RESUMO
Aim: In this research, we designed a direct Enzyme Linked Immunoassay method to detect Helicobacter pylori antigens in stool specimens
Background: Helicobacter pylori infection as the worldwide problem is related to many gastrointestinal disorders such as gastritis, gastric cancer, non-ulcer disease, peptic ulcer disease and duodenal ulcer
Methods: We produced and purified recombinant CagA and NapA antigens in Escherichia coli and extracted their antibodies from a panel of positive sera specimens. We designed a novel enzyme linked immunoassay direct method in combination with the whole cell for the qualitative and quantitative detection of Helicobacter pylori antigens in human stool. Assay performance was evaluated by histopathology staining and urease activity
Results: The sensitivity and specificity of assay was determined as 91.7 [95% confidence interval: 89.3-95.6%] and 93.1% [95% CI: 91.2-96.4%], respectively. Novel ELISA exhibits enhanced sensitivity and specificity of Helicobacter pylori detection in comparison with another commercially available kit
Conclusion: Combination of the recombinant antigens and whole cell of Helicobacter pylori in immunoassay designing is a new approach about early diagnosis, treatment and fallowing up of the Helicobacter pylori infected patients, especially in peptic cancer cases
RESUMO
Background and study aim: this study aimed to determine the antibacterial resistance patterns of extended spectrum b-lactamase [ESBL]-producing enteropathogenic Escherichia coli [EPEC] isolated from Iranian children and to investigate its genetic patterns
Patients and methods: 192 non-repeats EPEC isolates were collected from stool samples of the children with and without diarrhoea. The EPEC strains were isolated from 1355 stool specimens obtained from 247 children with diarrhoea [0-10 years old; mean age, 5.5 years] and 1108 children without any gastrointestinal symptoms [0-10 years old; mean age, 6.8 years] during the summer months in three Iranian provinces, Tehran, Ilam and Mazandaran. Strains biochemically identified as E. coli were selected and were identified by the presence of eaeA and bfpA as EPEC virulence genes. Antimicrobial susceptibilities were determined by disc diffusion method. The isolates were confirmed to be ESBL producers by the double disk synergy test [DDST]. The b-lactamase genes [blaTEM, blaSHV, blaCTX-M, blaOXA] and insertion sequence ISEcp1 were detected by PCR method
Results: the highest antibiotic susceptibility was detected to imipenem [100%], followed by gentamicin [82.3%] and ciprofloxacin [79.2%]. The highest resistance was detected to cefpodoxime [97.9%], trimethoprim [60.7%], and tetracycline [58.4%], respectively. Totally, 153 EPEC strains [79.7%] were ESBLproducing by DDST test. The PCR showed that 84 [43.8%] EPEC isolates were positive for ESBLs encoding genes. Among 153 ESBLs-producing EPEC, TEM was present in 9.2% of isolates. Also, CTX-M and SHV genes were detected in 7.2% and 7.8%, respectively. The SHV positive strains were associated with the highest resistance rate to tetracycline [56.5%], although the TEM and OXA were associated with the highest resistance rate to gentamicin [23.1%] and ciprofloxacin [21.4%]
Conclusions: the study revealed that 79.7% of EPEC isolates from Iranian children were ESBL-producing and were comparable with the non ESBL-producing isolates regarding susceptibility to the antibiotics
RESUMO
Background: Pseudomonas aeruginosa is a gram-negative pathogens opportunism which causes severe infections in human beings
The most common infection include: endocarditis, meningitis, septicemia and chronic lung infections in cystic fibrosis patients
This bacterium has many pathogenic factors including; exotoxin A, lipopoly-sacharide, phospholipase C, pili, elastase and alkaline protease. The purpose of this study was to evaluate the frequency of exotoxin A gene [ETA] as a strong virulence factor and sensitivity determination of polymerase chain reaction [PCR] in pseudomonas aeruginosa isolated from second and third-degree burn patients
Methods: This study has performed in Besat University Hospital in Hamadan from January to December 2012. We used 170 isolated samples
The samples were isolated from blood and skin biopsy in second and third-degree burn patients
We had 79 strains positive culture of pseudomonas aeruginosa. Forward and reverse primers used for PCR were designed by DNASIS and Oligo software. Then genomic of known strains were extracted by DNA purification kit and indemnified by PCR. The quality and quantity of the extracted DNA was determined using spectrophotometry
For determination of PCR sensitivity was used culture test as gold standard. DNA of pseudomonas aeruginosa [ATCC 27853] was used as a positive control. Finally data was analyzed using SPSS software
Results: Out of 170 isolated samples, 79 strains of pseudomonas aeruginosa isolated from burn patients had positive culture
PCR of isolated positive culture demonstrated that 5 strains [6.33%] were with out this virulence factor and 74 strains [93.67%] had ETA gene. So the sensitivity of test based on sensitivity formula was 94.04%. Conclusion: Our results showed that sensitivity of PCR mediated ETA gene in detection of pseudomonas aeruginosa strains is considerable and this factor can be used as a good factor identifying of pseudomonas aeruginosa. It seems more studies with larger sample size is necessary in this area