The objective of this study was to perform molecular surveillance for assessing the spread of carbapenemase-producing in Czech hospitals. One hundred thirty-six carbapenemase-producing isolates were recovered from 22 hospitals located throughout the country. Sequence type 357 (ST357) dominated ( = 120) among carbapenemase producers. One hundred seventeen isolates produced IMP-type (IMP-7 [ = 116] and IMP-1 [ = 1]) metallo-β-lactamases (MβLs), 15 produced the VIM-2 MβL, and the remaining isolates expressed the GES-5 enzyme. The -like genes were located in three main integron types, with In-p110-like being the most prevalent ( = 115). The two other IMP-encoding integrons (In1392 and In1393) have not been described previously. -carrying integrons included In59-like, In56, and a novel element (In1391). was carried by In717. Sequencing data showed that In-p110-like was associated with a Tn-like transposon inserted in genomic island LESGI-3 in the chromosome. The other integrons were also integrated into the chromosome. These findings indicated the clonal spread of ST357 , carrying the IMP-7-encoding integron In-p110, in Czech hospitals. Additionally, the sporadic emergence of producing different carbapenemase types, associated with divergent or novel integrons, punctuated the ongoing evolution of these bacteria.
Strains of genus Citrobacter (152 isolates from 1950 to 1988 deposited in the Czech National Collection of Type Cultures, Prague) were re-classified using biological and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) methods. One-hundred thirty-six strains (ca. 90 %) were identified to the species level using the biological method with evaluation by Farmer matrix. MALDI-TOF MS exhibited better identification capability, the data being more compact; the method was unambiguously successful in typing 145 (95 %) strains. Comparison of the results of identification by the two methods revealed differences (for 12 samples) in identified species which, considering all biochemical and/or MS characteristics, could be attributed to the natural variability of strains and close relation of the misidentified species (all of them belonged to the Citrobacter freundii complex). Taking into account all the above data, both methods can be considered reliable; however, the MALDI-TOF MS exhibits higher accuracy, efficiency, and rapidity.
PurposeThe aim of this study was to characterize serogroup 19 isolates resistant to macrolides and/or penicillin found among pneumococci recovered from cases of invasive and respiratory tract disease in the Czech Republic in 2014.MethodsPneumococcal isolates of serotypes 19A (n=26) and 19F (n=10) that were non-susceptible to penicillin and/or macrolides and had been collected in 2014 were analysed using multi-locus sequence typing (MLST). Four isolates representing the major clones were subjected to whole-genome sequencing (WGS).ResultsThe penicillin-susceptible macrolide-resistant isolates of serotype 19A were mainly associated with sequence type (ST) 416 belonging to clonal complex (CC) 199, and the penicillin-resistant isolates were of serotype 19F belonging to ST1464 (CC 320). WGS revealed the presence of pilus 1, in association with pilus 2, in serotype19F isolates belonging to CC 320. Another adhesin, pneumococcal serine-rich protein (PsrP), was only present in serotype 19A isolates of ST416. Analysis of the penicillin-binding proteins (PBPs) of serotype 19F penicillin-resistant isolates (ST1464 and ST271) performed on PBP1a, 2b and 2x identified a large number of mutations in comparison to the reference strain, R6. Both isolates contained a unique PBP profile; however, they were highly similar to PBP sequences of the Taiwan19F-14 reference strain. The Pbp2b sequences of both 19F isolates showed the lowest similarity to those of the Taiwan19F-14 strain (91 % similarity), while they were also found to be distantly related to each other (94 % similarity).ConclusionsWGS revealed specific virulence factors in antibiotic-resistant pneumococcal clones that spread rapidly in the post-vaccine era in the Czech Republic.
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