Antibiotic Resistance and Molecular Characterization of Cronobacter sakazakii Strains Isolated from Powdered Infant Formula Milk

Background: Cronobacter sakazakii is a new emerging foodborne bacterial pathogen associated with severe lethal diseases such as meningitis, necrotizing enterocolitis, and septicemia in infants and neonates. Powdered infant formula milk (PIFM) has been recognized as one of the main transmission vehicles and contaminated sources of this pathogen. This study aimed to investigate the prevalence rate, genotypic and phenotypic antibiotic resistance profile, and clonal relatedness of C. sakazakii strains isolated from 364 PIFM samples collected from Tehran city, Iran. Methods: Culture-based methods, Kirby–Bauer disk diffusion antibiotic resistance testing, conventional Polymerase Chain Reaction (PCR), and Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR) assays were used in this study to detect and characterize the C. sakazakii isolates. Results: We isolated 25 C. sakazakii strains from PIFM samples (6.86%). The isolates were highly resistant to amoxicillin-clavulanic acid, amoxicillin, ampicillin, cefoxitin, cefepime, erythromycin, ceftriaxone, ciprofloxacin, and chloramphenicol and susceptible to gentamicin, tetracycline, norfloxacin, and azithromycin antibiotics. The blaCTX-M-1 gene was detected in 96% of the isolates. The isolates were categorized into eight distinct clonal types using the ERIC-PCR method, showing a high genetic diversity among the isolates. However, there was a significant correlation between the genotypic and phenotypic antibiotic resistance properties of the isolates. Conclusions: Novel microbial surveillance systems for detecting multi-drug-resistant C. sakazakii are required to control the contamination of this foodborne pathogen in infant foods

A quantitative prevalence of Escherichia coli O157 in different food samples using real-time qPCR method

Escherichia coli serogroup O157 is the main causative agent of several intestinal and extra-intestinal foodborne diseases in humans through consumption of low-dose contaminated foods such as milk, beef, and vegetables. To date, studies regarding the quantitative prevalence of E. coli O157 in foods are so limited. Therefore, this study aimed to evaluate the quantitative prevalence rate of E. coli serogroup O157 in raw milk (n = 144), vegetable salad (n = 174), and minced beef samples (n = 108) using the real-time qPCR SYBR green melting curve method targeting the rfbA gene. First, we evaluated the method and found a sensitive and specific qPCR assay with 1 log of CFU/ml detection limit to detect E. coli O157 (Tm = 80.3 ± 0.1°C). About 2.77%, 10.18%, and 9.19% of raw milk, minced beef, and vegetable salad samples, respectively, were contaminated with E. coli O157. Minced beef and vegetable salad samples were significantly more contaminated than raw milk samples. Population average of E. coli O157 in raw milk, minced beef, and vegetable salad samples were 2.22 ± 0.57, 3.30 ± 0.40, and 1.65 ± 0.44 log CFU/ml or gr, respectively. Significantly higher levels of population of E. coli O157 were observed in minced beef samples. Minced beef can be regarded as the main food in the transmission of this foodborne pathogen. Routine quantitative rapid monitoring is strongly suggested to be carried out to prevent foodborne diseases caused by E. coli O157

Anticancer Properties of Probiotic Saccharomyces boulardii Supernatant on Human Breast Cancer Cells

Saccharomyces boulardii, a variety of S. cerevisiae, is used as a probiotic yeast in food and drug industries. However, S. boulardii is an opportunistic pathogen, and the supernatant of this organism has recently been recommended for its healthpromoting benefts. Breast cancer is the most frequent cancer disease in women worldwide. The objective of this study was to investigate the efects of S. boulardii supernatant (SBS) on cell viability, inducing apoptosis and suppression of survivin gene expression in MCF-7 and MCF-7/MX as human non-drug-resistant and multidrug-resistant breast cancer cells respectively. The IC50 value of SBS against MCF-7 was calculated 1037, 542, and 543 µg/mL for 24, 48, and 72 h treatments, respectively. Also, this value against MCF-7/MX cells were measured 1242, 616, and 444 µg/mL after 24, 48, and 72 h respectively. We found that suppression of survivin gene expression should be one of the main molecular antitumor mechanisms which is contributed to apoptosis in breast cancer cells. However, anticancer activity of SBS was observed more efcient against MCF-7 than that against MCF-7/MX cells. SBS is suggested to be considered as one of the prospective anticancer drugs to treat human breast carcinoma. More investigations especially in vivo studies are strongly recommended to be implemented to characterize other antitumor mechanisms of SBS against breast carcinoma. Keywords Anticancer properties · Breast carcinoma · In vitro study · Probiotic Saccharomyces boulardii · Yeast supernatan

Production of Bovine Collagen Hydrolysate with Antioxidant Activity; Optimized by Response Surface Methodology

