H.-J. Tietz

Identification of clinical strains of Candida albicans by DNA fingerprinting with the polymerase chain reaction

Summary. DNA polymorphisms generated by the polymerase chain reaction (PCR) were used to differentiate clinical isolates of Candida. This PCR method employed single primers that were originally designed as hybridization probes for DNA fingerprinting experiments to probe mini‐satellite and microsatellite DNA sequences. To evaluate this procedure, 35 isolates from 20 patients in several intensive care units and 12 isolates obtained from the oral cavities of healthy dental patients were fingerprinted. The PCR‐fingerprint patterns of isolates of Candida albicans from the immunocompromised patients revealed fewer differences than isolates from the dental service. Multiple isolates from different body sites of the same patients revealed that patients may harbour isolates of Candida with the same or different PCR‐fingerprints. Since this method is generally simpler and faster than established methods of biotyping medically important yeasts, PCR‐fingerprinting may prove useful for the surveying of large numbers of pathogens for epidemi‐ological studies.

Candida africana sp. nov., a new human pathogen or a variant of Candida albicans?

Summary.  Atypical Candida strains were isolated from patients in Madagascar, Angola and Germany. These isolates were slow growing and were unable to produce chlamydospores. They had atypical carbohydrate assimilation profiles. All strains were unable to assimilate the amino sugars N‐acteylglucosamine and glucosamine as well as the disaccharide trehalose and the organic acid dl‐lactate. They were germ‐tube‐positive in serum, but only some of these organisms produced pseudohyphae after a long incubation. As shown by Fourier transform infrared spectroscopy the atypical Candida isolates clustered as a monophyletic group different from C. albicans and C. dubliniensis. All strains belonged to C. albicans serotype B. Considering all data presented here, this group of Candida strains differs from any other known member of the genus Candida. Therefore, it is suggested to represent a new species within the genus Candida for which the name Candida africana is proposed.

Case report. Osteomyelitis caused by high resistant Candida guilliermondii

We describe a case of a 57‐year‐old patient with osteomyelitis at a finger of his right hand caused by Candida guilliermondii. The strains isolated were highly resistant to fluconazole and itraconazole. Using the three methods, microdilution, agardilation and E‐test, the highest minimum inhibitory concentrations (MICs) amounted to >256 μg ml−1 for fluconazole and >32 μg ml−1 for itraconazole. To our knowledge, this is the first time such high values have been described for C. guilliermondii. They correlated with the therapeutic non‐response to a triazole therapy in our patient. The patient was cured by partial amputation of the affected finger.

Wandel des dermatomykologischen Erregerspektrums

Zusammenfassung. In der vorliegenden Arbeit wurde das Erregerspektrum bei 3607 Patienten mit Verdacht auf Dermatomykose im Einzugsgebiet der Berliner Charité untersucht. Die Identifizierung von Dermatophyten und Schimmelpilzen erfolgte konventionell, die der Hefen unter Einbeziehung biochemischer und genetischer Verfahren. Charakteristisch für den gegenwärtigen Erregerwandel sind Veränderungen innerhalb der Dermatophytenflora und die wachsende Bedeutung von opportunistischen Hefen. Ausgehend von einem stabilen 5‐Arten‐Grundbestand aus Trichophyton rubrum, T. mentagrophytes, Candida albicans, C. parapsilosis und Trichosporon cutaneum wird über die zunehmende Verbreitung von Microsporum canis, T. mentagrophytes var. granulosum und T. tonsurans berichtet.

First isolation of Trichophyton raubitschekii (syn. T. rubrum) in Europe

Summary. Trichophyton raubitschekii is a rare dermatophyte which belongs to the Trichophyton rubrum species complex. Since 1981, only a few cases of dermatophytosis due to this anthropophilic causative agent were published. In this paper the authors report the first cases of Tinea corporis caused by Trichophyton raubitschekii (syn. T. rubrum) in Europe. The patients, one immigrant from Ghana and three from Cameroon, had typical lesions of tinea corporis. Four strains were isolated and characterized by conventional and molecular methods. On morphological and physiological grounds the isolates were identified as T. raubitschekii by the following phenotypical features: (1) velvety colony texture; (2) brown pigment; (3) abundant macroconidia and (4) positive urease activity. Molecular diagnostics were performed by single strand conformation polymorphism (SSCP) and sequence analysis of the ATPase9 intron of the mitochondrial (mt) DNA and the internal transcribed spacer (ITS) region of the rDNA, respectively. The ITS sequences and SSCP patterns of the ATPase9 intron were found to be identical among the four strains and also when compared to reference strains of T. rubrum. As shown in the present paper, T. raubitschekii is genetically identical to T. rubrum but differs in some phenotypical characteristics. Since misidentification with other dark‐coloured dermatophyte variants is possible, medical mycologists should bear in mind the special morphological characteristics of T. raubitschekii (syn. T. rubrum) for future identifications.

Assessment of genetic relatedness of vaginal isolates of Candida albicans from different geographical origins.

PCR fingerprinting with single non-specific primers was used to type vaginal isolates of C. albicans from Portugal, Angola, Madagascar, and two regions of Germany (Berlin and Munich). In addition to analysing isolates that exhibited the normal biotype of C. albicans, the study included atypical strains that failed to assimilate glucosamine and N-acetylglucosamine, which were isolated from women in Angola and Madagascar. A total of 212 strains of C. albicans were studied, representing 87 different multi-locus genotypes. The genotypes of strains from each geographical population were highly similar but not identical. There was one exception: a strain from Portugal grouped with the typical strains from Angola. The typical and especially the atypical populations from Africa displayed less genotype variation than the populations from Europe. The Portuguese samples exhibited the greatest genotypic heterogeneity. Distance analysis (UPGMA) revealed a statistically weak correlation between genotype and geographical origin of the C. albicans isolates.

