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Candida auris has become a serious threat to public health. The mechanisms of how this fungal pathogen adapts to the mammalian host are poorly understood. Here we report the rapid evolution of an adaptive C. auris multicellular aggregative morphology in the murine host during systemic infection. C. auris aggregative cells accumulate in the brain and exhibit obvious advantages over the single-celled yeast-form cells during systemic infection. Genetic mutations, specifically de novo point mutations in genes associated with cell division or budding processes, underlie the rapid evolution of this aggregative phenotype. Most mutated C. auris genes are associated with the regulation of cell wall integrity, cytokinesis, cytoskeletal properties, and cellular polarization. Moreover, the multicellular aggregates are notably more recalcitrant to the host antimicrobial peptides LL-37 and PACAP relative to the single-celled yeast-form cells. Overall, to survive in the host, C. auris can rapidly evolve a multicellular aggregative morphology via genetic mutations. Bing et al. report that Candida auris undergoes rapid evolution via de novo genetic mutations and forms multicellular aggregates that exhibit a survival advantage over the single-celled yeast-form phenotype during host infection. [ABSTRACT FROM AUTHOR]

ESX‐3 is a secretion pathway which is essential for mycobactin‐mediated iron acquisition under iron‐limited conditions. Although present in all Mycobacterium sp., ESX‐3 remains to be elucidated in Mycobacterium abscessus. In the study reported here, impaired ESX‐3 seriously restricts the growth of M. abscesses under iron‐limited conditions; growth is salvaged by functional ESX‐3 or iron supplementation. Notably, impaired ESX‐3 does not kill M. abscesses when environmental iron is insufficient but induces persistence to bedaquiline, a diarylquinoline class antibiotic used to treat multidrug‐resistant mycobacteria. One potential mechanism contributing to persistence is the iron deficiency due to impaired ESX‐3 suppressing succinate dehydrogenase activity, which dysregulates the tricarboxylic acid cycle and inactivates bedaquiline. Experiments conducted here also demonstrate that the regulator, MtrA, can bind ESX‐3 and promote the survival of M. abscessus. As such, this study suggests that a novel pathway involving MtrA, ESX‐3, iron metabolism, and the TCA cycle contributes to bedaquiline persistence in M. abscesses growing under iron‐limited conditions. [ABSTRACT FROM AUTHOR]

Non‐tuberculous mycobacterial infections are gradually increasing worldwide, with slow‐growing mycobacteria such as Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium kansasii accounting for the majority of cases. The use of tetracyclines has received renewed attention in recent years, and this study was designed to investigate the antibacterial activity of omadacycline, eravacycline, tigecycline, sarecycline, minocycline and doxycycline against M. avium, M. intracellulare and M. kansasii. Susceptibility testing of six tetracyclines was conducted against M. avium, M. intracellulare and M. kansasii isolates, and all the clinical isolates were collected from January 2012 to December 2018. All six agents exhibited poor antibacterial activity against slowly growing mycobacteria (SGM) isolates of three subspecies with MIC50 and MIC90 ≥8 μg/mL. M. intracellulare and M. kansasii had lower resistance rates to omadacycline than the other five drugs. The severe resistance of SGM to tetracycline suggests that developing tetracycline‐class antibiotics needs to overcome existing resistance mechanisms. [ABSTRACT FROM AUTHOR]

Background: During infection, Mycobacterium abscessus encounters numerous environmental changes and adapts to them using a variety of complex mechanisms. Non‐coding small RNAs (sRNAs) have been shown in other bacteria to be involved in post‐transcriptional regulatory pathways, including environmental stress adaptation. However, the potential role of sRNAs in the resistance to oxidative stress in M. abscessus was not clearly described. Methods: In the present study, we analyzed putative sRNAs identified by RNA‐sequencing (RNA‐seq) experiments in M. abscessus ATCC_19977 under oxidative stress, and the transcription profiles of sRNAs with differential expression were verified by quantitative reverse transcription‐PCR (qRT‐PCR). Six sRNA overexpression strains were constructed, and the differences in growth curves between these strains and the control strain were verified. An upregulated sRNA under oxidative stress was selected and named sRNA21. The survival ability of the sRNA21 overexpression strain was assessed, and computer‐based approaches were used to predict the targets and pathways regulated by sRNA21. The total ATP production and NAD+/NADH ratio of the sRNA21 overexpression strain were measured. The expression level of antioxidase‐related genes and the activity of antioxidase were tested to confirm the interaction of sRNA21 with the predicted target genes in silico. Results: In total, 14 putative sRNAs were identified under oxidative stress, and the qRT‐PCR analysis of six sRNAs showed comparable results to RNA‐seq assays. Overexpression of sRNA21 in M. abscessus increased cell growth rate and intracellular ATP level before and after peroxide exposure. The expression of genes encoding alkyl hydroperoxidase and superoxide dismutase was significantly increased, and superoxide dismutase activity was enhanced in the sRNA21 overexpression strain. Meanwhile, after sRNA21 overexpression, the intracellular NAD+/NADH ratio decreased, indicating changes in redox homeostasis. Conclusions: Our findings show that sRNA21 is an oxidative stress‐induced sRNA that increases M. abscessus survival and promotes the expression of antioxidant enzymes under oxidative stress. These findings may provide new insights into the adaptive transcriptional response of M. abscessus to oxidative stress. [ABSTRACT FROM AUTHOR]

