Bution of SeroCP IgA index in relation to MIF IgA antibody seropositivity in the control group. T... more Bution of SeroCP IgA index in relation to MIF IgA antibody seropositivity in the control group. The continuous lines are the manufacturer's cut off indices, and the discontinuous lines are the optimized cut off values.<b>Copyright information:</b>Taken from "Evaluation and optimization of a commercial enzyme linked immunosorbent assay for detection of IgA antibodies"http://www.biomedcentral.com/1471-2334/8/98BMC Infectious Diseases 2008;8():98-98.Published online 26 Jul 2008PMCID:PMC2515311.
E differences between OD 450 nm values were less than 20%.<b>Copyright information:</b&g... more E differences between OD 450 nm values were less than 20%.<b>Copyright information:</b>Taken from "Evaluation and optimization of a commercial enzyme linked immunosorbent assay for detection of IgA antibodies"http://www.biomedcentral.com/1471-2334/8/98BMC Infectious Diseases 2008;8():98-98.Published online 26 Jul 2008PMCID:PMC2515311.
Background/Aims: We aimed to describe spontaneous short-term hepatitis B Virus (HBV) DNA fluctuat... more Background/Aims: We aimed to describe spontaneous short-term hepatitis B Virus (HBV) DNA fluctuations and to assess the usefulness of quantitative HBsAg (qHBsAg) in Tunisian patients with HBeAg-negative chronic HBV infection.Methods: We included 174 treatment-naïve patients with chronic HBeAg-negative HBV. A one-year prospective follow-up was carried out with serial determinations of HBV DNA, alanine aminotransferase (ALT) levels and qHBsAg. Patients were classified into three groups: inactive carriers (G1), patients with HBeAg negative CHB (G2) and patients with “indeterminant state” (G3). For this latter group, a liver biopsy was indicated.Results: Genotype D was the only detected. During the follow-up, 21.6% and 19.5% of patients with low initial (<2000 IU/mL) and intermediate viral load (2000-20000 IU/mL), experienced a subsequent increase in their HBV DNA levels above 2000 and 20000 IU/mL, respectively. Significant variations of HBV DNA levels (≥0.5 log10 IU/mL) were observe...
L'objectif de notre etude etait d'analyser les aspects epidemiologiques et le profil bact... more L'objectif de notre etude etait d'analyser les aspects epidemiologiques et le profil bacteriologique des endocardites infectieuses (El) dans la region de Sfax (Tunisie). Nous avons mene une etude retrospective interessant tous les cas d'El certaines selon les criteres de Duke hospitalises au CHU Hedi Chaker de Sfax entre janvier 1997 et decembre 2000. Le diagnostic bacteriologique a ete base sur les hemocultures, la culture de la valve cardiaque et la serologie. Soixante-douze cas d'El ont ete retenus. L'âge moyen etait de 32,3 ans ; 47,3 % des patients n'avaient pas d'antecedent cardiaque connu, 25 % avaient une prothese valvulaire, 20,8 % une valvulopathie native et 6,9 % une cardiopathie congenitale. Un antecedent de RAA a ete note dans 66 % des El sur valvulopathie native et dans 55,5 % des El sur prothese. Le siege de l'El etait mitral dans 39 % des cas, aortique (27,5 %) et mitro-aortique (26 %). La porte d'entree etait retrouvee ou presumee...
Les auteurs rapportent les resultats d'une enquete cas temoins realisee en collaboration entr... more Les auteurs rapportent les resultats d'une enquete cas temoins realisee en collaboration entre les services de medecine du travail et d'immunologie du CHU Hedi CHAKER, Sfax au cours de l'annee 2000. L'objectif est de rechercher un controle genetique par le systeme HLA classe I, et d'evaluer la contribution eventuelle d'autres facteurs favorisants (tabac, sexe, âge) la non reponse au vaccin anti hepatitique B. Ainsi, dans une population de 32 agents de sante depistes non repondeurs au VAHB grâce au dosage des anticorps anti HBs, nous avons realise le phenotypage HLA A, B par la technique de microcytotoxicite complement dependant. La frequence des antigenes HLA classe I etudies, a ete comparee pour le groupe des non repondeurs a la frequence observee dans un groupe temoin fait de 52 agents de sante depistes repondeurs. Le taux de non reponse a la vaccination antihepatitique B est evalue a 5 %. Une difference a ete constatee au niveau des marqueurs HLA-A1 et-B44...
