Euphorbia royleana Boiss Derived Silver Nanoparticles and Their Applications as a Nanotherapeutic Agent to Control Microbial and Oxidative Stress-Originated Diseases.

Nanotechnology is one of the most advance and multidisciplinary fields. Recent advances in nanoscience and nanotechnology radically changed the way we diagnose, treat, and prevent various diseases in all aspects of human life. The use of plants and their extracts is one of the most valuable methods towards rapid and single-step protocol preparation for various nanoparticles, keeping intact "the green principles" over the conventional ones and proving their dominance for medicinal importance. A facile and eco-friendly technique for synthesizing silver nanoparticles has been developed by using the latex of Euphorbia royleana as a bio-reductant for reducing Ag+ ions in an aqueous solution. Various characterization techniques were employed to validate the morphology, structure, and size of nanoparticles via UV-Vis spectroscopy, XRD, SEM, and EDS. FTIR spectroscopy validates different functional groups associated with biomolecules stabilizing/capping the silver nanoparticles, while SEM and XRD revealed spherical nanocrystals with FCC geometry. The results revealed that latex extract-mediated silver nanoparticles (LER-AgNPs) exhibited promising antibacterial activity against both gram-positive and -negative bacterial strains (Bacillus pumilus, Staphylococcus aureus, E. coli, Pseudomonas aeruginosa, and Streptococcus viridians). Both latex of E. royleana and LER-AgNPs were found to be potent in scavenging DPPH free radicals with respective EC50s and EC70s as 0.267% and 0.518% and 0.287% and 0.686%. ROSs produced in the body damage tissue and cause inflammation in oxidative stress-originated diseases. H2O2 and OH* scavenging activity increased with increasing concentrations (20-100 µg/mL) of LER-AgNPs. Significant reestablishment of ALT, AST, ALP, and bilirubin serum levels was observed in mice intoxicated with acetaminophen (PCM), revealing promising hepatoprotective efficacy of LER-AgNPs in a dose-dependent manner.

Microfluidizing Technique Application for Algerian Cymbopogon citratus (DC.) Stapf Effects Enhanced Volatile Content, Antimicrobial, and Anti-Mycotoxigenic Properties.

Medicinal plant extracts are a promising source of bioactive minor contents. The present study aimed to evaluate the distinguished volatile content of Algerian Cymbopogon citratus (DC.) Stapf before and after the microfluidization process and their related antimicrobial and anti-mycotoxigenic impacts and changes. The GC-MS apparatus was utilized for a comparative examination of Algerian lemongrass essential oil (LGEO) with its microfluidization nanoemulsion (MF-LGEO) volatile content. The MF-LGEO was characterized using Zetasizer and an electron microscope. Cytotoxicity, antibacterial, and antifungal activities were determined for the LGEO and MF-LGEO. The result reflected changes in the content of volatiles for the MF-LGEO. The microfluidizing process enhanced the presence of compounds known for their exceptional antifungal and antibacterial properties in MF-LGEO, namely, neral, geranial, and carvacrol. However, certain terpenes, such as camphor and citronellal, were absent, while decanal, not found in the raw LGEO, was detected. The droplet diameter was 20.76 ± 0.36 nm, and the polydispersity index (PDI) was 0.179 ± 0.03. In cytotoxicity studies, LGEO showed higher activity against the HepG2 cell line than MF-LGEO. Antibacterial LGEO activity against Gram-positive bacteria recorded an inhibitory zone from 41.82 ± 2.84 mm to 58.74 ± 2.64 mm, while the zone ranged from 12.71 ± 1.38 mm to 16.54 ± 1.42 mm for Gram-negative bacteria. Antibacterial activity was enhanced to be up to 71.43 ± 2.54 nm and 31.54 ± 1.01 nm for MF-LGEO impact against Gram-positive and Gram-negative pathogens. The antifungal effect was considerable, particularly against Fusarium fungi. It reached 17.56 ± 1.01 mm and 13.04 ± 1.37 mm for LGEO and MF-LGEO application of a well-diffusion assay, respectively. The MF-LGEO was more promising in reducing mycotoxin production in simulated fungal growth media due to the changes linked to essential compounds content. The reduction ratio was 54.3% and 74.57% for total aflatoxins (AFs) and ochratoxin A (OCA) contents, respectively. These results reflect the microfluidizing improvement impact regarding the LGEO antibacterial, antifungal and anti-mycotoxigenic properties.

