Isolation and identification of nontuberculous mycobacteria from raw milk and traditional cheese based on the 16S rRNA and hsp65 genes, Tehran, Iran

As an important source of human food, milk can be a carrier of human pathogenic bacteria, including tuberculous and nontuberculous mycobacteria (NTM), in its raw and unpasteurized state. In this research, 175 raw milk samples and 175 traditional cheese samples were collected from traditional dairy stores in 22 regions of Tehran in a 9- month period from August 2019 to May 2020. Samples were prepared and transferred to a specialized laboratory, where they were inoculated in Lowenstein-Jensen (LJ) medium containing glycerol or sodium pyruvate, as well as Herrold's egg-yolk with and without Mycobactin J. to determine the sample's identity of samples. The recommended 16S rRNA (1436 bp) and hsp65 (644 bp) gene fragments from the positive isolates identified in Ziehl-Neelsen (Z-N) staining were amplified and sequenced using PCR and compared with the sequences of the gene fragments of reference strains available in the global GenBank database. No mycobacterial species were isolated from traditional cheese samples in microbial culture. In case of raw milk samples, a total of four bacteria were collected, all of which were found in the genetic differential testing to be NTM, including n = 1 Mycobacterium heraklionense, n = 2 Mycolicibacterium fortuitum, and n = 1 Mycobacterium thermoresistibile. The analysis of the results obtained by isolate sequencing using the 16S rRNA gene showed higher discriminatory power and percentage similarities in the identification of the isolates than the hsp65 gene.

Effect of lipopeptide extracted from Bacillus licheniformis on the expression of bap and luxI genes in multi-drug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa

Recently, opportunistic pathogens like Acinetobacter baumannii and Pseudomonas aeruginosa have caused concern due to their ability to cause antibiotic resistance in weakened immune systems. As a result, researchers are always seeking efficient antimicrobial agents to tackle this issue. The hypothesis of the recent study was that probiotic products derived from bacteria would be effective in reducing drug resistance in other bacteria. This research aimed to investigate the antimicrobial properties of probiotic products from various bacterial strains, including Lactobacillus rhamnosus, Pediococcus acidilactisi, Bacillus coagulans, Bacillus subtilis, and Bacillus licheniformis. These were tested against multi-drug-resistant (MDR) standard strains A. baumannii and P. aeruginosa. B. licheniformis was found to be the most effective probiotic strain, possessing the LanA and LanM lantibiotic genes. The lipopeptide nature of the probiotic product was confirmed through high-performance liquid chromatography (HPLC) and Fourier-transform infrared spectroscopy (FTIR) techniques. The anti-biofilm and antimicrobial properties of this probiotic were measured using an SEM electron microscope and minimum inhibitory concentration (MIC) test. Real-time PCR (qPCR) was used to compare the expression of bap and luxI genes, which are considered virulence factors of drug-resistant bacteria, before and after treatment with antimicrobial agents. The MIC results showed that the probiotic product prevented the growth of bacteria at lower concentrations compared to antibiotics. In addition, the ΔΔCqs indicated that gene expression was significantly down-regulated following treatment with the obtained probiotic product. It was found that B. licheniformis probiotic products could reduce drug resistance in other bacteria, making it a potential solution to antibiotic resistance.

Characterization of green synthesized selenium nanoparticles (SeNPs) in two different indigenous halophilic bacteria

BACKGROUND

In the biological method, using nonpathogenic and extremophile bacteria systems are not only safe and highly efficient but also a trump card for synthesizing nanoparticles. Halomonas elongata QW6 IBRC-M 10,214 (He10214) and Salinicoccus iranensis IBRC-M 10,198 (Si10198), indigenous halophilic bacteria, can be used for synthesizing selenium nanoparticles (SeNPs).

METHODS

SeNP biosynthesis was optimized in two halophilic bacteria and characterized by UV-Vis, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), zeta potential, and energy dispersive X-ray (EDX).

RESULTS

Optimized conditions for synthesizing SeNPs was at 300 °C at 150 rpm for 72 h and 6 mM or 8 mM concentration of Na2SeO3. UV-Vis indicated a sharp absorption peak at 294 nm. Spherical-shaped nanoparticles by a diameter of 30-100 nm were observed in FESEM and TEM microscopy images. The produced SeNPs were identified by a peak in FTIR spectra. In XRD analysis, the highest peak diffraction had a relationship with SeNPs. The zeta potential analysis showed SeNP production, and elemental selenium was confirmed by EDX.

