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Salmonella diarizonae (IIIb) is frequently isolated from reptiles and less frequently from birds and mammals. However, its isolation from invasive human infections has not been widely reported. Migratory mallard ducks are excellent bioindicators of pathogen presence and pathogen antibiotic resistance (AMR). We present the first isolation from a mallard duck in central Europe of the antibiotic-resistant Salmonella enterica subsp. diarizonae with the unique antigenic pattern 58:r:z53 and report its whole-genome sequencing, serosequencing, and genotyping, which enabled the prediction of its pathogenicity and comparison with phenotypic AMR. The isolated strain was highly similar to S. diarizonae isolated from humans and food. Twenty-four AMR genes were detected, including those encoding aminoglycoside, fluoroquinolone, macrolide, carbapenem, tetracycline, cephalosporin, nitroimidazole, peptide antibiotic, and disinfecting agent/antiseptic resistance. Six Salmonella pathogenicity islands were found (SPI-1, SPI-2, SPI-3, SPI-5, SPI-9, and SPI-13). An iron transport system was detected in SPI-1 centisome C63PI. Plasmid profile analyses showed three to be present. Sequence mutations in the invA and invF genes were noted, which truncated and elongated the proteins, respectively. The strain also harbored genes encoding type-III secretion-system effector proteins and many virulence factors found in S. diarizonae associated with human infections. This study aims to elucidate the AMR and virulence genes in S. enterica subsp. diarizonae that may most seriously threaten human health. [ABSTRACT FROM AUTHOR]

Background: Daptomycin is an optimal choice for outpatient parenteral antibiotic therapy (OPAT) because of its safety, once-daily administration and its activity against Gram-positive bacteria. Although daptomycin is increasingly being used in OPAT, limited information about its safety in this scenario is available. Methods: We performed a prospective multicentre pilot study to evaluate the safety of daptomycin in outpatients with proved or suspected Gram-positive infections (DAPTODOM). The primary objective was to evaluate the safety and the secondary objective to evaluate the efficacy in OPAT. We also looked at the development of daptomycin resistance in those cases with microbiological failure. Results: We included 54 patients from 12 Spanish hospitals, 67% male with a mean age of 67.1 years. Most patients (87%) had chronic underlying diseases. The main reason for inclusion was skin and soft-tissue infections in 52%, followed by bacteremia or endocarditis in 34%. Staphylococcus aureus accounted for 44% of the isolates (24% were methicillin-resistant), coagulase-negative staphylococci 15% and enterococci 7%. Two patients (4%) had to be readmitted because of complications; only one patient had an adverse effect related to daptomycin (increase in serum creatine kinase levels), which disappeared after discontinuation (2%). At the end of follow-up, 96% of patients had good outcome and only 4% of patients did not have a clinical or microbiological cure. The use of a 2-minute bolus in 18 cases was not associated with adverse effects. Conclusions: Daptomycin was safe and efficacious in outpatients with Gram-positive bacterial infections and can be administered in 2-minute bolus infusion. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides are ubiquitous components of eukaryotic innate immunity. Defensins are a well-known family of antimicrobial peptides, widely distributed in ticks, insects, plants and mammals, showing activity against bacteria, viruses, fungi, yeast and protozoan parasites. Ixodes ricinus is the most common tick species in Europe and is a vector of pathogens affecting human and animal health. Recently, six defensins (including two isoforms) were identified in I . ricinus . We investigated the evolution of the antimicrobial activity of I . ricinus defensins. Among the five unique defensins, only DefMT3, DefMT5 and DefMT6 showed in vitro antimicrobial activity. Each defensin was active against rather distantly-related bacteria (P < 0.05), significantly among Gram-negative species (P < 0.0001). These three defensins represent different clades within the family of tick defensins, suggesting that the last common ancestor