Performance and impact of rapid multiplex PCR on diagnosis and treatment of ventilated hospital-acquired pneumonia in patients with extended-spectrum ß-lactamase-producing Enterobacterales rectal carriage.

BACKGROUND: Antimicrobial stewardship (AMS) for ventilator-associated pneumonia (VAP) or ventilated hospital-acquired pneumonia (vHAP) in extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-E) carriers is challenging. BioFire® FilmArray® Pneumonia plus Panel (mPCR) can detect bacteria and antibiotic resistance genes, including blaCTX-M, the most common ESBL-encoding gene. METHODS: This monocentric, prospective study was conducted on a group of ESBL-E carriers from March 2020 to August 2022. The primary objective was to evaluate the concordance between the results of mPCR and conventional culture performed on respiratory samples of ESBL-E carriers to investigate suspected VAP/vHAP. The secondary objective was to appraise the impact of performing or not mPCR on initial antibiotic therapy adequacy in ESBL-E carriers with confirmed VAP/vHAP. RESULTS: Over the study period, 294 patients with ESBL-E carriage were admitted to the ICU, of who 168 (57%) were mechanically ventilated. (i) Diagnostic performance of mPCR was evaluated in suspected 41 episodes of VAP/vHAP: blaCTX-M gene was detected in 15/41 (37%) episodes, where 9/15 (60%) were confirmed ESBL-E-induced pneumonia. The culture and blaCTX-M were concordant in 35/41 (85%) episodes, and in all episodes where blaCTX-M was negative (n = 26), the culture never detected ESBL-E. (ii) The impact of mPCR on initial antibiotic therapy adequacy was assessed in 95 episodes of confirmed VAP/vHAP (22 episodes were tested with mPCR and 73 without); 47 (49%) episodes were ESBL-E-induced, and 24 (25%) were carbapenem-resistant bacteria-induced. The use of mPCR was significantly associated with higher prescription of adequate empirical antibiotic therapy in the multivariable logistic regression (adjusted odds ratio (aOR) (95% CI) of 7.5 (2.1-35.9), p = 0.004), propensity-weighting (aOR of 5.9 (1.6-22.1), p = 0.008), and matching-cohort models (aOR of 5.8 (1.5-22.1), p = 0.01). CONCLUSION: mPCR blaCTX-M showed an excellent diagnostic value to rule out the diagnosis of ESBL-E related pneumonia in ESBL-E carriers with suspected VAP/vHAP. In addition, in patients with confirmed VAP/vHAP, a mPCR-based antibiotic therapy was associated with an increased prescription of adequate empirical antibiotic therapy. Performing mPCR on respiratory samples seems to be a promising tool in ESBL-E carriers with suspected vHAP/VAP. However, if mPCR is used in very low pre-test clinical probability of pneumonia, due to the high sensitivity and the rate of overdiagnosed pneumonia, the risk of overconsumption of carbapenem may prevail. Further studies are warranted.

Clinical features and treatment outcomes of bone and joint nontuberculous mycobacterial infections according to immune status: a 9-year retrospective observational cohort.

OBJECTIVES: Nontuberculous mycobacteria (NTM) bone and joint infections (BJIs) are uncommon. We evaluated the characteristics of BJIs and identified differences according to immune status. METHODS: We performed a multicenter retrospective study in France involving patients with documented NTM BJI over a 9-year period. We collected the clinical and microbiological characteristics, management, and clinical outcomes of the patients. RESULTS: Overall, 95 patients were included, of whom 50.5% (48/95) were immunosuppressed. Tenosynovitis was more frequent in the immunocompetent group, and native arthritis more common in the immunosuppressed group. Mycobacerium marinum and M. abscessus complex were significantly more frequent in the immunocompetent group, and M. avium and M. xenopi were significantly more frequent in the immunosuppressed group. The combination of antibiotherapy with surgery tended to be more frequent in the immunocompetent than the immunosuppressed group (63.8% (30/47) vs 47.8% (22/46), respectively); of the latter, 45.7% (21/46) received antimicrobial therapy alone, a higher frequency than in the immunocompetent group (23.4%, 11/47). The median duration of antimicrobial treatment was similar in the two groups (11 months). Mortality was significantly higher in the immunosuppressed group. CONCLUSIONS: Although the clinical presentations and the NTM species involved in BJI differed according to immune status, most recovered completely after treatment.

First report of Acinetobacter pittii acute community-acquired pneumonia in an immunocompetent patient in France following a heat wave.

BACKGROUND: In recent years, Acinetobacter baumannii-calcoaceticus complex (ABC) infections have attracted attention, mainly because of the impact of carbapenem-resistant isolates in hospital-acquired infections. However, acute community-acquired ABC infections are not uncommon in warm and humid countries, where they are responsible for community-acquired infections with specific clinical features. To date, such infection has not been reported in France. CASE PRESENTATION: We report the case of a 55-year-old non-immunocompromised patient living in France with no known risk factors for community-acquired ABC infections who presented pneumonia with bloodstream infection due to wild-type A. pittii. The outcome was favorable after 7 days of antibiotic treatment with cefepime. We confirmed bacterial identification with whole-genome sequencing, and we examined the A. pitii core-genome phylogeny for genomic clusters. CONCLUSIONS: This situation is uncommon in Europe and occurred after a heat wave in France with temperatures above 38 °C. Herein, we discuss the possibility that this pneumonia may be emerging in the current context of global warming.