Antifungal susceptibility patterns for Aspergillus, Scedosporium, and Exophiala isolates recovered from cystic fibrosis patients against amphotericin B, and three triazoles and their impact after long-term therapies.

In cystic fibrosis (CF) patients, fungal colonization of the respiratory tract is frequently found. Aspergillus fumigatus, Scedosporium genus, and Exophiala dermatitidis are the most commonly isolated moulds from the respiratory tract secretions of CF patients. The aim of this 5-year surveillance study was to identify trends in species distribution and susceptibility patterns of 212 mould strains identified as Aspergillus spp., Scedosporium spp., and Exophiala spp., isolated from sputum of 63 CF patients who received long-term therapy with itraconazole (ITR) and/or voriconazole (VRC). The Aspergillus isolates were identified as members of the sections Fumigati (n = 130), Flavi (n = 22), Terrei (n = 20), Nigri (n = 8), Nidulantes (n = 1), and Usti (n = 1). Among the 16 species of the genus Scedosporium, 9 were S. apiospermum, 3 S. aurantiacum, and 4 S. boydii. Among the 14 Exophiala species, all were molecularly identified as E. dermatitidis. Overall, 94% (15/16) of Scedosporium spp., 50% (7/14) of E. dermatitidis, and 7.7% (14/182) of Aspergillus spp. strains showed high MIC values (≥8 µg/ml) for at least one antifungal. Particularly, 8.9% (19/212) of isolates showed high MIC values for amphotericin B, 11.7% (25/212) for ITR, 4.2% (9/212) for VRC, and 3.3% (7/212) for posaconazole. In some cases, such as some A. fumigatus and E. dermatitidis isolates recovered from the same patient, susceptibility to antifungal azoles decreased over time. We show that the use of azoles for a long time in CF patients causes the selection/isolation of mould strains with higher MIC values.

The use of azoles for a long time in cystic fibrosis patients causes the selection/isolation of Aspergillus, Scedosporium, and Exophiala species with higher MIC values.

A Novel Combination of CYP51A Mutations Confers Pan-Azole Resistance in Aspergillus fumigatus.

The treatment of invasive and chronic aspergillosis involves triazole drugs. Its intensive use has resulted in the selection of resistant isolates, and at present, azole resistance in Aspergillus fumigatus is considered an emerging threat to public health worldwide. The aim of this work is to uncover the molecular mechanism implicated in the azole resistance phenotype of three Aspergillus fumigatus clinical strains isolated from an Argentinian cystic fibrosis patient under long-term triazole treatment. Strain susceptibilities were assessed, and CYP51A gene sequences were analyzed. Two of the studied Aspergillus fumigatus strains harbored the TR34-L98H allele. These strains showed high MIC values for all tested triazoles (>16.00 µg/ml, 1.00 µg/ml, 1.00 µg/ml, and 2.00 µg/ml for itraconazole, isavuconazole, posaconazole, and voriconazole, respectively). The third strain had a novel amino acid change (R65K) combined with the TR34-L98H mutations. This new mutation combination induces a pan-azole MIC augment compared with TR34-L98H mutants (>16 µg/ml, 4.00 µg/ml, 4.00 µg/ml, and 8.00 µg/ml for itraconazole, isavuconazole, posaconazole, and voriconazole, respectively). The strain harboring the TR34-R65K-L98H allele showed no inhibition halo when voriconazole susceptibility was evaluated by disk diffusion. The effect of these mutations in the azole-resistant phenotype was confirmed by gene replacement experiments. Transformants harboring the TR34-L98H and TR34-R65K-L98H alleles mimicked the azole-resistant phenotype of the clinical isolates, while the incorporation of the TR34-R65K and R65K alleles did not significantly increase azole MIC values. This is the first report of the TR34-L98H allele in Argentina. Moreover, a novel CYP51A allele (TR34-R65K-L98H) that induces a pan-azole MIC augment is described.

Molecular epidemiology of Aspergillus species and other moulds in respiratory samples from Argentinean patients with cystic fibrosis.

