Molecular Characteristics and Antibiotic Resistance of Staphylococcus aureus Isolated from Patient and Food Samples in Shijiazhuang, China.

Staphylococcus aureus (S. aureus) is a common opportunistic and zoonotic pathogen in the world and could easily cause human infections and food contaminations. This study investigated the sequence typing and resistance profiles of S. aureus isolates from patient and food samples in Shijiazhuang, China. A total of 101 S. aureus isolates were distributed into six clonal complexes (CCs) and 16 singletons. A total of 86 patient isolates were distributed into six clonal CCs and 12 singletons, including a new ST. CC59, CC5, CC22, and CC398 were the predominant CCs of patient isolates. A total of 15 foodborne S. aureus isolates were distributed into 3 CCs and 4 STs, and CC1 was the most prevalent CC. Moreover, 101 S. aureus isolates had high resistance to penicillin and low resistance to chloramphenicol and rifampicin. A total of 39 strains of methicillin-resistant Staphylococcus aureus (MRSA) were detected in this study, including thirty-eight strains of patient isolates (44.2%, 38/86) and one strain of food isolates (6.7%, 1/15). MRSA-ST5, MRSA-ST59, and MRSA-ST239 were the predominant MRSA isolates in hospitals. The present study explained the relationship between S. aureus isolated from patient and food samples and indicated the risks of S. aureus in infectious diseases.

All-Optical Reconfigurable Electronic Memory in a Graphene/SrTiO3 Heterostructure.

Direct optical data coding in an electronic device is meaningful for photonic technology. Herein, we report electronic memory in a graphene/SrTiO3 heterostructure, which presents the all-optical logic operation (encoding and decoding). The underlying physics have been elucidated in which the synergistic effect of surface localization with interface band bending is responsible for optical encoding and decoding in the electronic memory device of the graphene/SrTiO3 heterostructure. Further, we demonstrate a robust retention and synaptic-like processing of optical signals, which may lead to significant applications in neuromorphic imaging sensors.

Blood Neutrophil Counts Define Specific Clusters of Bronchiectasis Patients: A Hint to Differential Clinical Phenotypes.

We sought to investigate differential phenotypic characteristics according to neutrophil counts, using a biostatistics approach in a large-cohort study from the Spanish Online Bronchiectasis Registry (RIBRON). The 1034 patients who met the inclusion criteria were clustered into two groups on the basis of their blood neutrophil levels. Using the Mann-Whitney U test to explore potential differences according to FACED and EFACED scores between the two groups, a neutrophil count of 4990 cells/µL yielded the most balanced cluster sizes: (1) above-threshold (n = 337) and (2) below-threshold (n = 697) groups. Patients above the threshold showed significantly worse lung function parameters and nutritional status, while systemic inflammation levels were higher than in the below-threshold patients. In the latter group, the proportions of patients with mild disease were greater, while a more severe disease was present in the above-threshold patients. According to the blood neutrophil counts using biostatistics analyses, two distinct clinical phenotypes of stable patients with non-CF bronchiectasis were defined. Patients falling into the above-threshold cluster were more severe. Severity was characterized by a significantly impaired lung function parameters and nutritional status, and greater systemic inflammation. Phenotypic profiles of bronchiectasis patients are well defined as a result of the cluster analysis of combined systemic and respiratory variables.

Profile of Clinical and Analytical Parameters in Bronchiectasis Patients during the COVID-19 Pandemic: A One-Year Follow-Up Pilot Study.

