Diagnostic multiplex PCR assay for the identification of the Liverpool, Midlands 1 and Manchester CF epidemic strains of Pseudomonas aeruginosa
ABSTRACT Individual PCR amplification tests have been developed for three UK CF epidemic strains, the Liverpool epidemic strain (LES), Midlands 1 and the Manchester epidemic strain (MES). We report a simple diagnostic multiplex PCR test that can be used to screen for all three of these strains. To evaluate the test, we screened collections of LES, MES and Midlands 1 isolates, along with various CF and non-CF non-epidemic Pseudomonas aeruginosa strains. The test was 100% sensitive and 100% specific in the identification of these UK CF epidemic strains.
Full-textDOI: · Available from: Craig Winstanley, Sep 02, 2015
- SourceAvailable from: Michael Hornsey
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- "The presence of OXA-type carbapenemases in A. baumannii was determined using the assay described by Woodford et al.  with the addition of bla OXA-143 specific primers , whilst other ␤-lactamase genes were sought using the series of multiplex PCR assays described by Dallenne et al. . Clinical isolates of E. coli and P. aeruginosa were assigned to epidemic lineages using the PCR-based assays described by Clermont et al.  and Fothergill et al.  "
ABSTRACT: The problem of antimicrobial resistance is exemplified by multidrug-resistant (MDR) isolates of Gram-negative species. Of particular concern are expanded-spectrum cephalosporin-resistant isolates of Enterobacteriaceae, epidemic lineages of Acinetobacter baumannii producing OXA-type carbapenemases, and MDR Pseudomonas aeruginosa. In this study, the in vitro activity of the novel monosulfactam BAL30072 was investigated both alone and in combination with meropenem against a diverse collection of commonly encountered Gram-negative pathogens. Thirty-one isolates were studied, including type strains and clinical isolates with defined mechanisms conferring resistance to various antimicrobial agents including to carbapenems, colistin and tigecycline. BAL30072 minimum inhibitory concentrations (MICs) were determined in the presence and absence of meropenem (1:1, w/w) by agar dilution. Potential synergy or antagonism between BAL30072 and meropenem was investigated using standard chequerboard assays. Versus MDR A. baumannii strains producing class D oxacillinases, BAL30072 MICs were all ≤4mg/L with the exception of the isolate belonging to the UK 'Burn' lineage. BAL30072 exhibited MIC values of 0.5mg/L to >64mg/L towards the five P. aeruginosa strains. Against three meropenem-susceptible Escherichia coli, including the CTX-M-15 extended-spectrum β-lactamase-producer, BAL30072 exhibited MICs of 0.25-2mg/L; higher MICs were recorded against some of the Enterobacteriaceae isolates tested. The in vitro data suggest that BAL30072 has a potential role in the treatment of infections due to Gram-negative pathogens, including those with important resistances to other agents. In addition, BAL30072 shows powerful synergistic activity in combination with meropenem, potentially expanding its coverage for the treatment of infections caused by problematic species.International journal of antimicrobial agents 07/2013; 42(4). DOI:10.1016/j.ijantimicag.2013.05.010 · 4.26 Impact Factor
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- "2008–2009: In March 2008, by combining the specific primers and modifying the product mix we identified LES, Manchester and Midlands1 strains from one test (combined multiplex PCR).26 Primer F9 added to the PCR mix increased the specificity of the test to identify LES. "
ABSTRACT: To assess if cohort segregation policies are effective in preventing cross-infection in cystic fibrosis (CF) clinics. A prospective cohort study. A large adult CF centre in Northwest England. All CF patients cared for at the Liverpool adult CF centre 2003-2009. Regular sputum sampling with genotyping of pseudomonas aeruginosa (Psa) isolates led to a policy of inpatient and outpatient segregation by microbiological group. Prevalence and cross-infection/super-infection rates of a transmissible Psa strain, i.e. the Liverpool epidemic strain (LES) in adult CF patients at the Liverpool adult CF centre from 2003 to 2009. There was a decline in the proportion of patients with LES (71-53%) and an increase in those with unique strains (23-31%) and without Psa infection (6-17%) from 2003 to 2009. There were two cases of LES super-infection and one case of new chronic Psa infection (with a unique strain). There were no cases of transmissible strain infection in patients previously uninfected by Psa. Our segregation policy has halted the spread of the commonest highly transmissible strain in the UK (LES) in our clinic, without endangering patients who were not previously infected with Psa. It confirms that if genotypic surveillance is used, it is unnecessary to segregate patients infected with unique strains from those without Psa infection.01/2013; 4(1):1. DOI:10.1258/shorts.2012.012018
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- "All patients submit microbiological samples at every clinic visit/inpatient stay: chronic infection with Psa is defined by at least three positive sputum samples within a 6-month period.10 Our unit has pioneered Psa genotyping methodology in CF, and we regularly genotype the Psa isolates from our patients to aid cross-infection control measures within the clinic: those without known LES infection undergo genotyping using PCR every 3 months to identify unique and other transmissible Psa strains,11 while those infected with LES undergo a genotypic check (using PCR and primers PS21 & F9)12 on a yearly basis. Using this system, we are aware of the Psa genotypes infecting our CF patients at all times. "
ABSTRACT: To assess the impact on health-related quality of life (HRQoL) in adult cystic fibrosis (CF) patients of chronic infection with the Liverpool Epidemic Strain (LES) of Pseudomonas aeruginosa (Psa). Cohort study. Adult CF patients attending a single CF centre. Outpatient clinic. HRQoL measures of adult CF patients chronically infected with LES and Psa strains measured by CFQ-UK. Patients infected by transmissible Psa strains had worse physical functioning, respiratory symptoms, treatment burden, vitality, role, health perception and emotion than those with unique Psa strains (P < 0.01), and significantly poorer physical functioning, respiratory symptoms, treatment burden, body image, weight, role, and emotion than those without any Psa infection (P < 0.05). Furthermore, in a matched cohort of 39 patients, those with LES infection reported significantly worse physical functioning, treatment burden, respiratory symptoms and health perception than those with unique Psa infection (P < 0.02). Chronic infection with transmissible Psa strains, particularly LES, confers a worse quality of life in adult CF patients. Coupled with the established poorer clinical outcome, this reinforces the need to prevent the spread of such strains in CF community.02/2012; 3(2):12. DOI:10.1258/shorts.2011.011119