scholarly journals Effects of glucose, growth temperature, and pH on listeriolysin O production in Listeria monocytogenes.

1993 ◽  
Vol 59 (10) ◽  
pp. 3495-3497 ◽  
Author(s):  
A R Datta ◽  
M H Kothary
Keyword(s):  
Listeria Monocytogenes ◽  
Growth Temperature ◽  
Listeriolysin O

Virulence of Listeria monocytogenes Propagated in NaCl Containing Media at 4, 25 and 37°C

1994 ◽  
Vol 57 (6) ◽  
pp. 475-478 ◽  
Author(s):  
ERIC R. MYERS ◽  
SCOTT E. MARTIN
Keyword(s):  
Superoxide Dismutase ◽  
Listeria Monocytogenes ◽  
Sodium Chloride ◽  
Mouse Model ◽  
Virulence Factor ◽  
Growth Temperature ◽  
Lethal Dose ◽  
Listeriolysin O ◽  
Sod Activity ◽  
Approximate Lethal Dose

Virulence, as determined in a mouse model, and virulence factor activities of catalase (CA), superoxide dismutase (SOD) and listeriolysin O (LLO), was examined in Listeria monocytogenes 10403S. Cells were propagated in media containing various concentrations of sodium chloride (NaCl) at 4, 25 and 37°C. Strain 10403S exhibited significant increases in CA activity and LLO when grown in media containing 428 mM of NaCl at 37°C. The CA activities at 4 and 25°C were significantly less, and the cells exhibited similar increases and decreases as cells grown at 37°C. When comparing the growth temperatures, the CA activity decreased as the growth temperature decreased. The SOD activity was significantly increased only when cells were propagated in media containing either 428 or 1,112 mM of NaCl. The SOD activity increased as the growth temperature decreased. No LLO activity was detected when cells were grown at 4 and 25°C. The production of these enzymes appeared to be thermoregulated. In addition, approximate lethal dose (ALD50) values were determined after intragastric (i.g.) and intraperitoneal (i.p.) infection. Each method of infection indicated that LLO was required for virulence, while growth in salt containing media, growth at 4°C, or the production of higher levels of CA, SOD and LLO did not appear to influence the virulence of L. monocytogenes.

Su.78. Analysis of T-Cell Responses to Listeria Monocytogenes Listeriolysin O in Healthy Adults

2006 ◽  
Vol 119 ◽  
pp. S186
Author(s):  
Johannes Hampl ◽  
Shruti Mathur ◽  
Weiqun Liu ◽  
Peter Lauer ◽  
Thomas Dubensky ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
T Cell ◽  
T Cell Responses ◽  
Healthy Adults ◽  
Listeriolysin O ◽  
Cell Responses

scholarly journals Effect of lactic acid bacteria on Listeria monocytogenes infection and innate immunity in rabbits

2020 ◽  
Vol 65 (No. 1) ◽  
pp. 23-30 ◽  
Author(s):  
Heping Zhao ◽  
Feike Zhang ◽  
Jun Chai ◽  
Jianping Wang
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Positive Control ◽  
Negative Control ◽  
Listeriolysin O ◽  
Serum Iga ◽  
Probiotic Lactic Acid Bacteria ◽  
Spleen And Lymph Nodes ◽  
Proinflammatory Factors

The present study aimed to investigate the effect of probiotic lactic acid bacteria (LAB) addition on Listeria monocytogenes translocation and its toxin listeriolysin O (LLO), proinflammatory factors, immune organ indexes and serum immunoglobulins in farmed rabbits. Five treatments included negative control (NC), positive control (PC) with L. monocytogenes infection and supplemental LAB at 3.0 × 10<sup>6 </sup>(low-LAB, L-LAB), 3.0 × 10<sup>8</sup> (medium-LAB, M-LAB) and 3.0 × 10<sup>10 </sup>(high-LAB, H-LAB) CFU/kg of diet, respectively. The LAB was a mixture of equal amounts of Lactobacillus acidophilus (ACCC11073), Lactobacillus plantarum (CICC21863) and Enterococcus faecium (CICC20430). A total of 180 weaned rabbits (negative for L. monocytogenes) were randomly assigned to 5 groups with 6 replicates of 6 rabbits each in response to the 5 treatments. L. monocytogenes infection occurred on the first day of feeding trial and dietary LAB supplementation lasted for 14 days. The results showed that on days 7 and 14 post administration, L. monocytogenes in caecum, liver, spleen and lymph nodes was reduced in M-LAB and H-LAB compared to PC (P &lt; 0.05), and linear and quadratic reducing trends were found in liver on day 7 (P ≤ 0.002). On day 14, mucosa LLO mRNA expression and serum TNFα, IL1β and IFNγ were reduced in the three LAB treatments (P &lt; 0.05), and linear and quadratic trends were found on TNFα and IL1β (P ≤ 0.025); indexes of thymus and spleen, serum IgA and IgG were increased in the LAB treatments (P &lt; 0.05). It is concluded that LAB can be used to alleviate L. monocytogenes infection and to improve the immune function of farmed animals.