Whether the COVID-19 pandemic may have modified the clinical planning and course in bronchiectasis patients remains to be fully elucidated. We hypothesized that the COVID-19 pandemic may have influenced the management and clinical outcomes of bronchiectasis patients who were followed up for 12 months. In bronchiectasis patients (n = 30, 23 females, 66 years), lung function testing, disease severity [FEV1, age, colonization, radiological extension, dyspnea (FACED), exacerbation (EFACED)] and dyspnea scores, exacerbation numbers and hospitalizations, body composition, sputum microbiology, and blood analytical biomarkers were determined at baseline and after a one-year follow-up. Compared to baseline (n = 27, three patients dropped out), in bronchiectasis patients, a significant increase in FACED and EFACED scores, number of exacerbations, and erythrocyte sedimentation rate (ESR) was observed, while FEV1, ceruloplasmin, IgE, IgG, IgG aspergillus, IgM, and IgA significantly decreased. Patients presenting colonization by Pseudomonas aeruginosa (PA) remained unchanged (27%) during follow-up. In bronchiectasis patients, FEV1 declined only after a one-year follow-up along with increased exacerbation numbers and disease severity scores, but not hospitalizations. However, a significant decrease in acute phase-reactants and immunoglobulins was observed at the one-year follow-up compared to baseline. Despite the relatively small cohort, the reported findings suggest that lung function impairment may not rely entirely on the patients' inflammatory status.

Respiratory and Peripheral Muscle Weakness and Body Composition Abnormalities in Non-Cystic Fibrosis Bronchiectasis Patients: Gender Differences.

As demonstrated in COPD, bronchiectasis patients may experience respiratory and peripheral muscle dysfunction. We hypothesized that respiratory and peripheral (upper and lower limbs) muscle function and nutritional status may be more significantly altered in female than in males for identical age and disease severity. In mild-to-moderate bronchiectasis patients (n = 150, 114 females) and 37 controls (n = 37, 21 females), radiological extension, maximal inspiratory and expiratory pressures (MIP and MEP), sniff nasal inspiratory pressure (SNIP), hand grip and quadriceps muscle strengths, body composition, and blood analytical biomarkers were explored. Compared to the controls, in all bronchiectasis patients (males and females), BMI, fat-free mass index (FFMI), fat tissue, upper and lower limb muscle strength, and respiratory muscle strength significantly declined, and FFMI, fat tissue, and quadriceps muscle function were significantly lower in female than male patients. In patients with mild-to-moderate bronchiectasis, respiratory and peripheral muscle function is significantly impaired and only partly related to lung disease status. Quadriceps muscle strength was particularly weakened in the female patients and was negatively associated with their exercise tolerance. Muscle weakness should be therapeutically targeted in bronchiectasis patients. Body composition and peripheral muscle function determination should be part of the comprehensive clinical assessment of these patients.

Do Redox Balance and Inflammatory Events Take Place in Mild Bronchiectasis? A Hint to Clinical Implications.

We hypothesized that in mild bronchiectasis patients, increased systemic inflammation and redox imbalance may take place and correlate with clinical parameters. In plasma samples from patients with very mild bronchiectasis, inflammatory cells and molecules and redox balance parameters were analyzed. In the patients, lung function and exercise capacity, nutritional status, bacterial colonization, and radiological extension were assessed. Correlations between biological and clinical variables were determined. Compared to healthy controls, levels of acute phase reactants, neutrophils, IgG, IgA, myeloperoxidase, protein oxidation, and GSH increased and lung function and exercise capacity were mildly reduced. GSH levels were even greater in ex-smoker and Pseudomona-colonized patients. Furthermore, radiological extension inversely correlated with airway obstruction and, disease severity, and positively correlated with neutrophil numbers in mild bronchiectasis patients with no nutritional abnormalities. In stable patients with mild bronchiectasis, several important inflammatory and oxidative stress events take place in plasma. These findings suggest that the extension of bronchiectasis probably plays a role in the development of redox imbalance and systemic inflammation in patients with mild bronchiectasis. These results have therapeutic implications in the management of bronchiectasis patients.

Systemic Profiles of microRNAs, Redox Balance, and Inflammation in Lung Cancer Patients: Influence of COPD.

