Further characterization of porcine Brachyspira hyodysenteriae isolates with decreased susceptibility to tiamulin

Karlsson, Märit; Aspán, Anna; Landén, Annica; Franklin, A.

doi:10.1099/jmm.0.05395-0

Cited by 38 publications

(53 citation statements)

References 9 publications

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“…Evaluations of isolates in Europe have identified significant increases in MIC 90 of B. hyodysenteriae against tiamulin over time. 7,9,18 In the Czech 14,18 Based on the current study, an increased MIC against tiamulin does not appear to be widespread in U.S. isolates. A previous study 4 identified MIC 90 of U.S. Brachyspira (Serpulina) isolates at 0.5 µg/ml; the MIC 90 in these isolates from 2008-2010 was 1 µg/ml, which is not significantly different from that seen in 1998.…”

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confidence: 99%

Species characterization and minimum inhibitory concentration patterns of Brachyspira species isolates from swine with clinical disease

et al. 2011

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Abstract. Typhlocolitis and dysentery due to Brachyspira hyodysenteriae infection represent an economically important disease syndrome in growing pigs. Largely disappearing from U.S. swine herds in the late 1990s and early 2000s, Brachyspiraassociated disease and bacterial isolation from swine with clinical disease has increased in the last several years, and non-B. hyodysenteriae isolates are commonly identified. Antimicrobial resistance has been demonstrated in Brachyspira spp. isolates from Europe and Asia, and may be the reason for the resurgence in U.S. herds. Seventy-nine clinical isolates identified at the Iowa State University Veterinary Diagnostic Lab were tested with multiple polymerase chain reaction assays to establish species identity, and evaluated for minimum inhibitory concentrations (MICs) using an agar dilution method against lincomycin, gentamicin, valnemulin, tiamulin, salinomycin, and carbadox. Only 38.0% of isolates could be confirmed as the known pathogens B. hyodysenteriae (30.4%) or Brachyspira pilosicoli (7.6%). Twenty of the 79 isolates (25.3%) were identified as Brachyspira murdochii, and 13.9% could not be identified to species. The MIC values were consistently high against lincomycin and moderately high against gentamicin. The remaining antimicrobials had MICs that were at the low end of the test ranges. Brachyspira murdochii and Brachyspira spp. had significantly greater MIC values against several of these drugs than other Brachyspira spp. examined. The increased incidence of these less definitively characterized Brachyspira species with increased MIC values to commonly prescribed antimicrobials may, at least in part, explain the increased prevalence and severity of this disease complex in recent years. Further research is necessary to understand these changes.

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confidence: 99%

Species characterization and minimum inhibitory concentration patterns of Brachyspira species isolates from swine with clinical disease

et al. 2011

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“…A decrease in susceptibility to tiamulin in different countries has been observed (Karlsson et al 2004, Lobová et al 2004, Duinhof et al 2008, Pringle et al 2012. Other commonly used drugs, such as lincomycin and tylosin, show high levels of resistance (Hommez et al 1998, Karlsson et al 2002.…”

Section: Discussionmentioning

confidence: 99%

“…High resistance to tylosin was expected based on the selective pressure caused by the widespread use of this drug in therapeutic and prophylactic programmes in recent years (Karlsson et al 2002, Rohde et al 2004, Hidalgo et al 2009, 2011, Zmudzki et al 2012, Alvarez et al 2013, Mirajkar & Gebhart 2013. The mechanism of tylosin resistance is related to mutations in the 23S ribosomal RNA gene at position 2058, inhibiting its binding (Karlsson et al 1999(Karlsson et al , 2004.…”

Section: Discussionmentioning

confidence: 99%

“…The presence of Brachyspira spp. strains with a low response to previously effective antimicrobial agents has been demonstrated in different studies in several countries (Karlsson et al 2004, Lobová et al 2004, Duinhof et al 2008, Pringle et al 2012. Thus, evaluation of the antimicrobial susceptibility of clinical isolates is essential to obtain a better understanding of this situation.…”

Section: Introductionmentioning

confidence: 99%

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Minimum inhibitory concentration of Brazilian Brachyspira hyodysenteriae strains

et al. 2017

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The objectives of this study were to characterize Brachyspira hyodysenteriae isolates and to evaluate the antimicrobial susceptibility patterns of strains obtained from pigs in Brazil based on the minimal inhibitory concentration test (MIC). The MIC was performed for 22 B. hyodysenteriae isolates obtained from 2011 to 2013 using the following antimicrobial drugs: tylosin, tiamulin, valnemulin, doxycycline, lincomycin and tylvalosin. Outbreaks of swine dysentery were diagnosed based on clinical presentation, bacterial isolation, gross and microscopic lesions, duplex PCR for B. hyodysenteriae and B. pilosicoli and nox gene sequencing. All obtained MIC values were consistently higher or equal to the microbiological cut-off described in the literature. The MIC 90 values for the tested drugs were 8μg/ml for doxycycline, >4μg/ml for valnemulin, 8μg/ml for tiamulin, 32μg/ml for tylvalosin, >64μg/ml for lincomycin and >128μg/ml for tylosin. These results largely corroborate those reported in the literature. Tiamulin, doxycycline and tylvalosin showed the lowest MIC results. All of the samples subjected to phylogenetic analysis based on the nox gene sequence exhibited similar results, showing 100% identity to B. hyodysenteriae. This is the first study describing the MIC pattern of B. hyodysenteriae isolated in Brazil.

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“…Laboratory tests have shown that this is due to an increase in the MIC values for the first choice antibiotics pleuromutilins in the treatment of B. hyodysenteriae isolates (Karlsson et al 2002(Karlsson et al , 2003Smola and âíÏek 2003). To determine susceptibility of B. hyodysenteriae to doxycycline, the ADM was used.…”

Section: Discussionmentioning

confidence: 99%

Susceptibility of Brachyspira hyodysenteriae Isolates to Doxycycline using Agar Dilution and Epsilometer Test

Lobová¹,

Čížek²

2004

Acta Vet. Brno

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Lobová D., A. âíÏek: Susceptibility of Brachyspira hyodysenteriae Isolates to Doxycycline using Agar Dilution and Epsilometer Test. Acta Vet. Brno 2004, 73: 329-333.The agar dilution method and the Epsilometer test were used to evaluate antibacterial susceptibility of 49 Brachyspira hyodysenteriae field isolates to doxycycline. A comparison of results obtained by the two methods revealed agreement for 84% of B. hyodysenteriae isolates; with 16% of isolates the Minimal Inhibitory Concentration values differing by two and more dilutions. Out of the total of B. hyodysenteriae isolates tested, 36 (73%) were classified as sensitive, 13 (27%) as intermediary, and none of the strains were found doxycycline-resistant. The demonstrated susceptibility of B. hyodysenteriae isolates to doxycycline suggests the possibility of using it for combination therapy with pleuromutilins of swine dysentery. The Epsilometer test has proved a practical alternative to dilution methods of B. hyodysenteriae susceptibility testing.

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Further characterization of porcine Brachyspira hyodysenteriae isolates with decreased susceptibility to tiamulin

Cited by 38 publications

References 9 publications

Species characterization and minimum inhibitory concentration patterns of Brachyspira species isolates from swine with clinical disease

Species characterization and minimum inhibitory concentration patterns of Brachyspira species isolates from swine with clinical disease

Minimum inhibitory concentration of Brazilian Brachyspira hyodysenteriae strains

Susceptibility of Brachyspira hyodysenteriae Isolates to Doxycycline using Agar Dilution and Epsilometer Test

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