Myroides odorarus another one from the new emerging pathogens in cystic fibrosis – case report

Chronic lung infection is one of the hallmarks in cystic fibrosis (CF). Respiratory cultures from CF patients usually indicate colonization most commonly with Staphylococcus aureus, followed by Pseudomonas aeruginosa and Burkholderia cepacia, all of them listed as a classic pathogen for CF. We present a case of 15-year-old patient with CF, diagnosed at the age of 2 years due to failure to thrive and recurrent lung infections. He survived severe peritonitis at the age of 5 years, when he was colonized with P.aeruginosa for the first time. Following strict intravenous (piperacillin/tazobactam or ceftazidime) and inhaled antibiotic regimens (tobramycin, colistin and azytromycin), he is P.aeruginosa free for the last 6 years. However, in his sputum samples grew constanly Achrombacter xylosoxidans. Rigourous inhaled colistin and sulfomethaxasole/trimethoprim therapy was followed until the germ was resistant to every antibiotic tested but meropenem. Last year he was on inhaled meropenem with favorable effect – no A.xylosoxidans in his sputum from more than 6 months. His lung health was relatively stable at FVE1 of about 45-50% for almost 2 years, but this summer he had experienced new exacerbation and FEV1 drop to 26%. At that moment we found Myroides odoratus in his sputum sampled. The therapy was modified. Three months later in the sputum of the patient we found only S.aureus and some fungal colonies, his FEV1 is back at 50% and he gained 2 kilos. Myroides remains an uncommon pathogen that is ubiquitous in the environment. Clinicians should remain alert to the possibility of this one or other new emerging pathogens in CF when there is a lack of response from routine treatment