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1.
Int J Mol Sci ; 23(3)2022 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-35162991

RESUMO

Malaria parasites require multiple phosphorylation and dephosphorylation steps to drive signaling pathways for proper differentiation and transformation. Several protein phosphatases, including protein phosphatase 1 (PP1), one of the main dephosphorylation enzymes, have been shown to be indispensable for the Plasmodium life cycle. The catalytic subunit of PP1 (PP1c) participates in cellular processes via dynamic interactions with a vast number of binding partners that contribute to its diversity of action. In this study, we used Plasmodium berghei transgenic parasite strains stably expressing PP1c or its inhibitor 2 (I2) tagged with mCherry, combined with the mCherry affinity pulldown of proteins from asexual and sexual stages, followed by mass spectrometry analyses. Mapped proteins were used to identify interactomes and to cluster functionally related proteins. Our findings confirm previously known physical interactions of PP1c and reveal enrichment of common biological processes linked to cellular component assembly in both schizonts and gametocytes to biosynthetic processes/translation in schizonts and to protein transport exclusively in gametocytes. Further, our analysis of PP1c and I2 interactomes revealed that nuclear export mediator factor and peptidyl-prolyl cis-trans isomerase, suggested to be essential in P. falciparum, could be potential targets of the complex PP1c/I2 in both asexual and sexual stages. Our study emphasizes the adaptability of Plasmodium PP1 and provides a fundamental study of the protein interaction landscapes involved in a myriad of events in Plasmodium, suggesting why it is crucial to the parasite and a source for alternative therapeutic strategies.


Assuntos
Malária/parasitologia , Plasmodium berghei/fisiologia , Proteína Fosfatase 1/metabolismo , Proteínas/metabolismo , Proteômica/métodos , Animais , Sítios de Ligação , Cromatografia Líquida , Estágios do Ciclo de Vida , Masculino , Camundongos , Organismos Geneticamente Modificados , Plasmodium berghei/patogenicidade , Domínios Proteicos , Mapas de Interação de Proteínas , Proteína Fosfatase 1/genética , Proteínas/genética , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Espectrometria de Massas em Tandem
2.
J Fungi (Basel) ; 7(11)2021 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-34829225

RESUMO

Histoplasmosis and pneumocystosis co-infections have been reported mainly in immunocompromised humans and in wild animals. The immunological response to each fungal infection has been described primarily using animal models; however, the host response to concomitant infection is unknown. The present work aimed to evaluate the pulmonary immunological response of patients with pneumonia caused either by Histoplasma capsulatum, Pneumocystis jirovecii, or their co-infection. We analyzed the pulmonary collectin and cytokine patterns of 131 bronchoalveolar lavage samples, which included HIV and non-HIV patients infected with H. capsulatum, P. jirovecii, or both fungi, as well as healthy volunteers and HIV patients without the studied fungal infections. Our results showed an increased production of the surfactant protein-A (SP-A) in non-HIV patients with H. capsulatum infection, contrasting with HIV patients (p < 0.05). Significant differences in median values of SP-A, IL-1ß, TNF-α, IFN-γ, IL-18, IL-17A, IL-33, IL-13, and CXCL8 were found among all the groups studied, suggesting that these cytokines play a role in the local inflammatory processes of histoplasmosis and pneumocystosis. Interestingly, non-HIV patients with co-infection and pneumocystosis alone showed lower levels of SP-A, IL-1ß, TNF-α, IFN-γ, IL-18, IL-17A, and IL-23 than histoplasmosis patients, suggesting an immunomodulatory ability of P. jirovecii over H. capsulatum response.

