Different scenarios for Candida parapsilosis fungaemia reveal high numbers of mixed C-parapsilosis and Candida orthopsilosis infections

Nosocomial fungal bloodstream infections (BSI) are increasing significantly in hospitalized patients and Candida parapsilosis has emerged as an important pathogen responsible for numerous outbreaks. The objective of this study was to evaluate C. parapsilosis sensu lato infection scenarios, regarding species distribution and strain relatedness. One hundred isolates of C. parapsilosis sensu lato derived from blood cultures and catheter tips were analysed by multiplex microsatellite typing and by sequencing D1/D2 regions of the ribosomal DNA. Our results indicate that 9.5 % of patients presented infections due to C. parapsilosis and Candida orthopsilosis, 57.1 % due to C. parapsilosis, 28.3 % due to C. orthopsilosis and 4.8% due to Candida metapsilosis. Eighty per cent of the C. parapsilosis BSIs were due to a single strain that was also identified in the catheter, but in 10% of the cases C. parasilosis was identified in the catheter but the BSI was due to C. orthopsilosis. There is a significant probability that C. parapsilosis isolates collected from the same patient at more than 3 months interval are of different strains (P=0.0179). Moreover, several isolates were identified persistently in the same hospital, infecting six different patients. The incidence of polyfungal BSI infections with C. parapsilosis and C. orthopsilosis is reported herein for the first time, emphasizing the fact that the species identified in the catheter is not always responsible for the BSI, thus impacting the treatment strategy. The observation that strains can remain in the hospital environment for years highlights the possible existence of reservoirs and reinforces the need for accurate genotyping tools, such as the markers used for elucidating epidemiological associations and detecting outbreaks.Financial support was provided by CAPES Foundation (BEX 19194/12-9), Ministry of Education of Brazil, Brasilia (DF 70.040-020), by FEDER through POFC-COMPETE and by Portuguese funds from FCT (PEst-OE/BIA/UI4050/2014). R.M.Z.-O. is supported in part by CNPq (350338/2000-0) and FAPERJ E (26/103.157/2011). We are grateful to Ronaldo Rozembaun from HSE and SAM and Andrea Pussenti Derossi from HUPE for providing the Candida isolates and technical assistance in sampling. Automated sequencing was done using the genomic platform/DNA sequencing platform at Fundacao Oswaldo Cruz, PDTIS/FIOCRUZ (RPT01A), Brazil. The authors declare that they have no conflict of interest.info:eu-repo/semantics/publishedVersio

Determinação da susceptibilidade aos fármacos antifúngicos de amostras do complexo de espécies de Candida parapsilosis isoladas de pacientes com fungemia

Made available in DSpace on 2014-12-22T16:37:26Z (GMT). No. of bitstreams: 2 maria_carvalho_ipec_mest_2012.pdf: 3003635 bytes, checksum: 510838807146764c9ee0f462f0cf0ea7 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2014-10-07Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas, Rio de Janeiro, RJ, Brasil.Dentre as espécies de Candida não-albicans, Candida parapsilosis vem emergindo como importante patógeno de infecções fúngicas invasivas com disseminação hematogênica nas últimas décadas em diferentes continentes, principalmente, na Europa e na América Latina. C. parapsilosis foi considerada por muito tempo um complexo de três grupos distintos nomeados I, II e III. Tavanti et al (2005), baseado na tipagem da sequência multilocus (MLST), propôs o reconhecimento dos grupos II e III, como duas novas espécies: C. orthopsilosis e C. metapsilosis, respectivamente, mantendo o grupo I como C. parapsilosis stricto sensu. Até agora só tem sido possível distinguir essas três espécies por análise molecular. Métodos comerciais para testes de susceptibilidade aos antifúngicos vêm sendo utilizados para avaliar o comportamento de Candida spp. frente às drogas de uso clínico, incluindo o Etest® e o sistema Vitek® 2. Neste trabalho, estes dois métodos foram comparados ao método de referência de microdiluição em caldo pelo CLSI (M27-A3) para determinar a susceptibilidade in vitro de isolados clínicos do complexo psilosis aos fármacos antifúngicos anfotericina B, fluconazol, voriconazol e itraconazol. Um total de 53 isolados do complexo psilosis oriundos de hemoculturas obtidas de pacientes hospitalizados no município do Rio de Janeiro, entre 1998 e 2006, associados a episódios de fungemia, foram analisados Cinquenta e um isolados foram discriminados pela PCR, utilizando primers espécie-específicos, e dois isolados, pelo sequenciamento, sendo caracterizados como C. parapsilosis stricto sensu (75,4%), C. orthopsilosis (20,8%) e C. metapsilosis (3,8%). Os testes de susceptibilidade aos antifúngicos indicaram que a maioria dos isolados de C. parapsilosis stricto sensu foi sensível a todos os fármacos testados. Entretanto, um único isolado de C. parapsilosis stricto sensu apresentou uma CIM = 2 [g/mL para a anfotericina B. Três isolados de C. orthopsilosis apresentaram CIM entre 2 e 8 [g/mL para o fluconazol pelo Etest® e Vitek® 2 e CIM entre 0,19 e 0,25 [g/mL para o itraconazol pelo Etest®. Os isolados de C. metapsilosis foram sensíveis a todos os fármacos testados. A concordância essencial entre Etest® ou Vitek® 2 com CLSI foi excelente (100%), exceto para o itraconazol (90,9%). Por outro lado, a concordância categórica foi 72,7% para o itraconazol pelo Etest® e 100% para os outros fármacos por ambos os métodos. Para anfotericina B, a concordância categórica foi de 100% para o Etest® e de 97,5% pelo Vitek® 2 em relação ao CLSI. Este estudo reforça a importância dos métodos Etest® e Vitek® 2 que podem ser empregados nos laboratórios rotineiros de microbiologia clínica para monitorar e detectar diferenças no perfil de susceptibilidade aos antifúngicos dos isolados de C. parapsilosis stricto sensu, C. orthopsilosis e C. metapsilosisAmong non-albicans Candida species, Candida parapsilosis has emerged as an important agent of invasive fungal infections, and several cases associated with fungemia have been reported worldwide in last decade, mostly in Europe and Latin America. For many years, C. parapsilosis has been characterized as a complex composed of three genetically distinct groups (groups I, II, and III). Tavanti et al. (2005) based on multilocus sequence typing (MLST) technique, proposed the recognition of groups II and III as two different species: C. orthopsilosis and C. metapsilosis, respectively, maintaining the group I as C. parapsilosis sensu stricto. Up to now only has been possible to distinguish these three species just by molecular analysis. Commercial antifungal susceptibility methods including Etest® and Vitek® 2 system have been used to test the antifungal susceptibility of Candida spp. In this study, these methods were compared to the CLSI broth microdilution (BMD) reference method to determine in vitro susceptibility of clinical C. parapsilosis complex isolates to amphotericin B, fluconazole, voriconazole, and itraconazole. A total of 53 C. parapsilosis complex isolates from blood cultures obtained of patients who were hospitalized in the city of Rio de Janeiro between 1998 and 2006 associated with episodes of fungemia were analysed. Fifty-one isolates were discriminated by PCR using species-specific primers and two isolates by sequencing, being characterized as C. parapsilosis sensu stricto (75.4%), C. orthopsilosis (20.8%), and C. metapsilosis (3.8%). Antifungal susceptibility tests indicated that most of C. parapsilosis sensu stricto isolates were susceptible to all tested drugs. However, a single C. parapsilosis sensu stricto isolate presented MIC = 2 [g/ml for amphotericin B. Three C. orthopsilosis isolates showed MIC between 2-8 [g/ml for fluconazole by Vitek® 2 and MIC between 0.19-0.25 [g/ml for itraconazole by Etest®. C. metapsilosis isolates were susceptible to all tested drugs. The essential agreement between the Etest® or Vitek® 2 with the CLSI BMD for all drugs was excellent (100%), except for itraconazole (90.9%). The categorical agreement was 72.7% for itraconazole by Etest®, 97.5% for amphotericin B by Vitek® 2, and 100% for the other drugs by both methods compared with CLSI BMD. This study reinforces the importance of Etest® and Vitek® 2 methods in routine clinical microbiologycal laboratories to survey and detect differences in the profile of the antifungal susceptibility of C. parapsilosis sensu stricto, C. orthopsilosis, and C. metapsilosis isolates

