Multiplex real-time PCR assays for the prediction of cephalosporin, ciprofloxacin and azithromycin antimicrobial susceptibility of positive Neisseria gonorrhoeae nucleic acid amplification test samples.

BACKGROUND: The incidence of antimicrobial-resistant Neisseria gonorrhoeae (GC) is rising in Canada; however, antimicrobial resistance (AMR) surveillance data are unavailable for infections diagnosed directly from clinical specimens by nucleic acid amplification tests (NAATs), representing over 80% of diagnoses. We developed a set of 10 improved molecular assays for surveillance of GC-AMR and prediction of susceptibilities in NAAT specimens. METHODS: Multiplex real-time PCR (RT-PCR) assays were developed to detect SNPs associated with cephalosporin (ponA, porB, mtrR -35delA, penA A311V, penA A501, N513Y, G545S), ciprofloxacin (gyrA S91, parC D86/S87/S88) and azithromycin [23S (A2059G, C2611T), mtrR meningitidis-like promoter] resistance. The assays were validated on 127 gonococcal isolates, 51 non-gonococcal isolates and 50 NAATs with matched culture isolates. SNPs determined from the assay were compared with SNPs determined from in silico analysis of WGS data. MICs were determined for culture isolates using the agar dilution method. RESULTS: SNP analysis of the 50 NAAT specimens had 96% agreement with the matched culture RT-PCR analysis. When compared with MICs, presence of penA A311V or penA A501 and two or more other SNPs correlated with decreased susceptibility and presence of three or more other SNPs correlated with intermediate susceptibility to cephalosporins; presence of any associated SNP correlated with ciprofloxacin or azithromycin resistance. NAAT-AMR predictions correlated with matched-culture cephalosporin, ciprofloxacin and azithromycin MICs at 94%, 100% and 98%, respectively. CONCLUSIONS: We expanded molecular tests for N. gonorrhoeae AMR prediction by adding new loci and multiplexing reactions to improve surveillance where culture isolates are unavailable.

Forecasting Trends in Invasive Pneumococcal Disease among Elderly Adults in Quebec.

Background. In Canada, the current recommendation is to offer PPV23 to adults ≥ 65 years. PCV13 is now licensed for adults. Methods. Invasive pneumococcal disease (IPD) cases in adults 65-74 years of age in the Quebec notifiable diseases registry were classified into five serotype categories. Poisson regression models were fitted to monthly rates observed in 2000-2014 and predictions were made for 2015-2024, using theoretical assumptions regarding indirect effects of childhood vaccination and serotype replacement. Results. IPD rates caused by PCV7 serotypes decreased markedly since PCV7 introduction for children in December 2004. This trend is also underway for additional PCV13 serotypes except serotype 3. Additional PPV23 serotypes and nonvaccine serotypes have been on rise since 2004 and this is expected to continue. A small decrease in overall IPD incidence in the next decade is predicted. The proportion of PCV13 serotypes represented 33% of IPD cases in 2014 and would be 20% (95% CI: 15% to 28%) in 2024. PPV23 coverage was 53% in 2014 and is expected to be 47% (95% CI: 26% to 85%) in 2024. Conclusion. The potential usefulness of a combined PCV13 + PPV23 program for elderly adults would decrease over time but PCV13 would be the only option to prevent serotype 3 IPD.

Decline in Decreased Cephalosporin Susceptibility and Increase in Azithromycin Resistance in Neisseria gonorrhoeae, Canada.

Antimicrobial resistance profiles were determined for Neisseria gonorrhoeae strains isolated in Canada during 2010-2014. The proportion of isolates with decreased susceptibility to cephalosporins declined significantly between 2011 and 2014, whereas azithromycin resistance increased significantly during that period. Continued surveillance of antimicrobial drug susceptibilities is imperative to inform treatment guidelines.

Molecular Assay for Detection of Ciprofloxacin Resistance in Neisseria gonorrhoeae Isolates from Cultures and Clinical Nucleic Acid Amplification Test Specimens.

We developed a real-time PCR assay to detect single nucleotide polymorphisms associated with ciprofloxacin resistance in specimens submitted for nucleic acid amplification testing (NAAT). All three single nucleotide polymorphism (SNP) targets produced high sensitivity and specificity values. The presence of ≥2 SNPs was sufficient to predict ciprofloxacin resistance in an organism.

