Mycobacterium celeriflavum sp. nov., a rapidly growing scotochromogenic bacterium isolated from clinical specimens.

Six strains of a rapidly growing scotochromogenic mycobacterium were isolated from pulmonary specimens of independent patients. Biochemical and cultural tests were not suitable for their identification. The mycolic acid pattern analysed by HPLC was different from that of any other mycobacterium. Genotypic characterization, targeting seven housekeeping genes, revealed the presence of microheterogeneity in all of them. Different species were more closely related to the test strains in various regions: the type strain of Mycobacterium moriokaense showed 99.0 % 16S rRNA gene sequence similarity, and 91.5-96.5 % similarity for the remaining six regions. The whole genome sequences of the proposed type strain and that of M. moriokaense presented an average nucleotide identity (ANI) of 82.9 %. Phylogenetic analysis produced poorly robust trees in most genes with the exception of rpoB and sodA where Mycobacterium flavescens and Mycobacterium novocastrense were the closest species. This phylogenetic relatedness was confirmed by the tree inferred from five concatenated genes, which was very robust. The polyphasic characterization of the test strains, supported by the ANI value, demonstrates that they belong to a previously unreported species, for which the name Mycobacterium celeriflavum sp. nov. is proposed. The type strain is AFPC-000207(T) ( = DSM 46765(T) = JCM 18439(T)).

Leclercia adecarboxylata and catheter-related bacteraemia: review of the literature and outcome with regard to catheters and patients.

Infection is a common complication in patients carrying a central venous catheter (CVC) and is associated with increased morbidity and mortality. Leclercia adecarboxylata is an unusual but emerging pathogen in healthy and immunocompromised patients. We report a case of L. adecarboxylata bacteraemia in a patient with a haemodialysis tunnelled CVC. In accordance with the susceptibility to the tested antimicrobials, a long-course treatment with intravenous gentamicin plus amoxicillin-clavulanic acid and gentamicin-lock therapy was adopted. The patient had a full recovery and the catheter was not removed. We also performed a systematic PubMed/Medline and Scopus review of peer-reviewed English papers on L. adecarboxylata infections, focusing on bacteraemia in patients with different types of CVCs. Moreover, we suggest a treatment algorithm to preserve the patient and maintain the CVC.