Antibodies Directed toward Neuraminidase N1 Control Disease in a Mouse Model of Influenza.

There is increasing evidence to suggest that antibodies directed toward influenza A virus (IAV) neuraminidase (NA) are an important correlate of protection against influenza in humans. Moreover, the potential of NA-specific antibodies to provide broader protection than conventional hemagglutinin (HA) antibodies has been recognized. Here, we describe the isolation of two monoclonal antibodies, N1-7D3 and N1-C4, directed toward the N1 NA. N1-7D3 binds to a conserved linear epitope in the membrane-distal, carboxy-terminal part of the NA and reacted with the NA of seasonal H1N1 isolates ranging from 1977 to 2007 and the 2009 H1N1pdm virus, as well as A/Vietnam/1194/04 (H5N1). However, N1-7D3 lacked NA inhibition (NI) activity and the ability to protect BALB/c mice against a lethal challenge with a range of H1N1 viruses. Conversely, N1-C4 bound to a conformational epitope that is conserved between two influenza virus subtypes, 2009 H1N1pdm and H5N1 IAV, and displayed potent in vitro antiviral activity mediating both NI and plaque size reduction. Moreover, N1-C4 could provide heterosubtypic protection in BALB/c mice against a lethal challenge with 2009 H1N1pdm or H5N1 virus. Glutamic acid residue 311 in the NA was found to be critical for the NA binding and antiviral activity of monoclonal antibody N1-C4. Our data provide further evidence for cross-protective epitopes within the N1 subtype and highlight the potential of NA as an important target for vaccine and therapeutic approaches.IMPORTANCE Influenza remains a worldwide burden on public health. As such, the development of novel vaccines and therapeutics against influenza virus is crucial. Human challenge studies have recently highlighted the importance of antibodies directed toward the viral neuraminidase (NA) as an important correlate of reduced influenza-associated disease severity. Furthermore, there is evidence that anti-NA antibodies can provide broader protection than antibodies toward the viral hemagglutinin. Here, we describe the isolation and detailed characterization of two N1 NA-specific monoclonal antibodies. One of these monoclonal antibodies broadly binds N1-type NAs, and the second displays NA inhibition and in vitro and in vivo antiviral activity against 2009 H1N1pdm and H5N1 influenza viruses. These two new anti-NA antibodies contribute to our understanding of the antigenic properties and protective potential of the influenza virus NA antigen.

The choroid plexus epithelium as a novel player in the stomach-brain axis during Helicobacter infection.

Several studies suggest a link between shifts in gut microbiota and neurological disorders. Recently, we reported a high prevalence of Helicobacter suis (H. suis) in patients with Parkinson's disease. Here, we evaluated the effect of gastric H. suis infection on the brain in mice. One month of infection with H. suis resulted in increased brain inflammation, reflected in activation of microglia and cognitive decline. Additionally, we detected choroid plexus inflammation and disruption of the epithelial blood-cerebrospinal fluid (CSF) barrier upon H. suis infection, while the endothelial blood-brain barrier (BBB) remained functional. These changes were accompanied by leakage of the gastrointestinal barrier and low-grade systemic inflammation, suggesting that H. suis-evoked gastrointestinal permeability and subsequent peripheral inflammation induces changes in brain homeostasis via changes in blood-CSF barrier integrity. In conclusion, this study shows for the first time that H. suis infection induces inflammation in the brain associated with cognitive decline and that the choroid plexus is a novel player in the stomach-brain axis.

Helicobacter suis induces changes in gastric inflammation and acid secretion markers in pigs of different ages.

