Medical Microbiology: Escherichia Coli and Chagas Disease - Essay Example

? Medical Microbiology Medical Microbiology Case Escherichia Coli is a bacteriumthat normally lives inside the mammalian intestines without causing any diseases however some strains of the bacteria can cause infectious diseases including diarrhea, and food poisoning. The symptoms of abdominal pain and fever indicate the presence of a similar infectious disease caused by E. coli. The examination of the feces of the two schoolboys showed the presence of gram negative rod bacteria which was identified as the causative agent for diarrhea. These gram negative bacteria seem most likely to be E. coli. During the 1950s a series of cases of Diarrhea were reported in which the enteropathogenic strain of E. coli (EPEC) was identified as the pathogenic agent (DuPont, Estrada-Garcia & Jiang 2009). This case is likely to be one of the similar cases which occurred as a result of E. coli during the time. Initially, in the 1940s serological methods were used to identify the EPEC strains of E. coli. This was done by examining the somatic and flagellar antigens that triggered immune responses by the antibodies. The best technique in order to identify EPEC bacteria is by means of their effacing histopathology and their properties while they attach to the intestines (DuPont, Estrada-Garcia & Jiang 2009). The laboratory diagnosis of bloody diarrhea caused by O157:H7 strain of E. coli involves sample taking of the feces which is then tested for the presence of O157 antigens by inoculating the sample onto sorbitol agar. Not only this, but other immunodiagnostic techniques are also present to be used for diagnosis (Engelkirk & Duben-Engelkirk 2008). The epidemiology of diarrhea involves several environmental factors including sanitation practices, the kind of immune response, and so on. Also, the toxin, Shiga produced by E. coli O157:H7 is one of the risk factors which aid the growth of the disease in the kidney (Manning 2010). All the risk factors collectively cause diarrhea. . A great amount of diarrheagenic E. coli is spread from food that is made at home. Since the bacteria E. coli can also be transferred via contaminated food therefore an effort was made by Healthy People 2010 so as to prevent infections that are spread from infected food (Manning 2010). Although E. coli is not the only causative agent for diarrhea however in this case the disease is caused by the gram negative pathogen. The first line of treatment of diarrhea caused by E. coli involves controlling and preventing the loss of nutrients and electrolytes from the body. Anti-diarrheal drugs may also be used as secondarily treatment which may have some adverse side effects. So as to prevent mineral dehydration, oral rehydration solution (ORS) is administered continually in addition to home available fluids (HAFs) (Ghosh 2013). Along with ORS, use of healthy nutrition that contains food of high energy density is recommended (Ghosh 2013). Also, antibiotics are of critical importance in the treatment of diarrhea as it prevents other infections associated with diarrhea. However strains of E. coli including ETEC, EIEC, and EHEC may not be able to be treated using antibiotics (Ghosh 2013). In case 1, the administration of raw yogurt eventually led to the eradication of E. coli because of its probiotic nature and its ability to create a balance of bacteria within the body. The use of pro-biotics has shown to reduce the period of the disease by at least 1 day. Other non-specific anti-diarrheal drugs have also shown to be useful (Ghosh 2013). If the disease is treated on time and sufficiently, the prognosis may prove to be good. However the conditions in which E. coli is spread may result in the recurrence of the disease in dirty and contaminated surroundings. Also, other complications may occur that may prove to be fatal (Ghosh 2013). Case 6 The Chagas disease is distributed across central and south America and is also known as the American trypanosomiasis (Moorhouse 2005; “American Trypanosomiasis” 2009). The disease is transmitted via a vector which transmits the parasite Trypanosoma cruzi from an infected host to another host (Brasil, Castro, Hasslocher-Moreno, Sangenis & Braga 2010). The vector in this disease is the kissing bug also known as triatomes which takes a blood meal from an infected host taking in the parasite T. cruzi and on its next blood meal, it transfers the parasite into its body thereby causing the Chagas disease (Moorhouse 2005). The disease is distributed in areas which favor the growth of the insect vector and is