ABSTRACT
Dehydroepiandrosterone (DHEA) is a steroid hormone secreted by the adrenal glands, gonads and brain. It is a precursor to sex hormones and also is known to have immune modulatory activity. However, little is known about the relationship between DHEA and neutrophils and thus our study evaluates the influence of DHEA in the effector functions of neutrophils. Human neutrophils were treated in vitro with DHEA and further infected with Salmonella enterica serovar Typhimurium. The treatment of neutrophils with 0.01 µM of DHEA increased the phagocytosis of Salmonella independent of TLR4 as the treatment did not modulate the TLR4 expression. Additionally, DHEA caused a decrease in ROS (reactive oxygen species) production and did not influence the formation of the neutrophil extracellular trap (NET). Steroid treated neutrophils, infected or stimulated with LPS (lipopolysaccharide), showed reduced production of IL-8, compared to untreated cells. Also, the protein levels of p-NFκB were decreased in neutrophils treated with DHEA, and this reduction could explain the reduced levels of IL-8. These results led us to conclude that the steroid hormone DHEA has important modulatory functions in neutrophils
Subject(s)
Humans , Male , Adult , In Vitro Techniques , Dehydroepiandrosterone/analysis , Neutrophils/metabolism , Phagocytosis/genetics , Gonadal Steroid Hormones/pharmacology , Adrenal Glands/metabolism , Salmonella enterica/classificationABSTRACT
Purpose:Infections due to invasive non-typhoid salmonella can be dangerous and fatal. The mode of infection and the severity varies from the typhoidal fevers. It is important to find the association between clinical features and the infecting serovar to understand the pathophysiology and course of treatment Methods:In the present study, extra-intestinal specimens (blood, cerebrospinal fluid and pus) from three patients suffering from septicaemia, meningitis and osteomyelitis were received. Micro-biological and biochemical test for species identification and antibiotic susceptibility was done as per standard protocol.Further, PCR based amplification and sequencing of a portion of the flagellin gene (FliC) was done to confirm the serovar.Results: Salmonellaentericawas identified from all the threeby microbiological and biochemical examination.The sequence of the Flic gene confirmed the serovar to be S.typhimurium. All the patients were treated successfully for the infectionby appropriate antibiotic therapy. Conclusion:The study highlights that serovarTyphimurium is common in invasive non-typhoidal salmonellosis and its pathophysiology and virulence factors expression should be understood in various organ types for better treatment options and outcomes
ABSTRACT
RESUMEN En la industria avícola, las infecciones por Salmonella son un problema, debido a los efectos sobre la producción y los riesgos a la salud pública. En las aves infectadas puede ocurrir una diseminación sistémica de las bacterias, que afecta los órganos y favorece, tanto la transmisión entre las aves como la contaminación de los productos avícolas, tales como las carnes, durante el proceso de sacrificio de los animales. Se decidió evaluar el efecto que diferentes combinaciones de glucosa oxidasa (GOX) y glucosa tienen sobre el crecimiento de diversos serotipos de Salmonella aislados de aves en crecimiento y de engorde, y determinar su potencial como antibacteriano. Se tomaron muestras de corazón y de ciego de aves de 7 y 42 días de edad y se aislaron e identificaron S. typhimurium y S. enteritidis. Estas bacterias fueron cultivadas en medio Luria-Bertani (LB) en presencia de GOX (0,5; 1 y 2U/mL) y glucosa (0,5, 1 y 2%), en combinaciones bajo un diseño factorial 32. El crecimiento fue monitoreado por el cambio de absorbancia a 600 nm, durante 6 horas de incubación. Se observó una reducción significativa del crecimiento de ambos serotipos al utilizar 2U/mL de GOX y diferentes concentraciones de glucosa, lo cual, demostró la capacidad antibacteriana que posee el sistema GOX/glucosa sobre este género, por lo que se podría emplear como un aditivo para la conservación de carnes de aves y productos derivados, a fin de alargar su vida de anaquel y minimizar riesgos a la salud.
