Mycoplasma Pneumoniae Infections

2020 ◽  
Author(s):  
T. Prescott Atkinson ◽  
William M. Geisler ◽  
Ken B. Waites

The class Mollicutes includes organisms in the genera Mycoplasma and Ureaplasma. They are prokaryotes that lack a cell wall, and are among the smallest known living organisms in both cellular dimensions and genome sizes. At least 17 different species inhabit the mucosae of the respiratory and urogenital tracts of humans, several of which are pathogenic in a variety of clinical illnesses. Their fastidious nature and often slow growth in vitro have hampered understanding of their roles as agents of human disease. Mycoplasma pneumoniae is an important cause of community acquired respiratory infections that occur endemically and epidemically worldwide in persons of all ages and ranges in severity from mild to life-threatening. Molecular-based laboratory techniques have resulted in increased understanding of the pathogenesis and epidemiology M. pneumoniae infections as well as improved means for laboratory detection. Resistance of M. pneumoniae to macrolide antimicrobials has emerged worldwide over the past several years, complicating treatment strategies. This review contains 2 figures, 1 table and 58 references Key Words: Antimicrobial Resistance, Ciliated respiratory epithelium, Community Acquired Pneumonia, Cytadherence, Mycoplasma pneumoniae, Reinfections

2020 ◽  
Vol 41 (04) ◽  
pp. 538-554
Author(s):  
Joseph P. Lynch ◽  
Gail Reid ◽  
Nina M. Clark

AbstractMembers of the Nocardia genus are ubiquitous in the environment. These aerobic, gram-positive organisms can lead to life-threatening infection, typically in immunocompromised hosts such as solid organ transplant recipients or those receiving immunosuppressive medications for other reasons. This current review discusses the microbiology of nocardiosis, risk factors for infection, clinical manifestations, methods for diagnosis, and treatment. Nocardiosis primarily affects the lung but may also cause skin and soft tissue infection, cerebral abscess, bloodstream infection, or infection involving other organs. Although rare as a cause of community-acquired pneumonia, Nocardia can have severe morbidity and mortality, particularly in patients with comorbidities or compromised immunity. Early diagnosis and timely initiation of therapy are critical to optimizing patient outcomes. Species identification is important in determining treatment, as is in vitro susceptibility testing. Sulfonamide therapy is usually indicated, although a variety of other antimicrobials may be useful, depending on the species and susceptibility testing. Prolonged therapy is usually indicated, for 6 to 12 months, and in some cases surgical debridement may be required to resolve infection.


2020 ◽  
Vol 148 ◽  
Author(s):  
Haitao Li ◽  
Meihong Guo ◽  
Congmin Wang ◽  
Yibo Li ◽  
Anne Marie Fernandez ◽  
...  

Abstract Trichosporon is a yeast-like basidiomycete, a conditional pathogenic fungus that is rare in the clinic but often causes fatal infections in immunocompromised individuals. Trichosporon asahii is the most common pathogenic fungus in this genus and the occurrence of infections has dramatically increased in recent years. Here, we report a systematic literature review detailing 140 cases of T. asahii infection reported during the past 23 years. Statistical analysis shows that T. asahii infections were most frequently reported within immunodeficient or immunocompromised patients commonly with blood diseases. Antibiotic use, invasive medical equipment and chemotherapy were the leading risk factors for acquiring infection. In vitro susceptibility, clinical information and prognosis analysis showed that voriconazole is the primary drug of choice in the treatment of T. asahii infection. Combination treatment with voriconazole and amphotericin B did not show superiority over either drug alone. Finally, we found that the types of infections prevalent in China are significantly different from those in other countries. These results provide detailed information and relevant clinical treatment strategies for the diagnosis and treatment of T. asahii infection.


1986 ◽  
Vol 20 (4) ◽  
pp. 267-270 ◽  
Author(s):  
Patricia L. Cole ◽  
Thomas W. Smith

The narrow margin between therapeutic and toxic effects of digitalis glycosides renders patients taking these drugs particularly susceptible to serious consequences of accidental or deliberate overdosage, including life-threatening arrhythmias. Until recently, the treatment of digitalis intoxication has been largely supportive. In the past decade, however, digoxin-specific antibodies have been developed and have proven to be effective in rapidly reversing the electrophysiologic and metabolic manifestations of digitalis intoxication, both in vitro and in vivo. Enzymatic cleavage of the intact antibody population into Fab fragments results in a more rapidly effective and less immunogenic antidote to digitalis excess. More recently, monoclonal antibodies with high affinity and specificity for digoxin have been produced by the technique of somatic cell fusion; application of this technique to the production of anti-digoxin antibodies has potential implications for the production of a highly purified homogeneous product, but this approach has not yet been tested clinically.