Gastric mRNA expression of markers for acid secretion and inflammation and presence of gastric ulceration was studied in naturally Helicobacter suis-infected and non-infected 2-3 months old, 6-8 months old and adult pigs. In H. suis-infected 2-3 months old pigs, IL-8 and IL-1ß transcript levels were upregulated in the pyloric gland zone, indicating an innate immune response. A similar response was demonstrated in the fundic gland zone of adult pigs, potentially due to a shift of H. suis colonization from the pyloric to the fundic gland zone. A Treg response in combination with decreased expressions of IL-8, IL-17A and IFN-γ was indicated to be present in the H. suis-infected 6-8 months old pigs, which may have contributed to persistence of H. suis. In H. suis-infected adult pigs, a Treg response accompanied by a Th17 response was indicated, which may have played a role in the decreased number of H. suis bacteria in the stomach of this age group. The decreased G-cell mass and upregulated expression of somatostatin indicated decreased acid secretion in H. suis-infected 6-8 months old pigs. In H. suis-infected adult pigs, upregulation of most markers for gastric acid secretion and increased G-cell mass was detected. Presence of severe hyperkeratosis and erosions in the non-glandular part of the stomach were mainly seen in the H. suis-positive groups. These results show that H. suis infection affects the expression of markers for acid secretion and inflammation and indicate that these effects differ depending on the infection phase.

Selection and transfer of an IncI1-tet(A) plasmid of Escherichia coli in an ex vivo model of the porcine caecum at doxycycline concentrations caused by crosscontaminated feed.

AIMS: The aim of this study was to investigate the effect of subtherapeutic intestinal doxycycline (DOX) concentrations (4 and 1 mg l-1 ), caused by cross-contamination of feed, on the enrichment of a DOX-resistant commensal Escherichia coli and its resistance plasmid in an ex vivo model of the porcine caecum. METHODS AND RESULTS: A DOX-resistant, tet(A)-carrying, porcine commensal E. coli strain (EC 682) was cultivated for 6 days in the porcine caecum model under different conditions (0, 1 and 4 mg l-1 DOX). EC 682, other coliforms and anaerobic bacteria were enumerated daily. A selection of isolated DOX-resistant coliforms (n = 454) was characterized by rep-PCR clustering, PCR assays (Inc1 and tet(A)) and micro broth dilution susceptibility tests (Sensititre). Both 1 and 4 mg l-1 DOX-enriched medium had a significantly higher selective effect on EC 682 and other resistant coliforms than medium without DOX. Transconjugants of EC 682 were isolated more frequently in the presence of 1 and 4 mg l-1 DOX compared to medium without DOX. CONCLUSIONS: Subtherapeutic intestinal DOX concentrations have the potential to select for DOX-resistant E. coli, and promote the selection of transconjugants in a porcine caecum model. SIGNIFICANCE AND IMPACT OF THE STUDY: Cross-contamination of feed with antimicrobials such as DOX likely promotes the spread of antimicrobial resistance. Therefore, it is important to develop or fine-tune guidelines for the safe use of antimicrobials in animal feed and its storage.

Presence of antimicrobial resistance in coliform bacteria from hatching broiler eggs with emphasis on ESBL/AmpC-producing bacteria.

Antimicrobial resistance is recognized as one of the most important global health challenges. Broilers are an important reservoir of antimicrobial resistant bacteria in general and, more particularly, extended-spectrum ß-lactamases (ESBL)/AmpC-producing Enterobacteriaceae. Since contamination of 1-day-old chicks is a potential risk factor for the introduction of antimicrobial resistant Enterobacteriaceae in the broiler production chain, the presence of antimicrobial resistant coliform bacteria in broiler hatching eggs was explored in the present study. Samples from 186 hatching eggs, collected from 11 broiler breeder farms, were inoculated on MacConkey agar with or without ceftiofur and investigated for the presence of antimicrobial resistant lactose-positive Enterobacteriaceae, particularly, ESBL/AmpC-producers. Escherichia coli and Enterobacter cloacae were obtained from the eggshells in 10 out of 11 (10/11) sampled farms. The majority of the isolates were recovered from crushed eggshells after external decontamination suggesting that these bacteria are concealed from the disinfectants in the egg shell pores. Antimicrobial resistance testing revealed that approximately 30% of the isolates showed resistance to ampicillin, tetracycline, trimethoprim and sulphonamides, while the majority of isolates were susceptible to amoxicillin-clavulanic acid, nitrofurantoin, aminoglycosides, florfenicol, neomycin and apramycin. Resistance to extended-spectrum cephalosporins was detected in eight Enterobacteriaceae isolates from five different broiler breeder farms. The ESBL phenotype was confirmed by the double disk synergy test and blaSHV-12, blaTEM-52 and blaACT-39 resistance genes were detected by PCR. This report is the first to present broiler hatching eggs as carriers and a potential source of ESBL/AmpC-producing Enterobacteriaceae for broiler chicks.

