Abstract
Clinical strains of Stenotrophomonas maltophilia, identified by a commercial system as resistant to trimethoprim/sulfamethoxazole (TMP/SMX), were analyzed in detail, to confirm their taxonomic positions, to determine their susceptibilities to various classes of antibiotics, and to assess this information with respect to the epidemiological relevance. The majority of strains were isolated from respiratory and wound specimens from patients admitted tointensive care units. Multi-locus sequence analyses (MLSA) of 16S ribosomal RNA (rRNA) and gyrase subunit B (gyrB) genes were applied for genotypic-based characterization. The minimal inhibitory concentrations (MICs) of ten antimicrobial agents were determined, using the E-test method. The MIC values of TMP/SMX for the clinical isolates of S. maltophilia were greater than 32 mg/L, which confirmed their preliminary assessment as resistant. Minocycline, levofloxacin, and ciprofloxacin exhibited the lowest MICs. All strains were observed to be susceptible to minocycline and levofloxacin. The emergence of clinical strains of S. maltophilia resistant to TMP/SMX is increasingly problematic as this antimicrobial agent is accepted as the "drug of choice" for treating infections caused by this bacterium. However, minocycline and levofloxacin demonstrated excellent in-vitro activities and could be considered as alternative options to counter TMP/SMX-resistant strains of S. maltophilia.
References
Swings J, DeVos P,Van den Mooter M, De Ley J. Transfer of Pseudomonas maltophilia Hugh 1981 to the genus Xanthomonas as Xanthomonas maltophilia (Hugh 1981) comb. nov. Int J Syst Bacteriol.1983;(33):409-13.
Hugh R. Pseudomonas maltophilia sp. nov. nom. rev.IntJ SystBacteriol. 1981;(31):195.
Amar R, Alcaide E, Garay E. Numerical taxonomy of pseudomonads isolated from water, sediment and eels. Syst Appl Microbiol. 1992;(14):235-46.
Berg G, Marten P, Ballin G. Stenotrophomonas maltophilia in the rhizosphere of oilseed rap occurrence, characterization and interaction with phytopathogenic fungi. Microbiol Res . 1996;(151):19-27.
Hauben L, Vauterin L, Moore ERB, Hoste B, Swings J. Genomic diversity of the genus Stenotrophomonas. Int J Syst Bacteriol. 1999;(49) :1749-60.
Crossman LC, Gould VC, Dow JM, Vernikos GS, Okazaki A, Sebaihia M et al. The complete genome, comparative and functional analysis of Stenotrophomonas maltophilia reveals an organism heavily shielded by drug resistance determinants.Genome Biol. 2008;(9):R74.1-13.
Vartivarian SE, Papadakis KA, Anaissie EJ. Stenotrophomonas (Xanthomonas) maltophilia urinary tract infection. A disease that is usually severe and complicated. Arch Intern Med. 1996;(156):433-5.
Senol E. Stenotrophomonas maltophilia: the significance and role as a nosocomial pathogen. J Hosp Infect. 2004;(57):1-7.
Denton M, Kerr KG. Microbiological and clinical aspects of infections associated with Stenotropho monas maltophilia. Clin Microbiol Rev. 1998; (11): 57-80.
Endimiani A, Luzzaro F, Tamborini A, Lombardi G, Elia V, Belloni R et al. Identification and antimicrobial susceptibility testing of clinical isolates of nonfermenting gram-negative bacteria by the Phoenix automated microbiology system. Microbiologica. 2002;(25):323-9.
Stefaniuk: E, Baraniak A, Gniadkowski M, Hryniewicz W. Evaluation of the BD Phoenix automated identification and susceptibility testing system in clinical microbiology laboratory practice. Eur J Clin Microbiol Infect Dis. 2003;(22):479-85.
Shelly DB, Spilker T, Gracely EJ, Coenye T, Vandamme P, LiPuma JJ.Utility of commercial Systems for identification of Burkholderia cepacia complex from cystic fibrosis sputum culture. J ClinMicrobiol.2000;(38):3112-5.
Coenye T, Gevers D, Van de Peer Y,Vandamme P, Swings J. Towards aprokaryotic genomic taxono my.FEMS Microbiol Rev.2005;(29):147-67.
Ludwig W. Nucleic acid techniques in bacterial systematics and identification . Int J Food Microbiol. 2007;(120):225-36 .
Petti CA. Detection and identification of microorganisms by gene amplification and sequencing. MedMicrobiol. 2007;(44):1108-14.
