25 results on '"Aliouat A"'
Search Results
2. SYTO-13, a Viability Marker as a New Tool to Monitor In Vitro Pharmacodynamic Parameters of Anti-Pneumocystis Drugs.
- Author
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Annie Standaert-Vitse, Cécile-Marie Aliouat-Denis, Anna Martinez, Sara Khalife, Muriel Pottier, Nausicaa Gantois, Eduardo Dei-Cas, and El Moukhtar Aliouat
- Subjects
Medicine ,Science - Abstract
While Pneumocystis pneumonia (PcP) still impacts the AIDS patients, it has a growing importance in immunosuppressed HIV-negative patients. To determine the anti-Pneumocystis therapeutic efficacy of new compounds, animal and in vitro models have been developed. Indeed, well-designed mouse or rat experimental models of pneumocystosis can be used to describe the in vivo anti-Pneumocystis activity of new drugs. In vitro models, which enable the screening of a large panel of new molecules, have been developed using axenic cultures or co-culture with feeder cells; but no universally accepted standard method is currently available to evaluate anti-Pneumocystis molecules in vitro. Thus, we chose to explore the use of the SYTO-13 dye, as a new indicator of Pneumocystis viability. In the present work, we established the experimental conditions to define the in vitro pharmacodynamic parameters (EC50, Emax) of marketed compounds (trimethoprim/sulfamethoxazole, pentamidine, atovaquone) in order to specifically measure the intrinsic activity of these anti-P. carinii molecules using the SYTO-13 dye for the first time. Co-labelling the fungal organisms with anti-P. carinii specific antibodies enabled the measurement of viability of Pneumocystis organisms while excluding host debris from the analysis. Moreover, contrary to microscopic observation, large numbers of fungal cells can be analyzed by flow cytometry, thus increasing statistical significance and avoiding misreading during fastidious quantitation of stained organisms. In conclusion, the SYTO-13 dye allowed us to show a reproducible dose/effect relationship for the tested anti-Pneumocystis drugs.
- Published
- 2015
- Full Text
- View/download PDF
3. What do Pneumocystis organisms tell us about the phylogeography of their hosts? The case of the woodmouse Apodemus sylvaticus in continental Europe and western Mediterranean islands.
- Author
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Christine Demanche, Manjula Deville, Johan Michaux, Véronique Barriel, Claire Pinçon, Cécile Marie Aliouat-Denis, Muriel Pottier, Christophe Noël, Eric Viscogliosi, El Moukhtar Aliouat, Eduardo Dei-Cas, Serge Morand, and Jacques Guillot
- Subjects
Medicine ,Science - Abstract
Pneumocystis fungi represent a highly diversified biological group with numerous species, which display a strong host-specificity suggesting a long co-speciation process. In the present study, the presence and genetic diversity of Pneumocystis organisms was investigated in 203 lung samples from woodmice (Apodemus sylvaticus) collected on western continental Europe and Mediterranean islands. The presence of Pneumocystis DNA was assessed by nested PCR at both large and small mitochondrial subunit (mtLSU and mtSSU) rRNA loci. Direct sequencing of nested PCR products demonstrated a very high variability among woodmouse-derived Pneumocystis organisms with a total number of 30 distinct combined mtLSU and mtSSU sequence types. However, the genetic divergence among these sequence types was very low (up to 3.87%) and the presence of several Pneumocystis species within Apodemus sylvaticus was considered unlikely. The analysis of the genetic structure of woodmouse-derived Pneumocystis revealed two distinct groups. The first one comprised Pneumocystis from woodmice collected in continental Spain, France and Balearic islands. The second one included Pneumocystis from woodmice collected in continental Italy, Corsica and Sicily. These two genetic groups were in accordance with the two lineages currently described within the host species Apodemus sylvaticus. Pneumocystis organisms are emerging as powerful tools for phylogeographic studies in mammals.
