Influence of Escherichia coli on motility parameters of human spermatozoa in vitro

Abstract

The influence of E. coli on human sperm motility was studied in vitro. Semen samples were prepared by a swim-up technique and adjusted to 22 x 10(6) spermatozoa/ml. Samples were then inoculated with different concentrations of a uropathogenic strain of E. coli, serotype 06, with initial sperm/bacteria ratios varying between 10:1 and 10000:1. Motion parameters were analysed by computer-aided motility analysis directly, and 2, 4 and 6 h after inoculation. In a second series of experiments, bacterial replication was inhibited by addition of chloramphenicol. In a third series, the effect of E. coli culture filtrates on sperm motility was investigated. The direct inhibitory effect of E. coli on progressive motility of spermatozoa was found to depend upon the bacterial concentration. A distinct inhibitory effect was observed only at a sperm/bacteria ratio of approximately 1, achieved by growth of E. coli during the experiments. For modality of motion, no distinct changes were observed. When growth of bacteria was prevented by chloramphenicol, no inhibitory effect on sperm motility was detected. Sperm motility was not inhibited by E. coli culture filtrates. Analysis by electron microscopy revealed multiple adhesions of E. coli to spermatozoa, causing variable ultrastructural damage as probable morphological correlates of immobilization.

The Impact of Bacterial Infections on Human Spermatozoa

“…Fraczek et al (53) concluded that E. coli and serotype O75:HNT have a negative effect on human sperm motility. An inhibitory effect of E. coli, serotype 06, on sperm motility has been investigated by some authors (105). Sperm incubated with E. coli demonstrated significant alterations in motility (78,106).…”

“…Sperm incubated with E. coli demonstrated significant alterations in motility (78,106). Some investigators revealed that the immobilization of spermatozoa may occur as a result of direct contact of the sperm with bacterial cells (105,107).…”

Agglutination of Human Spermatozoa Due to Human Semen Culture Bacterial Isolates Bearing Sperm Ligand

“…Paulson & Polakoski (1977) investigated the mechanism of how E. coli immobilizes spermatozoa and they reported a factor, apparently excreted by the bacteria which immobilizes spermatozoa without agglutinating it. However, Diemer et al (1996) reported that E. coli inhibits sperm motility by directly adhering to and agglutinating spermatozoa. Rapidity and extent of sperm-E. coli agglutination indicated strong adhesive forces.…”

Isolation of Moraxella bovis from frozen bovine semen and determination of microbial load

“…1 The fi ndings of the present study may be compared with the previous reports [12] (1.1 × 10 2 mL -1 in crossbred bull) whereas, some other workers have reported signifi cantly higher bacterial load in semen samples (8.1-390.4 × 10 2 mL˜1 in frozen semen of Holstein stored for 15 days, 1.0-50.0 × 10 2 mL -1 in buffalo semen) [13,14]. The signifi cantly lower bacterial load from the frozen semen samples in the present study may be due to maintenance of strict aseptic conditions at the time of semen collection and processing during the entire steps from collection of semen to making of straws.…”

“…The bacterial contaminants of semen have been a major concern for the most semen production laboratories as contamination adversely affects the semen quality [1] and subsequently the fertility [2,3]. Artifi cial insemination is an important procedure for increasing animal production and frozen bovine semen is most commonly used for the same.…”