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2. Outbreak of Imported Seventh Pandemic Vibrio cholerae O1 El Tor, Algeria, 2018

Author

Benamrouche, Nabila, Belkader, Chafika, Njamkepo, Elisabeth, Zemam, Sarah Sihem, Sadat, Soraya, Saighi, Karima, Boutabba, Dalila Torkia, Mechouet, Faiza, Benhadj-Slimani, Rym, Zmit, Fatma-Zohra, Rauzier, Jean, Kias, Farid, Zouagui, Souad, Ruckly, Corinne, Yousfi, Mohamed, Zertal, Amel, Chouikrat, Ramdane, Quilici, Marie-Laure, and Weill, Francois-Xavier

Subjects
Epidemics -- Statistics -- Causes of, Vibrio cholerae -- Statistics -- Identification and classification -- Genetic aspects -- 2018 AD, Cholera -- Statistics -- Causes of, Health
Abstract

Cholera, a life-threatening diarrheal disease, is caused by Vibrio cholerae O1, or more rarely O139, serogroup bacteria that produce cholera toxin (CTX) and induce rapid massive loss of body fluids [...]

Published
2022
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4. ShigaPass: an in silico tool predicting Shigella serotypes from whole-genome sequencing assemblies

Author

Yassine, Iman, primary, Hansen, Elisabeth E., additional, Lefèvre, Sophie, additional, Ruckly, Corinne, additional, Carle, Isabelle, additional, Lejay-Collin, Monique, additional, Fabre, Laetitia, additional, Rafei, Rayane, additional, Pardos de la Gandara, Maria, additional, Daboussi, Fouad, additional, Shahin, Ahmad, additional, and Weill, François-Xavier, additional

Published
2023
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5. Rapid emergence of extensively drug-resistant Shigella sonnei in France

Author

Lefèvre, Sophie, primary, Njamkepo, Elisabeth, additional, Feldman, Sarah, additional, Ruckly, Corinne, additional, Carle, Isabelle, additional, Lejay-Collin, Monique, additional, Fabre, Laëtitia, additional, Yassine, Iman, additional, Frezal, Lise, additional, de la Gandara, Maria Pardos, additional, Fontanet, Arnaud, additional, and Weill, François-Xavier, additional

Published
2022
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7. From tailor-made to ready-to-wear meningococcal B vaccines: longitudinal study of a clonal meningococcal B outbreak

Author

Caron, François, du Châtelet, Isabelle Parent, Leroy, Jean-Philippe, Ruckly, Corinne, Blanchard, Myriam, Bohic, Nicole, Massy, Nathalie, Morer, Isabelle, Floret, Daniel, Delbos, Valérie, Hong, Eva, Révillion, Martin, Berthelot, Gilles, Lemée, Ludovic, Deghmane, Ala-Eddine, Bénichou, Jacques, Lévy-Bruhl, Daniel, and Taha, Muhamed-Kheir

Published
2011
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9. Global phylogeography and evolutionary history of Shigella dysenteriae type 1

Author

Njamkepo, Elisabeth, Fawal, Nizar, Tran-Dien, Alicia, Hawkey, Jane, Strockbine, Nancy, Jenkins, Claire, Talukder, Kaisar A., Bercion, Raymond, Kuleshov, Konstantin, Kolínská, Renáta, Russell, Julie E., Kaftyreva, Lidia, Accou-Demartin, Marie, Karas, Andreas, Vandenberg, Olivier, Mather, Alison E., Mason, Carl J., Page, Andrew J., Ramamurthy, Thandavarayan, Bizet, Chantal, Gamian, Andrzej, Carle, Isabelle, Sow, Amy Gassama, Bouchier, Christiane, Wester, Astrid Louise, Lejay-Collin, Monique, Fonkoua, Marie-Christine, Le Hello, Simon, Blaser, Martin J., Jernberg, Cecilia, Ruckly, Corinne, Mérens, Audrey, Page, Anne-Laure, Aslett, Martin, Roggentin, Peter, Fruth, Angelika, Denamur, Erick, Venkatesan, Malabi, Bercovier, Hervé, Bodhidatta, Ladaporn, Chiou, Chien-Shun, Clermont, Dominique, Colonna, Bianca, Egorova, Svetlana, Pazhani, Gururaja P., Ezernitchi, Analia V., Guigon, Ghislaine, Harris, Simon R., Izumiya, Hidemasa, Korzeniowska-Kowal, Agnieszka, Lutyńska, Anna, Gouali, Malika, Grimont, Francine, Langendorf, Céline, Marejková, Monika, Peterson, Lorea A.M., Perez-Perez, Guillermo, Ngandjio, Antoinette, Podkolzin, Alexander, Souche, Erika, Makarova, Mariia, Shipulin, German A., Ye, Changyun, Žemličková, Helena, Herpay, Mária, Grimont, Patrick A. D., Parkhill, Julian, Sansonetti, Philippe, Holt, Kathryn E., Brisse, Sylvain, Thomson, Nicholas R., and Weill, François-Xavier

