Clade 2.2 H5N1 influenza viruses have caused an unusually high number of human infections, providing a unique opportunity to investigate early molecular steps associated with host adaptation. Although most work has focused on hemagglutinin (HA), the contribution of neuraminidase (NA) to these early adaptive events has remained unclear. By analyzing publicly available sequences from clade 2.2-infected patients, we identified 20 NA mutations and compared their phenotypes to 20 mutations acquired during diversification in primary human airway cells under drug-free conditions. Most patient-derived NA mutations resulted in modest reductions in sialidase activity, keeping activity within a functional range that supported improved replication in α2,6 sialylglycan (α2,6 Sia)-dominant environments, whereas excessive reduction impaired fitness. Notably, the phenotypes of culture-selected and patient-derived mutations were highly concordant, suggesting that these NA changes arose through natural selection rather than antiviral pressure. Re-analysis of patient sequences further revealed that many adaptive NA mutations co-occur with HA mutations that confer only weak, partial α2,6 Sia binding. Using reverse genetics, we found that such naturally occurring HA/NA mutation pairs acted cooperatively in a receptor-context-dependent manner to support α2,6-associated replication relative to HA-only mutants, placing these variants within a constrained "early-adaptation space" characterized by limited α2,6 engagement and moderately reduced NA activity. Together, these findings indicate that early human adaptation of clade 2.2 H5N1 involves not only HA and PB2, but also incremental, cooperative tuning of NA function. Monitoring coordinated HA-NA evolution may therefore improve risk assessment frameworks for zoonotic influenza viruses poised at early stages of human host adaptation.

ObjectivesStreptococcus pneumoniae, a human respiratory pathogen, causes diseases with severe morbidity and mortality rates worldwide. The two-component regulatory system (TCS) is an important signaling pathway that enables regulation of gene expression in response to environmental cues, thereby allowing an organism to adapt to a variety of host niches. Here we examined the contribution of pneumococcal TCS08 to bacterial colonization, the development of pneumonia, and pulmonary dysfunction.MethodsWe employed an hk08 knockout mutant (Δhk08) with a background of the TIGR4 wild-type (WT) strain to verify whether TCS08 is associated with bacterial colonization and the development of pneumonia in a murine infection model. To clarify the association of hk08 inactivation-induced phenotypic changes with their virulence, we examined pneumococcal capsule production, colony morphology, and surface-displayed protein profiles.ResultsPneumococcal TCS08 was involved in bacterial colonization in the respiratory tract. Interruption of the signaling pathway of TCS08 by hk08 inactivation impaired mouse survival and increased the bacterial burden within the respiratory tract. Furthermore, a histopathological examination revealed massive inflammatory cell infiltration, edema formation, and diffuse alveolar damage in the lung tissues of mice infected with Δhk08 versus the WT or complemented strain. Interestingly, virulence-associated phenotype changes, including capsule production, increased chain length, and surface-displayed protein profile, were observed in the Δhk08 strain.ConclusionsThe present findings indicate that TCS08 contributes to pneumococcal colonization and pulmonary dysfunction by assisting adaptation to the respiratory tract milieu, leading to the development of pneumonia.

