[Plant-derived contaminants in food : Occurrence, effects and risk assessment]. / Pflanzliche Kontaminanten in Lebensmitteln : Vorkommen, Wirkung und Risikobewertung.

Among the various contaminants, the group of natural plant-derived substances in the modern food chain has been generating increasing concern in recent years. The adverse effects encountered may be diverse and pose risks of acute, subchronic or chronic toxicity. The underlying mechanisms of toxicity may be thresholded or be based on interactions with DNA, as for genotoxic carcinogens, for which the existence of a threshold cannot be assumed. This article gives an overview of the major plant-derived contaminants of present concern in the modern food chain and describes their mode of action and adverse effects.

Improving the food safety of bakery products by simultaneously monitoring the occurrence of pyrrolizidine, tropane and opium alkaloids.

The exponential number of food alerts about concerning levels of some plant-alkaloids, such as pyrrolizidine, tropane and opium alkaloids, have stressed the need to monitor their occurrence in foods to avoid toxic health effects derived from their intake. Therefore, analytical strategies to simultaneously monitor the occurrence of these alkaloids should be developed to ensure food safety an comply with regulations. Accordingly, this work proposes an efficient multicomponent analytical strategy for the simultaneous extraction of these alkaloids from commercial bakery products. The analytical method was validated and applied to the analysis of 15 samples, revealing that 100% of them contained at least one of the target alkaloids, in some cases exceeding the maximum limits legislated. Moreover, in two samples the 3 different alkaloid families were detected. These results confirm the importance of simultaneously monitoring these alkaloids in food and highlight also considering some opium alkaloids in current legislation.

Lead poisoning due to ingestion of lead-contaminated opium: A diagnostic study on patients' imaging findings.

OBJECTIVES: Our study attempts to determine if for patients following ingestion of lead-contaminated opium, radiographs [plain X-ray (KUB)] or unenhanced computed tomography (CT scan) of the abdomen may be predictive of lead poisoning. METHODS: Our study is concerned with patients of >21 years with elevated lead concentrations, who had undergone KUB or CT. Patients with other toxicities who had undergone similar imaging profiles but who had low blood lead level (BLL) were enrolled as controls. RESULTS: We evaluated a total of 79 cases and 79 controls with median [IQR] BLLs of 126 [97.4, 160] µg/dL and 8.7 [5.5, 15] µg/dL. All cases and eleven controls (13.9%) were addicted to oral opium, and of these cases, anemia (94.9%) and abdominal pain (92.4%) were the two most common clinical manifestations. Two radiologists reviewed the X-ray and non-contrast CTs. Fifty (63.3%) and 53 (67.1%) cases and controls underwent CT scanning with 34 (68%) vs. 6 (11.3%) positive CTs (P < 0.001) while 43 (54.4%) and 39 (43.3%) underwent X-rays with 21 (48.8%) vs. 4 (11.8%) positive X-rays, respectively (P < 0.001). Positive CT is associated with BLL between 10 and 45 µg/dL with a specificity of 96.9%, 88.7% and positive predictive value of 97.5% and 85% respectively. CONCLUSIONS: In suspected cases of lead exposure due to ingested opium, and if BLL is not readily available, a positive imaging result may guide radiologists and physicians to consider lead poisoning.

Identification of Listeria monocytogenes from unpasteurized apple juice using rapid test kits.

A microbiological survey of 50 retail juices was conducted in the fall of 1996. These juices were analyzed for Listeria monocytogenes, Escherichia coli O157:H7, Salmonella, coliforms, fecal coliforms, and pH. Two unpasteurized juices were positive for L. monocytogenes: an apple juice and an apple raspberry blend with a pH of 3.78 and 3.75, respectively. Three L. monocytogenes isolates were characterized. The colonies were typical for Listeria sp. on Oxford and lithium chloride-phenylethanol-moxalactam agars and were beta-hemolytic on sheep blood agar. The isolates required 5 days of incubation at 35 degrees C to produce a positive rhamnose reaction in a phenol red carbohydrate broth. This slow rhamnose utilization resulted in these isolates not being identified using the Micro-ID test strip (Organon Technika). However, the isolates were positive for L. monocytogenes using the API Listeria strip (BioMerieux) and a multiplex polymerase chain reaction for detection of the hemolysis (hyla) and invasion-associated protein (iap) genes.

Comparison of cytotoxic extracts from fruiting bodies, infected insects and cultured mycelia of Cordyceps formosana.

A resazurin method was employed to test and compare cytotoxicity of extracts from fruiting bodies, insects and cultured mycelia of Cordyceps formosana against Chinese hamster ovary (CHO) cells. Results showed that the cultured mycelia had much stronger cytotoxicity than that of the fruiting bodies and infected insects. This suggests that using cultured mycelia to substitute a natural Cordyceps may result in poisoning. A combined method of HPLC-PAD-HRMS and cytotoxic analysis revealed that the most toxic compound (Compound 1) was found mainly in the cultured mycelia and also a small amount in the infected insect body of the Cordyceps, but not in the fruiting body. The second toxic compound (Compound 2) was found in all structures of Cordyceps and in cultured mycelia. Different contents of the toxic compounds resulted in the different cytotoxicity of the extracts. Compound 1 and Compound 2 were prepared with preparative HPLC as yellow and orange powders, respectively. Cytotoxic tests showed that the median lethal dose (LD50) against CHO cells of Compound 1 was 18.3 ± 0.2 and 103.7 ± 5.9 µg/mL for Compound 2. Compound 1 and Compound 2 were identified as rugulosin and skyrin by HRMS, UV and NMR data. The two compounds were never previously isolated from the genera Cordyceps and Hirsutella and their cytotoxicity against CHO cells was also reported for the first time.

