Three classic IBDV strains were previously isolated from commercial layer chicken flocks and shown to be phylogenetically related to vaccine strains but pathogenic in susceptible chickens. In this study, their viral genomes were sequenced and compared to sequences of vaccines being used in those flocks. The vaccine strains examined were sequenced directly from the manufacturer and had identical genome segment B sequences. Compared to these vaccines, the GA-1, H-30 and CS-2-35 isolates each had one silent mutation in the gene that encodes VP1. Compared to the two vaccines used at the time CS-2-35 was isolated, the segment A sequence of CS-2-35 contained numerous nucleotide and amino acid mutations suggesting the CS-2-35 virus was not closely related to these vaccines. This virus however did have amino acid mutations in VP2 that are reported to be necessary for replication in cell culture and lacked two of the three amino acid mutations previously shown to be necessary for virulence. These data suggest that CS-2-35 was a descendant from an attenuated strain of IBDV. When the segment A genomic sequences of the GA-1 and H-30 viruses were compared to the vaccines being used in those flocks they were most closely related to the attenuated D78 vaccine strain. In genome segment A, three nucleotide mutations in GA-1 and four in H-30 were observed compared to the D78 classic vaccine. These nucleotide mutations caused one amino acid (H253N) change in the GA-1 virus and two amino acids (H253Q and G259D) were different in the H-30 virus. In addition, both the GA-1 and H-30 viruses had the amino acid G76 in VP2 that appears to be unique to the vaccine D78. The data suggest that GA-1 and H-30 are genetically related and have a common ancestor even though they were isolated from geographically distant flocks. The evidence also suggests that GA-1, H-30 and CS-2-35 could be reversions from attenuated vaccine viruses or by coincidence genetically resemble classic IBDV vaccines. It should be noted that some of the classic virus vaccines were not being used according to the manufacturer's recommendations at the time the GA-1, H-30 and CS-2-35 strains were isolated. Together, the molecular and pathogenicity data indicate that a single amino acid mutation from Histidine (H) to Glutamine (Q) or Asparagine (N) at position 253 in VP2 will markedly increase the virulence of an attenuated IBDV.
Bacteria are omnipotent and they can be found everywhere. The study of bacterial pathogens has been happening from olden days to prevent epidemics, food spoilage, losses in agricultural production, and loss of lives. Modern techniques in DNA based species identification are considered. So, there is a need to acquire simple and quick identification technique. Hence, this review article covers the efficacy of DNA barcoding of bacteria. Routine DNA barcoding involves the production of PCR amplicons from particular regions to sequence them and these sequence data are used to identify or “barcode” that organism to make a distinction from other species.
Aim:The aim of this study was to characterize beta-lactamase antimicrobial resistance in Klebsiella and Enterobacter species isolated from healthy and diarrheic dogs in Andhra Pradesh.Materials and Methods:A total of 136 rectal swabs were collected from healthy (92) and diarrheic (44) dogs, bacteriological cultured for Klebsiella and Enterobacter growth and screened for beta-lactamase antimicrobial resistance phenotypically by disc diffusion method and genotypically by polymerase chain reaction targeting blaTEM, blaSHV, blaOXA, blaCTX-M Group 1, 2, blaAmpC, blaACC, and blaMOX genes.Results:A total of 33 Klebsiella and 29 Enterobacter isolates were recovered. Phenotypic beta-lactamase resistance was detected in 66.6% and 25% of Klebsiella and Enterobacter isolates, respectively, from healthy dogs and 66.6% and 60% of Klebsiella and Enterobacter isolates, respectively, from diarrheic dogs. Overall, incidence of extended-spectrum beta-lactamase (ESBL) phenotype was found to be 21.2% (7/33) in Klebsiella isolates, whereas none of the Enterobacter isolates exhibited ESBL phenotype. Predominant beta-lactamase genes detected in Klebsiella species include blaSHV (84.8%), followed by blaTEM (33.3%), blaCTX-M Group 1 (15.1%), and blaOXA (6.1%) gene. Predominant beta-lactamase genes detected in Enterobacter species include blaSHV (48.2%), followed by blaTEM (24.1%), blaAmpC (13.7%), and blaOXA (10.3%) gene.Conclusion:The present study highlighted alarming beta-lactamase resistance in Klebsiella and Enterobacter species of canine origin in India with due emphasis as indicators of antimicrobial resistance.
