Role of nonpneumoniae mycoplasma in the pathogenesis of ventilator-associated pneumonia: an in vitro assessment

TJ Nolan,AC Morris,A Rossi,T Walsh

doi:10.1186/cc14071

Abstract

Mycoplasma organisms are the smallest bacteria capable of self-replication [1] and include species capable of causing disease (for example, Mycoplasma pneumoniae, Mycoplasma genitalium) as well as those that are generally thought to exist synergistically with their human host (for example, Mycoplasma salivarium). The Edinburgh critical care group (Prof TW/ACM) has recently identified a high prevalence of M. salivarium in the bronchoalveolar lavage washings from patients with confirmed and suspected ventilator-associated pneumonia (VAP) (Figure (Figure1)1) [2]. The aim of this study was to examine the effect of M. salivarium on human immune cells in vitro. Specifically, we measured cytokine production and phagocytosis activity in response to M. salivarium exposure. Figure 1 Combined mycoplasma detection by PCR in the prospective and clinical groups. Methods Whole human blood was obtained from healthy donor volunteers and cell types were isolated using diffusion gradients and magnetic labeling as appropriate. Monocytes and macrophages were incubated with M. salivarium for 24 hours before a subsequent LPS stimulus. Macrophage phagocytosis assays were conducted after exposure times of 60 minutes and 24 hours to M. salivarium. Cytokines were measured using ELISA and human cytokine bead array kits.

Highlights

During the course of systemic inflammation, most of the immune cell types get activated to a certain degree as part of, or contributing to, the cascade of physiopathological events
After the development of sepsis we detected in all patients significantly increased heart rate, respiratory rate per minute, leukocytosis, anemia, worse glucose metabolism and renal function (Table 1)
Free KDO in the used concentration was inactive in regulation of TLR4, CD11b and CD14 expression and did not induce tumor necrosis factor alpha (TNFa) release but its impact in biological activity was detected when KDO was applied as constituent of Re-LPS

Summary

Introduction

During the course of systemic inflammation, most of the immune cell types get activated to a certain degree as part of, or contributing to, the cascade of physiopathological events. This study aimed to find out whether mean differences of 6-hour, 12-hour, and 24-hour lactate clearance were observed between nonsurvivors and survivors of acute phase mortality in severe sepsis and septic shock patients. Conclusion: A two-phase retrospective chart review study demonstrated that the SSST utilized at a community hospital in Miami had a sensitivity value of 41.49% and a specificity value of 90.53% when evaluating medical surgical patients These results indicate the tool is accurate in detecting patients that are not septic; it is not reliable in identifying patients who are truly septic. This study was aimed to address the association of achieving either one or two targets of microcirculatory end point resuscitation and early mortality in severe sepsis and septic shock patients. Conclusion: Achieving both lactate clearance and ScvO2 targets in 6 hours after onset of resuscitation associates with lowest early mortality risk in severe sepsis and septic shock patients. Other blood samples were collected in blood culture tubes for culturing to verify septicemia depending on the clinical evidence

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