Prevention of Spread of the Emerging Pathogens - Term Paper Example

 «Prevention of Spread of the Emerging Pathogens Out lines» Introduction 1.1 Factors giving rise to Emerging Pathogens 2.1 E.Coli 2.1.1 Types of E.Coli 2.2.2 Diagnosis of the Emerging Pathogen E.Coli 2.2 Vibrio Cholerae 2.2.1 Vibrio Cholerae an Emerging Pathogen 2.2.2 Disease caused by Vibrio Cholerae 2.2.3 Diagnosis 2.2.4 treatment 3. Prevention of Spread of the Emerging Pathogens 4. Conclusion 5. References Introduction Some bacteria are beneficial in other ways like they are used in agriculture for plant growth and some are used for cleansing of water. (Jeremy & Simon 2004). These bacteria act as pathogens which are destroying the health of many individuals in the society. Many pathogens are emerging in the society as antibiotics are getting resistant to the old pathogens. Emerging pathogens are the ones which are now entering the society or have previously remained dormant in nature. New pathogens are emerging in the society because of many reasons such as travelling, reservoirs, novel foods and increased animal contact. Some new emerging pathogens are Vibrio Cholerae, Campylobacter jejuni, Escherichia coli O157:H7 and related E. coli (e.g., O111:NM, O104:H21) (Tauxe 1997). The emerging pathogens are those pathogens which have previously not been discovered in the society. These emerging pathogens are different in nature from the current pathogens and are harmful to the human existence. They arise from different factors which are discussed subsequently and are difficult to treat as they have just entered the society (Sheridan & McDowell 1998). 1.1 Factors giving rise to Emerging Pathogens The emerging pathogens are very difficult to encounter as the exact factors causing them to rise are not yet understood fully. The foodborne pathogens are known to arise through a variety of changes in the previous genotypes and demographics of the bacteria. Novel foods are one of the most important aspects which cause these foodborne pathogens to arise. Novel food is giving a way to bacteria to ferment and make their way through the stresses encountered by them in the human body. It is believed that the bacteria possess some genes which undergo mutation when exposed to certain stresses and these help them to adapt to the new environment. Mutation is the key factor which is giving the emerging pathogens a way to rise in the novel food. Novel food applies the same techniques of pH, heat and disinfectants as before and these same techniques are providing the bacteria to adapt themselves (Sheridan & McDowell 1998). The most difficult task in encountering the emerging pathogens is that no one actually knows as to what the new pathogen would be or from where it would arise. The new bacteria has changed in nature and has adapted to the current methods of prevention hence it would be difficult to treat them without an appropriate new treatment method. Many of the pathogens are believed to be emerging from direct contact of human beings with the animals. Sea food is one type of food which is giving rise to many pathogens (Levinson 2008). Some pathogens entering the society at large become an epidemic for the society because of travelling patterns. For example an Indian living in forests can be a reservoir for some pathogen which may be unknown in the cities. This Indian can then travel to large cities to act as a host in transmitting certain pathogens. All these factors together are causing an increased risk of the emerging pathogens (Buchanan 1997; Skoovgard 2007). Environmental stress to the bacteria is also a pathway for the new pathogens to enter the society. Environmental stress here refers to the techniques through which the food is disinfected. This environmental stress at first suppresses the growth of bacteria but if the bacteria adapts to the environmental stress then it may cause the bacteria to become even more resistant to disinfectants (New). Increased contact with animals is believed to cause emerging pathogens to rise. The bacteria for tuberculosis are believed to enter the human society from cattle because of the increased contact between humans and cattle. Moreover even now it is seen that human beings are in great contact with the animals which provides a way to pathogens to enter the society. In some animals pathogens are dormant but when they enter a human body they become active (Levinson 2008). Some of the emerging pathogens would be discussed in this essay. The two most important emerging pathogens are E.Coli and Vibrio Cholerae which are both waterborne. 