Mutans streptococci are frequently isolated from dental plaque and carious lesions. These bacteria have been identified by conventional methods such as biochemical and serologic tests followed by the isolation of colonies on the mitis‐salivarius agar, which are sometimes inconsistent. Recently, species‐specific polymerase chain reaction (PCR) has been reported to rapidly identify Streptococcus mutans and Streptococcus sobrinus. However, in the case of identification and classification into several species, e.g. within the group of mutans streptococci consisting of seven species, the identification using species‐specific PCR seems somewhat inefficient because of need for the development and preparation of specific primers for each species. Therefore, in this study we developed a simple method using restriction fragment length polymorphism analysis of PCR‐amplified 16S ribosomal RNA genes (16S rRNA genes PCR‐RFLP) for the identification of seven different species included in the group of mutans streptococci. We amplified 16S rRNA gene sequences from genomic DNA samples by PCR using universal primers and digested the PCR products with the restriction endonucleases, HpaII and HaeIII. HpaII produced six RFLP patterns for eight reference strains, since the patterns for S. sobrinus, Streptococcus downei and Streptococcus ferus were similar. RFLP patterns produced with HaeIII could separate these three species. Furthermore, the RFLP patterns predicted from the 16S rRNA gene sequences in the GenBank database agreed with the actual RFLP patterns produced in the present study. The 16S rRNA sequence comparisons can be used to identify oral mutans streptococci; however, the identification by sequencing is sometimes difficult in large‐scale studies and for small laboratories. Therefore, 16S rRNA genes PCR‐RFLP, using HpaII and HaeIII, could be an alternative method for the identification of mutans streptococci, and may be applicable for large‐scale studies on the cariogenicity of mutans streptococci. 相似文献
Porcine reproductive and respiratory syndrome virus (PRRSV) is an RNA virus that causes reproductive failure in sows and respiratory problems in piglets. PRRSV infection leads to substantial pig mortality and causing huge economic losses so that disease outbreaks caused by the new PRRSV strain from other regions have caused great concern in China. In this study, we analysed the pathogenicity of the novel ORF5 RFLP 1‐7‐4‐like PRRSV strain, named PRRSV‐ZDXYL‐China‐2018‐1 in pigs. The viral challenge test showed that PRRSV‐ZDXYL‐China‐2018‐1 infection can cause persistent fever, moderate dyspnoea, serum viraemia and interstitial pneumonia in piglets. The levels of viral loads in serum and PRRSV‐specific antigen were also detected in lung tissues were used one‐step Taq‐Man RT‐qPCR and Immunohistochemistry, respectively. At 28dpi, the level of specific antibodies was increased among infected piglets. Importantly, the new virus appeared be a moderately virulent isolate with pathogenicity compared to HP‐PRRSV strain LQ (JXA1‐like strain). Histological examination revealed severe monocyte haemorrhage and interstitial pneumonia associated with monocyte infiltration in the lung tissue of pigs infected with PRRSV‐ZDXYL‐China‐2018‐1 and LQ‐JXA1 strains. Immunohistochemistry (IHC) results showed positive brown‐red epithelial cells and macrophages in pig lungs. Therefore, it is critical to establish an effective strategy to control the spread of PRRSV in China. 相似文献
Objective: To study the relation between CD226 rs763361 gene polymorphism and CD226 serum level and to evaluate their role in susceptibility and disease activity of RA in a cohort of Egyptian individuals.
Methods: The serum level of CD226 was measured using a suitable ELISA kit and the CD226 rs763361 gene polymorphism was typed by PCR-RFLP for 112 RA patients and 100 healthy controls.
Results: Significant association with RA was found with CD226 T allele (OR (95%CI) = 1.6 (1.04–2.4), P = 0.032), and higher CD226 serum level (P = 0.001). Higher CD226 levels were associated with higher ESR values (P = 0.035), positive CRP (0.048), increased number of tender joints (P = 0.045), and higher DAS score (P = 0.035). Serum CD226 is an independent risk factor for the prediction of RA (P = 0.001). No correlations were found between the serum level of CD226 and different CD226 genotypes and also between them and RA activity grades.
Conclusion: The CD226 T allele may be susceptibility risk factors for the development of RA and the higher serum level of CD226 may be involved in the pathogenesis of RA in Egyptian patients. The serum level of CD226 and not CD226 genotypes could be considered as an independent risk factor for the prediction of RA within healthy individuals and also for RA disease activity. 相似文献
The trematodes of the genus Fasciola (the liver flukes) are among the well-known instances of food-borne parasites worldwide. Differentiation of Fasciola species is important because of their different transmission and epidemiological characteristics. The current study was undertaken to discriminate Fasciola species in the domestic ruminants of Urmia city, Iran.
