bluuebunny/crossref_metadata_2025 huggingface dataset:
Pharmacokinetics of Second-Line Antituberculosis Drugs after Multiple Administrations in Healthy Volunteers
Authors: Park Sang-In , Oh Jaeseong , Jang Kyungho , Yoon Jangsoo , Moon Seol Ju , Park Jong Sun , Lee Jae Ho , Song Junghan , Jang In-Jin , Yu Kyung-Sang , Chung Jae-Yong
Published: May 2015

Therapeutic drug monitoring (TDM) of second-line antituberculosis drugs would allow for optimal individualized dosage adjustments and improve drug safety and therapeutic outcomes. To evaluate the pharmacokinetic (PK) characteristics of clinically relevant, multidrug treatment regimens and to improve the feasibility of TDM, we conducted an open-label, multiple-dosing study with 16 healthy subjects who were divided into two groups. Cycloserine (250 mg),
p
-aminosalicylic acid (PAS) (5.28 g), and prothionamide (250 mg) twice daily and pyrazinamide (1,500 mg) once daily were administered to both groups. Additionally, levofloxacin (750 mg) and streptomycin (1 g) once daily were administered to group 1 and moxifloxacin (400 mg) and kanamycin (1 g) once daily were administered to group 2. Blood samples for PK analysis were collected up to 24 h following the 5 days of drug administration. The PK parameters, including the maximum plasma concentration (
C
max
) and the area under the plasma concentration-time curve during a dosing interval at steady state (AUC
τ
), were evaluated. The correlations between the PK parameters and the concentrations at each time point were analyzed. The mean
C
max
and AUC
τ
, respectively, for each drug were as follows: cycloserine, 24.9 mg/liter and 242.3 mg · h/liter; PAS, 65.9 mg/liter and 326.5 mg · h/liter; prothionamide, 5.3 mg/liter and 22.1 mg · h/liter; levofloxacin, 6.6 mg/liter and 64.4 mg · h/liter; moxifloxacin, 4.7 mg/liter and 54.2 mg · h/liter; streptomycin, 42.0 mg/liter and 196.7 mg · h/liter; kanamycin, 34.5 mg/liter and 153.5 mg · h/liter. The results indicated that sampling at 1, 2.5, and 6 h postdosing is needed for TDM when all seven drugs are administered concomitantly. This study indicates that PK characteristics must be considered when prescribing optimal treatments for patients. (This study has been registered at ClinicalTrials.gov under registration no. NCT02128308.)
Evaluation of Ceftaroline Alone and in Combination against Biofilm-Producing Methicillin-Resistant Staphylococcus aureus with Reduced Susceptibility to Daptomycin and Vancomycin in an
In Vitro
Pharmacokinetic/Pharmacodynamic Model
Authors: Barber Katie E. , Smith Jordan R. , Ireland Cortney E. , Boles Blaise R. , Rose Warren E. , Rybak Michael J.
Published: May 2015

Annually, medical device infections are associated with >250,000 catheter-associated bloodstream infections (CLABSI), with up to 25% mortality.
Staphylococcus aureus
, a primary pathogen in these infections, is capable of biofilm production, allowing organism persistence in harsh environments, offering antimicrobial protection. With increases in
S. aureus
isolates with reduced susceptibility to current agents, ceftaroline (CPT) offers a therapeutic alternative. Therefore, we evaluated whether CPT would have a role against biofilm-producing methicillin-resistant
S. aureus
(MRSA), including those with decreased susceptibilities to alternative agents. In this study, we investigated CPT activity alone or combined with daptomycin (DAP) or rifampin (RIF) against 3 clinical biofilm-producing MRSA strains in an
in vitro
biofilm pharmacokinetic/pharmacodynamic (PK/PD) model. Simulated antimicrobial regimens were as follows: 600 mg of CPT every 8 h (q8h) (free maximum concentration of drug [
fC
max
], 17.04 mg/liter; elimination half-life [
t
1/2
], 2.66 h), 12 mg/kg of body weight/day of DAP (
fC
max
, 14.7 mg/liter;
t
1/2
, 8 h), and 450 mg of RIF q12h (
fC
max
, 3.5 mg/liter;
t
1/2
, 3.4 h), CPT plus DAP, and CPT plus RIF. Samples were obtained and plated to determine colony counts. Differences in log
10
CFU/cm
2
were evaluated by analysis of variance with Tukey's
post hoc
test. The strains were CPT and vancomycin susceptible and DAP nonsusceptible (DNS). CPT displayed activity throughout the experiment. DAP demonstrated initial activity with regrowth at 24 h in all strains. RIF was comparable to the drug-free control, and little benefit was observed when combined with CPT. CPT plus DAP displayed potent activity, with an average log
10
CFU/cm
2
reduction of 3.33 ± 1.01 from baseline. CPT demonstrated activity against biofilm-producing DNS MRSA. CPT plus DAP displayed therapeutic enhancement over monotherapy, providing a potential option for difficult-to-treat medical device infections.
Mode of Action of Clofazimine and Combination Therapy with Benzothiazinones against Mycobacterium tuberculosis
Authors: Lechartier Benoit , Cole Stewart T.
Published: May 2015

