Programme Hospitalier Recherche Clinique, Institut Pasteur, Inserm, French Public Health Agency.

Significant advances in brain imaging, minimally invasive neurosurgery, molecular biology and antibacterial agents have dramatically improved the prognosis of brain abscess in immunocompetent patients over the last decades.

Sepsis is accompanied by the initial activation of proinflammatory pathways and long-lasting immunosuppression that appears to contribute to late-occurring mortality. Although high-mobility group box 1 (HMGB1) is involved in many aspects of inflammation, its role in sepsis-induced immune suppression remains unclear. In this study, we examined HMGB1's contribution to neutrophil NADPH oxidase activity dysfunction and associated neutrophil-dependent bacterial clearance in mice subjected to sepsis and in patients who survive septic shock. Using a murine model of polymicrobial septic peritonitis, we demonstrated that treatment with anti-HMGB1 Ab significantly diminished sepsis-induced dysfunction of neutrophil NADPH oxidase activity. In a subsequent set of experiments, we found that blocking HMGB1 preserved the ability of neutrophils from patients recovering from septic shock to activate NADPH oxidase. Taken together, our data suggest that HMGB1 accumulation in the late phase of sepsis plays a specific role in the development of postsepsis immunosuppression and specifically affects neutrophil-dependent antibacterial defense mechanisms. Thus, blocking HMGB1 may be a promising therapeutic intervention to diminish the adverse effects of sepsis-induced immunosuppression.

No abstract

The local IRB (« comité d'éthique du CHU de Rennes ») approved the study (N°19.53) the 12 of may 2019.

E. Forestier). y Forestier Emmanuel and Claire Roubaud-Baudron are joint first authors.x The members of the collab group AEPEI and the GInGer Elderl-IE study group are listed under the Acknowledgements section. Contents lists available at ScienceDirect Clinical Microbiology and Infectionj o u r n a l h o m e p a g e : w w w . c l i n i c a l m i c r o b i o l o g y a n d i n f e c t i o n . c o m

The spectrum of community-acquired pneumonia (CAP) due to Chlamydophila psittaci ranges from mild, self-limited CAP, to acute respiratory failure. We performed a retrospective study of 13 consecutive patients with CAP due to C. psittaci and 51 patients with legionellosis admitted in one intensive care unit (ICU) (1993-2011). As compared to patients with legionellosis, patients with psittacosis were younger (median age 48 [38-59] vs. 60 [50-71] years, p = 0.007), less frequently smokers (38 vs. 79 %, p < 0.001), with less chronic disease (15 vs. 57 %, p = 0.02), and longer duration of symptoms before admission (median 6 [5-13] vs. 5 [3-7] days, p = 0.038). They presented with lower Simplified Acute Physiology Score II (median 28 [19-38] vs. 39 [28-46], p = 0.04) and less extensive infiltrates on chest X-rays (median 2 [1-3] vs. 3 [3-4] lobes, p = 0.007). Bird exposure was mentioned in 100 % of psittacosis cases, as compared to 5.9 % of legionellosis cases (p < 0.0001). Extrapulmonary manifestations, biological features, and mortality (15.4 vs. 21.6 %, p = 0.62) were similar in both groups. In conclusion, severe psittacosis shares many features with severe legionellosis, including extrapulmonary manifestations, biological features, and outcome. Psittacosis is an important differential diagnosis for legionellosis, especially in cases of bird exposure, younger age, and more limited disease progression over the initial few days.

Diagnosing infections involving this species by routine methods is difficult.