Efficient production and characterization of melanin from Thermothelomyces hinnuleus SP1, isolated from the coal mines of Chhattisgarh, India.

In the present study, fungi were isolated and screened from barren land in south-eastern Coalfields limited (SECL) in Chhattisgarh, India. Out of 14 isolated fungi, only three fungal isolates exhibited pigmentation in screening studies. The isolated fungal strain SP1 exhibited the highest pigmentation, which was further utilized for in vivo production, purification, and characterization of melanin pigment. The physical and chemical properties of the fungal pigment showed insolubility in organic solvents and water, solubility in alkali, precipitation in acid, and decolorization with oxidizing agents. The physiochemical characterization and analytical studies of the extracted pigment using ultraviolet-visible spectroscopy and Fourier transform infrared (FTIR) confirmed it as a melanin pigment. The melanin-producing fungus SP1 was identified as Thermothelomyces hinnuleus based on 18S-rRNA sequence analysis. Furthermore, to enhance melanin production, a response surface methodology (RSM) was employed, specifically utilizing the central composite design (CCD). This approach focused on selecting efficient growth as well as progressive yield parameters such as optimal temperature (34.4°C), pH (5.0), and trace element concentration (56.24 mg). By implementing the suggested optimal conditions, the production rate of melanin increased by 62%, resulting in a yield of 28.3 mg/100 mL, which is comparatively higher than the actual yield (17.48 ± 2.19 mg/100 mL). Thus, T. hinnuleus SP1 holds great promise as a newly isolated fungal strain that could be used for the industrial production of melanin.

Response Surface Methodology (RSM) Optimization of the Physicochemical Quality Attributes of Ultraviolet (UV-C)-Treated Barhi Dates.

Barhi date fruit is one of the most important fruits that has high consumer preference and market value at the Khalal maturity stage. However, this stage is very short and the fruit is vulnerable to decay and the ripening process under improper handling and storage conditions. Thus, the purpose of this study was to evaluate the feasibility of utilizing ultraviolet (UV-C) as a method to preserve the qualitative features of Barhi dates under various storage circumstances. The core of this study was defining the best conditions for UV-C treatment of Barhi dates, which was accomplished using a response surface methodology (RSM) model with a central composite, rotating four-factors-mixed-levels design (CCRD). The impacts of independent variables [UV-C exposure time (1, 2, 3, 4 min), UV-C dose (1, 3, 5, 7 kJ/m2), storage time (1, 6, 11, 16, 21 days) and storage temperature (1, 5, 15, 25 °C)] on the moisture content (MC), total soluble solids (TSS), total color changes (E), firmness, total phenolic content (TPC), total viable count (TVC), DPPH antiradical activity, fructose and glucose were investigated. The results revealed that the optimum UV-C treatment and storage settings for keeping the quality features of the dates were the UV-C exposure period and dosage of 1 min and 2.07 kJ/m2, and the storage time and temperature of 18 days and 12.36 °C, respectively. At the optimum conditions, the values of 59.66% moisture content, 38.24% TSS, 60.24 N firmness value, 48.83 ΔE, 0.07 log CFU/g TVC, 5.29 mg GAE/g TPC, 56.32% DPPH antiradical activity, 6.87 g/100 g fructose and 14.02 g/100 g glucose were comparable predicted values demonstrating the suitability of the used RSM models. Overall, the perfect UV-C treatment and storage circumstances for extending the storability and shelf life and maintaining the quality features of Barhi dates were identified in this study.