of tick defensins may have had comparable antimicrobial activity. Differences in electrostatic potential, and amino acid substitutions in the β-hairpin and the loop bridging the α-helix and β-sheet may affect the antimicrobial activity in DefMT2 and DefMT7, which needs to be addressed. Additionally, the antimicrobial activity of the γ-core motif of selected defensins (DefMT3, DefMT6, and DefMT7) was also tested. Interestingly, compared to full length peptides, the γ-core motifs of these defensins were effective against less species of bacteria. However, the antifungal activity of the γ-core was higher than full peptides. Our results broaden the scope of research in the field of antimicrobial peptides highlighting the overlooked ability of arthropod defensins to act against distantly-related microorganisms. [ABSTRACT FROM AUTHOR]

Introduction: Daptomycin, a rapid concentration-dependent bactericidal antibiotic, is approved at a dose of 4 mg/kg/day for the treatment of complicated skin and soft tissue infections (cSSTI) and at a dose of 6 mg/kg/day for the treatment of Staphylococcus aureus right-sided infective endocarditis (RIE) and bacteremia associated with cSSTI and RIE. Studies have reported the successful use of high-dose daptomycin (>6 mg/kg/day) in patients with difficult-to-treat infections. The present analysis evaluated the effectiveness and safety of high doses (>6 mg/kg/day) of daptomycin for the treatment of different Gram-positive infections.Methods: European Cubicin(®) Outcomes Registry and Experience (EU-CORE) is a non-interventional, multicenter, retrospective, patient registry designed to collect real-world data from patients treated with daptomycin between 2006 and 2012. Clinical outcomes were assessed at the end of daptomycin treatment for three dose groups: ≤6, >6 to <8, and ≥8 mg/kg/day. Safety was assessed for up to 30 days post-daptomycin treatment.Results: Of the 6075 patients enrolled in EU-CORE, 4892 patients received daptomycin doses ≤6 mg/kg/day, while 1097 patients received high doses (>6 mg/kg/day). The primary infections with the largest proportion of patients treated with a high dose (>6 mg/kg/day) were osteomyelitis (37.1%), foreign body/prosthetic infection (31.6%), and endocarditis (27.6%). S. aureus was identified in 42.9% of patients with positive cultures treated with either ≤6 or >6 mg/kg/day. The overall clinical success rate was 82.0% (899/1097) with high doses (>6 mg/kg/day) and 80.3% (3928/4890) with doses ≤6 mg/kg/day. Numerically higher clinical success rate was observed for endocarditis and foreign body/prosthetic infection, as well as for coagulase-negative staphylococcal and enterococcal infections, with high-dose daptomycin treatment. There were no new or unexpected safety findings at doses >6 mg/kg/day.Conclusion: These results suggested that daptomycin at doses >6 mg/kg/day was effective and well tolerated. High-dose daptomycin is a potential therapeutic option in patients with difficult-to-treat Gram-positive infections.Funding: This study was funded by Novartis Pharma AG. [ABSTRACT FROM AUTHOR]

Background: Ixodes ricinus is the main tick vector of the microbes that cause Lyme disease and tick-borne encephalitis in Europe. Pathogens transmitted by ticks have to overcome innate immunity barriers present in tick tissues, including midgut, salivary glands epithelia and the hemocoel. Molecularly, invertebrate immunity is initiated when pathogen recognition molecules trigger serum or cellular signalling cascades leading to the production of antimicrobials, pathogen opsonization and phagocytosis. We presently aimed at identifying hemocyte transcripts from semi-engorged female I. ricinus ticks by mass sequencing a hemocyte cDNA library and annotating immune-related transcripts based on their hemocyte abundance as well as their ubiquitous distribution. Methodology/principal findings: De novo assembly of 926,596 pyrosequence reads plus 49,328,982 Illumina reads (148 nt length) from a hemocyte library, together with over 189 million Illumina reads from salivary gland and midgut libraries, generated 15,716 extracted coding sequences (CDS); these are displayed in an annotated hyperlinked spreadsheet format. Read mapping allowed the identification and annotation of tissue-enriched transcripts. A total of 327 transcripts were found