فهرست مطالب

Medical Microbiology and Infectious Diseases - Volume:7 Issue:1, 2019
  • Volume:7 Issue:1, 2019
  • تاریخ انتشار: 1397/10/11
  • تعداد عناوین: 8
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  • Ali Akbar Heydari* Pages 1-5

    Brucellosis and Crimean Congo Hemorrhagic Fever (CCHF) are both common zoonoses that may co-occur in similar epidemiological conditions, e.g., among young livestock breeders, veterinarians, and farmers in rural areas. Transmission of Brucella bacteria is through ingestion of contaminated dairy products, while CCHF virus infection occurs via infective tick bite or exposure of damaged skin and mucosa to the tissues and blood of viremic animals. Brucellosis occurs almost in all seasons, while CCHF is of lower incidence in the cold seasons due to decreased activity of tick vectors. CCHF mimics brucellosis and vice versa, mainly when the latter manifests severe thrombocytopenia and hemorrhage. Occasionally, the two illnesses present similar clinical features and laboratory results, e.g., fever, muscle aches, increased liver enzymes, and thrombocytopenia. This article discusses the similar clinical, epidemiological and laboratory aspects of the two diseases and warns physicians to avoid the inappropriate use of drugs such as ribavirin, which is dangerous in patients with kidney failure and pregnancy.

    Keywords: Thrombocytopenia, Brucella, Crimean-Congo Hemorrhagic Fever
  • Mahboubeh Soleimani Sasani, Fereshteh Eftekhar*, Masoud Hosseini Pages 6-11
    Introduction

    Phage therapy has gained interest as a potential alternative for treatment of infections caused by multidrug-resistant (MDR) pathogens. This study aimed to isolate a lytic bacteriophage with the potential to lyse clinical isolates of Klebsiella pneumoniae.

    Methods

    Water samples were collected from a hospital waste-water treatment plant in Tehran. The samples were filtered and mixed with an overnight grown culture of K. pneumoniae. (ATCC 10031) followed by incubation at 37°C overnight. Phage titration, latent period, and burst size measurements were carried out by the double-layer agar method using the K. pneumoniae ATCC strain. The isolated phage w:as char:acterized by transmission electron microscopy (TEM), thermal, pH, and chloroform stability. Susceptibility of Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa, ESBL producing K. pneumoniae and 51 MDR K. pneumoniae isolates was measured by placing 20 µl of the phage suspension (108 PFU) onto bacterial lawns followed by incubation at 37°C overnight. Formation of clear zones indicated susceptibility.

    Results

    The isolated lytic bacteriophage formed small clear plaques with a latent period of 40 min and a burst time of 52 min, corresponding to 35-40 phage particles per infected cell. TEM results showed that the phage resembled the tailed Siphoviridae family and was designated vB_KpnS-Teh.1. The phage vB_KpnS-Teh.1 was most stable at 37°C, pH 7 and was resistant to chloroform.

    Conclusion

    The isolated lytic phage showed specificity towards K. pneumoniae. Further research will determine its potential in the treatment of K. pneumoniae infections.

    Keywords: Klebsiella pneumoniae, Bacteriophage, Waste-water, Siphoviridae
  • Farideh Pidaei, Anoosheh Sharifan*, Ramona Masoud Pages 12-18
    Introduction

    The demand for consuming healthy food has increased due to the developed techniques for assessing food safety and detection of microbial contamination. Among the non-thermal processing methods, using cold plasma along with atmospheric pressure, has received much attention. The present study aims to investigate the effect of cold plasma, the combination of argon and helium gases, on the reduction of microbial load and physicochemical changes in minced sheep meat.

    Methods

    In this study, minced sheep meat was subjected to 36 cold atmospheric plasma treatments with different time intervals (3, 6, and 9 min) and argon/helium gas ratios (1:8 and 2:7). Microbial counts and physiochemical properties (moisture, color, free fatty acids, and pH) were measured according to the Iranian national standards.

