Abstract

       Background and Objective: the Formation of urinary infection by uropathogenic E.coli needs   numerous virulence factors and biofilm formation is among these factors. Bacteria that form biofilms express phenotype traits that appear according to the bacteria type. Cellulose is an important compound on the outside of E.coli causing bacterial cell-cell reactions and connection to nonliving surfaces. Curli pili cause the reaction between cell-cell and surface-cell in biofilms and lead to bacteria aggregation. Microorganisms’ ability to form biofilm on a surface depends on the surface nature and its conditions. This study aimed at determining the production ability of cellulose polysaccharide and curli pili in UPEC strains, and its correlation with formation and intensity of biofilm.

       Methods: In this study carried out to compare the ability of cellulose and pili curli production ability in  40 uropathogenic E.coli isolates ,by morphotype  method in Congo Red medium (CR), each isolate was incubated at 37 ^oC, for 24 hours. After 24 hours, all colonies’ morphology characteristics were studied

     Results: It was shown that 67.5% of strains produced cellulose and 72.5% produced curli pili. In addition, 92.6% and 89% of isolates that produce cellulose and curli, respectively, had a moderate to strong biofilm. Moreover, it was shown that there is a significant correlation between cellulose and / or curli pili production with biofilm intensity.

       Conclusion: About 70% of E.coli isolates from patients' urine are able to produce cellulose or curli pili; therefore, it can be concluded that the production of these two combinations is effective in amount and intensity of biofilm formation.

       Keywords: Escherichia coli; Cellulose Polysaccharide; Curli Pili; Biofilm.

ABSTRACT

      Background and Objective: Chlamydia trachomatis is one of the most common causes of genital infection in men and women. Genital chlamydial infections in women are clinically asymptomatic in 70-80% of the cases; therefore, the lack of timely diagnosis and treatment leads to complications such as infertility and ectopic pregnancy. The aim of this study was to evaluate the frequency of chlamydial infection in symptomatic and asymptomatic women in the Golestan province.

      Methods: This cross-sectional study was conducted on 150 cervical swab samples obtained from 150 women referred to the clinic, after obtaining written consent and completion of questionnaires. The swab samples were transferred to laboratory in phosphate-buffered saline solution and DNA extraction was carried out using phenol-chloroform and boiling methods. The frequency of chlamydial infection was evaluated by PCR.

       Results: None of the tested samples were found as Chlamydia-positive.

      Conclusion: The findings require that some more extensive research with larger sample sizes and dispersed population be performed to determine the true prevalence.  Considering the serious complications of chlamydial infections and its asymptomatic nature, a highly sensitive and specific method such as PCR should be used to detect Chlamydia. It is suggested that this method be used along with a complementary test to obtain the results that are more accurate. Furthermore, conducting simultaneous studies on other populations at risk will be very helpful in obtaining representable national data.

 

ABSTRACT
         Background and Objective: Vibrio is a genus of bacteria that are widely distributed in aquatic environments. The genus includes several important pathogens that endanger farm animals and humans who ingest seafood or water contaminated with the bacteria. Virulence of Vibrio spp. is regulated by ctxAB and tcpA genes. The aim of this study was to determine the prevalence of Vibrio spp., and tcpA and ctxB virulence genes in isolates from surface water and salt water samples collected from Golestan Province, Iran.
          Methods: Overall, 115 water samples were collected from the Caspian Sea coast, lagoons and rivers in the Golestan Province. The samples were filtered by membrane filtration method, and enriched in alkaline peptone water with 1% NaCl. The isolates were grown on TCBS agar, and identified by biochemical tests. Presence of the tcpA and ctxB virulence genes was investigated by polymerase chain reaction.
          Results: In this study, Vibrio alginolyticus was the predominant species (38%) isolated from the seawater and surface water samples, followed by Vibrio parahaemolyticus (23%), Vibrio harvei (15%), Vibrio fluvialis (14%) and Vibrio damsela (10%). The virulence genes were not detected in any of the isolates found in the study.
        Conclusion: This study indicates that V. alginolyticus is the most prevalent Vibrio spp. in surface water and seawater samples collected from the Golestan Province, Iran.
          Keywords: Environmental Vibrio, Surface water, ctx B gene, tcpA gene.

ABSTRACT
             Background and Objectives: Aging is a multi-agent phenomenon due to prolonged inflammation and stress. CD33 or Siglec3 is a membrane receptor that acts against aging by inhibiting inflammatory reactions. The aim of this study was to evaluate a possible relationship between CD33 copy number and lifespan of an Iranian population.
             Methods: The study included 50 individuals with cancer or Alzheimer's disease as the case group and 50 members of a family over 70 years old as the control group. Blood samples were collected and transferred to the laboratory. CD33 copy number was calculated using the QX100 Droplet Digital PCR system. A number of CD33 single-nucleotide polymorphisms including rs3865444, rs273634 and rs3852865 were genotyped using specific primers and the PCR method.
             Results: The mean number of CD33 copies among the case group (7.78) was significantly lower (P<0.05) than control group (12.72). In the case group, the mean number of CD33 copies was 7.83 among men and 7.73 among women. In the control group, the mean number of CD33 copies was 12.73 among men and 12.71 among women.
             Conclusion: CD33rSiglecs counteract random molecular damage, which is the main driver of aging. Therefore, the CD33rSiglec gene number may be correlated with longevity. Our results indicate that there may be a link between reduced CD33rSiglec copy number and development of diseases.
             Keywords: Gene Copy Number, Siglec-3, CD33 Antigens, Cancer.