The antibiotic options available for Mycobacterium abscessus (M. abscessus) infection are limited and no definitive therapeutic strategies have been formulated. The recent discovery that rifabutin is active against M. abscessus has raised interest in using rifabutin to treat this intractable disease. In this study, we evaluated the in vitro activity of rifabutin against 194 M. abscessus clinical isolates collected during 2012 January to 2017 December. As expected, rifabutin demonstrated considerably lower MICs against M. abscessus, with an MIC50 of 2 μg/mL and MIC90 of 4 μg/mL, respectively. Notably, the anti‐M.abscessus activity was even stronger among clarithromycin‐insusceptible strains. In addition, M. abscessus isolates with a rough morphotype were more sensitive to rifabutin compared with those forming smooth colonies when considered as a whole or in separate subspecies. Results from synergistic experiments revealed that the in vitro activity of rifabutin was significantly enhanced by the addition of amikacin, suggesting a promising strategy for M. abscessus infection combination treatment. Finally, five and three mutation patterns in rpoB and arr, respectively, were identified among the 194 strains through whole genome sequencing. However, none of them conferred rifabutin resistance. Our study is among the first to report the susceptibility of M. abscessus to rifabutin in vitro with a large amount of clinical isolates, suggesting that rifabutin is active, both alone and in combination, against M. abscessus and is worth considering as part of a combination treatment regimen for M. abscessus infections. [ABSTRACT FROM AUTHOR]

Therapeutic options for treating Mycobacterium abscessus infections are extremely limited; quinolones are important. The in vitro anti- M. abscessus activities of nine quinolones, emphasizing sitafloxacin, were investigated. Antimicrobial susceptibility testing was performed on 10 non-tuberculous mycobacterium reference strains and 194 clinical, M. abscessus isolates. The activity of sitafloxacin against intracellular M. abscessus residing within macrophages was also evaluated. A checkerboard assay was conducted to determine synergy between sitafloxacin and 10 clinically important antibiotics. Among the nine quinolones tested, sitafloxacin exhibited the greatest anti- M. abscessus activity with MIC50 and MIC90 of 1 and 2 mg/L, respectively. Sitafloxacin exerted a bacteriostatic effect on M. abscessus and inhibited the intracellular growth of M. abscessus at concentrations equivalent to clarithromycin. No antagonism between sitafloxacin and 10 clinically important anti- M. abscessus antibiotics was evident. In summary, sitafloxacin exhibited a significant advantage relative to other quinolones in inhibiting the growth of M. abscessus in vitro , suggesting the potential inclusion of sitafloxacin in new strategies to treat M. abscessus infections. [ABSTRACT FROM AUTHOR]

Erjing prescription (EJP) was an ancient formula that was recorded in the General Medical Collection of Royal Benevolence of the Song Dynasty. It has been frequently used to treat type 2 diabetes mellitus (T2DM) in the long history of China. The formula consists of Lycium barbarum L. and Polygonatum sibiricum F. Delaroche with a ratio of 1 : 1. This study aimed to identify the potential effects and mechanisms of EJP treatment T2DM. The target proteins and possible pathways of EJP in T2DM treatment were investigated by the approach of network pharmacology and real-time PCR (RT-PCR). 99 diabetes-related proteins were regulated by 56 bioactive constituents in EJP in 26 signal pathways by Cytoscape determination. According to GO analysis, 606 genes entries have been enriched. The PPI network suggested that AKT1, EGF, EGFR, MAPK1, and GSK3β proteins were core genes. Among the 26 signal pathways, the PI3K-AKT signal pathway was tested by the RT-PCR. The expression level of PI3K p85, AKT1, GSK3β, and Myc mRNA of this pathway was regulated by EJP. The study based on network pharmacology and RT-PCR analysis revealed that the blood sugar level was regulated by EJP via regulating the PI3K-AKT signal pathway. Plenty of new treatment methods for T2DM using EJP were provided by network pharmacology analysis. [ABSTRACT FROM AUTHOR]