2021 ◽  
Vol 2021 ◽  
pp. 1-23
Author(s):  
Jamie Mollentze ◽  
Chrisna Durandt ◽  
Michael S. Pepper

The use of stem cells in regenerative medicine, including tissue engineering and transplantation, has generated a great deal of enthusiasm. Mesenchymal stromal/stem cells (MSCs) can be isolated from various tissues, most commonly, bone marrow but more recently adipose tissue, dental pulp, and Wharton’s jelly, to name a few. MSCs display varying phenotypic profiles and osteogenic differentiating capacity depending and their site of origin. MSCs have been successfully differentiated into osteoblasts both in vitro an in vivo but discrepancies exist when the two are compared: what happens in vitro does not necessarily happen in vivo, and it is therefore important to understand why these differences occur. The osteogenic process is a complex network of transcription factors, stimulators, inhibitors, proteins, etc., and in vivo experiments are helpful in evaluating the various aspects of this osteogenic process without distractions and confounding variables. With that in mind, the results of in vitro experiments need to be carefully considered and interpreted with caution as they do not perfectly replicate the conditions found within living organisms. This is where in vivo experiments help us better understand interactions that might occur in the osteogenic process that cannot be replicated in vitro. Potentially, these differences could also be exploited to develop an optimal MSC cell therapeutic product that can be used for bone disorders. There are many bone disorders, most of which cause a great deal of discomfort. Clinically acceptable protocols could be developed in which MSCs are used to aid in bone regeneration providing relief for patients with chronic pain. The aim of this review is to examine the differences between studies conducted in vitro and in vivo with regard to the osteogenic process to better define the gaps in current osteogenic research. By better understanding osteogenic differentiation, we can better define treatment strategies for various bone disorders.


2021 ◽  
pp. 2100129
Author(s):  
Ruben Cornelis Anthonie de Groot ◽  
Silvia Cristina Estevão ◽  
Patrick Michael Meyer Sauteur ◽  
Aditya Perkasa ◽  
Theo Hoogenboezem ◽  
...  

Mycoplasma pneumoniae is the most common bacterial cause of pneumonia in children hospitalised for community-acquired pneumonia. Prevention of infection by vaccines may be an important strategy in the presence of emerging macrolide resistant M. pneumoniae. However, knowledge of immune responses to M. pneumoniae is limited, complicating vaccine design. We therefore studied the antibody response during M. pneumoniae infection and asymptomatic carriage.In a nested case-control study (n=80) of M. pneumoniae carriers and matched controls we observed that carriage by M. pneumoniae does not lead to a rise in either mucosal or systemic M. pneumoniae-specific antibodies, even after months of persistent carriage. We replicated this finding in a second cohort (n=69) and also found that during M. pneumoniae community-acquired pneumonia, mucosal levels of M. pneumoniae-specific IgA and IgG did increase significantly. In vitro adhesion assays revealed that high levels of M. pneumoniae-specific antibodies in nasal secretions of paediatric patients prevented the adhesion of M. pneumoniae to respiratory epithelial cells.In conclusion, our study demonstrates that M. pneumoniae-specific mucosal antibodies protect against bacterial adhesion to respiratory epithelial cells and are induced only during M. pneumoniae infection and not during asymptomatic carriage. This is strikingly different from carriage with bacteria such as Streptococcus pneumoniae where mucosal antibodies are induced by bacterial carriage.


Cancers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1679 ◽  
Author(s):  
Kathryn T. T. T. Nguyen ◽  
Judy M. Y. Wong

Telomerase reverse transcriptase (TERT)—the catalytic subunit of telomerase—is reactivated in up to 90% of all human cancers. TERT is observed in heterogenous populations of protein complexes, which are dynamically regulated in a cell type- and cell cycle-specific manner. Over the past two decades, in vitro protein–protein interaction detection methods have discovered a number of endogenous TERT binding partners in human cells that are responsible for the biogenesis and functionalization of the telomerase holoenzyme, including the processes of TERT trafficking between subcellular compartments, assembly into telomerase, and catalytic action at telomeres. Additionally, TERT have been found to interact with protein species with no known telomeric functions, suggesting that these complexes may contribute to non-canonical activities of TERT. Here, we survey TERT direct binding partners and discuss their contributions to TERT biogenesis and functions. The goal is to review the comprehensive spectrum of TERT pro-malignant activities, both telomeric and non-telomeric, which may explain the prevalence of its upregulation in cancer.


