فهرست مطالب

Microbiology - Volume:6 Issue: 6, Dec 2014

Iranian Journal of Microbiology
Volume:6 Issue: 6, Dec 2014

  • تاریخ انتشار: 1393/11/18
  • تعداد عناوین: 11
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  • Abbas Allami, Navid Mohammadi Pages 372-381
    Objectives
    To generate synthesized information on the epidemiology of VZV infection, as well as an estimation of prevalence of age-specific antibody in Iranian less than 40.
    Material And Methods
    After exclusion of irrelevant and overlapping reports, 15 papers were included (from nine major cities). Studies were pooled according to the heterogeneity test results. Random effect model methods were used for meta­ analysis where significant heterogeneity was observed (age 1-16years).For other age groups, fixed model were used.
    Results
    Significant heterogeneity was observed in prevalence rates of all childhood age-groups. The seropositivity prevalence increased steeply from the age of 1-5 to 6-10 [from 21.9% (95% CI; 10.8-33.1) to 42.1 %(95% CI; 33.6-50.6)]. At the age of 11–15, 59.4% (95% CI; 46.1-72.8) of children showed to be infected. The rate of seropositivity was more than 87% in individuals of 40 and older.
    Conclusion
    The varicella seroeprevalence in Iran is in accordance with average tropical and temperate areas. Comparison of conducted studies during 2003 to 2011 didn’t show any alteration in VZV seroprovalence in Iran.
    Keywords: Varicella, meta, analysis, seroepidemiologic study, Iran
  • Mohammad Taghi Haghi Ashtiani, Majid Sadeghian, Bahram Nikmanesh, Babak Pourakbari, Shima Mahmoudi, Setareh Mamishi Pages 382-386
    Background And Objectives
    The appearance of antibiotic resistance in Streptococcus pneumoniae has raised a global concern over the past three decades. This study was conducted to determine the antimicrobial susceptibility of S. pneumoniae isolated from patients in Children´s Medical Center (CMC) Hospital during 2001 to 2011.
    Materials And Methods
    During the 11 years period, a total of 194 S. pneumoniae isolates were collected in CMC Hospital. Antimicrobial susceptibility testing was performed by the Kirby-Bauer disk diffusion method and time-series analysis was used to evaluate the antimicrobial susceptibility changes over the time.Results and
    Conclusion
    Antimicrobial susceptibility of S. pneumoniae to different antibiotics decreased from 2001 to 2011 as: penicillin from 78% to 32%, erythromycin from 75% to 35%, chloramphenicol from 94% to 55%, ampicillin from 70% to 62%, ceftriaxone from 100% to 87%, sulfametoxazole from 57% to 40%. We did not find any significant difference between the susceptibility of isolates from sterile and non-sterile sources. It would be an important key to consider antimicrobial stewardship as an essential factor to prevent the development of antimicrobial resistance.
    Keywords: pneumonia, antibiotic resistance, Iran
  • Iraj Sedighi, Abbas Solgi, Ali Amanati, Mohammad Yousef Alikhani Pages 387-391
    Background And Objectives
    Urinary Tract Infections (UTIs) are of the most common bacterial diseases worldwide. We investigate the antibiotic susceptibility patterns of Escherichia coli (E. coli) strains isolated from pediatric patients with community acquired urinary tract infection (UTI) to find a clinical guidance for choosing a right empirical antibiotic in these patients.
    Materials And Methods
    In this cross sectional study, 100 urine specimens which were positive for E. coli had been investigated for antibiotics susceptibility pattern. The susceptibility to Co-trimoxazol (25µg), Amikacin (30µg), Ceftriaxone (30µg), Nalidixic Acid (30µg), Cefixime (5µg), and Nitrofurantoin (300µg) tested with Disk diffusion agar and MIC determined with the E-test.
    Results
    Mean age of patients was 38 Months. Girls had greater proportion than boys (74 versus 26%). In Disk diffusion method, 26% of the isolates were susceptible to cotrimoxazole. Susceptibility to amikacin, ceftriaxone, nitrofurantoin, nalidixic acid and cefixime was 94%, 66%, 97%, 62% and 52%, respectively. By E-Test method and according to CLSI criteria susceptibility for co-trimoxazol, amikacin, ceftriaxone and nalidixic acid was 37%, 97%, 67% and 50%, respectively. The highest percentage of agreement between Disk diffusion and E-Test method was found for amikacin (96%) and the lowest percentage for co-trimoxazole (89%).
