Characterisation of multiresistant <i>Brachyspira hyodysenteriae</i> isolates from Czech pig farms

Šperling, Daniel; Smoła, J.; Čížek, Alois

doi:10.1136/vr.c4247

Cited by 29 publications

(31 citation statements)

References 17 publications

(26 reference statements)

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“…Our observations suggest that B. hyodysenteriae isolates from the United States (Table 2) are more susceptible to tiamulin and valnemulin than are isolates from Germany, Italy, Japan, Poland, Spain, the Czech Republic, and the United Kingdom (21)(22)(23)(24)(26)(27)(28), which have reported strains resistant to tiamulin and/or valnemulin. Interestingly, we found a similar MIC 50 value but higher MIC 90 value for B. hyodysenteriae (Table 2), compared with those reported for Australia and Sweden (13,15).…”

Section: Discussionmentioning

confidence: 64%

“…This indicates the presence of occasional isolates with low pleuromutilin susceptibility in the United States. The observation of tiamulin and/or valnemulin resistance reported from Europe has been associated with the intensive use of pleuromutilins for the treatment of swine dysentery (20,21,28). Swine dysentery continues to be a major clinical problem in most of Europe, and the lack of commercial vaccines has led to a reliance on antimicrobial therapy to control the disease (22).…”

Section: Discussionmentioning

confidence: 99%

“…The stepwise development of the mutations observed in vitro and in vivo suggests that multiple mutations are likely required for the development of increasing degrees of resistance, gradually altering the conformation of the drug binding site (27,35). This gradual development of pleuromutilin-resistant strains may be facilitated by the frequent and long-term use of these antimicrobials in a herd (20,21,28) and could possibly explain the presence of a few tiamulin-resistant strains of Brachyspira species among the U.S. isolates.…”

Section: Discussionmentioning

confidence: 99%

“…hyodysenteriae and/or B. pilosicoli strains from numerous countries, including Australia (13), Belgium (20), the Czech Republic (21), Germany (22), Italy (23), Japan (24), Netherlands (25), Poland (26), Spain (27), Sweden (15), and the United Kingdom (28), were reported to have low susceptibilities to one or more antimicrobial agents. Some studies have also identified resistant strains in several farms or regions as a result of clonal dissemination (23,28).…”

mentioning

confidence: 99%

“…Such trends of low susceptibilities of B. hyodysenteriae and B. pilosicoli to multiple antimicrobials complicate disease control efforts. Although substantial information on the antimicrobial susceptibilities of Brachyspira isolates is available from Europe (15,(21)(22)(23)(26)(27)(28), Australia (13), and Asia (24), limited information is available from North America (9). Recent studies have characterized the genotypes of B. hyodysenteriae and B. hampsonii circulating in commercial swine herds in the United States (2,8).…”

mentioning

confidence: 99%

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Antimicrobial Susceptibility Patterns of Brachyspira Species Isolated from Swine Herds in the United States

2016

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Outbreaks of swine dysentery, caused by Brachyspira hyodysenteriae and the recently discovered "Brachyspira hampsonii," have reoccurred in North American swine herds since the late 2000s. Additionally, multiple Brachyspira species have been increasingly isolated by North American diagnostic laboratories. In Europe, the reliance on antimicrobial therapy for control of swine dysentery has been followed by reports of antimicrobial resistance over time. The objectives of our study were to determine the antimicrobial susceptibility trends of four Brachyspira species originating from U.S. swine herds and to investigate their associations with the bacterial species, genotypes, and epidemiological origins of the isolates. We evaluated the susceptibility of B. hyodysenteriae, B. hampsonii, Brachyspira pilosicoli, and Brachyspira murdochii to tiamulin, valnemulin, doxycycline, lincomycin, and tylosin by broth microdilution and that to carbadox by agar dilution. In general, Brachyspira species showed high susceptibility to tiamulin, valnemulin, and carbadox, heterogeneous susceptibility to doxycycline, and low susceptibility to lincomycin and tylosin. A trend of decreasing antimicrobial susceptibility by species was observed (B. hampsonii > B. hyodysenteriae > B. murdochii > B. pilosicoli). In general, Brachyspira isolates from the United States were more susceptible to these antimicrobials than were isolates from other countries. Decreased antimicrobial susceptibility was associated with the genotype, stage of production, and production system from which the isolate originated, which highlights the roles of biosecurity and husbandry in disease prevention and control. Finally, this study also highlights the urgent need for Clinical and Laboratory Standards Institute-approved clinical breakpoints for Brachyspira species, to facilitate informed therapeutic and control strategies.

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