Sequence Type 5 (ST5) as a Possible Predictor of Bacterial Persistence in Adult Patients with Methicillin-Resistant Staphylococcus aureus Pneumonia Treated with Vancomycin.

Vancomycin remains the mainstay of treatment for methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. This study assessed risk factors for vancomycin failure in 63 patients with MRSA pneumonia through detailed clinical, microbiological, pharmacokinetic/pharmacodynamic, and genetic analyses of prospective multicenter studies conducted from February 2012 to July 2018. Therapeutic drug monitoring was performed during vancomycin treatment, and the 24-h area under the curve (AUC0-24) was calculated. All baseline strains were collected for MIC determination, heterogeneous vancomycin-intermediate S. aureus (hVISA) screening, and biofilm determination. Whole-genome sequencing was performed on the isolates to analyze their molecular typing and virulence and adhesion genes. Clinical signs and symptoms improved in 44 patients (44/63, 69.8%), with vancomycin daily dose (P = 0.045), peak concentration (P = 0.020), and sdrC (P = 0.047) being significant factors. Isolates were eradicated in 51 patients (51/63, 81.0%), with vancomycin daily dose (P = 0.009), cardiovascular disease (P = 0.043), sequence type 5 (ST5; P = 0.017), tst (P = 0.050), and sec gene (P = 0.044) associated with bacteriological failure. Although the AUC0-24/MIC was higher in the groups with bacterial eradication, the difference was not statistically significant (P = 0.108). Multivariate analysis showed that no variables were associated with clinical efficacy; ST5 was a risk factor for bacterial persistence (adjusted odds ratio, 4.449; 95% confidence interval, 1.103 to 17.943; P = 0.036). ST5 strains had higher frequencies of the hVISA phenotype, biofilm expression, and presence of some adhesion and virulence genes such as fnbB, tst, and sec than non-ST5 strains. Our study suggests that ST5 is a possible predictor of bacterial persistence in MRSA pneumonia treated with vancomycin. IMPORTANCE Few studies have simultaneously examined the influence of clinical characteristics of patients with pneumonia, the vancomycin pharmacokinetic/pharmacodynamic (PK/PD) index, and the phenotypic and genetic characteristics of methicillin-resistant Staphylococcus aureus (MRSA) strains. We assessed risk factors for vancomycin failure in patients with MRSA pneumonia by analyzing these influences in a prospective multicenter study. Sequence type 5 (ST5) was a possible predictor of bacterial persistence in adult patients with MRSA pneumonia (adjusted odds ratio, 4.449). We found that this may be related to ST5 strains having higher levels of vancomycin heterogeneous resistance, biofilms, and the presence of adhesion and virulence genes such as fnbB, tst, and sec.

Pharmacokinetics and Safety of Single-Dose Amphotericin B Colloidal Dispersion in Healthy Chinese Subjects and Population Pharmacokinetic/Pharmacodynamic Analysis to Inform Clinical Efficacy in Invasive Infections Caused by Candida albicans.

PURPOSE: Amphotericin B colloidal dispersion (ABCD) is a less toxic formulation of amphotericin B for the treatment of invasive fungal infections. The pharmacokinetic (PK) profile and safety of a generic ABCD were investigated after a single dose (0.5 to 1.5 mg/kg) administered as an intravenous infusion in 30 healthy Chinese subjects. METHODS: PK data from healthy Chinese male subjects were applied for developing a population PK model to predict the PK profiles of standard doses (3 or 4 mg/kg) in patients. A 5000-time Monte Carlo simulation of AUC0-24/MIC target was implemented to determine the probability of target attainment (PTA) and cumulative fraction of response (CFR) under standard doses. FINDINGS: The PK profiles of intravenous administration of ABCD were best described by a 3-compartmental model with a time-varying clearance and a dose-dependent volume of distribution in the peripheral compartment. PK/pharmacodynamic (PK/PD) analysis revealed that 3 or 4 mg/kg ABCD once a day resulted in favorable CRF (>98%) with 2-log reduction of Candida albicans. A high PTA (>90%) was achieved at MIC ≤2 mg/L for the dosing regimen of ABCD 3 mg/kg and 4 mg/kg for MIC ≤4 mg/L. IMPLICATIONS: PK/PD analysis indicated that a favorable efficacy of ABCD could be reached at a dose of 3 or 4 mg/kg once daily for 14 to 28 days to treat invasive fungal infections caused by C albicans. ClinicalTrials.gov identifier: NCT03577509.