Molecular Assay for Detection of Genetic Markers Associated with Decreased Susceptibility to Cephalosporins in Neisseria gonorrhoeae.

The incidence of antimicrobial-resistant Neisseria gonorrhoeae continues to rise in Canada; however, antimicrobial resistance data are lacking for approximately 70% of gonorrhea infections that are diagnosed directly from clinical specimens by nucleic acid amplification tests (NAATs). We developed a molecular assay for surveillance use to detect mutations in genes associated with decreased susceptibility to cephalosporins that can be applied to both culture isolates and clinical samples. Real-time PCR assays were developed to detect single nucleotide polymorphisms (SNPs) in ponA, mtrR, penA, porB, and one N. gonorrhoeae-specific marker (porA). We tested the real-time PCR assay with 252 gonococcal isolates, 50 nongonococcal isolates, 24 N. gonorrhoeae-negative NAAT specimens, and 34 N. gonorrhoeae-positive NAAT specimens. Twenty-four of the N. gonorrhoeae-positive NAAT specimens had matched culture isolates. Assay results were confirmed by comparison with whole-genome sequencing data. For 252 N. gonorrhoeae strains, the agreement between the DNA sequence and real-time PCR was 100% for porA, ponA, and penA, 99.6% for mtrR, and 95.2% for porB. The presence of ≥2 SNPs correlated with decreased susceptibility to ceftriaxone (sensitivities of >98%) and cefixime (sensitivities of >96%). Of 24 NAAT specimens with matched cultures, the agreement between the DNA sequence and real-time PCR was 100% for porB, 95.8% for ponA and mtrR, and 91.7% for penA. We demonstrated the utility of a real-time PCR assay for sensitive detection of known markers for the decreased susceptibility to cephalosporins in N. gonorrhoeae. Preliminary results with clinical NAAT specimens were also promising, as they correlated well with bacterial culture results.

Serratia marcescens harbouring SME-type class A carbapenemases in Canada and the presence of blaSME on a novel genomic island, SmarGI1-1.

OBJECTIVES: An increasing prevalence since 2010 of Serratia marcescens harbouring the Ambler class A carbapenemase SME prompted us to further characterize these isolates. METHODS: Isolates harbouring bla(SME) were identified by PCR and sequencing. Phenotypic analysis for carbapenemase activity was carried out by a modified Hodge test and a modified Carba NP test. Antimicrobial susceptibilities were determined by Etest and Vitek 2. Typing was by PFGE of macrorestriction digests. Whole-genome sequencing of three isolates was carried out to characterize the genomic region harbouring the bla(SME)-type genes. RESULTS: All S. marcescens harbouring SME-type enzymes could be detected using a modified Carba NP test. Isolates harbouring bla(SME) were resistant to penicillins and carbapenems, but remained susceptible to third-generation cephalosporins, as well as fluoroquinolones and trimethoprim/sulfamethoxazole. Isolates exhibited diverse genetic backgrounds, though 57% of isolates were found in three clusters. Analysis of whole-genome sequence data from three isolates revealed that the bla(SME) gene occurred in a novel cryptic prophage genomic island, SmarGI1-1. CONCLUSIONS: There has been an increasing occurrence of S. marcescens harbouring bla(SME) in Canada since 2010. The bla(SME) gene was found on a genomic island, SmarGI1-1, that can be excised and circularized, which probably contributes to its dissemination amongst S. marcescens.

Complete sequences of a novel blaNDM-1-harbouring plasmid from Providencia rettgeri and an FII-type plasmid from Klebsiella pneumoniae identified in Canada.

