Variability in cell division among anatomical sites shapes Escherichia coli antibiotic survival in a urinary tract infection mouse model.

Urinary tract infection (UTI), mainly caused by Escherichia coli, are frequent and have a recurrent nature even after antibiotic treatment. Potential bacterial escape mechanisms include growth defects, but probing bacterial division in vivo and establishing its relation to the antibiotic response remain challenging. Using a synthetic reporter of cell division, we follow the temporal dynamics of cell division for different E. coli clinical strains in a UTI mouse model with and without antibiotics. We show that more bacteria are actively dividing in the kidneys and urine compared with the bladder. Bacteria that survive antibiotic treatment are consistently non-dividing in three sites of infection. Additionally, we demonstrate how both the strain in vitro persistence profile and the microenvironment impact infection and treatment dynamics. Understanding the relative contribution of the host environment, growth heterogeneity, non-dividing bacteria, and antibiotic persistence is crucial to improve therapies for recurrent infections.

Evaluation of the contribution of shotgun metagenomics in the microbiological diagnosis of liver abscesses.

BACKGROUND: Shotgun metagenomics (SMg) sequencing has gained a considerable interest, as it enables the detection of any microorganisms through a single analysis. Due to the limitations of standard microbiological approaches, the microbial documentation of liver abscesses (LA), which is crucial for their medical management, can be difficult. Here we aimed to compare the performance of SMg with standard approaches for the microbiological documentation of LA. METHODS: In this retrospective study conducted at two centers, we compared the results of standard microbiology with metagenomics analysis of consecutive LA samples. For samples tested positive for Klebsiella pneumoniae, we compared the analysis of virulence and resistance genes using metagenomics data to whole-genome sequencing of corresponding isolates obtained in culture. RESULTS: Out of the 62 samples included, standard approaches and SMg yielded documentation in 80.6% and 96.8%, respectively. In 37.1% (23/62) of cases, both methods showed identical results, whereas in 43.5% (27/62) of cases, the samples were positive by both methods, but SMg found additional species in 88.9% (24/27), mostly anaerobes. When the standard approaches were negative, the SMg was able to detect microorganisms in 80.0% of cases (8/10). Overall, SMg identified significantly more microorganisms than culture (414 vs.105; p<0.05). K. pneumoniae genome analysis was able to detect resistance and virulence genes with a level of sensitivity depending on the depth of sequencing. DISCUSSION: Overall, we showed that SMg had better performance in detecting and identifying microorganisms from LA samples and could help characterizing strain's resistome and virulome. Although still costly and requiring specific skills and expensive equipment, MGs methods are set to expand in the future.

Acute myocarditis revealing autoimmune and inflammatory disorders: Clinical presentation and outcome.

BACKGROUND: Acute myocarditis (AM) may be the heralding manifestation of autoimmune and inflammatory disorders (AIID). We aimed to describe the clinical presentation and outcome of patients with AM revealing AIID. METHODS: All consecutive adult patients with AM admitted in a department of Cardiology (Bichat Hospital, Paris, France) from January 2011 to January 2019 were included. Diagnosis of AM was based on clinical manifestations, elevated Troponin, myocardial inflammation on CMR and no evidence for coronary artery disease. AIID were classified using international criteria. RESULTS: Two-hundred and eighteen (35.3 [26.4-47.1] years, 75.2% males) patients with AM were included. Overall, AM revealed AIID in 15 (6.9%), including systemic lupus erythematosus (n = 3), adult onset Still's disease (n = 3), sarcoidosis (n = 2), mixed connective tissue disease (n = 1), anti-Jo1 syndrome (n = 1), eosinophilic granulomatosis with polyangiitis (n = 1), antiphospholipid syndrome (n = 1), reactive arthritis (n = 1), Graves' disease (n = 1) and Crohn's colitis (n = 1). Left ventricular ejection fraction (LVEF) at onset was <30% in 5 (33.3%) patients with AIID. All but 2 patients with AIID were treated with steroids, immunosuppressive and/or immunomodulatory drugs and LVEF normalized in all by the end of follow-up. By comparing patients with AIID to patients with idiopathic AM (n = 203), multivariable analysis showed that pericardial effusion, lack of chest pain and high CRP level at onset were independently associated with AIID. CONCLUSION: Acute myocarditis revealing AIID may be life-threatening at the acute phase but has an overall good prognosis under specific treatment. Pericardial effusion and CRP level at admission suggest an AIID as the cause for AM.