SUMMARY In the poultry industry, Salmonella infections are a problem due to the effects on production and risks to public health. In infected birds, a systemic spread of bacteria can occur, which affects the organs and favors both the transmission between birds and the contamination of poultry products, such as meat, during the animal´s slaughter process. It was evaluated the effect that different combinations of glucose oxidase (GOX) and glucose have on the growth of different Salmonella serotypes isolated from broilers, and thus determine their potential as antibacterial. Heart and caecal samples were taken from birds 7 and 42 days old. S. typhimurium and S. enteritidis were isolated and identified. These bacteria were cultured in Luria-Bertani medium (LB) in the presence of GOX (0.5, 1 and 2U/mL) and glucose (0.5, 1 and 2%) in combinations under a factorial design 32. Growth was monitored by absorbance change at 600nm for 6 hours of incubation. A significant reduction of the growth of both serotypes was observed when using 2 U/mL of GOX and different concentrations of glucose. This demonstrated the antibacterial capacity that the GOX/glucose system has on this genus, so it could be used as an additive for the preservation of poultry meats and derived products, in order to lengthen its storage time and minimize health risks.
ABSTRACT
Objective To establish a C57BL/6 mouse model of intestinal infection induced by S.Typhimurium.Methods In order to improve the infectious sensitivity of S.Typhimurium, C57BL/6 mice were intragastrically given 5% (w/v) NaHCO3.Then mice were challenged with S.Typhimurium.The health condition, survival and body weight of mice were observed from day 0 to day 7 after the bacterial infection.The pathological changes were also examined.Results the mice challenged with S.Typhimurium showed decreased body weight and typical clinical signs, including in appetence, piloerection and low survival rate.Macroscopic dissection revealed that intestinal hyperemia and swelling were founded in the mice challenged with S.Typhimurium.Histopathology showed intestinal epithelial and mucosal damages.Conclusions We have successfully established a C57BL/6 mouse model of S.Typhimurium infection.This model may be of crucial significance for studying the biological functions of associated immunological molecules or cytokines in the process of inflammatory bowel disease induced by S.Typhimurium.
ABSTRACT
S. typhimurium is an important socioeconomic problem in several countries, mainly in developing countries where it is reported as the main responsible for the food-borne disease outbreaks. A biofilm can be explained as a group of cells, diverse species or mono-species that are fixed to a surface and/or to one another. This study aimed to evaluate the biofilm formation of S. typhimurium on the plastic surface as well as to determine the relationship between contact time and incubation temperature. Crystal violet assay was performed to quantify the biofilm formation with and without treatments based on the value of optical density at 600nm of the destaining crystal violet at different interval of time. The outcomes of the result indicated that, the attachment of bacterial cells to the plastic surfaces increased with the increased contact time and determined by temperature. The values of OD600 at 37 °C for 24, 48 and 72 hours were 0.770, 0.968 and 2.363 respectively. This indicated that, the formation of biofilm by S. typhimurium on plastic surfaces varied with contact time. For the disinfectant treatments, hydrogen peroxide with 91 % sensitivity was the highest in treatment of S. typhimurium cells, followed by the mixture of sodium hypochloride and paracetic acid with 70 %, then paracetic acid with 67 %. Considering this result, S. typhimurium formed a biofilm on the plastic surface, hygienic activities on a plastic surface in food industry during handling, processing, distribution and storage of food should be a concerned and these disinfectants are suggested for the treatment of S. typhimurium.
ABSTRACT
Objective:To investigate the effect of its invasion capacity after the sipB and crp gene deletion strains of Salmonella typhimurium SL1344.Methods:Salmonella typhimurium SL1344 ΔsipB and Δcrp biological characteristics and invasion capacity were studied .Results:The SL1344Δcrp mutant was not able to ferment maltose, lactose, and sorbitol.The growth rate of the mutant was more slowly than SL1344 strain.The dynamic distribution measurement results showed that the number of bacteria in the two experimental groups of mice were isolated from the liver and spleen were lower than in the SL1344 control group .Next HeLa cells infected results showed that lack of the adhesion rate and invasion rate of theΔsipB strain group was lower thanΔcrp strain group and the SL1344 control group .Conclusion: These results showed that the SipB protein play an important role in the process of bacteria infection the body.
