Performance of different methods for testing polymyxin B: comparison of broth microdilution, agar dilution and MIC test strip in mcr-1 positive and negative Escherichia coli

Antimicrobial susceptibility testing with the last-resort antibiotics polymyxins (polymyxin B and colistin) is associated with several methodological issues. Currently, broth microdilution (BMD) is recommended for colistin and polymyxin B. BMD is laborious and the utility of alternative methods needs to be evaluated for polymyxin B susceptibility testing. In this study, using BMD as a reference method, the performance of agar dilution (AD) and MIC test strips (MTS) were evaluated in polymyxin B susceptibility testing. BMD, AD and MTS were used to determine MICs of 193 clinical isolates of Escherichia coli. Seventy-nine were positive for the polymyxin resistance gene mcr-1. Method performances were evaluated based on pair-wise agreements with the reference method (BMD) and statistical testing. AD and MTS showed an unacceptable number of very major errors (VMEs) compared with BMD, 9·3 and 10·7%, respectively. The essential agreement (EA) was low for AD (49·7%), but high for MTS (97·8%). However, statistical testing showed that MTS tended to yield a one-step lower MIC (P < 0·01) compared with BMD. The discordances observed with MTS and AD in comparison with BMD for polymyxin B susceptibility testing for E. coli suggest their inapplicability in routine testing. A large number of isolates clustered around the susceptibility breakpoint (2-4 mg l^-1 ) and several mcr-1 positive isolates (17%) were determined as susceptible with BMD. A screening breakpoint for mcr-1 of 2 mg l^-1 should also be considered.

MDR Salmonella enterica serovar Typhimurium ST34 carrying mcr-1 isolated from cases of bloodstream and intestinal infection in children in China

OBJECTIVES

Children are vulnerable to Salmonella infection due to their immature immune system. Cases of infection with mcr-1-harbouring Salmonella in child inpatients have not been reported in China before.

METHODS

Salmonella isolates from gastroenteritis and bacteraemia were screened using primers targeting mcr-1. Complete genome sequences of mcr-1-harbouring isolates were determined using the PacBio RS II platform. The transferability of mcr-1-harbouring plasmids was verified by conjugation.

RESULTS

We investigated two mcr-1-carrying polymyxin-resistant Salmonella enterica serovar Typhimurium ST34 isolates, S61394 and S44712, from bloodstream and intestinal Salmonella infection of two child inpatients, respectively. Both isolates were non-susceptible to commonly used antibiotics for children that compromised the success of clinical treatment and infection control. The mcr-1-harbouring plasmids pLS61394-MCR and pLS44712-MCR (from S61394 and S44712, respectively) were both conjugative pHNSHP45-2-like IncHI2-type epidemic plasmids carrying multiple resistance genes. Compared with pHNSHP45-2, a ∼33 kb insertion region encoding Tn7 transposition protein and heavy metal resistance proteins was identified in pLS61394-MCR, which might enhance adaptation of bacteria carrying this plasmid to various ecological niches. The phylogenetic tree of worldwide mcr-harbouring Salmonella indicated a host preference of mcr and a worldwide and cross-sectoral prevalence of the mcr-positive Salmonella ST34 clone.

CONCLUSIONS

To our knowledge, for the first time we report completed whole genomes of mcr-1-positive MDR Salmonella Typhimurium ST34 isolated from infected children in China, suggesting that improved surveillance is imperative for tackling the dissemination of mcr-harbouring MDR Salmonella Typhimurium ST34.

Plasma metabolome alteration in dairy cows with left displaced abomasum before and after surgical correction

