RESUMO
Traditional manual blood smear diagnosis methods are time-consuming and prone to errors, often relying heavily on the experience of clinical laboratory analysts for accuracy. As breakthroughs in key technologies such as neural networks and deep learning continue to drive digital transformation in the medical field, image recognition technology is increasingly being leveraged to enhance existing medical processes. In recent years, advancements in computer technology have led to improved efficiency in the identification of blood cells in blood smears through the use of image recognition technology. This paper provides a comprehensive summary of the methods and steps involved in utilizing image recognition algorithms for diagnosing diseases in blood smears, with a focus on malaria and leukemia. Furthermore, it offers a forward-looking research direction for the development of a comprehensive blood cell pathological detection system.
Assuntos
Células Sanguíneas , Processamento de Imagem Assistida por Computador , Patologia Clínica , Patologia Clínica/métodos , Patologia Clínica/tendências , Células Sanguíneas/microbiologia , Células Sanguíneas/parasitologia , Células Sanguíneas/patologia , Malária/diagnóstico por imagem , Leucemia/diagnóstico por imagem , Algoritmos , Aprendizado de Máquina , Contagem de Células Sanguíneas , HumanosRESUMO
Improved sample preparation has the potential to address unmet needs for fast turnaround sepsis tests. In this work, we report elasto-inertial based rapid bacteria separation from diluted blood at high separation efficiency. In viscoelastic flows, we demonstrate novel findings where blood cells prepositioned at the outer wall entering a spiral device remain fully focused throughout the channel length while smaller bacteria migrate to the opposite wall. Initially, using microparticles, we show that particles above a certain size cut-off remain fully focused at the outer wall while smaller particles differentially migrate toward the inner wall. We demonstrate particle separation at 1 µm resolution at a total throughput of 1 mL/min. For blood-based experiments, a minimum of 1:2 dilution was necessary to fully focus blood cells at the outer wall. Finally, Escherichia coli spiked in diluted blood were continuously separated at a total flow rate of 1 mL/min, with efficiencies between 82 and 90% depending on the blood dilution. Using a single spiral, it takes 40 min to process 1 mL of blood at a separation efficiency of 82%. The label-free, passive, and rapid bacteria isolation method has a great potential for speeding up downstream phenotypic and genotypic analysis.
Assuntos
Bactérias , Técnicas Analíticas Microfluídicas , Sepse , Bactérias/isolamento & purificação , Células Sanguíneas/microbiologia , Humanos , Microfluídica , Sepse/sangue , Sepse/microbiologiaRESUMO
Streptococcus pyogenes (group A Streptococcus [GAS]) is an important human pathogen causing a broad spectrum of diseases and associated with significant global morbidity and mortality. Almost all GAS isolates express a surface hyaluronic acid capsule, a virulence determinant that facilitates host colonization and impedes phagocyte killing. However, recent epidemiologic surveillance has reported a sustained increase in both mucosal and invasive infections caused by nonencapsulated GAS, which questions the indispensable role of hyaluronic acid capsule in GAS pathogenesis. In this study, we found that pilus of M4 GAS not only significantly promotes biofilm formation, adherence, and cytotoxicity to human upper respiratory tract epithelial cells and keratinocytes, but also promotes survival in human whole blood and increased virulence in murine models of invasive infection. T4 antigen, the pilus backbone protein of M4 GAS, binds haptoglobin, an abundant human acute-phase protein upregulated upon infection and inflammation, on the bacterial surface. Haptoglobin sequestration reduces the susceptibility of nonencapsulated M4 GAS to antimicrobial peptides released from activated neutrophils and platelets. Our results reveal a previously unappreciated virulence-promoting role of M4 GAS pili, in part mediated by co-opting the biology of haptoglobin to mitigate host antimicrobial defenses.IMPORTANCE Group A Streptococcus (GAS) is a strict human pathogen causing more than 700 million infections globally each year. The majority of the disease-causing GAS are encapsulated, which greatly guarantees survival and dissemination in the host. Emergence of the capsule-negative GAS, such as M4 GAS, in recent epidemiologic surveillance alarms the necessity to elucidate the virulence determinants of these pathogens. Here, we found that M4 pili play an important role in promoting M4 GAS adherence and cytotoxicity to human pharyngeal epithelial cells and keratinocytes. The same molecule also significantly enhanced M4 GAS survival and replication in human whole blood and experimental murine infection. T4 antigen, which composes the backbone of M4 pili, was able to sequester the very abundant serum protein haptoglobin to further confer M4 GAS resistance to antibacterial substances released by neutrophils and platelets.