- Published
- 2015
- Full Text
- View/download PDF
4. Growth and airborne transmission of cell-sorted life cycle stages of Pneumocystis carinii.
- Author
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Anna Martinez, Marie C M Halliez, El Moukhtar Aliouat, Magali Chabé, Annie Standaert-Vitse, Emilie Fréalle, Nausicaa Gantois, Muriel Pottier, Anthony Pinon, Eduardo Dei-Cas, and Cécile-Marie Aliouat-Denis
- Subjects
Medicine ,Science - Abstract
Pneumocystis organisms are airborne opportunistic pathogens that cannot be continuously grown in culture. Consequently, the follow-up of Pneumocystis stage-to-stage differentiation, the sequence of their multiplication processes as well as formal identification of the transmitted form have remained elusive. The successful high-speed cell sorting of trophic and cystic forms is paving the way for the elucidation of the complex Pneumocystis life cycle. The growth of each sorted Pneumocystis stage population was followed up independently both in nude rats and in vitro. In addition, by setting up a novel nude rat model, we attempted to delineate which cystic and/or trophic forms can be naturally aerially transmitted from host to host. The results showed that in axenic culture, cystic forms can differentiate into trophic forms, whereas trophic forms are unable to evolve into cystic forms. In contrast, nude rats inoculated with pure trophic forms are able to produce cystic forms and vice versa. Transmission experiments indicated that 12 h of contact between seeder and recipient nude rats was sufficient for cystic forms to be aerially transmitted. In conclusion, trophic- to cystic-form transition is a key step in the proliferation of Pneumocystis microfungi because the cystic forms (but not the trophic forms) can be transmitted by aerial route from host to host.
- Published
- 2013
- Full Text
- View/download PDF
5. Initial data on the molecular epidemiology of cryptosporidiosis in Lebanon.
- Author
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Marwan Osman, Dima El Safadi, Sadia Benamrouz, Karine Guyot, Eduardo Dei-Cas, El Moukhtar Aliouat, Colette Creusy, Hassan Mallat, Monzer Hamze, Fouad Dabboussi, Eric Viscogliosi, and Gabriela Certad
- Subjects
Medicine ,Science - Abstract
Cryptosporidium spp. represent a major public health problem worldwide and infect the gastrointestinal tract of both immunocompetent and immunocompromised persons. The prevalence of these parasites varies by geographic region, and no data are currently available in Lebanon. To promote an understanding of the epidemiology of cryptosporidiosisin this country, the main aim of this study was to determine the prevalence Cryptosporidium in symptomatic hospitalized patients, and to analyze the genetic diversity of the corresponding isolates. Fecal specimens were collected in four hospitals in North Lebanon from 163 patients (77 males and 86 females, ranging in age from 1 to 88 years, with a mean age of 22 years) presenting gastrointestinal disorders during the period July to December 2013. The overall prevalence of Cryptosporidium spp. infection obtained by modified Ziehl-Neelsen staining and/or nested PCR was 11%, and children
- Published
- 2015
- Full Text
- View/download PDF
6. Identification of Cryptosporidium Species in Fish from Lake Geneva (Lac Léman) in France.
- Author
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Gabriela Certad, Jean Dupouy-Camet, Nausicaa Gantois, Ourida Hammouma-Ghelboun, Muriel Pottier, Karine Guyot, Sadia Benamrouz, Marwan Osman, Baptiste Delaire, Colette Creusy, Eric Viscogliosi, Eduardo Dei-Cas, Cecile Marie Aliouat-Denis, and Jérôme Follet
- Subjects
Medicine ,Science - Abstract
Cryptosporidium, a protozoan parasite that can cause severe diarrhea in a wide range of vertebrates including humans, is increasingly recognized as a parasite of a diverse range of wildlife species. However, little data are available regarding the identification of Cryptosporidium species and genotypes in wild aquatic environments, and more particularly in edible freshwater fish. To evaluate the prevalence of Cryptosporidiumspp. in fish from Lake Geneva (Lac Léman) in France, 41 entire fish and 100 fillets (cuts of fish flesh) were collected from fishery suppliers around the lake. Nested PCR using degenerate primers followed by sequence analysis was used. Five fish species were identified as potential hosts of Cryptosporidium: Salvelinus alpinus, Esox lucius, Coregonus lavaretus, Perca fluviatilis, and Rutilus rutilus. The presence of Cryptosporidium spp. was found in 15 out of 41 fish (37%), distributed as follows: 13 (87%) C. parvum, 1 (7%) C. molnari, and 1 (7%) mixed infection (C. parvum and C. molnari). C. molnari was identified in the stomach, while C. parvum was found in the stomach and intestine. C. molnari was also detected in 1 out of 100 analyzed fillets. In order to identify Cryptosporidium subtypes, sequencing of the highly polymorphic 60-kDa glycoprotein (gp60) was performed. Among the C. parvum positive samples, three gp60 subtypes were identified: IIaA15G2R1, IIaA16G2R1, and IIaA17G2R1. Histological examination confirmed the presence of potential developmental stages of C. parvum within digestive epithelial cells. These observations suggest that C. parvum is infecting fish, rather than being passively carried. Since C. parvum is a zoonotic species, fish potentially contaminated by the same subtypes found in terrestrial mammals would be an additional source of infection for humans and animals, and may also contribute to the contamination of the environment with this parasite. Moreover, the risk of human transmission is strengthened by the observation of edible fillet contamination.