CONCLUSIONS

Halophilic bacteria, owing to easy manipulation to create optimization conditions and high resistance, could serve as appropriate organisms for the bioproduction of nanoparticles. The biological method, due to effectiveness, flexibility, biocompatibility, and low cost, could be used for the synthesis of reproducible and stable nanoparticles.

More insights about genomic population structure of Mycobacterium avium subspecies paratuberculosis (Map) from multiple hosts in west and central provinces of Iran using a boosted genotyping approach

To investigate the population genetic of Mycobacterium avium subsp. paratuberculosis (Map) in Iran, Mycobacterial Interspersed Repetitive Units (MIRUs) and Multi Locus Short Sequence Repeat (MLSSR) system were employed. Numerous genotypes by MIRU (N = 11) and MLSSR (N = 9) methods bearing discriminatory indices of 0.90 and 0.79 respectively, were obtained. Browsing the INRA-Nouzilly list (http://mac-inmv.tours.inra.fr/) detected 3 of the found patterns as new types. Some loci either MIRU-VNTR or SSR proved more polymorphic and therefore are recommended to be applied in priority for strain typing in the Iranian environment. While identical MIRU-VNTR or MLSSR patterns were detected among different conspecifics and geographical locations, dissimilar types were also observed at the same farms an indication of coexistence of Map strains within one herd. We suggest extension of the genotyping work described here to include more endogenous isolates in order to better analysis of transmission and virulence in epidemiology and control of paratuberculosis.

The efficacy of massage as a nightly bedtime routine on infant sleep condition and mother sleep quality: A randomized controlled trial

BACKGROUND AND PURPOSE

Infants' sleep disorders and parents' insufficient sleep are common problems in the infant care. The current study was conducted to assess the effectiveness of infant massage on infants' night-time sleep condition and mothers' sleep quality.

PROCEDURES

140 infants were randomly put into two different groups, experimental group with fifteen-minute bedtime messages for two weeks and the control group with normal infant routine care. The Brief Infant Sleep Questionnaire, a personal information submission form, and Pittsburgh Sleep Quality Index for the mothers were the tools used to gather data in this study.

RESULTS

Infants in experimental group showed meaningful differences in variables such as, sleep latency (P <  0001, eta = 0.099), number of night waking (P = 0.03, eta = 0.027) and longest continuous sleep period (P = 0.03, eta = 0.026). As for other variables no meaningful differences were observed. There wasn't meaningful difference in the mother's overall night-time sleep quality between the two groups (P = 0.184, eta = 0.012) except for the duration of the mother's night-time sleep (P = 0.028, eta = 0.026) and the reduction of maternal sleep disorder (P = 0.020 eta = 0.029).

CONCLUSION

The findings indicated that infants' bedtime massages would improve some of the sleep markers of mothers and infants, and therefore, can be suggested as a practical, harmless, and cost-free method to improve sleep.

Molecular Docking, Anti-Biofilm & Antibacterial Activities and Therapeutic Index of mCM11 Peptide on Acinetobacter baumannii Strains

Despite the huge efforts of microbiologists, infectious diseases have yet remained one of the leading causes of death in humans, further highlighting the research priority for controlling opportunistic pathogens. Many researchers have used antibacterial peptides to solve the problem of antibiotic resistance. This research is thus conducted to investigate the antibacterial and anti-biofilm activity of a novel modified cecropin-melittin 11-peptide with improved therapeutic properties and lower side effects. After synthesis and purification of mCM11 (NH2-WRLFRRILRVL-NH2) by solid-phase synthesis and HPLC methods, respectively, the antibacterial and biofilm inhibitory activities were explored in vitro. TMHMM was used to confirm the reaction of mCM11 on the plasma membrane of the prokaryotic cells. The interaction between mCM11 on Acinetobacter baumannii strains was investigated by molecular docking using ClusPro2.0. Hemolysis and therapeutic indexes were also calculated to quantify the relative safety and adverse effects of mCM11. According to the results, mCM11 has a high inhibitory and lethal effect on A. baumannii strains due to its cationic properties and new specific sequence. Molecular docking revealed the release of a significant amount of energy when mCM11 binds to the surface of A. baumannii in an appropriate site. The findings indicated that mCM11 IC50 (4 μg/mL) lysed 2.78% of RBCs; moreover, 8 strains of Acinetobacter baumannii showed a favorable therapeutic index. The mCM11 exhibits strong antibacterial and antibiofilm activities against A. baumannii strains, suggesting its potential therapeutic role in infections caused by these strains. Similar to its impact on A. baumannii, mCM11 could be a suitable alternative to antibiotics in combat against antibiotic-resistant bacteria in the in vivo experiments.