significantly over expressed in the hemocyte libraries, including those coding for scavenger receptors, antimicrobial peptides, pathogen recognition proteins, proteases and protease inhibitors. Vitellogenin and lipid metabolism transcription enrichment suggests fat body components. We additionally annotated ubiquitously distributed transcripts associated with immune function, including immune-associated signal transduction proteins and transcription factors, including the STAT transcription factor. Conclusions/significance: This is the first systems biology approach to describe the genes expressed in the haemocytes of this neglected disease vector. A total of 2,860 coding sequences were deposited to GenBank, increasing to 27,547 the number so far deposited by our previous transcriptome studies that serves as a discovery platform for studies with I. ricinus biochemistry and physiology. Author Summary: Ixodes ricinus transmits Lyme disease and tick-borne encephalitis in Europe. Tick-borne pathogens ingested with a blood meal persist in the tick gut and, during the next feeding stage, disseminate through the haemolymph to pass into a vertebrate host via the salivary glands. Invertebrate immunity is initiated when tick pathogen recognition molecules trigger serum or cellular signalling cascades. We aimed to identify haemocyte transcripts from semi-engorged female I. ricinus ticks by deep sequencing a haemocyte cDNA library and by annotating immune-related transcripts based on their abundance in haemocytes and their sequence divergence when compared to their arthropod homo(ortho)logues. 15,716 extracted coding sequences (CDS) were generated in total, and 327 transcripts were significantly overexpressed in haemocytes. These included those coding for scavenger receptors, antimicrobial peptides, pathogen recognition proteins, proteases, and protease inhibitors. Transcriptional enrichment of vitellogenin and lipid metabolism effectors suggests that body fat components mediate tick innate immunity. Annotation of ubiquitously distributed transcripts associated with immune function and their phylogenetic analysis provide insights into the evolution of major protein families involved in tick innate immunity. [ABSTRACT FROM AUTHOR]

The pollen beetle ( Meligethes aeneus) is a major pest of oilseed rape ( Brassica napus) and other cruciferous crops in Europe. Pesticide-resistant pollen beetle populations are emerging, increasing the economic impact of this species. We isolated total RNA from the larval and adult stages, the latter either naïve or immunized by injection with bacteria and yeast. High-throughput RNA sequencing ( RNA- Seq) was carried out to establish a comprehensive transcriptome catalogue and to screen for developmental stage-specific and immunity-related transcripts. We assembled the transcriptome de novo by combining sequence tags from all developmental stages and treatments. Gene expression data based on normalized read counts revealed several functional gene categories that were differentially expressed between larvae and adults, particularly genes associated with digestion and detoxification that were induced in larvae, and genes associated with reproduction and environmental signalling that were induced in adults. We also identified many genes associated with microbe recognition, immunity-related signalling and defence effectors, such as antimicrobial peptides ( AMPs) and lysozymes. Digital gene expression analysis revealed significant differences in the profile of AMPs expressed in larvae, naïve adults and immune-challenged adults, providing insight into the steady-state differences between developmental stages and the complex transcriptional remodelling that occurs following the induction of immunity. Our data provide insight into the adaptive mechanisms used by phytophagous insects and could lead to the development of more effective control strategies for insect pests. [ABSTRACT FROM AUTHOR]