OBJECTIVES: Emergence of plasmids harbouring bla(NDM-1) is a major public health concern due to their association with multidrug resistance and their potential mobility. METHODS: PCR was used to detect bla(NDM-1) from clinical isolates of Providencia rettgeri (PR) and Klebsiella pneumoniae (KP). Antimicrobial susceptibilities were determined using Vitek 2. The complete DNA sequence of two bla(NDM-1) plasmids (pPrY2001 and pKp11-42) was obtained using a 454-Genome Sequencer FLX. Contig assembly and gap closures were confirmed by PCR-based sequencing. Comparative analysis was done using BLASTn and BLASTp algorithms. RESULTS: Both clinical isolates were resistant to all ß-lactams, carbapenems, aminoglycosides, ciprofloxacin and trimethoprim/sulfamethoxazole, and susceptible to tigecycline. Plasmid pPrY2001 (113 295 bp) was isolated from PR. It did not show significant homology to any known plasmid backbone and contained a truncated repA and novel repB. Two bla(NDM-1)-harbouring plasmids from Acinetobacter lwoffii (JQ001791 and JQ060896) shared 100% similarity to a 15 kb region that contained bla(NDM-1). pPrY2001 also contained a type II toxin/antitoxin system. pKp11-42 (146 695 bp) was isolated from KP. It contained multiple repA genes. The plasmid backbone had the highest homology to the IncFIIk plasmid type (51% coverage, 100% nucleotide identity). The bla(NDM-1) region was unique in that it was flanked upstream by IS3000 and downstream by a novel transposon designated Tn6229. pKp11-42 also contained a number of mutagenesis and plasmid stability proteins. CONCLUSIONS: pPrY2001 differed from all known plasmids due to its novel backbone and repB. pKp11-42 was similar to IncFIIk plasmids and contained a number of genes that aid in plasmid persistence.

Differential susceptibility of invasive Haemophilus influenzae serotype a and serotype b to ampicillin and other commonly prescribed antibiotics.

UNLABELLED: Haemophilus influenzae serotype a (Hia) has become an important pathogen in the post-H. influenzae serotype b (Hib) vaccine era. Antibiotic resistance in H. influenzae is a global phenomenon, but few studies have looked at antibiotic resistance profiles with regard to serotype. Invasive Hia (n = 157), noninvasive Hia (n = 2) and invasive Hib (n = 42) collected over the last two decades from three Canadian Provinces were examined for resistance to several commonly prescribed antibiotics, and sequence types (STs) were determined by MLST. Only 1·9% of Hia showed antibiotic resistance, while 31% of Hib were resistant to one or more antibiotic. Resistance to ampicillin, sulfamethoxazole-trimethoprim, chloramphenicol and tetracycline was observed, with ß-lactamase-mediated ampicillin resistance being the most common. Nine STs were identified for Hia with 7 STs belonging to the same clonal complex. Ten STs were observed in Hib strains, and all of them belonged to a single clonal complex. A possible correlation between sequence type and ampicillin resistance was observed for Hib, while no correlations were observed for Hia. SIGNIFICANCE AND IMPACT OF THE STUDY: Despite H. influenzae serotype b (Hib) vaccine programs, invasive disease due to Hib still exists in Canada and is either second or third most common behind nontypeable and/or serotype a (Hia). Many previous studies on antibiotic resistance have focussed on respiratory isolates, and few have looked at resistance with regard to serotype. This study analysed antibiotic resistance in invasive Hia and Hib collected over 20 years from three provinces, and results found that significantly more Hib showed resistance compared to Hia. This provides a small snapshot of H. influenzae disease in Canada and highlights the importance to continually monitor antibiotic resistance profiles.

Adaptive changes of human islets to an obesogenic environment in the mouse.

AIMS/HYPOTHESIS: In this study, we used an immunodeficient mouse model to explore, in vivo, the longitudinal adaptation of human islets to an obesogenic environment. METHODS: Non-diabetic Rag2 (-/-) mice (n = 61) were transplanted with human islets (400 islet equivalents [IEQ]) from six pancreases: four non-diabetic and two with overt metabolic dysfunction (older, high HbA(lc) or history of diabetes). Animals were fed for 12 weeks with a control or high-fat diet (HFD), and followed for weight, serum triacylglycerol, fasting blood glucose and human C-peptide. After the mice were killed, human grafts and the endogenous pancreas were analysed for endocrine volume, distribution of beta and alpha cells, and proliferation. RESULTS: Transplanted mice on an HFD gained significantly more weight (p < 0.001) and had higher fasting glycaemia (2-12 weeks; p = 0.0002) and consistently higher fasting human C-peptide levels (2-12 weeks; p = 0.04) compared with those on the control diet. Histology demonstrated doubling of human islet graft volume at 12 weeks in animals on the HFD and increased beta cell volume (p < 0.001), but no change in alpha cell volume. Human islet function (hyperbolic product HOMA2%BS) at 12 weeks was four times lower in HFD animals (p < 0.001 vs controls) because of insufficient beta cell adaptation to decreased (70%) sensitivity (HOMA%S). Human islets obtained from donors with metabolic dysfunction failed to adapt to the HFD. CONCLUSIONS/INTERPRETATION: This longitudinal study provides direct evidence that human islets adapt both endocrine and beta cell mass, function and gene expression to obesity in vivo. The present model will facilitate the identification of mechanisms by which human islets adapt to obesity in vivo and the cell type(s) responsible, and factors predisposing human beta cells to decompensation.