Lung cancer (LC) risk increases in patients with chronic respiratory diseases (COPD). MicroRNAs and redox imbalance are involved in lung tumorigenesis in COPD patients. Whether systemic alterations of those events may also take place in LC patients remains unknown. Our objectives were to assess the plasma levels of microRNAs, redox balance, and cytokines in LC patients with/without COPD. MicroRNAs (RT-PCR) involved in LC, oxidized DNA, MDA-protein adducts, GSH, TEAC, VEGF, and TGF-beta (ELISA) were quantified in plasma samples from non-LC controls (n = 45), LC-only patients (n = 32), and LC-COPD patients (n = 91). In LC-COPD patients compared to controls and LC-only, MDA-protein adduct levels increased, while those of GSH decreased, and two patterns of plasma microRNA were detected. In both LC patient groups, miR-451 expression was downregulated, while those of microRNA-let7c were upregulated, and levels of TEAC and TGF-beta increased compared to the controls. Correlations were found between clinical and biological variables. A differential expression profile of microRNAs was detected in patients with LC. Moreover, in LC patients with COPD, plasma oxidative stress levels increased, whereas those of GSH declined. Systemic oxidative and antioxidant markers are differentially expressed in LC patients with respiratory diseases, thus implying its contribution to the pathogenesis of tumorigenesis in these patients.

General synthesis of mixed-dimensional van der Waals heterostructures with hexagonal symmetry.

The combination of two-dimensional (2D) materials with non-2D materials (quantum dots, nanowires and bulk materials), i.e. mixed-dimensional van der Waals (md-vdW) heterostructures endow 2D materials with remarkable electronics properties. However, it remains a big challenge to synthesize md-vdW heterostructures because of the difference of crystal symmetry between 2D and non-2D materials. Meanwhile, it is difficult to initiate the nucleation due to the lack of chemical active sites on chemical inert surfaces of 2D materials. Herein, we design a general chemical vapor deposition method for synthesizing a broad class of md-vdW heterostructures with well-aligned hexagonal symmetry including MoS2/FeS, MoS2/CoS, MoS2/MnS, MoS2/ZnS, Mo(SxSe1-x)2/ZnSxSe1-x, Mo(SxSe1-x)2/CdSxSe1-x. Combining with DFT calculation, we find that the hexagonal symmetry and the centered clusters of MoS2and Mo(SxSe1-x)2nanoflakes are two crucial factors to launch the hexagonally oriented growth and nucleation of non-2D materials on 2D materials. Our discovery opens an opportunity for the versatile hetero-integration of 2D materials and allows systematic investigation of physical properties in a wide variety of md-vdW heterostructures.

Molecular Characteristics of Staphylococcus aureus From Food Samples and Food Poisoning Outbreaks in Shijiazhuang, China.

As an opportunistic pathogen worldwide, Staphylococcus aureus can cause food poisoning and human infections. This study investigated the sequence typing, the penicillin (blaZ) and methicillin (mec) resistance profiles of S. aureus from food samples and food poisoning outbreaks in Shijiazhuang City, and the staphylococcal enterotoxin (SE) types of the S. aureus isolates from food poisoning. A total of 138 foodborne S. aureus isolates were distributed into 8 clonal complexes (CCs) and 12 singletons. CC1, CC5, CC8, CC15, CC97, CC59, CC398, CC88, and CC7 were the predominant CCs of foodborne S. aureus isolates. Moreover, CC59, CC15, and CC5 were the most prevalent CCs in food poisoning outbreaks. SEE was the most commonly detected SE in food poisoning isolates. One hundred thirty-three S. aureus isolates harbored the penicillin-resistant gene blaZ, and nine isolates carried the mec gene. The present study further explained the relationship between S. aureus and foods and food poisoning and indicated the potential risk of S. aureus infection.

B Cells and Tertiary Lymphoid Structures Influence Survival in Lung Cancer Patients with Resectable Tumors.

