Joanna Mokracka

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We analyzed the ability of extraintestinal strains of Enterobacter spp. and Citrobacter spp. to employ different siderophore-mediated strategies of iron acquisition. All strains produced iron-chelating compounds. Cross-feeding assays indicated that most isolates of both Enterobacter spp. and Citrobacter spp. excreted catecholate siderophore enterobactin,(More)
In this study, 1832 strains of the family Enterobacteriaceae were isolated from different stages of a municipal wastewater treatment plant, of which 221 (12.1%) were intI-positive. Among them 61.5% originated from raw sewage, 12.7% from aeration tank and 25.8% from the final effluent. All of the intI-positive strains were multiresistant, i.e. resistant to(More)
The presence and persistence of antibiotic resistant bacteria in the environment is thought to be a growing threat to public health. The route of the spread of multiresistant bacteria from human communities to aquatic environment may lead through wastewater treatment plants that release treated wastewater to a water reservoir. In this study we used(More)
Thirty-three isolates of Proteus mirabilis and two P. vulgaris were examined for their antimicrobial resistance, the presence of integrons with regard to gene cassette content, and genetic determinants of β-lactam and low-level quinolone resistance. Integrons were detected in 23 (69.7%) P. mirabilis isolates; six (18.2%) of them had class 1 integrons, 11(More)
We investigated phylogenetic affiliation, occurrence of virulence genes and quinolone resistance in 109 integron-containing strains of Escherichia coli isolated from a wastewater treatment plant. Selection for integron-bearing strains caused a shift toward phylogroup D, which was most numerous, followed by A, B1 and B2. Phylogroups D and B2, both of which(More)
Ninety-six class 1 integron-positive and 96 integron-negative Escherichia coli isolates cultured from the water of the Warta River, Poland, were characterized for their phylogenetic group affiliation and for the presence of genes associated with virulence. Most strains belonged to phylogenetic group A, but phylogenetic group affiliation was not related with(More)
Strains of the Enterobacter cloacae complex are becoming increasingly important human pathogen. The aim of the study was to identify, by sequencing the hsp60 gene, the species of clinical isolates phenotypically identified as E. cloacae and to examine them for virulence-associated properties: the ability of adhesion, invasion to HEp-2 cells and the induced(More)
We examined 55 Enterobacter cloacae isolates from clinical specimens for the production of cytotonic and cytotoxic toxins and the presence of the type III secretion system (TTSS). Twelve isolates (22%) revealed cytotoxic activity that caused destruction of Vero cells, whereas 28 (51%) strains induced lysis of the murine macrophage J774 cell line. TTSS genes(More)
In the study we examined the production of cytotonic and cytotoxic toxins and the presence of a type III secretion system (TTSS) in 64 Aeromonas spp. strains isolated from fecal specimens of patients with gastroenteritis. We observed that contact of the bacteria with host epithelial cells is a prerequisite for their cytotoxicity at 3 h incubation.(More)
The mechanism of pathogenicity of 13Aeromonas caviae strains isolated from fecal specimens of children with diarrhea was examined. Isolates possessed several virulence agents. Six of 13 isolates produced cholera-like toxin, all strains exhibited adhesive ability and secreted catecholate siderophores. Six isolates were able to grow in heat-inactivated serum.(More)