Heterogenicity within the LPS Structure in Relation to the Chosen Genomic and Physiological Features of the Plant Pathogen Pectobacterium parmentieri.

Pectobacterium parmentieri is a pectinolytic plant pathogenic bacterium causing high economic losses of cultivated plants. The highly devastating potential of this phytopathogen results from the efficient production of plant cell wall-degrading enzymes, i.e., pectinases, cellulases and proteases, in addition to the impact of accessory virulence factors such as motility, siderophores, biofilm and lipopolysaccharide (LPS). LPS belongs to pathogen-associated molecular patterns (PAMPs) and plays an important role in plant colonization and interaction with the defense systems of the host. Therefore, we decided to investigate the heterogeneity of O-polysaccharides (OPS) of LPS of different strains of P. parmentieri, in search of an association between the selected genomic and phenotypic features of the strains that share an identical structure of the OPS molecule. In the current study, OPS were isolated from the LPS of two P. parmentieri strains obtained either in Finland in the 1980s (SCC3193) or in Poland in 2013 (IFB5432). The purified polysaccharides were analyzed by utilizing 1D and 2D NMR spectroscopy (1H, DQF-COSY, TOCSY, ROESY, HSQC, HSQC-TOCSY and HMBC) in addition to chemical methods. Sugar and methylation analyses of native polysaccharides, absolute configuration assignment of constituent monosaccharides and NMR spectroscopy data revealed that these two P. parmentieri strains isolated in different countries possess the same structure of OPS with a very rare residue of 5,7-diamino-3,5,7,9-tetradeoxy-l-glycero-l-manno-non-2-ulosonic acid (pseudaminic acid) substituted in the position C-8: →3)-ß-d-Galf-(1→3)-α-d-Galp-(1→8)-ß-Pse4Ac5Ac7Ac-(2→6)-α-d-Glcp-(1→6)-ß-d-Glcp-(1→. The previous study indicated that three other P. parmentieri strains, namely IFB5427, IFB5408 and IFB5443, exhibit a different OPS molecule than SCC3193 and IFB5432. The conducted biodiversity-oriented assays revealed that the P. parmentieri IFB5427 and IFB5408 strains possessing the same OPS structure yielded the highest genome-wide similarity, according to average nucleotide identity analyses, in addition to the greatest ability to macerate chicory tissue among the studied P. parmentieri strains. The current research demonstrated a novel OPS structure, characteristic of at least two P. parmentieri strains (SCC3193 and IFB5432), and discussed the observed heterogenicity in the OPS of P. parmentieri in a broad genomic and phenotype-related context.

The structure of the O-polysaccharide isolated from pectinolytic gram-negative bacterium Dickeya aquatica IFB0154 is different from the O-polysaccharides of other Dickeya species.

The species Dickeya aquatica was established in 2014 after the genomic characterization of the pectinolytic bacteria isolated from water. It was demonstrated that D. aquatica was able to cause symptoms of soft rot on the fruit of tomato and cucumber. According to earlier works, lipopolysaccharides are regarded as an important virulence factor of Pectobacteriaceae. An O-specific polysaccharide containing d-Fuc and l-Rha was obtained by mild acid hydrolysis of the lipopolysaccharide of D. aquatica IFB0154 (strain Dw044 isolated in Finland). By means of compositional analyses and NMR spectroscopy, the chemical repeating unit of the polymer was identified as a linear disaccharide of the structure shown below. The rhamnose residue was partially acetylated at O-2 or O-3. OAc (~40%) ↓2 →3)-α-d-Fucp-(1 â†’ 4)-α-l-Rhap-(1→ ↑3 OAc (~30%) The O-polysaccharides isolated from Dickeya dianthicola IFB0485 and Dickeya zeae IPO946 have a different structure, identical to that previously described for several strains of Dickeya solani and Dickeya dadantii 3937.

The uniform structure of O-polysaccharides isolated from Dickeya solani strains of different origin.

O-polysaccharides were isolated from lipopolysaccharides obtained from four different strains of plant pathogenic bacteria belonging to the species Dickeya solani: two of them were isolated in Poland (IFB0099 and IFB0158), the third in Germany (IFB0223) and the last one, D. solani Type Strain IPO2222, originated from the Netherlands. In addition, the O-polysaccharide of a closely related species D. dadantii strain 3937 was isolated. The purified polysaccharides of the five strains were analyzed using NMR spectroscopy and chemical methods. Sugar and methylation analyses, including absolute configuration assignment, together with NMR data revealed that all O-polysaccharides tested are homopolymers of 6-deoxy-d-altrose (d-6dAlt) the following structure: →2)-ß-d-6dAltp-(1→.

Structural characterization of the O-polysaccharide isolated from Franconibacter helveticus LMG23732(T).

The bacterial strain Franconibacter helveticus LMG 23732(T) was previously misidentified as the neonatal pathogen Cronobacter zurichensis. O-polysaccharide (OPS) is a part of lipopolysaccharide (LPS), which is an important cell envelope compound of Gram-negative bacteria. OPS isolated from the bacterium Franconibacter helveticus LMG23732(T) was characterized by chemical analyses as well as 1D and 2D NMR experiments. Compositional analyses indicated the presence of glucose and unusual 6-deoxy sugar - 6-deoxy-talose (6-dTal). The studied strain produced OPS, which consists of 6-l-dTalp in main chain and terminal d-Glcp as a branch: This is the first structural determination of the OPS isolated from genus Franconibacter.