Pharmacokinetics, pharmacodynamics, and safety of single- and multiple-dose intravenous ceftobiprole in healthy Chinese participants.

BACKGROUND: Ceftobiprole is a novel ß-lactam cephalosporin with activity against Gram-positive and -negative bacteria. The aim of the present study was to investigate the pharmacokinetics (PK), pharmacokinetics/pharmacodynamics (PK/PD), safety and tolerance of ceftobiprole in Chinese participants, to evaluate this dosage regimen for the treatment of community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP) in China. METHODS: The use of ceftobiprole was investigated in a single-center, open-label, single- and multiple-dose study using 12 healthy Chinese participants (6 males and 6 females). Ceftobiprole plasma and urine concentrations were analyzed using a validated liquid chromatography-tandem mass spectrometry assay. The PK/PD characteristics of 500 mg ceftobiprole every 8 h at 1.5-, 2-, 3-, or 4-h infusion time were analyzed by Monte Carlo simulations (MCS). RESULTS: The maximum plasma concentration of ceftobiprole was observed 2 h after dosage; its terminal half-life was about 3 h. Ceftobiprole was predominantly eliminated in urine, and the cumulative excretion in 24 h was >90%. There was no accumulation after multiple dosing. Both single and multiple doses were well tolerated, with no severe or serious adverse events (AEs). PK/PD analysis indicated that Staphylococcus pneumoniae (S. pneumoniae) and Staphylococcus aureus (S. aureus) were sensitive to ceftobiprole. About half of extended-spectrum ß-lactamase (ESBL) non-producing Enterobacteriaceae are sensitive to ceftobiprole, according to PK/PD results of ceftobiprole. For Pseudomonas aeruginosa (P. aeruginosa), no regimen was found to be effective against strains. CONCLUSIONS: The PK/PD results indicated that 500 mg ceftobiprole every 8 h at 2-h infusion time is expected to achieve good microbiological efficacy in the treatment of CAP and HAP in China.

Effects of Different Component Contents of Colistin Methanesulfonate on the Pharmacokinetics of Prodrug and Formed Colistin in Human.

PURPOSES: To evaluate the effects of component contents in different colistin methanesulfonate (CMS) formulas on their clinical pharmacokinetics of the prodrug CMS and the formed colistin. METHODS: Two CMS formulas (CTTQ and Parkedale) were investigated in a single dose, randomized, open-label, crossover study conducted in 18 healthy Chinese subjects. Both CMS formulas met the requirements of European Pharmacopoeia 9.2 with 12.1% difference in the two major active components (CMS A and CMS B). The PK parameters after a single intravenous infusion of CMS at 2.5 mg/kg were calculated and the steady-state plasma colistin concentrations (Css,avg) following multiple dosing, once every 12 h for 7 days, were simulated with the non-compartment model. RESULTS: The systemic exposure (AUC0-inf) of CMS were 59.49 ± 5.90 h·µg/mL and 51.09 ± 4.70 h·µg/mL, and the AUC0-inf of colistin were 15.39 ± 2.63 h·µg/mL and 12.36 ± 2.10 h·µg/mL for CTTQ and Parkedale, respectively. The ratios (90% CI) of geometric mean of AUC0-inf of CTTQ to Parkedale were 116.38% (112.95%, 119.91%) and 124.49% (120.76%, 128.35%) for CMS and colistin, respectively. The predicted Css,avg (95% CI) were 0.92 (0.85, 0.99) µg/mL and 0.74 (0.69, 0.79) µg/mL for CTTQ and Parkedale, respectively. CONCLUSION: The difference in component content in the two CMS formulas had a significant (P < 0.001) impact on the systemic exposure of colistin in human, thus, warranted essential considerations in clinical applications.

Pharmacokinetics of colistin methanesulfonate (CMS) in healthy Chinese subjects after single and multiple intravenous doses.

