Table 2.
Percentage of contaminated extended semen samplesa in which different bacteria were isolated and their effect on sperm quality
| Bacteria | Althouse and Lu. [67] | Schulze et al., [13] | Úbeda et al. [28] | Effect on sperm |
|---|---|---|---|---|
| % of conatminated samples (n/total samples) | 31.2% (78/250) | 25.6% (88/344) | 14.7% (263/1785) | Reduced sperm quality |
| Achromobacter xylosoxidans | 10.3% | 3.4% | ND | Agglutination, poor motility, damaged acrosomes, acidic pH [44] |
| Burkholderia cepacia | 2.6% | ND | ND | Agglutination, poor motility, damaged acrosomes, acidic pH [44] |
| Clostridium perfringens | ND | ND | ND | Poor sperm viability and motility [72] |
| Enterobacter cloacae | 2.6% | 13.6% | ND | Agglutination, poor motility, damaged acrosomes, acidic pH, decreased the osmotic resistance [44; 74] |
| Enterococcus spp. | 20.5% | 8% | ND | ND |
| Escherichia coli | 6.4% | ND | 1.5% | Agglutination, poor motility, damaged acrosomes [44] |
| Klebsiella spp. | 3.8% | 8% | 11.8% | Poor motility [28] |
| Leifsonia aquatic | ND | 20.5% | ND | ND |
| Morganella morganii | ND | ND | 3.8% | Poor motility, damage acrosome, poorer response to the hypoosmoic swelling test [28] |
| Proteus mirabilis | 1.3% | 5.7% | 1.9% | poor motility, abnormal forms [28] |
| Providencia spp. | 3.8% | ND | 9.1% | ND |
| Pseudomonas spp. | 6.4% | 5.7% | ND | P. aureaginosa reduced total and progressive sperm motility, sperm viability and acrosome integrity |
| Ralstonia pickettii | ND | 11.4% | ND | ND |
| Stenotrophomonas maltophilia | 15.4% | ND | ND | Agglutination, poor motility, damaged acrosomes |
| Serratia marcescens | 10.3% | 2.3% | 12.5% | Agglutination, poor motility, damaged acrosomes, acidic pH [44] |
aThe percentage refers to the total contaminated samples. Bacteria present in a percentage of samples lower than 5% and identified only in one of the studies and for which no effect on sperm quality has been described, are not included in the Table
ND not described
The effect on sperm refers also to studies where semen was challenged with the different pathogens