Gales AC, Jones RN, Forward KR, Linares J, Sader HS, Verhoef J. Emerging importance of Acinetobacter species and Stenotrophomonas maltophilia as pathogens in severely ill patients: geographic patterns, epidemiological features, and trends in the SENTRYAntimicrobial Surveillance program (1997-1999). Clin Infect Dis. 2001;32(Suppl):Sl04-13.
Hauben L, Vauterin L, Swings J, Moore ERB. Comparison ofl6S Ribosomal DNA sequences of all Xanthomonas species. Int J Syst Bacteriol. 1997;(47):328-335.
Cochrane G, Akhtar R, Aldebert P, Althorpe N, Baldwin A, Bates K et al. Priorities for nucleotide trace, sequence and annotation data capture at the Ensembl TraceArchive and the EMBLNucleotide Sequence Database. Nucl Acids Res . 2008;(36):05-12.
Tsushima S, Shinohara H, Nakazato T, Ando S, Sugisawa T, Tabei Y. Phylogenetic analysis of Xanthomonas albilineans strains from Okinawa, Japan, through a comparison of the gyrB and rpoD genes in geographically distinct strains. Journal of phytopathology.2006;(154):683-7.
Hugh R, Ryschenkow E. Pseudomonas malto philia, an Alcaligenes-like species. J. Gen Microbiol.1961;(26):123-32.
Palleroni N, Bradbury JF. Stenotrophomonas, a new bacterial genus forXanthomonas maltophilia (Hugh 1980) Swings et al. Int J Syst Bacteriol. 1983:(43):606-9.
Clarridge JE, m. Impact of 16S rRNA gene sequence analysis for identification of bacteria on clinical microbiology and infectious diseases. Clin Microbiol Rev.2004;(17):840-62.
Petti CA,Polage CR, Schreckenberger P. The role of l6S rRNA gene sequencing in identification of microorganisms misidentified by conventional methods. JClinMicrobiol. 2005;(43):6123-5.
Drancourt M,Bollet C, Raoult D.Stenotrophomo nas africana sp. nov., an opportunistic human pathogen in Africa. Int J Syst Bacteriol; 1997; (47):160-3.
Coenye T, Vanlaere E, Falsen E,Vandamme P. Stenotrophomonas africana Drancourt et al. 1997 is a later synonym of Stenotrophomonas maltophi lia (Hugh 1981) Palleroni and Bradbury 1993.IntJ Syst Evol Microbiol.2004 ;(54):1235-7. 26.Berg G, Roskot N, Smalla K.Genotypic andphe notypic relationships between clinical and envi ronmental isolates of Stenotrophomonas maltophilia .J ClinMicrobiol. 1999;(37):3594-600.
Turner D, Tumg B,Lilli H, Hong J, Yu C.Antibio tic susceptibility testing of Stenotrophomonas maltophilia with trimethoprim/sulfamethoxazol e using the Phoenix™System. As presented atthe 9th ECCMID, March 1999,Berlin, Germany.
Nicodemo AC, Araujo MRE, Ruiz AS, Gales AC. In vitro susceptibility of Stenotrophomonas maltophilia isolates: comparison of disc diffusion, E-test and agar dilution methods J Antimicrob Chemother.2004;(53):604-8.
Sanchez-Hernandez J, Manzanares MA, Gutierrez Zufiaurre MN, Muiioz Criado S, Muiioz Bellido JL, Garcia-Rodriguez JA. In vitro activity of eight fluoroquinolones against multiresistant Stenotrophomonas maltophilia . Rev EspQuimioter.1999;(12):234-6.
Bonfiglio G, Cascone C, Azzarelli C, Cafiso V, Marchetti F, Stefani S. Levofloxacin in vitro activity and time-kill evalua tion of Stenotrophomonas maltophilia clinical isolates. J Antimicrob Chemoth. 2000;(45):115-7.
Valdezate S,Vmdel A, Loza E, Baquero F,Canton R.Antimicrobial susceptibilities of unique Stenotrophomonas maltophilia clinical strains. AntimicrobAgentsChemother .2001;(45):1581-4.
Kurlandsky LE, Fader RC. In vitro activity of minocycline against respiratory pathogens from patients with cystic fibrosis. Pediatr Pulmonol. 2000;(29):210-2.
Gabriel PS, Zhou J, Tabibi S, Chen Y, Trauzzi M, Saiman L. Antimicrobial susceptibility and synergy studies of Stenotrophomonas maltophilia isolates from patients with cystic fibrosis. Antimicrob Agents Chemother.2004;(48):168-71.