Systematic evaluation of organochlorine pesticide residues in Chinese materia medica.

A systematic evaluation on the levels of organochlorine pesticide residues (OCP) was conducted on four selected, authentic Chinese materia medica, namely: Radix Angelicae Sinensis, Radix Notoginseng, Radix Salviae Miltiorrhizae and Radix Ginseng. Altogether ten representative batches of samples were analysed for each herb. Six batches were collected in the major cultivation areas of the Mainland whilst the remaining four batches were procured in the Hong Kong herbal market. All except Radix Angelicae Sinensis have been identified as containing quintozene and hexachlorocyclohexane in various levels. Hexachlorobenzene and lindane were also reported in samples of Radix Ginseng. The banned pesticide, DDT and its derivatives, was also observed in one of the Radix Notoginseng samples. The investigation will be continued for a target list of common used herbs in Hong Kong. All the results will be gathered and analysed for setting up regulatory permissible limits of OCP residues in Chinese materia medica used in Hong Kong.

The isolation and detection of Escherichia coli O157 by use of immunomagnetic separation and immunoassay procedures.

The use of immunomagnetic separation (IMS) techniques has been reported to reduce the total test time, and improve the sensitivity, of microbiological tests done on foods. This approach is being adopted in epidemiological investigations into suspected foodborne outbreaks of Escherichia coli O157 infection and has gained acceptance by public health laboratories and the food industry. This study demonstrated the ability of a commercially available IMS procedure, Dynabeads anti-E. coli O157, to enable detection of a few cells of E. coli O157 in 25 g of inoculated minced beef, giving results 1 d earlier than a cultural analysis of similar sensitivity. With correct choice of enrichment broths, IMS may increase isolation rate of E. coli O157 compared to that obtained using conventional cultural methods. It is suggested that this may be due to an increase in relative concentration of E. coli O157 compared with the background microflora present in minced beef, which may reduce reliability of non-IMS detection procedures by masking or mimicking target cells on selective/differential solid media. The use of an immunoassay incorporating an IMS step, EHEC-Tek (Organon-Teknika), enabled detection of a few cells of E. coli O157 in 25 g of minced beef. Comparison of the IMS-ELISA with a standard ELISA procedure (Tecra) indicated the sensitivity of the latter system to be greater, perhaps resulting in the higher isolation rate. The use of a method to reliability isolate and detect extremely low levels of E. coli O157 in a food is necessary to aid reduction in the incidence of this most serious of foodborne pathogens.

Consideraciones ecológicas y de inocuidad alimentaria en productos de origen vegetal / Ecological and food safety considerations in productos of plant origin

En años recientes los medios de comunicación han prestado mucha atención a problemas microbiológicos emergentes en alimentos de origen vegetal. Las posibilidades de contaminaciónde las frutas y hortalizas son altas debido a la gran variedad de condiciones a las que son expuestas durante el cultivo, cosecha , procedimiento y distribución. Estas consideraciones adquieren gran interés en el panorama actual presentado por las nuevas técnicas de procedimiento que ofrecen atributos de conveniencia y frescura en respuesta a los cambios en los patrones de consumo y la gran demanda de frutas y vegetales frescos o minimamente procesados. Existe entonces ahora una gran dependencia del uso de refrigeración y de nuevos materiales y técnicas de empaque. Aunque los productos vegetales frescos no habían sido considerados vectores de importancia en la transmisión de enfermedades, las nuevas tecnilogías que aumentan su vida útil, aumentar los riesgos asociados con organismos patógenos en especial de naturaleza psicrotrófica al retardar el desarrollo de la flora competitiva deteriorativa. Adicionalmente cualquier etapa del procedimiento puede modificar los microambientes de los alimentos y abrir nuevas posibilidades a patógenos que por razones ecológicas nunca hubiesen estado presentes naturalemente en el producto. En este artículo se revisan aspectos ecológicos y de inocuidad así como brotes de enfermedades atribuidas al consumo de productos de origen vegetales causados por Salmonella y Shigella spp, Listeria monocytogenes, Clostridium botulinum, Aeromonas hydrophila y Campylobacter jejuri

Aspectos clínico-epidemiológicos de 60 casos de cólera atendidos en el Hospital Central Militar de 1991 a 1995 / Clinical and epidemiological aspects in 60 cases of cholera who were treated in the Military

La reciente epidemia de cólera se extendió en la mayor parte del país lo que motivó a proporcionar al personal médico y paramédico una capacitación y actualización en los conocimientos que se tenían de la enfermedad. En epidemias pasadas no se tiene conocimiento de casos atendidos en el HCM, fue en noviembre de 1991 cuando se presentó el primer caso de los pacientes que se atendieron hasta junio de 1995. A través de un estudio observacional, descriptivo y retrospectivo se llevó a cabo la revisión de los casos diagnosticados como cólera, la información se recabó de los expedientes en el archivo clínico de la institución. Se encontraron 38 pacientes del sexo masculino y 22 del sexo femenino. El 100 por ciento de los casos ingresó a la unidad hospitalaria con diversos grados de deshidratación y del total de pacientes el 12 por ciento tenía antecedente de diabetes mellitus. El 67 por ciento habían consumido alimentos en la vía pública. Todos recibieron solución de Ringer lactado, el medicamento utilizado fue trimetropim-sulfametoxazol; el 100 por ciento respondió favorablemente al tratamiento en un periodo de 3 a 5 días. El tratamiento oportuno disminuye la letalidad