Extending the Shelf Life of Fresh Khalal Barhi Dates via an Optimized Postharvest Ultrasonic Treatment.

The Barhi date is a high-quality date cultivar whose fruits (dates) are plucked and eaten fresh when they reach the Khalal maturity stage due to their sweetness, crispiness, and yellow skin color. After harvesting, Khalal Barhi fruits rapidly matured to the Rutab stage, where their tissues become soft and their skin color browner. This results in a decrease in their market value and customer demand. This study aims at investigating the effectiveness of the postharvest ultrasonic treatment in conserving the physical, microbial, and nutritional quality of Barhi fruits and extending their shelf life. To achieve the goals of the present work, the response surface methodology (RSM) was used for the optimization of the ultrasonic intensity (50, 100, 150, and 200 W/cm2) and application time (5, 10, 15, and 20 min) to preserve the Barhi dates high quality features for varied storage temperatures (1, 5, 15, and 25 °C) and duration (1, 6, 16, and 21 days). In RSM, a four-factors-mixed-levels central composite rotatable design (CCRD) was applied to optimize the ultrasound treatment and storage environments for better-quality physical [total soluble solids (TSS), firmness, and total color changes (ΔE)], microbial [total viable count (TVC)], nutritional [total phenolic content (TPC), DPPH antiradical activity, glucose, and fructose] features of Barhi dates. The outcomes showed that ultrasound intensity and its application time, storage temperature, and storage period influence the physical, microbial, and nutritional quality attributes in different magnitudes. The ideal settings for lessening the changes in the physical attributes, eliminating the microbial growth, and improving the nutritional quality attributes were 140 W/cm2, 5.2 min, 20.9 °C, and 21 days for ultrasound intensity, ultrasound exposure duration, storage temperature, and storage duration, respectively. In conclusion, this study proved the potential application of ultrasound for persevering the excellence aspects of Barhi dates and identified the ideal ultrasound environments for maintaining the physical, microbial, and nutritional quality features of Barhi dates during extended storing.

Physicochemical, Microbiological and Microstructural Characteristics of Sucrose-Free Probiotic-Frozen Yogurt during Storage.

Frozen yogurt is known as ice cream with some properties of yogurt. Frozen yogurts are a rich source of sucrose levels between 15% and 28% of total ingredients. Consumers suffering from lactose intolerance and metabolic syndrome are looking for sugar-free products. The current study investigates the sugar replacements by using sweeteners (stevia, sucralose and sorbitol) on physicochemical, microbiological, microstructural and sensory characteristics of probiotic-frozen yogurt. Four different treatments of probiotic-frozen yogurts were studied (control probiotic-frozen yogurt with sucrose (F1), probiotic-frozen yogurt with stevia (F2), probiotic-frozen yogurt with sucralose (F3) and probiotic-frozen yogurt with sorbitol (F4)). The chemical properties were not significantly present p > 0.05) during storage in all treatments. In the F1 treatment, sucrose value was higher (14.87%) and not detected in the F2, F3 and F4 treatments. The highest values of overrun, hardness and viscosity (p < 0.05) were detected in the F2, F3 and F3 samples, but the lowest value was detected in the F1 treatment. Total Str. thermophilus and Lb. delbrueckii ssp. bulgaricus counts were gradually decreased (p < 0.05) during storage periods. At 1 day, the Bifidobacteria counts ranged from 7.56 to 7.60 log10 CFU g−1 in all groups and gradually decreased during storage, but these bacterial counts remained viable (>6.00 log10 CFU g−1) during storage periods up to 60 d. During storage periods, the highest scores of total acceptability were detected in the F3, F4 and F2 treatments. Scanning electron microscopy (SEM) micrographs of all probiotic-frozen yogurt treatments illustrated that the microstructures showed a difference with a fine network, size pores and structure between the frozen yogurt with sweeteners (F2, F3 and F3) and control frozen yogurt (F1).