Assuntos
Proteínas de Bactérias/metabolismo , Fímbrias Bacterianas/imunologia , Evasão da Resposta Imune , Streptococcus pyogenes/imunologia , Streptococcus pyogenes/patogenicidade , Animais , Aderência Bacteriana/imunologia , Biofilmes/crescimento & desenvolvimento , Células Sanguíneas/microbiologia , Feminino , Fímbrias Bacterianas/classificação , Células HaCaT , Haptoglobinas/metabolismo , Humanos , Queratinócitos/microbiologia , Camundongos , Camundongos Endogâmicos ICR , Neutrófilos/microbiologia , Fenótipo , Infecções Estreptocócicas/sangue , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/microbiologia , Streptococcus pyogenes/genética , Virulência , Fatores de Virulência/metabolismoRESUMO
Osteoporosis is defined as a metabolic skeletal disease characterized by a decrease of the bone mass per unit volume, caused by a variety of reasons. Increasing evidence indicate that the host inflammatory response was correlated with the occurrence and development of osteoporosis, and it has been recognized that T lymphocytes and B lymphocytes play a critical role in pathogenesis of inflammatory bone disease. Between January 2018 and December 2018, retrospective analysis of 487 patients (exclusion of patients with recent infections and hematologic disorders whose leukocyte counts or classifications are markedly abnormal) who underwent bone mineral density (BMD) examinations in Huzhou Central Hospital. The patients were divided into normal bone density group, osteopenia group, and osteoporosis group according to the T score of BMD in the left femoral neck, respectively. Statistics of the lymphocyte ratio and the monocyte ratio in the blood routine examination results during the same period were performed so as to make a comparison of the differences among the groups. The correlation of the lymphocyte ratio and monocyte ratio with the T score of BMD in the left femoral neck was also analyzed. The difference between neutrocyte ratio lymphocyte ratio and the monocyte ratio was statistically significant in both males and females among the normal bone density group, osteopenia group and osteoporosis group (Pâ<â.01 or Pâ<â.05). Inflammation plays an important role in the progression of osteoporosis. By monitoring these three indicators in blood routine examination, early intervention for osteoporosis may become possible.
Assuntos
Biomarcadores/análise , Células Sanguíneas/microbiologia , Osteoporose/diagnóstico , Idoso , Biomarcadores/sangue , Índice de Massa Corporal , Densidade Óssea/fisiologia , China , Correlação de Dados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose/sangue , Estudos Retrospectivos , Fatores de RiscoRESUMO
A series of aggregation-induced emission (AIE)-based imidazolium-type ionic liquids (ILs) were designed and synthesized for bacterial killing and imaging, cell labeling, and bacterial detection in blood cells. The AIE-based ILs showed antibacterial activities against both Escherichia coli and Staphylococcus aureus. The carbon chain length of substitution at the N3 position of the imidazolium cations highly affects the antibacterial properties of ILs. Owing to their AIE characteristics, the ILs could selectively capture fluorescence image of dead bacteria while killing the bacteria. The fluorescence intensity varied with the concentration of bacteria, indicating that AIE-based ILs has potential as an antibacterial material and an efficient probe for bacterial viability assay. In addition, the synthesized AIE-based ILs exhibit relatively low cytotoxicity and hemolysis rate and therefore potential for cell labeling, as well as bacterial detection in blood cells. STATEMENT OF SIGNIFICANCE: Bacteria are ubiquitous, especially the pathogenic bacteria, which pose a serious threat to human health. There is an urgent need for materials with efficient antibacterial properties and biocompatibility and without causing drug resistance. In this work, we synthesized a series of aggregation-induced emission (AIE)-doped imidazolium type ionic liquids (ILs) with multifunction potential of bacterial killing and imaging, cell labeling, and detection of bacteria from blood cells. The synthesized AIE-based ILs can image dead bacteria at the same time of killing these bacteria, which can avoid the fluorescent dyeing process. Simultaneously, the fluorescent imaging of dead bacteria can be distinguished by the naked eye, and the fluorescence intensity from the AIE-based ILs varied with the concentration of bacteria. In addition, the AIE-based ILs exhibit relatively low cytotoxicity and hemolysis rate and therefore potential for cell labeling as well as detection of bacteria from red blood cell suspension.
