Case report. Fungaemia due to Penicillium piceum, a member of the Penicillium marneffei complex.

Due to the inability of most Penicillium species to grow at 37 degrees C, systemic non-marneffei infections are very rare in the human host. We describe a case of fungemia due to Penicillium piceum in a female patient, who died a few days after repeated isolation of this fungus from blood cultures. The species is a member of the section Biverticillata of Penicillium, as was confirmed by rDNA Internal Transcribed Spacer (ITS) sequence data, and hence may share virulence factors with P. marneffei.

Geographic grouping of Cryptococcus neoformans var. gattii by random amplified polymorphic DNA fingerprint patterns and ITS sequence divergence.

Eleven reference strains of Cryptococcus neoformans var. gattii were analyzed by random amplified polymorphic DNA (RAPD) patterns using three oligo primers. Three major RAPD pattern profiles (profiles I, II and III) were identified with A-1 oligo primer. Each profile was found to relate to a geographic region. Since the strains which belong to profiles I and II were mainly the isolates from America, and profile III from Asia with A-1 primer, these three profiles were assigned to the geographic grouping of America-1, America-2 and Asia, respectively. Analysis of rDNA sequences coding an internal transcribed spacer (ITS) region of C. neformans var. gattii revealed that the fungus with each RAPD profile has characteristic base sequences at the four positions (10 and 15 positions in ITS1 and 8 and 56 positions at ITS2) of the ITS regions. On the basis of the combinations of the four bases specific for the ITS regions, four ITS types, AAGG (America-1), AAAC (America-2), GGGC (Asia-1) and AGGC (Asia-2) were identified: the geographic group of Asia was further classified into two subgroups of Asia-1 and Asia-2 based on the ITS typing. Clinical isolates from Thailand (6 strains) and Brazil (7 strains) were found to belong to the geographic group of America-1 nd America-2, respectively. Five reference strains of C. neoformans var. gattii from the CBS culture collection were classified into two America-2, one Asia-1 and two Asia-2 groups. This ITS region analysis allowed us to distinguish all isolates of C. neoformans var. gattii into four geographic groups based on the ITS base sequence, and further molecular epidemiological and ecological research on this fungus is recommended.

Genetic analysis of Histoplasma capsulatum strains isolated from clinical specimens in thailand by a PCR-based random amplified polymorphic DNA method.

Thirteen strains of Histoplasma capsulatum were isolated from clinical specimens, including those from AIDS patients, in Thailand. Random amplified polymorphic DNA (RAPD) analysis with three different PCR primers showed that the DNA fingerprint patterns of the Thai isolates were very similar to each other and homogeneous, with only one exceptional strain, although the patterns were clearly different from those of a reference North American strain with all primers tested. Although the difference in the DNA fingerprinting patterns was minor, Thai isolates could be classified into two to four groups. A common PCR band (about 700 bp) in the patterns of all H. capsulatum strains was extracted, and its DNA sequence was determined. A new PCR primer set for the identification of H. capsulatum species was developed based on this sequence information. This primer set was 100% successful in the identification of the reference strain as well as all Thai isolates. The results of specificity tests of the primer set for the identification of the fungus are also discussed.

Serotyping of Cryptococcus neoformans strains isolated from clinical specimens in Thailand and their susceptibility to various antifungal agents.

One hundred and thirty-nine strains of Cryptococcus neoformans were isolated in Thailand from clinical specimens including 97 AIDS patients: 67 from Northern, 48 from Central, 17 from Northeastern and 7 from Southern regional hospitals. Six out of the 139 strains were serotype B and the remaining 133 were A. There was no correlation between serotypes and regional distribution. To our knowledge, this is the first report of serotyping studies on C. neoformans in Thailand. Studies on random amplified polymorphic DNA (RAPD) analysis showed that this method is useful for the differentiation of C. neoformans var. gattii (serotypes B and C) and C. neoformans var. neoformans (serotypes A and D). They also indicated that Thai isolates of C. neoformans var. gattii (serotype B) were a homogeneous group on the basis of their genotypes. Antifungal susceptibility tests using 5 antifungal agents including amphotericin B, fluconazole, flucytosine, itraconazole and micronazole against 50 selected strains of C. neoformans showed that they were sensitive to all of the antifungal agents tested except for one strain that was resistant to flucytosine.

