Challenges and Limits Using Antimicrobial Peptides in Boar Semen Preservation

Abstract

Contents Antibiotics are of great importance for the preservation of ejaculates for livestock breading. The use of antibiotics, however, is not an appropriate compensation for a lack of hygiene standards in artificial insemination (AI) centres. Sophisticated hygiene management and the proper identification of hygienic critical control points (HCCPs) at AI centres provide the basis for counteracting the development of antibiotic resistance in contaminant bacteria and their settlement in AI centres. In recent years, efforts have been made to use antimicrobial peptides (AMPs) in the preservation of boar semen. Investigations have included the testing of synthetic magainin derivatives and cyclic hexapeptides. One prerequisite for the application of AMPs is that they have a minor impact on eukaryotic cells. Bacterial selectivity, proteolytic stability, thermodynamic resistance, and mechanisms including synergistic interaction with conventional antibiotics have made cyclic hexapeptides highly promising candidates for potential application as peptide antibiotics for semen preservation.

Contaminantes bacterianos y perfil de susceptibilidad del semen porcino en centros de recogida em Brasil

“…Antibiotics were added to semen extenders as a preventive measure to reduce bacterial contamination (5,6). Some level of drug resistance has been observed among isolates from boar semen against antibiotics commonly used as preservative antimicrobials in commercial porcine semen extenders (3,8 On the other hand, our results showed an important resistance to penicillin (>75%) and lincomycin (>87.5%). It has been shown that when utilizing β-lactams in a mixed bacterial population of susceptible and resistant cells, resistant cells quickly (in as little as 2.5 h) degrade the β-lactam, eliminating whatever selection pressure the antimicrobial provided (25).…”

“…Water was the major source of contamination. Additionally, our results on evaluation of susceptibility to antimicrobial agents has shown a good efficacy (in vitro) of aminoglycosides (neomycin and gentamicin) on de semen porcino comercial (3,8 Por otro lado, nuestros resultados mostraron una importante resistencia a la penicilina (>75%) y a la lincomicina (>87.5%). Se ha demostrado que al utilizar β-lactams en una población bacteriana mixta de células susceptibles y resistentes, las células resistentes degradan rápidamente (en tan sólo 2,5 h) el β-lactam, eliminando cualquier presión de selección que proporcione el antimicrobiano (25).…”

“…Following distribution, the Petri dishes were incubated in aerobiosis at 37°C for up to 48 h. Next, the colonies in each plate añaden antibióticos a los diluyentes de semen como medida preventiva para reducir la contaminación bacteriana (4)(5)(6). Sin embargo, se ha observado resistencia antimicrobiana a la limitada cantidad de clases de antibióticos utilizados habitualmente como conservantes en los diluyentes de esperma porcino comercial entre los aislados del esperma porcino (8). Además, la resistencia de las bacterias a los antibióticos en el semen porcino extendido está aumentando en todo el mundo (9); por lo tanto, la identificación de tipos y fuentes de contaminación puede reforzar las bases para el uso de semen porcino libre de antibióticos, una línea de investigación de tendencia actual.…”

“…Además, se semen extenders has been observed among isolates from boar semen (8). Furthermore antibiotic resistance of bacteria in extended boar semen is increasing worldwide (9); therefore, the identification of types and sources of contaminations may strength the bases for the use of boar semen free of antibiotics, a current trending research line.…”

Immunological tolerance, pregnancy and pre-eclampsia: the roles of semen microbes and the father1

“…Their presence in the cells and tissues of the uterus, fetus and the neonate indicates an important role in immunity during pregnancy and in early life [625; 632-636]. Unsurprisingly, they have been proposed as agents for use in preventing the transmission of STDs [637; 638], and as antimicrobials for addition to stored semen for use in agriculture [639][640][641][642][643]. Our interest here, however, is around whether there are natural AMPs in human (or animal) semen, and the answer is in the affirmative.…”