Pseudomonas spp. Most Pseudomonas spp. are environmental organisms that can cause opportunistic infections in a healthcare environment. Pseudomonas Aeruginosa This organism is widespread in the environment, but rare in the…
Salmonella There are two Salmonella species that account for the majority of human and animal infections: S. enterica and S. bongori. Salmonellosis Salmonella are host-adapted to animals and humans. Infection…
The Enterobacteriaceae are a large family (>20 genera and 100 species) of facultatively anaerobic Gram-negative bacilli that are easily cultured, reduce nitrate and ferment glucose. The wide diversity of named…
Haemophilus Haemophilus spp. are fastidious Gram-negative coccobacilli that colonize mucosal surfaces. H. influenzae and H. ducreyi are the main pathogenic species. Haemophilus Influenzae Haemophilus influenzae expresses an antiphagocytic polysaccharide capsule…
Neisseria gonorrhoeae Infection with Neisseria gonorrhoeae, a Gram-negative diplococcus, is most common in individuals between 15 and 35 years of age. It is almost exclusively spread by sexual contact. Pathogenesis…
Non-sporing anaerobes form the major part of the normal human bacterial flora, outnumbering all other organisms in the gut by a factor of 103. They are also found in the…
Clostridium spp. are anaerobic spore-forming organisms that are able to survive well in the environment. Their normal habitats are soil, water and the intestinal tract of humans and animals. Only…
Mycobacteria possess a lipid-rich cell wall that retains some dyes, resisting decolourization with acid (hence they are known as acid-fast). There are more than 50 species; although most are environmental…
These three organisms are from widely differing taxonomic groups but are linked by being important diseases of childhood that are mediated by toxins and can be prevented by childhood immunization…
Listeria Listeria are important Gram-positive organisms that can grow at low temperatures (4–10 °C); Listeria monocytogenes is associated with human disease. Epidemiology Listeria spp. are found in soil or animal…
