Occurrence and Antimicrobial Susceptibility Profiles of <i>Streptococcus equi</i> subsp. <i>zooepidemicus</i> Strains Isolated from Mares with Fertility Problems

• Main Authors: Francesca Paola Nocera (Author), Elena D'Eletto (Author), Monica Ambrosio (Author), Filomena Fiorito (Author), Ugo Pagnini (Author), Luisa De Martino (Author)
• Format: Book
• Published: MDPI AG, 2021-12-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.3390/antibiotics11010025; 2079-6382
• Keywords: <i>Streptococcus equi</i> subsp. <i>zooepidemicus</i>; antibiotic resistance; mares; endometritis; Therapeutics. Pharmacology; RM1-950
• Source: Antibiotics, Vol 11, Iss 1, p 25 (2021)

<i>Streptococcus equi</i> subsp. <i>zooepidemicus</i> (<i>S. zooepidemicus</i>), is a β-hemolytic <i>Streptococcus</i> belonging to the Lancefield group C; it is a rare human pathogen, but in horses, it is frequently associated with endometritis. This study aimed to isolate <i>S. zooepidemicus</i> strains, associated with bacterial endometritis in mares, and to define their antimicrobial resistance profile. Twenty-three isolates were recovered from one hundred ninety-six equine uterine swabs (11.7%). Bacterial identification was carried out by Api 20 Strep and confirmed by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS), while antimicrobial susceptibility testing was performed by disk diffusion method on Muller Hinton agar plates. The antibiotic resistance profiles of the isolates revealed a high percentage of resistance to amikacin (95.6%), ampicillin (73.9%) and tetracycline (69.6%), while ceftiofur and ceftriaxone were highly effective with 82.6% and 78.3% of the isolates inhibited, respectively. An intriguing value of resistance to penicillin (34.8%), which represents the first-choice antibiotic in equine <i>S. zooepidemicus</i> infections, was observed. Furthermore, a high prevalence of multidrug-resistant strains (82.6%) was recorded. Continuous surveillance of this potential zoonotic pathogen and an appropriate antimicrobial stewardship program with the promotion of correct use of antimicrobials, after a proper diagnosis, are needed to allow an effective therapy.