致脓癣的须癣毛癣菌鉴定及体外药敏试验

须癣毛癣菌是皮肤癣菌病中常见的致病真菌之一,其分型复杂,具有多个变种和有性型,引起脓癣的常为亲动物性分离菌。从形态学角度难以明确区分不同种型,需要从分子生物学角度加以鉴定。rDNA序列测定是目前最常用于真菌鉴定的一种方法。我们从一脓癣患儿头部分离出一株须癣毛癣菌,对其形态学、rDNA序列和体外对抗真菌药物的敏感性进行了研究。     

Dermatophytosis of pigs by Trichophyton mentagrophytes

We describe the isolation of Trichophyton mentagrophytes in two family-operated farms where the animals were suffering skin ailments characterized by a swelling and a reddening of the back and flanks.This condition affected 2 and 5% respectively of the animals on the farms, the younger ones being more frequently affected.     

须癣毛癣菌肉芽肿1例

1 临床资料 患者男,31岁,因右小腿皮损伴痒痛2年 ,于1997年6月23日就诊。2年前患者无明显诱因于右小腿屈侧出现一处铜钱大小环形红斑,外用中药治疗无效。皮损逐渐向外扩大,伴剧烈瘙痒。之后皮损表面出现硬结,破溃及化脓,有时疼痛。患者既往病史不详,查体：一般情况可,浅表淋巴结未触及肿大,皮肤科检查：右小腿外侧,屈侧可见隆起的环形红斑,边界清楚,表面有丘疹,脓疱及脱屑。     

Morphological response of Trichophyton mentagrophytes to keratin

Summary The protein keratin can induce a reversible change in morphology of some granular strains ofTrichophyton mentagrophytes leading to a gross appearance which is indistinguishable from the pleomorphic mutation. The only other chemical which induced the same morphological change was a low concentration of sodium acetate. Pleomorphic cultures ofT. mentagrophytes were unaffected.     

A microautomated dilution method for susceptibility testing with antifungal drugs

The authors perfected, for standardization purposes, a microautomated system (Dynatech MIC 2000 Inoculator) to obtain the accurate quantitative results, i.e., determination of minimum inhibitory (MIC) and fungicidal (MFC) concentrations, avoiding the work and time consuming procedure of the classic broth dilution method in tubes. The spectrum of activity of seven antifungal antibiotics against 204 yeast isolates of six different species, in two different media comparatively, is described.     

应用CLSI M38-A2方案测定须癣毛癣菌对抗真菌药物敏感性

目的:对我国代表地区须癣毛癣菌临床分离株作抗真菌药物敏感性测定,进一步验证CLSI的M38-A2方案.方法:选取我国南北方8个省市地区经表型和分子生物学鉴定的趾间型毛癣菌38株和苯海姆节皮菌6株,采用M38-A2方案测定氟康唑、伊曲康唑、伏立康唑、特比萘芬、灰黄霉素、联苯苄唑、环吡酮胺和阿莫罗芬等8种常见抗真菌药物的最小抑菌浓度(minimal inhibitory concentration,MIC).结果:氟康唑、伊曲康唑、伏立康唑、特比萘芬、灰黄霉素、联苯苄唑、环吡酮胺和阿莫罗芬对趾间型毛癣菌株的MIC值(μg/mL)范围分别为0.25-32、0.0312-1、0.0156-0.0625、0.000937-0.00781、0.0625-1、0.0312-2、1-2、0.00781-0.0625;对苯海姆节皮菌株的MIC值(μg/mL)范围分别为≥64、2、0.25-0.5、0.000937-0.00381、1、2-4、1-2、0.0312-0.0625.不同抗真菌药物对趾间型毛癣菌及苯海姆节皮菌的药敏有明显差别(P<0.001);趾间型毛癣菌和苯海姆节皮菌对伊曲康唑、灰黄霉素、环吡酮胺、伏立康唑和氟康唑的药敏差异有统计学意义,对特比萘芬、阿莫罗芬和联苯苄唑的药敏差异无统计学意义.结论:趾间型毛癣菌和苯海姆节皮菌之间对伊曲康唑、灰黄霉素、环吡酮胺、伏立康唑和氟康唑的药敏有明显差异.M38-A2方案有较好的重复性和稳定性,适合用来体外测定须癣毛癣菌对抗真菌药物的敏感性.     

