Journal of Food Microbiology: 2 (2)

Open Access Article

1 - Molecular analysis of the genes encoding colibactin production in Klebsiella pneumoniae isolated from raw milk by Multiplex-PCR as an agent for colorectal cancer
Marziyeh Radaei Alamoli sedigheh mehrabian kumarss amini parisa mobasseri

Klebsiella pneumoniae is a Gram-negative, non-motile, encapsulated, lactose-fermenting, facultatively anaerobic, rod-shaped bacterium.It has traditionally been considered an opportunistic pathogen and is a common cause of nosocomial infections. The pks gene cluster enco More

Klebsiella pneumoniae is a Gram-negative, non-motile, encapsulated, lactose-fermenting, facultatively anaerobic, rod-shaped bacterium.It has traditionally been considered an opportunistic pathogen and is a common cause of nosocomial infections. The pks gene cluster encodes enzymes responsible for the synthesis of colibactin. Colibactin is a genotoxin that has been shown to induce DNA damage and contribute to increased virulence. Colibactin is also strongly suspected of being involved in the development of colorectal cancer. The present study investigated the prevalence of pks, clbN, and clbB genes in Klebsiella pneumoniae isolates. In this study, 220 samples were obtained from raw milk. Then, all samples were cultured in the violet red bile agar and then cultured in blood agar, MacConkey agar, and chocolate agar for bacterial isolation. Biochemical and microbiological tests were performed for confirmation of the bacteria. DNA was extracted from all isolates using a genomic DNA extraction kit. Then multiplex polymerase chain reaction (M-PCR) method was performed using specific primers. It was found that 60 K. pneumonia isolates out of 220 samples (27.27%) were confirmed by standard phenotypic tests. The PCR test indicated that 6 (10%) strains carried clbN and clbB genes. The pks positive K. pneumoniae was more prevalent in our samples. Owing to its pleiotropic effects, colibactin profoundly influences cellular physiology, inducing DNA breaks that lead to senescence or apoptosis. It seems that the identification of the pks positive K. pneumoniae in milk is essential to prevent colorectal cancer. Manuscript profile

Open Access Article

2 - Prevalence and antimicrobial resistance pattern of Pseudomonas aeruginosa strains isolated from rose water and herbal distillates in Kashan, 2018
Reza sharafati chaleshtori navid Mazroii Arani Elahe Alizadeh Alireza Etemadi

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic gram-negative and pathogenic bacterium that can be transmitted through food to humans. Antibiotic-resistant infections of this bacterium are a severe public health issue. This study aimed to determine the preval More

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic gram-negative and pathogenic bacterium that can be transmitted through food to humans. Antibiotic-resistant infections of this bacterium are a severe public health issue. This study aimed to determine the prevalence and antibiotic resistance pattern of P. aeruginosa strains isolated from rose water and herbal distillates in Kashan. In this cross-sectional study, 400 rose water and herbal distillate samples were randomized purchased of local markets in Kashan and evaluated for the occurrence of P. aeruginosa by culturing methods. The obtained isolates were subjected to the disc diffusion antimicrobial susceptibility tests. Out of 400 samples, 16 (4 %) samples were contaminated withP. aeruginosa. The 100 % of isolates were resistant to ticarcillin, ceftazidime, colistin, and gentamicin. Also, the 13 (81.25 %) samples were sensitive to imipenem. The results showed a high occurrence of the antibiotic resistance P. aeruginosa strains isolated from rose water and herbal distillates. Manuscript profile

Open Access Article

3 - The effect of application of bioactive packing cover on the basis of natural preservative (chitosan / natamycin) and microalgae, Spirolina platensis and Chlorella vulgaris on Quality Characteristics and Beef Shelf Life
reza shafiei toktam mostaghim

The aim of this study was to investigate the effects of antimicrobial coating based on chitosan, and natamycin, Chlorella vulgaris, Spirolina platensis for increasing the survival rate of beef. For this purpose, the values of zero, 1, 1.5 and 2 percent of the compounds More

The aim of this study was to investigate the effects of antimicrobial coating based on chitosan, and natamycin, Chlorella vulgaris, Spirolina platensis for increasing the survival rate of beef. For this purpose, the values of zero, 1, 1.5 and 2 percent of the compounds were used during the days of zero, 7, 14 and 28 days storage in the packaging. Physicochemical meat tests including pH, ash percentage, protein, volatile nitrogen, index of thiobarbituric acid, texture index (Hardness, elasticity, cohesively, consistency, chewiness), total microbial population, sensory evaluation (crispiness, taste, wateriness, overall acceptance) in a completely randomized design with three repetitions at a significant level of 95% confidence has been checked. The results of the experiments were analyzed by using Minitab 17.2 software. The results showed that there were significant differences between the calf meat treatment Physicochemical and sensory with the testator treatment and increasing the use of chitosan, algae and also kanamycin, increase of microbial index rate, volatile nitrogen index (TVBN), thiobarbituric index (TB) during storage time for 28 days will be happened by less intensity. But the percentage of ash index did not show significant differences (p<0.05). The use of algae in packaging formulations increases by up to 1%, increased hardness, decreased elasticity, chewiness and cohesiveness, as well as gumminess. With the increasing in the use of chitosan and the prevention of microbial and antioxidant damage as well as the use of algae due to its antioxidant properties, the rheological properties of the tissue as well as sensory evaluation were significantly less than the control treatment. Finally, taking into account the Physicochemical properties, the sensory packaging coverage by using 1% platinaceous algae, Chlorella vulgaris1% ,Spirolina platensis,1% chitosan and 1% natamycin was used as the best composition in order to cover packaging. Manuscript profile

