Campylobacter jejuni strain CG8421: a refined model for the study of Campylobacteriosis and evaluation of Campylobacter vaccines in human subjects

BACKGROUND

A robust human challenge model for Campylobacter jejuni is an important tool for the evaluation of candidate vaccines. The previously established model conveys a potential risk of Guillain-Barré syndrome attributable to lipooligosaccharide ganglioside mimicry. This work establishes a new C. jejuni human challenge model that uses a strain (CG8421) without ganglioside mimicry and that applies Campylobacter-specific cellular immunity screening to achieve high attack rates at lower inoculum doses.

METHODS

Healthy Campylobacter-naive adults participated in an open-label challenge trial. Participants were dosed with C. jejuni CG8421 and followed as inpatients. Pattern of illness, bacterial shedding, and immunologic responses were determined.

RESULTS

Following screening, 23 subjects received 1 X 10(6) or 1 X 10(5) colony-forming units of C. jejuni, with attack rates (percentage of patients who became ill) of 100% (1 X 10(6) colony-forming units) or 93% (1 X 10(5) colony-forming units). Every subject shed CG8421; the median time to diarrhea onset was 72.3 h (interquartile range, 53.9-99.9 h). Symptoms included abdominal cramps (74%), nausea (65%), and fever (39%). No major safety concerns occurred, including bacteremia, hypotension, or postinfectious sequelae. Unexpectedly, recrudescent infection occurred in 2 subjects (1 subject without Campylobacter-specific adaptive immune responses and 1 with azithromycin resistance acquired in vivo); both infections cleared after receipt of additional antibiotics. Cumulative Campylobacter-specific immune responses were as follows: serologic response occurred in 87% (immunoglobulin [Ig] A) and 48% (IgG) of subjects, in vitro interferon-gamma production occurred in 91% of subjects, and 96% of subjects had IgA antibody-secreting cells and fecal IgA detected.

CONCLUSIONS

The C. jejuni CG8421 challenge model provides a safe and effective tool, without the risk of Guillain-Barré syndrome. The model demonstrates high attack rates after lower doses of challenge inoculum, provides further understanding of immunologic responses, and permits future investigation of candidate Campylobacter vaccines.

Epidemiology of spine tumors presenting to musculoskeletal physiatrists

OBJECTIVE

To report the incidence and epidemiologic formation of previously undetected primary and secondary spine tumors presenting as spinal and/or extremity pain to a physiatrist practicing in an academic or private practice multidisciplinary spine center.

DESIGN

Multicenter retrospective chart review.

SETTING

Three multidisciplinary spine settings (1 academic, 2 private).

PARTICIPANTS

Charts of patients from 33 academic and 18 private practice settings.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Epidemiologic data collected included incidence, age, gender, race, and duration of symptoms before initial presentation. Symptom presentation data collected included intensity of pain when supine, sitting, standing, or walking; character of the pain; pain intensity as measured on the visual analog scale (VAS); spontaneous versus traumatic etiology; unexplained weight loss; presence of night pain; and fever. In addition, the results of radiographic studies including plain films, imaging, bone scan, and magnetic resonance imaging were recorded. The type of neoplastic disease was also assessed, primary versus metastatic, as well as the metastatic source.

RESULTS

The incidence of spine tumors was.69% in academic multidisciplinary spine centers and.12% in private practice multidisciplinary spine centers. Patients with spinal pain because of neoplastic disease who presented to musculoskeletal physiatrists were an average age of 65.3 years and reported a relatively high likelihood of night pain, aching character of symptom manifestation, spontaneous onset of symptoms, history of cancer, standing and walking provoking symptoms, and unexplained weight loss. In addition, the pain intensity level ranged widely, with an average VAS score of 6.8.

CONCLUSIONS

There are many similarities and differences in the clinical presentation of patients with spinal pain from spine tumors who present to musculoskeletal physiatrists practicing in multidisciplinary spine centers when compared with those presenting to a primary care setting.

