Heba Roshdy

Bio: Heba Roshdy is an academic researcher from Minia University. The author has contributed to research in topics: Biology & Microbiology. The author has an hindex of 1, co-authored 1 publications receiving 34 citations.

Distribution pattern of antibiotic resistance genes in Escherichia coli isolated from colibacillosis cases in broiler farms of Egypt

Abstract: Background and Aim: Multidrug resistance (MDR) of Escherichia coli has become an increasing concern in poultry farming worldwide. However, E. coli can accumulate resistance genes through gene transfer. The most problematic resistance mechanism in E. coli is the acquisition of genes encoding broad-spectrum β-lactamases, known as extended-spectrum β-lactamases, that confer resistance to broad-spectrum cephalosporins. Plasmid-mediated quinolone resistance genes (conferring resistance to quinolones) and mcr-1 genes (conferring resistance to colistin) also contribute to antimicrobial resistance. This study aimed to investigate the prevalence of antimicrobial susceptibility and to detect β-lactamase and colistin resistance genes of E. coli isolated from broiler farms in Egypt. Materials and Methods: Samples from 938 broiler farms were bacteriologically examined for E. coli isolation. The antimicrobial resistance profile was evaluated using disk diffusion, and several resistance genes were investigated through polymerase chain reaction amplification. Results: Escherichia coli was isolated and identified from 675/938 farms (72%) from the pooled internal organs (liver, heart, lung, spleen, and yolk) of broilers. Escherichia coli isolates from the most recent 3 years (2018–2020) were serotyped into 13 serotypes; the most prevalent serotype was O125 (n = 8). The highest phenotypic antibiotic resistance profiles during this period were against ampicillin, penicillin, tetracycline, and nalidixic acid. Escherichia coli was sensitive to clinically relevant antibiotics. Twenty-eight selected isolates from the most recent 3 years (2018–2020) were found to have MDR, where the prevalence of the antibiotic resistance genes ctx, tem, and shv was 46% and that of mcr-1 was 64%. Integrons were found in 93% of the isolates. Conclusion: The study showed a high prevalence of E. coli infection in broiler farms associated with MDR, which has a high public health significance because of its zoonotic relevance. These results strengthen the application of continuous surveillance programs.

Virulence Range and New Pathological Pictures of Salmonella enteridits and Salmonella typhimurium Isolated from Ducklings in Experimental Infected Chicks

Abstract: Salmonellosis is a major global pathogen in the poultry industry and is a significant public health concern. Ducks are known to be carriers of Salmonella . Therefore, monitoring salmonellosis is the most important strategy for preventing the disease. An experimental design was planned to study the pathogenicity of two Salmonella strains. One hundred and fifty chicks were divided into three groups; group one was inoculated with the Salmonella enteritidis strain, group two was inoculated with the Salmonella typhimurium strain, and group three was UN inoculated. Symptoms, postmortem lesions and mortality rate were recorded. The chick growth performance parameters were also determined. Using ANOVA for statistical analysis, there was a significant difference in body weight, body gain, feed consumption, and feed conversion ratio between the two infected groups and the blank group (uninoculated group). In this study, the prevalence of Salmonella enteritidis was (1.73%) and Salmonella typhimurium (0.43%) in imported ducklings in Egypt. Both Salmonella strains were subjected to an antimicrobial sensitivity test. It showed that Salmonella enteritidis had a 60% antimicrobial resistance profile and Salmonella typhimurium had a 20% antimicrobial resistance profile. Furthermore, genotypic characterization was performed and the seven virulence genes(stn, avrA, sopB, ompF, invA, Mgtc, Ssaq) were found. New pathological lesions of Salmonella infection were discovered, such as skull hemorrhage at 3 days and 6 days of age, and a liver similar to a button shape in necropsied infected chicks with Salmonella typhimurium at 21 days of age. Furthermore, hemorrhagic spots were observed on the duodenum. In the presence of Salmonella , Clostridium perferingens was discovered in a bacteriological investigation of duodenal lesions samples from infected chicks. At 30 days of age, administration of acetic acid (1%) as an alternative tool for controlling Salmonella . In conclusion, salmonellosis is a risk factor for necrotic enteritis, and using acetic acid to eliminate salmonella infection is insufficient.