Microbiological investigation study for Apis mellifera yemenitica and Apis mellifera carnica bee venoms on selected bacterial strains.

Bees are one of the ancient and the most social insects worldwide. They are of great economic and medical importance. Bee venom (BV) has many therapeutic effects and has been used since ancient times for the treatment of many diseases. The present study aimed to evaluate and compare the antibacterial effect of BV from two different bee subspecies Apis mellifera yemenitica (A. m. yemenitica) (indigenous strain) and Apis mellifera carnica (A. m. carnica) (carniolan strain) against selected Gram-positive and Gram-negative bacteria. Experimentally, venoms were extracted using an electrical venom collector from honey bee colonies of the subspecies, A. m. yemenitica and A. m. carnica, in Hail, Saudi Arabia. Each venom was tested against selected medically important Gram-negative strains, Salmonella Typhimurium, Pseudomonas aeruginosa, and Escherichia coli, while Staphylococcus aureus was selected as Gram-positive test organism. The minimum inhibitory concentration (MIC) method was used to compare the effect of BV from the two subspecies on the growth of the selected bacterial strains. Results showed that BV from both subspecies could equally inhibit the growth of Salmonella Typhimurium, Pseudomonas aeruginosa, and Escherichia coli at an MIC of 10 mg/ml. However, S. aureus was inhibited by an MIC of 5 and 10 mg/ml of BV from A. m. carnica and A. m. yemenitica, respectively. This suggested that the BV of the carnica subspecie was more inhibitory to this Gram-positive pathogen than its counterpart produced by the yemenitica subspecies. The present study shows that bee venom has a promising antibacterial effect.

Spent Coffee Grounds Valorization as Bioactive Phenolic Source Acquired Antifungal, Anti-Mycotoxigenic, and Anti-Cytotoxic Activities.

Spent coffee grounds (SCGs), which constitute 75% of original coffee beans, represent an integral part of sustainability. Contamination by toxigenic fungi and their mycotoxins is a hazard that threatens food production. This investigation aimed to examine SCGs extract as antimycotic and anti-ochratoxigenic material. The SCGs were extracted in an eco-friendly way using isopropanol. Bioactive molecules of the extract were determined using the UPLC apparatus. The cytotoxicity on liver cancer cells (Hep-G2) showed moderate activity with selectivity compared with human healthy oral epithelial (OEC) cell lines but still lower than the positive control (Cisplatin). The antibacterial properties were examined against pathogenic strains, and the antifungal was examined against toxigenic fungi using two diffusion assays. Extract potency was investigated by two simulated models, a liquid medium and a food model. The results of the extract showed 15 phenolic acids and 8 flavonoids. Rosmarinic and syringic acids were the most abundant phenolic acids, while apigenin-7-glucoside, naringin, epicatechin, and catechin were the predominant flavonoids in the SCGs extract. The results reflected the degradation efficiency of the extract against the growth of Aspergillus strains. The SCGs recorded detoxification in liquid media for aflatoxins (AFs) and ochratoxin A (OCA). The incubation time of the extract within dough spiked with OCA was affected up to 2 h, where cooking was not affected. Therefore, SCGs in food products could be applied to reduce the mycotoxin contamination of raw materials to the acceptable regulated limits.

Boiling Technique-Based Food Processing Effects on the Bioactive and Antimicrobial Properties of Basil and Rosemary.

