Isolation and characterization of mutations affecting expression of the Δ9- fatty acid desaturase gene, OLE1, in Saccharomyces cerevisiae

AbstractExpression of the Δ9- fatty acid desaturase gene, OLE1, of Saccharomyces cerevisiae is negatively regulated transcriptionally and post-transcriptionally by unsaturated fatty acids. In order to isolate mutants exhibiting irregulation of OLE1 expression, we constructed an OLE1p–PHO5 fusion gene as a reporter consisting of the PHO5 gene encoding repressible acid phosphatase (rAPase) under the control of the OLE1 promoter (OLE1p). By EMS mutagenesis, we isolated three classes of mutants, pfo1, pfo2 and pfo3 (positive regulatory factor for OLE1) mutants, which show decreased rAPase activity under derepression conditions (absence of oleic acid). Analysis of the transcription of OLE1 in these pfo mutants revealed that pfo1 and pfo3 mutants have a defect in the regulation of OLE1 expression at the transcriptional level while pfo2 mutants were suggested to have a mutation affecting OLE1 expression at a post-transcriptional step. In addition, four other classes of mutants, nfo1, nfo2, nfo3 and nfo4 (negative factor for OLE1) mutants that have mutations causing strong expression of the OLE1p–PHO5 fusion gene under repression conditions (presence of oleic acid), were isolated. Results of Northern analysis of OLE1 as well as OLE1p-PHO5 transcripts in nfo mutants suggested that these mutations occurred in genes encoding global repressors. We also demonstrated that TUP1 and SSN6 gene products are required for full repression of OLE1 gene expression, by showing that either tup1 or ssn6 mutations greatly increase the level of the OLE1 transcript

Isolation of a Δ5-fatty acid desaturase gene from Mortierella alpina

Arachidonic acid (C20:4 Δ5,8,11,14)) is a polyunsaturated fatty acid synthesized by the ?-fatty acid desaturation of di-homo-?-linolenic acid (C20:3 Δ8,11,14)). In mammals, it is known to be a precursor of the prostaglandins and the leukotrienes but it is also accumulated by the filamentous fungus Mortierella alpina. We have isolated a cDNA encoding the Δ5-fatty acid desaturase from M. alpina via a polymerase chain reaction- based strategy using primers designed to the conserved histidine box regions of microsomaL desaturases, and confirmed its function by expression in the yeast Saccharomyces cerevisiae. Analysis of the lipids from the transformed yeast demonstrated the accumulation of arachidonic acid. The M. alpina Δ5- desaturase is the first example of a cloned Δ5-desaturase, and differs from other fungal desaturases previously characterized by the presence of an N- terminal domain related to cytochrome b5

Prevalence of Hookworm infection and Strongyloidiasis in Cats and Potential Risk Factor of Human Diseases

Hookworm infection and Stronyloidiasis are public health problem in the worldwide which both of them could infective in human by penetrated on skin and they have potential risk from Gastrointestinal zoonotic helminths of pets, including cats. We investigated the prevalence soil transmitted helminths infection in human and cats used modified Formal-Ether Concentration and agar plate culture. Fecal samples of 23 cats and human from Naitung and Subua Villages (area study 1), and fecal samples of 15 cats and 17 humans from Thasala Beach villages (area study 2) were collected. Result of study in area study 1 showed prevalence of infection in human was not hookworm and strongyloidiasis but 10% humans have infected Ascaris and Tricuris, and in cats have infected by hookworm 75.2% and S. strercoralis 8.5%, toxocara 13%, spirometra 13% and overall prevalence 82.5%. In area study 2 showed in human has infected by Trichuris 100% and S. stercoralis 29.4% and in cats have infected by hookworm 100% and S. strercoralis 40%, toxocora 20%, and spirometra 20%. Helminth infection found in both humans in two areas study are S. strercoralis. Hookworms were the most common helminth in cats but did not connection with infection in human, while S. strercoralis was helminth infection in cats which has potential zoonotic disease to human

Prevalence of Hookworm infection and Strongyloidiasis in Cats and Potential Risk Factor of Human Diseases

