MARWA ALI MOHAMED TAMMAM

08/10/2021

https://gutpathogens.biomedcentral.com/articles/10.1186/s13099-021-00454-0

MARWA ALI MOHAMED TAMMAM

Amr Ali Hemeda , Amal Ahmed Mohamed, , Ramy Karam Aziz, Mohamed Salaheldin Abdel-Hakeem

01/04/2021

Complications of hepatitis C virus (HCV) chronic infection cause ~400,000 deaths worldwide annually. One complication, liver fibrosis, is influenced by host genetic factors. Genes influencing fibrosis include immune, metabolic, oxidative stress, and viral entry genes, such as interleukin 10 (IL-10), microsomal triglyceride-transfer protein (MTP), superoxide dismutase-2 (SOD2), and apolipoprotein E (ApoE)-encoding genes, respectively. Thus, correlating variations in these genes with HCV-induced fibrosis represents an attractive biomarker for the prognosis of fibrosis severity in chronically infected patients. Here, we aimed to test whether polymorphisms in IL-10, MTP, SOD2, and ApoE genes correlated with severity of fibrosis induced by HCV genotype 4 (HCV-gt4) in a cohort of chronically infected Egyptian patients. Our results demonstrate a significant association between severity of fibrosis and specific SNPs in IL-10, SOD2, and ApoE encoding genes. Haplotype-combination analysis for IL10, MTTP, SOD2, and APOE genes showed statistically significant associations between specific haplotype-combinations and fibrosis severity. Identifying biomarkers correlating with severity of HCV-gt4-induced fibrosis would significantly impact precision prophylaxis and treatment of patients at risk.

MARWA ALI MOHAMED TAMMAM

Amal Ahmed Mohamed, Amr Ali Hemeda, Ramy Karam Aziz, Mohamed Salaheldin Abdel-Hakeem

01/10/2020

Background Viral hepatitis is the seventh leading cause of mortality globally, and half of this mortality is attributed to Hepatitis C virus (HCV). Egypt has the highest HCV prevalence worldwide, with an estimated 14.7% of the population being HCV positive. HCV infection is the primary cause of liver fibrosis, cirrhosis and hepatocellular carcinoma. Liver fibrosis varies in severity during chronic HCV infection, and 10-20% of chronic hepatitis C (CHC) patients with severe fibrosis develop cirrhosis. The goal of this work was to asses clinico-demographic predictors of severity of HCV-induced fibrosis in a cohort of Egyptian patients. Results: A cohort of Egyptian patients with chronic HCV genotype 4a infection showed significant association between severe fibrosis stages and obesity, represented by a higher body mass index (BMI), low albumin level, high alpha feto-protein (AFP) level, low thyroid stimulating hormones (TSH) level and high alkaline phosphatase (ALP) level. Multivariate analysis delineated BMI, TSH, and ALP as independent significant variables that could predict the risk of fibrosis severity in HCV infections. Conclusion: This study argues in favor of using the biomarker profile of CHC patients infected with HCV genotype 4a to identify patients at higher risk of developing severe fibrosis, which is a necessary first step towards precision medicine via patient stratification.

MARWA ALI MOHAMED TAMMAM

01/06/2019

Background: Quorum quenching, the interference of a Quorum sensing (QS) system that contributes to the pathogenesis through triggering the production of various virulence determinants, is among the newly suggested antivirulence strategies. Purpose: This study aimed at screening of N-Acyl homoserine lactonase activity from local bacterial isolate, and investigating its effect on Pseudomonas aeruginosa (P. aeruginosa) virulence and biofilm formation. Materials and methods: Soil bacteria were screened for aiiA gene coding for lactonase enzyme by Polymerase Chain reaction and sequencing of aiiA gene homologs. Lactonase activity and spectrum were assessed in the cell-free lysate by well diffusion assay using Agrobacterium tumafaciens KYC55. A bacterial isolate showing the highest N-acyl-homoserine lactones degradation percentage was identified by gene amplification and sequencing of the 16S rRNA gene and its aiiA gene homolog. High performance liquid chromatography was used to confirm N-acyl-homoserine lactone degradation. The effect of cell-free lysate on the biofilm formation ability and cytotoxicity of P. aeruginosa PAO1 and P. aeruginosa clinical isolates from different clinical sources were assessed by static microtiter plate and viability assay, respectively Results: Lactonase gene and activity were identified in three Bacillus spp. isolates. They showed broad catalytic activities against tested N-acyl-homoserine lactones. However, The lactonase activity in the cell- free lysate of isolate 30b showed the highest significant degradation percentage on all tested signals; N-butanoyl-L-homoserine lactone (71%), N-hexanoyl-l-homoserine lactone (100%), N-decanoyl-homoserine lactone (100%), N-(3-oxohexanoyl)-L-homoserine lactone (37.5%), N-(oxodecanoyl)-L-homoserine lactone (100%), and N-(3-oxododecanoyl)-L-homoserine lactone (100%). Alignment of the amino acid sequences of AiiA protein of isolate 30b showed 96% identity with Bacillus cereus (B. cereus) homologous lactonases in the GenBank database, and the isolate was designated as B. cereus isolate 30b. Cell-free lysate of B. cereus isolate 30b reduced biofilm formation significantly in 93% of P. aeruginosa isolates. The highest mean percentage of reduction in the biofilm was 86%. Moreover, the viability percentage of human lung carcinoma A549 cells infected by P. aeruginosa and treated with cell-free lysate of B. cereus isolate 30b increased up to 15%. Conclusion: The results of this study highlight the potential of lactonases as a promising strategy to combat Pseudomonas aeruginosa virulence.

