Efficacy of Two Antibiotic-Extender Combinations on Mycoplasma bovis in Bovine Semen Production

Abstract

Mycoplasma bovis is an important bovine pathogen. Artificial insemination (AI) using contaminated semen can introduce the agent into a naïve herd. Antibiotics, most often gentamycin, tylosin, lincomycin, spectinomycin (GTLS) combination are added to semen extender to prevent transmission of pathogenic bacteria and mycoplasmas. In a commercial AI straw production system with industrial scale procedures, we analyzed the mycoplasmacidal efficacy of GTLS and ofloxacin on M. bovis ATCC and wild type strain isolated from commercial AI straws. The strains were spiked at two concentrations (106 and 103 CFU/mL) into semen. Viable M. bovis in frozen semen straws was detected by enrichment culture and real-time PCR. We also compared different protocols to extract M. bovis DNA from spiked semen. None of the antibiotic protocols had any effect on the viability of either of the M. bovis strains at high spiking concentration. At low concentration, the wild type was inhibited by all other protocols, except low GTLS, whereas the ATCC strain was inhibited only by high GTLS. The InstaGene™ matrix was the most effective method to extract M. bovis DNA from semen. When there is a low M. bovis contamination level in semen, GTLS used at high concentrations, in accordance with Certified Semen Services requirements, is more efficient than GTLS used at concentrations stated in the OIE Terrestrial Code.

Comparative Study of Bacterial Contamination in Local Iraqi Sheep and Goats Semen

“…This study revealed that the external parts of the genital system of rams carried many bacterial species. This finding agrees with other studies (Al-Zubaidy & Zaid, 2009;Pohjanvirta et al, 2020). The present results revealed that the bacteria cultured from male semen were partly similar to those found in other studies (Zaid et al, 2007).…”

“…However, diseases caused by them may reduce reproductive system immunity (Noakes et al, 2019). Also, mating with polluted semen is considered one of the etiologies of uterus infection (Pohjanvirta et al, 2020). So the male is responsible for semen pollution through contamination during semen collection with the glans penis and prepuce.…”

A Longitudinal Characterization of the Seminal Microbiota and Antibiotic Resistance in Yearling Beef Bulls Subjected to Different Rates of Gain

“…Among the antibiotics that did not inhibit the growth of some seminal bacterial isolates are those that are commonly used in the cattle industry to treat bovine respiratory disease ( 53 ) and liver abscesses (tetracycline and macrolide [clindamycin]) ( 54 ), mastitis (cefazolin) ( 55 ), and metritis (penicillin) ( 56 ). Gentamicin, which is often included in extenders when preparing and storing semen for artificial insemination (AI) ( 57 ), was also found to be ineffective against several seminal isolates tested. Overall, our results suggest that antibiotic-resistant bacteria are present in the urogenital tract of bulls and that semen may transfer AMR from bulls to the female reproductive tract and may even spread AMR among female cattle during breeding, as a single bull will often mate with many females.…”

Multi‐drug resistant Salmonella ser. Dublin cultured from cryopreserved Holstein semen

“…16 There is some contention that this antibiotic cocktail effectively controls Mycoplasma bovis. 17,18 Antimicrobial susceptibility breakpoints for Salmonella ser. Dublin do not exist in cattle; therefore, it is necessary to extrapolate from human breakpoints or bovine breakpoints for other bacterial pathogens to monitor trends in resistance.…”

“…It is generally accepted that the use of the GTLS antibiotic cocktail has both bactericidal and bacteriostatic effects on bovine venereal pathogens 16 . There is some contention that this antibiotic cocktail effectively controls Mycoplasma bovis 17,18 …”