Gallo M G, Lanfranchi P, Poglayen G, Calderola S, Menzano A, Ferroglio E, Peano A
Dipartimento di Produzioni Animali, Epidemiologia ed Ecologia, Sezione Parassitologia e Malattie Parassitarie, Grugliasco, Turin, Italy.
Med Mycol. 2005 Jun;43(4):373-9. doi: 10.1080/13693780400008282.
Two hundred and six samples of alpine marmot (Mamota marmota) hair (148 from adults and 58 from young subjects), 102 soil samples from the entrances to the burrows of the above individuals and 20 control specimens (obtained from adjoining areas away from the burrow systems where the rodents are not usually present) were examined from May 1994 to September 1997. Seventy-five isolates belonging to six species of dermatophytes were found in 69 of the 206 hair samples examined (33.5%). Two species were zoophilic, Microsporum canis (7.8%) and Trichophyton mentagrophytes (11.2.%), and four geophilic, Microsporum cookei (2%), M. gypseum (5.8%), Trichophyton ajelloi (3.9%) and T. terrestre (5.8%). The prevalence of each species in the hair samples did not change significantly according to year, season (chi-squared test [limit significance: P <0.05] gives no significant values [P>0.05] both in year and in season comparison) or age/sex (adult versus juvenile: P=0.1; male versus female: P=0.8) of the marmot. Twenty-three of the 102 soil samples (22.5%) were positive for dermatophytes found in the hair of marmots from the same burrow systems. Five of the 20 control soil samples (25%) were positive for dermatophytes. One isolate of M. gypseum, three of T. terrestre and one of T. mentagrophytes were obtained. Compared with other free-ranging rodent hosts studied in Europe, this mycoflora is characterized by the presence and relatively high prevalence of M. canis, frequently reported in symptomatic and asymptomatic cats, dogs and fur animals. M. canis has not been isolated in other rodents in the wild. However, it has recently been reported in asymptomatic foxes (Vulpes vulpes) from northern Italy. The close link between V vulpes and M. marmota, with the former representing the most important mammal predator of the latter in the Alps (only a fraction of the predator's attacks result in the death of the rodent) may have favoured the adaptation of M. canis to this rodent host. The stable character of the M. canis/M. marmota relationship (no seasonally or annually related difference in the prevalence of this dermatophyte has been found) suggests the inclusion of the alpine marmot in the reservoir of this zoophilic pathogenic agent. In this situation, hibernation in labyrinthine burrow systems, where temperature and moisture ranges are quite uniform the whole year round, may favour the viability of M. canis arthroconidia, whose survival in mountain habitat might otherwise be compromised. This seems to be confirmed by the fact that the fungus has never been found in the control samples collected at a distance of 300 m from the outer edge of the sampled burrow systems.
1994年5月至1997年9月，对206份高山旱獭（Mamota marmota）毛发样本（148份来自成年个体，58份来自幼年个体）、上述个体洞穴入口处的102份土壤样本以及20份对照样本（从远离洞穴系统的相邻区域获取，这些区域通常没有啮齿动物）进行了检测。在检测的206份毛发样本中，有69份（33.5%）发现了属于六种皮肤癣菌的75个分离株。两种是亲动物性的，犬小孢子菌（7.8%）和须癣毛癣菌（11.2%），四种是嗜土性的，库克小孢子菌（2%）、石膏样小孢子菌（5.8%）、阿杰洛毛癣菌（3.9%）和土生毛癣菌（5.8%）。毛发样本中各菌种的流行率在年份、季节（卡方检验[显著性界限：P<0.05]在年份和季节比较中均无显著值[P>0.05]）或旱獭的年龄/性别（成年与幼年：P = 0.1；雄性与雌性：P = 0.8）方面没有显著变化。102份土壤样本中有23份（22.5%）对来自同一洞穴系统旱獭毛发中发现的皮肤癣菌呈阳性。20份对照土壤样本中有5份（25%）对皮肤癣菌呈阳性。获得了1株石膏样小孢子菌、3株土生毛癣菌和1株须癣毛癣菌。与欧洲研究的其他自由放养的啮齿动物宿主相比，这种真菌区系的特点是犬小孢子菌的存在和相对较高的流行率，犬小孢子菌在有症状和无症状的猫、狗及毛皮动物中经常被报道。犬小孢子菌在其他野生啮齿动物中尚未分离到。然而，最近在意大利北部无症状的狐狸（Vulpes vulpes）中报道了该菌。赤狐与高山旱獭之间的密切联系，前者是后者在阿尔卑斯山最重要的哺乳动物捕食者（捕食者的攻击只有一小部分导致啮齿动物死亡），这可能有利于犬小孢子菌适应这种啮齿动物宿主。犬小孢子菌/高山旱獭关系的稳定性（未发现这种皮肤癣菌的流行率存在季节性或年度差异）表明高山旱獭可作为这种亲动物性病原的储存宿主。在这种情况下，在迷宫般的洞穴系统中冬眠，那里全年温度和湿度范围相当均匀，可能有利于犬小孢子菌关节孢子的生存能力，否则其在山区栖息地的存活可能会受到影响。从距离采样洞穴系统外缘300米处采集的对照样本中从未发现该真菌这一事实似乎证实了这一点。
