This new urethra both in men and women is fairly gently colonized, even when Staph
The fresh blossoms of the pharynx and you will windpipe start around both ?- and you can ?-haemolytic streptococci along with a great amount of anaerobes, staphylococci (as well as Staph. aureus), Neisseria and you may diphtheroids. Brand new respiratory system is often a bit sterile, inspite of the normal intake out of bacteria by breathing. Although not, good-sized numbers of clinically normal somebody will get carry this new fungi Pneumocystis jirovecii (in past times also known as P. carinii) within their lungs.
The stomach normally harbours only transient organisms, its acidic pH providing an effective barrier. However, the gastric mucosa may be colonized by acid-tolerant lactobacilli and streptococci. Helicobacter pylori, which can cause gastric ulcers (see twenty two), is carried without symptoms by large numbers of people, the bacterium being in mucus and neutralizing the local acidic environment. The upper intestine is only lightly colonized (10 4 organisms/g), but populations increase markedly in the ileum, where streptococci, lactobacilli, enterobacteriaceae and Bacteroides may all be present. Bacterial numbers are very high (estimated at 10 11 /g) in the large bowel, and many species can be found (Fig. 8.dos). The vast majority (95–99%) are anaerobes, Bacteroides being especially common and a major component of faecal material; E. coli is also carried by most individuals. Bacteroides and E. coli are among the species capable of causing severe disease when transferred into other sites in the body.