Sporadic Legionnaires' disease: the role of domestic electric hot-water tanks.

Sporadic community-acquired legionellosis (SCAL) can be acquired through contaminated aerosols from residential potable water. Electricity-dependent hot-water tanks are widely used in the province of Quebec (Canada) and have been shown to be frequently contaminated with Legionella spp. We prospectively investigated the homes of culture-proven SCAL patients from Quebec in order to establish the proportion of patients whose domestic potable hot-water system was contaminated with the same Legionella isolate that caused their pneumonia. Water samples were collected in each patient's home. Environmental and clinical isolates were compared using pulsed-field gel electrophoresis. Thirty-six patients were enrolled into the study. Legionella was recovered in 12/36 (33%) homes. The residential and clinical isolates were found to be microbiologically related in 5/36 (14%) patients. Contaminated electricity-heated domestic hot-water systems contribute to the acquisition of SCAL. The proportion is similar to previous reports, but may be underestimated.

Coadministration of coenzyme Q prevents rosiglitazone-induced adipogenesis in ob/ob mice.

OBJECTIVE: The aim of this study is to determine the effect of coenzyme Q (Q) on ob/ob mice treated or not with thiazolidinedione (TZD). DESIGN AND MEASUREMENTS: Ob/ob mice were treated with Q, Rosiglitazone or a combination of both molecules for 13 days; physical and metabolic parameters as well as oral glucose tolerance test were assessed. mRNA expression of genes of energy dissipation and storage were measured by real-time PCR. RESULTS: Q treatment improved some metabolic parameters in ob/ob mice. Surprisingly, cotreatment with Rosiglitazone and Q improved metabolic parameters and prevented TZD increase in body weight and adiposity, mainly by increasing lipid oxidation in adipose tissue, reducing lipid synthesis and balancing adipokine gene expression. CONCLUSIONS: Our finding suggests that Rosiglitazone and coenzyme Q bitherapy could prevent the body weight gain associated with adipogenesis and could improve the clinical use of these compounds.

Validity of the polymyalgia rheumatica activity score in primary care practice.

OBJECTIVE: To evaluate the validity and reliability of the polymyalgia rheumatica (PMR) activity score (PMR-AS) for relapse diagnosis by general practitioners (GPs) who manage a large proportion of patients with PMR. METHODS: Seven clinical vignettes of PMR were used, for which 35 rheumatologists previously made a diagnosis of relapse or no relapse with greater than 80% agreement. These vignettes were submitted to 163 GPs, who were asked to assess disease activity using a visual analogue scale (VASph), this being the only physician-dependent component of the PMR-AS. The 1116 available vignette-GP combinations were used to assess differences in VASph assessed by GPs versus rheumatologists. Statistical associations linking a relapse diagnosis by the rheumatologists (the reference standard) to the value of the GP-assessed PMR-AS or its components (GP-assessed VASph, visual analogue scale pain score, C-reactive protein, morning stiffness and elevation of upper limbs) were evaluated. RESULTS: No significant differences were found between VASph scores by GPs versus rheumatologists for any of the vignettes. A relapse diagnosis was strongly associated with PMR-AS values of 7 or more (sensitivity 99.4%; specificity 93.3%; agreement 95.9% (95% CI 94.5% to 97.0%) with kappa = 0.92). Of the 590 GP-vignette combinations with PMR-AS values lower than 7, all but three (0.5%) had no relapse diagnosis. Of 510 combinations with PMR-AS values of 7 or more, only 42 (8%) had no flare diagnosis. CONCLUSIONS: This study supports the validity of the PMR-AS in primary care practice and provides evidence that a good scoring system can be useful to guide clinical and therapeutic decisions.

Genotype comparison of sorbitol-negative Escherichia coli isolates from healthy broiler chickens from different commercial farms.