Effect of biosynthesized selenium nanoparticles using Nepeta extract against multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii

The problems of drug resistance in bacteria have become one of the daily challenges of the clinical treatment of patients, which inevitably forces us to use agents other than common antibiotics. Among these, we can take help from different properties and applications of nanoparticles (NPs). In this work, we evaluate the antibacterial activity of biosynthesized selenium nanoparticles (SeNPs) against standard strains of multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii. The production of biosynthesized SeNPs was proved by ultraviolet-visible, Fourier transform infrared, X-ray diffractometer, Field Emission Scanning Electron Microscopy, Dynamic light scattering, and Zeta potential methods. The cytotoxicity effect of SeNPs was investigated by MTT assay. Disk diffusion agar (DDA) and minimum inhibitory concentration (MIC) tests were performed on the mentioned bacteria using different classes of standard antibiotics and SeNPs separately. The impact of SeNPs combined with the desired antibiotics for better treatment of these infections was evaluated by checkerboard assay to determine the synergism effect. After the confirmation results based on the biosynthesis of SeNPs, both standard bacterial strains were susceptible to SeNPs and had a zone of inhibition using the DDA test. Also, the results of MICs showed that biosynthesized SeNPs in lower concentrations than antibiotics cause no growth of bacteria. On the other hand, according to the checkerboard assay, SeNPs had a synergistic effect with conventional antibiotics. The antibacterial sensitivity tests demonstrated the inhibition of bacterial growth in the presence of lower concentrations of SeNPs than common antibiotics. This property can be exerted in future applications to solve the drug resistance obstacle of microorganisms in bacterial diseases.

Green synthesis of selenium nanoparticles and evaluate their effect on the expression of ERG3, ERG11, and FKS1 antifungal resistance genes in Candida albicans and Candida glabrata

Drug resistance in Candida species has been considerably increased in the last decades. Given the opposition to antifungal agents, toxicity, and interactions of the antimicrobial drugs, identifying new antifungal agents seems essential. This study assessed the antifungal effects of nanoparticles (NPs) on the standard strains of Candida albicans and Candida glabrata and determined the expression genes, including ERG3, ERG11, and FKS1. Selenium nanoparticles (Se-NPs) were biosynthesized with a standard strain of C. albicans and approved by several methods including, UV-Vis spectrophotometer, XRD technique, FTIR analysis, FESEM microscopy, and EDX diagram. The antifungal susceptibility testing performed the minimum inhibitory concentrations (MICs) using the CLSI M27-A3 and M27-S4 broth microdilution method. The expression of the desired genes was examined by the real-time PCR assay between untreated and treated by antifungal drugs and Se-NPs. The MICs of itraconazole, amphotericin B, and anidulafungin against C. albicans and C. glabrata were 64, 16, and 4 µg/ml. In comparison, reduced the MIC values ​​for samples treated with Se-NPs to 1 and 0.5 µg/ml. The results obtained from real-time PCR and analysis of the ∆∆C_q values showed that the expression of ERG3, ERG11, and FKS1 genes was significantly down-regulated in Se-NPs concentrations (P<0.05). This study's evidence implies biosafety Se-NPs have favorable effects on the reducing expression of ERG3, ERG11, and FKS1 antifungal resistance genes in C. albicans and C. glabrata.

