Browsing by Issue Date, starting with "2014-09-21"
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- Surveillance of Listeria monocytogenes in food catering establishmentsPublication . Maia, Carla; Barreira, Maria JoãoSurveillance of Listeria monocytogenes in RTE (Ready To Eat) Foods sampled in canteens in Lisbon area and surroundings and presentation of a case study (Listeria spp. in a Hospital kitchen.)
- First case of infant botulism in PortugalPublication . Costa Bonito, Maria ConceiçãoInfant botulism is a very rare neuroparalytic disease that can occur in babies under two years of age, caused by ingestion of Clostridium botulinum, an ubiquitous gram positive bacilli that grows better under anaerobic, low salt and low acid conditions. The spores formed by this bacterium are not inactivated, unless the food is heated under high pressure to 121ºC, for at least 20 minutes. This rare occurrence is due to the toxin produced by the bacteria, after ingestion of the spores and their germination in the infant’s intestine. Those neurotoxins interfere with the presynaptic release of acetylcholine at the neuromuscular junction. The first case detected in Portugal occurred in 2009. The patient was a boy aged one month. The child was breastfed, but sometimes his parents used to give him wild herbal chamomile infusion and honey. After refusing to eat for three days, the boy was taken to the Hospital, with the symptoms overlapping with botulism. The laboratory identification was performed using mouse bioassay, according to standard procedures issued by the Center for Disease Control (CDC), Atlanta, USA. Type B botulinum toxin was detected in the infant´s faeces sample. Clostridium botulinum type B was isolated from the faeces as well as from honey and chamomile herbs samples. In contrast to foodborne botulism, associated to the ingestion of botulinum toxin pre-formed in foods, infant botulism occurs after ingestion of the spores and subsequent production of the toxin in the children’s intestine because of their still weak defences. One way to prevent this disease is not to give honey and wild herbal tea to the infants under two years of age.
- Halogenated polycyclic aromatic hydrocarbons associated with drinking water disinfectionPublication . José, S. S.; Pinto, M.; Antunes, A.M.M.; Louro, H.; Silva, M.J.; Cardoso, A.S.Introduction: Disinfection by-products (DBPs) have been identified in chlorinated water. This fact justifies the growing concern about the potential health effects of emerging unregulated DBPs, some of which appear to be more genotoxic than the regulated DBPs[1]. Polycyclic aromatic hydrocarbons (PAHs) are among the most persistent contaminants detected in environmental samples such as river sediments and tap water. A few studies have already proven that water disinfection can lead to the formation of halogenated derivatives of PAHs, such as chlorinated and brominated PAHs[2] . The available toxicological studies have shown that these compounds possess, in general, greater mutagenicity than the corresponding parent PAHs. Our research group has also shown that exposure of HepG2 cells to a dose-range of 6-Cl-benzo[a]pyrene (6-ClBaP) and BaP resulted in cytotoxicity above 50 µM and that, at the equimolar doses of 100 and 125 µM, 6-ClBaP was able to induce a significantly higher level of DNA damage than BaP[3] . The present study had two main objectives: 1) identification of the major chlorinated and brominated derivatives of benzo[a]anthracene (BaA) and pyrene (Pyr) formed as disinfection by-products and 2) evaluation of their potential hazard to humans, through the characterization of their potential cytotoxic and genotoxic effects in a human cell line.
- Exploring the toxic effects of MYCOtoxins MIXtures in infant food and potential health impactPublication . Alvito, Paula; Arruda, Noélia; Assunção, Ricardo; Barreira, M.J.; Vasco, Elsa; Tavares, Ana; Calhau, Maria AntóniaThere is growing concern within public health about mycotoxin involvement in human diseases particularly related to children´s exposure through contaminated food1 . The natural co-occurrence of mycotoxins is an increasing concern which could be expected to exert greater toxicity and carcinogenicity than exposure to single mycotoxins2. The present project aimed to study the occurrence of multiple mycotoxins and toxicity interactions in baby foods and cereals consumed by Portuguese children. Scarce data are available in the literature concerning the co-occurrence of mycotoxins in infant food and their combined toxicity and no data exists in Portugal concerning this issue. This project gathered a multidisciplinary team in order to answer to several questions: 1) Are children exposed daily to mycotoxins through food? 2) What are the quality and quantity that characterize this exposure? 3) Can this exposure bring harm to children? Will it put them on risk? The co-occurrence of several mycotoxins were evaluated in different infant foods (cereal based) marketed at Portugal (Lisboa). These results, combined with the consumption data from a food consumption survey performed at the Primary Health Care Unit from Cidadela, Cascais (children aged until 3 years old) were used to estimate the intake of mycotoxins in Portugal, through a probabilistic approach using @Risk software. Toxicological studies including bioavailability and absorption of mycotoxins3 and its interactive effects4 were also performed.