2.1 E.Coli 2.1.1 Types of E.Coli The E.coli can cause diarrhea, urinary tract infections, sepsis and meningitis. The diarrhea that occurs due to the E. coli is caused by four classes of this bacterium which function in different ways. The first one is the Enteropathogenic E. coli that affect usually infants below the age of two years and hence occurrences are mostly reported from maternity homes. This group of E.coli has the capability of binding to the cells of the intestine and destructs its microvillus which leads to diarrhea. The spread occurs through the consumption of water or via the sea food that infants consume (Jordan et al 1999; Buchanan & Doyle 1997). The next group of E. coli is Enterocytotoxigenic E. coli. This group is the major cause for traveler’s diarrhea in all age groups. It produces exotoxins which are known as heat labile and heat stable exotoxins. They have an effect on adenylate cyclase and guanylate cyclase respectively. These enzymes lead to a cascade of reactions which cause retention of fluid and electrolytes with the passage of the intestine. This is turn results in diarrhea. The cause for this infection is also via the dietary intake (Levinson 2008). The world health organization has reported that this group of E. coli accounts for a mortality rate which is very high that is 380,000 deaths and 210 million people suffer from this infection every year (Levinson 2008). Enteroinvasive E. coli as the name indicates is a strain of E. coli which takes over the cell and it also has the capability of moving ahead from one cell to another. It enters a cell by endocytosis and within the cell it replicates and starts spreading to other cells. Contaminated water, cheese and human contact are the ways of its spread (Levinson 2008). The patient presents with mucus or blood in stools, high body temperature and discomfort in the abdomen. This dysentery caused by enteroinvasive E. coli accounts for the mortality of 500,000 children in the developing nations of the world every year (Levinson 2008; Buchanan & Doyle 1997) The last group is the enterohemorrhagic E. coli. This strain of E. coli is responsible for the production of verotoxin which is an exotoxin. This produces toxigenic effects for the colonic cells (Levinson 2008). According to a report of the Centers for Disease Control and Prevention, each year 70,000 people are affected by this strain of E. coli. This strain spreads from the ingestion of beef that has not been cooked completely and properly. This toxin can lead to a halt in the formation of proteins by disrupting the RNA. This can lead to inflammation associated with bleeding in the colon. It can also result in a fatal condition which is known as hemolytic uremic syndrome. This condition occurs when the verotoxin enters the circulation of a person (Levinson 2008; Buchanan, R. L., & Doyle 1997). The E. coli bacteria can also affect the urinary tract resulting in urinary tract infections. The sign and symptoms include hematuria, dysuria, urinary frequency and pyuria. Hematuria is the presence of red blood cells in urine and it is also known as hemoglobinuria because hemoglobin is a the most important component of red blood cells. Dysuria means difficulty in urination and pyuria means pus in urine or white blood cells in urine. When there are 4 or more neutrophils present in the urine then the condition is called pyuria. The pili of E. coli bind to the cells of the urinary tract and lead to these infections. These infections can be restricted to the lower urinary tract and they also have the ability to move up towards the kidneys and lead to renal infection (Levinson 2008) E.coli can also spread into the blood and lead to septic shock in a person and especially newborns are more prone to E. coli sepsis because they lack IgM antibodies. This spread can also lead to a raised body temperature and hypotension. The bacteria E. coli also causes meningitis chiefly in infants. Antigen K1 is present in 75% of the E. coli bacteria discovered that causes meninigitis and the antigen cross reacts with B carpuscular polysaccharide. However the antigen K1’s virulence mechanism is not understood. These symptoms of E. coli infections take 48 to 96 hours to develop mostly but sometimes they may take one whole week to appear (Levinson 2008; Benjamin & Datta 1995). 2.1.2 Diagnosis of the Emerging Pathogen E.Coli In laboratory E. coli can be easily cultured on the nutrient agar as well as the Mac Conkey agar and the Eosin methylene Blue agar. They provide with grey, bright pink and metallic sheen colonies on the agars respectively. The most feasible temperature for E. coli is 37 degrees. Some of the E.coli strain forms lactose and if this lactose containing bacteria ferments then it would give a pink color with the Mac Conkey agar. While the ones which do not form lactose give a colorless result. It is seen that the bacteria gives different colors in different mediums. With EMB agar, the bacteria E.Coli gives a green sheen color. In laboratory diagnosis it is very important that the tests are able to differentiate between different bacteria. The characteristic feature which differentiates the E.coli bacteria from other lactose fermenting gram rods is its ability to produce