Comparison of the Legiolert enzyme-substrate method and the conventional cultivation for the detection of Legionella pneumophila in water samples from public places / 公共卫生与预防医学

Objective To compare the detection effects of Legionella pneumophila in water samples from public places by the Legiolert enzyme-substrate method and the conventional cultivation. Methods The Legiolert enzyme-substrate method and the conventional cultivation method were used to detect Legionella pneumophila in cooling water and shower water samples collected in public places. Isolated strains were verified and serotyped. Results A total of 68 samples were collected and tested. The positive rate of the conventional cultivation and the Legiolert enzyme-substrate method were 5.88%（4/68）and 35.29%（24/68）, respectively, with a significant difference （χ2=16.41，P2=16.41，P=0.000). A total of 25 strains of Legionella pneumophila were isolated，and the serum types were mainly LP1（14/25）. Conclusion The Legiolert enzyme-substrate method represente a higher detection rate of Legionella pneumophila in water samples from public places than the conventional cultivation.

Molecular diagnosis of the curly lettuce parasitic contamination from hydroponic cultivation from supermarkets / Diagnóstico molecular da contaminação parasitária de alface crespa de cultivo hidropônico em supermercados

Abstract The consumption of vegetables has increased in recent years due to the search for a healthier diet that is rich in fiber and has fewer calories. To assess the parasitic contamination of lettuce sold in markets, a survey of parasites was carried out from a supermarket chain in the city of Londrina, Paraná. A total of thirty samples of lettuce were purchased in the ten markets visited, three in each, of which ten were conventionally cultivated, ten were hydroponically cultivated, and ten were organically cultivated. All samples were analyzed using the sedimentation methods of Hoffman, Pons and Janer and the fluctuation method of Faust and colleagues and Willis with adaptations. In addition, the samples were subjected to DNA extraction by a commercial kit and polymerase chain reaction to detect Toxoplasma gondii, Cryptosporidium spp. and Giardia spp., which are protozoa that cause food and waterborne parasitic outbreaks. All samples were negative for sedimentation and flotation techniques. One of the hydroponically cultivated samples was positive for T. gondii. The results demonstrate the risk of curly lettuce contamination from hydroponic cultivation and the need for proper cleaning of these foods before consumption.

Resumo O consumo de vegetais aumentou nos últimos anos devido à busca de uma dieta mais saudável, rica em fibras e com menos calorias. Para avaliar a contaminação parasitária de alface vendida nos mercados, foi realizado um levantamento de parasitas em vegetais folhosos de uma cadeia de supermercados da cidade de Londrina, Paraná. Um total de 30 amostras foram compradas nos dez mercados visitados, três em cada, dos quais dez foram convencionalmente cultivados, dez cultivados hidroponicamente e dez foram cultivados organicamente. Todas as amostras foram analisadas, usando-se os métodos de sedimentação de Hoffman, Pons e Janer e o método de flutuação de Faust e colaboradores e Willis com adaptações. Além disso, as amostras foram submetidas à extração de DNA por um kit comercial e reação em cadeia da polimerase (PCR) para detectar Toxoplasma gondii, Cryptosporidium spp. e Giardia spp., que são protozoários causadores de surtos transmitidos pela água e alimentos. Todas as amostras foram negativas para técnicas de sedimentação e flutuação. Uma das amostras cultivadas hidroponicamente foi positiva para T. gondii. Os resultados demonstram o risco de contaminação por alface crespa do cultivo hidropônico e a necessidade de limpeza adequada desses alimentos antes do consumo.

Morphological Characteristics of Some Pepper Genotypes (Capsicum annuum L.) Grown in Conventional and Organic Agricultural Systems: Comparative Analysis

Long-term research in pepper organic production are scarce in Republic of Macedonia. Plant and fruit morphological traits of important pepper varieties organically produced were compared to pepper produced in conventional systems. Conceivably, this is the first morphological traits comparative study of locally important pepper genotypes (Capsicum annuum L.) in Republic of Macedonia in organic and conventional open-field production. The aim of the research is to determine the differences in pepper morphological traits when produced organically in comparison to conventional production. Eight plants and fruits were used for morphological traits determination of plant and fruit in six locally important pepper genotypes (Strumicka Kapija, Strumicka Vezena, Piran, Zupska Rana, Duga Bela and Kurtovska Kapija) grown in an organic and conventional production system. The traits number or branches per plant, fruit width and fruit index were significantly affected by the production manner resulting in less branches per plant, lower fruit width and lower fruit index in organic production. The traits fruit weight, pericarp thickness and fruit flesh percentage, which are the most important for pepper crop yield and utilisation of pepper fruits were not significantly affected by the production practice. Organic production has limited influence on pepper plant and fruit traits, but not in a manner to decrease the production, which generally is the main fear of conversion from conventional to organic production in vegetables. Appropriate selection of pepper varieties with application of suitable cultivation and management practices can contribute to successful organic production resulting in high quality pepper production.

Vitamin C and Total Antioxidant Content in Pepper Fruits (Capsicum annuum L.): Comparative Analysis of Peppers Grown in Conventional and Organic Agricultural Systems

Up-to-date, there is no methodical and long-term research on fruit quality and nutritional characteristics of peppers grown in organic production system in Republic of Macedonia. Still, there are debates in broad sense about the advantage of organic vegetable production compared to conventional one in terms of quality characteristics. Led by this idea, this research was conducted with an aim to study vitamin C content and total antioxidant content in fruits of six pepper genotypes as most important fruit quality characteristics and to determine if there are differences in fruit quality properties between those grown in organic and conventional production system. Fruits of six different pepper genotypes Strumicka Kapija, Strumicka Vezena, Piran, Zupska Rana, Duga Bela and Kurtovska Kapija cultivated in organic and conventional production systems were used for determination of vitamin C and total antioxidant content. The extraction of vitamin C and total antioxidants were performed in a plant tissue extractor with orthophosphoric acid and methanol as extracting reagents, respectively. Vitamin C content was determined by HPLC instrument, while total antioxidant content was measured with potentionstat instrument. The genotype Strumicka Kapija was characterized with the highest content of vitamin C in both cultivation systems. In all genotypes under study, except Zupska Rana, the vitamin C content was higher in fruits from organic production as compared to pepper fruits from the conventional system. Generally, the total antioxidant content in pepper fruits from the conventional system was averagely lower than the total antioxidant content measured in pepper fruits from the organic production system. These findings are a prove that production system is very important for the fruit quality characteristic and the organic production of peppers results with production of fruits with higher content of vitamin C and antioxidants compared to conventional ones, therefore organic peppers give more nutrition and health benefits to consumers.