Browsing by Sujet Nosocomial infections are infections contracted during a stay in a health establishment (hospital, clinic, etc.). Pathological products are biological products in which the micro- organisms responsible for the infection have multiplied. Our study is based on the isolation of the bacterial flora isolated from pathological products (stool urine (in a hospital environment from samples taken in the microbiology laboratory department of the Dr Benzerdjeb hospital, According to the comparative study of previous work on the bacteriology of pathological products, we have found that E. COLI bacteria present a predominance with a too high rate in the urine. On the other hand, E. COLI and staphylococcus aureus present a predominance and a too high rate. raised in the stool. The study of sensitivity to antibiotics has confirmed to us that among the species isolated bacteria, some exhibit resistance to the various antibiotics used.