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result(s) for
"Radouani, Fouzia"
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An overview of genes and mutations associated with Chlamydiae species’ resistance to antibiotics
by
Sanak, Kholoud
,
Azzouzi, Maryame
,
Radouani, Fouzia
in
Aminoglycosides
,
Animal behavior
,
Anti-Bacterial Agents - pharmacology
2021
Background
Chlamydiae are intracellular bacteria that cause various severe diseases in humans and animals. The common treatment for chlamydia infections are antibiotics. However, when antibiotics are misused (overuse or self-medication), this may lead to resistance of a number of chlamydia species, causing a real public health problem worldwide.
Materials and methods
In the present work, a comprehensive literature search was conducted in the following databases: PubMed, Google Scholar, Cochrane Library, Science direct and Web of Science. The primary purpose is to analyse a set of data describing the genes and mutations involved in Chlamydiae resistance to antibiotic mechanisms. In addition, we proceeded to a filtration process among 704 retrieved articles, then finished by focusing on 24 studies to extract data that met our requirements.
Results
The present study revealed that
Chlamydia trachomatis
may develop resistance to macrolides via mutations in the
23S rRNA
,
rplD
,
rplV
genes, to rifamycins via mutations in the
rpoB
gene, to fluoroquinolones via mutations in the
gyrA
,
parC
and
ygeD
genes, to tetracyclines via mutations in the
rpoB
gene, to fosfomycin via mutations in the
murA
gene, to MDQA via mutations in the secY gene. Whereas,
Chlamydia pneumoniae
may develop resistance to rifamycins via mutations in the
rpoB
gene, to fluoroquinolones via mutations in the
gyrA
gene. Furthermore, the extracted data revealed that
Chlamydia psittaci
may develop resistance to aminoglycosides via mutations in the
16S rRNA
and
rpoB
genes, to macrolides via mutations in the
23S rRNA
gene. Moreover,
Chlamydia suis
can become resistance to tetracyclines via mutations in the
tet(C)
gene
.
In addition,
Chlamydia caviae
may develop resistance to macrolides via variations in the
23S rRNA
gene. The associated mechanisms of resistance are generally: the inhibition of bacteria’s protein synthesis, the inhibition of bacterial enzymes’ action and the inhibition of bacterial transcription process.
Conclusion
This literature review revealed the existence of diverse mutations associated with resistance to antibiotics using molecular tools and targeting chlamydia species’ genes. Furthermore, these mutations were shown to be associated with different mechanisms that led to resistance. In that regards, more mutations and information can be shown by a deep investigation using the whole genome sequencing. Certainly, this can help improving to handle chlamydia infections and healthcare improvement by decreasing diseases complications and medical costs.
Journal Article
Adoption of an in-silico analysis approach to assess the functional and structural impacts of rpoB-encoded protein mutations on Chlamydia pneumoniae sensitivity to antibiotics
by
Radouani, Fouzia
,
Benamri, Ichrak
,
Lamzouri, Afaf
in
Amino acids
,
Anti-Bacterial Agents - pharmacology
,
Antibiotic
2025
Background
Antibiotics are frequently used to treat infections caused by
Chlamydia pneumoniae
; an obligate intracellular gram-negative bacterium commonly associated with respiratory diseases. However, improper or overuse of these drugs has raised concerns about the development of antibiotic resistance, which poses a significant global health challenge. Previous studies have revealed a link between mutations in the
rpoB
-encoded protein of
C. pneumoniae
and antibiotic resistance. This study assessed these mutations via various bioinformatics tools to predict their impact on function, structural stability, antibiotic binding, and, ultimately, their effect on bacterial sensitivity to antibiotics.
Results
Eight mutations in the
rpoB
-encoded protein (R421S, F450S, L456I, S454F, D461E, S476F, L478S, and S519Y) are associated with resistance to rifampin and rifalazil. These mutations occur in conserved regions of the protein, leading to decreased stability and affecting essential functional sites of RNA polymerase, the target of these antibiotics. Although the structural differences between the native and mutant proteins are minimal, notable changes in local hydrogen bonding have been observed. Despite similar binding energies, variations in hydrogen bonds and hydrophobic interactions in certain mutants (for instance, D461E for rifalazil and S476F for rifampin) indicate that these changes may diminish ligand affinity and specificity. Furthermore, protein-protein network analysis demonstrated a strong correlation between wild-type
rpoB
and ten
C. pneumoniae
proteins, each fulfilling specific functional roles. Consequently, some of these mutations can reduce the bacterium’s sensitivity to rifampin and rifalazil, thereby contributing to antibiotic resistance.