Incidence and risk factors for limb fracture in greyhound racing in Western Australia.

Identification of risk factors for race day injury can improve greyhound welfare. Race day fractures are the most significant injury event and have the greatest negative impact on dog welfare and the industry's social license to operate. This study aimed to describe the incidence and risk factors for race-related fractures in greyhounds racing in Western Australia. Electronic extracts describing race level data and race day injuries were provided by Racing and Wagering Western Australia (RWWA). The incidence rate (IR) of fractures for all greyhound race starts in Western Australia from 1 January 2017-31/12/2023 was calculated per 1000 starts. Univariable and multivariable models using Poisson regression were used to calculate the IR ratio of fracture type based on race and greyhound-level factors. There were 198,008 racing starts and 662 (n = 643, 97.1% involving the limbs) fractures resulting in an IR of 3.3 fractures per 1000 starts (95%CI 3.1-3.6). Greyhounds that had an injury in their previous race were 2.3 times (95%CI1.4-4.3) more likely to have a forelimb fracture than greyhounds that did not have an injury (P = 0.013). The risk of tarsal bone fracture was greater in greyhounds older than 30 months and greyhounds that had not raced in the previous 15 days. Risk factors for fractures in the forelimb were associated with trauma after interference or dog collisions, whereas tarsal fractures were associated with strain and cyclic loading from race training/racing. Changes to racing structure, rules and policies based on these risk factors may help to reduce fracture incidence in racing greyhounds.

Decontamination of the digestive tract and oropharynx in ICU patients.

BACKGROUND: Selective digestive tract decontamination (SDD) and selective oropharyngeal decontamination (SOD) are infection-prevention measures used in the treatment of some patients in intensive care, but reported effects on patient outcome are conflicting. METHODS: We evaluated the effectiveness of SDD and SOD in a crossover study using cluster randomization in 13 intensive care units (ICUs), all in The Netherlands. Patients with an expected duration of intubation of more than 48 hours or an expected ICU stay of more than 72 hours were eligible. In each ICU, three regimens (SDD, SOD, and standard care) were applied in random order over the course of 6 months. Mortality at day 28 was the primary end point. SDD consisted of 4 days of intravenous cefotaxime and topical application of tobramycin, colistin, and amphotericin B in the oropharynx and stomach. SOD consisted of oropharyngeal application only of the same antibiotics. Monthly point-prevalence studies were performed to analyze antibiotic resistance. RESULTS: A total of 5939 patients were enrolled in the study, with 1990 assigned to standard care, 1904 to SOD, and 2045 to SDD; crude mortality in the groups at day 28 was 27.5%, 26.6%, and 26.9%, respectively. In a random-effects logistic-regression model with age, sex, Acute Physiology and Chronic Health Evaluation (APACHE II) score, intubation status, and medical specialty used as covariates, odds ratios for death at day 28 in the SOD and SDD groups, as compared with the standard-care group, were 0.86 (95% confidence interval [CI], 0.74 to 0.99) and 0.83 (95% CI, 0.72 to 0.97), respectively. CONCLUSIONS: In an ICU population in which the mortality rate associated with standard care was 27.5% at day 28, the rate was reduced by an estimated 3.5 percentage points with SDD and by 2.9 percentage points with SOD. (Controlled Clinical Trials number, ISRCTN35176830.)

Selective decontamination of the oral and digestive tract in surgical versus non-surgical patients in intensive care in a cluster-randomized trial.