In cystic fibrosis (CF) patients, fungal colonization of the respiratory tract is frequently found. Aspergillus fumigatus is the most frequently recorded and is associated with loss of pulmonary function and allergic disease (ABPA). The knowledge on prevalence rates of filamentous fungi in CF patients in Latin America is scarce. One hundred and seventy-six fungal isolates recovered from the upper respiratory tract of CF patients from Argentina were identified to species by morphology and DNA sequencing. In total, 90% of CF patients were colonized by Aspergillus sp., followed by Exophiala sp. (14%) and Scedosporium sp. (10%). Among Aspergillus, six species complexes (Fumigati, Flavi, Terrei, Nigri, Usti, and Nidulante) and different cryptospecies were found. Among Scedosporium, three species were observed (Scedosporium apiospermum, Scedosporium aurantiacum and Scedosporium boydii). All Exophiala isolates were identified as Exophiala dermatitidis. Rare filamentous fungi were also found. All cases of ABPA were associated to the presence of A. fumigatus. Mixed colonization with other mould or rare fungi was observed in half of them. To our knowledge, this is the first prospective study of mould species in CF using molecular methods in Latin America. This study shows that Aspergillus sp., E. dermatitidis and Scedosporium sp. have a high frequency in CF patients from Argentina, and by far, A. fumigatus was the most commonly cultured species. Continuous clinical surveillance is required to detect the emergence of new fungal pathogens and to detect resistant or difficult-to-treat species capable of chronic colonizing the airways and of hematogenous dissemination in case of lung transplantation.

High prevalence of triazole-resistant Aspergillus fumigatus sensu stricto in an Argentinean cohort of patients with cystic fibrosis.

BACKGROUND: Triazole resistance in Aspergillus fumigatus sensu stricto due to mutations in the cyp51A gene has been widely reported. Data from Argentina, and particularly from cystic fibrosis (CF) patients, are limited. OBJECTIVES: To investigate the prevalence and molecular mechanisms of azole resistance in A. fumigatus sensu stricto recovered from this population. METHODS: Ninety-three A. fumigatus isolates from 50 CF patients were retrospectively analysed for azole resistance using the standard microbroth dilution method according to CLSI M38-A2 guidelines. Sequencing analysis of the cyp51A gene and its promoter region was conducted in those isolates displaying high MIC values to itraconazole, voriconazole and/or posaconazole. RESULTS: Overall, 14% of isolates displayed high MIC values to at least one azole. Of them, 30.7% had the mutation TR34-L98H. No mutations in the cyp51A gene or its promoter were found in the remaining non-wild-type strains. Therefore, other mechanisms associated with azole resistance can be highly prevalent in these isolates. CONCLUSIONS: To the best of our knowledge, this is the first study in Latin America reporting azole-resistant A. fumigatus strains recovered from respiratory secretions of CF patients. Noteworthy, the prevalence of azole resistance in A. fumigatus sensu stricto in the studied Argentinean CF population is alarmingly high.

[Neurohistoplasmosis and cutaneous leishmaniasis in an immunocompetent patient]. / Neurohistoplasmosis y leishmaniasis cutánea en paciente inmunocompetente.

Histoplasmosis and leishmaniasis are neglected and endemic diseases in Argentina, and generally are found associated with immunosuppression. We report the case of an immunocompetent 16-years-old man with simultaneous occurrence of central nervous system histoplasmosis and cutaneous leishmaniasis. Upon admission, the patient showed a one-month old skin lesion in a leg and mild paraparesis. Imaging studies detected thickening and edema in the spinal cord and the cerebrospinal fluid analysis was within normal range. The case was diagnosed as a demyelinating disorder and treated with high-dose short-term steroids. Seventy-two hours later the patient showed severe paraparesis and nuclear magnetic resonance imaging revealed nodular lesions in the spinal cord. Histoplasma capsulatum belonging to the phylogenetic species LamB was isolated from cerebrospinal fluid samples. The patient received intravenous antifungal therapy with amphotericin B for 30 days, followed by oral fluconazole and itraconazole for one year. Three months after initiation of antifungal treatment, the cutaneous lesion recrudesced and Leishmania amastigotes were observed on microscopic examination. The cutaneous leishmaniasis was treated with intramuscular meglumine antimoniate. The patient's outcome was favorable after treatment for both diseases.

La histoplasmosis y la leishmaniasis son enfermedades olvidadas, endémicas en Argentina, y generalmente se asocian a inmunocompromiso. Presentamos el caso de un varón de 16 años, inmunocompetente, con histoplasmosis del sistema nervioso central y leishmaniasis cutánea. Inicialmente, el paciente presentó una lesión en la pierna de un mes de evolución seguida de paraparesia leve, diagnosticada como un proceso de desmielinización mediante estudios de imágenes. El cuadro fue tratado con altas dosis de corticoides y en 72 horas evolucionó a paraparesia grave con lesiones nodulares en las vértebras cervicales, observadas en las imágenes de resonancia magnética nuclear. Se aisló Histoplasma capsulatum de líquido cefalorraquídeo, genotípicamente identificado como perteneciente a la especie filogenética LamB. El paciente recibió tratamiento intravenoso con anfotericina B deoxicolato durante 30 días y posteriormente fluconazol e itraconazol oral durante un año. A los tres meses de iniciado el tratamiento con antifúngicos se reactivó la lesión de la pierna y en el examen directo se observaron amastigotes de Leishmania. La leishmaniasis cutánea fue tratada con antimoniato de meglumina intramuscular. La respuesta clínica al tratamiento de ambas enfermedades fue favorable.

