Andrea Maria Schmidt-Westhausen

In vivo transcript profiling of Candida albicans identifies a gene essential for interepithelial dissemination

Candida albicans is the most common oral fungal pathogen of humans, but the mechanisms by which C. albicans invades and persists within mucosal epithelium are not clear. To understand oral pathogenesis, we characterized the cellular and molecular mechanisms of epithelial–fungus interactions using reconstituted human oral epithelium (RHE). We observed that hyphal formation facilitates epithelial invasion via both active (physical penetration) and passive (induced endocytosis) processes. Genome wide transcript profiling of C. albicans experimental RHE infection was compared with that from 11 patient samples with pseudomembranous candidiasis to identify genes associated with disease development in vivo. Expression profiles reflected the morphological switch and an adaptive response to neutral pH, non‐glucose carbon sources and nitrosative stress. We identified several novel infection‐associated genes with unknown function. One gene, upregulated in both RHE infection and patients, named EED1, was essential for maintenance of hyphal elongation. Mutants lacking EED1 showed transient cell elongation on epithelial tissue, which enabled only superficial invasion of epithelial cells. Once inside an epithelial cell, Δeed1 cells could proliferate as yeasts or pseudohyphae but remained trapped intracellularly. Our results suggest that the adaptive response and morphology of C. albicans play specific roles for host–fungal interactions during mucosal infections.

Oral candidosis and associated Candida species in HIV‐infected Cambodians exposed to antimycotics

Although human immundeficiency virus (HIV) infection is endemic in Southeast Asia, data on oral mycotic flora in this disease in Asians are sparse. The aim of this study was to determine the prevalence of Candida species in HIV‐infected Cambodians with oral candidosis, unexposed (group 1) and exposed to antimycotics (group 2) and a healthy population (group 3). In 161 HIV patients with oral candidosis (group 1: 121 pts; group 2: 40 pts) and in 81 controls (group 3) swab samples of tongue and palate were obtained. Oral candidosis was detected in 100 and 70% of groups 1 and 2 respectively. Candida spp. were isolated from 91 and 100% of groups 1 and 2, respectively, and from 79% of controls. Candida albicans was the most common, with non‐albicans species such as C. tropicalis and C. krusei being notable. Our data indicate that variants of oral candidal infections in HIV disease are similar to those seen in the pre‐HAART era. The particularly high rate of C. krusei isolation in all groups is noteworthy.

Oral Syphilis: A Series of 5 Cases

Syphilis is an infectious, usually sexually transmitted, disease caused by Treponema pallidum, subspecies pallidum. Because of the increasing prevalence in Europe during the past few years, dentists could be confronted with patients with oral manifestations of syphilis. Because oral lesions are highly contagious, it is vital to make the correct diagnosis quickly to initiate the proper therapy and to interrupt the chain of infection. We present the cases of 5 patients with syphilis-related oral lesions. These cases are representative because of their clinical presentation, age, and gender distribution and the diagnostic approach. The aim of the present report is to emphasize the importance of the dentist knowing and identifying syphilis in different stages to diagnose the disease and institute treatment at an early stage.

Adjuvant antifungal therapy using tissue tolerable plasma on oral mucosa and removable dentures in oral candidiasis patients: a randomised double‐blinded split‐mouth pilot study

Extended use of antimycotics in oral candidiasis therapy gives rise to problems related to fungal drug resistance. The aim of this pilot study was to investigate the efficacy of tissue tolerable plasma (TTP) in denture stomatitis patients. It was hypothesised that (I): erythema and (IIa): complaint remission would be accelerated and (IIb): colony forming unit (CFU) reduction would be improved. The halves of the upper jaws of eight patients were randomly assigned to control (nystatin, chlorhexidine and placebo treatment) and test sides (nystatin, chlorhexidine and TTP administered six times each 7 days). The patients and the investigators, who were different from the therapists, were both blinded. Compared to the control sides, the erythema surface was reduced significantly more extensively on the test sides between 2 and 6 weeks of antifungal therapy (P ≤ 0.05). Visual analogue scale values and the frequency of moderate or heavy growth of Candida post‐treatment did not differ significantly between both sides (P > 0.05). The primary hypothesis was confirmed, which may be interpreted as an accelerated remission. As drug therapy is usually limited to the time in which signs of infection are present, TTP might help reducing antifungal use. Even though the secondary hypotheses were not confirmed, persistence of Candida might be only colonisation.