- Published
- 2015
- Full Text
- View/download PDF
7. Ploidy of cell-sorted trophic and cystic forms of Pneumocystis carinii.
- Author
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Anna Martinez, El Moukhtar Aliouat, Annie Standaert-Vitse, Elisabeth Werkmeister, Muriel Pottier, Claire Pinçon, Eduardo Dei-Cas, and Cécile-Marie Aliouat-Denis
- Subjects
Medicine ,Science - Abstract
Once regarded as an AIDS-defining illness, Pneumocystis pneumonia (PcP) is nowadays prevailing in immunocompromised HIV-negative individuals such as patients receiving immunosuppressive therapies or affected by primary immunodeficiency. Moreover, Pneumocystis clinical spectrum is broadening to non-severely-immunocompromised subjects who could be colonized by the fungus while remaining asymptomatic for PcP, thus being able to transmit the infection by airborne route to susceptible hosts. Although the taxonomical position of the Pneumocystis genus has been clarified, several aspects of its life cycle remain elusive such as its mode of proliferation within the alveolus or its ploidy level. As no long-term culture model exists to grow Pneumocystis organisms in vitro, an option was to use a model of immunosuppressed rat infected with Pneumocystis carinii and sort life cycle stage fractions using a high-through-put cytometer. Subsequently, ploidy levels of the P. carinii trophic and cystic form fractions were measured by flow cytometry. In the cystic form, eight contents of DNA were measured thus strengthening the fact that each mature cyst contains eight haploid spores. Following release, each spore evolves into a trophic form. The majority of the trophic form fraction was haploid in our study. Some less abundant trophic forms displayed two contents of DNA indicating that they could undergo (i) mating/fusion leading to a diploid status or (ii) asexual mitotic division or (iii) both. Even less abundant trophic forms with four contents of DNA were suggestive of mitotic divisions occurring following mating in diploid trophic forms. Of interest, was the presence of trophic forms with three contents of DNA, an unusual finding that could be related to asymmetrical mitotic divisions occurring in other fungal species to create genetic diversity at lower energetic expenses than mating. Overall, ploidy data of P. carinii life cycle stages shed new light on the complexity of its modes of proliferation.
- Published
- 2011
- Full Text
- View/download PDF
8. Evidence of airborne excretion of Pneumocystis carinii during infection in immunocompetent rats. Lung involvement and antibody response.
- Author
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Jean Menotti, Alexandra Emmanuel, Chafia Bouchekouk, Magali Chabe, Firas Choukri, Muriel Pottier, Claudine Sarfati, El Moukhtar Aliouat, and Francis Derouin
- Subjects
Medicine ,Science - Abstract
To better understand the role of immunocompetent hosts in the diffusion of Pneumocystis in the environment, airborne shedding of Pneumocystis carinii in the surrounding air of experimentally infected Sprague Dawley rats was quantified by means of a real-time PCR assay, in parallel with the kinetics of P. carinii loads in lungs and specific serum antibody titres. Pneumocystis-free Sprague Dawley rats were intratracheally inoculated at day 0 (d0) and then followed for 60 days. P. carinii DNA was detected in lungs until d29 in two separate experiments and thereafter remained undetectable. A transient air excretion of Pneumocystis DNA was observed between d14 and d22 in the first experiment and between d9 and d19 in the second experiment; it was related to the peak of infection in lungs. IgM and IgG anti-P. carinii antibody increase preceded clearance of P. carinii in the lungs and cessation of airborne excretion. In rats receiving a second challenge 3 months after the first inoculation, Pneumocystis was only detected at a low level in the lungs of 2 of 3 rats at d2 post challenge and was never detected in air samples. Anti-Pneumocystis antibody determinations showed a typical secondary IgG antibody response. This study provides the first direct evidence that immunocompetent hosts can excrete Pneumocystis following a primary acquired infection. Lung infection was apparently controlled by the immune response since fungal burdens decreased to become undetectable as specific antibodies reached high titres in serum. This immune response was apparently protective against reinfection 3 months later.
- Published
- 2013
- Full Text
- View/download PDF
9. BCG induces protection against Mycobacterium tuberculosis infection in the Wistar rat model.
- Author
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Amit Singhal, Vanessa Mathys, Mehdi Kiass, Colette Creusy, Baptiste Delaire, El Moukhtar Aliouat, Véronique Dartois, Gilla Kaplan, and Pablo Bifani
- Subjects
Medicine ,Science - Abstract
Our understanding of the correlation of Mycobacterium bovis Bacille Calmette-Guerin (BCG)-mediated immune responses and protection against Mycobacterium tuberculosis (Mtb) infection is still limited. We have recently characterized a Wistar rat model of experimental tuberculosis (TB). In the present study, we evaluated the efficacy of BCG vaccination in this model. Upon Mtb challenge, BCG vaccinated rats controlled growth of the bacilli earlier than unvaccinated rats. Histopathology analysis of infected lungs demonstrated a reduced number of granulomatous lesions and lower parenchymal inflammation in vaccinated animals. Vaccine-mediated protection correlated with the rapid accumulation of antigen specific CD4(+) and CD8(+) T cells in the infected lungs. Immunohistochemistry further revealed higher number of CD8(+) cells in the pulmonary granulomas of vaccinated animals. Evaluation of pulmonary immune responses in vaccinated and Mtb infected rats by real time PCR at day 15 post-challenge showed reduced expression of genes responsible for negative regulation of Th1 immune responses. Thus, early protection observed in BCG vaccinated rats correlated with a similarly timed shift of immunity towards the Th1 type response. Our data support the importance of (i) the Th1-Th2 balance in the control of mycobacterial infection and (ii) the value of the Wistar rats in understanding the biology of TB.
