The September 11, 2001 Attack On The United States

The September 11, 2001 attack on the United States will forever be remembered as one of the darkest days we faced as a nation. Almost 3000 lives were taken that day by a terrorist group using four commercial planes as weapons. Two of those planes were crashed into the World Trade Center, the third into the Pentagon and the fourth falling short of the White House landing in a field in Pennsylvania. The imagery of that heinous act still lingers among many including myself. I can recall exactly where I was and what I was doing. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦..This horrific misfortune on our country has forever changed our lives and the way we travel. In the days following the 9-11 tragedy, the level of fear and uncertainty crippled our nation and its†¦show more content†¦People were terrified of flying and thus, the number of passengers flown started to decline. Rather than taking vacations, the vast majority of people were taking â€Å"staycation†. It took the airline industry about â€Å"three years to start recovering from this terrible disaster† (IATA). The government always had resources and efforts focused at counterterrorism but it was never a top priority until the 9-11 attack. Government. The public did not feel safe and blamed the government for letting this catastrophe come to our home front. Our government was under a lot of pressure and felt something need to be done quickly. On November 19, 2002 President George W. Bush passed the Homeland Security Act (HSA). †¦Ã¢â‚¬ ¦. This act was created to â€Å"prevent terrorist attacks within the United States, reduce the vulnerability of the United states to terrorism, and minimize damage and assist in recovery for terrorist attacks that occur in the United States†(†¦Ã¢â‚¬ ¦). This HSA drastically restructured our government agencies in an effort to heighten national security and laid the foundation establishing the Department of Homeland Security (DHS). This was the most drastic change of government agencies since the National Security Act of 1947. There were some shifting around of agencies and their roles after the reorganization. For example, the Coast guard use to fall under the Department of Transportation and after the HSA was passed,

Skin Cancer Essay - 1178 Words

The Causes and Symptoms of Skin Cancer The Causes and symptoms of Skin Cancer While tanning beds and extreme use/exposure to UV rays are ways to get skin cancer, there are also various other ways to get it. Many don’t know that genetics and traits can actually play a huge role in developing this dangerous disease. They also don’t know that skin cancer is the most common type of cancer in the U.S. today. According to the Skin Cancer Foundation more people over the last 300 years have had skin cancer than all of the other cancers combined. They say that one in five people develop skin cancer throughout their lifetime; some surviving, some moribund. Skin cancer starts in the outermost layer of skin called the epidermis. The epidermis†¦show more content†¦Basal cell carcinoma treatment is very important because it can eventually grow deeper into your skin and destroy the tissue and/ or bone (Carucci JA, 2013). It usually looks like a raised, smooth, pearly bump on sun-exposed skin of the head, neck shou lders or back of hands. BCC is often mistaken for a sore that does not heal. (Staff, Skin Cancer Causes, 2012). Squamous Cell Cancer (SCC) is the next most common type of skin cancer. It accounts for about fifteen to twenty percent of skin cancers in individuals. SCC is two times as frequent in men as women and usually catches up with the victim at an older age. If the amount of sun/UV ray/lamp exposure is extremely great, it is possible to get it while at a young age also. Almost all of squamous cell carcinomas result from extreme exposure to UV rays, the sun, and/or lamps (Staff, Skin Cancer Causes, 2012). It is possible to get squamous cell carcinoma on any part of your body. A common place for women to get SCC is on their legs. Some types of SCC look like a common, well-defined, thick, red, scaly patch/ bump on one’s skin. If it is left untreated, it can form into a big mass and possibly spread to other parts of the body (Michael S Lehrer, 2013). The least common, yet mos t harmful, type of skin cancer is called malignant melanoma. It accounts for less than ten percent of skin cancers in individuals. This type of cancer can and most likely will kill a victim if not found earlier in a cancerShow MoreRelatedSkin Cancer1352 Words   |  6 Pagesare not taking skin cancer seriously after knowing its significance. Skin cancer has been a growing problem in the United States and millions of people have suffered from it every year. The three most common skin cancers are Melanoma, Basal cell, and Squamous cell, which can cause bumps, sores, growths, etc. Skin cancer is a deadly disease with many causes, but the advantage is that it can be prevented. Problem/Definition Skin cancer is a disease where cancer (malignant) cellsRead MoreEssay On Skin Cancer1814 Words   |  8 PagesSkin cancer is a very real and common health problem for Australians, with 2 in 3 developing this deadly disease by the age of 70 (Lynch, 2006). â€Å"Due to the Australian climate and lifestyle, as well as a predominantly fair skinned population, skin cancer is the most prevalent form of cancer in Australia,† (Australian Institute of Health and Welfare, 2000). For the most effective prevention against skin cancer, it is recommended that a combination of sun safety measures are met; slip, slop, slap,Read MoreSkin Cancer Essays629 Words   |  3 PagesSkin Cancer What is it and how to prevent it Skin cancer is the most prevalent of all cancers. There are three types of skin cancer: basal cell carcinoma, squamous cell carcinoma, and malignant melanoma. In this presentation I plan to discuss a little about each of these cases as well as tell ways to prevent and treat them. The first most common skin cancer is basal cell carcinoma. This cancer develops in the basal or bottom layer of the epidermis, which is the top layer of the skinRead MoreLiterature Review On Skin Cancer2421 Words   |  10 PagesLiterature Review Skin cancers have become increasingly prevalent over the last 30 years, with 87,000 new melanoma diagnoses per year in the United States (American Cancer Association, 2016). With regards to skin melanoma, medical professionals struggle most with the diagnosis rather than the treatment (Ferris et al., 2017). Therefore, it is important for the medical community to focus on diagnosis- related struggles. Pigmented Lesions and Routine Dermopathy There are various types of pigmentedRead More Melanoma (Skin Cancer) Essay1411 Words   |  6 PagesUV-B rays from the sun lead to premature aging of the skin, as well as the possible formation of skin cancer, know as melanoma. An appearance of a tan is actually a stage of burning and damage to the skin. Although a tan may be desirable to many, the fact remains that more people need to be educated on the dangers of the sun’s harmful rays, and the possible health complications of overexposure.   Ã‚  Ã‚  Ã‚  Ã‚  There are three main types of skin cancer. These are malignant melanoma, basal cell carcinoma,Read MoreIncidence Rate Of Skin Cancer1095 Words   |  5 PagesAbstract: Incidence rate of skin cancer are increasing day by day. Skin cancer is one of the deadliest forms of cancer but detected earlier can save the life time of the human being. An automated screening system is introduced to identify the presence of skin cancer in advance. In this paper, texture distinctiveness lesion segmentation algorithm is used. Experience and training-based characteristics of back propagation neural network is used with texture distinctiveness lesion segmentation algorithmRead MoreSkin Cancer Essay1118 Words   |  5 PagesTopic: Skin Cancer Thesis: Skin cancer is the most common type of cancer in the United States but is highly curable if detected early and treated properly. Specific Purpose: to inform the audience about the different kinds of skin cancer and what preventive measures you can take to protect yourself from skin cancer. I. Introduction A. Do you know that skin cancer is the most common type of cancer in the United States; two million people are diagnosed annually. B. Skin cancer is theRead MoreEssay about Skin Cancer and Expert Knowledge1495 Words   |  6 Pagesbody are both a source of material risk, from cancers, and a symbolic risk, such as being pale and unhealthy looking (Carter and Jordan, p. 76). This example shows how expert knowledge in the form of medical advice tells us to keep our skin covered so as to prevent exposure from the sun that could cause skin cancer, and how this is interpreted by society using the cultural practice of booking holidays and how they balance the material risk of skin cancer with the symbolic risk of getting a tan inRead MoreSkin Cancer : A Significant And An Increasing Health Problem Worldwide1638 Words   |  7 Pages Arjun Ramakrishnan Morgan State University Skin Cancer April 28, 2016 Health Education 103.001 Abstract Skin cancer is becoming a significant and an increasing health problem worldwide. The main cause of this type of cancer is due to the damage done by the Ultraviolet (UV) radiation from sun. There are many other causes and behaviors which contribute towards skin cancer. Protecting the skin from sun by wearing appropriate clothing, a sunscreen with appropriate sun protectionRead MoreSkin Cancer Essay553 Words   |  3 Pagesâ€Å"Cancer†, its a disease that has claim the lives of millions, its a disease that so far has no known cure, and its a disease that has many different forms. Cancer is defined as â€Å"a malignant form of tumors, which are tissue masses that arise through mutations in the genes that govern cell growth and division† (Starr, 1999, p. 213). Skin cancer is just one of the many forms of cancer that effects us and is the most common cancer in the U.S. Like so many others, I would assume that the major cause of

