EV0601 ePoster Viewing Emerging infectious diseases " maceachernii – a case report indicating the impact of real-time PCR for Legionella species in a front-line syndromic molecular testing algorithm in intensive care"

J. Kenicer1, R. Weir1, K.E. Templeton1, H. Austin2, J. Stevenson2, E.S. Wilson3, D.S. Lindsay4, I.F. Laurenson1 1Clinical Microbiology- Department of Laboratory Medicine, Royal Infirmary of Edinburgh, Edinburgh, United Kingdom 2Health Protection Team- Department of Public Health, NHS Lothian, Edinburgh, United Kingdom 3Critical Care Medicine- Royal Infirmary of Edinburgh, Edinburgh, United Kingdom 4Scottish - Legionella, Meningococcus and Pneumococcus Reference Laboratory, Glasgow Royal Infirmary, Glasgow, United Kingdom

Objectives: While serogroup 1 remains the predominant pathogenic species, other Legionella species are emerging as significant pathogens. L. longbeachae cases are increasing globally. and at least 24 other Legionella species have been described in clinical cases. One of these is Legionella maceachernii; rarely reported and mostly in relation to non-European travel. Diagnosis of Legionella species can be overlooked as many laboratories employ non-optimal means to detect Legionella species. We aim to describe this case and determine the clinical and public health benefits of using Legionella species real-time PCR as part of a syndromic molecular testing algorithm in a diagnostic laboratory. Methods: We report to our knowledge the first case of a L. maceachernii acquired in UK or mainland Europe. Previously it has been found in environmental water or severely immunocompromised patients returning from travel outside the UK. Results: Case Presentation: A 70 year old male patient presented with severe community-acquired-, neutropenic sepsis and a five day history of breathlessness. His chest X-ray was performed and showed a severe right-sided pneumonia. He had associated acute kidney injury and septic shock. He was transferred to the intensive care unit, intubated and mechanically ventilated. He rapidly deteriorated into multiple organ failure. His profound lymphopenia was thought to be due to a new presentation of a lymphoproliferative disorder. Despite full supportive measures and appropriate antibiotic treatment, he died 12 days into admission. Laboratory Testing: The patient tested positive by in-house real-time PCR for Legionella spp from a tracheal aspirate four days after admission (CT21), and then from a Bronchoalveolar lavage (BAL) from the right lung lower lobe (CT 23), the following day. A second BAL was then taken and set up for Legionella culture and the remaining portion of the sample was sent to the Scottish Haemophilus, Legionella, Meningococcus and Pneumococcus Reference Laboratory (SHLMPRL) for confirmatory testing. There was no reaction with the Legionella pneumophila serogroup 1 latex agglutination test (Thermoscientific) consistent with an unusual spp. This second BAL specimen was extracted, amplified and sequenced for the macrophage infectivity potentiator (mip) gene and identified as Legionella macechernii. The BAL culture yielded moderate numbers of Legionella species after culture for two weeks on BCYE agar, and on directing testing by MALDI-tof (Brucker) an identity of Legionella macechernii was confirmed (MALDITOF ID Probability 2.242). Environmental testing did not identify any source of this infection. Conclusion: Legionella species PCR has been a part of our syndromic respiratory molecular testing algorithm for patients with severe pneumonia for the last four years. This approach enabled early detection of severe pneumonia caused by L. maceachernii. L. macechernii is a severe pathogen in immunocompromised hosts and although rare, clinical teams need to ensure that diagnostic procedures can determine presence of this pathogen.