Rosemary (Rosmarinus officinalis) and basil (Ocimum sanctum Linn) are mostly used as herbal teas, made by steeping whole or ground herbs in boiling water. Hence, it is important to know the effect of boiling time on the bioactivity of these herbs. The effect of different boiling times (5, 10, and 15 min) on the antioxidant and antimicrobial properties, and some selected phenolic compounds of these herbs was examined in this study. Experimental results revealed that basil displayed the highest total polyphenol content (TPC), total flavonoid content (TFC), and antioxidant activity when it was boiled for 5 min, and the lowest TPC was obtained when it was boiled for 15 min. On the other hand, rosemary had the highest TPC, TFC, and antioxidant potential after being boiled for 15 min, while it had the lowest after being boiled for 5 min. There was no growth inhibition of rosemary extracts against gram-negative bacteria, whereas higher growth inhibition was observed against gram-positive bacteria. The MIC and MBC of rosemary ethanolic extract against Listeria monocytogenes were 5 and 5 mg/mL and against B. subtilis were 10 and 10 mg/mL, respectively. While MIC and MBC of methanolic extract against L. monocytogenes were 5 and 5 mg/mL and against Bacillus subtilis were and 5 and 5 mg/mL, respectively. Salicylic acid was the most abundant (324.7 mg/100 g dry weight (dw)) phenolic compound in the rosemary sample boiled for 5 min, and acetyl salicylic acid was the most abundant (122.61 mg/10 g dw) phenolic compound in the basil sample boiled for 15 min.

Detection of Campylobacter jejuni and Salmonella typhimurium in chicken using PCR for virulence factor hipO and invA genes (Saudi Arabia).

Campylobacter jejuni and Salmonella typhimurium are the leading causes of bacterial food contamination in chicken carcasses. Contamination is particularly associated with the slaughtering process. The present study isolated C. jejuni and S. typhimurim from fifty chicken carcass samples, all of which were acquired from different companies in Riyadh, Saudi Arabia. The identification of C. jejuni was performed phenotypically by using a hippurate test and genetically using a polymerase chain reaction with primers for 16S rRNA and hippurate hydrolase (hipO gene). For the dentification of S. typhimurim, a serological Widal test was carried out using serum anti-S. typhimurium antibodies. Strains were genetically detected using invA gene primers. The positive isolates for C. jejuni showed a specific molecular size of 1448 bp for 16S rRNA and 1148 bp for hipO genes. However, the positive isolates of the invA gene exhibited a specific molecular size at 244 bp using polymerase chain reaction (PCR). Comparing sequencing was performed with respect to the invA gene and the BLAST nucleotide isolates that were identified as Salmonella enterica subsp. enterica serovar typhimurium strain ST45, thereby producing a similarity of 100%. The testing identified C.jejuni for hippuricase, GenBank: Z36940.1. While many isolates of Salmonella spp. that contained the invA gene were not necessarily identified as S. typhimurim, the limiting factor for the Widal test used antiS. typhimurum antibodies. The multidrug resistance (MDR) of C. jejuni isolates in chickens was compared with the standard C. jejuni strain ATCC 22931. Similarly, S. typhimurium isolates were compared with the standard S. typhimurium strain ATCC 14028.

New Antifungal Microbial Pigment Applied to Improve Safety and Quality of Processed Meat-Products.

Minced meat is involved within numerous products, where their color attributes are affected by consumer preferences. This study was aimed to ameliorate processed meat color, using a microbial red pigment. Antibacterial, antifungal, citrinin-free, and toxicity of pigment were determined. Meatballs and burgers were manufactured using pigment at 3 mg/g of meat. Texture, color, shelf life extension, and organoleptic properties were estimated for treated meats. Results were expressed by a real antimicrobial for pigment, even via several extracting systems. The MIC and MFC of pigment were 320 µg/g and 2.75 mg/g media, respectively. Bioactive components of pigment were detected using the GC-MS and the FTIR apparatus. The bioactive carbohydrates include oligo and polysaccharides were manifested with real curves. Secretion of ochratoxin A and aflatoxins in fungal media receives pigment was decreased by up to 54% and 45%, respectively. The presence of bioactive carbohydrates may trap mycotoxin out of the recovered amounts. The manufactured products were enhanced for their color and taste with fine texture changes. The shelf life of colored-frying meat was recorded by an extension compared to the control. In conclusion, the results were recommended microbial red-pigment implementation in meats manufacturing for ameliorating recorded of color, as antimycotoxigenic, and shelf life extension.