Background Dalbavancin is a lipoglycopeptide approved in the United States (US; 2014) and Europe (2015) to treat skin and skin structure infections in adults with a convenient parenteral administration of either a single dose of 1500 mg or a dose of 1000 mg followed by 500 mg a week later. We evaluated dalbavancin in vitro spectrum and potency against Gram-positive isolates from pediatric patients. Method 4,487 consecutive, unique pediatric patient isolates of clinical significance were collected from 32 US and 34 European medical centers and tested for susceptibility to dalbavancin and comparators by broth microdilution. The most common organisms were Staphylococcus aureus (n=2,633), Streptococcus pneumoniae (n=689), and beta-hemolytic streptococci (BHS; n=584). Susceptibility results were analyzed by patient age group: ≤1 years old (yo; n=1,459), 2-5 (1,106), 6-12 (1,164), and 13-17 (758). Results Dalbavancin showed complete activity against S. aureus (100% susceptibility), with a highest MIC value of 0.12 mg/L and consistent activity against all age groups (MIC50/90 of 0.03/0.03 mg/L for the US and Europe as well as the MSSA and MRSA subsets). MRSA rates were higher in the US (32.4% overall) than Europe (14.0%). In the US, MRSA rates were 38.7%, 34.2%, 28.4%, and 25.0% in the ≤1, 2-5, 6-12, and 13-17 yo groups, respectively; whereas, in Europe, it was slightly lower in the 2-5 yo group (11.5%) compared to the other age groups (14.1-14.8%). Ceftaroline was consistently active against S. aureus isolates from all age groups, with susceptibility rates ranging from 99.4% (13-17 yo) to 99.8% (2-5 yo) in the US and from 95.3% (≤1 yo) to 100.0% (2-5 yo) in Europe. Dalbavancin showed consistent activity against S. pneumoniae from all age groups (MIC50/90 of 0.008/0.015 mg/L for all age groups in the US and Europe) with a highest MIC value of 0.06 mg/L (1 isolate). All S. pneumoniae isolates were susceptible to ceftaroline, and susceptibility to ceftriaxone (at ≤1 mg/L; non-meningitis breakpoint) ranged from 92.7% (13-17 yo) to 100.0% (≤1 yo), or 97.8% overall. Dalbavancin was also highly active against BHS (n=584; MIC50/90, 0.008/0.015 mg/L; highest MIC, 0.06 mg/L), coagulase-negative staphylococci (n=240; MIC50/90, 0.03/0.06 mg/L; highest MIC, 0.25 mg/L), Enterococcus faecalis (n=200; MIC50/90, 0.03/0.06 mg/L; highest MIC, 0.06 mg/L), viridans group streptococci (n=102; MIC50/90, 0.008/0.03 mg/L; highest MIC, 0.12 mg/L), and vancomycin-susceptible E. faecium (n=26; MIC50/90, 0.03/0.12 mg/L; highest MIC, 0.25 mg/L), but showed limited activity against vancomycin-resistant E. faecium (VREFM; n=13 [0.3% of the organism collection]; MIC50/90, >2/>2 mg/L). Conclusion Dalbavancin showed potent in vitro activity against a large collection of Gram-positive isolates from pediatric patients, independent of patient age and geographic region (US and Europe). Only 13 of 4,487 (0.3%) isolates exhibited a dalbavancin MIC >0.25 mg/L, all of which were VREFM. These in vitro results support further clinical development of dalbavancin for treatment of Gram-positive infections in children. [ABSTRACT FROM AUTHOR]

The emergence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) antimicrobial resistance and epidemic genetic lineages is posing a challenge in veterinary medicine due to the limited therapeutical options. MRSP has been identified as an important canine pyoderma pathogen. Thus, we aimed to characterize the antimicrobial resistance and clonal lineages of MRSP isolated from canine cutaneous pyoderma. Thirty-one MRSP isolates recovered from pyoderma were further characterized. The antimicrobial susceptibility testing of the isolates was performed by the Kirby-Bauer disc diffusion method against 14 antimicrobial agents. The presence of antimicrobial and virulence genes was carried out by PCR. Multilocus sequence typing was performed in all isolates. All strains had a multidrug-resistant profile showing resistance mainly to penicillin, macrolides and lincosamides, aminoglycosides, tetracycline and trimethoprim-sulfamethoxazole, which was encoded by the blaZ, ermB, msr(A/B), aac(6′)-Ie-aph(2′′)-Ia, aph(3′)-IIIa, ant(4′)-Ia, tetM, tetK and dfrG genes. All isolates harbored the lukS-I/lukF-I virulence factors. Isolates were ascribed to nine previously described sequence types (STs): ST123, ST339, ST727, ST71, ST537, ST45, ST1029, ST118 and ST1468; and to five STs first described in this study: ST2024, ST2025, ST2026, ST2027 and ST2028. In this study, most isolates belonged to ST123 (n = 16), which belongs to CC71 and is the most common clone in Europe. All isolates were multidrug-resistant, which may impose a serious threat to animal health. [ABSTRACT FROM AUTHOR]