Absence of mutations associated with resistance to benzimidazole in the beta-tubulin gene of Ascaris suum

Abstract INTRODUCTION: Benzimidazoles are commonly used for the control of veterinary nematodes. Resistance to benzimidazoles has been associated with three single nucleotide polymorphisms in the β-tubulin gene of common nematodes. However, these mutations are infrequent in the genus Ascaris spp. METHODS: In order to determine mutations associated with benzimidazole resistance in Ascaris suum, worms were collected from slaughtered pigs and a partial region of the β-tubulin gene was sequenced. RESULTS: All parasites showed the wildtype genotype for codons 167, 198, and 200 of the β-tubulin gene. CONCLUSIONS: This is the first report of genetic sequences associated with benzimidazole resistance in A. suum.

The expression of beta-tubulin gene in myelodysplastic syndrome evoluting to leukemia / 中华内科杂志

Objective Based on our previous established cohort of myelodysplastic syndrome (MDS), we investigated the potential effect of beta-tubulin (TUBB) gene in the transformation of MDS into acute leukemia Methods From our nested case-control study cohort of MDS patients, we chose 11 paired transformed and nontransformed MDS patients.TUBB gene expression was tested by quantitative real-time PCR.TUBB-siRNA transfection was used to down-regulate TUBB gene expression in SKM-1 cell line.The function of TUBB gene in SKM-1 cell line was evaluated by cell proliferation, soft agar clone formation and electron microscope.Results TUBB gene expression in MDS patients in transformed group were significantly higher than that in control group (2.91 ± 0.41 vs 0.90 ± 0.23, P ＜0.01).After TUBB-siRNA transfection, A450/630nm of SKM-1 cells at 24 h, 48 h and 72 h were 0.299 ± 0.045, 0.526 ± 0.034 and 0.652 ± 0.035, respectively, which were significantly decreased than those in negative-siRNA group (0.438 ±0.074, 0.858 ±0.064 and 0.974 ±0.044) (P ＜0.05).Soft agar clone formation in TUBB-siRNA group was (7.0 ±0.2)％, which was significantly reduced than that of negative-siRNA group (25.0 ± 0.2)％ (P ＜ 0.01).Electron microscope showed significant apoptotic signs in TUBB-siRNA group, including vacuoles in cytoplasm and karyorrhexis.Conclusion Our results indicate that TUBB gene may play a role in the transformation of MDS into acute leukemia by affecting the proliferation of malignant clones.

First Report of Anthracnose Caused by Colletotrichum fioriniae on Chinese Matrimony Vine in Korea

A fungus, Colletotrichum fioriniae, was isolated for the first time from fruits of Chinese matrimony vine (Lycium chinense Mill.) in Korea. It was classified as C. fioriniae based on the morphological characteristics and nucleotide sequence of glyceraldehyde-3-phosphate-dehydrogenase and β-tubulin. To the best of our knowledge, this is the first report of C. fioriniae causing anthracnose of Chinese matrimony vine in Korea.

The First Report of Penicillium georgiense in Malaysia

Penicillium georgiense was isolated from sandy beach soil from Batu Ferringhi beach, Penang Island, Malaysia. The identification was based on morphological characteristics and phylogenetic analysis of internal transcribed spacer regions and beta-tubulin sequences. To the best of our knowledge, this is the first report of P. georgiense in Malaysia.

A New Record of Penicillium pimiteouiense from Beach Soil in Malaysia

Three isolates of Penicillium pimiteouiense were recovered from sandy beach soil samples in Penang Island, Peninsular Malaysia. All the isolates were identified based on morphological characteristics and phylogenetic analysis of internal transcribed spacer regions and beta-tubulin gene. This is a first record of P. pimiteouiense in Malaysia.

Blockade of VEGFR-1 and VEGFR-2 Enhances Paclitaxel Sensitivity in Gastric Cancer Cells

