Occurrence of Yersinia spp. in food in Brazil

Over the past 9 years, 468 bacterial strains isolated from raw and pasteurized milk, beef and pork, bovine and chicken liver, chicken heart, gizzards and lung sausage, hamburger, cheese and lettuce in different regions of the State of Sao Paulo and in the city of Rio de Janeiro were received by the Reference Laboratory for Yersinia in Brazil. All were confirmed to be Yersinia spp. The 468 Yersinia isolates were grouped as 184 strains because some of the bacteria isolated from the same food sample belonged to the same species, and were considered to be a single strain. The Yersinia food strains were classified as Y. enterocolitica (46), Y. intermedia (67), Y. frederiksenii (20), Y. kristensenii (8) and 43 of them were biochemically atypical. Pathogenic types were not detected.

Ocorrência de Staphylococcus aureus em queijo tipo frescal

OBJETIVO: Verificar a ocorrência de Staphylococcus aureus em uma amostra de queijo tipo Minas frescal comercializado na cidade de Poços de Caldas, MG, de modo a obter subsídios que permitam avaliar o risco potencial que este produto pode representar para a saúde da população consumidora. MÉTODOS: Foi investigada a presença e o número de cepas de Staphylococcus aureus em 80 amostras de queijo tipo Minas frescal produzido artesanalmente e comercializado na cidade de Poços de Caldas, MG, Brasil. RESULTADOS: Os resultados obtidos evidenciaram a presença de S. aureus em 40 (50,0%) amostras, cujas contagens revelaram valores médios em torno de 10(5)/g. CONCLUSÕES: Tais achados parecem ser extremamente preocupantes, pois além de se situarem acima do limite máximo de 10³/g estabelecido pelo Ministério da Saúde, estes valores mostraram-se muito próximos dos requeridos para a produção de enterotoxinas em quantidades suficientes para a ocorrência de surtos de intoxicação alimentar estafilocócica.

Barium uptake by maize plants as affected by sewage sludge in a long-term field study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Exame microbiológico de sorvetes não pasteurizados

Realizou-se exame microbiológico em 24 amostras de sorvetes não pasteurizados, todos preparados de maneira não industrial e à base de leite (creme, nata, chocolate), fabricados por 12 sorveterias diferentes da cidade de Araraquara, SP. Colheram-se duas amostras de cada sorveteria com intervalo de 15 dias entre as colheitas. Realizaram-se as seguintes provas: contagem de bactérias aeróbicas ou facultativas mesófilas e psicrófilas e de Staphylococcus aureus; determinação do Número Mais Provável (NMP) de coliformes totais e fecais e da presença de Salmonella. As técnicas utilizadas foram aquelas convencionalmente usadas para tais determinações. Não foi encontrada Salmonella em nenhuma das amostras e de cerca de 16,6% delas isolou-se Staphylococcus aureus. em proporções variáveis verificou-se a presença de microrgarnismos deteriorantes e daqueles indicadores de poluição de origem fecal.

Atividade inseticida das plantas e aplicações: revisão

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bioaccumulation of Microcystins In Lettuce

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

CONDICOES BACTERIOLOGICAS DE LEITE CRU E DE LEITE PASTEURIZADO NA REGIAO DE ARARAQUARA, SP, BRASIL

Milk can be an important spreading vehicle of pathogenic agents mainly for young children who are an important group of milk consumers. 135 milk samples (77 of raw milk and 58 of pasteurized milk) were analysed in order to verify the number of heterotrophic bacteria, of Staphylococcus aureus and of total coliforms, as well as to determine presence of Salmonella, Shigella, enteropathogenic Escherichia coli (EPEC) and enteroinvasive Escherichia coli (EIEC). The results were negative for Salmonella, Shigella and EIEC. EPEC serotypes 0:28, 0:111 and 0:55 were isolated in 4 of raw milk samples. The heterotrophic bacteria was found in counts over 30.000 UFC/mL in 91%, 25% and 68,75% respectively of raw milk, milk grade B and grade C. Counts over 30.000 coliforms/mL were found in 70,13%, 6,25% and 6,24% of the raw milk, B and C, respectively. 32,40% of the raw milk had counts of S. aureus over 3.000 UFC/mL.

HPLC determination of flumethrin, deltamethrin, cypermethrin, and cyhalothrin residues in the milk and blood of lactating dairy cows

A procedure to determine residue concentrations of synthetic pyrethroid insecticides (flumethrin, deltamethrin, cypermethrin and cyhalothrin) in the milk and blood of lactating dairy cows was developed. Extraction was performed with acetonitrile, n-hexane partitioning, and silica gel column cleanup with n-hexane and diethyl ether. Analysis was carried out by high- performance liquid chromatography and ultraviolet detection. Recovery of the four pyrethroids averaged 78 to 91% with a minimum detectable concentration of 0.001 mg/kg. The method was reproducible and sensitive.

Incidence of patulin in fruits and fruit juices marketed in Campinas, Brazil

One hundred and eleven samples of processed fruit juices (apple, grape, pineapple, papaya, guava, banana and mango) and 38 samples of sound fruits (apple, papaya, mango, pear and peach) produced and marketed in Brazil, were analysed for patulin by HPLC. Only one out of 30 samples of apple juice was found positive at 17 μg/l. Patulin was not detected in the other foodstuffs. It was found in 14 samples of spoiled fruit samples of apple (150-267 μg/kg), pear (134-245 μg/kg) and peach (92-174 μg/kg). Confirmation of the identity of patulin was based on the UV spectrum obtained by the HPLC diode array detector, compared with that of standard patulin, TLC developed by several solvent systems and sprayed with 3-methyl-2-benzothiazolinone hydrazone, and by acetylation with acetic anhydride.