Student with Challenging Behavior Learning Disability

Question: Discuss about theStudent with Challenging Behavior forLearning Disability. Answer: Introduction: The challenging behavior of students with disabilities leads to learning disability becoming a significant barrier to their academic and social inclusion. A learning definition can be defined by three main requisites, those are, impairment of adaptive and social functioning and beginning in childhood. The disabilities that are associated with learning are variant from specific learning difficulties such as dyslexia, which, do not influence the intellectual capability. The term learning disability is the most accepted term all over the world. The amount of support that a person with learning disability needs depends on the seriousness of the disability. It is therefore important that each student be treated as a separate individual having certain strengths and weaknesses and needs (Chandler Dahlquist, 2014). This report discusses the development and maintenance of challenging behavior along with the strategies that is to be used by teachers and schools to prevent challenging behavior s. Additionally, the report shall also consist of a comparison between school wide positive behavior and positive behavior supports that are planned for individual students. The Development and Maintenance of Challenging Behavior: Emerson et al. developed the definition of challenging behavior, and the definition has become widely used in the perspective of learning disabilities. According to him, behavior of such intensity, frequency and duration that the physical safety of the person or others is likely to be placed in serious jeopardy or behavior which is likely to seriously limit or delay access to, and use of ordinary facilities. According to the National Institute for Health and Care Excellence (NICE), children with learning disabilities display behavior that are challenging. Children possessing behavior that are challenging is an indication that such kind of behavior is a challenge to their family, services and take carers. Some of the typical behavior that students with challenging behavior have are attracting attention of other people, avoiding demands of peer group and lack of communication (Friend, 2013). This kind of behavior is an outcome of personal and environmental interaction including aggression, stereotypic behavior and self-injury, destructive behavior and withdrawal. Sometimes, it also includes sexual abuse, arson and violence and children may encounter the criminal justice system. Thus, it is easy for children with learning disabilities to encounter behavior that are challenging. The behavior becomes more challenging if students have severe disabilities (McLeskey et al., 2012). However, according to Janes et al., (2013) the prevalence rate of challenging behavior is between 5 to 15 percent in social care, health and educational services. The rates go higher in teenagers, especially children in their early twenties. For example, 30 to 45 percent in health care setting. People who have disabilities in learning also have specific communication problems, sensory impairments, physical or mental problems, dementia, autism, and other behavioral challenges. The behavior is visible only in certain kind of environment and the same behavior may be deemed as challenging in some other social or cultural setting. The behavior is an outcome of sensory impairment or avoiding demands. Typically care environments that in which there is lack of social interaction and significant occupation, lack of sensory input and lack of choice and sometimes too much noise. Moreover, it also included care environments that are unresponsive, unpredictable and crowded characterized by abuse and avoidance. To be able to identify the behavior that are challenging in nature proper risk assessments should be conducted, keeping in mind their biological and environmental need along with assessment of their functions. The interventions differ from child to child depending on the triggers that may be set at multiple levels of treatment. The aim should always be to protect the quality of life of the children. Effective Strategies that can be used by Schools and Teachers to Prevent or Reduce Challenging Behaviors: It was held by Cortiella Horowitz, 2014, that one of the most effective ways of managing challenging behavior that is developed by teachers is to attempt to prevent it from happening in the first place. Many schools have come up with many strategies that develop and promote positive behavior. This idea is an evolution that is based on the assumption that all kind of behavior whether negative or positive is learned and hence, acceptable behavior can be learned. Behavior is circumstantial so students can be taught to behave in a certain way in the context of school. Acceptable behavior of children should be reinforced by the school that should be supported with positive behavior. According to Bryant et al., 2016, many mainstream schools have become inclusive in their approach for