scholarly journals Use of a dynamic in vitro attachment and invasion system (DIVAS) to determine influence of growth rate on invasion of respiratory epithelial cells by group B Streptococcus

2001 ◽  
Vol 98 (23) ◽  
pp. 13335-13340 ◽  
Author(s):  
G. Malin ◽  
L. C. Paoletti
Keyword(s):  
Growth Rate ◽  
Epithelial Cells ◽  
Group B Streptococcus ◽  
Respiratory Epithelial Cells ◽  
Group B ◽  
Respiratory Epithelial

Growth rate and oxygen regulate the interactions of group BStreptococcuswith polarized respiratory epithelial cells

2005 ◽  
Vol 51 (4) ◽  
pp. 283-286 ◽  
Author(s):  
Atul K Johri ◽  
Vilas Patwardhan ◽  
Lawrence C Paoletti
Keyword(s):  
Growth Rate ◽  
Epithelial Cells ◽  
Dissolved Oxygen ◽  
Cell Mass ◽  
Group B Streptococcus ◽  
Growth Conditions ◽  
Respiratory Epithelial Cells ◽  
Human Respiratory Epithelial Cells ◽  
Group B ◽  
Respiratory Epithelial

We investigated growth conditions that regulate the ability of group B Streptococcus (GBS) to attach to, invade, and translocate through polarized human respiratory epithelial cells (RECs). GBS grown in a chemostat at a fast cell mass doubling time (td = 1.8 h), invaded RECs from both the apical and basolateral surfaces in higher numbers compared with those held at a td = 11 h. With the exception of adherence from the basolateral surface, GBS reached peak adherence to, invasion of, and translocation through RECs when held at the fast tdwith 15% dissolved oxygen compared with 0% dissolved oxygen. Growth rate and oxygen level strongly influence the interaction of GBS with polarized RECs and likely GBS pathogenicity.Key words: group B Streptococcus, oxygen, invasion, host–pathogen interactions, regulation, translocation.

scholarly journals Oxygen Regulates Invasiveness and Virulence of Group B Streptococcus

2003 ◽  
Vol 71 (12) ◽  
pp. 6707-6711 ◽  
Author(s):  
Atul K. Johri ◽  
Joahnna Padilla ◽  
Gennady Malin ◽  
Lawrence C. Paoletti
Keyword(s):  
Epithelial Cells ◽  
Cell Mass ◽  
Group B Streptococcus ◽  
Positive Association ◽  
The Elderly ◽  
Opportunistic Pathogen ◽  
Human Epithelial Cells ◽  
Group B ◽  
In Vitro Invasiveness

ABSTRACT The facultative anaerobe group B Streptococcus (GBS) is an opportunistic pathogen of pregnant women, newborns, and the elderly. Although several virulence factors have been identified, environmental factors that regulate the pathogenicity of GBS have not been well characterized. Using the dynamic in vitro attachment and invasion system (DIVAS), we examined the effect of oxygen on the ability of GBS to invade immortalized human epithelial cells. GBS type III strain M781 invaded human epithelial cells of primitive neurons, the cervix, the vagina, and the endometrium in 5- to 400-fold higher numbers when cultured at a cell mass doubling time (td ) of 1.8 h than at a slower td of 11 h. Invasion was optimal when GBS was cultured at a td of 1.8 h in the presence of ≥5% oxygen and was significantly reduced without oxygen. Moreover, GBS grown in a chemostat under highly invasive conditions (td of 1.8 h, with oxygen) was more virulent in neonatal mice than was GBS grown under suboptimal invasion conditions (td of 1.8 h, without oxygen), suggesting a positive association between in vitro invasiveness with DIVAS and virulence.

scholarly journals Mycoplasma pneumoniae carriage evades induction of protective mucosal antibodies

2021 ◽  
pp. 2100129
Author(s):  
Ruben Cornelis Anthonie de Groot ◽  
Silvia Cristina Estevão ◽  
Patrick Michael Meyer Sauteur ◽  
Aditya Perkasa ◽  
Theo Hoogenboezem ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Mycoplasma Pneumoniae ◽  
Community Acquired Pneumonia ◽  
Respiratory Epithelial Cells ◽  
Specific Antibodies ◽  
Asymptomatic Carriage ◽  
Nasal Secretions ◽  
Respiratory Epithelial ◽  
Nested Case Control