Molecular identification of Campanulotes bidentatus Scopoli, 1763 (Phthiraptera, Philopteridae) infecting the domestic pigeon Columba livia from Saudi Arabia.

The taxonomy of the order Phthiraptera is unstable and still problematic to researchers. Most of the current taxon classifications are mainly based on morphological features. Campanulotes bidentatus belongs to the chewing lice of the Philopteridae family that mostly parasitic on birds. There is a lack of sequence data and phylogenetic analyses on the family Philopteridae. In the current study, C. bidentatus was collected from the domestic pigeon Columba livia and identified morphologically and molecularly based on the mitochondrial cytochrome c oxidase subunit 1 gene (COI). The infection rate of the Campanulotes genus was approximately 58.82% in this study. Phylogenetic analysis based on the mt COI gene was informative for members of Philopteridae and the group taxon genera formed distinct clades. Future studies were recommended using the 16s rRNA to enhance the tree topology and obtain clear differentiation between genera.

Improving the Quality and Safety of Fresh Camel Meat Contaminated with Campylobacter jejuni Using Citrox, Chitosan, and Vacuum Packaging to Extend Shelf Life.

Camel meat is one of the most consumed meats in Arab countries. The use of natural antimicrobial agents to extend the shelf life of fresh camel meat, control Campylobacter jejuni contamination, and preserve meat quality is preferred. In this study, we determined the antimicrobial effects of using 1% or 2% Citrox alone or in combination with 1% chitosan on the survival of C. jejuni in vitro and on camel meat samples during storage at 4 or 10 °C for 30 days in vacuum packaging. We determined the total viable count (TVC (cfu/g)), total volatile base nitrogen (TVB-N) content, and pH of the treated camel meat samples every three days during storage. The shelf lives of camel meat samples treated with 2% Citrox alone or in combination with 1% chitosan were longer than those of camel meat samples treated with 1% Citrox alone or in combination with 1% chitosan at both the 4 and 10 °C storage temperatures, with TVCs of <100 cfu/g after the first ten days and six days of storage at 4 and 10 °C, respectively. The addition of Citrox (1% and 2%) and 1% chitosan to camel meat samples and the application of vacuum storage were more effective than using Citrox (1% and 2%) alone and led to a reduction in C. jejuni in approximately 4.0 and 3.5 log cycles at 4 and 10 °C, respectively. The experimental results demonstrated that using a Citrox-chitosan combination improved the quality of camel meat and enhanced the long-term preservation of fresh meat for up to or more than 30 days at 4 °C.

Preventive role of probiotic bacteria against gastrointestinal diseases in mice caused by Giardia lamblia.

Giardiasis is one of the most prevalent gastrointestinal diseases in the world. It is caused by Giardia, Giardia lamblia, a common and opportunistic zoonotic parasite. The aim of our work is to find a natural and safe alternative treatment for giardiasis, specifically, to determine if probiotic bacteria (Lactobacillus acidophilus, Bifidobacterium bifidum, and Lactobacillus helveticus) can contribute to treatment, and act as preventives. Sixty weanling albino mice, Mus musculus, were divided into control and experimental, probiotic-fed groups. We determined infection intensity, and cure and prevention rates of giardiasis through ELISA (enzyme-linked immunosorbent assay) of stool samples and histopathological comparison of intestinal tissue. In experimental groups, there was a significant reduction in infection intensity (P<0.001) on days 10, 15, and 20, while cure rate reached 87.5%. The control group showed no signs of reduced infection or cure and only the group treated with probiotics prior to infection showed significant prevention rates. In the experimental groups, intestinal changes due to giardiasis appeared 7 days post-infection. However, almost all of these changes disappeared by the 25th day. Our results suggest a beneficial and significant effect of probiotics in the prevention and treatment of giardiasis in mice.

Prevalence and antibiotic resistance of Listeria monocytogenes in camel meat.

