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1.
Int J Mol Sci ; 20(13)2019 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-31323925

RESUMO

The Tunisian durum wheat germplasm includes modern cultivars and traditional varieties that are still cultivated in areas where elite cultivars or intensive cultivation systems are not suitable. Within the frame of a collection program of the National Gene Bank of Tunisia (NGBT), durum wheat germplasm was collected from different Tunisian agro-ecological zones. The collected samples were studied using simple sequence repeats (SSRs) markers to explore the genetic diversity and evaluate the genetic structure in Tunisian germplasm. The results demonstrated significant diversity in the Tunisian durum wheat germplasm, with clear differentiation between traditional varieties and modern cultivars. The population structure analysis allowed the identification of five subpopulations, two of which appear to be more strongly represented in germplasm collected in central and southern Tunisia, where environmental conditions at critical development phases of the plant are harsher. Moreover these subpopulations are underrepresented in modern varieties, suggesting that traits of adaptation useful for breeding more resilient varieties might be present in central and southern germplasm. Moreover, our results will support, the activity of in situ on farm conservation of Tunisian durum wheat germplasm started by the National Gene Bank of Tunisia along with the ex situ approach.


Assuntos
Cruzamento , Triticum/genética , Variação Genética/genética , Repetições de Microssatélites/genética , Filogenia
2.
Int J Antimicrob Agents ; 52(6): 906-909, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29958975

RESUMO

Emergence of the New Delhi metallo-ß-lactamase (NDM-1), an Ambler class B metallo-ß-lactamase able to hydrolyse all ß-lactams except monobactams, constitutes a critical and increasingly important medical issue. The acquisition of blaNDM-1 is of particular concern for Proteus mirabilis, which is intrinsically resistant to tetracycline, tigecycline and colistin, as this will make clinical treatment extremely difficult. To the authors' knowledge, this is the first report of the blaNDM-1 gene in an extensively-drug-resistant P. mirabilis clinical isolate carrying plasmid-mediated resistance to carbapenems (blaNDM-1), cephalosporins (blaCMY-4), aminoglycosides (aph3 VIa and aph3 Ia) and fluoroquinolones (qnrA6).


Assuntos
Farmacorresistência Bacteriana Múltipla , Plasmídeos/análise , Infecções por Proteus/microbiologia , Proteus mirabilis/efeitos dos fármacos , beta-Lactamases/metabolismo , Idoso , Antibacterianos/farmacologia , Humanos , Unidades de Terapia Intensiva , Masculino , Proteus mirabilis/genética , Proteus mirabilis/isolamento & purificação , Tunísia , beta-Lactamases/genética
3.
Int J Antimicrob Agents ; 52(6): 898-905, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29621592

RESUMO

In Klebsiella pneumoniae, loss of the two major outer membrane porins (OMPs) OmpK35 and OmpK36 confers resistance to carbapenems in strains producing extended-spectrum ß-lactamases (ESBLs) or plasmid-mediated AmpC-type ß-lactamases. This study investigated mechanisms responsible for carbapenem resistance in non-carbapenemase-producing K. pneumoniae (NCPK). All carbapenem-resistant Enterobacteriaceae (CRE) at Charles Nicolle Hospital (Tunis, Tunisia) were collected over a 6-year period (2010-2015). Among the 334 CRE strains collected, 44 (13.2%) were NCPK. MIC ranges for ertapenem, imipenem and meropenem were 1 to >32 mg/L, 0.125-8 mg/L and 0.125-32 mg/L, respectively. All strains showed a multidrug-resistant (MDR) phenotype and were negative for carbapenemase activity. None of the carbapenemase genes searched for were found. ESBL production was confirmed in all isolates except one [CTX-M-15 (n = 39) and SHV-5 (n = 4)]. Three isolates produce DHA-1 (associated with CTX-M-15 in two strains). Molecular fingerprints grouped the 44 NCPK isolates into seven clusters. In seven representative strains of these clusters, SDS-PAGE results showed that four isolates lacked the OmpK35 porin, one isolate lacked OmpK36 and two isolates lacked both OmpK35 and OmpK36. Sequencing of the corresponding porin genes showed amino acid insertions and deletions leading to early termination of translation, point mutations in the promoter region, or insertion sequences disrupting the gene coding sequence. Loss or deficiency of OMPs, coupled with ESBL and/or AmpC production, plays an important role in conferring carbapenem resistance in K. pneumoniae. Dissemination of these MDR bacteria in our hospital may create serious therapeutic problems in the future.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Carbapenêmicos/farmacologia , Farmacorresistência Bacteriana Múltipla , Klebsiella pneumoniae/efeitos dos fármacos , Porinas/genética , beta-Lactamases/genética , Proteínas de Bactérias/análise , Eletroforese em Gel de Poliacrilamida , Humanos , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , Tipagem Molecular , Mutação , Porinas/deficiência , Análise de Sequência de DNA , Tunísia , beta-Lactamases/análise , beta-Lactamases/metabolismo
4.
Microb Drug Resist ; 24(8): 1137-1147, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29373087