Immune profile of B and T cells and tertiary lymphoid structures (TLSs) may differ in tumors of lung cancer (LC) patients with/without chronic obstructive pulmonary disease (COPD), and may also influence patient survival. We sought to analyze: (1) TLSs, germinal centers (GCs), B and T cells, and (2) associations of the immune biomarkers with the patients' 10-year overall survival (OS). TLSs (numbers and area), B [cluster of differentiation (CD) 20], and T (CD3), and GCs cells were identified in both tumor and non-tumor specimens (thoracotomy) from 90 LC-COPD patients and 43 LC-only patients. Ten-year OS was analyzed in the patients. Immune profile in tumors of LC-COPD versus LC: TLS numbers and areas significantly decreased in tumors of LC-COPD compared to LC patients. No significant differences were observed in tumors between LC-COPD and LC patients for B or T cells. Immune profile in tumors versus non-tumor specimens: TLS areas and B cells significantly increased, T cells significantly decreased in tumors of both LC and LC-COPD patients. Survival: in LC-COPD patients: greater area of TLSs and proportion of B cells were associated with longer survival rates. The immune tumor microenvironment differs in patients with underlying COPD and these different phenotypes may eventually impact the response to immunotherapy in patients with LC.

Immune Cell Subtypes and Cytokines in Lung Tumor Microenvironment: Influence of COPD.

BACKGROUND: The immune microenvironment plays a role in tumorigenesis. Chronic Obstructive Pulmonary Disease (COPD) is an independent risk factor for lung cancer (LC). We hypothesized that immune profile characterized by T regulatory (Treg), natural killer (NK), and plasma cells, as well as interleukin (IL)-10 and interferon-gamma, may differ within tumors of LC patients with/without COPD. METHODS: Treg (anti-CD3 and anti-forkhead boxP3 antibodies), NK (anti-NCR1 antibody), IgG (anti-CD138-IgG antibody), IgA (anti-CD138-IgA antibody) using immunohistochemistry, and both IL-10 and interferon-gamma (ELISA) were quantified in tumor and non-tumor specimens (thoracotomy for lung tumor resection) from 33 LC-COPD patients and 20 LC-only patients. RESULTS: Immune profile in tumor versus non-tumor specimens: Treg cell counts significantly increased in tumors of both LC and LC-COPD patients, while in tumors of the latter group, IgG-secreting plasma cells significantly decreased and IL-10 increased. No significant differences were seen in levels of NK cells, IgA-secreting cells, IgA/IgG, or interferon-gamma. Immune profile in tumors of LC-COPD versus LC: No significant differences were observed in tumors between LC-COPD and LC patients for any study marker. CONCLUSIONS: Immune cell subtypes and cytokines are differentially expressed in lung tumors, and the presence of COPD elicited a decline in IgG-secreting plasma cell levels but not in other cell types.

Lineage, Antimicrobial Resistance and Virulence of Citrobacter spp.

Citrobacter spp. are opportunistic human pathogens which can cause nosocomial infections, sporadic infections and outbreaks. In order to determine the genetic diversity, in vitro virulence properties and antimicrobial resistance profiles of Citrobacter spp., 128 Citrobacter isolates obtained from human diarrheal patients, foods and environment were assessed by multilocus sequence typing (MLST), antimicrobial susceptibility testing and adhesion and cytotoxicity testing to HEp-2 cells. The 128 Citrobacter isolates were typed into 123 sequence types (STs) of which 101 were novel STs, and these STs were divided into five lineages. Lineages I and II contained C. freundii isolates; Lineage III contained all C. braakii isolates, while Lineage IV and V contained C. youngae isolates. Lineages II and V contained more adhesive and cytotoxic isolates than Lineages I, III, and IV. Fifty-one of the 128 isolates were found to be multidrug-resistant (MDR, ≥3) and mainly distributed in Lineages I, II, and III. The prevalence of quinolone resistance varied with Lineage III (C. braakii) having the highest proportion of resistant isolates (52.6%), followed by Lineage I (C. freundii) with 23.7%. Seven qnrB variants, including two new alleles (qnrB93 and qnrB94) were found with Lineage I being the main reservoir. In summary, highly cytotoxic MDR isolates from diarrheal patients may increase the risk of severe disease.