MARWA ALI MOHAMED TAMMAM

Abdelgawad M. Hashem , Ramy K. Aziz

01/04/2019

The gut microbiota enriches the human gene pool and contributes to xenobiotic metabolism. Microbial azoreductases modulate the reduction of azo-bonds, activating produgs and azo polymer-coated dosage forms, or degrading food additives. Here, we aimed to screen the healthy human gut microbiota for food colorant-reducing activity and to characterize factors modulating it. Four representative isolates from screened fecal samples were identified as E. coli (AZO-Ec), E. faecalis (AZO-Ef), E. avium (AZO-Ev) and B. cereus (AZO-Bc). Both AZO-Ef and AZO-Ev decolorized amaranth aerobically and microaerophilically while AZO-Ec and AZO-Bc had higher aerobic reduction rates. The isolates varied in their activities against different dyes, and the azo-reduction activity mostly followed zero-order reaction kinetics, with a few exceptions. Additionally, the isolates had different pH dependence, e.g., AZO-Ec was not affected by pH variation while AZO-Bc exhibited variable degradation kinetics at different pH levels. Cell-free extracts showed NADH-dependent enzymatic activities 14–19 times higher than extracellular fractions. FMN did not affect the reducing activity of AZO-Ef cell-free extract, whereas AZO-Ec, AZO-Ev and AZO-Bc had significantly higher reduction rates in its presence (P values = 0.02, 0.0001 and 0.02, respectively). Using Degenerate primers allowed the amplification of azoreductase genes, whose sequences were 98–99% similar to genes encoding FMN-dependent-NADH azoreductases.

MARWA ALI MOHAMED TAMMAM

Mohamed H. Roshdy, Nour M. Abd El-Kader,Isabel Fuentes,Magdy M. Mohamed, Nabila A. El-Sheikh, Jose Miguel Rubio

01/01/2017

Amoebiasis is a human disease produced by Entamoeba histolytica which causes widespread mortality and morbidity worldwide through diarrheal disease and abscess establishment in parenchymal tissues such as liver, lung, and brain. The true prevalence of infection is unknown for most areas of the world due to the difficulty to characterise Entamoeba histolytica versus other non-pathogenic amoebas with identical morphology, as Entamoeba dispar, and Entamoeba moshkovskii. To overcome microscopy misidentification issues, we tested a nested multiplex polymerase chain reaction (PCR) and a real-time PCR on 194 stool samples collected from incoming dysentery patients in Cairo hospitals diagnosed with E. histolytica by microscopy. Nested PCR showed only 20 (10.3%) samples positive to E. histolytica and 17 (8.7%) to E. dispar. The real-time PCR detected only 19 and 11 samples positive to E. histolytica and E. dispar respectively, showing less sensitivity than the nested PCR. The data show that prevalence of E. histolytica in Cairo is lower when specific diagnosis methods are used instead of traditional microscopy, allowing to differentiate between morphologically identical human amoebas species.

MARWA ALI MOHAMED TAMMAM

Mohamed H. Roshdy, Nour M. Abd El-Kader, Marwa Ali-Tammam, Isabel Fuentes,, Magdy M. Mohamed, Nabila A. El-Sheikh and Jose Miguel Rubio

01/10/2016

Amoebiasis is a human disease produced by Entamoeba histolytica which causes widespread mortality and morbidity worldwide through diarrheal disease and abscess establishment in parenchymal tissues such as liver, lung, and brain. The true prevalence of infection is unknown for most areas of the world due to the difficulty to characterise Entamoeba histolytica versus other non-pathogenic amoebas with identical morphology, as Entamoeba dispar, and Entamoeba moshkovskii. To overcome microscopy misidentification issues, we tested a nested multiplex polymerase chain reaction (PCR) and a real-time PCR on 194 stool samples collected from incoming dysentery patients in Cairo hospitals diagnosed with E. histolytica by microscopy. Nested PCR showed only 20 (10.3%) samples positive to E. histolytica and 17 (8.7%) to E. dispar. The real-time PCR detected only 19 and 11 samples positive to E. histolytica and E. dispar respectively, showing less sensitivity than the nested PCR. The data show that prevalence of E. histolytica in Cairo is lower when specific diagnosis methods are used instead of traditional microscopy, allowing to differentiate between morphologically identical human amoebas species.

MARWA ALI MOHAMED TAMMAM

Marwa M. Raafat , Marwa Ali-Tammam and Amal E. Ali1,

01/10/2016

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen and a leading cause of hospitalacquired infections. Characterization of the isolates from different infection sites might help to control infections caused by the pathogen. The aim of the present work is to characterize P. aeruginosa isolates recovered from different clinical specimens at two hospitals in Cairo with regard to their antibiogram, genotypes and virulence factors. The highest antimicrobial resistance pattern was exhibited by isolates from sputum. Resistance rate recorded for sputum samples to different in- use antibiotics was 80, 80-100, 36, 54 and 54% for Penicillins, Cephems, Carbapenems, Aminoglycosides and Fluoroquinolones, respectively. Phenotypic detection of virulence factors in P. aeruginosa isolates included detection of protease, lecithinase, DNase, hemolysin and pyocyanin revealed that, each isolate had at least one virulence factor. Protease and lecithinase were the most commonly detected, where 68 and 66% of the isolates showed positive protease and lecithinase activities respectively. Random amplified polymorphic DNA (RAPD) genotyping using 2 random primers revealed 22 and 14 different genetic profiles. Phylogenetic trees based on genetic distances showed 3 clusters with obvious similarity between some isolates, indicating common sources of infection. No association could be found between clustering pattern of the isolates, their antibiogram and virulence. Key words: Pseudomonas aeruginosa, antibiogram, genotypes, random amplified polymorphic DNApolymerase chain reaction (RAPD-PCR).