جستجوی مقالات مرتبط با کلیدواژه « vbnc » در نشریات گروه « پزشکی »

Recent studies suggest that the viable but nonculturable (VBNC) bacteria could cause inflammatory diseases. The aim of this study was to detect and investigate the expression of nuc and rfbE genes in blood samples of patients with rheumatoid arthritis (RA).

In this experimental study, 102 blood samples were collected from patients with RA and universal and specific primers were designed. Then, the genome was extracted and PCR reaction was performed to confirm the presence of universal and specific genes. Finally, RT-Real Time PCR reaction was carried out to evaluate the expression of marker genes associated with VBNC bacteria. Data were grouped and analyzed descriptively.

PCR showed nuc and rfbE genes in 54 (52.9%) and 12 samples, respectively, while according to RT-Real Time PCR these genes were expressed in 80% of the blood samples of patients with RA.

In current study, the VBNC state of Escherichia coli and Staphylococcus aureus were present in the blood samples of patients with RA. Accordingly, and due to the pathogenicity of VBNC bacteria, different diagnostic methods and treatments should be considered for RA.

Listeria monocytogenes is a gram-positive and foodborne pathogen that is psychrophilic and has the ability to tolerate a high percentage of salt by more than 10%. This bacterium grows in many food products that have a long shelf life. This study was performed to evaluate the expression of genes hly and inlA of Listeria monocytogenes bacteria in the viable but non-culturable (VBNC) condition in temperatures of 4 degrees Celsius.

In this descriptive laboratory study, bacteria in 106 counts in mid log phase were inoculated into BHI Agar rich medium and It was investigated and stored at refrigerated temperature (4 degrees Celsius) until the cultivate was lost. At the end of the 16S rRNA gene, the hly and inlA genes were studied as pathogenic genes of this bacterium. The expression of these genes before and after entering to VBNC state was performed to compare their expression.

Listeria bacteria lost its cultivation ability after 5 months of storage at a refrigerated temperature. The results of the gene expression analysis showed that at the end of the period, the bacterium entered "Viable But non-Culturable" form; also the hly and inlA pathogenic genes were not expressed in riched medium. By adding blood to the rich culture medium of this bacterium, the hemolysin O pathogen gene was re-illuminated.

The results of this study show that the possibility of bacterial entry into VBNC mode occurs at the refrigerator condition, and the expression of its pathogenic genes is affected. Blood and its agents can act as an agent for the induction and clarification of the hly gene. Therefore, it is necessary to review the microbial quality control of fishery products.

The purpose of this study was to investigate the possibility of Listeria monocytogenes entering the VBNC state during the frozen storage and the expression of its pathogenic genes Bacteria in 106 Colony counts of in mid log phase were inoculated into three Culture medium including Normal Saline (NS), BHI Broth and Fish Broth (FB) and kept at -18ºCfor 2 months and examined. Then, bacteria were evaluated on enriched medium BHI agar using culture methods (colony count) over times 4 and 8 hours, 2, 4, 8, 20, 30 and 60 days after the freezing shock using the method of RT-PCR for investigating the expression of 16S rRNA, hly and inlA genes; they were evaluated before and after the freezing shock. This bacterium retained its ability to cultivate until the end of the shock, but reduced its number. Freezing stopped the expression of genes of hly and inlA, as these genes were not expressed in a rich culture medium either. By adding blood to the rich culture medium of this bacterium, only the hemolysin O pathogen gene was expressed. Although freezing does not lead to the introduction of this bacterium into the VBNC state, it is effective as an adverse environmental factor for the bacteria in the expression of its pathogenic genes. Blood and its agents can act as an agent for the induction and clarification of the hly gene, and the expression of pathogenic bacterial genes are independent of each other.

L. monocytogenes is a foodborne pathogen which has a high ability for adapting to unfavorable conditions and is able to growth at refrigerator temperature. An important subject about these bacteria is entering into Viable but non-culturable (VBNC) state under stress. The aim of the present study is considering the culturability of this pathogen under refrigeration (4°C) in rainbow trout fillet matrix. For this purpose bacteria was considered in four treatments: starvation at refrigerator temperature, starvation and high salinity at refrigerator temperature, fish fillet matrix at refrigerator temperature and salted fish fillet matrix at refrigerator temperature during time period by standard cultural methods and 16SrRNA gene expression. The obtained results showed that starvation at refrigerator temperature and high salinity at refrigerator temperature treatments lost their culturability at 13 and 27 days, respectively. The results of gene expression of these bacteria also showed they enter in to viable but non culturable state. The results of fish fillet matrix at refrigerator temperature and fish fillet matrix at refrigerator temperature treatments showed that these bacteria in fish fillet matrix at refrigerator temperature keep their culturability and did not enter in to viable but non-culturable state. Regarded to obtained results in this study could conclude that there is the entering possibility of L. monocytogenes in to VBNC state at refrigerator temperature in view point of bacteria environment and it is necessary to review the microbial quality control methods for refrigeration products.