Transformed Recombinant Enrichment Profiling Rapidly Identifies HMW1 as an Intracellular Invasion Locus in Haemophilus influenzae

Abstract Background: Recurrent tonsillitis is one of the most common otolaryngological disorders caused by bacteria invading cells such as Streptococcus pyogenes (S. pyogenes) and Haemophilus influenzae. The aim of this study was to investigate the effect of antibacterial drugs against bacteria that have invaded cells.Results: The intracellular invasion of Detroit 562 cells by five strains of nontypeable Haemophilus influenzae (NTHi) and four strains of Streptococcus pyogenes was investigated. The antibacterial drugs used were garenoxacin (GRNX), clarithromycin (CAM), amoxicillin (AMPC), cefditoren pivoxil (CDTR-PI), and levofloxacin (LVFX). Both NTHi and S. pyogenes fully invaded Detroit 562 cells in 6 h. Both NTHi and S. pyogenes had reduced susceptibility to CAM. GRNX, CAM, and LVFX were effective against bacteria invading the cells, but AMPC and CDTR-PI were not effective. GRNX was the most effective.Conclusion: GRNX was the most effective agent against bacteria invading cells.

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Correction: Transformed Recombinant Enrichment Profiling Rapidly Identifies HMW1 as an Intracellular Invasion Locus in Haemophilus influenzae

PLoS Pathogens ◽

10.1371/journal.ppat.1005681 ◽

2016 ◽

Vol 12 (5) ◽

pp. e1005681

Author(s):

Keyword(s):

Haemophilus Influenzae ◽

Intracellular Invasion

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Effectiveness of antibacterial agents against cell-invading bacteria such as Streptococcus pyogenes and Haemophilus influenzae

BMC Microbiology ◽

10.1186/s12866-021-02217-y ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Hiroyuki Iuchi ◽

Junichiro Ohori ◽

Satoshi Kiyama ◽

Naoko Imuta ◽

Junichiro Nishi ◽

...

Keyword(s):

Haemophilus Influenzae ◽

Streptococcus Pyogenes ◽

Antibacterial Agents ◽

Recurrent Tonsillitis ◽

Effective Agent ◽

Intracellular Invasion

Abstract Background Recurrent tonsillitis is one of the most common otolaryngological disorders caused by cell-invading bacteria, such as Streptococcus pyogenes (S. pyogenes) and Haemophilus influenzae. The aim of this study was to investigate the effect of antibacterial agents against cell-invading bacteria. Methods The intracellular invasion of Detroit 562 cells by five strains of nontypeable Haemophilus influenzae (NTHi) and four strains of S. pyogenes was investigated. The antibacterial agents used were garenoxacin (GRNX), clarithromycin (CAM), amoxicillin (AMPC), cefditoren pivoxil (CDTR-PI), and levofloxacin (LVFX). Results Both NTHi and S. pyogenes fully invaded Detroit 562 cells in 6 h and were less sensitive to CAM. GRNX, CAM, and LVFX were effective against bacteria invading the cells, but AMPC and CDTR-PI were not effective. GRNX was the most effective. Conclusion GRNX was the most effective agent against bacteria invading cells.

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Ultrastructural studies on the interaction of haemophilus influenzae with human endothelial cells in vitro

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010016073x ◽

1990 ◽

Vol 48 (3) ◽

pp. 636-637

Author(s):

D.J.P. Ferguson ◽

M. Virji ◽

H. Kayhty ◽

E.R. Moxon

Keyword(s):

Endothelial Cells ◽

Haemophilus Influenzae ◽

Intercellular Junctions ◽

Blood Stream ◽

Ultrastructural Studies ◽

Endothelial Barriers ◽

Serotype B ◽

Meningitis In Children ◽

Respiratory Epithelial

Haemophilus influenzae is a human pathogen which causes meningitis in children. Systemic H. influenzae infection is largely confined to encapsulated serotype b organisms and is a major cause of meningitis in the U.K. and elsewhere. However, the pathogenesis of the disease is still poorly understood. Studies in the infant rat model, in which intranasal challenge results in bacteraemia, have shown that H. influenzae enters submucosal tissues and disseminates to the blood stream within minutes. The rapidity of these events suggests that H. influenzae penetrates both respiratory epithelial and endothelial barriers with great efficiency. It is not known whether the bacteria penetrate via the intercellular junctions, are translocated within the cells or carried across the cellular barrier in 'trojan horse' fashion within phagocytes. In the present studies, we have challenged cultured human umbilical cord_vein endothelial cells (HUVECs) with both capsulated (b+) and capsule-deficient (b-) isogenic variants of one strain of H. influenzae in order to investigate the interaction between the bacteria and HUVEC and the effect of the capsule.

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