Biomedical subjects

Deanna A Sutton

Publications and source records attributed to Deanna A Sutton.

At least 19 recordsLinked to original sources

PubMed2006

Severe osteomyelitis caused by Myceliophthora thermophila after a pitchfork injury.

BACKGROUND: Traumatic injuries occurring in agricultural settings are often associated with infections caused by unusual organisms. Such agents may be difficult to isolate, identify, and treat effectively. CASE REPORT: A 4-year-old boy developed an extensive infection of his knee and distal femur following a barnyard pitchfork injury. Ultimately the primary infecting agent was determined to be Myceliophthora thermophila, a thermophilic melanized hyphomycete, rarely associated with human infection, found in animal excreta. Because of resistance to standard antifungal agents including amphotericin B and caspofungin, therapy was instituted with a prolonged course of terbinafine and voriconazole. Voriconazole blood levels demonstrated that the patient required a drug dosage (13.4 mg/kg) several fold greater than that recommended for adults in order to attain therapeutic blood levels. CONCLUSION: Unusual pathogens should be sought following traumatic farm injuries. Pharmacokinetic studies may be of critical importance when utilizing antifungal therapy with agents for which little information exists regarding drug metabolism in children.

Child, Preschool↗

PubMed2006

Review of in vitro activity of sertaconazole nitrate in the treatment of superficial fungal infections.

The evaluation of susceptibility patterns of clinical and laboratory isolates of dermatophytes and Candida to sertaconazole nitrate has been determined using macrodilution and microdilution test methods in laboratories worldwide. Antimycotics that have been compared to sertaconazole nitrate include itraconazole, clotrimazole, miconazole, and terbinafine. A comparison of the minimum inhibitory concentrations clearly shows differences in potency and spectrum among the various agents. This article reviews the antifungal activity of sertaconazole nitrate against major fungal pathogens that cause and complicate tinea pedis. In light of the new topical formulation of sertaconazole nitrate, this compilation of data from the literature is helpful for relating in vitro data to the tissue concentrations required for effective eradication of cutaneous fungal infections.

Administration, Topical↗

PubMed2006

Antifungal susceptibility testing.

Antifungal susceptibility testing has been in routine use now for more than 15 years and has become a useful tool for clinicians who are faced with difficult treatment decision. Although most clinicians order susceptibility testing, much confusion still exists regarding the use of the results. Sufficient data have been generated to determine susceptibility trends for specific fungi against specific agents, but correlation data are minimal. Despite the lack of correlation data, antifungal susceptibility testing continues to provide useful information to assist with patient care.

Antifungal Agents↗

PubMed2006

Phialemonium curvatum arthritis of the knee following intra-articular injection of a corticosteroid.

Phialemonium curvatum arthritis of the knee developed in a diabetic man following intra-articular injection of a corticosteroid. Cure was achieved with a 6-week course of intravenous amphotericin B deoxycholate. P.curvatum is commonly found in the environment and is often considered a contaminant; yet, its pathogenic potential should be seriously considered in selected patients.

Adrenal Cortex Hormones↗

PubMed2006

Relationship between metabolism and biomass of medically important zygomycetes.

Little is known about the relationships between metabolic activity and fungal biomass or time of incubation for medically important fungal pathogens. Understanding these relationships may be especially relevant for rapidly growing organisms, such as zygomycetes. A range of inocula of five clinical isolates of zygomycetes (one each of Rhizopus oryzae,Rhizopus microsporus, Cunninghamella bertholletiae, Mucor circinelloides and Absidia corymbifera) were incubated for 6, 8, 12, 24 and 48 h, after which hyphal mass was assessed spectrophotometrically and metabolic activity was measured using various concentrations of XTT and menadione. Both linear regression and the Boltzmann sigmoid model were used and compared for description of relationships between metabolic activity, biomass and time of incubation. Modeling was further applied to eleven additional zygomycete isolates. The relationships of biomass or metabolic activity as a function of time of incubation were well described with the Boltzmann sigmoid model. The latter was superior to linear regression in describing the relationship between metabolic activity and fungal biomass. For all isolates of zygomycetes, increases in metabolic activity preceded increases in biomass. Inter-species differences in growth patterns were observed, with Rhizopus microsporus and Mucor spp. reaching the plateau of growth earlier compared to other species. These findings on the temporal relationship and inter-species differences of hyphal growth and metabolic activity for zygomycetes may be useful in the design and interpretation of in vitro studies of these emerging pathogens.

Humans↗

PubMed2006

Fungal endophthalmitis caused by Aspergillus ustus in a patient following cataract surgery.