Hybridization on arrays was used to assess the presence of virulence-associated genes and to determine the relatedness of 32 non-O157 sorbitol-negative Escherichia coli isolates from healthy broiler chickens. These isolates were from commercial farms that used feed supplemented with different antimicrobial agents (virginiamycin, bacitracin, salinomycin, narasin, nicarbazin, or diclazuril). For each isolate, fluorescent probes were made from genomic DNA and were hybridized on DNA arrays composed of genes associated with general functions, virulence, iron uptake systems, and DNA repair genes (e.g., mut genes). Hybridization on arrays results showed that isolates from the same farm tended to be clustered but actually represented 18 genetically distinct groups of isolates. Results revealed that some isolates showed similarity to human uropathogenic E. coli or avian pathogenic E. coli. Four avian pathogenic E. coli-like isolates were detected. Another isolate possessed the intimin gene (eaeA) and typical genes of the type 3 secretion system associated with enteropathogenic E. coli and enterohemorrhagic E. coli strains. Genes from a second system (secondary type 3 secretion system) homologous to that found in Salmonella Typhimurium were detected in many isolates. Several of the studied isolates also possessed the aerobactin, salmochelin, and yersiniabactin genes involved in iron acquisition in pathogenic bacteria. Our results clearly suggest that commensal E. coli isolates from chickens are reservoirs of virulence-associated genes and may represent colibacillosis and zoonotic risks.

Impact of a mass vaccination campaign against Serogroup B meningococcal disease in the Saguenay-Lac-Saint-Jean region of Quebec four years after its launch.

In the Saguenay-Lac-Saint-Jean region of Quebec, 83% of the population ≤20 years (n ≅ 59,500) was immunized in 2014 with the four-component Serogroup B meningococcal vaccine to control a long-lasting outbreak caused by a virulent ST-269 Serogroup B Neisseria meningitidis clone. Following the campaign, invasive meningococcal B disease (B-IMD) incidence fell sharply in the target population from 11.4/100,000 in 2006-2014 to 0.4/100,000 in 2014-2018 (p < 0.0001). Five B-IMD cases occurred in the region from July 2014 to June 2018, including one vaccinated child, one unvaccinated young adult and 3 unvaccinated elderly adults. Estimate of direct vaccine protection was 79% [95%CI:-231%;99%]. The overall campaign impact in the region taking into account the decrease in B-IMD incidence at provincial level was a 86% [95%CI:-2%;98%] decrease in B-IMD risk. The campaign impact was mostly seen in the target age-group suggesting no herd effect among unvaccinated older adults.

Increase in ST-11 serogroup W Neisseria meningitidis invasive meningococcal disease in Canada, 2016-2018.

BACKGROUND: Many countries have experienced increases in invasive meningococcal disease (IMD) due to a serogroup W Neisseria meningitidis (MenW) strain of the multilocus sequence type (ST)-11 clonal complex (CC). MenW ST-11 was first reported in Ontario, Canada, in 2014. By 2016, this strain caused IMD in five provinces and was responsible for 18.8% of the IMD cases in Canada. OBJECTIVE: To provide an update on invasive MenW disease in Canada including the strain characteristics, specimen source of isolates, age, sex and geographic distribution of cases. METHODS: N. meningitidis from culture-positive IMD cases are routinely submitted to the National Microbiology Laboratory (NML) for serogroup, serotype, serosubtype and sequence type analysis. The data from January 1, 2016 to December 31, 2018 were analyzed by calculating the proportion of IMD cases caused by MenW compared with other serogroups. In addition, trends based on age, sex and geographic distribution of cases and specimen source of isolates were analyzed based on information on specimen requisition forms. RESULTS: Over the 3-year period, 292 individual IMD case isolates were analyzed. The percentage of IMD case isolates typed as MenW more than doubled from 19% (n=15) to 44% (n=51) in 2018 when MenW became the most common serogroup, exceeded the number of MenB, MenC or MenY. In total, 93 MenW case isolates were identified, 91% (n=85) belonged to the ST-11 CC. The increase in MenW affected all age groups (but was most common in those older than 60) and both sexes, and occurred across the country but most prevalent in western Canada. The most common specimen source was blood. CONCLUSION: In 2018, MenW was the most common serogroup for isolates received by the NML from culture-positive IMD cases in Canada. Over 90% of the MenW serogroup isolates belonged to the ST-11 CC. The quadrivalent ACWY meningococcal conjugate vaccine protects against IMD caused by strains in the A, C, W or Y serogroups and therefore may protect against IMD caused by the new MenW ST-11 strain; however, more research is needed. The emergence of variant strains highlight the importance of strain characterization in IMD surveillance and research.