Hookworm infection and Stronyloidiasis are public health problem in the worldwide which both of them could infective in human by penetrated on skin and they have potential risk from Gastrointestinal zoonotic helminths of pets, including cats. We investigated the prevalence soil transmitted helminths infection in human and cats used modified Formal-Ether Concentration and agar plate culture. Fecal samples of 23 cats and human from Naitung and Subua Villages (area study 1), and fecal samples of 15 cats and 17 humans from Thasala Beach villages (area study 2) were collected. Result of study in area study 1 showed prevalence of infection in human was not hookworm and strongyloidiasis but 10% humans have infected Ascaris and Tricuris, and in cats have infected by hookworm 75.2% and S. strercoralis 8.5%, toxocara 13%, spirometra 13% and overall prevalence 82.5%. In area study 2 showed in human has infected by Trichuris 100% and S. stercoralis 29.4% and in cats have infected by hookworm 100% and S. strercoralis 40%, toxocora 20%, and spirometra 20%. Helminth infection found in both humans in two areas study are S. strercoralis. Hookworms were the most common helminth in cats but did not connection with infection in human, while S. strercoralis was helminth infection in cats which has potential zoonotic disease to human

Environmental Factors and Prevalence of Hookworm infection and Strongyloidiasis in Rural East Kalimantan, Indonesia

The prevalence of hookworm infection and strongyloidiasis is serious public health concern globally. In rural East Kalimantan, Indonesia has high-risk environmental factors of the prevalence of hookworm infection and strongyloidiasis. In this study would show the infection rates, correlation analysis between environmental risk factors and prevalence of hookworm infection with statistical analysis. We performed a cross-sectional study among 213 participants from rural community of East Kalimantan Province, Indonesia. In this study used two diagnostic methods: Kato Katz and Koga agar plate culture/KAP culture for diagnosing of hookworm and Strongyloides infections. Chi-square analysis was used for study correlation between environmental factors and hookworm infection. Hookworm, strongyloides, and ascaris infections were found in this study; 44.1%, 16.4%, and 7.5% respectively. Environmental risk factors such as; rainy season, quality of soil and infection hookworm and strongyloides in pet have significant correlation (p-value < 0.05) with hookworm infection and strongyloidiasis. The prevalence of hookworm infection and strongyloidiasis has correlation with environmental factors, and the finding in this research could be contributed to decreasing program of hookworm infection and strongyloidiasis especially in rural community area

Factors Affecting Recovery of Strongyloides stercoralis Larvae: an Approach to a Newly Modified Formalin-Ether Concentration Technique for Diagnosis of Strongyloidiasis▿

To improve the diagnosis efficiency of human strongyloidiasis by using formalin-ether concentration technique (FECT), the effects of various factors on the recovery rates of Strongyloides stercoralis larvae were comparatively evaluated. Fresh stool and a short time exposure of larvae to formalin yielded significantly higher numbers of larvae than preserved stool and 10-min exposure. Likewise, straining through wire mesh yielded a significantly higher number of larvae recovered than straining through gauze did. In addition, centrifugation for 5 min for separation of larvae from debris yielded a significantly greater number of larvae recovered than centrifugation for 2 min did. The efficacies of the five versions of FECT with different factors-FECT 1, FECT 2, FECT 3, FECT 4, and FECT 5-were then compared. It was found that FECT 5 was 1.8, 2.0, 1.9, and 1.4 times more effective than FECT 1, FECT 2, FECT 3, and FECT 4, respectively. FECT 5 is a modified FECT method, whose modifications included using fresh stool without a preservative substance; a short-time rather than 10-min formalin exposure; and the use of wire mesh instead of gauze

Albendazole Stimulates the Excretion of Strongyloides stercoralis Larvae in Stool Specimens and Enhances Sensitivity for Diagnosis of Strongyloidiasis▿

We succeeded in stimulation of excretion of Strongyloides stercoralis larvae in stool by oral administration of a single dose of 400 mg albendazole to strongyloidiasis patients. This result overcame the false-negative results of stool examination due to low larval numbers. Stool samples were collected from 152 asymptomatic strongyloidiasis patients in the morning, prior to eating. After breakfast, they were given a dose of 400 mg albendazole, and stool samples were collected the following morning. Agar plate culture (APC), modified formalin-ether concentration technique (MFECT), and direct-smear (DS) methods were used to examine stool specimens within 3 h after defecation. The results before and after albendazole was taken were compared. All APCs that were positive became negative after albendazole administration, while MFECT showed a 1.4- to 18.0-fold increase in larval numbers in 97.4% (148/152) of the samples. The DSs were positive in 3 out of 3 smears at a larval number of ≥45 larvae per g (lpg) of stool, and in 1or 2 out of 3 smears at a larval number between 35 and 44 lpg. At a larval number of <35 lpg, the DS became negative. Interestingly 90.5% (19/21) of the samples that were negative by all methods before albendazole administration became positive by MFECT after the treatment. Thus, MFECT can be effectively used for diagnosis of strongyloidiasis with prior administration of albendazole to the subject