The effect of biosynthesized selenium nanoparticles on the expression of CYP51A and HSP90 antifungal resistance genes in Aspergillus fumigatus and Aspergillus flavus

The application of biological nanoparticles (NPs) can be considered as a way to overcome the problem of antifungal resistance in pathogenic fungi. This study takes a new approach to biosynthesized NPs influence on the expression of CYP51A and HSP90 antifungal resistance genes in Aspergillus fumigatus and A. flavus, and comparison with antifungal agents. Selenium NPs (Se-NPs) were biosynthesized using Aspergillus strains and their production was proved by several methods including, UV-Vis, XRD, FTIR, FESEM, and EDX techniques. The minimum inhibitory concentrations (MICs) of Aspergillus strains were determined using the CLSI M38-A2 broth microdilution method. The differences in expression levels of CYP51A and HSP90 genes were examined between untreated and treated of A. fumigatus and A. flavus using itraconazole and amphotericin B and biosynthesized Se-NPs through real-time PCR. After confirming the results of NPs synthesis, the MIC of itraconazole and amphotericin B against A. fumigatus and A. flavus was 4 μg/ml. Based on the real-time PCR results, the obtained ∆∆CTs for these strains were -0.18, -1.46, and -1.14. Whereas the MIC values for treated samples with Se-NPs have decreased to 0.5 μg/ml, and the ∆∆CTs for these were -0.25, -1.76, and -1.68. The expression of CYP51A and HSP90 genes was significantly down-regulated through the use of Se-NPs against A. fumigatus and A. flavus.

Experiences of the mothers of infants hospitalized in the neonatal intensive care unit (NICU)

BACKGROUND

The mother-newborn relationship is more important in neonates hospitalized in the NICU than in healthy neonates. This study was conducted to explore the experiences of the mothers of infants hospitalized in the NICU.

MATERIALS AND METHODS

This qualitative study was done in 2016 by adopting a conventional content analysis approach. Thirty-five mothers in the NICUs, Imam Hossein Hospital and Fatemieh Hospital were selected. Their experiences were assessed using in-depth individual semi-structured interviews. Sampling was purposive and was continued until reaching data saturation.

RESULTS

Two hundred and nine primary codes were extracted. After removing duplicates and overlaps, 95 primary codes were categorized in 8 subcategories, 2 accessory categories and 1 main category based on their appropriateness, agreement, and similarity. The accessory categories of "mothers' worries" and "mothers' hopes" were merged into a more general, abstract category named "dual feelings about the baby".

CONCLUSIONS

The nurses' awareness of the mothers' experiences can help design interventions to promote the quality of care for mothers and infants in the critical period of the NICU admission.

The Relationship Between the Dietary Inflammatory Index and Metabolic Syndrome in Ravansar Cohort Study

PURPOSE

The aim of this study was to investigate the association between dietary inflammatory index (DII) and metabolic syndrome (MetS) and its components using data of Ravansar non-communicable diseases (RaNCD) cohort study.

PATIENTS AND METHODS

The present cross-sectional study was performed using the information of 6538 participants in the RaNCD study in Iran. A validated 125-item food frequency questionnaire (FFQ) was used to acquire DII scores. MetS was defined based on national cholesterol education program-adult treatment panel III (NCEP-ATP III) criteria. The association between DII and MetS and its components was investigated by the logistic regression model using STATA software.

RESULTS

A significant association was found between DII and MetS (OR _trend: 1.08, 95% CI: 1.01-1.15, P =0.017), triglyceride (TG) (OR _trend: 1.06, 95% CI: 1.00-1.12, P=0.030), fasting blood glucose (FBG) (OR _trend: 1.10, 95% CI: 1.01-1.20, P=0.018) and high density lipoprotein cholesterol (HDL-C) (OR _trend: 1.07, 95% CI: 1.02-1.12, P= 0.005) after adjustment for all covariates. Also, there was a significant relationship between DII score and waist circumference (WC) (OR _trend: 1.07, 95% CI: 1.01-1.14, P=0.016).

CONCLUSION

Higher DII score (a pro-inflammatory diet) had a significant association with the risk of MetS and its components, even after adjustment for different potential confounding factors including socio-demographic data and lifestyle habits. However, further longitudinal investigations with more dietary parameters are needed to elucidate the role of the pro-inflammatory diet in the etiology of MetS.