Assuntos
Células Sanguíneas/microbiologia , Escherichia coli/crescimento & desenvolvimento , Líquidos Iônicos , Staphylococcus aureus/crescimento & desenvolvimento , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Células Sanguíneas/metabolismo , Linhagem Celular , Líquidos Iônicos/química , Líquidos Iônicos/farmacologia , Camundongos , Viabilidade Microbiana/efeitos dos fármacosRESUMO
Interferon-γ inducible protein 10 (IP-10), is a potent chemoattractant that promotes migration of monocytes and activated T-cells to inflammation foci. IP-10 is elevated in serum of patients with chronic hepatitis C virus (HCV) and tuberculosis (TB) infections, although it remains to be determined the contribution of IP-10 in restricting Mycobacterium tuberculosis (Mtb) replication. Here, we investigated the impact of IP-10 on mycobacteria replication using the ex vivo model of human whole-blood (WB) assay. In particular, we compared the levels of IP-10 upon infection with different Mtb clinical strains and species of non-tuberculous mycobacteria (NTM) and evaluated how IP-10 may contain bacterial replication. Interestingly, we observed that the inhibition of the host enzyme dipeptidyl peptidase IV (DPP-IV), which inactivates IP-10 through cleavage of two amino acids at the chemokine N-terminus, restricted mycobacterial persistence in WB, supporting the critical role of full length IP-10 in mediating an anti-Mtb response. Addition of recombinant IP-10 expressed in eukaryotic cells enhanced the anti-mycobacterial activity in WB, although no differences were observed when IP-10 containing different proportions of cleaved and non-cleaved forms of the chemokine were added. Moreover, recombinant IP-10 did not exert a direct anti-mycobacterial effect. Our results underscore the clinical relevance of IP-10 in mycobacteria pathogenesis and support the potential outcomes that may derive by targeting the IP-10/CXCR3 pathway as host directed therapies for the treatment of Mtb or NTM infections.
Assuntos
Células Sanguíneas/microbiologia , Quimiocina CXCL10/imunologia , Mycobacterium tuberculosis/crescimento & desenvolvimento , Adulto , Bioensaio , Humanos , Masculino , Micobactérias não Tuberculosas/crescimento & desenvolvimento , Tuberculose/microbiologia , Células Tumorais CultivadasRESUMO
Product safety assurance is crucial for the clinical use of manufactured cellular therapies. A rational approach for delivering products that fail release criteria (because of potentially false-positive sterility results) is important to avoid unwarranted wastage of highly personalized and costly therapies in critically ill patients where benefits may outweigh risk. Accurate and timely interpretation of microbial sterility assays represents a major challenge in cell therapies. We developed a systematic protocol for the assessment of positive microbial sterility test results using retrospective data from 2007 to 2016. This protocol was validated and applied prospectively between October 2016 and September 2017 to 13 products from which positive sterility results had been reported. Viable and nonviable environmental monitoring (EM) data were collected concurrently as part of a facility control assessment. Three of 13 (23%) positive sterility results were attributable to bone marrow collections that had been contaminated with skin flora during harvest; all were infused without pertinent infectious sequelae. Of the remaining 10, 1 was deemed a true positive and was discarded before infusion, whereas 9 were classified as false positives attributed to laboratory sampling and/or culturing processes. Three products deemed false positive were infused and 6 were withheld because of patient issues unrelated to microbial sterility results. No postinfusion-associated infectious complications were documented. Almost half of the positive EM findings were skin flora. Paired detection of an organism in both product and associated EM was identified in 1 case. Application of our validated protocol to positive product sterility test results allowed for systematic data compilation for regulatory evaluation and provided comprehensive information to clinical investigators to ensure timely and strategic management for product recipients.
