Knowledge Retention over a Two Year Period Following Completion of an Online Course on The Science of Energy Balance

Objective: To evaluate knowledge retention among students who had taken an online Science of Energy Balance course over a one to two year follow up period. Design: This study used a validated knowledge assessment from the online course The Science of Energy Balance. The assessment was delivered using LimeSurvey. The data were analyzed using MS Excel. Setting: This study was conducted at the University of Vermont. Participants: Twenty-three students who had previously taken the online Science of Energy Balance course were recruited as study participants. Ten students who had never taken a nutrition course were recruited as control participants. Intervention(s): Participants were asked to complete an online validated knowledge assessment. Main Outcome Measure(s): Original scores act as the covariant and the newest scores are the dependent variable. All scores were calculated out of a maximum score of 25. Analysis: Two experimental group differences were analyzed using ANCOVA. T-tests were performed to analyze experimental group scores against control group scores as well as experimental group original scores against new scores. Results: There was no significant difference between experimental group new scores and the control group new scores. There was no significant difference between the new scores of 1 year and 2 year post course. The pooled experimental group had a significant decrease from old score to new score. Conclusions and Implications: Due to the small sample size and the unexpectedly high control group mean scores, we were not able to show a significant knowledge retention among students who had previously taken the online Science of Energy Balance

Study of inter- and intra-individual variations in the salivary microbiota

<p>Abstract</p> <p>Background</p> <p>Oral bacterial communities contain species that promote health and others that have been implicated in oral and/or systemic diseases. Culture-independent approaches provide the best means to assess the diversity of oral bacteria because most of them remain uncultivable.</p> <p>Results</p> <p>The salivary microbiota from five adults was analyzed at three time-points by means of the 454 pyrosequencing technology. The V1-V3 region of the bacterial 16S rRNA genes was amplified by PCR using saliva lysates and broad-range primers. The bar-coded PCR products were pooled and sequenced unidirectionally to cover the V3 hypervariable region. Of 50,708 obtained sequences, 31,860 passed the quality control. Non-bacterial sequences (2.2%) were removed leaving 31,170 reads. Samples were dominated by seven major phyla: members of Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes and candidate division TM7 were identified in all samples; Fusobacteria and Spirochaetes were identified in all individuals, but not at all time-points. The dataset was represented by 3,011 distinct sequences (100%-ID phylotypes) of ~215 nucleotides and 583 phylotypes defined at ≥97% identity (97%-ID phylotypes). We compared saliva samples from different individuals in terms of the phylogeny of their microbial communities. Based on the presence and absence of phylotypes defined at 100% or 97% identity thresholds, samples from each subject formed separate clusters. Among individual taxa, phylum Bacteroidetes and order Clostridiales (Firmicutes) were the best indicators of intraindividual similarity of the salivary flora over time. Fifteen out of 81 genera constituted 73 to 94% of the total sequences present in different samples. Of these, 8 were shared by all time points of all individuals, while 15-25 genera were present in all three time-points of different individuals. Representatives of the class Sphingobacteria, order Sphingobacteriales and family Clostridiaceae were found only in one subject.</p> <p>Conclusions</p> <p>The salivary microbial community appeared to be stable over at least 5 days, allowing for subject-specific grouping using UniFrac. Inclusion of all available samples from more distant time points (up to 29 days) confirmed this observation. Samples taken at closer time intervals were not necessarily more similar than samples obtained across longer sampling times. These results point to the persistence of subject-specific taxa whose frequency fluctuates between the time points. Genus <it>Gemella</it>, identified in all time-points of all individuals, was not defined as a core-microbiome genus in previous studies of salivary bacterial communities. Human oral microbiome studies are still in their infancy and larger-scale projects are required to better define individual and universal oral microbiome core.</p