RESUMO

OBJECTIVES: To describe clinical and molecular characteristics of an outbreak due to metallo-ß-lactamases (MBLs) producing Klebsiella pneumoniae collected at Charles Nicolle Hospital of Tunis and to analyze the impact of outer membrane porin (OMP) loss on carbapenem resistance levels. METHODS: Between 2010 and 2015, 178 carbapenem-resistant Enterobacteriaceae were isolated. Screening for MBL production was performed using combined disk diffusion method, with imipenem and ethylene diamine tetraacetic acid (EDTA) as inhibitors. Resistance genes and virulence factors were identified by polymerase chain reaction (PCR) and sequencing. Genotyping was performed by pulsed-field gel electrophoresis and multilocus sequence typing. Genetic environment of carbapenemase genes was determined by PCR mapping. Conjugation assays were performed, and plasmids were assigned to incompatibility groups by PCR-based replicon typing. OMPs were profiled by sodium dodecyl sulfate-polyacrilamide gel electrophoresis, and porin genes were sequenced. RESULTS: Nineteen K. pneumoniae (10.6%) showing MBL activity were isolated from patients hospitalized on four different wards. NDM-1 was the only MBL identified, in association with blaOXA-48. All strains lacked at least one OMP, and carbapenem resistance levels were remarkably elevated in strains lacking OmpK35 and OmpK36. blaNDM-1 was located in IncFIA-type conjugative plasmid, with the same genetic context in all strains. The epidemiological diffusion of blaNDM-1 was due to two clones, one major clone belonging to sequence type (ST) 147 (n = 16) and the other clone belonging to ST307 (n = 3). CONCLUSIONS: This study describes an outbreak of NDM-1-producing K. pneumoniae strains, isolated from a Tunisian hospital, caused by two clones belonging to ST147 and ST307; and highlights the role of OMPs loss, in combination with ß-lactamase expression, in conferring high carbapenem resistance.


Assuntos
Proteínas de Bactérias/genética , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/genética , Porinas/genética , beta-Lactamases/genética , Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Surtos de Doenças , Humanos , Imipenem/farmacologia , Infecções por Klebsiella/tratamento farmacológico , Klebsiella pneumoniae/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Plasmídeos/genética , Tunísia
5.
J Infect Dev Ctries ; 12(5): 313-320, 2018 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31865292

RESUMO

INTRODUCTION: Salmonella enterica infections are a significant public health concern worldwide, being Salmonella Typhimurium one of the most prevalent serovars. Human salmonellosis is typically associated with the consumption of contaminated foods, such as poultry, eggs and processed meat. The extensive use of antimicrobials in humans and animals has led to an increase in multidrug resistance among Salmonella strains, becoming multidrug-resistant (MDR) strains a major public health concern. METHODOLOGY: This study was designed to investigate the antimicrobial susceptibility and the genotypic diversity of Salmonella Typhimurium strains isolated in Tunisia from human and poultry sources from 2009 to 2015. Fortyfive strains were analyzed by disk-diffusion test to determine the antimicrobial susceptibility. The presence of antimicrobial resistance genes was tested by PCR, and genotyping was performed using multiple-locus variable-number tandem repeats analysis (MLVA). RESULTS: About 50% of the strains were resistant to at least 3 antibiotics (multidrug-resistant strains, MDR). The most frequent resistance profile in clinical strains was AMP-TIC-TET-MIN-SXT (n = 7) and TET-MIN in poultry origin strains (n = 7). The MLVA typing grouped the strains in 2 main clusters. Cluster I was mostly formed by human isolates, whereas in cluster II both human and poultry isolates were grouped. Simpson's diversity index was 0.870 and 0.989 for antimicrobial resistance profiles and MLVA, respectively. CONCLUSIONS: Multiresistance is common in Salmonella Typhimurium isolated from human and poultry sources in Tunisia. The genotyping results suggest that some strains isolated from both sources may descend from a common subtype.