Left displaced abomasum (LDA) leads to substantial changes in the metabolism of dairy cows. Surgical correction of LDA can rapidly improve the health of cows; however, changes in metabolism following surgery are rarely described. To investigate the changes of plasma metabolome in cows with LDA before and after surgical correction, blood samples were collected from 10 healthy postpartum cows and 10 cows with LDA on the day of diagnosis, then again from the LDA cows 14 d after surgery. Serum nonesterified fatty acid, β-hydroxybutyric acid, cortisol and histamine concentration, and antioxidant enzyme (superoxide dismutase and glutathione peroxidase) activities were evaluated, and the metabolic profile in plasma was analyzed using ultra-high-performance liquid chromatography time-of-flight mass spectrometry. The results demonstrated that cows with LDA experienced severe negative energy balance and oxidative stress, which can be improved by surgical correction. The metabolic profile was analyzed using multidimensional and univariate statistical analyses, and different metabolites were identified. In total, 102 metabolites differed between cows with LDA and healthy cows. After surgical correction, 65 metabolites changed in cows with LDA, compared with these cows during the LDA event. Following surgical correction, AA levels tended to increase, and lipid levels tended to decrease in cows with LDA. Pathway analysis indicated marked changes in linoleic acid metabolism, Arg biosynthesis, and Gly, Ser, and Thr metabolism in cows at the onset of LDA and following surgical correction. Surgical treatment reversed the changes in AA and lipid metabolism in cows with LDA.

[Mechanism of Ziyin recipe for treatment of ovulatory infertility: a network pharmacology-based study and clinical observations]

OBJECTIVE

To explore the mechanisms of Ziyin recipe for treatment of ovulatory infertility based on network pharmacology analysis and evaluate the clinical efficacy of this recipe.

OBJECTIVE

TCMSP, PubChem, Genecards, String, Swiss Target Prediction, and Uniprot databases were searched to identify all the action targets of Ziyin recipe and ovulatory infertility to construct the PPI network. Gene ontology (GO) and KEGG pathway enrichment analyses were performed and the "TCM-active ingredient-target-pathway" network was constructed using Cytoscape 3.6.0. We also designed a controlled clinical trial to verify the clinical effectiveness of Ziyin recipe. The patients were randomized into 2 groups to receive treatment with Western medicine including CC and HMG (control group) and additional treatment with Ziyin recipe, and the dosage of GN, follicular development days, E₂ level of a single dominant follicle on trigger day, ovulation rate, the rate of LUFS, and clinical pregnancy rate were compared between the two groups.

OBJECTIVE

We identified 22 active ingredients and 354 targets of action in Ziyin recipe, 791 targets of ovulatory infertility, and 96 common targets of action shared by Ziyin recipe and ovulatory infertility. According to Degree, the key targets included SRC, MAPK1, HSP90aa1, MAPK3, PTPN11, ESR1, Akt1, EGFR, NR3C1 and KNG1. Enrichment analysis of GO biological process showed that Ziyin recipe mainly focused on steroid hormonemediated signaling pathway, oxidation, reduction, and apoptosis. The most significantly enriched signaling pathways included PI3K-Akt signaling pathway, RAP1 signaling pathway, HIF-1 signaling pathway, estrogen signaling pathway, ovarian steroid production, and steroid hormone biosynthesis. The results of the clinical trial showed that Ziyin recipe significantly reduced the dose of GN, accelerated follicle development, increased E₂ level of single dominant follicle on the trigger day, and increased the cycle ovulation rate and pregnancy rate.

OBJECTIVE

The therapeutic effects of Ziyin recipe are probably mediated through different pathways to promote follicle development, thus improving ovulation rate and clinical pregnancy rate of infertile patients with ovulatory disorders.

[Occlusion variation of posterior implant-supported single crown: a prospective 4-year follow-up study]

