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1.
BMC Infect Dis ; 22(1): 424, 2022 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-35505308

RESUMO

BACKGROUND: Atypical pathogens (AP), present in some patients with community-acquired pneumonia (CAP), are intrinsically resistant to betalactam drugs, the mainstay of empirical antibiotic treatment. Adding antibiotic coverage for AP increases the risk of adverse effects and antimicrobial selection pressure, while withholding such coverage may worsen the prognosis if an AP is causative. A clinical model predicting the presence of AP would allow targeting atypical coverage for patients most likely to benefit. METHODS: This is a secondary analysis of a multicentric randomized controlled trial that included 580 adults patients hospitalized for CAP. A predictive score was built using independent predictive factors for AP identified through multivariate analysis. Accuracy of the score was assessed using area under the receiver operating curve (AUROC), sensitivity, and specificity. RESULTS: Prevalence of AP was 5.3%. Age < 75 years (OR 2.7, 95% CI 1.2-6.2), heart failure (OR 2.6, 95% CI 1.1-6.1), absence of chest pain (OR 3.0, 95% CI 1.1-8.2), natremia < 135 mmol/L (OR 3.0, 95% CI 1.4-6.6) and contracting the disease in autumn (OR 2.7, 95% CI 1.3-5.9) were independently associated with AP. A predictive score using these factors had an AUROC of 0.78 (95% CI 0.71-0.85). A score of 0 or 1 (present in 33% of patients) had 100% sensitivity and 35% specificity. CONCLUSION: Use of a score built on easily obtained clinical and laboratory data would allow safe withholding of atypical antibiotic coverage in a significant number of patients, with an expected positive impact on bacterial resistance and drug adverse effects. TRIAL REGISTRATION: NCT00818610.


Assuntos
Infecções Comunitárias Adquiridas , Pneumonia , Adulto , Idoso , Antibacterianos/efeitos adversos , Antibioticoprofilaxia , Infecções Comunitárias Adquiridas/tratamento farmacológico , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , Humanos , Pneumonia/tratamento farmacológico , Pneumonia/epidemiologia , Pneumonia/microbiologia , beta-Lactamas/uso terapêutico
2.
BMC Infect Dis ; 22(1): 203, 2022 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-35236305

RESUMO

PURPOSE: Studies on aetiology of community-acquired pneumonia (CAP) vary in terms of microbial sampling methods, anatomical locations, and laboratory analyses, since no gold standard exists. In this large, multicentre, retrospective, regional study from Norway, our primary objective was to report the results of a strategic diagnostic stewardship intervention, targeting diagnostic yield from lower respiratory tract sampling. The secondary objective was to report hospitalized CAP aetiology and the diagnostic yield of various anatomical sampling locations. METHODS: Medical records from cases diagnosed with hospitalized CAP were collected retrospectively from March throughout May for three consecutive years at six hospitals. Between year one and two, we launched a diagnostic stewardship intervention at the emergency room level for the university teaching hospital only. The intervention was multifaceted aiming at upscaling specimen collection and enhancing collection techniques. Year one at the interventional hospital and every year at the five other emergency hospitals were used for comparison. RESULTS: Of the 1280 included cases of hospitalized CAP, a microbiological diagnosis was established for 29.1% among 1128 blood cultures and 1444 respiratory tract specimens. Blood cultures were positive for a pathogenic respiratory tract microbe in 4.9% of samples, whereas upper and lower respiratory tract samples overall provided a probable microbiological diagnosis in 21.3% and 47.5%, respectively. Expectorated or induced sputum overall provided aetiology in 51.7% of the samples. At the interventional hospital, the number of expectorated or induced sputum samples were significantly increased, and diagnostic yield from expectorated or induced sputum was significantly enhanced from 41.2 to 62.0% after the intervention (p = 0.049). There was an over-representation of samples from the interventional hospital during the study period. Non-typeable Haemophilus influenza and Streptococcus pneumoniae accounted for 25.3% and 24.7% of microbiologically confirmed cases, respectively. CONCLUSION: Expectorated or induced sputum outperformed other sampling methods in providing a reliable microbiological diagnosis for hospitalized CAP. A diagnostic stewardship intervention significantly improved diagnostic yield of lower respiratory tract sampling.


Assuntos
Infecções Comunitárias Adquiridas , Pneumonia , Infecções Comunitárias Adquiridas/diagnóstico , Infecções Comunitárias Adquiridas/microbiologia , Humanos , Pneumonia/diagnóstico , Pneumonia/microbiologia , Estudos Retrospectivos , Escarro/microbiologia , Streptococcus pneumoniae
3.
Comput Math Methods Med ; 2022: 8660752, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35132333

RESUMO

Swine pneumonia commonly known as swine pasteurellosis is an infectious disease of swine caused by Pasteurella multocida infection. It has been reported that Toll-like receptors (TLRs) play a vital role in swine pneumonia progression. However, the underlying mechanism has not been elucidated. This research was aimed at investigating the molecular mechanism by which TLR9 regulates swine pneumonia progression. Our findings illustrated that the HD-13 strain of Pasteurella multocida D (HD-13) accelerated TLR9 expression in porcine alveolar macrophage 3D4/21 cells; HD-13 activated the inflammatory response via accelerating TLR9 expression. Mechanistically, HD-13 activated mitogen-activated protein kinase (MAPK) and nuclear factor kB (NF-κB) signals. In conclusion, HD-13 may activate MAPK and NF-κB pathways via accelerating TLR9 expression, thereby accelerating the inflammatory response in the progression of swine pneumonia. TLR9 may serve as a novel therapeutic target for swine pneumonia. Our research may provide a theoretical basis for the prevention and treatment of swine pneumonia.


