Prevalence of Salmonella enterica subsp. diarizonae serotype 61:k:1:5:(7) in nasal secretions and stool of sheep flocks with and without cases of chronic proliferative rhinitis

Prevalence and antimicrobial resistance of Salmonella enterica subsp. diarizonae serovar 61:k:1,5,(7) in Swiss sheep flocks

“…Considering the abovementioned findings, the prevalence of S. IIIb 61:k:1,5,( 7) at the flock level in Switzerland, seems to be much higher than that in Northern Europe but more comparable to that found in Middle Europe or the US, although flock sizes were smaller. Only in Spain was a comparable study to our study conducted on the basis of nasal secretion, which revealed a very high prevalence of S. IIIb 61:k:1, 5,(7) of 90% on the flock level (Figueras et al, 2020). However, only ten flocks located in the region of Aragon were sampled, therefore lacking representativity.…”

“…Recently, a high prevalence of S. IIIb 61:k:1,5,(7) was detected in both, nasal secretions and faeces of sheep flocks in the Spanish region of Aragon, leading the authors to assume that S. IIIb 61:k:1,5,( 7) is endemic in Spanish sheep flocks. It is noteworthy that the isolation proportion in nasal swabs (38.5%) was higher than that in faecal samples (22.5%) (Figueras et al, 2020).…”

“…Minimal inhibitory concentration (MIC) distributions of 146 Salmonella enterica subspecies diarizonae (IIIb) serovar 61:k:1,5,( 7 contrast, sheep flocks in Germany (82%) and the US (72%) revealed a much higher flock prevalence of S. IIIb 61:k:1,5,(7) on the basis of faecal samples from clinically healthy sheep (Dargatz et al, 2015;Methner and Moog, 2018). In previous studies, the detection proportion of S. IIIb 61: k:1,5,(7) in faecal samples resulted in a lower prevalence than in nostrils (Stokar-Regenscheit et al, 2017;Figueras et al, 2020). Therefore, it can be assumed that the prevalence in the abovementioned countries would be even higher if samples from the nose were included.…”

“…It remains unclear, whether and how the high prevalence of S. IIIb 61:(k)k:1,5,(7) in nasal cavities impacts the upper respiratory tract of Swiss sheep. Figueras et al (2020) showed that the prevalence of S. IIIb 61:k:1,5,(7) in flocks with previous cases of CPR had a higher likelihood of harbouring a sheep that tested positive compared to flocks without a previous history of CRP. Worth mentioning in this context is the fact that, the majority of antimicrobial treatment in Swiss sheep is due to respiratory tract disorders.…”

“…Salmonella (S.) enterica subspecies diarizonae (IIIb) serovar 61:k:1,5, (7) (S. IIIb 61:k:1,5,( 7)) is considered to be sheep-associated, as it can be found in the intestine and tonsils of clinically healthy sheep, but has also been described in different clinical disorders. It has been detected in the intestine of sheep without clinical signs or pathological findings in several European countries, such as Norway, Germany, Sweden, Switzerland and Spain, as well as in the US (Alvseike and Skjerve, 2002;Zweifel et al, 2004;Sörén et al, 2015;Dargatz et al, 2015;Methner and Moog, 2018;Figueras et al, 2020). Moreover, S. IIIb 61:k:1,5,(7) could be isolated from ovine tonsils sampled at slaughterhouses in Iceland and Switzerland (Hjartardóttir et al, 2002;Bonke et al, 2012).…”