The impact of Staphylococcus aureus and Escherichia coli loads on semen quality in asymptomatic men: A cross-sectional study.

Abstract

Background: Staphylococcus aureus (S. Aureus) and Escherichia coli (E. Coli) are the most commonly considered causes of infection in genitourinary system. Asymptomatic bacteriospermia could contribute to infertility due to late detection. Pathogen quantity may impact semen quality.

Objective: This study examined how S. aureus and E. coli loads may affect semen quality of asymptomatic men.

Materials and methods: In this cross-sectional study, 130 asymptomatic men who were referred to Yas hospital complex in vitro fertilization center, Tehran, Iran, for infertility evaluation were enrolled after eligibility screening via a structured interview. Their semen samples were collected and analyzed. Microscopic and macroscopic examinations were performed using a computer-aided sperm analysis system and World Health Organization guidelines. The presence and number of leukocytes in semen were determined using the peroxidase staining method. For quantitative analysis, 2 semen samples were cultured simultaneously on blood and MacConkey agar.

Results: The results of semen analysis in 2 groups of men with and without positive culture showed significant differences in most parameters. The frequency of S. aureus and E. coli in semen samples was 20 (15.4%) and 10 (7.7%), respectively. Higher colony counts of S. aureus (p < 0.001) and E. coli (p = 0.022) were observed in semen samples with abnormal parameters, whereas samples with normal parameters generally showed lower bacterial loads.

Conclusion: Higher bacterial loads of S. aureus and E. coli were associated with poorer semen quality in this sample of asymptomatic men referred for infertility evaluation. Bacterial load assessment may be useful as an adjunct in semen evaluation.