Tags: Endocarditis

Penicillium Infections

Penicillium spp. are ubiquitous in nature and may be recovered with ease from a variety of sources within the hospital environment. These molds commonly contaminate clinical specimens and cause contamination in the laboratory. Colonization of nonsterile anatomical sites in humans is common. In most cases where Penicillium spp. are recovered from clinical specimens, they represent colonization.

Aspergillus, Pseudallescheria, & Agents of Mucormycosis

Aspergillus spp. are found worldwide and grow in a variety of conditions. They commonly grow in soil and moist locations and are among the most common molds encountered on spoiled food and decaying vegetation, in compost piles, and in stored hay and grain. Aspergillus spp. often grow in houseplant soil, and such soil may be a source of Aspergillus conidia or spores in the home, office, or hospital setting. The airborne conidia are extremely heat resistant and can withstand extreme environmental conditions.

Mucormycosis: Clinical Syndromes

Rhinocerebral mucormycosis occurs most commonly in patients with uncontrolled diabetes, especially after an episode of diabetic ketoacidosis. It may also occur in leukemic patients who have had prolonged neutropenia and therapy with broad-spectrum antibiotics and occasionally in organ transplant recipients. The earliest symptoms in rhinocerebral mucormycosis are facial pain, headache, and nasal stuffiness.

Candida Species

Candida organisms are commensal with humans and, in the absence of alterations in host defense mechanisms, usually do not cause disease. Candida exists as normal flora within the oral cavity, throughout the gastrointestinal (GI) tract, in expectorated sputum, in the vagina, and in the bladder of patients with indwelling catheters. There are >150 species within the genus Candida, although the majority are not known to cause disease in humans. C albicans, C krusei, C glabrata, C tropicalis, C pseudotropicalis, C guilliermondii, C parapsilosis, C lusitaniae, and C rugosa are known human pathogens.

Histoplasma Capsulatum

Histoplasma capsulatum, the etiologic agent of histoplasmosis, is an endemic, dimorphic fungus that causes a wide spectrum of disease in both immunocompetent and immunocompromised individuals. It is found in temperate zones around the world. In the United States, it is endemic within the Ohio and Mississippi River Valleys.

Bartonella

There are currently 11 known species of Bartonella, four of which are considered to be pathogenic in humans, namely B bacilliformis, B quintana, B henselae, and Bartonella elizabethae. B henselae and B elizabethae have only recently been isolated and identified, but B quintana and B bacilliformis have long been known as the causes of trench fever (B quintana) and Oroya fever and verruga peruana (B bacilliformis). The bartonellae establish intimate relationships with animal hosts, often within the vascular compartment but without causing disease. The relationship between B bacilliformis and the other three Bartonella species that are pathogenic in humans was established in the early 1990s.

Fever & Bacteremia/Trench Fever/Endocarditis

Patients complain of fever, myalgias, malaise, headache, bone pain — particularly of the legs, and a transient macular rash. Usually the illness continues for 4-6 weeks.

Coxiella, Ehrlichia, & Rickettsia

Once inside a host cell, Coxiella and Ehrlichia spp. remain within a vacuole where they progress through distinct developmental stages; in contrast, the Rickettsia spp. escape the endocytic vacuole and replicate within the host cell cytoplasm. Ehrlichia and Rickettsia spp. are transmitted by arthropod vectors. Coxiella burnetii is the causative agent of Query or Q fever.

Chlamydia

Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae are among the most prevalent microbial pathogens in humans worldwide. C trachomatis is responsible for a variety of sexually transmitted disease (STD) syndromes in both sexes. In addition, certain serotypes of C trachomatis are responsible for trachoma, the most common infectious cause of blindness in humans. C psittaci is a zoonotic pathogen associated with atypical pneumonia.

Chlamydia Psittaci Infections

Pneumonia, pericarditis, myocarditis, and endocarditis have been attributed to C psittaci infection (psittacosis or ornithosis) (Box 5). The incubation period for the pneumonia is usually 1-2 weeks. Its onset is gradual with body temperature increasing over a period of 5-7 days; however, there are cases in which the onset is sudden with rigors and temperatures as high as 104 °F.