12 research outputs found

    MgrB Inactivation Is Responsible for Acquired Resistance to Colistin in Enterobacter hormaechei subsp. steigerwaltii

    Get PDF
    Multidrug-resistant strains belonging to the Enterobacter cloacae complex (ECC) group, and especially those belonging to clusters C-III, C-IV, and C-VIII, have increasingly emerged as a leading cause of health care-associated infections, with colistin used as one of the last lines of treatment. However, colistin-resistant ECC strains have emerged. The aim of this study was to prove that MgrB, the negative regulator of the PhoP/PhoQ two-component regulatory system, is involved in colistin resistance in ECC of cluster C-VIII, formerly referred to as Enterobacter hor-maechei subsp. steigerwaltii. An in vitro mutant (Eh22-Mut) was selected from a clinical isolate of Eh22. The sequencing analysis of its mgrB gene showed the presence of one nucleotide deletion leading to the formation of a truncated protein of six instead of 47 amino acids. The wild-type mgrB gene from Eh22 and that of a clinical strain of Klebsiella pneumoniae used as controls were cloned, and the corresponding recombinant plasmids were used for complementation assays. The results showed a fully restored susceptibility to colistin and confirmed for the first time that mgrB gene expression plays a key role in acquired resistance to colistin in ECC strains

    Incomplete hippocampalInversion : a comprehensive MRI study of over 2000 subjects

    Full text link
    The incomplete-hippocampal-inversion (IHI), also known as malrotation, is an atypical anatomical pattern of the hippocampus, which has been reported in healthy subjects in different studies. However, extensive characterization of IHI in a large sample has not yet been performed. Furthermore, it is unclear whether IHI are restricted to the medial-temporal lobe or are associated with more extensive anatomical changes. Here, we studied the characteristics of IHI in a community-based sample of 2008 subjects of the IMAGEN database and their association with extra-hippocampal anatomical variations. The presence of IHI was assessed on T1-weighted anatomical magnetic resonance imaging (MRI) using visual criteria. We assessed the association of IHI with other anatomical changes throughout the brain using automatic morphometry of cortical sulci. We found that IHI were much more frequent in the left hippocampus (left: 17%, right: 6%, χ2−test, p < 10−28). Compared to subjects without IHI, subjects with IHI displayed morphological changes in several sulci located mainly in the limbic lobe. Our results demonstrate that IHI are a common left-sided phenomenon in normal subjects and that they are associated with morphological changes outside the medial temporal lobe

    First description of NDM-1-positive Klebsiella pneumoniae in the Tunisian community