Emergence of antimicrobial resistance (AMR) among fish bacterial pathogens is one of the major global public threats. Attempts are being made to develop novel alternatives as a promising approach to combat multidrug resistance disease-causing bacteria. Natural antimicrobials such as essential oils (EOs) are a potential unique strategy to treat bacterial infections with a reduced risk of resistance developing. This study aimed to evaluate the antimicrobial activity of some essential oils (EOs) namely, cinnamon (Cinnamomum zeylanicum), clove (Syzygium aromaticum), Peppermint (Mentha piperita) , and black cumin (Nigella sativa) against some fish pathogens implicated with aquaculture disease outbreaks like Aeromonas hydrophilia, Pseudomonas fluorescence, Photobacterium damselae and Streptococcus agalactiae using agar well diffusion assay. We found significant differences on the antibacterial activity depending on the type of essential oils and bacterial strain. Among all the tested EOs, cinnamon essential oil (CEO) was shown to be the most effective with minimum bactericidal concentration (MBC) ranged from 0.0156-0.125 ml/ml. As a result, it was selected for our in vivo investigations. We next aimed to investigate the effects of dietary CEO on growth performance, disease resistance and immune response of fish. A total of 150 striped catfish (Pangasianodon hypophthalmus) were fed with different levels of CEO (0, 1.50, 2.0, 2.50, and 3.0 mL/kg diets) (assigned as control, Diet 1, Diet 2, Diet 3 and Diet 4) for 60 days. Compared to control, fish fed with graded levels of dietary CEO showed significant (P < 0.05) increase in final body weight, weight gain %, and specific growth rate particularly at fish group fed diet 3. Of interest, there were no significant differences (P > 0.05) in feed conversion ratio and survival rates among control and CEO-supplemented groups. Moreover, we found significant (P < 0.05) increases in plasma lysozyme activity and total IgM levels in a dose dependent manner with dietary CEO supplementation. After feeding trials, we investigated their potential to defend striped catfish against A. hydrophila challenge. Fish fed control diet had the highest mortality rates; in contrast, fish fed diets supplemented with CEO had higher levels of resistance to the bacterial infection, with the lowest mortality rates in the fish group fed diet 3. Overall, these findings showed that EOs exhibit a great potential to be used as antimicrobial agents against fish pathogens. Moreover, dietary administration of CEO, particularly at 2.5 ml/kg feed, can be regarded as a promising component for improving growth, immunological responses and potential alternatives to conventional antimicrobials for control of microbial infections in fish.

Abstract The antibacterial activity of zinc oxide nanoparticles (ZnO NPs) has received significant attention worldwide due to the emergence of multidrug-resistant microorganisms. Shiga toxin-producing Escherichia coli is a major foodborne pathogen that causes gastroenteritis that may be complicated by hemorrhagic colitis or hemolytic uremic syndrome. Therefore, this study aimed to evaluate the antimicrobial effect of ZnO NPs against E. coli O26 and its Shiga toxin type 2 (Stx2). Multidrug resistance phenotype was observed in E. coli O26, with co-resistance to several unrelated families of antimicrobial agents. Different concentrations of ZnO NPs nanoparticles (20 nm) were tested against different cell densities of E. coli O26 (108, 106 and 105 CFU/ml). The minimum inhibitory concentration (MIC) value was 1 mg/ml. Minimum bactericidal concentration (MBC) was 1.5 mg/ml, 2.5 mg/ml and 3 mg/ml, respectively, depending on ZnO NPs concentrations and bacterial cell density. Results showed a significant (P≤0.05) decrease in Stx2 level in a response to ZnO NPs treatment. As detected by quantitative real-time PCR, ZnO NPs down-regulated the expression of the Stx2 gene (P≤0.05). Moreover, various concentrations of ZnO NPs considerably reduced the total protein content in E. coli O26. There was a significant reduction in protein expression with increased ZnO NPs concentration compared to the non-treated control. Scanning electron micrographs (SEM) of the treated bacteria showed severe disruptive effects on E. coli O26 with increasing ZnO NPs concentration. The results revealed a strong correlation between the antibacterial effect and ZnO NPs concentrations. ZnO NPs exert their antibacterial activities through various mechanisms and could be used as a potent antibacterial agent against E. coli O26.

Infectious bursal disease is an acute highly contagious disease affecting young chickens causing increased mortality and severe immunosuppression.Therefore, additional approaches together with vaccination are required to overcome its endemicity.Here, ten males Bosch rabbit of 3 months old (2-3 kg/ weight) were used for production of IgG against IBDV.The produced rabbit IgGs were titrated using Passive Hemagglutination (PHA) and evaluated experimentally for their protection against vvIBDV challenge in commercial broiler chickens.Daily observation of clinical signs, mortalities and postmortem changes were recorded till 10 days post-infection.The spleen and bursa were collected for histopathological examination and cloacal swabs were collected to evaluate viral shedding by real time-PCR.The results indicated the effectiveness of the anti-vvIBDV IgG in protection against vvIBDV and in the reduction of viral shedding.These results suggested that IgG produced in rabbits may help in IBDV control and decrease its commercial economic losses.