Conclusion
The findings of this study indicate that mutations in the
rpoB
gene, which encodes the beta subunit of RNA polymerase, are pivotal in the resistance of
C. pneumoniae
to rifampin and rifalazil. Some of these mutations may result in reduced protein stability and changes in the structure, function, and antibiotic binding. As a consequence, the efficacy of these drugs in inhibiting RNA polymerase is compromised, allowing the bacteria to persist in transcription and replication even in the presence of antibiotics. Overall, these insights enhance our understanding of the resistance mechanisms in
C. pneumoniae
and could guide the development of strategies to address this challenge.
Clinical trial number
Not applicable.
Journal Article
An in silico analysis of rpoB mutations to affect Chlamydia trachomatis sensitivity to rifamycin
by
Azzouzi, Maryame
,
Radouani, Fouzia
,
Benamri, Ichrak
in
Analysis
,
biochemistry
,
bioinformatics
2022
Chlamydia trachomatis is an obligate intracellular gram-negative pathogen, responsible for diverse affections, mainly trachoma and sexually transmitted diseases. Antibiotics are the commonly used drugs to tackle chlamydiae infections. However, when overused or wrongly used this may lead to strains' resistance to antibiotics, this phenomenon represents a real health problem worldwide. Numerous studies showed the association of Chlamydia trachomatis resistance with mutations in different genes; these mutations could have a deleterious or neutral impacts on the encoded proteins. The aim of this study is to perform an in silico analysis of C. trachomatis rpoB-encoded proteins using numerous bioinformatics tools and to identify the functional and structural-related effects of the mutations and consequently their impact on the bacteria sensitivity to antibiotics. The analysis revealed that the prediction of the damaging impact related to the mutations in rpoB-encoded proteins showed eight mutations: V136F, Q458K, V466A, A467T, H471N, H471Y, H471L, and I517M with big deleterious effects. Among them, six mutations, V136F, Q458K, V466A, A467T, H471N, and I517M, are located in a highly conserved regions decreasing the protein's stability. Furthermore, the structures analysis showed that the mutations A467T, H471N, I517M, and V136F models had a high deviation compared to the wild type. Moreover, the prediction of protein-protein network indicated that rpoB wild type interacts strongly with 10 proteins of C. trachomatis, which are playing different roles at different levels. As conclusion, the present study revealed that the changes observed in the encoded proteins can affect their functions and structures, in addition to their interactions with other proteins which impact the bacteria sensitivity to antibiotics. Consequently, the information revealed through this in silico analysis would be useful for deeper exploration to understand the mechanisms of C. trachomatis resistance and enable managing the infection to avoid its complications. We recommend further investigations and perform deeper experimental analysis with collaboration between bioinformaticians, physicians, biologists, pharmacists, and chemistry and biochemistry scientists.
Journal Article
Exome sequencing reveals new insights into the germline landscape of inflammatory breast cancer among Tunisian patients
2025
Background
Inflammatory breast cancer (IBC) is a rare and aggressive form of breast cancer, characterized by distinct clinicopathological features and a relatively high frequency in North African countries. While several studies have explored the genetic basis of breast cancer, limited research has looked into the specific genetic features of this aggressive form. This study aims to investigate the genetic factors associated with IBC in North Africa, particularly among Tunisian patients.
Methods
Whole exome sequencing was performed for 13 patients with IBC. Clinicopathological data have been collected to assess the phenotype-genotype correlation. Both germline point mutations and copy number variations (CNVs) were analyzed. Genes and variants were prioritized through phenotype and genotype-driven approaches. Variants were filtered based on pathogenicity predictions and ACMG classification. A Gene-Disease association analysis was conducted using DisGeNET data and the VarElect online tool to select candidate genes most likely involved in disease onset. The predictive and prognostic values of the relevant genes were assessed using publicly available datasets.
Results
Our investigations revealed relevant genetic variants within established cancer predisposing genes, inflammatory pathways, and potential candidate predisposing genes, including
BRCA2
c.1794_1798del, a novel mutation in
RAD54L
gene (c.1712T > C) and c.555_559del in
IFNAR2
gene. CNVs in
ABRAXAS1, XRCC2
and
FANC
genes were identified. We have also found that the high expression levels of
RAD54L
and
MTHFR
are correlated with good survival rates. The genetic makeup of IBC seems to be very heterogeneous. For the same patient, we have detected several relevant variants that might explain disease development and progression, and this was consistent with the family history of cancer observed in the investigated families.
Conclusions
Our findings revealed a complex and heterogeneous genetic background of IBC in the Tunisian population that might contribute to disease susceptibility and impact disease prognosis. The genetic features of IBC presented in this study provide valuable insights into the molecular mechanisms underlying the disease offering not only a deeper understanding within the context of Tunisia but also shedding light on its relevance to other North African populations characterized by similar epidemiological and genetic features.