In the present study, a total of 50 raw camel meat samples were analyzed for the presence of Listeria monocytogenes. The isolates were characterized via morphological and culture analyses; identification of isolates was confirmed by polymerase chain reaction (PCR) and sequencing of the listeriolysin O gene. The API Listeria system was used for further chemical identification and verification of the strains. L. monocytogenes was identified in eight raw camel meat samples, which was the highest incidence (16%) of contamination, followed by L. seeligeri 3(6%), L. innocua and L. welshimeri 2 (2% each), and L. grayi 1 (1%). According to Basic Local Alignment Search Tool (BLAST) analysis, isolated strains that were positive for the listeriolysin O gene were >99% similar to the published database sequences for L. monocytogenes strain LM850658 (sequence ID: CP009242.1). We studied the antibiotic resistance profile of the L. monocytogenes strains with common antibiotics used to treat human listeriosis and demonstrated that almost all strains tested were susceptible to the antibiotics.

Prevalence of methicillin-resistant (mecA gene) and heat-resistant Staphylococcus aureus strains in pasteurized camel milk.

Staphylococcus aureus is a significant opportunistic pathogen in humans, dairy cattle, and camels. The presence of antibiotic-resistant and heat-resistant bacteria in camel milk has become a potential public health issue. The phenotypic and molecular characterization of methicillin-resistant staphylococcal strains recovered from pasteurized camel milk distributed in retail markets of Saudi Arabia was assessed. A total of 100 samples were collected between March and May 2017. Out of the 20 S. aureus isolates that were recovered from the pasteurized camel milk, 10 were found to be resistant to cefoxitin (30 µg) and, thus, were designated as methicillin-resistant strains. The resistance ratio of methicillin-resistant S. aureus isolates for a different class of antibiotics was determined by performing the antimicrobial susceptibility test and was estimated to be approximately 60%. Polymerase chain reaction assay was performed to amplify the methicillin-resistant gene mecA, and furthermore, nucleotide sequencing was performed to detect and verify the presence of methicillin-resistant strains. Upon sequencing the putative S. aureus methicillin-resistant strains, we obtained 96 to 100% similarity to the penicillin-binding protein 2a gene (mecA) of the S. aureus strain CS100. Moreover, the 10 methicillin-resistant S. aureus isolates were also identified to be heat resistant and were stable at temperatures up to 85°C for 60 s, with 3 isolates being heat resistant even at 90°C for 60 or 90 s. The mean decimal reduction time (D85 value) was 111 s for all the 10 isolates. No difference was observed in the profile of total protein between the 10 methicillin- and heat-resistant S. aureus isolates and the S. aureus strain ATCC 29737, which was determined by sodium dodecyl sulfate-PAGE analyses. Therefore, we could conclude that a relatively high percentage of the tested pasteurized camel milk samples were contaminated with S. aureus (20%) and methicillin- and heat-resistant S. aureus (10%).

The Beneficial Effect of Eco-Friendly Green Nanoparticles Using Garcinia mangostana Peel Extract against Pathogenicity of Listeria monocytogenes in Female BALB/c Mice.

Listeria monocytogenes is a psychrophilic bacterium, which causes widespread zoonosis in the natural environment, and mainly affects goat, sheep, and cattle herds. Recently, we predicted that it can be transmitted through food. It causes listeriosis, a severe infectious disease, which occurs with food contaminated with the pathogenic bacterium. Anti-inflammatory factors are important to treat the dangers of chronic inflammation associated with chronic diseases. Natural foodstuffs have made and are continuing to make vital contributions to the search for new antilisterial agents. The use of natural products in association with silver nanoparticles has drawn attention because of its easy, nonpathogenic, eco-friendly, and economical protocol. Hence, we aimed to biosynthesize silver nanoparticles (Ag-NPs) using Garcinia mangostana peel extract, which was found to be a good source for the synthesis of silver nanoparticles, their formation being confirmed by color change and stability in solution, and investigated the antilisterial activity of these nanoparticles in a murine model of L. monocytogenes infection. A total of 28 mice were divided into four groups-healthy control, infected, infected mice treated with green Ag-NPs biosynthesized with G. mangostana (5 mg/mL), and infected mice pretreated with Ag-NPs. From our results, oral treatment with Ag-NPs biosynthesized with G. mangostana peel extract resulted in a significant reduction in malondialdehyde (MDA), enhanced antioxidant enzyme activities, and increased the levels of the antiapoptotic protein, compared with the untreated mice. These results indicate that G. mangostana may provide therapeutic value against L. monocytogenes-induced oxidative stress and histopathological alterations, and that these effects may be related to antiapoptotic and antioxidant activities.