Author(s):  
T. V. Bushueva ◽  
N. A. Roslaya

Inpatient examination covered 46 workers of main occupations in chrysotile asbestos production, with diagnosed occupational disease “asbestosis”, and reference group comprising 20 healthy workers of the same enterprise. Th e results present comparative analysis of clinical and anamnesis data in dependence on the past pneumonia, studies of immune state in the asbestosis patients and the healthy workers, data on high occurrence of pneumonia in the workers, comparative analysis of respiratory infections occurrence and concomitant diseases according to the outpatients records and medical examinations. Findings are reliable diff erences and earlier respiratory manifestations in the past-pneumonia workers exposed to chrysotile asbestos, higher occurrence (1.3-fold) of chronic bronchitis and severe disorders of bronchial patency. Immune response factors were characterized as pathogenetic links of pneumococcus infectious invasion. Additional risk factors of pneumonia appeared to be frequent respiratory infections, chronic diseases of upper respiratory tract and middle ear, lower functional state of neutrophils, increased auto-reactivity. To evaluate signifi cance of risk factors infl uence, the authors used fi tt ing criterion X2 (chi-square). Intensity of relationships between the risk factor and outcome was evaluated by contingency coeffi  cient of Pearson. Signifi cance level (p) for all the calculation was accepted less than 0.05.


2011 ◽  
Vol 79 (10) ◽  
pp. 4010-4018 ◽  
Author(s):  
Michael H. Norris ◽  
Katie L. Propst ◽  
Yun Kang ◽  
Steven W. Dow ◽  
Herbert P. Schweizer ◽  
...  

ABSTRACTBurkholderia pseudomallei, the cause of serious and life-threatening diseases in humans, is of national biodefense concern because of its potential use as a bioterrorism agent. This microbe is listed as a select agent by the CDC; therefore, development of vaccines is of significant importance. Here, we further investigated the growth characteristics of a recently createdB. pseudomallei1026b Δasdmutantin vitro, in a cell model, and in an animal model of infection. The mutant was typified by an inability to grow in the absence of exogenous diaminopimelate (DAP); upon single-copy complementation with a wild-type copy of theasdgene, growth was restored to wild-type levels. Further characterization of theB. pseudomalleiΔasdmutant revealed a marked decrease in RAW264.7 murine macrophage cytotoxicity compared to the wild type and the complemented Δasdmutant. RAW264.7 cells infected by the Δasdmutant did not exhibit signs of cytopathology or multinucleated giant cell (MNGC) formation, which were observed in wild-typeB. pseudomalleicell infections. The Δasdmutant was found to be avirulent in BALB/c mice, and mice vaccinated with the mutant were protected against acute inhalation melioidosis. Thus, theB. pseudomalleiΔasdmutant may be a promising live attenuated vaccine strain and a biosafe strain for consideration of exclusion from the select agent list.


2017 ◽  
Vol 114 (31) ◽  
pp. 8342-8347 ◽  
Author(s):  
Samira Asgari ◽  
Luregn J. Schlapbach ◽  
Stéphanie Anchisi ◽  
Christian Hammer ◽  
Istvan Bartha ◽  
...  

Viral respiratory infections are usually mild and self-limiting; still they exceptionally result in life-threatening infections in previously healthy children. To investigate a potential genetic cause, we recruited 120 previously healthy children requiring support in intensive care because of a severe illness caused by a respiratory virus. Using exome and transcriptome sequencing, we identified and characterized three rare loss-of-function variants in IFIH1, which encodes an RIG-I-like receptor involved in the sensing of viral RNA. Functional testing of the variants IFIH1 alleles demonstrated that the resulting proteins are unable to induce IFN-β, are intrinsically less stable than wild-type IFIH1, and lack ATPase activity. In vitro assays showed that IFIH1 effectively restricts replication of human respiratory syncytial virus and rhinoviruses. We conclude that IFIH1 deficiency causes a primary immunodeficiency manifested in extreme susceptibility to common respiratory RNA viruses.


2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Ahmed El-Balat ◽  
Rudy Leon DeWilde ◽  
Iryna Schmeil ◽  
Morva Tahmasbi-Rad ◽  
Sandra Bogdanyova ◽  
...  

Myomas, also known as fibroids, are a specific characteristic of the human species. No other primates develop fibroids. At a cellular level, myomas are benign hyperplastic lesions of uterine smooth muscle cells. There are interesting theoretical concepts that link the development of myomas in humans with the highly specific process of childbirth from an upright position and the resulting need for greatly increased “expulsive” forces during labor. Myomas might be the price our species pays for our bipedal and highly intelligent existence. Myomas affect, with some variability, all ethnic groups and approximately 50% of all women during their lifetime. While some remain asymptomatic, myomas can cause significant and sometimes life-threatening uterine bleeding, pain, infertility, and, in extreme cases, ureteral obstruction and death. Traditionally, over 50% of all hysterectomies were performed for fibroids, leading to a significant healthcare burden. In this article, we review the developments of the past 20 years with regard to multiple new treatment strategies that have evolved during this time.


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