Adverse effects of members of the Enterobacteriaceae family on boar sperm quality

• Published in: Theriogenology Vol. 80; no. 6; pp. 565 - 570
• Main Authors: Úbeda, Juan Luis, Ausejo, Raquel, Dahmani, Yahya, Falceto, Maria V., Usan, Adan, Malo, Clara, Perez-Martinez, Francisco C.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2013
• Subjects: acrosome; adverse effects; agglutination; Animals; artificial insemination; bacterial contamination; boars; breeds; Enterobacteriaceae - isolation & purification; Enterobacteriaceae - pathogenicity; Enterobacteriaceae - physiology; Enterobacteriaceae family; Enterobacteriaceae Infections - complications; Enterobacteriaceae Infections - epidemiology; Enterobacteriaceae Infections - pathology; Escherichia coli; Escherichia coli - isolation & purification; Incidence; Insemination, Artificial; Klebsiella; Klebsiella oxytoca; Male; Morganella; Morganella morganii; Proteus; Proteus mirabilis; Providencia stuartii; quality control; semen; Semen - microbiology; Semen Analysis - statistics & numerical data; Semen Analysis - veterinary; semen extenders; Serratia; Serratia marcescens; smell; sperm concentration; Sperm motility; Swine - microbiology; Swine Diseases - epidemiology; Swine Diseases - microbiology; Klebsiella; Proteus; Enterobacteriaceae family; Sperm motility; Serratia; Morganella
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/j.theriogenology.2013.05.022

Semen samples collected in 2012 from 1785 boars belonging to five different breeds were recruited from the quality control laboratory of Magapor SL, Spain. These samples came from 43 boar studs and resulted from diluting the ejaculates in commercial semen extenders. Evaluation of the semen sample characteristics (color, smell, pH, osmolality, concentration, motility of sperm cells, agglutination, acrosome integrity, short hypoosmotic swelling test, and abnormal forms) revealed that they met the international standards. The samples were also tested for the presence of aerobic bacterial contamination. In the present study, 14.73% (n = 263) of the semen samples were contaminated above 3 × 102 colony-forming units/mL with at least one type of bacteria. The Enterobacteriaceae family was by far the major contaminant, being present in 40.68% of the contaminated samples (n = 107). Bacterial strains of the Enterobacteriaceae family isolated from boar semen samples were in order of incidence (percentage of the contaminated samples): Serratia marcescens (12.55%), Klebsiella oxytoca (11.79%), Providencia stuartii (9.12%), Morganella morganii (3.80%), Proteus mirabilis (1.90%), and Escherichia coli (1.52%). We have seen that the presence in semen samples of S. marcescens, K. oxytoca, M. morganii, or P. mirabilis, but not P. stuartii or E. coli, was negatively associated with sperm motility (P < 0.05). The mean sperm concentration (P < 0.05), the mean percentage of spermatozoa with curled tails after the short hypoosmotic swelling test (P < 0.01), and the incidence of morphologically normal acrosomes (P < 0.05) were also lower in semen samples infected with M. morganii compared with uninfected ones. Moreover, P. mirabilis was negatively associated with the presence of abnormal forms. Thus, on the basis of the pathological effects that some of these strains may have on boar sperm quality, bacterial contamination should always be examined in semen samples prepared for artificial insemination.