Fungal Culture Results Research Articles

Granulomatous Skin Infection Caused by Malassezia pachydermatis in a Dog Owner

Malassezia pachydermatis is part of the normal cutaneous microflora of dogs and many other mammals. M pachydermatis has not yet been reported as an agent that causes skin infection in humans, although it has been found to cause fungemia and other nosocomial infections in preterm newborns and immunocompromised adults. Malassezia pachydermatis was isolated from the facial granuloma of a healthy woman and her dog's skin scrapings and cerumen. The yeast identity was established by standard methods and scanning electron microscopy. A skin biopsy specimen showed chronic inflammatory granuloma, numerous purple-red round or ovoid spores in the superficial necrotic tissue, and sparse red spores in the dermis. The skin lesions healed after oral fluconazole and cryotherapy. Definite diagnosis of M pachydermatis-induced skin infection principally depends on the results of fungal culture and histologic examination, and the combination of oral fluconazole and adjunctive cryotherapy seems to be an effective therapeutic regimen.

Infection in Renal Transplantation: A Case of Acute Q Fever

Acute Q fever is a zoonotic infection that most often occurs as an asymptomatic or very mild febrile illness. A small percentage of patients go on to develop chronic Q fever months or even years after the acute infection. We present a case of acute Q fever occurring in a renal transplant recipient who developed severe systemic disease with renal involvement. Serological diagnosis was carried out, and the patient was treated successfully with antibiotic therapy. This case emphasizes Q fever as one of the atypical infectious agents that may have serious consequences in immunocompromised renal transplant recipients and reminds us of the importance of careful inquiry regarding personal or occupational activities that could lead to exposure to specific organisms.

Delaying the Empiric Treatment of Candida Bloodstream Infection until Positive Blood Culture Results Are Obtained: a Potential Risk Factor for Hospital Mortality

Fungal bloodstream infections are associated with significant patient mortality and health care costs. Nevertheless, the relationship between a delay of the initial empiric antifungal treatment until blood culture results are known and the clinical outcome is not well established. A retrospective cohort analysis with automated patient medical records and the pharmacy database at Barnes-Jewish Hospital was conducted. One hundred fifty-seven patients with a Candida bloodstream infection were identified over a 4-year period (January 2001 through December 2004). Fifty (31.8%) patients died during hospitalization. One hundred thirty-four patients had empiric antifungal treatment begun after the results of fungal cultures were known. From the time that the first blood sample for culture that was positive was drawn, 9 (5.7%) patients received antifungal treatment within 12 h, 10 (6.4%) patients received antifungal treatment between 12 and 24 h, 86 (54.8%) patients received antifungal treatment between 24 and 48 h, and 52 (33.1%) patients received antifungal treatment after 48 h. Multiple logistic regression analysis identified Acute Physiology and Chronic Health Evaluation II scores (one-point increments) (adjusted odds ratio [AOR], 1.24; 95% confidence interval [CI], 1.18 to 1.31; P < 0.001), prior antibiotic treatment (AOR, 4.05; 95% CI, 2.14 to 7.65; P = 0.028), and administration of antifungal treatment 12 h after having the first positive blood sample for culture (AOR, 2.09; 95% CI, 1.53 to 2.84; P = 0.018) as independent determinants of hospital mortality. Administration of empiric antifungal treatment 12 h after a positive blood sample for culture is drawn is common among patients with Candida bloodstream infections and is associated with greater hospital mortality. Delayed treatment of Candida bloodstream infections could be minimized by the development of more rapid diagnostic techniques for the identification of Candida bloodstream infections. Alternatively, increased use of empiric antifungal treatment in selected patients at high risk for fungal bloodstream infection could also reduce delays in treatment.

A Comparison of Results from Two Mycology Laboratories for the Diagnosis of Onychomycosis

An investigative study was performed to compare the results from two mycology laboratories for the diagnosis of onychomycosis in a geriatric population and to determine the possible pharmacologic treatments based on the two laboratories' results. In this study, 85 cases of suspected onychomycosis involving men and women 65 years and older from a nursing home setting in South Florida were used. Samples were taken from the hallux toenail and sent to two different mycology laboratories for fluorescent potassium hydroxide preparation and microscopic examination of a fungal culture. Of the 85 cases studied, the two mycology laboratories reported similar potassium hydroxide preparation results for 58.8% of the patients and similar fungal culture results for genus and species identification for 37.6% of the patients. When the potassium hydroxide preparation and fungal culture results were combined, the two mycology laboratories reported similar results for only 27.1% of the patients. As a result of the two mycology laboratories' findings, the possible US Food and Drug Administration-approved pharmacologic treatments may differ for 43.5% of the patients studied. The discrepancy between the two independent laboratories leaves physicians to question the reproducibility of fluorescent potassium hydroxide preparation and fungal culture analysis in a geriatric patient population for the diagnosis of onychomycosis.

