**3. Discussion**

The catheters which were investigated in this study originated from many different stations of mainly two hospitals. The analyses of the genotypes of 123 *C. albicans* strains collected from these samples give many interesting points to think about. The comparison of the CDC3, EF3, and HIS3 genotyping results from the two hospitals (data not shown) did not provide suitable data for distinguishing the epidemiological distribution of *C. albicans*. The contribution of the genotypes was consistent within the University Hospital of Graz compared with the AKH Vienna hospital. This was also true for the aggregation of the data, no significantly dominant genotype was detected, only a group of 11 (8.9%) strains (Table 2) was found to be the most frequent genotype with the multilocus genotype characterised by CDC3: 117-129, EF3: 130-139, and HIS3 154-154. All other groups within this study consist of at most 5 strains. These results are comparable to those of Eloy et al. (2006) who studied the genotypes of *C. albicans* in two different hospitals using the CDC3, EF3, and HIS3 typing system. An overall number of 67 isolates were tested and 50 different genotypes were found. Eight patients shared the same genotype in one hospital; the same genotype was also present in 3 strains in the second hospital. Botterel et al. (2001) tested 100 isolates for their microsatellite profile. They detected 5, 12, and 18 alleles in the CDC3, EF3, and HIS3 system, respectively. The different associations of this alleles led to 10 CDC3, 22 EF3, and 25 HIS3 allele associations within this system. A group of 17 isolates was found to share the genotype.

This genotype was the same as reported by Eloy et al. (2006) in the group of 11 genotype identical strains. Both authors reported the multilocus genotype characterised by CDC3: 117-125, EF3: 126-135, and HIS3 162-162 for their most common strains.

**Patient sample biofilm allele 1 allele 2 allele 1 allele 2 allele 1 allele 2**

K17 + 117 129 130 139 154 K18 - 117 129 129 139 154

K59 + 117 129 129 137 154 K60 - 117 129 130 139 154

The catheters which were investigated in this study originated from many different stations of mainly two hospitals. The analyses of the genotypes of 123 *C. albicans* strains collected from these samples give many interesting points to think about. The comparison of the CDC3, EF3, and HIS3 genotyping results from the two hospitals (data not shown) did not provide suitable data for distinguishing the epidemiological distribution of *C. albicans*. The contribution of the genotypes was consistent within the University Hospital of Graz compared with the AKH Vienna hospital. This was also true for the aggregation of the data, no significantly dominant genotype was detected, only a group of 11 (8.9%) strains (Table 2) was found to be the most frequent genotype with the multilocus genotype characterised by CDC3: 117-129, EF3: 130-139, and HIS3 154-154. All other groups within this study consist of at most 5 strains. These results are comparable to those of Eloy et al. (2006) who studied the genotypes of *C. albicans* in two different hospitals using the CDC3, EF3, and HIS3 typing system. An overall number of 67 isolates were tested and 50 different genotypes were found. Eight patients shared the same genotype in one hospital; the same genotype was also present in 3 strains in the second hospital. Botterel et al. (2001) tested 100 isolates for their microsatellite profile. They detected 5, 12, and 18 alleles in the CDC3, EF3, and HIS3 system, respectively. The different associations of this alleles led to 10 CDC3, 22 EF3, and 25 HIS3 allele associations within this system. A group of 17 isolates was found to share the genotype.

This genotype was the same as reported by Eloy et al. (2006) in the group of 11 genotype identical strains. Both authors reported the multilocus genotype characterised by CDC3:

117-125, EF3: 126-135, and HIS3 162-162 for their most common strains.

Table 3. Microsatellite models of 12 strains from six patients (two strains each).

K15 - 125 126 133 166 182 K16 + 125 123 133 166 182

K49 - 117 125 120 129 162 198 K50 + 117 125 120 129 162 198

K67 + 117 130 139 154 158 K69 + 117 129 130 139 154 158

W15 - 125 126 133 166 182 W16 - 125 123 133 166 182

1

2

3

4

5

6

**3. Discussion** 

(+: biofilm positive; -: biofilm negative)

CDC3/CDC3R EF3/EF3R HIS3/HIS3R

Totally different data were provided from Shi et al. (2007) who collected isolates by female and male patients with genital infection, rectal and oral samples. The authors reported 54.9% of the strains investigated to show the same multilocus genotype, these results were clearly different from all other studies.

The CDC3 locus showed 12 different allele pairs, the EF3 locus 25 allele pairs, and the HIS3 locus 50 allele pairs. This is convergent with the data within the three loci and leads to 94 multilocus genotypes. When compared with the results of Botterel et al. (2001) who reported 65 different multilocus genotypes with different allele associations of 10 for CDC3, 22 for EF3, and 25 for HIS3, it is obvious that the HIS3 locus was clearly more divergent within the current study. However, it remains unclear whether this variation is typical for *C. albicans* strains collected from BSI, or if the discriminatory power (DP) of the HIS3 locus (0.91) is not strong enough. The calculated overall DP for the CDC3, EF3, and HIS3 multilocus genotyping was 0.97. It is worth noting that the DP of HIS3 alone was the highest of the three loci (CDC3: 0.77, EF3: 0.86) (Botterel et al., 2001). Nevertheless, a comparison of the typing information without the HIS3 locus showed that the groups of strains sharing the same genotype do not increase significantly (data not shown).

The comparison of the genotyping of biofilm forming *C. albicans* strains with non-biofilm forming *C. albicans* species shows also a consistent distribution of genotypes. There is no literature to compare these specific results with, but as aforementioned, a consistent contribution of genotype data collected with the CDC3, EF3, and HIS3 multilocus genotyping system seems to be normal for *C. albicans* strains.

The collected information about strains from the same patients are worth a closer look: Only one patient out of six showed 2 strains sharing the multilocus genotype. Using the same typing system, Beretta et al. (2006) investigated 14 isolates of eight patients and reported 4 strains with the same genotype for one patient out of three. Another patient had 2 of 3 strains sharing the genotypes (Beretta et al., 2006). When only HIS3 and CDC3 alleles were compared, five out of the six patients in the current study show the same strain twice. Because of these findings, the typing was done without EF3 locus information, and as it is mentioned above for the typing without HIS3 allele information, no significant increase in the numbers of strains sharing the same multilocus genotype could be seen (data not shown).

Recapitulating the multilocus genotyping with the CDC3, EF3, and HIS3 system during this study, the data presented here is in good agreement with the authors mentioned above.