scholarly journals The Listeria monocytogenes hemolysin has an acidic pH optimum to compartmentalize activity and prevent damage to infected host cells

2002 ◽  
Vol 156 (6) ◽  
pp. 1029-1038 ◽  
Author(s):  
Ian J. Glomski ◽  
Margaret M. Gedde ◽  
Albert W. Tsang ◽  
Joel A. Swanson ◽  
Daniel A. Portnoy
Keyword(s):  
Listeria Monocytogenes ◽  
Bacterial Pathogen ◽  
Cytolytic Activity ◽  
Host Cells ◽  
Adaptive Mutation ◽  
Acidic Ph ◽  
Listeriolysin O ◽  
Lysosomal Hydrolases ◽  
Ph Optimum ◽  
Neutral Ph

Listeria monocytogenes is a facultative intracellular bacterial pathogen that escapes from a phagosome and grows in the host cell cytosol. The pore-forming cholesterol-dependent cytolysin, listeriolysin O (LLO), mediates bacterial escape from vesicles and is ∼10-fold more active at an acidic than neutral pH. By swapping dissimilar residues from a pH-insensitive orthologue, perfringolysin O (PFO), we identified leucine 461 as unique to pathogenic Listeria and responsible for the acidic pH optimum of LLO. Conversion of leucine 461 to the threonine present in PFO increased the hemolytic activity of LLO almost 10-fold at a neutral pH. L. monocytogenes synthesizing LLO L461T, expressed from its endogenous site on the bacterial chromosome, resulted in a 100-fold virulence defect in the mouse listeriosis model. These bacteria escaped from acidic phagosomes and initially grew normally in cells and spread cell to cell, but prematurely permeabilized the host membrane and killed the cell. These data show that the acidic pH optimum of LLO results from an adaptive mutation that acts to limit cytolytic activity to acidic vesicles and prevent damage in the host cytosol, a strategy also used by host cells to compartmentalize lysosomal hydrolases.

scholarly journals Listeriolysin O is essential for virulence of Listeria monocytogenes: direct evidence obtained by gene complementation.

1989 ◽  
Vol 57 (11) ◽  
pp. 3629-3636 ◽  
Author(s):  
P Cossart ◽  
M F Vicente ◽  
J Mengaud ◽  
F Baquero ◽  
J C Perez-Diaz ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Direct Evidence ◽  
Listeriolysin O ◽  
Gene Complementation

scholarly journals Effect of honokiol on exotoxin proteins listeriolysin O and p60 secreted by Listeria monocytogenes

2015 ◽  
Vol 64 (12) ◽  
pp. 1474-1480
Author(s):  
Rizeng Meng ◽  
Ziwen Zhao ◽  
Na Guo ◽  
Zonghui Liu ◽  
Xingchen Zhao ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Listeriolysin O

scholarly journals A Randomized Phase 2 Study of ADXS11-001 Listeria monocytogenes–Listeriolysin O Immunotherapy With or Without Cisplatin in Treatment of Advanced Cervical Cancer

2018 ◽  
Vol 28 (4) ◽  
pp. 764-772 ◽  
Author(s):  
Partha Basu ◽  
Ajay Mehta ◽  
Minish Jain ◽  
Sudeep Gupta ◽  
Rajnish V. Nagarkar ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Listeria Monocytogenes ◽  
Adverse Events ◽  
Progression Free Survival ◽  
Combination Group ◽  
Listeriolysin O ◽  
Phase 2 ◽  
Safety And Efficacy ◽  
Treatment Groups ◽  
Phase 2 Study

ObjectivesA global unmet medical need exists for effective treatments for persistent, recurrent, or metastatic cervical cancer, as patients have a short life expectancy. Recently, immunotherapies have shown promising survival benefits for patients with advanced forms of cancer. Axalimogene filolisbac (ADXS11-001), aListeria monocytogenesimmunotherapy with a broad effect on the immune system, is under investigation for treatment of human papillomavirus–associated cancers including cervical cancer.MethodsThis phase 2 study evaluated the safety and efficacy of ADXS11-001, administered with or without cisplatin, in patients with recurrent/refractory cervical cancer following prior chemotherapy and/or radiotherapy. A total of 109 patients were treated, and 69 were evaluable for tumor response at equal to or more than 3 months postbaseline.ResultsMedian overall survival (OS) was comparable between treatment groups (ADXS11-001: 8.28 months; 95% confidence interval [CI], 5.85–10.5 months; ADXS11-001 + cisplatin: 8.78 months; 95% CI, 7.4–13.3 months). The 12- and 18-month milestone OS rates were 30.9% versus 38.9%, and 23.6% versus 25.9% for each group, respectively (34.9% and 24.8% combined). Median progression-free survival (6.10 vs 6.08 months) and the overall response rate (17.1% vs 14.7%) were similar for both groups. ADXS11-001 was generally well tolerated; adverse events were predominantly mild to moderate in severity and not related to treatment. More adverse events were reported in the combination group (429 vs 275).ConclusionsThese promising safety and efficacy results, including the encouraging 12-month 34.9% combined OS rate, warrant further investigation of ADXS11-001 for treatment of recurrent/refractory cervical cancer.

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