Assuntos
Infecções por Pasteurella/veterinária , Pasteurella multocida/patogenicidade , Pneumonia/veterinária , Doenças dos Suínos/imunologia , Doenças dos Suínos/microbiologia , Receptor Toll-Like 9/imunologia , Animais , Células Cultivadas , Biologia Computacional , Citocinas/genética , Citocinas/imunologia , Progressão da Doença , Sistema de Sinalização das MAP Quinases/imunologia , NF-kappa B/imunologia , Infecções por Pasteurella/imunologia , Infecções por Pasteurella/microbiologia , Pasteurella multocida/classificação , Pasteurella multocida/imunologia , Pneumonia/imunologia , Pneumonia/microbiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/imunologia , Sus scrofa , Suínos , Doenças dos Suínos/genética , Receptor Toll-Like 9/genética , Regulação para Cima
4.
PLoS Pathog ; 18(2): e1010259, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35176118

RESUMO

At the end of 2019 Wuhan witnessed an outbreak of "atypical pneumonia" that later developed into a global pandemic. Metagenomic sequencing rapidly revealed the causative agent of this outbreak to be a novel coronavirus denoted SARS-CoV-2. To provide a snapshot of the pathogens in pneumonia-associated respiratory samples from Wuhan prior to the emergence of SARS-CoV-2, we collected bronchoalveolar lavage fluid samples from 408 patients presenting with pneumonia and acute respiratory infections at the Central Hospital of Wuhan between 2016 and 2017. Unbiased total RNA sequencing was performed to reveal their "total infectome", including viruses, bacteria and fungi. We identified 35 pathogen species, comprising 13 RNA viruses, 3 DNA viruses, 16 bacteria and 3 fungi, often at high abundance and including multiple co-infections (13.5%). SARS-CoV-2 was not present. These data depict a stable core infectome comprising common respiratory pathogens such as rhinoviruses and influenza viruses, an atypical respiratory virus (EV-D68), and a single case of a sporadic zoonotic pathogen-Chlamydia psittaci. Samples from patients experiencing respiratory disease on average had higher pathogen abundance than healthy controls. Phylogenetic analyses of individual pathogens revealed multiple origins and global transmission histories, highlighting the connectedness of the Wuhan population. This study provides a comprehensive overview of the pathogens associated with acute respiratory infections and pneumonia, which were more diverse and complex than obtained using targeted PCR or qPCR approaches. These data also suggest that SARS-CoV-2 or closely related viruses were absent from Wuhan in 2016-2017.


Assuntos
COVID-19/epidemiologia , Surtos de Doenças , Pneumonia/epidemiologia , Infecções Respiratórias/epidemiologia , SARS-CoV-2/isolamento & purificação , Doença Aguda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Líquido da Lavagem Broncoalveolar/microbiologia , COVID-19/virologia , China/epidemiologia , Estudos de Coortes , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , Metagenômica , Pessoa de Meia-Idade , Filogenia , Pneumonia/microbiologia , Infecções Respiratórias/microbiologia , Adulto Jovem
5.
PLoS One ; 17(2): e0262956, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35104293

RESUMO

INTRODUCTION: Community-acquired pneumonia is associated with higher morbidity, hospitalization, and mortality in adults. Likewise, antimicrobial resistance has increased in recent decades in Ethiopia. Therefore, this study was aimed to determine the bacterial isolates, their antimicrobial susceptibility patterns, and factors associated with community-acquired pneumonia among adult patients in Gondar, Northwest Ethiopia. MATERIALS AND METHODS: This institutional-based cross-sectional study was conducted from April to June 2021. Sociodemographic, clinical, and other relevant data were collected using a pre-tested questionnaire. A total of 312 sputum specimens were collected using sputum cups and inoculated into blood agar, chocolate agar, mannitol salt agar, and MacConkey agar plates, which were then incubated at 37°C for 24 hours. The bacterial isolates were identified based on Gram staining, colony characteristics, and biochemical tests. Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method. Inducible clindamycin resistance among the S. aureus isolates was detected by the D-test. Data were entered using EPI data version 4.6 and analyzed using SPSS version 20. P-value ≤ 0.05 at 95% CI was considered statistically significant. RESULTS: Of 312 cases, 39.4% (n = 123; 95% CI: 34.1%-44.9%) were found to have culture-confirmed pneumonia. The most common isolates were K. pneumoniae (31.0%, n = 39), S. pneumoniae (26.2%, n = 33), and S. aureus (20.6%, n = 26). The gram-positive bacteria were susceptible to chloramphenicol (100%) and clindamycin (96.6%). Gram-negative bacteria were susceptible to gentamicin (87.5%), azithromycin (87.1%), ciprofloxacin (86.6%), and ceftriaxone (79.0%) but highly resistant to ampicillin (100%), followed by tetracycline (87.1%), doxycycline (86.4%), co-trimoxazole (80.6%), and amoxicillin-clavulanic acid (79.0%). Overall, 72.2% of the isolates were multi-drug resistant to K. pneumoniae (94.9%, n = 37), E. coli (93.8%, n = 15), and S. pneumoniae (72.7%, n = 24). Only, 7.7% of S. aureus isolates showed inducible clindamycin resistance. Aging (AOR: 3.248, 95% CI: 1.001-10.545, p = 0.050), a history of pneumonia (AOR: 7.004, 95% CI: 3.591-13.658, p = 0.001), alcohol use (AOR: 6.614, 95% CI: 3.399-12.872, p < 0.001), and overcrowded living conditions (AOR: 4.348, 95% CI: 1.964-9.624, p = 0.001) were significantly associated with culture-positive sputum. CONCLUSION AND RECOMMENDATIONS: This study found a high prevalence of bacteria-caused community-acquired pneumonia among adults and low susceptibility to ampicillin, tetracyclines, and amoxicillin-clavulanic acid. Therefore, culture-based bacterial identification and local antibiotic susceptibility testing should be performed regularly. Additionally, new insights into vaccine coverage against highly multi-drug resistant bacteria, particularly K. pneumoniae, are necessary.


