Fluoroquinolone-resistant Achromobacter xylosoxidans clinical isolates from Serbia: high prevalence of the aac-(6′)-Ib-cr gene among resistant isolates
The aim of this study was to evaluate the contribution of plasmid-mediated genes and efflux to fluoroquinolone resistance in collection of Achromobacter spp. gathered during a 3-year period. Susceptibility to ciprofloxacin and levofloxacin was tested by disk diffusion and microdilution tests for a collection of 98 Achromobacter spp. clinical isolates. Identification of fluoroquinolone-resistant isolates was performed by sequencing and phylogenetic analyses of the nrdA gene. Genetic relatedness among resistant isolates was determined by pulsed-field gel electrophoresis (PFGE) analysis. The influence of an H+ conductor cyanide m-chlorophenyl hydrazone (CCCP) and a resistance-nodulation-division-type efflux pump inhibitor phenylalanine-arginine beta-naphthylamide (PAβN) on minimal inhibitory concentration (MIC) value was evaluated by broth microdilution. The presence of the plasmid-mediated qnrA, qnrB, qnrC, qnrS, and aac-(6′)-Ib-cr genes was investigated by PCR and sequencing. Achromobacter spp. isolates that were resistant or intermediately resistant to fluoroquinolones in disk diffusion tests (44/98) were subjected to microdilution. As a result, 20/98 isolates were confirmed to be resistant to ciprofloxacin while 10/98 was resistant to levofloxacin. CCCP decreased twofold MIC value for ciprofloxacin in six isolates and more than 16 times in one isolate, while MIC value for levofloxacin was decreased in all isolates (twofold to more than eightfold). Fluoroquinolone-resistant isolates were identified as A. xylosoxidans with the nrdA gene sequencing. PFGE revealed that resistant isolates belonged to seven different genotypes. Ten isolates belonging to four genotypes were positive for the aac-(6′)-Ib-cr gene. Although resistance to fluoroquinolones was not widespread among analyzed isolates, detected contribution of efflux pumps and the presence of the aac-(6′)-Ib-cr gene present a platform for emergence of more resistant strains.
This study was funded by the Ministry of Education, Science and Technological Development of the Republic of Serbia (grant no. 173019).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
Ethics Committee of the Mother and Child Health Care Institute “Dr. Vukan Cupic” (approval no. 8/6)
- Adam P, Czapiewski P, Colak S, Kosmidis P, Tousseyn T, Sagaert X, Boudova L, Okon K, Morresi-Hauf A, Agostinelli C, Pileri S, Pruneri G, Martinelli G, Du MQ, Fend F (2014) Prevalence of Achromobacter xylosoxidans in pulmonary mucosa-associated lymphoid tissue lymphoma in different regions of Europe. Br J Haemotol 164(6):804–810. https://doi.org/10.1111/bjh.12703 CrossRefGoogle Scholar
- Amoureux L, Bador J, Fardeheb S, Mabille C, Couchot C, Massip C, Salignon AL, Berlie G, Varin V, Neuwirth C (2013) Detection of Achromobacter xylosoxidans in hospital, domestic, and outdoor environmental samples and comparison with human clinical isolates. Appl Environ Microbiol 79(23):7142–7149CrossRefGoogle Scholar
- Clinical and Laboratory Standards Institute. Performance standards for antimicrobial susceptibility testing; Twenty-Fourth Informational Supplement (M100–S24). CLSI, Wayne, PA, USA, 2014Google Scholar
- Filipic B, Malesevic M, Vasiljevic Z, Lukic J, Novovic K, Kojic M, Jovcic (2017) Uncovering differences in virulence markers associated with Achromobacter species of CF and non-CF origin. Front Cell Infect Microbiol 29(7): 224Google Scholar
- Gales A, Jones RN, Andrade SS, Sader HS (2005) Antimicrobial susceptibility patterns of unusual nonfermentative gram-negative bacilli isolated from Latin America: report from the SENTRY Antimicrobial Surveillance Program (1997-2002). Mem Inst Oswaldo Cruz Rio de Janeiro 100(6):571–577CrossRefGoogle Scholar
- Jacoby GA, Strahilevitz J, Hooper D (2014) Plasmid-mediated quinolone resistance. Microbiol Spectr 2(2): doi: https://doi.org/10.1128/microbiolspec.PLAS-0006-2013
- Lomovskaya O, Warren MS, Lee A, Galazzo J, Fronko R, Lee M, Blais J, Cho D, Chamberland S, Renau T, Leger R, Hecker S, Watkins W, Hoshino K, Ishida H, Lee VJ (2001) Identification and characterization of inhibitors of multidrug resistance efflux pumps in Pseudomonas aeruginosa: novel agents for combination therapy. Antimicrob Agents Chemother 45(1):105–116CrossRefGoogle Scholar
- Schlossberg D, ed. Clinical infectious diseases. Cambridge University Press, Cambridge UK, 2008. https://doi.org/10.1017/CBO9780511722240
- Tenover FC, Arbeit RD, Goering RV, Mickelsen PA, Murray BE, Persing DH, Swaminathan B (1995) Interpreting chromosomal DNA restriction patterns produced by pulsed-field gel electrophoresis: criteria for bacterial strain typing. J Clin Microbiol 33: 2233–2239Google Scholar
- Traglia GM, Almuzara M, Merkier AK, Adams C, Galanternik L, Vay C, Centron D, Soledad Ramirez M (2012) Achromobacter xylosoxidans: an emerging pathogen carrying different elements involved in horizontal genetic transfer. Curr Microbiol 65(6):673–678 https://doi.org/10.1007/s00284-012-0213-5 CrossRefGoogle Scholar