Oleaginous fungi: a promising source of biofuels and nutraceuticals with enhanced lipid production strategies.

Oleaginous fungi have attracted a great deal of interest for their potency to accumulate high amounts of lipids (more than 20% of biomass dry weight) and polyunsaturated fatty acids (PUFAs), which have a variety of industrial and biological applications. Lipids of plant and animal origin are related to some restrictions and thus lead to attention towards oleaginous microorganisms as reliable substitute resources. Lipids are traditionally biosynthesized intra-cellularly and involved in the building structure of a variety of cellular compartments. In oleaginous fungi, under certain conditions of elevated carbon ratio and decreased nitrogen in the growth medium, a change in metabolic pathway occurred by switching the whole central carbon metabolism to fatty acid anabolism, which subsequently resulted in high lipid accumulation. The present review illustrates the bio-lipid structure, fatty acid classes and biosynthesis within oleaginous fungi with certain key enzymes, and the advantages of oleaginous fungi over other lipid bio-sources. Qualitative and quantitative techniques for detecting the lipid accumulation capability of oleaginous microbes including visual, and analytical (convenient and non-convenient) were debated. Factors affecting lipid production, and different approaches followed to enhance the lipid content in oleaginous yeasts and fungi, including optimization, utilization of cost-effective wastes, co-culturing, as well as metabolic and genetic engineering, were discussed. A better understanding of the oleaginous fungi regarding screening, detection, and maximization of lipid content using different strategies could help to discover new potent oleaginous isolates, exploit and recycle low-cost wastes, and improve the efficiency of bio-lipids cumulation with biotechnological significance.

Characteristics and kinetics of thermophilic actinomycetes' amylase production on agro-wastes and its application for ethanol fermentation.

Thermophilic actinomycetes are commonly found in extreme environments and can thrive and adapt to extreme conditions. These organisms exhibit substantial variation and garnered significant interest due to their remarkable enzymatic activities. This study evaluated the potential of Streptomyces griseorubens NBR14 and Nocardiopsis synnemataformans NBRM9 strains to produce thermo-stable amylase via submerged fermentation using wheat and bean straw. The Box-Behnken design was utilized to determine the optimum parameters for amylase biosynthesis. Subsequently, amylase underwent partial purification and characterization. Furthermore, the obtained hydrolysate was applied for ethanol fermentation using Saccharomyces cerevisiae. The optimal parameters for obtaining the highest amylase activity by NBR14 (7.72 U/mL) and NBRM9 (26.54 U/mL) strains were found to be 40 and 30 °C, pH values of 7, incubation time of 7 days, and substrate concentration (3 and 2 g/100 mL), respectively. The NBR14 and NBRM9 amylase were partially purified, resulting in specific activities of 251.15 and 144.84 U/mg, as well as purification factors of 3.91 and 2.69-fold, respectively. After partial purification, the amylase extracted from NBR14 and NBRM9 showed the highest activity level at pH values of 9 and 7 and temperatures of 50 and 60 °C, respectively. The findings also indicated that the maximum velocity (Vmax) for NBR14 and NBRM9 amylase were 57.80 and 59.88 U/mL, respectively, with Km constants of 1.39 and 1.479 mM. After 48 h, bioethanol was produced at concentrations of 5.95 mg/mL and 9.29 mg/mL from hydrolyzed wheat and bean straw, respectively, through fermentation with S. cerevisiae. Thermophilic actinomycetes and their α-amylase yield demonstrated promising potential for sustainable bio-ethanol production from agro-byproducts.

Antibiotic Resistance, Virulence Gene Detection, and Biofilm Formation in Aeromonas spp. Isolated from Fish and Humans in Egypt.

