Since the first report of Nocardia as a pathogen in 1888, multiple species have been recognized as serious human pathogens. Molecular analysis has identified to date 92 species in the Nocardia genus with 54 species shown to be clinically significant…
The growing importance of nontuberculous mycobacteria (NTM) in the past 2 decades prompted development of sophisticated microbiologic techniques that enable more rapid and accurate identification of older species and those that are emerging as human pathogens. More than 180 species…
The genus Mycobacterium consists of a diverse group of acid-fast bacilli (AFB) with a lipid-rich cell wall. The bacilli are aerobic, non–spore-forming, nonmotile, and slightly curved or straight organisms. Mycobacteria take up stain poorly but retain specific dyes despite treatment…
A number of pleomorphic, non-sporulating, and gram-positive bacilli have been identified in the past as “diphtheroids” or “coryneform” bacteria and dismissed as contaminants. However, many of these organisms can cause endocarditis and other serious infections, especially in immunocompromised patients. For…
Acknowledgment The author acknowledges the substantial contributions to this chapter from previous editions of the textbook and the skillful work that created Fig. 132.2 . The bacterium Listeria monocytogenes is a rare but important cause of severe illness in neonates,…
You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here
Diphtheria is a toxicosis caused by infection with Corynebacterium diphtheriae. The genus and species names are derived from Greek roots: korynee (“club”) after the microscopic appearance of the organisms and diphtheria (“leather hide”) for the pseudomembrane that is the hallmark…
Bacillus species, ubiquitous in the environment, are found in soil, water, dust, and air. With the exception of B. anthracis, which causes anthrax, Bacillus spp. previously have been considered nonpathogenic when isolated from clinical specimens. However, nonanthrax species are increasingly…
Arcanobacterium haemolyticum was first identified as Corynebacterium haemolyticum in 1946 in pharyngeal cultures of World War II soldiers and Pacific Islanders with pharyngitis that was indistinguishable clinically from infection caused by group A Streptococcus . Epidemiology Humans are the primary…
Neisseria gonorrhoeae and N. meningitidis are the 2 most pathogenic Neisseria species. Other Neisseria species are common commensal inhabitants of the upper respiratory tract and oral cavity of humans and other animals, but they have been implicated in clinical disease…