فهرست مطالب

Infection, Epidemiology And Medicine - Volume:2 Issue: 2, 2016
  • Volume:2 Issue: 2, 2016
  • 36 صفحه،
  • تاریخ انتشار: 1395/04/01
  • تعداد عناوین: 8
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  • Meysam Hasannejad Bibalan, Fatemeh Shakeri, Naeme Javid, Ezzat Allah Ghaemi Page 1
    Background
    In this study, we investigated the prevalence of Staphylococcus aureus agr groups to detect the predominant type according to the source of isolation and assessed the possible relationship between agr groups, types of infection and susceptible or resistance to methicillin.
    Materials And Methods
    DNA of 194 S. aureus isolates were extracted by lysozyme-phenol chloroform method that included 85clinical samples, 58 samples were isolated from nose of health care workers and 51 were obtained from food products in Gorgan, North of Iran. PCR-based assays were used for the identification of agr specificity group and mecA gene.
    Results
    The majority of isolates belonged to agr group I (43.3%), followed by agr group III (28.87%), agr group II (22.68%), agr group IV (5.15%) and 40.7% of strains were MRSA. In our study, the majority of S. aureus isolates recovered from health care workers and food products were agr group I and isolates recovered from patients were agr group III, these differences were statistically significant (P-value
    Conclusion
    Theagr group I was predominant among isolates of health care workers and food products specimens in Gorgan, North of Iran, while agr group III was predominant in MRSA strains and the isolates from patients. Investigation of the possible role of agr group III in S.aureus infections in the further studies is recommended.
    Keywords: S. aureus, agr genes, PCR
  • Farzaneh Mehraban, Mahmoud Nateghi Rostami, Masoumeh Douraghi, Masoumeh Dolati Page 5
    Background
    The role of the hospital environment as a source of dissemination of pathogens is critical. Environmental surfaces in the Intensive Care Units (ICUs) are suitable for the growth of Gram-negative bacteria that normally circulate between the environment and patients and can cause outbreaks of nosocomial infections. In this study, the prevalence of Gram-negative bacilli in the environment of the ICUs and neonatal ICU (NICU) of hospitals in the city of Qom was evaluated.
    Materials And Methods
    During a 6 month period from November 2012 to April 2013, samples were collected from environmental surfaces of ICUs of four hospitals and NICU of one hospital located in the city of Qom. Sampling was done from equipment, fluids, and surfaces and identification was carried out based on culture and biochemical tests for Gram-negative bacilli.
    Results
    A total of 230 swab samples was collected and 50 colonies of Gram-negative bacilli were isolated from environmental surfaces. Overall, 64% of the isolates belonged to non-fermentative bacteria and 36% of the isolates belonged to Enterobacteriaceae family. Strains of Pseudomonas aeruginosa and Acinetobacter baumannii complex accounted for the highest rates of environmental isolates. In addition, Klebsiella pneumoniae was isolated from NICU.
    Conclusion
    The high frequency of genus Acinetobacter among Gram negative bacteria isolated from environmental surfaces has a public health impact and Acinetobacter spp. should be considered in the infection control programs in hospitals. Isolation of K. pneumoniae should be regarded as a risk factor for fatal neonatal infections.
    Keywords: Nosocomial infections, Environmental surfaces, Gram, negative bacteria
  • Leila Firouzi, Dalvand, Mehdi Pooladi, Jamileh Nowroozi, Abbas Akhvan, Sepahi, Mansooreh Hooshiyar Page 8
    Background
    Pseudomonas aeruginosa is considered an opportunistic pathogen; several reports indicate that the organism can also cause infections in healthy hosts. Four effector proteins have been described in P. aeruginosa: exoU, exoS, exoT, and exoY. These genes that are translated into protein products related to type III secretion systems.
    Materials And Methods
    A total of 134 samples were isolated, and P. aeruginosa was identified using biochemical tests. Bacterial genomic DNA was extracted, and the presence of the exoSand exoUgenes were detected by PCR. Biofilms were formed by culturing P. aeruginosaon glass slides in rich medium.
    Results
    The exoU(73%), exoS (62%) genes were detected from infections caused by P. aeruginosa in urinary tract infection patients. Among the 119 strains isolated from patients with urinary tract infections.