    Conclusions
    Treatment failure, prolonged or repeated hospitalization, increased costs of care, and increased mortality are some consequence of bacterial resistance in UTIs. Misuse of antibiotics in each geographic location directly affects antibiotic resistance pattern. In the treatment of UTI, proper selection of antimicrobial agents should be relevant to the bacterial susceptibility testing surveillance. According to our results, amikacin as an injectable drug and nitrofurantoin as an oral agent could be used as a drug of choice in our region for children with UTIs.
    Keywords: Antibiotic susceptibility, Escherichia coli, Urinary Tract Infections, Disk diffusion agar, E, Test
  • Amjad Ahmadi, Mazaher Khodabandehloo, Rashid Ramazanzadeh, Fariba Farhadifar, Bahram Nikkhoo, Nasrin Soofizade, Masoome Rezaii Pages 392-397
    Background And Objectives
    Ureaplasma urealyticum can colonize women genital tract and be isolated from the amniotic fluid of women with adverse pregnancy outcomes. The association of U. urealyticum with spontaneous abortion remains controversial. The aim of this study was to evaluate the frequency of U. urealyticum infection among pregnant women and its association with spontaneous abortion.
    Materials And Methods
    In this case-control study we included 109 women with spontaneous abortion with gestation age between 10-20 weeks (Cases), and 109 women with normal pregnancy with gestation age between 20-30 weeks (Controls) in Sanandaj, Iran. Using specific primers and extracted DNA from endocervical swabs, a PCR test was conducted for detection of U. urealyticum in both women groups.
    Results
    Total prevalence of U. urealyticum infection in women was 26 out of 218 cases (11.92%). The prevalence of U. urealyticum infection was 18 out of 109 (16.5%) and 8 out of 109 (7.3%) in case (spontaneous abortion) and control groups, respectively. Using chi-square test, association between U. urealyticum infection and spontaneous abortion was statistically significant (P<0.05).
    Conclusions
    colonization of U. urealyticum in genital tract of women, and its asymptomatic feature in combination with other factors such as other microorganisms or cervical incompetence may induce spontaneous abortion. Further studies are needed to confirm this possibility.
    Keywords: Ureaplasma urealyticum, endocervical infection, spontaneous abortion, pregnancy outcomes
  • Atefeh Mousavi, Fariba Farhadifar, Reza Mirnejad, Rashid Ramazanzadeh Pages 398-403
    Background And Objectives
    Women reproductive system is a suitable environment for growth of various pathogen and nonpathogenic microorganisms. Mycoplasmataceae is a family of bacteria which cause oligosymptomatic genital infections. The complications caused by these bacteria may lead to infertility in women. The aim of this study was detection of genital Mycoplasma hominis, Ureaplasmaurealyticum and Mycoplasma genitalium among infertile females who referred to the infertility clinics.
    Materials And Methods
    A total of 104 infertile women (in reproductive age) who referred to infertility clinics in the city of Sanandaj, Kurdistan, Iran, from February to May 2013 were selected for this study. Cervical swabs were collected from all patients. The presence of genital Mycoplasmas was detected by multiplex-PCR. All data were analyzed statistically.
    Results
    Out of 104 patients, 39 cases (37.5%) were infected with U. urealyticum. Mycuplasma. genitalium and M. homimis were detected in 3 (2.9%) of the infertile women. Co-infection was seen in 3.8% of the patients. There was no statistically significant difference between the infections and patient age, educational levels, literacy, situation of employment, age of first sexual intercourse, history of abortion, type of infertility and infertility duration (p value > 0.05).
    Conclusions
    The data showed a low percentage of infection for M. genitalium and M. hominis in the studied women while the prevalence of U. urealyticum was high. Despite having no symptoms of an ongoing acute inflammation of the reproductive tract, many women may have genital mycoplasmas in the cervix. We concluded that multiplex PCR using a pair of primers is a useful and cost-effective method for diagnosis of female genital infections.
    Keywords: PCR, Mycoplasma hominis, Mycoplasma genitalium, Ureaplasmaurealyticum
  • Mahdieh Ghiasi, Hoda Fazaely, Naser Kalhor, Mohsen Sheykh-Hasan, Reza Tabatabaei-Qomi Pages 404-408
    Background And Objectives
    Bacterial vaginosis (BV) is a common disorder which happens when the balance of bacterial flora in vagina is disrupted by a shift in concentration of lactobacillus and pathogenic bacteria. It has significant sequelae including increased rates of late miscarriage when diagnosed in early pregnancy, premature rupture of the membranes, endometritis, preterm labour and delivery and tubal factor infertility. So it seems to be necessary to evaluate the prevalence of BV among women with primary infertility.