3.
Med Mycol ; 60(1)2021 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-34734270

RESUMO

Pneumocystis jirovecii colonization is frequent during chronic obstructive pulmonary disease (COPD) and patients constitute potential contributors to its interhuman circulation. However, the existence of an environmental reservoir cannot be excluded. We assessed the prevalence and factors associated with Pneumocystis colonization during COPD, and studied circulation between patients and their domestic environment. Pneumocystis molecular detection and mtLSU genotyping were performed in oro-pharyngeal washes (OPW) sampled in 58 patients with COPD acute exacerbation, and in indoor dust, sampled in patients' homes using electrostatic dust collectors (EDCs). Lung and systemic inflammation was assessed. Pneumocystis carriage was evaluated in 28 patients after 18 months at stable state. Pneumocystis was detected in 11/58 OPWs during exacerbation (19.0%). Colonized patients presented a significantly lower body mass index, and higher serum IL-17 and CD62P. One patient presented positive detection of typable isolates in both OPW and EDC, with both isolates harboring mtLSU genotype 3. Pneumocystis genotype 1 was further detected in EDCs from three non-colonized patients and one colonized patient with non-typable isolate. Genotypes 1 and 2 were predominant in clinical isolates (both 42%), with genotype 3 representing 16% of isolates. Pneumocystis was detected in 3/28 patients at stable state (10.7%). These data suggest that Pneumocystis colonization could be facilitated by a lower BMI and be related to acute alteration of lung function during COPD exacerbation. It also suggests Th17 pathway and platelet activation could be involved in the anti-Pneumocystis response during colonization. Last, Pneumocystis detection in EDCs supports its potential persistence in indoor dust. LAY SUMMARY: Chronic obstructive pulmonary disease patients tend to be more frequently colonized by Pneumocystis during exacerbation (19.0%) than at stable state (10.7%). Factors associated with colonization include lower BMI, higher IL-17, and CD62P. Pneumocystis detection in patients' dwellings suggests potential persistence in indoor dust.


Assuntos
Pneumocystis carinii , Pneumonia por Pneumocystis , Doença Pulmonar Obstrutiva Crônica , Genótipo , Ambiente Domiciliar , Humanos , Doença Pulmonar Obstrutiva Crônica/complicações
4.
Int J Infect Dis ; 86: 65-72, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31207386

RESUMO

BACKGROUND: Histoplasma capsulatum and Pneumocystis jirovecii are respiratory fungal pathogens that principally cause pulmonary disease. Coinfection with both pathogens is scarcely reported. This study detected this coinfection using specific molecular methods for each fungus in the bronchoalveolar lavage (BAL) of patients from a tertiary care hospital. MATERIALS AND METHODS: BAL samples from 289 hospitalized patients were screened by PCR with specific markers for H. capsulatum (Hcp100) and P. jirovecii (mtLSUrRNA and mtSSUrRNA). The presence of these pathogens was confirmed by the generated sequences for each marker. The clinical and laboratory data for the patients were analyzed using statistical software. RESULTS: The PCR findings separated three groups of patients, where the first was represented by 60 (20.8%) histoplasmosis patients, the second by 45 (15.6%) patients with pneumocystosis, and the last group by 12 (4.2%) patients with coinfection. High similarity among the generated sequences of each species was demonstrated by BLASTn and neighbor-joining algorithms. The estimated prevalence of H. capsulatum and P. jirovecii coinfection was higher in HIV patients.


Assuntos
Coinfecção/epidemiologia , Histoplasmose/epidemiologia , Pneumocystis carinii , Pneumonia por Pneumocystis/epidemiologia , Adulto , Idoso , Lavagem Broncoalveolar , Feminino , Infecções por HIV/complicações , Histoplasma/genética , Histoplasma/isolamento & purificação , Histoplasmose/microbiologia , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Pneumocystis carinii/genética , Pneumocystis carinii/isolamento & purificação , Pneumonia por Pneumocystis/microbiologia , Reação em Cadeia da Polimerase , Centros de Atenção Terciária
5.
JMIR Med Educ ; 5(1): e10766, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30973341