The genus Aeromonas is widely distributed in aquatic environments and is recognized as a potential human pathogen. Some Aeromonas species are able to cause a wide spectrum of diseases, mainly gastroenteritis, skin and soft-tissue infections, bacteremia, and sepsis. The aim of the current study was to determine the prevalence of Aeromonas spp. in raw fish markets and humans in Zagazig, Egypt; identify the factors that contribute to virulence; determine the isolates' profile of antibiotic resistance; and to elucidate the ability of Aeromonas spp. to form biofilms. The examined samples included fish tissues and organs from tilapia (Oreochromis niloticus, n = 160) and mugil (Mugil cephalus, n = 105), and human skin swabs (n = 51) and fecal samples (n = 27). Based on biochemical and PCR assays, 11 isolates (3.2%) were confirmed as Aeromonas spp. and four isolates (1.2%) were confirmed as A. hydrophila. The virulence genes including haemolysin (hyl A) and aerolysin (aer) were detected using PCR in A. hydrophila in percentages of 25% and 50%, respectively. The antimicrobial resistance of Aeromonas spp. was assessed against 14 antibiotics comprising six classes. The resistance to cefixime (81.8%) and tobramycin (45.4%) was observed. The multiple antibiotic resistance (MAR) index ranged between 0.142-0.642 with 64.2% of the isolates having MAR values equal to 0.642. Biofilm formation capacity was assessed using a microtiter plate assay, and two isolates (18.1%) were classified as biofilm producers. This study establishes a baseline for monitoring and controlling the multidrug-resistant Aeromonas spp. and especially A. hydrophila in marine foods consumed in our country to protect humans and animals.

Anti-Staphylococcal, Anti-Candida, and Free-Radical Scavenging Potential of Soil Fungal Metabolites: A Study Supported by Phenolic Characterization and Molecular Docking Analysis.

Staphylococcus and Candida are recognized as causative agents in numerous diseases, and the rise of multidrug-resistant strains emphasizes the need to explore natural sources, such as fungi, for effective antimicrobial agents. This study aims to assess the in vitro anti-staphylococcal and anti-candidal potential of ethyl acetate extracts from various soil-derived fungal isolates. The investigation includes isolating and identifying fungal strains as well as determining their antioxidative activities, characterizing their phenolic substances through HPLC analysis, and conducting in silico molecular docking assessments of the phenolics' binding affinities to the target proteins, Staphylococcus aureus tyrosyl-tRNA synthetase and Candida albicans secreted aspartic protease 2. Out of nine fungal species tested, two highly potent isolates were identified through ITS ribosomal gene sequencing: Aspergillus terreus AUMC 15447 and A. nidulans AUMC 15444. Results indicated that A. terreus AUMC 15447 and A. nidulans AUMC 15444 extracts effectively inhibited S. aureus (concentration range: 25-0.39 mg/mL), with the A. nidulans AUMC 15444 extract demonstrating significant suppression of Candida spp. (concentration range: 3.125-0.39 mg/mL). The A. terreus AUMC 15447 extract exhibited an IC50 of 0.47 mg/mL toward DPPH radical-scavenging activity. HPLC analysis of the fungal extracts, employing 18 standards, revealed varying degrees of detected phenolics in terms of their presence and quantities. Docking investigations highlighted rutin as a potent inhibitor, showing high affinity (-16.43 kcal/mol and -12.35 kcal/mol) for S. aureus tyrosyl-tRNA synthetase and C. albicans secreted aspartic protease 2, respectively. The findings suggest that fungal metabolites, particularly phenolics, hold significant promise for the development of safe medications to combat pathogenic infections.

Resveratrol biosynthesis, optimization, induction, bio-transformation and bio-degradation in mycoendophytes.

Resveratrol (3,4,5-trihydroxystilbene) is a naturally occurring polyphenolic stilbene compound produced by certain plant species in response to biotic and abiotic factors. Resveratrol has sparked a lot of interest due to its unique structure and approved therapeutic properties for the prevention and treatment of many diseases such as neurological disease, cardiovascular disease, diabetes, inflammation, cancer, and Alzheimer's disease. Over the last few decades, many studies have focused on the production of resveratrol from various natural sources and the optimization of large-scale production. Endophytic fungi isolated from various types of grapevines and Polygonum cuspidatum, the primary plant sources of resveratrol, demonstrated intriguing resveratrol-producing ability. Due to the increasing demand for resveratrol, one active area of research is the use of endophytic fungi and metabolic engineering techniques for resveratrol's large-scale production. The current review addresses an overview of endophytic fungi as a source for production, as well as biosynthesis pathways and relevant genes incorporated in resveratrol biosynthesis. Various approaches for optimizing resveratrol production from endophytic fungi, as well as their bio-transformation and bio-degradation, are explained in detail.