Bacterial diseases are one of the most challenging issues facing aquaculture sector. Pseudomonas aeruginosa (P. aeruginosa) has been regarded as one of the most significant threats to the fishing industry, which also affects public health. We aimed to elucidate the occurrence and antibiogram profile of P. aeruginosa recovered from Nile tilapia (Oreochromis niloticus) and smoked herring (Clupea harengus) with emphasis on their antibiotic resistance genes (blaTEM, blaSHV, blaOXA-1 and ampC) and virulence determinant genes (oprL and toxA). A total of 150 fish samples (110 diseased Nile tilapia, and 40 smoked herring) were collected randomly from retails of Gharbia Governorate, Egypt. The retrieved isolates were phenotypically characterized using standard methods of culturing and biochemical tests. Then, verified using molecular assay, 16S rRNA gene was detected in 100% of the tested isolates. The overall incidence of P. aeruginosa was 33.3%, out of which 45% from smoked herring and 29% from Nile Tilapia. The occurrence of P. aeruginosa in various infected organs of O. niloticus showed that the gills were the most obviously infected organ followed by kidney, liver, and spleen, respectively. A significant difference (P< 0.05) was noticed in the distribution of P. aeruginosa among O. niloticus internal organs. The phenotypic susceptibility to nine commonly used antimicrobial agents was detected using disc diffusion assay. The tested strains were extremely susceptible to ciprofloxacin, amikacin, and imipenem, whereas exhibited remarkable resistance to oxacillin, cefpodoxime, amoxicillin with clavulanic acid, ceftriaxone, and nalidixic acid. Interestingly, 100% of P. aeruginosa isolates were multiple antimicrobial resistant (MAR). Three resistance phenotypes profiles were identified with MAR index ranged from 0.4-0.5. Screening for antibiotic resistance genes revealed a diversity of β-lactamases in P. aeruginosa isolates, with blaTEM being the most dominant gene (100%), followed by blaSHV, blaOXA-1 and ampC with a total prevalence of 66.6% to all of them. The identified antimicrobial resistance phenotypes and genotypes were found to be significantly correlated. Subsequently, the distribution of virulence determinants in these strains was identified. These isolates had 100% prevalence of oprL and toxA virulence genes. In conclusion, the emergence of MDR P. aeruginosa in fish particularly ESBL and AmpC beta-lactamases producers could pose a potential health hazard to consumers. Thus, antimicrobial susceptibility must be continuously monitored to assess potential risks to human health. Ciprofloxacin, amikacin, and imipenem were the most efficient antibiotics for treatment of the identified P. aeruginosa, ESBL and AmpC beta-lactamases producers.

In this study, the bacterium Sphingomonas sphingomonas 503 was isolated from water samples.One ml of water sample was cultured on MH broth for enriching bacterial growth then subcultured on MH agar plates till obtaining pure separate deep yellow-pigmented colonies (after four subcultures).The bacteria were cultured on blood agar and chromogenic agar, giving white hemolytic and green colonies, respectively.The bacterial isolates showed Gram-negative, polymorphic rods without special arrangement.The bacteria was identified by the VITEK Compaq® 2 system as Sphingomonas paucimobilis 503 and assayed for antibiotic susceptibility using Ampicillin, Ampicillin/sulbactam, Piperacillin/tazobactam, Cefazolin, Ceftazidime, Ceftriaxone, Cefepime, Meropenem, Amikacin, Gentamycin, Tobramycin, Ciprofloxacin, Levofloxacin, Nitrofurantoin, Trimethoprim/Sulfamethazole.This bacterium was sensitive to all tested antibiotics except Ceftazidime, which showed the highest MIC ≥ 64, while the lowest MIC was that of Levofloxacin ≤0.12and Ciprofloxacin ≤ 0.25.

Staphylococcus aureus (S. aureus) is a Gram-positive bacteria considered one of the leading causes of community and hospital-acquired illnesses or public health concerns. Antibiotic resistance in this microorganism is one of the greatest issues in global health care. The use of metal nanoparticles and their oxides is one of the potential approaches to combating bacteria resistance to antibiotics. The antibacterial properties of ZnO NPs against enterotoxigenic S. aureus were studied. ZnO NPs were tested in vitro by agar diffusion test. They resulted in 26 and 22 mm zones of inhibition for a size of 20 nm and a concentration of 20 mM against 105 and 107 CFU/mL S. aureus, respectively. The MIC of ZnO NPs of various sizes, 20 and 50 nm, with 105 CFU/mL was 2.5 and 5 mM, respectively. MIC with 107 CFU/mL was five mM for 20 and 50 nm ZnO NPs. Further, the highest growth reduction percentage, 98.99% in the counts of S. aureus was achieved by ZnO NPs of size 20 nm and concentration of 10 mM. Moreover, the obtained ELISA results indicated a significantly decreased concentration of enterotoxin A with all concentrations and sizes of ZnO NPs. PCR analysis showed a significant effect on sea gene in response to ZnO NPs treatments leading to loss of the gene, unlike the unaffected nuc gene. Moreover, morphological changes and cell shape distortion were detected by scanning electron microscope for bacterial cells treated with ZnO NPs.

