Transmission study of Andes hantavirus infection in wild sigmodontine rodents

Our study was designed to contribute to an understanding of the timing and conditions under which transmission of Andes hantavirus in Oligoryzomys longicaudatus reservoir populations takes place. Mice were caged in test habitats consisting of steel drums containing holding cages, where seronegative rodents were exposed to wild seropositive individuals by freely sharing the same cage or being separated by a wire mesh. Tests were also performed for potential viral transmission to mice from excrement-tainted bedding in the cages. Andes virus transmitted efficiently; from 130 attempts with direct contact, 12.3% resulted in virus transmission. However, if we consider only those rodents that proved to be infectious, from 93 attempts we obtained 16 infected animals (17.2%). Twelve of them resulted from intraspecies O. longicaudatus encounters where male mice were differentially affected and 4 resulted from O. longicaudatus to Abrothrix olivaceus. Experiments using Abrothrix longipilis as receptors were not successful. Transmission was not observed between wire mesh-separated animals, and mice were not infected from excrement-tainted bedding. Bites seemed not to be a requisite for oral transmission. Genomic viral RNA was amplified in two out of three saliva samples from seropositive rodents, but it was not detected in urine samples obtained by vesicle puncture from two other infected rodents. Immunohistochemistry, using antibodies against Andes (AND) hantavirus proteins, revealed strong reactions in the lung and salivary glands, supporting the possibility of oral transmission. Our study suggests that AND hantavirus may be principally transmitted via saliva or saliva aerosols rather than via feces and urine.

Onychomycosis caused by Fusarium solani and Fusarium oxysporum in São Paulo, Brazil

Fusarium species are common soil saprophytes and plant pathogens that have been frequently reported as etiologic agents of opportunistic infections in humans. We report eight cases of onychomycosis caused by Fusarium solani (4) and Fusarium oxysporum (4) in São Paulo, Brazil. These species were isolated from toenails in all cases. The infections were initially considered to be caused by dermatophytes. The clinical appearance of the affected toenails was leukonychia or distal subungual hyperkeratosis with yellowish brown coloration. The eight cases reported here suggest that Fusarium spp. should be taken into consideration in the differential diagnosis of tinea unguium.

Dermatomycoses caused by Nattrassia mangiferae in São Paulo, Brazil

Nattrassia mangiferae formerly known as Hendersonula toruloidea, is a phaeoid coelomycete described by Nattrass in 1933. We report five cases of N. mangiferae infections in São Paulo, Brazil. This fungus was isolated from interdigital lesions on the feet in one patient, toenails in three cases and fingernails in the other one. The infections were initially considered to be caused by a dermatophyte. Although there are only a few cases described in the medical literature, the five cases reported suggest that N. mangiferae should be taken into consideration in the differential diagnosis of tinea pedis infections.

Phaeoisaria clematidis as a cause of keratomycosis

We report the first case of human infection by Phaeoisaria clematidis. This fungus caused a corneal ulcer in a Brazilian man who had previously suffered an eye injury. Diagnosis was established by positive direct examination and repeated cultures. The isolate was clearly resistant in vitro to the six antifungal agents tested.

Subcutaneous hyalohyphomycosis caused by Colletotrichum gloeosporioides

The coelomycete Colletotrichum gloeosporioides was isolated in pure culture from subcutaneous nodules of the left forearm and elbow of a farmer after traumatic injury. To our knowledge, we report the first case involving this fungus as an etiological agent of subcutaneous infection. The in vitro inhibitory activities of amphotericin B, itraconazole, ketoconazole, miconazole, flucytosine, and fluconazole were studied.

[Antibiotic effect of wild Streptomyces strains isolated from Chilean soils]

BACKGROUND

The soils of the southern part of Chile, that are isolated, cold, humid, poorly oxygenated and with a low acidity, could contain new strains of antimicrobial producing Streptomyces.

AIM

To demonstrate that the soil of the Southern region of Chile contains Streptomyces strains with antimicrobial activity towards pathogenic bacteria and fungi.

MATERIAL AND METHODS

Two hundred fifty eight soil and sediment samples were collected from 148 places in Southern regions of Chile. They were cultured in Küster-Williams growth media and the presence of Streptomyces was confirmed by microscopic examination and biochemical characterization. The antimicrobial activity against reference microorganisms of each wild strain was tested using the disk method. Among active Streptomyces strains, 38 with the higher activity were selected and tested against 142 clinical microorganisms.