Safety of discontinuation of maintenance therapy for disseminated histoplasmosis after immunologic response to antiretroviral therapy.

We performed a prospective observational study to assess the safety of stopping maintenance therapy for disseminated histoplasmosis among human immunodeficiency virus infected patients after response to antiretroviral therapy. All subjects received at least 12 months of antifungal therapy and 6 months of antiretroviral therapy before entry. Negative results of fungal blood cultures, urine and serum Histoplasma antigen level of <4.1 units, and CD4+ T cell count of >150 cells/mm3 were required for eligibility. Thirty-two subjects were enrolled; the median CD4+ T cell count at study entry was 289 cells/mm3. No relapses of histoplasmosis occurred after a median duration of follow-up of 24 months. This corresponded to an observed relapse rate of 0 cases per 65 person-years. The median CD4+ T cell count at final study visit was 338 cells/mm3. Discontinuation of antifungal maintenance therapy appears to be safe for patients with acquired immunodeficiency syndrome with previously treated disseminated histoplasmosis and sustained immunologic improvement in response to antiretroviral therapy.

Inflammatory tinea pedis/manuum masquerading as bacterial cellulitis.

Tinea pedis and tinea manuum in children are more common than previously recognized. Clinical presentations of dermatophyte infections may vary in children and may be difficult to diagnose. To show the necessity of potassium hydroxide preparations and/or fungal cultures in assessing suspicious cases of cellulitis in children who may have dermatophyte infections. We describe 4 children with inflammatory tinea pedis or tinea manuum who were initially misdiagnosed as having bacterial cellulitis. A potassium hydroxide examination was performed on 3 patients. Fungal cultures were performed on 2 patients. Inflammatory/bullous dermatophyte infections were detected by potassium hydroxide examination in all 4 patients and all 4 children successfully responded to topical antifungal therapy. These cases demonstrate that inflammatory tinnea pedis/manuum can masquerade as cellulitis in children. Early potassium hydroxide examination can allow appropriate antifungal treatment to be initiated before fungal culture results are finalized.

Office practice-based confirmation of onychomycosis: a US nationwide prospective survey.

Onychomycosis is sufficiently prevalent to be seen and treated by primary care physicians. The diagnosis of onychomycosis is most often confirmed from nail specimens by microscopy and fungal culture done at a central laboratory; these are relatively expensive tests with a turnaround time of a month or more. This study was conducted (1) to evaluate the use of in-office dermatophyte test medium (DTM) culture, and (2) to determine the epidemiology of onychomycosis in a large, nationwide sample of patients who were not participants in a clinical trial. A nationwide sample of primary care physicians and podiatrists enrolled 670 patients with clinical signs of toenail onychomycosis. Dermatophyte test medium cultures were performed in the office and the results were compared with fungal cultures performed by a central laboratory. Central laboratory fungal cultures were positive in 44% (n = 297) of patients and DTM cultures in 51% (n = 345). Dermatophytes accounted for 93% of the confirmed infections and nondermatophyte molds the rest. In the 617 patients with paired dermatophyte test medium and laboratory fungal culture results, the 2 tests were in agreement (both positive or both negative) in 68% of cases (kappa, 0.37; asymptotic SE, 0.04; 95% confidence interval, 0.299-0.441). A DTM culture is a relatively rapid, easy, and inexpensive method to confirm dermatophyte infections in patients with signs of onychomycosis in the primary care setting. Because the available drugs for treating onychomycosis are effective against all dermatophyte species, the confirmation of dermatophyte infection, without further identification of genus and species, is sufficient evidence to begin treatment.

Use of lufenuron for treating fungal infections of dogs and cats: 297 cases (1997-1999).