the indole ring from the amino acid Tryptophan. Other than that it also has the characteristics of decarboxylation as it has the ability to decarboxylate the amino acid Lysine. E.Coli only uses acetate to produce carbon whereas other bacteria also have other sources to produce carbon. E.Coli O157:H7 does not have the ability to form the alcohol known as sorbitol whereas other bacteria do have the ability to form it. All these together can help to differentiate between other bacteria and E.Coli in laboratory diagnosis. If a human being is suspected to have this bacteria then majority of the tests are carried out on the stools. These stools show a positive sign of the bacteria if it is present in the human subject (Levinson 2008; Buchanan & Doyle 1997). E.Coli O157 is one of the deadliest strains of the bacteria. Different characteristics of this strain make it difficult for diagnosis and treatment. It is spread through animal carriers which are very difficult to be pinpointed as animals can catch the bacterium from many different sources. The outbreaks of this strain have reported to cause many illnesses in recent years and different treatment strategies have been formed in order to cure individuals who have consumed this bacterium. The mechanism of how O157 acts, mentioned above may be a breakthrough in the treatment strategies of the bacterium. The outbreaks of the E. coli O157 can also be controlled if strict measures regarding the feeding of animals are taken as the strain spreads only through feces and substances which have been contaminated previously. The strain has been widely studied upon and effective strategies to combat the diseases caused by it are underway! (Todd, 2007). 2.2 Vibrio Cholerae 2.2.1 Vibrio Cholerae an Emerging Pathogen Vibrio cholerae is the major pathogen belonging to the group of vibrio which causes cholera. Vibrio cholerae are gram negative rods which are shaped like a comma. This bacteria can be divided into two groups in accordance to the antigen present in the cell wall. It is divided into O1 and non O1 respectively. The O1 bacterium always causes an epidemic disease where as the non O1 would may or may not cause a sporadic disease. Vibrio Cholerae is transmitted like E.Coli through contamination of the food or water with fecal material. In human beings this bacteria is either active or in a non active state which may make the individual asymptomatic. Sea animals such as oysters and shrimps carry the bacteria and if they are not cooked enough before eating they may transmit the bacteria to the host (Levinson 2008; Ramana 2004) 2.2.2 Disease caused by Vibrio Cholerae The bacteria acts on the small intestinal walls where it colonizes itself and secretes enterotoxins. Colonization is a difficult process and to adhere to the intestinal walls the bacteria have to secrete mucinase. This mucinase dissolves the glycoproteins on the intestinal walls because of which the bacteria adheres to the walls of the intestine. Moreover an acidic medium may destroy the bacteria hence people who have taken antacids are more susceptible to the bacteria. Once the bacteria adheres to the walls it secretes an enterotoxin known as choleragen which produces the symptoms of cholera. Choleragen has two subunits known as the A and B subunit. With the help of the A subunit the bacteria is able to catalyze a reaction on the G8 protein. This G8 protein which becomes overly active then produces increased amounts of adenylate cyclise. This adenylate cyclise then activates protein kinases which opens ion channels. This is the major cause of loss of water from the cells as the ions along with them take the water to the lumen of the gut. This would then cause excessive diarrhea as occurs in cholera. The gene which codes for cholera toxin is the CTX gene (Levinson 2008; Ramana 2004). 2.2.3 Diagnosis Watery diarrhea is a symptom of cholera caused by vibrio cholerae. It can be diagnosed on the basis of laboratory diagnosis. Stool is cultured which shows the presence of bacteria through colourless colonies of the agar MacConkey. Lactose is slowly fermented in the bacteria because of which MacConkey agar works on it. TSI agar can also be used on it because the bacterium ferments sucrose. TSI agar shows an acid butt without gas when the bacteria is cultured with it (Ramana 2004; Sharma et al 2003). 2.2.4 Treatment The treatment in the case of cholera is adequate infusion of water and electrolytes in the body of the patient. This would balance his extracellular fluid and hence the person would not be affected majorly by the bacterium. Antibiotics can also be used in the case of these sporadic diseases. But they would not prove to be much effective when it comes to the destroying the bacteria. It may in some other way enhance the excretion of the bacteria from the body (Sharma et al 2003; Ramana 2004). 