Objective: To analyze the longitudinal variation of occlusal force distribution and occlusal contact time in posterior implant-supported single crown with the computerized occlusal analysis system. Methods: Partially edentulous patients who visited the Department of Prosthodontics, Peking University School and Hospital of Stomatology between December 2012 and December 2013, and had received implant-supported single crown in the posterior region were enrolled. The participants underwent occlusal examinations with the computerized occlusal analysis system at 2 weeks, 3 and 6 months, 1, 2, 3, and 4 years after implant prosthesis delivery. The relative occlusal force (ROF) of implant prostheses, mesial adjacent teeth, and control teeth (corresponding teeth on the contralateral side) were recorded, and implant prosthesis occlusion time ratios (implant prosthesis occlusion time/occlusion time) were calculated. The interproximal contact between implant prostheses and adjacent teeth was evaluated using metal contact gauge and dental floss. Mechanical complications of implant prostheses were recorded. The paired t test or Wilcoxon signed-rank test was used to compare the implant prosthesis occlusion time ratios and ROF of implant prostheses at 2 different times as a self-control. The differences in ROF between implant prostheses and control teeth in the same participant at the same time were also analyzed using paired t test. Using a complementary log-log model, the correlation between the occurrence of veneering material fracture and ROF of implant prosthesis was analyzed with gender, age and follow-up time as the control variables. Results: Thirty-seven posterior fixed implant-supported single crowns in 33 participants, including 16 men and 17 women aged (42.8±12.9) years (23.9 to 70.0 years) were followed up for 2 weeks to 4 years [(38.3±15.2) months]. The ROF of implant prostheses increased significantly (P<0.01) from 2 weeks [(7.0±4.2)%] to 3 months [(9.9±6.8)%], whereas those of control natural teeth decreased significantly (P<0.05) from (13.1±6.1)% to (11.4±5.5)%. The ROF of implant prostheses continued to increase from 6 months to 1 year, from 1 year to 2 years and from 2 years to 3 years, with significant differences (P<0.05). Implant prosthesis occlusion time ratios also increased significantly between 2 weeks and 3 months and between 3 months and 6 months (P<0.05). No significant differences were found between other time points (P>0.05). For comparison between implant prosthesis and control teeth at the same time point, the ROF of the implant prostheses [(7.5±4.2)%] were significantly lower than those of the control teeth [(13.8±6.0)%] at 2 weeks (P<0.01). While at 4 years, ROF of implant prostheses [16.7% (8.6%, 32.4%)] became significantly higher than those of control teeth [9.5% (4.9%, 18.0%)] (P<0.05). ROF of the implant prostheses did not differ significantly with those of the control teeth in other follow-up time points (P>0.05). The 4-year cumulative incidence of proximal contact loss rate was 32% (22/68). The incidences of veneering material fracture and prostheses loosening were 16% (6/37) and 8% (3/37), respectively. Logistic regression showed a significant correlation between veneering material fracture and ROF of implant prostheses (r=0.26, P<0.05). Conclusions: The occlusal force and occlusal contact time of posterior implant-supported single crown change over time in 4-year follow-up period, which is mainly reflected in the increasing occlusal force and occlusal contact time. The occlusion of posterior implant prostheses should be carefully monitored during follow-up examinations, and occlusal adjustment should be considered when necessary.

Change in Antibiotic Use in Secondary and Tertiary Hospitals Nationwide After a National Antimicrobial Stewardship Campaign Was Launched in China, 2011-2016: An Observational Study

BACKGROUND

An antimicrobial stewardship campaign was launched in 2011 by the Ministry of Health. This study aimed to assess the achievements and trends in the clinical use of antibiotics in secondary and tertiary hospitals following this campaign in China.

METHODS

This observational study analyzed nationwide hospital antibiotic procurement and consumption data and antibiotic-resistance surveillance data based on claims filed in 2010-2016.

RESULTS

After a 6-year national campaign, the proportion of outpatients and surgical patients who received antibiotic treatment decreased from 19.5% to 8.5% and from 97.9% to 38.3%, respectively. The intensity of antibiotic use among inpatients decreased from 85.3±29.8 defined daily dosage (DDD) per 100 patient days to 48.5±8.0 DDD per 100 patient days. Moreover, the antibiotic procurement expenditure among hospitals declined from 22.3% of total drug procurement costs in 2010 to 12.1% in 2016, although total drug procurement costs doubled during that time. The incidence of methicillin-resistant Staphylococcus aureus isolates also dropped (from 54.4% in 2010 to 34.4% in 2016), as did the proportion of carbapenem-resistant Pseudomonas aeruginosa isolates (from 30.8% to 22.3%).

CONCLUSIONS

The 6-year campaign successfully reduced antibiotic consumption and irrational drug use in Chinese hospitals which was associated with declines in the prevalence of common antibiotic-resistant bacteria.

Wza gene knockout decreases Acinetobacter baumannii virulence and affects Wzy-dependent capsular polysaccharide synthesis

To investigate the virulence of capsular polysaccharide export protein (Wza) in carbapenem-resistant Acinetobacter baumannii and its effect on capsule formation.

wza gene knockout and complementation strains were constructed, and changes in bacterial virulence were observed using in vitro adhesion, antiserum complement killing, anti-oxidation experiments, and infections in Galleria mellonella and mice. The effect of wza knockout on the genes wzb and wzc and wzi were assessed by RT-PCR.

