Listeriosis: Foodborne Infection

TASK 2 Infectious diseases are the invasion of host organisms, (microbes) which can be invisible to the eyes. The microbes are also known as pathogens. A microbe infects an organism (which is known as the host of the microbe). In a human host, the microorganism causes a disease by either disrupting an important body process or by stimulating the immune system to mount a defensive reaction. The pathogen, interferes with the normal functioning of the host and can lead to chronic wounds, gangrene, loss of an infected limb, and even death.

The purpose of this lab report is to employ a myriad of skills, tools and, methods learned throughout this semester to perform the appropriate tests for the identification of the assigned unknown bacteria. Add more background information here!!! The most important tools and techniques used during this identification include aseptic technique, microscopic examination and, the use of selective and differential media. Aseptic technique is an important tool for microbiologists. It is imperative that aseptic technique is maintained throughout the length of any test to avoid any cross-contamination that may lead to inaccurate results.

PHAR 100 Assignment 3 1. Antibiotics are a form of medicine that seek out and destroy the bacteria that make us feel sick. Antibiotics work great against bacteria, however they don’t work against viruses. Penicillin was the first antibiotic to be discovered by Alexander Fleming, and it was first used to treat infections. Essentially, these powerful medicines fight bacterial infections, and have the potential to save lives.

The tube was placed back in incubation for 96 more hours to observe any more positives. 2.10 Catalase Test A trypticase soy agar plate was used and after incubation, four drops of 3% Hydrogen Peroxide was added to the plate to flow over the bacterial growth. A presence of bubbling was observed. 2.11 Starch Hydrolysis

By what mechanism do the authors propose that the mcr-1 gene confers colistin resistance, and what evidence do they use to support this assertion? The protein sequence of mcr-1 showed its similarity to the polymyxin-producing bacterium, Paenibacillus spp., which showed the possibility of gene transfer occurring. The mcr-1 gene enables protection from polymyxin. The mechanism that the authors proposed on how the mcr-1 gene confers colistin resistance is that mcr-1 causes a modification in lipid A, present in the lipopolysaccharides of most bacteria, which leads to lessened polymyxin affinity.

It is also stated some Exclusions and hygiene practice Some common types of food poisoning are succeeding Salmonella, Campylobacter, Cryptosporidium, Ecoli O157, Listeria Monocytogenes, Shigella - Bacillary Dysentery, Small Round Structured Virus. In Campylobacter, Symptoms include an overall feeling of disease, diarrhea, severe abdominal pain, high fever and sometimes vomiting. First symptoms can take up to 4 days from the eating of polluted food, but is more usually 12 - 48 hours. This infection normally continues 3 weeks but can last longer. This contagion is caused by large numbers of bacteria living on food.

The gram negative species are apart of the Enterobacteriaceae family. These are gram-negative rods, which are facultatively aerobic - either respiring or fermenting. Most are motile via a flagella (Carson, 2015). Salmonella enterica and Yersinia enterocolitica are both paracolons, which lack the ability to ferment lactose. Conversely, Klebsiella pneumoniae and Escherichia coli are both coliforms, which are able to ferment lactose.

This type of bacteria is normally a chemotroph however some are actually photosynthetic and will absorb sunlight to obtain energy. Eubacteria is a simple cell with rough walls. This type of bacteria is seen with a flagella which is a tail-like structure attached to the cell. Eubacteria can be found in nearly every environment such as soil, oceans and deserts. While some bacteria are autotrophs and are photosynthetic on the other hand some are heterotrophs for example, parasites that live on the host and decomposers.

After he found the cause of infection, Lister began to find ways to prevent infection. He had read about a chemical called carbolic acid that was poured on fertilizer to stop the spread of disease. Unfortunately, carbolic acid was so strong that it could burn skin, so Lister had to mix it with water to prevent it from harming the patient too much. The first time he used carbolic acid was on an eleven-year-old boy who had broken his leg. Lister covered the boy’s leg with a cloth covered in carbolic acid and the wound healed with no infection.

The unknown bacteria was then tested on multiple selective and differential media. Growth was present on the MacConkey Agar and the colonies were the same color as the plate, which told me my bacteria was gram negative and did not ferment lactose. There was no growth on the Mannitol Salt Agar, and this told me the unknown was not salt tolerant and did not

The second ½ of the organism was used for gram staining. The gram stain method was performed on the unknown organism per lab manual page 42 and two gram stain reactions were identified. Organism B was gram positive cocci in grape like clusters. Because organism B was positive I could eliminate Escherichia coli, Enterobacter aerogenes and Proteus vulgaris because these bacteria would be rod shapes. Organism A was gram negative pink rod shaped and because of gram positive morphology I could eliminate Staphylococcus aureus, Streptococcus lactis and Bacillus subtilis.

After experiment on microscope under oil immersion, I learned that my Unknown is gram positive. Under the lens, the bacteria appears in purple color. Its morphology is cocci arranged in cluster. However, during decolorizing process, I put too much alcohol to the crystal violet-iodine complex making the color overly removed. That led to the result of my gram positive has slightly redish

Approximately 60-90% of the Gram-positive bacterial cell wall is made up of peptidoglycan and interwoven teichoic acid, while only

I. There are numerous amounts of diseases all over the world. In the present time, these diseases are cured or contained by vaccines. A couple centuries ago, doctor Edward Jenner developed the first vaccine in 1796. He discovered this vaccine by observing his ambiance. Jenner realized that milkmaids (tend to cattle) frequently contracted cowpox, but after they convalesced they were immune to the deadlier disease smallpox.

S. aureus is a non-motile facultative anaerobic bacteria. This bacteria can survive long periods in the environment; so it is readily transmissible. S. aureus causes a number of medical infections and is the leading cause of wound infections. It is an opportunistic bacteria, and infects any population. It favors the skin, since it is part of the normal flora.