PURPOSE: Hypoxia-inducible factor-1alpha (HIF-1alpha) increases transcription of the vascular endothelial growth factor (VEGF) gene. Inhibition of VEGF abolishes VEGF mediated induction of HIF-1alpha. Recent reports suggested that HIF-1alpha also mediated the induction of class III beta-tubulin (TUBB3) in hypoxia. TUBB3 confers resistance to taxanes. Inhibition of VEGF may decrease the expression of HIF-1alpha and TUBB3. This study was undertaken to investigate the roles of vascular endothelial growth factor receptor (VEGFR) in gastric cancer cell behavior and to identify methods to overcome paclitaxel resistance in vitro. MATERIALS AND METHODS: The protein expression levels of HIF-1alpha and TUBB3 were measured in human gastric cancer cell lines (AGS) under normoxic and hypoxic conditions. The relationship between TUBB3 and paclitaxel resistance was assessed with small interfering TUBB3 RNA. AGS cells were treated with anti-VEGFR-1, anti-VEGFR-2, placental growth factor (PlGF), bevacizuamb, and paclitaxel. RESULTS: Hypoxia induced paclitaxel resistance was decreased by knockdown of TUBB3. Induction of HIF-1alpha and TUBB3 in AGS is VEGFR-1 mediated and PlGF dependent. Hypoxia-dependent upregulation of HIF-1alpha and TUBB3 was reduced in response to paclitaxel treatment. Expressions of HIF-1alpha and TUBB3 were most decreased when AGS cells were treated with a combination of paclitaxel and anti-VEGFR-1. AGS cell cytotoxicity was most increased in response to paclitaxel, anti-VEGFR-1, and anti-VEGFR-2. CONCLUSION: We suggest that blockade of VEGFR-1 and VEGFR-2 enhances paclitaxel sensitivity in TUBB3-expressing gastric cancer cells.

Taxonomy of Ganoderma lucidum from Korea Based on rDNA and Partial beta-Tubulin Gene Sequence Analysis

In the present study, a phylogenetic analysis was undertaken based on the internal transcribed spacer (ITS) rDNA and partial beta-tubulin gene sequence of the Ganoderma species. The size of the ITS rDNA regions from different Ganoderma species varied from 625 to 673 bp, and those of the partial beta-tubulin gene sequence were 419 bp. Based on the results, a phylogenetic tree was prepared which revealed that Korean Ganoderma lucidum strains belong in a single group along with a G. lucidum strain from Bangladesh.

Molecular characterization of beta-tubulin from Phakopsora pachyrhizi, the causal agent of Asian soybean rust

β-tubulins are structural components of microtubules and the targets of benzimidazole fungicides used to control many diseases of agricultural importance. Intron polymorphisms in the intron-rich genes of these proteins have been used in phylogeographic investigations of phytopathogenic fungi. In this work, we sequenced 2764 nucleotides of the β-tubulin gene (Pp tubB) in samples of Phakopsora pachyrhizi collected from seven soybean fields in Brazil. Pp tubB contained an open reading frame of 1341 nucleotides, including nine exons and eight introns. Exon length varied from 14 to 880 nucleotides, whereas intron length varied from 76 to 102 nucleotides. The presence of only four polymorphic sites limited the usefulness of Pp tubB for phylogeographic studies in P. pachyrhizi. The gene structures of Pp tubB and orthologous β-tubulin genes of Melampsora lini and Uromyces viciae-fabae were highly conserved. The amino acid substitutions in β-tubulin proteins associated with the onset of benzimidazole resistance in model organisms, especially at His6, Glu198 and Phe200, were absent from the predicted sequence of the P. pachyrhizi β-tubulin protein.

Identification and Characterization of Eurotium rubrum Isolated from Meju in Korea

We isolated and identified a strain of Eurotium rubrum from Meju that has not been reported in Korea. This fungus is yellowish brown; reverse dark brown on CYA and PDA while yellow on 2% MEA at 25degrees C. Cleistothecia are first bright yellow and gradually turned brown. Mycerial growth on CYA attained a diameter of 30 mm at 20degrees C, 37 mm at 25degrees C and 32 mm at 30degrees C after 15 days. The isolate grew slower on 2% MEA (< 20 mm 15 days at 25degrees C) compared to CYA and PDA (< 40 mm 15 days at 25degrees C). Cleistothecia are superficial, yellow to light brown, globose to subglobose, 40~75 microm in diameter. Asci are 8-spored and globose to subglobose 8~11 microm. Ascospores are disciform, 4.0~5.0 microm in length and 4.2~4.5 microm in width. Conidia are ovate or bacillar, finely roughened to densely spinulose, 4.6~6.0 microm in length and 3.0~4.3 microm in width. Compared to known Eurotium rubrum, the Korean isolate showed 99% sequence similarity in ITS rDNA (554 bp) and calmodulin (750 bp) gene and 100% in beta-tubulin (1016 bp) gene. The E. rubrum isolate also had weak beta-glucosidase and protease activities.

Characterization of a Sapstaining Fungus, Ophiostoma floccosum, Isolated from the Sapwood of Pinus thunbergii in Korea

An Ophiostoma fungus was isolated from a stump of Pinus thunbergii in a forest on the West coast of Korea. Microscopic analysis using a light microscope, a stereo microscope, and a scanning electron microscope revealed that it had morphological features of Pesotum and Sporothix synanarmorphs. Based on the beta-tubulin gene sequence analysis, the fungus was identified as the anamorph of Ophiostoma floccosum. Mycological properties of the species including its growth properties on different culture media were described.

