Multilocus sequence typing of sequentialCandida albicansisolates from patients with persistent or recurrent fungemia

Abstract

Multilocus sequence typing (MLST) is a useful tool to explore the phylogenetics and epidemiology of Candida albicans isolates recovered from cases of invasive candidiasis. The goal of this study was to determine whether the same or different strains were responsible for persistent or recurrent fungemia through the use of MLST and ABC typing on sequential C. albicans isolates from the same patient. We applied both typing methods to 21 C. albicans strains recovered from 8 patients with persistent or recurrent candidemia. The isolates were collected during a multicenter surveillance study in four public tertiary care hospitals in Brazil. Persistent candidemia was defi ned as two or more blood cultures positive for C. albicans on 2 or more separate days. Recurrent candidemia was defi ned as an episode of candidemia occurring at least 1 month after the apparent complete resolution of an infectious episode caused by Candida species. We observed that, except for one patient, all strains from the fi rst and second samples of the same patient showed the same MLST diploid sequence type (DST), ABC type and susceptibility profi le to antifungals. Three distinct strains, well discriminated by MLST, were found in the seven samples collected sequentially over 10 days from one patient. The strains from the fi rst four samples were indistinguishable, the fi fth and sixth were also indistinguishable but different from the fi rst four and seventh samples. Signifi cantly, the seventh strain was the only C. albicans clade 2 isolate found in our total collection involving 61 patients, although clade 2 is commonly found worldwide. To the best of our knowledge, this is the fi rst study describing the recovery of three distinct C. albicans strains in the same patient with a persistent blood stream infection within a short period of time.

Multilocus sequence typing of Candida albicans isolates from a burn intensive care unit in Iran

“…MLST is a powerful and useful technique for understanding the epidemiological and evolutionary relationships of pathogenic micro-organisms (Taylor & Fisher, 2003;Urwin & Maiden, 2003;Maiden, 2006;Cliff et al, 2008;Odds & Jacobsen, 2008;Da Matta et al, 2010;Shin et al, 2011). Prevalence of C. albicans infections in the BICU of the Zare hospital (Sari, Iran) led us to investigate the epidemiological relationship of 30 isolates involved using the MLST method.…”

Analysis of strain relatedness using High Resolution Melting in a case of recurrent candiduria

“…Several methods have been developed to analyze microevolution and structure of C. albicans species. Although MLST (MultiLocus Sequence Typing) has been chosen as the most discriminatory technique [5,32], several articles have recently pointed towards the suitability of MLP [14-16,29]. In this study, nine isolates from a case of recurrent urinary infection were genotyped using microsatellites and a new HRM analysis method.…”

“…Recurrent and/or persistent infections by Candida species are frequent, particularly in oropharyngeal and vaginal candidiasis, although it has also been described in urinary tract infections [2]. Studies describing recurrent infections have focused on determining the relatedness between colonizing and infective strains [3,4], as well as between successive infective strains [5-9]. It seems clear now that the majority of commensal and infecting populations of C .…”

“…It seems clear now that the majority of commensal and infecting populations of C . albicans from the same individuals are clonal in origin but subsequently undergo microevolution at the site of colonization and through recurrent episodes of infection [5,10,11]. The microevolution of the strains is a frequent process in recurrent infections and it takes place in response to adaptive changes [9,12].…”

Association of cytokine gene polymorphisms with susceptibility to invasive candidiasis

“…Patients with invasive candidiasis might have complications such as endocarditis, abscesses, or chronic-disseminated candidiasis. Previous studies have reported that persistent fungemia is one of the complications found in patients with candidemia, occurring in over 10% of the patients (Da Matta et al, 2010). Some studies have shown that the immune response can influence the infection, comorbidities, and efficacy of pharmacologic therapy of patients with invasive candidiasis (Garey et al, 2006).…”