Cytotoxic Potential of Alternaria tenuissima AUMC14342 Mycoendophyte Extract: A Study Combined with LC-MS/MS Metabolic Profiling and Molecular Docking Simulation.

Breast, cervical, and ovarian cancers are among the most serious cancers and the main causes of mortality in females worldwide, necessitating urgent efforts to find newer sources of safe anticancer drugs. The present study aimed to evaluate the anticancer potency of mycoendophytic Alternaria tenuissima AUMC14342 ethyl acetate extract on HeLa (cervical cancer), SKOV-3 (ovarian cancer), and MCF-7 (breast adenocarcinoma) cell lines. The extract showed potent effect on MCF-7 cells with an IC50 value of 55.53 µg/mL. Cell cycle distribution analysis of treated MCF-7 cells revealed a cell cycle arrest at the S phase with a significant increase in the cell population (25.53%). When compared to control cells, no significant signs of necrotic or apoptotic cell death were observed. LC-MS/MS analysis of Alternaria tenuissima extract afforded the identification of 20 secondary metabolites, including 7-dehydrobrefeldin A, which exhibited the highest interaction score (-8.0156 kcal/mol) in molecular docking analysis against human aromatase. Regarding ADME pharmacokinetics and drug-likeness properties, 7-dehydrobrefeldin A, 4'-epialtenuene, and atransfusarin had good GIT absorption and water solubility without any violation of drug-likeness rules. These findings support the anticancer activity of bioactive metabolites derived from endophytic fungi and provide drug scaffolds and substitute sources for the future development of safe chemotherapy.

In Vitro and In Silico Antioxidant Efficiency of Bio-Potent Secondary Metabolites From Different Taxa of Black Seed-Producing Plants and Their Derived Mycoendophytes.

Oxidative stress is involved in the pathophysiology of multiple health complications, and it has become a major focus in targeted research fields. As known, black seeds are rich sources of bio-active compounds and widely used to promote human health due to their excellent medicinal and pharmaceutical properties. The present study investigated the antioxidant potency of various black seeds from plants and their derived mycoendophytes, and determined the total phenolic and flavonoid contents in different extracts, followed by characterization of major constituents by HPLC analysis. Finally, in silico docking determined their binding affinities to target myeloperoxidase enzymes. Ten dominant mycoendophytes were isolated from different black seed plants. Three isolates were then selected based on high antiradical potency and further identified by ITS ribosomal gene sequencing. Those isolated were Aspergillus niger TU 62, Chaetomium madrasense AUMC14830, and Rhizopus oryzae AUMC14823. Nigella sativa seeds and their corresponding endophyte A. niger had the highest content of phenolics in their n-butanol extracts (28.50 and 24.43 mg/g), flavonoids (15.02 and 11.45 mg/g), and antioxidant activities (90.48 and 81.48%), respectively, followed by Dodonaea viscosa and Portulaca oleracea along with their mycoendophytic R. oryzae and C. madrasense. Significant positive correlations were found between total phenolics, flavonoids, and the antioxidant activities of different tested extracts. The n-butanol extracts of both black seeds and their derived mycoendophytes showed reasonable IC50 values (0.81-1.44 mg/ml) compared to the control with significant correlations among their phytochemical contents. Overall, seventeen standard phenolics and flavonoids were used, and the compounds were detected in different degrees of existence and concentration in the examined extracts through HPLC analysis. Moreover, the investigation of the molecular simulation results of detected compounds against the myeloperoxidase enzyme revealed that, as a targeted antioxidant, rutin possessed a high affinity (-15.3184 kcal/mol) as an inhibitor. Taken together, the black seeds and their derived mycoendophytes are promising bio-prospects for the broad industrial sector of antioxidants with several valuable potential pharmaceutical and nutritional applications.

Genetic characterization of upper respiratory tract virome from nonvaccinated Egyptian cow-calf operations.