Background: Escherichia coli ST131 is a multidrug pandemic clone causing serious infections parti... more Background: Escherichia coli ST131 is a multidrug pandemic clone causing serious infections particularly in humans. We investigate the colonization status and prevalence of E. coli ST131 and its subclones H30 and H30Rx on collections of extended spectrum beta-lactamase (ESBL)-producing E. coli isolates (EPE) obtained from healthy animal and human carriers and community and nosocomial human infections.
Hepatitis A and Other Associated Hepatobiliary Diseases [Working Title]
Improvements in hygiene and socioeconomic conditions in many parts of the world have led to an ep... more Improvements in hygiene and socioeconomic conditions in many parts of the world have led to an epidemiological shift in hepatitis A with a transition from high to low endemicity. Consequently, in these areas, higher proportion of symptomatic disease among adolescents resulting in large-scale community outbreaks has been described. In Tunisia, an increase in the average age at the time of infection has been reported, hence resulting in regular outbreaks, especially household and primary school epidemics. Molecular investigation of such outbreaks, based on the determination of viral genotype and genetic relatedness between hepatitis A virus (HAV) strains, is a useful tool to identify the potential source of HAV contamination but also to assess the virus molecular dynamics over time, such as the introduction of a new genotype or a specific clustering of HAV strains according to the geographical origin. In Sfax city, (Center-East of Tunisia), only HAV strains of genotype IA are circulating. In rural areas, HAV infection is still highly endemic with probably a water-borne transmission pattern. Nevertheless, the considerable genetic heterogeneity observed in urban areas highlights the changing pattern of hepatitis A epidemiology in these settings. Further molecular studies are strongly needed to better understand HAV epidemiology in Tunisia.
Four group A streptococcus (GAS) bacteraemia occurred in a small burn unit within 2 weeks. The GA... more Four group A streptococcus (GAS) bacteraemia occurred in a small burn unit within 2 weeks. The GAS patient isolates, characterized as emm89, shared the same PFGE pulsotype with two other strains isolated 2 months later. The outbreak investigation revealed that a nurse was the most likely source of GAS transmission, as she was confirmed to carry the same outbreak strain in her throat and had direct and regular contact with the six outbreak patients in the unit. The outbreak was controlled after the nurse had undergone eradication treatment. This report highlights the emergence of the emm89 clone and its capacity to elicit invasive GAS outbreaks.
Despite the potential biological importance of lipopeptides from Bacillus amyloliquefaciens as an... more Despite the potential biological importance of lipopeptides from Bacillus amyloliquefaciens as antimicrobial compounds, their effects on Agrobacterium tumefaciens biofilms have not been previously studied. These latter are important virulence factors for the development and re-occurrence of crown gall disease. As part of the development of a new biopesticide acting as anti-biofilm and biocontrol agent, we investigated for the first time the ability of a mixture of lipopeptides produced by B. amyloliquefaciens strain 32a to inhibit the tumor formation on plants and to reduce the formation of biofilms by the phytopathogenic A. tumefaciens strains C58 and B6. The mixture was found to display a strong biosurfactant activity as well as bactericidal activity against planktonic Agrobacterium cells. Moreover, the lipopeptide treatment inhibited biofilm formation in the range of 79.58 ± 0.60–100.00 ± 0.00% and dislodged 43.42 ± 0.91–93.89 ± 2.70% of preformed biofilm. For these assays, fluorescence microscopy did not show any adherent cell in the anti-adhesive assay and only few ones in the cell-dislodging assay. More importantly, lipopeptide-enriched extract inhibits tumor formation on tomato stem when treatments were applied after pathogen adhesion to wounded tissues. By virtue of its ability to inhibit biofilms formed on biotic and abiotic surfaces and to control efficiently tumor development, the 32a lipopeptide mixture may represent an excellent new tool for an efficient biocontrol of crown gall disease.