managing children with disabilities. Mainstream schools, almost every day, encounter situations in which they have to manage children with challenging behaviors. Schools should have Code of Behavior that regulates the behavior of children with learning disabilities. Children are born with an inherent need for safe and secure environment. The classrooms of children can be one of the safest and stable environments for children. Children learn many behavioral aspects from their classrooms. Teachers have the obligation of modeling positive behavior with students by having a more positive approach towards them. According Matson et al., 2014, children are responsive to attention and react positively to behaviors that are reinforced. Teachers often catch children that are being good and reward them positively, and praise them for such actions. When children are reinforced with a positive attitude towards them, it enables them to cope up with behavioral issues easily. Many teachers have developed a formalized manner of praise and approach where children can earn points, stickers and rewards for positive behavior. Chung et al., 2012, provides advice to teachers and schools for the use of rewards for positive behavior: Reward properly for positive behavior as soon as possible The pay offs should be made small and easily achievable The rewards should be made cumulative The pay offs should be made cooperative A reward should not be taken back The element of surprise should always be made a part of rewards However, many disruptive behaviors are also a part of classroom activities at times especially when moving from one activity to the other activity. Thus, it is advisable for teachers and schools to plan their daily routines accordingly. It is also advisable for teachers and schools to give clear instructions to students and clarify their doubts with love and affection. Teachers give many set of instructions to students hence, it is important for teachers to ensure that children understand their instructions carefully. A Comparison Between School Wide Positive Behavior Supports and Positive Behavior Supports that are Planned and Implemented for Individual Students: Many strategies have been developed by schools as part of whole school approach for the promotion of positive behavior. Schools have reported that such a kind of approach has been more effective for children with challenging behavior. Many advantages are related with wide school approach. According to Bethune Wood, 2013, a common belief that schools that focus on care, respect and responsibility can be both a commencing point as well as an outcome of positive behavior. Some of the examples of ethos include assemblies where success of students is celebrated, positive attitude of parents and helping children with special educational needs. The keystone of such a belief is that is shared by the whole school community including children, parents, teacher and board of management. Whereas, the positive behavior approach (PBS) is variant from the wide school approach having less number of inclusions for controlling challenging behavior. According to Gebbie et al., 2012, challenging behaviors are learned and acquired and therefore they can be easily changed. According to the believers of the PBS approach, there is no wrong in wanting attention or escaping from a difficult situation. The PBS approach helps the children in attaining the life they need and this they do by increasing the ways of achieving the things children look for or rather hunt. The PBS approach helps people in acquiring new skills. The reason why they focus on children in acquiring new skills is that it shall help them in overcome difficult situations (Snell Brown, 2014). The PBS plan focuses on the development of two major strategies those are: Proactive Strategies: The proactive strategies allows children to get what they want on a daily basis and also teach them the appropriate skills for communication Reactive Strategies: The reactive strategies help the children to be safe and protected in an environment where they have no sense of fear. The PBS notes the reaction of children when they are placed in such a kind of environment and note their behavior accordingly. Therefore, it may be said that the wide school approach focuses more on reinforcement and having a positive attitude towards children whereas the PBS focuses more on the development of the adaptive skills of children. Conclusion: Teachers in isolation cannot meet the needs of children; there is a need of support of the whole community to address the issues related with challenging behavior. The support of wide school community in promotion of positive behavior is essential. This report has focused on the wide school approach as against the PBS approach for managing children with challenging behavior. Additionally, the report has also discussed appropriate strategies for managing children with challenging behavior. References: Bethune, K. S., Wood, C. L. (2013). Effects of coaching on teachers use of function-based