The high prevalence of extensively drug-resistant Gram-negative pathogens has forced clinicians to use colistin as a last-line therapy. Knowledge on the pharmacokinetics of colistin methanesulfonate (CMS), an inactive prodrug, and colistin has increased substantially; however, the pharmacokinetics in the Chinese population is still unknown due to lack of a CMS product in China. This study aimed to evaluate the pharmacokinetics of a new CMS product developed in China in order to optimise dosing regimens. A total of 24 healthy subjects (12 female, 12 male) were enrolled in single- and multiple-dose pharmacokinetic (PK) studies. Concentrations of CMS and formed colistin in plasma and urine were measured, and PK analysis was conducted using a non-compartmental approach. Following a single CMS dose [2.36 mg colistin base activity (CBA) per kg, 1 h infusion], peak concentrations (Cmax) of CMS and formed colistin were 18.0 mg/L and 0.661 mg/L, respectively. The estimated half-life (t1/2) of CMS and colistin were 1.38 h and 4.49 h, respectively. Approximately 62.5% of the CMS dose was excreted via urine within 24 h after dosing, whilst only 1.28% was present in the form of colistin. Following multiple CMS doses, colistin reached steady-state within 24 h; there was no accumulation of CMS, but colistin accumulated slightly (RAUC = 1.33). This study provides the first PK data in the Chinese population and is essential for designing CMS dosing regimens for use in Chinese hospitals. The urinary PK data strongly support the use of intravenous CMS for serious urinary tract infections.

64-Slice spiral double-low CT to evaluate the degree of stenosis and plaque composition in diagnosing coronary artery disease.

This study examined the application of 64-slice spiral double-low computed tomography (CT) to evaluate the degree of coronary artery stenosis. We examined 45 patients with coronary heart disease by 64-slice spiral double-low CT and coronary angiography (CAG) to determine CT accuracy in evaluating coronary artery stenosis. Imaging analysis from 64-slice spiral double-low CT identified 199 segments with coronary stenosis from 45 patients, including 46 segments with mild stenosis, 38 with moderate stenosis and 115 with severe stenosis or artery occlusion. CT analysis agreed with CAG on the identification of the degree of stenosis in 122 segments, with an overall accuracy of 61.3%. The accuracy for serious stenosis or occlusion was the highest at 69.6%. We also found a strong correlation between coronary plaque compositions and the degree of stenosis. Correspondence analysis showed that the presence of soft plaques closely correlated with severe stenosis, whereas mixed plaques closely correlated with moderate stenosis. Overall, 64-slice spiral double-low CT imaging can effectively assess the degree of coronary artery stenosis in patients with coronary heart disease and accurately detect plaque composition. Thus, 64-slice spiral double-low CT imaging can predict the risk of coronary heart disease and the degree of coronary artery stenosis, which is helpful for early diagnosis and treatment of coronary heart disease.

Pharmacokinetics and pharmacodynamics of multiple-dose intravenous nemonoxacin in healthy Chinese volunteers.

This study evaluated the safety and pharmacokinetic/pharmacodynamic profiles of nemonoxacin in healthy Chinese volunteers following multiple-dose intravenous infusion once daily for 10 consecutive days. The study was composed of two stages. In the open-label stage, 500 mg or 750 mg of nemonoxacin (n = 12 each) was administered at an infusion rate of 5.56 mg/min. In the second stage, with a randomized double-blind placebo-controlled design, 500, 650, or 750 mg of nemonoxacin (n = 16 in each cohort; 12 subjects received the drug and the other 4 subjects received the placebo) was given at an infusion rate of 4.17 mg/min. The results showed that, in the first stage, the maximal nemonoxacin concentrations (mean ± SD) at steady state (Cmax_ss) were 9.60 ± 1.84 and 11.04 ± 2.18 µg/ml in the 500-mg and 750-mg cohorts, respectively; the areas under the concentration-time curve at steady state (AUC0-24_ss) were 44.03 ± 8.62 and 65.82 ± 10.78 µg · h/ml in the 500-mg and 750-mg cohorts, respectively. In the second stage, the nemonoxacin Cmax_ss values were 7.13 ± 1.47, 8.17 ± 1.76, and 9.96 ± 2.23 µg/ml in the 500-mg, 650-mg, and 750-mg cohorts, respectively; the AUC0-24_ss values were 40.46 ± 9.52, 54.17 ± 12.10, and 71.34 ± 17.79 µg · h/ml in the 500-mg, 650-mg, and 750-mg cohorts, respectively. No accumulation was found after the 10-day infusion with any regimen. The drug was well tolerated. A Monte Carlo simulation indicated that the cumulative fraction of response of any dosing regimen was nearly 100% against Streptococcus pneumoniae. The probability of target attainment of nemonoxacin therapy was >98% when the MIC of nemonoxacin against S. pneumoniae was ≤1 mg/liter. It is suggested that all of the studied intravenous nemonoxacin dosing regimens should have favorable clinical and microbiological efficacies in future clinical studies. (This study has been registered at ClinicalTrials.gov under registration no. NCT01944774.).