Dermatomykose durch Trichophyton verrucosum bei Mutter und Kind

ZusammenfassungVon verschiedenen Begleitfaktoren unterstützt, erleben zoophile Dermatomykosen seit wenigen Jahren eine epidemiologische Renaissance. Die gegenwärtig wichtigsten Erreger sind Microsporum canis, Trichophyton mentagrophytes var. granulosum und, wie im vorliegenden Fall, Trichophyton verrucosum. Es handelt sich um einst meldepflichtige Erreger mit hoher Virulenz und Kontagiosität. Das hier vorgestellte Beispiel einer ausgedehnten, zunächst verkannten Tinea corporis et faciei bei Mutter und Kind zeigt die aktuelle Bedeutung von Trichophyton verrucosum, aber auch die diagnostischen Schwierigkeiten im Umgang mit einer vormals seltenen Infektionskrankheit. Die phlegmasisch-entzündliche Symptomatik der tiefen Trichophytie mit unmittelbarer Gefahr von Narbenbildung begründete die synergistische Kombinationstherapie bei beiden Patientinnen. Waren zu Beginn des epidemiologischen Aufschwungs die Infektionsquellen zoophiler Dermatomykosen fast ausschließlich in mediterranen Gebieten zu suchen, mehren sich die Hinweise auf einheimische Erregerreservoire. Angesichts der Vernachlässigung der konsequenten Immunisierung von Viehbeständen gegen Rindertrichophytie sowie der fehlenden Meldepflicht ist mit einem Anstieg der Erkrankungszahlen auch beim Menschen zu rechnen.SummaryIn recent years, there has been an epidemiological renaissance of zoophilic dermatophytoses caused by a variety of factors. At present, the most important causative organisms are Microsporum canis, Trichophyton mentagrophytes var. granulosum and, as in the present case, Trichophyton verrucosum. These are formerly notifiable pathogens which are highly virulent and contagious. The example of an extensive, originally unrecognized tinea corporis et faciei in mother and child presented here shows the current importance of Trichophyton verrucosum, but also the diagnostic difficulties in dealing with a formerly rare infection disease. The inflammatory symptoms of deep trichophytosis with imminent danger of scar formation was the basis of synergistic combination therapy in the two patients. The source of infection for zoophilic dermatomycosis at the beginning of the epidemiological increase were looked for almost exclusively in Mediterranean countries. However, there are now increased indications of indigenous pools. In view of the neglect of consistent immunization of livestock and the lack of a requirement to notify the disease, a further rise in the number of cases in humans is to be expected.

Anwendung molekularbiologischer Methoden für Diagnostik und Epidemiologie humaner Pilzinfektionen

Zusammenfassung. Für molekularbiologische Methoden in der mykologischen Diagnostik existieren zwei prospektive Anwendungsgebiete: der Direktnachweis des Erregers ohne vorherige Anzucht und die molekulare Identifizierung von Spezies und Subspezies. Für den Nachweis von Infektionserregern werden vor allem spezifische DNA‐Sonden und/oder die Polymeraseketten‐reaktion (PCR) genutzt, wobei nur die PCR eine ausreichende Empfindlichkeit für den Direktnachweis der Erreger im biologischen Material erreicht. Die in der Literatur beschriebenen Anwendungen der PCR für die Detektion humanpathogener Pilze werden hinsichtlich ihrer Möglichkeiten und Grenzen kritisch beleuchtet.

Invasive metastasing pulmonary aspergillosis under polychemotherapy

Summary. We report on a female patient who received a polychemotherapy because of an extensive pemphigus vulgaris. Under this therapy, the general condition of the patient worsened. Non‐characteristic symptoms, such as dyspnoea and tachycardia occurred. In spite of comprehensive, also invasive diagnostics, pulmonary foci demonstrable by X‐ray morphology and computer tomography could not be specified. In the course of treatment, a cerebral compression symptomatology developed. Post mortem, a pulmonary aspergillosis with abscess‐formation in the brain was found. The antigen identification completed the diagnosis. The increasing significance of Aspergillus infections is pointed out. The results of clinical examination and the differential diagnosis as well as the possibility of the diagnosis of pulmonary aspergillosis are demonstrated.

Identification and characterization of medically importantCandida species by using PCR-fingerprinting

in the same reaction vial together with the template, amplified copy numbers can be quantified.We have constructed a standard for the PCR-detection of the insertion element IS 6110 of Mycobacterium tuberculosis. The PCR-MIMIC construction kit of Clontech was used. In this reaction the same primers amplify a template sequence of 123 bp and the standard of 360 bp. The standard is added in 3 different concentrations (6, 60, 600 molecules per sample), the probe is amplified and the products are separated, blotted and detected with enhanced chemiluminiscence. The results show that the lower detection limit is not constant. In some experiments only 600 molecules of the standard were detectable. This varying efficiency may be caused by inhibitors within the individual sample. Especially in the case of negative results, one has to consider this phenomenon. The use of internal standards gives information concerning the lower detection limit and prevents false negative results.