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*

OBJECTIVEThrough analyzing the typhoid epidemics and to determine and monitor regional resistance characteristics of the shift of drug resistant profile on Salmonella (S.) Typhi, to understand the related epidemiological characteristics of typhoid fever and to provide evidence for the development of strategies, in Guangxi.

METHODSData of typhoid fever from surveillance and reporting system between 1994 to 2013 was collected and statistically analyzed epidemiologically. The susceptibility of 475 S. Typhi isolates from patients on ten antibiotics was tested by broth micro-dilution method and minimum inhibition concentration was obtained and interpreted based on the CLSI standard.

RESULTSFrom 1994 to 2013, a total of 57 928 cases of typhoid fever were reported in Guangxi province with an annual incidence of 6.29/100 000 and mortality as 0.03%. The higher incidence was observed in the population under 20 years of age. There was no significant difference on incidence between male and female, but farmers and students were among the hardest hit groups. More cases were seen from the northern part of the province. Cases appeared all year round with the peak from May to October. A total of 13 major outbreaks during 2001 to 2013 were reported and the main transmission route was water-borne. All the strains were sensitive to third generation cephalosporins cefotaxime and fluoroquinolones norfloxacin. The susceptibility rates to tetracycline, chloramphenicol, ampicillin and gentamicin was around 98% but relative lower susceptible rate to ciprofloxacin was seen as 89.89% . The lowest susceptibility was found for streptomycin and sulfamethoxazole agents, with the rates as 67.73% and 65.89% , respectively. One strain was found to have been resistant to ciprofloxacin and another 47 isolates with reduced susceptibility to ciprofloxacin. Twenty eight isolates were found to be resistant to multiple antibiotics and one displayed ampicillin, chloramphenicol, streptomycin, sulfamethoxazole tetracycline and nalidixic acid (ACSSxT-NAL) resistance profile. This was the first report in China. Multi-drug resistant strains were frequently isolated from small scale outbreaks of typhoid fever.

CONCLUSIONThe incidence of typhoid fever in Guangxi was still high and some strains showed multi-drug resistance and reduced susceptibility to ciprofloxacin, indicating that the surveillance and monitor programs on drug resistance of S. Typhi should be strengthened, to prevent large scale outbreaks of typhoid fever in this province.

China ; epidemiology ; Disease Outbreaks ; Drug Resistance, Multiple, Bacterial ; Female ; Humans ; Male ; Salmonella typhi ; drug effects ; isolation & purification ; Typhoid Fever ; epidemiology

We report a relapsed case of a 25 year-old man with multi-drug resistant Salmonella serovar Typhi (MDRST) bacteremia who had recently returned from travel in India. Due to unresponsiveness to ciprofloxacin and ceftriaxone, we examined the strain's resistance to quinolones and extended-spectrum beta-lactamases (ESBLs). The strain had a single gyrA mutation at codon 83 (Ser83Phe), which explains its decreased susceptibility to fluoroquinolone and resistance to nalidixic acid. In the screening tests of ESBLs, TEM-1 was positive, which is beta-lactamase but not ESBL. The patient was finally successfully treated with meropenem and aztreonam. In the presence of clinical unresponsiveness despite favorable sensitivity tests, further laboratory evaluations are needed, which should include studies of genes related to antibiotic resistance and ESBLs. In addition, further prospective trials should be done about the possible inclusion of antibiotics not yet mentioned in the current guidelines. With MDRST on the rise worldwide, the most optimal and effective line of antibiotic defense needs to be devised.
Adult ; Anti-Bacterial Agents/*administration & dosage ; Aztreonam/*administration & dosage ; Bacteremia/drug therapy/microbiology ; Drug Resistance, Bacterial/genetics ; Drug Resistance, Multiple/genetics ; Drug Therapy, Combination ; Humans ; Male ; Salmonella typhi/*drug effects/genetics ; Thienamycins/*administration & dosage ; Typhoid Fever/*drug therapy