Melanins protect Sporothrix brasiliensis and Sporothrix schenckii from the antifungal effects of Terbinafine

Submitted by Janaína Nascimento ([email protected]) on 2019-02-14T11:41:57Z No. of bitstreams: 1 ve_Almeida-Paes_Rodrigo _etal_INI_2016.pdf: 952268 bytes, checksum: 08aab92130361de68f6f82001812a154 (MD5)Approved for entry into archive by Janaína Nascimento ([email protected]) on 2019-02-15T13:24:17Z (GMT) No. of bitstreams: 1 ve_Almeida-Paes_Rodrigo _etal_INI_2016.pdf: 952268 bytes, checksum: 08aab92130361de68f6f82001812a154 (MD5)Made available in DSpace on 2019-02-15T13:24:17Z (GMT). No. of bitstreams: 1 ve_Almeida-Paes_Rodrigo _etal_INI_2016.pdf: 952268 bytes, checksum: 08aab92130361de68f6f82001812a154 (MD5) Previous issue date: 2016Fundação Oswaldo Cruz. Instituto Nacional de Infectologia Evandro Chagas. Laboratório de Micologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Nacional de Infectologia Evandro Chagas. Laboratório de Micologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Nacional de Infectologia Evandro Chagas. Laboratório de Micologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Nacional de Infectologia Evandro Chagas. Laboratório de Micologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Nacional de Infectologia Evandro Chagas. Laboratório de Micologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Nacional de Infectologia Evandro Chagas. Laboratório de Micologia. Rio de Janeiro, RJ, Brasil.Terbinafine is a recommended therapeutic alternative for patients with sporotrichosis who cannot use itraconazole due to drug interactions or side effects. Melanins are involved in resistance to antifungal drugs and Sporothrix species produce three different types of melanin. Therefore, in this study we evaluated whether Sporothrix melanins impact the efficacy of antifungal drugs. Minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) of two Sporothrix brasiliensis and four Sporothrix schenckii strains grown in the presence of the melanin precursors L-DOPA and L-tyrosine were similar to the MIC determined by the CLSI standard protocol for S. schenckii susceptibility to amphotericin B, ketoconazole, itraconazole or terbinafine. When MICs were determined in the presence of inhibitors to three pathways of melanin synthesis, we observed, in four strains, an increase in terbinafine susceptibility in the presence of tricyclazole, a DHN-melanin inhibitor. In addition, one S. schenckii strain grown in the presence of L-DOPA had a higher MFC value when compared to the control. Growth curves in presence of 2×MIC concentrations of terbinafine showed that pyomelanin and, to a lesser extent, eumelanin were able to protect the fungi against the fungicidal effect of this antifungal drug. Our results suggest that melanin protects the major pathogenic species of the Sporothrix complex from the effects of terbinafine and that the development of new antifungal drugs targeting melanin synthesis may improve sporotrichosis therapies