[Examination of the genetic variability among biofilm-forming Candida albicans clinical isolates]. / Estudio de la variabilidad genética entre aislamientos clínicos de Candida albicans formadores de biopelículas.

Biofilms are microbial communities encased in a self-produced polymeric matrix and represent a common mode of microbial growth. Candida albicans is able to colonize the surface of catheters, prostheses, and epithelia, forming biofilms that are highly resistant to antimicrobial drugs. The objective of this study was the genotypic characterization of biofilm-forming C. albicans clinical isolates using RAPD (Random Amplified Polymorphic DNA). We have studied 25 clinical isolates of C. albicans from oral cavities, blood, skin, nail, stool, oesophagus biopsy and vaginal fluids from patients suffering from candidiasis. For each strain biofilm formation was analysed by measuring the ability to adhere to and grow on polystyrene plastic surfaces using XTT [2,3-bis(2-methoxi-4nitro-5sulfophenil)-2H tetrazolium-5carboxanilide] reduction assay. The similarity coefficients generated by RAPD using four different primers varied from 49 to 91%, indicating a high degree of genetic variability between the clinical isolates. The dendrogram clustered the isolates in four related groups, all groups included strains with very different abilities to form biofilms. The isolates with similar genotypes often showed very different biofilm formation abilities. Strains were grouped into clusters independently of their clinical sources. Our results suggested that a direct correlation does not exist between the biofilm-forming ability of natural populations of C. albicans and the genotype as determined by RAPD.

Subgingival distribution of yeast and their antifungal susceptibility in immunocompetent subjects with and without dental devices.

Yeasts colonize the subgingival biofilm, which becomes a reservoir that favors their reproduction. The purpose of the present work was to determine the prevalence of yeasts of the Candida genus in the subgingival biofilm of gingivoperiodontal disease patients, including users and non-users of dental devices, and their susceptibility to fluconazole and voriconazole. Samples of subgingival pockets of immunocompetent nonsmokers showing gingivitis and periodontitis were inoculated in a differential chromogenic medium. Sixty three percent of subjects used dental devices. Yeasts were identified and susceptibility to fluconazole and voriconazole was tested following CLSI M44-A standards. The prevalence of yeasts in the subgingival biofilm was 40% CI 95% (30.5-50.3); 10% were patients who did not use dental appliances. The most frequently observed yeasts were C. albicans, and C. parapsilosis, C. dubliniensis, C. tropicalis and C. guilliermondii. Only C. dubliniensis and C. guilliermondii showed resistance to azoles. The use of dental devices significantly increased the prevalence of yeasts in periodontal pockets inpatients presenting gingivitis. It is noteworthy that non albicans Candida species, such as C. dubliniensis and C. guilliermondii, considered emerging species, which have a diminished susceptibility to antifungal agents were found in the crevicular fluid of immunocompetent patients.

Fusarium spp infections in a pediatric burn unit: nine years of experience.

INTRODUCTION: Fusarium spp are ubiquitous fungi recognized as opportunistic agents of human infections, and can produce severe infections in burn patients. The literature on Fusarium spp infections in pediatric burn patients is scarce. OBJECTIVES: To describe the clinical and epidemiological features as well as outcome of Fusarium spp infections in pediatric burn patients. PATIENTS AND METHODS: Retrospective, descriptive study of Fusarium spp infections in a specialized intensive care burn unit. RESULTS: In 15 patients Fusarium spp infections were diagnosed. Median age was 48 months. Direct fire injury was observed in ten patients. The median affected burn surface area was 45%. Twelve patients had a full thickness burn. Fourteen patients had a Garces Index ≥3. Fungal infection developed at a median of 11 days after burn injury. Fungi were isolated from burn wound in 14 patients and from the bone in one patient. Amphotericin B was the drug of choice for treatment followed by voriconazole. Median time of treatment completion was 23 days. One patient (7%) died of fungal infection-related causes. CONCLUSION: In our series Fusarium spp was an uncommon pathogen in severely burnt patients. The burn wound was the most common site of infection and mortality was low.