ABSTRACT
Aims: To prove the effect of S. typhimurium vaccine on inhibiting foam cell formation and arterial wall thickness, and also to decrease body weight and abdominal visceral fat. Study Design: This experimental research was conducted using rat models. Place and Duration of Study: Faculty of Medicine, Brawijaya University, Indonesia, between February – May 2011. Methodology: The vaccine was 108 CFU of heat-killed S. typhimurium/100μl vaccine per rat. The adjuvant was CFA-IFA 100μl per rat. Twenty Wistar rats were divided into fivegroups: a negative control group (have normal diet), and four treatment groups which were given with atherogenic diet. The four treatment groups were positive control group (atherogenic diet only), vaccine + adjuvant group (added with the vaccine + adjuvants), vaccine group (added with vaccine only), and adjuvant group (added with adjuvant only). The vaccines were injected intraperitoneally, five times in two-week intervals. Results: There was no significantly difference in the average diet intake every day among the groups (P=0.17). The administration of ‘vaccine + adjuvants’, ‘vaccine only’ and ‘adjuvants only’ could decrease foam cell formation and arterial wall thickness compared to the positive control group (P= .00). The ‘vaccine alone’ treatment returned the foam cell numbers to be a normal value just like negative control (P=.15), but ‘vaccine + adjuvants ‘and ‘adjuvant alone’ did not (P=.01). There was a strong and significantly correlation between the foam cell formation with arterial wall thickness (R=0.842, P=.00). In addition, administration of ‘vaccine only’ decreased the rats’ body weight and abdominal visceral fat accumulation significantly compared to the positive control (P=.04 and P=.00 respectively). Conclusion: The heat-killed Salmonella typhimurium vaccine without CFA-IFA adjuvant decreases foam cells expression and aortic wall thickness, body weight, and abdominal visceral fat accumulation in rat-induced atherogenic diet. In suggestion, heat-killed S. typhimurium is a potential antigen to be developed as an atherosclerosis vaccine in the future.
ABSTRACT
Objective: To optimize Helicobacter pylori(H.pylori)oipA gene and develop strain of vaccine in Attenuated Salmonella typhimurium SL7207 haxboring recombinant plasmid pVAX1-oipA and pVAX1-optioipA, then to study its protection against H.pylori in C57BL/6 mice.Methods: oipA gene was modified by codon optimization,inserting the Kozak sequence and engineering CpG motifs.The optioipA gene and oipA gene was inserted into the eukaryotic expressing vector pVAX1 respectively to develop recombinant plasmid pVAX1-optioipA and pVAX1-oipA.The AGS cells were transfected by pVAX1-oipA,pVAX1-optioipA and pVAX1 respectively.Then the OipA protein expression was confirmed by Western blot.pVAX1-oipA,and pVAX1-optioipA were converted to LB5000 for methylation and then the modified eukaryoticvector was electrotransfered to final host SL7207 respectively, SL7207/pVAX1-oipA, SL7207/pVAX1-optioipA was identified with PCR and enzyme digestion.Specific serum IgG antibody was detected by indirect ELISA after oral inoculation with vaccine strains.Mice were challenged with live Sydney strain(SS1)three times at 0,2,4 d(5 × 10~8CFU/each mouse).Fonr weeks after challenge, the mice were sacrificed.The colonization of H.pylori in gastric mucosa were detected by rapid urease test and quantitative culture of H.pylori.Results: The AGS cells transfected with pVAX1-oipA and pVAX1-optioipA had expressed corresponding production, moreover, the expression level of pVAX1-optioipA was higher than those of pVAX1-oipA,SL7207/pVAX1-oipA and SL7207/pVAX1-optioipA confirmed with PCR,enzyme digestion;Two weeks after last immunization,immunized mice.were induced to produce anti-OipA IgG antibodies, and the levels of anti-OipA IgG antibody in pVAX1-optioipA group was obviously higher than in pVAX1-oipA group(P＜0.01); After challenged with SS1, the infection rate of pVAX1-oipA and pVAX1-optioipA group was 60%(9/15)and 26.67%(4/15), which was significantly lower than 100%(10/10)in the control group(P＜0.01).Conclusion:Attenuated Salmonella typhimurium SL7207 containing pVAX1-oipA, pVAX1-optioipA is successfully constructed.It can protect mice from H pylori infection and optimizing oipA gene can enhance the protection efficiency.