    Get PDF
    First description of NDM-1-positive Klebsiella pneumoniae in the Tunisian community Sir, Multidrug-resistant bacteria, especially carbapenemase-producing Enterobacteriaceae, are a major public health-threat worldwide. As part of a collaborative monitoring programme, our laboratory at the University of Bordeaux has received a collection of multidrug-resistant bacterial strains to further characterise their ÎČ-lactamase content. They were sent from private Tunisian diagnostic laboratories and were collected from community patients suffering from urinary tract infection. In this context, multidrug-resistant isolate 18TA was collected in January 2018 in Sfax region from the urine of a 45-year old female with no previous hospitalisation during the preceding month and no history of recent foreign travel. Strain 18TA had been initially classified as Enterobacter spp. by biochemical tests (API 10S gallery). Following matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS) (Bruker Daltonics) and confirmation by PCR amplification and sequencing of 16S rDNA, strain 18TA was re-identified as Klebsiella pneumoniae. Multilocus sequence typing (MLST) (http:// bigsdb.pasteur.fr/klebsiella/klebsiella.html) indicated that strain 18TA belonged to Sequence Type (ST), ST147. Minimum inhibitory concentrations (MICs) of various anti-microbials were determined using a BD Phoenix TM 100 automated system (BD Diagnostic Systems, Le Pont-de-Claix, France) and the results were interpreted using BD EpiCenter TM software (BD Diagnostic Systems). The MICs for ciprofloxacin and colistin were also determined by the broth microdilution method according to European Committee on Antimicrobial Susceptibility Testing 2019 guidelines (https://www.sfm-microbiologie.org/2019/05/06/ casfm-eucast-2019-v2/). Strain 18TA was resistant to all tested ÎČ-lactams, including carbapenems (Table 1). The strain was also resistant to gentamicin, tobramycin, quinolones (nalidixic acid), fluoroquinolones (cipro-floxacin) and trimethoprim/sulfamethoxazole (SXT) and showed decreased susceptibility to tigecycline (MIC = 2 mg/mL). It remained susceptible to amikacin, fosfomycin and colistin (Table 1). The imipenem/ethylene diamine tetra-acetic acid (EDTA) combined disk diffusion test was positive since the inhibition zone increased by 7 mm with the imipenem/EDTA disk compared with the imipenem disk alone, suggesting the presence of a metallo-ÎČ-lactamase (MBL) [1]. In addition, the double-disk synergy test (between amoxicillin/clavulanic acid and broad-spectrum cepha-losporins) showed the presence of an extended-spectrum ÎČ-lactamase (ESBL)-producing phenotype (data not shown). The transferability of the ÎČ-lactam resistance determinant was assessed by conjugation assay using an azide-resistant (Az R) mutant of Escherichia coli C600 as the recipient strain. Selection was performed on Mueller-Hinton agar plates supplemented with sodium azide (300 mg/mL) and ertapenem (4 mg/mL). A transfer frequency of ca. 10-4 transconjugants per donor was observed. Comparison of MICs between the transconjugant (Tc-18TA) and its recipient strain (C600 Az R) showed increased resistance not only to the tested