Role of outer membrane vesicles of hypervirulent Klebsiella pneumoniae isolated from bovine uterine discharge in pro-inflammatory dysregulation

Numerous research studies have established a connection between hypervirulent Klebsiella pneumo-niae (hvKP) and bovine abortion, as well as other complications and clinical illnesses. These bacteria, which belong to the Gram-negative group, release outer membrane vesicles (OMVs), believed to play a...

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Main Authors: A. F. Daham, A. H. Jaber, A. Neamah, H. Al-Karagoly
Format: Article
Language:English
Published: Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria 2025-03-01
Series:Bulgarian Journal of Veterinary Medicine
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author A. F. Daham
A. H. Jaber
A. Neamah
H. Al-Karagoly
author_facet A. F. Daham
A. H. Jaber
A. Neamah
H. Al-Karagoly
author_sort A. F. Daham
collection DOAJ
description Numerous research studies have established a connection between hypervirulent Klebsiella pneumo-niae (hvKP) and bovine abortion, as well as other complications and clinical illnesses. These bacteria, which belong to the Gram-negative group, release outer membrane vesicles (OMVs), believed to play a crucial role in transporting effector molecules to their target cells. To investigate this further, OMVs of hvKP were collected from 47 clinical isolates from bovine uterine discharge samples using ultra-centrifugation. Confirmation of the 47 isolates was carried out through a standard PCR test targeting the 16S rRNA gene. Subsequently, a multiplex PCR was used to verify positive 16S rRNA gene re-sults by detecting specific virulence genes (fimH, acrAB, traT, and rmpA). The standard PCR test showed that 27 out of the 47 isolates (57.45%) tested positive for the 16S rRNA gene, with all 27 of these isolates also testing positive for the rmpA and traT genes. Additionally, 30% of the isolates (8.1 out of 27) tested positive for AcrAB, while 70% of the isolates (18.9 out of 27) tested positive for FimH. During SDS-Western blotting, ten protein bands with molecular weights ranging from 18 to >60 kDa were identified in K. pneumoniae-derived OMV preparations. These bands included OmpX, flagellin, MipA, OmpA, OmpC, and OmpF (4244 kDa), a strong OmpA band at 45 KDa, and a faint band at 60 kDa of GroEL as an oligomer of OmpA. Furthermore, hvKP OMVs displayed varying cytotoxic effects on the L929 and THP-1 cell lines. Notably, incubating THP-1 cells with high con-centrations of hvKP OMVs inhibited IL-1β and TNF responses, indicating that these OMVs may not only facilitate the internalisation of the bacterium by THP-1 cells but also suppress the cells’ innate immune response to hvKP infection. This ability of hvKP OMVs to evade the immune system and modulate host responses contributes significantly to the bacterium’s pathogenicity.
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institution Kabale University
issn 1311-1477
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language English
publishDate 2025-03-01
publisher Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria
record_format Article
series Bulgarian Journal of Veterinary Medicine
spelling doaj-art-541003255df5444b847373af495ec1322025-01-30T07:42:35ZengFaculty of Veterinary Medicine, Trakia University, Stara Zagora, BulgariaBulgarian Journal of Veterinary Medicine1311-14771313-35432025-03-0128111713210.15547/bjvm.2023-0098Role of outer membrane vesicles of hypervirulent Klebsiella pneumoniae isolated from bovine uterine discharge in pro-inflammatory dysregulationA. F. Daham0A. H. Jaber1A. Neamah 2H. Al-Karagoly3College of Veterinary Medicine, University of Al-Qadisiyah, Al-Diwaniyah, IraqCollege of Veterinary Medicine, University of Al-Qadisiyah, Al-Diwaniyah, IraqCollege of Veterinary Medicine, University of Al-Qadisiyah, Al-Diwaniyah, IraqCollege of Veterinary Medicine, University of Al-Qadisiyah, Al-Diwaniyah, IraqNumerous research studies have established a connection between hypervirulent Klebsiella pneumo-niae (hvKP) and bovine abortion, as well as other complications and clinical illnesses. These bacteria, which belong to the Gram-negative group, release outer membrane vesicles (OMVs), believed to play a crucial role in transporting effector molecules to their target cells. To investigate this further, OMVs of hvKP were collected from 47 clinical isolates from bovine uterine discharge samples using ultra-centrifugation. Confirmation of the 47 isolates was carried out through a standard PCR test targeting the 16S rRNA gene. Subsequently, a multiplex PCR was used to verify positive 16S rRNA gene re-sults by detecting specific virulence genes (fimH, acrAB, traT, and rmpA). The standard PCR test showed that 27 out of the 47 isolates (57.45%) tested positive for the 16S rRNA gene, with all 27 of these isolates also testing positive for the rmpA and traT genes. Additionally, 30% of the isolates (8.1 out of 27) tested positive for AcrAB, while 70% of the isolates (18.9 out of 27) tested positive for FimH. During SDS-Western blotting, ten protein bands with molecular weights ranging from 18 to >60 kDa were identified in K. pneumoniae-derived OMV preparations. These bands included OmpX, flagellin, MipA, OmpA, OmpC, and OmpF (4244 kDa), a strong OmpA band at 45 KDa, and a faint band at 60 kDa of GroEL as an oligomer of OmpA. Furthermore, hvKP OMVs displayed varying cytotoxic effects on the L929 and THP-1 cell lines. Notably, incubating THP-1 cells with high con-centrations of hvKP OMVs inhibited IL-1β and TNF responses, indicating that these OMVs may not only facilitate the internalisation of the bacterium by THP-1 cells but also suppress the cells’ innate immune response to hvKP infection. This ability of hvKP OMVs to evade the immune system and modulate host responses contributes significantly to the bacterium’s pathogenicity.bovine uterine dischargehvkpomvspro-inflammatory responsesds-western blottingvirulence genes
spellingShingle A. F. Daham
A. H. Jaber
A. Neamah
H. Al-Karagoly
Role of outer membrane vesicles of hypervirulent Klebsiella pneumoniae isolated from bovine uterine discharge in pro-inflammatory dysregulation
Bulgarian Journal of Veterinary Medicine
bovine uterine discharge
hvkp
omvs
pro-inflammatory response
sds-western blotting
virulence genes
title Role of outer membrane vesicles of hypervirulent Klebsiella pneumoniae isolated from bovine uterine discharge in pro-inflammatory dysregulation
title_full Role of outer membrane vesicles of hypervirulent Klebsiella pneumoniae isolated from bovine uterine discharge in pro-inflammatory dysregulation
title_fullStr Role of outer membrane vesicles of hypervirulent Klebsiella pneumoniae isolated from bovine uterine discharge in pro-inflammatory dysregulation
title_full_unstemmed Role of outer membrane vesicles of hypervirulent Klebsiella pneumoniae isolated from bovine uterine discharge in pro-inflammatory dysregulation
title_short Role of outer membrane vesicles of hypervirulent Klebsiella pneumoniae isolated from bovine uterine discharge in pro-inflammatory dysregulation
title_sort role of outer membrane vesicles of hypervirulent klebsiella pneumoniae isolated from bovine uterine discharge in pro inflammatory dysregulation
topic bovine uterine discharge
hvkp
omvs
pro-inflammatory response
sds-western blotting
virulence genes
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