6.
Diagn Microbiol Infect Dis ; 87(2): 188-192, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27856044

RESUMO

The spread of extended spectrum ß-lactamases (ESBL) and plasmid mediated AmpC ß-lactamases (pAmpC) was evaluated in Escherichia coli strains collected from the intestinal microbiota of healthy children in Tunisia. The carriage rate of CTXRE. coli was 6.6% (7 of 105 samples) and one strain/sample was further characterized (7 isolates). These isolates harbored blaCTX-M-1 (n = 4), blaCTX-M-15 (n = 2), and blaCMY-2 gene (n = 1), which were usually located on FIB replicon type and carried class 1 integrons. The acc(6')-Ib-cr variant was identified in one isolate that harbored blaCTX-M-15. CTXRE. coli isolates were genetically unrelated and belonged to B1 (n = 3/ST155/ST398/ST58), D (n = 2/ST117/ST493), B2 (n = 1/ST127), and A (n = 1/ST746) phylogroups. Strain virulence scores varied from 3 to 12, and frequently harbored the pathogenicity island PAI IV536. The intestinal tract of healthy children constitute an important reservoir of ESBL producing E. coli. Thus, improvement of hygiene measures mainly in the school environment and rational use of antibiotics would be of great help in preventing selection and diffusion of resistant strains from intestinal microbiota.


Assuntos
Antibacterianos/farmacologia , Portador Sadio/epidemiologia , Cefalosporinas/farmacologia , Infecções por Escherichia coli/epidemiologia , Escherichia coli/efeitos dos fármacos , Fezes/microbiologia , Resistência beta-Lactâmica , Portador Sadio/microbiologia , Criança , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Feminino , Genótipo , Humanos , Integrons , Masculino , Tipagem Molecular , Plasmídeos/análise , Prevalência , Tunísia/epidemiologia , Fatores de Virulência/genética
7.
AIDS Res Hum Retroviruses ; 33(1): 77-81, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27473255

RESUMO

In this study, the genetic diversity of HIV-1 in Tunisia was analyzed. For this, 193 samples were collected in different regions of Tunisia between 2012 and 2015. A protease and reverse transcriptase fragment were amplified and sequenced. Phylogenetic analyses were performed through maximum likelihood and recombination was analyzed by bootscanning. Six HIV-1 subtypes (B, A1, G, D, C, and F2), 5 circulating recombinant forms (CRF02_AG, CRF25_cpx, CRF43_02G, CRF06_cpx, and CRF19_cpx), and 11 unique recombinant forms were identified. Subtype B (46.4%) and CRF02_AG (39.4%) were the predominant genetic forms. A group of 44 CRF02_AG sequences formed a distinct Tunisian cluster, which also included four viruses from western Europe. Nine viruses were closely related to isolates collected in other African or in European countries. In conclusion, a high HIV-1 genetic diversity is observed in Tunisia and the local spread of CRF02_AG is first documented in this country.


Assuntos
Variação Genética , Infecções por HIV/virologia , HIV-1/classificação , HIV-1/genética , Análise por Conglomerados , Europa (Continente) , Genótipo , Infecções por HIV/epidemiologia , Protease de HIV/genética , Transcriptase Reversa do HIV/genética , HIV-1/isolamento & purificação , Humanos , Epidemiologia Molecular , Filogenia , Reação em Cadeia da Polimerase , Recombinação Genética , Análise de Sequência de DNA , Tunísia/epidemiologia
8.
Front Microbiol ; 7: 1859, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27965626