interventions for students with severe disabilities.Teacher Education and Special Education: The Journal of the Teacher Education Division of the Council for Exceptional Children,36(2), 97-114. Bryant, D. P., Bryant, B. R., Smith, D. D. (2016).Teaching students with special needs in inclusive classrooms. SAGE Publications. Bulgren, J. A., Sampson Graner, P., Deshler, D. D. (2013). Literacy challenges and opportunities for students with learning disabilities in social studies and history.Learning Disabilities Research Practice,28(1), 17-27. Chandler, L. K., Dahlquist, C. M. (2014).Functional assessment: Strategies to prevent and remediate challenging behavior in school settings. Pearson Higher Ed. Chung, Y. C., Carter, E. W., Sisco, L. G. (2012). Social interactions of students with disabilities who use augmentative and alternative communication in inclusive classrooms.American Journal on Intellectual and Developmental Disabilities,117(5), 349-367. Cortiella, C., Horowitz, S. H. (2014). The state of learning disabilities: Facts, trends and emerging issues.New York: National Center for Learning Disabilities. Friend, M. (2013).Special education: Contemporary perspectives for school professionals. Pearson Higher Ed. Gebbie, D. H., Ceglowski, D., Taylor, L. K., Miels, J. (2012). The role of teacher efficacy in strengthening classroom support for preschool children with disabilities who exhibit challenging behaviors.Early Childhood Education Journal,40(1), 35-46. Matson, J. L., Hess, J. A., Mahan, S. (2013). Moderating effects of challenging behaviors and communication deficits on social skills in children diagnosed with an autism spectrum disorder.Research in Autism Spectrum Disorders,7(1), 23-28. McLeskey, J. M., Rosenberg, M. S., Westling, D. L. (2012).Inclusion: Effective practices for all students. Pearson Higher Ed. Rispoli, M., Ninci, J., Neely, L., Zaini, S. (2014). A systematic review of trial-based functional analysis of challenging behavior.Journal of Developmental and Physical Disabilities,26(3), 271-283. Snell, M. E., Brown, F. E. (2014).Instruction of students with severe disabilities. Pearson Higher Ed.

Listeria Monocytogenes free essay sample

The bacterium was named monocytogenes because one distinguish characteristic of infection in rabbits, which was the production of monocytosis in blood (Shuin et al. , 1982). L. monocytogenes is phychrophilic, has a temperature for growth of 0Â °C to 45Â °C (Barbosa et al. 1994), and enjoys a competitive advantage against other gram-positive and gram-negative microorganisms in cold environments, such as refrigerators. Recent investigations indicate that the organism can initiate growth at pH values as low as 4. 4. Also, it grows optimally at water activity of 0. 97. For the majority of strains, the minimum water activity needed for growth is 0. 93 (Lou et al. , 1999); however, some strains may be able to grow at water activity values as low as 0. 90 and survive for long periods of time at 0. 83 (Shahamat et al. , 1980). L. onocytogenes is able to grow in the presence of 10 to 12% sodium chloride; it grows to high populations in moderate salt concentrations (6. 5%). The bacterium survival in high-salt environments is significantly increased by lowering the temperature. We will write a custom essay sample on Listeria Monocytogenes or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Route of Exposure L. monocytogenes is particularly interesting as a foodborne pathogen in that it is ubiquitous in nature. The current understanding of human listeriosis epidemiology suggests that the organism is a common contaminant of food products. This contamination usually takes place on the surface of the products, with up to 15% harboring the organism. The presence of L. monocytogenes in the food processing chain is evidence by the widespread distribution of the listeriae in processed products. Occurrence of sporadic listeriosis appears to be more common in the spring and summer months. This could be explained by seasonal variations in the type of food products eaten by human populations, with higher-risk products eaten in the warmer months. Some outbreaks investigations suggest that certain ready-to-eat processed foods pose a high risk of contracting listeriosis for susceptible populations. These foods are usually preserved by refrigeration and offer an ppropriate environment for the multiplication of L. monocytogenes during manufacture, aging, transportation and storage. The entry of L. monocytogenes into food processing plants occurs through soil on clothing or equipments, contaminated hides or surfaces, and possibly healthy human carriers. The humidity and presence of nutrients support the growth of Listeria, which is commonly found in moist areas such as processing equipment, drains, etc (Cox et al. , 1989). In addition, Listeria can attach to different types of surfaces and biofilm formation has been observed in meat and dairy processing environment (Jeong et al. 1994). Post-processing contamination is the most likely route of contamination of