A multiplex assay of Trichomonas vaginalis, Chlamydia trachomatis and Neisseria gonorrhoeae infections in genital specimens

INTRODUCTION

A significant proportion of patients with Sexually Transmitted Infections (STIs) are coinfected with multiple pathogens. We report here development of a multiplex PCR for simultaneous detection of Chlamydia trachomatis (C.trachomatis), Neisseria gonorrhoeae (N.gonorrhoeae) and Trichomonas vaginalis (T.vaginalis) in genital specimens from women.

METHODOLOGY

After detection of the organisms by routine techniques including PCR, culture and direct smear, multiplex-PCR was optimized to detect ompI gene of CT, parC of NG, ITS ribosomal RNA of TV as target genes. The limit of detection (LOD) was determined using serially diluted genomic DNA from known number of each pathogen.

RESULTS

Totally 300 volunteers with mean age of 36.5 ±7.03 years were included and 266 (88.7%) had genitourinary clinical manifestations. Of 300 women, 150 (50.0%) were infected. Of them, 17 (5.7%) had N. gonorrhoeae, 98 (32.7%) T. vaginalis and 35 (11.7%) C. trachomatis. Multiplex-PCR revealed a total of 10 coinfections (3.3%) including 2 specimens of C. trachomatis/ N. gonorrhoeae, 3 specimens of C .trachomatis/ T. vaginalis and 5 specimens of N. gonorrhoeae/T. vaginalis coinfections. The sensitivity and specificity of multiplex-PCR for detecting N. gonorrhoeae were 100% and 98.59% (279 of 283) respectively and, for C. trachomatis and T. vaginalis were 100%. The LOD was 0.1 pg of DNA for C. trachomatis and N. gonorrhoeae, and 1.5 pg for T. vaginalis.

CONCLUSIONS

The performance of this multiplex-PCR makes it a sensitive, rapid and affordable technique in clinical laboratory for simultaneous detection of STIs.

Genital infections and reproductive complications associated with Trichomonas vaginalis, Neisseria gonorrhoeae, and Streptococcus agalactiae in women of Qom, central Iran

BACKGROUND

Trichomonas vaginalis (T.vaginalis) and Neisseria gonorrhoeae (N.gonorrhoeae) are two most common non-viral sexually transmitted infections in the world. No data are available regarding the epidemiology of genital infections in women of Qom, central Iran.

OBJECTIVE

Epidemiological investigation of sexually transmitted infections in genital specimens of women referred to the referral gynecology hospital in Qom, central Iran.

MATERIALS AND METHODS

Genital swab specimens were collected from women volunteers and used for identification of bacterial and protozoal infections by conventional microbial diagnostics, porA pseudo gene LightCycler^® real-time PCR (for N.gonorrhoeae) and ITS-PCR (for T.vaginalis).

RESULTS

Of 420 volunteers, 277 (65.9%) had genital signs/symptoms, including 38.3% malodorous discharge, 37.9% dyspareunia, and 54.8% abdominal pain. Totally, 2 isolates of Streptococcus agalactiae were identified. Five specimens (1.2%) in Thayer-Martin culture and 17 (4.1%) in real-time PCR were identified as N.gonorrhoeae. Fifty-four specimens (12.9%) in wet mount, 64 (15.2%) in Dorset's culture, and 81 (19.3%) in ITS-PCR showed positive results for T.vaginalis. Five mixed infections of T.vaginalis+ N.gonorrhoeae were found. The risk of T.vaginalis infection was increased in women with low-birth-weight (p=0.00; OR=43.29), history of abortion (p=0.00; OR=91.84), and premature rupture of membranes (PROM) (p=0.00; OR=21.75). The probability of finding nuclear leukocytes (p=0.00; OR=43.34) in vaginal smear was higher in T.vaginalis infection.

CONCLUSION

The significant prevalence of trichomoniasis and gonorrhea emphasizes the need for accurate diagnosis and effective surveillance to prevent serious reproductive complications in women.