Clofazimine (CZM) is an antileprosy drug that was recently repurposed for treatment of multidrug-resistant tuberculosis. In
Mycobacterium tuberculosis
, CZM appears to act as a prodrug, which is reduced by NADH dehydrogenase (NDH-2), to release reactive oxygen species upon reoxidation by O
2
. CZM presumably competes with menaquinone (MK-4), a key cofactor in the mycobacterial electron transfer chain, for its reduction by NDH-2. We studied the effect of MK-4 supplementation on the activity of CZM against
M. tuberculosis
and found direct competition between CZM and MK-4 for the cidal effect of CZM, against nonreplicating and actively growing bacteria, as MK-4 supplementation blocked the drug's activity against nonreplicating bacteria. We demonstrated that CZM, like bedaquiline, is synergistic
in vitro
with benzothiazinones such as 2-piperazino-benzothiazinone 169 (PBTZ169), and this synergy also occurs against nonreplicating bacteria. The synergy between CZM and PBTZ169 was lost in an MK-4-rich medium, indicating that MK-4 is the probable link between their activities. The efficacy of the dual combination of CZM and PBTZ169 was tested
in vivo
, where a great reduction in bacterial load was obtained in a murine model of chronic tuberculosis. Taken together, these data confirm the potential of CZM in association with PBTZ169 as the basis for a new regimen against drug-resistant strains of
M. tuberculosis
.
Effect of Resistance Mechanisms on the Inoculum Effect of Carbapenem in Klebsiella pneumoniae Isolates with Borderline Carbapenem Resistance
Authors: Adler Amos , Ben-Dalak Ma'ayan , Chmelnitsky Ina , Carmeli Yehuda
Published: May 2015

We aimed to examine the effects of resistance mechanisms on several resistance phenotypes among carbapenem-resistant
Klebsiella pneumoniae
isolates with borderline carbapenem MICs. We compared carbapenemase-negative
K. pneumoniae
with carbapenemase-producing
K. pneumoniae
(CPKP) isolates with similar MICs. CPKP isolates exhibited a marked inoculum effect and were more resistant to the bactericidal effect of meropenem. This suggests that MIC measurements alone may not be sufficient in predicting the therapeutic efficacy of carbapenems against CPKP.
Superior Serum Concentrations with Posaconazole Delayed-Release Tablets Compared to Suspension Formulation in Hematological Malignancies
Authors: Cumpston Aaron , Caddell Ryan , Shillingburg Alexandra , Lu Xiaoxiao , Wen Sijin , Hamadani Mehdi , Craig Michael , Kanate Abraham S.
Published: May 2015

Posaconazole (PCZ), approved for prophylaxis against invasive fungal disease in high-risk patients, is commercially available orally as a suspension formulation (PCZ-susp) and as a delayed-release tablet (PCZ-tab). We evaluated the serum steady-state concentrations (
C
ss
) of PCZ stratified by the administered formulation for antifungal prophylaxis in patients with myeloid malignancies (
n
= 150). The primary outcome was the attainment rate of the target
C
ss
of ≥700 ng/ml. Secondary outcomes included toxicity assessment (hepatotoxicity and corrected QT [QTc] interval prolongation) and breakthrough fungal infections. Patients who received the PCZ-susp (
n
= 118) or PCZ-tab (
n
= 32) and had PCZ
C
ss
assessment after at least 7 days of therapy were eligible. The median
C
ss
in the PCZ-susp group was 390 ng/ml (range, 51 to 1,870 ng/ml; mean, 436 ng/ml) compared to 1,740 ng/ml (range, 662 to 3,350 ng/ml; mean, 1,781 ng/ml) in the PCZ-tab group (
P
< 0.0001). The percentages of patients achieving the target goal of ≥700 ng/ml were 17% versus 97%, respectively (
P
< 0.0001). Hepatotoxicity (grade 2 or higher) occurred in 1 patient in each group. QTc interval measurements were available for 32 patients in the PCZ-susp group and for 12 patients in the PCZ-tab group, and prolonged intervals of grade 2 or higher were noted in 9% (
n
= 3) and 17% (
n
= 2), respectively (
P
= 0.6). Breakthrough fungal infections in the PCZ-susp and PCZ-tab groups were 7% (
n
= 8) and 3% (
n
= 1), respectively (
P
= 0.68). We conclude that the use of PCZ-tab was associated with higher
C
ss
and with the probability of achieving therapeutic goals without worsening of adverse effects.
Risk Factors for Acquisition and Loss of Clostridium difficile Colonization in Hospitalized Patients
Authors: Dubberke Erik R. , Reske Kimberly A. , Seiler Sondra , Hink Tiffany , Kwon Jennie H. , Burnham Carey-Ann D.
Published: May 2015

Asymptomatic colonization may contribute to
Clostridium difficile
transmission. Few data identify which patients are at risk for colonization. We performed a prospective cohort study of
C. difficile
colonization and risk factors for
C. difficile
acquisition and loss in hospitalized patients. Patients admitted to medical or surgical wards at a tertiary care hospital were enrolled; interviews and chart review were performed to determine patient demographics,
C. difficile
infection (CDI) history, medications, and health care exposures. Stool samples/rectal swabs were collected at enrollment and discharge; stool samples from clinical laboratory tests were also included. Samples were cultured for
C. difficile
, and the isolates were tested for toxins A and B and ribotyped. Chi-square tests and univariate logistic regression were used for the analyses. Two hundred thirty-five patients were enrolled. Of the patients, 21% were colonized with
C. difficile
(toxigenic and nontoxigenic) at admission and 24% at discharge. Ribotype 027 accounted for 6% of the strains at admission and 12% at discharge. Of the patients colonized at admission, 78% were also colonized at discharge. Cephalosporin use was associated with
C. difficile
acquisition (47% of patients who acquired
C. difficile
versus 25% of patients who did not;
P
= 0.03). β-lactam–β-lactamase inhibitor combinations were associated with a loss of
C. difficile
colonization (36% of patients who lost
C. difficile
colonization versus 8% of patients colonized at both admission and discharge;
P
= 0.04), as was metronidazole (27% versus 3%;
P
= 0.03). Antibiotic use affects the epidemiology of asymptomatic
C. difficile
colonization, including acquisition and loss, and it requires additional study.
Response to Switch from Intermittent Therapy to Daily Therapy for Refractory Nodular Bronchiectatic Mycobacterium avium Complex Lung Disease
Authors: Koh Won-Jung , Jeong Byeong-Ho , Jeon Kyeongman , Park Hye Yun , Kim Su-Young , Huh Hee Jae , Ki Chang-Seok , Lee Nam Yong , Shin Sung Jae , Daley Charles L.
Published: May 2015