    Conclusion
    An improved understanding of virulence genes and biofilm formation in P.aeruginosa may facilitate the future development of novel vaccines and drug treatments.
    Keywords: Pseudomonas aeruginosa, exoU, exoS, urinary tract infection, Biofilm
  • Mehdi Ghasemi, Yemen Atakishiyeva Page 12
    Background
    Pneumonia and respiratory tract infections, is associated with high mortality and complications in humans. Current antibiotics are used to treat this infectious disease, but may lead to many problems such as unwanted side effects and resistance to antibiotics. This study investigated the antibacterial activity of the hydro alcoholic extracts of the native medicinal plants Peganum harmala, Mentha pulegium and Alcea rosea, in Baku, as a natural alternative to antibiotics, on antibiotic-resistant Streptococcus pneumoniae and Klebsiella pneumoniae,the main bacteria that cause pneumonia.
    Materials And Methods
    Antibacterial activity of the hydro alcoholic extracts of medicinal part of these plants was evaluated by the disk diffusion susceptibility test method and the broth dilution test method on bacteria.
    Results
    The rate of MIC of P. harmala, M. pulegium and A. rosea extracts of S. pneumoniae were 80, 110 and 375μgμL-1 and for K. pneumoniae were 150, 230 and 680μgμL-1 respectively, and the rate of MBC were 120, 165 and 550μgμL-1 for S. pneumoniae and 210, 315 and 800μgμL-1 forK. pneumonia respectively; The maximum amount of inhibition zone diameter in500μgμL-1 concentration ofP. harmala, M. pulegium and A. rosea extracts for S. pneumoniae were 21.2mm, 17.2mm, 6.9mmand for K. pneumonia were10.1mm, 8.1mm, 3.2mm, respectively.
    Conclusion
    This work showed that substances in the hydro-alcoholic extracts of medicinal plants prevented the growth of bacteria. So these plants with having effective ingredients can be used as an affordable and available source for medicinal purposes.
    Keywords: Pneumonia, Peganum harmala, Mentha pulegium, Alcea rosea, Baku, Azerbaijan
  • Hossein Kazemian, Hamid Heidari, Jalil Kardan Yamchi, Aref Shavalipour, Sobhan Ghafourian, Reza Mohebi, Hamidreza Houri, Nourkhoda Sadeghifard Page 15
    Background
    Helicobacter pylori is the most common cause of chronic infection in the human stomach. The infection has universe prevalence in all age groups. Probably, this bacterium is the cause of most common chronic bacterial infection in human beings and infects approximately half of the world population. H. pylori produces urease, an enzyme that degrades the urea in the stomach’s mucous to ammonia resulting in biochemical reaction that leads to increase in pH of the stomach lumen. This allows pathogenic intestinal protozoa to take the opportunity to cross through stomach’s increased pH and cause disease. The aim of this study was to evaluate the relationship between H. pylori infection and prevalence of parasitic infection in patients in Ilam.
    Materials And Methods
    Following stool samples collection during 2013 in patients with abdominal pain in Ilam, Iran. H. pylori infection was investigated based on stool antigen analysis (HPSA) by enzyme-linked immunosorbent assay (ELISA) method in patients who had recurrent abdominal pain. Stool specimens were examined using the direct examination and the spontaneous sedimentation method for detecting the trophozoite and cyst of parasites.
    Results
    In this study, we found 65 patients with H. pylori infection. Out of these 65 patients, the percentage of patients with positive results for Giardia lamblia was 30.7% and for Entamoebahistolytica/dispar was 12.3%.
    Conclusion
    The results of this study suggest that H. pylori infection may provide favorable conditions for giardiasis infection; however, this presumption needs further studies with larger sample size.
    Keywords: Helicobacter pylori, parasitic infection, Giardia lamblia
  • Zahra Nasrollahi, Mohammad Hossein Yadegari Page 18
    Background
    Iranian (Lahijan) black tea caffeine has been previously shown to have antifungal activity against Candida albicans. The aim of this study was to investigate whether the combination of caffeine and fluconazole (FLU) has an effective antifungal activity on a FLU-resistant (MIC >64mgL-1) C. albicans PTCC5027.
