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Introduction Methicillin-resistant Staphy lococcus aureus (MRSA) causes severe community and hospital acquired infections. Identification of staphylococcal cassette chromosome mec (SCCmec), multilocus-sequence typing, and sequencing of S. aureus protein A (spa) gene are used for MRSA typing. The aim was to investigate the spa types of MRSA isolates in a tertiary hospital in Greece and analyse the whole genome sequences of two t127 MRSA isolates. Methods Totally, 39 MRSA isolates collected from July 2019 to June 2020 in “Georgios Gennimatas” General Hospital of Thessaloniki, Greece, were included in the study. Identification and antimicrobial susceptibility testing were performed using VITEK II automated system, and spa typing was performed. A minimum spanning tree was used to display the spa type frequencies and the genetic distances among them. Two t127-MRSA isolates (IM-MRSA and PD-MRSA) were selected for WGS. Results Six isolates (15.4%) were resistant to mupirocin, 18 (46.2%) to fusidic acid, three (7.7%) to vancomycin and two (5.1%) to teicoplanin. Twenty-two different spa types were detected, with t002, t003, and t422 being the most frequent (5/39, 12.8% each), followed by t1994 (4/39, 10.3%). The isolates presented high genetic diversity and, taking into account the time between hospital admission and sampling, intrahospital spread did not occur. Even the two t127 isolates were assigned to different sequence types, ST9-XII-t127 and ST1-IVa-t127. Plasmids and genes conferring antimicrobial resistance and virulence were also identified. Conclusions Various spa types were identified and together with the information about the time between hospital admission and sampling supports polyclonal MRSA spread in the hospital excluding a nosocomial infection. WGS provides a more detailed analysis distinguishing even the isolates belonging to the same spa type.

The epidemiology of West Nile virus (WNV) is unpredictable and changing. Availability of whole genome sequences enables the detailed molecular epidemiology studies and the evaluation and design of diagnostic tools. In the present study we provide two PCR-based protocols which can be applied directly on biological samples from hosts infected by WNV strains belonging to lineage 1 or lineage 2. It was shown that the protocols worked successfully even on samples with relatively low viral load.

Human respiratory syncytial virus (RSV) is the leading cause of acute bronchiolitis in infants and young children. Children under the age of 2 years, hospitalized for bronchiolitis in the pediatric clinic of a tertiary hospital in northern Greece, were tested for RSV infection during two RSV seasons (2016–2017 and 2017–2018). RSV was detected in 37 of 71 (52.1%) patients, most of them younger than 6 months. Both RSV subtypes were detected – RSV-A (54.1%) and RSV-B (45.9%) – with predominance of RSV-A during the 2016–2017 and RSV-B during the 2017–2018 season. RSV-A and RSV-B sequences clustered within the ON1 and BA genotypes, respectively. Compared to the prototype strains, several amino acid substitutions were observed in the duplication region of the G gene. The study provides a first insight into the molecular epidemiology of RSV in Greece.

During the 2020 West Nile virus (WNV) transmission season, Greece was the most affected EU Member State. More than one third of human cases occurred in Serres regional unit in northern Greece, which is characterized by the presence of a major wetland (Kerkini lake and Strimon river). A total of 2809 Culex pipiens mosquitoes collected in Serres were grouped into 70 pools and tested for WNV. Ten (14.3%) pools were found positive, and all WNV sequences belonged to the Central European subclade of WNV lineage 2. The first human case occurred in a village nearby the lake, and all following cases occurred across the connected river and its tributaries. Similar distribution presented the sites where WNV-positive mosquitoes were detected. The number of Culex spp. mosquitoes per trap per night was higher in 2020 than in previous years (2017-2019). The spatial and temporal distribution of human cases and WNV-positive mosquitoes in 2020 in Serres regional unit suggest that the upsurge of the virus circulation was probably related with factors that affected the ecosystem of the wetland.

Background Human cases of West Nile virus (WNV) infection are recorded since 2010 in Greece, with seasonal outbreaks occurring almost annually. Enhanced surveillance has been implemented since 2010, to promptly characterise cases’ temporal and geographical distribution and inform authorities for implementation of appropriate measures (mosquito control, health education, blood safety). Aim We describe the epidemiology of WNV human infections in Greece focusing on the 2018 season. Methods The National Public Health Organization advised physicians to test all suspect WNV infection cases and refer samples to reference laboratories. Laboratories notified diagnosed cases on a daily basis. Treating physicians, patients, and infected blood donors were interviewed within 48 hours after diagnosis and the probable infection location was identified. Hospitalised cases were followed up until discharge. Results A total of 317 autochthonous WNV infection cases were diagnosed in 2018. Among them, 243 cases had neuroinvasive disease (WNND), representing a 23% increase of WNND cases compared with 2010, the previous most intense season. There were 51 deaths. Cases started occurring from week 22, earlier than usual. Both rural and urban areas were affected, with 86 (26% of the total) municipalities belonging to seven (54% of the total) regions recording cases. Two major epicentres were identified in Attica and Central Macedonia regions. Conclusions The largest number of human cases of WNV infection ever recorded in Greece occurred in 2018, with a wide geographical distribution, suggesting intense virus circulation. Enhanced surveillance is vital for the early detection of human cases and the prompt implementation of response measures.

