1.A Case of Pneumonia Caused by Pneumocystis jirovecii Resistant to Trimethoprim/Sulfamethoxazole in the Absence of Previous Drug Exposure.
Ari AHN ; Jeonghyun CHANG ; Heungsup SUNG ; Mi Na KIM
Laboratory Medicine Online 2016;6(4):250-254
Pneumocystis jirovecii pneumonia is a common opportunistic infection seen in patients with human immunodeficiency virus (HIV) infection. Dihydropteroate synthase (DHPS) is a target of sulfa drugs, and mutations in DHPS gene are associated with failure in treatment and prophylaxis of P. jirovecii infections in HIV-infected patients. Here, we report a case of a patient with P. jirovecii infection, harboring DHPS gene mutations, who had not been previously treated with trimethoprim/sulfamethoxazole (TMP/SMX). A 50-yr-old man was admitted to the hospital with symptoms such as fever, cough, sputum, and sore throat. Chest computed tomography scanning revealed diffuse ground glass opacity in both the lungs, and the patient was diagnosed as having HIV infection with a CD4+ T cell count of 22/µL. Immunohistochemical test results were positive for P. jirovecii. He was treated with TMP/SMX; however, his symptoms and laboratory findings did not improve. The treatment was changed to clindamycin and primaquine, and his symptoms improved after 3 days. Molecular testing of the sample for the detection of DHPS gene mutations and the typing of mitochondrial large subunit rRNA (mtlsurRNA) revealed DHPS gene mutations at codon 55 and 57, respectively, and the case had type 3 mtlsurRNA. This case study illustrates that DHPS mutation test results can be positive even in patients without previous exposure to TMP/SMX.
Cell Count
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Clindamycin
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Codon
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Cough
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Dihydropteroate Synthase
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Fever
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Glass
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HIV
;
HIV Infections
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Humans
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Lung
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Opportunistic Infections
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Pharyngitis
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Pneumocystis jirovecii*
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Pneumocystis*
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Pneumonia*
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Primaquine
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Sputum
;
Thorax
2.Genetic Polymorphisms in Plasmodium vivax Dihydrofolate Reductase and Dihydropteroate Synthase in Isolates from the Philippines, Bangladesh, and Nepal.
Pimwan THONGDEE ; Jiraporn KUESAP ; Kanchana RUNGSIHIRUNRAT ; Shyam Prakash DUMRE ; Effie ESPINO ; Harald NOEDL ; Kesara NA-BANGCHANG
The Korean Journal of Parasitology 2015;53(2):227-232
Genetic polymorphisms of pvdhfr and pvdhps genes of Plasmodium vivax were investigated in 83 blood samples collected from patients in the Philippines, Bangladesh, and Nepal. The SNP-haplotypes of the pvdhfr gene at the amino acid positions 13, 33, 57, 58, 61, 117, and 173, and that of the pvdhps gene at the positions 383 and 553 were analyzed by nested PCR-RFLP. Results suggest diverse polymorphic patterns of pvdhfr alone as well as the combination patterns with pvdhps mutant alleles in P. vivax isolates collected from the 3 endemic countries in Asia. All samples carried mutant combination alleles of pvdhfr and pvdhps. The most prevalent combination alleles found in samples from the Philippines and Bangladesh were triple mutant pvdhfr combined with single mutant pvdhps allele and triple mutant pvdhfr combined with double wild-type pvdhps alleles, respectively. Those collected from Nepal were quadruple mutant pvdhfr combined with double wild-type pvdhps alleles. New alternative antifolate drugs which are effective against sulfadoxine-pyrimethamine (SP)-resistant P. vivax are required.
Amino Acid Sequence
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Bangladesh
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Base Sequence
;
Dihydropteroate Synthase/*genetics
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Humans
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Malaria, Vivax/*parasitology
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Molecular Sequence Data
;
Nepal
;
Philippines
;
Plasmodium vivax/*enzymology/*genetics/isolation & purification
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*Polymorphism, Genetic
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Tetrahydrofolate Dehydrogenase/*genetics