RESUMO

BACKGROUND: During their studies, pharmacy students must acquire the specific skills in clinical virology required for their subsequent professional practice. Recent experiments on teaching and learning in higher education have shown that hybrid courses strengthen the students' commitment to learning and enable high-quality knowledge acquisition. OBJECTIVE: This study concerned the design and deployment of a hybrid course that combines face-to-face and Web-based instruction in clinical virology for fourth-year pharmacy students. The study's objectives were to (1) measure the students' level of involvement in the course, (2) gauge their interest in this type of learning, and (3) highlight any associated difficulties. METHODS: The study included 194 fourth-year pharmacy students from the Lille Faculty of Pharmacy (University of Lille, Lille, France) between January and June 2017. The students followed a hybrid course comprising an online learning module and 5 tutorial sessions in which professional situations were simulated. The learning module and 3 online evaluation sessions were delivered via the Moodle learning management system. Each tutorial session ended with an evaluation. The number of Moodle log-ins, the number of views of learning resources, and the evaluation marks were recorded. The coefficient for the correlation between the marks in the online evaluation and those in the tutorials was calculated. The students' opinions and level of satisfaction were evaluated via a course questionnaire. RESULTS: The course's learning resources and Web pages were viewed 21,446 and 3413 times, respectively. Of the 194 students, 188 (96.9%) passed the course (ie, marks of at least 10 out of 20). There was a satisfactory correlation between the marks obtained in the online evaluations and those obtained after the tutorials. The course met the students' expectations in 53.2% of cases, and 57.4% of the students stated that they were able to work at their own pace. Finally, 26.6% of the students stated that they had difficulty organizing their work around this hybrid course. CONCLUSIONS: Our results showed that pharmacy students were strongly in favor of a hybrid course. The levels of attendance and participation were high. However, teachers must be aware that some students will encounter organizational difficulties.

6.
Front Microbiol ; 9: 2617, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30429842

RESUMO

With its multiple regulatory partners, the conserved Protein Phosphatase type-1 (PP1) plays a central role in many functions of the biology of eukaryotic cells, including Plasmodium falciparum. Here, we characterized a protein named PfRCC-PIP, as a major partner of PfPP1. We established its direct interaction in vitro and its presence in complex with PfPP1 in the parasite. The use of Xenopus oocyte model revealed that RCC-PIP can interact with the endogenous PP1 and act in synergy with suboptimal doses of progesterone to trigger oocyte maturation, suggesting a regulatory effect on PP1. Reverse genetic studies suggested an essential role for RCC-PIP since no viable knock-out parasites could be obtained. Further, we demonstrated the capacity of protein region containing RCC1 motifs to interact with the parasite kinase CDPK7. These data suggest that this protein is both a kinase and a phosphatase anchoring protein that could provide a platform to regulate phosphorylation/dephosphorylation processes.

7.
Future Microbiol ; 13: 659-669, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29790796

RESUMO

AIM: To explore Aspergillus interactions with platelets in the blood, especially during clot formation. MATERIALS & METHODS: Aspergillus fumigatus resting or swollen conidia, germlings or hyphae were inoculated into blood sampled into tubes with or without anticoagulant. Interactions were explored using microscopy, and chemokine levels were determined. RESULTS: Anatomopathological examination of the clot revealed conidia and germlings colocalization with platelet aggregates, and neutrophil recruitment around aggregates. Transmission electron microscopy showed conidia and hyphae surrounded by neutrophils. Increased CCL5 and CXCL4 when conidia or germlings but not hyphae were added suggested they could be involved in neutrophil recruitment around aggregates. CONCLUSION: These data suggest platelets could trigger coagulopathy and activate neutrophils during aspergillosis. They open up new perspectives for aspergillosis management.


Assuntos
Aspergillus fumigatus/imunologia , Coagulação Sanguínea , Plaquetas/metabolismo , Neutrófilos/imunologia , Quimiocinas/análise , Voluntários Saudáveis , Humanos , Hifas/imunologia , Microscopia , Microscopia Eletrônica de Transmissão , Esporos Fúngicos/imunologia
9.
Med Mycol ; 55(5): 568-572, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-27811179

RESUMO

In a prospective bicentric study, Pneumocystis jirovecii excretion and diffusion was explored in air samples collected in the rooms occupied by 17 Pneumocystis-colonized patients. P. jirovecii DNA was detected by real-time PCR in the air collected from 3 patients' rooms (17.6%), with identical genotypes in corresponding clinical and air samples. Pneumocystis DNA was detected for 2/3 patients with autoimmune disease treated with corticosteroids versus 1/6 patients with hematologic disease and 0/5 kidney transplant recipients. These data confirm the possible excretion of the fungus by Pneumocystis-colonized patients and thus bring additional arguments for the prevention of airborne transmission in hospital wards.