To evaluate use of lufenuron for treating cutaneous fungal infections in dogs and cats. Retrospective study. 156 dogs and 201 cats with dermatophytosis or superficial dermatomycoses. Medical records were reviewed for dogs and cats that had been treated for dermatophytosis or other fungal infections by administration of lufenuron and 18 dogs and 42 cats that were not treated and served as a control group. Dogs were treated once by oral administration of lufenuron tablets at doses ranging from 54.2 to 68.3 mg/kg (24.6 to 31.0 mg/lb) of body weight. Samples of skin, scrapings, and hair were obtained daily from 14 dogs with dermatophytosis; mean durations from time of treatment to time of negative fungal culture results and resolution of gross lesions were 14.5 and 20.75 days, respectively. In all treated dogs, gross lesions resolved within approximately 21 days. Cats were treated once by oral administration of lufenuron suspension in doses ranging from 51.2 to 266 mg/kg (23.3 to 120.9 mg/lb). Samples were obtained daily from 23 cats; mean durations from time of treatment to time of negative fungal culture results and resolution of gross lesions were 8.3 and 12 days, respectively. Time to resolution of lesions in most untreated control animals was approximately 90 days. Adverse effects of treatment were not detected. Results of this study suggest that lufenuron provides an effective, convenient, and rapid method for treating fungal infections in dogs and cats.

Tinea pedis in Korean children

Tinea pedis is an infrequent disease in children before the age of puberty. There are few epidemiologic and clinical data regarding cases of tinea pedis observed in children. Materials and methods We prospectively collected all cases of tinea pedis in children diagnosed during the years 1995-1997. Only those showing a positive result with potassium hydroxide preparation were included in the study. We performed fungal cultures in Sabouraud's agar in all cases to document the etiologic fungi. The clinical characteristics were investigated. A total of 21 children, aged 3 months to 14 years, were included. Fifteen patients were boys and six were girls. The mean age was 7.1 years. All the children were otherwise healthy. Prior to the establishment of the diagnosis of tinea pedis, 17 patients (80.9%) were treated for eczema without improvement. The intertriginous type was most common (53.3%). The first or second toe-webs were the sites of predilection (32.3%). Eighteen children (86%) had a family history of tinea pedis and more than half of cases (52.4%) showed occurrence in the summer. The results of fungal cultures were positive in 13 patients (57%). Trichophyton rubrum was the most commonly isolated pathogen (69.2%). The other associated dermatoses were onychomycosis (33.3%), atopic dermatitis (14%), plantar warts (10%), and chronic urticaria (5%). Tinea pedis and onychomycosis cleared after treatment with topical antifungals with or without systemic antifungals in all cases. Tinea pedis in children can occur more frequently than suspected. Our study shows the strong association with a family history and the seasonal relationship with occurrence in summer in more than half of cases. We suggest that tinea pedis should be considered in the differential diagnosis of foot dermatitis in children.

Diagnosis of onychomycosis made simple

Because onychomycosis requires long-term systemic therapy, it is essential to diagnose the infection accurately. Although in theory this diagnosis should be simple, results achieved in practice are uneven. Clinicians should be aware of the need to collect an adequate specimen and of the possible need for repeat collections. Direct microscopic techniques for examination of nail scrapings include 10% potassium hydroxide (KOH) with Parker ink, 10% KOH with dimethyl sulfoxide, and 10% KOH with Calcofluor white. When interpreting fungal culture results, it should be noted that negative results are frequent and that contaminant yeasts and molds are common, but that nondermatophytes such as Candida , Scopulariopsis , and Scytalidium can infrequently cause onychomycosis. (J Am Acad Dermatol 1999;40:S3-8.)

Utility of routine testing of bronchoalveolar lavage fluid for cryptococcal antigen.

All cryptococcal antigen (CrAg) testing performed at our institution between 1989 and 1994 was reviewed for utility of routinely testing of bronchoalveolar lavage fluid (BAL) for this antigen. Forty-two of 1,506 BAL specimens were positive. Seventeen of these were felt to represent false positives (sensitivity, 71%; positive predictive value, 0.59). The data on CrAg in cerebrospinal fluid and serum and the fungal culture and histological results of BAL specimens did not support continued, routine testing of BALs for CrAg to diagnose cryptococcosis.

Efficacy of oral administration of itraconazole to cats with dermatophytosis caused by Microsporum canis

