibrios isolated from fresh and frozen oysters

INTRODUCTION: The present study aimed to survey the Vibrio microbiota of oysters (Crassostrea rhizophorae) obtained from restaurants in Fortaleza, State of Ceará, Brazil, and to identify virulence factors. METHODS: The isolated vibrios were submitted to biochemical identification and were tested for hemolytic and urease activities. RESULTS: The isolated strains belonged to 13 species, with predominance of Vibrio mimicus. Of the strain isolates only from fresh samples, 20.5% and 2.8% showed hemolytic and urease activities, respectively. CONCLUSIONS: The findings support the little-publicized claim that Vibrio species other than V. parahaemolyticus and V. vulnificus can represent a health risk to public health.

Uso de soro de leite bovino para elaboração de meios de cultura para Staphylococcus aureus / Culture media made by bovine whey for Staphylococcus aureus growth

Foi investigada a eficiência do cultivo de Staphylococcus aureus ATCC 25923 em meios experimentais elaborados com soro de leite bovino. Foram preparados meios líquido (caldo soro – CS) e sólido (ágar soro – AS) suplementados com cloreto de sódio (CS+NaCl e AS+NaCl) e extrato de levedura (CS+Lev eAS+Lev). No meio AS, foi testado o enriquecimento com extrato de levedura (0,1%) e diluição em água(40%) (AS+H2O+Lev). Os meios comerciais de caldo infusão cérebro coração (BHI) e ágar Baird-Parker(BP) foram utilizados como controle. A eficiência dos meios experimentais foi avaliada por determinação da biomassa e contagem de colônias, utilizando-se a cepa S. aureus ATCC 25923. Em todos os testes, o crescimento bacteriano foi compatível à quantificação observada nos meios utilizados como controle e houve desenvolvimento de colônias com características morfológicas típicas de S. aureus, principalmente no meio AS+H2O+Lev. Concluiu-se que o soro de leite bovino pode ser utilizado como componente alternativo na elaboração de meio de cultura para S. aureus.

Antibiotic resistance of Vibrio parahaemolyticus isolated from pond-reared Litopenaeus vannamei marketed in Natal, Brazil

Ten out of fifty fresh and refrigerated samples of shrimp (Litopenaeus vannamei) collected from retailers in Natal (Rio Grande do Norte, Northeastern Brazil) tested positive for Vibrio parahaemolyticus. The Kanagawa test and multiplex PCR assays were used to detect TDH and TRH hemolysins and the tdh, trh and tlh genes, respectively. All strains were Kanagawa-negative and tlh-positive. Antibiotic susceptibility testing was done for seven antibiotics by the agar diffusion technique. Five strains (50 percent) presented multiple antibiotic resistance to ampicillin (90 percent) and amikacin (60 percent), while two strains (20 percent) displayed intermediate-level resistance to amikacin. All strains were sensitive to chloramphenicol. Intermediate-level susceptibility and/or resistance to other antibiotics ranged from 10 to 90 percent, with emphasis on the observed growing intermediate-level resistance to ciprofloxacin. Half our isolates yielded a multiple antibiotic resistance index above 0.2 (range: 0.14-0.29), indicating a considerable risk of propagation of antibiotic resistance throughout the food chain.

Staphylococcus coagulase-positiva e enterobactérias em camarão Litopenaeus vannamei comercializado in natura / Coagulase-positive staphylococci and enterobacteria in fresh shrimp Litopenaeus vannamei

A qualidade microbiológica de camarões (Litopenaeus vannamei) comercializados in natura em Fortaleza(CE) foi investigada por meio de quantificação de Staphylococcus coagulase-positiva (Sph CP), coliformes totais (CT) e termotolerantes (CTT) e também pela detecção de Salmonella e isolamento de Escherichiacoli. Das 24 amostras adquiridas no comércio varejista, quatro (16,7 por cento) apresentaram índices de Sph CP acima de 103/g. Não foi detectada Salmonella nas amostras analisadas. O número de amostras positivas para CT, CTT e E. coli foi, respectivamente, de 23 (95,8 por cento), 13 (54,2 por cento) e 6 (25 por cento). De acordo com a legislação vigente no Brasil, as quatro amostras com contagens de Sph CP > 103/g são consideradas impróprias para o consumo. Ademais, chama-se a atenção para a ocorrência de E. coli em 25 por cento das amostras analisadas, uma vez que essa bactéria é indicadora de contaminação fecal.

Antibiotic resistance of Vibrio parahaemolyticus isolated from pond-reared Litopenaeus vannamei marketed in natal, brazil.

Ten out of fifty fresh and refrigerated samples of shrimp (Litopenaeus vannamei) collected from retailers in Natal (Rio Grande do Norte, Northeastern Brazil) tested positive for Vibrio parahaemolyticus. The Kanagawa test and multiplex PCR assays were used to detect TDH and TRH hemolysins and the tdh, trh and tlh genes, respectively. All strains were Kanagawa-negative and tlh-positive. Antibiotic susceptibility testing was done for seven antibiotics by the agar diffusion technique. Five strains (50%) presented multiple antibiotic resistance to ampicillin (90%) and amikacin (60%), while two strains (20%) displayed intermediate-level resistance to amikacin. All strains were sensitive to chloramphenicol. Intermediate-level susceptibility and/or resistance to other antibiotics ranged from 10 to 90%, with emphasis on the observed growing intermediate-level resistance to ciprofloxacin. Half our isolates yielded a multiple antibiotic resistance index above 0.2 (range: 0.14-0.29), indicating a considerable risk of propagation of antibiotic resistance throughout the food chain.