BACKGROUND: Selective digestive decontamination (SDD) and selective oropharyngeal decontamination (SOD) are effective in improving survival in patients under intensive care. In this study possible differential effects in surgical and non-surgical patients were investigated. METHODS: This was a post hoc subgroup analysis of data from a cluster-randomized multicentre trial comparing three groups (SDD, SOD or standard care) to quantify effects among surgical and non-surgical patients. The primary study outcome was 28-day mortality rate. Duration of mechanical ventilation, duration of intensive care unit (ICU) and hospital length of stay, and bacteraemia rates were secondary outcomes. RESULTS: The subgroup analyses included a total of 2762 surgical and 3165 non-surgical patients. Compared with standard care, adjusted odds ratios (ORs) for mortality were comparable in SDD-treated surgical and non-surgical patients: 0·86 (95 per cent confidence interval 0·69 to 1·09; P = 0·220) and 0·85 (0·70 to 1·03; P = 0·095) respectively. However, duration of mechanical ventilation, ICU stay and hospital stay were significantly reduced in surgical patients who had SDD. SOD did not reduce mortality compared with standard treatment in surgical patients (adjusted OR 0·97, 0·77 to 1·22; P = 0·801); in non-surgical patients it reduced mortality (adjusted OR 0·77, 0·63 to 0·94; P = 0·009) by 16·6 per cent, representing an absolute mortality reduction of 5·5 per cent with number needed to treat of 18. CONCLUSION: Subgroup analysis found similar effects of SDD in reducing mortality in surgical and non-surgical ICU patients, whereas SOD reduced mortality only in non-surgical patients. The hypothesis-generating findings mandate investigation into mechanisms between different ICU populations.

Helicobacter heilmannii sp. nov., isolated from feline gastric mucosa.

Three gram-negative, microaerophilic bacteria, strains ASB1(T), ASB2 and ASB3, with a corkscrew-like morphology isolated from the gastric mucosa of cats were studied using a polyphasic taxonomic approach. The isolates grew on biphasic culture plates under microaerobic conditions at 37 °C and exhibited urease, oxidase and catalase activities. They were also able to grow in colonies on dry agar plates. Based on 16S rRNA gene sequence analysis, ASB1(T), ASB2 and ASB3 were identified as members of the genus Helicobacter and showed 98 to 99 % sequence similarity to strains of Helicobacter felis, Helicobacter bizzozeronii, 'Candidatus Helicobacter heilmannii', Helicobacter cynogastricus, Helicobacter baculiformis and Helicobacter salomonis, six related Helicobacter species previously detected in feline or canine gastric mucosa. Sequencing of the partial hsp60 gene demonstrated that ASB1(T), ASB2 and ASB3 constitute a separate taxon among the feline and canine Helicobacter species. The urease gene sequences of ASB1(T), ASB2 and ASB3 showed approximately 91 % similarity to those of 'Candidatus Helicobacter heilmannii'. Protein profiling, the absence of alkaline phosphatase activity and several other biochemical characteristics also allowed strains ASB1(T), ASB2 and ASB3 to be differentiated from other Helicobacter species of feline or canine gastric origin. The results of this polyphasic taxonomic study show that the cultured isolates constitute a new taxon corresponding to 'Candidatus Helicobacter heilmannii', which was previously demonstrated in the stomach of humans, wild felidae, cats and dogs. The name Helicobacter heilmannii sp. nov. is proposed for these isolates; the type strain is ASB1(T) (=DSM 24751 (T) =LMG 26292(T)) [corrected].

The basilic vein and the cephalic vein perform equally in upper arm arteriovenous fistulae.