ÎČ-lactams but also to gentamicin, tobramycin and SXT (Table 1). Total genomic DNA of strain 18TA was screened using different multiplex PCR amplifications for various ÎČ-lactamase genes (bla TEM-like , bla SHV-like , bla OXA-1-like , bla CTX-M groups 1, 2, 9, 18 and 25, bla OXA-48-like , bla KPC and bla GES and the MBL genes bla VIM , bla IMP and bla NDM) as described previously [2]. Amplification results following agarose gel electrophoresis analysis showed the presence of group 1 bla CTX-M and bla NDM genes together with bla TEM-like , bla SHV-like and bla OXA-1-like genes. Except for the bla SHV gene that was found in strain 18TA but not in the transconjugant Tc-18TA and that was attributed to the chromosomally-encoded species-specific enzyme of K. pneumoniae, the four other ÎČ-lactamases were also found in transconjugant Tc-18TA (Table 1). Amplification of the entire bla genes was performed and subsequent sequencing ((Custom DNA sequencing; Eurofins Genomics GmbH, Ebersberg, Germany) showed the presence of the narrow-spectrum ÎČ-lactamase genes bla TEM-1B and bla OXA-1 associated with the bla CTX-M-15 ESBL gene and the bla NDM-1 MBL gene both in 18TA and Tc-18TA (Table 1). Furthermore, amplifications searching for aac(3)-IIa (gentamicin and tobramycin resistance) and sul1 and dfrA1 (sulfamethoxazole and trimetho-prim resistance, respectively) were positive both in 18TA and Tc-18TA. These genes were also present in Kp3771, a ST147 NDM-1-producing K. pneumoniae strain recently recovered from a patient hospitalised in an intensive care unit of University Hospital Tahar Sfar in Tunisia [3]. NDM-1-positive K. pneumoniae strains have been previously described in Tunisia, but only from hospitalised patients [1-5]. The current study reports the first description of K. pneumoniae carrying the carbapenemase NDM-1 in the Tunisian community http://dx

    A Comprehensive MRI Study of Over 2000 Subjects

    Get PDF
    The incomplete-hippocampal-inversion (IHI), also known as malrotation, is an atypical anatomical pattern of the hippocampus, which has been reported in healthy subjects in different studies. However, extensive characterization of IHI in a large sample has not yet been performed. Furthermore, it is unclear whether IHI are restricted to the medial-temporal lobe or are associated with more extensive anatomical changes. Here, we studied the characteristics of IHI in a community-based sample of 2008 subjects of the IMAGEN database and their association with extra-hippocampal anatomical variations. The presence of IHI was assessed on T1-weighted anatomical magnetic resonance imaging (MRI) using visual criteria. We assessed the association of IHI with other anatomical changes throughout the brain using automatic morphometry of cortical sulci. We found that IHI were much more frequent in the left hippocampus (left: 17%, right: 6%, χ2−test, p < 10−28). Compared to subjects without IHI, subjects with IHI displayed morphological changes in several sulci located mainly in the limbic lobe. Our results demonstrate that IHI are a common left-sided phenomenon in normal subjects and that they are associated with morphological changes outside the medial temporal lobe