Dental implants in patients with oral mucosal diseases - a systematic review.

To reveal dental implants survival rates in patients with oral mucosal diseases: oral lichen planus (OLP), Sjögrens syndrome (SjS), epidermolysis bullosa (EB) and systemic sclerosis (SSc). A systematic literature search using PubMed/Medline and Embase databases, utilising MeSH and search term combinations identified publications on clinical use implant-prosthetic rehabilitation in patients with OLP, SjS, EB, SSc reporting on study design, number, gender and age of patients, follow-up period exceeding 12 months, implant survival rate, published in English between 1980 and May 2015. After a mean observation period (mOP) of 53·9 months (standard deviation [SD] ±18·3), 191 implants in 57 patients with OLP showed a survival rate (SR) of 95·3% (SD ±21·2). For 17 patients with SjS (121 implants, mOP 48·6 ± 28·7 months), 28 patients with EB (165 implants, mOP 38·3 ± 16·9 months) and five patients with SSc (38 implants, mOP 38·3 ± 16·9 months), the respective SR was 91·7 ± 5·97% (SjS), 98·5 ± 2·7% (EB) and 97·4 ± 4·8% (SSc). Heterogeneity of data structure and quality of reporting outcomes did not allow for further comparative data analysis. For implant-prosthetic rehabilitation of patients suffering from OLP, SjS, EB and SSc, no evidence-based treatment guidelines are presently available. However, no strict contraindication for the placement of implants seems to be justified in patients with OLP, SjS, EB nor SSc. Implant survival rates are comparable to those of patients without oral mucosal diseases. Treatment guidelines as for dental implantation in patients with healthy oral mucosa should be followed.

Identification of signature volatiles to discriminate Candida albicans, glabrata, krusei and tropicalis using gas chromatography and mass spectrometry

Oral candidiasis is the most frequent fungal infection of the oral cavity. Clinical diagnoses require mycological confirmation, which is time‐consuming in case of culture testing. The aim of the study was to identify signature volatiles to develop a chairside breath test to diagnose oral candidiasis. Headspaces above Candida albicans, glabrata, tropicalis, krusei cultures, and growth media as control were analysed after eight and 24 h using offline gas chromatography and mass spectrometry. The identification of signature volatiles was assisted using various microbial databases. Retrieved volatile patterns enabled Candida species discrimination in vitro. For C. albicans 3‐methyl‐2‐butanone and styrene and for C. krusei a combination of p‐xylene, 2‐octanone, 2‐heptanone and n‐butyl acetate were found to be specific. 1‐hexanol was found in C. tropicalis, but is emitted by a variety of other microorganisms. C. glabrata was characterised through the absence of these volatiles. The development of a breath test is a promising approach in confirming suspicions of oral candidiasis. To confirm the retrieved results in vivo, breath tests in affected and healthy subjects have to be performed.

Bactericidal efficacy of tissue tolerable plasma on microrough titanium dental implants: An in-vitro-study.

Surface decontamination remains challenging in peri-implant infection therapy. To investigate the bactericidal efficacy of tissue tolerable plasma, S. mitis biofilms were created in vitro on 32 microrough titanium dental implants. Biofilm imaging was performed by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The implants were either rinsed with 1% NaCl as negative control (C) or irradiated with a diode laser (DL) for 60 sec as positive control or plasma (TTP60, TTP120) for 60 or 120 sec. Subsequently, colony forming units (CFU) were counted. Post-treatment, implants were further examined using fluorescence microscopy (FM). Median CFU counts differed significantly between TTP60, TTP120 and C (2.19 and 2.2 vs. 3.29 log CFU/ml; p = 0.012 and 0.024). No significant difference was found between TTP60 and TTP120 (p = 0.958). Logarithmic reduction factors were (TTP60) 2.21, (TTP120) 1.93 and (DL) 0.59. Prior to treatment, CLSM and SEM detected adhering bacteria. Post-treatment FM recorded that the number of dead cells was higher using TTP compared to DL and C. In view of TTPs effectiveness, regardless of resistance patterns and absence of surface alteration, its use in peri-implant infection therapy is promising. The results encourage conducting clinical studies to investigate its impact on relevant parameters.

