Difference between revisions of "Nocardia brasiliensis"
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Latest revision as of 13:55, 4 October 2017
Description and Significance
Nocardia brasiliensis is a Gram-positive branching, aerobic bacteria that forms white, chalky colonies on Columbia blood agar (Paramythiotou, 2012). Columbia blood agar is a common media, made from sheep, rabbit or horse blood that is used to isolate and cultivate hemolytic reactions of pathogenic microorganisms (Neogen, 2011). This organism lives in soil (good source of oxygen as plants produce oxygen) and lives on dead or decaying plants and usually enters the body through inhalation or inoculation (puncture wound) by something contaminated with N. brasiliensis (Shachor-Meyouhas, 2012).
This microbe causes Nocardiosis, which is a rare but potentially fatal infection. Nocardia brasiliensis creates an immunosuppressive environment in the body by interfering with the function of T. cells in the host (Rosas-Taraco, 2012). Entry into the body is usually the lungs, but skin lesions may be the first symptom of infection. Infections are most common in immunocompromised patients, HIV patients, bone marrow transplant recipients, and long time users of corticosteroids (Paramythiotou, 2012). It can cause a wide range of disease, infecting the lungs, skin/soft tissue and in some cases the central nervous system (CNS) (Smego, 1984). With this infection the pulmonary system is the most common receptor, this is due to inhalation being the primary source of exposure to this microbe. The symptoms of this include: coughing, shortness of breath, chest pain, hemoptysis, fever, night sweats, weight loss and fatigue. Also primary cutaneous and soft tissue Nocardiosis can occur from any sort of injury to the skin that involves contamination with soil. With this the skin can develop superficial abscess or localized cellulitis. (Wilson, 2012)
Doctors determine if a person has Nocardiosis by taking tissue samples and sending them in for staining and culturing. The type of sample that is usually taken from a patient includes sputum, a mucous that is coughed up from the lower airways, bronchoscopy, which is from the lungs, and skin and brain biopsies. This disease on a culture is shown by hyphae, which are long branching filaments and it also omits a mildew odor. Nocardia is a slow growing disease that may take up to four weeks to show a positive test. At this point in time, there are no serological methods available for diagnosis (Rull 2011).
Treatment in severe infection may involve surgery, this, accompanied by antibiotic therapy can show a positive prognosis. The most common drug/antibiotic therapy for Nocardiosis is trimethoprim/sulfamethoxazole. But there are other antibiotics that are also used to treat this infection: amikacin, imipenem, third-generation cephalosporins, minocyclin, and amoxicillin-clavulanic acid and recently, linezolid. Even with the antibiotics, this infection takes an extended period of time to recover from, ranging from weeks to months. (Paramythiotou, 2012) In one study at Duke University Medical Center, all patients whose skin/soft tissue were affected recovered with antibiotic treatment, but for those who had a central nervous system (CNS) infection the mortality rate was 67% (Smego, 1984).
N. brasiliensis is predominantly found in the soil and usually in tropical climates. In the United States it is mainly found in southeastern and southwestern regions (Paramythiotou, 2012). It can infect people with a healthy immune system, but those cases are very rare (Kumar, 2005). One case study was an eight year old girl who developed an ulcer in her leg, tenderness and swelling in the area, and a fever. The girl had never traveled or been exposed to any strange animals, for that reason the doctors grew a culture and found out she had contracted the infection of Nocardiosis, after some investigating they found out that she had been spending extended periods of time in the garden, where they believe she got the infection. (Shachor-Meyouhas, 2012)
Kumar, T.; Scott, JX; Viswanathan, S.; Agarwal, L;, Raj, PM; Lalitha, MK. (2005). Cervicofacial nocardiosis in an immunocompetent child. Acta Paediatr, 94(9), 1342-3.
A 1 year old patient with no immunodeficiency problems is found to have an infection of Nocardia brasiliensis. This is very rare for a patient with a healthy immune system to contract this type of infection. The patient responded to antibiotic treatment.
Moeller, C., Schwartz JG, McGough DA, Thorner RE, Fetchick RJ, Tio FO, Rinaldi MG. (1986). Primary lymphocutaneous nocardia brasiliensis infection. JAMA Dermatology, 122(10), 1180-1182.