Background. Our aim was to compare clinical, laboratory and radiological features of spontaneous ... more Background. Our aim was to compare clinical, laboratory and radiological features of spontaneous spondylodiscitis secondary to tuberculosis and brucellosis. Methods. A retrospective study which included 86 patients diagnosed as spondylodiscitis with confirmed aetiology between 1995 and 2012. Of these patients, 56 (65.1%) had tuberculous spondylodiscitis (TS) and 30 (34.9%) had brucellar spondylodiscitis (BS). Results. The clinical, laboratory and radiological features of TS and BS were summarized in the table.
To study the epidemiological, clinical and bacteriological aspects and outcome of purulent neonat... more To study the epidemiological, clinical and bacteriological aspects and outcome of purulent neonatal meningitis (PNM). Retrospective analysis of 55 cases of PNM hospitalized in the pediatric ward of Hedi Chaker Hospital from 1990 to 2012. Infants less than 29 days of age were included. The diagnosis was made on either the presence of bacteria in the cerebrospinal fluid (CSF) or the combination of pleocytosis &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;30 cells/mm(3), protein level &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;1.3 g/l and glucose level &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;2.2 mmol/l or CSF/blood glucose ratio &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.4. The male:female sex ratio was 1.75. One or more maternal risk factors for infection were found in 24 cases. The main symptoms were fever and poor feeding. Soluble antigen was positive in four cases and cultures had isolated the bacteria in 28 cases. The mortality rate was 40%. The sequelae rate in the survivors was 16.4%. This study emphasizes the severity of PNM with high rates of mortality and neurological sequelae.
The American journal of tropical medicine and hygiene, 2005
Bartonella quintana is a fastidious microorganism associated with blood culture negative endocard... more Bartonella quintana is a fastidious microorganism associated with blood culture negative endocarditis. In this study, 40 sera with cross-reactivity between Chlamydia species from patients from Sfax, Tunisia, were serologically tested for Bartonella. Thirteen sera were positive for Bartonella with IgG titers >/=1:800. Western blot and cross-absorption confirmed the diagnosis of Bartonella quintana endocarditis in 12 cases and Bartonella henselae endocarditis in 1 case. These sera were also positive by LightCycler nested PCR amplification for the rnpb (7 of 13) and fur (11 of 13) genes. Eleven patients had a definite diagnosis of endocarditis, which represents 9.8% of all endocarditis. Because Bartonella endocarditis seems to be very common in Tunisia, we suggest that its serology be performed systematically whenever endocarditis is suspected.
Because a multiresistant K. pneumoniae outbreak detected in an intensive care unit of a parisian ... more Because a multiresistant K. pneumoniae outbreak detected in an intensive care unit of a parisian hospital, combined to the production of the plasmid-encoded cephalosporinase ACC-1, a probable importation via a patient was suggested from another country (Tunisia). The investigation was conducted to examine 35 clinical strains of enterobacteria resistant to ceftazidime without synergy towards Augmentin. Other test of synergy with two inhibitors, BRL 42715, Ro 48-5545 was performed by diffusion method and deposit of 10 micrograms of inhibitor on disks containing ceftazidime, cefoxitin and cefotetan. Synergies were obtained suggesting a probable production of ACC-1 type among six isolates of K. pneumoniae (two), Proteus mirabilis (one) and Salmonella (three) issued from different units. The isoelectric focusing on gel revealed at least one band of beta-lactamase activity at 7.8 but also demonstrated the simultaneous production of several probable beta-lactamases including TEM-type, SHV-...