Published
2016
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10. Population structure analysis and laboratory monitoring of Shigella with a standardised core-genome multilocus sequence typing scheme: a validation study

Author

Yassine, Iman, primary, Lefèvre, Sophie, additional, Hansen, Elisabeth E., additional, Ruckly, Corinne, additional, Carle, Isabelle, additional, Lejay-Collin, Monique, additional, Fabre, Laëtitia, additional, Rafei, Rayane, additional, Clermont, Dominique, additional, de la Gandara, Maria Pardos, additional, Dabboussi, Fouad, additional, Thomson, Nicholas R., additional, and Weill, François-Xavier, additional

Published
2021
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13. Erratum: Global phylogeography and evolutionary history of Shigella dysenteriae type 1

Author

Njamkepo, Elisabeth, Fawal, Nizar, Tran-Dien, Alicia, Hawkey, Jane, Strockbine, Nancy, Jenkins, Claire, Talukder, Kaisar A, Bercion, Raymond, Kuleshov, Konstantin, Kolínská, Renáta, Russell, Julie E, Kaftyreva, Lidia, Accou-Demartin, Marie, Karas, Andreas, Vandenberg, Olivier, Mather, Alison AE, Mason, Carl J, Page, Andrew J, Ramamurthy, Thandavarayan, Bizet, Chantal, Gamian, Andrzej, Carles, Isabelle, Sow, Amy Gassama, Bouchier, Christiane, Wester, Astrid Louise, Lejay-Collin, Monique, Fonkoua, Marie-Christine, Hello, Simon Le, Blaser, Martin J, Jernberg, Cecilia, Ruckly, Corinne, Mérens, Audrey, Page, Anne-Laure, Aslett, Martin, Roggentin, Peter, Fruth, Angelika, Denamur, Erick, Venkatesan, Malabi, Bercovier, Hervé, Bodhidatta, Ladaporn, Chiou, Chien-Shun, Clermont, Dominique, Colonna, Bianca, Egorova, Svetlana, Pazhani, Gururaja GP, Ezernitchi, Analia V, Guigon, Ghislaine, Harris, Simon R, Izumiya, Hidemasa, Korzeniowska-Kowal, Agnieszka, Lutyńska, Anna, Gouali, Malika, Grimont, Francine, Langendorf, Céline, Marejková, Monika, Peterson, Lorea A M LA, Perez-Perez, Guillermo, Ngandjio, Antoinette, Podkolzin, Alexander, Souche, Erika, Makarova, Mariia, Shipulin, German A, Ye, Changyun, Zemlickova, Helena, Herpay, Mária, Grimont, Patrick A D PA, Parkhill, Julian, Sansonetti, Philippe, Holt, Kathryn KE, Brisse, Sylvain, Thomson, Nicholas R, Weill, François-Xavier, Njamkepo, Elisabeth, Fawal, Nizar, Tran-Dien, Alicia, Hawkey, Jane, Strockbine, Nancy, Jenkins, Claire, Talukder, Kaisar A, Bercion, Raymond, Kuleshov, Konstantin, Kolínská, Renáta, Russell, Julie E, Kaftyreva, Lidia, Accou-Demartin, Marie, Karas, Andreas, Vandenberg, Olivier, Mather, Alison AE, Mason, Carl J, Page, Andrew J, Ramamurthy, Thandavarayan, Bizet, Chantal, Gamian, Andrzej, Carles, Isabelle, Sow, Amy Gassama, Bouchier, Christiane, Wester, Astrid Louise, Lejay-Collin, Monique, Fonkoua, Marie-Christine, Hello, Simon Le, Blaser, Martin J, Jernberg, Cecilia, Ruckly, Corinne, Mérens, Audrey, Page, Anne-Laure, Aslett, Martin, Roggentin, Peter, Fruth, Angelika, Denamur, Erick, Venkatesan, Malabi, Bercovier, Hervé, Bodhidatta, Ladaporn, Chiou, Chien-Shun, Clermont, Dominique, Colonna, Bianca, Egorova, Svetlana, Pazhani, Gururaja GP, Ezernitchi, Analia V, Guigon, Ghislaine, Harris, Simon R, Izumiya, Hidemasa, Korzeniowska-Kowal, Agnieszka, Lutyńska, Anna, Gouali, Malika, Grimont, Francine, Langendorf, Céline, Marejková, Monika, Peterson, Lorea A M LA, Perez-Perez, Guillermo, Ngandjio, Antoinette, Podkolzin, Alexander, Souche, Erika, Makarova, Mariia, Shipulin, German A, Ye, Changyun, Zemlickova, Helena, Herpay, Mária, Grimont, Patrick A D PA, Parkhill, Julian, Sansonetti, Philippe, Holt, Kathryn KE, Brisse, Sylvain, Thomson, Nicholas R, and Weill, François-Xavier