Intermittent three-times-weekly antibiotic therapy is recommended for the initial treatment of patients with noncavitary nodular bronchiectatic
Mycobacterium avium
complex lung disease. Although some experts recommend switching from intermittent to daily therapy for patients whose sputum has persistent positive cultures after intermittent therapy, the clinical efficacy of these modifications is unknown. Of 20 patients whose sputum had persistent positive cultures after 12 months of intermittent antibiotic therapy, specimens from 6 patients (30%) achieved a negative culture after a change to daily therapy.
Systematic Review and Meta-Analysis To Estimate Antibacterial Treatment Effect in Acute Bacterial Skin and Skin Structure Infection
Authors: Cates Jordan E. , Mitrani-Gold Fanny S. , Li Gang , Mundy Linda M.
Published: May 2015

A systematic literature review and meta-analysis were conducted to estimate the antibacterial treatment effect for linezolid and ceftaroline to inform on the design of acute bacterial skin and skin structure infection (ABSSSI) noninferiority trials. The primary endpoints included an early clinical treatment response (ECTR) defined as cessation of lesion spread at 48 to 72 h postrandomization and the test-of-cure (TOC) response defined as total resolution of the infection at 7 to 14 days posttreatment. The systematic review identified no placebo-controlled trials in ABSSSI, 4 placebo-controlled trials in uncomplicated skin and soft tissue infection as a proxy for placebo in ABSSSI, 12 linezolid trials in ABSSSI, 3 ceftaroline trials in ABSSSI, and 2 trials for nonantibacterial treatment. The ECTR rates at 48 to 72 h and corresponding 95% confidence intervals (CI) were 78.7% (95% CI, 61.1 to 96.3%) for linezolid, 74.0% (95% CI, 69.7 to 78.3%) for ceftaroline, and 59.0% (95% CI, 52.8 to 65.3%) for nonantibacterial treatment. The early clinical treatment effect could not be estimated, given no available placebo or proxy for placebo data for this endpoint. Clinical, methodological, and statistical heterogeneity influenced the selection of trials for the meta-analysis of the TOC treatment effect estimation. The pooled estimates of the TOC treatment response were 31.0% (95% CI, 6.2 to 55.9%) for the proxy for placebo, 88.1% (95% CI, 81.0 to 95.1%) for linezolid, and 86.1% (95% CI, 83.7 to 88.6%) for ceftaroline. The TOC clinical treatment effect estimation was 25.1% for linezolid and 27.8% for ceftaroline. The antibacterial treatment effect estimation at TOC will inform on the design and analysis of future noninferiority ABSSSI clinical trials.
The Carbonic Anhydrase Inhibitor Ethoxzolamide Inhibits the Mycobacterium tuberculosis PhoPR Regulon and Esx-1 Secretion and Attenuates Virulence
Authors: Johnson Benjamin K. , Colvin Christopher J. , Needle David B. , Mba Medie Felix , Champion Patricia A. DiGiuseppe , Abramovitch Robert B.
Published: May 2015

Mycobacterium tuberculosis
must sense and adapt to host environmental cues to establish and maintain an infection. The two-component regulatory system PhoPR plays a central role in sensing and responding to acidic pH within the macrophage and is required for
M. tuberculosis
intracellular replication and growth
in vivo
. Therefore, the isolation of compounds that inhibit PhoPR-dependent adaptation may identify new antivirulence therapies to treat tuberculosis. Here, we report that the carbonic anhydrase inhibitor ethoxzolamide inhibits the PhoPR regulon and reduces pathogen virulence. We show that treatment of
M. tuberculosis
with ethoxzolamide recapitulates
phoPR
mutant phenotypes, including downregulation of the core PhoPR regulon, altered accumulation of virulence-associated lipids, and inhibition of Esx-1 protein secretion. Quantitative single-cell imaging of a PhoPR-dependent fluorescent reporter strain demonstrates that ethoxzolamide inhibits PhoPR-regulated genes in infected macrophages and mouse lungs. Moreover, ethoxzolamide reduces
M. tuberculosis
growth in both macrophages and infected mice. Ethoxzolamide inhibits
M. tuberculosis
carbonic anhydrase activity, supporting a previously unrecognized link between carbonic anhydrase activity and PhoPR signaling. We propose that ethoxzolamide may be pursued as a new class of antivirulence therapy that functions by modulating expression of the PhoPR regulon and Esx-1-dependent virulence.
Colistin and Fusidic Acid, a Novel Potent Synergistic Combination for Treatment of Multidrug-Resistant Acinetobacter baumannii Infections
Authors: Phee Lynette M. , Betts Jonathan W. , Bharathan Binutha , Wareham David W.
Published: May 2015

