35 research outputs found

    Comparative Phylogenetic and Residue Analysis of Hepatitis C Virus E1 Protein from the Middle East and North Africa Region

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    Hepatitis C virus (HCV) is a major public health problem in the Middle East and North Africa (MENA) region with an estimate of over 15 million chronically infected patients. However, molecular characterization of circulating genotypes in the MENA region remains elusive. Here, we performed a comparative phylogenomic analysis of so-far available E1 gene sequences (937), originating from eight countries in the MENA region. All HCV E1 protein sequences present in NCBI from the MENA region were retrieved and cataloged per year and country of origin. Phylogenetic analysis revealed a maximum diversity of genotypes and subtypes in South Arabia [G-1 (1a, 1b, 1g), G-2 (2a, 2c), G-3 (3a) and G-4 (4a, 4d, 4n, 4o, 4r, 4s)] followed by Egypt [G-1 (1b, 1g) and G-4 (4a, 4l, 4n, 4m, 4u)], Iran [G-1 (1b) and G-3 (3a) G-6 (6a)], Tunisia [G-1 (1b) and G-2 (2a, 2b, 2c)], Algeria [G-1 (1i), 4(4f), Pakistan [G-1 (1a), G-3(3a, 3b)], Afghanistan [G-1 (1a), GT-3 (3a)], and 5(5a), and Yemen [G-4 (4r)]. The calculated evolution rate of retrieved sequences was 1.601 × 10−3 substitutions/site/year and the mean nucleotide diversity rate was 0.2684 (P < 0.001). The ratio of synonymous to non-synonymous (mean dN/dS) substitutions was higher in genotypes 2 and 4 compared to the genotypes 1 and 3. A higher degree of nucleotide identity in E1 gene was found between subtypes 1a and 1b, between 2c and 2g, and between 4a, 4d, and 4o. Comparative residue analysis of E1 protein epitope sequences of previously reported H111, A4, and A6 monoclonal antibodies showed relatively poor and genotype-specific conservancy. Perhaps, none of the reported epitope sequences had immunogenicity score higher than 0.4 (A minimum threshold for vaccine sequence prediction). Furthermore, these epitope sequences were heavily glycosylated at amino acid 196, 209, and 234 sites in all GTs. In conclusion, a high genetic variability in E1 protein coupled with increased glycosylation may deduce heterogeneity and subsequent escape from vaccine-generated immune response, thereby ascertaining necessary interventions for disease management and control.The work was performed at BRC internal resource

    Polymerase chain reaction ribotyping of Clostridium difficile isolates in Qatar: a hospital-based study

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    Background Clostridium difficile infection (CDI) is not generally reported to public health authorities in the Middle East and its true prevalence remains largely unknown. The aims of this study were to determine the prevalence of CDI and its associated ribotypes among C. difficile isolates in Qatar. Influence of age and correlation with other risk factors e.g. proton pump inhibitor use, antibiotic use, existence of chronic conditions, etc was also investigated for CDI positive patients. Methods A total of 1,532 patients with suspected CDI were recruited from two hospitals between 2011 and 2012. C. difficile was identified using glutamate dehydrogenase (GDH) lateral flow assay and toxins A and B Enzyme Immunoassay (EIA). The C. difficile positive samples were then cultured for PCR-ribotyping. Results 122 of the 1,532 (7.9%) samples from individual patients were identified as C.difficile positive; and 79 of these were viably cultured (~65%). From these, 36 different PCR ribotypes were isolated, of which strains 258 (6 [7.6%]), 01/014/046 (5 [6.3%]), and 011/053/056/107 (4 [5%]) were the most prevalent. The prevalence of PCR-ribotype 027 was 1.3% (n = 1). An age of ≥65 years and treatment with proton pump inhibitors correlated with higher frequency of CDI. Treatment with third generation cephalosporins (50 [41%]) and piperacillin/tazobactam antibiotics (55 [45.1%]) was most frequently associated with CDI. Conclusion The most common C. difficile ribotype identified in Qatar was 258, which is different from those found in North America, Europe and Asia. The prevalence of CDI was higher in Qatar than Europe; though comparable to other Middle Eastern countries. These findings underscore the importance of local surveillance to detect and control C. difficile infection

    Helminth infections among long-term residents and settled immigrants in Qatar in the decade from 2005 to 2014: temporal trends and varying prevalence among subjects from different regional origins