RESULTS

Seventy seven percent of soils were positive and 542 wild strains of Streptomyces were isolated; of these, 266 had antimicrobial activity. Fifty three percent of isolates had activity against S aureus 43% against B subtilis and 0.7% against E coli. Most Streptomyces were active against more than one organism. When there was activity against single organisms, these were mostly eucariotic, such as C albicans and T mentagrophytes. Among clinical microorganisms, 29% of S aureus strains were inhibited, while P aeruginosa, Alternaria sp, P vulgaris and Y enterocolitica strains were not inhibited. The most frequent Streptomyces morphotypes were those showing pigmented colonies with flexuous and spiral shaped chains of arthrospores.

CONCLUSIONS

Soils of the Southern region of Chile allow the growth of abundant native strains of Streptomyces with a promising antimicrobial activity.

[Mycetomas caused by Microsporum canis. Report of one case]

We report an eight years old boy presenting with a pyogenic granuloma of the scalp, generalized alopecia, descamative plates in the neck, trunk and limbs and nail involvement. Cultures for fungus of all these lesions disclosed Microspore canis. The patient was treated with oral griseofulvin, miconazole and topical tolnaftate. Five years later and after several incomplete treatments, the patient returns with a fistulous mass of 15 x 8 cm in the dorsal area whose culture revealed Microspore canis. The mass was excised and oral ketoconazole was indicated. After three months of follow up, the patient was lost from control.

Ultrastructural aspects of hair digestion in black piedra infection

The ultrastructural pattern of human hair infection by Piedraia hortae in vivo has been studied. The fungus destroyed the cuticular layers of the hair and was able to penetrate deeply into the cortex. The course of destruction of human hair is described and compared with that produced by other fungi. Two well-defined types of cortex digestion were characterized. The slow rate of keratin degradation at the cortex together with the compacted stromatic organization of the nodules are argued as the main reasons that guarantee the long survival of the fungus, and therefore the chronic course of the disease. The data provided in this paper may help to understand the mechanisms that regulate the pathogenicity of this fungus.

Isolation of Malassezia furfur from patients with onychomycosis

Malassezia furfur (Pityrosporum ovale IP. orbiculare) was found microscopically and by culture in the nails in 14 of 370 patients seen for treatment of onychomycosis in São Paulo, Brazil. The clinical features, predisposing factors and laboratory diagnosis are discussed.

[White piedra. Report of a case]

The most common superficial mycosis caused by Trichosporon beigelii is white piedra. We report a 18 years old male that had in several hairs of the scalp, white-yellowish nodules of 1 mm diameter, agglutinated or forming chains, even forming threads, with a greasy aspect. Trichosporon beigelii was identified in cultures. Oral and topical antimycotics were prescribed and the patient was lost from follow up.

[The differentiation of Candida albicans strains by the killer system]

The authors studied the killer effect of nine standard strains of yeasts on 146 samples of Candida albicans isolated from the following clinical specimens: oral mucosa, feces, bronchial wash, sputum, vaginal secretion, urine, skin lesion, nail lesion and blood. Using this system it was possible to differentiate 23 biotypes of Candida albicans. The biotypes 211, 111 and 811 were most frequently isolated. Most of the samples of C. albicans (98.6%) were sensitive to at least one or more of the nine killer strains. Using the killer system it was possible to show that two patients harbored the same killer biotypes, 111 and 211, respectively, in different clinical specimens and another patient harbored the same biotype (211) in bloodcultures effected in different ocasions. The utilization of the killer system to differentiate types among species of pathogenic yeasts can be a useful method to establish the eventual source of infection, and it is a valuable tool to control and watch for nosocomial infections caused by yeasts.

[Kerion Celsi. A diagnostic problem? Experience with 6 cases]

We report six patients with Kerion Celsi due to Trichophyton verrucosum. Five of the patients were hospitalized with the diagnosis of Staphylococcal abscess. This confusion is due to that highly suppurative and inflammatory nature of the infection. Griseofulvin is the antimicrobial of choice for treatment, associated with imidazolics and corticosteroids to prevent alopecia. The authors suggest that an adequate use of simple microbiological diagnostic tests in the diagnosis of pyodermitis in rural children, may prevent unnecessary hospitalizations and permanent hair loss.

Agarose gel immunodiffusion tests with the addition of PEG (polyethylene glycol 6000) for the diagnosis and serological follow up of paracoccidioidomycosis infection

By using PEG (polyethylen glycol 6000) in the gel immunodiffusion tests (ID), the precipitin lines were increased in 25.5% of the 192 sera reactions and the titers were increased from one to four serial dilutions in 44.6% of the 139 serum samples. Owing to its sensitivity, easy interpretation of the results and low cost, the use of 2% PEG incorporated into the gel in ID tests is recommended for the diagnosis and serological follow-up of paracoccidioidomycosis infections.

