The Gelatin-Coated Nanostructured Lipid Carrier (NLC) Containing Salvia officinalis Extract: Optimization by Combined D-Optimal Design and Its Application to Improve the Quality Parameters of Beef Burger.

The current study aims to synthesize the gelatin-coated nanostructured lipid carrier (NLC) to encapsulate sage extract and use this nanoparticle to increase the quality parameters of beef burger samples. NLCs were prepared by formulation of gelatin (as surfactant and coating biopolymer), tallow oil (as solid lipid), rosemary essential oil (as liquid lipid), sage extract (as active material or encapsulant), polyglycerol ester and Tween 80 (as low-molecular emulsifier) through the high-shear homogenization-sonication method. The effects of gelatin concentrations and the solid/liquid ratio on the particle size, polydispersity index (PDI), and encapsulation efficiency (EE%) of sage extract-loaded NLCs were quantitatively investigated and optimized using a combined D-optimal design. Design expert software suggested the optimum formulation with a gelatin concentration of 0.1 g/g suspension and solid/liquid lipid ratio of 60/40 with a particle size of 100.4 nm, PDI of 0.36, and EE% 80%. The morphology, interactions, thermal properties, and crystallinity of obtained NLC formulations were investigated by TEM, FTIR, DSC, and XRD techniques. The optimum sage extract-loaded/gelatin-coated NLC showed significantly higher antioxidant activity than free extract after 30 days of storage. It also indicated a higher inhibitory effect against E. coli and P. aeruginosa than free form in MIC and MBC tests. The optimum sage extract-loaded/gelatin-coated NLC, more than free extract, increased the oxidation stability of the treated beef burger samples during 90 days of storage at 4 and -18 °C (verified by thiobarbituric acid and peroxide values tests). Incorporation of the optimum NLC to beef burgers also effectively decreased total counts of mesophilic bacteria, psychotropic bacteria, S. aureus, coliform, E. coli, molds, and yeasts of treated beef burger samples during 0, 3, and 7 days of storage in comparison to the control sample. These results suggested that the obtained sage extract-loaded NLC can be an effective preservative to extend the shelf life of beef burgers.

Prevalence of Brucella spp. in raw milk and artisanal cheese tested via real-time qPCR and culture assay.

Brucellosis is one of the most prevalent zoonotic diseases with worldwide distribution. Although the incidence of brucellosis varies widely in different regions, it is a major concern for public health around the world. This study aimed to determine the prevalence and quantity of Brucella spp. in sheep and goat raw milk, as well as artisanal cheeses produced in the North-west of Iran. To evaluate the intrinsic parameters that may affect the survival of Brucella spp., some of the cheese properties (e.g., pH, salt, moisture, and storage time before selling) were also assessed. A total of 572 samples consisting in 214 sheep raw milk, 92 goat raw milk, and 266 local artisanal cheese samples were collected. The artisanal cheeses were manufactured from a mixture of raw sheep and goat milk. According to the results, using quantitative real-time PCR (qPCR), 17.29%, 15.22%, and 22.93% of the sheep raw milk, goat raw milk, and artisanal cheese samples were found positive for Brucella spp., respectively. In comparison with culture assay, qPCR was 3.5 to 5 times (p < 0.05) more sensitive in the detection of Brucella spp. The results also revealed that the mean values of Brucella spp. load in sheep and goat raw milk and artisanal cheeses were 1.22, 1.55, and 1.43 log cell/ml or g, respectively. A positive correlation was found between Brucella load and successful detection of Brucella spp. by culture assay. Data also suggested a correlation (p < 0.01) between the load of Brucella spp. estimated by qPCR and pH value, salt content, and storage period of the cheese samples. However, Brucella spp. load did not correlate significantly with the moisture content. Based on the results, in any of the cheese samples with a pH value less than 4.5 and a storage period more than five months, no contamination with Brucella spp. was detected.

Development and characterization of carboxymethyl cellulose based probiotic nanocomposite film containing cellulose nanofiber and inulin for chicken fillet shelf life extension.

Bioactive packaging is an alternative new technology for preserving the quality and safety of food products with providing health benefits. In this way, the Lactobacillus plantarum, cellulose nanofiber (CNF) and inulin incorporated carboxymethyl cellulose (CMC) based probiotic nanocomposite film was prepared. The fabricated film samples were characterized by FTIR, FE-SEM, XRD and DSC analyses, that the obtained results indicated the good compatibility between CMC, CNF, and inulin. As a result, the CMC-based probiotic films containing CNF and inulin exhibited satisfactory water barrier and mechanical properties. Additionally, the viability of probiotic bacteria in the CMC-based films was significantly (p < 0.05) increased (36%) by addition of inulin as a prebiotic ingredient during storage time. Probiotic film sample showed antibacterial activity against nine pathogens and also extended the chicken fillet shelf life when wrapped on the meat. In conclusion, the application of CNF and inulin incorporated CMC-based probiotic nanocomposite film as a bioactive food packaging system opens up a new horizon for improving the shelf life of food products and providing the health benefits for consumers.