The spread of multidrug-resistant
Acinetobacter baumannii
(MDRAB) has led to the renaissance of colistin (COL), often the only agent to which MDRAB remains susceptible. Effective therapy with COL is beset with problems due to unpredictable pharmacokinetics, toxicity, and the rapid selection of resistance. Here, we describe a potent synergistic interaction when COL was combined with fusidic acid (FD) against
A. baumannii
. Synergy
in vitro
was assessed against 11 MDRAB isolates using disc diffusion, checkerboard methodology (fractional inhibitory concentration index [FICI] of ≤ 0.5, susceptibility breakpoint index [SBPI] of >2), and time-kill methodology (≥2 log
10
CFU/ml reduction). The ability of FD to limit the emergence of COL resistance was assessed in the presence and absence of each drug alone and in combination. Synergy was demonstrated against all strains, with an average FICI and SBPI of 0.064 and 78.85, respectively. In time-kill assays, COL-FD was synergistic and rapidly bactericidal, including against COL-resistant strains. Fusidic acid prevented the emergence of COL resistance, which was readily selected with COL alone. This is the first description of a novel COL-FD regimen for the treatment of MDRAB. The combination was effective at low concentrations, which should be therapeutically achievable while limiting toxicity. Further studies are warranted to determine the mechanism underlying the interaction and the suitability of COL-FD as an unorthodox therapy for the treatment of multidrug-resistant Gram-negative infections.
Combinations of β-Lactam Antibiotics Currently in Clinical Trials Are Efficacious in a DHP-I-Deficient Mouse Model of Tuberculosis Infection
Authors: Rullas Joaquín , Dhar Neeraj , McKinney John D. , García-Pérez Adolfo , Lelievre Joël , Diacon Andreas H. , Hugonnet Jean-Emmanuel , Arthur Michel , Angulo-Barturen Iñigo , Barros-Aguirre David , Ballell Lluís
Published: May 2015

We report here a dehydropeptidase-deficient murine model of tuberculosis (TB) infection that is able to partially uncover the efficacy of marketed broad-spectrum β-lactam antibiotics alone and in combination. Reductions of up to 2 log CFU in the lungs of TB-infected mice after 8 days of treatment compared to untreated controls were obtained at blood drug concentrations and time above the MIC (
T
>MIC
) below clinically achievable levels in humans. These findings provide evidence supporting the potential of β-lactams as safe and mycobactericidal components of new combination regimens against TB with or without resistance to currently used drugs.
Effect of Variants of Penicillin-Binding Protein 2 on Cephalosporin and Carbapenem Susceptibilities in Neisseria gonorrhoeae
Authors: Bharat Amrita , Demczuk Walter , Martin Irene , Mulvey Michael R.
Published: May 2015

To characterize the relationship between penicillin-binding protein 2 (PBP2/
penA
) and susceptibility to extended-spectrum cephalosporins (ESCs) and carbapenem antibiotics, we compared 17 PBP2 variants in
Neisseria gonorrhoeae
. Nonmosaic and mosaic variants of PBP2 caused decreased susceptibility to ESCs and, to a lesser extent, to carbapenems. An A501P substitution in mosaic XXXIV_A501P conferred decreased susceptibility to ESCs but restored carbapenem susceptibility to wild-type levels. These results could aid the molecular surveillance of antimicrobial resistance to these agents.
Streptococcus pyogenes Triggers Activation of the Human Contact System by Streptokinase
Authors: Nitzsche Ramona , Rosenheinrich Maik , Kreikemeyer Bernd , Oehmcke-Hecht Sonja
Published: May 2015

Severe invasive infectious diseases remain a major and life-threatening health problem. In serious cases, a systemic activation of the coagulation cascade is a critical complication that is associated with high mortality rates. We report here that streptokinase, a group A streptococcal plasminogen activator, triggers the activation of the human contact system. Activation of contact system factors at the surface of the
Streptococcus pyogenes
serotype M49 is dependent on streptokinase and plasminogen. Our results also show that secreted streptokinase is an efficient contact system activator, independent from a contact surface. This results in the processing of high-molecular-weight kininogen and the release of bradykinin, a potent vascular mediator. We further investigated whether the ability of 50 different clinical
S. pyogenes
isolates to activate the contact system is associated with an invasive phenotype. The data reveal that isolates from invasive infections trigger an activation of the contact system more potently than strains isolated from noninvasive infections. The present study gives new insights into the mechanisms by which
S. pyogenes
triggers the human contact system and stresses the function of soluble and surface located plasmin exploited as a group A streptococcal virulence factor through the action of streptokinase.
Regulation of the Min Cell Division Inhibition Complex by the Rcs Phosphorelay in Proteus mirabilis
Authors: Howery Kristen E. , Clemmer Katy M. , Şimşek Emrah , Kim Minsu , Rather Philip N.
Published: May 2015

A key regulator of swarming in
Proteus mirabilis
is the Rcs phosphorelay, which represses
flhDC
, encoding the master flagellar regulator FlhD
4
C
2
. Mutants in
rcsB
, the response regulator in the Rcs phosphorelay, hyperswarm on solid agar and differentiate into swarmer cells in liquid, demonstrating that this system also influences the expression of genes central to differentiation. To gain a further understanding of RcsB-regulated genes involved in swarmer cell differentiation, transcriptome sequencing (RNA-Seq) was used to examine the RcsB regulon. Among the 133 genes identified,
minC
and
minD
, encoding cell division inhibitors, were identified as RcsB-activated genes. A third gene,
minE
, was shown to be part of an operon with
minCD
. To examine
minCDE
regulation, the
min
promoter was identified by 5′ rapid amplification of cDNA ends (5′-RACE), and both transcriptional
lacZ
fusions and quantitative real-time reverse transcriptase (qRT) PCR were used to confirm that the
minCDE
operon was RcsB activated. Purified RcsB was capable of directly binding the
minC
promoter region. To determine the role of RcsB-mediated activation of
minCDE
in swarmer cell differentiation, a polar
minC
mutation was constructed. This mutant formed minicells during growth in liquid, produced shortened swarmer cells during differentiation, and exhibited decreased swarming motility.