We successfully constructed wza knockout and complementation strains. Compared with wild-type (WT) strains, wza knockout strains displayed lower adhesion to A549 cells (p = 0.044), lower antiserum complement killing ability (p = 0.001), and lower mortality of G. mellonella (p = 0.010) and mice (p = 0.033). Expression levels of wzb, wzc and wzi were decreased in wza knockout strains. The antioxidant capacity of Wza knockout bacteria was only slightly decreased. Complementation of the wza gene returned the adhesion ability, antiserum complement killing ability, and mortality of G. mellonella and mice to WT levels. Expression of wzb, wzc and wzi was also returned to WT levels following wza complementation.

The results clearly demonstrate that Wza is toxic. Wza affects the expression of other proteins of the Wzy capsule polysaccharide synthesis pathway, which affects the assembly, export, and extracellular fixation of capsular polysaccharide, resulting in synergistic effects that decrease bacterial virulence.

Serotype Is Associated With High Rate of Colistin Resistance Among Clinical Isolates of Salmonella

To investigate the prevalence, probable mechanisms and serotype correlation of colistin resistance in clinical isolates of Salmonella from patients in China, Salmonella isolates were collected from fecal and blood samples of patients. In this study, 42.8% (136/318) clinical isolated Salmonella were resistant to colistin. MIC distribution for colistin at serotype level among the two most prevalent serotypes originating from humans in China indicated that Salmonella Enteritidis (83.9% resistance, 125/149) were significantly less susceptible than Salmonella Typhimurium (15.3% resistance, 9/59, P < 0.01). mcr genes and mutations in PmrAB confer little for rate of colistin resistant Salmonella isolated from human patients. Phylogenetic tree based on core-genome single nucleotide polymorphisms (SNPs) was separately by the serotypes and implied a diffused distribution of MICs in the same serotype isolates. Relatvie expression levels of colistin resistant related pmr genes were significantly higher in non-mcr colistin resistant S. Typhimurium than in colistin sensitive S. Typhimurium, but no discernable differences between colistin resistant and sensitive S. Enteritidis, indicating a different mechanism between colistin resistant S. Typhimurium and S. Enteritidis. In conclusion, colistin susceptibility and colistin resistant mechanism of clinical isolated Salmonella were closely associated with specific serotypes, at least in the two most prevalent serotype Enteritidis and Typhimurium. We suggest clinical microbiology laboratory interpreting Salmonella colistin MIC results in the serotype level.

China's experience in COVID-19 prevention and control among children in its different regions

OBJECTIVE

To summarize the experience of three Chinese cities (Wuhan, Shanghai and Haikou) and provide a reference for global efforts to combat COVID-19 spread among children.

MATERIALS AND METHODS

Through collecting the measures and outcomes of preventing and controlling COVID-19 in China's three hospitals, we compared the effect of different strategies.

RESULTS

From January to March 2020, the number of suspected and confirmed COVID-19 cases in Wuhan increased exponentially, and Wuhan Children's Hospital as a whole was transformed into a designated quarantine and treatment facility, which is the "Wuhan Model". Shanghai has more children's hospitals with better capabilities to tackle public health emergency. Besides, it is far away from Wuhan and had a small caseload. Children's Hospital of Fudan University, a facility in Shanghai to treat pediatric infectious diseases, is famous for its well-equipped building for infectious disease treatment and professional medical team, and therefore no major transformation was required. That is the "Shanghai Model". Haikou is located on an island. Amid the outbreak, large numbers of tourists and travelers from Hubei had already arrived in Haikou. Hainan Women and Children's Medical Center, as the only pediatric care hospital in Hainan Province, did not have a separate building for infectious disease treatment. After a citywide survey of the medical resources and facilities available, a temporarily idle hospital 3 kilometers away from Hainan Women and Children's Medical Center was requisitioned as the quarantine and treatment facility for pediatric cases. That is the "Hainan Model". The three models enabled the treatment of all suspected and confirmed cases and no fatality was reported.

