Ingestion and survival of Y. pseudotuberculosis in HeLa cells

1975 ◽  
Vol 21 (12) ◽  
pp. 1997-2007 ◽  
Author(s):  
Åke Bovallius ◽  
Gustaf Nilsson
Keyword(s):  
Cell Culture ◽  
Hela Cells ◽  
Yersinia Pseudotuberculosis ◽  
Fluorescent Antibody ◽  
Cell System ◽  
Viable Count ◽  
Linear Increase ◽  
Intracellular Bacteria ◽  
Antibody Staining ◽  
Upper Limit

HeLa cells were infected with Yersinia pseudotuberculosis for 0.5–3 h. Intracellular bacteria could then be demonstrated by three different techniques: viable count, fluorescent-antibody staining, and electron microscopy. Most of the bacteria seemed to be viable, since there was a good positive correlation (0.94) between viable and fluorescent bacteria. The bacterial uptake seemed to be mediated by a phagocytic-like procedure. The intracellular bacteria seemed to reside in vacuoles some of which increased in size as a function of time. The kinetics of infection was studied after addition of 107 or 109 bacteria per cell culture (2 × 106 cells). After a lag period of about 30 min there was a linear increase of intracellular bacteria, and this uptake proceeded for 1–2 h until most of the bacteria were ingested or an upper limit of ingested bacteria was reached. The upper limit was calculated to be a mean of 60 per infected cell in the cell culture. More than 90% of the cells could be infected and a reasonable number of the bacteria survive in the cells for at least 3 days, as demonstrated by the viable-count technique.The bacteria–cell system may be used to study, for example, the effect of antibiotics or antibodies on intracellular bacteria and pathogenicity of intracellular diseases.

scholarly journals Chlamydia pneumoniae in a Free-Ranging Giant Barred Frog (Mixophyes iteratus) from Australia

1999 ◽  
Vol 37 (7) ◽  
pp. 2378-2380 ◽  
Author(s):  
Lee Berger ◽  
Kym Volp ◽  
Sarah Mathews ◽  
Rick Speare ◽  
Peter Timms
Keyword(s):  
Electron Microscopy ◽  
Cell Culture ◽  
16S Rrna ◽  
Chlamydia Pneumoniae ◽  
Fluorescent Antibody ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Antibody Staining ◽  
Free Ranging ◽  
Fluorescent Antibody Staining

The koala biovar of Chlamydia pneumoniae was identified in lung tissue from a sick, free-ranging giant barred frog (Mixophyes iteratus) by using electron microscopy, C. pneumoniae-specific fluorescent-antibody staining, cell culture, and sequencing of the ompA, ompB and 16S rRNA genes. This is the first report of a chlamydial strain infecting both a homeotherm and a poikilotherm and only the fourth host (in addition to humans, koalas, and horses) to be naturally infected with this species of Chlamydia. The frog had severe, chronic, mononuclear pneumonia and nonregenerative anemia and pancytopenia.

scholarly journals Use of Fluorescent-Antibody Staining of Cytocentrifuge-Prepared Smears in Combination with Cell Culture for Direct Detection of Respiratory Viruses

1998 ◽  
Vol 36 (7) ◽  
pp. 2112-2114 ◽  
Author(s):  
Kirk M. Doing ◽  
Mary Ann Jerkofsky ◽  
Elaine G. Dow ◽  
Jo Ann Jellison
Keyword(s):  
Cell Culture ◽  
Direct Detection ◽  
Fluorescent Antibody ◽  
Respiratory Viruses ◽  
Antibody Staining ◽  
Fluorescent Antibody Staining

Over a 3-year period, 1,003 respiratory samples were collected and examined for selected respiratory viruses with cytocentrifuged prepared smears stained with fluorescently labeled antibodies (IFA) in conjunction with cell culture. IFA results were compared with results obtained by cell culture. Viruses were isolated or detected by direct means in 401 samples. Agreement between culture and IFA was 90%.

A Most Probable Number Method for the Enumeration of Legionella Bacteria in Water

1991 ◽  
Vol 24 (2) ◽  
pp. 143-147 ◽  
Author(s):  
N. A. Grabow ◽  
R. Kfir ◽  
W. O. K. Grabow
Keyword(s):  
Water Samples ◽  
Membrane Filtration ◽  
Quantitative Method ◽  
Fluorescent Antibody ◽  
Most Probable Number ◽  
Probable Number ◽  
Comparative Tests ◽  
Antibody Staining ◽  
Direct Fluorescent Antibody ◽  
Yeast Extract Agar

A new quantitative method for the enumeration of Legionella bacteria in water is described. Appropriate tenfold serial dilutions of water samples concentrated by membrane filtration are plated in triplicate on buffered charcoal yeast extract agar. After incubation for 3 days representative smears from individual plates are tested for the presence of Legionella by direct fluorescent antibody staining. The number of positive plates in each dilution is used to calculate the Legionella count by means of conventional most probable number statistics. In comparative tests on a variety of water samples this method yielded significantly higher counts than previously used procedures.

scholarly journals Type III Secretion Decreases Bacterial and Host Survival following Phagocytosis of Yersinia pseudotuberculosis by Macrophages

2008 ◽  
Vol 76 (9) ◽  
pp. 4299-4310 ◽  
Author(s):  
Yue Zhang ◽  
James Murtha ◽  
Margaret A. Roberts ◽  
Richard M. Siegel ◽  
James B. Bliska
Keyword(s):  
Cell Death ◽  
Type Iii Secretion ◽  
Yersinia Pseudotuberculosis ◽  
De Novo ◽  
Host Cells ◽  
Host Responses ◽  
Intracellular Bacteria ◽  
Wild Type ◽  
Macrophage Response ◽  
Type Iii