须癣毛癣菌致儿童脓癣1例

报道由须癣毛癣菌引起的儿童头部脓癣1例.患儿为4岁幼女,因头皮部丘疹1个月,脓肿4d就诊.内服青霉素V钾无效.取断发镜检查见发外真菌孢子,培养鉴定为须癣毛癣菌,细菌培养为棒状杆菌.经内服和外用特比萘芬抗真菌,静脉输入头孢噻肟钠联合克林霉素及万古霉素抗细菌治疗,12d后脓肿减轻,细菌培养阴转,但真菌培养仍阳性,继续抗真菌治疗2个月后皮损消退,真菌检查阴性.     

Spore differentiation in a clinical strain of Trichophyton mentagrophytes

Spore differentiation and, in particular, arthrosporogenesis in a clinical strain of T. mentagrophytes was investigated using a variety of methods and by altering environmental conditions. Results are discussed with reference to the in vivo situation. Arthrospores were obtained in the presence of increased CO2 tension but not increased N2 tension. High humidity was necessary for arthrospore formation but maturity (i.e. crops of single spores) was associated with conditions of reduced humidity. Desiccation reduced arthrospore viability. Glucose and peptone based media were suitable for arthrospore formation. Arthrospores were produced at 30 degrees C and 37 degrees C, but 30 degrees C is preferred since chlamydospores were prevalent at 37 degrees C. Conditions for production of arthrospore, microconidial and mycelial suspensions are presented.     

Biofilm formation by and antifungal susceptibility of Candida isolates from urine

Biofilm formation (BF) in the setting of candiduria has not been well studied. We determined BF and MIC to antifungals in Candida spp. isolates grown from urine samples of patients and performed a retrospective chart review to examine the correlation with risk factors. A total of 67 Candida spp. isolates were grown from urine samples from 55 patients. The species distribution was C. albicans (54%), C. glabrata (36%), and C. tropicalis (10%). BF varied greatly among individual Candida isolates but was stable in sequential isolates during chronic infection. BF also depended on the growth medium and especially in C. albicans was significantly enhanced in artificial urine (AU) compared to RPMI medium. In nine of the C. albicans strains BF was 4- to 10-fold higher in AU, whereas in three of the C. albicans strains and two of the C. glabrata strains higher BF was measured in RPMI medium than in AU. Determination of the MICs showed that planktonic cells of all strains were susceptible to amphotericin B (AMB) and caspofungin (CASPO) and that three of the C. glabrata strains and two of the C. albicans strains were resistant to fluconazole (FLU). In contrast, all biofilm-associated adherent cells were resistant to CASPO and FLU. The biofilms of 14 strains (28%) were sensitive to AMB (MIC(50) of <1 mug/ml). Correlation between degree of BF and MIC of AMB was not seen in RPMI grown biofilms but was present when grown in AU. A retrospective chart review demonstrated no correlation of known risk factors of candiduria with BF in AU or RPMI. We conclude that BF is a stable characteristic of Candida strains that varies greatly among clinical strains and is dependent on the growth medium. Resistance to AMB is associated with higher BF in AU, which may represent the more physiologic medium to test BF. Future studies should address whether in vitro BF can predict treatment failure in vivo.     

Assimilation of nail keratin by Trichophyton mentagrophytes (Morphological study)

Summary In the course of onychomycosis due toTrichophyton mentagrophytes histological studies of nail plate were carried out in order to study growth of the fungus in the nail. The tissue changes caused by assimilation of the nail keratin by the fungus were also studied. Three phases of this process have been described: 1) growth of the fungus in the intercellular spaces, 2) corrosion of nail tissue, 3) gas production. The gas tunnels make an anatomic substratum of the transverse net (Alkiewicz 1948) and of the spriggy net (Sowiski). The fungus has grown in a monomorphic way in the nail and only arthrospores (spore chains) have been observed.