CONCLUSIONS

The COVID-19 coping strategies for children should be designed according to the existing conditions of the local children's hospitals and the risk levels of the epidemic.

Suppression of myocardial HIF-1 by pubertal insulin resistance compromises metabolic adaptation and impairs cardiac function in patients with cyanotic congenital heart disease

Background

Cyanotic congenital heart disease (CCHD) is a complex pathophysiological condition involving systemic chronic hypoxia (CH). A proportion of CCHD patients are unoperated due to various reasons. These patients remain CH all their lives and are at increased risk of heart failure as they age. Hypoxia activates cellular metabolic adaptation to balance energy demands by accumulation of hypoxia-inducible factor 1α (HIF-1α).

Purpose

The aim of this study was to determine the effect of CH on cardiac metabolism and function in CCHD patients and how it relates with age. The mechanistic role of HIF-1α in this process was investigated and potential therapeutic targets were explored.

Methods

CCHD patients (n=20) were evaluated for cardiac metabolism and function by positron-emission tomography/computed tomography and magnetic resonance imaging. Heart tissues collected during surgical intervention were subjected to metabolomic and protein analyses. CH rodent models were generated to enable continuous observation of changes in cardiac metabolism and function. The role of HIF-1α in cardiac metabolic adaptation to CH was investigated using genetically modified animals and isotope-labeled metabolomic-pathway tracing studies.

Results

Prepubertal CCHD patients had glucose-dominant cardiac metabolism and normal cardiac function. By comparison, among patients who had entered puberty, the level of myocardial glucose uptake and glycolytic intermediates were significantly lower, but fatty acids were significantly higher, along with decreased left ventricular ejection fraction. These clinical phenotypes were replicated in CH rodent models. In patients and animals with CH, myocardial HIF-1α was upregulated prior to puberty, but was significantly downregulated during puberty. In cardiomyocyte-specific Hif-1α-knockout mice, CH failed to initiate the switch of myocardial substrates from fatty acids to glucose, leading to inhibition of ATP production and impairment of cardiac function. Increased insulin resistance (IR) suppressed myocardial HIF-1α and was responsible for cardiac metabolic maladaptation under CH during puberty. Pioglitazone significantly reduced myocardial IR, restored glucose metabolism, and improved cardiac function in pubertal animals.

Conclusions

In CCHD patients, maladaptation of cardiac metabolism occurred during puberty, impairing cardiac function. HIF-1α was identified as the key regulator of cardiac metabolic adaptation under CH but its expression was suppressed by pubertal IR. The use of pioglitazone during puberty might help improve cardiac function in these patients.

Metabolic maladaptation in CCHD patients

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): National Natural Science Foundation of China (81525002, 31971048) and Shanghai Outstanding Medical Academic Leader

Comparative Analysis of Virulence and Toxin Expression of Vancomycin-Intermediate and Vancomycin-Sensitive Staphylococcus aureus Strains

Previous studies on vancomycin-intermediate Staphylococcus aureus (VISA) have mainly focused on drug resistance, the evolution of differences in virulence between VISA and vancomycin-sensitive S. aureus (VSSA) requires further investigation. To address this issue, in this study, we compared the virulence and toxin profiles of pair groups of VISA and VSSA strains, including a series of vancomycin-resistant induced S. aureus strains—SA0534, SA0534-V8, and SA0534-V16. We established a mouse skin infection model to evaluate the invasive capacity of VISA strains, and found that although mice infected with VISA had smaller-sized abscesses than those infected with VSSA, the abscesses persisted for a longer period (up to 9 days). Infection with VISA strains was associated with a lower mortality rate in Galleria mellonella larvae compared to infection with VSSA strains (≥ 40% vs. ≤ 3% survival at 28 h). Additionally, VISA were more effective in colonizing the nasal passage of mice than VSSA, and in vitro experiments showed that while VISA strains were less virulent they showed enhanced intracellular survival compared to VSSA strains. RNA sequencing of VISA strains revealed significant differences in the expression levels of the agr, hla, cap, spa, clfB, and sbi genes and suggested that platelet activation is only weakly induced by VISA. Collectively, our findings indicate that VISA is less virulent than VSSA but has a greater capacity to colonize human hosts and evade destruction by the host innate immune system, resulting in persistent and chronic S. aureus infection.

