Epidemiology and susceptibility to antimicrobial agents of the main Nocardia species in Spain

• Published in: Journal of antimicrobial chemotherapy 2017-03, Vol.72 (3), p.754-761
• Main Authors: Valdezate, Sylvia, Garrido, Noelia, Carrasco, Gema, Medina-Pascual, María J, Villalón, Pilar, Navarro, Ana M, Saéz-Nieto, Juan A
• Format: Article
• Language: English
• Subjects: Amikacin - therapeutic use; Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - therapeutic use; Humans; Imipenem - therapeutic use; Linezolid - pharmacology; Microbial Sensitivity Tests; Nocardia - classification; Nocardia - drug effects; Nocardia - genetics; Nocardia - isolation & purification; Nocardia Infections - drug therapy; Nocardia Infections - epidemiology; Nocardia Infections - microbiology; Prevalence; RNA, Ribosomal, 16S; Spain - epidemiology; Trimethoprim, Sulfamethoxazole Drug Combination - pharmacology; Trimethoprim, Sulfamethoxazole Drug Combination - therapeutic use
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/dkw489

The aims of this study were to explore the clinical distribution, by species, of the genus Nocardia and to assess the antimicrobial susceptibilities of the 10 most prevalent species identified in Spain. Over a 10 year period (2005-14), 1119 Nocardia strains were molecularly identified and subjected to the Etest. The distribution and resistance trends over the sub-periods 2005-09 and 2010-14 were also examined. Of the strains examined, 82.9% belonged to the following species: Nocardia cyriacigeorgica (25.3%), Nocardia nova (15.0%), Nocardia abscessus (12.7%), Nocardia farcinica (11.4%), Nocardia carnea (4.3%), Nocardia brasiliensis (3.5%), Nocardia otitidiscaviarum (3.1%), Nocardia flavorosea (2.6%), Nocardia rhamnosiphila (2.6%) and Nocardia transvalensis (2.4%). Their prevalence values were similar during 2005-09 and 2010-14, except for those of N. abscessus , N. farcinica and N. transvalensis , which fell significantly in the second sub-period ( P ≤  0.05). The major location of isolation was the respiratory tract (∼86%). Half (13/27) of all strains from the CNS were N. farcinica . Significant differences in MIC results were recorded for some species between the two sub-periods. According to the CLSI's breakpoints, low resistance rates (≤15%) were recorded for seven species with respect to cefotaxime, imipenem and tobramycin; five species showed similar rates with respect to trimethoprim/sulfamethoxazole. Linezolid and amikacin were the most frequently active agents. The accurate identification of the infecting species and the determination of its susceptibility to antimicrobial agents, given the large number of strains with atypical patterns, are crucial if patients with nocardiosis are to be successfully treated.