Purpose: Imipenem is one of the very few effective options for treating Mycobacterium abscessus (M. abscessus) infections; the development of imipenem resistance is a major health concern. Materials and Methods: The susceptibility of 194 clinical M. abscessus isolates to imipenem was determined. The ability of imipenem to synergize with N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), a zinc chelator and a metallo-β-lactamases (MBLs) inhibitor, to inhibit M. abscessus growth was also assessed. Results: M. abscessus exhibited an elevated resistance to imipenem (MIC50 = 16 mg/L, MIC90 = 64 mg/L). A combination of TPEN and imipenem synergized to inhibit the growth of 100% of imipenem-resistant and 79.2% of imipenem-resistance intermediate isolates; no synergy was observed treating imipenem-sensitive isolates. A remarkable decrease in the MIC50 (from 16 to 4 mg/L) and MIC90 (from 64 to 8 mg/L) of imipenem was observed when it was combined with TPEN; the portion of imipenem-resistant isolates also decreased (from 48.4% to 0%). Consistent with these results demonstrating synergy, a time-kill assay showed the addition of TPEN significantly improved the bactericidal activity of imipenem toward M. abscessus. Similarly, EDTA (a potent MBLs inhibitor) promoted the anti-M. abscessus activity of imipenem in a disk assay, corroborating the effect of TPEN and supporting the role of MBLs in imipenem resistance exhibited by some isolates. Conclusion: These findings demonstrate that TPEN can reduce the resistance of M. abscessus to imipenem and suggest that the inhibition of MBLs activity is the underlying mechanism. [ABSTRACT FROM AUTHOR]

Background: Smooth and rough colony morphotypes of Mycobacterium abscessus are associated with virulence, but some isolates form both smooth and rough colonies, impeding successful morphotype identification. Reportedly, smooth/rough morphotypes are also related to the glycopeptidolipid (GPL) genotype. However, the accuracy of GPL genotyping to discriminate morphotypes and the relationship between GPL genotype and clinical characteristics of M abscessus lung disease have not been verified.Methods: A retrospective analysis of colony morphology, GPL genotype, and clinical data from 182 patients with M abscessus lung disease was conducted.Results: Of 194 clinical isolates, 126 (65.0%), 15 (7.7%), and 53 (27.3%) exhibited rough, smooth, and mixed colony morphotypes, respectively. Glycopeptidolipid genotyping indicated that 86.7% (13 of 15) of smooth isolates belonged to the GPL-wild type (WT) group, whereas 98.4% (124 of 126) of rough isolates belonged to the GPL-mutant type (MUT) group. Therefore, GPL genotyping accurately distinguished between smooth and rough morphotypes. Mixed colony morphotypes were also divided into GPL-WT (18.9%) and GPL-MUT (81.1%) groups. Further analysis revealed that patients infected with the GPL-MUT group presented with significantly worse baseline clinical characteristics and exacerbated episodes of lung disease.Conclusions: Glycopeptidolipid genotyping accurately distinguishes smooth and rough colony morphotypes. Patients infected with the GPL-MUT genotype exhibit worse clinical characteristics and are at a higher risk of exacerbated lung disease. [ABSTRACT FROM AUTHOR]

Purpose: The emergence of clarithromycin resistance is a challenge in treating Mycobacterium abscessus infections. Known mechanisms that contribute to intrinsic clarithromycin resistance focus on rrl gene-related mutations, but resistant clinical isolates often exhibit an inconsistent rrl genotype. Patients and Methods: In this study, 194 clinical Mycobacterium abscessus isolates were collected from patients with lung infections and the whole genome of each isolate was sequenced. A comprehensive examination of the molecular mechanisms underlying intrinsic clarithromycin resistance was performed, combining MIC determination, comparative genome sequence analysis and qRT-PCR. Results: Of the 194 isolates, 13 (6.7%) were clarithromycin resistant; only seven of these harbored a rrl 2270/2271 mutation. The remaining six resistant isolates did not exhibit a specific resistance-associated mutation in the clarithromycin target-site genes, rrl, rplC, rplD and rplV, or in the rrl modification gene erm(41). qRT-PCR analysis showed that the increased expression of the efflux pump genes, MAB_2355c, MAB_1409c and MAB_1846, as well as their positive regulatory gene whiB7, consistently correlated with increased clarithromycin resistance. The presence of efflux pump inhibitors significantly decreased the MIC of clarithromycin for nonsusceptible isolates, especially the intrinsic resistant isolates that exhibited no rrl 2270/2271 mutation. Conclusion: These findings indicate that efflux pumps play a prominent role in the intrinsic resistance of M. abscessus to clarithromycin, complementing other known resistance mechanisms. [ABSTRACT FROM AUTHOR]