In vitro antifungal activity of the new triazole D0870 against Penicillium marneffei compared with that of amphotericin B, fluconazole, itraconazole, miconazole and flucytosine.

The in vitro activity of D0870, a new triazole, was compared with that of fluconazole, itraconazole, miconazole, amphotericin B and flucytosine against recent clinical isolates of Penicillium marneffei in Thailand. The minimum inhibitory concentrations (MIC) values were determined by a microbroth dilution method using morpholinopropanesulphonic acid (MOPS)-buffered RPMI-1640 and brain heart infusion (BHI) medium. Yeast nitrogen base (YNB) medium with glucose was also used for the assay of flucytosine. D0870 was less active against P. marneffei than itraconazole, but its activity was similar to that of miconazole, superior to that of amphotericin B and markedly superior to that of fluconazole and flucytosine. Much lower MIC values of D0870 were observed with BHI medium.

Pathogenic Nocardia isolated from clinical specimens including those of AIDS patients in Thailand.

Forty strains of nocardioform microorganisms were isolated as clinical specimens including several from AIDS patients in Thailand. Among them, 37 strains were found to belong to the genus Nocardia. Our identification studies revealed that most of the strains (25 strains) belong to the N. asteroides group, i.e., N. asteroides sensu stricto and N. farcinica. Three strains were identified as N. otitidiscaviarum and two strains N. brasiliensis. In addition, 7 strains of rare pathogenic N. transvalensis were also isolated.

PIP: Nocardia is an aerobic gram-positive and partly acid-fast bacterium that belongs to the pathogenic actinomycetes. Nocardia can cause both systemic and cutaneous diseases. Cutaneous nocardiosis is thought to be induced by various predisposing factors, the most common of which include corticosteroid therapy, immunosuppressive therapy, and hematological malignancy. In recent years cases of infection have been increasing coupled with the increased use of immunosuppressive agents and the number of AIDS patients. Characterization studies of pathogenic Nocardia isolated clinically in Thailand from 1990 to 1994 were reported. 40 strains of nocardioform microorganisms (Nocardia like actinomycetes with meso-DAP, arabinose, galactose, and mycolic acid) were isolated as clinical specimens including several from AIDS patients. All 40 strains were isolated from clinical specimens at seven hospitals in Bangkok using Sabouraud dextrose agar medium or Ogawa medium. The analysis of mycolic acid profiles on thin-layer chromatography (TLC) plate showed that one strain had the same Rf values as that of Mycobacterium sp. and the remaining 39 strains had similar Rf values to those of Nocardia, Rhodococcus, and Gordona spp. Studies on their menaquinone composition showed that among 39 isolates, 37 strains had MK-8H4 (cycl.) as predominant menaquinone. 2 strains had MK-8(H2) as a predominant menaquinone and both were identified as Rhodococcus spp. 25 strains were found to belong to the N. asteroides group and were further divided into respective species, i.e., 12 strains of N. asteroides in a strict sense and 13 strains of N. farcinica on the basis of Na-citrate utilization, susceptibility to antimicrobial and antitumor agent (tobramycin and 5-fluorouracil), and ability to grow at 45 degrees Celsius. Three strains of N. otitidiscaviarum and two strains of N. brasiliensis were also identified and the remaining seven strains were eventually identified as N. transvalensis. Results of the drug susceptibility pattern test of Nocardia isolates correlated well with those obtained by the traditional identification system. Among 37 cases, there were 10 HIV seropositive and 2 seronegative patients, and the remaining cases were unknown. Further epidemiological studies may be needed to determine a possible association between AIDS and nocardiosis.