Immuno-detection of Staphylococcus aureus biofilm on a cochlear implant

Abstract : Case presentation: : A 46-year-old man suffering from progressive deafness since childhood received a Clarion 90 K cochlear implant with the HiRes® preformed electrode in his left ear in October 2006. A persistent Staphylococcus aureus infection failed to be treated with corticoids, amoxicillin/ clavulanate, ciprofloxaxin, and rifampin. The processor was removed on July 2007. Interventions: : The removed cochlear implant processor was treated with different reagents, with the aim of detecting a S. aureus and S. aureus biofilm: (1) fluorescein-coupled Fc of anti-human serum, (2) polyclonal anti-polysaccharide intercellular adhesion antibodies coupled to Alexa Fluor 568 goat anti-rabbit immunoglobulin (Ig)G, (3) crystal violet, (4) methylene blue, (5) acridine orange, (6) Gram stain, and (7) live/dead fluorescent stain. Results: : S. aureus and the major constituent of the S. aureus biofilm, the polysaccharide intercellular adhesion, were detected on the surface of the implant. S. aureus was isolated after a simple contact between the implant and a solid growth medium. The ability of the isolated S. aureus strain to produce biofilm in vitro was confirmed. Interpretation: : S. aureus biofilm was documented on the implant. Initial bacterial colonization could be related to the pocket of the removable magnet. Colonies of S. aureus without biofilm were found attached to the electrode wire. Conclusion: : We report one case of a S. aureus biofilm infection documented on a cochlear implant, as assessed by immuno-microscopy. The biofilm was likely responsible for the persistent infection which manifested for many months after the implant surgery and could explain the unusual bacterial phenotypic resistance against administered antimicrobial agent

Génomique et métagénomique bactériennes: applications cliniques et importance médicale [Bacterial genomics and metagenomics: clinical applications and medical relevance]

New sequencing technologies provide in a short time and at low cost high amount of genomic sequences useful for applications such as: a) development of diagnostic PCRs and/or serological tests; b) detection of virulence factors (virulome) or genes/SNPs associated with resistance to antibiotics (resistome) and c) investigation of transmission and dissemination of bacterial pathogens. Thus, bacterial genomics of medical importance is useful to clinical microbiologists, to infectious diseases specialists as well as to epidemiologists. Determining the microbial composition of a sample by metagenomics is another application of new sequencing technologies, useful to understand the impact of bacteria on various non-infectious diseases such as obesity, asthma, or diabetes. Genomics and metagenomics will likely become a specialized diagnostic analysis

Retrospective data analysis for definition of multidrug resistance in gram-negative bacteria - a consensus proposal.

AIM OF THE STUDY The main objective of this study was to propose a common definition of multidrug-resistant gram-negative organisms (GN-MDRO), which may be used for epidemiological surveillance and benchmarking. METHODS In this retrospective data analysis, we used interpreted qualitative susceptibility data (SIR) from blood culture isolates of different gram-negative microorganisms from the ANRESIS database from 2017-2021. We first analysed testing algorithms used by different Swiss laboratories and investigated cross-resistance patterns within antibiotic groups. Comparing these data with existing international definitions, we developed two different GN-MDRO definitions, an extended one for surveillance purposes (ANRESIS-extended) and a more stringent one for clinical purposes, aimed primarily at the identification of difficult-to-treat GN-MDRO (ANRESIS-restricted). Using these novel algorithms, the rates of invasive GN-MDRO identified in our national dataset were compared with international and national definitions: the European Centre for Disease Prevention and Control (ECDC) definition, the Commission for Hospital Hygiene and Infection (KRINKO) definition and the definition proposed by the University Hospital Zurich. RESULTS SIR data of a total of 41,785 Enterobacterales, 2,919 , and 419 spp. isolates were used for the analyses. Five antibiotic categories were used for our MDRO definition: aminoglycosides, piperacillin-tazobactam, third- and fourth-generation cephalosporins, carbapenems and fluoroquinolones. Large differences were found between the testing algorithms of the different laboratories. Cross-resistance analysis within an antibiotic group revealed that the substance most likely to be effective against a particular gram-negative bacterium was not preferentially tested (e.g. amikacin for the aminoglycosides). For all bacterial species tested, the highest rates of multidrug-resistant isolates were found using the ECDC-MDR definition, followed by the ANRESIS-extended definition. The number of MDR-Enterobacterales identified using the ANRESIS-restricted definition (n = 627) was comparable to those identified using the KRINKO (n = 622) and UHZ definitions (n = 437). However, the isolates classified as MDR-Enterobacterales according to the KRINKO, UHZ and ANRESIS-restricted definitions (total n = 870) differed considerably. Only 242 of the isolates (27.8%) were uniformly classified as MDRO according to the KRINKO, UHZ and ANRESIS-restricted definitions. Comparable findings were made for Klebsiella spp. and Pseudomonas aeruginosa. CONCLUSIONS The application of different MDRO definitions leads to significant differences in not only MDRO rates but also the isolates that are eventually classified as MDRO. Therefore, defining a nationwide MDRO algorithm is crucial if data are compared between hospitals. The definition of a minimal antibiotic susceptibility testing panel would improve comparability further