Treatment of Mycobacterium abscessus pulmonary infection requires long-term administration of multiple antibiotics. Little is known, however, about the impact of each antibiotic on treatment outcomes. A retrospective analysis was conducted to evaluate the efficacy and adverse effects of antibiotics administered in 244 cases of M. abscessus pulmonary disease. Only 110 (45.1%) patients met the criteria for treatment success. The efficacy of treating M. abscessus pulmonary disease continues to be unsatisfactory especially for infections involving M. abscessus subsp. abscessus. Treatment with drug combinations that included amikacin [adjusted odds ratio (AOR), 3.275; 95% confidence interval (CI), 1.221–8.788], imipenem (AOR, 2.078; 95% CI, 1.151–3.753), linezolid (AOR, 2.231; 95% CI, 1.078–4.616), or tigecycline (AOR, 2.040; 95% CI, 1.079–3.857) was successful. Adverse side effects affected the majority of patients (192/244, 78.7%). Severe effects that resulted in treatment modification included: gastrointestinal distress (29/60, 48.3%) mostly caused by tigecycline, ototoxicity (14/60, 23.3%) caused by amikacin; and myelosuppression (6/60, 10%) caused mainly by linezolid. In conclusion, the success rate of treatment of M. abscessus pulmonary disease is still unsatisfactory. The administration of amikacin, imipenem, linezolid, and tigecycline correlated with increased treatment success. Adverse side effects are common due to long-term, combination antibiotic therapy. Ototoxicity, gastrointestinal distress, and myelosuppression are the most severe. [ABSTRACT FROM AUTHOR]

Pulmonary alveolar proteinosis (PAP) is a rare diffuse lung disease characterized by the accumulation of intra-alveolar lipoprotein-like surfactants. Lung core biopsy and bronchoalveolar lavage (BAL) fluid are currently the two major sources of sampling for diagnosis. In the present study, we assessed the value of induced sputum in diagnosing PAP by transmission electron microscopy and examined the PAP 2-year death rate in Asians. Transmission electron microscopy was performed on the samples from 17 patients with PAP, 13 patients with inflammatory lung diseases, and 13 healthy adults. The PAP patients were followed up for 3–156 months, and inflammatory lung diseases patients or healthy adults for 12–36 months. The ultrastructural features including diagnostic lamellar bodies of induced sputum deposition (ISD) samples were similar to that of the BAL fluid sediment. However, the rates of lamellar bodies were 73.7% in the ISD group, significantly higher than the spontaneous sputum deposition (SSD) group (42.1%, P <.0487) and similar to the BAL sediment (76.2%) and the lung biopsy (54.5%) groups. The overall 2-year death rate of our PAP patients was 17.6% (3/17), not statistically different from the healthy adults and patients with inflammatory diseases (0/13, P =.237 for both). ISD may be the preferred non-invasive sampling method for diagnosing PAP by electronic microscopy because of the higher diagnostic yield than SSD. The diagnostic yields of this noninvasive method were similar to that of lung core biopsy and BAL. [ABSTRACT FROM AUTHOR]

The cytokine-inducible SRC homology 2 domain ( CISH) gene is up-regulated by IL-2 in response to infection, and inhibits microbial infection. The objective of the present study was to examine whether genetic variants of CISH (SNPs) are associated with increased susceptibility to tuberculosis (TB) in individuals of Chinese Han ethnicity. We sequenced five previously identified SNPs of CISH in patients with TB or healthy controls. Three of the SNPs, rs148685070 [position −639; C/C], rs414171 [position −292; A/T], and rs6768300 [position −163; C/G]) are located in the promoter region, while the fourth (rs2239751 [position +1320; A/C]) near the translation start site, and the fifth (rs622502 [position +3415; C/G]) in the third intron. The AA genotypes of the SNPs rs2239751 and rs414171 were significantly associated with TB. Multivariate logistic regression analysis demonstrated that subjects with the rs414171 AA genotype were more likely to have TB than those with the AT genotype. By contrast, we did not observe genetic variants of the rs148685070 SNP. In conclusion, two genetic variants in CISH gene appear to increase susceptibility to TB in Chinese Han population. [ABSTRACT FROM AUTHOR]

