Light micrograph of Staphylococcus epidermidis (formerly albus), a Gram positive cocci bacteria seen here in a specimen of urine. These bacteria are commonly found on the skin & in the upper respiratory tract. They are normally commensal & at most low-grade pathogens. Recently they have been implicated in bacteraemia, an infection which may occur around artificial heart valves, implants & other prostheses. Staph. epidermidis is also implicated in urinary tract infections in elderly males, particularly after bladder instrumentation or prostatectomy. Magnification: X 250 (at 35mm size).