Verona integron-encoded metallo-Beta-lactamase (VIM) and Vietnam extended-spectrum Beta-lactamase (VEB) producing pseudomonas balearica from a clinical specimen.

Pseudomonas balearica, a saprophyte found in marshy and marine habitats, is not routinely differentiated from P. aeruginosa and P. stutzeri using automated systems and hence has not been reported from clinical samples. This study describes the identification of P. balearica using MALDI-TOF-MS and 16S rDNA sequence from a patient admitted to an intensive care unit (I.C.U.). The isolate was found to be Verona integron-mediated Metallo-b-lactamase (V.I.M.), and Vietnam extended-spectrum b-lactamase (V.E.B.) producer and resistant to Ceftriaxone, Imipenem, and Tobramycin. P. balearica can be a source for horizontal transfer of blaVEB and blaVIM. Its pathogenesis has yet to be understood.

Tuberculosis bacillary load, an early marker of disease severity: the utility of tuberculosis Molecular Bacterial Load Assay.

In this comparative biomarker study, we analysed 1768 serial sputum samples from 178 patients at 4 sites in Southeast Africa. We show that tuberculosis Molecular Bacterial Load Assay (TB-MBLA) reduces time-to-TB-bacillary-load-result from days/weeks by culture to hours and detects early patient treatment response. By day 14 of treatment, 5% of patients had cleared bacillary load to zero, rising to 58% by 12th week of treatment. Fall in bacillary load correlated with mycobacterial growth indicator tube culture time-to-positivity (Spearmans r=-0.51, 95% CI (-0.56 to -0.46), p<0.0001). Patients with high pretreatment bacillary burdens (above the cohort bacillary load average of 5.5log10eCFU/ml) were less likely to convert-to-negative by 8th week of treatment than those with a low burden (below cohort bacillary load average), p=0.0005, HR 3.1, 95% CI (1.6 to 5.6) irrespective of treatment regimen. TB-MBLA distinguished the bactericidal effect of regimens revealing the moxifloxacin-20 mg rifampicin regimen produced a shorter time to bacillary clearance compared with standard-of-care regimen, p=0.008, HR 2.9, 95% CI (1.3 to 6.7). Our data show that the TB-MBLA could inform clinical decision making in real-time and expedite drug TB clinical trials.

High prevalence of latent tuberculosis and bloodborne virus infection in a homeless population.

INTRODUCTION: Urban homeless populations in the UK have been shown to have high rates of active tuberculosis, but less is known about the prevalence of latent tuberculosis infection (LTBI). This study aimed to estimate the prevalence of LTBI among individuals using homeless hostels in London. METHODS: We performed a cross-sectional survey with outcome follow-up in homeless hostels in London. Our primary outcome was prevalence of LTBI. Recruitment for the study took place between May 2011 and June 2013. To estimate an LTBI prevalence of 10% with 95% CIs between 8% and 13%, we required 500 participants. RESULTS: 491/804 (61.1%) individuals agreed to be screened. The prevalence of LTBI was 16.5% (81/491; 95% CI 13.2 to 19.8). In UK-born individuals, a history of incarceration was associated with increased risk of LTBI (OR 3.49; 95% CI 1.10 to 11.04; P=0.018) after adjusting for age, length of time spent homeless and illicit drug use. Of the three subjects who met English treatment guidelines for LTBI at the time of the study, none engaged with services after referral for treatment. Prevalence of past hepatitis B infection was 10.4% (51/489; 95% CI 7.7 to 13.1), and 59.5% (291/489; 95% CI 55.1 to 63.9) of individuals were non-immune. Prevalence of current hepatitis C infection was 10.4% (51/489; 95% CI 7.8 to 13.1). CONCLUSIONS: This study demonstrates the high prevalence of LTBI in homeless people in London and the associated poor engagement with care. There is a large unmet need for LTBI and hepatitis C infection treatment, and hepatitis B vaccination, in this group.

