جستجوی مقالات مرتبط با کلیدواژه « cheese » در نشریات گروه « زیست شناسی »

Brucella spp are small, immobile, gram-negative bacteria that are lacking capsules and formed like cocobacillus. Brucellosis is a zoonosis infection between humans and animals that can lead to miscarriages, fertility disorders, genital infections, reduction in milk production, urethritis, and epididymitis in the original host, resulting in many medical disorders in patients and unnecessary treatment expenses. Moreover, farmers would end up facing significant economic losses. Despite advances in blood culture techniques and serological tests to detect specific antibiotics, there are still significant difficulties in the diagnosis of brucellosis; therefore, a new laboratory test is needed for a better examination. One of the most recent quantitative methods that have already caught the attention of many researchers is the detection of bacteria by Real Time PCR method. The aim of this study is to identify bacteria of the genus Brucella, both in milk and cheese samples, by the method of Real Time PCR. 25 samples of cow's milk and twenty-five samples of cheese were collected from different parts of Shahrekord city. DNA extraction was performed using the DNA extraction kit (Cinnagen company) for the molecular diagnosis. Then, by the use of Real Time PCR reaction (Corbett Rotor-Gene Model, manufactured in Australia), samples were studied. In this study, fifty samples were examined, and only two samples (4%) were diagnosed with Brucella abortus, meanwhile, there were no reports on infections by Brucella in the cheese samples. Conclusion This study shows that molecular techniques such as Real Time PCR can be used as a complementary method for the detection of Brucella, alongside all the other common methods.

Lactobacilli are Gram-positive, catalase-negative, non-spore forming, rod-shaped organisms. So far, more than 90 species of these bacteria have been identified. There are several strains of probiotic Lactobacilli in a wide range of human food products. Identification of these bacteria in traditional dairy products makes it possible to use them in the production of delicious industrial dairy products. The selection of reliable methods for the identification of Lactobacilli is of a particular importance. Biochemical methods are time consuming and ambiguous. Molecular methods are more appropriate and precise and can be a substitute for previous methods. The purpose of this study is the isolation of Lactobacilli from bacterial flora in Bandar Abbas traditional cheese and identification these bacteria by using PCR as an effective tool for the recognizing the isolated strains.

Fifty samples of traditional cheese were collected from Bandar Abbas and strains were obtained by phenotypic methods.16 s rRNA primers were used to identify their molecular identity. Then the PCR product was sent to Poya Gene Gostar for sequencing. Obtained sequences were blasted in NCBI GenBank.

3 strains of Lactobacillus include Lactobacillus murinus, Lactobacillus helviticus and Lactobacillus planatrum were identified.

These three strains improve the quality of dairy products in this area and can be used in products manufactured in the industry.

Aim and Brucella spp. is a gram negative coco bacillus which has different hosts including human، cow، sheep and goat. Brucella spp. is transferred via milk and dairy products causing a Malta fever in human. Serological methods for Brucella spp. detection do not have sufficient sensitivity and accuracy; in addition، they have great false positive and negative results. The aim of this study is determination of the hemi nested PCR technique sensitivity for detection of Brucella spp. in raw milk and cheese. In this study 15 raw milk samples، 15 pasteurized cheese samples and 15 traditional cheese samples were collected from Tehran and suburbs. DNA was extracted using DNP kit from samples. After optimization of first and second round of PCR، sensitivity and specificity of reactions were examined. Then all samples were tested using developed PCR. The PCR product which was obtained from first PCR round had 443 bp length، and the second round fragment had 225bp. The PCR sensitivity up to 100 particles was observed. Among 15 samples of raw milk، 10 cases were PCR positive. In 15 pasteurized cheese samples only 6 cases were PCR positive، and finally from 15 traditional cheese samples 8 were PCR positive. With respect to this result، it could be said that in comparison with conventional detection technique for Brucella spp. diagnosis، PCR has a significant sensitivity and accuracy. Furthermore، it seems that using molecular detection technique as confirmative tests for detection of Brucella spp. is inevitable.

Listeria bacteria are widespread and commonly found in soil, sewage, dust and water. Listeria monocytogenes and the other Listeria species have been isolated from a variety of raw and processed foods as well. The objective of this study was to determine the prevalence of Listeria spp. in retail stores located retail raw milk, traditional cheese and ice-cream in Shahrekord and Shiraz. A total of 178 samples of raw cow milk (n=45), raw goat milk (n=32), traditional cheese (n=41) and traditional ice-cream (n=60) collected randomly. All the samples were evaluated for the presence of Listeria spp. by using standard cultural methods, then confirmed with Polymerase Chain Reaction (PCR). Based on conventional bacteriologic tests, 24 of 178 samples (13.5%) were positive for Listeria spp. The prevalence of Listeria in raw cow milk, raw goat milk, traditional cheese and traditional ice-cream were 11.1%, 3.1%, 24.4% and 13.3%, respectively. The most species isolated was L. innocua (62.5%) and the others were L. monocytogenes (37.5%). Our results indicate the potential risk of infection with Listeria among people who consume raw and unpasteurized dairy products. Further intensive studies is suggested to evaluate of the prevalence of Listeria spp. in the other food products especially ready to eat foods.