scholarly journals Biochemical and molecular characterization of Alternaria alternata isolates highly resistant to procymidone from broccoli and cabbage

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Bingran Wang ◽  
Tiancheng Lou ◽  
Lingling Wei ◽  
Wenchan Chen ◽  
Longbing Huang ◽  
...  
Keyword(s):  
Alternaria Alternata ◽  
Single Point ◽  
Sodium Dodecyl ◽  
Cross Resistance ◽  
Molecular Characteristics ◽  
Single Point Mutation ◽  
Wide Range ◽  
Significant Difference ◽  
Leaf Blights ◽  
High Level

AbstractAlternaria alternata, a causal agent of leaf blights and spots on a wide range of hosts, has a high risk of developing resistance to fungicides. Procymidone, a dicarboximide fungicide (DCF), has been widely used in controlling Alternaria leaf blights in China for decades. However, the resistance of A. alternata against DCFs has rarely been reported from crucifer plants. A total of 198 A. alternata isolates were collected from commercial fields of broccoli and cabbage during 2018–2019, and their sensitivities to procymidone were determined. Biochemical and molecular characteristics were subsequently compared between the high-level procymidone-resistant (ProHR) and procymidone-sensitive (ProS) isolates, and also between ProHR isolates from broccoli and cabbage. Compared with ProS isolates, the mycelial growth rate, sporulation capacity and virulence of most ProHR isolates were reduced; ProHR isolates displayed an increased sensitivity to osmotic stresses and a reduced sensitivity to sodium dodecyl sulfate (SDS); all ProHR isolates showed a reduced sensitivity to hydrogen peroxide (H2O2) except for the isolate B102. Correlation analysis revealed a positive cross-resistance between procymidone and iprodione, or fludioxonil. When treated with 10 μg/mL of procymidone, both mycelial intracellular glycerol accumulations (MIGAs) and relative expression of AaHK1 in ProS isolates were higher than those in ProHR isolates. Sequence alignment of AaHK1 from ten ProHR isolates demonstrated that five of them possessed a single-point mutation (P94A, V612L, E708K or Q924STOP), and four isolates had an insertion or a deletion in their coding regions. No significant difference in biochemical characteristics was observed among ProHR isolates from two different hosts, though mutations in AaHK1 of the cabbage-originated ProHR isolates were distinct from those of the broccoli-originated ProHR isolates.

Detection and fitness of dicarboximide-resistant isolates of Alternaria alternata from Dendrobium officinale, a Chinese indigenous medicinal herb.

Plant Disease ◽  
2020 ◽  
Author(s):  
Weicheng Zhao ◽  
Chunxia Sun ◽  
Lingling Wei ◽  
Wenchan Chen ◽  
Bingran Wang ◽  
...  
Keyword(s):  
Alternaria Alternata ◽  
Mycelial Growth ◽  
Medicinal Herb ◽  
Dendrobium Officinale ◽  
Cross Resistance ◽  
Resistance Pattern ◽  
Amino Acid Sequence Alignment ◽  
Group I ◽  
Black Spots ◽  
Significant Difference

Black spots caused by Alternaria Alternata poses a sever threat to the industry of Dendrobium officinale, a Chinese indigenous medicinal herb. Dicarboximide fungicides (DCFs) are intensively used to control this disease for decades in China, and offering excellent efficacy. The resistance of phytopathogenic pathogens against DCFs are reportedly selected in fields; however, the DCF-resistance of A. alternata from D. officinale is not well understood. The low procymidone-resistant (ProLR) isolates of A. alternata were detected in the commercial orchards of D. officinale in China in 2018 and biochemically characterized in this study. The result showed that the low procymidone-resistant (ProLR) isolates were selected in the commercial orchards with the resistance frequency of 100 %, and no significant difference in mycelial growth, sporulation and virulence was observed among the ProLR and ProS isolates. A positive cross-resistance pattern was exhibited between procymidone and iprodione. Amino acid sequence alignment results of AaOS-1 from the tested isolates showed that all the ProLR genotypes could be categorized into two groups, including group I (mutations at AaOs-1) and group II (no mutation). On procymidone (5.0 μg/ml) treatment condition, the AaOs-1 expression levels increased in the ProS isolates ranged from 2.94~3.69 folds higher than those on procymidone-free condition, while the AaOs-1 expressions of the ProLR isolates were significantly lower than those in the ProS isolates on the same conditions. The data indicated that the mutations at AaOs-1 are involved in the DCF-resistance of A. alternata selected in the D. officinale orchards.