ABSTRACT Yersinia pseudotuberculosis uses a plasmid (pYV)-encoded type III secretion system (T3SS) to translocate a set of effectors called Yops into infected host cells. YopJ functions to induce apoptosis, and YopT, YopE, and YopH act to antagonize phagocytosis in macrophages. Because Yops do not completely block phagocytosis and Y. pseudotuberculosis can replicate in macrophages, it is important to determine if the T3SS modulates host responses to intracellular bacteria. Isogenic pYV-cured, pYV+ wild-type, and yop mutant Y. pseudotuberculosis strains were allowed to infect bone marrow-derived murine macrophages at a low multiplicity of infection under conditions in which the survival of extracellular bacteria was prevented. Phagocytosis, the intracellular survival of the bacteria, and the apoptosis of the infected macrophages were analyzed. Forty percent of cell-associated wild-type bacteria were intracellular after a 20-min infection, allowing the study of the macrophage response to internalized pYV+ Y. pseudotuberculosis. Interestingly, macrophages restricted survival of pYV+ but not pYV-cured or ΔyopB Y. pseudotuberculosis within phagosomes: only a small fraction of the pYV+ bacteria internalized replicated by 24 h. In addition, ∼20% of macrophages infected with wild-type pYV+ Y. pseudotuberculosis died of apoptosis after 20 h. Analysis of yop mutants expressing catalytically inactive effectors revealed that YopJ was important for apoptosis, while a role for YopE, YopH, and YopT in modulating macrophage responses to intracellular bacteria could not be identified. Apoptosis was reduced in Toll-like receptor 4-deficient macrophages, indicating that cell death required signaling through this receptor. Treatment of macrophages harboring intracellular pYV+ Y. pseudotuberculosis with chloramphenicol reduced apoptosis, indicating that the de novo bacterial protein synthesis was necessary for cell death. Our finding that the presence of a functional T3SS impacts the survival of both bacterium and host following phagocytosis of Y. pseudotuberculosis suggests new roles for the T3SS in Yersinia pathogenesis.

scholarly journals SEQUENTIAL CELLULAR CHANGES PRODUCED BY TYPES 5 AND 7 ADENOVIRUSES IN HELA CELLS AND IN HUMAN AMNIOTIC CELLS

1959 ◽  
Vol 110 (5) ◽  
pp. 827-844 ◽  
Author(s):  
Georgiana S. Boyer ◽  
Floyd W. Denny ◽  
Harold S. Ginsberg
Keyword(s):  
Tissue Culture ◽  
Cell Nucleus ◽  
Hela Cells ◽  
Fluorescent Antibody ◽  
Intranuclear Inclusions ◽  
Culture Cells ◽  
Cellular Changes ◽  
Tissue Culture Cells ◽  
Cytological Changes ◽  
Amniotic Cells

The sequential cytological changes which develop in tissue culture cells infected with adenovirus types 5 and 7 are described and compared with those produced by adenovirus types 1, 2, 3, and 4. The evidence that is presented indicates that types 1, 2, and 5 belong to one major subdivision of the adenovirus group and types 3, 4, and 7 to another. That the host cell nucleus is the principal site of adenovirus synthesis has been confirmed by fluorescent antibody studies. They have demonstrated the occurrence of type-specific adenovirus antigen in the characteristic intranuclear inclusions and other virus-induced structures reported to contain virus-like particles or shown by electronmicroscopy.

Profilin is predominantly associated with monomeric actin in Acanthamoeba

1999 ◽  
Vol 112 (21) ◽  
pp. 3779-3790 ◽  
Author(s):  
D.A. Kaiser ◽  
V.K. Vinson ◽  
D.B. Murphy ◽  
T.D. Pollard
Keyword(s):  
Monoclonal Antibodies ◽  
Plasma Membrane ◽  
Fluorescent Antibody ◽  
Gel Filtration ◽  
Live Cells ◽  
A431 Cells ◽  
Antibody Staining ◽  
Large Particles ◽  
Biochemical Fractionation ◽  
Fluorescent Antibody Staining

We used biochemical fractionation, immunoassays and microscopy of live and fixed Acanthamoeba to determine how much profilin is bound to its known ligands: actin, membrane PIP(2), Arp2/3 complex and polyproline sequences. Virtually all profilin is soluble after gentle homogenization of cells. During gel filtration of extracts on Sephadex G75, approximately 60% of profilin chromatographs with monomeric actin, 40% is free and none voids with Arp2/3 complex or other large particles. Selective monoclonal antibodies confirm that most of the profilin is bound to actin: 65% in extract immunoadsorption assays and 74–89% by fluorescent antibody staining. Other than monomeric actin, no major profilin ligands are detected in crude extracts. Profilin-II labeled with rhodamine on cysteine at position 58 retains its affinity for actin, PIP(2) and poly-L-proline. When syringe-loaded into live cells, it distributes throughout the cytoplasm, is excluded from membrane-bounded organelles, and concentrates in lamellapodia and sites of endocytosis but not directly on the plasma membrane. Some profilin fluorescence appears punctate, but since no particulate profilin is detected biochemically, these spots may be soluble profilin between organelles that exclude profilin. The distribution of profilin in fixed human A431 cells is similar to that in amoebas. Our results show that the major pool of polymerizable actin monomers is complexed with profilin and spread throughout the cytoplasm.

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