Assuntos
Células Sanguíneas , Terapia Baseada em Transplante de Células e Tecidos , Desinfecção , Controle de Qualidade , Células Sanguíneas/microbiologia , Células Sanguíneas/virologia , Humanos , Estudos RetrospectivosRESUMO
Neisseria meningitidis (meningococcus) causes invasive diseases such as meningitis or septicaemia. Ex vivo infection of human whole blood is a valuable tool to study meningococcal virulence factors and the host innate immune responses. In order to consider effects of cellular mediators, the coagulation cascade must be inhibited to avoid clotting. There is considerable variation in the anticoagulants used among studies of N. meningitidis whole blood infections, featuring citrate, heparin or derivatives of hirudin, a polypeptide from leech saliva. Here, we compare the influence of these three different anticoagulants, and additionally Mg/EGTA, on host innate immune responses as well as on viability of N. meningitidis strains isolated from healthy carriers and disease cases, reflecting different sequence types and capsule phenotypes. We found that the anticoagulants significantly impact on cellular responses and, strain-dependently, also on bacterial survival. Hirudin does not inhibit complement and is therefore superior over the other anticoagulants; indeed hirudin-plasma most closely reflects the characteristics of serum during N. meningitidis infection. We further demonstrate the impact of heparin on complement activation on N. meningitidis and its consequences on meningococcal survival in immune sera, which appears to be independent of the heparin binding antigens Opc and NHBA.
Assuntos
Anticoagulantes/farmacologia , Imunidade Inata/efeitos dos fármacos , Infecções Meningocócicas/imunologia , Neisseria meningitidis/crescimento & desenvolvimento , Animais , Proteínas da Membrana Bacteriana Externa/metabolismo , Células Sanguíneas/imunologia , Células Sanguíneas/microbiologia , Proteínas de Transporte/metabolismo , Ácido Cítrico/farmacologia , Ativação do Complemento/efeitos dos fármacos , Heparina/farmacologia , Hirudinas/farmacologia , Humanos , Viabilidade Microbiana/efeitos dos fármacos , Modelos Biológicos , Neisseria meningitidis/efeitos dos fármacos , Neisseria meningitidis/imunologiaRESUMO
Mucosal antibodies constitute the first line of adaptive immune defence against invaders in the female genital tract (FGT), yet the sequence of events leading to their production is surprisingly poorly characterized. We explored the induction of pathogen-specific antibody-secreting cells (ASC) as a response to an acute infection in the upper FGT. We recruited 12 patients undergoing surgery due to an upper FGT infection (7/12 blood culture positive, 5/12 negative) and six healthy controls. Pathogens were sampled during surgery and PBMC collected in the acute phase of the disease (days 7-10). We searched by ELISPOT circulating pathogen-specific ASC and explored their frequency, immunoglobulin isotype distribution, and expressions of homing receptors (α4ß7, L-selectin, and CLA). All patients had circulating ASC specific to the infective bacteria; the geometric mean was 434 (95%CI 155-1234) ASC (IgAâ¯+â¯IgGâ¯+â¯IgM)/106 PBMC. IgA ASC predominated in 7/12, IgG ASC in 3/12, and IgM ASC in 2/12 cases. Of all the pathogen-specific ASC, 60% expressed α4ß7, 67% L-selectin, and 9% CLA. This study is the first to show induction of pathogen-specific ASC in the peripheral blood in bacterial infection in the human FGT. Our findings reveal that such FGT-originating pathogen-specific ASC are predominated by IgA ASC and exhibit a homing receptor profile resembling that of ASC in acute urinary tract infection. The data thus suggest a characteristic profile shared by the urogenital tract.