The complexity, relative value, and financial worth of curbside consultations in an academic infectious diseases unit

BACKGROUND

Curbside consultations are common in clinical practice. The complexity, relative value, and revenue loss associated with curbside consultations are not well defined.

METHODS

Curbside consultations performed during a 1-year period were studied. Each curbside consultation was assigned a Current Procedural Terminology (CPT) code on the basis of the inpatient versus outpatient status of the patient, initial versus subsequent care, and clinical complexity. On the basis of the CPT code, the physician work component of the relative value unit (wRVU) was assigned for each curbside consultation. The 2005 Centers for Medicaid and Medicare Services conversion factor of $37.89 per wRVU was used for cost estimates. Comparisons were made with formal consultations performed during the same time period.

RESULTS

A total of 1001 curbside consultations were fielded: 66% involved outpatients, and 97% were coded as initial consultations. A total of 78% of curbside consultations were considered complex in nature, being assigned a CPT code of level 4-5, including 84% of the inpatient and 75% of the outpatient curbside consultations. These curbside consultations would have generated 2480 wRVUs. During the same period, formal consultations generated 12,121 wRVUs. Thus, curbside consultations represented 17% (2480/14,601) of the clinical work value of the infectious diseases unit. If the infectious diseases unit had performed these curbside consultations as formal consultations, an additional $93,979 in revenue would have been generated.

CONCLUSIONS

Curbside consultations are common and complex. The curbside consultation should be incorporated into measures of infectious diseases providers' productivity and compensation.

Mitral valve replacement six years after cardiac transplantation

A 33-year-old man found to have increasing mitral regurgitation and decreasing exercise tolerance 6 years after cardiac transplantation received a mitral bioprosthesis. For 8 months he has been without complications from the valve replacement and is clinically and hemodynamically considerably improved.

The RN-BSN Bridge Course: Transitioning the Re-Entry Learner

BACKGROUND

Although most RN-to-BSN programs offer bridge courses, little can be found in the literature about common course objectives, content, or outcomes.

METHOD

This article details course objectives, course content, course implementation, and preliminary outcomes of a primarily distance learning RN-to-BSN bridge course at a northern California university.

RESULTS

Preliminary outcome assessments suggested greater than expected increases in role and campus socialization, as well as computer literacy, as a result of RN-to-BSN bridge course implementation.

CONCLUSION

The RN-to-BSN bridge course can successfully be used to transition the re-entry student and may be the link allowing RN-to-BSN students to effectively face the concurrent challenges of role socialization and computer literacy while mastering course content and course objectives.

Field-modulated selective ion storage in a quadrupole ion trap

A new method of selective ion storage in a quadrupole ion trap is described. Broadband waveforms were applied to the endcaps of an ion trap to eject unwanted ions by resonance excitation, which enhanced the storage of selected target ions. A unique trapping field amplitude modulation technique allowed the use of waveforms with fewer frequency components. The requirements and methods of calculations for frequency-optimized wave-forms are discussed. Advantages of this method include the reduction of target ion loss that results from collision-activated dissociation. In other applications, equivalent performance, relative to methods that use nonmodulated trapping fields combined with waveforms that have a higher frequency density, was shown.

Comparing antimicrobial resistant genes and phenotypes across multiple sequencing platforms and assays for Enterobacterales clinical isolates

INTRODUCTION

Whole genome sequencing (WGS) of bacterial isolates can be used to identify antimicrobial resistance (AMR) genes. Previous studies have shown that genotype-based AMR has variable accuracy for predicting carbapenem resistance in carbapenem-resistant Enterobacterales (CRE); however, the majority of these studies used short-read platforms (e.g. Illumina) to generate sequence data. In this study, our objective was to determine whether Oxford Nanopore Technologies (ONT) long-read WGS would improve detection of carbapenem AMR genes with respect to short-read only WGS for nine clinical CRE samples. We measured the minimum inhibitory breakpoint (MIC) using two phenotype assays (MicroScan and ETEST) for six antibiotics, including two carbapenems (meropenem and ertapenem) and four non-carbapenems (gentamicin, ciprofloxacin, cefepime, and trimethoprim/sulfamethoxazole). We generated short-read data using the Illumina NextSeq and long-read data using the ONT MinION. Four assembly methods were compared: ONT-only assembly; ONT-only assembly plus short-read polish; ONT + short-read hybrid assembly plus short-read polish; short-read only assembly.