- Published
- 2011
- Full Text
- View/download PDF
10. Experimental tuberculosis in the Wistar rat: a model for protective immunity and control of infection.
- Author
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Amit Singhal, El Moukhtar Aliouat, Maxime Hervé, Vanessa Mathys, Mehdi Kiass, Colette Creusy, Baptiste Delaire, Liana Tsenova, Laurence Fleurisse, Julie Bertout, Luis Camacho, Damian Foo, Hui Chien Tay, Jie Yee Siew, Warda Boukhouchi, Marta Romano, Barun Mathema, Véronique Dartois, Gilla Kaplan, and Pablo Bifani
- Subjects
Medicine ,Science - Abstract
BACKGROUND: Despite the availability of many animal models for tuberculosis (TB) research, there still exists a need for better understanding of the quiescent stage of disease observed in many humans. Here, we explored the use of the Wistar rat model for the study of protective immunity and control of Mycobacterium tuberculosis (Mtb) infection. METHODOLOGY/PRINCIPAL FINDINGS: The kinetics of bacillary growth, evaluated by the colony stimulating assay (CFU) and the extent of lung pathology in Mtb infected Wistar rats were dependent on the virulence of the strains and the size of the infecting inoculums. Bacillary growth control was associated with induction of T helper type 1 (Th1) activation, the magnitude of which was also Mtb strain and dose dependent. Histopathology analysis of the infected lungs demonstrated the formation of well organized granulomas comprising epithelioid cells, multinucleated giant cells and foamy macrophages surrounded by large numbers of lymphocytes. The late stage subclinical form of disease was reactivated by immunosuppression leading to increased lung CFU. CONCLUSION: The Wistar rat is a valuable model for better understanding host-pathogen interactions that result in control of Mtb infection and potentially establishment of latent TB. These properties together with the ease of manipulation, relatively low cost and well established use of rats in toxicology and pharmacokinetic analyses make the rat a good animal model for TB drug discovery.
- Published
- 2011
- Full Text
- View/download PDF
11. Correction: What Do Pneumocystis Organisms Tell Us about the Phylogeography of Their Hosts? The Case of the Woodmouse Apodemus sylvaticus in Continental Europe and Western Mediterranean Islands
- Author
-
Demanche, Christine, primary, Deville, Manjula, additional, Michaux, Johan, additional, Barriel, Véronique, additional, Pinçon, Claire, additional, Aliouat-Denis, Cécile Marie, additional, Pottier, Muriel, additional, Noël, Christophe, additional, Viscogliosi, Eric, additional, Aliouat, El Moukhtar, additional, Dei-Cas, Eduardo, additional, Morand, Serge, additional, and Guillot, Jacques, additional
- Published
- 2017
- Full Text
- View/download PDF
12. Growth and Airborne Transmission of Cell-Sorted Life Cycle Stages of Pneumocystis carinii
- Author
-
El Moukhtar Aliouat, Annie Standaert-Vitse, Emilie Fréalle, Anthony Pinon, Magali Chabé, Marie C. M. Halliez, Cécile-Marie Aliouat-Denis, Anna Martinez, Muriel Pottier, Nausicaa Gantois, and Eduardo Dei-Cas
- Subjects
Cell ,Population ,Air Microbiology ,lcsh:Medicine ,Biology ,Pneumocystis carinii ,Airborne transmission ,Microbiology ,Rats, Nude ,medicine ,Animals ,lcsh:Science ,education ,Trophic level ,education.field_of_study ,Multidisciplinary ,Host (biology) ,lcsh:R ,food and beverages ,Cell sorting ,In vitro ,Rats ,Pneumocystis Infections ,medicine.anatomical_structure ,lcsh:Q ,Research Article - Abstract
Pneumocystis organisms are airborne opportunistic pathogens that cannot be continuously grown in culture. Consequently, the follow-up of Pneumocystis stage-to-stage differentiation, the sequence of their multiplication processes as well as formal identification of the transmitted form have remained elusive. The successful high-speed cell sorting of trophic and cystic forms is paving the way for the elucidation of the complex Pneumocystis life cycle. The growth of each sorted Pneumocystis stage population was followed up independently both in nude rats and in vitro. In addition, by setting up a novel nude rat model, we attempted to delineate which cystic and/or trophic forms can be naturally aerially transmitted from host to host. The results showed that in axenic culture, cystic forms can differentiate into trophic forms, whereas trophic forms are unable to evolve into cystic forms. In contrast, nude rats inoculated with pure trophic forms are able to produce cystic forms and vice versa. Transmission experiments indicated that 12 h of contact between seeder and recipient nude rats was sufficient for cystic forms to be aerially transmitted. In conclusion, trophic- to cystic-form transition is a key step in the proliferation of Pneumocystis microfungi because the cystic forms (but not the trophic forms) can be transmitted by aerial route from host to host.
