Molecular epidemiology of noroviruses in children in South Greece, 2013-2015.

Noroviruses constitute the leading cause of acute, nonbacterial gastroenteritis that affects both children and adults in healthcare and community settings. The current study attempted to provide insight on the molecular epidemiology of noroviruses in children in South Greece. Genotypic characterization of 69 norovirus strains detected in stool samples from children with gastroenteritis during a period of 30 months (January 2013 to June 2015) was performed on the basis of ORF2 (VP1 capsid) gene sequences. The results revealed the circulation of a diverse variety of norovirus genotypes. GII.4 was the predominant genotype (74%), followed by GII.2 (8.7%), GII.3 (5.8%), GII.6 (2.9%), GI.2 (2.9%), and four strains identified as GII.1, GII.7, GII.8, and GII.13, respectively. Phylogenetic analysis showed that most of the strains were closely associated with norovirus strains that circulated globally either in outbreaks and sporadic cases of gastroenteritis or in the environment during the last 4 years. Οf the GII.4 strains, 80.4% were detected between January 2013 and February 2014, indicating a possible ongoing epidemic. The incidence of other genotypes remained constant throughout the study period. Genotypic and phylogenetic analysis showed the predominance of the "Sydney 2012" variant among the GII.4 strains, whereas one GII.4 strain was identified as a "New Orleans 2009" variant. Five GII.4 strains showed significant nucleotide and amino acid sequence divergence from either the "Sydney 2012" or the "New Orleans 2009" variant, and these divergent strains might represent an emerging GII.4 variant.

Biofilm-Forming Bacteria Implicated in Complex Otitis Media in Children in the Post-Heptavalent Pneumococcal Conjugate Vaccine (PCV7) Era.

Background: Chronic media with effusion (COME) and recurrent acute otitis media (RAOM) are closely related clinical entities that affect childhood. The aims of the study were to investigate the microbiological profile of otitis-prone children in the post-PCV7 era and, to examine the biofilm-forming ability in association with clinical history and outcome during a two-year post-operative follow-up. Methods: In this prospective study, pathogens from patients with COME and RAOM were isolated and studied in vitro for their biofilm-forming ability. The minimum inhibitory concentrations (MIC) of both the planktonic and the sessile forms were compared. The outcome of the therapeutic method used in each case and patient history were correlated with the pathogens and their ability to form biofilms. Results: Haemophilus influenzae was the leading pathogen (35% in COME and 40% in RAOM), and Streptococcus pneumoniae ranked second (12% in COME and 24% in RAOM). Polymicrobial infections were identified in 5% of COME and 19% of RAOM cases. Of the isolated otopathogens, 94% were positive for biofilm formation. Conclusions: This is the first Greek research studying biofilm formation in complex otitis media-prone children population in the post-PCV7 era. High rates of polymicrobial infections, along with treatment failure in biofilms, may explain the lack of antimicrobial efficacy in otitis-prone children.

Cefditoren: Comparative efficacy with other antimicrobials and risk factors for resistance in clinical isolates causing UTIs in outpatients.

BACKGROUND: To investigate a possible role of Cefditoren, a recently marketed in Greece third-generation oral cephalosporin in urinary infections of outpatients. METHODS: During a multicenter survey of Enterobacteriaceae causing UTIs in outpatients during 2005-2007, Cefditoren MICs were determined by agar dilution method in a randomly selected sample of uropathogens. Susceptibility against 18 other oral/parenteral antimicrobials was determined according to Clinical and Laboratory Standards Institute methodology. RESULTS: A total of 563 isolates (330 Escherichia coli, 142 Proteus mirabilis and 91 Klebsiella spp) was studied; MIC50/MIC90 of Cefditoren was 0.25/0.5 mg/L respectively, with 97.1% of the isolates being inhibited at 1 mg/L. All 12 strains producing ESBLs or AmpC enzymes were resistant to cefditoren. Susceptibility rates (%) for amoxicillin/clavulanic acid, cefuroxime axetil, cefotaxime, ciprofloxacin, trimethoprim/sulfamethoxazole and fosfomycin were 93.1- 94.1- 96.8-93.1-71.9 and 92.8% respectively. Cefditoren MIC was significantly higher in nalidixic/ciprofloxacin non-susceptible strains; resistance to cefditoren was not associated with resistance to mecillinam, fosfomycin nitrofurantoin and aminoglycosides. Multivariate analysis demonstrated history of urinary infection in the last two weeks or three months as risk factors for cefditoren resistance. CONCLUSIONS: Cefditoren exhibited enhanced in vitro activity against the most common uropathogens in the outpatient setting, representing an alternative oral treatment option in patients with risk factors for resistance to first-line antibiotics.

Evaluation of different laboratory tests for the detection of metallo-beta-lactamase production in Enterobacteriaceae.

OBJECTIVES: Clinical isolates of Klebsiella pneumoniae (91), Escherichia coli (49), Enterobacter spp. (27), Proteus mirabilis (17), Citrobacter freundii (2), Providencia stuartii (3) and Serratia spp. (5), with various MICs of imipenem, were examined for production of metallo-beta-lactamases (MBLs) with different phenotypic laboratory tests that have been previously published to detect MBLs in Pseudomonas aeruginosa and Acinetobacter spp. METHODS: A total of 194 (95 MBL-positive and 99 MBL-negative) clinical isolates with imipenem MICs < or = 0.25 to > 256 mg/L were examined. All isolates were evaluated by the double-disc synergy test (DDST), the combination disc test (CDT), the MBL Etest and the modified Hodge test. The presence of bla(VIM) and bla(IMP) genes was evaluated by in situ hybridization with specific probes and was certified by PCR. RESULTS: In 30 bla(VIM)-positive isolates that exhibited MICs of imipenem < or = 4 mg/L, MBL Etest could not be evaluated. CDT with ceftazidime and 1900 or 750 microg of EDTA, and DDST after applying an imipenem disc 10 mm apart from a disc containing approximately 1900 microg of EDTA, showed the highest sensitivity (97.9% to 100%) and specificity (87.9% to 96%) rates among the analysed procedures. CDT with imipenem and 1900 microg of EDTA exhibited a sensitivity of 94.7% and showed very good specificity (98%). CONCLUSIONS: The CDT with imipenem/imipenem+0.5 M EDTA or ceftazidime/ceftazidime+0.2 M EDTA and the DDST with imipenem 10 mm apart from EDTA are the most effective methods for the detection of MBLs in Enterobacteriaceae.