Listeria Monocytogenes

Often scientists work with bacteria that do not come in a labeled test tube— for example, bacterial samples taken from infected human tissue or from the soil—and the scientist must then identify the unknown microorganism in order to understand what behavior to expect from the organism, for example, a certain type of infection or antibiotic resistance. However, because of the relatively few forms of bacteria compared to animals and because of the lack of bacterial fossil records due to their asexually reproductive nature, the taxonomy used to classify animals cannot be applied to bacteria (Brown 275). In order to classify unknown bacteria, a variety of physiological and metabolic tests are available to narrow a sample down from the fathomless number of possibilities into a more manageable range. Once these tests have been performed, the researcher can consult Bergey’s Manual of Determinative Bacteriology, a systematically arranged and continually updated collection of all known bacteria based on their structure, metabolism, and other attributes.

Over the years, there have been several studies published on the health effect of yogurt and the bacteria that companies use to produce yogurt. There have been studies done on animals and humans to investigate the benefits. According to The American Journal of Clinical Nutrition, “the United States uses lactic acid producing bacteria known as (LAB) which

The review indicated that there were several deficiencies existed at this plant, which contributed to the outbreak. For example, Maple Leaf Foods’ plant was aware that it had occurrences of Listeria in the plant in 2007 and 2008, and tried to correct the problem with sanitation procedures. As a result, the plant’s management thought Listeria was under control. Maple Leaf Foods did not conduct the trend analysis required under its Listeria control policy. Without this analysis, the recurring positive results were not identified. Also, the company did not establish an effective escalation process for the repeated occurrence of the bacteria. Furthermore, as a response to a market opportunity, Maple Leaf Foods produced large quantity of its deli meat products, targeted specifically to institutions such as hospitals and long-term care facilities serving high risk individuals, using a low-sodium recipe that increased the potential for Listeria to grow3. However, Maple Leaf Foods did not make corresponding adjustments or improvements to enhance its food safety procedures to reflect the higher risk identified in this special kind of deli products. Apparently, in this issue, Maple Leaf Foods was an active agent; it purposely reduced the sodium to cater

I inoculated a T-Soy agar with bacteria number 118, for this I used a streak isolation method. Next, in order to distinguish between Gram positive and Gram negative I used a streak isolation technique on a CNA plate, then performed the same exact procedure on a MacConkey plate. The results from the CNA plate showed the Gram Positive bacteria was an Alpha hemolyzer. Next, I used a P Disc on a T-Soy agar inoculated with bacteria 118 and determined the Gram Positive bacteria was not sensitive to P Disc antibiotics. This revealed the Gram Positive bacteria to be Streptococcus Mitis. The results from the MacConkey plate proved the Gram Negative bacteria to be a lactose fermenter. With the Gram Negative bacteria I performed a lysine test with positive results. Next, I performed an ornithine test on the Gram Negative bacteria, with negative results, therefore I concluded the Gram Negative bacteria was Klebsiella pneumoniae.

The consumption of fruits and vegetables have been regarded as a case contributing to the foodborne microbial disease outbreak. The contributor of the largest number of outbreak reported is melon. There were three outbreaks associated with melon including an outbreak of listeriosis in melon in 2009 which caused 9 people received treatment and 2 died, an outbreak of salmonella saintpaul in the same year, nearly 100 suspected and confirmed cases, 9 people received treatment and other suspected in outbreak of Cyclospora in 2010 resulting in at least 314 people becoming ill.There was an outbreak report of hepatitis in 2009, which is one of the largest foodborne disease outbreaks related to the consumption of fruit in Australia. This outbreak caused

The bacterium is largely spread in nature and be present in soil, water and contaminated foods. Animals and fresh produce are prone to contamination in foul environment. How this affected Enterprise Food, is the factory workers were in the presence of the bacterium while they were producing the perishable, and from the above research listeriosis shows that it has the ability to affect the working environment through oxygen ‘inhaling’, and through quality checks when the quality in spectator test the product as for quality protocol by tasting the perishable meat. Infection of the bacterium can cause in mild to severe febrile gastroenteritis and in pregnant women, the bacterium can cause pregnancy loss. (National institute for communicable

A wide range of food products have been associated with the transmission of listeriosis, primarily milk and dairy products, meat products (cooked chicken, pate, rillettes, sausages, salami), vegetables (coleslaw and rice salads, celery, alfalfa) and, in a lesser degree, fish products (smoked fish, shellfish, shrimp). Generally, these foods have extended shelf life, do not require further cooking and support the growth of the bacterium.