Restriction fragment length polymorphism pattern of Mycobacterium isolates from rodents in infected cattle farms

OBJECTIVE/BACKGROUND

Mycobacterium tuberculosis, the etiologic agent of tuberculosis, causes large-scale morbidity and mortality, particularly in developing countries. In recent years, there has been a significant increase in the drug-resistant ability of M. tuberculosis, triggering a major public health crisis. A detailed analysis of the evolution of the mycobacterial genome helps to better understand the genotype-phenotype relationship in this bacterium. Different strain typing methods have already revealed the worldwide diversity of mycobacterial isolates. Therefore, DNA-fingerprinting tools have been developed to improve tuberculosis case detection and control. Molecular typing techniques allow to detect and follow the spread of individual strains of the M. tuberculosis complex (MTC), complementing conventional epidemiological methods. Among these techniques, restriction fragment length polymorphism (RFLP) has been considered the standard method for genotyping of MTC. The aim of this work was to isolate M. tuberculosis from rodents in cattle farms contaminated with MTC located in the city of Booin-Zahra, Iran.

METHODS

A total of 100 samples were collected from the rodents in the contaminated farms and analyzed for the presence of Mycobacterium by growing the samples on Lowenstein-Jensen medium. All isolates were further identified by RFLP and DNA hybridization studies.

RESULTS

As much as five samples showed the presence of Mycobacterium and these were subjected to PCR-16SrRNA, PCR-IS6110, and RD Typing (RD1, RD4, RD9, and RD12) methods. Further differentiation was performed with PvuII digestion (RFLP) and DNA hybridization using the polymorphic guanine/cytosine-rich repetitive sequences (PGRS) probe. The PGRS probe results classified two of the isolates as belonging to one cluster, whereas the remaining isolates were classified as belonging to different clusters. An analysis of the obtained genetic pattern and a comparison of these patterns with the genetic pattern of other infected farms allowed us to record the similarities and difference. The results indicated the transmission of Mycobacterium from infected rodents to the cows located in the same farm.

CONCLUSION

These results highlight the possible danger of transmission of Mycobacterium among animals.

Molecular identification of Mycobacterium tuberculosis complex by region of differentiation-typing and polymerase chain reaction-restriction fragment length polymorphism method

Tuberculosis (TB) is one of the most common zoonotic infectious diseases in the world. Identification of Mycobacterium isolates is essential for proper treatment of TB. The aim of this study was to identify Mycobacterium isolates collected from TB patients in Alborz Province, Iran, by region of differentiation (RD)-typing. Fifty samples from tuberculosis patients were cultured in pyruvate and glycerinated Lowenstein-Jensen medium. DNA was extracted from the isolates by the van Solingen method and subjected to polymerase chain reaction (PCR)-16SrRNA, PCR-IS6110, and RD-typing with primers RD1, RD4, RD9, and RD12, respectively. Out of 50 isolates, only one isolate appeared negative in IS6110-PCR and was considered nontuberculosis complex. The remaining isolates gave PCR products of approximately 543bp, 245bp, 146bp, 172bp, 235bp, and 369bp with 16s-rRNA, IS6110-PCR, RD-1, RD-4, RD-9, and RD-12 PCR, respectively. PCR-restriction fragment length polymorphism of oxyR pseudogene confirmed the results. All isolates except one from Alborz Province appeared positive for Mycobacterium tuberculosis. Based on the obtained results, all isolates except one were identified as M. tuberculosis. The only negative isolate appeared 93% and 97% similar to Nocardia or Mycobacterium sp. (Mycobacterium neoaurum), respectively, based on sequencing and alignment of 16s-rRNA and hsp65. Accurate identification of Mycobacterium isolates is of utmost importance for proper and immediate treatment of TB patients. In this study, RD-typing appeared to be a suitable method for correct identification of M. tuberculosis isolates.

Comparison of clinical performance of antigen based-enzyme immunoassay (EIA) and major outer membrane protein (MOMP)-PCR for detection of genital Chlamydia trachomatis infection

BACKGROUND

Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen worldwide. Early detection and treatment of C.trachomatis genital infection prevent serious reproductive complications.

OBJECTIVE

Performances of enzyme immunoassay (EIA) and major outer membrane protein (MOMP)-polymerase chain reaction (PCR) for diagnosis of genital C.trachomatis infection in women were compared.

MATERIALS AND METHODS

In this cross sectional study a total of 518 women volunteers were included (33.67±8.3 yrs) who had been referred to Gynecology clinics of Qom province, Iran, were included. Endocervical swab specimens were collected to detect lipopolysaccharide (LPS) antigen in EIA and to amplify MOMP gene of C.trachomatis in PCR. Results were confirmed using ompI nested-PCR. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were calculated for performance of the tests. Odds ratios were determined using binary logistic regression analysis.