RESUMO

Healthcare-associated infections due to cefotaxime-resistant (CTX-R) Enterobacteriaceae have become a major public health threat, especially in intensive care units (ICUs). Often acquired nosocomially, CTX-R Enterobacteriaceae can be introduced initially by patients at admission. This study aimed to determine the prevalence and genetic characteristics of CTX-R Enterobacteriaceae-intestinal carriage in ICU patients, to evaluate the rate of acquisition of these organisms during hospitalization, and to explore some of the associated risk factors for both carriage and acquisition. Between December 2014 and February 2015, the 63 patients admitted in the ICU of Charles Nicolle hospital were screened for rectal CTX-R Enterobacteriaceae colonization at admission and once weekly thereafter to identify acquisition. CTX-R Enterobacteriaceae fecal carriage rate was 20.63% (13/63) at admission. Among the 50 non-carriers, 35 were resampled during their hospitalization and the acquisition rate was 42.85% (15/35). Overall, 35 CTX-R Enterobacteriaceae isolates were collected from 28 patients (25 Klebsiella pneumoniae, seven Escherichia coli, and three Enterobacter cloacae strains). Seven patients were simultaneously colonized with two CTX-R Enterobacteriaceae isolates. CTX-M-15 was detected in most of the CTX-R Enterobacteriaceae isolates (30/35, 88.23%). Three strains co-produced CMY-4 and 22 strains were carbapenem-resistant and co-produced a carbapenemase [OXA-48 (n = 13) or NDM-1 (n = 6)]. Molecular typing of K. pneumoniae strains, revealed eight Pulsed field gel electrophoresis (PFGE) patterns and four sequence types (ST) [ST101, ST147, ST429, and ST336]. However, E. coli isolates were genetically unrelated and belonged to A (n = 2), B1 (n = 2) and B2 (n = 3) phylogenetic groups and to ST131 (two strains), ST572 (two strains), ST615 (one strain) and ST617 (one strain). Five colonized patients were infected by CTX-R Enterobacteriaceae (four with the same strain identified from their rectal swab and one with a different strain). Whether imported or acquired during the stay in the ICU, colonization by CTX-R Enterobacteriaceae is a major risk factor for the occurrence of serious nosocomial infections. Their systematic screening in fecal carriage is mandatory to prevent the spread of these multidrug resistant bacteria.

9.
Tunis Med ; 94(2): 95-101, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27532523

RESUMO

BACKGROUND: Identifying the infecting bacterial flora is one of the main rules to be followed to ensure the success of antibiotherapy in the treatment of the infected diabetic foot. The aim of the work was to define the bacteriological profile of the bacteria causing the infection of the diabetic foot at the surgery unit B of Charles Nicolle's hospital in Tunis and determine the prognostic factors of this condition. METHODS: It was an open prospective study. It concerned 100 diabetic patients operated on for diabetic foot infection. All patients had bacteriological samples taken through deep scraping and swabing carried out in the operating room. RESULTS: The average age of patients was 59,5 ±11 years, with a sex-ratio of 2,4. The foot infection was represented in 82 % of cases by a wet gangrene. The enterobacteria were the most frequently isolated bacteria (73%), followed by streptococcus (10%), Staphylococcus aureus (9%). The rate of multidrug-resistant bacteria was of 9,5%. The empiric antibiotic therapy used (fusidic acid +amoxicillin/ clavulanic acid) was inactiveon 44,1% of the isolated bacteria. When we compared the group of patients with unfavourable development (who have been reoperated) and the group of patients with favourable development, we have found two poor prognosis factors : arteritis  (p=0,018 ; OR=23,7) and presence of multidrug-resistant bacteria (p=0,027 ; OR=5,8). CONCLUSION: The enterobacteria were the main bacteria causing the infection of diabetic foot. The prognostic factors found, arteritis and isolation of multidrug-resistant bacteria, outpoint the importance of multidisciplinary care.


Assuntos
Pé Diabético/tratamento farmacológico , Pé Diabético/microbiologia , Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana Múltipla , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Infecção dos Ferimentos/tratamento farmacológico , Infecção dos Ferimentos/microbiologia
11.
Diagn Microbiol Infect Dis ; 79(2): 247-51, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24731835

