Endocarditis of Native Valve due to Proteus mirabilis: Case Report and Literature Review

Endocarditis due to Proteus mirabilis is very uncommon and the optimal surgical and/or antibiotic treatment is not well defined. Guidelines from the AHA and ESC recommend prolonged courses of combined antibiotic therapy but information regarding the clinical presentation, the choice of treatment, the surgical management, and the duration of therapy can only be taken from clinical cases reported in literature. We describe a case of native valve endocarditis due to Proteus mirabilis, successfully treated with antibiotic therapy alone with a review of the relevant literature on this topic.

Antimicrobial Stewardship Program, COVID-19, and Infection Control: Spread of Carbapenem-Resistant Klebsiella Pneumoniae Colonization in ICU COVID-19 Patients. What Did Not Work?

The Italian burden of disease associated with infections due to antibiotic-resistant bacteria has been very high, largely attributed to Carbapenem-Resistant Klebsiella pneumoniae (CR-Kp). The implementation of infection control measures and antimicrobial stewardship programs (ASP) has been shown to reduce healthcare-related infections caused by multidrug resistance (MDR) germs. Since 2016, in our teaching hospital of Terni, an ASP has been implemented in an intensive care unit (ICU) setting, with the “daily-ICU round strategy” and particular attention to infection control measures. We performed active surveillance for search patients colonized by Carbapenem-Resistant Enterobacteriaceae (CRE). In March 2020, coronavirus disease 2019 (COVID-19) arrived and the same ICU was reserved only for COVID-19 patients. In our retrospective observational study, we analyzed the bimonthly incidence of CRE colonization patients and the incidence of CRE acquisition in our ICU during the period of January 2019 to June 2020. In consideration of the great attention and training of all staff on infection control measures in the COVID-19 era, we would have expected a clear reduction in CRE acquisition, but this did not happen. In fact, the incidence of CRE acquisition went from 6.7% in 2019 to 50% in March–April 2020. We noted that 67% of patients that had been changed in posture with prone position were colonized by CRE, while only 37% of patients that had not been changed in posture were colonized by CRE. In our opinion, the high intensity of care, the prone position requiring 4–5 healthcare workers (HCWs), equipped with personal protective equipment (PPE) in a high risk area, with extended and prolonged contact with the patient, and the presence of 32 new HCWs from other departments and without work experience in the ICU setting, contributed to the spread of CR-Kp in our ICU, determining an increase in CRE acquisition colonization.

Fate of human albumin microsphere and spherocyte radioaerosols in the human tracheobronchial tree

Human albumin microspheres (99mTc-HAM; 7-25 microns) and spherocytes (99mTc-S; 4-4.5 mu) are particles used for lung mucociliary clearance (MCC) measurements. If radiolabelled HAM aerosols are sent through an airway model to a screen, they appear peripherally distributed, whereas S present a more central and homogeneous distribution. The radioscanning evaluation of particle sedimentation in saline-filled tubes shows quite a different behavior pattern for S, HAM, and surfactant-coated HAM (S-C HAM). In these experimental conditions, S-C HAM and HAM floating properties were better than those of S. This could be explained by physical-chemical factors. Looking for the fate of organic particles after inhalation, we performed multiple bronchial biopsies in seven bronchitic patients, 2 h following inhalation of HAM and S. Scanning electron microscopy revealed that most of S was floating on the mucus layer, while HAM appeared deeply imbedded inside the mucus and partially digested. The same study performed on three bronchitic patients after S-C HAM inhalation, shows that S-C HAM float like S. In vitro, the time-course of tryptic digestion is similar for HAM and for S. However, in vivo, the different location of each particle on the bronchial surface might lead to a different digestion by trypsin and by PZ-peptidase, which are dosable in pathologic mucus. In our opinion, if HAM are coated with surfactant, this should improve the mucus-HAM interaction, thus helping to control variability in lung radioaerosol MCC studies.