Molecular Heterogeneity of Salmonella Gene Isolated from Chickens, Ducks, Pigeons, and Rabbits in Egypt

Abstract: A total 250 fecal samples were collected from chicken, duck, pigeon, and rabbits for detection of Salmonella species. Salmonella species were detected in 42 out of 250 samples 16.8% and the most predominant species were Salmonella Enteritis was detected in 11 out 42 (26.2%) of total isolates and Salmonella Typhimurum was detected in 9 out 42 (21.4% ) of total isolates. All isolates were examined for antibiotics sensitivity by using disc diffusion technique against 10 different antibiotics Ampicillin , Amoxicillin-clavulanic acid , ciprofloxacin , cefotaxime , ceftriaxone , doxycycline , Norfloxacin , streptomycin , tetracycline and Gentamicin), and found that highest percentage of resistance in all species was seen with amoxicillin with clavulanic acid and the lowest percentage of resistance was seen with gentamicin, ciprofloxacine and norfloxacine. The molecular identification of virulence-associated genes in Salmonella strains which isolated from different poultry species and rabbits (n=42)revealed the detection of invA, , mgtC, bcfC, sopBand ssaG genes in 100% of the examined isolates, while avrA gene found to be in 90.5%Analyzing of nucleotide sequence of sopB virulence gene of identities between the isolated Egyptian Salmonella strains and different Salmonella strains uploaded from gene bank from different places all over the world revealed a 98.6% to 100% homology.

Controlled Self-Assembly of Sm2O3 Nanoparticles into Nanorods: Simple and Large Scale Synthesis using Bulk Sm2O3 Powders

Abstract: Monodisperse samaria nanospheres and nanorods have been synthesized from commercial bulk Sm 2 O 3 powders and various capping long-chain alkyl acids (e.g., oleic acid, myristic acid, decanoic acid). The synthesized materials were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform IR, thermogravimetric analysis, and N 2 adsorption/desorption isotherms was employed to characterize these materials. The results revealed that the synthesis of nanorods consists of two steps of growth: (i) the nanoparticles were formed at relatively low temperature (120-140 °C) by Ostwald ripening and (ii) were followed by oriented attachment of these nanoparticles at higher temperature (160-200 °C) to produce the nanorods (average size of 7 nm x 160 nm). Furthermore, the width of nanorods can be controlled by the length of capping alkyl chain agents; on the basis of the experimental results, it seems that a longer alkyl chain agent leads to thinner nanorods; however, the length of nanorods remains unchanged. For the whole process, the possible Ostwald ripening and oriented attachment mechanisms were also discussed. The XPS results for the calcined nanorods sample shows the presence of two oxidation states, Sm 3+ /Sm 2+ (it is found to be 40% Sm 2+ ), and three components by deconvolution of O Is peak indicating the defected structure. The surface chemical composition is found to be Sm 2 O 3-x (x = 1.8). We believe that this synthetic method is simple, highly reproducible, inexpensive, and applicable for large-scale production.

Modelling and optimization of syngas production by methane dry reforming over samarium oxide supported cobalt catalyst: response surface methodology and artificial neural networks approach

Abstract: The reforming of methane by carbon dioxide for the production of syngas is a potential technological route for the mitigation of greenhouse gases. However, the process is highly endothermic and often accompanied by catalyst deactivation from sintering and carbon deposition. Besides, the applications of dissimilar catalytic systems in methane dry reforming have made it difficult to obtain generalized optimum conditions for the desired products. Hence, optimization studies of any catalytic system often resulted in a unique optimum condition. The present study aimed to investigate optimum conditions of variables such as methane (CH4) partial pressure, carbon dioxide (CO2) partial pressure and reaction temperature that will maximize syngas yields from methane dry reforming over samarium oxide supported cobalt (Co/Sm2O3) catalyst. The Co/Sm2O3 catalyst was synthesized using wet-impregnation method and characterized by thermogravimetric analysis), field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray powder diffraction and nitrogen (N2) physisorption. Syngas production by methane dry reforming over the synthesized Co/Sm2O3 catalyst was investigated in a stainless steel fixed-bed reactor. The process variables (CH4 partial pressure, CO2 partial pressure and reaction temperature) for the syngas production were optimized using response surface methodology (RSM). The RSM and artificial neural networks (ANNs) were used to predict the syngas production from the experimental data. The comparative analysis between the two models showed that the ANN model has better prediction of the syngas yields compared to the RSM model as evident from the good agreement between the observed and the predicted values. At maximum desirability value of 0.97, optimum CH4 and CO2 partial pressures of 47.9 and 48.9 kPa were obtained at reaction temperature of 735 °C resulting in syngas yield of ~79.4 and 79.0% for hydrogen (H2) and carbon monoxide (CO), respectively.