The first case of postoperative endophthalmitis after cataract surgery caused by Aspergillus ustus, a species that has only rarely been implicated in human disease, is described. Six weeks after cataract surgery, a 67-year-old medically controlled diabetic patient presented with uveitis, mild ciliary injection and ocular discomfort. Anterior chamber paracentesis, vitreous tap and finally complete vitrectomy with removal of the capsular bag including the intraocular lens were performed and several sets of culture yielded A. ustus. Despite vigorous systemic (itraconazole and caspofungin) and intravitreal (amphotericin B and caspofungin) antifungal therapy, the endophthalmitis did not improve. The painful eye with marked inflammation was finally enucleated. In vitro susceptibility testing of the isolate showed that it appeared resistant to amphotericin B, caspofungin, itraconazole, voriconazole, and posaconazole, and susceptible to terbinafine.

Aged↗

PubMed2006

Members of the Fusarium solani species complex that cause infections in both humans and plants are common in the environment.

Members of the Fusarium solani species complex (FSSC) are increasingly implicated as the causative agents of human mycoses, particularly in the expanding immunocompromised and immunosuppressed patient populations. Best known as ubiquitous plant pathogens and saprotrophs, the FSSC comprises over 45 phylogenetically distinct species distributed among three major clades. To identify which species are associated with human infections, we generated multilocus haplotypes based on four partial gene sequences from 471 isolates. Of these, 278 were from human patients, 21 were from hospital environments, and 172 were from other sources. Phylogenetic trees inferred from an ergosterol biosynthesis gene (erg-3) were highly discordant with those inferred from the three other partial gene sequences; therefore, this partition was analyzed separately. Multilocus analysis showed that isolates from humans were restricted to but spread throughout clade 3 of the FSSC phylogeny, comprising at least 18 phylogenetically distinct species. The majority (74.5%) of the clinical isolates, however, were associated with four major lineages, designated groups 1 to 4. Groups 1 and 2 were strongly supported as phylogenetic species, whereas groups 3 and 4 were not. Although isolates from ocular infections were found in all four groups, they had a significant tendency to belong to group 3 (P < 0.001). Human clinical isolates shared identical multilocus haplotypes with isolates from plants, other animals, and from hospital environments, suggesting potential nosocomiality. The major finding of this study is that FSSC-associated mycoses of humans and other animals have origins in a broad phylogenetic spectrum, indicating widespread ability to cause infection in this diverse species complex.

Animals↗

PubMed2006

Catheter-related fungemia due to Candida thermophila.

We report a case of bloodstream infection caused by Candida thermophila, a yeast not previously associated with human disease. The infection occurred in a 13-year-old boy with medulloblastoma who presented with 1 day of fever. Multiple blood cultures were positive for yeast. Removal of the catheter resulted in prompt resolution of the fever and sterilization of the blood cultures. The species was identified by sequencing domains 1 and 2 of the large subunit rRNA gene. Antifungal susceptibility testing was also performed.

Adolescent↗

PubMed2005

Lung infection due to opportunistic fungus, Phialemonium obovatum, in a bone marrow transplant recipient: an emerging infection with fungemia and Crohn disease-like involvement of the gastrointestinal tract.

We report the first case of Phialemonium obovatum fungemia with subsequent caseating granulomatas in the lung and Crohn disease-like involvement of the gastrointestinal tract in a bone marrow transplant recipient. This phaeoid fungus has been rarely described as an opportunistic infection in immunosuppressed patients. The patient was diagnosed with chronic myelogenous leukemia and underwent subsequent peripheral bone marrow transplant. After 6 months, he developed graft-versus-host disease of the skin and liver with fever and severe diarrhea. Fecal bacterial cultures and cytomegalovirus serologies were negative. Computed tomographic scan showed a peripheral pulmonary mass. A lung wedge biopsy of the lesion showed septate branching hyphae (4-5 microm in diameter) with terminal globular structures (10 microm in diameter). The hyphae were similar in width to that of an Aspergillus species but had a more moniliform appearance. Blood cultures grew a pure culture of P. obovatum. He was treated with amphotericin B and itraconazole for 6 months without remission of the diarrhea. Biopsies of the stomach, colon, and rectum showed granulomatous inflammation with marked crypt distortion simulating Crohn disease. In retrospect, the fungus was found to be resistant to both of the aforementioned drugs and susceptible to voriconazole and posaconazole. The gastrointestinal findings raise the possibility of further dissemination of a partially treated Phialemonium infection.

Amphotericin B↗

PubMed2005

In vitro activities of new and established triazoles against opportunistic filamentous and dimorphic fungi.

