Analysis of the Antibiotic Resistance Profiles in Methicillin-Sensitive S. aureus Pathotypes Isolated on a Commercial Rabbit Farm in Italy

Abstract

The breeding of meat rabbits is an important sector in the livestock industry in Italy. The focus of this study was to describe the antibiotic resistance profile distribution among the Methicillin-sensitive Staphylococcus aureus isolated in a rabbit farm. From 400 animals of different ages and three farm workers, 96 randomly selected strains isolated from various anatomical sites and lesions were analysed. According to spa typing and the resistance profiles towards veterinary and human antibiotics, 26 pathotypes were identified. The highest resistance was observed against Tetracyclines (92.3%) and Macrolides (80.8%), while almost all were susceptible to Penicillins, according to the limited use of β-lactams on the farm. In total, 92.3% of pathotypes were multidrug resistant (MDRs). Two MDR pathotypes belonging to the t2802 spa type were isolated from both farmers and rabbits. Age categories harboured significantly different pathotypes (p = 0.019), while no association was found between pathotypes and lesions (p = 0.128) or sampling sites (p = 0.491). The antibiotic resistance was observed to increase with the time spent in the farm environment (age category). The selective pressure exerted by antibiotic use acted by giving advantage to more resistant strains rather than by lowering susceptibility to various drug categories within strains.

Molecular detection and antibiogram of Staphylococcus aureus in rabbits, rabbit handlers, and rabbitry in Terengganu, Malaysia

“…In this study, none of the S. aureus harbored the mecA gene, indicating the absence of MRSA. The finding agrees with the study of Attili et al [ 3 ], which reported a 0% MRSA prevalence rate among live rabbits from Italy. However, another previous study reported MRSA among rabbit handlers and rabbits, with the prevalence rate recorded at 32% and 3%, respectively [ 2 ].…”

“…A similar result was also reported by Wang et al [ 14 ], where the antibiotic-resistance rates of S. aureus against penicillin (11%), kanamycin (19.6%), gentamicin (10%), and ciprofloxacin (3.9%) were less than 20%. However, a previous study conducted in Italy reported that most of the S. aureus isolated from rabbits were highly resistant against tetracyclines (96%) and macrolides (94%) [ 3 ].…”

“…In rabbits, S. aureus can be commonly found on the skin. It is one of the primary pathogens related to dermatitis, mastitis, and metritis infections, causing losses in the rabbit farming industry [ 2 , 3 ]. A previous study indicated that both asymptomatic carriers and infected individuals could transmit S. aureus to others via direct and indirect pathways [ 4 ].…”

“…Similar to other animals, rabbits are also prone to various bacterial infections [ 3 ]. Medication level in rabbit farming is the highest among food-producing animals [ 7 ].…”

“…Thus, this creates an optimum environment for the emergence of AMR bacterium. Recently, rabbits carrying S. aureus with AMR traits have been reported [ 3 ]. Moreover, livestock-associated MRSA ST398 has been described to be present in both farm and pet rabbits [ 2 , 8 ].…”