Fungemia and interstitial lung compromise caused by Malassezia sympodialis in a pediatric patient.

A case of fungemia with interstitial lung compromise caused by Malassezia sympodialis is reported in an obese pediatric patient on long-term treatment with inhaled corticosteroids for asthma. The patient was hospitalized due to a post-surgical complication of appendicitis. The patient was treated with amphotericin B for 3 weeks, with good clinical evolution and subsequent negative cultures.

Neurohistoplasmosis y leishmaniasis cutánea en paciente inmunocompetente / Neurohistoplasmosis and cutaneous leishmaniasis in an immunocompetent patient

La histoplasmosis y la leishmaniasis son enfermedades olvidadas, endémicas en Argentina, y generalmente se asocian a inmunocompromiso. Presentamos el caso de un varón de 16 años, inmunocompetente, con histoplasmosis del sistema nervioso central y leishmaniasis cutánea. Inicialmente, el paciente presentó una lesión en la pierna de un mes de evolución seguida de paraparesia leve, diagnosticada como un proceso de desmielinización mediante estudios de imágenes. El cuadro fue tratado con altas dosis de corticoides y en 72 horas evolucionó a paraparesia grave con lesiones nodulares en las vértebras cervicales, observadas en las imágenes de resonancia magnética nuclear. Se aisló Histoplasma capsulatum de líquido cefalorraquídeo, genotípicamente identificado como perteneciente a la especie filogenética LamB. El paciente recibió tratamiento intravenoso con anfotericina B deoxicolato durante 30 días y posteriormente fluconazol e itraconazol oral durante un año. A los tres meses de iniciado el tratamiento con antifúngicos se reactivó la lesión de la pierna y en el examen directo se observaron amastigotes de Leishmania. La leishmaniasis cutánea fue tratada con antimoniato de meglumina intramuscular. La respuesta clínica al tratamiento de ambas enfermedades fue favorable.

Histoplasmosis and leishmaniasis are neglected and endemic diseases in Argentina, and generally are found associated with immunosuppression. We report the case of an immunocompetent 16-years-old man with simultaneous occurrence of central nervous system histoplasmosis and cutaneous leishmaniasis. Upon admission, the patient showed a one-month old skin lesion in a leg and mild paraparesis. Imaging studies detected thickening and edema in the spinal cord and the cerebrospinal fluid analysis was within normal range. The case was diagnosed as a demyelinating disorder and treated with high-dose short-term steroids. Seventy-two hours later the patient showed severe paraparesis and nuclear magnetic resonance imaging revealed nodular lesions in the spinal cord. Histoplasma capsulatum belonging to the phylogenetic species LamB was isolated from cerebrospinal fluid samples. The patient received intravenous antifungal therapy with amphotericin B for 30 days, followed by oral fluconazole and itraconazole for one year. Three months after initiation of antifungal treatment, the cutaneous lesion recrudesced and Leishmania amastigotes were observed on microscopic examination. The cutaneous leishmaniasis was treated with intramuscular meglumine antimoniate. The patient´s outcome was favorable after treatment for both diseases.

[Outbreak of histoplasmosis in province of Neuquén, Patagonia Argentina]. / Brote de histoplasmosis en la provincia de Neuquén, Patagonia Argentina.

BACKGROUND: In Argentina, there are no reports of autochthonous cases of histoplasmosis in the southern regions of the country. AIM: To report a histoplasmosis outbreak in Zapala town, Province of Neuquén, Patagonia Argentina. METHODS: We evaluated the clinical and epidemiological characteristics of 5 patients involved in the outbreak. Environmental studies were conducted to determine the source of infection. The genetic profile of Histoplasma capsulatum strains isolated from the index case (IC) were compared with clinical isolates from Argentinean patients not related to the outbreak, using RAPD-PCR with primers 1281-1283. RESULTS: The patients were residents of Zapala, and had not visited other geographical areas before. All patients had an influenza-like syndrome, and X-ray revealed disseminated micronodular images throughout the lung parenchyma. The IC needed specific antifungal therapy; the remaining 4 patients had mild symptoms, and did not require therapy. All of them had a good clinical outcome. Strains of H. capsulatum isolated from blood culture and lung biopsy of the IC showed a genetic profile different from other strains analyzed. The presence of the fungus in the environment was demonstrated by the detection of anti-Histoplasma antibodies in BALB/c mice inoculated with soil obtained in a culvert where workers had dug up earth after a landslide. CONCLUSIONS: This outbreak suggests the histoplasmosis endemic area is under the 38° S parallel. Patients from Neuquén, Patagonia Argentina, with compatible symptoms of histoplasmosis should be tested, regardless of their travel or exposure history.