Frequency, Antimicrobial Resistance and Genetic Diversity of Klebsiella pneumoniae in Food Samples.

This study aimed to assess the frequency of Klebsiella pneumoniae in food samples and to detect antibiotic resistance phenotypes, antimicrobial resistance genes and the molecular subtypes of the recovered isolates. A total of 998 food samples were collected, and 99 (9.9%) K. pneumoniae strains were isolated; the frequencies were 8.2% (4/49) in fresh raw seafood, 13.8% (26/188) in fresh raw chicken, 11.4% (34/297) in frozen raw food and 7.5% (35/464) in cooked food samples. Antimicrobial resistance was observed against 16 antimicrobials. The highest resistance rate was observed for ampicillin (92.3%), followed by tetracycline (31.3%), trimethoprim-sulfamethoxazole (18.2%), and chloramphenicol (10.1%). Two K. pneumoniae strains were identified as extended-spectrum ß-lactamase (ESBL)-one strain had three beta-lactamases genes (blaSHV, blaCTX-M-1, and blaCTX-M-10) and one had only the blaSHV gene. Nineteen multidrug-resistant (MDR) strains were detected; the percentage of MDR strains in fresh raw chicken samples was significantly higher than in other sample types (P<0.05). Six of the 18 trimethoprim-sulfamethoxazole-resistant strains carried the folate pathway inhibitor gene (dhfr). Four isolates were screened by PCR for quinolone resistance genes; aac(6')-Ib-cr, qnrB, qnrA and qnrS were detected. In addition, gyrA gene mutations such as T247A (Ser83Ile), C248T (Ser83Phe), and A260C (Asp87Ala) and a parC C240T (Ser80Ile) mutation were identified. Five isolates were screened for aminoglycosides resistance genes; aacA4, aacC2, and aadA1 were detected. Pulsed-field gel electrophoresis-based subtyping identified 91 different patterns. Our results indicate that food, especially fresh raw chicken, is a reservoir of antimicrobial-resistant K. pneumoniae, and the potential health risks posed by such strains should not be underestimated. Our results demonstrated high prevalence, antibiotic resistance rate and genetic diversity of K. pneumoniae in food in China. Improved control and prevention strategies are urgently needed.

Molecular characterization of foodborne-associated Staphylococcus aureus strains isolated in Shijiazhuang, China, from 2010 to 2012.

Staphylococcus aureus is an opportunistic pathogen commonly identified from food poisoning-associated foodstuffs. From 1996 to the present, S. aureus isolates have been found to exhibit increasing resistance to antimicrobial drugs. The aim of this study was to assess the molecular epidemiology properties of various S. aureus isolates through molecular typing and to investigate their characterization based on their production of enterotoxins and hemolysins and their resistance to antibiotics. A total of 78 coagulase-positive staphylococcal strains isolated from food or clinical samples were analyzed. Eight VNTR loci were used to genotype the 78 isolates, and this analysis resulted in 39 different multilocus variable number tandem repeat analysis (MLVA) profiles. The isolates recovered from a single outbreak exhibited the same MLVA profile. According to CLSI, 97.4% of the isolates were resistant to penicillin, whereas only 3.8% were methicillin-resistant Staphylococcus aureus strains. Through multiplex PCR, 87.2% of the isolates were shown to be enterotoxigenic (SEs), and the most common genes present were sea, sem, seg, seu, and sek. In conclusion, this study demonstrates the prevalence of staphylococcal enterotoxins, the contents of virulent factors, and the characteristics of ß-lactam antibiotic resistance in 78 S. aureus isolates. These findings emphasize the need to prevent the presence of S. aureus strains and SE production in foods. Our results also demonstrate that MLVA is a useful and powerful method for epidemiological studies of S. aureus. In contrast to multilocus sequence typing, the MLVA method is a simpler and more rapid method for epidemiological typing with a higher discriminatory power.