The in vitro activities of three new triazoles were determined and compared to those of itraconazole and fluconazole against 306 clinical isolates of Blastomyces dermatitidis, Cladophialophora carrionii, Coccidioides immitis, Fonsecaea pedrosoi, Fusarium spp., Histoplasma capsulatum, Paecilomyces lilacinus, Pseudallescheria boydii and Sporothrix schenckii. Minimum inhibitory concentrations (MIC) were determined by a broth macrodilution method of the National Committee for Clinical Laboratory Standards M38-A procedure. Itraconazole (geometric mean MIC, 0.16-0.65 microg/ml), voriconazole (geometric mean MIC, 0.18-1.44 microg/ml), ravuconazole (geometric mean MIC, 0.18-1.09 microg/ml), and posaconazole (geometric mean MIC, 0.18-1.38 microg/ml), had relatively uniform values showing potent in vitro inhibitory activity against B. dermatitidis, C. carrionii, C. immitis, F. pedrosoi, H. capsulatum, and S. schenckii. The in vitro activity was variable with strains of P. boydii, P. lilacinus and Fusarium spp.

Antifungal Agents↗

PubMed2005

Species of Phaeoacremonium associated with infections in humans and environmental reservoirs in infected woody plants.

To date, three species of Phaeoacremonium have been associated with phaeohyphomycosis. These are P. parasiticum (formerly Phialophora parasitica), P. inflatipes, and P. rubrigenum. Numerous unknown isolates resembling Phaeoacremonium spp. have in recent years been isolated from human patients as well as from woody plants that appear to be the main environmental source of these fungi. Nine new Phaeoacremonium species, of which six were obtained as etiologic agents of human opportunistic infection, are reported. They can be identified based on their cultural and morphological characters, and the identifications are strongly supported in phylogenetic analyses of partial sequences of the actin, beta-tubulin, and calmodulin genes. A multiple-entry electronic key based on morphological, cultural, and beta-tubulin sequence data was developed to facilitate routine species identification. Reexamination of all isolates of P. inflatipes associated with human disease showed them to be misidentified and to belong to the new taxa described here.

Actinidia↗

PubMed2005

Isolation of Cokeromyces recurvatus, initially misidentified as Coccidioides immitis, from peritoneal fluid in a cat with jejunal perforation.

Cokeromyces recurvatus, a zygomycete, was isolated by fungal culture from the peritoneal fluid of a cat with jejunal perforation secondary to intestinal lymphosarcoma. This organism has not been recovered previously from a veterinary patient. The tissue form of C. recurvatus is morphologically similar to those of Coccidioides immitis and Paracoccidioides brasiliensis and may be misdiagnosed as 1 of these organisms on the basis of cytologic or histopathologic specimens, particularly in geographic regions where these organisms are not endemic.

Animals↗

PubMed2004

Phialemonium: an emerging mold pathogen that caused 4 cases of hemodialysis-associated endovascular infection.

Phialemonium species are emerging as fungal opportunistic pathogens of humans; infections caused by these fungi often have a fatal outcome. We report a series of 4 patients undergoing chronic hemodialysis who developed intravascular infection with Phialemonium curvatum. All isolates were of a distinct morphological type but were shown by partial ribosomal sequencing to be closely related to reference isolates of P. curvatum. Two patients in our case series died; both developed overwhelming infection associated with fungemia and endocarditis. Recent literature corroborates our experience that Phialemonium infection presents unique diagnostic challenges and that optimal management, particularly with regard to antifungal therapy, is not known.

Adult↗

PubMed2004

Resistant Candida parapsilosis associated with long term fluconazole prophylaxis in an animal model.

We report an increased occurrence of fluconazole-resistant Candida parapsilosis after a 4-year period of antifungal prophylaxis in a premature animal neonatal intensive care unit. Although prevention of nosocomial fungal infections in premature infants is desirable, implementation of fluconazole prophylaxis should be undertaken with caution. Where such programs are in place, evaluation of fungal isolates for drug resistance should be considered.

Animals↗

PubMed2004

Genetic diversity of human pathogenic members of the Fusarium oxysporum complex inferred from multilocus DNA sequence data and amplified fragment length polymorphism analyses: evidence for the recent dispersion of a geographically widespread clonal lineage and nosocomial origin.