    Analyse de la rĂ©sistance aux antibiotiques chez les entĂ©robactĂ©ries et Ă©tude d’une potentielle voie alternative aux traitements antibiotiques

    Full text link
    The increase of multidrug-resistant bacteria (BMR) to antibiotics is a major public health problem. The first objective of the thesis was to search for the presence of BMR, poorly documented in the community in Tunisia. For the first time, we isolate a Klebsiella pneumoniae belonging to the sequence type ST147 producing carbapenemase NDM-1 in this setting, at Sfax. Our data also indicate an unusually high proportion (47%) of Escherichia coli producing committally two extended-spectrum ß-lactamases. Four of them, with CTX-M-15 and CTX-M-27, are divided into 2 clonal strains of type A-ST617 (2 isolates) and B2-ST131 subclade C2 (2 isolates). All contain a plasmid with the same allelic combination, F31: A4: B1; suggesting a possible dissemination of this replicon. In another study (community-based, Djerba), a multiresistant clonal strain Eh22 of Enterobacter hormaechei, containing a 300 kbp conjugative plasmid of IncHI2, was isolated from 2 patients without apparent epidemiological relationship. The plasmid was sequenced and shows the presence of different resistance genes including 4 genes encoding ÎČ-lactamases (blaTEM-1, blaDHA-1, blaCTX-M-3 and blaSHV-12). In a second part, we studied in Eh22, the resistance to colistin (CS), antibiotic of last resort. After selection of an in vitro mutant, we showed for the first time, in Enterobacter spp, that this resistance can be due to a mutation in the gene encoding MgrB, a negative regulator of the 2-component PhoQP system that allows the synthesis of cationic residues on lipopolysaccharide, target of CS. In the last part, bacteriocins-like molecules active on BMR were searched in a collection of Bacillus thurengiensis. One of them, BUPM103, inhibits the growth of BMR. The gene for a potential bacthuricin F103 (11 kDa) was identified by an in silico analysis and it was produced in E. coli. The filtered supernatant secretion showed a growth inhibitory activity against a multiresistant K. pneumoniae, in contrast to control (without secretion). This recombinant bacthuricine could constitute a therapeutic alternative for the BMR treatment.L’augmentation des bactĂ©ries multirĂ©sistantes (BMR) aux antibiotiques est un problĂšme majeur de santĂ© publique. Le premier objectif de la thĂšse a Ă©tĂ© de rechercher la prĂ©sence, peu documentĂ©e, de BMR dans la communautĂ© en Tunisie. Pour la premiĂšre fois, nous isolons une Klebsiella pneumoniae de sĂ©quence type ST147 productrice de la carbapĂ©nĂšmase NDM-1 dans ce milieu, Ă  Sfax. Nos donnĂ©es indiquent aussi une proportion inhabituellement Ă©levĂ©e (47%) d’Escherichia coli produisant deux ß-lactamases Ă  spectre Ă©largi. Quatre d’entre eux, avec CTX-M-15 et CTX-M-27, se divisent en 2 souches clonales de type A-ST617 (2 isolats) et B2-ST131 subclade C2 (2 isolats). Toutes contiennent un plasmide avec la mĂȘme combinaison allĂ©lique, F31:A4:B1 ; suggĂ©rant une possible dissĂ©mination de ce rĂ©plicon. Lors d’une autre Ă©tude (milieu communautaire, Djerba), une souche clonale Eh22 d’Enterobacter hormaechei multirĂ©sistante, contenant un plasmide conjugatif IncHI2 de 300 kpb, a Ă©tĂ© isolĂ©e chez 2 patients sans lien Ă©pidĂ©miologique apparent. Le plasmide a Ă©tĂ© sĂ©quencĂ© et montre la prĂ©sence de diffĂ©rents gĂšnes de rĂ©sistance incluant 4 gĂšnes codant pour des ß-lactamases (blaTEM-1, blaDHA-1, blaCTX-M-3 et blaSHV-12). Dans une seconde partie, nous avons Ă©tudiĂ© chez Eh22 la rĂ©sistance Ă  la colistine (CS), antibiotique de dernier recours. AprĂšs avoir sĂ©lectionnĂ© un mutant in vitro, nous avons montrĂ© pour la premiĂšre fois, chez Enterobacter spp, que cette rĂ©sistance pouvait ĂȘtre due Ă  une mutation dans le gĂšne codant pour MgrB, un rĂ©gulateur nĂ©gatif du systĂšme Ă  2 composants PhoQP qui permet la synthĂšse de groupements cationiques sur le lipopolysaccharide, cible de la CS. Dans une derniĂšre partie, des molĂ©cules de type bactĂ©riocines actives sur les BMR ont Ă©tĂ© recherchĂ©es Ă  partir d’une collection de Bacillus thurengiensis. L’une d’elle, BUPM103, inhibe la croissance de BMR. Une analyse in silico a permis d’identifier le gĂšne d’une potentielle bacthuricine F103 (11 kDa) qui a Ă©tĂ© produite dans E. coli. Le surnageant de sĂ©crĂ©tion filtrĂ© a montrĂ© une activitĂ© d’inhibition de la croissance de K. pneumoniae multirĂ©sistante, contrairement au contrĂŽle (sans sĂ©crĂ©tion). Cette bacthuricine recombinante pourrait constituer une alternative thĂ©rapeutique pour le traitement des BMR