Assuntos
Antibacterianos/farmacologia , Infecções Comunitárias Adquiridas/microbiologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Pneumonia/microbiologia , Adolescente , Adulto , Idoso , Cloranfenicol/farmacologia , Ciprofloxacina/farmacologia , Infecções Comunitárias Adquiridas/patologia , Estudos Transversais , Etiópia , Feminino , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Positivas/isolamento & purificação , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Pneumonia/patologia , Escarro/microbiologia , Adulto Jovem
6.
Med Princ Pract ; 31(1): 98-102, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34638123

RESUMO

Invasive candidiasis is predominantly seen in immunosuppressed patients and carries a significant mortality. The clinical spectrum of invasive candidiasis encompasses candidemia and disseminated infection (intra-abdominal abscess, osteomyelitis, endophthalmitis, and Candida meningitis). The existence of Candida pneumonia has been largely debated over the years due to its rarity and presence of frequent colonization. Demonstration of Candida species by lung biopsy along with evidence of inflammation is the only way to confirm this entity. The interpretation of Candida in respiratory specimens and the decision to initiate antifungal therapy is controversial due to the lack of clinical evidence. In this mini-review, we discuss the currently available clinical data from the literature on Candida pneumonia and future perspectives regarding the need for antifungal therapy in such patients.


Assuntos
Candidíase Invasiva , Pneumonia , Antifúngicos/uso terapêutico , Candida , Candidíase , Candidíase Invasiva/tratamento farmacológico , Humanos , Pneumonia/tratamento farmacológico , Pneumonia/microbiologia
7.
Am J Physiol Lung Cell Mol Physiol ; 322(1): L116-L128, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34850640

RESUMO

Obesity impairs host defense against Klebsiella pneumoniae, but responsible mechanisms are incompletely understood. To determine the impact of diet-induced obesity on pulmonary host defense against K. pneumoniae, we fed 6-wk-old male C57BL/6j mice a normal diet (ND) or high-fat diet (HFD) (13% vs. 60% fat, respectively) for 16 wk. Mice were intratracheally infected with Klebsiella, assayed at 24 or 48 h for bacterial colony-forming units, lung cytokines, and leukocytes from alveolar spaces, lung parenchyma, and gonadal adipose tissue were assessed using flow cytometry. Neutrophils from uninfected mice were cultured with and without 2-deoxy-d-glucose (2-DG) and assessed for phagocytosis, killing, reactive oxygen intermediates (ROI), transport of 2-DG, and glucose transporter (GLUT1-4) transcripts, and protein expression of GLUT1 and GLUT3. HFD mice had higher lung and splenic bacterial burdens. In HFD mice, baseline lung homogenate concentrations of IL-1ß, IL-6, IL-17, IFN-γ, CXCL2, and TNF-α were reduced relative to ND mice, but following infection were greater for IL-6, CCL2, CXCL2, and IL-1ß (24 h only). Despite equivalent lung homogenate leukocytes, HFD mice had fewer intraalveolar neutrophils. HFD neutrophils exhibited decreased Klebsiella phagocytosis and killing and reduced ROI to heat-killed Klebsiella in vitro. 2-DG transport was lower in HFD neutrophils, with reduced GLUT1 and GLUT3 transcripts and protein (GLUT3 only). Blocking glycolysis with 2-DG impaired bacterial killing and ROI production in neutrophils from mice fed ND but not HFD. Diet-induced obesity impairs pulmonary Klebsiella clearance and augments blood dissemination by reducing neutrophil killing and ROI due to impaired glucose transport.


Assuntos
Dieta , Glucose/metabolismo , Interações Hospedeiro-Patógeno , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/fisiologia , Neutrófilos/metabolismo , Obesidade/microbiologia , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/metabolismo , Adiposidade/efeitos dos fármacos , Animais , Carga Bacteriana/efeitos dos fármacos , Transporte Biológico/efeitos dos fármacos , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Medula Óssea/patologia , Líquido da Lavagem Broncoalveolar/citologia , Citocinas/metabolismo , Desoxiglucose/farmacologia , Dieta Hiperlipídica , Transportador de Glucose Tipo 1/genética , Transportador de Glucose Tipo 1/metabolismo , Transportador de Glucose Tipo 3/genética , Transportador de Glucose Tipo 3/metabolismo , Glicólise/efeitos dos fármacos , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Infecções por Klebsiella/sangue , Infecções por Klebsiella/complicações , Klebsiella pneumoniae/efeitos dos fármacos , Contagem de Leucócitos , Pulmão/microbiologia , Pulmão/patologia , Masculino , Camundongos Endogâmicos C57BL , Neutrófilos/efeitos dos fármacos , Obesidade/sangue , Obesidade/complicações , Fagocitose/efeitos dos fármacos , Pneumonia/microbiologia , Pneumonia/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Baço/microbiologia
8.
Vet Microbiol ; 264: 109303, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34923246

RESUMO

In this study, whether H9N2 influenza A virus (IAV) infection contributed to secondary Klebsiella pneumoniae infection was investigated. From post-infection onwards, clinical symptoms were monitored, examined and recorded daily for 11 days. As a result, no clinical signs were observed in the mice infected with single H9N2 IAV, implying that H9N2 IAV was less pathogenic to mice. Compared to single K. pneumonia infection, K. pneumoniae infection following H9N2 IAV infection exacerbates lung histopathological lesions and apoptosis, resulting in more severe diseases. Lung index of the mice with H9N2 IAV and K. pneumoniae co-infection was significantly higher than those in the other groups. Bacterial loads in the tissues in H9N2 IAV and K. pneumoniae co-infection group were significantly higher than those in the single K. pneumoniae infection group at 7 dpi. It demonstrated that prior H9N2 IAV infection contributed to K. pneumonia proliferation and delayed bacterial clearance in mice. Secondary K. pneumoniae infection influences seroconversion of anti-H9N2 antibody titers and the cytokine profiles. The findings demonstrated that H9N2 IAV infection facilitated secondary K. pneumonia infection, causing severe the diseases in mice.