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    Background: Travel and migration from developing regions, where tropical diseases are common, to more developed industrialised nations can contribute to the introduction and subsequent spread of infections. With its rapidly expanding economy, Qatar has attracted vast numbers of immigrant workers in the last two decades, often from countries with poor socio-economic levels. Many used to arrive with patent intestinal parasitic infections. Methods: We analysed the prevalence of helminth infections in a dataset of 29,286 records of subjects referred for stool examination at the Hamad Medical Corporation over the course of a decade (2005 to 2014, inclusive). Results: Overall prevalence of combined helminth infections was low (1.86 %) but there were significant temporal trends, age and sex effects and those arising from the region of origin of the subjects. The most common helminths were hookworms (overall prevalence 1.22 %), which accounted for 70.1 % of cases, and therefore patterns for combined helminth infections were largely driven by hookworms. In both cases, and also in Trichuris trichiura and Ascaris lumbricoides, prevalence peaked in 2008, since when prevalence has been steadily falling. Helminth infections were largely concentrated among subjects from five Asian countries (Nepal, Bangladesh, Sri Lanka, India and Pakistan), and there was a highly biased prevalence in favour of male subjects in all cases. Prevalence of all three nematodes peaked in age class 7 (mean age 25.5 years, range = 20–29) and there were significant interactions between region of origin, sex of subjects and prevalence of hookworms. Conclusion: These results offer optimism that prevalence will continue to decline in the years ahead, especially if control is targeted at those most at risk of carrying infections.Qatar National Research Fund (QRNF) at Qatar Foundation for supporting this study through the National Priorities Research Program (NPRP) (Project No. NPRP 4-1283-3-327)

    Occurrence of Mycotoxins and Toxigenic Fungi in Cereals and Application of Yeast Volatiles for Their Biological Control

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    Fungal infections in cereals lead to huge economic losses in the food and agriculture industries. This study was designed to investigate the occurrence of toxigenic fungi and their mycotoxins in marketed cereals and explore the effect of the antagonistic yeast Cyberlindnera jadinii volatiles against key toxigenic fungal strains. Aspergillus spp. were the most frequent contaminating fungi in the cereals, with an isolation frequency (Fr) of 100% in maize, followed by wheat (88.23%), rice (78.57%) and oats (14.28%). Morphological and molecular identification confirmed the presence of key toxigenic fungal strains in cereal samples, including A. carbonarius, A. flavus, A. niger, A. ochraceus and A. parasiticus. Aflatoxins (AFs) were detected in all types of tested cereal samples, with a significantly higher level in maize compared to wheat, rice, oats and breakfast cereals. Ochratoxin A (OTA) was only detected in wheat, rice and maize samples. Levels of mycotoxins in cereals were within EU permissible limits. The volatiles of Cyberlindnera jadinii significantly inhibited the growth of A. parasiticus, A. niger and P. verrucosum. The findings of this study confirm the presence of toxigenic fungi and mycotoxins in cereals within the EU permissible limits and the significant biocontrol ability of Cyberlindnera jadinii against these toxigenic fungi

    Molecular analysis of the enteric protozoa associated with acute diarrhea in hospitalized children

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    Pediatric diarrhea is a common cause of death among children under 5 years of age. In the current study, we investigated the frequency of intestinal parasites among 580 pediatric patients with chronic diarrhea. Parasitic protozoa (all species combined) were detected by molecular tools in 22.9% of the children and the most common parasite was Cryptosporidiumspp. (15.1%). Blastocystis hominis was detected in 4.7%, Dientamoeba fragilis in 4%, Giardia duodenalis in 1.7%, and Entamoeba histolytica in 0.17%. Protozoan infections were observed among all regional groups, but prevalence was highest among Qatari subjects and during the winter season. Typing of Cryptosporidium spp. revealed a predominance of Cryptosporidium parvum in 92% of cases with mostly the IIdA20G1 subtype. Subtypes IIdA19G2, IIdA18G2, IIdA18G1, IIdA17G1, IIdA16G1, and IIdA14G1 were also detected. For Cryptosporidium hominis, IbA10G2 and IbA9G3 subtypes were identified. This study provides supplementary information for implementing prevention and control strategies to reduce the burden of these pediatric protozoan infections. Further analyses are required to better understand the local epidemiology and transmission of Cryptosporidium spp. in Qatar.This study was funded by the Qatar National Research Fund (QRNF) at Qatar Foundation through the National Priorities Research Program (Project No. NPRP8-1556-3-313)

    Molecular epidemiology and genotype distribution of Human Papillomavirus (HPV) among Arab women in the state of Qatar