Fusarium oxysporum is a phylogenetically diverse monophyletic complex of filamentous ascomycetous fungi that are responsible for localized and disseminated life-threatening opportunistic infections in immunocompetent and severely neutropenic patients, respectively. Although members of this complex were isolated from patients during a pseudoepidemic in San Antonio, Tex., and from patients and the water system in a Houston, Tex., hospital during the 1990s, little is known about their genetic relatedness and population structure. This study was conducted to investigate the global genetic diversity and population biology of a comprehensive set of clinically important members of the F. oxysporum complex, focusing on the 33 isolates from patients at the San Antonio hospital and on strains isolated in the United States from the water systems of geographically distant hospitals in Texas, Maryland, and Washington, which were suspected as reservoirs of nosocomial fusariosis. In all, 18 environmental isolates and 88 isolates from patients spanning four continents were genotyped. The major finding of this study, based on concordant results from phylogenetic analyses of multilocus DNA sequence data and amplified fragment length polymorphisms, is that a recently dispersed, geographically widespread clonal lineage is responsible for over 70% of all clinical isolates investigated, including all of those associated with the pseudoepidemic in San Antonio. Moreover, strains of the clonal lineage recovered from patients were conclusively shown to genetically match those isolated from the hospital water systems of three U.S. hospitals, providing support for the hypothesis that hospitals may serve as a reservoir for nosocomial fusarial infections.

Animals↗

PubMed2004

Interlaboratory comparison of results of susceptibility testing with caspofungin against Candida and Aspergillus species.

Seventeen laboratories participated in a study of interlaboratory reproducibility with caspofungin microdilution susceptibility testing against panels comprising 30 isolates of Candida spp. and 20 isolates of Aspergillus spp. The laboratories used materials supplied from a single source to determine the influence of growth medium (RPMI 1640 with or without glucose additions and antibiotic medium 3 [AM3]), the same incubation times (24 h and 48 h), and the same end point definition (partial or complete inhibition of growth) for the MIC of caspofungin. All tests were run in duplicate, and end points were determined both spectrophotometrically and visually. The results from almost all of the laboratories for quality control and reference Candida and Aspergillus isolates tested with fluconazole and itraconazole matched the NCCLS published values. However, considerable interlaboratory variability was seen in the results of the caspofungin tests. For Candida spp. the most consistent MIC data were generated with visual "prominent growth reduction" (MIC(2)) end points measured at 24 h in RPMI 1640, where 73.3% of results for the 30 isolates tested fell within a mode +/- one dilution range across all 17 laboratories. MIC(2) at 24 h in RPMI 1640 or AM3 also gave the best interlaboratory separation of Candida isolates of known high and low susceptibility to caspofungin. Reproducibility of MIC data was problematic for caspofungin tests with Aspergillus spp. under all conditions, but the minimal effective concentration end point, defined as the lowest caspofungin concentration yielding conspicuously aberrant hyphal growth, gave excellent reproducibility for data from 14 of the 17 participating laboratories.

Antifungal Agents↗

PubMed2003

Primary central nervous system phaeohyphomycosis: a review of 101 cases.

Phaeohyphomycosis refers to infections caused by darkly pigmented fungi. These fungi rarely cause life-threatening disease. We reviewed 101 cases of culture-proven primary central nervous system phaeohyphomycosis reported in the English-language literature from 1966 to 2002. The most frequently isolated species was Cladophialophora bantiana. The next most frequent isolate was Ramichloridium mackenziei, seen exclusively in patients from the Middle East. More than one-half of the cases occurred in patients with no known underlying immunodeficiency. Mortality rates were high regardless of immune status. Therapy is not standardized, although the combination of amphotericin B, flucytosine, and itraconazole may improve survival rates. Newer azoles, such as voriconazole, also have a broad spectrum of activity against these fungi, although clinical experience is limited. Complete excision of brain lesions may provide better results than simple aspiration. An aggressive medical and surgical approach is warranted in treating these infections to optimize outcomes.

Adolescent↗

PubMed2003

In vitro activities of new antifungal agents against Chaetomium spp. and inoculum standardization.

Chaetomium is an unusual etiological agent of human infections, but the mortality rate among immunocompromised patients is considerably greater than that among nonimmunocompromised individuals. We investigated the in vitro antifungal susceptibilities to novel antifungal agents of 19 strains belonging to three species of Chaetomium which have been involved in human infections, i.e., Chaetomium globosum, C. atrobrunneum, and C. nigricolor, and one strain of the closely related species Achaetomium strumarium. A modification of the NCCLS reference microdilution method (M38-A) was used to evaluate the in vitro activities of ravuconazole, voriconazole, albaconazole, and micafungin. Micafungin was not active at all, while the geometric mean MICs and minimum effective concentrations of the three triazoles were less than 0.5 and 0.4 micro g/ml, respectively.

Antifungal Agents↗