Assuntos
Vírus da Influenza A Subtipo H9N2 , Klebsiella pneumoniae , Infecções por Orthomyxoviridae , Pneumonia , Animais , Coinfecção , Vírus da Influenza A Subtipo H9N2/fisiologia , Klebsiella pneumoniae/fisiologia , Camundongos , Infecções por Orthomyxoviridae/microbiologia , Infecções por Orthomyxoviridae/virologia , Pneumonia/microbiologia , Pneumonia/virologia
9.
BMJ ; 375: e065871, 2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-34872910

RESUMO

Severe pneumonia is associated with high mortality (short and long term), as well as pulmonary and extrapulmonary complications. Appropriate diagnosis and early initiation of adequate antimicrobial treatment for severe pneumonia are crucial in improving survival among critically ill patients. Identifying the underlying causative pathogen is also critical for antimicrobial stewardship. However, establishing an etiological diagnosis is challenging in most patients, especially in those with chronic underlying disease; those who received previous antibiotic treatment; and those treated with mechanical ventilation. Furthermore, as antimicrobial therapy must be empiric, national and international guidelines recommend initial antimicrobial treatment according to the location's epidemiology; for patients admitted to the intensive care unit, specific recommendations on disease management are available. Adherence to pneumonia guidelines is associated with better outcomes in severe pneumonia. Yet, the continuing and necessary research on severe pneumonia is expansive, inviting different perspectives on host immunological responses, assessment of illness severity, microbial causes, risk factors for multidrug resistant pathogens, diagnostic tests, and therapeutic options.


Assuntos
Anti-Infecciosos/uso terapêutico , Gestão de Antimicrobianos/normas , Cuidados Críticos/métodos , Pneumonia/terapia , Anti-Infecciosos/farmacologia , Cuidados Críticos/normas , Estado Terminal/terapia , Resistência a Múltiplos Medicamentos , Fidelidade a Diretrizes/estatística & dados numéricos , Humanos , Unidades de Terapia Intensiva/normas , Pneumonia/diagnóstico , Pneumonia/epidemiologia , Pneumonia/microbiologia , Guias de Prática Clínica como Assunto , Fatores de Risco , Índice de Gravidade de Doença , Resultado do Tratamento
10.
mBio ; 12(6): e0322321, 2021 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-34872353

RESUMO

Mice immunized with a combination of an adenovirus vector (Ad5-YFV) and live-attenuated (LMA)-based vaccines were evaluated for protective efficacy against pneumonic plague. While the Ad5-YFV vaccine harbors a fusion cassette of three genes encoding YscF, F1, and LcrV, LMA represents a mutant of parental Yersinia pestis CO92 deleted for genes encoding Lpp, MsbB, and Ail. Ad5-YFV and LMA were either administered simultaneously (1-dose regimen) or 21 days apart in various orders and route of administration combinations (2-dose regimen). The 2-dose regimen induced robust immune responses to provide full protection to animals against parental CO92 and its isogenic F1 deletion mutant (CAF-) challenges during both short- and long-term studies. Mice intranasally (i.n.) immunized with Ad5-YFV first followed by LMA (i.n. or intramuscularly [i.m.]) had higher T- and B-cell proliferative responses and LcrV antibody titers than those in mice vaccinated with LMA (i.n. or i.m.) first ahead of Ad5-YFV (i.n.) during the long-term study. Specifically, the needle- and adjuvant-free vaccine combination (i.n.) is ideal for use in plague regions of endemicity. Conversely, with a 1-dose regimen, mice vaccinated with Ad5-YFV i.n. and LMA by the i.m. route provided complete protection to animals against CO92 and its CAF- mutant challenges and elicited Th1/Th2, as well as Th17 responses, making it suitable for emergency vaccination during a plague outbreak or bioterrorist attack. This is a first study in which a viral vector-based and live-attenuated vaccines were effectively used in combination, representing adjuvant- and/or needle-free immunization, with each vaccine triggering a distinct cellular immune response. IMPORTANCE Yersinia pestis, the causative agent of plague, is a Tier-1 select agent and a reemerging human pathogen. A 2017 outbreak in Madagascar with >75% of cases being pneumonic and 8.6% causalities emphasized the importance of the disease. The World Health Organization has indicated an urgent need to develop new-generation subunit and live-attenuated plague vaccines. We have developed a subunit vaccine, including three components (YscF, F1, and LcrV) using an adenovirus platform (Ad5-YFV). In addition, we have deleted virulence genes of Y. pestis (e.g., lpp, msbB, and ail) to develop a live-attenuated vaccine (LMA). Both of these vaccines generated robust humoral and cellular immunity and were highly efficacious in several animal models. We hypothesized the use of a heterologous prime-boost strategy or administrating both vaccines simultaneously could provide an adjuvant- and/or a needle-free vaccine(s) that has attributes of both vaccines for use in regions of endemicity and during an emergency situation.