RESUMO

The prevalence of plasmid-mediated quinolone resistance (PMQR) determinants was investigated in a Tunisian collection of 300 uropathogenic Escherichia coli. PMQR genes were detected in 68 isolates (22.7%) as follows: aac(6')-Ib-cr (n=66), qnrB1 (n=3), qnrA6 (n=1), and qnrS1 (n=1). Three isolates carried the 2 determinants aac(6')-Ib-cr and qnrB1. aac(6')-Ib-cr was usually carried on IncF-type plasmids (n=47/60) and frequently associated with blaCTX-M-15 (n=60). Substitutions in gyrA and parC genes were detected in 57.5% of strains. A major cluster including 29 isolates was individualized, 28 of them belonged to the virulent ST131 clone. In our hospital, the high prevalence of PMQR in E. coli isolates was due to horizontal transfer but also to the spread of ST131 clone.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Infecções por Escherichia coli/epidemiologia , Quinolonas/farmacologia , Escherichia coli Uropatogênica/efeitos dos fármacos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Análise por Conglomerados , Infecções por Escherichia coli/microbiologia , Feminino , Genes Bacterianos , Hospitais Universitários , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Tipagem Molecular , Plasmídeos/análise , Prevalência , Tunísia/epidemiologia , Escherichia coli Uropatogênica/classificação , Escherichia coli Uropatogênica/genética , Escherichia coli Uropatogênica/isolamento & purificação , Fatores de Virulência/genética , Adulto Jovem
12.
Folia Microbiol (Praha) ; 59(3): 257-62, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24258848

RESUMO

A collection of 201 Escherichia coli strains isolated from urine of patients in a Tunisian hospital between January 2006 and July 2008 was studied. Microbial identification was done by conventional methods, and antibiotic susceptibility with disk diffusion method was performed according to the Clinical Laboratory and Standards Institute guidelines. Detection of extended-spectrum beta-lactamase (ESBL) was performed by double-disk synergy test (DDST) and identification was done by PCR and sequencing. ESBL-producing isolates were subjected to molecular typing by random amplified polymorphic DNA (RAPD) and ST131 detection by PCR. Four phylogenetic groups (A, B1, B2 and D), 18 virulence genes and CTX-M group were individualized using PCR. Statistical analysis was done by Pearson χ2 test and Mann-Whitney U test. The strains were recovered primarily from urology (28%), maternity (19%) and medicine (16%) wards. Antibiotic resistance rates were ampicilin (72.1%), nalidixic acid (41.8%), ciprofloxacin (38.8%), gentamicin (23.9%) and cefotaxime (17.4%). Thirty-one of cefotaxime-resistant isolates (n = 35) had a positive DDST and harboured bla CTX-M-15 gene. Twenty of them (64.5%) belonged to the ST131 clone and showed the same RAPD DNA profile. Ciprofloxacin- and cotrimoxazole-susceptible isolates were significantly associated with phylogenetic group B2, whereas isolates that were resistant to these molecules were associated with B1 and D phylogenetic groups, respectively. Virulence genes were significantly more frequent among ciprofloxacin- and cotrimoxazole-susceptible strains than those resistant to these antibiotics. However, CXT-M-15-producing isolates were associated with many virulence genes. Isolates concomitantly susceptible to the three antimicrobials agents (ciprofloxacin, cefotaxime and cotrimoxazole) were significantly associated with group B2 and high virulence score, whereas isolates with resistance patterns especially those including resistance to ciprofloxacin belonged predominantly to B1 phylogroup and haboured few virulence genes. The emergence of virulent and multidrug-resistant E. coli is a concerning development that deserves close attention in our institution.


Assuntos
Infecção Hospitalar , Farmacorresistência Bacteriana Múltipla , Infecções por Escherichia coli/microbiologia , Genótipo , Infecções Urinárias/microbiologia , Escherichia coli Uropatogênica/efeitos dos fármacos , Escherichia coli Uropatogênica/genética , beta-Lactamases/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/epidemiologia , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Filogenia , Tunísia , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/epidemiologia , Escherichia coli Uropatogênica/classificação , Escherichia coli Uropatogênica/isolamento & purificação , Virulência/genética , beta-Lactamases/metabolismo
13.
J Biomol Struct Dyn ; 32(8): 1202-10, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23869485