Interaction of N-methyl-2-alkenyl-4-quinolones with ATP-dependent MurE ligase of Mycobacterium tuberculosis: antibacterial activity, molecular docking and inhibition kinetics.

OBJECTIVES: The aim of this study was to comprehensively evaluate the antibacterial activity and MurE inhibition of a set of N-methyl-2-alkenyl-4-quinolones found to inhibit the growth of fast-growing mycobacteria. METHODS: Using the spot culture growth inhibition assay, MICs were determined for Mycobacterium tuberculosis H(37)Rv, Mycobacterium bovis BCG and Mycobacterium smegmatis mc(2)155. MICs were determined for Mycobacterium fortuitum, Mycobacterium phlei, methicillin-resistant Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa using microplate dilution assays. Inhibition of M. tuberculosis MurE ligase activity was determined both by colorimetric and HPLC methods. Computational modelling and binding prediction of the quinolones in the MurE structure was performed using Glide. Kinetic experiments were conducted for understanding possible competitive relations of the quinolones with the endogenous substrates of MurE ligase. RESULTS: The novel synthetic N-methyl-2-alkenyl-4-quinolones were found to be growth inhibitors of M. tuberculosis and rapid-growing mycobacteria as well as methicillin-resistant S. aureus, while showing no inhibition for E. coli and P. aeruginosa. The quinolones were found to be inhibitory to MurE ligase of M. tuberculosis in the micromolar range (IC(50) ∼40-200 µM) when assayed either spectroscopically or by HPLC. Computational docking of the quinolones on the published M. tuberculosis MurE crystal structure suggested that the uracil recognition site is a probable binding site for the quinolones. CONCLUSIONS: N-methyl-2-alkenyl-4-quinolones are inhibitors of mycobacterial and staphylococcal growth, and show MurE ligase inhibition. Therefore, they are considered as a starting point for the development of increased affinity MurE activity disruptors.

Managing pulmonary nontuberculous mycobacterial infection. time for a patient-centered approach.

The incidence of nontuberculous mycobacteria is increasing worldwide. However, the evidence base for clinical management comprises mostly expert opinion, case series, and few randomized clinical trials. Most currently recommended treatment regimens entail prolonged use of multiple antimicrobial agents associated with multiple self-limited and persistent potential adverse effects, including irreversible impairments of hearing, vision, and kidney function. Yet, little is known about how treatment impacts an individual patient's overall health status. Current treatment guidelines, although of undoubted value, are constrained by these limitations. Here we call for new studies that reassess recommendations for medical management of pulmonary nontuberculous mycobacteria infections, in particular Mycobacterium avium-intracellulare complex and Mycobacterium abscessus complex. We propose pragmatic, person-centered outcome measures that might be used in clinical assessments and new research studies, including patient-reported experience measures and patient-reported outcome measures. This will enable patients and their health-care providers to make clinical management decisions that derive from a realistic view of what they can hope to achieve from treatment.

Utility and limitations of Spa-typing in understanding the epidemiology of Staphylococcus aureus bacteraemia isolates in a single University Hospital.

BACKGROUND: Staphylococcus aureus (SA) is a recognized cause of nosocomial infections with 8,767 SA bacteraemia (SAB) cases reported in England only in 2012. Different typing methods have been developed but they are not generally performed as a routine investigation in hospital laboratories. FINDINGS: We collected epidemiological data and spa-typed all SAB isolates over a 12 months period. Spa-typing was useful to detect two potential outbreaks of methicillin-sensitive SA (MSSA). In addition, the analysis of spa-types from individuals with multiple bacteriaemias helped to distinguish between relapse and re-infection. CONCLUSIONS: Spa-typing could be used as a rapid tool to understand the epidemiology of SAB, in particular the detection of hospital clusters and to distinguish relapse from re-infection, but clinicians should be aware of its possible limitations.