Browsing by Author "Figueira, Vânia"
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- Bacillus purgationiresistans sp. nov., isolated from a drinking-water treatment plantPublication . Vaz-Moreira, Ivone; Figueira, Vânia; Lopes, Ana R.; Lobo-da-Cunha, Alexandre; Sproer, Cathrin; Schumann, Peter; Nunes, Olga C.; Manaia, Célia M.A Gram-positive, aerobic, non-motile, endospore-forming rod, designated DS22T, was isolated from a drinking-water treatment plant. Cells were catalase- and oxidase-positive. Growth occurred at 15–37 6C, at pH 7–10 and with ,8% (w/v) NaCl (optimum growth: 30 6C, pH 7–8 and 1–3% NaCl). The major respiratory quinone was menaquinone 7, the G+C content of the genomic DNA was 36.5 mol% and the cell wall contained meso-diaminopimelic acid. On the basis of 16S rRNA gene sequence analysis, strain DS22T was a member of the genus Bacillus. Its closest phylogenetic neighbours were Bacillus horneckiae NRRL B-59162T (98.5% 16S rRNA gene sequence similarity), Bacillus oceanisediminis H2T (97.9 %), Bacillus infantis SMC 4352-1T (97.4 %), Bacillus firmus IAM 12464T (96.8 %) and Bacillus muralis LMG 20238T (96.8 %). DNA–DNA hybridization, and biochemical and physiological characterization allowed the differentiation of strain DS22T from its closest phylogenetic neighbours. The data supports the proposal of a novel species, Bacillus purgationiresistans sp. nov.; the type strain is DS22T (5DSM 23494T5NRRL B-59432T5LMG 25783T).
- Candidimonas nitroreducens gen. nov., sp. nov. and Candidimonas humi sp. nov., isolated from sewage sludge compostPublication . Vaz-Moreira, Ivone; Figueira, Vânia; Lopes, Ana R.; De Brandt, Evie; Vandamme, Peter; Nunes, Olga C.; Manaia, Célia M.Two bacterial strains (SC-089T and SC-092T) isolated from sewage sludge compost were characterized by using a polyphasic approach. The isolates were Gram-negative short rods, catalase- and oxidase-positive, and showed good growth at 30 °C, at pH 7 and with 1 % (w/v) NaCl. Ubiquinone 8 was the major respiratory quinone, and phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol were amongst the major polar lipids. On the basis of 16S rRNA gene sequence analysis, the strains were observed to be members of the family Alcaligenaceae, but could not be identified as members of any validly described genus. The low levels of 16S rRNA gene sequence similarity to other recognized taxa, together with comparative analysis of phenotypic traits and chemotaxonomic markers, supported the proposal of a new genus within the family Alcaligenaceae, for which the name Candidimonas gen. nov. is proposed. Strains SC-089T and SC-092T, which shared 99.1 % 16S rRNA gene sequence similarity, could be differentiated at the phenotypic level, and DNA–DNA hybridization results supported their identification as representing distinct species. The names proposed for these novel species are Candidimonas nitroreducens sp. nov. (type strain, SC-089T = LMG 24812T = CCUG 55806T) and Candidimonas humi sp. nov. (type strain, SC-092T = LMG 24813T = CCUG 55807T).
- Comparison of ubiquitous antibiotic-resistant Enterobacteriaceae populations isolated from wastewaters, surface waters and drinking watersPublication . Figueira, Vânia; Serra, Elizabete A.; Vaz-Moreira, Ivone; Brandão, Teresa R. S.; Manaia, Célia M.This study aimed at assessing the role of ubiquitous (non-Escherichia coli) Enterobacteriaceae in the dissemination of antimicrobial resistance through the urban water cycle. Enterobacteriaceae isolated from a municipal wastewater treatment plant (111 isolates), urban water streams (33 isolates) and drinking water (123 isolates) were compared in terms of: (i) genera distribution, (ii) resistance to 12 antibiotics, and (iii) class 1 and class 2 integrons. The predominant bacterial genera were the same in the different types of water, although with a distinct pattern of species. The most prevalent resistance phenotypes were observed for amoxicillin, ticarcillin, cephalothin and sulphamethoxazole (24–59% in the three types of water). No resistance against ceftazidime or meropenem was observed. Resistance to cephalothin, amoxicillin and sulphamethoxazole was significantly more prevalent in drinking water, water streams and wastewater, respectively, than in the other types of water. It was possible to recognize antibiotic-resistance associations, namely for the pairs streptomycin–tetracycline (positive) and ticarcillin–cephalotin (negative). Class 1 and/or class 2 integrons with similar gene cassettes were detected in the three types of water. This study demonstrated that Enterobacteriaceae are important vehicles of antibiotic resistance, namely in drinking water.
