Phenotypic properties, drug susceptibility and genetic relatedness of Stenotrophomonas maltophilia clinical strains from seven hospitals in Rio de Janeiro, Brazil

Abstract

Aims: To investigate phenotypic aspects including biotyping, drug susceptibility and production of extracellular enzymes and genetic diversity of Stenotrophomonas maltophilia clinical strains obtained from seven hospitals in Rio de Janeiro, Brazil. Methods and Results: Thirty-nine S. maltophilia strains were investigated by biotying, susceptibility testing, extracellular enzymes detection and by randomly amplified polymorphic DNA (RAPD)-PCR. Biotyping distinguished 13 biotypes among 39, and one of them was prevalent. The majority of the strains produced DNase, gelatinase and haemolysin. Protease, lipases and phospholipase C activities were observed in highly variable amounts. None of the strains was elastase producer. The percentage of full susceptibility, by agar dilution, was 100, 94AE8, 81AE6 and 26AE3% for trimethoprim/sulphametoxazole, ticarcillin/clavulanate, ciprofloxacin and ceftazidime, respectively. Thirty-three RAPD-PCR profiles were obtained suggesting multiple sources of acquisition. Conclusions:The results pointed out the necessity of monitoring S. maltophilia especially in critical hospital wards, to assure effective control measures. Significance and Impact of the Study: Despite of the genetic diversity among the strains, in two situations it was observed indistinguishable RAPD-PCR profiles among strains isolated from different patients who had been hospitalized in the same hospital ward, suggesting the possibility of nosocomial transmission that until now has been rarely related.

Isolation and characterization of bacterial strains with a hydrolytic profile with potential use in bioconversion of agroindustial by-products and waste

“…While soil and plants are its main environmental reservoir (RYAN et al, 2009), this bacterium has also been isolated from diverse effluent treatment plants and wastewater (YU; LIU; WANG, 2009;VERMA et al, 2010) and from a Brazilian sugar cane variety (RAMOS et al, 2011). In agreement with the results obtained, some researchers have described the production of extracellular enzymes by Stenotrophomonas including proteases, lipases, nucleases, and chitinases (TRAVASSOS et al, 2004;KUDDUS, RAMTEKE, 2011). Stenotrophomonas sp.…”

Stenotrophomonas maltophilia Encodes a Type II Protein Secretion System That Promotes Detrimental Effects on Lung Epithelial Cells

“…Given the conservation of xps genes among four other S. maltophilia genomes, we infer that Xps T2S is active in other strains of S. maltophilia. In support of this hypothesis, we along with other investigators have found protease activities in supernatants from a variety of other strains of S. maltophilia (3,20,23,45,46). The ϳ47-kDa protein that we observed in the K279a supernatant but not in the xps mutants' supernatants is likely to be StmPr1, a 47-kDa serine protease whose gene sequence encodes a signal sequence (23).…”

“…Initially, casein hydrolysis was determined by spotting a 5-l aliquot of a bacterial suspension on Mueller-Hinton agar (Becton, Dickinson) containing 3% (wt/vol) skim milk (Nestle Carnation, Solon, OH) while gelatinase activity was tested by spotting bacteria on LB agar containing 4% (wt/vol) gelatin (20). Prior to being spotted on the indicator plates, bacteria were grown overnight on LB agar, resuspended in phosphate-buffered saline (PBS; Corning) to an OD 600 equal to 0.1, and diluted 1:10 in PBS.…”

Stenotrophomonas maltophilia strains replicate and persist in the murine lung, but to significantly different degrees

“…The K279a genome sequence reveals a number of potential virulence factors and immune modulators, based upon the in vivo importance of their homologues in other bacteria (Crossman et al, 2008). These factors include type I, II, IV and V protein secretion systems, tissue-degradative exoenzymes, various pili, putative adhesins, flagella, LPS, putative exopolysaccharide, siderophores and quorum sensing (Crossman et al, 2008;Denton & Kerr, 1998;Fouhy et al, 2007;Huang & Wong, 2007;Looney et al, 2009;Minkwitz & Berg, 2001;Rocco et al, 2009;Travassos et al, 2004;Waters et al, 2007;Zgair & Chhibber, 2010b). Thus, the A/J mouse model can be used to compare wildtype K279a with its mutant derivatives in order to formally define the virulence factors of S. maltophilia.…”