Bacterial infections cause severe losses in poultry farming. Clostridium perfringens and Escherichia- coli are two major pathogenic bacteria readily found in the broiler environment. They cause high- morbidity and mortality in poultry worldwide as a result of necrotic enteritis and colibacillosis, respectively. Furthermore, Staphylococcus aureus is an important cause of omphalitis, bumble foot and gangrenous dermatitis. Antimicrobial resistance is one of the most serious global public health threats that necessitates alternative strategies. Probiotics have been emerging as a safe and effective alternative to antibiotics. Lactobacillus being the most commonly used probiotic. Therefore, here the antimicrobial activity of Lactobacillus acidophilus against some pathogens namely Clostridium perfringens, Staphylococcus aureus and Escherichia coli were tested. The antibacterial effect of L. acidophilus was investigated by time kill assay, agar well diffusion and agar spot test. The obtained results showed that L. acidophilus had strong antimicrobial activity against the three bacterial pathogens. Moreover, L. acidophilus exhibited a strong autoaggregating phenotype and marked coaggregation with Cl. perfringens. In addition, inhibition of gas production from Cl. perfringens by L. acidophilus was evaluated. Alpha-toxin has been implicated as one of the major virulence factors of Cl. perfringens inducing avian necrotic enteritis. To investigate whether alpha toxin have adverse effects on L. acidophilus, viability assay proved that L. acidophilus was not remarkably affected by incubation with different concentrations of alpha toxin and different incubation time. Our results suggest that L. acidophilus exhibits strong inhibitory effects against Cl. perfringens, E. coli and S. aureus, and has strong co-aggregation abilities

This study was conducted to examine cement kiln dust (CKD) efficiency for wastewater treatment. We analyzed the physicochemical characteristics of wastewater before and after treatment and then we determined its removal potential. The optimum factors of the treatment process were determined using a jar test technique. It was pH (8.1), dosage (1.9 g) and grain size (0.1 mm) with contact time of 30 min at 150 rpm. CKD pollutant removal efficiency reached 85.3, 81.6, 97.1, 86.8, 36, 74, 61.2, and 94.6% for BOD, COD, TP, TN, TDS, salinity, conductivity and turbidity, respectively, with an increase in the concentration of DO of 84%. On the other hand, removal percent of heavy metals achieved were 88.4, 90.9, 88.5, 97.2, 94.2, 70, and 79.9% for Pb, Cd, Zn, Fe, Co, Ni, and Cu, respectively. These results were compared with alum removal potential of wastewater treatment for confirmation. Alum pollutant removal efficiency reached 86.6, 79.6, 96.6, 59.9, 39.7, 65, 59 and 95.2% for BOD, COD, TP, TN, TDS, salinity, conductivity and turbidity, respectively, with an increase in the concentration of DO of 85.3%. On the other hand, removal percent of heavy metals achieved were 82.1, 90.6, 89.1, 96.8, 93.2, 72.8, and 84.1% for Pb, Cd, Zn, Fe, Co, Ni, and Cu, respectively. The methodology carried out in this study indicated that CKD can be used as a good environmental alternative coagulant for low to moderate wasted water as it achieved removal percent similar to that achieved by the common coagulant alum.

