University of Veterinary Science

About: University of Veterinary Science is a education organization based out in Pyinmana, Myanmar. It is known for research contribution in the topics: Population & Receptor. The organization has 597 authors who have published 650 publications receiving 14262 citations.

Plasmid-mediated colistin resistance among human clinical<i>Enterobacterales</i>isolates: National surveillance in the Czech Republic

Abstract: Abstract The occurrence of colistin resistance has increased rapidly among Enterobacterales around the world. We performed a national survey of plasmid-mediated colistin resistance in human clinical isolates by a retrospective analysis of samples from 2009-2017 and a prospective sampling in 2018-2020. The aim of this study was to identify and characterize isolates with mcr genes from various regions of the Czech Republic using whole genome sequencing (WGS). Of all 1932 colistin-resistant isolates analyzed, 73 (3.8%) were positive for mcr genes. Most isolates carried mcr-1 (48/73) and were identified as Escherichia coli (n=44) and Klebsiella pneumoniae (n=4) of various sequence types (ST). Twenty-five isolates including Enterobacter spp. (n=24) and Citrobacter freundii (n=1) carrying mcr-9 gene were detected, three of them ( Enterobacter kobei ST54) co-harbored the mcr-4 and mcr-9 genes. Multi-drug resistance phenotype was a common feature of mcr isolates and 14% (10/73) isolates also co-harboured clinically important beta-lactamases including 2 isolates with carbapenemases KPC-2 and OXA-48. Phylogenetic analysis of E. coli ST744, the dominant genotype in this study, with the global collection, showed Czech isolates belonged to two major clades, one containing isolates from Europe, while the second composed of isolates from diverse geographical areas. The mcr-1 gene was carried by IncX4 (34/73, 47%), IncHI2/ST4 (6/73, 8%) and IncI2 (8/73, 11%) plasmid groups. Small plasmids belonging to the ColE10 group were associated with mcr-4 in three isolates while mcr-9 was carried by IncHI2/ST1 plasmids (4/73, 5%) or the chromosome (18/73, 25%). We showed an overall low level of occurrence of mcr genes in colistin-resistant bacteria from human clinical samples in the Czech Republic.

Conversion of thyroxine to triiodothyronine in liver biopsy samples of beta-carotene and vitamin-A supplemented dairy cows.

Abstract: Summary The thyroid hormone economy of lactating cows supplied with beta-carotene or vitamin-A was investigated by means of in vitro 5′-monodeiodinase assay. Liver biopsy samples were taken together with blood samples within ten days after parturition. Results indicate clearly that beta-carotene supplementation enhances the activity of liver 5′-monodeiodinase and thus contributes to the increased production of triiodothyronine. Vitamin-A supplementation has similar effects but the degree of activation of the monodeiodinase enzyme exceeds that found in beta-carotene supplemented animals by a factor of two. In view of the contradictory results published on the interrelationship of thyroid economy with carotenoid status, the dynamic investigation of aspects of thyroid hormone metabolism will throw further light on new connections. Zusammenfassung Konversion von Thyroxin zu Triiodthyronin in Leberbiopsieproben von Milchkuhen nach Supplementation von β-Karotin und Vitamin A Die Schilddrusenhormonhaushalt von laktierenden Kuhen, denen β-Karotin und Vitamin A verabreicht worden war, wurde mittels eines in vitro-5′-Monodeiodinase-Assays untersucht. Innerhalb von 10 Tagen nach der Abkalbung wurden Blutproben und Leberbiopsieproben entnommen. Die Ergebnisse lassen klar erkennen, das die β-Karotin-Supplementierung die Aktivitat der 5′-Monodeiodinase in der Leber verstarkt und dadurch zu einer vermehrten Bildung von Triiodthyronin beitragt. Die Vitamin-A-Supplementation hatte ahnliche Wirkungen, der Aktivierungsgrad des Monodeiodinaseenzyms war jedoch etwa zweimal so gros wie bei den β-Karotin supplementierten Tieren. Im Hinblick auf die widerspruchlichen Ergebnisse, die bezuglich der Wechselwirkungen zwischen Schilddrusenaktivitat und β-Karotin vorliegen, vermogen Untersuchungen uber den Schilddrusenhormonstoffwechsel weitere Informationen uber derartige Beziehungen zu liefern. Resume Conversion de thyroxine en triiodothyronine dans des echantillons de biopsies hepatiques de vaches laitieres apres une supplementation en β-carotene et vitamine A La gestion de l'hormone thyroidienne de vaches laitieres recevant β-carotene et vitamine A a ete examinee au moyen d'un 5′-monodeiodinase- Assay in vitro. Des echantillons de sang et des biopsies hepatiques ont ete preleves durant 10 jours apres la mise-bas. Les resultats ont nettement montre que la supplementation en β-carotene renforcait l'activite de la 5′-monodeiodinase dans le foie et concourait par la a une plus grande formation de triiodthyronine. La supplementation en vitamine A a eu des effets semblables, le degre d'activation de l'enzyme de la monodeiodinase etant cependant deux fois plus grand que chez les animaux supplementes en β-carotene. En fonction des resultats contradictoires que existent sur les echanges entre l'activite de la glande thyroide et le β-carotene, des recherches sur le metabolisme de l'hormone thyroidienne permettent d'obtenir de nouvelles informations sur ces rapports. Resumen La conversion de tiroxina en triyodotironina en las muestras de biopsias hepaticas de vacas lecheras despues de una suplementacion de caroteno β y vitamina A Mediante un ensayo in vitro con 5′-monodeyodinasa se examino el metabolismo de las hormonas tiroideas de vacas lecheras que habian recibido caroteno β y vitamina A. Durante 10 dias despues del parto se tomaron muestras de sangre y de biopsias hepaticas. Los resultados permiten reconocer con toda claridad que la suplementacion de caroteno β refuerza la actividad de la 5′-monodeyodinasa en el higado y que contribuye de ese modo a la formacion aumentada de triyodotironina. La suplementacion de vitamina A tenia efectos similares, aunque el grado de activacion era dos veces mayor que en los animales suplementados con caroteno β. Con respecto a los resultados contradictorios que existen sobre las acciones reciprocas entre la actividad de la glandula tiroidea y el caroteno β, los estudios sobre el metabolismo de las hormonas tiroideas pueden proporcionar informaciones adicionales sobre semejantes relaciones.

The influence of thyroid hormones and sex steroids on the peripheral metabolism of corticosterone in the male and female japanese quail

Abstract: Publisher Summary This chapter describes the influence of thyroid hormones and sex steroids on the peripheral metabolism of corticosterone in the male and female Japanese quail. In the experiments described in the chapter, eight-week-old male and female Japanese quails exposed to short and long photoperiodes were applied. The surgical procedures performed on the quails include castration, ovariectomy, thyroidectomy and castration plus thyriodectromy. Thyroxine treatments were carried out by intramuscular injection, while sex steroids were applied in silastic tubes places subcutan. Thyroxine treatment increases the metabolic clearance rate (MCR) of corticosterone in sexually immaturated male and female birds, but thyroidectomy is ineffective. Hypo-, and hyperthyroxinaemie in sexually mature birds, inhibiting the sex steroid level, which stimulates the corticosterone metabolism, will result indirectly a decrease of MCR of corticosterone. The sex steroids increase the MCR both in male and female animals. The opposing effect of gonadectomy at the same time is less manifested, probably because of the increase of the thyroid function. The change in testosterone level does not affect the secretion rate of corticosterone in sexually immatured birds. In photogonadostimulated animals, both the plasma level of corticosterone and its secretion rate increase in spite of high testosterone and low thyroxine level.