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Zusammenfassung In Onychomykosen (Tr. mentagrophytes) wurden Nagelplatten histologisch untersucht, um das Pilzwachstum und die Folgen der Assimilation des Nagelkeratins zu studieren. Es wurden 3 Stadien festgelegt: 1) das interzelluläre Wachstum des Pilzes, 2) die Korrosion des Nagelgewebes, 3) die Gasbildung. Die langgestreckten gashaltigen Räume (Tunnels) sind das anatomische Substrat des transversalen Netzwerkes (Alkiewicz) und des zweigförmigen Netzes (Sowiski). Der Pilz wächst im Nagel monomorph und erscheint nur in Form von Arthrosporen (Sporenketten).

     

Fungitoxicity of 1,4-naphthoquinones to Candida albicans and Trichophyton mentagrophytes.

Twenty-one substituted 1,4-naphthoquinones and five 8-quinolinols and copper(II) chelates were tested for antifungal activity against Candida albicans and Trichophyton mentagrophytes. Compounds containing electron-releasing or weak electron-withdrawing groups in the 2 and 3 positions of the 1,4-naphthoquinone ring were the most active against C. albicans at pH 7.0 in the presence of beef serum in the following order: 2-CH3O = 2,3-(CH3O)2 greater than 2-CH3 greater than 2-CH3S greater than 2-NH2 greater than 2,6-(CH3)2. For T. mentagrophytes under the same conditions the inhibitory 1,4-naphthoquinones contained the substituents 2-CH3O greater than 2,3-(CH3O)2 greater than 2-CH2S greater than 2-CH3 greater than 2-CH3(NaHSO3) greater than 2-NH2 greater than 2-C2H5S, 3-CH3 greater than 2,6-(CH3)2 greater than 2,3-CL2 greater than 5,8-(OH)2.     

An epizootic outbreak of ringworm in a guinea-pig colony caused by Trichophyton mentagrophytes.

The disease was characterized by loss of hair, initially occurring at the tip of the nose and spreading throughout the body. Lesions appeared as circular, scaley alopecia with occasional scarring. Although spread of the infection in the colony was random, the most severe infection occurred in an inbred line with light coat colour. The unusually high temperature and humidity, and the open type of outdoor management, appear to have contributed to the high incidence and severity of infection. Electron microscopic observation indicated that the organism multiplied in the keratin layer of the skin. The hyphae as well as chlamydospores were readily demonstrable by electron microscopy.     

Extensive dermatophytoses caused by Trichophyton mentagrophytes and Microsporum canis in a patient with AIDS

Retrospective studies have shown the occurrence of episodes of deep or superficial fungal infections in 58 to 81% of HIV/AIDS patients as a result of impairment of cell immunity. We describe a case of disseminated cutaneous dermatophytoses caused by Trichophyton mentagrophytes and Microsporum canis in a patients with AIDS. Diagnostic and therapeutic problems in relation to this unsual presentation are emphasized as well as the importance of an early mycologic diagnosis to prescribe antifungal therapy.     

对多烯类药物耐药的1株黄曲霉临床株耐药性的初步研究

目的对1株分离自疑似侵袭性肺曲霉病患者肺泡灌洗液的黄曲霉进行常用抗真菌药物敏感性的测定,判断其药物敏感性。方法以形态学方法对该菌株进行菌种鉴定;然后按照美国临床和实验室标准研究所(CLSI)的丝状真菌抗真菌药物敏感性试验方案M38-A,测定常用抗真菌药物对该菌株的最低抑菌浓度、最低杀菌浓度;同时以E-test法测定该菌对两性霉素B和伊曲康唑的敏感性。结果微量液基稀释法显示,两性霉素B或制霉菌素对该菌的MIC值均为4μg/ml,MFC值均为16μg/ml;伊曲康唑的MIC值为0.5μg/ml,MFC值为2μg/ml;特比萘芬的MIC为0.03μg/ml,MFC为0.03μg/ml。E-test法结果显示,该菌对伊曲康唑敏感,对两性霉素B耐药。结论临床上可以分离到对多烯类抗真菌药物耐药的黄曲霉株,应该引起重视。