    Materials And Methods
    Caffeine from Lahijan black tea was extracted and its pharmacological effects against 20 clinical isolates of FLU-sensitive and resistant C. albicans was evaluated by Colony Forming Units (CFU) method. Furthermore, the synergistic effect of caffeine and FLU against PTCC-5027strain was investigated.
    Results
    Our results indicate the antifungal efficacy of Lahijan black tea caffeine on C. albicans isolates and subsequent identification of caffeine in combination with FLU againstPTCC-5027 strain. The concentrations of caffeine causing 90% growth inhibition (MIC90) for PTCC-5027 strain, FLU-resistant and -sensitive C. albicans isolates were 25mgL-1, 24.4mgL-1 and 37.2mgL-1,respectively. The combination of caffeine with FLU showed stronger antifungal activity against C. albicans PTCC5027. The addition of 12.5mgL-1 caffeine to FLU 10-50 mgL-1 (below MIC90) inhibited the growth of C. albicans PTCC5027 by 99.3%–99.7%, the concentrations at which neither caffeine nor FLU alone affected the growth.
    Conclusion
    It can be concluded that caffeine has antifungal effect on C. albicans and in combination with FLU can enhance the antifungal activity of FLU against C. albicans. The synergism of the combination of caffeine and FLU induces multiple antifungal effects, resulting in the use of lower doses of the FLU. It suggests that this can decrease the side effects of antifungal drugs.
    Keywords: Caffeine, Fluconazole, antifungal, Candida albicans
  • Mahdi Zareei, Alireza Mohammadi, Zeinab Borjian Borujeni, Seyed Jamal Hashemi Page 22
    Background
    Members of the Malassezia genus are often lipophilic, observed as budding yeasts and found as commensals in the skin of humans. This genus opportunistically reside in several areas including scalp where under the influence of particular predisposing factors, their proliferation is increased (e.g., high activation of sebaceous glands), and leads to dandruff and seborrheic dermatitis, which together affects >50% of human beings. The proliferation of yeasts in scalp creates health and hair hygiene problems. In this study we determined the type and frequency of Malassezia species in scalp dandruff in order to have epidemiologic and therapeutic understanding.
    Materials And Methods
    Differentiation tests were done for scalp samples, including: morphology, Tween 20, 40 and 80 assimilation tests, hydrolysis of bile-esculin, catalase and growth on Sabouraud dextrose agar with chloramphenicol and cycloheximide (SCC) and sediment production on mDixon agar medium.
    Results
    Frequency of various Malassezia species from 140 scalp samples from volunteers of both gender were found as: M. globosa (46.5%), followed by M. furfur (27.0%), M. restricta (12.7%), M. sympodialis (6.5%) and M. slooffiae (0.8%).
    Conclusion
    In view of high prevalence ofM. globosa, its invasive characteristics and the role of predisposing factors in the more proliferation of this species in scalp should be considered.
    Keywords: Malassezia, Scalp, Dandruff
  • Hajar Mohammadi Barzelighi, Bita Bakhshi, Mina Boustanshenas Page 26
    Vibrio cholerae O1 are classified into two biotypes, classical and El Tor based on susceptibility to bacteriophages and some biochemical properties, each encoding a biotype-specific genetic determinants. Before 1961, most epidemics had been caused by the classical biotype. However, with the passage of time, the classical biotype missed from the scenario and the El Tor emerged as the major biotype causing the cholera in humans. The present cholera global pandemic is attributed to a change among seventh pandemic strains and emergence of V. cholerae O139, V. cholerae O1 El Tor hybrid, and V. cholera O1 El Tor with altered cholera toxin subunit B. The V. cholerae biotypes are not only different in phenotype but also human infections caused by them are different clinically. Infection with classical V. cholerae O1 more frequently produces severe infection than does El Tor, suggesting that the genetic and phenotypic differences between the two biotypes may also be reflected in their pathogenic potential. Considering the recent emergence of “hybrid biotype” and “El Tor variant” in different areas and in our country, we reviewed differences in genetic structure of V. cholerae biotypes.
    Keywords: Genetic determinants, El Tor variant, hybrid biotype