    Analysis of antibiotic resistance in enterobacteria and study of a potential alternative way to antibiotic treatments

    Full text link
    L’augmentation des bactĂ©ries multirĂ©sistantes (BMR) aux antibiotiques est un problĂšme majeur de santĂ© publique. Le premier objectif de la thĂšse a Ă©tĂ© de rechercher la prĂ©sence, peu documentĂ©e, de BMR dans la communautĂ© en Tunisie. Pour la premiĂšre fois, nous isolons une Klebsiella pneumoniae de sĂ©quence type ST147 productrice de la carbapĂ©nĂšmase NDM-1 dans ce milieu, Ă  Sfax. Nos donnĂ©es indiquent aussi une proportion inhabituellement Ă©levĂ©e (47%) d’Escherichia coli produisant deux ß-lactamases Ă  spectre Ă©largi. Quatre d’entre eux, avec CTX-M-15 et CTX-M-27, se divisent en 2 souches clonales de type A-ST617 (2 isolats) et B2-ST131 subclade C2 (2 isolats). Toutes contiennent un plasmide avec la mĂȘme combinaison allĂ©lique, F31:A4:B1 ; suggĂ©rant une possible dissĂ©mination de ce rĂ©plicon. Lors d’une autre Ă©tude (milieu communautaire, Djerba), une souche clonale Eh22 d’Enterobacter hormaechei multirĂ©sistante, contenant un plasmide conjugatif IncHI2 de 300 kpb, a Ă©tĂ© isolĂ©e chez 2 patients sans lien Ă©pidĂ©miologique apparent. Le plasmide a Ă©tĂ© sĂ©quencĂ© et montre la prĂ©sence de diffĂ©rents gĂšnes de rĂ©sistance incluant 4 gĂšnes codant pour des ß-lactamases (blaTEM-1, blaDHA-1, blaCTX-M-3 et blaSHV-12). Dans une seconde partie, nous avons Ă©tudiĂ© chez Eh22 la rĂ©sistance Ă  la colistine (CS), antibiotique de dernier recours. AprĂšs avoir sĂ©lectionnĂ© un mutant in vitro, nous avons montrĂ© pour la premiĂšre fois, chez Enterobacter spp, que cette rĂ©sistance pouvait ĂȘtre due Ă  une mutation dans le gĂšne codant pour MgrB, un rĂ©gulateur nĂ©gatif du systĂšme Ă  2 composants PhoQP qui permet la synthĂšse de groupements cationiques sur le lipopolysaccharide, cible de la CS. Dans une derniĂšre partie, des molĂ©cules de type bactĂ©riocines actives sur les BMR ont Ă©tĂ© recherchĂ©es Ă  partir d’une collection de Bacillus thurengiensis. L’une d’elle, BUPM103, inhibe la croissance de BMR. Une analyse in silico a permis d’identifier le gĂšne d’une potentielle bacthuricine F103 (11 kDa) qui a Ă©tĂ© produite dans E. coli. Le surnageant de sĂ©crĂ©tion filtrĂ© a montrĂ© une activitĂ© d’inhibition de la croissance de K. pneumoniae multirĂ©sistante, contrairement au contrĂŽle (sans sĂ©crĂ©tion). Cette bacthuricine recombinante pourrait constituer une alternative thĂ©rapeutique pour le traitement des BMR.The increase of multidrug-resistant bacteria (BMR) to antibiotics is a major public health problem. The first objective of the thesis was to search for the presence of BMR, poorly documented in the community in Tunisia. For the first time, we isolate a Klebsiella pneumoniae belonging to the sequence type ST147 producing carbapenemase NDM-1 in this setting, at Sfax. Our data also indicate an unusually high proportion (47%) of Escherichia coli producing committally two extended-spectrum ß-lactamases. Four of them, with CTX-M-15 and CTX-M-27, are divided into 2 clonal strains of type A-ST617 (2 isolates) and B2-ST131 subclade C2 (2 isolates). All contain a plasmid with the same allelic combination, F31: A4: B1; suggesting a possible dissemination of this replicon. In another study (community-based, Djerba), a multiresistant clonal strain Eh22 of Enterobacter hormaechei, containing a 300 kbp conjugative plasmid of IncHI2, was isolated from 2 patients without apparent epidemiological relationship. The plasmid was sequenced and shows the presence of different resistance genes including 4 genes encoding ÎČ-lactamases (blaTEM-1, blaDHA-1, blaCTX-M-3 and blaSHV-12). In a second part, we studied in Eh22, the resistance to colistin (CS), antibiotic of last resort. After selection of an in vitro mutant, we showed for the first time, in Enterobacter spp, that this resistance can be due to a mutation in the gene encoding MgrB, a negative regulator of the 2-component PhoQP system that allows the synthesis of cationic residues on lipopolysaccharide, target of CS. In the last part, bacteriocins-like molecules active on BMR were searched in a collection of Bacillus thurengiensis. One of them, BUPM103, inhibits the growth of BMR. The gene for a potential bacthuricin F103 (11 kDa) was identified by an in silico analysis and it was produced in E. coli. The filtered supernatant secretion showed a growth inhibitory activity against a multiresistant K. pneumoniae, in contrast to control (without secretion). This recombinant bacthuricine could constitute a therapeutic alternative for the BMR treatment

    Analysis of antibiotic resistance in enterobacteria and study of a potential alternative way to antibiotic treatments