Assuntos
Adenoviridae/imunologia , Antígenos de Bactérias/administração & dosagem , Vacina contra a Peste/administração & dosagem , Peste/prevenção & controle , Pneumonia/prevenção & controle , Vacinas Atenuadas/administração & dosagem , Yersinia pestis/imunologia , Adenoviridae/genética , Adjuvantes Imunológicos/administração & dosagem , Administração Intranasal , Animais , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , Vetores Genéticos/genética , Vetores Genéticos/imunologia , Humanos , Camundongos , Peste/imunologia , Peste/microbiologia , Vacina contra a Peste/genética , Vacina contra a Peste/imunologia , Pneumonia/imunologia , Pneumonia/microbiologia , Células Th1/imunologia , Células Th17/imunologia , Células Th2/imunologia , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologia , Yersinia pestis/genética
11.
Microbiol Spectr ; 9(3): e0131021, 2021 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-34878306

RESUMO

Tigecycline is regarded as one of the few important last-resort antibiotics to treat complicated skin and intra-abdominal infections. Members of the genus Staphylococcus are zoonotic pathogens and pose a serious threat to public health. Tigecycline resistance in this species appears to be a rare phenomenon, and the mechanisms underlying tigecycline resistance have not been fully elucidated. Here, we report two novel variants of the tet(L) gene in Staphylococcus spp. from swine in China, designed as tet(L)F58L and tet(L)A117V. The tet(L)F58L was located within a 18,720 bp chromosomal multidrug resistance gene cluster flanked by two copies of IS257 in Staphylococcus cohnii 11-B-312, while the tet(L)A117V was located on a 6,292 bp plasmid in S. haemolyticus 11-B-93, which could be transferred to S. aureus by electrotransformation. Cloning of each of the two tet(L) variants into S. aureus RN4220 showed 16- or 8-fold increases in the minimal inhibition concentrations (MICs), which can fully confer the resistance to tigecycline (MICs from 0.125 to 2 mg/liter) and eravacycline (MICs from 0.125 to 1 or 2 mg/liter), but no increase in the MICs of omadacycline, compared with the MICs of the recipient strain S. aureus RN4220. In the in vivo murine sepsis and in the murine pneumonia models, an increase in CFU of S. aureus 29213_pT93 carrying the tet(L)A117V was seen despite tigecycline treatment. This observation suggests that the tet(L)A117V and its associated gene product compromise the efficacy of tigecycline treatment in vivo and may lead to clinical treatment failure. Our finding, that novel Tet(L) efflux pump variants which confer tigecycline and eravacycline resistance have been identified in Staphylococcus spp., requires urgent attention. IMPORTANCE Tigecycline and eravacycline are both important last-resort broad spectrum antimicrobial agents. The presence of novel Tet(L) efflux pump variants conferring the resistance to tigecycline and eravacycline in Staphylococcus spp. and its potential transmission to S. aureus will compromise the efficacy of tigecycline and eravacycline treatment for S. aureus associated infection in vivo and may lead to clinical treatment failure.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Transporte Proteico/genética , Staphylococcus aureus/metabolismo , Tetraciclinas/farmacologia , Tigeciclina/farmacologia , Animais , Antibacterianos/metabolismo , Proteínas de Bactérias/genética , Modelos Animais de Doenças , Farmacorresistência Bacteriana Múltipla/genética , Feminino , Genoma Bacteriano/genética , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Família Multigênica/genética , Pneumonia/microbiologia , Sepse/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Suínos , Doenças dos Suínos/microbiologia , Tetraciclinas/metabolismo , Tigeciclina/metabolismo , Sequenciamento Completo do Genoma
12.
PLoS One ; 16(12): e0260627, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34855837

RESUMO

Infectious pneumonia induced by multidrug resistant (MDR) Acinetobacter baumannii strains is among the most common and deadly forms of healthcare acquired infections. Over the years, different strategies have been put in place to increase host susceptibility to MDR A. baumannii, since only a self-limiting pneumonia with no or limited local bacterial replication was frequently obtained in mouse models. Direct instillation into the trachea or intranasal inoculation of the bacterial suspension are the techniques used to induce the infection in most of the preclinical models of pneumonia developed to date. More recently, the oropharyngeal aspiration procedure has been widely described in the literature for a variety of purposes including pathogens administration. Aim of this study was to compare the oropharyngeal aspiration technique to the intranasal inoculation and intratracheal instillation in the ability of inducing a consistent lung infection with two MDR A. baumannii clinical isolates in immunocompromised mice. Moreover, pneumonia obtained by bacteria administration with two out of three techniques, intratracheal and oropharyngeal, was characterised in terms of histopathology of pulmonary lesions, biomarkers of inflammation level and leukocytes cells infiltration extent after mice treatment with either vehicle or the antibiotic tigecycline. The data generated clearly showed that both strains were not able to colonize the lungs when inoculated by intranasal route. By contrast, the bacterial load in lungs of mice intratracheally or oropharyngeally infected significantly increased during 26 hours of monitoring, thus highlighting the ability of these strains to generate the infection when directly instilled into the lower respiratory airways. Furthermore, the intragroup variability of mice was significantly reduced with respect to those intranasally administered. Tigecycline was efficacious in lung bacterial load and cytokines release reduction. Findings were supported by semi-quantitative histopathological evaluation of the pulmonary lesions and by inflammatory biomarkers analysis. To conclude, both intratracheal instillation and oropharyngeal aspiration techniques showed to be suitable methods for inducing a robust and consistent pneumonia infection in mice when difficult MDR A. baumannii clinical isolates were used. Noteworthy, oropharyngeal aspiration not requiring specific technical skills and dedicated equipment, was proven to be a safer, easier and faster technique in comparison to the intratracheal instillation.


