Pathogenesis and Clinical Manifestations of Coxiella burnetii 3.67/5 (3)

Pathogenesis and Clinical Manifestations of Coxiella burnetii

Pathogenesis of Coxiella burnetii Human infection usually follows inhalation of aerosols containing C. burnetii. It is estimated that only between 1 and 10 bacteria are necessary to cause infection. C. burnetii has also been known to enter the body via other mucous membranes, abrasions, and the gastrointestinal tract through consumption of milk from infected animals. C. burnetii […]

Pathogenesis and Clinical Manifestations of Chlamydia trachomatis 5/5 (2)

Pathogenesis and Clinical Manifestations of Chlamydia trachomatis

Pathogenesis of Chlamydia trachomatis Chlamydia are acquired by direct contact with mucous membranes or abraded skin, that is, by sexual contact or by direct inoculation into the eye in the case of trachoma or neonatal conjunctivitis. Two forms of the organism are needed for infection and disease to occur: the infectious, extracellular form called an […]

Pathogenesis and Clinical Manifestations of Leptospira interrogans 5/5 (6)

Pathogenesis and Clinical Manifestations of Leptospira interrogans

Pathogenesis of Leptospira interrogans Leptospires usually enter the body through the mucous membranes of the upper respiratory tract or the conjunctivae, or through abraded skin, following exposure to contaminated water, infected urine or animal tissues. Ingestion is considered to be less important. The severity of the leptospirosis depends on (a) host immunity, (b) virulence of […]

Pathogenesis and Clinical Manifestations of Borrelia burgdorferi 4.6/5 (5)

Pathogenesis and Clinical Manifestations of Borrelia burgdorferi

Pathogenesis of Lyme disease caused by Borrelia burgdorferi Lyme disease is caused by the spirochete B. burgdorferi, which is transmitted by the bite of a small tick of the genus Ixodes. Humans are “accidental” hosts for B. burgdorferi because spirochetes from infected people are not transmitted to other hosts. While in the midgut of the Ixodes tick […]

Laboratory Diagnosis, Treatment and Prevention of Francisella tularensis 5/5 (6)

Laboratory diagnosis of Francisella tularensis

Laboratory diagnosis of Francisella tularensis Specimen Scrapings from infected ulcers, lymph node biopsies, and sputum, whole blood. Serum is generally collected from all patients early in disease and during convalescence. To minimize the loss of viable organisms, samples should be transported to the laboratory within 24 hours. If specimens are to be held longer than […]

Laboratory diagnosis of Legionella pneumophila 5/5 (7)

Laboratory diagnosis of Legionella pneumophila

Laboratory diagnosis of Legionella pneumophila Specimen: Respiratory secretions (sputum, bronchial aspirate or washings), as well as pleural fluid, lung biopsy or autopsy material. Microscopy Legionellae in clinical specimens stain poorly with Gram stain and the small, intracellular bacteria are rarely recognized. The organism will stain with nonspecific methods, such as Dieterle silver stain, but this […]

Laboratory diagnosis of Leprosy caused by Mycobacterium leprae 4.88/5 (8)

Laboratory diagnosis of Leprosy caused by Mycobacterium leprae

Laboratory diagnosis of Leprosy caused by Mycobacterium leprae Specimen Skin biopsies, nasal discharges, scrapings from the nasal mucosa and slit-skin smears which are prepared by making superficial incisions in the skin, scraping out some tissue fluid and cells. Skin smears The skin smears are collected from the leprous lesions, such as nodules, thick papules, and […]

Laboratory diagnosis, Treatment and Prevention of Mycoplasma pneumoniae 4.5/5 (20)

Laboratory diagnosis, Treatment and Prevention of Mycoplasma pneumoniae

Laboratory diagnosis of Mycoplasma pneumoniae Specimen Ideal specimens are throat swabs and nasopharyngeal aspirates, lung biopsies, expectorated sputum. Washings are more reliable than sputum specimens because most infected patients have a dry, nonproductive cough and do not produce sputum. Microscopy Test is not useful because organisms do not have a cell wall and do not […]

Laboratory diagnosis, Treatment and Prevention of Streptococcus pneumoniae 4.82/5 (11)

Laboratory diagnosis, Treatment and Prevention of Streptococcus pneumoniae

Laboratory diagnosis of Streptococcus pneumoniae Specimen: Sputum, blood, endotracheal aspirate, bronchoalveolar lavage, cerebrospinal fluid (CSF), pleural fluid, joint fluid, abscess fluid, bones, and other biopsy material. Microscopy Gram staining of sputum shows lancet shaped Gram-positive cocci in pairs. Fresh emulsified sputum mixed with antiserum causes capsule swelling (the quellung reaction) for identification of pneumococci. In […]

Virulence factors, Pathogenesis and Clinical manifestations of Streptococcus pneumoniae 4.55/5 (11)

Virulence factors, Pathogenesis and Clinical manifestations of Streptococcus pneumoniae

Virulence factors of Streptococcus pneumoniae Polysaccharide capsule The capsule is antiphagocytic, inhibiting complement deposition and phagocytosis. 2. Cell wall associated polymers and proteins Teichoic acid – binds to epithelial cells and activates alternative complement pathway Protein adhesion – binds to epithelial cells Peptidogylcan – activates alternative complement pathway Phosphorylcholine – mediates invasion of host cell […]

Laboratory diagnosis, treatment and prevention of Leptospira interrogans 4.45/5 (11)

Laboratory diagnosis, treatment and prevention of Leptospira interrogans

Laboratory diagnosis of Leptospira interrogans Specimens Specimens consist of aseptically collected blood in a heparin tube, CSF, urine, or tissues for microscopic examination and culture. Serum is collected for agglutination tests. Microscopy As leptospires are thin, they are at the limit of the resolving power of a light microscope and thus cannot be seen by […]

Pathogenesis and Clinical manifestations of Francisella tularensis 4.5/5 (10)

Pathogenesis and Clinical manifestations of Francisella tularensis

Pathogenesis of Francisella tularensis Francisella tularensis is carried by many species of wild rodents, rabbits, beavers. Humans become infected by handling the carcasses or skin of infected animals, by inhaling infective aerosols or ingesting contaminated water, through insect vectors and by being bitten by carnivores that have themselves eaten infected animals. Humans are infected by […]

Laboratory diagnosis, treatment and prevention of Borrelia burgdorferi 4.9/5 (10)

Laboratory diagnosis, treatment and prevention of Borrelia burgdorferi

Laboratory diagnosis of Borrelia burgdorferi Specimen Blood, cerebrospinal fluid, joint fluid, tissue biopsies Body fluids should be transported without any preservatives. Tissue biopsy specimens should be placed in sterile saline to prevent drying. Direct detection methods The organisms can be seen directly in wet preparations of peripheral blood (mixed with equal parts of sterile, non […]

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