    Full text link
    L’augmentation des bactĂ©ries multirĂ©sistantes (BMR) aux antibiotiques est un problĂšme majeur de santĂ© publique. Le premier objectif de la thĂšse a Ă©tĂ© de rechercher la prĂ©sence, peu documentĂ©e, de BMR dans la communautĂ© en Tunisie. Pour la premiĂšre fois, nous isolons une Klebsiella pneumoniae de sĂ©quence type ST147 productrice de la carbapĂ©nĂšmase NDM-1 dans ce milieu, Ă  Sfax. Nos donnĂ©es indiquent aussi une proportion inhabituellement Ă©levĂ©e (47%) d’Escherichia coli produisant deux ß-lactamases Ă  spectre Ă©largi. Quatre d’entre eux, avec CTX-M-15 et CTX-M-27, se divisent en 2 souches clonales de type A-ST617 (2 isolats) et B2-ST131 subclade C2 (2 isolats). Toutes contiennent un plasmide avec la mĂȘme combinaison allĂ©lique, F31:A4:B1 ; suggĂ©rant une possible dissĂ©mination de ce rĂ©plicon. Lors d’une autre Ă©tude (milieu communautaire, Djerba), une souche clonale Eh22 d’Enterobacter hormaechei multirĂ©sistante, contenant un plasmide conjugatif IncHI2 de 300 kpb, a Ă©tĂ© isolĂ©e chez 2 patients sans lien Ă©pidĂ©miologique apparent. Le plasmide a Ă©tĂ© sĂ©quencĂ© et montre la prĂ©sence de diffĂ©rents gĂšnes de rĂ©sistance incluant 4 gĂšnes codant pour des ß-lactamases (blaTEM-1, blaDHA-1, blaCTX-M-3 et blaSHV-12). Dans une seconde partie, nous avons Ă©tudiĂ© chez Eh22 la rĂ©sistance Ă  la colistine (CS), antibiotique de dernier recours. AprĂšs avoir sĂ©lectionnĂ© un mutant in vitro, nous avons montrĂ© pour la premiĂšre fois, chez Enterobacter spp, que cette rĂ©sistance pouvait ĂȘtre due Ă  une mutation dans le gĂšne codant pour MgrB, un rĂ©gulateur nĂ©gatif du systĂšme Ă  2 composants PhoQP qui permet la synthĂšse de groupements cationiques sur le lipopolysaccharide, cible de la CS. Dans une derniĂšre partie, des molĂ©cules de type bactĂ©riocines actives sur les BMR ont Ă©tĂ© recherchĂ©es Ă  partir d’une collection de Bacillus thurengiensis. L’une d’elle, BUPM103, inhibe la croissance de BMR. Une analyse in silico a permis d’identifier le gĂšne d’une potentielle bacthuricine F103 (11 kDa) qui a Ă©tĂ© produite dans E. coli. Le surnageant de sĂ©crĂ©tion filtrĂ© a montrĂ© une activitĂ© d’inhibition de la croissance de K. pneumoniae multirĂ©sistante, contrairement au contrĂŽle (sans sĂ©crĂ©tion). Cette bacthuricine recombinante pourrait constituer une alternative thĂ©rapeutique pour le traitement des BMR.The increase of multidrug-resistant bacteria (BMR) to antibiotics is a major public health problem. The first objective of the thesis was to search for the presence of BMR, poorly documented in the community in Tunisia. For the first time, we isolate a Klebsiella pneumoniae belonging to the sequence type ST147 producing carbapenemase NDM-1 in this setting, at Sfax. Our data also indicate an unusually high proportion (47%) of Escherichia coli producing committally two extended-spectrum ß-lactamases. Four of them, with CTX-M-15 and CTX-M-27, are divided into 2 clonal strains of type A-ST617 (2 isolates) and B2-ST131 subclade C2 (2 isolates). All contain a plasmid with the same allelic combination, F31: A4: B1; suggesting a possible dissemination of this replicon. In another study (community-based, Djerba), a multiresistant clonal strain Eh22 of Enterobacter hormaechei, containing a 300 kbp conjugative plasmid of IncHI2, was isolated from 2 patients without apparent epidemiological relationship. The plasmid was sequenced and shows the presence of different resistance genes including 4 genes encoding ÎČ-lactamases (blaTEM-1, blaDHA-1, blaCTX-M-3 and blaSHV-12). In a second part, we studied in Eh22, the resistance to colistin (CS), antibiotic of last resort. After selection of an in vitro mutant, we showed for the first time, in Enterobacter spp, that this resistance can be due to a mutation in the gene encoding MgrB, a negative regulator of the 2-component PhoQP system that allows the synthesis of cationic residues on lipopolysaccharide, target of CS. In the last part, bacteriocins-like molecules active on BMR were searched in a collection of Bacillus thurengiensis. One of them, BUPM103, inhibits the growth of BMR. The gene for a potential bacthuricin F103 (11 kDa) was identified by an in silico analysis and it was produced in E. coli. The filtered supernatant secretion showed a growth inhibitory activity against a multiresistant K. pneumoniae, in contrast to control (without secretion). This recombinant bacthuricine could constitute a therapeutic alternative for the BMR treatment

    Detection of extended-spectrum beta-lactamase and scarbapenemase-producing Enterobacteriaceae in Tunisia

