Quantitative Comparison of Selected Virulence Associated Characteristics in Food and Clinical Isolates of Listeria

Thirty food and clinical isolates of Listeria were compared quantitatively in regard to lethality in immunocompromised mice, hemolytic activity for sheep erythrocytes, invasiveness towards Hep-2 epithelial cells, and cytotoxicity to CHO cells. All Listeria monocytogenes isolates were hemolytic, invasive, weakly cytotoxic, and lethal to immunocompromised mice. Listeria ivanovii isolates expressed the first three properties but were non-virulent. There was little quantitative correlation among the virulence markers, suggesting that there may be additional virulence related factors that may influence the pathogenicity of L. monocytogenes isolates. No systematic differences between the clinical and food isolates were apparent. Electron and light microscopy of infected Hep-2 cells revealed L. monocytogenes and L. ivanovii encapsulated within cell processes containing an actin matrix.

Download Full-text

Listeria monocytogenes in Raw Milk: Detection, Incidence, and Pathogenicity

Journal of Food Protection ◽

10.4315/0362-028x-50.3.188 ◽

1987 ◽

Vol 50 (3) ◽

pp. 188-192 ◽

Cited By ~ 219

Author(s):

J. LOVETT ◽

D. W. FRANCIS ◽

J. M. HUNT

Keyword(s):

United States ◽

Listeria Monocytogenes ◽

Sampling Period ◽

Raw Milk ◽

The United States ◽

Isolation Method ◽

Listeria Species ◽

Adult Mice ◽

Listeria Ivanovii

To determine the incidence of Listeria monocytogenes in raw milk, an isolation method was evaluated and used to analyze milk from three areas of the United States. The incidence varied by area from 0% in California to 7% in Massachusetts, with an overall incidence of 4.2%. The highest incidence found in any area during a single sampling period was 12% in Massachusetts in March 1985. During that same sampling, the incidence for all Listeria species was 26%. Of the 27 L. monocytogenes strains isolated during the survey, 25 were pathogenic in adult mice. One of three Listeria ivanovii isolated was pathogenic. No other isolates demonstrated pathogenicity.

Download Full-text

Activity in vitro of 22 antimicrobial agents against clinical isolates of Listeria monocytogenes

Clinical Microbiology and Infection ◽

10.1111/j.1469-0691.1996.tb00202.x ◽

1996 ◽

Vol 2 (1) ◽

pp. 63-64 ◽

Cited By ~ 3

Author(s):

Rosa Blazquez ◽

Teresa Pelaez ◽

Patricia Muñoz ◽

Rosario Sanchez ◽

Marta Rodriguez-Creixems ◽

...

Keyword(s):

Listeria Monocytogenes ◽

Antimicrobial Agents ◽

Clinical Isolates

Download Full-text

Isolation of Listeria monocytogenes and Listeria ivanovii and its Nitric Oxide Expression Level in Serum, Brain and Reproductive Organs of Sheep

International Journal of Current Microbiology and Applied Sciences ◽

10.20546/ijcmas.2020.908.025 ◽

2020 ◽

Vol 9 (8) ◽

pp. 223-230

Author(s):

Nitasha Sambyal ◽

Varun Bassessar ◽

Rahul Singh ◽

Nafia Rufai ◽

Bharat Mengi

Keyword(s):

Nitric Oxide ◽

Listeria Monocytogenes ◽

Reproductive Organs ◽

Expression Level ◽

Listeria Ivanovii

Download Full-text

Expression of Internalin a and Biofilm Formation among Listeria Monocytogenes Clinical Isolates

International Journal of Immunopathology and Pharmacology ◽

10.1177/039463200902200121 ◽

2009 ◽

Vol 22 (1) ◽

pp. 183-193 ◽

Cited By ~ 33

Author(s):

G. Franciosa ◽

A. Maugliani ◽

C. Scalfaro ◽

F. Floridi ◽

P. Aureli

Keyword(s):

Listeria Monocytogenes ◽

Biofilm Formation ◽

Clinical Isolates ◽

Internalin A

Download Full-text

Impact of Human Factors on Measurement Errors

Advanced Instrument Engineering ◽

10.4018/978-1-4666-4165-5.ch020 ◽

2013 ◽

pp. 274-291 ◽

Cited By ~ 2

Author(s):

Vinodkumar Jacob ◽

M. Bhasi ◽

R. Gopikakumari

Keyword(s):

Experimental Study ◽

Statistical Analysis ◽

Measurement Error ◽

Measurement Errors ◽

Human Error ◽

Quantitative Comparison ◽

Measuring System ◽

Measuring Instrument ◽

Related Factors ◽

Human Errors

Measurement is the act or the result, of a quantitative comparison between a given quantity and a quantity of the same kind chosen as a unit. It is for observing and testing scientific and technological investigations and generally agreed that all measurements contain errors. In a measuring system where both a measuring instrument and a human being taking the measurement using a preset process, the measurement error could be due to the instrument, the process or human error. This study is devoted to understanding the human errors in measurement. Work and human involvement related factors that could affect measurement errors have been identified. An experimental study has been conducted using different subjects where the factors were changed one at a time and the measurements made by them recorded. Errors in measurement were then calculated and the data so obtained was subject to statistical analysis to draw conclusions regarding the influence of different factors on human errors in measurement. The findings are presented in the paper.

Download Full-text

Characterization of the pathogenesis and immune response to Listeria monocytogenes strains isolated from a sustained national outbreak

Scientific Reports ◽

10.1038/s41598-019-56028-3 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Pallab Ghosh ◽

Yan Zhou ◽

Quentin Richardson ◽

Darren E. Higgins

Keyword(s):

Listeria Monocytogenes ◽

Laboratory Strain ◽

The United States ◽

Clinical Isolates ◽

T Cell Antigens ◽

Life Threatening ◽

Cellular Immune ◽

The Brain

AbstractListeria monocytogenes is an intracellular pathogen responsible for listeriosis, a foodborne disease that can lead to life-threatening meningitis. The 2011 L. monocytogenes cantaloupe outbreak was among the deadliest foodborne outbreaks in the United States. We conducted in vitro and in vivo infection analyses to determine whether strains LS741 and LS743, two clinical isolates from the cantaloupe outbreak, differ significantly from the common laboratory strain 10403S. We showed that LS741 and LS743 exhibited increased virulence, characterized by higher colonization of the brain and other organs in mice. Assessment of cellular immune responses to known CD8+ T cell antigens was comparable between all strains. However, pre-existing immunity to 10403S did not confer protection in the brain against challenge with LS741. These studies provide insights into the pathogenesis of clinical isolates linked to the 2011 cantaloupe outbreak and also indicate that currently utilized laboratory strains are imperfect models for studying L. monocytogenes pathogenesis.

Download Full-text