ABSTRACT
Background & objectives: Previous studies on natural products had mainly dealt with their antimicrobial activity and studies on the interference of these bioactive compounds with host-bacterial interaction is limited. The present study was undertaken to investigate the effect of the sterols and fatty acids present in the chloroform fraction of crude methanol extract of Hemidesmus indicus root (CHI) on Salmonella enterica serovar Typhimurium (S. Typhimurium) mediated apoptosis in a murine macrophage cell line (P388D1). Methods: Bacterial sensitivity test was carried out with different concentrations of CHI and the optimum dose was fixed as 100 μg/ml for CHI, which was safe on host cells as the CD50 (50% of cell death) dose of CHI was determined to be 500 μg/ml in the P388D1 cell line. Results: The CHI-treated bacteria had negligible cytotoxicity and were less potent to invade and proliferate intracellularly. Murine macrophages infected with wild bacteria, stained with Hoechst 33258, had swollen and damaged morphology with characteristic apoptotic bodies whereas macrophages infected with treated bacteria had comparative normal architecture. Immunofluorescence and transmission electron micrographs both confirmed that CHI-treated bacteria were defective and smaller than the wild bacteria. Ultrastructures of P388D1 cells infected with wild bacteria showed many ingested bacteria and characteristic Salmonella-containing vacuoles (SCV). Some cells had condensed or fragmented nuclei with swollen mitochondria, whereas most of the cells infected with treated bacteria were normal in morphology and a few had internalized bacteria, but the typical bacteria laden SCV was not observed in cells infected with CHI-treated S. Typhimurium. Interpretation & conclusions: Our results showed that the choloroform fraction of H. indicus root blocked the cytotoxic activity of S. Typhimurium in a macrophage cell line. More studies need to be done to elaborate and confirm our findings.
ABSTRACT
The frequency of antibiotic resistance among Salmonella enterica serovar Typhimurium has increased due to the transfer of multiple resistance factors. We detected the 13 antibiotic resistance genes by multiplex-PCR and compared with the results of phage typing and antibiotic disk diffusion for 49 S. typhimurium isolated from food-poisoning outbreaks in Seoul from 1999 to 2002. Resistance genes for tetracycline, streptomycin, ampicillin, sulfonamide, amino-glycoside-modifying enzyme, chloramphenicol, kanamycin, and trimethoprim were detected in 67.3%, 57.1%, 26.5%, 8.1%, 8.1%, 5%, 2.0%, and 0% of isolates, respectively. Overall 28 isolates (57.1%) possessed two or more antibiotic resistance genes. Class 1 integron carrying multidrug resistace genes, ant(3")-IaB, blaPSE, qacE delta1/sul, and tet G were amplified especially in only DT104 isolates. Among the related resistance genes for same antibiotics, strA and strB for streptomycin resistance were simultaneously detected but tetA and tetB for tetracycline were sporadically detected. DT 104 isolates contained only aadA2 and tetG.
Subject(s)
Humans , Ampicillin , Anti-Bacterial Agents , Bacteriophage Typing , Chloramphenicol , Diffusion , Disease Outbreaks , Drug Resistance, Microbial , Integrons , Kanamycin , R Factors , Salmonella enterica , Salmonella , Seoul , Streptomycin , Tetracycline , TrimethoprimABSTRACT
The lipid A component of Re-lipopolysaccharide from S.typhimurium SL 1102 was prepared by hydrolysis with a 0.1 mol/L acetate buffer.Chemical as well as advanced l3C-,and 31P-NMR investigations revealed a ?1' ,6-interlinked D-glucosamine diasaccharide, which is substituted by two phosphate(P)groups, one being esterlinked to the non-reducing residue,and another bound glycosidically to the C1 of the reducing residue, is as the central backbone.Its structure is shown as follows:-P-GlcN(?1', 6)GlcN-P-The amino(2 and 2')and hydroxy(3 and 3')groups of the backone are substituted by 3-OH-14: 0, and unhydroxy fatty acids appear to be the subtituents of the hydroxy group of 3-OH-14 :0, in the means of formation of 3-acyloxyacyl ester and amides.