Methods:
Adult flukes were isolated from the naturally infected livers of the slaughtered water buffaloes and sheep. The flukes were initially identified based on morphological and morphometric parameters. A 618-bp-long fragment of the 28SrRNA gene of Fasciola was amplified by polymerase chain reaction (PCR). The amplified fragment was digested by DraII or AvaII enzymes for a restriction fragment length polymorphism (RFLP) analysis and sequenced for the phylogenetic tree construction.
Results:
Based on the morphometric examination, the flukes belonged to F. hepatica, F. gigantica and an intermediate Fasciola form. The PCR-RFLP analysis was able to differentiate F. hepatica from F. gigantica. While the phylogenetic reconstruction justified, to some extent, the morphological diagnosis, it failed to segregate F. hepatica from F. gigantica identified in this and the previous studies.
Conclusion:
To resolve fully the problem of taxonomy and evolution in Fasciola species, employing a broad range of molecular and morphological approaches is necessary. This is crucial for epidemiological surveys and successful clinical management of their infection. 相似文献
Given the importance of understanding the genetic variations involved in the pathogenesis of non-Hodgkin’s lymphoma (NHL), this pilot study was designed to investigate the impact of CD38 (184C/G; rs6449182) and IL-6 (?174 G/C; rs1800795) gene polymorphism on susceptibility of Egyptians to diffuse large B cell lymphoma (DLBCL); major types of NHL. To the best of our knowledge, this study is the first one that examines CD38 polymorphism in the NHL. Genotyping polymorphism is performed using restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) for CD38 and Mutagenically separated PCR (MS-PCR) for IL-6 in 100 Egyptian NHL patients with DLBCL subtype and 119 normal controls. The serum level of IL-6 was measured using Enzyme-linked immunosorbent assay (ELISA). CD38 (184C/G) genotype is significantly increased in NHL patients (p?<?0.01), while the GG genotype is significantly increased in controls (p?<?0.05). Only two genotypes were found (GG and GC) in IL-6 (?174), no CC in our NHL patients and only one case in the controls. Insignificant change in IL-6 (?174 G/C) genotypes was recorded. Significantly increased serum IL-6 (p?<?0.05) was positively correlated (r?=?0.17; p?<?0.05) with the disease. Taken together, our data stressed the importance of CD38 gene polymorphism in developing DLBCL. Our pilot study indicates that CD38 (184) CG genotype might play a role in DLBCL susceptibility in Egyptians. Additional prospective studies on larger population are needed to confirm our findings. 相似文献
Background Microscopy is unreliable to distinguish the pathogenic Entamoeba histolytica from the nonpathogenic Entamoeba dispar or Entamoeba moshkovskii in stool specimens.
Methods Nested polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was carried out to detect E. histolytica, E. dispar, and E. moshkovskii DNA in stool samples of 202 patients positive for E. histolytica, E. dispar, or E. moshkovskii by microscopy or culture and in 35 controls. The TechLab E. histolytica II enzyme-linked immunosorbent assay (ELISA) was performed to detect Gal/GalNAc lectin in 45 stool samples positive for E. histolytica, E. dispar, or E. moshkovskii by microscopy or culture. Rapid-indirect hemagglutination assay (IHA) was performed to detect serum antiamoebic antibodies
in the 85 patients positive for E. histolytica, E. dispar, or E. moshkovskii in their stool specimens and in the 35 controls.
Results Nested PCR-RFLP was positive in 175 of 202 (86.6%) patient stool samples and was negative in all 35 negative control stool
samples. ELISA was positive in 29 of 45 (64.4%) patient stool samples. The IHA test was positive in 19 of 85 (22.4%) patient
serum samples and in one (2.8%) of the 35 control serum samples. Nested PCR-RFLP detected E. histolytica DNA in stool specimens of 12 (63.2%) of 19 seropositive patients, and in 31 (47%) of 66 seronegative patients. TechLab E. histolytica II ELISA detected E. histolytica antigen in stool specimens of six (54.5%) of 11 seropositive patients, and in 23 (67.6%) of 34 seronegative patients.
Conclusions Nested PCR-RFLP was useful for the specific detection of E. histolytica, E. dispar, and E. moshkovskii in stool samples. 相似文献