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Michael Allen

Publications and source records attributed to Michael Allen.

At least 19 recordsLinked to original sources
PubMed2025

The British Society for Antimicrobial Chemotherapy Resistance Surveillance Project: methods and limitations.

OBJECTIVES: The BSAC Bacteraemia and Respiratory Resistance Surveillance Programmes provided long-term surveillance of antibiotic resistance in key pathogens of bloodstream and both community- and hospital-acquired respiratory infections in the UK and Ireland. This paper details the methodologies used. Data limitations are discussed. METHODS: Sentinel laboratories across the UK and Ireland contributed up to a fixed annual quota of isolates of defined bacterial groups. For each Programme, a Central Laboratory confirmed bacterial identifications, measured MICs by the BSAC agar dilution method, investigated mechanisms of resistance and determined serotypes of Streptococcus pneumoniae. Identification methods evolved over time, e.g. with adoption of MALDI-TOF. Classification of susceptibility and resistance follows the 2022 (not contemporaneous) EUCAST guidance. RESULTS: Seventy-nine laboratories contributed 30 716 community respiratory isolates from 1999/2000 to 2018/19; 65 laboratories contributed 13 508 hospital respiratory isolates from 2008/09 to 2018/19; 81 laboratories contributed 56 064 bacteraemia isolates from 2001 to 2019. Although large and teaching hospitals were over-represented, the resistance rates for bacteraemia organisms collected in England mirror more extensive (but less standardized or detailed) national data gathered from laboratories by the UK Health Security Agency and its predecessor organizations, which provided a bespoke data extract. CONCLUSIONS: These surveillance Programmes have provided comprehensive and reliable information on antibiotic susceptibility in the UK and Ireland over two decades. Detailed results, showing resistance trends and mechanisms of antibiotic resistance, are presented in five papers in this Supplement.

Antimicrobial Stewardship↗
PubMed2025

Antimicrobial resistance among Gram-positive agents of bacteraemia in the UK and Ireland: trends from 2001 to 2019.

OBJECTIVES: The BSAC Bacteraemia Resistance Surveillance collected isolates from UK and Irish hospitals for central testing. Concurrent UKHSA surveillance collated English hospitals' own susceptibility data. Results were collated and compared. METHODS: BSAC Surveillance collected quotas of isolates per site annually from 2001 to 2019. MIC testing was by BSAC agar dilution, with resistance mechanisms identified by synergy tests, interpretive reading and PCR. The UKHSA sought hospitals' data on all bacteraemia isolates. RESULTS: Both surveillance systems recorded dramatic falls in MRSA, from c. 40% of bloodstream Staphylococcus aureus in 2001 to <10% by 2019. Both noted rises in the proportion of MRSA (especially) and MSSA resistant to fusidic acid, along with declines of ciprofloxacin and macrolide resistance amongst MRSA. Methicillin resistance also fell among coagulase-negative staphylococci, albeit only modestly; fusidic acid resistance rose. Shifts for pneumococci were complex, reflecting vaccine-contingent serotype displacements; resistance rates remained low, with high-dose penicillin almost universally active. Enterococcus faecium became more prevalent relative to Enterococcus faecalis; vancomycin resistance averaged 29% among E. faecium versus 2% in E. faecalis, without trend. Erythromycin resistance rose among groups B, C and G (but not group A) streptococci. Oxazolidinones, tigecycline, daptomycin and anti-PBP2' cephalosporins retained near-universal activity against target species, except that tigecycline has been compromised by breakpoint reductions for streptococci. CONCLUSIONS: Gram-positive pathogens were the dominant historical pathogens of bacteraemia. The trends seen here-with many near-universally active antibiotics-indicate little hazard of this situation returning. Nevertheless, few treatments exist in some settings, notably multi-resistant E. faecium endocarditis.

Humans↗
PubMed2025

Antimicrobial resistance among Gram-negative agents of bacteraemia in the UK and Ireland: trends from 2001 to 2019.