RESUMO

We report the identification of a novel CC chemokine receptor 5 (CCR5) variant that seems associated with resistance to HIV-1 infection. The V130I mutation of the CCR5 receptor is located in the intracellular loop ICL2 known as DRY box and described in the literature as a nonsynonymous mutation present in nonhuman primates group. Extensive molecular modeling and dynamics simulations were performed to elucidate the mechanism by which the V130I mutation may induce conformational change of the CCR5 folding protein and prevent the interaction with the ß-arrestin protein. Our study provides new mechanistic insight into how a specific mutation in the regulatory domain of CCR5 might alter the structural folding of the DRY box and the possible ICL2 loop binding with the ß-arrestin protein, as described in our previous computational study. The results from our large-scale simulations complement recent experimental results and clinical features and offer useful insights into the mechanism behind CCR5 protein folding and signal transduction. In order for HIV, the entry of the virus to the cells must fuse with the CCR5 receptor that sits on the surface of T-helper immune cells. The described V130I mutation in the gene encoding the CCR5 protein may results in a defective CCR5-Arrestin binding complex that blocks entry of the virus.


Assuntos
Infecções por HIV/virologia , HIV-1/genética , Receptores CCR5/química , Sequência de Aminoácidos , Arrestinas/química , Resistência à Doença , Infecções por HIV/genética , HIV-1/metabolismo , Humanos , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Mutação , Ligação Proteica , Dobramento de Proteína , Receptores CCR5/genética , beta-Arrestinas
14.
Virus Genes ; 48(1): 189-92, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24174280

RESUMO

Glycosylation on the globular head of the hemagglutinin (HA) protein of influenza virus acts as an important target for recognition and destruction of virus by innate immune proteins of the collectin family. In the current study, we have characterized the dynamic amino acid changes at N-linked glycosylation sites of full length sequences of HA genes of 5 A/H3N2 Tunisian strains isolates from mild, severe, and fatal cases. Compared to the reference strain, A/Perth/16/2009 substitutions in potential N-glycosylation sites were observed in 5 HA genes at five different positions (45, 124, 128, 144, and 145) generating the losses and gains of N-linked glycosylation sites. Also the mutation N145S was presented in the receptor-binding site of all segments analyzed. Point mutations in several positions in the gene encoding the H3 of Tunisian strains were shown to ablate a glycan attachment site and also loss of a potential glycosylation site. The relation between these mutations and virulence of influenza A/H3N2 virus needed to be verified in the further experiments.


Assuntos
Glicosilação , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Vírus da Influenza A Subtipo H3N2/genética , Influenza Humana/virologia , Mutação Puntual , Adulto , Pré-Escolar , Feminino , Humanos , Lactente , Influenza Humana/epidemiologia , Influenza Humana/patologia , Masculino , Dados de Sequência Molecular , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , RNA Viral/genética , Análise de Sequência de DNA , Tunísia/epidemiologia , Virulência , Adulto Jovem
15.
PLoS One ; 8(9): e74064, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24069267

RESUMO

BACKGROUND: The data contribute to a better understanding of the circulation of influenza viruses especially in North-Africa. OBJECTIVE: The objective of this surveillance was to detect severe influenza cases, identify their epidemiological and virological characteristics and assess their impact on the healthcare system. METHOD: We describe in this report the findings of laboratory-based surveillance of human cases of influenza virus and other respiratory viruses' infection during three seasons in Tunisia. RESULTS: The 2008-09 winter influenza season is underway in Tunisia, with co-circulation of influenza A/H3N2 (56.25%), influenza A(H1N1) (32.5%), and a few sporadic influenza B viruses (11.25%). In 2010-11 season the circulating strains are predominantly the 2009 pandemic influenza A(H1N1)pdm09 (70%) and influenza B viruses (22%). And sporadic viruses were sub-typed as A/H3N2 and unsubtyped influenza A, 5% and 3%, respectively. Unlike other countries, highest prevalence of influenza B virus Yamagata-like lineage has been reported in Tunisia (76%) localised into the clade B/Bangladesh/3333/2007. In the pandemic year, influenza A(H1N1)pdm09 predominated over other influenza viruses (95%). Amino acid changes D222G and D222E were detected in the HA gene of A(H1N1)pdm09 virus in two severe cases, one fatal case and one mild case out of 50 influenza A(H1N1)pdm09 viruses studied. The most frequently reported respiratory virus other than influenza in three seasons was RSV (45.29%). CONCLUSION: This article summarises the surveillance and epidemiology of influenza viruses and other respiratory viruses, showing how rapid improvements in influenza surveillance were feasible by connecting the existing structure in the health care system for patient records to electronic surveillance system for reporting ILI cases.