scholarly journals High-Level Chromosomally Mediated Tetracycline Resistance in Neisseria gonorrhoeae Results from a Point Mutation in the rpsJ Gene Encoding Ribosomal Protein S10 in Combination with the mtrR and penB Resistance Determinants

2005 ◽  
Vol 49 (10) ◽  
pp. 4327-4334 ◽  
Author(s):  
Mei Hu ◽  
Sobhan Nandi ◽  
Christopher Davies ◽  
Robert A. Nicholas
Keyword(s):  
Amino Acids ◽  
Neisseria Gonorrhoeae ◽  
Ribosomal Protein ◽  
Point Mutation ◽  
Single Point ◽  
Ribosomal Subunit ◽  
Tetracycline Resistance ◽  
Saturation Mutagenesis ◽  
Single Point Mutation ◽  
High Level

ABSTRACT Neisseria gonorrhoeae becomes resistant to tetracycline by two major mechanisms: expression of a plasmid-encoded TetM protein and mutations in endogenous genes (chromosomally mediated resistance). Early studies by Sparling and colleagues (P. F. Sparling F. A. J. Sarubbi, and E. Blackman, J. Bacteriol. 124:740-749, 1975) demonstrated that three genes were involved in high-level chromosomally mediated tetracycline resistance (MIC of tetracycline ≥ 2 μg/ml): ery-2 (now referred to as mtrR), penB, and tet-2. While the identities of the first two genes are known, the tet-2 gene has not been identified. We cloned the tet-2 gene, which confers tetracycline resistance, from tetracycline-resistant clinical isolate N. gonorrhoeae FA6140 and show that resistance is due to a single point mutation (Val-57 to Met) in the rpsJ gene (rpsJ1) encoding ribosomal protein S10. Moreover, the identical mutation was found in six distinct tetracycline-resistant clinical isolates in which the MIC of tetracycline was ≥2 μg/ml. Site-saturation mutagenesis of the codon for Val-57 identified two other amino acids (Leu and Gln) that conferred identical levels of resistance as the Met-57 mutation. The mutation maps to the vertex of a loop in S10 that is near the aminoacyl-tRNA site in the structure of the 30S ribosomal subunit from Thermus thermophilus, and the residue equivalent to Val-57 in T. thermophilus S10, Lys-55, is within 8 to 9 Å of bound tetracycline. These data suggest that large noncharged amino acids alter the rRNA structure near the tetracycline-binding site, leading to a lower affinity of the antibiotic.

scholarly journals A Comparative Study of Distribution of Protein and Cholesterol in Various Fractions of Human Semen from Infertile and Fertile Subjects

2012 ◽  
Vol 3 (3) ◽  
pp. 78-82 ◽  
Author(s):  
MS Srinivas ◽  
Vickram Sundaram ◽  
M Ramesh Pathy ◽  
TB Sridharan
Keyword(s):  
Molecular Weight ◽  
Comparative Study ◽  
Seminal Plasma ◽  
Semen Analysis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Human Semen ◽  
Exact Function ◽  
Wide Range ◽  
Significant Difference