West Nile virus (WNV) emerged in Greece in 2010 and since then human outbreaks occurred every year except 2015 and 2016. An early start and prolonged WNV transmission season was observed in 2018 with a record number of 316 reported cases and 47 fatalities. The Greek WNV strains detected during 2010-2018 clustered within the central European subclade of lineage 2. A novel WNV genetic variant was detected in August 2018 in one human case in the north-eastern region of Greece, at the land cross-border with Turkey and Bulgaria. The strain belongs to the Eastern European subclade of lineage 2 suggesting a new virus introduction in the country and the continuously changing epidemiology of the disease.

Crimean-Congo hemorrhagic fever (CCHF) is endemic in Bulgaria. During 2013-2014, 11 confirmed CCHF cases have been reported in the country (seven in 2013 and four in 2014). The present study provides the CCHF molecular epidemiology in Bulgaria based on all currently available S, M, and L RNA segment nucleotide sequences spanning the years 1978-2014. A relatively low genetic difference (0-6%, the maximum seen in the M RNA segment) was seen among the CCHFV sequences suggesting that a slow evolving CCHFV strain belonging to "Europe 1" clade is present in Bulgaria. Although the virus emerged in new foci during the recent years, it is more active in the established endemic foci which seem to offer the most suitable ecosystem and environment. Understanding the CCHF epidemiology and virus evolution is the basis for public health programs and vaccine design.

Pneumonia is an inflammation of the lung caused by microbial or viral infection. It is an important factor of morbidity for children in the developed world, as well as a frequent cause of death of children in the developing world. Chemokines are a very important part of the immune system. The purpose of this study was to investigate the role of polymorphisms of chemokine RANTES (-28C/G and-403G/A) in the development of pneumonia in children. The study included two groups of children, the patient group and the control group. The patient group consisted of 60 children, who were hospitalized with the diagnosis of pneumonia from November 2009 until May 2010. The control group consisted of 135 healthy children who had no previous history of lower respiratory tract infections. According to the results, polymorphism of chemokine RANTES -28C/G was associated to the development of pneumonia in the studied population. Polymorphism of chemokine RANTES -403G/A was not associated to the development of pneumonia in the same population. Serum levels of chemokine RANTES were lower in children who were carriers of the polymorphism -28C/G compared to children who had the normal gene type. Also, serum levels of chemokine RANTES were higher in children with pneumococcal pneumonia compared to children with pneumonia caused by other pathogens.

Introduction Migraine is considered to be a multifactorial, complex disease. Various genetic and environmental factors contribute to the manifestation of this disease. The aim of this study was to determine whether polymorphisms in the tumour necrosis factor (TNF) region are associated with the risk of migraine. We examined the association between 6 single nucleotide polymorphisms in the coding regions of TNF-α and TNF-β genes and migraine. Material and methods The study included two groups of children (group A and group B). Group A consisted of 103 unrelated children with typical migraine without aura 5-14 years of age. Group B (control group) consisted of 178 unrelated healthy children. The diagnosis of migraine was, in all patients, made according to the International Classification of Headache Disorders (ICHD II). Results According to our results positive family history was present in 62.2% of patients of group A. No significant differences were found in the frequencies of genotypes or alleles between patients and controls. The non-parametric analyses of variance showed no significant differences in the age at onset between genotype groups of the TNF-α and TNF-β gene polymorphisms. Comparison of genotype frequencies between boys and girls in affected patients and control individuals were not significantly different (p = 0.089, p =0.073 respectively). The distribution of TNF polymorphisms was not associated with the presence of family history of migraine in patients. Conclusions Our data indicate that TNF-α and TNF-β gene polymorphisms are not a significant risk factor for migraine without aura in Greek children.

A 10 year old boy had visual deterioration in both eyes. Visual acuity was 0.2 in the right and 0.3 in the left eye. Further ophthalmologic findings were typical of posterior uveitis. The pediatric physical examination also disclosed aphthous stomatitis and recurrent aphthous genital ulcers. At diagnosis serum levels of IL-1β, IL-6, IL-8, TNF-α, sIL-2R, MCP-1, VEGF, tADA activity in the patient with active and ABD relapse were significantly higher than those in the inactive period of the disease, suggesting that these parameters may be related to disease activity. In addition to the proinflammatory chemokines and cytokines, plasma levels of VEGF and serum tADA activity may be used for the diagnosis of ABD and for monitoring the effect of treatment, as well as the follow-up period. Also, further studies of VEGF may lead to novel therapies with antibodies or other VEGF inhibitors.