Bovine respiratory disease (BRD) is the costliest complex disease affecting the cattle industry worldwide, with significant economic losses. BRD pathogenesis involves several interactions between microorganisms, such as bacteria and viruses, and management factors. The present study aimed to characterize the nasal virome from 43 pooled nasal swab samples collected from Egyptian nonvaccinated cow-calf operations with acute BRD from January to February 2020 using metagenomic sequencing. Bovine herpesvirus-1 (BHV-1), first detection of bovine herpesvirus-5 (BHV-5), and first detection of bovine parvovirus-3 (BPV-3) were the most commonly identified in Egyptian cattle. Moreover, phylogenetic analysis of glycoprotein B revealed that the BHV-1 isolate is closely related to the Cooper reference strain (genotype 1.1), whereas the BHV-5 isolate is closely related to the reference virus GenBank NP_954920.1. In addition, the whole-genome sequence of BPV-3 showed 93.02% nucleotide identity with the reference virus GenBank AF406967.1. In this study, several DNA viruses, such as BHV-1 and first detection BHV-5, and BPV-3, were detected and may have an association with the BRD in Egyptian cattle. Therefore, further research, including investigating more samples from different locations to determine the prevalence of detected viruses and their contributions to BRD in cattle in Egypt, is needed.

Harnessing Mucor spp. for Xylanase Production: Statistical Optimization in Submerged Fermentation Using Agro-Industrial Wastes.

Xylan is the primary hemicellulosic polymer found in lignocellulosic agricultural wastes and can be degraded by xylanase. In the current research, Mucor circinelloides and M. hiemalis were tested for their ability to produce xylanase from tangerine peel by submerged fermentation. Experiments on five variables were designed with Box-Behnken design and response surface methodology. Analysis of variance was exercised, the xylanase output was demonstrated with a mathematical equation as a function of the five factors, and the quixotic states for xylanase biosynthesis was secured. In addition, xylanase was partially purified, characterized, and immobilized on calcium alginate beads. The optimum parameters for xylanase production by M. circinelloides and M. hiemalis were consisted of incubation temperature (30 and 20°C), pH value (9 and 7) incubation period (9 and 9 days), inoculum size (3 and 3 mL), and substrate concentration (3 and 3 g/100 mL), respectively. M. circinelloides and M. hiemalis demonstrated the highest xylanase activities after RSM optimization, with 42.23 and 35.88 U/mL, respectively. The influence of single, interchange, and quadratic factors on xylanase output was investigated using nonlinear regression equations with significant R 2 and p values. The partial purification of M. circinelloides and M. hiemalis xylanase yielded 1.69- and 1.97-fold purification, and 30.74 and 31.34% recovery with 292.08 and 240.15 U/mg specific activity, respectively. Partially purified xylanase from M. circinelloides and M. hiemalis demonstrated the highest activity at neutral pH and 60 and 50°C, respectively. The immobilized M. circinelloides and M. hiemalis xylanase retained 84.02 and 79.43% activity, respectively. The production of xylanase from M. circinelloides and M. hiemalis utilizing RSM is deemed profitable for the decomposition of the agro-industrial wastes.

Environmental radiation and health risk assessment in the neighborhood of a radioactive waste management facility.

The Radioactive Waste Management Center (RWMC) of the Ghana Atomic Energy Commission (GAEC) operates a licensed radioactive waste management facility known as the Centralized Radioactive Waste Management Facility (CRWMF). The Center undertakes environmental radiation monitoring in which indoor dose rates at various microenvironments, and nearby ambient environments of the facility are measured. A 2-year radiation dose data (i.e., 2017 and 2018) obtained from the monitoring exercise was used to determine whole-body exposure and cancer risk analysis for adult and child age groups. With the exception of the high dose area of the facility, observed doses in all microenvironments of the facility as well as the ambient environment were below the regulatory dose limits of 1 mSv/y and 20 mSv/y, set for radiation workers and the general public, respectively. Dose rate variation for the 2017 and 2018 datasets were not significant (p > 0.05) at 95% confidence interval (CI). Cancer risks due to exposure to alpha, neutron, and gamma radiation sources for both adult and child age groups were above the global average value of 2.90 × 10-4 reported by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Gamma sources recorded the highest cancer risk followed by neutron and alpha sources with risk values of 3.95 × 10-1 and 3.92 × 10-2; 4.06 × 10-2 and 4.03 × 10-3; and 7.96 × 10-4 and 7.91 × 10-5 for the adult and child age groups, respectively. Radium (226Ra) recorded the highest activity concentration (9.62 × 1010 Bq) with 4 quantities in the inventory while plutonium-beryllium (as alloyed source) recorded the lowest activity concentration (9.82 × 1001) with 12 quantities in the inventory.