ABSTRACT Aim To elucidate the concentration of the protein and cholesterol in different fractions of human semen from different infertile categories and comparing them with the fertile group. Materials and methods The human semen was collected from different infertile categories including oligoasthenospermia, asthenospermia, azoospermia, normospermia, oligospermia and fertile group. Immediately after collection, the semen analysis was done as per WHO standard protocols. After that, the semen was centrifuged to get the different fractions. Four main fractions were obtained, (1) spermatozoa, (2) debris or material that precipitates at 12 K rpm for 10 minutes, (3) prostasomes which was precipitated at 20K rpm for 120 minutes, (4) seminal plasma. The protein concentration was done by Lowry's method and cholesterol was estimated by diagnostic kit. Results Sodium dodecyl sulfate—polyacrylamide gel electrophoresis (SDS PAGE) was run for all the categories of semen samples for their seminal plasma and the fertility associated protein was identified. A significant difference was found in the concentration of proteins in all subfractions when compared between control and infertile categories. Almost 86% of the protein was recovered from soluble fraction. In case of azoospermia, the protein content was very low when compared with fertile group. Seminal plasma proteins were visualized by silver staining. The molecular weight of the protein bands were ranging from 6.5 to 205 kDa. The band with molecular weight around 55 kDa was found to be missing in case of oligoasthenospermia. This particular protein is said to be fertility associated protein. The content of cholesterol for different subfraction of the human semen samples from infertile and fertile samples was compared. A wide range of cholesterol was recovered from prostasomes, that too purified. Conclusion A thrive study have to be done in all the subfractions of the semen irrespective of the category of samples to know the exact function of the each subfractions in terms of protein and cholesterol distribution. How to cite this article Sundaram V, Srinivas MS, Rao KA, Pathy MR, Sridharan TB. A Comparative Study of Distribution of Protein and Cholesterol in Various Fractions of Human Semen from Infertile and Fertile Subjects. Int J Infertility Fetal Med 2012;3(3):78-82.

37 Viability of sheep skin fibroblasts after vitrification

2019 ◽  
Vol 31 (1) ◽  
pp. 144
Author(s):  
Y. Toishibekov ◽  
E. Asanova ◽  
M. Yermekova ◽  
A. Seisenbayeva ◽  
D. Toishybek
Keyword(s):  
Culture Medium ◽  
Blue Staining ◽  
Crystal Formation ◽  
Wide Range ◽  
Significant Difference ◽  
Fetal Bovine ◽  
Breeding Pool ◽  
Student’S T ◽  
High Level ◽  
Skin Samples

Both tissue and cell cryopreservation can be applied for biodiversity conservation. The proper preservation of tissues and cells from a wide range of animals of different species is of paramount importance because these cell samples could be used to reintroduce lost genes back into the breeding pool by somatic cell cloning. The aim of this work was to investigate the effect of vitrification on viability of vitrified sheep fibroblasts for conservation of biodiversity so that it might be used in the future to provide nuclear donors. Skin samples collected from 10 adult sheep were cut into small pieces (1×1mm), placed into culture Petri dishes containing DMEM supplemented with 20% (vol/vol) fetal bovine serum, and covered with coverslips followed by incubation at 5% CO2, 95% RH, and 37°C. During culture, fibroblasts left skin samples and proliferated. Culture medium was changed every 4 days. After 21 to 22 days of incubation, a fibroblast monolayer was observed, culture medium was removed, and cells were incubated for 7 to 10min in the presence of Dulbecco’s PBS+0.25% trypsin. Dissociated fibroblasts were washed with DMEM by centrifugation at 300×g for 10min. For vitrification, fibroblast samples were then diluted at a concentration of 2×106cellsmL−1 in DMEM+ 20% ethylene glycol, 20% dimethylsulfoxide, and 0.5molL−1 of sucrose. The fibroblasts were then exposed to 50 and 100% vitrification solution (VS) at 37°C for 5min and 30s, respectively. Fibroblasts after saturation in VS were transferred and placed into 0.25-mL plastic straws. Straws were sealed with modelling clay and plunged into LN. Viability of frozen-thawed fibroblast samples was detected using the Trypan Blue staining method (frozen-thawed: 53.0±2.6%; control (fresh): 98.5±1.2%). The values obtained are expressed as mean±standard error of the mean. Statistical analysis was done using Student’s t-test. Results indicated that there was a significant difference in viability between fresh and cryopreserved fibroblasts. Importantly, our data suggest that the use of vitrification reduced the toxic elements contained in the cryopreservation solution while maintaining a similar ability to produce viable fibroblasts after cryopreservation. Although further work on the viability of sheep skin fibroblast with the vitrification method is needed, these data suggest that with vitrification a faster cooling rate and high level of cryoprotectants are able to minimize ice crystal formation and should be further evaluated as a routine mechanism for cryopreserving sheep fibroblasts.