Distinctive strains of Lactobacilli are used as health promoting probiotic ingredients since they have a several therapeutic functions including resistance to antibiotics, bile resilience and gastric juice resistance. Lactobacilli include a vast and differing gathering of Gram positive, non-spore forming, catalase negative, and rod shaped microscopic organisms able to convert lactic acid as the primary end product of the fermentation of carbohydrates. Different Lactobacillus species do not produce toxic substances and are nonpathogenic. As of late a lot of attention is being given to isolation of Lactobacilli from different sources which are also used as bio preservatives, traditional fermented milk products and is a very popular menu at the

L. bulgaricus are used as starter cultures during yogurt fermentation and are regarded as probiotics (Perna et al, 2008)

Listeriosis; a foodborne disease, has been considered to be an emerging zoonotic disease worldwide. Listeriosis caused by Listeria monocytogenes that is a ubiquitous bacterium, widely distributed in many natural and man-made environments where it can survive for long periods of time (USFDA, 2001). Listeriosis is a serious and potentially fatal foodborne disease, which mainly affects the persons who have underlying illness or are immunocompromised, the elderly and pregnant women. An increasing trend of reported Listeriosis was observed in recent two years (CHP, 2013).

Listeria Monovytogenes is a soil opptunistic bacterium that at same time is a food borne pathogen. Though its existence in nature can be as high as 20% in soil-plant sample, the infection occurs in healthy population is rare. However, to population that have immature or compromised immune systems, it is a dangerous pathogen; its infection has a mortality rate as high as 30%. The first record of L. Monovytogenes discovery was in 1926, when Department of Pathology of the University of Cambridge routinely autopsies their laboratory animals that died during breeding, they found six rabbits that suffered sudden death have similar lesions without exposure to evident toxic or infection (). Two months later, they obtained a pure culture of gram-positive bacilli that is associated with observed disease. It was first named by the experimenters as bacterium monocytogenes and later it was categorized in to Listeria genus. After its discovery, L. Monovytogenes was found associated with neonatal sepsis and meningitis by a coincidence. In 1950, East German scientist Potel and his coworkers discovered several case of septicemia in newborn baby that have common characteristics of focal necrosis while in West Germany, scientist Seelinger found that adult suffer listeria septicemia also have similar focal necrosis(), and later, their collaborate work confirmed that L. monocytogenes is a significant pathogen in perinatal infections. However, it was not until 1981 that people

Listeria monocytogenes, a motile, gram-positive rod, is an opportunistic food-borne pathogen capable of causing listeriosis in humans. Listeriosis includes manifestations of septicemia, meningitis, pneumonia, and encephalitis. L. monocytogenes is also implicated in miscarriages, stillbirth, and premature birth for pregnant women. L. monocytogenes is a tough bacterium resistant to freezing, drying, and heat; most strains have been shown to be pathogenic. It is hypothesized that 1-10% of humans are intestinal carriers of L. monocytogenes. Over 37 mammalian species, including wild and domestic animals, are capable of L. monocytogenes infection and transmission. Extensive environmental reservoirs for L.

Now, we consider L. monocytogenes as a widely pathogenic organism especially towards pregnant women, newborns, elderly, immunosuppressed, or even healthy individuals. It is also recognized as a food pathogen in the food industry (CDC 2014).

One of the most recent examples of Listeria outbreak in recent times has been that of Dole Salads. Dole Salads is a major US company with its products being sold under the umbrella of various brands in major supermarkets such as Lidl, Aldi, Walmart etc.

Live Lactobacillus casei Shirota strain, cultured and tested in our laboratory, is added to the tank. The temperature of the tank is then reduced until the contents are at 37°C (body temperature). The solution is allowed to ferment in the tank for 6-9 days or until the numbers of Lactobacillus casei bacteria reach their ideal concentration.