    Full text link
    The emergence of dramatic urinary tract infections (UTIs) caused by the members of the Enterobacteriales is an important public health problem in the community as well as in Tunisian hospitals. This study aims to investigate the prevalence of extended-spectrum &beta;-lactamase (ESBL) and carbapenemase-producing uropathogenic isolates of Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae).&nbsp;Based on decreased susceptibility to &beta;-lactams antibiotics and analyzed for the presence of ESBL and carbapenemase genes by Real Time- polymerase chain reaction (RT-PCR), 56 uropathogenic isolates of E. coli (n = 36) and K. pneumoniae (n = 20) were confirmed positive for ESBLs. The CTX-M-type &beta;-lactamases were mostly detected in E. coli isolates (21 strains, 58.33% [95% CI 38.09% - 72.06%]) followed by blaSHV-like (18 strains, 50% [95% CI 32.92% - 67.07%]), blaTEM-like and blaCMY-2-like simultaneously (15 strains, 41.67% [95% CI 25.51% - 59.24%]). Furthermore, the RT-PCR system on the K. pneumoniae strains demonstrated that blaSHV-12-like was the most predominant (16 strains, 80% [95% CI 56.33% - 94.26%]) followed by blaTEM-like (14 strains, 70% [95% CI 45.72% - 88.10%]), blaCTX-M belonging to groups 9 and 1 (11 strains, 55% [95% CI 31.52% - 76.94%]) and finally blaCMY-2-like (10 strains, 50% [95% CI 27.19% - 72.80%]). In addition, E. coli and K. pneumoniae strains harbored a carbapenemase gene blaOXA-48-like with 22.2% [95% CI 10.11% - 39.15%]; 20% [95% CI 12.83% - 43.66%], respectively.Our results confirm the need to monitor the resistance to extended-spectrum &beta;-lactams and to carbapenems among enterobacteria in Tunisia

    Characterization of Incomplete Hippocampal Inversions in a large dataset of young healthy subjects

    Get PDF
    International audienceIncomplete hippocampal inversion (IHI) is an atypical anatomical pattern of the hippocampus. It has been mostly described in patients with epilepsy, in particular with malformations of cortical development but also in temporal lobe epilepsy (Baulac et al. 1998; Bernasconi et al. 2005; Bajic et al. 2009), with a prevalence of 30%-50%. However, IHI are also found in healthy subjects, although with an apparently lower frequency (Bajic et al. 2008). A few studies have investigated the prevalence of IHI in subjects without seizures (Gamss et al. 2009; D. Bajic et al. 2008). However, these studies include a small number of subjects leading to an imprecise estimation of the prevalence of IHI, or included patients without epileptic seizures but referred for other neurological conditions. Therefore, the frequency of IHI in healthy subjects remains unclear.The purpose of our study was to investigate the prevalence of IHI in a large population of healthy subjects

    Detection of Clones B2-ST131-C2 and A-ST617 in Escherichia coli Producing Both CTX-M-15 and CTX-M-27 from Tunisian Community Patients

    Get PDF
    During a two-month period (2017&ndash;2018), 336 urine samples positive for Escherichia coli were collected from Tunisian patients. Of the 336 samples, 266 were collected from community patients and 70 from hospital settings. In all, 15 ESBL producers were identified (8 and 7, respectively) and assigned to 13 pulsotypes, including four ESBL-producing E. coli (ESBL-E) with E1 and E2 profiles (2 isolates each) from community patients. The two strains E1 were identified as B2-ST131 subclade C2 and the two isolates E2, A-ST617. The four strains carrying both CTX-M-15 and CTX-M-27, exhibited the multireplicon IncFII/F1A/F1B with the same formula F31:A4:B1. Two isolates with patterns E3 and E4 (Dice coefficient, 78.7%) isolated from community and hospital settings of two geographic areas were assigned to the emerging ST131 C1-M27 subclade and contained the replicon F1:A-:B20. The remaining ESBL-E divided into different sequence types/associated CTX-M: 2 ST131-C2/CTX-M-15 and ST744/CTX-M-55, ST617/CTM-15, ST2973/CTX-M-55, ST6448/CTX-M-15, ST224/CTX-M-15, ST1431/CTX-M-15, and ST38/CTX-M-27, one isolate each. Our study reports for the first time the presence in the Tunisian community of two clones of E. coli, including the virulent clone ST131-C2 harboring both CTX-M-15 and CTX-M-27, and confirms the spread of the emergent clone ST131-C1-M-27, notably in community urinary tract infections
    corecore