Assuntos
Anticorpos Antibacterianos/sangue , Células Produtoras de Anticorpos/fisiologia , Infecções Bacterianas/imunologia , Células Sanguíneas/fisiologia , Genitália Feminina/imunologia , Imunoglobulina A/sangue , Adolescente , Adulto , Células Sanguíneas/microbiologia , Células Cultivadas , ELISPOT , Feminino , Humanos , Imunidade Humoral , Integrinas/metabolismo , Selectina L/metabolismo , Antígenos CD15/análogos & derivados , Antígenos CD15/metabolismo , Pessoa de Meia-Idade , Oligossacarídeos/metabolismo , Antígeno Sialil Lewis X/análogos & derivados , Adulto JovemRESUMO
Levels of bacterial LPS, pro-inflammatory cytokines and IL-10 are related to the severity of meningococcal septicaemia. Patients infected with a Neisseria meninigitidis lpxL1 mutant ( Nm-mutant) with penta-acylated lipid A present with a milder meningococcal disease than those infected with hexa-acylated Nm wild type ( Nm-wt). The aim was to compare the pro-inflammatory responses after ex vivo incubation with the heat-inactivated Nm-wt or the Nm-mutant in citrated whole blood, and the modulating effects of IL-10. Concomitantly, we measured intracellular IL-6, IL-8 and TNF-α to elucidate which cell types were responsible for the pro-inflammatory responses. Incubation with Nm-wt (106/ml;107/ml;108/ml) resulted in a dose-dependent increase of the MyD88-dependent pro-inflammatory cytokines (IL-1ß, IL-6, IL-8, TNF-α), which were mainly derived from monocytes. In comparison, only 108/ml of the Nm-mutant significantly increased the concentration of these cytokines. The MyD88-independent cytokines (IP-10, RANTES) were evidently increased after incubation with the Nm-wt but were unaffected by the Nm-mutant. Co-incubation with IL-10 significantly reduced the concentrations of the MyD88-dependent cytokines induced by both the Nm-wt and the Nm-mutant, whereas the MyD88-independent cytokines were almost unaffected. In summary, the Nm-mutant is a weaker inducer of the MyD88-dependent/independent cytokines than the Nm-wt in whole blood, and IL-10 attenuates the Nm-stimulated increase in MyD88-dependent pro-inflammatory cytokines.
Assuntos
Aciltransferases/metabolismo , Proteínas de Bactérias/metabolismo , Células Sanguíneas/imunologia , Inflamação/imunologia , Infecções Meningocócicas/imunologia , Monócitos/imunologia , Neisseria meningitidis/fisiologia , Aciltransferases/genética , Proteínas de Bactérias/genética , Células Sanguíneas/microbiologia , Células Cultivadas , Citocinas/metabolismo , Temperatura Alta , Humanos , Mediadores da Inflamação/metabolismo , Interleucina-10/metabolismo , Monócitos/microbiologia , Mutação/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Transdução de SinaisRESUMO
Regulating gene expression during infection is critical to the ability of pathogens to circumvent the immune response and cause disease. This is true for the group A Streptococcus (GAS), a pathogen that causes both invasive (e.g., necrotizing fasciitis) and noninvasive (e.g., pharyngitis) diseases. The control of virulence (CovRS) two-component system has a major role in regulating GAS virulence factor expression. The regulator of cov (RocA) protein, which is a predicted kinase, functions in an undetermined manner through CovRS to alter gene expression and reduce invasive disease virulence. Here, we show that the ectopic expression of a truncated RocA derivative, harboring the membrane-spanning domains but not the dimerization or HATPase domain, is sufficient to complement a rocA mutant strain. Coupled with a previous bioinformatic study, the data are consistent with RocA being a pseudokinase. RocA reduces the ability of serotype M1 GAS isolates to express capsule and to evade killing in human blood, phenotypes that are not observed for M3 or M18 GAS due to isolates of these serotypes naturally harboring mutant rocA alleles. In addition, we found that varying the RocA concentration attenuates the regulatory activity of Mg2+ and the antimicrobial peptide LL-37, which positively and negatively regulate CovS function, respectively. Thus, we propose that RocA is an accessory protein to the CovRS system that influences the ability of GAS to modulate gene expression in response to host factors. A model of how RocA interacts with CovRS, and of the regulatory consequences of such activity, is presented.