Avian H9N2 influenza viruses in East Asia are genetically diversified and multiple genotypes (A-W) have been established in poultry. Genotype S strains are currently the most prevalent strains, have caused many human infections and pose a public health threat. In this study, human adaptation mutations in the PB2 polymerase in genotype S strains were identified by database screening. Several PB2 double mutations were identified that acted cooperatively to produce higher genotype S virus polymerase activity and replication in human cells than in avian cells and to increase viral growth and virulence in mice. These mutations were chronologically and phylogenetically clustered in a new group within genotype S viruses. Most of the relevant human virus isolates carry the PB2-A588V mutation together with another PB2 mutation (i.e. K526R, E627V or E627K), indicating a host adaptation advantage for these double mutations. The prevalence of PB2 double mutations in human H9N2 virus isolates has also been found in genetically related human H7N9 and H10N8 viruses. These results suggested that PB2 double mutations in viruses in the field acted cooperatively to increase human adaptation of the currently prevalent H9N2 genotype S strains. This may have contributed to the recent surge of H9N2 infections and may be applicable to the human adaptation of several other avian influenza viruses. Our study provides a better understanding of the human adaptation pathways of genetically related H9N2, H7N9 and H10N8 viruses in nature.

Avian Pathogenic Escherichia coli (APEC) infections concern economically the poultry industry inducing different disease syndromes leading to high mortality and condemnations. There is tremendous diversity in O serotypes within even a limited geographic region. It has been reported previously on a live E. coli vaccine's ability to protect against different O78 APEC in commercial broilers. Due to the diversity of APEC serotypes in the field, this study was conducted to measure that live attenuated E. coli (Poulvac® E. coli) vaccine's ability to cross-protect against three of the heterologous (non-O78) APEC isolates; O27, O8, and O115 compared to cefotaxime treatment through experimental infections in commercial broiler chickens. While the vaccination gave significant protection against the three serotypes tested there were at least subtle differences between them based on clinical signs, post-mortem lesions and mortality rate for 14 days post-challenge (dpc), E. coli re-isolation and histopathological examination at 4, 10 and 14 dpc., final body weight and feed conversion ratio at 35 days of age.

Adaptive mutations and/or reassortments in avian influenza virus polymerase subunits PA, PB1, and PB2 are one of the major factors enabling the virus to overcome the species barrier to infect humans. The majority of human adaptation polymerase mutations have been identified in PB2; fewer adaptation mutations have been characterized in PA and PB1. Clade 2.2.1 avian influenza viruses (H5N1) are unique to Egypt and generally carry the human adaptation PB2-E627K substitution during their dissemination in nature. In this study, we identified other human adaptation polymerase mutations by analyzing phylogeny-associated PA mutations that H5N1 clade 2.2.1 viruses have accumulated during their evolution in the field. This analysis identified several PA mutations that produced increased replication by contemporary clade 2.2.1.2 viruses in vitro in human cells and in vivo in mice compared to ancestral clade 2.2.1 viruses. The PA mutations acted cooperatively to increase viral polymerase activity and replication in both avian and human cells, with the effect being more prominent in human cells at 33°C than at 37°C. These results indicated that PA mutations have a role in establishing contemporary clade 2.2.1.2 virus infections in poultry and in adaptation to infect mammals. Our study provided data on the mechanism for PA mutations to accumulate during avian influenza virus evolution and extend the viral host range.IMPORTANCE Clade 2.2.1 avian influenza viruses (H5N1) are unique to Egypt and have caused the highest number of human H5N1 influenza cases worldwide, presenting a serious global public health threat. These viruses may have the greatest evolutionary potential for adaptation from avian hosts to human hosts. Using a comprehensive phylogenetic approach, we identified several novel clade 2.2.1 virus polymerase mutations that increased viral replication in vitro in human cells and in vivo in mice. These mutations were in the polymerase PA subunit and acted cooperatively with the E627K mutation in the PB2 polymerase subunit to provide higher replication in contemporary clade 2.2.1.2 viruses than in ancestral clade 2.2.1 viruses. These data indicated that ongoing clade 2.2.1 dissemination in the field has driven PA mutations to modify viral replication to enable host range expansion, with a higher public health risk for humans.