The structure of O-polysaccharides isolated from plant pathogenic bacteria Pectobacterium wasabiae IFB5408 and IFB5427.

O-Polysaccharides were isolated from the lipopolysaccharides of two strains of plant pathogenic bacteria Pectobacterium wasabiae isolated in Poland in 2013 (IFB5408 and IFB5427). The purified polysaccharides were analyzed using 1D and 2D NMR spectroscopy ((1)H, DQF-COSY, TOCSY, ROESY, HSQC, HSQC-TOCSY, and HMBC) and the chemical methods. Sugar and methylation analyses of native polysaccharides, absolute configuration assignment of constituent monosaccharides together with NMR spectroscopy data revealed that the chemical structures of both O-polysaccharides are the same.

Structural studies of O-polysaccharide isolated from Cronobacter sakazakii Sequence Type 12 from a case of neonatal necrotizing enterocolitis.

The O-polysaccharide (OPS) of Cronobacter sakazakii NTU 696 (Sequence Type 12) from a case of neonatal necrotizing enterocolitis was isolated from the polysaccharide fraction obtained after lipopolysaccharide (LPS) hydrolysis. Purified OPS was analyzed by NMR spectroscopy ((1)H, COSY, TOCSY, NOESY, HSQC, HSQC-TOCSY and HMBC experiments) and chemical methods. Obtained monosaccharide derivatives analyzed by gas chromatography and gas chromatography-mass spectrometry allowed the identification of six sugar components. Performed experiments enabled to establish a structure of the OPS repeating unit of C. sakazakii NTU 696, as: [structure: see text].

The structure of O-polysaccharide isolated from Cronobacter universalis NCTC 9529T.

The O-polysaccharide (OPS) was isolated from Cronobacter universalis NCTC 9529(T), a new species in the genus Cronobacter, which was created by the reclassification of the species Enterobacter sakazakii. Purified polysaccharide was analyzed by NMR spectroscopy ((1)H, COSY, TOCSY, ROESY, HSQC, and HSQC-TOCSY) and chemical methods. The monosaccharide derivatives were analyzed by gas chromatography and gas chromatography-mass spectrometry. These experiments enabled the type and number of monosaccharides in the repeating unit of OPS, their positions of linkages, and absolute configuration to be determined. Together the chemical analysis established a structure of the OPS of C. universalis NCTC 9529(T). [structure: see text]. OPS isolated from C. universalis was structurally characterized for the first time.

Chemical structure of the O-polysaccharides isolated from Cronobacter turicensis sequence type 5 strains 57, 564, and 566.

The Cronobacter spp. are Gram-negative bacterial pathogens that can cause infections in all age groups, and have a high mortality rate in neonates due to necrotizing enterocolitis and meningitis. Recent genotyping studies have revealed a strong clonal lineage in the genus, but this has not been compared with physiological traits. The O-polysaccharides (OPS) were isolated from three C. turicensis sequence type 5 strains (57, 564, and 566) and structurally characterized using (1)H and (13)C NMR spectroscopy, including two-dimensional DQF-COSY, TOCSY, ROESY, and HSQC analysis. Further compositional determination was undertaken using classical chemical methods followed by GLC, and GLC-MS analysis. The repeating unit of the isolated O-polysaccharides consists of GlcNAc, Rha, Glc, and had the structure shown below and therefore complemented the sequence type. [structure: see text].

A diurnal variation in testicular hormone production is maintained following gonadotrophin suppression in normal men.

OBJECTIVE: A diurnal variation in serum testosterone in adult men is well recognized, but whether this occurs during exogenous testosterone administration and the degree to which it is endogenous to the testis is unclear. DESIGN: A clinical research centre investigation of testicular function in normal men. PATIENTS: Twenty normal men were recruited, 10 of whom were investigated during administration of testosterone with etonogestrel to suppress gonadotrophin secretion. MEASUREMENTS: Hourly blood samples were taken over 24 h for measurement of testosterone, inhibin B, LH, FSH and cortisol. Urinary excretion of testosterone and the testicular steroid epitestosterone was also measured. RESULTS: In the controls, a diurnal variation in serum testosterone and LH but not FSH was detected. The treated group had similar testosterone concentrations but showed no diurnal variation. Periodicity was also detected in inhibin B concentrations in 5 of the controls and in 9 of the treated group, who also showed synchrony not seen in the controls. Both groups showed diurnal variation in cortisol. Urinary testosterone excretion did not show a diurnal variation in either group, but this was apparent for epitestosterone with a morning peak in both groups despite the markedly lower excretion in the treated men. CONCLUSIONS: The diurnal variation of testosterone in normal men is due to a change in secretion rather than in clearance and is largely LH driven. An endogenous rhythm in both testicular steroidogenesis (epitestosterone) and Sertoli cell function (inhibin B) is also present.