Assuntos
Influenza Humana/epidemiologia , Orthomyxoviridae/classificação , Vigilância em Saúde Pública , Geografia Médica , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , História do Século XXI , Humanos , Influenza Humana/história , Influenza Humana/virologia , Orthomyxoviridae/genética , Filogenia , Estações do Ano , Vigilância de Evento Sentinela , Tunísia
16.
Diagn Pathol ; 8: 124, 2013 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-23902660

RESUMO

BACKGROUND: The novel pandemic A (H1N1) pdm09 virus was first identified in Mexico in April 2009 and since then it spread worldwide over a short period of time. Although the virus infection is generally associated with mild disease and a relatively low mortality, it is projected that mutations in specific regions of the viral genome, especially within the receptor binding domain of the haemagglutinin (HA) protein could result in more virulent virus stains, leading to a more severe pathogenicity. METHODS: To monitor the genetic polymorphisms at position 222 of Haemagglutinin of influenza A(H1N1)pdm09 viruses from both outpatients with mild influenza and individuals with severe disease requiring hospitalization, during 2009-2010 and 2010-2011 seasons, a sequence-based genotypic assessment of viral populations to understand the prevalence of D222G mutation. RESULTS: The D222G was identified in clinical specimens from 3 out of 42 cases analyzed in Tunisia with severe outcome (7%). Interestingly, in one fatal case out of four viruses taken from fatal cases studied (25%). Also this mutation was found in one mild case out of 8 mild cases studied (0.1%). D222E substitution was found in virus taken from one patient with severe clinical syndrome (2%) out of 42 severe cases analyzed and E374K substitution was found in two severe cases (4%) out of 42 severe cases studied. CONCLUSIONS: A specific mutation in the viral haemagglutinin (D222G) was found in fatal, severe and mild case. Further virological, clinical and epidemiological investigations are needed to ascertain the role of this and other mutations that may alter the virulence and transmissibility of the pandemic influenza A (H1N1)pdm09. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1027334947811255.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/genética , Mutação , Pandemias , Adolescente , Adulto , Feminino , Frequência do Gene , Genótipo , Hospitalização , Humanos , Vírus da Influenza A Subtipo H1N1/patogenicidade , Influenza Humana/diagnóstico , Influenza Humana/epidemiologia , Influenza Humana/transmissão , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Fenótipo , Índice de Gravidade de Doença , Fatores de Tempo , Tunísia/epidemiologia , Virulência
17.
Virol J ; 10: 150, 2013 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-23679923

RESUMO

We present major results concerning isolation and determination of the nucleotide sequence of hemagglutinin (HA1) of the pandemic (H1N1)pdm09 influenza viruses found in Tunisia. Amino acid analysis revealed minor amino acid changes in the antigenic or receptor-binding domains. We found mutations that were also present in 1918 pandemic virus, which includes S183P in 4 and S185T mutation in 19 of 27 viruses analyzed from 2011, while none of the 2009 viruses carried these mutations. Also two specific amino acid differences into N-glycosylation sites (N288T and N276H) were detected. The phylogenetic analysis revealed that the majority of the Tunisian isolates clustered with clade A/St. Petersburg/27/2011 viruses characterized by D97N and S185T mutations. However it also reveals a trend of 2010 strains to accumulate amino acid variation and form new phylogenetic clade with three specific amino acid substitutions: V47I, E172K and K308E.


Assuntos
Variação Genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/virologia , Substituição de Aminoácidos , Análise por Conglomerados , Humanos , Dados de Sequência Molecular , Filogenia , RNA Viral/genética , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Tunísia
18.
Diagn Pathol ; 7: 138, 2012 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-23044036