Assuntos
Microbiologia do Ar , Infecção Hospitalar/transmissão , Pneumocystis carinii/isolamento & purificação , Pneumocystis carinii/fisiologia , Pneumonia por Pneumocystis/microbiologia , Pneumonia por Pneumocystis/transmissão , Adulto , Idoso , Infecção Hospitalar/microbiologia , DNA Fúngico/genética , DNA Fúngico/isolamento & purificação , Feminino , Genótipo , Humanos , Hospedeiro Imunocomprometido , Masculino , Pessoa de Meia-Idade , Pneumocystis carinii/genética , Estudos Prospectivos , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Risco , Adulto Jovem
10.
Respir Res ; 17(1): 66, 2016 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-27250970

RESUMO

Pulmonary surfactant is a complex fluid that comprises phospholipids and four proteins (SP-A, SP-B, SP-C, and SP-D) with different biological functions. SP-B, SP-C, and SP-D are essential for the lungs' surface tension function and for the organization, stability and metabolism of lung parenchyma. SP-A and SP-D, which are also known as pulmonary collectins, have an important function in the host's lung immune response; they act as opsonins for different pathogens via a C-terminal carbohydrate recognition domain and enhance the attachment to phagocytic cells or show their own microbicidal activity by increasing the cellular membrane permeability. Interactions between the pulmonary collectins and bacteria or viruses have been extensively studied, but this is not the same for fungal pathogens. SP-A and SP-D bind glucan and mannose residues from fungal cell wall, but there is still a lack of information on their binding to other fungal carbohydrate residues. In addition, both their relation with immune cells for the clearance of these pathogens and the role of surfactant proteins' regulation during respiratory fungal infections remain unknown. Here we highlight the relevant findings associated with SP-A and SP-D in those respiratory mycoses where the fungal infective propagules reach the lungs by the airways.


Assuntos
Pneumopatias Fúngicas/metabolismo , Pulmão/metabolismo , Pneumonia/metabolismo , Proteína A Associada a Surfactante Pulmonar/metabolismo , Proteína D Associada a Surfactante Pulmonar/metabolismo , Animais , Citocinas/imunologia , Citocinas/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Imunidade Inata , Mediadores da Inflamação/imunologia , Mediadores da Inflamação/metabolismo , Pulmão/imunologia , Pulmão/microbiologia , Pneumopatias Fúngicas/imunologia , Pneumopatias Fúngicas/microbiologia , Pneumonia/imunologia , Pneumonia/microbiologia , Proteína A Associada a Surfactante Pulmonar/imunologia , Proteína D Associada a Surfactante Pulmonar/imunologia
11.
J Eukaryot Microbiol ; 63(3): 309-17, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26509699

RESUMO

To quantitatively assess the risk of contamination by Pneumocystis depending on the degree of immunosuppression (ID) of the exposed rat hosts, we developed an animal model, where rats went through different doses of dexamethasone. Then, natural and aerial transmission of Pneumocystis carinii occurred during cohousing of the rats undergoing gradual ID levels (receivers) with nude rats developing pneumocystosis (seeders). Following contact between receiver and seeder rats, the P. carinii burden of receiver rats was determined by toluidine blue ortho staining and by qPCR targeting the dhfr monocopy gene of this fungus. In this rat model, the level of circulating CD4(+) and CD8(+) T lymphocytes remained significantly stable and different for each dose of dexamethasone tested, thus reaching the goal of a new stable and gradual ID rat model. In addition, an inverse relationship between the P. carinii burden and the level of circulating CD4(+) or CD8(+) T lymphocytes was evidenced. This rat model may be used to study other opportunistic pathogens or even co-infections in a context of gradual ID.


Assuntos
Microbiologia do Ar , Modelos Animais de Doenças , Hospedeiro Imunocomprometido , Pneumocystis carinii/fisiologia , Pneumonia por Pneumocystis/microbiologia , Pneumonia por Pneumocystis/transmissão , Aerossóis , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Contagem de Colônia Microbiana , Dexametasona/administração & dosagem , Genes Fúngicos , Pulmão/microbiologia , Masculino , Pneumocystis carinii/efeitos dos fármacos , Pneumocystis carinii/crescimento & desenvolvimento , Pneumocystis carinii/isolamento & purificação , Ratos
12.
PLoS One ; 10(6): e0130358, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26103633

RESUMO

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.