Assessment of brominated flame retardants in a small mixed waste electronic and electrical equipment (WEEE) plastic recycling stream in the UK.

Identifying the presence of brominated flame retardants (BFRs) within individual polymer types prior to extrusion has given us a unique perspective on which polymers may be problematic in meeting European Union (EU) low persistent organic pollutant (POP) content limits (LPCLs) and the potential for mixed engineering plastics (MEP) to be used as a viable recycled product. Our findings suggest that careful management of the polymer types within the feed chips prior to extrusion could deliver extruded polymer pellets that meet the EU LPCL values for POP-BFRs (i.e. <1000 mg/kg). Within this study, three fractions of extruded polymer pellets ("light", "medium", and "heavy" MEP) were created using density separation. Each fraction was characterised for 28 legacy and novel BFRs with brominated diphenyl ether-209 (BDE-209) (68-37,000 mg/kg) and tetrabromobisphenol-A (TBBP-A) (17-120,000 mg/kg) both predominant and ubiquitous. Portable X-ray fluorescence (XRF) was utilised to measure Br in 120 individual MEP chips of various polymer types. Those chips that XRF flagged as having high Br concentrations (>2500 mg/kg) were subjected to further evaluation for BFR content via mass spectrometry analysis and the results compared with the XRF Br data. This revealed that in 22% of the 120 chips studied, XRF incorrectly identified the LPCL to be exceeded. Our data also identifies the presence of the novel BFRs decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE) in plastics derived from waste electronic and electrical equipment (WEEE). While the "light-MEP" samples contained POP-BFR concentrations below LPCLs, the "medium-MEP" and "heavy-MEP" fractions exceeded such limits. Management of the polymer chips by colour sorting resulted in significant reductions in concentrations of all BFRs in the clear polymers such that LPCL limits were not exceeded; however, concentration reductions in white polymers were insufficient to meet LPCLs.

Methicillin- and Vancomycin-Resistant Staphylococcus aureus From Humans and Ready-To-Eat Meat: Characterization of Antimicrobial Resistance and Biofilm Formation Ability.

Methicillin-resistant and vancomycin-resistant Staphylococcus aureus (MRSA and VRSA) are zoonotic life-threatening pathogens, and their presence in food raises a public health concern. Yet, scarce data are available regarding MRSA and VRSA in both ready-to-eat (RTE) meat and food handlers. This study was undertaken to determine the frequency, antimicrobial resistance, and biofilm-forming ability of MRSA and VRSA isolated from RTE meat (shawarma and burger) and humans (food handlers, and hospitalized patients) in Zagazig city, Sharkia Governorate, Egypt. We analyzed 176 samples (112 human samples: 72 from hospitalized patients and 40 from food handlers, 64 RTE meat samples: 38 from shawarma and 26 from burger). Using phenotypic, PCR-based identification of nuc gene and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), 60 coagulase-positive S. aureus (COPS) isolates were identified in the samples as follow: RTE meat (15/64, 23.4%), hospitalized patients (33/72, 45.8%) and food handlers (12/40, 30%). All the COPS isolates were mecA positive (and thus were classified as MRSA) and multidrug resistant with multiple antibiotic resistance indices ranging from 0.25 to 0.92. Overall, resistance to cefepime (96.7%), penicillin (88.3%), were common, followed by ampicillin-sulbactam (65%), ciprofloxacin (55%), nitrofurontoin (51.7%), and gentamicin (43.3%). VRSA was detected in 30.3% of COPS hospitalized patient's isolates, 26.7% of COPS RTE meat isolates and 25% of COPS food handler's isolates. VanA, vanB, or both genes were detected in 64.7, 5.9, and 29.4% of all VAN-resistant isolates, respectively. The majority of the COPS isolates (50/60, 83.3%) have biofilm formation ability and harbored icaA (76%), icaD (74%), icaC (50%), and icaB (46%) biofilm-forming genes. The bap gene was not detected in any of the isolates. The ability of MRSA and VRSA isolates to produce biofilms in addition to being resistant to antimicrobials highlight the danger posed by these potentially virulent microorganisms persisting in RTE meat, food handlers, and patients. Taken together, good hygiene practices and antimicrobial surveillance plans should be strictly implemented along the food chain to reduce the risk of colonization and dissemination of MRSA and VRSA biofilm-producing strains.