RESUMO

In this study we report the prevalence of antiretroviral drug resistant HIV-1 genotypes of virus isolated from Djiboutian patients who failed first-line antiretroviral therapy (ART) and from ART naïve patients. PATIENTS AND METHODS: A total of 35 blood samples from 16 patients who showed first-line ART failure (>1000 viral genome copies/ml) and 19 ART-naïve patients were collected in Djibouti from October 2009 to December 2009. Both the protease (PR) and reverse transcriptase (RT) genes were amplified and sequenced using National Agency for AIDS Research (ANRS) protocols. The Stanford HIV database algorithm was used for interpretation of resistance data and genotyping. RESULTS: Among the 16 patients with first-line ART failure, nine (56.2%) showed reverse transcriptase inhibitor-resistant HIV-1 strains: two (12.5%) were resistant to nucleoside (NRTI), one (6.25%) to non-nucleoside (NNRTI) reverse transcriptase inhibitors, and six (37.5%) to both. Analysis of the DNA sequencing data indicated that the most common mutations conferring drug resistance were M184V (38%) for NRTI and K103N (25%) for NNRTI. Only NRTI primary mutations K101Q, K103N and the PI minor mutation L10V were found in ART naïve individuals. No protease inhibitor resistant strains were detected. In our study, we found no detectable resistance in ∼ 44% of all patients who experienced therapeutic failure which was explained by low compliance, co-infection with tuberculosis and malnutrition. Genotyping revealed that 65.7% of samples were infected with subtype C, 20% with CRF02_AG, 8.5% with B, 2.9% with CRF02_AG/C and 2.9% with K/C. CONCLUSION: The results of this first study about drug resistance mutations in first-line ART failures show the importance of performing drug resistance mutation test which guides the choice of a second-line regimen. This will improve the management of HIV-infected Djiboutian patients. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2051206212753973.


Assuntos
Antirretrovirais/uso terapêutico , Farmacorresistência Viral/genética , Infecções por HIV/tratamento farmacológico , Protease de HIV/genética , Transcriptase Reversa do HIV/genética , HIV-1/efeitos dos fármacos , Adulto , Contagem de Linfócito CD4 , Coinfecção , Comorbidade , Análise Mutacional de DNA , Djibuti/epidemiologia , Feminino , Genótipo , Infecções por HIV/diagnóstico , Infecções por HIV/virologia , HIV-1/genética , HIV-1/patogenicidade , Humanos , Masculino , Desnutrição/epidemiologia , Adesão à Medicação , Testes de Sensibilidade Microbiana , Mutação , Medição de Risco , Fatores de Risco , Falha de Tratamento , Tuberculose/epidemiologia
19.
Arch Virol ; 157(9): 1813-4, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22684533

RESUMO

Recently, the D222G substitution was observed in the HA of pandemic (H1N1) 2009 viruses isolated from fatal cases in several countries. We made a similar observation in one fatal case in Tunisia showing a D222G substitution in a virus isolate. The man was 47 years old and had no other subjacent pathologies or any known risk factors. He died after three days, suffering from severe respiratory symptoms of flu. The causal link of the D222G substitution in Tunisia with virulence must be verified. Further study is warranted to elucidate the intriguing relationship between the D222G substitution and severe disease. Constant molecular surveillance is important to monitor the pathogenicity of circulating strains and evaluate vaccine efficacy.


Assuntos
Hemaglutininas Virais/genética , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/virologia , Mutação de Sentido Incorreto , Substituição de Aminoácidos , Evolução Fatal , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/mortalidade , Influenza Humana/patologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Proteínas Mutantes/genética , RNA Viral/genética , Análise de Sequência de DNA , Tunísia
20.
Tunis Med ; 88(12): 890-3, 2010 Dec.
Artigo em Francês | MEDLINE | ID: mdl-21136355

RESUMO

BACKGROUND: A Cytomegalovirus infection (HCMV) causes severe complications in immunosuppressed individuals (transplant recipients and AIDS patients). AIM: To detect the DNA of the HCMV by three molecular methods, and to identify the fastest method and most significant. METHODS: we tested 50 samples in order to detect the presence of the HCMV. This research was carried out by molecular Hybridization, the pp65 Antigenemia and PCR on the blood of the patients presenting an infection to CMV. RESULTS: Molecular hybridization is positive for 64%, Antigenemia is detected in 26 cases (50%) and the plasmatic PCR is positive in 13 cases (26%). These studies demonstrated that molecular hybridization permitted CMV detection of different biological liquid but Antigenemia and PCR techniques were used to determine of from leukocytes. Plasma-PCR and Hybridization assay presented the qualitatifs results. CONCLUSION: These studies indicate that there is a combining virological between molecular methods.


Assuntos
Citomegalovirus/genética , DNA Viral/isolamento & purificação , Hospedeiro Imunocomprometido , Feminino , Técnicas Genéticas , Humanos , Masculino
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