Selective advantage of resistant strains at trace levels of antibiotics: a simple and ultrasensitive color test for detection of antibiotics and genotoxic agents.

Many studies have examined the evolution of bacterial mutants that are resistant to specific antibiotics, and many of these focus on concentrations at and above the MIC. Here we ask for the minimum concentration at which existing resistant mutants can outgrow sensitive wild-type strains in competition experiments at antibiotic levels significantly below the MIC, and we define a minimum selective concentration (MSC) in Escherichia coli for two antibiotics, which is near 1/5 of the MIC for ciprofloxacin and 1/20 of the MIC for tetracycline. Because of the prevalence of resistant mutants already in the human microbiome, allowable levels of antibiotics to which we are exposed should be below the MSC. Since this concentration often corresponds to low or trace levels of antibiotics, it is helpful to have simple tests to detect such trace levels. We describe a simple ultrasensitive test for detecting the presence of antibiotics and genotoxic agents. The test is based on the use of chromogenic proteins as color markers and the use of single and multiple mutants of Escherichia coli that have greatly increased sensitivity to either a wide range of antibiotics or specific antibiotics, antibiotic families, and genotoxic agents. This test can detect ciprofloxacin at 1/75 of the MIC.

Uncharted waters: mesenchymal stem cell treatment for pediatric refractory rheumatic diseases; a single center case series.

BACKGROUND: With the advent of innovative therapies including biologics and Janus kinase inhibitors, children with rheumatic diseases are more likely to have improved outcomes. Despite these advances, some children do not respond, or they, or their parents fear adverse events and seek other alternatives. Increasingly, private companies are offering mesenchymal stem cells (MSC) as an alternative, which are described as natural therapies for rheumatic diseases, often insinuating them as a cure. MSC have immunomodulatory properties, and transplantation of these stem cells have been used to successfully treat immunologic conditions like graft-versus-host disease. Lately, MSC research in adult lupus has been encouraging, but the clinical trials are still underway and in most, MSC therapy is not a standalone treatment. This retrospective case series will highlight three cases of pediatric refractory autoimmune disease whose parents sought out and received MSC therapy as a self-decision without first seeking medical advice from our specialty. The three families felt that their children were improved and in two believed that their child was cured. MSC have the potential of beneficial immunomodulation and may be a powerful tool in the therapy of rheumatic disease, but well controlled clinical trials are necessary and should be designed and monitored by experts in childhood rheumatic disease. CASE PRESENTATION: Three children with three different rheumatic diseases; systemic lupus erythematosus, mixed connective tissue disease and juvenile idiopathic arthritis were under the care of pediatric rheumatology at a large, tertiary-care, teaching institution. Multiple non-biologic and biologic disease-modifying anti-rheumatic drugs failed to significantly decrease disease activity, and as a result, the families chose to undergo MSC therapy. After transplantation, all children improved per patient and parent report and tapered off conventional immunosuppressive drugs. No serious adverse events occurred in these three patients. CONCLUSION: The three cases presented in this report reflect comparable beneficial outcomes and minimal risks published in adult studies. These were not controlled studies, however, and benefit was reported rather than documented. These cases suggest that MSC transplantation may prove a promising adjunctive treatment option; however, further research, development of standardized infusion therapy protocols, and well-designed monitored clinical trials are essential.

Association of mood disorders with cardiovascular disease risk factors in overweight and obese youth with elevated blood pressure.

The American Heart Association defines mood disorders (MDO) as a tier-II cardiovascular disease risk factor in children. Cross-sectional analysis of overweight/obese children referred to an obesity hypertension clinic revealed 37% had a MDO (defined by clinical diagnosis or Patient Health Questionnaire-9/-A score ≥10), 55% had confirmed hypertension, and 75% left ventricular hypertrophy (LVH). Children with MDOs were older, had greater measures of adiposity, and had a greater prevalence of hypertension (78%) than those without MDOs (42%; P = .04). Hypertensive children were 2.8 times more likely to have a MDO than those without (52% vs 18%; P = .02). Multivariable logistic regression revealed a statistically significant independent association of MDOs with hypertension (Odds Ratio [OR] 6.3, P = .048), but not LVH (LVMI ≥ 51 g/m2.7 ; OR 1.13, P = .88). Overall, the prevalence of MDOs in this group of overweight/obese children with elevated blood pressure was well above national averages, suggesting that at-risk youth, particularly those with confirmed hypertension, should be regularly screened for MDOs.

Association of Anticentromere Antibodies With More Severe Exocrine Glandular Dysfunction in Sjögren's Syndrome: Analysis of the Sjögren's International Collaborative Clinical Alliance Cohort.

OBJECTIVE: Anticentromere antibodies (ACAs) define a subset of primary Sjögren's syndrome (SS) with a unique phenotype, including features of limited cutaneous systemic sclerosis and a lower frequency of anti-SSA/SSB antibodies. We sought to determine whether ACAs are associated with more severe exocrine glandular dysfunction in a large cohort of primary SS subjects. METHODS: We performed a cross-sectional analysis of 1,361 subjects with primary SS from the Sjögren's International Collaborative Clinical Alliance Registry, stratified by the presence or absence of ACAs. ACAs were assayed by immunofluorescence staining on HEp-2 cells. RESULTS: ACAs were present in 82 of the 1,361 SS subjects (6%) and were associated with older age, female sex, and lower frequencies of anti-SSA/SSB, rheumatoid factor, and hyperglobulinemia. Among ACA-positive versus ACA-negative subjects, there was a higher frequency of a focus score ≥2 (71% versus 53%; P = 0.002), a higher median focus score (2.8 versus 2.5; P = 0.0440), and greater exocrine gland dysfunction: Schirmer's test value: median 4 versus 5 mm/5 minutes; P = 0.0003, and unstimulated whole saliva (UWS) flow rate: median 0.08 versus 0.37 ml/5 minutes; P < 0.0001. ACA-positive subjects had an increased risk of UWS <0.1 ml/minute (odds ratio [OR] 12.24 [95% confidence interval (95% CI) 4.91-41.02]) and Schirmer's test value <5 mm/5 minutes (OR 2.52 [95% CI 1.50-4.36]) after correcting for age, sex, anti-SSA/SSB, and focus score. Labial gland fibrosis was not different between the 2 groups. CONCLUSION: In a large international registry of SS, ACA had an independent association with more severe exocrine glandular dysfunction. This dysfunction was associated with more pronounced labial salivary glandular inflammation but not fibrosis.