Abstract

info:eu-repo/semantics/published

Published
2016

14. Erratum: Global phylogeography and evolutionary history of Shigella dysenteriae type 1

Author

Njamkepo, Elisabeth, primary, Fawal, Nizar, additional, Tran-Dien, Alicia, additional, Hawkey, Jane, additional, Strockbine, Nancy, additional, Jenkins, Claire, additional, Talukder, Kaisar A., additional, Bercion, Raymond, additional, Kuleshov, Konstantin, additional, Kolínská, Renáta, additional, Russell, Julie E., additional, Kaftyreva, Lidia, additional, Accou-Demartin, Marie, additional, Karas, Andreas, additional, Vandenberg, Olivier, additional, Mather, Alison E., additional, Mason, Carl J., additional, Page, Andrew J., additional, Ramamurthy, Thandavarayan, additional, Bizet, Chantal, additional, Gamian, Andrzej, additional, Carle, Isabelle, additional, Sow, Amy Gassama, additional, Bouchier, Christiane, additional, Wester, Astrid Louise, additional, Lejay-Collin, Monique, additional, Fonkoua, Marie-Christine, additional, Le Hello, Simon, additional, Blaser, Martin J., additional, Jernberg, Cecilia, additional, Ruckly, Corinne, additional, Mérens, Audrey, additional, Page, Anne-Laure, additional, Aslett, Martin, additional, Roggentin, Peter, additional, Fruth, Angelika, additional, Denamur, Erick, additional, Venkatesan, Malabi, additional, Bercovier, Hervé, additional, Bodhidatta, Ladaporn, additional, Chiou, Chien-Shun, additional, Clermont, Dominique, additional, Colonna, Bianca, additional, Egorova, Svetlana, additional, Pazhani, Gururaja P., additional, Ezernitchi, Analia V., additional, Guigon, Ghislaine, additional, Harris, Simon R., additional, Izumiya, Hidemasa, additional, Korzeniowska-Kowal, Agnieszka, additional, Lutyńska, Anna, additional, Gouali, Malika, additional, Grimont, Francine, additional, Langendorf, Céline, additional, Marejková, Monika, additional, Peterson, Lorea A.M., additional, Perez-Perez, Guillermo, additional, Ngandjio, Antoinette, additional, Podkolzin, Alexander, additional, Souche, Erika, additional, Makarova, Mariia, additional, Shipulin, German A., additional, Ye, Changyun, additional, Žemličková, Helena, additional, Herpay, Mária, additional, Grimont, Patrick A. D., additional, Parkhill, Julian, additional, Sansonetti, Philippe, additional, Holt, Kathryn E., additional, Brisse, Sylvain, additional, Thomson, Nicholas R., additional, and Weill, François-Xavier, additional

Published
2016
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15. Multicenter Study for Defining the Breakpoint for Rifampin Resistance in Neisseria meningitidis by rpoB Sequencing

Author

Taha, Muhamed-Kheir Hedberg, Sara Thulin Szatanik, Marek and Hong, Eva Ruckly, Corinne Abad, Raquel Bertrand, Sophie and Carion, Francoise Claus, Heike Corso, Alejandra Enriquez, Rocio Heuberger, Sigrid Hryniewicz, Waleria Jolley, Keith A. and Kriz, Paula Mollerach, Marta Musilek, Martin Neri, Arianna Olcen, Per Pana, Marina Skoczynska, Anna and Sorhouet Pereira, Cecilia Stefanelli, Paola Tzanakaki, Georgina and Unemo, Magnus Vazquez, Julio A. Vogel, Ulrich Wasko, Izabela

