Background: Rising antimicrobial resistance has led to a revived interest in inhaled colistin treatment in the critically ill patient with ventilator-associated respiratory infection (VARI). Nebulization via vibrating mesh nebulizers (VMNs) is considered the current standard-of-care, yet the use of generic jet nebulizers (JNs) is more widespread. Few data exist on the intrapulmonary pharmacokinetics of colistin when administered through VMNs, while there is a complete paucity regarding the use of JNs. Methods: In this study, 18 VARI patients who received 2 million international units of inhaled colistimethate sodium (CMS) through a VMN were pharmacokinetically compared with six VARI patients who received the same drug dose through a JN, in the absence of systemic CMS administration. Results: Surprisingly, VMN and JN led to comparable formed colistin exposures in the epithelial lining fluid (ELF) (median (IQR) AUC_0–24: 86.2 (46.0–185.9) mg/L∙h with VMN and 91.5 (78.1–110.3) mg/L∙h with JN). The maximum ELF concentration was 10.4 (4.7–22.6) mg/L and 7.4 (6.2–10.3) mg/L, respectively. Conclusions: Based on our results, JN might be considered a viable alternative to the theoretically superior VMN. Therapeutic drug monitoring in the ELF can be advised due to the observed low exposure, high variability, and appreciable systemic absorption.

Streptococcus alactolyticus, a member of the Streptococcus bovis/Streptoccus equinus complex, is primarily hosted in the gastrointestinal tract of animals and rarely of humans, with only scarce reports relating to human disease. We herein present a case of subacute infective endocarditis (IE) caused by S. alactolyticus in a 64-year old male with pre-existing mitral prolapse. Despite a 10-month history of low-grade fever and weight loss, the diagnosis of IE was triggered by left quadrant abdominal pain which revealed splenic infarcts on computed tomography. A definitive diagnosis of IE was subsequently established by four consecutive blood cultures positive for S.alactolyticus plus demonstration of a vegetation on the mitral valve by trans-esophageal ultrasound. Further workup revealed multiple embolic phenomena including brain and spine. A dental abscess was identified as the most probable origin of the bacteraemia, while colonoscopy revealed no evidence of cancer. The patient recovered uneventfully with antibiotic treatment and underwent successful cardiac surgery post-discharge. Although rare, IE caused by S. alactolyticus may be severe and of obscure origin; oral cavity should not be overlooked as a possible origin. Attention should be given in patients with preexisting risk factors.

Resistant Pseudomonas aeruginosa isolates are one of the major causes of both hospital-acquired infections (HAIs) and community-acquired infections (CAIs). However, management of P. aeruginosa infections is difficult as the bacterium is inherently resistant to many antibiotics. In this study, a collection of 75 P. aeruginosa clinical isolates from two tertiary hospitals from Athens and Alexnadroupolis in Greece was studied to assess antimicrobial sensitivity and molecular epidemiology. All P. aeruginosa isolates were tested for susceptibility to 11 commonly used antibiotics, and the newly introduced Double Locus Sequence Typing (DLST) scheme was implemented to elucidate the predominant clones. The tested P. aeruginosa isolates presented various resistant phenotypes, with Verona Integron-Mediated Metallo-β-lactamase (VIM-2) mechanisms being the majority, and a new phenotype, FEP_R-CAZ_S, being reported for the first time in Greek isolates. DLST revealed two predominant types, 32-39 and 8-37, and provided evidence for intra-hospital transmission of the 32-39 clone in one of the hospitals. The results indicate that DLST can be a valuable tool when local outbreaks demand immediate tracking investigation with limited time and financial resources.