Isolation and molecular identification of Lactobacillus with probiotic potential from abomasums driven rennet.

Lactobacillus species are beneficial for the functional food industry and preventive medicine. The complex microflora of traditional cheese depends on the cheese types (e.g., homemade rennets). Here, the abomasum driven rennet was assessed for the existence of lactobacilli. For differentiating lactobacilli, the bacterial suspension was screened for the acid and bile resistance. The isolated bacteria were evaluated for antibiotic susceptibility and antagonistic impacts on other pathogenic bacteria. The 16S rDNA gene was evaluated by the amplified ribosomal DNA restriction analysis (ARDRA) recruiting the restriction enzyme Taq I and compared to the virtually digested patterns of previous reports on lactobacilli. The isolates were examined by random amplified polymorphic DNA (RAPD) and distinctive lactobacilli were sequenced. ARDRA and RAPD data showed three distinct lactobacilli strains, including L. acidophilus, L. planetarum, and L. fermentum. The homemade rennet is proposed as the novel source of probiotic strains as an alternative to the traditional cheeses.

Pathogenicity of Helicobacter pylori in cancer development and impacts of vaccination.

Helicobacter pylori affect around 50% of the population worldwide. More importantly, the gastric infection induced by this bacterium is deemed to be associated with the progression of distal gastric carcinoma and gastric mucosal lymphoma in the human. H. pylori infection and its prevalent genotype significantly differ across various geographical regions. Based on numerous virulence factors, H. pylori can target different cellular proteins to modulate the variety of inflammatory responses and initiate numerous "hits" on the gastric mucosa. Such reactions lead to serious complications, including gastritis and peptic ulceration, gastric cancer and gastric mucosa-associated lymphoid structure lymphoma. Therefore, H. pylori have been considered as the type I carcinogen by the Global Firm for Research on Cancer. During the two past decades, different reports revealed that H. pylori possess oncogenic potentials in the gastric mucosa through a complicated interplay between the bacterial factors, various facets, and the environmental factors. Accordingly, numerous signaling pathways could be triggered in the development of gastrointestinal diseases (e.g., gastric cancer). Therefore, the main strategy for the treatment of gastric cancer is controlling the disease far before its onset using preventive/curative vaccination. Increasing the efficiency of vaccines may be achieved by new trials of vaccine modalities, which is used to optimize the cellular immunity. Taken all, H. pylori infection may impose severe complications, for resolving of which extensive researches are essential in terms of immune responses to H. pylori. We envision that H. pylori-mediated diseases can be controlled by advanced vaccines and immunotherapies.

Determining the Risk of Intra-Community Transmission of Tuberculosis in the Northwest of Iran Through 15 Loci Miru-Vntr Typing.

This study was carried out in order to investigating the effect of travelling on the transmission of tuberculosis from high- to low-burden TB countries. Mycobacteria samples isolated from patients of distinct and relatively co-related countries (Azerbaijan Republic and Tabriz [located in the northwest of Iran]) were analyzed through 15 loci MIRU-VNTR typing method. PCR was done using special primers for each of the loci; then the number of allele repeats for all loci were determined by the size of their fragments. Finally, the created numeric patterns for each isolate were analyzed and clustered, using MIRU-VNTRplus.org website. All 119 isolates dispersing at 106 distinct patterns were composed of 10 clusters with 23 members and 96 unique patterns. Nine and five loci had high and moderate discriminatory power, respectively, but only one of them was poor in clustering. The study showed that 89.08% of TB cases involved resulted from the reactivation pattern and 10.92% were related to ongoing transmission. Although Azerbaijan Republic is a higher-burden TB region than Tabriz and Azerbaijan people make frequent tours to Tabriz to receive low or free medical services, the findings showed no TB transmission from the regions at least during the year of the study.

Isolation and Molecular Identification of Streptomyces spp. with Antibacterial Activity from Northwest of Iran.