Assuntos
Infecções por Acinetobacter/patologia , Acinetobacter baumannii/fisiologia , Carga Bacteriana/métodos , Pneumonia/patologia , Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/isolamento & purificação , Administração Intranasal , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/microbiologia , Citocinas/metabolismo , Modelos Animais de Doenças , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Hospedeiro Imunocomprometido , Intubação Intratraqueal , Masculino , Camundongos , Orofaringe/microbiologia , Orofaringe/patologia , Pneumonia/tratamento farmacológico , Pneumonia/microbiologia , Tigeciclina/farmacologia , Tigeciclina/uso terapêutico
13.
Cell Mol Biol (Noisy-le-grand) ; 67(3): 129-132, 2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34933722

RESUMO

Lobar pneumonia is an inflammatory condition of the lung that mainly affects the lobes of the lungs and the alveoli, and it is usually caused by a bacterial infection. There are many ways to diagnosis this disease. But an early and accurate method for lobar pneumonia diagnosis has an important role in its treatment. Therefore, in this study, a comparison between the molecular diagnostic test and chest x-ray combined with multi-slice spiral CT was done to find out better diagnosis of lobar pneumonia. For this purpose, 122 individuals suspected of lobar pneumonia were studied by clinical examination, chest X-ray, and multi-slice spiral CT. For the molecular diagnosis test, the multiplex PCR was used for two main causes of the disease, Streptococcus pneumoniae and Klebsiella pneumoniae. Results showed that the specificity for Chest X-ray + Multi-slice Spiral CT had the highest amount (82.8%), but high sensitivity (100%) belonged to a molecular diagnostic test for both bacteria. On the other hand, the sensitivity and specificity of Streptococcus pneumoniae were better than Klebsiella pneumoniae and the possibility of error in Streptococcus pneumoniae was lower than Klebsiella pneumoniae. In general, although the Chest X-ray + Multi-slice Spiral CT method was better than the molecular diagnosis test, it could not identify the causative agent and did not show a difference between pathogens for better antibiotic treatment, and also the possibility of diagnosis is low at the beginning of the disease. Therefore, according to the results of the current study, the best way to diagnose lobar pneumonia is to use both methods, simultaneously.


Assuntos
Pulmão/diagnóstico por imagem , Técnicas de Diagnóstico Molecular/métodos , Pneumonia/diagnóstico , Radiografia Torácica/métodos , Tomografia Computadorizada Espiral/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , DNA Bacteriano/genética , Feminino , Humanos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/fisiologia , Pulmão/microbiologia , Pulmão/patologia , Masculino , Pessoa de Meia-Idade , Pneumonia/microbiologia , Reação em Cadeia da Polimerase/métodos , Sensibilidade e Especificidade , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/fisiologia , Adulto Jovem
14.
CMAJ Open ; 9(4): E1242-E1251, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34933882

RESUMO

BACKGROUND: Patient-level surveillance of antimicrobial use (AMU) in Canadian hospitals empowers the reduction of inappropriate AMU and was piloted in 2017 among 14 hospitals in Canada. We aimed to describe AMU on the basis of patient-level data in Canadian hospitals in 2018 in terms of antimicrobial prescribing prevalence and proportions, antimicrobial indications, and agent selection in medical, surgical and intensive care wards. METHODS: Canadian adult, pediatric and neonatal hospitals were invited to participate in the standardized web-based cross-sectional Global Point Prevalence Survey of Antimicrobial Consumption and Resistance (Global-PPS) conducted in 2018. An identified site administrator assigned all wards admitting inpatients to specific surveyors. A physician, pharmacist or nurse with infectious disease training performed the survey. The primary outcomes were point prevalence rates for AMU over the study period regarding prescriptions, indications and agent selection in medical, surgical and intensive care wards. The secondary outcomes were AMU for resistant organisms and practice appropriateness evaluated on the basis of quality indicators. Antimicrobial consumption is presented in terms of prevalence and proportions. RESULTS: Forty-seven of 118 (39.8%) hospitals participated in the survey; 9 hospitals were primary care centres, 15 were secondary care centres and 23 were tertiary or specialized care centres. Of 13 272 patients included, 33.5% (n = 4447) received a total of 6525 antimicrobials. Overall, 74.1% (4832/6525) of antimicrobials were for therapeutic use, 12.6% (n = 825) were for medical prophylaxis, 8.9% (n = 578) were for surgical prophylaxis, 2.2% (n = 143) were for other use and 2.3% (n = 147) were for unidentified reasons. A diagnosis or indication was documented in the patient's file at the initiation for 87.3% (n = 5699) of antimicrobials; 62.9% (n = 4106) of antimicrobials had a stop or review date; and 72.0% (n = 4697) of prescriptions were guided by local guidelines. INTERPRETATION: Overall, three-quarters of AMU was for therapeutic use across participating hospitals. Canadian hospitals should be further incentivized to create and adapt local guidelines on the basis of recent antimicrobial resistance data.


Assuntos
Antibacterianos/uso terapêutico , Gestão de Antimicrobianos/estatística & dados numéricos , Infecções Comunitárias Adquiridas/tratamento farmacológico , Infecção Hospitalar/tratamento farmacológico , Prescrições de Medicamentos/estatística & dados numéricos , Hospitalização/estatística & dados numéricos , Hospitais , Pneumonia/tratamento farmacológico , Adolescente , Adulto , Canadá/epidemiologia , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Estudos Transversais , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pneumonia/epidemiologia , Pneumonia/microbiologia , Prevalência , Inquéritos e Questionários , Resultado do Tratamento , Adulto Jovem
15.
Ann Intern Med ; 174(12): 1719-1726, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34904883

RESUMO

Community-acquired pneumonia is a major cause of morbidity and mortality in the United States, leading to 1.5 million hospitalizations and at least 200 000 deaths annually. The 2019 American Thoracic Society/Infectious Diseases Society of America clinical practice guideline on diagnosis and treatment of adults with community-acquired pneumonia provides an evidence-based overview of this common illness. Here, 2 experts, a general internist who served as the co-primary author of the guidelines and a pulmonary and critical care physician, debate the management of a patient hospitalized with community-acquired pneumonia. They discuss disease severity stratification methods, whether to use adjunctive corticosteroids, and when to prescribe empirical treatment for multidrug-resistant organisms such as methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa.


