Pujol Claude, Pfaller Michael A, Soll David R
Department of Biological Sciences, The University of Iowa, Iowa City, Iowa 52242, USA.
Antimicrob Agents Chemother. 2004 Jan;48(1):262-6. doi: 10.1128/AAC.48.1.262-266.2004.
Population studies have revealed that Candida albicans can be separated into five major clades, groups I, II, III, SA, and E. Groups SA and E are highly prevalent in South Africa and Europe, respectively, while group II is excluded from the southwestern portion of the United State. In each geographical locale, several clades exist side by side, suggesting little interclade recombination. These results suggest clade-specific phenotypes. In the present study we demonstrate that resistance to flucytosine (5FC MIC >/= 32 micro g/ml), an antifungal used for the treatment of systemic C. albicans infections, is restricted to clade I. In addition, while 97% of all strains for which 5FC MICs were >/=0.5 micro g per ml were members of group I, only 3% were members of the other groups. 5FC MICs were >/=0.5 micro g per ml for 72% of all group I isolates, while 5FC MICs were >/=0.5 micro g per ml for only 2% of all non-group I isolates. These results demonstrate for the first time the clade specificity of a clinically relevant trait (5FC resistance) and suggest that while intraclade recombination may be common, interclade recombination is rare.
群体研究表明,白色念珠菌可分为五个主要进化枝,即I、II、III、SA和E组。SA组和E组分别在南非和欧洲高度流行,而II组在美国西南部不存在。在每个地理区域,几个进化枝并存,这表明进化枝间的重组很少。这些结果表明存在进化枝特异性表型。在本研究中,我们证明对氟胞嘧啶(5FC MIC≥32μg/ml)的耐药性仅限于I进化枝,氟胞嘧啶是一种用于治疗全身性白色念珠菌感染的抗真菌药物。此外,所有5FC MIC≥0.5μg/ml的菌株中,97%属于I组,只有3%属于其他组。所有I组分离株中72%的5FC MIC≥0.5μg/ml,而所有非I组分离株中只有2%的5FC MIC≥0.5μg/ml。这些结果首次证明了临床相关性状(5FC耐药性)的进化枝特异性,并表明虽然进化枝内重组可能很常见,但进化枝间重组很少见。