Levels of indoor allergens in public hospitals in Thailand.

Objective: To determine levels of indoor allergens in five public hospitals in Thailand. Methods: A total of 90 dust samples were collected from five public hospitals in Bangkok, Thailand, during March 2002 to October 2003. These hospitals provide both adult and pediatric care to over 500 patients daily. Each dust sample was collected at 12.00-13.00 pm during the years 2002-2003. The total amount of dust was weighed and one hundred milligram of fine dust from each sample was extracted. A commercialized two-site monoclonal antibody-based immunoassay (Indoor Biotechnologies, Ltd., Manchester, UK) was used to quantify the levels of Der p1, Der f1, Can f1 and Fel d1. Results: Fifty-one out of 90 dust samples were positive for indoor allergens. Four common groups of allergens were analyzed and detected; Der p 1 8/90 (8.89%), Der f 1 1/90 (1.11%), Fel d 1 39/90 (43.33%) and Can f 1 3/90 (3.33%)(of total samples). The arithmetic mean and standard deviation were 0.06 ug/g±0.26, 0.08 x 10-2 ug/g ± 0.001, 0.39 ug/g± 0.71 and 0.06 ug/g±0.30 for Der p 1, Der f 1, Fel d 1 and Can f 1, respectively (p =0.004). Fel d 1, the highest density allergen extracted from dust samples from hospital no. 5 and it showed a statistical difference compared with hospitals no.1,2,3,4 was observed; p < 0.05.* Conclusion: Our findings indicated that cat allergen can be found in a hospital setting where no cat is present.

Zymogram patterns of Naegleria spp isolated from natural water sources in Taling Chan district, Bangkok.

A genetic approach was cited for species detection of the ameba genus Naegleria using allozyme electrophoresis to characterize the trophozoite stage of three strains of Naegleria fowleri isolated from patients with primary amebic meningoencephalitis, five thermophilic (45 degrees C) Naegleria spp isolated from natural water sources in the Taling Chan district, and a reference control strain, Naegleria fowleri CDC VO 3081. Isoenzymes of ameba whole-cell extracts were analyzed by vertical polyacrylamide slab gel electrophoresis to determine whether there was any correlation between different strains of the ameba. The results showed that five out of fifteen enzymes; aldehyde oxidase (ALDOX), aldolase (ALD), a-glycerophosphate dehydrogenase (a-GPDH), xanthine dehydrogenase (XDH), and glutamate oxaloacetate transaminase (GOT), were undetectable in the pathogenic strains, while the other enzymes; esterase (EST), fumerase (FUM), glucose-6-phosphate dehydrogenase (G-6-PDH), glucose phosphate isomerase (GPI), isocitate dehydrogenase (IDH), lactate dehydrogenase (LDH), leucine aminopeptidase (LAP), malic enzyme (ME), glucose phosphomutase (GPM), and malate dehydrogenase (MDH), were detected. Naegleria fowleri strains were biochemically the most homogeneous. They showed intraspecific isoenzyme variation that allowed them to be grouped. In contrast, the allozyme patterns (EST 1-7, IDH) of Naegleria spp isolated from the environment showed interspecific isoenzyme variations from the pathogenic Naegleria strain. In conclusion, this study recognized the zymograms of the Naegleria fowleri strains were heterogenically different from the thermophilic 45 degrees C Naegleria spp isolated from the environment.

Effect of antifungal drugs on pathogenic Naegleria spp isolated from natural water sources.

Five of 16 strains of pathogenic Naegleria spp isolated from 350 natural water sources in Taling Chan District, Bangkok had similar molecular weights and zymogram patterns to those of Naegleria fowleri CDCVO 3081 and Thai strain. The in vitro effects of antifungal drugs (amphotericin B, ketoconazole, fluconazole and itraconazole) were tested at the following concentrations: amphotericin B 0.01-0.55 microg/ml, ketoconazole 0.01-0.3 microg/ml, fluconazole 0.75-3.5 mg/ml and itraconazole 4-12 mg/ml respectively. Aliquots (15,000 cells/ml) of the amoebae were placed in the cells of the microtiter plate and incubated at 37 degrees C. Amoebae from each treatment sample were exposed to one of the four antifungal drugs. Statistical analysis was done by dependent t-test. The sensitivity of the antifungal drugs (MIC50) was as follows: amphotericin B 0.03-0.035 microg/ml ketoconazole 0.05-0.15 microg/ml fluconazole 1.75 mg/ml and itraconazole 8-9 mg/ml respectively (p < 0.005). CONCLUSION: Amphotericin B and ketoconazole are more active against Naegleria fowleri in vitro. The results of the present study should be used as an in vitro screening test for drugs that have potential amebicidal activity.

In vitro effect of antifungal drugs on pathogenic Naegleria spp.

An ameba of the genus Naegleria causing fatal meningoencephalitis in human subjects was investigated for its sensitivity to antifungal drugs: amphotericin B, ketoconazole, fluconazole and itraconazole. The efficacy of these antifungal drugs for pathogenic Naegleria spp was investigated in three strains isolated from patients who had died of primary amebic meningoencephalitis infection at Siriraj Hospital (1986), Ramathibodi Hospital (1987) and Chachoengsao Hospital (1987). All of the isolates were maintained in axenic culture in the Department of Parasitology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Thailand. The sensitivities of the antifungal drugs (MIC50) were: amphotericin B (0.05-0.5 microg/ml), ketoconazole (0.125 microg/ml), fluconazole (0.5-2.0 mg/ml), and itraconazole (10 mg/ml) (p < 0.05). It is important to explain that ketoconazole is slightly more effective than amphotericin B because its action is directed of the permeability of the amebic membrane. The amebae were more resistant ot fluconazole and itraconazole due to the action of the cytochrome P450 multienzyme (in the case of fluconazole) and the direct effect on heme-iron, blocking cytochrome P450-dependent chitin synthesis (in the case of itraconzole). We conclude that amphotericin B and ketoconazole remain the main drugs with proven activity against pathogenic Naegleria spp.

Parasitic infection of in-patient at Siriraj Hospital from 1991 to 1995.

A retrospective study was carried out on 15,396 samples at the Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University from January 1991 to December 1995. A total of 2,812 were found to have had parasitic infestation. Ages ranging from eight months to ninety-seven years old were recorded. The laboratories investigations including a simple saline smear, the sedimentation technique and special stains. The results were divided into four groups e.g., pathogenic protozoa (45.62%), nematode (40.36%); cestode and trematode. (8.67%) and non-pathogenic protozoa (5.33%) respectively. Pathogenic protozoan group comprised intestinal protozoa, blood and tissue sporozoa which were Blastocystis hominis (35.16%), Giardia lamblia (8.12%), Entamoeba histolytica (1.13%), Cryptosporidium sp. (0.90%), Plasmodium spp. (0.76%), Pneumocystis carinii (0.41%), Dientamoeba fragelis (0.22%) and Isospora belli (0.08%). The non pathogenic intestinal protozoa were Trichomonas hominess (2.80%), Entomoeba coli (2.51%), Endolimex nana (0.12%) and Iodamoeba buetschlii (0.02%). The intestinal nematode were found in the following percentages e.g., hookworms (20.43%), Strongyloides stercoralis (16.80%), Trichuris trichiura (0.61%), Ascaris lumbricolides (0.48%), Enterobius vermicularis (0.63%), and Capillaria philippinensis (0.12%). Angiosrongylus cantonensis was also observed in one case. The group was intestinal trematodes and cestodes consisted of Opisthorchis viverrini (6.02%), Taenia spp. (2.17%), Fasiola spp. (0.36%), Hymenolepis nana (0.12%).