Background and Aim:Flaxseeds are known to have varying antihypercholesterolemic and antiatherogenic activity due to its lignan secoisolariciresinol diglucoside, alpha-linolenic acid, and omega-3 fatty acids. The beneficial effect of whole grain dietary flaxseed was evaluated experimentally in high cholesterol diet (HCD)-fed Wistar albino rats.Materials and Methods:Male Wistar albino rats (200 g) were divided into four groups of 12 rats each. Group I rats kept as control and given basal rat chew diet, Group II as positive control for induction of hypercholesterolemia and atherosclerosis by addition of 1% cholesterol and 15% saturated edible oil to the 1000 g of standard rat chew diet (HCD), Group III rats fed with whole grain flaxseed powder at 7.5 g/kg of rat/day in the standard rat chew diet and kept as flaxseed control, and Group IV rats supplemented with flaxseed at 7.5 g/kg of rat/day along with HCD and maintained for 90 days.Results:Group II rats revealed significantly (p<0.05) higher total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and very LDL-C and significantly (p<0.05) reduced levels of high-density lipoprotein cholesterol (HDL-C), whereas tissue antioxidants such as catalase, superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione S transferase (GST) were significantly (p<0.05) reduced, and lipid peroxidation products of thiobarbituric acid reactive substances (TBARS) level were nonsignificantly (p<0.05) increased in the heart and liver tissues. Flaxseeds supplementation along with HCD significantly ameliorated the serum levels of TC, TG, LDL-C, and HDL-C along with cellular antioxidant enzymes such as catalase, SOD, GPx, GR, GST, and non-significant amelioration of TBARS in the heart and liver tissues compared to Group II rats. Majority of the histopathologically initiated atherosclerotic changes in the aorta and fatty change in the liver of Group II were not observed in the flaxseed supplemented Group IV; however, interestingly proliferation of endothelial cells with new vascular channel formation in the liver and in between cardiac muscle fibers was observed in Group I and Group IV rats.Conclusion:The present study established the hypercholesterolemia with initiated atherosclerotic lesion in the aorta but unable to establish the atheromatous plaque in the aorta. Flaxseed supplementation along with HCD showed significant antihypercholesterolemic effect and ameliorated the changes of initiated atherosclerosis in the aorta. It needs further studies to explore all the possible beneficial effects and angiogenic properties of flaxseeds in the laboratory animals and human trials.
The effects of single pulses and multiple pulses of 7 MV electrons on micronuclei (MN) induction in cytokinesis-blocked human peripheral blood lymphocytes (PBLs) were investigated over a wide range of dose rates per pulse (instantaneous dose rate). PBLs were exposed to graded doses of 2, 3, 4, 6, and 8 Gy of single electron pulses of varying pulse widths at different dose rates per pulse, ranging from 1 × 10(6) Gy s(-1) to 3.2 × 10(8) Gy s(-1). Different dose rates per pulse were achieved by changing the dose per electron pulse by adjusting the beam current and pulse width. MN yields per unit absorbed dose after irradiation with single electron pulses were compared with those of multiple pulses of electrons. A significant decrease in the MN yield with increasing dose rates per pulse was observed, when dose was delivered by a single electron pulse. However, no reduction in the MN yield was observed when dose was delivered by multiple pulses of electrons. The decrease in the yield at high dose rates per pulse suggests possible radical recombination, which leads to decreased biological damage. Cellular response to the presence of very large numbers of chromosomal breaks may also alter the damage.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.