Iranian Journal of Microbiology
Year:2017 | Volume:9 | Issue:3|Papers Count:8

Despite development of preventive and controlling strategies regarding infectious diseases, they are still considered as one of the most significant leading causes of morbidity and mortality, worldwide. Changes in humans’ demographics and behaviors, microbial and ecological alterations, agricultural development, international travels and susceptibility to infectious diseases have resulted in increased reports of emerging infectious diseases (EIDs) and reemerging infectious diseases (RIDs) in various geographical areas. Because of the various types of geographic properties in Iran, substantial climatic variability, as well as unstable political situations and poor public health conditions in some of neighboring countries, EIDs and RIDs are serious public health problems; among them, zoonotic and drug resistant diseases are the most significant. Hence, this review provides an overview of the significant bacterial, viral and fungal EIDs and RIDs in Iran regarding their epidemiological aspects.

Background and Objectives: Despite improvements in modern diagnosis and therapies, hospital acquired infections remain a leading problem of global health systems. Healthcare workers mobile phones is a reservoir for potential pathogens. Despite the high possibility of being contaminated, mobile phones are rarely clean and are often touched during or after examination of patients and handling of specimens without proper hand washing. The main objective of the present study was to isolate, identify different types of bacteria and their antibiotic sensitivity from mobile phones of healthcare workers and non-healthcare workers. Materials and Methods: Samples were collected aseptically by rolling over the exposed surfaces of the mobile phones inoculated on the agar plates and incubated aerobically. After incubation, plates were examined for growth. Bacteria were identified and antibiotic sensitivity was tested as per standard microbiological procedures. Results: In this study a total of 175 samples were examined, out of which 125 samples were from healthcare workers (HCWs), 50 samples were from non-healthcare workers (non-HCWs). Among the mobile phones of HCW’ s from ICUs, Acinetobacter baumannii (36. 84%) was the predominant organism isolated followed by methicillin resistant Staphylococcus aureus (MRSA) (21. 05%). Predominant organism isolated from HCW’ s in operation theater theater was MRSA (46. 66%). Out of 50 worker’ s non-HCWs mobile phones samples cultured, 23 (46. 00%) samples yielded growth of six different types of bacteria. Conclusion: Our study reveals that there is definite colonization of bacteria on mobile phones of the HCWs. It is not only capable of transferring message but also disease-producing microbes. In order to reduce incidence of nosocomial infections, there should be implementation of hand washing practices and regulations around the use of mobile telephones in hospital settings.

Background and Objectives: Staphylococcus aureus is one of the major causes of bovine mastitis, which can be transmitted from animals to humans. Methicillin-resistant S. aureus (MRSA) isolates are more attentive and if not treated promptly, they can cause death. The aim of this study was to determine the prevalence of methicillin resistance and frequency of selected virulence factors of S. aureus isolates with bovine mastitis milk origin in Ahvaz, southwest of Iran. Materials and Methods: During a two-year period (2014-2015), 75 S. aureus isolates were recovered from referred clinical and sub-clinical bovine mastitis milk samples. The isolates were phenotypically investigated for resistance to cefoxitin by Kirby-Bauer method. DNA were analyzed by PCR for mecA and selected genes that encode the virulence factors. Results: According to the results, the spa, ebpS, fnb, bbp, clfA, clfB, and cna genes were detected in 98. 7, 97. 3, 97. 3, 86. 7, 84, 84 and 65. 3% of the isolates, respectively. Among the 75 isolates, only one (1. 3%) isolate was methicillin-resistant. Totally, 39 isolates (50. 7%) had all of these virulence factors except mecA. The results showed that 96% of the isolates had at least the fnb, ebpS and spa genes, signifying the noteworthy role of these genes in the pathogenesis of S. aureus bovine intra-mammary infection in this area. Conclusion: In the present study, the prevalence of mecA was relatively low, possibly indicating that cows do not play a significant role in community-acquired MRSA infection in this area. According to the results, studied virulence factors were somewhat prevalent, bearing in mind the probable risk of transmission of these isolates from cows to humans, especially those that are in close contact with infected cattle. The data presented here can be used for the introduction of a protective vaccine against this infection.

Background and Objectives: Staphylococcus epidermidis produces biofilm by extracellular polysaccharides, causing bacterial adherence to different surfaces. Anti-microbial effects of nickel nanoparticles on some bacterial strains such as S. aureus and Escherichia coli have been determined in limited studies. The aim of the present study is to examine the inhibitory effect of nickel nanoparticles on biofilm formation using clinical isolates of S. epidermidis and its hemolytic effect on human red blood cells. Materials and Methods: Twenty two S. epidermidis isolates were collected and identified by standard microbiological methods. Microtiter plate method was used to determine the biofilm production in bacterial isolates. The amounts of biofilm formation by isolates in the presence of 0. 01, 0. 05, 0. 1, and 1 mg/mL concentrations of nickel nanoparticles were measured. Hemolytic activity of different concentrations of nickel nanoparticles was measured on human RBC suspensions. Results: Twenty isolates were strong, and two isolates were moderate biofilm producers. Biofilm formation significantly decreased in the presence of 0. 05, 0. 1, and 1 mg/mL of nickel nanoparticles (p<0. 05). Although in the presence of 0. 01 mg/mL of nickel nanoparticles, decrease in biofilm formation was observed but it was not statistically significant (p=0. 448). Slight hemolytic activity was seen in the presence of nickel nanoparticles. Conclusion: In this study, the ability of biofilm production was demonstrated for all clinical isolates of S. epidermidis. On the other hand, the lowering effects of nickel nanoparticles on biofilm formation were observed.