Assuntos
Antifúngicos/farmacologia , Biomarcadores/sangue , Pneumocystis carinii/isolamento & purificação , Pneumonia por Pneumocystis/tratamento farmacológico , Animais , Antifúngicos/uso terapêutico , Técnicas In Vitro , Testes de Sensibilidade Microbiana , Pneumocystis carinii/efeitos dos fármacos , Pneumonia por Pneumocystis/microbiologia , Ratos , Ratos Sprague-Dawley
13.
PLoS One ; 10(5): e0125129, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25950832

RESUMO

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 <5 years old showed a higher rate of Cryptosporidium spp. The PCR products of the 15 positive samples were successfully sequenced. Among them, 10 isolates (66.7%) were identified as C. hominis, while the remaining 5 (33.3%) were identified as C. parvum. After analysis of the gp60 locus, C. hominis IdA19, a rare subtype, was found to be predominant. Two C. parvum subtypes were found: IIaA15G1R1 and IIaA15G2R1. The molecular characterization of Cryptosporidium isolates is an important step in improving our understanding of the epidemiology and transmission of the infection.


Assuntos
Criptosporidiose/epidemiologia , Criptosporidiose/parasitologia , Cryptosporidium/genética , Cryptosporidium/isolamento & purificação , DNA de Protozoário/análise , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Fezes/parasitologia , Feminino , Humanos , Lactente , Pacientes Internados , Líbano/epidemiologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Adulto Jovem
14.
PLoS One ; 10(4): e0120839, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25830289

RESUMO

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.


Assuntos
Interações Hospedeiro-Patógeno , Murinae/microbiologia , Pneumocystis/fisiologia , Animais , DNA Fúngico/análise , Variação Genética , Pulmão/microbiologia , Ilhas do Mediterrâneo , Filogeografia , Pneumocystis/genética , Análise de Sequência de RNA
15.
Fungal Biol ; 118(11): 885-95, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25442292

RESUMO

Manganese-dependent superoxide dismutase (MnSOD) is one of the key enzymes involved in the cellular defense against oxidative stress. Previously, the Pneumocystis carinii sod2 gene (Pcsod2) was isolated and characterized. Based on protein sequence comparison, Pcsod2 was suggested to encode a putative MnSOD protein likely to be targeted into the mitochondrion. In this work, the Pcsod2 was cloned and expressed as a recombinant protein in EG110 Saccharomyces cerevisiae strain lacking the MnSOD-coding gene (Scsod2) in order to investigate the function and subcellular localization of P. carinii MnSOD (PcMnSOD). The Pcsod2 gene was amplified by PCR and cloned into the pYES2.1/V5-His-TOPO(®) expression vector. The recombinant construct was then transformed into EG110 strain. Once its expression had been induced, PcMnSOD was able to complement the growth defect of EG110 yeast cells that had been exposed to the redox-cycling compound menadione. N-term sequencing of the PcMnSOD protein allowed identifying the cleavage site of a mitochondrial targeting peptide. Immune-colocalization of PcMnSOD and yeast CoxIV further confirmed the mitochondrial localization of the PcMnSOD. Heterologous expression of PcMnSOD in yeast indicates that Pcsod2 encodes an active MnSOD, targeted to the yeast mitochondrion that allows the yeast cells to grow in the presence of reactive oxygen species (ROS).


Assuntos
Teste de Complementação Genética , Mitocôndrias/enzimologia , Pneumocystis carinii/enzimologia , Pneumocystis carinii/genética , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Superóxido Dismutase/deficiência , Clonagem Molecular , Expressão Gênica , Saccharomyces cerevisiae/química
16.
BMC Microbiol ; 14: 23, 2014 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-24495513

RESUMO

BACKGROUND: Histoplasma capsulatum and Pneumocystis organisms cause host infections primarily affecting the lung tissue. H. capsulatum is endemic in the United States of America and Latin American countries. In special environments, H. capsulatum is commonly associated with bat and bird droppings. Pneumocystis-host specificity has been primarily studied in laboratory animals, and its ability to be harboured by wild animals remains as an important issue for understanding the spread of this pathogen in nature. Bats infected with H. capsulatum or Pneumocystis spp. have been found, with this mammal serving as a probable reservoir and disperser; however, the co-infection of bats with both of these microorganisms has never been explored. To evaluate the impact of H. capsulatum and Pneumocystis spp. infections in this flying mammal, 21 bat lungs from Argentina (AR), 13 from French Guyana (FG), and 88 from Mexico (MX) were screened using nested-PCR of the fragments, employing the Hcp100 locus for H. capsulatum and the mtLSUrRNA and mtSSUrRNA loci for Pneumocystis organisms. RESULTS: Of the 122 bats studied, 98 revealed H. capsulatum infections in which 55 of these bats exhibited this infection alone. In addition, 51 bats revealed Pneumocystis spp. infection of which eight bats exhibited a Pneumocystis infection alone. A total of 43 bats (eight from AR, one from FG, and 34 from MX) were found co-infected with both fungi, representing a co-infection rate of 35.2% (95% CI = 26.8-43.6%). CONCLUSION: The data highlights the H. capsulatum and Pneumocystis spp.co-infection in bat population's suggesting interplay with this wild host.