Study of the presence of the spores of Clostridium botulinum in honey in Brazil

The isolation of Clostridium botulinum from honey samples is described. Botulism is characterized as an intoxication provoked by ingestion of contaminated foods with this toxin. Infant botulism happens by the ingestion of spores of C. botulinum together with food that in special conditions of the intestinal tract, such as those present in babies of less than 1 year old, will allow the germination and colonization of the intestine with production and absorption of botulinic toxin. The samples were subjected to dilution and to a thermal shock and cultivated in modified CMM (Difco). Cultures were subjected to Gram smears and toxicity tests in mice. The toxic cultures were purified in RFCA (Oxoid) plates and incubated in anaerobic jars. Positive samples were typed using the mouse assay neutralization test. From the 85 honey samples analyzed, six were positive for C. botulinum (7.06%), and identified as producers of type A, B, and D toxins.

Minimization of lead and copper interferences on spectrophotometric determination of cadmium using electrolytic deposition and ion-exchange in multi-commutation flow system

A new strategy for minimization of Cu2+ and Pb2+ interferences on the spectrophotometric determination of Cd2+ by the Malachite green (MG)-iodide reaction using electrolytic deposition of interfering species and solid phase extraction of Cd2+ in flow system is proposed. The electrolytic cell comprises two coiled Pt electrodes concentrically assembled. When the sample solution is electrolyzed in a mixed solution containing 5% (v/v) HNO3, 0.1% (v/v) H2SO4 and 0.5 M NaCl, Cu2+ is deposited as Cu on the cathode, Pb2+ is deposited as PbO2 on the anode while Cd2+ is kept in solution. After electrolysis, the remaining solution passes through an AG1-X8 resin (chloride form) packed minicolumn in which Cd2+ is extracted as CdCl4/2-. Electrolyte compositions, flow rates, timing, applied current, and electrolysis time was investigated. With 60 s electrolysis time, 0.25 A applied current, Pb2+ and Cu2+ levels up to 50 and 250 mg 1-1, respectively, can be tolerated without interference. For 90 s resin loading time, a linear relationship between absorbance and analyte concentration in the 5.00-50.0 μg Cd 1-1 range (r2 = 0.9996) is obtained. A throughput of 20 samples per h is achieved, corresponding to about 0.7 mg MG and 500 mg KI and 5 ml sample consumed per determination. The detection limit is 0.23 μg Cd 1-1. The accuracy was checked for cadmium determination in standard reference materials, vegetables and tap water. Results were in agreement with certified values of standard reference materials and with those obtained by graphite furnace atomic absorption spectrometry at 95% confidence level. The R.S.D. for plant digests and water containing 13.0 μg Cd 1-1 was 3.85% (n = 12). The recoveries of analyte spikes added to the water and vegetable samples ranged from 94 to 104%. (C) 2000 Elsevier Science B.V.

Isolation of Mycobacterium gordonae from poultry slaughterhouse water in São Paulo State, Brazil

Water samples (24 untreated water, 12 treated water and 24 served water) used in different stages of the slaughter process were examined to identify a possible source of pathogenic mycobacteria. The isolates were identified based on microscopy, morphological and biochemical features, mycolic acid analysis and molecular method - PCR-restriction-enzyme analysis. Eighteen mycobacterial strains were isolated from 60 water samples: 11 from untreated water, 5 from treated water and 2 from served water. All mycobacteria isolated were identified as Mycobacterium gordonae and showed the following PRA genotypes: III (27.8%), IV (38.9%) and V (33.3%).

Diphyllobothriasis, Brazil

Cases of human diphyllobothriasis have been reported worldwide. Only 1 case in Brazil was diagnosed by our institution from January 1998 to December 2003. By comparison, 18 cases were diagnosed from March 2004 to January 2005. All patients who became infected ate raw fish in sushi or sashimi.

Analysis of DNA damage induced by aflatoxin B1 in Dunkin-Hartley guinea pigs

Aflatoxin B1 (AFB1) is among the most potent naturally occurring carcinogens and classified as a group I carcinogen. Since the ingestion of aflatoxin-contaminated food is associated with several liver diseases, the aim of the present study was to evaluate the effect of 2, 20, and 200 ppb of AFB1 on DNA damage in peripheral blood lymphocytes and liver cells in Dunkin-Hartley guinea pigs. The animals were divided into four groups according to the given diet. After the treatment the lymphocytes and liver cells were isolated and DNA damage determined by Comet assay. The levels of DNA damage in lymphocytes were higher animals treated with 200 ppb of AFB1-enriched diet (P = 0.02). In the liver cells there were a relationship between the levels of DNA damage and the consumption of AFB1 in all studied groups. These results suggest that Comet assay performed on lymphocytes is a valuable genotoxic marker for high levels of exposure to AFB1 in guinea pig. Additionally our results indicate that the exposure to this toxin increases significantly and increases the level of DNA damage in liver cells, which is a key step on liver cancer development. We also suggest that the Comet assay is an useful tool for monitoring the genotoxicity of AFB1 in liver. © 2007 Springer Science+Business Media B.V.