Volatile organic compounds in the breath of oral candidiasis patients: a pilot study

ObjectivesThe aim of the study was to investigate whether specific volatile organic compounds (VOCs) can be detected in oral candidiasis patients using breath analysis in order to develop a point-of-care diagnostic tool.Patients/methodsBreath samples of 10 diseased patients and 10 subjects carrying no Candida spp. were analyzed using gas chromatography and mass spectrometry. In infected patients, breath tests were performed before and after antifungal therapy.ResultsBreath testing was positive for 143 volatiles in both healthy subjects and diseased patients. Among those, specific signature volatiles known to be emitted by Candida spp. in vitro were not detected. Even though no specific signature was retrieved from the diseased patients, a pattern containing nine compounds (2-methyl-2-butanol, hexanal, longifolene, methyl acetate, 1-heptene, acetophenone, decane, 3-methyl-1-butanol, chlorbenzene) was identified, which showed characteristic changes after antifungal therapy.ConclusionsFocusing on the identified pattern, breath analysis may be applied to confirm the absence of Candida spp. after therapy in terms of a confirmatory test supplementing clinical examination, thereby replacing microbial testing. However, microbial testing will still be needed to initially confirm clinical diagnoses, as no specific signature was found.Clinical relevance: A breath test may help in avoiding extended antifungal administration resulting in resistance development and might be useful in the monitoring of disease recurrences in vulnerable groups.

Professor Peter A. Reichart: an appreciation on the occasion of his 65th birthday

No other name is more closely associated with the field of oral medicine than that of Professor Peter A. Reichart, Head and Chairman of the Department of Oral Surgery and Dental Radiology at the Charité University Medicine, Berlin, who turns 65 on the 28th of March 2008. Peter A. Reichart graduated from dental school at the University of Munich in 1968. He went on to become a resident physician at the Department of Maxillofacial Surgery, University of Munich and Hanover with extensive training in oral and maxillofacial surgery including cleft lip and palate repair, tumour surgery, preprosthetic surgery and traumatology. A pivotal point in his life was moving in 1970 from Germany to Chiangmai, Thailand, where he took responsibility not only for the recently founded Department of Oral Surgery of Chiangmai Dental School, but for his young family. There he developed the curriculum, the Department of Oral Surgery itself, and established the surgical unit in the newly founded faculty of dentistry. The years from 1970 to 1973 gave rise to a deep-seated love of Asia, its people and its art. He is still able to speak Thai. Back in Europe, Peter A. Reichart completed his formal training at the Department of Oral Pathology of Professor Jens J. Pindborg (Royal Dental College Copenhagen). Following this contact, Jens Pindborg became his mentor, friend and research partner in numerous global projects (odontogenic tumours, human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS), epidemiological research on oral cancer). His thesis on “Clinical and experimental studies on the effect of Ra and Ra on the dental organ of rats” in 1978 pointed to one of his future areas of research: odontogenic tumours. To complete his knowledge on the field of oral pathology, he became a research fellow at the Department of Oral Pathology (under Prof. Mario Martinèz) in Birmingham, AL, USA. He was appointed a full professor in the Department of Oral Surgery and Dental Radiology North, at the Free University of Berlin, at the early age of 39. In 1994, the department was transferred to the Medical Faculty of the Charité. Peter A. Reichart is an internationally recognized scientist in the field of oral medicine, oral pathology and oral surgery. His reputation is based on his vast experience in oral precancer and cancer and various other fields such as odontogenic tumours, oral mucosal diseases, and, in particular, tropical diseases, such as oro-facial manifestaOral Maxillofac Surg (2008) 12:47–48 DOI 10.1007/s10006-008-0092-x