    Material And Methods
    All specimens were collected during vagina examination by use of a speculum and swabbing. A sampling swab was introduced into vaginal canal and rotated for at least 8 seconds before withdrawal. The vaginal swabs were examined in standard microbiological analysis including of microscopy, culture and sensitivity examination.Results and
    Conclusion
    Totally identified Gram positive bacteria were significantly higher in number than the Gram negative bacteria. We found that the prevalence of bacterial vaginosis as 70.34% among infertile women of Qom city. Staphylococcus aureus was the most prevalent vaginal pathogen (57.33%) followed by E. coli (25.33%). S. aureus showed maximum sensitivity to penicillin and gentamicin. It means that fortunately in Qom, this bacterium has not acquired resistance against penicillin yet. So, all physicians must have a high index of suspicion and use readily available screening methods to recognize and treat the patients with infectious vaginitis adequately.
    Keywords: Bacterial vaginosis, Microbial culture, Staphylococcus aureus, Antibiotic therapy
  • Frincy Khandelwal Baruah, Ajanta Sharma, Chanakya Das, Naba Kumar Hazarika, Jasmin Halim Hussain Pages 409-414
    Background And Objectives
    Bacterial vaginosis is a risk factor for obstetric infections, various adverse outcomes of pregnancy and pelvic inflammatory disease. The objectives of this study were to assess the prevalence of bacterial vaginosis in women attending Gynaecology Outpatient Department (O.P.D) and sexually transmitted disease (S.T.D.) clinic and to assess the role of Gardnerella vaginalis as an etiological agent of bacterial vaginosis.
    Materials And Methods
    Two hundred women attending Gynaecology O.P.D and S.T.D. clinic with symptoms suggesting lower genital tract infection were included in the study. pH of the vaginal discharge was measured and three high vaginal swabs were collected. Bacterial vaginosis was diagnosed using Amsel’s criteria and Nugent’s method. Gardnerella vaginalis was isolated and identified by standard methods.
    Results
    Prevalence of bacterial vaginosis using Amsel’s criteria and Gram stain scoring method was found to be 51.5% and 49% respectively. Gardnerella vaginalis was isolated in only 8.7% cases of bacterial vaginosis.
    Conclusion
    Our study showed a relatively high prevalence of bacterial vaginosis in the population under study. Women attending various healthcare facilities should be screened and treated properly to prevent recurrence. Low isolation rate of Gardnerella vaginalis may be attributed to factors like poor viability and fastidiousness of the organism to grow in various media.
    Keywords: Bacterial vaginosis, Gardnerella vaginalis, Gynaecology
  • Reza Golmohammadi, Ramezan Ali Ataee, Gholam Hossein Alishiri, Reza Mirnejad, Ali Mehrabi Tavana, Davoude Esmaieli Pages 415-420
    Background And Objectives
    Mycoplasma arthritidis mitogen (MAM) superantigen has been shown to induce chronic arthritis, which resembles human rheumatoid arthritis (RA) in a rodent model. However, its role as a causative agent in human RA is not well understood yet. The aim of this study was to investigate the presence of MAM superantigen gene in the synovial fluid (SF) of RA patients.
    Materials And Methods
    The MAM superantigen gene a reference was synthesized based on GenBank Data base (Gene ID: 6418105). Specific primer pairs were designed and PCR amplification was performed for MAM superantigen gene detection. A total of 133 SF samples of RA patients were assayed. The PCR products were subjected to sequencing and were descriptively analyzed.
    Results
    The results of the PCR product sequencing showed the method has objective applicability and accuracy. The sensitivity of the PCR reaction for the reference DNA template was 1ng/ml. The PCR results assay of the 133 SF samples raveled that, 9.7% and 22.5% of them were positive for the MAM superantigen gene and Mycoplasma pneumoniae (M. pneumoniae), respectively.
    Conclusion
    In this study, two Mycoplasma genomes were detected with increased frequency in RA SF patients’ samples. This finding appears to be a promising instrument in the etiological diagnostic of RA patients and could also lead to improved treatment selection. Further research on the other Mycoplasma species present in the SF of RA patients is essential.