- Published
- 2013
13. Identification of Cryptosporidium Species in Fish from Lake Geneva (Lac Léman) in France
- Author
-
Certad, Gabriela, Dupouy-Camet, Jean, Gantois, Nausicaa, Hammouma-Ghelboun, Ourida, Pottier, Muriel, Guyot, Karine, Benamrouz, Sadia, Osman, Marwan, Delaire, Baptiste, Creusy, Colette, Viscogliosi, Eric, Dei-Cas, Eduardo, Aliouat-Denis, Cecile Marie, and Follet, Jérôme
- Subjects
Geography ,animal diseases ,lcsh:R ,Fishes ,Cryptosporidium ,lcsh:Medicine ,Lakes ,Genetic Loci ,parasitic diseases ,RNA, Ribosomal, 18S ,Animals ,lcsh:Q ,France ,lcsh:Science ,Research Article - Abstract
Cryptosporidium, a protozoan parasite that can cause severe diarrhea in a wide range of vertebrates including humans, is increasingly recognized as a parasite of a diverse range of wildlife species. However, little data are available regarding the identification of Cryptosporidium species and genotypes in wild aquatic environments, and more particularly in edible freshwater fish. To evaluate the prevalence of Cryptosporidiumspp. in fish from Lake Geneva (Lac Léman) in France, 41 entire fish and 100 fillets (cuts of fish flesh) were collected from fishery suppliers around the lake. Nested PCR using degenerate primers followed by sequence analysis was used. Five fish species were identified as potential hosts of Cryptosporidium: Salvelinus alpinus, Esox lucius, Coregonus lavaretus, Perca fluviatilis, and Rutilus rutilus. The presence of Cryptosporidium spp. was found in 15 out of 41 fish (37%), distributed as follows: 13 (87%) C. parvum, 1 (7%) C. molnari, and 1 (7%) mixed infection (C. parvum and C. molnari). C. molnari was identified in the stomach, while C. parvum was found in the stomach and intestine. C. molnari was also detected in 1 out of 100 analyzed fillets. In order to identify Cryptosporidium subtypes, sequencing of the highly polymorphic 60-kDa glycoprotein (gp60) was performed. Among the C. parvum positive samples, three gp60 subtypes were identified: IIaA15G2R1, IIaA16G2R1, and IIaA17G2R1. Histological examination confirmed the presence of potential developmental stages of C. parvum within digestive epithelial cells. These observations suggest that C. parvum is infecting fish, rather than being passively carried. Since C. parvum is a zoonotic species, fish potentially contaminated by the same subtypes found in terrestrial mammals would be an additional source of infection for humans and animals, and may also contribute to the contamination of the environment with this parasite. Moreover, the risk of human transmission is strengthened by the observation of edible fillet contamination.