    Results

    Both ratios of argon/helium (1:8 and 2:7) were effective in reducing the microbial load of minced sheep meat via cold atmospheric plasma in all exposure intervals (3, 9 and 12 min). However, the argon/helium ratio of 2:7 and an exposure time of 12 min, was the most effective combination in decreasing microbial contamination.

    Conclusion

    Our findings elucidated that the cold plasma processing method was effective in reducing the microbial load of minced sheep meat. Furthermore, we concluded that both parameters of time and gas composition affect microbial load reduction by cold plasma.

    Keywords: Cold plasma, Microbial load, Physicochemical properties, Minced sheep meat
  • Elahe Soltani Fard, Mohammad Roayaei Ardakani, Hossein Motamedi* Pages 19-28
    Introduction

    Staphylococcus aureus is among the primary cause of hospitals and community-acquired infections. The emergence of methicillin-resistant S. aureus (MRSA) strains has resulted in the treatment failure of the infections caused by these bacteria. Hence, regional data on antibiotic resistance of S. aureus strains is necessary to adopt appropriate treatment regimens. This study aims to identify the diversities and their frequencies among MRSA isolates by molecular analysis of four genes.

    Methods

    In a cross-sectional study, 100 S. aureus isolates from patients hospitalized in two hospitals of Ahvaz, Iran were collected and identified. The MRSA isolates were identified by phenotypic method and amplification of the mecA gene. The diversity of MRSA isolates was investigated by amplification of the coa, spa, aroA, and gap genes followed by RFLP analysis using the AluI, HindIII, TaqI and RsaI restriction enzymes.

    Results

    In this study, we identified 50 MRSA isolates. Based on the analysis of coa gene, 8 types, spa gene 5 types and 17 subtypes, coa gene with AluI 13 types, and spa with HindIII 13 types were identified. Also, the RFLP analysis of gap gene with AluI revealed 3 types, and of aroA gene with TaqI and RsaI, 3 types and 2 subtypes, respectively. 

    Conclusion

    Our PCR-RFLP analysis revealed that diversities are present among MRSA isolates originated from clinical samples and showed that this method is simple, reproducible, and cost-effective.

    Keywords: Methicillin-resistant, Staphylococcus aureus, genetic diversity, Iran
  • Mehdi Borhani Zarandi, Saeid Reza Nourollahi Fard, Karim Parastouei, Amin Ahmadi* Pages 29-31
    Introduction

    Trichomoniasis is a protozoan infection of women that is transmitted via sexual intercourse. The present study was carried out to detect the prevalence of Trichomonas vaginalis and other vaginitis agents in women referred to Kerman health care centers.

    Methods

    The vaginal discharges of 3988 females were examined by microscopy for T. vaginalis infection as well as bacterial and fungal infections from April 2016 to March 2017.

    Results

    The prevalence rates of T. vaginalis, bacteria, and yeast were 0.2%, 27.3%, and 9.2% respectively. The highest rate of T. vaginalis infection among women belonged to the age group 41-50 (P<0.05). Our results showed Escherichia coli and Klebsiella in women with bacterial infections.

    Conclusion

    The results indicated that the prevalence of T. vaginalis in patients of this area was low, and other causes of vaginitis such as bacterial and fungal infections should be more considered.

    Keywords: Trichomonas vaginalis, Kerman, Vaginitis
  • Nahideh Mazhari*, Parisa Moosavi, Ehsan Mostafavi, Behzad Esfandiari, Iraj Mobedi, Bahman Rahimi Esboei, Gholamreza Mowlavi Pages 32-36
    Introduction

    Rodents are known as the reservoir of various zoonotic diseases and play a critical role in the transmission of pathogenic agents to humans. During an investigation on rodent reservoirs of leptospirosis in Caspian Sea littoral, northern Iran, we took advantage of the opportunity to examine the animals for intestinal helminth infections.

    Methods

    We received gastrointestinal tracts (GITs) of 132 rodents belonged to the genus Rattus, from Mazandaran, Gilan and Golestan Provinces. The GIT of the animals had been preserved in 10% formalin and transferred to Helminthology Laboratory of School of Public Health, Tehran University of Medical Sciences. We examined the GITs contents for helminths under a binocular followed by a microscope with different magnifications and identified the specimens according to reliable morphological keys.