IMPORTANCE
This work describes the regulation and role of the MinCDE cell division system in
P. mirabilis
swarming and swarmer cell elongation. Prior to this study, the mechanisms that inhibit cell division and allow swarmer cell elongation were unknown. In addition, this work outlines for the first time the RcsB regulon in
P. mirabilis
. Taken together, the data presented in this study begin to address how
P. mirabilis
elongates upon contact with a solid surface.
Environmental Sensing in Actinobacteria: a Comprehensive Survey on the Signaling Capacity of This Phylum
Authors: Huang Xiaoluo , Pinto Daniela , Fritz Georg , Mascher Thorsten
Published: May 2015

Signal transduction is an essential process that allows bacteria to sense their complex and ever-changing environment and adapt accordingly. Three distinct major types of signal-transducing proteins (STPs) can be distinguished: one-component systems (1CSs), two-component systems (2CSs), and extracytoplasmic-function σ factors (ECFs). Since
Actinobacteria
are particularly rich in STPs, we comprehensively investigated the abundance and diversity of STPs encoded in 119 actinobacterial genomes, based on the data stored in the Microbial Signal Transduction (MiST) database. Overall, we observed an approximately linear correlation between the genome size and the total number of encoded STPs. About half of all membrane-anchored 1CSs are protein kinases. For both 1CSs and 2CSs, a detailed analysis of the domain architectures identified novel proteins that are found only in actinobacterial genomes. Many actinobacterial genomes are particularly enriched for ECFs. As a result of this study, almost 500 previously unclassified ECFs could be classified into 18 new ECF groups. This comprehensive survey demonstrates that actinobacterial genomes encode previously unknown STPs, which may represent new mechanisms of signal transduction and regulation. This information not only expands our knowledge of the diversity of bacterial signal transduction but also provides clear and testable hypotheses about their mechanisms, which can serve as starting points for experimental studies.

IMPORTANCE
In the wake of the genomic era, with its enormous increase in the amount of available sequence information, the challenge has now shifted toward making sense and use of this treasure chest. Such analyses are a prerequisite to provide meaningful information that can help guide subsequent experimental efforts, such as mechanistic studies on novel signaling strategies. This work provides a comprehensive analysis of signal transduction proteins from 119 actinobacterial genomes. We identify, classify, and describe numerous novel and conserved signaling devices. Hence, our work serves as an important resource for any researcher interested in signal transduction of this important bacterial phylum, which contains organisms of ecological, biotechnological, and medical relevance.
Biochemical Characterization of Mycobacterium smegmatis RnhC (MSMEG_4305), a Bifunctional Enzyme Composed of Autonomous N-Terminal Type I RNase H and C-Terminal Acid Phosphatase Domains
Authors: Jacewicz Agata , Shuman Stewart
Published: May 2015

Mycobacterium smegmatis
encodes several DNA repair polymerases that are adept at incorporating ribonucleotides, which raises questions about how ribonucleotides in DNA are sensed and removed. RNase H enzymes, of which
M. smegmatis
encodes four, are strong candidates for a surveillance role. Here, we interrogate the biochemical activity and nucleic acid substrate specificity of
M. smegmatis
RnhC, a bifunctional RNase H and acid phosphatase. We report that (i) the RnhC nuclease is stringently specific for RNA:DNA hybrid duplexes; (ii) RnhC does not selectively recognize and cleave DNA-RNA or RNA-DNA junctions in duplex nucleic acid; (iii) RnhC cannot incise an embedded monoribonucleotide or diribonucleotide in duplex DNA; (iv) RnhC can incise tracts of 4 or more ribonucleotides embedded in duplex DNA, leaving two or more residual ribonucleotides at the cleaved 3′-OH end and at least one or two ribonucleotides on the 5′-PO
4
end; (v) the RNase H activity is inherent in an autonomous 140-amino-acid (aa) N-terminal domain of RnhC; and (vi) the C-terminal 211-aa domain of RnhC is an autonomous acid phosphatase. The cleavage specificity of RnhC is clearly distinct from that of
Escherichia coli
RNase H2, which selectively incises at an RNA-DNA junction. Thus, we classify RnhC as a type I RNase H. The properties of RnhC are consistent with a role in Okazaki fragment RNA primer removal or in surveillance of oligoribonucleotide tracts embedded in DNA but not in excision repair of single misincorporated ribonucleotides.

IMPORTANCE
RNase H enzymes help cleanse the genome of ribonucleotides that are present either as ribotracts (e.g., RNA primers) or as single ribonucleotides embedded in duplex DNA.
Mycobacterium smegmatis
encodes four RNase H proteins, including RnhC, which is characterized in this study. The nucleic acid substrate and cleavage site specificities of RnhC are consistent with a role in initiating the removal of ribotracts but not in single-ribonucleotide surveillance. RnhC has a C-terminal acid phosphatase domain that is functionally autonomous of its N-terminal RNase H catalytic domain. RnhC homologs are prevalent in
Actinobacteria
.
Lower socioeconomic status, adiposity and negative health behaviours in youth: a cross-sectional observational study
Authors: Lord Sarah , Manlhiot Cedric , Tyrrell Pascal N , Dobbin Stafford , Gibson Don , Chahal Nita , Stearne Karen , Fisher Amanda , McCrindle Brian W
Published: May 2015

Objective

Understanding obesity and its modifiable risk factors in youth is key to addressing the burden of cardiovascular disease later in life. Our aim was to examine the associations among adiposity, negative health behaviours and socioeconomic status in youth from the Niagara Region.