Antimicrobial resistance profile of Vibrio species isolated from marine shrimp farming environments (Litopenaeus vannamei) at Ceará, Brazil.

Brazilian shrimp culture industry has a great economic importance mainly to the northeast region. However, the accelerated development of this activity has resulted in the emergency of outbreaks of diseases from farming shrimp, and as a consequence the use of antimicrobial drugs to minimize the potential adverse effect under the shrimp production. The inappropriate use of antibiotics in aquaculture is one of the causes for the high incidence of antimicrobial resistant bacteria isolated from aquatic environments that represent a danger for aquatic organisms and human health. There is little information available on the level of antimicrobial resistance in pathogenic bacteria from shrimp farming environment. Therefore, this study aimed to evaluate the phenotypic resistance profile among Vibrio isolates from hatcheries water samples and from cultivated marine shrimp hepatopancreas (L. vannamei). Antimicrobial susceptibility testing was carried out by a standard disc diffusion method and the minimum inhibitory concentration (MIC) of oxytetracycline (OTC) for resistant Vibrio isolates was determinate by broth dilution method. The results showed a high incidence of resistance to ampicillin (45.2%) and to the tetracycline class (38.7%). Florfenicol and nitrofurantoin were 100% effective against Vibrio isolates. In this study, the OTC-resistant Vibrio spp. showed MIC values of more than 400mg/L and the presence of seawater did not influence the oxytetracycline bioactivity. The occurrence of antimicrobial multiresistance patterns was observed in 29% of Vibrio isolates. Fifty-five percent of multiresistant isolates of Vibrio lost one or more antibiotic resistance phenotype after procedure to curing of resistance plasmids. The oxytetracycline resistance was the phenotype most often lost among plasmid-cured isolates.

Bactérias entéricas presentes em amostras de água e camarão marinho litopenaeus vannamei oriundos de fazendas de cultivo no estado do Ceará, Brasil / Enteric bacteria in water samples and marine shrimp litopenaeus vannamei cultured in the state of Ceará, Brazil

Foram realizados a quantificação de coliformes totais (CT) e termotolerantes (CTT), isolamento e identificação de coliformes, e pesquisa de Salmonella em 28 amostras de água e 28 de camarão da espécie Litopenaeus vannamei, oriundas de duas fazendas de cultivo localizadas no Estado do Ceará, Brasil. Nenhuma amostra de água apresentou índice de CTT acima do limite de 2.500/100 mL preconizado pela legislação para águas salobras destinadas ao cultivo de organismos para fins de consumo. O Número Mais Provável (NMP/g) de CTT das amostras de camarão variou de <3 a 2,9 x 104. A maior frequência de isolamento de coliformes nas amostras de água e camarão foi a da espécie Escherichia coli. Em apenas três (5,35%), das 56 amostras analisadas, foi detectada a presença de Salmonella sorovar Newport e S. Saintpaul. Apesar do baixo índice de CTT e da baixa incidência de salmonela, a presença dessas bactérias entéricas em ambientes de cultivo de peneídeos é preocupante, uma vez que podem provocar infecções em humanos.

Samples of water (n = 28) and Litopenaeus vannamei (n = 28) from two shrimp farms in Ceará state, Brazil were evaluated for total coliforms (TC), total thermotolerant coliforms (TTC), coliform species diversity and Salmonella. No water sample presented TTC levels above the maximum level (2,500 MPN/100 mL) established by regulation for brackish water aquaculture producing seafood for human consumption. The most probable number (MPN) of TTC in shrimp samples ranged from <3 to 2.9 x 104 CFU/g. The coliform species most frequently isolated from water and shrimp was Escherichia coli. Only three (5.35%) of the 56 samples tested were positive for Salmonella (Newport and Saintpaul serovars). In spite of the low TTC levels observed, the presence of potentially pathogenic enteric bacteria in shrimp culture is a disquieting finding.

Antibacterial effect (in vitro) of Moringa oleifera and Annona muricata against Gram positive and Gram negative bacteria.

Antibacterial effects of aqueous and ethanolic extracts of seeds of moringa (Moringa oleifera) and pods of soursop (Annona muricata) in the concentration of 1:5 and 1:10 in volumes 50, 100, 150 and 200 microL were examined against Staphylococcus aureus, Vibrio cholerae, Escherichia coli (isolated from the organism and the aquatic environment) and Salmonella Enteritidis. Antibacterial activity (inhibition halo > 13 mm) against S. aureus, V. cholerae and E. coli isolated from the whiteleg shrimp, Litopenaeus vannmaei, was detected in aqueous and ethanolic extracts of moringa. E. coli isolated from tilapiafish, Oreochromis niloticus, was sensitive to the ethanolic extract of moringa. The aqueous extracts of soursop showed an antibacterial effect against S. aureus and V. cholerae, but the antibacterial activity by the ethanol extracts of this plant was not demonstrated.