OBJECTIVE: To compare the brachiocephalic (BC) and basilic vein transposition (BVT) arteriovenous fistula (AVF) with regard to maturation, patency, blood flow and complication rates. DESIGN: A retrospective chart review. MATERIALS AND METHOD: Between January 2000 and December 2010, consecutive patients undergoing BC or BVT AVF were included. Patient characteristics were collected retrospectively from digital patient files and a prospective database of haemodialysis patients. RESULTS: A total of 173 autologous upper arm AVFs (87 BC and 86 BVT) were created in 151 patients. Mean (±SEM) follow-up was 19 ± 1.4 months (range 0-100). There were no differences between the groups in respect to brachial artery and cubital fossa vein diameters, time to first use, flow and the number of secondary interventions. Operative time was significantly longer (P < 0.001) and the mid upper arm vein diameter before bifurcation greater (P = 0.038) in BVT patients. The 1- and 2-year primary patency rates for the whole cohort was 40.8% and 30.2% with secondary patency rates of 78.0% and 72.4%. There was no difference between the groups for these outcomes (P = 0.951, P = 0.516, respectively). CONCLUSION: With the exception of the efferent vein diameter in the mid upper arm and operative time, there was no difference between a BC and BVT AVF.

Perforating veins: an anatomical approach to arteriovenous fistula performance in the forearm.

OBJECTIVES: Arteriovenous fistulae (AVFs) play a key role for people who rely on chronic haemodialysis. Stenosis in the venous outflow of the AVF will cause an alternative route of the subcutaneous blood flow via the deeper venous pathways by means of side branches and the perforating veins (PVs). The purpose for the present study was to define the number and anatomical localisation of the perforating veins in the forearm. METHODS: Twenty forearms were dissected to study the venous anatomy. The localisation, size and connections of the perforators were recorded and stored digitally. RESULTS: In total, 189 PVs were defined (mean, 9.5 per arm; range, 6-19), with 60 (32%) PVs connected to the cephalic vein, 97 (51%) connections to the basilic vein and 32 (17%) PVs to the median vein of the forearm. Most PVs originate from the basilic vein and connect with the ulnar venae comitans. The cephalic vein connects equally to the radial venae comitans, interossea veins and the muscles. CONCLUSION: The cephalic vein has the fewest PVs and almost a third of them connect to the muscles. This is probably important for the maturation of the AVF, the superficial flow volume and the accessibility for puncture.

Risk factors for ceftiofur resistance in Escherichia coli from Belgian broilers.

A cross-sectional study on 32 different Belgian broiler farms was performed in 2007 and 2008 to identify risk factors for ceftiofur resistance in Escherichia coli. On each farm, one E. coli colony was isolated from 30 random birds. Following susceptibility testing of 14 antimicrobials, an on-farm questionnaire was used to obtain information on risk factors. Using a multilevel logistic regression model two factors were identified at the animal level: resistance to amoxicillin and to trimethoprim-sulfonamide. On the farm level, besides antimicrobial use, seven management factors were found to be associated with the occurrence of ceftiofur resistance in E. coli from broilers: poor hygienic condition of the medicinal treatment reservoir, no acidification of drinking water, more than three feed changes during the production cycle, hatchery of origin, breed, litter material used, and treatment with amoxicillin. This study confirms that not only on-farm antimicrobial therapy, but also management- and hatchery-related factors influence the occurrence of antimicrobial resistance.

In situ ESBL conjugation from avian to human Escherichia coli during cefotaxime administration.

AIMS: The behaviour of an Escherichia coli isolate of broiler origin harbouring a bla(TEM-52) -carrying plasmid (lactose-negative mutant of B1-54, IncII group) was studied in an in situ continuous flow culture system, simulating the human caecum and the ascending colon during cefotaxime administration. METHODS AND RESULTS: Fresh faeces from a healthy volunteer, negative for cephalosporin-resistant E. coli, were selected to prepare inocula. The microbiota was monitored by plating on diverse selective media, and a shift in the populations of bacteria was examined by 16S rDNA PCR denaturing gradient gel electrophoresis. Escherichia coli transconjugants were verified by plasmid and pulsed-field gel electrophoresis profiles (PFGE). The avian extended-spectrum ß-lactamase-positive E. coli was able to proliferate without selective pressure of cefotaxime, and E. coli transconjugants of human origin were detected 24 h after inoculation of the donor strain. Upon administration of cefotaxime to the fresh medium, an increase in the population size of E. coli B1-54 and the transconjugants was observed. PFGE and plasmid analysis revealed a limited number of human E. coli clones receptive for the bla(TEM-52) -carrying plasmid. CONCLUSIONS: These observations provide evidence of the maintenance of an E. coli strain of poultry origin and the horizontal gene transfer in the human commensal bowel microbiota even without antimicrobial treatment. SIGNIFICANCE AND IMPACT OF THE STUDY: The fact that an E. coli strain of poultry origin might establish itself and transfer its bla gene to commensal human E. coli raises public health concerns.

