Candida parapsilosis and Candida guillermondii: emerging pathogens in nail candidiasis.

BACKGROUND: Onychomycosis of the fingernails and toenails is generally caused by dermatophytes and yeasts. Toenail mycoses involve mainly dermatophytes but when Candida is also involved, the strain most commonly isolated worldwide is C. albicans. AIMS: To determine Candida strains prevailing in onychomycosis. MATERIALS AND METHODS: A retrospective, observational and descriptive study of fungal cultures retrieved from the registry of the microbiology laboratory of the Pontificia Universidad Católica was performed. Specimens obtained from patients attending the healthcare network between December 2007 and December 2010 was analyzed. STATISTICAL ANALYSIS: A descriptive statistical analysis was performed. RESULTS: Candida was retrieved from 467 of 8443 specimens (52% fingernails and 48% toenails). Cultures were negative in 5320 specimens (63.6%). Among Candida-positive cultures, parapsilosis was the most commonly isolated strain with 202 cases (43.3%). While isolates of Candida guillermondii were 113 (24.2%), those of Candida albicans were 110 (23.6%), those of spp. were 20 (4.3%) and there were 22 cases of other isolates (4.71%). Among the 467 patients with positive cultures for Candida, 136 (29,1%) were men and 331 (70,9%) were women. All patients were older than 18 years old. Clinical files were available for only 169 of the 467 patients with positive cultures for Candida. For those, age, gender, underlying illnesses and use of immunossupresive agents during the trial was reviewed. CONCLUSIONS: The present study shows that both C. parapsilosis as well as C. guillermondii appear as emerging pathogens that would be in fact taking the place of C. albicans as the most commonly isolated pathogen in patients with Candida onychomycosis. The relative percentage of C parapsilosis increases every year. Identification of Candida strains as etiological agents of nail candidiasis becomes relevant to the management both nail as well as systemic candidiasis, in view of the resistance to conventional treatments readily reported in the literature.

The first case of tinea faciei caused by Trichophyton mentagrophytes var. erinacei isolated in Chile.

BACKGROUND: Trichophyton mentagrophytes var. erinacei is a zoophilic dermatophyte transmitted by hedgehogs which human infections manifest as highly inflammatory and pruritic eruptions. METHODS: We report a 21-year-old woman who presented with a two-week history of a pruritic scaly erythematous plaque on the nose. The patient had kept hedgehogs as pets, and one had bitten her on the tip of the nose two months prior to the appearance of the nasal lesion. RESULTS: Fungal culture from the scales on the tip of the patient's nose was compatible with T. mentagrophytes var. erinacei. The strains isolated from cultures made from samples taken from the noses and ears of the pet hedgehogs were morphologically similar to the strain isolated from the patient. Morphological identification was confirmed by sequencing the internal transcribed spacer. The lesion was diagnosed as tinea faciei, and therapy was initiated with topical and systemic terbinafine 250mg/day for eight weeks, which resulted in complete improvement. CONCLUSIONS: Trichophyton mentagrophytes var. erinacei is the most common dermatophyte isolated in hedgehogs. Usually T. mentagrophytes var. erinacei infection manifests as an extremely inflammatory and pruritic eruption that is confined to the site of contact with the hedgehog. Although the identification of T. mentagrophytes by traditional methods is possible, identification by ITS region analysis is a fast, simple, and increasingly available method. The increasing frequency of the practice of keeping exotic animals as pets has resulted in the emergence of several zoonotic diseases that can potentially be transmitted to humans.

[Laboratory diagnosis of Treponema pallidum infection in patients with early syphilis and neurosyphilis through a PCR-based test]. / Diagnóstico de la infección por Treponema pallidum en pacientes con sífilis temprana y neurosífilis mediante reacción de la polimerasa en cadena.