Background and Objectives: Clostridium difficile is the leading cause of nosocomial diarrhea and pseudomembranous colitis. The prevalence of C. difficile infection differs in various geographical areas. The aim of this study was to determine the prevalence of C. difficile isolates and the prevalence of cdd3, tcdA and tcdB genes in beef samples in Kermanshah Province. Materials and Methods: One hundred ground beef samples were randomly collected from the butchers of Kermanshah province during March 2014 to March 2015. Following alcohol shock, minced meat samples were incubated in a specific culture medium for 5 to 7 days. The suspicious colonies were analyzed by biochemical tests and frequency of C. difficile and cdd3, tcdA and tcdB genes was assessed by PCR using specific primers. Results: In total, 30% samples were positive for C. difficile and all the isolates harbored Cdd3 gene. Combined dual-gene frequency of A+B+, A-B+ and A+B-strains in the positive were 0%, 3. 3%, and 26. 6% respectively, while 21 samples (70%) were non-toxigenic (A-B-). Conclusion: In this study, the presence of C. difficile in beef as a source of contamination was confirmed. It was also shown that the incidence of C. difficile in ground meat was relatively higher than many other studies.

Background and Objectives: Yearly epidemics of Dengue fever occur post-monsoon in India’ s capital, Delhi. A prospective observational study was conducted during the outbreak months to understand the epidemiology and outcome of this infection and its economic impact. Materials and Methods: Febrile hospitalized (n=219) patients with dengue fever diagnosed by a combination of MAC-ELISA, GAC-ELISA and NS1Antigen-ELISA were enrolled. Epidemiologic (including economic) parameters, clinical, radiological and laboratory manifestations were noted and patients followed up over the period of hospital stay. Patient management means and outcome were recorded and analysed. Results: As per WHO-2009, 153 (69. 9%) and 27 (12. 3%) patients were classified as dengue with warning signs and Severe Dengue respectively while according to WHO-1997 guidelines 39 (17. 8%) and 18 (8. 2%) patients were classified as DHF and DSS respectively. 216 patients were from the city while three were travellers; hospitalization was more frequent among the young and male gender. Fever, vomiting, aches and abdominal pain were the most common troublesome manifestations; classical dengue triad was present in 55 (25. 1%) patients; hemorrhagic, neurologic and mucocutaneous manifestations were present in 44 (20. 1%), 8 (3. 7%) and 70 (32%) patients. Ascitis, pleural effusion, and Gall bladder wall oedema was found in 53 (24. 2%), 31 (14. 1%) and 45 (20. 5%) patients respectively. Mortality was 1. 4% (3 deaths); in addition there was an intra-uterine fetal death; mean expenditure per patient during the illness was US$ 377. 25.

Background and Objectives: Human rotavirus (RV) is responsible for most cases of acute gastroenteritis in infants, worldwide. Today, in vitro transcription (IVT) assay is widely used to develop efficient RNA for the biological experiments such as gene function analysis and reverse genetics. The aim of this study was to develop optimal full-length transcripts of the VP7 segment, using in vitro transcription assay. Materials and Methods: Special primers were designed in order to synthesize VP7 sequence of sense RNA in the process of IVT using T7 RNA polymerase. RT-PCR was performed using forward and reverse primers, containing T7 promoter sequence and BstUI restriction enzyme site, respectively. In order to synthesize ssRNA VP7, in accordance with the IVT technique, RV4-VP7 fragment was subcloned into PTZ57 R/T plasmid and digested by BstUI enzyme. Results: The sequencing of the VP7 gene showed 99% identity withVP7 gene of rotavirus RV4 strain (Sequence ID: M64666. 1). The analysis of purity of DNA fragment and ssRNA VP7 segment revealed that OD ratio of A260/A280 and quantity of nucleic acids were (1. 9, 0. 036 μ g/μ L) and (2. 02, 0. 98 μ g/μ L), respectively. Conclusion: In the present study, a modified methodology of RNA synthetase was described by IVT assay, using T7RNA polymerase in order to transcribe the full-length transcripts of human VP7-RV4 strain. This method is applicable for reverse genetic approaches, especially for the production of reassortant RV vaccine.

Background and Objectives: Different studies show that the prevalence of hepatitis viruses in hemodialysis (HD) patients is much greater than general population. It is important to be aware of local prevalence data, in order to control infections and prevention of nosocomial transmission. The aim of this cross-sectional study was to investigate the seroprevalence of hepatitis B, C, and D viral infections among HD patients. Materials and Methods: During 2016, a cross-sectional study was conducted in Tehran, among 360 HD patients from 5 hemodialysis centers. All HBsAg positive subjects were screened for Hepatitis B surface Ag (HBsAg), Hepatitis C virus Ab (HCVAb) and Hepatitis D virus antibody (HDVAb), using specific enzyme linked immunoassay. Results: 360 patients were involved including 213 males (59. 17%) and 147 females (40. 83%). The mean age in current study was 53. 43 years. HBV positive (HBsAg positive) was found in 1. 39% of patients, HCVAb in 3. 06%, whereas no HDV positive patient was diagnosed. In HD, duration of 1-5 years has the highest frequency rate. Conclusion: Prevalence of HBV, HCV and HDV in hemodialysis patients seems low in Tehran province. Due to higher prevalence of HCV, it is recommended to check the patients for anti-HCV Ab before admission to the centers.