A targeted deletion of a region upstream from the Jkappa cluster impairs kappa chain rearrangement in cis in mice and in the 103/bcl2 cell line.

We have shown previously that a mutation of the KI-KII site immediately 5' to J(kappa)1 on the mouse immunoglobulin light chain kappa locus reduces the rearrangement level in cis, although it does not affect transcription. Here we deleted by homologous recombination in mouse embryonic stem cells a 4-kb DNA fragment, located immediately upstream of the KI-KII element, which contains the promoter of the long germline transcript. Analysis of gene-targeted heterozygous mouse splenic B cells showed a strong decrease in rearrangement for the allele bearing the deletion. When both the KI-KII mutation and the 4-kb deletion were present on the same allele, the overall reduction in rearrangement was stronger than with the 4-kb deletion alone underlying the role of these two elements in the regulation of rearrangement. The same deletion was performed by homologous recombination on one allele of the rearrangement-inducible mouse 103/bcl2-hygro(R) pre-B cell line, and resulted in a similar reduction in the induction of rearrangement of the mutated allele. This result validates this cell line as an in vitro model for studying the incidence of gene-targeted modifications of the kappa locus on the regulation of rearrangement.

Rearrangement-enhancing element upstream of the mouse immunoglobulin kappa chain J cluster.

Transcriptional regulatory elements have been shown to be necessary but not sufficient for the developmental regulation of immunoglobulin gene rearrangement in mouse precursor B cells. In the chicken lambda light chain locus, additional elements in the V-J intervening sequence are involved in negative and positive regulation of rearrangement. Here, mutation of the mouse homolog of a chicken element, located in the V(K)-J(K) intervening sequence upstream of the J(K) cluster, was shown to significantly decrease rearrangement. This cis-acting recombination-enhancing element affects the rearrangement process without being involved in regulating transcription.

Antimicrobial susceptibility pattern of Helicobacter suis isolates from pigs and macaques.

Helicobacter suis is a fastidious, Gram negative bacterium that colonizes the stomach of pigs and non-human primates. It has also been associated with gastric disease in humans. A combined agar and broth dilution method was used to analyze the activity of 15 antimicrobial agents against 20 and 15 H. suis isolates obtained from pigs and macaques, respectively. After 48 h microaerobic incubation, minimal inhibitory concentrations (MICs) were determined by software-assisted calculation of bacterial growth as determined by quantitative real-time PCR. A monomodal distribution of MICs was seen for ß-lactam antibiotics, macrolides, gentamicin, neomycin, doxycycline, metronidazole, and rifampicin. Presence of a bimodal distribution of MICs indicated that 2 porcine isolates did not belong to the wild type population (WTP) for fluoroquinolones. This was also the case for 1 porcine isolate for tetracycline, 1 porcine and 2 primate isolates for lincomycin, and 1 primate isolate for spectinomycin. Single nucleotide polymorphisms (SNPs) were present in the gyrA gene of the isolates not belonging to the WTP for fluoroquinolones and in ribosomal protein encoding genes of the isolates not belonging to the WTP for tetracycline and spectinomycin. MICs of ampicillin, tetracycline and doxycycline were higher for porcine H. suis isolates compared to primate isolates and in these porcine isolates SNPs were detected in genes encoding penicillin binding and ribosomal proteins. This study indicates that acquired resistance occasionally occurs in H. suis isolates and that zoonotically important porcine isolates may be intrinsically less susceptible to ß-lactam antibiotics and tetracyclines than primate isolates.