Some avian influenza (AI) viruses have a deletion of up to 20 to 30 amino acids in their neuraminidase (NA) stalk. This has been associated with changes in virus replication and host range. Currently prevalent H9N2 AI viruses have only a 2or 3-amino-acid deletion, and such deletions were detected in G1 and Y280 lineage viruses, respectively. The effect of an NA deletion on the H9N2 phenotype has not been fully elucidated. In this study, we isolated G1 mutants that carried an 8-amino-acid deletion in their NA stalk. To systematically analyze the effect of NA stalk length and concomitant (de)glycosylation on G1 replication and host range, we generated G1 viruses that had various NA stalk lengths and that were either glycosylated or not glycosylated. The stalk length was correlated with NA sialidase activity, using low-molecular-weight substrates, and with virus elution efficacy from erythrocytes. G1 virus replication in avian cells and eggs was positively correlated with the NA stalk length but was negatively correlated in human cells and mice. NA stalk length modulated G1 virus entry into host cells, with shorter stalks enabling more efficient G1 entry into human cells. However, with a hemagglutinin (HA) with a higher a2,6-linked sialylglycan affinity, the effect of NA stalk length on G1 virus infection was reversed, with shorter NA stalks reducing virus entry into human cells. These results indicate that a balance between HA binding affinity and NA sialidase activity, modulated by NA stalk length, is required for optimal G1 virus entry into human airway cells. IMPORTANCE H9N2 avian influenza (AI) virus, one of the most prevalent AI viruses, has caused repeated poultry and human infections, posing a huge public health risk. The H9N2 virus has diversified into multiple lineages, with the G1 lineage being the most prevalent worldwide. In this study, we isolated G1 variants carrying an 8-amino-acid deletion in their NA stalk, which is, to our knowledge, the longest deletion found in H9N2 viruses in the field. The NA stalk length was found to modulate G1 virus entry into host cells, with the effects being species specific and dependent on the corresponding HA binding affinity. Our results suggest that, in nature, H9N2 G1 viruses balance their HA and NA functions by the NA stalk length, leading to the possible association of host range and virulence in poultry and mammals during the evolution of G1 lineage viruses.

This study was conducted for isolation and identification of Streptococcus iniae from Oreochromis niloticusfish farms using traditional and molecular PCR techniques. Forty-seven isolates of Streptococcus were recovered from 232 fish samples from successive 4 seasons during 2015. Summer showed the highest prevalence with 34.9%. S. iniae was identified as the causative agent for streptococcosis in 3 seasons by PCR using S. iniae specific-16S rRNA primers. Experimental infection was performed to determine the pathogenicity of S. iniae for O.nloticus and the best antibiotics to be used for treatment of streptococcosis. S. iniae caused 70% mortalities in experimentally infected fish. Several histopathological alterations were observed in the liver, spleen, kidney and gills of the infected fish. The most effective antibiotics for treatment were Ampicillin with no mortalities, followed by Penicillin and Tetracycline with 10% mortality for both.

THIS study aimed to investigate the most effective treatment technique for the wastewater generated from food processing factory to be reused according to Egyptian standards. The discharged wastewater was highly polluted by organic load. As presented by average chemical oxygen demands (COD) value of 4950 mgO(2)L(-1). Four treatment scenarios were investigated to select the most appropriate module for reuse of wastewater. Chemical coagulation-flocculation followed by adsorption onto granular activated carbon (GAC) achieved 84% of COD removal. The Fenton oxidation followed by adsorption onto GAC achieved COD removal of 91%.The Aerobic treatment followed by adsorption onto GAC reached to 92% COD removals. The quality of treated effluent using the previous modules was far less than the required values stated in Egyptian code for reuse in agriculture (Grade A). Integration of the studied different treatment modules in the form of sedimentation then chemical coagulation-flocculation followed by aerobic treatment then sandwich filter using adsorption/filtration (Sand/GAC/Sand) produced water quality complying with the Egyptian code for reuse in agriculture with COD removal of 99.8%.

The present study was conducted to evaluate the prevalence of C. Perfringens in broiler chickens in El Behiera, Alexandria and Matrouh governorates. Samples (n= 400) were collected from intestine (n=200; 100 apparently healthy and 100 diseased birds), feed (n=100) and litter (n=100). The prevalence of C. Perfringens was 57, 88, 52 and 60% in apparently healthy birds, diseased birds, feed and litter, respectively. Isolates were confirmed by Matrix-assisted laser desorption/ionization (MALDI). Antimicrobial sensitivity of isolated C. perfringens showed sensitivity to Cefotaxime, Chloramphenicol, Bacitracin, Norfloxacin, Ciprofloxacin, Doxycycline, Amoxicillin + Clavulanic acid and Clindamycin. The isolates were resistant to Gentamycin, Erythromycin, Amoxicillin, Ampicillin and Neomycin. Eighteen C. perfringens isolates from different samples were examined by PCR for Alpha, Beta, Epsilon and Iota genes. The alpha gene was detected in 17 of the examined isolates. Only five isolates were positive for the Tpel toxin gene. Further, the Net-B toxin gene was detected in one isolate. Environmental factors (feed & litter) in poultry farms represent an important source of C. perfringens infection (toxigenic types) and apparently healthy birds may act as a major source of infection. Alpha toxin was the predominant major toxin in our investigation and the Tpel gene was detected more than the Net-B gene.