Abstract: Antioxidants are widely used in pharmaceutical industries. Gelatin is a byproduct of the meat industry and its hydrolysates showed several functionalities, such as antioxidant activity. The purpose of this study was to describe and optimize the enzymatic hydrolysis conditions including time, temperature, pH, and enzyme/substrate ratio (E/S) to produce protein hydrolysate with antioxidant functionality from bovine gelatin by RSM; the scavenging activity was evaluated using the DPPH method. The model observed was fitted with desirable adequacy and sufficiency. We found that the antioxidant activity increased significantly (p < 0.05) with the increase in pH value, E/S ratio, and time of enzymatic process; however, the temperature had no significant (p < 0.05) effect on the antioxidant activity of the hydrolysate. The optimum hydrolysis conditions were observed at a temperature of 35.3 ◦C, pH of 8.0, and E/S ratio at 2.5 after 2 h hydrolysis by trypsin enzyme. The results showed that the hydrolysate under these conditions, optimized by RSM, could be more effective on antioxidant activity. Regarding the antioxidant potential, gelatin hydrolysate can be used as an antioxidant supplement in pharmaceutical industries

ANTICANCER EFFECT OF PROBIOTIC SACCHAROMYCES BOULARDII SUPERNATANT ON HUMAN CACO-2 CELLS; AN IN VITRO STUDY

Colon cancer is an important worldwide cause of death in human which is treated commonly by chemotherapy, radiotherapy and surgery methods with different side effects. Natural treatment such as microbial cell wall extract is suggested to be used as an effective alternative of chemical drugs for treatment of colon cancers without any side effect. Saccharomyces boulardii is used in probiotic foods and supplement capsules in viable and yeast cell wall extract forms. At the present study, we in vitro investigate the anticancer properties of S. boulardii supernatant (SBS) on colon cancer cells. We found that, SBS without dilution after 72 hours successfully killed the colon cancer cells. Also, this treatment induced apoptosis and downregulated the expression of survivin gene significantly. However, effects of SBS without dilution after 24 and 48 hours were considerable. Downregulation of survivin gene expression by functional compounds in SBS induced apoptosis and killed the colon cancer cells successfully. However, future in vivo and in vitro investigation of anticancer effects of SBS on other cancer cells are suggested to be implemented

Anticancer Properties of Saccharomyces boulardii Metabolite Against Colon Cancer Cells

Saccharomyces cerevisiae var. boulardii has been used as a probiotic yeast in the medical and food industries. Colon cancers have been known as the third most common cancer type worldwide. Nowadays, cell-free extract and metabolites of probiotics have been employed for the treatment or prevention of different cancer diseases. This study investigates the anticancer properties of S. boulardii metabolites against human colon carcinoma. We evaluated cytotoxicity, apoptosis induction, and suppression of survivin, IL-8, and NFƙB gene expression effects of SBM against caco-2 cells after 24 and 48 h. IC50 concentrations of SBM were measured at 815 and 1411 µg/mL for 24 and 48 h treatments, respectively. The total proportion of apoptotic caco-2 cells treated with SBM after 24 and 48 h were calculated at 62.23 and 88.7%, respectively. Also, relative expression of survivin, IL-8, and NFƙB genes were significantly suppressed in caco-2 cells treated with SBM after 24 and 48 h. In conclusion, we found that SBM induced apoptosis, inhibited the growth rate, and suppressed the expression of the survivin, IL-8, and NFƙB genes in human colorectal cancer cells and it can be considered as a perspective supplement or drug for the treatment or prevention of colon cancer in humans

Prevalence of foodborne and zoonotic viral pathogens in raw cow milk samples

Foodborne and zoonotic viral pathogens are responsible for substantial morbidity and mortality worldwide. These viruses can be transmitted through foods such as dairy products to humans and cause several acute and chronic diseases. This study aimed to investigate the prevalence and profile of different foodborne and zoonotic viruses in raw cow milk samples. We collected 492 raw cow milk samples from local dairy markets in Qazvin, Iran. Then, we evaluated the presence of hepatitis A virus, noroviruses, rotavirus, astrovirus, bovine leukaemia virus (BLV), and tick-borne encephalitis virus (TBEV) in samples using conventional and nested RT-PCR methods. We found that 34.95, 7.72, 25.81, 14.63, 66.86, 12.80, and 21.34% of raw milk samples were contaminated with norovirus GI, norovirus GII, hepatitis A virus, rotavirus, astrovirus, BLV and TBEV viruses, respectively. Interestingly, the samples collected from the city's south area revealed a higher prevalence of foodborne and zoonotic viruses. Astrovirus and its combination with norovirus GI were the most prevalent virus profiles. Also, the highest correlations were observed among the presence of rotavirus and hepatitis A viruses (0.36) and TBEV and norovirus GII (0.31). Considering the prevalence rate and virus profiles of different foodborne and zoonotic viruses in raw milk samples, hygiene practices and the pasteurization process are strongly suggested to be conducted throughout the cow milk production chain and in dairy industries to prevent infections with these pathogens