A randomized controlled clinical trial of levofloxacin 750 mg versus 500 mg intravenous infusion in the treatment of community-acquired pneumonia.

The objective of this study was to compare the efficacy and safety of levofloxacin 750 mg for 5 days versus 500 mg for 7-14 days intravenous (IV) in the treatment of community-acquired pneumonia (CAP). This clinical trial was the first of its kind conducted in Chinese people and also in Asian population. A total of 241 were enrolled and randomized to 750 mg group (n = 121) or 500 mg (n = 120) group from 10 study centers. The median treatment duration was 5.0 days in 750 mg and 9.0 days in 500 mg group. The median total dose was 3750 mg in 750 mg and 4500 mg in 500 mg group. The bacterial eradication rate was 100% in both groups. The overall efficacy rate in 750 mg group was 86.2% (94/109), and 84.7% (94/111), in 500 mg group of full analysis set visit 4, 95% confidence interval of 1.6% (-7.8-10.9%); the statistical results showed that 750 mg group was non-inferior to 500 mg group. The most common clinical adverse drug reactions were injection site adverse reactions in both 750 mg group and 500 mg group; the other common adverse drug reactions were insomnia, nausea, skin rash, etc. The most common drug-related laboratory abnormalities were neutrophil percentage decreased, decreased white blood cell count, alanine aminotransferase, and aspartate aminotransferase elevation in both 750 mg group and 500 mg group. Most of adverse drug reactions were mild in severity and well-tolerated. In summary, the regimen of levofloxacin 750 mg IV for 5 days was at least as effective and well tolerated as 500 mg IV for 7-14 days for the treatment of CAP.

Safety, tolerability, and pharmacokinetics of intravenous nemonoxacin in healthy chinese volunteers.

Nemonoxacin (TG-873870) is a novel nonfluorinated quinolone with potent broad-spectrum activity against Gram-positive, Gram-negative, and atypical pathogens, including vancomycin-nonsusceptible methicillin-resistant Staphylococcus aureus (MRSA), quinolone-resistant MRSA, quinolone-resistant Streptococcus pneumoniae, penicillin-resistant S. pneumoniae, and erythromycin-resistant S. pneumoniae. This first-in-human study was aimed at assessing the safety, tolerability, and pharmacokinetic properties of intravenous nemonoxacin in healthy Chinese volunteers. The study comprised a randomized, double-blind, placebo-controlled, dose escalating safety and tolerability study in 92 subjects and a randomized, single-dose, open-label, 3-period Latin-square crossover pharmacokinetic study in 12 subjects. The study revealed that nemonoxacin infusion was well tolerated up to the maximum dose of 1,250 mg, and the acceptable infusion rates ranged from 0.42 to 5.56 mg/min. Drug-related adverse events (AEs) were mild, transient, and confined to local irritation at the injection site. The pharmacokinetic study revealed that after the administration of 250, 500, and 750 mg of intravenous nemonoxacin, the maximum plasma drug concentration (Cmax) values were 4.826 µg/ml, 7.152 µg/ml, and 11.029 µg/ml, respectively. The corresponding values for the area under the concentration-time curve from 0 to 72 hours (AUC0-72 h) were 17.05 µg · h/ml, 39.30 µg · h/ml, and 61.98 µg · h/ml. The mean elimination half-life (t1/2) was 11 h, and the mean cumulative drug excretion rate within 72 h ranged from 64.93% to 77.17%. Volunteers treated with 250 to 750 mg nemonoxacin exhibited a linear dose-response relationship between the AUC0-72 h and AUC0-∞. These findings provide further support for the safety, tolerability, and pharmacokinetic properties of intravenous nemonoxacin. (This study has been registered at ClinicalTrials.gov under registration no. NCT01944774.).

Linezolid for the treatment of infections caused by Gram-positive pathogens in China.

