Molecular typing of Candida albicans isolates from patients and health care workers in a neonatal intensive care unit

Abstract

Aims: The aim of this study was to investigate the genetic relatedness between Candida albicans isolates and to assess their nosocomial origin and the likeliness of cross‐transmission between health care workers (HCWs) and hospitalized neonates in a neonatal intensive care unit (NICU). Methods: We retrospectively analysed 82 isolates obtained from 40 neonates and seven isolates from onychomycosis of the fingers of five HCWs in a Tunisian NICU by using pulsed‐field gel electrophoresis (PFGE) and randomly amplified polymorphic DNA (RAPD) analysis with CA1 and CA2 as primers. Results: In RAPD analysis, the discriminatory power (DP) of CA1 and CA2 primers was 0·86 and 0·81, respectively. A higher DP was achieved by combining patterns generated by both primers (0·92), while PFGE karyotyping exhibited the lowest DP (0·62). The RAPD‐CA1/CA2 analysis revealed that 65·8% of isolates obtained from neonates derived from a limited number (6) of groups of genetically identical strains, that five temporal clusterings occurred during the study period and that three HCWs’ isolates and 11 isolates obtained from six neonates were identical. Conclusions: These findings argue for the nosocomial transmission of C. albicans in our NICU and for the transfer of strains from HCWs to patients. Significance and Impact of the Study: Identification of relatedness between Candida species obtained from neonates and health care workers by using molecular techniques with high discriminatory power is essential for setting up specific control measures in order to reduce the incidence of nosocomial candidiasis.

Positions and Numbers of FKS Mutations in Candida albicans Selectively Influence In Vitro and In Vivo Susceptibilities to Echinocandin Treatment

“…To determine whether strain RR CL evolved from S CL or replaced S CL under selection pressure of CAS, RAPD genotyping of the clinical isolates was performed. The efficacy of RAPD as a typing method for clinical C. albicans isolates was previously demonstrated (17,18). RAPD revealed a clonal relationship between the isolates (Fig.…”

Clinical and molecular characteristics of bloodstream infections caused by Candida albicans in children from 2003 to 2011

“…The strengths of MLST are not only a highly discriminative tool in analyzing the genetic relatedness among sequential isolates from the same or different study sites, but also allowing the inter-laboratory comparison worldwide. However, MLST may have some limitations in typing isolates from different patients, since some studies had shown different PFGE or fingerprinting patterns in shared DST isolates [19,41,42]..Although MLST has been proven superior to PFGE and at least comparable to Southern hybridization [43,44], a strict definition of a nosocomial cluster as those occurring within a period of 90 days [18] would make the cluster identification more effective and reliable.…”

“…In addition to MLST, the methods include polymerase chain reaction M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 15 fingerprinting and random amplification of polymorphic DNA [39], restriction fragment length polymorphism analysis [40], pulsed-field gel electrophoresis (PFGE) [19], and Southern blot hybridization with discriminating probes [38]. The strengths of MLST are not only a highly discriminative tool in analyzing the genetic relatedness among sequential isolates from the same or different study sites, but also allowing the inter-laboratory comparison worldwide.…”

“…DST693 and DST1849 were the two major types with 7 and 5 isolates, respectively (Table 3). In order to assign these isolates to [19,26]. Clade 1 (22.2%) constituted the greatest proportion of the isolates, followed by clade 4 (13.9%) and clade 3 (9.7%).…”

“…[15,16], it has comparable mortality rate [2] and is occasionally associated with clusters of nosocomial infection [17,18]. Identification of relatedness between Candida species by using molecular techniques with high discriminatory power is essential for setting up infection control measures to reduce nosocomial candidiasis [19,20]. However, information focused on C. albicans BSI in children, particularly regarding the clinical data and molecular epidemiology, is M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 6 ICUs in CGMH.…”