RESULTS

In total, 37 (7.14%) cases were positive by EIA and/or MOMP-PCR. All discrepant results were confirmed by nested-PCR. Sensitivity, specificity, PPV and NPV values of EIA were 59.46%, 100%, 100% and 96.98%, and those of MOMP-PCR were 97.30%, 100%, 100%, 99.79%, respectively. Reproductive complications including 2.7% ectopic pregnancy, 5.4% stillbirth, 5.4% infertility, and 10.8% PROM were recorded. The risk of developing chlamydiosis was increased 4.8-fold in volunteers with cervicitis (p<0.05; OR 4.80; 95% CI 1.25-18.48).

CONCLUSION

C.trachomatis infection should be regarded in women of reproductive ages especially those with cervicitis. Primary screening of women by using the low cost antigen-EIA is recommended; however, due to the low sensitivity of Ag-EIA, verification of the negative results by a DNA amplification method is needed.

Seroprevalence of anti-Helicobacter pylori and anti-cytotoxin-associated gene A antibodies among healthy individuals in center of Iran

OBJECTIVES

Helicobacter pylori infection occurs worldwide, but the prevalence of this infection varies greatly among different countries and population groups. The aim of this study was to determine the seroprevalence of anti-Helicobacter pylori and anti-cytotoxin-associated gene A (CagA) antibodies in asymptomatic healthy population in the center of Iran and to investigate the relation with different parameters.

MATERIALS AND METHODS

Totally, 525 individuals aged 17-60 years were enrolled in study. The serum samples of participants were tested for anti-H. pylori IgG and anti-CagA IgG by enzyme-linked immunosorbent method (ELISA). ABO blood grouping was also done by hemagglutination test.

RESULTS

The seroprevalence of anti-H. pylori IgG was 74.2% and their rates increased with age. The seroprevalence of anti-H. pylori IgG was higher in males (74.6%) than in females (71.6%). There was statistically inverse association between H. pylori infection and education level (P=0.04) and marital status (P=0.000). The most prevalent blood group was type AB with positive Rh-phenotype (82.4%). In H. pylori infected individuals the seroprevalence of anti-CagA antibody was 46.9%. The seroprevalence of anti-CagA IgG was in males 48.6% and in females 31.6%. There was no statistically significant association between anti-CagA IgG positivity and age, occupation, socioeconomic status, ABO blood groups and Rh status.

CONCLUSION

These results showed that H. pylori infection was common in the asymptomatic individuals. Almost half of the infected individuals acquire CagA-positive strains of H. pylori. Moreover, it seems that males are more susceptible to infection with CagA-positive strains compared to females.

Study of carD gene sequence in clinical isolates of Mycobacterium tuberculosis

Mycobacterium tuberculosis growth rate is closely coupled to rRNA transcription which is regulated through carD gene. The aim of this study was to determine the sequence of carD gene in drug susceptible and resistant clinical isolates of M. tuberculosis and designing of a PCR assay based on carD sequence for rapid detection of this bacterium.Specific primers for amplification of carD gene were carefully designed, so that whole sequence of gene could be amplified; therefore primers were positioned at the upstream (promoter of this gene and ispD gene) and downstream (in ispD gene). DNA from 41 clinical isolates of M. tuberculosis with different pattern of drug resistance was used in the study. PCR conditions and annealing temperature were designed by means of online programs. PCR products were sequenced by ABI system.PCR product of carD gene was a 524 bp fragment. This method could detect all resistant and susceptible strains of M. tuberculosis. The size of amplified fragment was similar in all investigated samples. Sequence analysis showed that there was similar sequence in all of our isolates therefore probably this gene is considered to be conservative. Translation of nucleotide mode to amino acids was showed that TRCF domain in N-terminal of protein CarD was found to be fully conservative.This is the first study on the sequence of carD gene in clinical isolates of M. tuberculosis. This conservative gene is recommended for use as a target for designing of suitable inhibitors as anti-tuberculosis drug because its importance for life of MTB. In the other hand, a PCR detection method based on detection of carD gene was recommended for rapid detection in routine test.