Assuntos
Regulação Bacteriana da Expressão Gênica , Genes Bacterianos , Streptococcus pyogenes/genética , Streptococcus pyogenes/patogenicidade , Transativadores/genética , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos , Cápsulas Bacterianas/genética , Cápsulas Bacterianas/metabolismo , Células Sanguíneas/imunologia , Células Sanguíneas/microbiologia , Catelicidinas/farmacologia , Cátions Bivalentes , Perfilação da Expressão Gênica , Teste de Complementação Genética , Humanos , Magnésio/farmacologia , Viabilidade Microbiana , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Análise de Sequência de RNA , Streptococcus pyogenes/efeitos dos fármacos , Streptococcus pyogenes/metabolismo , Transativadores/metabolismo , VirulênciaRESUMO
Staphylococcus aureus is a human commensal but also has devastating potential as an opportunistic pathogen. S. aureus bacteremia is often associated with an adverse outcome. To identify potential targets for novel control approaches, we have identified S. aureus components that are required for growth in human blood. An ordered transposon mutant library was screened, and 9 genes involved specifically in hemolysis or growth on human blood agar were identified by comparing the mutants to the parental strain. Three genes (purA, purB, and pabA) were subsequently found to be required for pathogenesis in the zebrafish embryo infection model. The pabA growth defect was specific to the red blood cell component of human blood, showing no difference from the parental strain in growth in human serum, human plasma, or sheep or horse blood. PabA is required in the tetrahydrofolate (THF) biosynthesis pathway. The pabA growth defect was found to be due to a combination of loss of THF-dependent dTMP production by the ThyA enzyme and increased demand for pyrimidines in human blood. Our work highlights pabA and the pyrimidine salvage pathway as potential targets for novel therapeutics and suggests a previously undefined role for a human blood factor in the activity of sulfonamide antibiotics.
Assuntos
Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidade , Fatores de Virulência/genética , Adenilossuccinato Liase/genética , Adenilossuccinato Liase/metabolismo , Adenilossuccinato Sintase/genética , Adenilossuccinato Sintase/metabolismo , Animais , Proteínas de Bactérias/metabolismo , Células Sanguíneas/microbiologia , Meios de Cultura/química , Elementos de DNA Transponíveis , Modelos Animais de Doenças , Embrião não Mamífero , Cavalos , Interações Hospedeiro-Patógeno/imunologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Ovinos , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/mortalidade , Staphylococcus aureus/metabolismo , Análise de Sobrevida , Virulência , Fatores de Virulência/metabolismo , Peixe-ZebraRESUMO
Group A streptococci (GAS) are highly prevalent human pathogens whose primary ecological niche is the superficial epithelial layers of the throat and/or skin. Many GAS strains with a strong tendency to cause pharyngitis are distinct from strains that tend to cause impetigo; thus, genetic differences between them may confer host tissue-specific virulence. In this study, the FbaA surface protein gene was found to be present in most skin specialist strains but largely absent from a genetically related subset of pharyngitis isolates. In an ΔfbaA mutant constructed in the impetigo strain Alab49, loss of FbaA resulted in a slight but significant decrease in GAS fitness in a humanized mouse model of impetigo; the ΔfbaA mutant also exhibited decreased survival in whole human blood due to phagocytosis. In assays with highly sensitive outcome measures, Alab49ΔfbaA was compared to other isogenic mutants lacking virulence genes known to be disproportionately associated with classical skin strains. FbaA and PAM (i.e., the M53 protein) had additive effects in promoting GAS survival in whole blood. The pilus adhesin tip protein Cpa promoted Alab49 survival in whole blood and appears to fully account for the antiphagocytic effect attributable to pili. The finding that numerous skin strain-associated virulence factors make slight but significant contributions to virulence underscores the incremental contributions to fitness of individual surface protein genes and the multifactorial nature of GAS-host interactions.