Open Access Article

4 - JFM_Volume 7_Issue 2_Pages 1-91

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Open Access Article

5 - Feasibility study of producing and evaluation the quality properties of probiotic and synbiotic jelly containing Bacillus coagulans
Elham Rajab Pour Nikoo Samar Mansouripour Javad Hamedi

In this research, jelly samples including probiotic (containing Bacillus coagulans), synbiotic (containing B.coagulans and galactooligosaccharide) and control (without probiotic and prebiotic) were produced and kept in the refrigerator for six weeks. Survival of probiot More

In this research, jelly samples including probiotic (containing Bacillus coagulans), synbiotic (containing B.coagulans and galactooligosaccharide) and control (without probiotic and prebiotic) were produced and kept in the refrigerator for six weeks. Survival of probiotics was evaluated weekly. In order to confirm the safety, microbial tests including E.coli, Salmonella, S.aureus and lactic acid bacteria were carried out. Physicochemical properties of jelly samples including pH, brix and syneresis were considered for six weeks. Sensory evaluation was performed by taste panel assessment. The results showed that there was a decreasing trend of probiotics in probiotic and synbiotic jelly samples within six weeks. The samples kept their probiotic property until sixth week but it was more desirable almost until the fourth and fifth weeks. In safety microbial tests, no growth of the tested microorganisms was observed. Brix test results showed that the trend of brix reduction in probiotic and synbiotic samples was more evident than control from fifth week. This difference was also significant in the sixth week (p<0.05). The pH of the samples did not show significant difference before the fourth week (p>0.05). But after that, the pH of probiotic and synbiotic samples was significantly less than the control (p<0.05). According to the syneresis test, no syneresis was observed in the samples. The results of taste panel showed no significant differences compared to control by adding probiotic or prebiotic to jelly samples (p<0.05). Therefore, according to the results of this research, probiotic and synbiotic jellies can be produced with proper quality characteristics. Manuscript profile

Open Access Article

6 - Effect of essential oil of Mentha spicata on the survival of the Escherichia coli O157:H7 during ripening of traditional Lighvan cheese
Mohammad Bafanadeh Zendeh Vadood Razavilar Hamid Mirzaei Khosrow Mohammadi

Vegetable essential oils and their components have anti-bacterial known effects. The aim of this study was to evaluate different concentrations of essential oils of Mentha spicata on the survival rate of Escherichia coli O157: H7 in traditional Lighvan cheese during rip More

Vegetable essential oils and their components have anti-bacterial known effects. The aim of this study was to evaluate different concentrations of essential oils of Mentha spicata on the survival rate of Escherichia coli O157: H7 in traditional Lighvan cheese during ripening. Essential oils were extracted using the Kelevenger apparatus, and they were analyzed by GC/MS. To determine the necessary oil concentration in terms of the organoleptic, sensory evaluation was conducted by a test panel. Cheese samples prepared with the help of local manufacturers based in the village of Lighvan in triplicates, including zero and 100 and 200 ppm from essential oils of Mentha spicataand doses of 103 and 105 CFU/mL from the E. coli O157: H7 bacterium. The numbers of the E. coli O157: H7 bacteria were analyzed during the days 0, 30, 60, and 90 of the ripening period.Mentha spicata essential oils had considerable antimicrobial effects against E. coli O157: H7. Using the vital oils caused a decrease in the numbers of E. coli O157: H7 bacteria in the 90th days of ripening (P<0.05). Using from Mentha spicata at a concentration of 200 ppm can reduce the survival of E. coli O157: H7 in Lighvan cheese. Therefore, it can be argued that the studied essential oil can be used as a natural preservative traditional Lighvan cheese but should be used in concentrations such that do not have any adverse effects on the flavor of food. Manuscript profile

Open Access Article

7 - Study the frequency of enterotoxin encoding genes and antibiotic resistance pattern of methicillin-resistant Staphylococcus aureus isolated from vegetable and salad samples in Chaharmahal Va Bakhtiari province
Manouchehr Momeni shahraki Amir Shakerian Ebrahim Rahimi Farhad Safarpoor Dehkordi

Methicillin-resistant Staphylococcus aureus (S. aureus) is one of the main emerging causative agents of antibiotic-resistant food poisoning in humans. The bacterium also has the ability to the production of heat resistant enterotoxin. The present study was done to asses More