Design, setting and participants

Cross-sectional observational study of 3467 grade 9 students during their mandatory health and physical education class to investigate the association between socioeconomic status (postal code), self-reported health behaviour and adiposity in the Niagara Region, Ontario, Canada.

Results

Median household income was $63 696 and overall percentage below the after-tax low-income cut-off was 4.2%. Negative health behaviours (especially skipped meals, lower fruit and vegetable consumption, higher screen time) were associated with lower income neighbourhoods, however, the absolute effect was small. Those participants in the lowest income quintile had a significantly greater body mass index z-score than those in the highest (0.72±1.19 vs 0.53±1.12), but the overall trend across quintiles was not statistically significant. A similar trend was noted for waist-to-height ratio. The lowest income neighbourhoods according to after-tax low-income cut-off had small but statistically significant associations with higher adiposity compared with the middle or highest income neighbourhoods.

Conclusions

Obesity prevention efforts should target modifiable behaviours, with particular attention to adolescents from lower income families and neighbourhoods.
Improving feedback from outpatient medical appointments attended by escorted psychiatric patients in the North London Forensic Service
Authors: McCurdy Kathleen , Croxford Anna
Published: May 2015

It is well established that patients with mental illness are known to have a high level of morbidity and mortality compared to the general population. This is particularly prominent in long-stay psychiatric patients, such as those in secure settings. The Royal College of Psychiatrists recommends that psychiatrists should promote the physical health of their patients and liaise with other specialties. However, there is evidence that communication between psychiatry and other specialties is poor.

A survey was carried out at the North London Forensic Service in June 2014. This looked at the views of clinical staff about the frequency and quality of feedback obtained when inpatients attend outpatient hospital appointments at local general hospitals. This survey highlighted the general perception among staff that feedback is poor, with 68.43% of respondents saying that they were “very unsatisfied” or “unsatisfied” with the level and quality of feedback. Clinical staff felt that many patients who attended hospital outpatient appointments, even when escorted by staff, returned with little or no feedback. This was confirmed by a baseline audit across 3 wards showing that details of the appointment (date, time, hospital, and specialty) were only documented in 54.5% of cases and the content of the appointment documented in even fewer cases.

A form was designed by junior doctors that provided a simple framework of 6 questions to be answered at the outpatient clinic about the problem, diagnosis, and further actions needed. This was introduced and its impact assessed with a 3-month and 6-month audit of electronic notes, as well as a follow-up survey after 6 months. The audit showed significant improvement in the quality of feedback about the appointment at both the 3-month and 6-month point. The follow-up survey showed that 70% of respondents were aware of the form and 100% of those who were aware of the form had used it at least once and found it helpful. The general satisfaction level improved, but remained low, with 40% of respondents saying that they were “very unsatisfied” or “unsatisfied” with the level and quality of feedback.

This QIP shows that the outpatient appointment form is a useful and effective tool when staff know about it and use it. We plan to look at the barriers to using the form and consider future solutions to the need for increased engagement with nursing staff stakeholders in future PDSA cycles.
UNDERSTANDING WHY AMBULANCES ARE CALLED FOR ‘PRIMARY CARE’ PROBLEMS: A SYSTEMATIC MAPPING REVIEW
Authors: Booker Matthew , Shaw Ali RG , Purdy Sarah
Published: May 2015

Background

Members of the public are increasingly turning to ambulance services for help with urgent problems that could successfully be managed in primary care. The reasons for this are complex, and it is unclear whether variation exists across different global settings and between ambulance systems.

Methods

A systematic mapping review is a type of systematic literature review used to summarise diverse and heterogeneous evidence, with the aim of focusing a more in-depth study. We conducted a comprehensive search of published and grey literature, in accordance with a prospectively published protocol. Inclusion criteria were any study from 1980 onwards that explored ambulance use for conditions amenable to primary care management. Perspectives of patients, families, carers, bystanders, health professionals (pre-hospital, in-hospital and primary care) and health service management were included. The ‘Phenomena of Interest’ (P-C) model underpinned the approach, therefore qualitative, quantitative, mixed-methods and interpretative reviews were all included as relevant. A total of 31 studies met inclusion criteria.

Results

We developed a literature map summarising the evidence under five broad categories. Ambulance use for ‘primary care problems’ appears associated with individual patient-factors, including personal anxieties and risk management strategies, level of health education, and several socio-demographic factors. The link with specific clinical conditions is weaker. Bystanders, carers and family members consistently exhibit strong influence on decision making across the variety of global pre-hospital systems. Health professionals determine ‘inappropriate’ ambulance use in inconsistent ways.