Economic Burden of Patients with Bloodstream Infections Caused by Extended-Spectrum β-Lactamase-Producing Escherichia coli

Background

The prevalence of infections with extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) is increasing worldwide, but the economic impact of ESBL-EC bloodstream infection (BSI) has not been comprehensively evaluated.

Patients and Methods

A retrospective cohort including patients hospitalized at a tertiary hospital between January 2013 and December 2016 who were confirmed with a BSI of ESBL-EC or non-ESBL-EC was set. Clinical data and medical costs were collected by chart review of electronic and paper medical records. The economic burden was evaluated with disability-adjusted life years (DALYs).

Results

A total of 580 patients with E. coli BSI, comprising 333 patients (57.4%) with ESBL-EC BSI and 247 patients (42.6%) with non-ESBL-EC BSI, were identified. There were no significant differences in comorbidity and severity of patients between ESBL-EC and non-ESBL-EC BSI. The median length of stay (LOS) after bacteremia was 12 days for ESBL-EC (interquartile range, 7 to 21) versus 11 days for non-ESBL-EC (interquartile range, 7 to 21) (P = 0.38), and appropriate empirical antimicrobial therapy occurred in 87.4% versus 89.9% (P = 0.353). The mortalities were 20.1% versus 17.4% (P = 0.41). Patients with ESBL-EC did not have significantly different in-hospital medical costs to those with non-ESBL-EC (median, $8048.68 vs $7476.84, respectively, with a difference of $571.84, P = 0.321). In the non-ESBL-EC group, 247 patients lost 531.05 DALYs in total, with an average of 2.15 DALYs per person, while in the ESBL-EC group, 333 patients lost 692.64 DALYs in total, with an average of 2.08 DALYs per person. There is no significant difference in average DALYs (P = 0.343).

Conclusion

In conclusion, patients with BSI due to ESBL-EC did not cost more than patients with BSI due to non-ESBL-EC. This phenomenon may be attributed to timely and effective antibiotic treatment, but the initial empiric therapy with second- or third-line antibiotics in non-ESBL-EC BSI should be corrected.

The Region of Interest in Boundary Calibration for Palatal Rugae Image of Forensic Identification

Objective To examine the method of least-square fitting for calibrating the palatal rugae boundary. Methods According to the distribution of the teeth, the feature points were selected; when they were fit, the boundary of the palatal rugae area was created, thereby constructing a mask. The mask was used to remove the part located outside the boundary and filter out the interference. Three samples were utilized for the experiments and analyses to come. Results To evaluate the quantitative results of the fitting curves, the correlation coefficients （r） of the samples and the relationship between the actual mean value and ideal mean value was obtained through six fitting processes. The differences between the actual mean and ideal mean were found to be significantly small （from 0.285 7 to 2.500 0） in the six fitting processes, with the range of r close to 1 （from 0.989 6 to 0.999 5）. Conclusion The effect of the cubic polynomial fitting method adopted in this study was stable.The proposed boundary calibration method can effectively locate the palatal rugae boundary and remove the interference area, further promoting the practice of forensic identification.

Construction of CTC-ALK gene fusion detection system based on the multi-site magnetic separation in lung cancer and its clinical verification

Detected in a variety of solid tumors, including lung cancer, the EML4-ALK fusion gene plays an important role in promoting the occurrence and development of cancer. The existing detection methods for EML4-ALK fusion gene are all targeted at surgical or post-sampling tumor tissues, which cannot achieve early detection and real-time monitoring; therefore, a minimally invasive ALK gene fusion detection system is explored and constructed. Vimentin, EpCAM, and EGFR antibodies were grafted, respectively, to prepare multi-site immunoliposome magnetic beads, so as to capture CTC in blood for RT-PCR detection, and then the feasibility of this method was verified by detecting the positive rate of the EML4-ALK fusion gene and clinical information in combination with WB and IHC. The prepared multi-site immunoliposome magnetic beads showed high specificity and stability, and the average proliferation rate and capture rate of cells were 95% and 85%, respectively. In clinical blood samples, the CTC level of the grade I (G1) patients before the operation was lower than grade 2 (G2), and that of grade II (G2) was significantly lower than grade III (G3), but the difference was not significant after the operation. The RT-PCR results of CTC and the RT-PCR, WB, and IHC results of tissues were highly consistent in the fusion gene detection, and the positive rate of ALK gene fusion in 60 lung cancer patients was 31.67% and 28.33% before and after the operation, mostly EML4-ALK (V3) gene fusion. The CTC-ALK gene fusion detection system constructed successfully could avoid the problem of difficult sampling and post-sampling complications, and truly achieve the minimally invasive biopsy, so it was of important clinical significance for the diagnosis and efficacy evaluation of lung.