- Published
- 2015
14. Initial data on the molecular epidemiology of cryptosporidiosis in Lebanon
- Author
-
Hassan Mallat, Marwan Osman, El Moukhtar Aliouat, Fouad Dabboussi, Karine Guyot, Colette Creusy, Dima El Safadi, Eduardo Dei-Cas, Eric Viscogliosi, Sadia Benamrouz, Monzer Hamze, and Gabriela Certad
- Subjects
Adult ,Male ,medicine.medical_specialty ,Veterinary medicine ,Adolescent ,Molecular Sequence Data ,lcsh:Medicine ,Cryptosporidiosis ,Cryptosporidium ,Feces ,Young Adult ,Epidemiology ,parasitic diseases ,medicine ,Humans ,Lebanon ,lcsh:Science ,Child ,Aged ,Aged, 80 and over ,Inpatients ,Multidisciplinary ,Molecular epidemiology ,biology ,lcsh:R ,Infant ,DNA, Protozoan ,Middle Aged ,biology.organism_classification ,Diarrhea ,Cryptosporidium parvum ,Child, Preschool ,lcsh:Q ,Female ,medicine.symptom ,Cardiobacterium hominis ,Nested polymerase chain reaction ,Research Article - Abstract
Cryptosporidium spp. represent a major public health problem worldwide and infect the gastrointestinal tract of both immunocompetent and immunocompromised persons. The prevalence of these parasites varies by geographic region, and no data are currently available in Lebanon. To promote an understanding of the epidemiology of cryptosporidiosisin this country, the main aim of this study was to determine the prevalence Cryptosporidium in symptomatic hospitalized patients, and to analyze the genetic diversity of the corresponding isolates. Fecal specimens were collected in four hospitals in North Lebanon from 163 patients (77 males and 86 females, ranging in age from 1 to 88 years, with a mean age of 22 years) presenting gastrointestinal disorders during the period July to December 2013. The overall prevalence of Cryptosporidium spp. infection obtained by modified Ziehl-Neelsen staining and/or nested PCR was 11%, and children
- Published
- 2014
15. SYTO-13, a Viability Marker as a New Tool to Monitor In Vitro Pharmacodynamic Parameters of Anti-Pneumocystis Drugs
- Author
-
Standaert-Vitse, Annie, primary, Aliouat-Denis, Cécile-Marie, additional, Martinez, Anna, additional, Khalife, Sara, additional, Pottier, Muriel, additional, Gantois, Nausicaa, additional, Dei-Cas, Eduardo, additional, and Aliouat, El Moukhtar, additional
- Published
- 2015
- Full Text
- View/download PDF
16. What Do Pneumocystis Organisms Tell Us about the Phylogeography of Their Hosts? The Case of the Woodmouse Apodemus sylvaticus in Continental Europe and Western Mediterranean Islands
- Author
-
Demanche, Christine, primary, Deville, Manjula, additional, Michaux, Johan, additional, Barriel, Véronique, additional, Pinçon, Claire, additional, Aliouat-Denis, Cécile Marie, additional, Pottier, Muriel, additional, Noël, Christophe, additional, Viscogliosi, Eric, additional, Aliouat, El Moukhtar, additional, Dei-Cas, Eduardo, additional, Morand, Serge, additional, and Guillot, Jacques, additional
- Published
- 2015
- Full Text
- View/download PDF
17. Growth and Airborne Transmission of Cell-Sorted Life Cycle Stages of Pneumocystis carinii
- Author
-
Martinez, Anna, primary, Halliez, Marie C. M., additional, Moukhtar Aliouat, El, additional, Chabé, Magali, additional, Standaert-Vitse, Annie, additional, Fréalle, Emilie, additional, Gantois, Nausicaa, additional, Pottier, Muriel, additional, Pinon, Anthony, additional, Dei-Cas, Eduardo, additional, and Aliouat-Denis, Cécile-Marie, additional
- Published
- 2013
- Full Text
- View/download PDF
18. Evidence of airborne excretion of Pneumocystis carinii during infection in immunocompetent rats. Lung involvement and antibody response
- Author
-
Jean, Menotti, Alexandra, Emmanuel, Chafia, Bouchekouk, Magali, Chabe, Firas, Choukri, Muriel, Pottier, Claudine, Sarfati, El Moukhtar, Aliouat, El Moukhtar, Aliout, and Francis, Derouin
- Subjects
Pulmonology ,Colony Count, Microbial ,Pneumocystis carinii ,Immunoglobulin G ,law.invention ,law ,Lung ,Polymerase chain reaction ,0303 health sciences ,Multidisciplinary ,biology ,Pneumonia, Pneumocystis ,Fungal Diseases ,Animal Models ,3. Good health ,Lower Respiratory Tract Infections ,medicine.anatomical_structure ,Infectious Diseases ,Medical Microbiology ,Medicine ,Antibody ,Research Article ,Science ,Mycology ,Environmental and Occupational Lung Diseases ,Microbiology ,Microbial Ecology ,Excretion ,03 medical and health sciences ,Immune system ,Model Organisms ,Microbial Control ,medicine ,Animals ,Biology ,Antibodies, Fungal ,030304 developmental biology ,030306 microbiology ,Pneumocystis ,Fungi ,Bacterial Load ,Rats ,Emerging Infectious Diseases ,Immunoglobulin M ,Immunology ,Respiratory Infections ,biology.protein ,Rat - Abstract
To better understand the role of immunocompetent hosts in the diffusion of Pneumocystis in the environment, airborne shedding of Pneumocystis carinii in the surrounding air of experimentally infected Sprague Dawley rats was quantified by means of a real-time PCR assay, in parallel with the kinetics of P. carinii loads in lungs and specific serum antibody titres. Pneumocystis-free Sprague Dawley rats were intratracheally inoculated at day 0 (d0) and then followed for 60 days. P. carinii DNA was detected in lungs until d29 in two separate experiments and thereafter remained undetectable. A transient air excretion of Pneumocystis DNA was observed between d14 and d22 in the first experiment and between d9 and d19 in the second experiment; it was related to the peak of infection in lungs. IgM and IgG anti-P. carinii antibody increase preceded clearance of P. carinii in the lungs and cessation of airborne excretion. In rats receiving a second challenge 3 months after the first inoculation, Pneumocystis was only detected at a low level in the lungs of 2 of 3 rats at d2 post challenge and was never detected in air samples. Anti-Pneumocystis antibody determinations showed a typical secondary IgG antibody response. This study provides the first direct evidence that immunocompetent hosts can excrete Pneumocystis following a primary acquired infection. Lung infection was apparently controlled by the immune response since fungal burdens decreased to become undetectable as specific antibodies reached high titres in serum. This immune response was apparently protective against reinfection 3 months later.