Enterotoxin gene profiles among Staphylococcus aureus isolated from raw milk

Milk is considered a nutritious food because it contains several important nutrients including proteins and vitamins. Conversely, it can be a vehicle for several pathogenic bacteria such as Staphylococcus aureus. This study aimed to analyze the frequency of genes encoding the nine Staphylococcal enterotoxins (SEs) and enterotoxin gene profiles in S. aureus isolates derived from raw bovine milk. A total of 52 S. aureus isolates were obtained from 246 milk samples of 246 dairy cows from eight different farms in Qom, Iran. On the basis of cultural and biochemical properties as well as by amplification of the 23S rRNA specific to S. aureus, all isolates could be identified as S. aureus. Of the 52 isolates studied, 80.7% were positive for one or more genes encoding the enterotoxins, and 12 different genotypes were identified. The gene encoding for enterotoxin A (Sea) was the most frequent (16 isolates, 30.7%), followed by Seb (14 isolates, 26.9%) and Sed (8 isolates, 15.37%). Among the genes encoding the other enterotoxins, Seg and Seh were the most frequently observed (8 isolates each, 15.38%), followed by Sej (6 isolates, 11.5%) and Sei (1 isolates, 3.84%). With the recent identification of new SEs, the frequency of enterotoxigenic strains has increased, suggesting that the pathogenic potential of Staphylococci may be higher than previously thought. These results of enterotoxin genes positivity of milk-derived Staphylococci constitute a potential risk for consumers' health.

Measuring Radionuclides Concentration in Rice Field Soils using Gamma Spectroscopy in Northern Iran

BACKGROUND

A few elements of soil are radioactive. Soil can transfer radionuclide into plants feeding human. Sometimes their levels are as high as to be concern of human healthy. Rice has an important share for Iranian foods especially in north of Iran. Therefore we decided to obtain radionuclides concentration emitting γ rays in Lahijan City (Northern Iran) rice fields using γ spectroscopy.

METHODS

Twenty eight samples from rice field's soils and 12 samples from superficial soils were collected at a square of 10*10 m2 to get 2kg weight. To make dry samples were put into oven at 105°C for 24h. Then they were milled and 950 gr of each sample was transferred to Marinelli container with 1000(cc) volume, sealed and left for 40 days to get secular equilibrium. After measuring Ph, Electric conductivity and organic carbon, γ spectroscopy was done to get sample gamma spectrum at 2000-6000 sec using HpGe detector.

RESULTS

It was found (226)Ra activity in rice fields of 29.273±0.72 Bqkg-1 and city soil of 31.02±1.1 Bqkg-1 and also 232Th activity of 37.47±1.12 Bqkg-1 for rice fields' soils and 40.47±1.68 Bqkg-1 for city soil were in standard mode.

CONCLUSION

(40)K activities mean value according to UNSCEAR; 2000 was found a little greater than standard. A little value of (137)Cs was found in Lahijan rice fields and city soils that could be as a result of Chernobyl accident. In except of 137Cs, for three other under studied city soil elements, activities were greater than that of rice fields.

In vitro inhibition of Helicobacter pylori urease with non and semi fermented Camellia sinensis

PURPOSE

Helicobacter pylori is the etiological agent in duodenal and peptic ulcers. The growing problem of antibiotic resistance by the organism demands the search for novel compounds, especially from natural sources. This study was conducted to evaluate the effect of Camellia sinensis extracts on the urease enzyme that is a major colonization factor for H. pylori.

METHODS

Minimum inhibitory concentrations of nonfermented and semifermented C. sinensis methanol: water extracts were assessed by broth dilution method. Examination of the urease function was performed by Mc Laren method, and urease production was detected on 12% SDS polyacrylamide gel electrophoresis from whole cell and membrane bound proteins.

RESULTS

Both extracts had inhibitory effects against H. pylori and urease production. At a concentration of 2.5 mg/ml of nonfermented extract and 3.5 mg/ml of semifermented extract the production of Ure A and Ure B subunits of the urease enzyme were inhibited completely. A concentration of 4 mg/ml of nonfermented and 5.5 mg/ml of semifermented extract were bactericidal for H. pylori.

CONCLUSIONS

C. sinensis extracts, especially the nonfermented, could reduce H. pylori population and inhibit urease production at lower concentrations. The superior effect of nonfermented extract is due to its rich polyphenolic compounds and catechin contents.