Methicillin-resistant Staphylococcus aureus (S. aureus) is one of the main emerging causative agents of antibiotic-resistant food poisoning in humans. The bacterium also has the ability to the production of heat resistant enterotoxin. The present study was done to assess the prevalence rate, antibiotic resistance pattern, and frequency of enterotoxin encoding genes in methicillin-resistant S. aureus strains isolated from vegetable and salad samples. In this study, 485 samples of vegetables and salad were collected and immediately transferred to the laboratory. The microbial culture was used to isolate S. aureus, and methicillin-resistant strains were approved using cefoxitin and oxacillin disks. Antibiotic resistance patterns and frequency of enterotoxin encoding genes were analyzed using disk diffusion and PCR methods, respectively. The prevalence rate of methicillin-resistant S. aureus in vegetable and salad samples were 7.2% and 8.51%, respectively. Methicillin-resistant S. aureus strains had the highest antibiotic resistance against penicillin (100%), co-amoxiclav (100%), ampicillin (100%) and ceftriaxone (100%) antibiotics. The prevalence of resistance against imipenem (10.52%) and chloramphenicol (23.68%) was lower than other antibiotics. SEA (63.15%) and SEB (52.26%) were the most frequently detected enterotoxins in methicillin-resistant S. aureus strains. The simultaneous presence of multiple enterotoxin encoding genes and multiple resistance against several antibiotics in methicillin-resistant S. aureus strains isolated from vegetable, and salad samples represent an important health-related concern in this kind of food samples. Preventing uncontrolled administration of antibiotics can reduce the risk of enterotoxigenic methicillin-resistant S. aureus enterotoxin in vegetables and salads. Manuscript profile

Open Access Article

8 - Investigation of Influencing Factors on Production of Chlorophyll and Carotenoid Pigments from Spirulina Platensis Using Platelet-Burman Design
Sepideh Banayan Mahshid Jahadi Mohammad Fazel

Spirulina platensis has attracted particular attention because of its importance as food, feed and natural pigments with specific functional properties .The purpose of this study is determination and screening of the most important factors including: light-dark cycles ( More

Spirulina platensis has attracted particular attention because of its importance as food, feed and natural pigments with specific functional properties .The purpose of this study is determination and screening of the most important factors including: light-dark cycles (12h light/12h dark and 16h light/8h dark), cultivation period (11 and 14 days), light-emitting diodes (LED) composition (6 blue/ 3 red/ 4 white  and 3 blue/6 red/4 white), nitrogen source (65 mg/l urea in fed batch mode and 40 mg/l urea in batch mode), carbon source (1 g/l date syrup in batch and fed batch mode),  inoculation size (OD: 0.4 and 0.6) and sodium chloride content (0 and 2 g/l) on the chlorophyll a and carotenoids pigments production in Spirulina Platensis using the Placket-Burman design. The results showed that among the investigated factors, sodium chloride, carbon source, light-emitting diodes composition, Cultivation period (p<0.01) and inoculation size (p<0.05) had significant effect on chlorophyll-a production and nitrogen source, carbon source and sodium chloride had significant effect (p <0.01) on carotenoids production. The highest production of these pigments was obtained 13.46 ± 0.9 and 8.21± 0.17 (μg/ml) for chlorophyll-a and carotenoids, respectively. Manuscript profile

Open Access Article

9 - Comparative study of antibacterial effects of polar, semi-polar, and nonpolar fractions of Rosa canina extract against some pathogenic bacteria
sanaz tahmasebi changiz ahmadizadeh

Due to the increasing demand for food worldwide, people inadvertently or deliberately, through the production, supply, import, and export of spoiled and contaminated food, cause instantaneous diseases, short-term, long-term, and even many deaths. Rose canina is one of t More

Due to the increasing demand for food worldwide, people inadvertently or deliberately, through the production, supply, import, and export of spoiled and contaminated food, cause instantaneous diseases, short-term, long-term, and even many deaths. Rose canina is one of the most valuable medicinal plants that most people use in their lands to treat some diseases. The purpose of this study was to investigate the antimicrobial effects of polar, semi-polar, and non-polar fractions of Rosa canina L. extract on Pseudomonas aeruginosa, Staphylococcus aureus, Listeria monocytogenes, and E. coli. In this study, Rosa canina was used. First, methanolic, chloroform and hexane extracts of R.canina were extracted, and the effects of different concentrations of these extracts were investigated. All experiments were carried out using the well-diffusion method and MIC and MBC determination on standard strains of Intended bacterias. The chloroform extract of the Rosa canina prevented at a concentration of 6.25 μg / ml has an inhibitory effect on Gram-positive bacteria in Listeria monocytogenes. While the impact on gram-negative bacteria of Pseudomonas aeruginosa and Escherichia coli is required for high concentrations of chloroform extract. Methanolic extract of Rosa canina at a concentration of 25 μg / ml has an inhibitory and killing effect on both gram-positive bacteria and gram-negative bacteria, and the chloroform extract of this plant has a most inhibitory effect on Listeria monocytogenes. In general, it can be concluded that the extract of Rosa canina has an antibacterial effect. Manuscript profile

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