Assuntos
Corticosteroides/uso terapêutico , Antibacterianos/uso terapêutico , Infecções Comunitárias Adquiridas/tratamento farmacológico , Tomada de Decisões , Hospitalização , Pneumonia/tratamento farmacológico , Idoso , Infecções Comunitárias Adquiridas/microbiologia , Humanos , Masculino , Massachusetts , Pneumonia/microbiologia , Índice de Gravidade de Doença , Visitas com Preceptor
16.
Cells ; 10(12)2021 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-34943813

RESUMO

Acute respiratory distress syndrome (ARDS) is a serious lung condition characterized by severe hypoxemia leading to limitations of oxygen needed for lung function. In this study, we investigated the effect of anandamide (AEA), an endogenous cannabinoid, on Staphylococcal enterotoxin B (SEB)-mediated ARDS in female mice. Single-cell RNA sequencing data showed that the lung epithelial cells from AEA-treated mice showed increased levels of antimicrobial peptides (AMPs) and tight junction proteins. MiSeq sequencing data on 16S RNA and LEfSe analysis demonstrated that SEB caused significant alterations in the microbiota, with increases in pathogenic bacteria in both the lungs and the gut, while treatment with AEA reversed this effect and induced beneficial bacteria. AEA treatment suppressed inflammation both in the lungs as well as gut-associated mesenteric lymph nodes (MLNs). AEA triggered several bacterial species that produced increased levels of short-chain fatty acids (SCFAs), including butyrate. Furthermore, administration of butyrate alone could attenuate SEB-mediated ARDS. Taken together, our data indicate that AEA treatment attenuates SEB-mediated ARDS by suppressing inflammation and preventing dysbiosis, both in the lungs and the gut, through the induction of AMPs, tight junction proteins, and SCFAs that stabilize the gut-lung microbial axis driving immune homeostasis.


Assuntos
Ácidos Araquidônicos/uso terapêutico , Endocanabinoides/uso terapêutico , Microbioma Gastrointestinal , Trato Gastrointestinal/patologia , Pulmão/patologia , Alcamidas Poli-Insaturadas/uso terapêutico , Síndrome do Desconforto Respiratório/tratamento farmacológico , Síndrome do Desconforto Respiratório/microbiologia , Animais , Ácidos Araquidônicos/farmacologia , Butiratos/metabolismo , Ceco/patologia , Separação Celular , Colo/efeitos dos fármacos , Colo/patologia , Análise Discriminante , Disbiose/complicações , Disbiose/microbiologia , Endocanabinoides/farmacologia , Enterotoxinas , Feminino , Trato Gastrointestinal/efeitos dos fármacos , Linfonodos/efeitos dos fármacos , Linfonodos/patologia , Ativação Linfocitária/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Pneumonia/tratamento farmacológico , Pneumonia/microbiologia , Alcamidas Poli-Insaturadas/farmacologia , Síndrome do Desconforto Respiratório/complicações , Linfócitos T/efeitos dos fármacos
17.
World J Microbiol Biotechnol ; 38(1): 6, 2021 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-34837116

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) is a multidrug-resistant pathogen that poses a significant risk to global health today. In S. aureus, α-hemolysin is an important virulence factor as it contributes to the capacity of the bacteria to infect the host. Here, we showed that biochanin A (bioA), an isoflavone present in red clover, cabbage and alfalfa, effectively inhibited hemolytic activity at a dose as low as 32 µg/mL. Further, western blot and RT-qPCR data showed that bioA reduced the production and expression of MRSA hemolysin in a dose-dependent manner. In addition, when different concentrations of bioA were added to a coculture system of A549 cells and S. aureus, it could significantly decrease cell injury. Importantly, the in vivo study showed that bioA could protect mice from pneumonia caused by a lethal dose of MRSA, as evidenced by improving their survival and reducing the number of bacterial colonies in lung tissues, the secretion of hemolysin into alveolar lavage fluid and the degree of pulmonary edema. In conclusion, biochanin A protected the host from MRSA infection by inhibiting the expression of the hemolysin of MRSA, which may provide experimental evidence for its development to a potential anti-MRSA drug.


Assuntos
Antibacterianos/administração & dosagem , Genisteína/administração & dosagem , Proteínas Hemolisinas/metabolismo , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Pneumonia/tratamento farmacológico , Infecções Estafilocócicas/tratamento farmacológico , Células A549 , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Genisteína/farmacologia , Proteínas Hemolisinas/genética , Hemólise/efeitos dos fármacos , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Camundongos , Pneumonia/microbiologia , Infecções Estafilocócicas/microbiologia
18.
Int J Mol Sci ; 22(22)2021 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-34829979

RESUMO

Influenza is a respiratory virus that alone or in combination with secondary bacterial pathogens can contribute to the development of acute pneumonia in persons >65 years of age. Host innate immune antiviral signaling early in response to influenza is essential to inhibit early viral replication and guide the initiation of adaptive immune responses. Using young adult (3 months) and aged adult mice infected with mouse adapted H1N1 or H3N2, the results of our study illustrate dysregulated and/or diminished activation of key signaling pathways in aged lung contribute to increased lung inflammation and morbidity. Specifically, within the first seven days of infection, there were significant changes in genes associated with TLR and RIG-I signaling detected in aged murine lung in response to H1N1 or H3N2. Taken together, the results of our study expand our current understanding of age-associated changes in antiviral signaling in the lung.


