Early treatment with inhaled antibiotics may prevent or postpone chronic infection with Achromobacter in CF patients.

Rapid antimicrobial susceptibility testing (AST) is essential for early and appropriate therapy. Methods with short detection time enabling same-day treatment optimisation are highly favourable. In this study, we evaluated the potential of a digital time-lapse microscope system, the oCelloScope system, to perform rapid AST. The oCelloScope system demonstrated a very high accuracy (96 % overall agreement) when determining the resistance profiles of four reference strains, nine clinical isolates, including multi-drug-resistant isolates, and three positive blood cultures. AST of clinical isolates (168 antimicrobial agent–organism combinations) demonstrated 3.6 % minor, no major and 1.2 % very major errors of the oCelloScope system compared to conventional susceptibility testing, as well as a rapid and correct phenotypic detection of strains with methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase (ESBL) profiles. The net average time-to-result was 108 min, with 95 % of the results being available within 180 min. In conclusion, this study strongly indicates that the oCelloScope system holds considerable potential as an accurate and sensitive AST method with short time-to-result, enabling same-day targeted antimicrobial therapy, facilitating antibiotic stewardship and better patient management. A full-scale validation of the oCelloScope system including more isolates is necessary to assess the impact of using it for AST.

Methicillin-resistant Staphylococcus aureus (MRSA) clonal complex (CC) 398 has spread from pigs to humans, but rarely from person to person. This strain of MRSA has been considered less virulent than others. Livestock-associated MRSA CC398 (LA-MRSA CC398) is particularly known to colonize pig farmers. Recent studies have shown an increasing number of people colonized with LA-MRSA CC398 and invasive infections caused by LA-MRSA CC398. The case of a previously healthy, 61-year-old woman admitted to a Danish regional hospital is reported here. She presented with fever, severe back pain, and bilateral hyperreflexia of patellar and Achilles reflexes. Blood tests revealed leukocytosis and elevated Creactive protein. Empiric antimicrobial therapy with intravenous piperacillin-tazobactam was initiated, but blood cultures grew MRSA and antimicrobial therapy was changed to intravenous vancomycin. Whole-genome sequencing showed that the MRSA strain belonged to LA-MRSA CC398 spa type t011 and was Panton-Valentine leukocidin-negative. Magnetic resonance imaging revealed an epidural abscess at the level of L1-L4. Surgery was performed and pus from the abscess grew MRSA. The duration of antimicrobial therapy was 12 weeks. This case report describes bacteremia with LA-MRSA CC398 in a previously healthy patient without exposure to livestock or previous admission to a hospital. This highlights the risk of person-to-person transmission of LA-MRSA CC398 and brings into question whether LA-MRSA CC398 may have a greater pathogenic potential than previously assumed.

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