Objective— To determine efficacy of orally administered itraconazole in cats with dermatophytosis caused by Microsporum canis. Design— Uncontrolled clinical trial. Animals— 15 cats with dermatophytosis caused by M canis. Procedure— All cats were treated with itraconazole (1.5 to 3.0 mg/kg [0.7 to 1.4 mg/lb] of body weight, PO, q 24 h, for 15 days). Six cats had been treated with griseofulvin (10 mg/kg [4.5 mg/lb], PO, q 24 h) during a 60-day period, but their clinical condition had not improved. Five cats treated at the highest dosage of itraconazole vomited or became anorectic. Consequently, dosages were progressively decreased for each cat until adverse effects were not evident. After treatment, samples of hair were submitted for fungal cultures, and if appropriate, treatment was repeated when culture results were positive. Results— 8 cats treated with itraconazole recovered completely, as indicated by resolution of lesions and negative results of fungal cultures. Six of these 8 cats received a single 15-day course of treatment, whereas the remaining 2 cats needed prolonged treatment (two 15-day courses of treatment and three 15-day courses of treatment). In 4 other cats that became clinically normal, M canis was isolated from hair samples obtained at the completion of treatment, even though only 1 colony or a small number of colonies was isolated. In the other 3 cats, itraconazole did not cause clinical improvement, and culture results remained positive. Clinical Implications— Oral administration of itraconazole at dosages of 1.5 to 3.0 mg/kg may be useful for the treatment of cats with dermatophytosis attributable to M canis infections. (J Am Vet Med Assoc 1998:213:993-995)

Outbreak of Tinea capitis caused by Microsporum ferrugineum in Thailand.

There was an outbreak of Tinea capitis at the Pak-kred Home for Mentally and Physically Handicapped Babies, Bangkok, Thailand in 1993. One hundred and thirty-eight cases were diagnosed as tinea capitis based on clinical signs and positive laboratory investigations. The results of Wood's light examination, KOH preparation and fungal culture were positive in 89.9, 75.9 and 27.4% respectively. The non-inflammatory form had a higher rate of positive KOH and culture than in the inflammatory form. Microsporum ferrugineum was the major pathogen (66.7%) and most of its infections (80.4%) caused a non-inflammatory type of tinea capitis. Griseofulvin, in a dosage of 10-15 mg/kg/day and selenium sulfide shampoos, yielded an 84.8% cure rate within 14.9 weeks. No recurrence or obvious adverse reactions were observed.

Candida Esophagitis in a Child with Achalasia

Candida Esophagitis in a Child with Achalasia

Microorganisms isolated from the corneal surface before and during topical cyclosporine treatment in dogs with keratoconjunctivitis sicca

SUMMARY The effect that topical administration of cyclosporine would have on the number and type of microorganisms isolated from the corneal surface of dogs with keratoconjunctivitis sicca was studied. Schirmer tear tests were performed on and corneal swab specimens were collected from 61 eyes of 31 dogs with keratoconjunctivitis sicca prior to and after 3, 6, and 12 months of treatment with cyclosporine. In eyes that responded to cyclosporine treatment (Schirmer tear test value increased by ≥ 5 mm/min, compared with pretreatment value), the percentage of eyes from which bacteria were isolated after 3, 6, and 12 months of treatment was significantly (P &lt; 0.001) less than the percentage from which bacteria were isolated prior to treatment. However, among eyes that did not respond to treatment, we did not detect a significant change over time in prevalence of bacteria or type of bacteria isolated. The percentage of eyes from which fungi were isolated decreased during treatment; however, the small number of eyes in which fungal culture results were initially positive precluded demonstration of a significant change. For all eyes, we did not detect any significant differences over time in the frequency with which specific bacterial genera were isolated, with the exception of β-hemolytic Streptococcus spp. Opportunistic comeal infections were not detected even though none of the dogs received antibiotics. An increase in production of tears, which contain anti-infection proteins, was believed to be the primary factor responsible for the decrease in the percentage of eyes from which microorganisms could be isolated.

Histologic Evaluation of Nail Clippings for Diagnosing Onychomycosis

Nail clippings from patients suspected of having onychomycosis were processed for histologic evaluation in the same manner as routine skin with the addition of a chitin-softening solution prior to processing. The sections were stained by the periodic acid-Schiff method and examined for fungal hyphae. The results were compared with the results of fungal cultures from the same nail. Our findings indicate that routine histopathologic analysis of the nail plate alone is a useful complementary method to fungal culture for diagnosing onychomycosis.

Corneal Microsporidiosis: A Case Report Including Ultrastructural Observations

Stromal keratitis and iritis developed in the left eye of a healthy 45year-old man with no history of ocular disease, trauma, or contact lens wear. The clinical course over a 2-year period was characterized by progressive central disciform keratitis, recurrent anterior stromal patchy infiltration, and iritis which was partially controlled with topical corticosteroids and broad-spectrum antibiotics. Results of bacterial, viral, fungal, and chlamydial cultures were negative. Results of histopathologic examination of a corneal biopsy specimen and, later, a penetrating keratoplasty specimen showed many extracellular and intracellular spores in degenerating keratocytes. By electron microscopy there were encapsulated oval structures measuring approximately 3.5 to 4 μm in length × 1.5 μm in width. Mature spores had well-developed cell walls that contained two abutted nuclei (diplokaryon) and a redundant polar tubule with six coils. These structures are characteristic of a protozoa in the genus Nosema.