- Published
- 2012
19. BCG induces protection against Mycobacterium tuberculosis infection in the Wistar rat model
- Author
-
Mehdi Kiass, Baptiste Delaire, Véronique Dartois, Pablo Bifani, El Moukhtar Aliouat, Amit Singhal, Colette Creusy, Gilla Kaplan, and Vanessa Mathys
- Subjects
CD4-Positive T-Lymphocytes ,Tuberculosis ,Immunology ,lcsh:Medicine ,CD8-Positive T-Lymphocytes ,Mycobacterium tuberculosis ,Immune system ,Immunity ,medicine ,Animals ,Cluster Analysis ,Rats, Wistar ,lcsh:Science ,Lung ,Biology ,Immunity to Infections ,Immune Response ,Inflammation ,Mycobacterium bovis ,Multidisciplinary ,Granuloma ,biology ,business.industry ,lcsh:R ,Interferon-alpha ,Interferon-beta ,Th1 Cells ,medicine.disease ,biology.organism_classification ,Immunohistochemistry ,Rats ,Vaccination ,Disease Models, Animal ,BCG Vaccine ,lcsh:Q ,Female ,Interleukin-4 ,business ,BCG vaccine ,Research Article - Abstract
Our understanding of the correlation of Mycobacterium bovis Bacille Calmette-Guerin (BCG)-mediated immune responses and protection against Mycobacterium tuberculosis (Mtb) infection is still limited. We have recently characterized a Wistar rat model of experimental tuberculosis (TB). In the present study, we evaluated the efficacy of BCG vaccination in this model. Upon Mtb challenge, BCG vaccinated rats controlled growth of the bacilli earlier than unvaccinated rats. Histopathology analysis of infected lungs demonstrated a reduced number of granulomatous lesions and lower parenchymal inflammation in vaccinated animals. Vaccine-mediated protection correlated with the rapid accumulation of antigen specific CD4(+) and CD8(+) T cells in the infected lungs. Immunohistochemistry further revealed higher number of CD8(+) cells in the pulmonary granulomas of vaccinated animals. Evaluation of pulmonary immune responses in vaccinated and Mtb infected rats by real time PCR at day 15 post-challenge showed reduced expression of genes responsible for negative regulation of Th1 immune responses. Thus, early protection observed in BCG vaccinated rats correlated with a similarly timed shift of immunity towards the Th1 type response. Our data support the importance of (i) the Th1-Th2 balance in the control of mycobacterial infection and (ii) the value of the Wistar rats in understanding the biology of TB.
- Published
- 2011
20. Initial Data on the Molecular Epidemiology of Cryptosporidiosis in Lebanon
- Author
-
Osman, Marwan, primary, El Safadi, Dima, additional, Benamrouz, Sadia, additional, Guyot, Karine, additional, Dei-Cas, Eduardo, additional, Aliouat, El Moukhtar, additional, Creusy, Colette, additional, Mallat, Hassan, additional, Hamze, Monzer, additional, Dabboussi, Fouad, additional, Viscogliosi, Eric, additional, and Certad, Gabriela, additional
- Published
- 2015
- Full Text
- View/download PDF
21. Ploidy of Cell-Sorted Trophic and Cystic Forms of Pneumocystis carinii
- Author
-
Martinez, Anna, primary, Aliouat, El Moukhtar, additional, Standaert-Vitse, Annie, additional, Werkmeister, Elisabeth, additional, Pottier, Muriel, additional, Pinçon, Claire, additional, Dei-Cas, Eduardo, additional, and Aliouat-Denis, Cécile-Marie, additional
- Published
- 2011
- Full Text
- View/download PDF
22. BCG Induces Protection against Mycobacterium tuberculosis Infection in the Wistar Rat Model
- Author
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Singhal, Amit, primary, Mathys, Vanessa, additional, Kiass, Mehdi, additional, Creusy, Colette, additional, Delaire, Baptiste, additional, Aliouat, El Moukhtar, additional, Dartois, Véronique, additional, Kaplan, Gilla, additional, and Bifani, Pablo, additional
- Published
- 2011
- Full Text
- View/download PDF
23. Experimental Tuberculosis in the Wistar Rat: A Model for Protective Immunity and Control of Infection
- Author
-
Singhal, Amit, primary, Aliouat, El Moukhtar, additional, Hervé, Maxime, additional, Mathys, Vanessa, additional, Kiass, Mehdi, additional, Creusy, Colette, additional, Delaire, Baptiste, additional, Tsenova, Liana, additional, Fleurisse, Laurence, additional, Bertout, Julie, additional, Camacho, Luis, additional, Foo, Damian, additional, Tay, Hui Chien, additional, Siew, Jie Yee, additional, Boukhouchi, Warda, additional, Romano, Marta, additional, Mathema, Barun, additional, Dartois, Véronique, additional, Kaplan, Gilla, additional, and Bifani, Pablo, additional