Detection of Pneumocystis jirovecii by Two Staining Methods and Two Quantitative PCR Assays

Abstract : Background: : Pneumocystis jirovecii is an opportunistic pathogen that causes pneumonia, particularly in immunodeficient hosts. Materials and Methods: : We retrospectively compared the results obtained by two staining methods (toluidine blue and calcofluor white) and two quantitative (q) real time PCR assays for the detection of P. jirovecii in bronchoalveolar lavage (BAL) specimens. For the qPCR assays, we used newly selected probes and primers targeting the Kex-1 gene, which codes for a serine endoprotease, and compared the results to those from the published assay targeting the β-tubulin gene. Results: : A total of 1,843 BAL specimens were analyzed microscopically in parallel, and 74 (4.0%) were found to be positive with both stains, 23 (1.2%) were positive only with the toluidine blue stain, and six (0.3%) only with the calcofluor stain (p = 0.003). Of these, a selection of 186 consecutive BAL fluid samples were tested by qPCR using the respective different primer pairs. 21 of the 186 samples (11.3%) were microscopically positive with both stains as well as qPCR positive after 18-31 cycles (corresponding to 5.24 × 106 copies/ml to 640 copies/ml of native BAL) using the Kex-1 primer pair and between 21-33 cycles using the β-tubulin assay. A good correlation between semi-quantitative microscopy and the number of PCR cycles needed for a positive signal was noted. Of the remaining 165 samples, 153 (82%) were both microscopically and PCR negative (PCR with the two sets of primers); the remaining 12 samples (7%) were Kex-1-based PCR positive (from cycles 33 to 41, corresponding to 160 copies/ml of BAL or less) but microscopically negative. Of these latter samples, ten (6%) were also positive (from cycles 34 to 38) with the primers targeting the β-tubulin gene. Taking microscopy as a reference, the sensitivity of qPCR targeting the Kex-1 gene was 100%, and the specificity was 92.4%. Conclusion: : The sensitive qPCR analysis proved to be a rapid and reliable method to detect P. jirovecii in BA

Trends in the treatment of orthopaedic prosthetic infections

The most commonly used therapy for prosthetic joint infection is a two-stage prosthetic exchange separated by 6 weeks of intravenous antibiotic therapy. This often results in long periods of hospitalization, morbidity, severe functional impairment and sometimes increased mortality. Therefore novel and challenging therapeutic approaches have been attempted, particularly in hip prosthetic infection. This includes, whenever possible, according to the type of microorganism, antibacterial susceptibility and clinical presentation (including age and comorbidities): (i) less aggressive surgical techniques (debridement and prosthesis retention, or re-implantation with a single-stage exchange arthroplasty); and (ii) antibiotic combinations active against biofilm-associated bacteria, including rifampicin (particularly with quinolones) with excellent bio-availability which allow prolonged and efficient oral therap

Temporal effects of antibiotic use and hand rub consumption on the incidence of MRSA and Clostridium difficile

Objectives The aim of this study was to determine the temporal relation between the use of antibiotics and alcohol-based hand rubs (ABHRs) and the incidence of methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile. Methods An interventional time-series analysis was performed to evaluate the impact of two promotion campaigns on the consumption of ABHRs and to assess their effect on the incidence of non-duplicate clinical isolates of MRSA and C. difficile from February 2000 through September 2006. This analysis was combined with a transfer function model of aggregated data on antibiotic use. Results Consumption of ABHRs correlated with MRSA, but not with C. difficile. The final model demonstrated the immediate effect of the second hand hygiene promotion campaign and an additional temporal effect of fluoroquinolone (time lag, 1 month; i.e. antibiotic effect delayed for 1 month), macrolide (lag 1 and 4 months), broad-spectrum cephalosporins (lag 3, 4 and 5 months) and piperacillin/tazobactam (lag 3 months) use. The final model explained 57% of the MRSA variance over time. In contrast, the model for C. difficile showed only an effect for broad-spectrum cephalosporins (lag 1 month). Conclusions We observed an aggregate-level relation between the monthly MRSA incidence and the use of different antibiotic classes and increased consumption of ABHR after a successful hand hygiene campaign, while no association with ABHR use was detected for C. difficil