Ringworm in calves: risk factors, improved molecular diagnosis, and therapeutic efficacy of an Aloe vera gel extract.

BACKGROUND: Dermatophytosis in calves is a major public and veterinary health concern worldwide because of its zoonotic potential and associated economic losses in cattle farms. However, this condition has lacked adequate attention; thus, to develop effective control measures, we determined ringworm prevalence, risk factors, and the direct-sample nested PCR diagnostic indices compared with the conventional methods of dermatophytes identification. Moreover, the phenolic composition of an Aloe vera gel extract (AGE) and its in vitro and in vivo antidermatophytic activity were evaluated and compared with those of antifungal drugs. RESULTS: Of the 760 calves examined, 55.79% (424/760) showed ringworm lesions; 84.91% (360/424) were positive for fungal elements in direct-microscopy, and 79.72% (338/424) were positive in culture. Trichophyton verrucosum was the most frequently identified dermatophyte (90.24%). The risk of dermatophytosis was higher in 4-6-month-old vs. 1-month-old calves (60% vs. 41%), and in summer and winter compared with spring and autumn seasons (66 and 54% vs. 48%). Poor hygienic conditions, intensive breeding systems, animal raising for meat production, parasitic infestation, crossbreeding, and newly purchased animals were statistically significant risk factors for dermatophytosis. One-step PCR targeting the conserved regions of the 18S and 28S genes achieved unequivocal identification of T. verrucosum and T. mentagrophytes in hair samples. Nested-PCR exhibited an excellent performance in all tested diagnostic indices and increased the species-specific detection of dermatophytes by 20% compared with culture. Terbinafine and miconazole were the most active antifungal agents for dermatophytes. Gallic acid, caffeic acid, chlorogenic acid, cinnamic acid, aloe-Emodin, quercetin, and rutin were the major phenolic compounds of AGE, as assessed using high-performance liquid chromatography (HPLC). These compounds increased and synergized the antidermatophytic activity of AGE. The treated groups showed significantly lower clinical scores vs. the control group (P < 0.05). The calves were successfully treated with topical AGE (500 ppm), resulting in clinical and mycological cure within 14-28 days of the experiment; however, the recovery was achieved earlier in the topical miconazole 2% and AGE plus oral terbinafine groups. CONCLUSIONS: The nested PCR assay provided a rapid diagnostic tool for dermatophytosis and complemented the conventional methods for initiating targeted treatments for ringworm in calves. The recognized antidermatophytic potential of AGE is an advantageous addition to the therapeutic outcomes of commercial drugs.

Prevalence of Enterotoxigenic Staphylococcus aureus and Shiga Toxin Producing Escherichia coli in Fish in Egypt: Quality Parameters and Public Health Hazard.

