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*

OBJECTIVETo investigate the antimicrobial resistance and resistance profiles of Salmonella isolates, from the pork production chain in several districts of Sichuan province and to determine the correlation between serotype and the pulse field gel electrophoresis (PFGE) patterns.

METHODSFrom 2010 to 2011, a total of 112 Salmonella isolates from pork production chain were examined for their antimicrobial susceptibility, using the micro-dilution method against 10 antimicrobial agents.

RESULTSwere assessed by the standard by the Clinical and Laboratory Standards Institute (CLSI, 2010). In addition, PFGE patterns were investigated among the Salmonella strains from different sources, under different serovars and antimicrobial profiles.

RESULTSFor Salmonella isolated from the pork production chain, resistance to tetracycline (89.29%) was frequently observed. Many isolates were resistant to spectinomycin (36.61%), trimethoprim/sulfamethoxazole (35.71%), nalidixic acid (33.93%) and ampicillin (24.11%), but all of the isolates were susceptible to ceftiofur. 33.93% of the isolates were multi-drug resistant. Salmonella isolates from the pork production chain had 19 antibiotic resistance profiles. Totally, 34 PFGE patterns were detected among 74 Salmonella isolates from the pork production chain, with the PFGE patterns of the 74 Salmonella isolates sharing 40% to 100% similarities.

CONCLUSIONThe antimicrobial resistances of the Salmonella isolates were commonly detected from the pork production chain in Sichuan province suggesting that Salmonella might horizontally spread from food animals to retail meat products.

Animals ; Drug Resistance, Bacterial ; Meat ; microbiology ; Salmonella ; drug effects ; isolation & purification ; Swine

OBJECTIVE: Salmonella enterica remains a major cause of food-borne disease in humans, and Salmonella Typhimurium (ST) contamination of poultry products is a worldwide problem. Since macrophages play an essential role in controlling Salmonella infection, the aim of this study was to evaluate the effect of glycyrrhizic acid (GA) on immune function of chicken HD11 macrophages. METHODS: Chicken HD11 macrophages were treated with GA (0, 12.5, 25, 50, 100, 200, 400, or 800 μg/ml) and lipopolysaccharide (LPS, 500 ng/ml) for 3, 6, 12, 24, or 48 h. Evaluated responses included phagocytosis, bacteria-killing, gene expression of cell surface molecules (cluster of differentiation 40 (CD40), CD80, CD83, and CD197) and antimicrobial effectors (inducible nitric oxide synthase (iNOS), NADPH oxidase-1 (NOX-1), interferon-γ (IFN-γ), LPS-induced tumor necrosis factor (TNF)-α factor (LITAF), interleukin-6 (IL-6), and IL-10), and production of nitric oxide (NO) and hydrogen peroxide (H₂O₂). RESULTS: GA increased the internalization of both fluorescein isothiocyanate (FITC)-dextran and ST by HD11 cells and markedly decreased the intracellular survival of ST. We found that the messenger RNA (mRNA) expression of cell surface molecules (CD40, CD80, CD83, and CD197) and cytokines (IFN-γ, IL-6, and IL-10) of HD11 cells was up-regulated following GA exposure. The expression of iNOS and NOX-1 was induced by GA and thereby the productions of NO and H₂O₂ in HD11 cells were enhanced. Notably, it was verified that nuclear factor-κB (NF-κB) and c-Jun N-terminal kinase (JNK) pathways were responsible for GA-induced synthesis of NO and IFN-γ gene expression. CONCLUSIONS Taken together, these results suggested that GA exhibits a potent immune regulatory effect to activate chicken macrophages and enhances Salmonella-killing capacity.
Animals ; Cells, Cultured ; Chickens ; Glycyrrhizic Acid/pharmacology* ; Macrophage Activation/drug effects* ; NF-kappa B/physiology* ; Phagocytosis/drug effects* ; Salmonella/drug effects* ; Signal Transduction/drug effects*

We designed and constructed an antibiotic screening system by using antibiotic responsive genes as reporters. Plasmid pCS26 carrying a promoterless luminescence reporter, luxCDABE, was used as the vector and the promoter regions of antibiotic responsive genes/operons from Escherichia coli were cloned upstream of the lux reporter to form the first part of the screening reporter array. Random promoter library of Salmonella enterica and Pseudomonas aeruginosa were screened for antibiotic responsive clones which consist of the second part of the screening array. The selected final reporter array responded to different antibiotics in distinct patterns and enabled in vivo high-throughput screening for antibiotics. Unknown antibiotics could, in general, be classified by analyzing the response patterns. This screening system is both sensitive and efficient and should prove to be a useful tool for screening new antibiotic compounds.
Anti-Bacterial Agents ; pharmacology ; Drug Evaluation, Preclinical ; methods ; Gene Expression Regulation, Bacterial ; drug effects ; Promoter Regions, Genetic ; genetics ; Pseudomonas aeruginosa ; drug effects ; genetics ; Salmonella enterica ; drug effects ; genetics