Syphilis is a sexually transmitted disease caused by Treponema pallidum. The diagnosis is based mainly in clinical presentation and non-specific assays. PCR-based diagnosis has been suggested as an attractive alternative method. The aim of this study was the validation of a PCR-based test for the diagnosis of early syphilis (ES) and neurosyphilis (NS). Clinical samples of mucocutaneous lesions and cerebrospinal fluid (CSF) specimens from patients previously diagnosed for ES and NS respectively using an enlarged gold standard, were tested by PCR. The reaction was done using primers targeting the tpN47 gene. Twenty out of 21 mucocutaneous samples from patients diagnosed with ES were positive by PCR, with a clinical sensitivity of 95%. Four out of 8 CSF samples from patients previously diagnosed with NS were positive by PCR, with a clinical sensitivity of 50%. The clinical specificity for both ES and NS was 100%. The PCR sensitivity and specificity for mucocutaneous samples allowed us to implement this assay in our laboratory for routine diagnosis. Although the sensitivity of the PCR in CSF was low, it may be useful to support clinical diagnosis.

[Antimicrobial susceptibility of Campylobacter jejuni isolates from stool cultures in Santiago, Chile]. / Susceptibilidad antimicrobiana de Campylobacter jejuni aislado de coprocultivos en Santiago de Chile.

Campylobacter jejuni is a common agent of enterocolitis in humans. Campylobacteriosis has been recognized as a zoonotic disease whose reservoir is the intestinal flora of poultry. The reposition of fluid and electrolytes is the recommended treatment, and antimicrobials are required only in severe and/or in prolonged disease. Given the emergence of resistance to drugs commonly used in the treatment of acute diarrhea, we studied the antimicrobial susceptibility of 73 strains of Campylobacter jejuni isolated from stool culture. The antimicrobials tested were: erythromycin, azithromycin, ampicillin and ciprofloxacin. Of the 73 strains tested by E-test, 32.4% were resistant to ciprofloxacin and 6.4% were resistant to ampicillin. Resistance to erythromycin and azithromycin was not detected. The surveillance of antimicrobial resistance of Campylobacter jejuni is important in the evaluation of empirically used antimicrobials in the treatment of bacterial enterocolitis.

[Utility of stool culture in inpatient]. / Evaluación del rendimiento del coprocultivo en pacientes hospitalizados.

Several studies have concluded that it is inappropriate to perform stool cultures (SC) to inpatients that have stayed hospitalized three days or more because nosocomial diarrhea is not due to enteric pathogenic bacteria that are searched through this exam. The aim of this paper was to analyze the SC yield performed to patients hospitalized in the UC Health Net since January to December 2002 and the rate of positive results obtained depending on the length of hospitalization in order to define if international guidelines are useful to the national reality. During twelve months 3474 SC were evaluated, 458 (13.2%) belonged to inpatients. Of them 16 (3.5%) were positive, 13 were obtained on the first day, 2 at the second day and 1 at the fifth day of hospitalization. Only 1/190 (0.5) SC obtained after two days of hospitalization yielded a positive result. These results reinforce the international recommendation of not performing SC to inpatients that have stayed more than three days at the hospital; besides, considering previous figures, we suggest to make a cutoff at day two of hospitalization, after two days there is no a significant clinical impact. This strategy means to reduce 41% of these analyses and to save the corresponding money.

[Antifungal susceptibility of yeasts by Etest. Comparison of 3 media]. / Susceptibilidad antifúngica de levaduras mediante Etest. Comparación de 3 medios.

BACKGROUND: The increasing frequency of systemic fungal infections and the emergency of secondary resistance to antifungals in the lasts years, has stimulated the use of methods for antifungal susceptibility testing. Etest is an easily performed quantitative method that has a good agreement with the broth microdilution reference method (NCCLS), if appropriate media are used. AIM: To compare the susceptibility to Amphotericin B (AmB) and Fluconazole (Flu) of 22 opportunistic yeast isolates (C albicans (7), C tropicalis (9), C parapsilosis (3) and Cryptococcus neoformans (3) by Etest, using three different media and to choose the best medium for each tested drug. The studied media were RPMI 1640, Casitone (Cas) and Sabouraud. RESULTS: The interpretation of minimal inhibitory concentration (MIC) endpoints on Sabouraud was difficult for AmB. The American Type Culture Collection (ATCC) strains MICs were out of the acceptable range in this medium. RPMI and Cas were suitable media to test AmB and Flu, but best endpoints were obtained for AmB in RPMI and Flu in Cas. CONCLUSIONS: The use of appropriate media for each antifungal drug optimizes the MIC readings by Etest. AmB should be tested in RMPI and Flu in Cas. Sabouraud must not be used.