Enumeration of pathogenic bacteria from sewage sludge in Kuwait.

Domestic sewage in Kuwait is mainly treated by an activated sludge process. Sewage sludges at different treatment stages and the digested sludge were studied for their content of pathogenic bacteria. Two Gram-positive cocci and eight Gram-negative bacilli were isolated and enumerated in the sewage sludges and in raw sewage. During March, Aeromonas hydrophila was the dominant bacterium isolated. Serratia liquefaciens in raw sewage and sludge-2, and Salmonella species in digested sludge were dominant during April. Enterobacter aerogenes was dominant in sewage samples in May. Various types of bacteria isolated were tested for their sensitivity to a wide range of antibiotics.