scholarly journals Identification of a New Equid Herpesvirus 1 DNA Polymerase (ORF30) Genotype with the Isolation of a C2254/H752 Strain in French Horses Showing no Major Impact on the Strain Behaviour

Viruses ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1160
Author(s):  
Gabrielle Sutton ◽  
Côme Thieulent ◽  
Christine Fortier ◽  
Erika S. Hue ◽  
Christel Marcillaud-Pitel ◽  
...  
Keyword(s):  
Viral Load ◽  
Respiratory Disease ◽  
Dna Polymerase ◽  
Single Point ◽  
Single Point Mutation ◽  
Equid Herpesvirus ◽  
New Genotype ◽  
Significant Difference ◽  
Herpesvirus 1

Equid herpesvirus 1 is one of the most common viral pathogens in the horse population and is associated with respiratory disease, abortion and still-birth, neonatal death and neurological disease. A single point mutation in the DNA polymerase gene (ORF30: A2254G, N752D) has been widely associated with neuropathogenicity of strains, although this association has not been exclusive. This study describes the fortuitous isolation of a strain carrying a new genotype C2254 (H752) from an outbreak in France that lasted several weeks in 2018 and involved 82 horses, two of which showed neurological signs of disease. The strain was characterised as UL clade 10 using the equid herpesvirus 1 (EHV-1) multi-locus sequence typing (MLST) classification but has not been identified or isolated since 2018. The retrospective screening of EHV-1 strains collected between 2016 and 2018 did not reveal the presence of the C2254 mutation. When cultured in vitro, the C2254 EHV-1 strain induced a typical EHV-1 syncytium and cytopathic effect but no significant difference was observed when compared with A2254 and G2254 EHV-1 strains. An experimental infection was carried out on four Welsh mountain ponies to confirm the infectious nature of the C2254 strain. A rapid onset of marked respiratory disease lasting at least 2 weeks, with significant virus shedding and cell-associated viraemia, was observed. Finally, an in vitro antiviral assay using impedance measurement and viral load quantification was performed with three antiviral molecules (ganciclovir (GCV), aciclovir (ACV) and aphidicolin (APD)) on the newly isolated C2254 strain and two other A/G2254 field strains. The three strains showed similar sensitivity to ganciclovir and aphidicolin but both C2254 and A2254 strains were more sensitive to aciclovir than the G2254 strain, based on viral load measurement.

scholarly journals Predictors of a suicidal behavior in patients with dementia

2017 ◽  
Vol 41 (S1) ◽  
pp. S399-S399
Author(s):  
N. Maruta ◽  
I. Mudrenko
Keyword(s):  
Suicidal Behavior ◽  
Suicide Risk ◽  
Rating Scale ◽  
Cognitive Disorders ◽  
Severe Depression ◽  
Control Group ◽  
Self Awareness ◽  
Wide Range ◽  
Significant Difference ◽  
High Level

IntroductionCognitive disorders are associated with a wide range of psychopathological syndromes and behavioral disorders, and suicidal manifestations in dementia are understudied nowadays.ObjectivesTo investigate clinical-psychopathological predictors of a suicidal behavior in patients with dementia.MethodologyForty-four patients with dementia were examined: 23 patients with suicidal manifestations and 21 patients without them (control group). Clinical and psychometrical methods were used: Mini Mental State Examination (MMSE) scale; Assessment of Suicide Risk scale; Hamilton Rating Scale for Depression (HDRS), and statistical ones.ResultsIt was determined that male patients with dementia had suicidal behavioral manifestations more often than female patients (69.6%; P < 0.05). An average age of the patients was 69.88 ± 1.85 years with no significant difference between the main and control groups.The majority of the patients with dementia (52.3%) had suicidal manifestations. Real suicidal intentions were the most frequent (25%; P < 0.05); 20.5% of patients expressed passive thoughts (anti-vital sentences, fantasies, ideas concerning death); 2 patients (6.82%; P < 0.05) had suicidal attempts. Patients with suicidal tendencies in their clinical picture more often had hallucinatory syndrome (39.1%; P < 0.05); features of severe depression (35.04 ± 1.54 points; P < 0.01); a high level of suicidal risk (26.34 ± 1.68 points; P < 0.01); a severe cognitive deficit (ММSE score 0–10); and a significantly lower level of self-awareness of death (18.53 ± 0.72 points; P < 0.05) in comparison with the control group.ConclusionsA high suicide risk in dementia correlated with a level of depressive symptoms (r = 0.6), moderate and/or severe grades of dementia (r = 0.45), and a low level of self-awareness of death (r = 0.35).Disclosure of interestThe authors have not supplied their declaration of competing interest.

