Osmotically stabilized media have been reported to increase the recovery rate of various bacteria from blood. This study was made to determine the effect of high concentrations of sucrose on the cultivation of S. typhi from blood. Sucrose in 15% or 30% concentration in the blood culture media retarded the growth. The mean incubation time for the appearance of growth was significantly longer in the media with sucrose. In those blood specimens which rendered growth of S. typhi in both media with and without sucrose, the incubation times were compared; and it was found that the majority of the specimens showed faster growth in the media without sucrose. Experimental cultures showed that the higher the sucrose concentration the lighter and slower were the growths of S. typhi. These tendencies were also observed in the growth of E. coli, P. aeruginosa, S. aureus, beta-hemolytic Streptococcus, alpha-hemolytic Streptococcus and S. pneumoniae.
Culture Media ; Human ; Salmonella typhi/drug effects ; Salmonella typhi/growth & development* ; Salmonella typhi/isolation & purification ; Sucrose/pharmacology*

Slower growth of S. typhi in hypertonic media, reported previously by the authors, was contradictory to other workers', results which showed better growth of some species of bacteria. To evaluate furthur the effect of hypertonic sucrose on the growth of S. typhi, organisms were suspended in saline or in blood with or without sodium polyanethol sulfonate (SPS) and stored up to 24 hours. And then viable counts were determined on tryptic soy agar (TSA) and experimental blood cultures were done in tryptic soy broth (TSB) and in TSB with 10% sucrose (TSB-H). S. typhi, suspended in blood and kept for 24 hours, were inoculated into TSB and TSB-H and after 4 hour incubation viable counts were made on TSA and on TSA with 10% sucrose (TSA-H). In this study it was found that, during the 24 hour storage, the viable counts of S. typhi suspended in saline with or without SPS were similar and those suspended in blood with SPS were incereasing. Comparison of the growth in TSB and in TSB-H did not show hyperonic media was better for the cultivation of S. thphi which was kept up to 24 hours before inoculation. On the contrary the growth was slower. Viable counts made on TSA and on TSA-H from the TSB and TSB-H, which were inoculated with S. typhi suspended in blood and incubated for 4 hours, showed similar results indicating TSB-H did not support faster growth. From the results of this experiment and of the previous clinical blood cultures, it is concluded that 0.1% SPS does not give adverse effect on S. typhi during the 24 hour storage and that hypertonic sucrose does not give better result in the cultivation of S. typhi.
Blood/microbiology* ; Culture Media ; Hypertonic Solutions ; Salmonella typhi/drug effects ; Salmonella typhi/growth & development* ; Sucrose/pharmacology*

Thiol broth is known to neutralize various antimicrobial agents. Positivity of growth of various species of bacteria from blood in thiol broth was reported as similar to that in tryptic soy broth (TSB). As blood cultures are often used for the diagnosis of typhoid fever, and as patients may receive antimicrobial therapy before blood culture, the positivity and rapidity of growth of Salmonella typhi in thiol broth were compared to those in TSB. Routine blood culture samples from Yonsei Medical Center patients were inoculated in 50-ml amounts of TSB and thiol broth. The media were prepared from dehydrated products and did not contain CO2, but TSB contained 0.025% sodium polyanethol sulfonate (SPS). Growth of S. paratyphi-A, Klebsiella pneumoniae, Enterobacter sp., Serratia marcescens and alpha-hemolytic Streptococcus were similar in both media. However, greater positivity and shorter incubation time for macroscopic detection were noted in TSB with S. typhi, Escherichia coli and Staphylococcus aureus. It is concluded that thiol broth is inferior to TSB plus SPS for the culture of S. typhi from blood.
Bacteriological Techniques ; Comparative Study ; *Culture Media ; Protein Hydrolysates ; Salmonella typhi/*growth & development ; *Sulfhydryl Compounds ; Support, Non-U.S. Gov't

OBJECTIVETo study the role of RpoE and RpoS on the influence of the metabolism and growth of bacterial under hyperosmotic stress.

METHODSThe rpoS/rpoE double deletion mutant of Salmonella enterica serovar typhi (S. typhi) was prepared by homologous recombination through the suicide plasmid mediated. The recombination was visualized by PCR. Growth curves were drawn by using photometric value A600 as the ordinate and cultivation time as abscissa. The survival abilities of bacterial were compared under hyperosmotic stress. Statistical differences of early logarithmic growth stage (4 h) and laters logarithmic growth stage (12 h) were analyzed by one-way ANOVA. The expression difference of metabolism related genes of wild-type and mutant strains of S. Typhi incubated under hyperosmotic stress were investigated by Salmonella genomic DNA microarray. Real-time quantitative PCR (qRT-PCR) was performed to validate the results of microarray assay in some selected genes.

RESULTSThe rpoS/rpoE double deletion mutant of S. Typhi was successfully generated. The analysis of growth curve showed that the 4-hour and 12-hour A600 values were separately 0.503 ± 0.018 and 2.060 ± 0.112 in rpoS deletion mutant strains, 0.293 ± 0.053 and 1.933 ± 0.115 in rpoE deletion mutant strains, and 0.051 ± 0.007 and 0.963 ± 0.111 in rpoS/rpoE double deletion mutant strains; all of which were lower than the values of wild-type strains, who were 0.725 ± 0.097 and 2.496 ± 0.171, respectively. The difference were statistically significant (P < 0.05). The genomic DNA microarray revealed that 42 genes relevant with bacterial metabolism were influenced by RpoE and RpoS. Results of qRT-PCR showed that the expression values of rpsE, rbsK, nusG and etuB in rpoS deletion mutant strains were (1.86 ± 0.14)×10(6), (1.37 ± 0.11)×10(6), (2.72 ± 0.58)×10(6) and (8.27 ± 1.01)×10(6) copies/µg, respectively; while those in rpoE deletion mutant strains were (2.19 ± 0.17)×10(6), (1.51 ± 0.12)×10(6), (2.73 ± 0.57)×10(6) and (9.63 ± 1.42)×10(6) copies/µg, respectively. Compared with the values in wild-type strains, which were separately (1.94 ± 0.10)×10(6), (1.52 ± 0.11)×10(6), (2.39 ± 0.52)×10(6) and (10.83 ± 1.52)×10(6) copies/µg, the differences was not statistical significance (P > 0.05). However, compared with the values in rpoS/rpoE double mutant strains, which were separately (5.64 ± 0.59)×10(6), (4.17 ± 0.40)×10(6), (9.44 ± 1.22)×10(6) and (2.95 ± 0.88)×10(6) copies/µg, the difference was significant (P < 0.05).

CONCLUSIONRpoE and RpoS could influence the expression of lots of metabolism genes. Together, they regulated the metabolism and growth of S. Typhi under hyperosmotic stress.

Bacterial Proteins ; genetics ; Gene Deletion ; Osmosis ; Salmonella typhi ; genetics ; growth & development ; metabolism ; Sigma Factor ; genetics ; Stress, Physiological