Bution of SeroCP IgA index in relation to MIF IgA antibody seropositivity in the control group. T... more Bution of SeroCP IgA index in relation to MIF IgA antibody seropositivity in the control group. The continuous lines are the manufacturer's cut off indices, and the discontinuous lines are the optimized cut off values.<b>Copyright information:</b>Taken from "Evaluation and optimization of a commercial enzyme linked immunosorbent assay for detection of IgA antibodies"http://www.biomedcentral.com/1471-2334/8/98BMC Infectious Diseases 2008;8():98-98.Published online 26 Jul 2008PMCID:PMC2515311.
E differences between OD 450 nm values were less than 20%.<b>Copyright information:</b&g... more E differences between OD 450 nm values were less than 20%.<b>Copyright information:</b>Taken from "Evaluation and optimization of a commercial enzyme linked immunosorbent assay for detection of IgA antibodies"http://www.biomedcentral.com/1471-2334/8/98BMC Infectious Diseases 2008;8():98-98.Published online 26 Jul 2008PMCID:PMC2515311.
Background/Aims: We aimed to describe spontaneous short-term hepatitis B Virus (HBV) DNA fluctuat... more Background/Aims: We aimed to describe spontaneous short-term hepatitis B Virus (HBV) DNA fluctuations and to assess the usefulness of quantitative HBsAg (qHBsAg) in Tunisian patients with HBeAg-negative chronic HBV infection.Methods: We included 174 treatment-naïve patients with chronic HBeAg-negative HBV. A one-year prospective follow-up was carried out with serial determinations of HBV DNA, alanine aminotransferase (ALT) levels and qHBsAg. Patients were classified into three groups: inactive carriers (G1), patients with HBeAg negative CHB (G2) and patients with “indeterminant state” (G3). For this latter group, a liver biopsy was indicated.Results: Genotype D was the only detected. During the follow-up, 21.6% and 19.5% of patients with low initial (<2000 IU/mL) and intermediate viral load (2000-20000 IU/mL), experienced a subsequent increase in their HBV DNA levels above 2000 and 20000 IU/mL, respectively. Significant variations of HBV DNA levels (≥0.5 log10 IU/mL) were observe...
L'objectif de notre etude etait d'analyser les aspects epidemiologiques et le profil bact... more L'objectif de notre etude etait d'analyser les aspects epidemiologiques et le profil bacteriologique des endocardites infectieuses (El) dans la region de Sfax (Tunisie). Nous avons mene une etude retrospective interessant tous les cas d'El certaines selon les criteres de Duke hospitalises au CHU Hedi Chaker de Sfax entre janvier 1997 et decembre 2000. Le diagnostic bacteriologique a ete base sur les hemocultures, la culture de la valve cardiaque et la serologie. Soixante-douze cas d'El ont ete retenus. L'âge moyen etait de 32,3 ans ; 47,3 % des patients n'avaient pas d'antecedent cardiaque connu, 25 % avaient une prothese valvulaire, 20,8 % une valvulopathie native et 6,9 % une cardiopathie congenitale. Un antecedent de RAA a ete note dans 66 % des El sur valvulopathie native et dans 55,5 % des El sur prothese. Le siege de l'El etait mitral dans 39 % des cas, aortique (27,5 %) et mitro-aortique (26 %). La porte d'entree etait retrouvee ou presumee...
Les auteurs rapportent les resultats d'une enquete cas temoins realisee en collaboration entr... more Les auteurs rapportent les resultats d'une enquete cas temoins realisee en collaboration entre les services de medecine du travail et d'immunologie du CHU Hedi CHAKER, Sfax au cours de l'annee 2000. L'objectif est de rechercher un controle genetique par le systeme HLA classe I, et d'evaluer la contribution eventuelle d'autres facteurs favorisants (tabac, sexe, âge) la non reponse au vaccin anti hepatitique B. Ainsi, dans une population de 32 agents de sante depistes non repondeurs au VAHB grâce au dosage des anticorps anti HBs, nous avons realise le phenotypage HLA A, B par la technique de microcytotoxicite complement dependant. La frequence des antigenes HLA classe I etudies, a ete comparee pour le groupe des non repondeurs a la frequence observee dans un groupe temoin fait de 52 agents de sante depistes repondeurs. Le taux de non reponse a la vaccination antihepatitique B est evalue a 5 %. Une difference a ete constatee au niveau des marqueurs HLA-A1 et-B44...