scholarly journals Transcription of the Salmonella Invasion Gene Activator, hilA, Requires HilD Activation in the Absence of Negative Regulators

2003 ◽  
Vol 185 (2) ◽  
pp. 525-533 ◽  
Author(s):  
Jennifer D. Boddicker ◽  
Boyd M. Knosp ◽  
Bradley D. Jones
Keyword(s):  
Rna Polymerase ◽  
Single Point ◽  
Negative Regulator ◽  
Single Point Mutation ◽  
Intestinal Epithelial ◽  
Negative Regulators ◽  
Α Subunit ◽  
Serovar Typhimurium ◽  
Low Levels ◽  
High Level

ABSTRACT Salmonella enterica serovar Typhimurium causes human gastroenteritis and a systemic typhoid-like infection in mice. Infection is initiated by entry of the bacteria into intestinal epithelial cells and is mediated by a type III secretion system that is encoded by genes in Salmonella pathogenicity island 1. The expression of invasion genes is tightly regulated by environmental conditions such as oxygen and osmolarity, as well as by many bacterial factors. The hilA gene encodes an OmpR/ToxR family transcriptional regulator that activates the expression of invasion genes in response to both environmental and genetic regulatory factors. HilD is an AraC/XylS regulator that has been postulated to act as a derepressor of hilA expression that promotes transcription by interfering with repressor binding at the hilA promoter. Our research group has identified four genes (hilE, hha, pag, and ams) that negatively affect hilA transcription. Since the postulated function of HilD at the hilA promoter is to counteract the effects of repressors, we examined this model by measuring hilA::Tn5lacZY expression in strains containing negative regulator mutations in the presence or absence of functional HilD. Single negative regulator mutations caused significant derepression of hilA expression, and two or more negative regulator mutations led to very high level expression of hilA. However, in all strains tested, the absence of hilD resulted in low-level expression of hilA, suggesting that HilD is required for activation of hilA expression, whether or not negative regulators are present. We also observed that deletion of the HilD binding sites in the chromosomal hilA promoter severely decreased hilA expression. In addition, we found that a single point mutation at leucine 289 in the C-terminal domain of the α subunit of RNA polymerase leads to very low levels of hilA::Tn5lacZY expression, suggesting that HilD activates transcription of hilA by contacting and recruiting RNA polymerase to the hilA promoter.

scholarly journals Linezolid Resistance in Staphylococcus aureus: Gene Dosage Effect, Stability, Fitness Costs, and Cross-Resistances

2008 ◽  
Vol 52 (4) ◽  
pp. 1570-1572 ◽  
Author(s):  
Silke Besier ◽  
Albrecht Ludwig ◽  
Johannes Zander ◽  
Volker Brade ◽  
Thomas A. Wichelhaus
Keyword(s):  
Staphylococcus Aureus ◽  
Gene Dosage ◽  
Single Point ◽  
23S Rrna ◽  
Cross Resistance ◽  
Single Point Mutation ◽  
Rrna Gene ◽  
Gene Dosage Effect ◽  
Linezolid Resistance ◽  
23S Rrna Gene

ABSTRACT Linezolid resistance in Staphylococcus aureus is typically associated with mutations in the 23S rRNA gene. Here we show that the accumulation of a single point mutation, G2576T, in the different copies of this gene causes stepwise increases in resistance, impairment of the biological fitness, and cross-resistance to quinupristin-dalfopristin and chloramphenicol.