We sought to study antibiotic resistance and molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) from lower respiratory tracts of patients in Shanghai Pulmonary Hospital. Hundred and seven strains of MRSA were isolated from the patients of nine wards. The tests for antibiotic resistance (Kirby-Bauer paper dispersion method), the Panton-Valentine Leukocidin (PVL) and Staphyloccoccal Cassette Chromosome mec (SCC mec) genes (PCR), and homology analysis (32 randomly selected MRSA strains; pulsed-field gel electrophoresis) were carried out. All 107 strains were susceptible to vancomycin, teicoplanin, and linezolid, but highly or completely resistant to tetracycline, gentamicin, clindamycin, levofloxacin, azithromycin, erythromycin, trimethoprim/sulphamethoxazole, and ciprofloxacin. All 107 strains were negative for PVL gene. Most of the strains (81.3 %) were SCC mec III type, while the SCC mec II and IV types were less frequent (15.9 and 2.8 %, respectively). No SCC mec I or V types were detected. The homology analysis test showed that 32 MRSA strains could be divided into 4 groups: type A (25 strains), type B (5 strains), type C (1 strain), and type D (1 strain). The type A included 3 subtypes: A1 (17 strains), A2 (1 strain), and A3 (7 strains). Further, most of the strains were isolated from the same wards or units (e.g., intensive care unit or tuberculosis wards) within a short period of time, indicating an outbreak status. In conclusion, the observed MRSA from low respiratory tracts from patients at Shanghai Pulmonary Hospital were multiple-resistant, with the SCC mec III being the main documented genotype. [ABSTRACT FROM AUTHOR]

Objective: To clarify the diagnostic value of sputum in pulmonary alveolar proteinosis (PAP) through transmission electron microscopy (TEM) of sputum deposition (SD). Methods: Eleven SD samples and 9 bronchoalveolar lavage (BAL) sediments from a PAP group including 11 patients were observed by TEM and compared with sputum direct smear, BAL cytology, and lung biopsy histopathology. Eleven healthy adults were chosen as controls. Results: The 11 sputum smears from the PAP group showed no diagnostic component, but TEM of SD revealed 7 of 11 samples had many myelin-like lamellar bodies with degeneration in the cytoplasm of macrophages, alveolar epithelial cells, and extracellular spaces, which suggested PAP. Especially, 2 patients on whom lung biopsy could not be performed and who failed to be diagnosed by BAL fluid were finally diagnosed by TEM of SD. TEM of BAL sediments showed 7 of 9 cases had diagnostic myelin-like lamellar bodies. No statistical significance was found between BAL fluid and SD by TEM. The control group didn't show diagnostic components by cytology or TEM of SD. Conclusion: TEM of SD is an important noninvasive diagnostic method especially for patients against lung biopsy and BAL. [ABSTRACT FROM AUTHOR]

Objective: The aim of the study was to explore the clinical value of a step-wise application of methylprednisolone (MP) compared to dexamethasone (DXM) in acute exacerbations of COPD. Methodology: One hundred and forty-two patients with an acute exacerbation of COPD were divided randomly into two groups: 71 patients were treated with MP and the other 71 patients were treated with DXM. Otherwise each group was given the same basic treatments: antibiotics, bronchodilators, oxygen therapy as well as standard hospital care. The patients in the MP group were given a tapering dose of MP for 7–14 days, and the patients in the DXM group were given a corresponding tapering dose of DXM for 7–14 days. Then both groups were given a gradually reducing dose of oral prednisone for 2–3 weeks. Two weeks before the prednisone was tapered off, inhaled corticosteroid was introduced. The patients’ symptom scores, physical signs, per cent predicted FEV1 %, and arterial blood gases were monitored before treatment and after the seventh day of treatment. Results: There was an obvious improvement in symptoms after 1–3 days in all 71 patients in the MP group, with their wheezing being distinctly reduced or disappearing entirely. The maximum benefit that occurred in the MP group (90.14%) was considerably higher than that of the DXM group (25.35%), P < 0.05. The predicted FEV1 % in the MP group increased from 46.7 ± 10.6 to 67.5 ± 12.4, compared with an increase in the DXM group from 50.1 ± 7.6 to 58.9 ± 10.8. The difference between the two groups was significant (P < 0.05). Conclusions: An adequate and tapering dose of MP used in acute exacerbations of COPD can relieve the inflammatory reaction in airways and reduce airway spasm more promptly than DXM. [ABSTRACT FROM AUTHOR]

An abstract of the study "Antibiotic Resistance and Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus From Lower Respiratory Tracts: Multiresistance and High Prevalence of SCCmecIII Type," by Haiqing Chu and colleagues is presented.

An abstract of the study "Clinical Features and Outcomes of Pulmonary Alveolar Proteinosis: An Analysis of 25 Cases" by Jinming Liu and colleagues is presented.