Determination of the therapeutic activity of caspofungin compared with the amphotericin B in an animal experimental model of histoplasmosis in hamster (Mesocrisetus auratus).

BACKGROUND: Treatment with amphotericin B is highly effective in histoplasmosis. Caspofungin has shown good activity against Candida and Aspergillus spp. In vitro studies have demonstrated that Histoplasma capsulatum is inhibited by caspofungin. OBJECTIVES: The purpose of this study was to evaluate the effectiveness of caspofungin in the treatment of histoplasmosis in an animal experimental model. METHODS: Three strains of Histoplasma capsulatum var. capsulatum were used. Treatment started one week post-inoculation and the animals were randomly assigned to six groups: amphotericin B 6mg/Kg/d, caspofungin 2mg/Kg/d, 4mg/Kg/d, 8mg/Kg/d and the other two groups received saline solution and dextrose solution. Blood samples for culture were obtained once a week, from day 7 to 35 post-inoculation. One week after the end of the treatment the animals were sacrificed and spleen cultures were performed. RESULTS: Blood cultures were negative in all the hamsters which received amphotericin B (100%, P<0.001); those treated with caspofungin and the control animals presented 30 and 32% of positive cultures respectively (P=0.59). Spleen cultures were negative in the animals treated with amphotericin B, while the percentage of positive spleen cultures in the caspofungin groups varied from 25 to 100%, and in the control groups from 35 to 94.8% (P=0.07). The statistical analysis of the undiluted cultures showed the use of amphotericin B as the only independent predictor of negative culture (P<0.001). CONCLUSIONS: The efficacy of amphotericin B is well known for the treatment of histoplasmosis, though we could not demonstrate that caspofungin is better than control.

[Fungal infections in a pediatric burn care]. / Infecciones fúngicas en una unidad de quemados pediátrica.

OBJECTIVE: Retrospective description of fungal infections in a specialized intensive care burn unit. RESULTS: A total of 41 (21%) of 195 patients admitted from January 2002 to March 2006 developed fungal infections at any site. The median age of patients was 48 months (interquartile range: 18-84), and the affected burn surface was 40% (interquartile range 30 and 65% The median time lapse between admission and fungal infections was 13 days (interquartile range 8-20 d) The most frequent site of isolation was burnt wound in 38 patients (93%) and in blood cultures in 3 patients (7%). In 93% of patients bacterial infections were also found. The predominant fungus recovered was Candida spp in 20 patients (49%); followed by Aspergillus sp in 6 patients (15%), Anphotericin B was the drug of choice. The median time of complete treatment was 23 days (interquartile range: 15-30). One patient died (2%) from causes related to fungal infection. CONCLUSION: A total of 41 (21%) of 195 patients admitted from January 2002 to March 2006 developed fungal infections. Candida sp was the most frequently found. Mortality was low.

Fungemia and interstitial lung compromise caused by Malassezia sympodialis in a pediatric patient / Fungemia con compromiso intersticial causada por Malassezia sympodialis en un paciente pediátrico

A case of fungemia with interstitial lung compromise caused by Malassezia sympodialis is reported in an obese pediatric patient on long-term treatment with inhaled corticosteroids for asthma. The patient was hospitalized due to a post-surgical complication of appendicitis. The patient was treated with amphotericin B for 3 weeks, with good clinical evolution and subsequent negative cultures (AU)

Presentamos un caso de fungemia con compromiso intersticial causado por Malassezia sympodialis en un paciente pediátrico obeso, asmático y con tratamiento prolongado con corticosteroides inhalados, que fue hospitalizado debido a una complicación posquirúrgica de una apendicectomía. El paciente fue tratado con anfotericina B durante 3 semanas con buena evolución clínica y negativización de los cultivos subsecuentes (AU)

Geographic variation in the frequency of isolation and fluconazole and voriconazole susceptibilities of Candida glabrata: an assessment from the ARTEMIS DISK Global Antifungal Surveillance Program.