Assuntos
Proteínas de Bactérias/genética , Proteínas de Transporte/genética , Regulação Bacteriana da Expressão Gênica , Infecções Estreptocócicas/microbiologia , Streptococcus pyogenes/genética , Streptococcus pyogenes/patogenicidade , Animais , Proteínas de Bactérias/metabolismo , Células Sanguíneas/imunologia , Células Sanguíneas/microbiologia , Proteínas de Transporte/metabolismo , Modelos Animais de Doenças , Frutose-Bifosfato Aldolase , Aptidão Genética , Interações Hospedeiro-Patógeno , Humanos , Impetigo/imunologia , Impetigo/microbiologia , Impetigo/patologia , Camundongos , Faringite/imunologia , Faringite/microbiologia , Faringite/patologia , Faringe/imunologia , Faringe/microbiologia , Faringe/patologia , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Pele/imunologia , Pele/microbiologia , Pele/patologia , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/patologia , Streptococcus pyogenes/metabolismo , VirulênciaRESUMO
Intracellular bacterial pathogens (IBPs) invade and replicate in different cell types including immune cells, in particular of the innate immune system (IIS) during infection in the acute phase. However, immune cells primarily function as essential players in the highly effective and integrated host defense systems comprising the IIS and the adaptive immune system (AIS), which cooperatively protect the host against invading microbes including IBPs. As countermeasures, the bacterial pathogens (and in particular the IBPs) have developed strategies to evade or reprogram the IIS at various steps. The intracellular replication capacity and the anti-immune defense responses of the IBP's as well as the specific antimicrobial responses of the immune cells of the innate and the AIS depend on specific metabolic programs of the IBPs and their host cells. The metabolic programs of the immune cells supporting or counteracting replication of the IBPs appear to be mutually exclusive. Indeed, recent studies show that upon interaction of naïve, metabolically quiescent immune cells with IBPs, different metabolic activation processes occur which may result in the provision of a survival and replication niche for the pathogen or its eradication. It is therefore likely that within a possible host cell population subsets exist that are metabolically programmed for pro- or anti-microbial conditions. These metabolic programs may be triggered by the interactions between different bacterial agonistic components and host cell receptors. In this review, we summarize the current status in the field and discuss metabolic adaptation processes within immune cells of the IIS and the IBPs that support or restrict the intracellular replication of the pathogens.
Assuntos
Bactérias/metabolismo , Infecções Bacterianas/metabolismo , Células Sanguíneas/metabolismo , Animais , Bactérias/genética , Bactérias/imunologia , Infecções Bacterianas/genética , Infecções Bacterianas/imunologia , Infecções Bacterianas/microbiologia , Células Sanguíneas/imunologia , Células Sanguíneas/microbiologia , Interações Hospedeiro-Patógeno , Humanos , Imunidade InataRESUMO
We assessed the diversity of culturable fungi associated with rocks of continental Antarctica to evaluate their physiological opportunistic virulence potential in vitro. The seventy fungal isolates obtained were identified as nine species of Acremonium, Byssochlamys, Cladosporium, Debaryomyces, Penicillium, and Rhodotorula. Acremonium sp., D. hansenii, P. chrysogenum, P. citrinum, P. tardochrysogenum, and R. mucilaginosa were able to grow at 37 °C; in addition, B. spectabilis displayed a high level of growth at 37 and 45 °C. Thirty-one isolates of P. chrysogenum, P. citrinum, and P. tardochrysogenum were able to produce partial haemolysis on blood agar at 37 °C. Acremonium sp., P. citrinum, and P. tardochrysogenum showed spore sizes ranging from 2.81 to 5.13 µm diameters at 37 °C. Of these, P. chrysogenum and P. tardochrysogenum displayed macro- and micro morphological polymorphism. Our results suggest that rocks of the ultra-extreme cold and dry environment of Antarctica harbour cryptic fungi phylogenetically close to opportunistic pathogenic and mycotoxigenic taxa with physiologic virulence characteristics in vitro.
