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Wattanaphansak S, Pereira CER, Kaenson W, Assavacheep P, Tantilertcharoen R, Resende TP, Barrera-Zarate JA, de Oliveira-Lee JSV, Klein U, Gebhart CJ, Guedes RMC. Isolation and in vitro antimicrobial susceptibility of porcine Lawsonia intracellularis from Brazil and Thailand. BMC Microbiol 2019; 19:27. [PMID: 30704407 PMCID: PMC6357443 DOI: 10.1186/s12866-019-1397-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 01/23/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Lawsonia intracellularis is an obligate intracellular bacterium which cannot be cultured by conventional bacteriological methods. Furthermore, L. intracellularis needs enriched medium and a unique atmosphere for isolation, cultivation and propagation. Because of this,there are only a few isolates of L. intracellularis available and few studies in vitro demonstrating the susceptibility of this bacterium to antimicrobial agents. The objectives of this study were to isolate South American and Southeast Asia strains of L.intracellularis and to determine the in vitro antimicrobial activity against these isolates. Tested antimicrobials included: chlortetracycline, lincomycin, tiamulin, tylosin and valnemulin(against both Brazilian and Thailand strains) and additionally, amoxicillin, zinc-bacitracin, carbadox, enrofloxacin, gentamicin, sulfamethazine, trimethoprim, spectinomycin and a combination (1:1) of spectinomycin and lincomycin were also tested against the Thai isolates. The minimum inhibitory concentration (MIC) was determined by the antimicrobial activity that inhibited 99% of L. intracellularis growth in a cell culture as compared to the control (antimicrobial-free). RESULTS Two strains from Brazil and three strains from Thailand were successfully isolated and established in cell culture. Each antimicrobial was evaluated for intracellular and extracellular activity. Pleuromutilin group (valnemulin and tiamulin) and carbadox were the most active against L. intracellularis strains tested. Tylosin showed intermediate activity, chlortetracycline had variable results between low and intermediate activity, as well as spectinomycin, spectinomycin and lincomycin, amoxicillin, sulfamethazine and enrofloxacin. L. intracellularis was resistant to lincomycin, gentamicin, trimethoprim, colistin and bacitracin in in vitro conditions. CONCLUSIONS This is the first report of isolation of L. intracellularis strains from South America and Southeast Asia and characterization of the antimicrobial susceptibility patterns of these new strains.
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Affiliation(s)
- Suphot Wattanaphansak
- Department of Veterinary Medicine, Faculty of Veterinary Science, Chulalongkorn University, Pathumwan, Bangkok, 10330, Thailand
| | - Carlos Eduardo Real Pereira
- Department of Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, PO Box 567, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Wenika Kaenson
- Department of Veterinary Medicine, Faculty of Veterinary Science, Chulalongkorn University, Pathumwan, Bangkok, 10330, Thailand
| | - Pornchalit Assavacheep
- Department of Veterinary Medicine, Faculty of Veterinary Science, Chulalongkorn University, Pathumwan, Bangkok, 10330, Thailand
| | - Rachod Tantilertcharoen
- Department of Veterinary Medicine, Faculty of Veterinary Science, Chulalongkorn University, Pathumwan, Bangkok, 10330, Thailand
| | - Talita Pilar Resende
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, 55108, USA
| | - Javier Alberto Barrera-Zarate
- Department of Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, PO Box 567, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Juliana Saes Vilaça de Oliveira-Lee
- Department of Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, PO Box 567, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Ulrich Klein
- Elanco Animal Health Inc., Mattenstrasse 24A, 4058, Basel, Switzerland
| | - Connie Jane Gebhart
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, 55108, USA
| | - Roberto Maurício Carvalho Guedes
- Department of Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, PO Box 567, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
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