Geographic differences in frequency and azole resistance among Candida glabrata may impact empiric antifungal therapy choice. We examined geographic variation in isolation and azole susceptibility of C. glabrata. We examined 23 305 clinical isolates of C. glabrata during ARTEMIS DISK global surveillance. Susceptibility testing to fluconazole and voriconazole was assessed by disk diffusion, and the results were grouped by geographic location: North America (NA) (2470 isolates), Latin America (LA) (2039), Europe (EU) (12 439), Africa and the Middle East (AME) (728), and Asia-Pacific (AP) (5629). Overall, C. glabrata accounted for 11.6% of 201 653 isolates of Candida and varied as a proportion of all Candida isolated from 7.4% in LA to 21.1% in NA. Decreased susceptibility (S) to fluconazole was observed in all geographic regions and ranged from 62.8% in AME to 76.7% in LA. Variation in fluconazole susceptibility was observed within each region: AP (range, 50-100% S), AME (48-86.9%), EU (44.8-88%), LA (43-92%), and NA (74.5-91.6%). Voriconazole was more active than fluconazole (range, 82.3-84.2% S) with similar regional variation. Among 22 sentinel sites participating in ARTEMIS from 2001 through 2007 (84 140 total isolates, 8163 C. glabrata), the frequency of C. glabrata isolation increased in 14 sites and the frequency of fluconazole resistance (R) increased in 11 sites over the 7-year period of study. The sites with the highest cumulative rates of fluconazole R were in Poland (22% R), the Czech Republic (27% R), Venezuela (27% R), and Greece (33% R). C. glabrata was most often isolated from blood, normally sterile body fluids and urine. There is substantial geographic and institutional variation in both frequency of isolation and azole resistance among C. glabrata. Prompt species identification and fluconazole susceptibility testing are necessary to optimize therapy for invasive candidiasis.

[Diminution of antifungal activity of fluconazole associated with ibuprofen and piroxicam in experimental histoplasmosis of hamsters (Mesocricetus auratus)] / Disminución de la actividad antifúngica del fluconazol asociada a ibuprofeno y piroxicam en la histoplasmosis experimental del hámster (Mesocricetus auratus).

The aim of this study was to determine if tha association of non-steroid antiinflammatory drugs (piroxicam and ibuprofen) with fluconazole, affects the antifungal activity of the azole compound, in an experimental model histoplasmosis in hamsters (Mesocricetus auratus). Sixty hamsters were intracardially inoculated with 4x10(6) yeasts of Histoplasma capsulatum var. capsulatum. Treatments began one week after the challenge and continued for three weeks. The hamsters were divided in six groups of ten animals each and received the following treatment: 1- fluconazole 8 mg/kg/day; 2- ibuprofen 20 mg/kg/day; 3- piroxicam 20 mg/kg/day; 4- fluconazole+ibuprofen; 5- fluconazole+piroxicam and 6- only received the solvent of these drugs. One week after ending the treatment, all the animals were sacrified and the evaluation of the treatments was based on the results of blood cultures, on the determination of colony forming units per gram of spleen, and the histopathologic studies of the same organ. The animals treated with fluconazole plus ibuprofen or piroxicam showed more colony colony forming units per gram (3.9x10(7) and 3.3x10(7)) when compared with the animals treated with fluconazole alone (0.9x10(7)). The histopathologic results of the hamsters that received fluconazole showed well-organized granulomas with few yeast-like elements inside the macrophages. In contrast, those which received fluconazole associated with antiinflammatory drugs presented lax granulomas containing numerous yeast-like elements. These findings let us to conclude that non-steroids antiinflammatory drugs diminish the antifungal efficacy of fluconazole in this animal model.

Brote de histoplasmosis en la provincia de Neuquén, Patagonia Argentina / Outbreak of histoplasmosis in province of Neuquén, Patagonia Argentina

Antecedentes. La República Argentina no registra casos autóctonos de histoplasmosis en regiones australes del país. Objetivo. Informar de un brote de histoplasmosis ocurrido en Zapala, Provincia de Neuquén, Patagonia Argentina. Métodos. Se evaluó el cuadro clínico y las características epidemiológicas de 5 pacientes involucrados en el brote. Se realizaron estudios ambientales para conocer la fuente de infección. Se analizó el perfil genético generado por RAPD-PCR con los primers 1281-1283 de los aislamientos de Histoplasma capsulatum del caso índice ( CI ) y se comparó con cepas de origen clínico no relacionadas con el brote. Resultados. Los pacientes residían en Zapala y no habían visitado otras áreas geográficas. Todos presentaron un síndrome gripal con imágenes radiológicas micronodulillares diseminadas. El CI necesitó tratamiento específico por la gravedad de su cuadro clínico, y los 4 pacientes restantes presentaron una sintomatología leve y no fueron tratados. La evolución clínica de todos fue favorable. Las cepas de H. capsulatum aisladas de hemocultivo y biopsia pulmonar del CI presentaron un perfil genético diferente al resto de las cepas analizadas. La presencia del hongo en el ambiente pudo inferirse mediante la detección de anticuerpos anti-Histoplasma en suero de ratones BALB/c inoculados con tierra de una alcantarilla que los trabajadores removieron después de un aluvión. Conclusiones. Este brote extiende el área endémica de histoplasmosis por debajo del paralelo 38° de latitud sur. El diagnóstico de histoplasmosis debe considerarse en pacientes de Neuquén, con síntomas compatibles con esta micosis, aun sin existir antecedentes epidemiológicos de viajes a áreas endémicas (AU)

