What does the growth of bacteria in the semen indicate?

Possible interpretations from this result: Probable contamination during collection of semen: There are plenty of bacteria around the male external genitalia. Contamination of the clinical sample is always a possibility, which needs to be excluded. Hence every such result needs to be clinically correlated, along with a microscopic examination to check for presence of pus cells. Proteus is a gram negative bacterium, which belongs to family of coliforms, which are abundantly present in our intestine, and they sometimes colonise our skin. In a young man complaining of burning sensation in penis, the particular symptom needs to be investigated. Whether it is a urinary tract infection or a sexually transmitted disease, depends on full history from the patient and if necessary further investigations. Proteus is known to cause urinary tract infections. To diagnose urinary tract infection, a clean catch mid stream urine needs to be processed by the microbiology laboratory for culture and sensitivity. As such, Proteus is not a sexually transmitted infection. Hence this result needs to be interpreted with caution as I explained before. This young man needs reassurance and if concerned and symptoms persist, needs to see a Urologist.