OBJECTIVES: The BSAC Bacteraemia Resistance Surveillance Programme collected isolates from UK and Irish hospitals for central testing. Concurrent UKHSA surveillance collected English hospitals' own susceptibility data. Results were reviewed and compared. METHODS: The BSAC surveillance collected fixed quotas of isolates per site annually from 2001 to 2019. MIC testing was by BSAC agar dilution. Resistance mechanisms were investigated by synergy tests, interpretive reading and PCR. The UKHSA seeks data on all bacteraemia isolates in England. RESULTS: For Escherichia coli, which now causes >30% of all bacteraemias, there were marked early (2002-06) rises in resistance to cephalosporins, fluoroquinolones and gentamicin, followed by small falls, stabilization, then from around 2015, very slow rises, with similar patterns seen for Klebsiella pneumoniae. Most cephalosporin resistance in these two species involved ESBLs, principally CTX-M types. Both species had frequent co-amoxiclav resistance. Cephalosporin resistance-mostly AmpC-mediated-declined in Enterobacter and Serratia spp., as did fluoroquinolone resistance, likely reflecting reduced use and selection pressure. Proteeae showed few changes; increasing dominance of Proteus mirabilis in the BSAC collection was not confirmed by the UKHSA dataset. Resistance in Pseudomonas aeruginosa was uncommon and showed little temporal change in either dataset. Carbapenemases remained extremely rare in all species. Newer and developmental agents covered many resistance types, but none covered all types. CONCLUSIONS: Except for early rises of cephalosporin, fluoroquinolone and gentamicin resistance in E. coli and K. pneumoniae, there was little evidence for rising resistance and some evidence of declining resistance, notably in species where it predominantly involves AmpC derepression.

Humans↗
PubMed2025

Antimicrobial resistance among agents of hospital-acquired lower respiratory tract infection in the UK and Ireland: trends from 2008/2009 to 2018/2019.

OBJECTIVES: To survey trends in antimicrobial resistance among the pathogens of hospital-acquired lower respiratory tract infection (HA-LRTI), which causes significant mortality and morbidity, particularly among ventilated patients. METHODS: The BSAC Surveillance collected quotas of major HA-LRTI pathogens from sentinel sites from 2008/09 (October to September) to 2018/19. MIC testing was by BSAC agar dilution. Resistance mechanisms were inferred from synergy tests, interpretive reading and PCR. RESULTS: Target numbers of Staphylococcus aureus, Pseudomonas aeruginosa and Enterobacterales-dominated by Escherichia coli and Klebsiella spp.-were reliably collected. Acinetobacter spp. collections were small, reflecting low incidence. Resistance rates fell or fluctuated, with no major rises. Notable declines included: (i) a fall in the proportion of MRSA among S. aureus from c. 40% to 10%; (ii) a halving, since 2012/13, in 'triple-resistance' to carbapenems, aminoglycosides and fluoroquinolones among Acinetobacter baumannii sensu stricto, from c. 24% to 9%; (iii) reductions in AmpC-associated cephalosporin resistance among Enterobacter cloacae and Serratia isolates, and (iv) falls in fluoroquinolone resistance among Enterobacterales, except Klebsiella pneumoniae. Resistance rates in P. aeruginosa remained low, though higher than in bacteraemia. Cephalosporin resistance in E. coli and K. pneumoniae was largely ESBL associated and, unlike AmpC-associated resistance in Enterobacter and Serratia spp., did not decline notably. Except for OXA-23 in A. baumannii, carbapenemases remained extremely rare. Antistaphylococcal oxazolidinones, tigecycline, ceftolozane/tazobactam, ceftazidime/avibactam and ceftobiprole retained uneroded activity. CONCLUSIONS: From 2008/09 to 2018/19, there were no major rises in resistance among the principal agents of HA-LRTI; for several important organisms/resistance combinations there were notable declines.

Humans↗
PubMed2025

Antimicrobial resistance among agents of community-associated lower respiratory tract infection in the UK and Ireland: trends from 1999/2000 to 2018/2019.