Point mutation in acetolactate synthase confers sulfonylurea and imidazolinone herbicide resistance in spiny annual sow-thistle [Sonchus asper (L.) Hill]

2012 ◽  
Vol 92 (2) ◽  
pp. 303-309 ◽  
Author(s):  
Kee Woong Park ◽  
Judith M. Kolkman ◽  
Carol A. Mallory-Smith
Keyword(s):  
Amino Acid ◽  
Point Mutation ◽  
Herbicide Resistance ◽  
Single Point ◽  
Acetolactate Synthase ◽  
Amino Acid Sequences ◽  
Cross Resistance ◽  
Single Point Mutation ◽  
Sonchus Asper

Park, K. W., Kolkman, J. M. and Mallory-Smith, C. A. 2012. Point mutation in acetolactate synthase confers sulfonylurea and imidazolinone herbicide resistance in spiny annual sow-thistle [Sonchus asper (L.) Hill]. Can. J. Plant Sci. 92: 303–309. Suspected thifensulfuron resistant spiny annual sow-thistle was identified near Colfax, Washington, in two fields with a winter wheat and lentil rotation. Therefore, studies were conducted to examine resistance of spiny annual sow-thistle to thifensulfuron and cross-resistance to other acetolactate synthase inhibitors and to determine the physiological and molecular basis for herbicide resistance. Whole-plant bioassay confirmed that the biotype was highly resistant to the sulfonylurea (SU) herbicides, thifensulfuron, metsulfuron, and prosulfuron. The resistant (R) biotype was also highly resistant to the imidazolinone (IMI) herbicides, imazamox and imazethapyr. An in vivo acetolactate synthase (ALS) assay indicated that the concentrations of SU and IMI herbicides required for 50% inhibition (I50) were more than 10 times greater for R biotype compared with susceptible (S) biotype. Analysis of the nucleotide and predicted amino acid sequences for ALS genes demonstrated a single-point mutation from C to T at the als1 gene, conferring the substitution of the amino acid leucine for proline in the R biotype at position197. The results of this research indicate that the resistance of spiny annual sow-thistle to SU and IMI herbicides is due to on altered target site and caused by a point mutation in the als1 gene.

scholarly journals Resistance to vancomycin and teicoplanin: an emerging clinical problem.

1990 ◽  
Vol 3 (3) ◽  
pp. 280-291 ◽  
Author(s):  
A P Johnson ◽  
A H Uttley ◽  
N Woodford ◽  
R C George
Keyword(s):  
Clinical Problem ◽  
Selective Advantage ◽  
Vancomycin Resistance ◽  
Cross Resistance ◽  
Resistant Bacteria ◽  
Coagulase Negative Staphylococci ◽  
Wide Range ◽  
Vancomycin Mics ◽  
High Level ◽  
Level Resistance

Vancomycin and teicoplanin are glycopeptides active against a wide range of gram-positive bacteria. For 30 years following the discovery of vancomycin in 1956, vancomycin resistance was not detected among normally susceptible bacteria recovered from human specimens. Since 1986, however, bacteria resistant to vancomycin or teicoplanin or both have been described. Strains of the genera Leuconostoc, Lactobacillus, Pediococcus, and Erysipelothrix seem inherently resistant to glycopeptides. Species and strains of enterococci and coagulase-negative staphylococci appear to have acquired or developed resistance. There are at least two categories of glycopeptide resistance among enterococci, characterized by either high-level resistance to vancomycin (MIC, greater than or equal to 64 mg/liter) and teicoplanin (MIC, greater than or equal to 8 mg/liter) or lower-level vancomycin resistance (MIC, 32 to 64 mg/liter) and teicoplanin susceptibility (MIC, less than or equal to 1 mg/liter). The two categories appear to have similar resistance mechanisms, although genetic and biochemical studies indicate that they have arisen independently. Among coagulase-negative staphylococci, strains for which vancomycin MICs are up to 20 mg/liter or teicoplanin MICs are 16 to 32 mg/liter have been reported, but cross-resistance between these glycopeptides varies. The selective advantage accorded to glycopeptide-resistant bacteria and the observation that high-level resistance in enterococci is transferable suggest that such resistance may be expected to increase in incidence. Clinicians and microbiologists need to be aware of this emerging problem.

Sign in / Sign up

Export Citation Format

Share Document