Fowl typhoid (FT) reported since 1992 in Korea is a septicemic disease of domestic birds caused by Salmonella gallinarum (S. gallinarum). The purpose of this study was to investigate the biochemical characteristics and antimicrobials susceptibility of field isolates of S. gallinarum isolated by year in Korea. A total of 258 isolates of S. gallinarum from 1995 to 2001 showed the same pattern in the majority of biochemical test such as IMViC (indole, methyl red, Voges-Proskauer and citrate utilization), carbohydrate fermentation and amino acid decarboxylation, and these results were almost in accordance with the traditional biochemical characteristics of S. gallinarum strain. When the antimicrobial susceptibility test against 258 isolates of S. gallinarum was performed by the disk diffusion method using 12 antimicrobial agents, all isolates from 1995 appeared to be susceptible to all of the antimicrobial agents tested except for tetracycline and oxytetracycline, whereas the vast majority of isolates from 2001 showed the reduced susceptibility to ampicillin (13.0%), gentamicin (43.4%), kanamycin (69.6%), enrofloxacin (6.5%), ciprofloxacin (10.9%), norfloxacin (52.5%) and ofloxacin (82. 6%). The prevalence of the prevalence of completely resisyany isolates resistant isolates to one or more drugs rapidly increased from 0% in 1995 to 93.5% in 2001. The minimal concentrations range of the majority of antimicrobial agents to inhibit 50% (MIC50s) against S. gallinarum isolates increased from 0.06 -- 8 microgram/ml in 1997 to 2 -- 256 microgram/ml in 2001. Especially, MIC50s for gentamicin and fluoroquinolones of isolates from 2001 increased over 10-fold than those of isolates from 1997. Therefore, our results indicate that sorbitol fermentation and arginine decarboxylation showed the diversity by isolates and the vast majority of isolates from 2001 showed the reduced susceptibility to antimicrobials tested.
Animals ; Anti-Bacterial Agents/*pharmacology ; Chickens ; Korea ; *Microbial Sensitivity Tests ; Poultry Diseases/microbiology ; Salmonella/*drug effects/isolation & purification ; Salmonella Infections, Animal/microbiology

Cells, Cultured ; Coal ; toxicity ; Dust ; Humans ; In Vitro Techniques ; Mutagenicity Tests ; Mutagens ; toxicity ; Mutation ; drug effects ; Salmonella typhimurium ; drug effects ; genetics ; Sister Chromatid Exchange ; drug effects

OBJECTIVESalmonella isolates recovered from retail meats that were collected in supermarkets and free markets in Xi'an and Yangling areas of Shaanxi province were studied to determine antibiotic susceptibility.

METHODAntimicrobial susceptibility to 14 antibiotics of 193 salmonella isolates were determined by using agar dilution method, which was recommended by National Committee of Clinical Laboratory Standard (NCCLS), and E.coli ATCC25922 and E.faecalis ATCC29212 as standard control strains.

RESULTSThe 44.6% of the salmonella isolates were resistant to sulfamethoxazole, followed by resistance to kanamycin (40.9%), tetracycline (37.8%), amoxicillin (26.9%), ampicillin (25.4%), gentamicin (23.3%) and chloramphenicol (21.8%). Some isolates also showed resistance to fluoroquinolones, the rates for ciprofloxacin, enrofloxacin, levofloxacin and gatifloxacin were 22.3%, 21.8%, 20.8% and 21.2%, respectively. 55 isolates (28.5%) were multidrug resistant (MDR) strains, 28 of 193 isolates (14.5%) could resist at least 13 antibiotics, 24 isolates (12.4%) were resistant to from 4 to 12 antibiotics.

CONCLUSIONSalmonella isolates recovered from retail meats in Xi'an district of Shaanxi province were seriously resistant to antimicrobials commonly used as human and veterinary medicine.

Animals ; Cattle ; Chickens ; Drug Resistance, Multiple, Bacterial ; Food Microbiology ; Goats ; Meat Products ; microbiology ; Salmonella ; drug effects ; isolation & purification ; Sheep ; Swine

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

OBJECTIVETo determine the contamination condition of Salmonella in broiler breeding and slaughter processing in China and to investigate the distribution of antimicrobial resistance profiles.

METHODSFive large-scale broiler holdings and fourteen slaughterhouses were chosen to detect Salmonella in Henan, Jiangsu, Sichuan and Shandong provinces in 2010. A total of 835 anal swabs and 744 chicken carcasses were sampled to compare the difference of Salmonella contamination rate.Salmonella isolates were identified by serotyping according to Kauffmann-White scheme.The antimicrobial susceptibilities of Salmonella isolates were determined by broth microdilution method and sixteen antimicrobial agents were chosen and examined.

RESULTSIn total, Salmonella isolates were recovered in 56 (6.7%) specimens among 835 collected anal swabs and 122 (16.4%) specimens among 744 broiler carcasses. Positive rate of Salmonella in broiler carcasses was higher than anal swabs (χ(2) = 36.94, P < 0.05). The dominant Salmonella serovars isolated from broiler anal swabs were S.enterica serovar Indiana and S.enterica serovar Enteritidis, accounting for 58.9% (33/56) and 32.1% (18/56) respectively. The prevalent serovars in broiler carcasses were also the two serovars and occupied 29.8% (37/124), 32.2% (40/124) respectively. Nearly 95.0% (171/180) Salmonella isolates were resistant to at least one antimicrobial, 78.3% (141/180) Salmonella strains were multi-drug resistant isolates and 20 (11.1%) Salmonella isolates were resistant to 14 antimicrobials.

CONCLUSIONOur findings indicated that Salmonella contamination was common and serious in commercial broiler production and processing course in China. Salmonella contamination rate in broiler slaughter processing performance was higher than broiler flocks. Additionally, antibiotic resistance of Salmonella was in serious situation.

Animals ; Chickens ; microbiology ; China ; Drug Resistance, Multiple, Bacterial ; Food Contamination ; Meat-Packing Industry ; Salmonella ; classification ; drug effects ; isolation & purification ; Serotyping