Bacteria Isolated From Equine Uteri in The United Arab Emirates: A Retrospective Study.

This study investigates bacterial isolates found in horse uteruses in the unique environment of the United Arab Emirates (UAE). It also looks at the antibiotic resistance of these bacteria, identifying the most and least effective antibiotics.

Introduction and Methodology

• The UAE’s environment offers distinctive conditions for horse breeding, with a non-conventional breeding season and high temperatures and humidity for most of the year.
• The research aimed to identify and compare bacterial isolates from mares in the UAE to those found elsewhere in the world, and to analyze bacterial antibiotic resistance to help future monitoring.
• 2,022 swabs were collected over five breeding seasons from the endometrium, or from uterine lavages, for bacterial culture and antibiotic sensitivity testing.

Results

• At 48 hours post-inoculation, 616 (30.5%) of the 2,022 cultures showed microbial growth, yielding 690 isolates.
• Most positive plates (548 of 616; 89%) grew one isolate. 68 cultures had two (62 of 616; 10.1%) or three (6 of 616; 1%) isolates.
• The most frequently isolated bacteria were β-hemolytic Streptococcus, E. coli, P. aeruginosa, K. pneumoniae, and Aeromonas hydrophila.

Antibiotic Resistance

• The lowest level of antibiotic susceptibility across all isolates was shown by trimethoprim-sulphonamide (36.4%; 198 of 544), while amikacin showed the highest (76.1%; 271 of 356).
• β-hemolytic Streptococcus had a significant decrease in susceptibility to doxycycline, enrofloxacin, and erythromycin. However, there was a significant increase for amoxicillin with clavulanic acid.
• E. coli showed a decrease in the susceptibility of trimethoprim-sulphonamide between two time periods.

Comparison With Other Studies

• Compared to other studies, UAE-based mares had a high incidence of P. aeruginosa and K. pneumoniae isolates. However, E. coli was represented far less frequently as an isolate.