Vital Members in the More Dysbiotic Oropharyngeal Microbiotas in H7N9-Infected Patients

The dysbiosis of oropharyngeal (OP) microbiota is associated with multiple diseases, including H7N9 infection. Different OP microbial colonization states may reflect different severities or stages of disease and affect the effectiveness of the treatments. Current study aims to determine the vital bacteria that could possibly drive the OP microbiota in the H7N9 patients to more severe microbial dysbiosis state. The OP microbiotas of 42 H7N9 patients and 30 healthy subjects were analyzed by a series of bioinformatics and statistical analyses. Two clusters of OP microbiotas in H7N9 patients, i.e., Cluster_1_Diseased and Cluster_2_Diseased, were determined at two microbial colonization states by Partition Around Medoids (PAM) clustering analysis, each characterized by distinct operational taxonomic units (OTUs) and functional metabolites. Cluster_1_Diseased was determined at more severe dysbiosis status compared with Cluster_2_Diseased, while OTU143_Capnocytophaga and OTU269_Treponema acted as gatekeepers for both of the two clustered microbiotas. Nine OTUs assigned to seven taxa, i.e., Alloprevotella, Atopobium, Megasphaera, Oribacterium, Prevotella, Stomatobaculum, and Veillonella, were associated with both H7N9 patients with and without secondary bacterial lung infection in Cluster_1. In addition, two groups of healthy cohorts may have potential different susceptibilities to H7N9 infection. These findings suggest that two OP microbial colonization states of H7N9 patients were at different dysbiosis states, which may help determine the health status of H7N9 patients, as well as the susceptibility of healthy subjects to H7N9 infection.

[The study on relationship of Shennong and Jingchu culture from unearthed literature]

Shennong is the founder of cultivation, inventor of medicine. There are various recordation and legends about Shennong regional culture around the whole Chinese nation. The author studied the source of Shennong and Jingchu culture by comprehensively sorting relative literature recordation, citing unearthed materials in recent years as evidence, and found that the legends of Shennong is wide-spread in both western and southern China which corresponding to the origin of farming. What is more, a lot of delicate cultural relics and bambooslip and silk manuscripts have been found in Hubei and Hunan in recent years, which proved that Chu was not a land of barbarians in traditional view but an area with developed culture, and Shennong had a deep historic relation with Jingchu culture.

Effect of Short-Term Antimicrobial Therapy on the Tolerance and Antibiotic Resistance of Multidrug-Resistant Staphylococcus capitis

Background

Bacteria undergo adaptive mutation in the host. However, the specific effect of antimicrobial use on bacterial evolution and genome mutations related to bacterial survival within a patient is unclear.

Materials and Methods

Three S. capitis strains were sequentially isolated from cerebrospinal fluid of a clinical inpatient. Antimicrobial susceptibility, growth rate, biofilm formation and whole blood survival of these strains were measured. Relative fitness was calculated. The virulence was examined in the Galleria mellonella model. Whole-genome sequencing and in silico analysis were performed to explore the genetic mechanisms of the changes in antimicrobial resistance phenotype. Hypothetical proteins are cloned, expressed and characterized by detection the susceptibility to gentamycin.