Assuntos
Ambientes Extremos , Sedimentos Geológicos/microbiologia , Hemólise , Micobioma , Acremonium/isolamento & purificação , Animais , Regiões Antárticas , Células Sanguíneas/microbiologia , Byssochlamys/isolamento & purificação , Cladosporium/isolamento & purificação , Temperatura Baixa , Penicillium/isolamento & purificação , Filogenia , Rhodotorula/isolamento & purificação , Ovinos , Esporos/citologiaRESUMO
The convergence of tuberculosis and diabetes represents a co-epidemic that threatens progress against tuberculosis. We have investigated type 2 diabetes as a risk factor for tuberculosis susceptibility, and have used as experimental model whole blood infected in vitro with Mycobacterium tuberculosis. Blood samples from diabetic patients were found to have a higher absolute neutrophil count that non-diabetic controls, but their immune functionality seemed impaired because they displayed a lower capacity to phagocytose M. tuberculosis, a finding that had been previously reported only for monocytes. In contrast, an increased production of TNFα was detected in infected blood from diabetic patients. Despite the altered phagocytic capacity showed by cells from these patients, the antimicrobial activity measured in both whole blood and monocyte derived macrophages was similar to that of controls. This unexpected result prompts further improvements in the whole blood model to analyze the immune response of diabetes patients to tuberculosis.
Assuntos
Células Sanguíneas/imunologia , Diabetes Mellitus Tipo 2/imunologia , Macrófagos/imunologia , Mycobacterium tuberculosis/imunologia , Neutrófilos/imunologia , Tuberculose/imunologia , Idoso , Idoso de 80 Anos ou mais , Células Sanguíneas/microbiologia , Células Cultivadas , Diabetes Mellitus Tipo 2/complicações , Feminino , Humanos , Imunidade Celular , Macrófagos/microbiologia , Masculino , Pessoa de Meia-Idade , Neutrófilos/microbiologia , Fagocitose , Risco , Tuberculose/complicações , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The most widely used ante-mortem diagnostic tests for tuberculosis in cattle are the tuberculin skin test and the interferon-gamma (IFN-γ) release assay, both of which measure cell-mediated immune responses to Mycobacterium bovis infection. However, limitations in the performance of these tests results in a failure to identify all infected animals. In attempting to increase the range of diagnostic tests for tuberculosis, measurement of the cytokine IP-10 in antigen-stimulated blood has previously been shown to improve the detection of M. tuberculosis and M. bovis infection, in humans and African buffaloes (Syncerus caffer), respectively. In the present study, 60 cattle were identified by the single intradermal comparative tuberculin test as tuberculosis reactors (n = 24) or non-reactors (n = 36) and the release of IFN-γ and IP-10 in antigen-stimulated whole blood from these animals was measured using bovine specific ELISAs. There was a strong correlation between IP-10 and IFN-γ production in these samples. Moreover, measurement of the differential release of IP-10 in response to stimulation with M. bovis purified protein derivative (PPD) and M. avium PPD distinguished between reactor and non-reactor cattle with a sensitivity of 100% (95% CI, 86%-100%) and a specificity of 97% (95% CI, 85%-100%). These results suggest that IP-10 might prove valuable as a diagnostic biomarker of M. bovis infection in cattle.