Biotypes and randomly amplified polymorphic DNA (RAPD

THE NEW MICROBIOLOGICA, 28, 75-82, 2005
Biotypes and randomly amplified polymorphic
DNA (RAPD) profiles of subgingival
Candida albicans isolates in HIV infection
Giuseppe Pizzo1, Giovanni M. Giammanco2, Sonia Pecorella1, Giuseppina Campisi1,
Caterina Mammina2, Matteo D’Angelo1
1Department
2Department
of Oral Sciences, University of Palermo, Italy
of Hygiene and Microbiology, University of Palermo, Italy
SUMMARY
A group of subgingival isolates of C. albicans recovered from Italian HIV-positive (HIV+) subjects were characterized both phenotypically and genotypically.
Phenotyping of the isolates was carried out by a biotyping method based on the enzyme profiles, carbohydrate
assimilation patterns and boric acid resistance of the yeasts. Genotyping was performed through randomly amplified polymorphic DNA (RAPD) analysis.
Five biotypes were found among the 29 subgingival C. albicans strains examined. The predominant biotypes were
A1R (55.17%), A1S (24.14%), and A2R (13.79%), while the biotypes A11R and A13R were represented by a single
isolate each. RAPD profiles identified 15 genotypes among the 29 isolates. Almost every individual harboured his/her
own specific isolate and in three out of the six subjects with multiple isolates (two to six each) more than one genotype (two to six) was found.
The biotype distribution we found is consistent with previous reports on C. albicans isolates from other oral sources, whereas the resistance to boric acid was highly frequent in subgingival strains. RAPD analysis showed high
genetic heterogeneity within subgingival isolates, also when isolates were phenotypically identical. These findings,
obtained from HIV+ subjects living in Southern Italy, may be useful as baseline information on subgingival C. albicans colonization in the Mediterranean area.
KEY WORDS: Candida albicans; biotypes; RAPD; HIV infection; subgingival microflora; Italy
Received October 2, 2004
INTRODUCTION
Candida albicans is the main yeast species residing in the oral cavity. Although mucosal surfaces
represent the primary oral reservoir for this
opportunistic pathogen, it can also be harboured
in dental plaque (Cannon et al., 1995; Nikawa et
al., 1998; Salam et al., 2001; Hossain et al., 2003).
Subgingival Candida colonization may occur in
Corresponding author
Giuseppe Pizzo
Dipartimento di Scienze Stomatologiche,
Università di Palermo
Via del Vespro 129
90127 Palermo, Italy
E-mail: [email protected]
Accepted December 4, 2004
periodontitis (Slots et al., 1988, 1990; Listgarten
et al., 1993, Dahlén et al., 1995; Olsvik et al., 1995;
Reynaud et al., 2001; Jabra-Rizk et al., 2001;
Järvensivu et al., 2004) and as a result of either
antibiotics or radiotherapy (Rams et al., 1990;
Helovuo et al., 1993; MacNeill et al., 1997; Leung
et al., 1998). The presence of C. albicans in the
subgingival environment has also been reported in HIV-infected (HIV+) individuals (Brady et
al., 1996; Lamster et al., 1998; Chattin et al., 1999;
Jabra-Rizk et al., 2001; Robinson et al., 2002).
Various phenotypic methods have been used to
characterize candidal isolates (Otero et al.,
1995; Lipperheide et al., 1996; Williams et al.,
2000; Ng et al., 2001). Among these, the biotyping system developed by Williamson et al., (1987)