Results

The first isolate was susceptible to rifampin (MIC=0.25 μg/mL), resistant to gentamicin (MIC=16 μg/mL), while the later two isolates were resistant to rifampin (MIC >64 μg/mL), susceptible to gentamicin (MIC=4 μg/mL). For the latter two strains, compared to the first, frameshift mutation in a hypothetical protein encoding gene and base substitutions (in genes saeR, moaA and rpoB) were discovered. The mutation of rpoB gene caused rifampicin resistance. Mutations in saeR, moaA and hypothetical gene are associated with changes in other biological traits. Amino acid sequence-based structure and function identification of the hypothetical protein indicated that a mutation in the encoding gene might be associated with altered aminoglycoside susceptibility. Growth curve showed that the later two isolates grew faster than the first isolate with a positive fitness advantage of 13.5%, and 14.8%, accordingly. Biofilm form ability and whole blood survival of the derivative mutants were also enhanced. No significant differences of virulence in the G. mellonella model were observed.

Conclusion

We report here for the first time that short-term clinical antibiotic use was associated with resistance mutations, collateral sensitivity, and positive in vivo fitness advantages to S. capitis during infection.

Nintedanib in patients with progressive fibrosing interstitial lung diseases-subgroup analyses by interstitial lung disease diagnosis in the INBUILD trial: a randomised, double-blind, placebo-controlled, parallel-group trial

BACKGROUND

The INBUILD trial investigated the efficacy and safety of nintedanib versus placebo in patients with progressive fibrosing interstitial lung diseases (ILDs) other than idiopathic pulmonary fibrosis (IPF). We aimed to establish the effects of nintedanib in subgroups based on ILD diagnosis.

METHODS

The INBUILD trial was a randomised, double-blind, placebo-controlled, parallel group trial done at 153 sites in 15 countries. Participants had an investigator-diagnosed fibrosing ILD other than IPF, with chest imaging features of fibrosis of more than 10% extent on high resolution CT (HRCT), forced vital capacity (FVC) of 45% or more predicted, and diffusing capacity of the lung for carbon monoxide (DLco) of at least 30% and less than 80% predicted. Participants fulfilled protocol-defined criteria for ILD progression in the 24 months before screening, despite management considered appropriate in clinical practice for the individual ILD. Participants were randomly assigned 1:1 by means of a pseudo-random number generator to receive nintedanib 150 mg twice daily or placebo for at least 52 weeks. Participants, investigators, and other personnel involved in the trial and analysis were masked to treatment assignment until after database lock. In this subgroup analysis, we assessed the rate of decline in FVC (mL/year) over 52 weeks in patients who received at least one dose of nintedanib or placebo in five prespecified subgroups based on the ILD diagnoses documented by the investigators: hypersensitivity pneumonitis, autoimmune ILDs, idiopathic non-specific interstitial pneumonia, unclassifiable idiopathic interstitial pneumonia, and other ILDs. The trial has been completed and is registered with ClinicalTrials.gov, number NCT02999178.

FINDINGS

Participants were recruited between Feb 23, 2017, and April 27, 2018. Of 663 participants who received at least one dose of nintedanib or placebo, 173 (26%) had chronic hypersensitivity pneumonitis, 170 (26%) an autoimmune ILD, 125 (19%) idiopathic non-specific interstitial pneumonia, 114 (17%) unclassifiable idiopathic interstitial pneumonia, and 81 (12%) other ILDs. The effect of nintedanib versus placebo on reducing the rate of FVC decline (mL/year) was consistent across the five subgroups by ILD diagnosis in the overall population (hypersensitivity pneumonitis 73·1 [95% CI -8·6 to 154·8]; autoimmune ILDs 104·0 [21·1 to 186·9]; idiopathic non-specific interstitial pneumonia 141·6 [46·0 to 237·2]; unclassifiable idiopathic interstitial pneumonia 68·3 [-31·4 to 168·1]; and other ILDs 197·1 [77·6 to 316·7]; p=0·41 for treatment by subgroup by time interaction). Adverse events reported in the subgroups were consistent with those reported in the overall population.

INTERPRETATION

The INBUILD trial was not designed or powered to provide evidence for a benefit of nintedanib in specific diagnostic subgroups. However, its results suggest that nintedanib reduces the rate of ILD progression, as measured by FVC decline, in patients who have a chronic fibrosing ILD and progressive phenotype, irrespective of the underlying ILD diagnosis.

FUNDING

Boehringer Ingelheim.