Milk is a substantial source of nutrients needed by all humans across lifespan development. Given its nutritional composition, milk is considered a vehicle for various microbes including beneficial and pathogenic bacteria. In this study, 270 milk samples comprising raw cow and buffalo milk and pasteurized milk with different shelf-life durations were tested along with pasteurized organic milk for the presence of Staphylococcus aureus and Escherichia coli. Collectively, 21 E. coli and 14 S. aureus isolates were cultivated and identified from total milk samples. All E. coli and S. aureus isolates exhibited resistance to erythromycin and penicillin, respectively. Serogroups O26, O128, and O111 were the most frequently identified amongst E. coli isolates, whereas staphylococcal enterotoxins (SEs) were inconsistently produced across S. aureus isolates. The molecular profile showed clustering of 6 isolates of E. coli by harboring stx1, stx2, eaeA genes, and 5 isolates of S. aureus by mecA gene. Findings revealed the bacteriological quality of popularly consumed milk in Egypt, including raw and pasteurized milk with preference to pasteurized organic milk and 7-day shelf life (7DSL) pasteurized milk. However, raw milk and 3MSL pasteurized milk were the major sources of E. coli and S. aureus, posing a serious public health issue. Key words: Raw milk, pasteurization, Staphylococcus aureus and Escherichia coli, shelf-life.

A COMPOSITE Hydrogel of carboxymethyl cellulose/acrylamide/powdered activated carbon (CMC/AM/PAC) were prepared by (sic)-irradiation and characterized by spectroscopic and electron microscopic techniques. The effect of monomer concentration on the percentage of composite hydrogel formation was studied. The composite hydrogel content reached the maximum gel percentage at radiation dose of 25 kGy, the formed composite was used for removal of natural organic matter (NOM) from raw water. The (NOM) uptake increased by increasing the pH of the medium until reached a maximum value at (pH5). The increase in contact time led to increase of the amount of (NOM) adsorbed until the equilibrium was reached within for (CMC/AM/PAC) composite Hydrogel. The optimum adsorbent dose of 0.4 g/L for (CMC/AM/PAC) composite Hydrogel. The potential applications of the newly sorbents is extraction (NOM) from real samples from raw water from Nile Rosetta branch. Also, Trihalomehanes (THM>s) produced as disinfection by-products (DBPs) formed from the reaction between chlorine and (NOM) were removed using the composite Hydrogel by a 1 minute rapid mix stage at 150 rpm followed by a 20 min flocculation stage at 40 rpm and a 30 min settlement period. Also, it is noticed that the prepared composite Hydrogel has the ability to remove NOM up to 66.8%.

Avian influenza virus H9N2 has been endemic in birds in the Middle East, in particular in Egypt with multiple cases of human infections since 1998. Despite concerns about the pandemic threat posed by H9N2, little is known about the biological properties of H9N2 in this epicentre of infection. Here, we investigated the evolutionary dynamics of H9N2 in the Middle East and identified phylogeny-associated PB2 mutations that acted cooperatively to increase H9N2 replication/transcription in human cells. The accumulation of PB2 mutations also correlated with an increase in H9N2 virus growth in the upper and lower airways of mice and in virulence. These mutations clustered on a solvent-exposed region in the PB2-627 domain in proximity to potential interfaces with host factors. These PB2 mutations have been found at high prevalence during evolution of H9N2 in the field, indicating that they have provided a selective advantage for viral adaptation to infect poultry. Therefore, continuous prevalence of H9N2 virus in the Middle East has generated a far more fit or optimized replication phenotype, leading to an expanded viral host range, including to mammals, which may pose public health risks beyond the current outbreaks.