OBJECTIVES: The BSAC Respiratory Surveillance Programme examined resistance trends among Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis from patients with community-acquired lower respiratory tract infection (CA-LRTI). METHODS: Quotas of isolates were sought per collecting site from 1999/00 to 2018/19; an annual October start date captured winter infection peaks within single years. MIC testing was by BSAC agar dilution. &#x3b2;-Lactamase detection with nitrocefin and pneumococcal serotyping by classical methods or WGS. RESULTS: Resistances were uncommon, except that &#x3b2;-lactamases occurred in c. 20% of H. influenzae from 2012/13 following earlier rises, and in >90% of M. catarrhalis throughout. Only 0.11% (12/10881) of S. pneumoniae were fully resistant to penicillin; co-amoxiclav inhibited 97.8% of 13526 H. influenzae and >99.9% of 6309 M. catarrhalis isolates. Cefotaxime inhibited >99% of all isolates at breakpoint, as did relevant fluoroquinolones in the fewer years tested. Tetracycline inhibited >98% of H. influenzae and M. catarrhalis and 85% of S. pneumoniae. Significant shifts were: (i) fluctuating resistances to tetracyclines, macrolides and penicillin in pneumococci, reflecting serotype replacements; (ii) expansion, from 2012/13, in the proportion of H. influenzae with &#x3b2;-lactamase-independent amoxicillin/co-amoxiclav resistance; and (iii) increasing high-level amoxicillin resistance (MIC &#x200a;>&#x200a;64&#x2005;mg/L) among &#x3b2;-lactamase-positive H. influenzae. MIC differentials were seen for cephalosporins between &#x3b2;-lactamase-positive and &#x3b2;-lactamase-negative M. catarrhalis, greatest (512-fold) for ceftaroline. CONCLUSIONS: CA-LRTI remains eminently treatable, yet shifts are occurring in the serotypes of S. pneumoniae most associated with resistance and in the nature of amoxicillin resistance in H. influenzae. &#x3b2;-Lactamase-related cephalosporin MIC differentials for M. catarrhalis are striking but their clinical significance remains uncertain.

Humans↗
PubMed2025

Trends of serotypes and resistance among Streptococcus pneumoniae in the UK and Ireland (1999-2019).

OBJECTIVES: This study aimed to report the serotype distribution of Streptococcus pneumoniae isolates from UK and Irish patients with bacteraemia or community-associated lower respiratory tract infections (CA-LRTI). Depending upon the year, these were from 23 to 39 sentinel laboratories and were collected between 1999 and 2019, thus spanning the introduction of pneumococcal conjugate vaccines, PCV7 and PCV13. METHODS: Pneumococcal identification, susceptibility testing and serotyping were undertaken by a central laboratory. Changes in serotype distributions and among the predominant types showing antibiotic non-susceptibility were reviewed in relation to vaccine deployment. RESULTS: Following the introduction of PCV7 (2006) and PCV13 (2010), major shifts occurred in serotype prevalence for both bacteraemia and CA-LRTI. PCV7 types and most PCV13 types (but not 3 and 19A) were largely or wholly displaced. Many of the displaced types (e.g. 6B, 9V, 14, 19F and 23B) had been internationally prevalent and were associated with antibiotic resistance. Other serotypes-many included within the older pneumococcal polysaccharide vaccine, PPV23-expanded into the space, with serotype 8 becoming especially prominent in bacteraemia, though not respiratory infections. Further increasingly prevalent types included 9N, 10A, 12F and 22F. Serotype 15A, often multi-resistant, rose then fell in relative importance after deployment of PCV13. Among the currently most prevalent types, serotype 3 is rarely resistant to agents besides tetracyclines and bloodstream serotype 8 isolates mostly are fully susceptible. CONCLUSIONS: These data offer a comparison of serotypes associated with bacteraemia and respiratory disease over two decades in the UK and Ireland.

Humans↗
PubMed2025

Applications and benefits of the British Society for Antimicrobial Chemotherapy Resistance Surveillance Project-legacy and future.

