Impact of micro‐environmental changes on respiratory tract infections with intracellular bacteria

Abstract

Edited by Wilhelm JustCommunity-acquired pneumonia is caused by intra-and extracellular bacteria, with some of these bacteria also being linked to the pathogenesis of chronic lung diseases, including asthma and chronic obstructive pulmonary disease. Chlamydia pneumoniae is an obligate intracellular pathogen that is highly sensitive to micro-environmental conditions controlling both pathogen growth and host immune responses. The availability of nutrients, as well as changes in oxygen, pH and interferon-c levels, have been shown to directly influence the chlamydial life cycle and clearance. Although the lung has been traditionally regarded as a sterile environment, sequencing approaches have enabled the identification of a large number of bacteria in healthy and diseased lungs. The influence of the lung microbiota on respiratory infections has not been extensively studied so far and data on chlamydial infections are currently unavailable. In the present study, we speculate on how lung microbiota might interfere with acute and chronic infections by focusing exemplarily on the obligate intracellular C. pneumoniae. Furthermore, we consider changes in the gut microbiota as an additional player in the control of lung infections, especially in view the increasing evidence suggesting the involvement of the gut microbiota in various immunological processes throughout the human body.

Infection-mediated asthma: etiology, mechanisms and treatment options, with focus on Chlamydia pneumoniae and macrolides

“…These authors also demonstrated that antibiotic usage disrupted this asymptomatic colonization and prevented asthmatic onset [27]. These findings support the hypothesis that colonization of the developing airway by certain microbes (both viral and bacterial) can significantly alter the airway architecture and overall immune function, influencing how the airway responds to a variety of insults [28]. These findings also suggest that antimicrobial agents may represent an effective therapeutic tool with the potential to curtail both the duration and severity of asthma exacerbations initiated by a variety of microbes and exposes the limitation of the hygiene hypothesis in this regard [26].…”

Chlamydia pneumoniae Influence on Cytokine Production in Steroid-Resistant and Steroid-Sensitive Asthmatics

“…Differences among adult asthmatics have also been demonstrated under specific circumstances such as pregnancy [30]. These findings point out the possibility of impaired cytokine responses under determined factors that can interfere with asthma pathogenesis and C. pneumoniae infection [31].…”

The airway microbiota in early cystic fibrosis lung disease

“…Over the past two decades, molecular techniques, including those targeting the variable regions of the bacterial 16S ribosomal RNA (16S rRNA) gene, next‐generation sequencing, and metagenomic analyses, have changed our understanding of the human microbiome, including the respiratory microbiome, in health and disease. At each body habitat, the microbiome is believed to have complex relationships, both in the dynamics of its core and satellite organisms, and with its host, where it has potential interactions with the developing immune system and regulation of the inflammatory response …”