Fcγ Receptors Contribute to the Antiviral Properties of Influenza Virus Neuraminidase-Specific Antibodies.

Influenza virus neuraminidase (NA) has been under intense study recently as a vaccine antigen, yet there remain unanswered questions regarding the immune response directed toward NA. Antibodies (Abs) that can inhibit NA activity have been shown to aid in the control of disease caused by influenza virus infection in humans and animal models, yet how and if interactions between the Fc portion of anti-NA Abs and Fcγ receptors (FcγR) contribute to protection has not yet been extensively studied. Herein, we show that poly- and monoclonal anti-NA IgG antibodies with NA inhibitory activity can control A(H1N1)pdm09 infection in the absence of FcγRs, but FcγR interaction aided in viral clearance from the lungs. In contrast, a mouse-human chimeric anti-NA IgG1 that was incapable of mediating NA inhibition (NI) solely relied on FcγR interaction to protect transgenic mice (with a humanized FcγR compartment) against A(H1N1)pdm09 infection. As such, this study suggests that NA-specific antibodies contribute to protection against influenza A virus infection even in the absence of NI activity and supports protection through multiple effector mechanisms.IMPORTANCE There is a pressing need for next-generation influenza vaccine strategies that are better able to manage antigenic drift and the cocirculation of multiple drift variants and that consistently improve vaccine effectiveness. Influenza virus NA is a key target antigen as a component of a next-generation vaccine in the influenza field, with evidence for a role in protective immunity in humans. However, mechanisms of protection provided by antibodies directed to NA remain largely unexplored. Herein, we show that antibody Fc interaction with Fcγ receptors (FcγRs) expressed on effector cells contributes to viral control in a murine model of influenza. Importantly, a chimeric mouse-human IgG1 with no direct antiviral activity was demonstrated to solely rely on FcγRs to protect mice from disease. Therefore, antibodies without NA enzymatic inhibitory activity may also play a role in controlling influenza viruses and should be of consideration when designing NA-based vaccines and assessing immunogenicity.

ESCMID-EUCIC clinical guidelines on decolonization of multidrug-resistant Gram-negative bacteria carriers.

SCOPE: The aim of these guidelines is to provide recommendations for decolonizing regimens targeting multidrug-resistant Gram-negative bacteria (MDR-GNB) carriers in all settings. METHODS: These evidence-based guidelines were produced after a systematic review of published studies on decolonization interventions targeting the following MDR-GNB: third-generation cephalosporin-resistant Enterobacteriaceae (3GCephRE), carbapenem-resistant Enterobacteriaceae (CRE), aminoglycoside-resistant Enterobacteriaceae (AGRE), fluoroquinolone-resistant Enterobacteriaceae (FQRE), extremely drug-resistant Pseudomonas aeruginosa (XDRPA), carbapenem-resistant Acinetobacter baumannii (CRAB), cotrimoxazole-resistant Stenotrophomonas maltophilia (CRSM), colistin-resistant Gram-negative organisms (CoRGNB), and pan-drug-resistant Gram-negative organisms (PDRGNB). The recommendations are grouped by MDR-GNB species. Faecal microbiota transplantation has been discussed separately. Four types of outcomes were evaluated for each target MDR-GNB:(a) microbiological outcomes (carriage and eradication rates) at treatment end and at specific post-treatment time-points; (b) clinical outcomes (attributable and all-cause mortality and infection incidence) at the same time-points and length of hospital stay; (c) epidemiological outcomes (acquisition incidence, transmission and outbreaks); and (d) adverse events of decolonization (including resistance development). The level of evidence for and strength of each recommendation were defined according to the GRADE approach. Consensus of a multidisciplinary expert panel was reached through a nominal-group technique for the final list of recommendations. RECOMMENDATIONS: The panel does not recommend routine decolonization of 3GCephRE and CRE carriers. Evidence is currently insufficient to provide recommendations for or against any intervention in patients colonized with AGRE, CoRGNB, CRAB, CRSM, FQRE, PDRGNB and XDRPA. On the basis of the limited evidence of increased risk of CRE infections in immunocompromised carriers, the panel suggests designing high-quality prospective clinical studies to assess the risk of CRE infections in immunocompromised patients. These trials should include monitoring of development of resistance to decolonizing agents during treatment using stool cultures and antimicrobial susceptibility results according to the EUCAST clinical breakpoints.