The BSAC Resistance Surveillance Project ran from 1999 to 2019, amassing an unrivalled collection of almost 100&#x200a;000 bacterial isolates from bloodstream and lower respiratory tract infections in the UK and Ireland. It was initiated in response to increasing antimicrobial resistance and supplemented existing surveillance schemes, enhancing the understanding of resistance epidemiology by estimating species prevalence within collection groups together with levels of antibacterial resistance, presented in terms of MICs and percentage susceptibility for each species/antibiotic combination tested. Generated data were explored to monitor and identify factors shaping resistance trends, and to profile antibacterial resistance patterns in specific geographies, settings and patient populations. The release of data and/or bacterial isolates led to a rich repository of published peer-reviewed papers. Additionally, the promotion of the BSAC standardized susceptibility testing method resulted in greater uniformity of antimicrobial susceptibility testing in hospital microbiology laboratories. Over time, public health laboratories' surveillance systems became increasingly comprehensive, and the BSAC Project ceased in 2019. This invaluable collection is now housed in the University of Dundee, in collaboration with the University of St Andrews. We highlight the collection's unique timeliness, and how the BSAC Project contributed to key interventions for infection prevention and control, public health and antimicrobial stewardship. We demonstrate the utility and benefits of the Project outlining the collection's future applications as an important bioresource. It comprises well-defined bacterial isolates-many now sequenced-with MIC data and demographic information. This legacy is available to researchers via the Tayside Biorepository and custodian contacts.

Humans↗
PubMed2007

Viewing videotape of themselves while experiencing delirium tremens could reduce the relapse rate in alcohol-dependent patients.

AIMS: The aim of this prospective randomized controlled study was to determine whether viewing videotape of themselves while experiencing delirium tremens (DT) reduces the relapse rate in alcohol-dependent patients. Our hypothesis about the efficacy of videotapes exposure to DT is consistent with a cognitive behavior model. DESIGN: Sixty patients with DT and a minimum of 3 years of severe alcohol dependence [Diagnostic and Statistical Manual version IV (DSM-IV criteria] were included in this study. Patients were videotaped during the acute phase of DT and randomized into two groups: group A patients received individual exposure to their videotape and an explanation of the symptoms by a psychiatrist; and control group B patients, who were without videotape experience. Both groups received the same treatment during the acute and the maintenance phases, without aversive therapy or psychotherapy. The two groups did not differ significantly in number of drinks per day prior to admission, age, marital status, social environment, education, professional and financial status or family psychiatric history. SETTING: An in-patient crisis unit for patients with alcohol dependence. MEASUREMENTS: All patients were observed for 6 months during monthly visits. Outcomes included relapse, drinking days per week and number of drinks per drinking day. All patients and their families signed informed consent. FINDINGS: The patients with videotape experience had a significantly lower relapse rate after the first month (0% versus 20%), 2 months (13.33% versus 46.67%) and 3 months (26.67% versus 53.33%). Patients with videotape experience had less severe relapses and consumed fewer units of alcohol than controls. CONCLUSIONS: Videotape exposure in delirium tremens is an original therapeutic method which seems to be effective in reducing relapse risk in patients with alcohol dependence.

Adult↗
PubMed2006

Facilitating interpersonal interaction and learning online: linking theory and practice.

INTRODUCTION: An earlier study of physicians' perceptions of interactive online learning showed that these were shaped both by program design and quality and the quality and quantity of interpersonal interaction. We explore instructor roles in enhancing online learning through interpersonal interaction and the learning theories that inform these. METHODS: This was a qualitative study using focus groups and interviews. Using purposive sampling, 50 physicians were recruited based on their experience with interactive online CME and face-to-face CME. Qualitative thematic and interpretive analysis was used. RESULTS: Two facilitation roles appeared key: creating a comfortable learning environment and enhancing the educational value of electronic discussions. Comfort developed gradually, and specific interventions like facilitating introductions and sharing experiences in a friendly, informative manner were helpful. As in facilitating effective small-group learning, instructors' thoughtful use of techniques that facilitated constructive interaction based on learner's needs and practice demands contributed to the educational value of interpersonal interactions. DISCUSSION: Facilitators require enhanced skills to engage learners in meaningful interaction and to overcome the transactional distance of online learning. The use of learning theories, including behavioral, cognitive, social, humanistic, and constructivist, can strengthen the educational design and facilitation of online programs. Preparation for online facilitation should include instruction in the roles and techniques required and the theories that inform them.

