Urinary tract infection is the most common urinary tract problem in children besides bedwetting. Urinary tract infection is second only to respiratory infection as the most common type of infection. These infections are much more common in girls and women than in boys and men younger than 50 years of age.
Prokaryotic Cells Bacteria are examples of the prokaryotic cell type. An example is E. coli. In general, prokaryotic cells are those that do not have a membrane-bound nucleus. In fact pro-karyotic is Greek for before nucleus. Besides bacteria, the cyanobacteria (blue-green algae) are a major group of prokaryotes.
While all bacterial cell walls (with a few exceptions e.g. extracellular parasites such as Mycoplasma) contain peptidoglycan, not all cell walls have the same overall structures. Since the cell wall is required for bacterial survival, but is absent in some eukaryotes, several antibiotics (notably the penicillins and cephalosporins) stop bacterial infections by interfering with cell wall synthesis, while having no effects on human cells which have no cell wall only a cell membrane. There are two main types of bacterial cell walls, those of gram-positive bacteria and those of gram-negative bacteria, which are differentiated by their Gram staining characteristics. For both these types of bacteria, particles of approximately 2 nm can pass through the peptidoglycan.