Abstract

Identification of clinical isolates of Neisseria meningitidis that are resistant to rifampin is important to avoid prophylaxis failure in contacts of patients, but it is hindered by the absence of a breakpoint for resistance, despite many efforts toward standardization. We examined a large number (n = 392) of clinical meningococcal isolates, spanning 25 years (1984 to 2009), that were collected in 11 European countries, Argentina, and the Central African Republic. The collection comprises all clinical isolates with MICs of >= 0.25 mg/liter (n = 161) received by the national reference laboratories for meningococci in the participating countries. Representative isolates displaying rifampin MICs of 1 mg/liter possessed rpoB alleles with nonsynonymous mutations at four critical amino acid residues, D542, H552, S548, and S557, that were absent in the alleles found in all isolates with MICs of

Published
2010

16. Rifampin-resistant Neisseria meningitidis

Author

Taha, Muhamed-Kheir, Zarantonelli, Maria Leticia, Ruckly, Corinne, Giorgin, Dario, and Alonso, Jean-Michel

Subjects
Neisseria meningitidis -- Diagnosis, Neisseria meningitidis -- Risk factors, Neisseria meningitidis -- Care and treatment
Abstract

To The Editor: Immediate management of meningococcal disease requires antimicrobial drug treatment of patients with [beta]-lactams and chemoprophylaxis of contact persons with rifampin. High-level resistance to rifampin (MIC >32 mg/L) [...]

Published
2006

17. Defining the breakpoint for resistance to rifampicin in Neisseria meningitidis by rpoB sequencing

Author

Taha, Muhamed-Kheir, Thulin Hedberg, Sara, Szatanik, Marek, Hong, Eva, Ruckly, Corinne, Abad, Raquel, Bertrand, Sophie, Carion, Francoise, Claus, Heike, Enríquez, Rocío, Heuberger, Sigrid, Jolley, Keith A., Kriz, Paula, Musilek, Martin, Neri, Arianna, Olcén, Per, Pana, Marina, Skoczynska, Anna, Stefanelli, Paola, Tzanakaki, Georgina, Unemo, Magnus, Vàzquez, Julio A., Vogel, Ulrich, Wasko, Izabela, Taha, Muhamed-Kheir, Thulin Hedberg, Sara, Szatanik, Marek, Hong, Eva, Ruckly, Corinne, Abad, Raquel, Bertrand, Sophie, Carion, Francoise, Claus, Heike, Enríquez, Rocío, Heuberger, Sigrid, Jolley, Keith A., Kriz, Paula, Musilek, Martin, Neri, Arianna, Olcén, Per, Pana, Marina, Skoczynska, Anna, Stefanelli, Paola, Tzanakaki, Georgina, Unemo, Magnus, Vàzquez, Julio A., Vogel, Ulrich, and Wasko, Izabela

Abstract

Clinical isolates of Neisseria meningitidis resistant to rifampicin are important to identify asthey lead to failure of chemoprophylaxis of meningococcal disease. However, theidentification of these isolates is hindered by the absence of a harmonized breakpoint despiteefforts of standardization. In the present study, a large number (n=352) of clinical N.meningitidis isolates from 12 mainly European countries and spanning over 25 years (1984 to2009) were examined. The collection comprised all clinical isolates with MIC 0.25 mg/lreceived by the national reference laboratories for meningococci in the participating countries(n=161). In addition, representative isolates displaying MIC of rifampicin <0.25 mg/l wereexamined (n=191). Phenotyping and genotyping of isolates were performed and a 660 bpDNA fragment of the rpoB gene was sequenced in all the included isolates. Sequencesdiffering by at least one nucleotide were defined as a unique rpoB allele (n=55). Geometricmeans of MIC were calculated for isolates displaying the same allele. All the clinical isolatesdisplaying MIC >1 mg/l of rifampicin possessed rpoB alleles with critical mutations (in total21 alleles), resulting in substitutions at the codon H552 and less frequently at nearby codons(S548 and S557). These alterations were absent in the alleles (n=34) found in all isolates withMIC 1 mg/l. Based on these findings, rifampicin susceptible isolates could be defined asthose with MIC 1 mg/l. A new web site was created based on the data from this work (http://neisseria.org/nm/typing/rpoB). The rifampicin resistant isolates belonged to diversegenetic lineages and provoked lower bacteremia levels in mice. This biological cost mayexplain the non-expansion of the rifampicin resistant isolates.