Multidrug-resistant and extensively drug-resistant Neisseria gonorrhoeae in Canada, 2012-2016.

BACKGROUND: Neisseria gonorrhoeae have acquired resistance to many antimicrobials, including third generation cephalosporins and azithromycin, which are the current gonococcal combination therapy recommended by the Canadian Guidelines on Sexually Transmitted Infections. OBJECTIVE: To describe antimicrobial susceptibilities for N. gonorrhoeae circulating in Canada between 2012 and 2016. METHODS: Antimicrobial resistance profiles were determined using agar dilution of N. gonorrhoeae isolated in Canada 2012-2016 (n=10,167) following Clinical Laboratory Standards Institute guidelines. Data were analyzed by applying multidrug-resistant gonococci (MDR-GC) and extensively drug-resistant gonococci (XDR-GC) definitions. RESULTS: Between 2012 and 2016, the proportion of MDR-GC increased from 6.2% to 8.9% and a total of 19 cases of XDR-GC were identified in Canada (0.1%, 19/18,768). The proportion of isolates with decreased susceptibility to cephalosporins declined between 2012 and 2016 from 5.9% to 2.0% while azithromycin resistance increased from 0.8% to 7.2% in the same period. CONCLUSION: While XDR-GC are currently rare in Canada, MDR-GC have increased over the last five years. Azithromycin resistance in N. gonorrhoeae is established and spreading in Canada, exceeding the 5% level at which the World Health Organization states an antimicrobial should be reviewed as an appropriate treatment. Continued surveillance of antimicrobial susceptibilities of N. gonorrhoeae is necessary to inform treatment guidelines and mitigate the impact of resistant gonorrhea.

Leukotriene B4: early mediator of atherosclerosis in obstructive sleep apnoea?

Severity of oxygen desaturation is predictive of early atherosclerosis in obstructive sleep apnoea (OSA). Leukotriene (LT)B(4) is a lipid mediator involved in atherogenesis. In 40 non-obese OSA patients, free of a cardiovascular history, and 20 healthy volunteers, the following were evaluated: 1) LTB(4) production by polymorphonuclear leukocytes (PMNs) stimulated with A23187; and 2) the relationships between LTB(4) production and both OSA severity and infraclinical atherosclerosis markers. The effect of continuous positive airway pressure (CPAP) on LTB(4) production was also studied. An overnight sleep study was followed by first-morning blood sampling. Isolated PMNs were stimulated with A23187 in order to induce LTB(4) production, which was measured by liquid chromatography-tandem mass spectrometry. Carotid intima-media thickness (IMT) and luminal diameter were measured in subset groups of 28 OSA patients and 11 controls. LTB(4) production was increased in OSA patients compared with controls. LTB(4) levels correlated with the mean and minimal arterial oxygen saturation (S(a,O(2))). LTB(4) production correlated with luminal diameter data in patients with a mean S(a,O(2)) of < or = 94% but not with IMT. Lastly, CPAP significantly reduced LTB(4) production by 50%. Leukotriene B(4) production is increased in obstructive sleep apnoea in relation to oxygen desaturation. Leukotriene B(4) could promote early vascular remodelling in moderate-to-severe hypoxic obstructive sleep apnoea patients.

The histone acetylase PCAF is a phorbol-ester-inducible coactivator of the IRF family that confers enhanced interferon responsiveness.

