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This study aims at genetic characterization and phylogenetic relationships of Nocardia brasiliensis focusing by using housekeeping rrs, hsp65, and sodA genes. N. brasiliensis is the species responsible for 80% of cases of actinomycetoma, one form of cutaneous nocardiosis which occurs mainly in tropical regions reaching immunocompetent patients in which the disease can lead to amputation. We analyze 36 indigenous cases of N. brasiliensis that happened in France. Phylogenetic analysis targeting rrs gene showed no robustness at phylogenetic nodes level. However, the use of a concatenation of hsp65 and sodA genes showed that the tested strains surprisingly ranked in 3 well-defined genotypes. Genotypes 2 and 3 were phylogenetically closer to each other and both diverged from genotype 1 sustained by a high bootstrap of 81%. This last genotype hosts all the cases of pulmonary forms (3), the sole cerebral form, and almost all the cases of immunocompromised patients (3 out of 4). Moreover, excepting one of them, all the strains belonging to this group present a susceptibility to imipenem which is not the case in the other genotypes that rarely count among them strains being susceptible to this drug. The haplotype diversity (Hd) of hsp65 (0.927) and sodA (0.885) genes was higher than that of rrs (0.824). For this gene, we obtained 16 polymorphic sites whereas, for hsp65 and sodA genes, up to 27 and 29 were identified, respectively. This study reveals that these two genes have an important genetic discriminatory power for the evaluation of the intraspecies genetic variability of N. brasiliensis and they may be useful for identification purposes at species level. This study also reveals the possible existence of a new species harbored by genotype 1. [ABSTRACT FROM AUTHOR]

Objectives: Nocardia, a Gram-positive bacterium, is responsible for rare and severe infections. Accurate microbiological data are essential to guide antibiotic treatment. Our primary objective was to describe species identification and results of antimicrobial susceptibility testing (AST) for Nocardia isolates analysed over a 6-year period. Secondary objectives were to study temporal trends in species distribution and AST results., Methods: We retrospectively analysed results from Nocardia isolates sent between January 2010 and December 2015 to a French laboratory dedicated to Nocardia (Observatoire Français des Nocardioses). Species identification was obtained by amplification and sequencing of a 600-bp fragment of the 16S rRNA gene (for all isolates) and of hsp65 (when required). AST was performed using disk diffusion., Results: We included 793 Nocardia isolates, mostly from the lungs (53.8%). The most frequent species were Nocardia farcinica (20.2%), Nocardia abscessus complex (19.9%) and Nocardia nova complex (19.5%). The proportion of N. farcinica increased significantly over time from 13% in 2010 to 27.6% in 2014. Linezolid, amikacin, trimethoprim-sulfamethoxazole, minocycline and imipenem were the most frequently identified active antibiotics with, respectively, 0% (0/734), 2.9% (21/730), 5.4% (40/734), 9.4% (69/734) and 19.5% (143/732) of isolates not susceptible. Nocardia farcinica was frequently not susceptible to cefotaxime (118/148, 79.7% of the isolates), but only about 5% of Nocardia cyriacigeorgica and N. abscessus complex isolates were not susceptible to cefotaxime., Conclusions: In this first epidemiological study of Nocardia isolated from human samples in France, N. farcinica was the species most frequently identified and its prevalence increased over time., (Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Some bacterial species recovered from the airways of cystic fibrosis (CF) patients are indisputably associated with lung infections, whereas the clinical relevance of others, such as Nocardia spp., remains unclear. Sixteen French CF cases of colonization/infection with Nocardia spp. were reviewed in order to evaluate the epidemiology, the clinical impact and the potential treatment of these bacteria, and results were compared to those of the literature. Five Nocardia species were identified, Nocardia cyriacigeorgica being the major species (50 % of cases). At first isolation, Nocardia was the sole pathogen recovered in six patients. Seven patients presented pulmonary exacerbation. For 12 patients, antimicrobial treatment against Nocardia was started immediately, mainly based on cotrimoxazole (6 of the 12 cases). In this study, we highlight the heterogeneity of the clinical management of Nocardia spp. in CF. Guidelines for the clinical management of Nocardia infections in CF patients are proposed.

The permanent contact between the nipple part of pacifiers and the oral microflora offers ideal conditions for the development of biofilms. This study assessed the microbial contamination on the surface of 25 used pacifier nipples provided by day-care centers. Nine were made of silicone and 16 were made of latex. The biofilm was quantified using direct staining and microscopic observations followed by scraping and microorganism counting. The presence of a biofilm was confirmed on 80% of the pacifier nipples studied. This biofilm was mature for 36% of them. Latex pacifier nipples were more contaminated than silicone ones. The two main genera isolated were Staphylococcus and Candida. Our results confirm that nipples can be seen as potential reservoirs of infections. However, pacifiers do have some advantages; in particular, the potential protection they afford against sudden infant death syndrome. Strict rules of hygiene and an efficient antibiofilm cleaning protocol should be established to answer the worries of parents concerning the safety of pacifiers.