Published
2009

19. Penicillin Binding Proteins as Danger Signals: Meningococcal Penicillin Binding Protein 2 Activates Dendritic Cells through Toll-Like Receptor 4

Author

Hill, Marcelo, primary, Deghmane, Ala-Eddine, additional, Segovia, Mercedes, additional, Zarantonelli, Maria Leticia, additional, Tilly, Gaëlle, additional, Blancou, Philippe, additional, Bériou, Gaëlle, additional, Josien, Régis, additional, Anegon, Ignacio, additional, Hong, Eva, additional, Ruckly, Corinne, additional, Antignac, Aude, additional, Ghachi, Meriem El, additional, Boneca, Ivo Gomperts, additional, Taha, Muhamed-Kheir, additional, and Cuturi, Maria Cristina, additional

Published
2011
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21. Multicenter Study for Defining the Breakpoint for Rifampin Resistance in Neisseria meningitidis by rpoB Sequencing

Author

Taha, Muhamed-Kheir, primary, Thulin Hedberg, Sara, additional, Szatanik, Marek, additional, Hong, Eva, additional, Ruckly, Corinne, additional, Abad, Raquel, additional, Bertrand, Sophie, additional, Carion, Francoise, additional, Claus, Heike, additional, Corso, Alejandra, additional, Enríquez, Rocío, additional, Heuberger, Sigrid, additional, Hryniewicz, Waleria, additional, Jolley, Keith A., additional, Kriz, Paula, additional, Mollerach, Marta, additional, Musilek, Martin, additional, Neri, Arianna, additional, Olcén, Per, additional, Pana, Marina, additional, Skoczynska, Anna, additional, Sorhouet Pereira, Cecilia, additional, Stefanelli, Paola, additional, Tzanakaki, Georgina, additional, Unemo, Magnus, additional, Vázquez, Julio A., additional, Vogel, Ulrich, additional, and Wasko, Izabela, additional

Published
2010
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23. Influenza A Virus Neuraminidase Enhances Meningococcal Adhesion to Epithelial Cells through Interaction with Sialic Acid-Containing Meningococcal Capsules

Author

Rameix-Welti, Marie-Anne, primary, Zarantonelli, Maria Leticia, additional, Giorgini, Dario, additional, Ruckly, Corinne, additional, Marasescu, Monica, additional, van der Werf, Sylvie, additional, Alonso, Jean-Michel, additional, Naffakh, Nadia, additional, and Taha, Muhamed-Kheir, additional

Published
2009
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26. Evaluation of CHROMagar STEC and STEC O104 Chromogenic Agar Media for Detection of Shiga Toxin-Producing Escherichia coliin Stool Specimens

Author

Gouali, Malika, Ruckly, Corinne, Carle, Isabelle, Lejay-Collin, Monique, and Weill, François-Xavier

Abstract

ABSTRACTThe performance of CHROMagar STEC and CHROMagar STEC O104 (CHROMagar Microbiology, Paris, France) media for the detection of Shiga toxin-producing Escherichia coli(STEC) was assessed with 329 stool specimens collected over 14 months from patients with suspected STEC infections (June 2011 to August 2012). The CHROMagar STEC medium, after an enrichment broth step, allowed the recovery of the STEC strain from 32 of the 39 (82.1%) Shiga toxin-positive stool specimens, whereas the standard procedure involving Drigalski agar allowed the recovery of only three additional STEC strains. The isolates that grew on CHROMagar STEC medium belonged to 15 serotypes, including the prevalent non-sorbitol-fermenting (NSF) O157:H7, O26:H11, and O104:H4 serotypes. The sensitivity, specificity, and positive and negative predictive values for the CHROMagar STEC medium were between 89.1% and 91.4%, 83.7% and 86.7%, 40% and 51.3%, and 98% and 98.8%, respectively, depending on whether or not stx-negative eae-positive E. coliwas considered atypical enteropathogenic E. coli(EPEC) or STEC that had lost Shiga toxin genes during infection. In conclusion, the good performance of CHROMagar STEC agar medium, in particular, the high negative predictive value, and its capacity to identify NSF O157:H7 as well as common non-O157 STEC may be useful for clinical bacteriology, public health, and reference laboratories; it could be used in addition to a method targeting Shiga toxins (detection of stxgenes by PCR, immunodetection of Shiga toxins in stool specimens, or Vero cell cytotoxicity assay) as an alternative to O157 culture medium. This combined approach should allow rapid visualization of both putative O157 and non-O157 STEC colonies for subsequent characterization, essential for real-time surveillance of STEC infections and investigations of outbreaks.