Background: Escherichia coli ST131 is a multidrug pandemic clone causing serious infections parti... more Background: Escherichia coli ST131 is a multidrug pandemic clone causing serious infections particularly in humans. We investigate the colonization status and prevalence of E. coli ST131 and its subclones H30 and H30Rx on collections of extended spectrum beta-lactamase (ESBL)-producing E. coli isolates (EPE) obtained from healthy animal and human carriers and community and nosocomial human infections.
Hepatitis A and Other Associated Hepatobiliary Diseases [Working Title]
Improvements in hygiene and socioeconomic conditions in many parts of the world have led to an ep... more Improvements in hygiene and socioeconomic conditions in many parts of the world have led to an epidemiological shift in hepatitis A with a transition from high to low endemicity. Consequently, in these areas, higher proportion of symptomatic disease among adolescents resulting in large-scale community outbreaks has been described. In Tunisia, an increase in the average age at the time of infection has been reported, hence resulting in regular outbreaks, especially household and primary school epidemics. Molecular investigation of such outbreaks, based on the determination of viral genotype and genetic relatedness between hepatitis A virus (HAV) strains, is a useful tool to identify the potential source of HAV contamination but also to assess the virus molecular dynamics over time, such as the introduction of a new genotype or a specific clustering of HAV strains according to the geographical origin. In Sfax city, (Center-East of Tunisia), only HAV strains of genotype IA are circulating. In rural areas, HAV infection is still highly endemic with probably a water-borne transmission pattern. Nevertheless, the considerable genetic heterogeneity observed in urban areas highlights the changing pattern of hepatitis A epidemiology in these settings. Further molecular studies are strongly needed to better understand HAV epidemiology in Tunisia.
Four group A streptococcus (GAS) bacteraemia occurred in a small burn unit within 2 weeks. The GA... more Four group A streptococcus (GAS) bacteraemia occurred in a small burn unit within 2 weeks. The GAS patient isolates, characterized as emm89, shared the same PFGE pulsotype with two other strains isolated 2 months later. The outbreak investigation revealed that a nurse was the most likely source of GAS transmission, as she was confirmed to carry the same outbreak strain in her throat and had direct and regular contact with the six outbreak patients in the unit. The outbreak was controlled after the nurse had undergone eradication treatment. This report highlights the emergence of the emm89 clone and its capacity to elicit invasive GAS outbreaks.
Despite the potential biological importance of lipopeptides from Bacillus amyloliquefaciens as an... more Despite the potential biological importance of lipopeptides from Bacillus amyloliquefaciens as antimicrobial compounds, their effects on Agrobacterium tumefaciens biofilms have not been previously studied. These latter are important virulence factors for the development and re-occurrence of crown gall disease. As part of the development of a new biopesticide acting as anti-biofilm and biocontrol agent, we investigated for the first time the ability of a mixture of lipopeptides produced by B. amyloliquefaciens strain 32a to inhibit the tumor formation on plants and to reduce the formation of biofilms by the phytopathogenic A. tumefaciens strains C58 and B6. The mixture was found to display a strong biosurfactant activity as well as bactericidal activity against planktonic Agrobacterium cells. Moreover, the lipopeptide treatment inhibited biofilm formation in the range of 79.58 ± 0.60–100.00 ± 0.00% and dislodged 43.42 ± 0.91–93.89 ± 2.70% of preformed biofilm. For these assays, fluorescence microscopy did not show any adherent cell in the anti-adhesive assay and only few ones in the cell-dislodging assay. More importantly, lipopeptide-enriched extract inhibits tumor formation on tomato stem when treatments were applied after pathogen adhesion to wounded tissues. By virtue of its ability to inhibit biofilms formed on biotic and abiotic surfaces and to control efficiently tumor development, the 32a lipopeptide mixture may represent an excellent new tool for an efficient biocontrol of crown gall disease.
