Macrolide-resistantMycoplasma pneumoniaein paediatric pneumonia: Table 1–

Macrolide-resistant Mycoplasma pneumoniae in paediatric pneumoniaTo the Editors:Mycoplasma pneumoniae is one of the most common causes of bacterial community-acquired pneumonia (CAP) in paediatrics, and can lead to severe and long-lasting disease [1].Macrolides are usually considered the first-choice antimicrobials for M. pneumoniae CAP in children because the alternatives (i.e.fluoroquinolones and tetracyclines) are not approved for use in the first years of life [2].Recent studies from Japan and China have shown macrolide resistance in up to 80% of M. pneumoniae strains [3,4], but it has been detected in relatively few cases in the USA, France and Germany, and not at all in other European countries [5][6][7].The mechanism of M. pneumoniae macrolide resistance is related to point mutations in domain V of the 23S rRNA gene of M. pneumoniae and macrolide resistance is usually detected at disease onset [4].We here describe the first case of macrolide-resistant M. pneumoniae detected during treatment with clarithromycin in an otherwise healthy child with CAP.An otherwise healthy 6-yr-old girl with an unremarkable medical history who had never travelled abroad was admitted in Bari, Italy, after suffering from a dry cough for 3 days with fever up to 40.5uC, accompanied by increasing malaise and dyspnoea.Upon admission, she was severely ill, with a high temperature, lethargy, an increased respiratory rate (60 breaths?min -1 ), tachycardia and normal blood pressure.Room air oximetry revealed 85% oxygen saturation, whereas arterial gas sampling showed severe hypoxaemia (50 mmHg) with hypocapnia and a normal pH.Other routine blood examinations revealed neutrophilia with increased C-reactive protein levels and a high erythrocyte sedimentation rate.A physical examination revealed diffuse crackles with reduced vesicular sounds on both lungs, and chest radiography showed an interstitial pattern with multiple ''ground-glass'' infiltrates.Blood, nasopharyngeal swab and sputum samples were immediately obtained for serology, real-time PCR, and respiratory virus and bacterial cultures.High-flow oxygen (8 L?min -1 ) was necessary to maintain saturation above 90%, and the girl also received nebulised albuterol, intravenous antibiotics (ampicillin/sulbactam 150 mg?kg -1 ?day -1 i.v. in three doses and clarithromycin 7.5 mg?kg -1 ?day -1 i.v. in two doses) and cristalloids.Table 1 shows the clinical and laboratory findings upon admission and during the course of hospitalisation.The results of microbiological tests of the samples obtained at admission (available over the following 3 days) were negative for respiratory syncytial virus, adenovirus, influenza viruses, parainfluenza viruses, human metapneumovirus,