This study investigated the prevalence of Staphylococcus aureus enterotoxin genes and shiga toxin -producing Escherichia coli (STEC) in fish and evaluated quality parameters of examined fish. A total of 150 fish samples belonging to 6 species (25/each species) were cultured on Baird-Parker agar and eosin methylene blue agar. Staphylococcal enterotoxin genes and virulence genes (stx1, stx2, and eaeA genes) in E. coli serotypes were determined by multiplex PCR. Aerobic plate count (APC), Enterobacteriaceae count, coliform count, and Pseudomonas count were performed. Also, levels of total volatile base nitrogen and histamine in fish were determined. The prevalence of S. aureus ranged from 4% to 36% and count from 2 to 4 log10CFU/g. The sed, sea, and seb genes in S. aureus isolates were detected with percentages of 40%, 26.6%, and 20%, respectively. The E. coli serotype O26 carried stx1, stx2, and eaeA. The APCs, Enterobacteriaceae counts, and Pseudomonas counts ranged from 5.1 to 7.2, from 2.01 to 3.9, and from 2.1 to 3.1 log10 CFU/g, respectively. The most probable number (MPN) of coliform ranged from 1.3 to 3.6 log10/g. Levels of total volatile basic nitrogen and histamine ranged from 29.2 to 12.2 and from 0.6 to 4.6 mg/100 g, respectively. Also, the value of thiobarbituric acid was highly significant (1.1 ± 0.084 mg MDA/kg) in Trachurus mediterraneus samples compared with those levels obtained from other fish species. Our findings concluded that those fish species could constitute a public health hazard as fish are reservoirs for enterotoxigenic S. aureus and Shiga toxin producing E. coli strains. This study highlighted the importance of screening of fish for enterotoxigenic S. aureus strains and STEC isolates, and also assessing the quality parameters of fish.

Molecular Screening and Genotyping of Cryptosporidium Species in Household Dogs and In-Contact Children in Egypt: Risk Factor Analysis and Zoonotic Importance.

Cryptosporidiosis is a parasitic zoonosis implicated in severe diarrhoea in pets and humans. This study aimed to determine the prevalence and genotypes of Cryptosporidium spp. in household dogs and in-contact children, and the risk factors associated with infection in children in Sharkia Province, Egypt. Fecal samples of 100 children (2-12 years old) and 50 dogs (3 months-1 year old) were randomly collected from both rural (children: n = 85, dogs: n = 40) and urban (children: n = 15, dogs: n = 10) households. Initial parasite detection was done by light microscopy, while, genotyping was based on molecular diagnostic assays. The overall prevalence of Cryptosporidium spp. infection in children was 35% using microscopy and 14% using nested polymerase chain reaction (PCR). In dogs, it was 34% using microscopy and 24% using nested PCR. Cryptosporidium spp. from children were identified as distinct genotypes, with the predominance of human genotype I (Cryptosporidium hominis) over the zoonotic genotype II (Cryptosporidium parvum). Moreover, only zoonotic genotype II (C. parvum) was identified in dog samples. The significant risk factors associated with the prevalence of Cryptosporidium infection in children were the presence of diarrheal episodes during time of survey, improper disposal of garbage, and dog feces and contact with other livestock (p ≤ 0.05). This study concluded that the existence of C. parvum in children and dogs residing the same households confirm the zoonotic transmission and its public health significance. Also, the study recommended the necessity of hygienic disposal of dog feces and preventing direct contact of dogs with other livestock.

Molecular Characterization of Cronobacter sakazakii in Egypt, Survival and Thermoresistance at Different Temperatures: A Potential Public Health Risk.

Cronobacter sakazakii has been implicated in causing serious infections in neonates due to consumption of contaminated infant powdered milk. The zoonotic potential of the organism was not clear due to scarce evidence about the role of food animals in the transmission of infection. C. sakazakii was identified in infant powdered milk (n = 100), infant stool (n = 100), and dairy animal feces (n = 100) with the percentages of 1%, 2%, and 4%, respectively. The outer membrane protein A (ompA) gene was characterized in all isolates of different origin, while gene encoding for zinc-metaloprotease (zpx) was only identified in isolates from animal feces. Genotyping of C. sakazakii isolates using enterobacterial repetitive intergenic consensus polymerase chain reaction revealed heterogenicity. The survival and thermotolerance of one potentially virulent C. sakazakii isolate of animal origin were examined at different temperatures. The isolate could survive with a stationary number at refrigeration temperature and the number increased significantly at room temperature after 24 h. The isolate showed thermoresistance when subjected to temperature range from 54°C to 64°C with D values ranged from 13.79 and 4.64 min and z value of 14.42. To the best of our knowledge, this is the first report of C. sakazakii isolation from buffalo feces in Egypt.

