Impact of the Timing of Antibiotic Administration on Digestive Colonization with Carbapenemase-Producing Enterobacteriaceae in a Murine Model.

While antibiotic use is a risk factor of carbapenemase-producing Enterobacteriaceae (CPE) acquisition, the importance of timing of antibiotic administration relative to CPE exposure remains unclear. In a murine model of gut colonization by New Delhi metallo-beta-lactamase-1 (NDM-1)-producing Klebsiella pneumoniae, a single injection of clindamycin within at most 1 week before or after CPE exposure induced colonization persisting up to 100 days. The timing of antibiotic administration relative to CPE exposure may be relevant to infection control and antimicrobial stewardship approaches.

Impact of subglottic secretion drainage on microaspiration in critically ill patients: a prospective observational study.

BACKGROUND: Microaspiration is a major factor in ventilator-associated pneumonia (VAP) pathophysiology. Subglottic secretion drainage (SSD) aims at reducing its incidence. METHODS: Single-center prospective observational study, performed in a French intensive care unit (ICU) from March 2012 to April 2013, including adult patients mechanically ventilated for at least 24 hours divided in two groups: patients in the SSD group intubated using tracheal tubes allowing SSD and patients in the control group intubated with standard tracheal tubes. Pepsin and salivary amylase concentrations were measured for 24 hours in all tracheal aspirates. Primary objective was to determine the impact of SSD on gastric or oropharyngeal microaspiration using pepsin or amylase concentration in tracheal aspirates. RESULTS: Fifty-five patients were included in the SSD group and 45 in the control group. No difference was found between groups regarding the incidence of microaspiration defined as at least one tracheal aspirate positive for either pepsin or amylase [49 (89%) vs. 37 (82%), P=0.469]. Percentage of patients with VAP [16 (29%) vs. 11 (24%), P=0.656], ventilator-associated tracheobronchitis (VAT) [7 (13%) vs. 4 (9%), P=0.750] or early airway colonization [15 (35%) vs. 8 (18%), P=0.219] were not significantly different in study groups. CONCLUSIONS: SSD did not reduce the incidence of microaspiration, VAP, VAT or airway colonization in this observational study.

The next generation of rapid point-of-care testing identification tools for ventilator-associated pneumonia.

Ventilator-associated pneumonia (VAP) is a frequent issue in intensive care units (ICU), with a major impact on morbidity, mortality and cost of care. VAP diagnosis remains challenging: traditional culture-based microbiological techniques are still the gold-standard, but are too slow to enable clinicians to improve prognosis with timely antimicrobial therapy adjustment. Prolonged exposure to inappropriate antibiotics has also been shown to increase the incidence of multi-drug-resistant organisms (MDROs). Point-of-care testing (POCT) tools are diagnostic testing methods that can be used at or near the bedside, with delays ranging from a couple minutes to a few hours. The use of POCTs for VAP could allow for faster diagnosis and antimicrobial therapy adjustments. Despite uncertainty regarding their diagnostic value, C-reactive protein (CRP) and procalcitonin (PCT) can be detected using POCTs in few minutes. In VAP, CRP showed a sensitivity of 56% to 88% and specificity of 86% to 91%; PCT showed a sensitivity of 78% to 100% and a specificity between 75% and 97% using non-POCT methods. Automated microscopy could also be used in clinical ICU setting, with reported sensitivity of 100% and specificity of 97%, allowing for antibiotic susceptibility testing (AST) in less than 12 h. Multiplex polymerase chain reaction (MPCR) could allow for identification and AST approximation through the detection of drug-resistance genes in about 6 h, with reported sensitivity of 89.2% and specificity of 97.1%; although use as POCT was shown to result in test failure in about 40% of samples. Despite being at an early development stage, exhalome analysis, which allows for non-invasive fast identification, and chromogenic tests, more suited for the detection of drug-resistance enzymes, are also promising techniques for POCT diagnosis of VAP.