therefore spread across Mexico and South America (“American Trypanosomiasis” 2009). The initial symptoms for acute Chagas disease occur within one week of the infection and involve fever, lymphadenopathy, malaise, and occasional hepatosplenomegaly (“Chagas Disease” 2007). In most cases, the infectious symptoms go unnoticed due to their mild nature. Among immuno-compromised patients signs of the Chagas disease are often noticed at sites around the central nervous system. In case of chronic Chagas disease the initial signs may take up to many years to show up. Cardiac abnormalities occur that can result in congestive heart failure (“Chagas Disease” 2007). Various techniques including microscopy, parasite isolation, serology and other molecular methods can be used for the diagnosis of Chagas disease. Samples of blood, CSF (Cerebral-Spinal Fluid), and tissues stained with Giemsa or Wright can be used to detect the presence of T. cruzi during microscopic examination. The parasite is found in muscle cells and also in chagomas sometimes (“American Trypanosomiasis” 2009). In some patients, it may also be found in unconventional sites such as bone marrow, pericardial fluid, and other fluids. In another diagnostic test, numerous media are used for culturing T. cruzi from blood or tissue samples. However due to the slow and time consuming process of agent isolation, it is usually used when other methods prove to be unsatisfactory. Among serological tests include ELISA (Enzyme Linked Immuno-sorbent Assay) and IFA (Immunoflourescent) test. Molecular methods of diagnosis include polymer chain reactions (PCR) and Western Blotting (“American Trypanosomiasis” 2009). Treatment has proved to be most effective during the chronic phase. Antiparasitic drugs such as benznidazole and nifurtimox are available under specific drug protocols (“American Trypansomiasis” 2009; “Chagas Disease” 2007). Treatment through these drugs is advised for the prevention of further development of chronic disease. However these antiparasitic drugs are less efficient in treating Chagas disease in its chronic stage and may have several side effects along with it. The treatment of heart abnormalities in the infection is similar to other causes of heart diseases where a pacemaker may be used. Surgeries can be done to treat megaesophagus or megacolon caused due to Chagas disease (“American Trypansomiasis” 2009). Since there is no vaccine present for the Chagas disease, prevention involves precautionary measure so as to reduce the risk of getting infected in areas where the disease is widespread. The vector insect, triatomes usually feeds at night therefore houses should be improved such that there should be no holes or cracks where the insect vector can hide during the day. People should sleep in safe places or under nets in order to avoid being bitten by the triatomes. Animal pens should be made away from homes and the spraying of insecticides may kill the insects that may potentially be the disease carriers. Furthermore, blood donors should be screened for the absence of the parasite in their blood to prevent the transmission of the disease during blood transfusion. Other measures can be used to control the presence of insects around areas populated by humans. In particular, travelers should be aware of the prevention techniques so as to prevent them from acquiring the disease during their travel (“American Trypansomiasis” 2009). References Brasil, PE, Castro, LD, Hasslocher-Moreno, AM, Sangenis, LH & Braga, JU. 2010, ‘ELISA versus PCR for diagnosis of chronic Chagas disease: systematic review and meta-analysis’, BMC Infectious Diseases. Available from: BioMed Central [14 October 2013]. County of Los Angeles 2007, ‘Chagas Disease’, Acute Communicable Disease Control Manual. Available from: County of Los Angeles [14 October 2013]. DuPont, HL, Estrada-Garcia, MT & Jiang, ZD. 2009, ‘Escherichia coli Diarrhea’, Bacterial Infections of Humans, pp 299-314. Engelkirk, PG & Duben-Engelkirk, JL. 2008. Laboratory Diagnosis of Infectious Diseases: Essentials of Diagnostic Microbiology. New York: Lippincott Williams & Wilkins. Ghosh, A. 2013. Treatment & Prognosis in Pediatrics. London: JP Medical Ltd. Manning, SD. 2010. Escherichia Coli Infections. New York: Infobase Publishing. Moorhouse, A. 2005, ‘The Fight for Recognition: Chagas' Disease Meets Controversy’, Journal of Young Investigators. Available from: JYI [14 October 2013]. The Center for Food Security & Public Health 2009, ‘American Trypanosomiasis’, Iowa State University. Available from: College of Veterinary Medicine [14 October 2013]. Read More