Reidentification of Aspergillus spp. Isolated from Clinical Specimens of Patients Suspected as Pulmonary Aspergillosis in Korea / 대한의진균학회지

Korean Institute of Tuberculosis (KIT) collected 129 strains of Aspergillus spp. from clinical specimens of patient suspected as pulmonary Aspergillosis. On the basis of morphological characteristics, these strains were identified as A. fumigatus (62 strains), A. niger (37), A. flavus (26), A. versicolor (1), A. nidulans (1), A. clavatus (1) and Neosartorya fennelliae (1). These strains were re-identified according to recent Aspergillus classification system which is mainly based on molecular characters. The strains were grouped by Randomly Amplified Polymorphic DNA (RAPD). The representative strains from each group were sequenced with partial betatubulin gene and compared with those of reference strains in the Aspergillus and were identified by the sequence. The identification was confirmed by morphological examination. As the results, they are reidentified as A. fumigatus (58), A. niger (11), A. tubingensis (26), A. flavus (27), A. sydowii (3), A. nidulans (1), A. clavatus (1), Neosartorya fennelliae (1), N. fischeri (1). This is also the first report of A. tubuingensis in clinical field in Korea.

Reidentification of Aspergillus spp. Isolated from Clinical Specimens of Patients Suspected as Pulmonary Aspergillosis in Korea / 대한의진균학회지

Korean Institute of Tuberculosis (KIT) collected 129 strains of Aspergillus spp. from clinical specimens of patient suspected as pulmonary Aspergillosis. On the basis of morphological characteristics, these strains were identified as A. fumigatus (62 strains), A. niger (37), A. flavus (26), A. versicolor (1), A. nidulans (1), A. clavatus (1) and Neosartorya fennelliae (1). These strains were re-identified according to recent Aspergillus classification system which is mainly based on molecular characters. The strains were grouped by Randomly Amplified Polymorphic DNA (RAPD). The representative strains from each group were sequenced with partial betatubulin gene and compared with those of reference strains in the Aspergillus and were identified by the sequence. The identification was confirmed by morphological examination. As the results, they are reidentified as A. fumigatus (58), A. niger (11), A. tubingensis (26), A. flavus (27), A. sydowii (3), A. nidulans (1), A. clavatus (1), Neosartorya fennelliae (1), N. fischeri (1). This is also the first report of A. tubuingensis in clinical field in Korea.

Two Species of Penicillium Associated with Blue Mold of Yam in Korea

During 2007 survey of post-harvest diseases of yam performed in May and June, severe tuber loss caused by blue mold was observed in Iksan, Cheonbuk Province. Two species of Penicillium were isolated from the infected tubers. Based on beta-tubulin gene sequence analysis, and cultural and morphological characteristics, the isolates were identified as Penicillium sclerotigenum and P. polonicum. P. sclerotigenum, which is a novel to Korea, is presently described and illustrated.

Six Species of Penicillium Associated with Blue Mold of Grape

Grape fruits with blue mold symptoms were collected from house storages in different locations in Korea and were investigated for their association with Penicillium species. A total of 12 isolates of Penicillium were isolated from the collected fruits. Based on morphological and cultural characteristics and beta-tublin gene sequence data analysis, they were identified as P. bialowiezense, P. citrinum, P. echinulatum, P. expansum, P. solitum and unidentified Penicillium species. P. solitum was the predominant followed by P. expansum. P. bialowiezense and P. echinulatum were newly recorded in Korea. beta-Tubulin gene sequences could be used to distinguish each species of Penicillium and the molecular groups were correlated well with the morphological species. The unidentified species was supposed to be a new species, not previously reported in literature.

Two New Records of Penicillium Associated with Blue Moldy Bulbs of Lily in Korea

Two new records of Penicillium from blue moldy bulbs of lily are reported in Korea. The Korean isolates of P. albocoremium (Frisvad) Frisvad and P. tulipae Overy and Frisvad were phylogenetically identical to the reference species based on DNA sequence of the beta-tubulin gene. P. albocoremium and P. tulipae are described and illustrated.

First Report of Penicillium brasilianum and P. daleae Isolated from Soil in Korea

In this study, a total of 300 isolates of Penicillium and related teleomorphic genera were collected from soils of 17 locations in Korea from April to May, 2004. Ninety four isolates were identified as the species of Penicillium subgenus Furcatum based on cultural and morphological characteristics and beta-tubulin gene sequences. Among the species, Korean isolates of P. brasilianum Bat. and P. daleae K. M. Zalessky were phylogenetically identical to the reference species based on DNA sequence of the beta-tubulin gene. Here we described and illustrated P. brasilianum and P. daleae that are new in Korea.