processed foods. Currently, there is no evidence to indicate that L. monocytogenes can survive heat processing protocols. However, because it is a frequent contaminant of raw material used in food processing plants, there are plenty opportunities for reintroduction of listeriae into food processing facilities by cross contamination (Doyle, 1988). If the product is contaminated during its elaboration, the bacteria can survive and multiply throughout storage causing disease when it is consumed. In conclusion, epidemiologic investigations have repeatedly revealed that the consumption of contaminated food is the primary mode of transmission of listeriosis. Food has been identified as the vehicle of several major outbreaks of listeriosis investigated since 1981. Food Associated Some of the food products associated with L. monocytogenes include unpasteurized milk and products prepared from unpasteurized milk, soft cheeses, frankfurters, delicatessen meats and poultry products, and some seafood. Raw milk is a well-known source of L. monocytogenes. Pasteurization effectively inactivates this organism. However, fluid milk that is contaminated after pasteurization and stored under refrigeration may achieve very high populations of L. monocytogenes after one week; Furthermore, temperature abuse may enhance the multiplication of bacterial cells. L. monocytogenes can also be found in cheese because of its relative hardiness to temperature fluctuations, ability to multiply at refrigeration temperature and salt tolerance. During manufacturing process, L. monocytogenes is primarily concentrate in the cheese curd, with only a very small portion of cells appearing in the whey. Then, during ripening of the cheese, the numbers of cells may increase (Camembert), decrease gradually (Colby or cheddar), or decrease rapidly (blue cheese) and then stabilize. In addition, cooked and ready-to-eat meat and poultry products have been implicated as the source of sporadic and epidemic listeriosis on several occasions in North America and Europe (Schwartz et al. , 1989). L. monocytogenes attaches strongly to the surface of raw meats and is difficult to remove or inactivate. The multiplication in meat and poultry depends on the type of meat, pH, and the type of cell populations of competitive flora (Farber et al. 1999). However, it has been shown that poultry supports the growth of L. monocytogenes better than other meats. Furthermore, the incidence of L. monocytogenes in ready-to-eat products has become a major concern for the meat processing industry. Ready-to-eat meat products that have been received a heat treatment followed by cooling in brine before packaging may provide a particularly conducive environment for multiplication of L. monocytogenes because of the reduction in competitive flora and the high salt tolerance of the organism. L. onocytogenes has also been isolated from domestic and imported, fresh, frozen, and processed seafood products, including crustaceans, molluscan shellfish and finfish (Jinneman et al. , 1999). However, seafood consumption is still much less when with consumption of meats and cheeses. Also, the production of seafood products is done on a much smaller scale than meat and cheese manufacture. This may be the reason that large outbreaks have not been reported and that case-control studies have not identified this group as a major risk of listeriosis (Rocourt et al. 2000) Characteristics of the disease Human disease usually occurs in high risk groups, who have a predisposing disease that leads to impairment of their T-cell mediated immunity. However, may occasionally occur in individuals with no predisposing conditions. Some of the high risk groups may include pregnant woman, neonates, and immunocompromised adults (Goulet et al. , 1996). On average, there are 0. 7 cases of listeriosis per 100,000 people, but the disease is seen three times higher in the elderly (gt;70) and 17 times higher in pregnant women. A wide variety of clinical syndromes have been associated with L. monocytogenes in both humans and animals. In healthy individuals, the disease can take the form of mild to substantial flu-like symptoms, including: fever, fatigue, nausea, cramps, vomiting and diarrhea. More severe complications can include: encephalitis, septicemia, mononucleosis-like syndrome, pneumonia, endocarditis, aortic aneurysm, hepatitis, urethritis, rhombencephalitis, peritonitis, liver abscess, febrile gastroenteritis, CAPD peritonitis, septic arthritis, etc. (Dalton et al. , 1997). Lonocytogenes in pregnant women can lead to an intrauterine infection, resulting in stillbirths and miscarriages. Newborns can develop meningitis after birth via transplacental transmission. The onset time for serious complications of listeriosis can be anywhere from a couple of days to three weeks. Mortality of untreated infections is among the highest of all foodborne illnesses, 70 percent. The infective dose of L. monocytogenes is not yet known, it is related to variables, including: strain, susceptibility of the victim, type