    Keywords: Rheumatoid arthritis, Mycoplasma arthritidis mitogen, Synovial fluid, Superantigen, PCR
  • Mojtaba Moosavian, Saeed Shoja, Soodabeh Rostami, Maryam Torabipour, Zahra Farshadzadeh Pages 421-427
    Background And Objectives
    Resistance to macrolide can be mediated by erm and msrA genes in Staphylococcus aureus. There are the evidences that show erm genes may be causative agent of inducible or constitutive resistance. The aim of this study was to investigate the incidence of inducible clindamycin resistance and determine the most frequency of erm and msrA genes among S. aureus isolates.
    Materials And Methods
    In this study a total of 124 non duplicated clinical isolates of S. aureus were tested with disk diffusion method. All isolates were tested by PCR for mecA, ermA, ermB, ermC and msrA genes.
    Results
    According to PCR results, 48.4% had mecA gene and 51.6% were mecA negative. By phenotypic D-test method, 32.3% revealed inducible resistance and recorded as D and D+. Sensitive and constitutive phenotypes were found in 54.8% and 12.9% of isolates respectively. Inducible clindamycin resistance was more prevalent in MRSA (29%) than MSSA isolates (2.4%). Among studied erm genes, the most frequency genes were ermA and ermC with 41.1% and 17.7% respectively. Three isolates of them had D phenotype, while the PCR results of erm genes were negative. All isolates were negative for ermB or msrA genes.
    Conclusion
    Since S. aureus isolates with inducible resistance may mutate and change to constitutive resistance, to prevent treatment failure, we suggest that inducible resistance test be performed on erythromycin resistant/clindamycin sensitive isolates.
    Keywords: D, test, Inducible clindamycin resistance, Staphylococcus aureus
  • Morahem Ashengroph, Sajad Ababaf Pages 428-436
    Background And Objectives
    Microbial caffeine removal is a green solution for treatment of caffeinated products and agro-industrial effluents. We directed this investigation to optimizing a bio-decaffeination process with growing cultures of Pseudomonas pseudoalcaligenes through Taguchi methodology which is a structured statistical approach that can be lowered variations in a process through Design of Experiments (DOE).
    Material And Methods
    Five parameters, i.e. initial fructose, tryptone, Zn+2 ion and caffeine concentrations and also incubation time selected and an L16 orthogonal array was applied to design experiments with four 4-level factors and one 3-level factor (44× 13). Data analysis was performed using the statistical analysis of variance (ANOVA) method. Furthermore, the optimal conditions were determined by combining the optimal levels of the significant factors and verified by a confirming experiment. Measurement of residual caffeine concentration in the reaction mixture was performed using high-performance liquid chromatography (HPLC).
    Results
    Use of Taguchi methodology for optimization of design parameters resulted in about 86.14% reduction of caffeine in 48 h incubation when 5g/l fructose, 3 mM Zn+2 ion and 4.5 g/l of caffeine are present in the designed media. Under the optimized conditions, the yield of degradation of caffeine (4.5 g/l) by the native strain of Pseudomonas pseudoalcaligenes TPS8 has been increased from 15.8% to 86.14% which is 5.4 fold higher than the normal yield.
    Conclusion
    According to the experimental results, Taguchi methodology provides a powerful methodology for identifying the favorable parameters on caffeine removal using strain TPS8 which suggests that the approach also has potential application with similar strains to improve the yield of caffeine removal from caffeine containing solutions.
    Keywords: Caffeine removal, Process optimization, Pseudomonas pseudoalcaligenase, Taguchi methodology
  • Raheem Haddad, Esmat Alemzadeh, Ali-Reza Ahmadi, Ramin Hosseini, Maryam Moezzi Pages 437-442
    Background And Objectives
    Chlorophyceae are important constituents of marine phytoplankton. The taxonomy of Chlorophyceae was traditionally based solely on morphological characteristics. In the present research project, genetic diversity was investigated to analyze five species of Chlorophyceae from waters of the Persian Gulf.
    Materials And Methods
    A clone library of the ribosomal small subunit RNA gene (18S rDNA) in the nuclear genome was constructed by PCR, and then, after examining the clones, selected clones were sequenced. The determined clone sequences were analyzed by a similarity search of the NCBI GenBank database using BLAST.Results and
    Conclusion
    Eleven sequences were identified correctly and used for phylogenetic analysis. We identified species of Chlorophyta (Chlorella sorokiniana, Chlamydomonas sp., Neochloris aquatic, Picochlorum sp. and Nannochloris atomus) without the need to conduct extensive colony isolation techniques. Therefore, this improved molecular method can be used to generate a robust database describing the species diversity of environmental samples.
    Keywords: 18S rDNA, Chlorophyceae, Clone library, Phylogeny, Persian Gulf