An elderly diabetic man presents with infection one month after inoculation by a contaminated needle. There were no symptoms prior to the trip to the hospital. Treatment required 2 surgeries and months of antibiotic therapy.
Neogen Corporation. (2011) Columbia Blood Agar Base. Neogen Corporation.
Columbia Blood Agar is used with blood to isolate and cultivate a wide variety of microorganisms. Columbia blood agar media are usually made up with sheep, rabbit, or horse blood for use in isolating, cultivating and determining disease causing microorganisms. This type of media was developed after the Columbia Agar formulation described by Ellner et al. from Columbia University.
Paramythiotou E, Papadomichelakis E, Vrioni G, Pappas G, Pantelaki M, Kontos F, Zerva L, Armaganidis A. (2012). A life-threatening case of disseminated nocardiosis due to nocardia brasiliensis . Indian Journal of Critical Care Medicine, 16 (4), 234-237. doi: 10.4103/0972-5229.106512
A 67 year-old male came into the emergency room with a fever and skin lesions. His BP was low and soon he soon went into respiratory failure, was intubated and sent to the ICU. Chest x-rays showed his lungs were compromised. Gram stains of bronchial secretions showed the infection was a result of nocardia brasiliensis. The patient was treated with antibiotics and discharged 10 days after admission to the hospital.
Rosas-Taraco, A., Perez-Liñan AR, Bocanegra-Ibarias P, Perez-Rivera LI, Salinas-Carmona MC. (2012). Nocardia brasiliensis induces an immunosuppressive microenvironment that favors chronic infection in balb/c mice. Infection and Immunity, 80(7), 2493-2499.
This study looked specifically at the immunosuppressive qualities of Nocardia brasiliensis. They did this by looking at the number of Treg cells. It was determined that this bacteria creates an immunosuppressive environment that benefits the survival of the bacteria.
Rull, Gurvinderv (2011). Nocardia. Patient.co.uk. 1655 (23). Nocardia is a Gram-positive bacillus which causes multiple illnesses which includes nocardiosis. This organism is found in the soil where it breaks down the organic matter in the soil for its food. It is found all throughout the world. Diagnosis of the disease is confirmed by the growth of nocardia in the tissue samples which are sent for staining and culturing. This microbe tends to give off a mildew odor. At this time in the world there are no serological methods available for diagnosis. The types of specimens that can be sent include sputum, bronchoscopy specimens, and skin or brain biopsies. Nocardia is a very slow-growing which can take up to four weeks to get a positive result. Patients with Norcardosis are usually treated with a round of antibiotics to begin with which slows the growth of the nocardia.
Shachor-Meyouhas, Y., Ravid S, Suhair H, Kassis I. (2012). Primary cutaneous nocardia brasiliensis cellulitis in immunocompetent child. Harefuah, 151(8), 476-8.
This article follows an 8 year old girl who developed an ulcer on her leg. She had a fever and pain/swelling in the area. She had never traveled or had exposure to strange animals. They believe the infection came from the small garden at her house. A culture grew Nocardia brasiliensis and she recovered after 8 weeks of antibiotic treatment.
Smego Jr., R., Gallis HA. (1984). The clinical spectrum of nocardia brasiliensis infection in the united states. Clinical Infectious Diseases, 6 (2), 164-180.
The research done on patients who have had infections from Nocardia brasiliensis showed that this particular infection can cause multiple diseases. Some patients presented with problem in their soft tissues, other had problems within their nervous system and some had pleurapulmonary disease. It was suspected that the patients inhaled the bacteria or received it through inoculation. All patients with infection of skin or soft tissues recovered but the mortality rate was 67% among studied cases.
Wilson, John H. 2012. Nocardiosis: Updates and Clinical Overview. Mayo Clinic Proceedings.
Nocardia, a gram-positive bacillus, which shows hyphae that branch out. This is mostly seen through a microscopic appearance as it is a small organism. This microorganism can produce the disease, Nocardiosis, in the correct host cell. To achieve the most success, there must be early diagnosis and antibiotic therapy. Nocardiosis occurs mostly in people with immunosuppressive diseases, or in some cases it may occur in patients that are immocompetent, which means their immune system does not work as it should.