[Less ventilator-associated pneumonia after oral decontamination with chlorhexidine; a randomised trial]. / Minder beademingspneumonieën door orale decontaminatie met chloorhexidine; gerandomiseerde trial.

OBJECTIVE: To determine the effect of oral decontamination with either chlorhexidine (CHX, 2%) or the combination chlorhexidine-colistin (CHX-COL, 2%-2%) on the frequency and the time to onset of ventilator-associated pneumonia in Intensive Care patients. DESIGN: Double blind, placebo-controlled, multicentre, randomised trial. METHODS: Consecutive ICU patients needing at least 48 h of mechanical ventilation were enrolled in a randomized trial with 3 arms: CHX, CHX-COL, and placebo (PLAC). The trial medication was administered in the oral cavity every 6 h. Oropharyngeal swabs were obtained daily and analysed quantitatively for Gram-positive and Gram-negative microorganisms. Endotracheal colonisation was monitored twice weekly. Ventilator-associated pneumonia was diagnosed on the basis of a combination of clinical, radiological and microbiological criteria. RESULTS: Of 385 patients included, 130 received PLAC, 127 CHX and 128 CHX-COL. Baseline characteristics in the three groups were comparable. The daily risk of ventilator-associated pneumonia was reduced in both treatment groups compared to PLAC: 65% (HR= 0.352; 95% CI: 0.160-0.791; p = 0.012) for CHX and 55% (HR= 0.454; 95%/ CI: 0.224-0.925; p = 0.030) for CHX-COL. CHX-COL provided a significant reduction in oropharyngeal colonisation with both Gram-negative and Gram-positive microorganisms, whereas CHX significantly affected only colonisation with Gram-positive microorganisms. There were no differences in the duration of mechanical ventilation, ICU-stay or ICU-survival. CONCLUSION: Oral decontamination of the oropharyngeal cavity with chlorhexidine or the combination chlorhexidine-colistin reduced the incidence and the time to onset ofventilator-associated pneumonia.

Multi-slice computed tomographic angiography for stenosis detection in forearm hemodialysis arteriovenous fistulas.

PURPOSE: A method of diagnosing the extent and severity of arteriovenous fistula (AVF) stenoses is multislice computed tomographic angiography (MS-CTA). The aim of this prospective study was to assess the accuracy of MS-CTA for the detection and grading of stenoses in AVF in comparison to digital subtraction angiography (DSA), which was used as the gold standard of reference. METHODS: Fifteen hemodialysis (HD) patients with dysfunctioning forearm AVF were included. These AVFs were evaluated by both DSA and MS-CTA and were read in a prospective, blinded manner by two radiologists experienced in vascular imaging. RESULTS: ROC analysis revealed areas under the curve of 0.90+/-0.07 for observer I and 0.87+/-0.08 for observer II at a stenosis cut-off level of >or=50% diameter reduction. The combined results for MS-CTA showed sensitivity, specificity and positive and negative predictive values of 82%, 98%, 82% and 98% for stenoses>or=50% and 71%, 99%, 77% and 98% for stenoses>or=75%. Inter-observer agreement for the detection of stenoses>or=50% diameter reduction was 0.70 and 1.0, for MS-CTA and DSA, respectively. CONCLUSION: MS-CTA can provide good visualization of forearm HD access AVF and has moderate sensitivity, but high specificity for the detection of flow-limiting stenoses.