    Results

    Out of the 132 rats, 83 (62.87%) harbored helminth parasites. We identified 11 helminth species among which the zoonotic cestodes, Hymenolepis diminuta (29.5%) and Hymenolepis nana (18.18%) exhibited the highest prevalence. The species Euparyphium murinum and Skerjabinotaenia abnormalis are reported here for the first time from Iran.

    Conclusion

    The Caspian Sea littoral of Iran is a suitable area for the breeding of the commensal rodents. In this study, the rats from this area exhibited a high burden of helminth infections, with some species of public health importance.

    Keywords: Rattus spp., Intestinal parasites, Caspian Sea, Iran
  • Saba Davoodi, Azam Bolhassani*, Seyed Mehdi Sadat, Shiva Irani Pages 37-43
    Introduction

    The human immunodeficiency virus type 1 (HIV-1) Nef regulatory protein is known as a candidate for the design of therapeutic HIV DNA and protein vaccines. One of the limitations of these vaccines is the inability of DNA and protein to pass through the cell membrane. Various delivery systems have been developed to transfer DNA and protein into cells. Cell penetrating systems such as MPG and Cylop-1 are among delivery systems, which can deliver DNA and protein cargoes into the cells, respectively.

    Methods

    In this study, we produced the recombinant Nef protein in Escherichia coli expression system. Then, the formation of CPP/DNA and CPP/protein nanoparticles was confirmed by agarose gel retardation, scanning electron microscope (SEM), Zetasizer and SDS-PAGE, and their stability was evaluated against nucleases and proteases. Finally, the delivery of the nanoparticles into HEK-293T cells was assessed by fluorescent microscopy, flow cytometry, and western blotting.

    Results

    Our data confirmed the formation of stable nanoparticles through non-covalent bonds with a diameter of less than 200 nm. Moreover, the results of fluorescence microscopy, flow cytometry, and western blotting demonstrated that these CPPs could successfully deliver the Nef protein and DNA into HEK-293T cells.

    Conclusion

    Our results indicated that the MPG and CyLoP-1 CPPs are suitable candidates for the delivery of DNA and protein cargoes into mammalian cells, respectively.

    Keywords: HIV infections, Gene products nef, Cell penetrating peptides, Transfection
  • Mansoureh Paknejadi, Mansour Bayat*, Vadood Razavilar Pages 44-51
    Introduction

    Vulvovaginal Candidiasis (VVC) is one of the most common genital tract infections among women, especially in diabetic patients. The increasing prevalence of recurrent infections caused by drug-resistant non-albicans species necessitates further studies on diabetic patients and the identification of causative agents by reliable molecular techniques. The obtained results can assist in adopting proper treatment procedures and prevention of recurrent vulvovaginitis (RVVC).

    Methods

    In a cross-sectional study, 150 vaginal discharge samples were collected from diabetic women suspected of candidiasis referring to health centers in Tehran province. Following the culture of samples on SDA, CHROMagar Candida and PCR-RFLP were used for presumptive and definitive identification of Candida species, respectively.

    Results

    Out of 115 positive patients, 105 showed infection with one species, and 10 had a mixed infection with two species. The frequency of Candida glabrata isolated from non-mixed and mixed infections in RVVC group was higher than Candida albicans (27.8% vs. 9.6%), which contradicted the results of the VVC group (6.1% vs. 24.3%). In the RVVC group, therefore, the patients were more infected with non-albicans species than C. albicans (47.8% vs. 9.6%), while in the VVC group the non-albicans were of lower frequency (18.3% vs. 24.3%).

    Conclusion

    Our findings showed a statistically significant correlation (P<0.001) between the frequency of C. glabrata and the prevalence of RVVC. On the other hand, that blood sugar, duration of diabetes, and antibiotics usage had significant correlations (P<0.001) with the recurrence of severe symptoms.

    Keywords: Candida glabrata, Diabetes Mellitus, Polymerase Chain Reaction, Vulvovaginal candidiasis, Iran