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Influenza remains an important threat for human health, despite the extensive study of influenza viruses and the production of effective vaccines. In contrast to virus genetics determinants, host genetic factors with clinical impact remained unexplored until recently. The association between three single nucleotide polymorphisms (SNPs) and influenza outcome in a European population was investigated in the present study. All samples were collected during the influenza A(H1N1)pdm09 post-pandemic period 2010–11 and a sufficient number of severe and fatal cases was included. Host genomic DNA was isolated from pharyngeal samples of 110 patients from northern Greece with severe (n = 59) or mild (n = 51) influenza A(H1N1)pdm09 disease, at baseline, and the genotype of CD55 rs2564978, C1QBP rs3786054 and FCGR2A rs1801274 SNPs was investigated. Our findings suggest a relationship between the two complement-related SNPs, namely, the rare TT genotype of CD55 and the rare AA genotype of C1QBP with increased death risk. No significant differences were observed for FCGR2A genotypes neither with fatality nor disease severity. Additional large-scale genetic association studies are necessary for the identification of reliable host genetic risk factors associated with influenza A(H1N1)pdm09 outcome. Prophylactic intervention of additional high-risk populations, according to their genetic profile, will be a key achievement for the fight against influenza viruses. [ABSTRACT FROM AUTHOR]

Abstract: The objectives of this research is molecular and phylogenetic analysis of pandemic influenza A(H1N1) 2009 strains that circulated in northern Greece, focusing on severe or fatal infections, identification of sequence variations in relation with the severity of the illness and comparison of circulating viruses with the vaccine strain. A total of 1598 infections were attributed to the novel influenza A(H1N1) virus. Molecular analysis revealed a number of variations at the HA1 sequences of northern Greek circulating strains, some of which were more frequent in viruses that caused severe or fatal infections. Such mutations, the most common being D222G, demand close monitoring to continuously assess associated risks. Phylogenetic analysis confirmed the close match of the majority of circulating strains with A/California/7/09. However it also reveals a trend of 2010 strains to accumulate amino acid variations and form new plylogenetic clades. Constant molecular surveillance is important to monitor the pathogenicity of circulating strains and evaluate the vaccine efficacy. [Copyright &y& Elsevier]

Abstract: Influenza A viruses are characterized by a unique genome structure, causing genetic instability, especially to the genes of haemagglutinin and neuraminidase. The objectives of this research was molecular and phylogenetic analysis of influenza A(H3N2) strains that circulated in Northern Greece since 2004, particularly the identification of sequence variations and the comparison of circulating viruses with vaccine strains. Since 2004 in Northern Greece, a total of 216 clinical samples were positive for influenza virus infections, of which 83 (38.4%) were attributed to influenza A(H3N2). Molecular analysis of the HA genes of 23 isolates showed that all circulating strains had variations at antigenic sites. Receptor binding sites were conserved in 2004–2005 and 2005–2006 strains whereas a variation was observed in all 2006–2007 strains (H195Y). Furthermore, alternative amino acids for sialic acid receptor binding sites were observed in most of the 2004–2006 isolates. Some amino acid substitutions were also observed at the neuraminidase sequences, which however had no effect on the antigenicity of the viruses. Phylogenetic analysis of each year''s circulating strains revealed a relatively low match with the vaccine strains A/Fujian/411/02 and A/California/7/04 for 2004–2005 and 2005–2006, respectively, whereas most 2006–2007 isolates match with the vaccine strain, A/Wisconsin/67/05. This year, unique variations were observed at antigenic and glycosylation sites of A/Serres/77/07-like stains. Constant surveillance of yearly variations is of great importance, so that vaccine strains can be evaluated. [Copyright &y& Elsevier]

The present study evaluated the carbapenem resistance mechanisms of Klebsiella pneumoniae strains isolated in two Greek tertiary teaching hospitals and their susceptibility to currently used and novel antimicrobial agents.Forty-seven carbapenem resistant K. pneumoniae strains were collected in G. Papanikolaou and Ippokrateio hospital of Thessaloniki between 2016 and 2018. Strain identification and antimicrobial susceptibility was conducted by Vitek 2 system (Biomérieux France). Susceptibility against new antimicrobial agents was examined by disk diffusion method. Polymerase chain reaction (PCR) was used to detect blaKPC, blaVIM, blaNDM and blaOXA-48 genes.The meropenem-EDTA and meropenem-boronic acid synergy test performed on the 24 K. pneumoniae strains demonstrated that 8 (33.3%) yielded positive for metallo-beta-lactamases (MBL) and 16 (66.6%) for K. pneumonia carbapenemases (KPC) production. Colistin demonstrated the highest in vitro activity (87.7%) among the 47 K. pneumoniae strains followed by gentamicin (76.5%) and tigecycline (51%). Among new antibiotics ceftazidime/avibactam showed the highest sensitivity (76.6%) in all strains followed by eravacycline (66.6%). The blaKPC gene was present in 30 strains (63.8%), the blaNDM in 11 (23.4%) and the blaVIM in 6 (12.8%). The blaOXA-48 gene was not detected.Well established antimicrobial agents such as colistin, gentamicin and tigecycline and novel antibiotics like ceftazidime/avibactam and eravacycline can be reliable options for the treatment of invasive infections caused by carbapenem-resistant K. pneumoniae.

Since its appearance, influenza A(H1N1)pdm09 caused considerable morbidity and mortality in Northern Greece. Genetic analysis of post-pandemic circulating strains scoped to investigate any correlation between genetic variations that emerged during viral evolution and severity of infection. Pharyngeal swabs/aspirates (n = 1,870) were examined with real-time reverse transcription-polymerase chain reaction. Hemagglutinin sequences were analyzed on 110 strains (37 fatal/73 non-fatal cases), followed by statistical and phylogenetic analysis. Influenza A(H1N1)pdm09 was detected in 848 samples. Coexistence of clusters 3, 4, 5, 6, and 7 indicated co-circulation of lineages in Northern Greece. Genetic analysis showed that HA sequences had 96-99% sequence similarity with the vaccine strain and that there was no association between any co-circulating lineage and severity. Several viruses accumulated variations in HA antigenic sites. D222G was significantly associated with fatal infections, supporting its association with increased viral pathogenesis. On the other hand, four variations were associated with milder disease outcomes. Certain signature amino acid changes persisted during and/or after the pandemic, indicating their offer of selective advantages to the virus. Negative selection was observed in 70% of pandemic variations as they probably did not contribute to the virus fitness. It is of interest that persistent variations were highly identified in the vicinity of antigenic or receptor-binding sites. Of those, K171R was associated only with fatal infections. Also of interest, only strains that were isolated from fatal infections had variations that altered both their acid-base and polarity properties. Genetic changes that may alter the antigenicity, pathogenicity and transmissibility of circulating virus variants need to be determined and closely monitored., (© 2014 Wiley Periodicals, Inc.)