Assuntos
Quirópteros , Coinfecção/veterinária , Histoplasma/isolamento & purificação , Histoplasmose/veterinária , Infecções por Pneumocystis/veterinária , Pneumocystis/isolamento & purificação , Animais , Argentina , Guiana , México , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Ribossômico/genética , Análise de Sequência de DNA
17.
PLoS One ; 8(11): e79958, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24223207

RESUMO

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.


Assuntos
Infecções por Pneumocystis/transmissão , Pneumocystis carinii/patogenicidade , Microbiologia do Ar , Animais , Infecções por Pneumocystis/microbiologia , Ratos , Ratos Nus
18.
Pharmaceuticals (Basel) ; 6(7): 837-50, 2013 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24276317

RESUMO

Some compounds articulated around a piperazine or an ethylenediamine linker have been evaluated in vitro to determine their activity in the presence of a 3T6 fibroblast cell line and an axenic culture of Pneumocystis carinii, respectively. The most efficient antifungal derivatives, namely N,N'-bis(benzamidine-4-yl)ethane-1,2-diamine (compound 6, a diamidine) and N-(benzamidine-4-yl)-N'-phenylethane-1,2-diamine (compound 7, a monoamidine), exhibited no cytotoxicity and were evaluated in vivo in a rat model. Only the diamidine 6 emerged as a promising hit for further studies.

19.
PLoS One ; 8(4): e62155, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23626781

RESUMO

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.


Assuntos
Pneumocystis carinii/isolamento & purificação , Pneumonia por Pneumocystis/microbiologia , Pneumonia por Pneumocystis/transmissão , Animais , Anticorpos Antifúngicos/imunologia , Carga Bacteriana , Contagem de Colônia Microbiana , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Pulmão/imunologia , Pulmão/microbiologia , Pneumocystis carinii/imunologia , Pneumonia por Pneumocystis/imunologia , Ratos
20.
J Zoo Wildl Med ; 44(1): 15-20, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23505698

RESUMO

Histoplasma capsulatum is a dimorphic fungus that is widely distributed in the tropical or subtropical areas of the world and infects several mammalian hosts, mainly bats. Infective propagules grow in bat and bird droppings. A specific molecular marker, a highly sensitive fragment of a co-activator protein-coding gene (Hcp100), was used to detect H. capsulatum in lung samples of wild and captive bats from France using a nested polymerase chain reaction. To determine whether bats in France are potential carriers of H. capsulatum, 83 bats were sampled from two regions in France. Sixty-one specimens belonging to the Pteropus rodricensis (n = 45) and Rousettus aegyptiacus (n = 16) species were collected from a zoologic park (La Palmyre, western France). Twenty-two specimens were recovered from the Natural History Museum (Bourges) including the species Plecotus austriacus (n = 1), Pipistrellus pipistrellus (n = 3), and Nyctalus noctula (n = 18). From the lung DNA samples of 83 dead bats, only one sample of an N. noctula bat from Bourges amplified the H. capsulatum Hcp100 marker. The amplified product was sequenced and revealed a high similarity to the G217B H. capsulatum reference strain sequence that was deposited in the GenBank database. This finding suggests that H. capsulatum is an environmental pathogen in France that may infect bats.


Assuntos
Quirópteros/fisiologia , Histoplasma/isolamento & purificação , Histoplasmose/veterinária , Pneumopatias/microbiologia , Animais , Sequência de Bases , DNA Fúngico , França/epidemiologia , Histoplasmose/epidemiologia , Pneumopatias/epidemiologia , Reação em Cadeia da Polimerase/veterinária
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