Conclusion

There is evidence to suggest socioeconomic and demographic characteristics traditionally associated with minority status and deprivation are associated with ambulance use for primary care problems. The role of formal and informal care-givers in influencing risk management warrants deeper exploration. There is a lack of consensus in the literature on what defines ‘inappropriate’ ambulance use, and from who's perspective this should be determined. Further work needs to explore these conflicts.
THE JAM IN THE SANDWICH, DOWN HERE IN A&E': STAFF PERSPECTIVES ON THE IMPACT AND CAUSES OF HANDOVER DELAYS BETWEEN THE AMBULANCE SERVICE AND THE EMERGENCY DEPARTMENT
Authors: Porter Alison , Evans Bridie Angela , Gammon Becky , Mayes Robert Harris , Poulden Mark , Rees Nigel , Snooks Helen , Toghill Alun , Wells Bridget , Whitfield Richard
Published: May 2015

Background

Delays to the handover of patients from ambulances to the emergency department (ED) cause operational challenges for hospitals and the ambulance service, and have attracted considerable public and policy concern. As part of a wider study of handover delays, we sought to understand the perspective of health service staff on their impact and causes, in the ED of a large teaching hospital.

Methods

We conducted semi-structured interviews with a stratified sample of key staff from the hospital and the ambulance service, including doctors (n=5); nurses (n=7); hospital based support staff (n=2); paramedics and ambulance technicians (n=12); and other ambulance service staff (n=8). All interviews were recorded and transcribed in full, then analysed using the framework approach.

Results

All staff groups expressed concerns about the impact of crowding and handover delays on the quality of patient care, with a minority of respondents identifying clinical risk to patients. Handover delays were associated with high levels of stress for all staff groups, and in particular frustration for ambulance clinicians tied up waiting with patients outside the hospital. Delays were felt to have an impact on the relationship between professional groups. The negative impact on ambulance service performance measures was felt to be substantial.

There was a high level of consensus that problems of crowding in the ED were complex, with issues right through the system. Almost all respondents identified lack of capacity elsewhere in the hospital as an immediate cause, and reflected positively on the impact of recent initiatives to improve patient flow. Batched arrival of ambulances, associated in part with shift patterns, was reported as causing knock-on delays from which it was hard to recover.

Conclusions

Handover delays at the ED have a negative impact on patients, staff and health service organisations. System-wide impacts suggest that system-wide approaches to resolving delays are required.
FEASIBILITY STUDY OF A NOVEL PAIN ASSESSMENT TOOL FOR IMPROVING PREHOSPITAL PAIN MANAGEMENT
Authors: Iqbal Mohammad , Anne Spaight P , Kane Ros , Asghar Zahid , Niroshan Siriwardena A
Published: May 2015

Background

Pain affects 4 out of 5 patients presenting to ambulance services and is often poorly assessed and treated. Currently, patients' pain is assessed by ambulance clinicians using a numerical verbal (zero to ten) pain score (NVPS). Our previous qualitative study showed that NVPS were poorly understood by patients and that a better pain assessment tool was needed. This current study sought to develop and test a novel pain assessment tool ‘Patient Reported Outcome Measure for Pain Treatment (PROMPT)’ for feasibility of use by ambulance paramedics.

Methods

The study was conducted in the East Midlands Ambulance Service NHS Trust. We conducted secondary analysis of an existing qualitative dataset to develop a draft tool. This was revised following an expert panel review by a group of 10 experienced ambulance clinicians to assess content and face validity. The feasibility study was conducted with participating paramedics using the tool in patients presenting with pain, to determine the feasibility, reliability and validity of PROMPT; to gather initial data on its effect on prehospital pain management comparing reduction in pain score and use of analgesia compared with a baseline period using regression.

Results

Eighteen paramedics, using PROMPT, collected data on pain management from 132 patients. PROMPT had high internal consistency (>0.8). There were significant reductions in pain score (p=0.027) and significantly greater use of analgesics (p<0.001) in patients when PROMPT was used compared with baseline for paramedics involved in the study after adjusting for differences in patients' age, clinical condition and pain score before treatment.

Conclusions

Preliminary findings suggest that PROMPT is reliable, feasible to use, and has face, content and predictive validity. In order to evaluate the effectiveness of the tool, we are conducting a non-randomised control group study comparing pain management provided by paramedics using the tool with paramedics following their usual practice.
IMPROVING POST-RESUSCITATION CARE FOLLOWING OUT-OF-HOSPITAL CARDIAC ARREST
Authors: Lynde Jessica , Zorab Ollie
Published: May 2015

Background

Improving sustained ROSC rates following out-of-hospital cardiac arrest is a key focus for ambulance services. Accordingly, a Quality Improvement (QI) project was initiated whereby an Intensive Care Society post-resuscitation care bundle of evidence-based interventions was adapted for use by pre-hospital clinicians. The objective was to introduce and embed this care bundle, in order to increase its delivery.

Apr & May 2012Apr & May 2013Apr & May 2014No. of patients9610697Complete Care Bundle8.3%32.1%35.1%12—Lead ECG60%71.7%81.4%Blood Sugar43%94.3%95.9%Cooling Started49%69.8%62.9%Ventilatory Support53%52.8%73.2%Haemodynamic Support74%82.1%82.5%

Method

A baseline audit of care bundle compliance was conducted in April–May 2012 to act as a pilot bundle and provide a baseline. The final care bundle, comprising five key elements, was introduced during a QI event attended by 60 clinicians in April 2013. Since then, care bundle delivery has been regularly monitored. To sustain early gains, a Post-ROSC checklist was distributed to frontline vehicles, and a QI Collaborative discussed individual elements. A defibrillator ‘aide memoire’ sticker was developed, and will be trialled using a PDSA cycle.

Results

Care bundle delivery has progressed between the pilot period, and in the two subsequent years, demonstrating the success of the QI programme in embedding these interventions. Ventilatory support has received a particular focus, and the impact on provision is marked.

In future, the care bundle will be updated to reflect the latest research evidence, including new guidance on cooling. SPC charts will monitor the impact of QI activities.