Attitude of Health Personnel↗
PubMed2006

Influences of hyperbaric oxygen on blood pressure, heart rate and blood glucose levels in patients with diabetes mellitus and hypertension.

BACKGROUND: We investigated the influences of hyperbaric oxygen (HBO(2)) on systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) and blood glucose level (BGL). METHODS: Forty one patients with hypertension (HTN), diabetes mellitus (DM), HTN and DM and/or no HTN or DM underwent HBO(2) sessions (15-40 sessions for each patient). SBP, DBP, HR and BGL (for diabetics) were recorded before and after each session. RESULTS: HBO(2) caused significant elevation in SBP (11%) and DBP (12%) and a decrease in HR (18%) (p <0.001). Patients with DM and HTN showed higher elevation in SBP and DBP. HBO(2) lowered BGL by 23% (p <0.001). When basal BGL was in the range of 120-170 mg/dl, it dropped to <100 mg/dl in 31/60 treatment sessions (52%). When basal BGL was <120 mg/dl it dropped to <70 mg/dl in 8/34 sessions. There was a possibility of lowered BGL when basal BGL was <170 mg/dl and a marked reduction in BGL occurred when basal BGL was <120 mg/dl. HBO(2) caused a marked elevation in SBP and DBP when basal SBP was >140 mmHg. Critical elevation was obtained when SBP was >160 mmHg. The use of beta blockers caused significant elevation of blood pressure while reducing HR. CONCLUSIONS: HBO(2) causes elevation of blood pressure and lowering of HR and BGL, which were augmented in the presence of HTN, DM, or beta blocker. The use of beta blockers for the management of HTN should be avoided during HBO(2) therapy.

Adrenergic beta-Antagonists↗
PubMed2005

Serotonin gene polymorphisms and bipolar I disorder: focus on the serotonin transporter.

The pathogenesis of bipolar disorder may involve, at least in part, aberrations in serotonergic neurotransmission. Hence, serotonergic genes are attractive targets for association studies of bipolar disorder. We have reviewed the literature in this field. It is difficult to synthesize results as only one polymorphism per gene was typically investigated in relatively small samples. Nevertheless, suggestive associations are available for the 5HT2A receptor and the serotonin transporter genes. With the availability of extensive polymorphism data and high throughput genotyping techniques, comprehensive evaluation of these genes using adequately powered samples is warranted. We also report on our investigations of the serotonin transporter, SLC6A4 (17q11.1-q12). An insertion/deletion polymorphism (5HTTLPR) in the promoter region of this gene has been investigated intensively. However, the results have been inconsistent. We reasoned that other polymorphism/s may contribute to the associations and the inconsistencies may be due to variations in linkage disequilibrium (LD) patterns between samples. Therefore, we conducted LD analyses, as well as association and linkage using 12 polymorphisms, including 5HTTLPR. We evaluated two samples. The first sample consisted of 135 US Caucasian nuclear families having a proband with bipolar I disorder (BDI, DSM IV criteria) and available parents. For case-control analyses, the patients from these families were compared with cord blood samples from local Caucasian live births (n = 182). Our second, independent sample was recruited through the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD, 545 cases, 548 controls). No significant associations were detected at the individual polymorphism or haplotype level using the case-control or family-based analyses. Our analyses do not support association between SLC6A4 and BDI families. Further studies using sub-groups of BDI are worthwhile.

Bipolar Disorder↗
PubMed2004

Interactive on-line continuing medical education: physicians' perceptions and experiences.