Transcription factors of the interferon regulatory factor (IRF) family bind to the type I interferon (IFN)-responsive element (ISRE) and activate transcription from IFN-inducible genes. To identify cofactors that associate with IRF proteins, DNA affinity binding assays were performed with nuclear extracts prepared from tissue culture cells. The results demonstrated that the endogenous IRFs bound to the ISRE are complexed with the histone acetylases, PCAF, GCN5, and p300/CREB binding protein and that histone acetylase activities are accumulated on the IRF-ISRE complexes. By testing recombinant proteins, we show that PCAF directly binds to some but not all members of the IRF family through distinct domains of the two proteins. This interaction was functionally significant, since transfection of PCAF strongly enhanced IRF-1- and IRF-2-dependent promoter activities. Further studies showed that expression of PCAF and other histone acetylases was markedly induced in U937 cells upon phorbol ester treatment, which led to increased recruitment of PCAF to the IRF-ISRE complexes. Coinciding with the induction of histone acetylases, phorbol ester markedly enhanced IFN-alpha-stimulated gene expression in U937 cells. Supporting the role for PCAF in conferring IFN responsiveness, transfection of PCAF into U937 cells led to a large increase in IFN-alpha-inducible promoter activity. These results demonstrate that PCAF is a phorbol ester-inducible coactivator of the IRF proteins which contributes to the establishment of type I IFN responsiveness.

[Treatment of thoracolumbar junction burst fractures (Magerl A3) by balloon kyphoplasty: anatomic study]. / Traitement des burst fractures (Magerl A3) de la charnière thoracolombaire par cyphoplastie à ballonnets: étude anatomique.

PURPOSE OF THE STUDY: Balloon kyphoplasty is a not widely used method for the treatment of vertebral burst fractures with displacement of the posterior wall. The purpose of this study was to measure the posterior height of the vertebral body and the posttraumatic canal surface area before and after balloon kyphoplasty for the treatment of burst fractures (Magerl A3). MATERIAL AND METHODS: This anatomic study was conducted on ten experimental burst fractures of the thoracolumar junction prepared on cadaver specimens. The surface area of the canal and the height of the posterior wall were measured by computed tomography before and after balloon kyphoplasty. These two variables were then compared with search for correlation. RESULTS: The posttraumatic canal surface area increased significantly after kyphoplasty (p=0.02). Gain in posterior height was not significant and there was no correlation between the two variables. Cement leakage into the canal was not observed. DISCUSSION: It is known that balloon kyphoplasty can re-establish anterior height and correct for the posttraumatic kyphosis in patients with compression fractures of osteoporotic vertebrae. The present cadaver study shows that when the posterior wall is displaced posteriorly, balloon expansion does not exaggerate the wall displacement. On the contrary, the posttraumatic canal surface area is increased due to the ligamentotaxis effect. CONCLUSION: Balloon kyphoplasty could be an alternative to posterior instrumentation for burst fractures without associated neurological deficit, even if the posterior wall is damaged. This technique can be used to reduce and stabilize the fracture while sparing the adjacent levels and limiting the risk inherent with an extensive surgical approach.

Management of a hospital outbreak of extensively drug-resistant Acinetobacter baumannii using a multimodal intervention including daily chlorhexidine baths.

BACKGROUND: Extensively drug-resistant Acinetobacter baumannii (XDR-Ab) is an increasingly important cause of healthcare-associated infection. Uncertainties remain concerning optimal control measures for healthcare-associated outbreaks. AIM: To describe the epidemiology and control of an XDR-Ab outbreak that involved multiple units of a large hospital from March 2012 to January 2014. METHODS: Case-finding included screening of rectum, groin, throat, nose, wounds, iatrogenic portals of entry, and catheterized sites. Antimicrobial susceptibility was evaluated by disc diffusion and E-test. Resistance genes were detected by polymerase chain reaction. Clonality was assessed by pulsed-field gel electrophoresis. Charts of cases were reviewed to identify risk factors for invasive infection. Control measures included isolation and cohorting of cases, hand hygiene reinforcement, environmental decontamination, and source control with daily baths using wipes pre-impregnated with chlorhexidine gluconate. FINDINGS: A single clonal strain of XDR-Ab colonized or infected 29 patients. Five patients died of XDR-Ab bacteraemia. Transmission occurred primarily on two wards. Colonization was detected at all anatomical screening sites; only 57% (16/28) of cases were rectal carriers. Advanced malignancy was a risk factor for bacteraemia (relative risk: 5.8; 95% confidence interval: 1.2-27.0). Transmission ended following implementation of the multimodal control strategy. No additional nosocomial cases occurred during the following 20 months. CONCLUSION: Our study highlights the need to screen multiple anatomic sites to diagnose carriage and identifies risk factors for XDR-Ab bacteraemia. A multimodal intervention that included daily chlorhexidine baths for cases was rapidly followed by the termination of the outbreak. Hospitals should consider similar interventions when managing future XDR-Ab outbreaks.