In this randomised, double-blind, comparator-controlled, multicentre study conducted in China, 142 hospitalised patients aged 18-75 years with pneumonia (n=80) or complicated skin and soft-tissue infection (cSSTI) (n=62) due to suspected or known Gram-positive pathogens were randomised (1:1) to receive either linezolid 600mg (n=71) or vancomycin 1g in patients aged < or =60 years or 0.75g in patients aged >60 years (n=71) intravenously every 12h. The duration of treatment was 10-21 days for patients with pneumonia and 7-21 days for patients with cSSTI. Clinical outcomes were assessed at end-of-treatment (EOT) visit and follow-up (FU) visit 7-28 days post therapy. Staphylococcus aureus was the most common pathogen at baseline and most of these isolates were resistant to meticillin. All isolates were susceptible to linezolid and vancomycin. For the evaluable patients, the effective treatment rate for linezolid was higher than that for vancomycin at EOT (86.9% (53/61) vs. 61.7% (37/60)) and at FU (83.1% (49/59) vs. 64.9% (37/57)). Pathogen eradication rates for the microbiologically evaluable patients at FU were 79.2% (42/53) for linezolid and 61.5% (32/52) for vancomycin. The incidence of drug-related adverse events (AEs) was 25.4% (18/71) for linezolid and 16.9% (12/71) for vancomycin. Four (5.6%) linezolid-treated and eight (11.3%) vancomycin-treated patients discontinued the study drug because of an AE. Linezolid was well tolerated and effective for the treatment of infections caused by Gram-positive pathogens, including meticillin-resistant S. aureus.

Antinucleosome antibodies correlate with the disease severity in children with systemic lupus erythematosus.

We compared the serum levels of antinucleosome antibodies (anti-NCS Abs) in thirty pediatric systemic lupus erythematosus (SLE) patients by using enzyme-linked immunosorbent assay (ELISA) to 29 adult SLE patients, 30 healthy controls, 21 juvenile idiopathic arthritis (JIA) and 23 Henoch-Schonlein purpura (HSP) patients as autoimmune disease controls. The mean anti-NCS Ab titer in the pediatric SLE patients was 1552.7+/-1842.2 U/ml, higher than those of adult SLE patients (194.3+/-402.7 U/ml), normal controls (9.5+/-5.7 U/ml) and disease controls (JIA: 7.7+/-4.0 U/ml, HSP: 5.7+/-4.4 U/ml) (p<0.05). The prevalence of both anti-NCS Ab (90%) and anti-ds DNA Ab (76.7%) in pediatric SLE patients were higher (p<0.05) than that of adult SLE patients (58.6% and 48.3%). A positive correlation was demonstrated between anti-NCS Ab and anti-dsDNA Ab as well as the SLEDAI scores in pediatric and adult patients (p<0.05). The inverse correlation of anti-NCS Ab levels with C3 was observed in both pediatric and adult SLE patients (pediatrics, r=-0.61, p=0.0003; adult, r=-0.44, p=0.02). Our data suggested that in pediatric SLE patients, anti-NCS Ab could be as good a marker for SLE diagnosis and disease activity assessment as in adult SLE patients.

[The adverse reactions of parenteral norvancomycin in 1031 patients].

OBJECTIVE: To investigate the safety of norvancomycin, and provide basis for its rational use in clinical practice. METHODS: We documented all adverse events occurred in inpatients who receive intravenous infusion of norvancomycin, then we evaluated the relationship between adverse events and norvancomycin and calculated the rates of adverse reaction. RESULTS: 1031 patients were enrolled in this study from March 2002 to June 2003 and 965 of them could be evaluated. 80 adverse reactions occurred in 965 patients who received norvancomycin, giving a total adverse reaction rate of 8.29%. The systemic adverse reactions included renal impairment (4.04%), hepatic impairment (2.38%) and allergic reaction (1.76%). 15 patients discontinued the treatment because of the adverse reaction. The rates were higher in patients who use other antimicrobial agents concomitantly or whose age >/= 60 years. The rates of renal impairment were higher in those with age >/= 60 years, and the rates of hepatic impairment were higher in whose received this agent longer than 14 days. These factors were independent risk factors (P < 0.05). CONCLUSIONS: The overall adverse reaction rate of norvancomycin was low. A few patients experienced drug-related reaction, most of these adverse reactions were mild and tolerable. The adverse reactions tended to occur in older patients, those who use other antibiotic concomitantly or those who receive this agent longer than 14 days.