- Differential patterns of antimicrobial resistance in population subsets of Escherichia coli isolated from waste- and surface watersPublication . Figueira, Vânia; Serra, Elizabete; Manaia, Célia M.The species Escherichia coli comprises different subgroups with distinct phylogeny, physiology and ecology and, thus, presumably, with different roles in antimicrobial resistance dissemination. E. coli strains isolated from raw and treated municipal wastewater and from urban water streams were characterized in terms of phylogenetic groups, antimicrobial resistance patterns and the presence of class 1 and class 2 integrons. Our main objective was to investigate the contribution of the different phylo-groups in antimicrobial resistance dissemination in urban waters. Groups A and B1 were predominant in all types of water, evidencing, respectively, the lowest and the highest resistance prevalence. Municipal wastewater treatment was accompanied by significant increases of ciprofloxacin and streptomycin resistance (pb0.01). Antimicrobial resistance prevalence differed significantly between the different phylo-groups and within the same group, mainly in group A. Such differences contributed to explain the higher ciprofloxacin and streptomycin resistance rates observed in treated effluent in comparison with the raw wastewater. We conclude that the dynamics of the bacterial populations has a major role on the dissemination of antimicrobial resistance in the environment.
- Paenibacillus residui sp. nov., isolated from urban waste compostPublication . Vaz-Moreira, Ivone; Figueira, Vânia; Lopes, Ana Rita; Pukall, Rüdiger; Spröer, Cathrin; Schumann, Peter; Nunes, Olga C.; Manaia, Célia M.Two bacterial strains, MC-246T and MC-247, were isolated from municipal urban waste compost and characterized by a polyphasic approach. Both isolates were Gram-stain-variable, endosporeforming rods that were catalase-, oxidase- and b-galactosidase-positive, and able to grow at 25– 50 6C and pH 7.0–9.0, with optimum growth at 37 6C and pH 7. The predominant cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0, iso-C16 : 0, anteiso-C17 : 0 and iso-C17 : 0; the major respiratory quinone was menaquinone MK-7; the cell wall peptidoglycan was of type A1c; and the DNA G+C content was 49 mol%. These characteristics, as well as data from 16S RNA gene sequence analysis, showed that these strains were affiliated with the genus Paenibacillus; the type strains of Paenibacillus ginsengarvi and Paenibacillus hodogayensis were among their closest neighbours (,94.2 % sequence similarity). Nevertheless, the hypothesis that strains MC246T and MC-247 could represent a novel species was supported by the low 16S rRNA gene sequence similarity values shared with other members of the genus Paenibacillus and by the observation of distinct biochemical and physiological traits. Strains MC-246T and MC-247 shared 99.6 % 16S rRNA gene sequence similarity and showed almost identical MALDI-TOF mass spectra, but could be distinguished at the phenotypic and genotypic level. However, DNA–DNA hybridization between strains MC-246T and MC-247 resulted in values above 70 % indicating that both organisms represent a single species, for which the name Paenibacillus residui sp. nov. is proposed; the type strain is MC-246T (5DSM 22072T 5CCUG 57263T).
- A survey of the bacterial diversity in the cup filler of dental chair unitsPublication . Silva, Vítor; Figueira, Vânia; Figueira, Helena; Manaia, Célia M.Water from the cup filler of dental chair units (CFDC) was observed to contain sphingomonads, environmental mycobacteria and methylobacteria, among other minor bacteria. Some of the bacteria detected are recognized opportunistic pathogens. Some of these, tended to persist over time.