دو ماهنامه میکروب شناسی پزشکی ایران
سال پانزدهم شماره 4 (امرداد و شهریور 1400)

Hydroxyapatite (HA) has many applications in medicine, dentistry, diagnosis, drug delivery systems, sewage treatment, bone remodeling, concentrating bacteria, covering implants, and antibacterial activity. Despite the numerous current applications of calcium phosphate compounds, particularly HA, their producing methods are being investigated to find the best processes. Several chemical and biological methods are used in calcium phosphate compounds synthesis. Researches have shown that compared to micrometer models, nanostructured HA has higher mechanical features and better biocompatibility in the human body. These properties optimize when nanometer components of HA are in similar size and shape with the least agglomerations. Biomineralization by microorganisms, which is a bacterial route, is a recent HA synthesis method. This paper is a review on the biosynthesis of HA emphasizing microbial methods. In this method, some bacteria and mold could be used in the nanometer production of HA. This type of bacterium commonly has a high amount of alkaline phosphatase enzymes. Desirable similarity to natural HA in the human body is the noticeable features of bacterial HA. Uniformity in the shape and size of synthesized particles that have the same crystallization is of other merits. Producing bacterial HA is easily reachable, one-step, inexpensive, harmless, and with high purity, and contrary to chemical synthesis, does not need heat treatment and precise pH adjustment.

Food poisoning due to Clostridium perfringens (C. perfringens) is a major food health problem, particularly in terms of meat consumption. Due to human’s susceptibility to this pathogen, detection methods and prevention measures should be implemented to reduce its incidence. Several pathogenic strains of C. perfringens have been identified so far. One of the potential concerns about this bacterium is its toxin-producing characteristic that causes food poisoning. It has seven toxin types (A-G) according to the existence of four unique toxin genes. This study aimed to assess the prevalence of food poisoning caused by C. perfringens in meat and meat-derived products in Iran. We collected and categorized all the available data on this issue in Iran. Moreover, we summarized some methods used to detect toxins and genes and finally placed a prevention section for clarifying how to prevent such events. The best method for preventing such an organism’s growth is by keeping foods in their normal state (hot and cold criteria) and chilling prepared foods in shallow containers as soon as possible.

 The major pneumococcal pathogenesis factor is the capsular polysaccharide. the production of polysaccharide is regulated by cpsB and cpsD genes. Thus, every agent that induce or inhibition of expression of these genes probably increased pathogenesis of bacteria, intracellular survival and vis versa. The aim of this study was to assay the effect of Xylitol on Streptococcus pneumoniae cpsB, cpsD, psaA and aroE genes expression by Real Time RT-PCR.

During 2019 in Baqiyatallah university laboratories, 20 clinical isolates and a reference strain Streptococcus pneumoniae (ATCC 6305) were studied. To assay the effect of Xylitol and fructose، different concentration of these sugars were exposed to BHI Broth media. Thereafter, the bacterial suspension was added to 5% Xylitol, 5%Xylitol + 5% fructose and control medium for 3hours. RNA was extracted and cDNA synthesis was carried out. Then, the cpsB, cpsD and psaA genes expression levels were measured.

 The mean of cpsB gene expression ratio in presence of the % 5 Xylitol treated media compared with those in the control media and % 5 Xylitol + 5% fructose were 0.022 and 0.027 respectively. The means of the cpsD and psaA genes expression ratio in the % 5 Xylitol treated media compared with those in the control media and % 5 Xylitol + 5% fructose were 1.659 and 0.056, and 0.633 and 3.294 respectively.

 Our finding revealed that, the 5% Xylitol inhibit the cpsB gene expression properly. Therefore, it is possible to use of Xylitol for reductive on cpsB gene expression and superficial pneumococcal infections control.

 Influenza is a global epidemic disease that always causes irreparable damage to individuals and countrieschr('39') health, and the amount of research in this area is increasing. The primary purpose this study is to discover the hidden patterns and emerging events of global influenza publications.

 This article is an applied type was done with an analytical approach and using the Co-word analysis method. This researchchr('39')s statistical population includes all the keywords of documents indexed with influenzachr('39')s subject in the WOSCC in the last two decades. The number of keywords studied in this article is 26767. MeSH was used to determine the search strategy for document retrieval.

 The keywords "Avian Influenza" and "Influenza Vaccine" with a frequency of 1302 and 1264 were the most frequent keywords in the subject area of influenza. Findings related to the analysis of clusters by the hierarchical clustering method created 21 clusters in the field of influenza. Seventeen clusters with the most keywords were the largest cluster. The strategic diagram indicated that most influenza subject area clusters are located in the third quadrant of the strategic diagram and are considered emerging or declining subjects.