Background: In Argentina, there are no reports of autochthonous cases of histoplasmosis in the southern regions of the country. Aim: To report a histoplasmosis outbreak in Zapala town, Province of Neuquén, Patagonia Argentina. Methods: We evaluated the clinical and epidemiological characteristics of 5 patients involved in the outbreak. Environmental studies were conducted to determine the source of infection. The genetic profile of Histoplasma capsulatum strains isolated from the index case (IC) were compared with clinical isolates from Argentinean patients not related to the outbreak, using RAPD-PCR with primers 1281-1283. Results: The patients were residents of Zapala, and had not visited other geographical areas before. All patients had an influenza-like syndrome, and X-ray revealed disseminated micronodular images throughout the lung parenchyma. The IC needed specific antifungal therapy; the remaining 4 patients had mild symptoms, and did not require therapy. All of them had a good clinical outcome. Strains of H. capsulatum isolated from blood culture and lung biopsy of the IC showed a genetic profile different from other strains analyzed. The presence of the fungus in the environment was demonstrated by the detection of anti- Histoplasma antibodies in BALB/c mice inoculated with soil obtained in a culvert where workers had dug up earth after a landslide. Conclusions: This outbreak suggests the histoplasmosis endemic area is under the 38◦ S parallel. Patients from Neuquén, Patagonia Argentina, with compatible symptoms of histoplasmosis should be tested, regardless of their travel or exposure history (AU)

Evaluación de la actividad de caspofungina comparada con anfotericina B en un modelo experimental de histoplasmosis en hámsters (Mesocrisetus auratus) / Determination of the therapeutic activity of caspofungin compared with the amphotericin B in an animal experimental model of histoplasmosis in hamster (Mesocrisetus auratus)

Antecedentes. La anfotericina B es un fármaco efectivo para el tratamiento de la histoplasmosis. La caspofungina es activa contra especies de Candida y Aspergillus. Estudios in vitro han demostrado el efecto inhibitorio de este fármaco en Histoplasma capsulatum. Objetivo. Evaluar la eficacia de la caspofungina comparada con la anfotericina B para el tratamiento de histoplasmosis en un modelo experimental en hámster. Métodos. Se utilizaron tres cepas de Histoplasma capsulatum var. capsulatum. El tratamiento comenzó una semana tras la inoculación y los animales fueron distribuidos aleatoriamente en 6 grupos, según los fármacos utilizados: anfotericina B 6mg/kg/día, caspofungina en dosis de 2, 4 y 8mg/kg/día, solución fisiológica y dextrosa al 5%. Se tomaron muestras semanales para hemocultivos a partir del séptimo día postinfección y a los 7 días de finalizado el tratamiento los animales fueron sacrificados, realizándose cultivos del bazo. Resultados. Los resultados obtenidos de los hemocultivos realizados al finalizar el tratamiento fueron negativos en un 100% en el grupo tratado con anfotericina B, frente al 30% en el grupo tratado con caspofungina y el 32% en el grupo control (p=0,59). Los cultivos de bazo fueron negativos en el grupo de anfotericina B, mientras que en el grupo de caspofungina los valores fluctuaron entre el 25 y el 100%, y en el grupo control entre el 35 y el 94,8% (p=0,07). En el análisis estadístico del cultivo de la suspensión de bazo sin diluir el uso de anfotericina B fue el único predictor independiente de cultivos negativos (p=0,001). Conclusiones. La anfotericina B es un fármaco efectivo para el tratamiento de la histoplasmosis. La administración de caspofungina no demostró mayor eficacia en comparación con el grupo control(AU)