Treating tinea capitis: Should ketoconazole replace griseofulvin?

We undertook a randomized double-blind comparison of griseofulvin and ketoconazole for the treatment of tinea capitis. The outcome was based on fungal culture results and changes in clinical signs and symptoms determined by an assessment system that yielded a severity score. Patients were evaluated at 4-week intervals for 12 weeks. Seventy-nine patients were enrolled; 46 received griseofulvin, and 33 received ketoconazole. Forty-eight patients (26 griseofulvin, 22 ketoconazole) were considered evaluable. Pathogenic fungi were isolated from 78% of the enrolled and 87% of the evaluable patients. Trichophyton tonsurans was the predominant dermatophyte isolated. Potassium hydroxide preparation correlated poorly with culture results (sensitivity 59%). Of 22 evaluable ketoconazole patients, 16 (73%) were considered to have been treated successfully; 25 of 26 (96%) patients who received griseofulvin were successfully treated (chi-square = 3.54, p less than 0.10). The proportion of culture-positive patients at each follow-up visit appeared somewhat greater for the ketoconazole-treated group than for the griseofulvin-treated group, but the differences were not statistically significant. Analysis of severity scores revealed no significant differences between the groups (t test and Mann-Whitney U test). No significant hepatotoxicity or other adverse reactions were observed. We conclude that griseofulvin should remain the drug of choice for treating tinea capitis.

Growth, Colonial Size and Sporulation of Lyophilized Cultures of the Genus Trichophyton on Agar Media

RybnikH A.: Growth, Colonial Size and Sporulation of Lyophilized Cultures of the Genus Trichophyton on Agar Media. Acta vet., Brno, 55, 1986: 73 -80. Lyophilized cultures of 4 species of the genus Trichophyton Malmsten 1845 were diluted with saline after one year of storage and inoculated onto agar media. Trichophyton equinum grew best on malt media, T. mentagrophyfes on Mycological Agar, T. terrestre on Trichophyton Agars 1, 4 and 5, and T. verrucosum on Sabou­ raud's agar. The rate of colonial size increase of all the four cultures was highest on Sabouraud's agar, malt media and Mycological Agar. The formation of micro­ conidia showed the highest values on malt media with all the cultures except T. terrestre which sporulated best on Sabouraud's agar. It is concluded that malt agar media and Sabouraud's agar are suitable culture media for recultivation of lyophilized dermatophyte cultures. Dermatophyte lyophilizate, recultivation, colonial size, formation of microconidia. Cultures of microscopic fungi deposited in culture collections as well as those used for pro­ duction purposes undergo gradual loss of viability on long-term storage. In recultivating frozen­ lyophilized or otherwise preserved fungal strains it is therefore necessary to choose optimum procedures and conditions that would allow one to obtain viable, well-growing and sporulating cultures. One of the major factors involved is the choice of a suitable culture medium. Its choice may also considerably affect the results of testing fungal cultures for their growth and sporulation capacity and may lead to changes in the characteristics of the strains on passage. These aspects are particularly important in dermatophytic fungi, causative agents of mycoses in numerous animal species and man. The present study is concerned with the choice of agar culture media for recultivation, growth and sporulation of four species of the genus Trichophyton maintained in the lyophilized state for one year. These were three zoophilic dermatophytes, namely T. equinum, T. mentagrophytes and T. verrucosum, and one geophilic species, T. terrestre, which lives as a saprophyte on keratin structures in soil and very rarely attacks man and animals.

Aspergillus antigen detection in bronchoalveolar lavage fluid from patients with invasive aspergillosis and aspergillomas

Improved diagnostic techniques have been needed for pulmonary aspergillosis, a common opportunistic fungal infection with a high mortality rate. Radioimmunoassay was used in this study to detect Aspergillus antigen in bronchoalveolar lavage fluid. In four patients with invasive aspergillosis or aspergillomas, Aspergillus antigen was detected in bronchoalveolar lavage fluid. In two patients, results of fungal cultures were negative or delayed. The specificity of antigen detection in bronchoalveolar lavage fluid was 91 percent in 35 control patients with a variety of pulmonary disorders. The technique of radioimmunoassay detection of microbial antigen in bronchoalveolar lavage fluid appears promising for the diagnosis of aspergillosis.