Molecular detection of methicillin heat-resistant Staphylococcus aureus strains in pasteurized camel milk in Saudi Arabia.

Antibiotic- and heat-resistant bacteria in camel milk is a potential public health problem. Staphylococcus aureus (S. aureus) is an opportunistic pathogen in humans, dairy cattle and camels. We characterized the phenotype and genotype of methicillin-resistant staphylococcal strains recovered from pasteurized and raw camel milk (as control) distributed in the retail markets of Saudi Arabia. Of the 100 samples assessed between March and May 2016, 20 S. aureus isolates were recovered from pasteurized milk, 10 of which were resistant to cefoxitin, and as such, were methicillin-resistant. However, raw camel milk did not contain methicillin-resistant S. aureus (MRSA). Antimicrobial susceptibility tests showed that the resistance ratio for other antibiotics was 60%. We performed a polymerase chain reaction (PCR) assay using primers for the methicillin-resistant gene mecA and nucleotide sequencing to detect and verify the methicillin-resistant strains. Basic local alignment search tool (BLAST) analysis of the gene sequences showed a 96-100% similarity between the resistant isolates and the S. aureus CS100 strain's mecA gene. Ten of the methicillin-resistant isolates were heat-resistant and were stable at temperatures up to 85°C for 60 s, and three of these were resistant at 90°C for 60 or 90 s. The mean decimal reduction time (D85-value) was 111 s for the ten isolates. Sodium dodecyl sulfate (SDS)/polyacrylamide gel electrophoresis (PAGE) showed that there was no difference in the total protein profiles for the ten methicillin heat-resistant S. aureus (MHRSA) isolates and for S. aureus ATCC 29737. In conclusion, a relatively high percentage of the tested pasteurized camel milk samples contained S. aureus (20%) and MHRSA (10%).

Heat resistance and presence of genes encoding staphylococcal enterotoxins evaluated by multiplex-PCR of Staphylococcus aureus isolated from pasteurized camel milk.

Milk pasteurization eliminates vegetative pathogenic microorganisms and reduces microorganisms associated with spoilage. Camel milk is a well-accepted, traditionally consumed food in Arab countries. The present study aimed to investigate the microflora of pasteurized camel milk sold in Riyadh City, Saudi Arabia. The heat resistance of the microflora was tested in culture medium and lab-sterilized milk, and its composition was verified by multiplex polymerase chain reaction (PCR) using specific primers. Further verification was performed by using separate specific primers. The identified strain survived heat treatment at 65, 72, 80, 85, and 90°C for 30, 15, 10, 5, and 2 min, respectively. An unanticipated result was obtained when an enterotoxin producing strain of Staphylococcus aureus showed abnormal resistance to heat treatment. The enterotoxin gene within the PCR fragment was identified as enterotoxin C by DNA sequencing. During Basic Local Alignment Search Tool (BLAST) analysis, the isolated enterotoxin C genes showed >99% similarity to published database sequences of the Staphylococcus aureus strain SAI48 staphylococcal enterotoxin C variant v4 (sec) gene. The decimal reduction value (D-value) at 90°C (D90) was determined after 10 s. This is the first time to report this abnormally heat resistant and enterotoxin-producing strain of Staphylococcus aureus. The use of ultra-high temperatures (UHTs) is preferable for reducing or killing bacteria in camel milk, especially if this problem is encountered in many camel milk factories.