RESULTS

Consistent with previous studies, our results suggest that the hybrid assembly produced the highest quality results as measured by gene completeness and contig circularization. However, ONT-only methods had minimal impact on the detection of AMR genes and plasmids compared to short-read methods, although, notably, differences in gene copy number differed between methods. All four assembly methods showed identical presence/absence of the blaKPC-2 carbapenemase gene for all samples. The two phenotype assays showed 100% concordant results for the non-carbapenems, but only 65% concordance for the two carbapenems. The presence/absence of AMR genes was 100% concordant with AMR phenotypes for all four non-carbapenem drugs, although only 22%-50% sensitivity for the carbapenems.

CONCLUSIONS

Overall, these findings suggest that the lack of complete correspondence between CRE AMR genotype and phenotype for carbapenems, while concerning, is independent of sequencing platform/assembly method.

Fluoroscopically-Guided Cervical Zygapophyseal Therapeutic Joint Injections May Reduce the Need for Radiofrequency

BACKGROUND

There is a paucity of literature studying therapeutic intraarticular zygapophyseal (commonly referred to as facet) joint injections in the atraumatic patient population. As a result of this, intraarticular injections have been dismissed as a possible treatment for cervical zygapophyseal joint-mediated pain. Radiofrequency neurotomy (RFN) is currently the accepted treatment for facet joint neck pain.

OBJECTIVE

This prospective observational study investigated injection response in an atraumatic population to determine treatment viability and whether injections reduce the need for RFN in neck pain patients.

STUDY DESIGN

Observational case series study.

SETTING

This study took place in the outpatient clinic of a private practice.

METHODS

The double-block paradigm (DBP) was used to determine if symptoms were zygapophyseal joint-mediated. Lidocaine and bupivacaine diagnostic injections were used. Participants passing the DBP underwent fluoroscopically-guided cervical zygapophyseal joint injections (betamethasone and 1% lidocaine) and 1 year of follow-up. Outcomes were a Verbal Numeric Scale score (VNS) > 2, 50% decrease in VNS, patient-reported improvement, and opioid use at the 1-year follow-up.

RESULTS

One hundred and eighteen patients were enrolled; 51 passed the DBP. These 51 patients underwent injections. Forty-four patients (59 joints) were surveyed 1 year later with 7 follow-up losses. Thirty-four of 59 joints showed ≥2-point VNS reductions or ≥ 50% overall symptomatic improvement after 1 year. Twenty-four of 44 ceased narcotics use.

LIMITATIONS

The limitations of this research included the lack of randomization and blinding, smaller sample size, and reliance on subjective reporting from the participants both immediately after the procedures and at follow-up. As this was a prospective observational study, there is the possibility of unintended bias by both patients as well as the authors.

CONCLUSION

Cervical zygapophyseal joint injections may reduce the need for RFN; additional studies are required.

KEY WORDS

Neck pain, facet joint, cervical zygapophyseal joint injections, radiofrequency neurotomy.