Conclusion

The care bundle model, alongside targeted QI activities, has proved successful in ensuring best-practice care is more routinely provided. These methods promote clinician co-production of practice development, and are adaptive to evolving clinical evidence.
DEVELOPMENT OF A PATIENT REPORTED EXPERIENCE MEASURE (PREM) FOR USE IN THE AMBULANCE SERVICE
Authors: Togher Fiona , Siriwardena Aloysius Niroshan , Windle Karen
Published: May 2015

Background

NHS health policy emphasises the crucial role of patient experience as a core component of high quality care, alongside effectiveness and safety. Patient Reported Experience Measures (PREMs) measure patients' experiences with their healthcare. They are increasingly being seen as valuable for assessing patient outcomes and differences in quality between health care providers.

Previous patient surveys to assess ambulance service care have not been implemented routinely or in a standardised way. This research forms part of a doctoral study to develop a PREM for use in UK ambulance services.

Methods

The study comprised three subsections:

A secondary analysis of interview data exploring patients' experiences of their prehospital care.

Development of questionnaire items based on those themes emerging from the secondary analysis.

Semi-structured interviews with service users that explore their opinions of the questionnaire items and whether the PREM includes all aspects of the ambulance service experience that should be encompassed.

Results

The secondary data analysis revealed specific ‘processes of importance’ to service users accessing ambulance care i.e. ‘timeliness’ and parallel ‘experiential components of care’ i.e. ‘reassurance’ that either enhanced or reduced the perception that the ‘processes of care’ were undertaken to a high standard.

The key themes formed the foundation for generating the 53 item questionnaire. The interview stage is on-going and the data obtained are being used to amend the questionnaire items.

Conclusions

The construction of the PREM has incorporated the views of patients that the measure is ultimately designed for, and conforms to the concept of patient-centred care—the theoretical foundation of the research.

Once completed, the PREM will enable ambulance trusts to measure differences in patient experiences, between and within organisations. This can result in positive changes to patient experience through the introduction of feedback, training and education to prehospital clinicians.
DOES DEMENTIA MATTER: IS DEMENTIA AN IMPORTANT FACTOR IN 999 CALL-OUTS TO OLDER PEOPLE?
Authors: Buswell Marina , Amado Sarah , Goodman Claire , William Julia , Fleming Jane , Lumbard Phillip , Prothero Larissa
Published: May 2015

Background

Care for older people with dementia (OPWD) is a major concern across all care settings. Ambulance services are in the spotlight as pressures on emergency services and calls for admission avoidance are policy priorities. Around 1/3 of emergency call-outs are to people 75 and over, a significant proportion of whom may have dementia. There is a perception that dementia may be an issue but we do not understand how much this affects use of emergency services.

Methods

We reviewed 358 ambulance service paper-based patient care records (PCRs) to test the feasibility of using them as a source of information about ambulance service use by OPWD and, conducted critical incident reviews of 999 callouts to understand factors associated with emergency ambulance call-outs. We took our emerging findings to a stakeholder meeting where we established areas of consensus and key research questions.

Results

Fifty-two (14.5%) of the PCRs reviewed had dementia recorded, this is in line with current prevalence estimates for ≥75-year-olds. However, we had to use paper PCRs as dementia recording in ePCRs is more complex.

The critical incident reviews identified a wide spectrum of experience of emergency ambulance use by OPWD and their carers, from pre-diagnosis through to end-of-life scenarios.

It was new for many of the stakeholders to think about the role of ambulance services in the care of OPWD. There was consensus that the contribution family and paid carers make in decision making; explaining the OPWD's needs and changed condition, is underused.

Conclusions

There is little current research that understands what ambulance clinicians are doing with respect to caring for OPWD.

Research questions should focus on how communication between the person with dementia, formal/informal carers, healthcare professionals and emergency services affects the care provided for older people with dementia during and immediately after urgent care events.
Validation of ICDPIC software injury severity scores using a large regional trauma registry
Authors: Greene Nathaniel H , Kernic Mary A , Vavilala Monica S , Rivara Frederick P
Published: May 2015

Background

Administrative or quality improvement registries may or may not contain the elements needed for investigations by trauma researchers. International Classification of Diseases Program for Injury Categorisation (ICDPIC), a statistical program available through Stata, is a powerful tool that can extract injury severity scores from ICD-9-CM codes. We conducted a validation study for use of the ICDPIC in trauma research.

Methods

We conducted a retrospective cohort validation study of 40 418 patients with injury using a large regional trauma registry. ICDPIC-generated AIS scores for each body region were compared with trauma registry AIS scores (gold standard) in adult and paediatric populations. A separate analysis was conducted among patients with traumatic brain injury (TBI) comparing the ICDPIC tool with ICD-9-CM embedded severity codes. Performance in characterising overall injury severity, by the ISS, was also assessed.

Results

The ICDPIC tool generated substantial correlations in thoracic and abdominal trauma (weighted κ 0.87–0.92), and in head and neck trauma (weighted κ 0.76–0.83). The ICDPIC tool captured TBI severity better than ICD-9-CM code embedded severity and offered the advantage of generating a severity value for every patient (rather than having missing data). Its ability to produce an accurate severity score was consistent within each body region as well as overall.

Conclusions

The ICDPIC tool performs well in classifying injury severity and is superior to ICD-9-CM embedded severity for TBI. Use of ICDPIC demonstrates substantial efficiency and may be a preferred tool in determining injury severity for large trauma datasets, provided researchers understand its limitations and take caution when examining smaller trauma datasets.