Assuntos
Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H3N2/genética , Influenza Humana/genética , Pneumonia/genética , Células A549 , Animais , Proteína DEAD-box 58/genética , Modelos Animais de Doenças , Regulação Viral da Expressão Gênica/genética , Humanos , Imunidade Inata/genética , Vírus da Influenza A Subtipo H1N1/patogenicidade , Vírus da Influenza A Subtipo H3N2/patogenicidade , Influenza Humana/microbiologia , Influenza Humana/virologia , Pulmão/metabolismo , Pulmão/microbiologia , Pulmão/patologia , Camundongos , Infecções por Orthomyxoviridae/genética , Infecções por Orthomyxoviridae/microbiologia , Infecções por Orthomyxoviridae/virologia , Pneumonia/microbiologia , Pneumonia/virologia , Receptores Toll-Like/genética , Replicação Viral/genética
19.
Physiol Rep ; 9(22): e15116, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34822216

RESUMO

Obesity alters the risks and outcomes of inflammatory lung diseases. It is important to accurately recapitulate the obese state in animal models to understand these effects on the pathogenesis of disease. Diet-induced obesity is a commonly used model of obesity, but when applied to other disease models like acute respiratory distress syndrome, pneumonia, and asthma, it yields widely divergent. We hypothesized high-fat chow storage conditions would affect lipid oxidation and inflammatory response in the lungs of lipopolysaccharide (LPS)-challenged mice. For 6 weeks, C57BL/6crl mice were fed either a 10% (low-fat diet, LFD) or 60% (high-fat diet, HFD) stored at room temperature (RT, 23°C) for up to 7, 14, 21, or 42 days. Mice were treated with nebulized LPS to induce lung inflammation, and neutrophil levels in bronchoalveolar lavage were determined 24 h later. Lipid oxidation (malondialdehyde, MDA) was assayed by thiobarbituric acid reactive substances in chow and mouse plasma. Concentrations of MDA in chow and plasma rose in proportion to the duration of RT chow storage. Mice fed a HFD stored <2 weeks at RT had an attenuated response 24 h after LPS compared with mice fed an LFD. This effect was reversed after 2 weeks of chow storage at RT. Chow stored above freezing underwent lipid oxidation associated with significant alterations in the LPS-induced pulmonary inflammatory response. Our data show that storage conditions affect lipid peroxidation, which in turn affects pulmonary inflammatory responses in a mouse model of disease. It also suggests changes in the microbiome, although not significantly different suggests decreased variety and richness of bacteria in the gut, a large aspect of the immune system. Dietary composition and storage of chow may also affect pulmonary inflammation and the gut microbiome in humans.


Assuntos
Lesão Pulmonar Aguda/metabolismo , Ração Animal , Dieta Hiperlipídica , Armazenamento de Alimentos , Inflamação/metabolismo , Malondialdeído/metabolismo , Obesidade/metabolismo , Pneumonia/metabolismo , Temperatura , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/microbiologia , Animais , Dieta com Restrição de Gorduras , Modelos Animais de Doenças , Microbioma Gastrointestinal , Inflamação/microbiologia , Metabolismo dos Lipídeos , Lipopolissacarídeos/toxicidade , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/microbiologia , Pneumonia/induzido quimicamente , Pneumonia/microbiologia
20.
Front Immunol ; 12: 701341, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34777335

RESUMO

The essential micronutrient Selenium (Se) is co-translationally incorporated as selenocysteine into proteins. Selenoproteins contain one or more selenocysteines and are vital for optimum immunity. Interestingly, many pathogenic bacteria utilize Se for various biological processes suggesting that Se may play a role in bacterial pathogenesis. A previous study had speculated that Francisella tularensis, a facultative intracellular bacterium and the causative agent of tularemia, sequesters Se by upregulating Se-metabolism genes in type II alveolar epithelial cells. Therefore, we investigated the contribution of host vs. pathogen-associated selenoproteins in bacterial disease using F. tularensis as a model organism. We found that F. tularensis was devoid of any Se utilization traits, neither incorporated elemental Se, nor exhibited Se-dependent growth. However, 100% of Se-deficient mice (0.01 ppm Se), which express low levels of selenoproteins, succumbed to F. tularensis-live vaccine strain pulmonary challenge, whereas 50% of mice on Se-supplemented (0.4 ppm Se) and 25% of mice on Se-adequate (0.1 ppm Se) diet succumbed to infection. Median survival time for Se-deficient mice was 8 days post-infection while Se-supplemented and -adequate mice was 11.5 and >14 days post-infection, respectively. Se-deficient macrophages permitted significantly higher intracellular bacterial replication than Se-supplemented macrophages ex vivo, corroborating in vivo observations. Since Francisella replicates in alveolar macrophages during the acute phase of pneumonic infection, we hypothesized that macrophage-specific host selenoproteins may restrict replication and systemic spread of bacteria. F. tularensis infection led to an increased expression of several macrophage selenoproteins, suggesting their key role in limiting bacterial replication. Upon challenge with F. tularensis, mice lacking selenoproteins in macrophages (TrspM) displayed lower survival and increased bacterial burden in the lung and systemic tissues in comparison to WT littermate controls. Furthermore, macrophages from TrspM mice were unable to restrict bacterial replication ex vivo in comparison to macrophages from littermate controls. We herein describe a novel function of host macrophage-specific selenoproteins in restriction of intracellular bacterial replication. These data suggest that host selenoproteins may be considered as novel targets for modulating immune response to control a bacterial infection.


Assuntos
Francisella tularensis/imunologia , Interações Hospedeiro-Patógeno/imunologia , Macrófagos/imunologia , Macrófagos/metabolismo , Selenoproteínas/metabolismo , Tularemia/etiologia , Tularemia/metabolismo , Animais , Modelos Animais de Doenças , Suscetibilidade a Doenças , Francisella tularensis/genética , Francisella tularensis/patogenicidade , Camundongos , Pneumonia/imunologia , Pneumonia/metabolismo , Pneumonia/microbiologia , Pneumonia/patologia , Tularemia/mortalidade , Virulência/genética , Fatores de Virulência/genética
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