 Discovering the intellectual structure, presenting hidden patterns and emerging events of global publications in the field of influenza infections can help governments, communities, and research centers in understanding research advances, optimizing and managing future research topics, and effectively monitoring and policy-making activities-new research and allocation of facilities and budget.

 The purpose of the present study is thematic analysis and scientific collaborations of research related to Covid 19 vaccine in Iran and the world based on scientific products indexed in Web of Science (WOS).

 The present study is a descriptive-analytical study with a scientometric approach and using the methods of content analysis and techniques of co-word analysis, hierarchical clustering, Strategic graph and social network analysis. The research population is scientific products related to Covid 19 vaccine in the world and in Iran. Data analysis was performed by HistCite, Bibexecl, Gephi and SPSS software; and the data mapping is done by VOSviewer.

 Between 2019 and 2021, 6005 related studies were retrieved. Unites states is followed by India and China, and the United Kingdom has the most Links. Iran’s rank is 10th with 196 studies. Hierarchical clustering in global research led to the formation of 3 clusters (vaccine development strategy, medical prevention and immunotherapy) and in Iranian research led to the formation of 4 clusters (immunotherapy, diagnosis and treatment cycle, medical prevention and immunology). From scientific collaborations at the country level in world and Iranian studies, 5 clusters were formed, at the level of institutions, 17 and 10 clusters, respectively, and at the level of researchers, 10 and 8 clusters, respectively.

 Analysis and comparison of world and Iranian studies leads to a better understanding of the prevailing currents, Gaps and discourse in order to increase the quantity and quality of studies, followed by controlling and the eradication of Covid 19 in the shortest possible time.

 Beta-lactamases are the most important factors in the resistance to beta-lactam antibiotics among gram-negative bacteria, especially Klebsiella pneumoniae. Nowadays, the prevalence of infections caused by extended-spectrum β-lactamases (ESBLs)-producing K. pneumoniae is increasing, as one of the emerging health problems throughout the world. This study aimed to investigate the prevalence of blaTEM and blaSHV genes in K. pneumoniae isolated from the clinical specimens in Miandoab in West Azerbaijan province.

 In this study, 120 K. pneumoniae strains which were isolated from the clinical specimens in Miandoab hospitals were used. Then, an antibiotic susceptibility test was performed to determine ESBL-producing K. pneumoniae isolates using the combined disk method. The presence of blaTEM and blaSHV genes was detected by the polymerase chain reaction (PCR) technique.

 In the combined disk method, of 120 strains of K. pneumoniae, 71 (59.2%) were positive for ESBL. The blaTEM and blaSHV ESBLs were detected in 35 (49.3%) and 31 (43.7%) strains respectively. Eventually, the co-existence of blaTEM and blaSHV was detected in 5 (7%) isolates.

 blaTEM was the most common gene with a frequency of 49.3% in K. pneumonia isolates.

In the summer of 2018, this study was performed on 50 Koi fish transferred to Razef Research Complex. In this study, after observing macroscopic symptoms in fish, including lethargy and immobility, imbalance, darkening of the skin, skin wounds, petechiae in the abdomen, opacity of the eye and anophthalmia, anorexia, and sitting on the bottom of the aquarium, sampling was performed to diagnose the pathogens and examine the pathological changes. According to microbial tests on skin samples and internal organs, Aeromonas hydrophila was reported, and septicemia in 48% of the studied fish. In necropsy specimens, the organs were pale, the liver was enlarged, and petechiae were observed on the surface of the liver. The microbial contamination also led to considerable tissue damages, including the destruction of gill filaments, nuclear pycnosis in the liver, and the infiltration of inflammatory cells into the heads of all fish. Considering the significant losses due to the pathogenicity of Aeromonas hydrophila in different fish species and the importance of Koi fish, observing quarantine and hygienic principles to prevent sepsis was very important. Early diagnosis and use of appropriate treatment protocols for this disease are recommended.

Pulmonary coccidioidomycosis is an infection in the lungs caused by the fungus Coccidioides. The disease is very rare in India and only a few cases have been reported so far. The diagnosis of pulmonary coccidioidomycosis is very challenging because it mimics other lower respiratory tract infections. Both clinical suspicion and laboratory confirmation plays a very important role in the diagnosis of this infection and in resource limited settings only culture and microscopy play a vital role in the diagnosis. Early diagnosis helps in appropriate therapy to avoid later complications.