Possible Protective Effects of Quercetin and Sodium Gluconate Against Colon Cancer Induction by Dimethylhydrazine in Mice.

Micronutrients in food have been found to have chemopreventive effects, supporting the conclusions from epidemiologie studies that consumption of fresh fruits and vegetables reduces cancer risk. The present study was carried out to evaluate the role of querctin (Q) and sodium gluconate (GNA) supplementation separately or in combination in ameliorating promotion of colon tumor development by dimethyl-hydrazine (DMH) in mice. Histopathological observation of colons in mice treated with DMH showed goblet cell dysplasia with inflammatory cell infiltration. This pathological finding was associated with significant alteration in oxidative stress markers in colon tissues and carcinoembryonic antigen (CEA) levels in plasma. Mice co-treated with GNA and Q showed mild changes of absorptive and goblet cells and inflammatory cell infiltration in lamina properia, with improvement in oxidative stress markers. In conclusion, findings of the present study indicate significant roles for reactive oxygen species (ROS) in pathogenesis of DMH-induced colon toxicity and initiation of colon cancer. Also, they suggest that Q, GNA or the combination of both have a positive beneficial effect against DMH induced colonic cancer induction in mice.

The structure-activity relationship of ferric pyoverdine bound to its outer membrane transporter: implications for the mechanism of iron uptake.

Under iron limitation, Pseudomonas aeruginosa ATCC 15692 secretes a major siderophore, pyoverdine I (PvdI). This molecule chelates iron in the extracellular medium and shuttles it into the cells via a specific outer membrane transporter, FpvAI. PvdI consists of a fluorescent chromophore derived from 2,3-diamino-6,7-dihydroxyquinoline and containing one of the bidentate groups involved in iron chelation, linked to a peptide moiety containing the two other bidentate groups required for binding to Fe(3+). Kinetic studies, based on the fluorescence properties of this siderophore, showed that pH 8.0 was optimal for the binding of PvdI and PvdI-Fe to FpvAI. We investigated the mechanism of interaction of PvdI and PvdI-Fe with FpvAI, by synthesizing various analogues of this siderophore, determining their affinity for FpvAI in vitro and in vivo and their ability to transport iron, and interpreting the results obtained in light of the structure of FpvAI-PvdI. Our findings demonstrate that the succinyl moiety linked to the chromophore of PvdI and the first amino acid of the peptide moiety can be sterically hindered with no effect on binding or the iron uptake properties of PvdI-Fe. Moreover, the sequence and the structure of the peptide moiety of PvdI seems to be more important for the iron uptake step than for the binding of the siderophore to FpvAI. Finally, the efficiency of iron uptake and of recycling of the various PvdI analogues after iron release suggests that iron dissociates from PvdI on FpvAI or in the periplasm. All these data have serious implications for the specificity and mechanism of PvdI-mediated iron transport in P. aeruginosa.

Histological study of necrolytic acral erythema.

Described in 1996, necrolytic acral erythema remains the sole diagnostic cutaneous marker for hepatitis C virus infection. To date only eight cases have been described in literature, a fact that makes full histological description and appreciation of the disease process inadequate. Thirty necrolytic acral erythema cases were biopsied and detailed histological description was performed by three separate dermatopathologists who were blinded as to clinical presentation. Clinicopathological correlation was used to evaluate the disease progress. In the early stage, there is moderate regular acanthosis with variable spongiosis and inflammation, progressing to a picture resembling nummular eczema. In its fully evolved form, necrolytic acral erythema shows psoriasiform epidermal hyperplasia with marked papillomatosis. Associated findings include parakeratosis, focal hypergranulosis, subcorneal pustule, epidermal pallor, necrotic keratinocytes, which sometimes become confluent in the upper epidermis and/or track along the acrosyringia, vascular ectasia and papillary dermal inflammation. Late stage samples display some remaining acanthosis with variable inflammation. Pigment incontinence is seen in all stages.