[NO TITLE AVAILABLE]

Antígeno del polisacárido capsular (Ag PC) de Cryptococcus neoformans fue detectado por la técnica de aglutinación de latex (AL) en LCR y suero de pacientes con Sindrome de Inmunodeficiencia Adquirida (SIDA) y primer episodio de neurocriptococosis, usando como patrón el examen micológico (examen directo y cultivo) de LCR. Se obtuvo una sensibilidad del 100% de AL para detectar AgPC de C. neoformans, el cual por su rápidez permite tratamiento específico precoz. Títulos iniciales de AgPC de la levadura en esos pacientes pueden ser > 1.000.000, pareciendo que cuando esos títulos están presentes en suero, se relacionan con mortalidad durante el tratamiento. En los pacientes que sobrevivieron se observó que el examen micológico directo y AgPC de C. neoformans, en LCR y suero, permanecen positivos aún después de tratamiento y mejoría clínica del paciente.

[Detection of capsular polysaccharide antigen of Cryptococcus neoformans in patients with AIDS and neurocryptococcosis in São Paulo, Brazil]

Capsular polysaccharide antigen (AgPC) of Cryptococcus neoformans was detected by latex agglutination technique (LA) in cerebrospinal fluid and serum of patients with AIDS during their first central nervous system manifestation of the disease. Direct mycological examination and culture were used as controls. Sensitivity was 100% by LA allowing an early specific treatment of cryptococcosis. Initial titres of AgPC in such patients can be > 1000000 and it appears that when such titres are present in the serum they are related to mortality during treatment. Surviving patients showed positivity of the direct mycological examination and AgPC of C. neoformans in cerebrospinal fluid and sera even after treatment and clinical recovery.

Otomycosis in São Paulo

In view of the lack of researches on otomycosis in Brazil, we have tried to study their incidence, their clinical characteristics and the predispondent factors. During one year, 22 suspected cases were seen, 20 of them corresponded to otomycosis infections. The most frequent species were Aspergillus niger (35%) and Candida albicans (20%). The genus Aspergillus represented 75% of the isolates. Itching and hyperaemia (70%), otalgia (65%), hipoacusia (50%) were the commonest signs. Lack of cerumen (70%) chronic otitis (30%) previous antibiotic therapy and eczema (25%) were the most outstanding predispondent factors.

Dermatophytes in healthy Chilians

To study the presence of dermatophytes in healthy persons, 1060 skin samples from the scalp, complexion, inguinal region and sole were taken from 265 healthy individuals who live in Valdivia, Chile. The carpet technique of Mariat and Tapia was used. The isolated dermatophytes were identified according to Rebell and Taplin. Zoophilic dermatophytes were isolated in only 4.9% of the healthy individuals. Microsporum canis was found in the scalp and inguinal area of children (1.5%). Trichophyton mentagrophytes was isolated from the feet and inguinal skin of adults (3.4%). Measures to avoid a mycosis or/and to reduce the risk of infections are suggested.

[Tinea caused by Microsporum canis in children under 30 days of age]

Six cases of ringworm due to Microsporum canis are reported in infants no more than 30 days old. The infections came from cats. The patients responded to therapy with griseofulvin and tolnaftate, miconazole or iodine.

[Immunodiffusion tests in gel media with the addition of polyethyleneglycol 6000 for the serodiagnosis of mycoses]

Different immunodiffusion techniques with and without the addition of polyetilenglycol 6000 (PEG), were studied to determine its effect on the sensitivity of these reactions. One hundred thirteen sera from patients who suffered or had suffered deep mycoses (paracoccidioidomycosis: 49, histoplasmosis: 25, aspergillosis: 25, candidiasis: 8 and coccidioidomycosis: 6) were examined by the quantitative Ouchterlony's immunodiffusion procedure. Regular medium and media with 2% and 4% PEG were used. Eighty two out of the one hundred thirteen sera were positive for the regular medium and 91 for the medium containing 2% of PEG; furthermore, an increase of 1 or 2 two fold dilutions in the titers was observed in 40% of the sera, for the later media. Twenty one sera from aspergillosis cases were examined by agarose gel immunoelectrophoresis, 80% had more precipitin bands in the medium with 2% of PEG. Thirty four serum samples of patients suffering aspergillosis, paracoccidioidomycosis and histoplasmosis were studied using the agarose electroosmophoresis with the secondary immunodiffusion test. An increase in the number of the anodic bands were observed in 55% while 64% presented more catodic bands, when the PEG medium was used. This results would indicate that the addition of 2% PEG 6000 to the regular medium improves the sensitivity of the immunodiffusion tests for mycoses.