Susceptibility to pleuromutilins inBrachyspira(Serpulina)hyodysenteriae

Karlsson, Märit; Gunnarsson, A.; Franklin, A.

doi:10.1079/ahrr200118

Cited by 46 publications

(46 citation statements)

References 38 publications

(48 reference statements)

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“…This is in agreement with previous findings confirming universal, worldwide resistance of B. hyodysenteriae isolates to tylosin (Binek et al 1994, Molnar 1996, Gresham et al 1998, Fossi et al 1999, Kärlsson et al 2001, 2003, Rohde et al 2004, Uezato et al 2004, Hidalgo et al 2009). It is known that the point mutation that causes tylosin resistance at position 2058 in the 23S rRNA gene is also known to increase the MICs for the lincosamide antibiotics (Kärlsson et al 1999), and this also may help to explain the trend for the increased MICs to lincomycin that was found in our study.…”

Section: Discussionsupporting

confidence: 82%

Antimicrobial susceptibility of Brachyspira hyodysenteriae isolated from 21 Polish farms

Żmudzki

Szczotka²,

Nowak³

et al. 2012

Polish Journal of Veterinary Sciences

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Swine dysentery (SD) is a common disease among pigs worldwide, which contributes to major production losses. Antimicrobial susceptibility testing of B. hyodysenteriae, the etiological agent of SD, is mainly performed by the agar dilution method. This method has certain limitations due to difficulties in interpretation of results. The aim of this study was the analysis of antimicrobial susceptibility of Brachyspira hyodysenteriae (B. hyodysenteriae) Polish field isolates by broth microdilution procedure. The study was performed on 21 isolates of B. hyodysenteriae, collected between January 2006 to December 2010 from cases of swine dysentery. VetMIC TM Brachyspira panels with antimicrobial agents (tiamulin, valnemulin, doxycycline, lincomycin, tylosin and ampicillin) were used for susceptibility testing of B. hyodysenteriae. The minimal inhibitory concentration (MIC) was determined by the broth dilution procedure. The lowest antimicrobial activity was demonstrated for tylosin and lincomycin, with inhibition of bacterial growth using concentrations >128 μg/ml and 32 μg/ml, respectively. In the case of doxycycline, the MIC values were ≤ 2.0 μg/ml. No decreased susceptibility to tiamulin was found among the Polish isolates and MIC values for this antibiotic did not exceed 1.0 μg/ml. The results of the present study confirmed that Polish B. hyodysenteriae isolates were susceptible to the main antibiotics (tiamulin and valnemulin) used in treatment of swine dysentery. Further studies are necessary to evaluate a possible slow decrease in susceptibility to tiamulin and valnemulin of B. hyodysenteriae strains in Poland.

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Section: Discussionsupporting

confidence: 82%

Antimicrobial susceptibility of Brachyspira hyodysenteriae isolated from 21 Polish farms

Żmudzki

Szczotka²,

Nowak³

et al. 2012

Polish Journal of Veterinary Sciences

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“…For some isolates, this decrease most likely will be sufficient to cause treatment failure. In vitro resistance following subculturing in the presence of tiamulin also develops slowly and stepwise (10). About two-thirds of the B. hyodysenteriae isolates from 1996 to 1999 were resistant to tylosin.…”

Section: Discussionmentioning

confidence: 99%

Antimicrobial Susceptibility Testing of Porcine Brachyspira ( Serpulina ) Species Isolates

Karlsson¹,

Fellström

Gunnarsson

et al. 2003

J Clin Microbiol

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No standardized method for susceptibility testing of Brachyspira spp. is currently available. A broth dilution procedure was evaluated and used to test the activities of six antimicrobial agents for 108 isolates of Swedish porcine Brachyspira spp. representing biochemical groups I, II, and III. Group I corresponds to Brachyspira hyodysenteriae, group II corresponds to B. intermedia, and group III corresponds to B. murdochii and B. innocens. A panel was designed with the antimicrobial agents dried in tissue culture trays with wells that allowed a liquid volume of 0.5 ml in each and agitation of the broth when incubated on a shaker. The MICs were determined by using brain heart infusion broth with 10% fetal calf serum. For 10 isolates, the results obtained in broth were compared to the MICs obtained on two different types of agar. Different inoculum densities and incubation times were also compared. The concentrations at which 90% of the B. hyodysenteriae isolates (n ‫؍‬ 72) were inhibited in the broth dilution test by tiamulin (0.25 g/ml), tylosin (>256 g/ml), erythromycin (>256 g/ml), clindamycin (>4 g/ml), virginiamycin (4 g/ml), and carbadox (0.06 g/ml) were determined. The MICs tended to be lower in broth than on agar. Differences in inoculum densities and incubation times had little influence on the MICs. The evaluated broth dilution test was simple to perform, the end points were easily read, and the results were reproducible and reliable. No isolates with decreased susceptibility to tiamulin were found among the Swedish isolates tested.

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“…Several point mutations in domain V of the 23S rRNA gene and/or the ribosomal protein L3 gene are associated with decreased pleuromutilin susceptibility of clinical and laboratory-selected B. hyodysenteriae isolates (27,34). Although cross-resistance has not been specifically studied in Brachyspira, valnemulin resistance has been observed in B. pilosicoli during selection for tiamulin resistance in vitro (35). 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).…”

Section: Discussionmentioning

confidence: 99%

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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Susceptibility to pleuromutilins inBrachyspira(Serpulina)hyodysenteriae

Cited by 46 publications

References 38 publications

Antimicrobial susceptibility of Brachyspira hyodysenteriae isolated from 21 Polish farms

Antimicrobial susceptibility of Brachyspira hyodysenteriae isolated from 21 Polish farms

Antimicrobial Susceptibility Testing of Porcine Brachyspira ( Serpulina ) Species Isolates

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

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