INTRODUCTION: Although research in continuing medical education (CME) demonstrates positive outcomes of on-line CME programs, the effectiveness of and learners' satisfaction with interpersonal interaction in on-line CME are lower Defined as faculty-learner or learner-learner interpersonal interaction, this study explores physicians' perceptions of and experiences in interactive on-line CME and factors influencing these. METHODS: Focus groups and interviews were undertaken by three Canadian universities. Using purposive sampling, we recruited physicians based on their experiences with interactive on-line CME. Content analysis was applied first, followed by a comparative analysis to confirm themes and findings. RESULTS: Physicians based their perceptions of interactive on-line CME by comparing it with what they know best, face-to-face CME. Although perceptions about access and technical competency remained important, two other themes emerged. The first was the capacity of on-line CME to meet individual learning preferences, which, in turn, was influenced by the quality of the program, the degree of self-pacing or self-direction, opportunity for reflection, and educational design. The second was the quality and quantity of interpersonal interaction, which was shaped by perceptions of social comfort, the educational value of interactions, and the role of the facilitator. Prior experience with on-line CME moderated perceptions. DISCUSSION: The extent that on-line CME programs reflected characteristics of high-quality CME and individual learning preferences appeared to shape perceptions about it. It is important to incorporate the characteristics of effective CME into the design and implementation of interactive on-line programs, considering diverse learning preferences, providing faculty development for on-line facilitators, and grounding this work in learning theory.

Attitude of Health Personnel↗
PubMed2004

Physician perceptions of the effect of telemedicine on rural retention and recruitment.

We conducted a postal survey of 140 family and community specialist physicians in a predominantly rural area which had received clinical telemedicine services and videoconferenced continuing medical education (CME) for two years. The questionnaire contained 46 items. The response rate was 47%. Most respondents (83%) reported having attended videoconferenced CME sessions and 45% reported having referred patients for teleconsultation. Physicians in more rural areas used these services more frequently. Ratings of two statements assessing the value of telemedicine in community support were significantly and positively correlated with the number of videoconferenced CME sessions attended and the number of telemedicine services used. In relation to their decision to stay in their community for at least one year, respondents rated telemedicine lower in importance than all but one of 17 other factors expected to influence physician recruitment and retention in rural communities. The influences on physician rural recruitment and retention are complex. However, telemedicine was used more frequently by the more rural physicians, and there was a relationship between higher usage and higher ratings of its value as a community support.

Adult↗
PubMed2003

Arabidopsis CHL27, located in both envelope and thylakoid membranes, is required for the synthesis of protochlorophyllide.

CHL27, the Arabidopsis homologue to Chlamydomonas Crd1, a plastid-localized putative diiron protein, is required for the synthesis of protochlorophyllide and therefore is a candidate subunit of the aerobic cyclase in chlorophyll biosynthesis. delta-Aminolevulinic acid-fed antisense Arabidopsis plants with reduced amounts of Crd1/CHL27 accumulate Mg-protoporphyrin IX monomethyl ester, the substrate of the cyclase reaction. Mutant plants have chlorotic leaves with reduced abundance of all chlorophyll proteins. Fractionation of Arabidopsis chloroplast membranes shows that Crd1/CHL27 is equally distributed on a membrane-weight basis in the thylakoid and inner-envelope membranes.

Aminolevulinic Acid↗
PubMed2003

Waking Rip van Winkle: why developments in the last 20 years should teach the mental health system not to use housing as a tool of coercion.

Many housing programs for people with mental illnesses rely on models that require the person to adhere to treatment as a condition of continuing access to housing. These models that 'bundle' housing and treatment are relics of a past in which persons with mental illnesses were afforded little real choice in treatment, housing and other social supports. Conditioning access to housing in this manner is coercive and at odds with current thinking regarding treatment, as well as legal principles that shape the environment in which treatment is provided. This article summarizes the reasons why housing for people with mental illnesses should be provided free of the use of coercion.

Coercion↗