Mycoplasma pneumoniae is the most common bacterial cause of pneumonia in children hospitalised for community-acquired pneumonia. Prevention of infection by vaccines may be an important strategy in the presence of emerging macrolide resistant M. pneumoniae. However, knowledge of immune responses to M. pneumoniae is limited, complicating vaccine design. We therefore studied the antibody response during M. pneumoniae infection and asymptomatic carriage.In a nested case-control study (n=80) of M. pneumoniae carriers and matched controls we observed that carriage by M. pneumoniae does not lead to a rise in either mucosal or systemic M. pneumoniae-specific antibodies, even after months of persistent carriage. We replicated this finding in a second cohort (n=69) and also found that during M. pneumoniae community-acquired pneumonia, mucosal levels of M. pneumoniae-specific IgA and IgG did increase significantly. In vitro adhesion assays revealed that high levels of M. pneumoniae-specific antibodies in nasal secretions of paediatric patients prevented the adhesion of M. pneumoniae to respiratory epithelial cells.In conclusion, our study demonstrates that M. pneumoniae-specific mucosal antibodies protect against bacterial adhesion to respiratory epithelial cells and are induced only during M. pneumoniae infection and not during asymptomatic carriage. This is strikingly different from carriage with bacteria such as Streptococcus pneumoniae where mucosal antibodies are induced by bacterial carriage.

scholarly journals Anti-proliferative activities of Centella asiatica extracts on human respiratory epithelial cells in vitro

2014 ◽  
Vol 8 (24) ◽  
pp. 864-869 ◽  
Author(s):  
M. Y. Mohd Heikal ◽  
Mariam, H Siti ◽  
Ilham, A. Mohd ◽  
Fong, C. Mee ◽  
B. S. Aminuddin, ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Centella Asiatica ◽  
Respiratory Epithelial Cells ◽  
Human Respiratory Epithelial Cells ◽  
Respiratory Epithelial

Murine Tracheal and Nasal Septal Epithelium for Air–Liquid Interface Cultures: A Comparative Study

2007 ◽  
Vol 21 (5) ◽  
pp. 533-537 ◽  
Author(s):  
Bradford A. Woodworth ◽  
Marcelo B. Antunes ◽  
Geeta Bhargave ◽  
James N. Palmer ◽  
Noam A. Cohen
Keyword(s):  
Epithelial Cells ◽  
Respiratory Epithelium ◽  
Liquid Interface ◽  
Respiratory Epithelial Cells ◽  
Cell Counts ◽  
Total Cell Population ◽  
Respiratory Epithelial ◽  
Air Liquid Interface ◽  
Ciliated Epithelial Cells

Background Air–liquid interface cultures using murine tracheal respiratory epithelium have revolutionized the in vitro study of airway diseases. However, these cultures often are impractical because of the small number of respiratory epithelial cells that can be isolated from the mouse trachea. The ability to study ciliary physiology in vitro is of utmost importance in the research of chronic rhinosinusitis (CRS). Our hypothesis is that the murine nasal septum is a better source of ciliated respiratory epithelium to develop respiratory epithelial air–liquid interface models. Methods Nasal septa and tracheas were harvested from 10 BALB/c mice. The nasal septa were harvested by using a simple and straightforward novel technique. Scanning electron microscopy was performed on all specimens. Cell counts of ciliated respiratory epithelial cells were performed at one standard magnification (1535×). Comparative analysis of proximal and distal trachea, midanterior and midposterior nasal septal epithelium, was performed. Results Independent cell counts revealed highly significant differences in the proportion of cell populations (p < 0.00001). Ciliated cell counts for the trachea (106.9 ± 28) were an average of 38.7% of the total cell population. Nasal septal ciliated epithelial cells (277.5 ± 16) comprised 90.1% of the total cell population. Conclusion To increase the yield of respiratory epithelial cells harvested from mice, we have found that the nasal septum is a far superior source when compared with the trachea. The greater surface area and increased concentration of ciliated epithelial cells has the potential to provide an eightfold increase in epithelial cells for the development of air–liquid interface cultures.

scholarly journals Moxifloxacin and Azithromycin but not Amoxicillin Protect Human Respiratory Epithelial Cells against Streptococcus pneumoniae In Vitro when Administered up to 6 Hours after Challenge

2005 ◽  
Vol 49 (12) ◽  
pp. 5119-5122 ◽  
Author(s):  
Martina Ulrich ◽  
Cordula Albers ◽  
Jan-Georg Möller ◽  
Axel Dalhoff ◽  
Gisela Korfmann ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Epithelial Cells ◽  
Protective Effect ◽  
Respiratory Epithelial Cells ◽  
Human Respiratory Epithelial Cells ◽  
Respiratory Cells ◽  
Respiratory Epithelial

ABSTRACT We determined the protective effect of moxifloxacin, azithromycin, and amoxicillin against Streptococcus pneumoniae infection of respiratory cells. Moxifloxacin and azithromycin effectively killed intracellular S. pneumoniae strains and protected respiratory epithelial cells significantly even when given 6 h after S. pneumoniae challenge. Amoxicillin was less effective.

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