It is estimated that approximately 1% of babies born per year result from in vitro fertilization and embryo transfer, and other assisted reproductive technologies. In humans, the exact mechanisms that lead to embryonic attachment to the endometrial epithelium and invasion into the endometrial stroma have not been fully characterized. The aim of the study is to estimate serum total adenosine deaminase and isoenzymes ADA1, ADA2, as well as MMP-2, MMP-3, MMP-13 and MIP-1a as parameters for pregnancy following IVF-ET. The study group comprised seventeen women who conceived (Group A) and nineteen women aged 21–42 years who did not conceive (Group B) after IVF-ET. Blood samples were collected between 09.00 and 10.00 a.m. during IVF-ET treatment at two different periods. The first blood sample was collected before ET and the second sample 14 days after ET. All serum samples were assayed for the MMP-2, MMP-3 MMP-13 and MIP-1a concentrations with ELISA assay. Serum tADA activity was measured by a spectrophotometer using adenosine as the substrate (Method by Giusti). According to our results it was demonstrated that women who successfully conceived after IVF-ET showed significantly lower serum concentrations of ADA1, MMP-2, MMP-3 and higher serum concentration of MMP-13 at 14 days following ET. In conclusion, ADA1 may play a protective role at the hemochorial interface. Thus, our results suggest that ADA1 may have a modulatory role in the implantation and duration of the pregnancy. In women with successful or unsuccessful pregnancy compared with normal women the levels of ADA and MMPs may be affected by the exogenous hormone therapy according to the protocol of ovarian stimulation during IVF-ET.

The NF-κB pathway gene expression profiles were compared between 10, 20 and 39 days after Trichinella spiralis experimental infection in BALB/c mice. Out of 128 genes, 19 (14.8%) genes were present in non-infected and post-infected mice. The expression of 7 (36.8%) genes was downregulated 10 and 20 days post-infection while 3 (15.8%) genes were upregulated 39 days post-infection. The present study lists the candidate genes of the NF-κB signaling pathway that were commonly and differentially expressed between the specific points of T. spiralis infection, thus suggesting that these genes need to be further investigated to reveal the mechanism of the T. spiralis modulation of the NF-κB signaling pathways.

Infections caused by the nematode Trichinella spiralis (T. spiralis) are chatacterized by an inflammatory response in the host. The aim of this study was to identify and evaluate markers for monitoring mice infected with T. spiralis and treated with or without mimosine. The markers that have been used were total and differential white blood cell counts, subpopulations of lymphocytes, serum tADA and its isoenzymes ADA1 and ADA2 activity. The study included 3 groups of BALB/c mice. Group A consisted of 16 healthy mice, Group B of 16 mice infected with T. spiralis and treated with saline, and Group C of 16 mice infected with T. spiralis and treated with mimosine. The measurements were made once per week for the first six weeks continuously following the infection. According to our results, leukocytosis, lymphocytosis and increased percentages of adhesion molecules and CD4 lymphocytes were present in groups B and C one week post-infection. Total ADA activity as well as ADA1 and ADA2 was higher in groups B and C versus group A from the first week post-infection. The levels of tADA activity, ADA1 and ADA2 were higher in group B compared to those of group C and the difference was statisticaly sigificant (pth week post-infection. The majority of tADA activity, essential for an efficient immune response, was derived from ADA1 which may have been produced by infected tissues. The elevated activities of tADA and ADA1 may be sensitive markers for infection of T. spiralis and for monitoring the course of the infection.

Clinical manifestations of respiratory syncytial virus (RSV) infection vary from minimal disease to severe acute bronchiolitis. The structural complex of TLR4/CD14 participates in the virus recognition as a component of natural immune response. Genetic variations of TLR4/CD14 may explain great variations in disease severity. The aim of this study was to investigate the possible role of polymorphisms of TLR4, Asp299Gly and Thr399Ile and CD14, C-159T and C-550T in the development of RSV bronchiolitis. Our study included two groups of Greek infants and young children (A and B). Group A consisted of 50 infants ≤2 years of age hospitalised with bronchiolitis and group B of 99 previously healthy children aged 4–14 years (control group) with a free past medical history. RSV was indentified by PCR of genetic material that was extracted from nasopharyngeal samples collected from all patients. Blood samples were used to extract DNA and by using the PCR-RFLP method we performed TLR4 and CD14 genotyping. We found no association between TLR4 polymorphisms (Asp299Gly and Thr399Ile) and the development of acute bronchiolitis. For CD14 polymorphisms, a positive association was found between the C-159T and the development of bronchiolitis (p=0.05) but not for the other loci. There were no differences detected in the frequencies of the four polymorphisms studied among infants with RSV and non-RSV bronchiolitis. It is concluded that protein CD14 may have a functional role in the viral conjunction to the structural complex TLR4/CD14. The association between the polymorphism C-159T and the manifestation of disease found in our study points out that the severity in the development of acute bronchiolitis is not specified exclusively by the pathogen, but the immune response of the host also plays a significant role. More extensive multicentric studies need to take place, in order to lead to safer conclusions.