Background. Our aim was to compare clinical, laboratory and radiological features of spontaneous ... more Background. Our aim was to compare clinical, laboratory and radiological features of spontaneous spondylodiscitis secondary to tuberculosis and brucellosis. Methods. A retrospective study which included 86 patients diagnosed as spondylodiscitis with confirmed aetiology between 1995 and 2012. Of these patients, 56 (65.1%) had tuberculous spondylodiscitis (TS) and 30 (34.9%) had brucellar spondylodiscitis (BS). Results. The clinical, laboratory and radiological features of TS and BS were summarized in the table.
To study the epidemiological, clinical and bacteriological aspects and outcome of purulent neonat... more To study the epidemiological, clinical and bacteriological aspects and outcome of purulent neonatal meningitis (PNM). Retrospective analysis of 55 cases of PNM hospitalized in the pediatric ward of Hedi Chaker Hospital from 1990 to 2012. Infants less than 29 days of age were included. The diagnosis was made on either the presence of bacteria in the cerebrospinal fluid (CSF) or the combination of pleocytosis &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;30 cells/mm(3), protein level &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;1.3 g/l and glucose level &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;2.2 mmol/l or CSF/blood glucose ratio &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.4. The male:female sex ratio was 1.75. One or more maternal risk factors for infection were found in 24 cases. The main symptoms were fever and poor feeding. Soluble antigen was positive in four cases and cultures had isolated the bacteria in 28 cases. The mortality rate was 40%. The sequelae rate in the survivors was 16.4%. This study emphasizes the severity of PNM with high rates of mortality and neurological sequelae.
The American journal of tropical medicine and hygiene, 2005
Bartonella quintana is a fastidious microorganism associated with blood culture negative endocard... more Bartonella quintana is a fastidious microorganism associated with blood culture negative endocarditis. In this study, 40 sera with cross-reactivity between Chlamydia species from patients from Sfax, Tunisia, were serologically tested for Bartonella. Thirteen sera were positive for Bartonella with IgG titers >/=1:800. Western blot and cross-absorption confirmed the diagnosis of Bartonella quintana endocarditis in 12 cases and Bartonella henselae endocarditis in 1 case. These sera were also positive by LightCycler nested PCR amplification for the rnpb (7 of 13) and fur (11 of 13) genes. Eleven patients had a definite diagnosis of endocarditis, which represents 9.8% of all endocarditis. Because Bartonella endocarditis seems to be very common in Tunisia, we suggest that its serology be performed systematically whenever endocarditis is suspected.
Because a multiresistant K. pneumoniae outbreak detected in an intensive care unit of a parisian ... more Because a multiresistant K. pneumoniae outbreak detected in an intensive care unit of a parisian hospital, combined to the production of the plasmid-encoded cephalosporinase ACC-1, a probable importation via a patient was suggested from another country (Tunisia). The investigation was conducted to examine 35 clinical strains of enterobacteria resistant to ceftazidime without synergy towards Augmentin. Other test of synergy with two inhibitors, BRL 42715, Ro 48-5545 was performed by diffusion method and deposit of 10 micrograms of inhibitor on disks containing ceftazidime, cefoxitin and cefotetan. Synergies were obtained suggesting a probable production of ACC-1 type among six isolates of K. pneumoniae (two), Proteus mirabilis (one) and Salmonella (three) issued from different units. The isoelectric focusing on gel revealed at least one band of beta-lactamase activity at 7.8 but also demonstrated the simultaneous production of several probable beta-lactamases including TEM-type, SHV-...
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