title: The presence of bacteria species in semen and sperm quality.
abstract: OBJECTIVE
  To verify the prevalence of semen bacterial contamination and whether the contamination could decrease sperm quality.
  
  
  METHODS
  Spermiogram, semen culture, and sperm transmission electron microscopy (TEM) analysis were performed. TEM data were elaborated using a mathematical formula that calculates a fertility index (FI)--able to define patients as fertile or infertile--and the percentage of sperm apoptosis, immaturity and necrosis. We aligned the amino acid sequence of beta-tubulin with protein of the most frequent species isolated from semen.
  
  
  RESULTS
  Patients were divided according to the contaminating species; in each group, we observed fertile individuals, in whom the semen quality was similar to that of controls and infertile men whose sperm quality was significantly decreased, in terms of motility, FI, apoptosis and necrosis. Partial homology between beta-tubulin and bacterial proteins was observed.
  
  
  CONCLUSIONS
  Sperm bacterial contamination is quite frequent and could contribute to the deterioration of the sperm quality of infertile men.
authors.affiliation: Department of Biomedical Sciences, Biology Section, Interdepartmental Centre for Research and Therapy of Male Infertility, University of Siena, Policlinico Le Scotte, Siena, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Moretti
authors.forename: Serena
authors.initials: S
authors.lastname: Capitani
authors.forename: Natale
authors.initials: N
authors.lastname: Figura
authors.forename: Andrea
authors.initials: A
authors.lastname: Pammolli
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Federico
authors.forename: Valentina
authors.initials: V
authors.lastname: Giannerini
authors.forename: Giulia
authors.initials: G
authors.lastname: Collodel
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D006090:Gram-Negative Bacteria / Q000737:chemistry / Q000302:isolation & purification; D006095:Gram-Positive Cocci / Q000737:chemistry / Q000302:isolation & purification; D006801:Humans; D007248:Infertility, Male / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D012661:Semen / Q000382:microbiology* / Q000502:physiology; D055101:Semen Analysis; D013081:Sperm Motility; D013094:Spermatozoa / Q000382:microbiology / Q000502:physiology* / Q000648:ultrastructure; D014404:Tubulin / Q000737:chemistry; D014552:Urinary Tract Infections / Q000150:complications / Q000382:microbiology* / Q000503:physiopathology
chemical_list: D014404:Tubulin