Published
2013
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27. Multicenter Study for Defining the Breakpoint for Rifampin Resistance in Neisseria meningitidisby rpoBSequencing

Author

Taha, Muhamed-Kheir, Thulin Hedberg, Sara, Szatanik, Marek, Hong, Eva, Ruckly, Corinne, Abad, Raquel, Bertrand, Sophie, Carion, Francoise, Claus, Heike, Corso, Alejandra, Enríquez, Rocío, Heuberger, Sigrid, Hryniewicz, Waleria, Jolley, Keith A., Kriz, Paula, Mollerach, Marta, Musilek, Martin, Neri, Arianna, Olcén, Per, Pana, Marina, Skoczynska, Anna, Sorhouet Pereira, Cecilia, Stefanelli, Paola, Tzanakaki, Georgina, Unemo, Magnus, Vázquez, Julio A., Vogel, Ulrich, and Wasko, Izabela

Abstract

ABSTRACTIdentification of clinical isolates of Neisseria meningitidisthat are resistant to rifampin is important to avoid prophylaxis failure in contacts of patients, but it is hindered by the absence of a breakpoint for resistance, despite many efforts toward standardization. We examined a large number (n= 392) of clinical meningococcal isolates, spanning 25 years (1984 to 2009), that were collected in 11 European countries, Argentina, and the Central African Republic. The collection comprises all clinical isolates with MICs of ≥0.25 mg/liter (n= 161) received by the national reference laboratories for meningococci in the participating countries. Representative isolates displaying rifampin MICs of <0.25 mg/liter were also examined (n= 231). Typing of isolates was performed, and a 660-bp DNA fragment of the rpoBgene was sequenced. Sequences differing by at least one nucleotide were defined as unique rpoBalleles. The geometric mean of the MICs was calculated for isolates displaying the same allele. The clinical isolates displaying rifampin MICs of >1 mg/liter possessed rpoBalleles with nonsynonymous mutations at four critical amino acid residues, D542, H552, S548, and S557, that were absent in the alleles found in all isolates with MICs of ≤1 mg/liter. Rifampin-susceptible isolates could be defined as those with MICs of ≤1 mg/liter. The rpoBallele sequence and isolate data have been incorporated into the PubMLST Neisseriadatabase (http://pubmlst.org/neisseria/). The rifampin-resistant isolates belonged to diverse genetic lineages and were associated with lower levels of bacteremia and inflammatory cytokines in mice. This biological cost may explain the lack of clonal expansion of these isolates.

Published
2010
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28. Differential modulation of TNF-alpha-induced apoptosis by Neisseria meningitidis.

Author

Deghmane AE, Veckerlé C, Giorgini D, Hong E, Ruckly C, and Taha MK

Subjects
Analysis of Variance, Bacterial Proteins metabolism, Cell Adhesion, Cell Line, Tumor, Endotoxins metabolism, Flow Cytometry, Gene Expression Regulation, Bacterial, Humans, Microscopy, Fluorescence, Neisseria meningitidis metabolism, Receptors, Tumor Necrosis Factor, Type I metabolism, Signal Transduction, Apoptosis, Carrier State microbiology, Meningococcal Infections microbiology, Neisseria meningitidis pathogenicity, Tumor Necrosis Factor-alpha metabolism
Abstract

Infections by Neisseria meningitidis show duality between frequent asymptomatic carriage and occasional life-threatening disease. Bacterial and host factors involved in this balance are not fully understood. Cytopathic effects and cell damage may prelude to pathogenesis of isolates belonging to hyper-invasive lineages. We aimed to analyze cell-bacteria interactions using both pathogenic and carriage meningococcal isolates. Several pathogenic isolates of the ST-11 clonal complex and carriage isolates were used to infect human epithelial cells. Cytopathic effect was determined and apoptosis was scored using several methods (FITC-Annexin V staining followed by FACS analysis, caspase assays and DNA fragmentation). Only pathogenic isolates were able to induce apoptosis in human epithelial cells, mainly by lipooligosaccharide (endotoxin). Bioactive TNF-alpha is only detected when cells were infected by pathogenic isolates. At the opposite, carriage isolates seem to provoke shedding of the TNF-alpha receptor I (TNF-RI) from the surface that protect cells from apoptosis by chelating TNF-alpha. Ability to induce apoptosis and inflammation may represent major traits in the pathogenesis of N. meningitidis. However, our data strongly suggest that carriage isolates of meningococci reduce inflammatory response and apoptosis induction, resulting in the protection of their ecological niche at the human nasopharynx.

Published
2009
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