- Published
- 2011
- Full Text
- View/download PDF
24. Growth and Airborne Transmission of Cell-Sorted Life Cycle Stages of Pneumocystis carinii.
- Author
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Martinez, Anna, Halliez, Marie C. M., Moukhtar Aliouat, El, Chabé, Magali, Standaert-Vitse, Annie, Fréalle, Emilie, Gantois, Nausicaa, Pottier, Muriel, Pinon, Anthony, Dei-Cas, Eduardo, and Aliouat-Denis, Cécile-Marie
- Subjects
CYTOLOGY ,LIFE cycle costing ,PNEUMOCYSTIS carinii ,CELL culture ,FOLLOW-up studies (Medicine) ,CELL differentiation - Abstract
Pneumocystis organisms are airborne opportunistic pathogens that cannot be continuously grown in culture. Consequently, the follow-up of Pneumocystis stage-to-stage differentiation, the sequence of their multiplication processes as well as formal identification of the transmitted form have remained elusive. The successful high-speed cell sorting of trophic and cystic forms is paving the way for the elucidation of the complex Pneumocystis life cycle. The growth of each sorted Pneumocystis stage population was followed up independently both in nude rats and in vitro. In addition, by setting up a novel nude rat model, we attempted to delineate which cystic and/or trophic forms can be naturally aerially transmitted from host to host. The results showed that in axenic culture, cystic forms can differentiate into trophic forms, whereas trophic forms are unable to evolve into cystic forms. In contrast, nude rats inoculated with pure trophic forms are able to produce cystic forms and vice versa. Transmission experiments indicated that 12 h of contact between seeder and recipient nude rats was sufficient for cystic forms to be aerially transmitted. In conclusion, trophic- to cystic-form transition is a key step in the proliferation of Pneumocystis microfungi because the cystic forms (but not the trophic forms) can be transmitted by aerial route from host to host. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
25. Growth and Airborne Transmission of Cell-Sorted Life Cycle Stages of Pneumocystis carinii.
- Author
-
Martinez, Anna, Halliez, Marie C. M., Moukhtar Aliouat, El, Chabé, Magali, Standaert-Vitse, Annie, Fréalle, Emilie, Gantois, Nausicaa, Pottier, Muriel, Pinon, Anthony, Dei-Cas, Eduardo, and Aliouat-Denis, Cécile-Marie
- Subjects
- *
CYTOLOGY , *LIFE cycle costing , *PNEUMOCYSTIS carinii , *CELL culture , *FOLLOW-up studies (Medicine) , *CELL differentiation - Abstract
Pneumocystis organisms are airborne opportunistic pathogens that cannot be continuously grown in culture. Consequently, the follow-up of Pneumocystis stage-to-stage differentiation, the sequence of their multiplication processes as well as formal identification of the transmitted form have remained elusive. The successful high-speed cell sorting of trophic and cystic forms is paving the way for the elucidation of the complex Pneumocystis life cycle. The growth of each sorted Pneumocystis stage population was followed up independently both in nude rats and in vitro. In addition, by setting up a novel nude rat model, we attempted to delineate which cystic and/or trophic forms can be naturally aerially transmitted from host to host. The results showed that in axenic culture, cystic forms can differentiate into trophic forms, whereas trophic forms are unable to evolve into cystic forms. In contrast, nude rats inoculated with pure trophic forms are able to produce cystic forms and vice versa. Transmission experiments indicated that 12 h of contact between seeder and recipient nude rats was sufficient for cystic forms to be aerially transmitted. In conclusion, trophic- to cystic-form transition is a key step in the proliferation of Pneumocystis microfungi because the cystic forms (but not the trophic forms) can be transmitted by aerial route from host to host. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
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