3.1 Prevention of Spread of the Emerging Pathogens Emerging pathogens are posing difficulties to be contained as they are new to the society. An example of combating the emerging pathogen E.Coli is given here. Vaccination for infections caused by E. coli does not exist but measures can be taken to prevent the occurrence of disease states associated with this bacterium. The water lines that are serving the purpose of supplying water that is used for consumption should be tested for the presence of bacteria. The presumptive coliform test is performed for checking the infiltration of water by feces and the coli levels according to this test should have a higher value tan 3 in a sample of 100 ml. The milk should also be examined and tests to check the presence of bacteria should be seen. In the hospital setting it should be made sure that those patients who are catheterized are given antibiotics prior to the process so that their chances of acquiring urinary tract infections are lowered. If patients who are on intravenous drugs or medications get infections again and again, these should also be removed. The cranberry juice contains tannins which have the ability to inhibit the binding of pili of that strain of E. coli which causes urinary tract infections to the urinary bladder epithelium. So the cranberry juice is used for the prevention of urinary tract infections. A person who gets traveler’s diarrhea should take medications like doxycycline in advance so that he cannot get infected. It should also be ensured that one is on a healthy diet which includes food that is properly cooked and water that is clean and these precautions should particularly be taken when travelling to areas where bacterial infections are common. (Levinson 2008; Lammerding & Paoli 1997). The above written methods can be carried out to contain many waterborne emerging pathogens from spreading. Surveillance is an important factor which can contain the emerging pathogens from entering the society. CDC is playing an important role in the surveillance programs in the United States of America. It is seen at many instances that these programs have been enhanced to contain the spread of the pathogen. Surveillance can include researches which can analyze pathogens which are currently dormant in the society or can analyze the pathogens which are far away in villages and are yet contained. Moreover animals are an important source through which the pathogens are being transmitted. Hence it is necessary that animals are looked upon by the scientists in seeing as to how they are transmitting the pathogens. The pathogens inside the animals should also be analyzed so that things about the pathogens are already known to the society. The role of the veterinary researchers can be highlighted in all these aspects here (Skovgaard 2007). In order to control the spread of emerging pathogens many measures can be taken. First and above all research should be done to find out the measures which can be carried out to avoid the pathogens from arising. New methods should be carried out in processing foods so that the pathogens cannot bear the stress. The bacteria emerging have presumably got resistant to factors like heat and cold hence other measures such as new disinfectants can be used when processing food. Seawater is becoming contaminated and this is a source of pathogens hence it should be made sure that seawater is kept clean. The contact between human beings and animals should be reduced to a minimum extent or tests should be carried out on animals to find out if they have a pathogen present or not. Travelling patterns should be analyzed and increased tests should be carried out on individuals who are moving from one area to the other. All these measures would help to contain the pathogens from spreading or emerging (Sheridan & McDowell 1998; Tauxe 1997) 4.1 Conclusion Emerging pathogens are important to curb in the society before they enter it and create an epidemic. Several of the prevention methods can be followed to keep a check on these emerging pathogens. The waterborne bacteria such as Vibrio cholera and E.Coli can prove to be deadly if not treated within the specified time. The diseases caused by these bacteria have decreased in the developed countries in comparison to the underdeveloped countries. If certain measures are taken in the underdeveloped countries then the effects of the waterborne pathogens can be decreased even more. Thus it is necessary that certain measures are taken to contain the effects of the emerging pathogens. References Benjamin, M. M., & Datta, A. R. (January 01, 1995). Acid tolerance of enterohemorrhagic Escherichia coli. Applied and Environmental Microbiology, 61, 4, 1669-72. Buchanan, R. L. (January 01, 1997). Identifying and controlling emerging foodborne pathogens: research needs. Emerging Infectious Diseases, 3, 4.) Buchanan, R. L., & Doyle, M. P. (January 01, 1997). 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