INTRODUCTION: Streptomyces are a group of prokaryotes that are usually found in all types of ecosystems including water and soil. This group of bacteria is noteworthy as antibiotic producers; so the isolation and characterization of new species seemed to be crucial in introduction of markedly favorable antibiotics. Therefore, in this study we aim to isolate and characterize novel strains of Streptomyces with high antibiotic production capability. METHODS: To achieve this goal, from 140 isolates collected throughout northwest of Iran, 12 selected Streptomyces isolates which exhibited high antibacterial activity against pathogenic bacteria were subjected to PCR reaction for identification via 16S rDNA gene and random amplified polymorphic DNA (RAPD) pattern analysis. RESULTS: Analysis of morphological and biochemical characteristics and the 16S rDNA gene sequence indicated that all 12 selected isolates belonged to the genus Streptomyces. Moreover, screening of the isolates with regard to their antimicrobial activity against indicator bacteria as well as their classification using RAPD analysis revealed that G614C1 and K36C5 isolates have considerable antimicrobial activity and high similarity to Streptomyces coelicolor and Sreptomyces albogriseolus, respectively. CONCLUSION: Since many isolates in this study showed inhibitory effects against pathogenic bacteria, soil of northwest of Iran could be used as a rich source to be explored for novel Streptomyces strains with high potency of antibiotic production.

Quantitative real-time PCR and culture examination of Mycobacterium avium subsp. paratuberculosis at farm level.

Mycobacterium avium subsp. paratuberculosis (MAP) causes Johne's disease in ruminants and may contribute to Crohn's disease in humans. The aim of this study was to determine the occurrence and quantity of MAP in cattle feces and milk in the Iranian context. In addition, we evaluated the effect of cattle age as well as farming system as risk factors contributing to MAP load. For this, a total sample of 373 consisting of 150 cattle feces (CF), 150 individual cow's milk (ICM), as well as 73 bulk-tank milk (BTM) was collected randomly and regardless of the cattle health status. The samples were assayed using F57 quantitative real-time PCR (qPCR) and culture method. According to the results of qPCR which was found ≈ 10 times more sensitive than culture assay, MAP was detected in 68.66% (103/150) of the CF, 12% (18/150) of the ICM and 52.05% (38/73) of the BTM samples. In contrast to the previous reports, the quantity of MAP in the BTM (2.03-5.97 log cfu/50 ml) was statistically (p<0.01) higher than the ICM (0.90-1.97 log cfu/50 ml). Data suggested a direct relation (p<0.01) between the cattle age and the quantity of MAP in the CF samples, while the relation was not statistically significant (p>0.05) for the ICM. In addition, MAP load in the BTM samples obtained from traditional farms was significantly (p<0.01) higher than that of the industrial ones, while the differences in CF and ICM was not significant (p>0.05).

Fate of Yersinia enterocolitica during manufacture, ripening and storage of Lighvan cheese.

This study aimed to evaluate the behavior of virulent Yersinia enterocolitica (YE) during the manufacture, ripening and storage of Lighvan cheese with particular reference to strains of YE, initial inoculation level, and storage time. Three strains of YE with low (1 log cfu/ml) and high (3 log cfu/ml) inoculation levels were inoculated to raw whole ewe's milk which was then used for manufacturing of Lighvan cheese. Throughout the manufacturing, ripening and storage periods the number of YE was counted on selective media. Enumerated colonies were then confirmed by duplex PCR using ail and virF genes. Moreover, some microbial and physiochemical characteristics of the cheese samples were examined. According to the results, initial inoculation level and storage time had statistically significant (P<0.01) effects on persistency of YE, while strain type exhibited no statistically significant (P>0.01) impact on survival of the pathogen. Results showed a rapid increase in the number of YE during manufacturing, however, in the ripening and storage periods the number of YE was decreased and eventually it was eliminated in all cheese batches after 4 months of storage.

Prevalence of virulent Yersinia enterocolitica in bulk raw milk and retail cheese in northern-west of Iran.

To determine the prevalence of virulent Yersinia enterocolitica, 554 samples consisting of 354 bulk raw milks and 200 traditional cheeses were collected from different parts of Eastern-Azerbaijan province, during a 23-month period from 2008 to 2010. The occurrence of virulent strains of Y. enterocolitica in samples enriched in peptone sorbitol bile broth (PSBB) was evaluated via the detection of attachment invasion locus (ail) gene by PCR. The viability of virulent Y. enterocolitica in the PCR-positive samples was tested using conventional culture method and the isolates were confirmed by the second-phase ail-PCR. According to the results, 8.66% of total samples including 7.62% of bulk raw milks and 10.5% of raw milk cheeses were found ail-positive by PCR method; subsequently Y. enterocolitica was isolated by the culture method and confirmed by the second phase ail-PCR in 2.88% of total samples including 2.26% of raw milks and 4% of cheese samples. It was concluded that, a sample enrichment followed by ail-PCR was more sensitive and robust to detect and distinguish the virulent strains of Y. enterocolitica compared to the conventional culture method.