Journal Article
Developing Clinical Phenotype Data Collection Standards for Research in Africa
2023
Modern biomedical research is characterised by its high-throughput and interdisciplinary nature. Multiproject and consortium-based collaborations requiring meaningful analysis of multiple heterogeneous phenotypic datasets have become the norm; however, such analysis remains a challenge in many regions across the world. An increasing number of data harmonisation efforts are being undertaken by multistudy collaborations through either prospective standardised phenotype data collection or retrospective phenotype harmonisation. In this regard, the Phenotype Harmonisation Working Group (PHWG) of the Human Heredity and Health in Africa (H3Africa) consortium aimed to facilitate phenotype standardisation by both promoting the use of existing data collection standards (hosted by PhenX), adapting existing data collection standards for appropriate use in low- and middle-income regions such as Africa, and developing novel data collection standards where relevant gaps were identified. Ultimately, the PHWG produced 11 data collection kits, consisting of 82 protocols, 38 of which were existing protocols, 17 were adapted, and 27 were novel protocols. The data collection kits will facilitate phenotype standardisation and harmonisation not only in Africa but also across the larger research community. In addition, the PHWG aims to feed back adapted and novel protocols to existing reference platforms such as PhenX.
Journal Article
A review of clinical pharmacogenetics Studies in African populations
by
Masilela, Phumlani
,
Mulder, Nicola
,
Masimirembwa, Collen
in
Africa
,
African Continental Ancestry Group - genetics
,
Clinical Trials as Topic
2020
Effective interventions and treatments for complex diseases have been implemented globally, however, coverage in Africa has been comparatively lower due to lack of capacity, clinical applicability and knowledge on the genetic contribution to disease and treatment. Currently, there is a scarcity of genetic data on African populations, which have enormous genetic diversity. Pharmacogenomics studies have the potential to revolutionise treatment of diseases, therefore, African populations are likely to benefit from these approaches to identify likely responders, reduce adverse side effects and optimise drug dosing. This review discusses clinical pharmacogenetics studies conducted in African populations, focusing on studies that examined drug response in complex diseases relevant to healthcare. Several pharmacogenetics associations have emerged from African studies, as have gaps in knowledge.
Journal Article
Molecular characterisation of Chlamydia pneumoniae associated to atherosclerosis
by
Bouazza, Mohamed
,
El Yazouli, Loubna
,
Aroussi Alami, Aziz
in
Arteriosclerosis
,
Asthma
,
Atherogenesis
2017
Chlamydia pneumoniae is a respiratory pathogen associated with chronic inflammatory diseases such as asthma and atherosclerosis, and its detection in human carotid and coronary atheroma suggests some support for its involvement in atherogenesis. The main objective of our study was to evaluate the association between Chlamydia pneumoniae and atherosclerosis in Moroccan patients through a case-control approach and detected strain genotyping. A total of 137 cases and 124 controls were enrolled, nested PCR was performed for Chlamydia pneumoniae screening of the peripheral blood mononuclear cells (PBMCs) of both cases and controls as well as atheroma plaques from 37 cases, and positive samples were subjected to sequencing for genotyping and phylogenetic analysis. The results showed 54% and 18%, respectively, for positivity in cases and control PBMCs and 86.5% in atheroma plaques, the difference being significant between the two groups (P < 0.001, ORa = 8.580, CI, 95% [3.273-22.491]). Strain sequence analyses showed more than 98% similarity with human reference strains, and revealed various genotypes. This study supports the involvement of Chlamydia pneumoniae in atherosclerosis in the studied population and genotyping revealed that detected strains were identical to human strains circulating worldwide.
Journal Article
African Genomic Medicine Portal: A Web Portal for Biomedical Applications
2022
Genomics data are currently being produced at unprecedented rates, resulting in increased knowledge discovery and submission to public data repositories. Despite these advances, genomic information on African-ancestry populations remains significantly low compared with European- and Asian-ancestry populations. This information is typically segmented across several different biomedical data repositories, which often lack sufficient fine-grained structure and annotation to account for the diversity of African populations, leading to many challenges related to the retrieval, representation and findability of such information. To overcome these challenges, we developed the African Genomic Medicine Portal (AGMP), a database that contains metadata on genomic medicine studies conducted on African-ancestry populations. The metadata is curated from two public databases related to genomic medicine, PharmGKB and DisGeNET. The metadata retrieved from these source databases were limited to genomic variants that were associated with disease aetiology or treatment in the context of African-ancestry populations. Over 2000 variants relevant to populations of African ancestry were retrieved. Subsequently, domain experts curated and annotated additional information associated with the studies that reported the variants, including geographical origin, ethnolinguistic group, level of association significance and other relevant study information, such as study design and sample size, where available. The AGMP functions as a dedicated resource through which to access African-specific information on genomics as applied to health research, through querying variants, genes, diseases and drugs. The portal and its corresponding technical documentation, implementation code and content are publicly available.
Journal Article