Prevalence and Characterisation of Multiresistant Bacterial Strains Isolated in Pigs from the Island of Tenerife

Abstract

Background: Antibiotic-resistant bacteria can circulate among human and animal populations through direct contact with animals, as well as via food and the environment. The purpose of this study was to examine the prevalence and characterisation of multiresistant bacteria in pig samples. Methods: 224 samples of pig livestock were taken at the slaughterhouse on the island of Tenerife. A nasal and a rectal sample were collected from each pig. The presence of methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus coagulase-negative (MRCoNS), vancomycin-resistant Enterococcus (VRE), extended-spectrum ß-lactamase-producing Enterobacteriaceae (BLEE), carbapenemase-producing Enterobacteriaceae (CPE), and colistin-resistant Enterobacteriaceae was investigated. The resistance genes of the isolated bacteria were characterised by specific PCRs depending on the microorganism to be studied, and in vitro antimicrobial resistance was determined using the broth microdilution method (Vitek®2 system bioMérieux®, Nurtingen, Germany). Results: MRSA prevalence was 73.21% (164 isolates). MRCoNS prevalence was 9.8% (22 isolates), S. sciuri being the prevalent species. Six isolates presented a 2.7% prevalence of extended-spectrum ß-lactamase-producing Escherichia coli (BLEE) in the CTX-M-1 group. No vancomycin-resistant Enterococcus (VRE), carbapenemase-producing Enterobacteriaceae (CRE), or colistin-resistant Enterobacteriaceae were isolated. Conclusion: we found a high presence of multiresistant bacteria, suggesting the need for increased control and surveillance of this type of strains in pig livestock and a better understanding of the possible transmission routes of these microorganisms through livestock products.

The Importance of the Slaughterhouse in Surveilling Animal and Public Health: A Systematic Review

“…Although the data indicated that most bacteria are still sensitive to individual antimicrobials, the multi-resistance characteristics of foodborne pathogens have been referred to as an important issue [ 173 , 174 ].…”

A review of new emerging livestock-associated methicillin-resistant Staphylococcus aureus from pig farms

“…Several studies have reported that people that work or live in pig farms, including farmers and their families, abattoir staff, and veterinarians, are at high risk of contracting LA-MRSA from pigs [4,13,33,34,43,78,[108][109][110][111][112]. In Belgium, 37.8% of people working or living in 25 out of the 49 pig farms investigated were infected with LA-MRSA CC398 [108].…”

“…To date, LA-MRSA has rarely been reported outside communities exposed to LA-MRSA-positive pigs [35,43,98,[119][120][121]. Several studies analyzed the human-to-human transmission of LA-MRSA CC398 in hospitals.…”

“…In addition, as LA-MRSA CC398 does not significantly impact the health of pigs, it is questionable if the implementation of an expensive national LA-MRSA control and eradication program is feasible. However, the ability of LA-MRSA CC398 to transfer from pigs to other pigs or from pigs to humans is a matter of serious concern because people who have frequent direct contact with pigs are at high risk of becoming infected with LA-MRSA CC398 [4,13,43,108,110], even though cases of LA-MRSA CC398 infection in humans are rare [120,126,[131][132][133][134][135][136].…”

“…Livestock-associated-methicillin-resistant S. aureus CC398 infection in pigs was first discovered and reported in several European countries, such as Denmark [ 33 ], Italy [ 42 ], Spain [ 43 ], Germany [ 44 ], and Portugal [ 45 ]. Then, it was reported in North America [ 46 ], South Africa [ 47 ], Australia [ 48 ], and Asia [ 49 ].…”