food from which is was consumed, etc. Mode of Action Listeria monocytogenes is the most invasive bacteria known. The principal site of infection is the liver, but it can invade many cell lines of different types (microphages, fibroblast, hepatocytes and epithelial cells). Listeria monocytogenes infects the host via oral route. Once the bacteria are ingested, they reach the intestine and are translocated between enterocytes and M cells (Pron et al. , 1998); however, the intestinal dendritic cells in the Peyer’s patches appear to be the preferred site for invasion and multiplication (Kolb-Maurer et al. 2000). Bacteria are then internalized by resident macrophages, in which they can survive and replicate. They are subsequently transported via the blood to regional lymph nodes. When they reach the liver and the spleen, most listeriae are rapidly killed. Depending on the level of T-cell response induced in the first days following initial infection, further dissemination via the blood to the brain or, in the pregnant individuals, the placenta may subsequently occur. In addition, bacteria are internalized in membrane-bound vacuoles, which are lysed within 30 minutes. Intracellular bacteria are released to the cytosol and begin to multiply with doubling time of about one hour. These intracytoplasmic bacteria become progressively covered by a cloud of cell actin filaments that later rearrange into a polarized comet tail up to 40 ? m in length (Crossart, 1995). The actin comet tail is made of actin microfilaments that are continuously assembled in the vicinity of the bacterium, then realeased and cross-linked. The entire bacteria cycle is completed in about 5 hours. If cytochalasin D is added after entry, bacteria do not spread within the cytosol. They replicate and form microcolonies in the vicinity of the nucleus. Hence, actin polymerization is essential to intracellular movement and cell-to-cell spreading. In summary, the pathogenic mechanism of L. monocytogenes involves the following steps: adhesion to the host cells, lysis of the phagosome, replication in the host cytoplasm, actin-based intracellular movement and propulsion, and the intercellular spread. Biotransformation Listeria monocytogenes is of interest to a board range of investigators, including food microbiologist, clinicians, immunologist, medical microbiologist, and even cell biologist because it is developing resistance to most currently used antibiotics. In the past, individuals who develop listeriosis have usually been treated with penicillin or ampicillin in conjunction with an aminoglycoside (Charpentier et al. , 1999), although tetracycline, erythromycin or chloramphenicol, alone or in combination, has also been used (Hof et al. , 1991). More recently, reports of resistance in Listeria spp. have been published. Such increases in antibiotic resistance have been linked to over-use of antibiotics in animals and humans (Rao, 1998) since these therapeutic compounds were identified nearly 60 years ago. This resistance may arise from a mutation in an intrinsic chromosomal gene, or by acquisition of exogenous genetic material carrying single or multiple resistance determinants (Levy, 1994). It is now clear that such transfer is possible between unrelated bacterial species (Kruse et al. 1994), and that these interactions are a frequent and important means of genetic exchanges among microorganisms. In conclusion, it is evident that antibiotic resistance is becoming more and more widely reported in all bacteria. Control and Prevention Because L. monocytogenes can grow at refrigerator temperatures, the Center of Disease Control and Prevention (CDC) advise all consumers to reduce the risk of illness by using a refrigerator thermometer to make sure that the refrigerator always stays at 40 Â °F or below and using perishable items that are precooked or ready-to-eat as soon as possible (CDC, 2005). For high risk groups it is recommended to not consume hot dogs and luncheon meats, unless they are reheated until steaming hot; not eat soft cheese such as Feta, Brie, and Camembert cheeses, unless it is labeled as made with pasteurized milk; not eat refrigerated smoked seafood, unless it is contained in a cooked dish; and not drink raw (unpasteurized) milk or eat foods that contain unpasteurized milk. Therapy When listeriosis is a likely diagnosis, the use of ampicillin or, in penicillin-allergic patients, vancomycin will provide empiric coverage for L. onocytogenes until the diagnosis is made by culture. Once listeriosis is confirmed, a combination of ampicillin and gentamicin is the current therapy of choice for all forms of listeriosis. The duration of the treatment for invasive listeriosis has not been studied. Relapses appear to be uncommon, and two to three weeks of therapy with ampicillin and gentamicin is sufficient for most forms of listeriosis. Rhombencephalitis with abscess formation in the central nervous system may require more prolonged therapy, but data are not available that support treatment beyond four weeks (Lorber, 1997).