Staphylococcus aureus Nasal Colonization Differs among Pig Lineages and Is Associated with the Presence of Other Staphylococcal Species

Abstract

Staphylococcus aureus is a common colonizer in pigs, with methicillin-resistant S. aureus (MRSA) in particular being a potential health risk to humans. To reduce the exposure to humans, the colonization in pigs should be reduced. The aim of this study was to quantitatively compare the susceptibility of pig lineages for S. aureus colonization, and if the absence of S. aureus could be associated with the presence or absence of other staphylococcal species. Nasal samples (n = 129) were obtained from seven different pig lineages in the Netherlands, France, and Germany. S. aureus and other staphylococci were enumerated from these samples by real-time (RT)-PCR and culture. Associations were explored between the presence of S. aureus and other staphylococci. S. aureus was detected by RT-PCR on all farms and in samples from pigs of all lineages. Twenty-five percent of the pigs from lineage F (from two farms) were colonized with S. aureus, while in all other lineages it was more than 50% (p < 0.01). Moreover, in S. aureus-positive samples from pigs of lineage F smaller amounts of S. aureus were found than in other lineages. Staphylococcus sciuri, Staphylococcus cohnii, and Staphylococcus saprophyticus were usually not found in combination with S. aureus in these samples. In conclusion: (i) pigs from different genetic lineages have different susceptibilities for colonization with S. aureus. These pigs might contain a genetic factor influencing nasal colonization. (ii) Colonization of S. aureus is also associated with the absence of S. sciuri, S. cohnii, or S. saprophyticus. (iii) The farm environment seems to influence the presence of S. aureus in pigs.

Effect of Co-inhabiting Coagulase Negative Staphylococci on S. aureus agr Quorum Sensing, Host Factor Binding, and Biofilm Formation

“…In our investigation we also found S. sciuri to be the most prevalent CoNS being isolated from 40% of the pigs followed by S. lentus and S. xylosus. Unlike the Verstappen study though, we did not isolate S. saprophyticus or S. cohnii which were the other most prominent species identified along with S. sciuri (Verstappen et al, 2017).…”

“…Likewise, pigs have been reported to be colonized by a variety of CoNS with one study describing 10 species including S. hyicus , Staphylococcus haemolyticus , Staphylococcus warneri , S. simulans , S. xylosus , and S. sciuri to be isolated at approximately equal frequency (Nagase et al, 2002). Others document higher CoNS species numbers (between 18 and 20 different CoNS) including the afore-mentioned, as well as S. saprophyticus and S. cohnii (Schoenfelder et al, 2017; Verstappen et al, 2017). However, both the latter studies report a marked increase in S. sciuri prevalence over the other species amounting to between 30 and 46% of the total colonizing CoNS species (Schoenfelder et al, 2017; Verstappen et al, 2017).…”

“…Others document higher CoNS species numbers (between 18 and 20 different CoNS) including the afore-mentioned, as well as S. saprophyticus and S. cohnii (Schoenfelder et al, 2017; Verstappen et al, 2017). However, both the latter studies report a marked increase in S. sciuri prevalence over the other species amounting to between 30 and 46% of the total colonizing CoNS species (Schoenfelder et al, 2017; Verstappen et al, 2017). In our investigation we also found S. sciuri to be the most prevalent CoNS being isolated from 40% of the pigs followed by S. lentus and S. xylosus.…”

“…Commonly, the CoNS are not pathogens and their presence has been suggested to influence S. aureus colonization. For example, in humans it has been proposed that Staphylococcus epidermidis may prevent colonization by S. aureus (Iwase et al, 2010), whereas in pigs, S. aureus colonization was not observed in the presence of Staphylococcus sciuri , Staphylococcus cohnii , or Staphylococcus saprophyticus (Verstappen et al, 2017). Interestingly, CoNS also encode AIP-like molecules and some of these are able to inhibit S. aureus agr (Otto et al, 1999; Canovas et al, 2016; Gless et al, 2017, 2019; Mahmmod et al, 2018).…”

Staphylococcal Communities on Skin Are Associated with Atopic Dermatitis and Disease Severity

“…S. hominis and S. capitis proportional abundances were not associated with either AD disease or disease exacerbation in children [ 4 , 19 ], however, these studies included less than 12 volunteers, which limits their ability to detect such associations. The importance of S. cohnii for human skin health is not clear, but one study has shown a negative correlation between S. aureus and S. cohnii colonization of the nasal epithelium in pigs [ 55 ]. This may indicate an antagonistic interaction between S. aureus and S. cohnii .…”