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    Background: Human Papilloma Virus (HPV) infection is the major cause of cervical cancer worldwide. With limited data available on HPV prevalence in the Arab countries, this study aimed to identify the prevalence and genotypic distribution of HPV in the State of Qatar. Methods: 3008 cervical samples, exclusively of women with Arabic origin residing in Qatar were collected from the Women’s Hospital and Primary Health Care Corporation in Doha, State of Qatar. HPV DNA detection was done using GP5+/6+ primers based real time-polymerase chain reaction (RT-PCR) assay followed by the usage of HPV type specific primers based RT- PCR reactions and Sanger sequencing for genotype identification. Results: Similar prevalence rates of HPV infection was identified in both Qatari and non-Qatari women at 6.2% and 5.9% respectively. HPV prevalence rate of 5.8% and 18.4% was identified in women with normal cytology and in women with abnormal cytology respectively. HPV 81, 11 and 16, in decreasing order were the most commonly identified genotypes. HPV 81 was the most frequent low-risk genotype among women with both normal (74.0%) and abnormal (33.3%) cytology. HPV 16 (4.6%) was identified as the predominant high-risk HPV genotype among women with normal cytology and HPV 16, HPV 18, and HPV 56 (22.2% each) were the most common identified high-risk genotypes in women with abnormal cytology Conclusions: The overall HPV prevalence in Arab women in Qatar was identified as 6.1% with an increased HPV prevalence seen in women with abnormal cytology results and no significant trends seen with age. In contrast to Western countries, we report a varied genotypic profile of HPV with a high prevalence of low-risk HPV genotype 81 among the Arab women residing in Qatar.Weill Cornell Medical College in Qatar; and by a grant from the Qatar National Research Fund (NPRP- 09-344-3-082)

    Identification of mcr-8 in Clinical Isolates From Qatar and Evaluation of Their Antimicrobial Profiles

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    This study was performed to investigate the genotypic causes of colistin resistance in 18 colistin-resistant Klebsiella pneumoniae (n = 13), Escherichia coli (n = 3) and Pseudomonas aeruginosa (n = 2) isolates from patients at the Hamad General Hospital, Qatar. MIC testing for colistin was performed using Phoenix (BD Biosciences, Heidelberg, Germany) and then verified with SensiTest Colistin (Liofilchem, Zona Ind. le, Italy). Strains determined to be resistant (MIC > 4-16 μg/mL) were then whole-genome sequenced (MiSeq, Illumina, Inc.). Sequences were processed and analysed using BacPipe v1.2.6, a bacterial whole genome sequencing analysis pipeline. Known chromosomal modifications were determined using CLC Genomics Workbench v.9.5.3 (CLCbio, Denmark). Two K. pneumoniae isolates (KPN-15 and KPN-19) harboured mcr-8.1 on the IncFII(K) plasmids, pqKPN-15 and pqKPN-19, and belonged to ST383 and ST716, respectively. One E. coli isolate harboured mcr-1.1 on the IncI2 plasmid pEC-12. The other 15 isolates harboured known chromosomal mutations linked to colistin resistance in the PhoPQ two-component system. Also, three K. pneumoniae strains (KPN-9, KPN-10 and KPN-15) showed disruptions due to IS elements in mgrB. To our knowledge, this marks the first description of mcr-8.1 in K. pneumoniae of human origin in Qatar. Currently, more research is necessary to trace the source of mcr-8.1 and its variants in humans in this region.Hamad Medical Corporatio

    Comparative analysis of within-host diversity among vaccinated COVID-19 patients infected with different SARS-CoV-2 variants

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    Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a rapidly evolving RNA virus that mutates within hosts and exists as viral quasispecies. Here, we evaluated the within-host diversity among vaccinated and unvaccinated individuals (n = 379) infected with different SARS-CoV-2 Variants of Concern. The majority of samples harbored less than 14 intra-host single-nucleotide variants (iSNVs). A deep analysis revealed a significantly higher intra-host diversity in Omicron samples than in other variants (p value < 0.05). Vaccination status and type had a limited impact on intra-host diversity except for Beta-B.1.315 and Delta-B.1.617.2 vaccinees, who exhibited higher diversity than unvaccinated individuals (p values: <0.0001 and <0.0021, respectively). Three immune-escape mutations were identified: S255F in Delta and R346K and T376A in Omicron-B.1.1.529. The latter 2 mutations were fixed in BA.1 and BA.2 genomes, respectively. Overall, the relatively higher intra-host diversity among vaccinated individuals and the detection of immune-escape mutations, despite being rare, suggest a potential vaccine-induced immune pressure in vaccinated individuals.The authors are grateful for the leadership and assistance provided by the Ministry of Public Health in Qatar, the virology laboratory staff at Hamad Medical Corporation, and Qatar Biobank (QBB) team. This project was funded by Qatar National Research Fund (QNRF; Project number UREP28-164-3-048) and Qatar University (Project number QUCG-BRC-22/23-547). The article processing charges were paid from grant no. QUCG-BRC-2022/23-578
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