Investigation on Antibiotic-Resistance, Biofilm Formation and Virulence Factors in Multi Drug Resistant and Non Multi Drug Resistant Staphylococcus pseudintermedius

Abstract

Staphylococcus pseudintermedius is a commensal bacterium frequently isolated from canine skin and recognized as a zoonotic agent especially for dog-owners. This study focused on (a) the antibiotic-resistance phenotypes; (b) the ability to produce biofilm (slime); and (c) the dissemination of virulence factors in S. pseudintermedius strains. Seventy-three S. pseudintermedius strains were screened for antibiotic-resistance against 22 different molecules by means of Kirby-Bauer assay. The ability to produce biofilm was investigated using the microtiter plate assay (MtP) and the amplification of icaA and icaD genes. Virulence factors such as cytotoxins (lukI), enterotoxins (seC), and exfoliative toxins (siet, expA, and expB) were evaluated. The antibiotic-resistance profiles revealed 42/73 (57%) multi-drug resistant (MDR) strains and 31/73 (43%) not-MDR. All the MDR strains and 8/31 (27%) of not-MDR resulted in biofilm producers. Leukotoxin LukI was found in 70/73 (96%) of the isolates. Moreover, the enterotoxin gene seC was detected in 47/73 (64%) of the strains. All the isolates carried the siet gene, whereas expA and expB were found in 3/73 (4%) and 5/73 (7%), respectively. In conclusion, S. pseudintermedius should be considered a potential zoonotic and human agent able to carry different virulence determinants and capable of producing biofilm which facilitates horizontal gene transfer.

In Vitro Efficacy of Essential Oils from Melaleuca Alternifolia and Rosmarinus Officinalis, Manuka Honey-based Gel, and Propolis as Antibacterial Agents Against Canine Staphylococcus Pseudintermedius Strains

“…This study investigated the antimicrobial properties of two EOs and two honeybee products against S. pseudintermedius strains isolated from canine pyoderma. Clonal relatedness confirmed the findings of previous studies in which MRSP ST71 is considered the most prevalent in Europe, even though a novel MRSP clone (ST106) is rapidly spreading in North Europe (Norway) [8,13,[38][39][40]. The identification of ST 44 as one of the main STs susceptible to the majority of antibiotic molecules, with a prevalence of 26.1%, was in accordance with the study of Gharsa (2013); this author analyzed 55 SP strains-all of them were MSSP, and 27% were susceptible to all the antibiotics tested [40].…”

“…From the first documented identification of this pathogen [6], SP was considered to be exclusive to animals until [7] described the first case of human infection. As it belongs to the Staphylococcus genus, SP can easily exchange genomic material [8,9], and in this context, the spread of antibiotic resistance genes (ARG) is a huge challenge for both human and animal health [10][11][12][13]. The evolution of methicillin-resistant SP strains (MRSP, mecA-positive) rapidly emerged as a significant health problem in veterinary medicine because of the molecular mechanism responsible for β lactam-resistance (SCCmec element) that is transferable between different species 2 of 14 of staphylococci [14][15][16].…”

“…Furthermore, MRSP strains are often resistant to more than three classes of antibiotics (multidrug-resistant (MDR)). This antibiotic resistance applies to all classes of antimicrobials, and is mainly mediated by resistance genes carried by mobile genetic elements (MGE) [13,17]. Some resistances (e.g., to fluoroquinolone) are linked to single nucleotide polymorphism (SNP) [18].…”

“…Some resistances (e.g., to fluoroquinolone) are linked to single nucleotide polymorphism (SNP) [18]. Nowadays, the zoonotic potential of SP is under constant investigation, and different authors have studied its virulence factors, including its ability to form biofilms [3,13,19].…”

In Vitro Antibacterial Activity of Biological-Derived Silver Nanoparticles: Preliminary Data

“…In reptiles, one of the most isolated bacteria is P. aeruginosa, often displaying resistance to multiple veterinary prescribed antibiotics [21]. In dogs, S. pseudintermedius is considered one of the main causative agents of canine pyoderma able to carry Staphylococcal Cassette Chromosome mec (SCCmec), coding for methicillin resistance, and being able to produce several virulence factors, including biofilm [22].…”