Background. Treatment with amphotericin B is highly effective in histoplasmosis. Caspofungin has shown good activity against Candida and Aspergillus spp. In vitro studies have demonstrated that Histoplasma capsulatum is inhibited by caspofungin. Objectives. The purpose of this study was to evaluate the effectiveness of caspofungin in the treatment of histoplasmosis in an animal experimental model. Methods. Three strains of Histoplasma capsulatum var. capsulatum were used. Treatment started one week post-inoculation and the animals were randomly assigned to six groups: amphotericin B 6mg/Kg/d, caspofungin 2mg/Kg/d, 4mg/Kg/d, 8mg/Kg/d and the other two groups received saline solution and dextrose solution. Blood samples for culture were obtained once a week, from day 7 to 35 post-inoculation. One week after the end of the treatment the animals were sacrificed and spleen cultures were performed. Results. Blood cultures were negative in all the hamsters which received amphotericin B (100%, P<0.001); those treated with caspofungin and the control animals presented 30 and 32% of positive cultures respectively (P=0.59). Spleen cultures were negative in the animals treated with amphotericin B, while the percentage of positive spleen cultures in the caspofungin groups varied from 25 to 100%, and in the control groups from 35 to 94.8% (P=0.07). The statistical analysis of the undiluted cultures showed the use of amphotericin B as the only independent predictor of negative culture (P<0.001). Conclusions. The efficacy of amphotericin B is well known for the treatment of histoplasmosis, though we could not demonstrate that caspofungin is better than control(AU)

Subgingival distribution of yeast and their antifungal susceptibility in immunocompetent subjects with and without dental devices

Las levaduras del genero Candida colonizan el biofilm subgingival.Su hallazgo constituye un reservorio favorable para su multiplicación. El propósito de éste trabajo fue investigar la presencia de levaduras del género Candida en el biofilm subgingivalde individuos con enfermedad gingivoperiodontal a fin de establecer la prevalencia de especies y los perfiles desusceptibilidad a fluconazol y voriconazol de las mismas. Se obtuvieron muestras del biofilm subgingival en cien pacientes inmunocompetentes, no fumadores, con salud gingivoperiodontal, gingivitis y periodontitis, con y sin aparatologíabucal. Las muestras se sembraron en medio cromogénico diferencial y las levaduras aisladas se identificaronmediante micromorfología y pruebas bioquímicas. Los estudios de sensibilidad a fluconazol y voriconazol se realizaron según las normas CLSI M44-A. La prevalencia de levadurasen el biofilm subgingival fue del 40 por ciento IC95 por ciento (30.5-50.3) siendo el 10 por ciento y 30 por ciento la frecuencia de las mismas para los pacientes sin y con aparatología bucal respectivamente.C. albicans fue la levadura más frecuente. Encontramos otras especies como C. parapsilosis, C. dubliniensis, C. tropicalis, C. guilliermondii y C. sake. Solo se observó resistencia a los azoles en C. dubliniensis y C. guilliermondii. El tratamiento con aparatología bucal incrementó la prevalencia de levadurasen bolsa periodontal en forma significativa. Es importante destacar la presencia en el fluido subgingival de especies de Candida no albicans consideradas emergentes y con sensibilidad disminuida a los antifúngicos como C. dubliniensisy C. guilliermondii (AU)

Yeasts colonize the subgingival biofilm, which becomes a reservoir that favors their reproduction. The purpose of the present work was to determine the prevalence of yeasts of the Candida genus in the subgingival biofilm of gingivoperiodontal disease patients, including users and non-users of dental devices, and their susceptibility to fluconazole and voriconazole. Samples of subgingival pockets of immunocompetent nonsmokers showing gingivitis and periodontitis were inoculated in a differential chromogenic medium. Sixty three percent of subjects used dental devices. Yeasts were identified and susceptibility to fluconazole and voriconazole was tested following CLSI M44-A standards. The prevalence of yeasts in the subgingival biofilm was 40% CI 95% (30.5-50.3); 10% were patients who did not use dental appliances. The most frequently observed yeasts were C. albicans, and C. parapsilosis, C. dubliniensis, C. tropicalis and C. guilliermondii. Only C. dubliniensis and C. guilliermondii showed resistance to azoles. The use of dental devices significantly increased the prevalence of yeasts in periodontal pockets inpatients presenting gingivitis. It is noteworthy that non albicans Candida species, such as C. dubliniensis and C. guilliermondii, considered emerging species, which have a diminished susceptibility to antifungal agents were found in the crevicular fluid of immunocompetent patients.(AU)