Fluoroscopically-Guided Cervical Zygapophyseal Therapeutic Joint Injections May Reduce the Need for Radiofrequency Neurotomy

Background: There is a paucity of literature studying therapeutic intraarticular zygapophyseal (commonly referred to as facet) joint injections in the atraumatic patient population. As a result of this, intraarticular injections have been dismissed as a possible treatment for cervical zygapophyseal joint-mediated pain. Radiofrequency neurotomy (RFN) is currently the accepted treatment for facet joint neck pain. Objective: This prospective observational study investigated injection response in an atraumatic population to determine treatment viability and whether injections reduce the need for RFN in neck pain patients. Study Design: Observational case series study. Setting: This study took place in the outpatient clinic of a private practice. Methods: The double-block paradigm (DBP) was used to determine if symptoms were zygapophyseal joint-mediated. Lidocaine and bupivacaine diagnostic injections were used. Participants passing the DBP underwent fluoroscopically-guided cervical zygapophyseal joint injections (betamethasone and 1% lidocaine) and 1 year of follow-up. Outcomes were a Verbal Numeric Scale score (VNS) > 2, 50% decrease in VNS, patient-reported improvement, and opioid use at the 1-year follow-up. Results: One hundred and eighteen patients were enrolled; 51 passed the DBP. These 51 patients underwent injections. Forty-four patients (59 joints) were surveyed 1 year later with 7 follow-up losses. Thirty-four of 59 joints showed ≥ 2-point VNS reductions or ≥ 50% overall symptomatic improvement after 1 year. Twenty-four of 44 ceased narcotics use. Limitations: The limitations of this research included the lack of randomization and blinding, smaller sample size, and reliance on subjective reporting from the participants both immediately after the procedures and at follow-up. As this was a prospective observational study, there is the possibility of unintended bias by both patients as well as the authors. Conclusion: Cervical zygapophyseal joint injections may reduce the need for RFN; additional studies are required. Key words: Neck pain, facet joint, cervical zygapophyseal joint injections, radiofrequency neurotomy

Clinical significance of weight difference between donor and recipient in heart transplantation

A standard and important criterion for donor acceptance is to match the donor's body weight to within 20% of the recipient's body weight. However, to meet the increasing demand of patients who need heart transplantation, frequently a heart that is below the standard criteria for donation is accepted. Of the 200 consecutive patients who underwent heart transplantation at the University of Arizona, 27 patients received a heart from a smaller donor with a weight difference of more than 30% (range 30% to 46%). The early mortality and late survival of these 27 patients were not different when compared with those of the patients who received transplants from donors with a weight difference of less than 30%. The probability of freedom from rejection and infection and postoperative ejection fraction were also similar between the two groups. Therefore, we believe that the widely accepted donor-recipient weight-match criterion of 20% can be safely extended.

Whole-genome sequencing of carbapenem-resistant Enterobacterales isolates in southeast Louisiana reveals persistent genetic clusters spanning multiple locations

BACKGROUND

We investigated 51 g-negative carbapenem-resistant Enterobacterales (CRE) isolates collected from 22 patients over a five-year period from six health care institutions in the Ochsner Health network in southeast Louisiana.

METHODS

Short genomic reads were generated using Illumina sequencing and assembled for each isolate. Isolates were classified as Enterobacter spp. (n = 20), Klebsiella spp. (n = 30), and Escherichia coli (n = 1) and grouped into 19 different multi-locus sequence types (MLST). Species and patient-specific core genomes were constructed representing ∼50% of the chromosomal genome.

RESULTS

We identified two sets of patients with genetically related infections; in both cases, the related isolates were collected > 6 months apart, and in one case, the isolates were collected in different locations. On the other hand, we identified four sets of patients with isolates of the same species collected within 21 days from the same location; however, none had genetically related infections. Genes associated with resistance to carbapenem drugs (blaKPC and/or blaCTX-M-15) were found in 76% of the isolates. We found three blaKPC variants (blaKPC-2, blaKPC-3, and blaKPC-4) associated with four different Enterobacter MLST variants, and two blaKPC variants (blaKPC-2, blaKPC-3) associated with seven different Klebsiella MLST variants.

CONCLUSIONS

Molecular surveillance is increasingly becoming a powerful tool to understand bacterial spread in both community and clinical settings. This study provides evidence that genetically related infections in clinical settings do not necessarily reflect temporal associations, and vice versa. Our results also highlight the regional genomic and resistance diversity within related bacterial lineages.