Isolation and molecular typing of Cronobacter spp. in commercial powdered infant formula and follow-up formula.

Cronobacter spp. (Enterobacter sakazakii) are important foodborne pathogens. Infections with this pathogen can lead to neonatal meningitis, necrotizing enterocolitis, and bacteremia. This study examined Cronobacter spp. contamination in commercial powdered infant formulas (PIFs) and follow-up formulas (FUFs) in China. Forty-nine of 399 samples were contaminated with Cronobacter spp. and 10.2% of the isolates were resistant to cefotaxime; in contrast, all of the tested isolates were susceptible to amikacin, amoxicillin/clavulanic acid, cefepime, ciprofloxacin, imipenem, and meropenem. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) analyses produced a total of 16 PFGE banding patterns and 11 sequence types (STs), including 7 novel STs. In summary, the rates at which Cronobacter spp. were isolated from commercial PIF and FUF samples in China were relatively high, and the isolated strains exhibited high susceptibility in vitro to most antibiotics. The PFGE method exhibited higher typing capability than the MLST method, and molecular typing results revealed that the contamination of PIF and FUF with Cronobacter spp. in China may be mainly due to the addition of contaminated materials. Thus, the development of more effective control strategies during the manufacturing process is needed.

[Co-culture of human extravillous cytotrophoblasts and decidual stromal cells in vitro].

OBJECTIVE: To develop a convenient method for isolation and purification of human extravillous cytotrophoblasts (EVCTs) and decidual stromal cells (DSCs) and establish a co-culture system. METHODS: The DSCs were digested with trypsin and purified by Percoll gradient. The EVCTs were digested with trypsin and purified by BSA gradient. Immunohischemistry and immunofluorescent study are performed to characterize these isolated cells. The EVCTs and DSCs were placed in Matrigel-coated Transwell upper and lower chamber, respectively, to study the invasive ability of the EVCTs. RESULTS: Immunohischemistry revealed that the purity of EVCTs and DSC exceeded 95%. Cultured EVCTs retained their capacity to invade Matrigel-coated Transwell filters with the invasion index of 3.22-/+0.04. CONCLUSION: This co-culture model established by isolating highly purified EVCTs and DSCs in vitro can be useful for studying the trophoblast invasion mechanisms.

Effect of nitric oxide synthase inhibitor on proteoglycan metabolism in repaired articular cartilage in rabbits.

OBJECTIVE: To study the effect of nitric oxide synthase inhibitor, S-methyl thiocarbamate (SMT), on proteoglycan metabolism in repaired articular cartilage in rabbits. METHODS: Twenty-four male New Zealand white rabbits, aged 8 months and weighing 2.5 kg+/-0.2 kg, were used in this study. Cartilage defects in full thickness were created on the intercondylar articular surface of bilateral femurs of all the rabbits. Then the rabbits were randomly divided into 3 groups (n=8 in each group). The defects in one group were filled with fibrin glue impregnated with recombinant human bone morphogenetic protein-2 (rhBMP-2, BMP group), in one group with fibrin glue impregnated with rhBMP-2 and hypodermic injection with SMT (SMT group) and in the other group with nothing (control group). All the animals were killed at one year postoperatively. The tissue sections were stained with safranine O-fast green and analyzed by Quantiment 500 system to determine the content of glycosaminoglycan through measuring the percentage of safranine O-stained area, the thickness of cartilages and the mean gray scale (average stain intensity). Radiolabelled sodium sulphate (Na(2)(35)SO(4)) was used to assess the proteoglycan synthesis. RESULTS: At one year postoperatively, the percentage of safranine O-stained area, the mean gray scale and the cartilage thickness of the repaired tissues in SMT group were significantly higher than those of BMP group (P<0.01) and the control group (P<0.05). Result of incorporation of Na(2)(35)SO(4) showed that the proteoglycan synthesis in SMT group was higher than those of BMP group and the control group (P<0.01). CONCLUSIONS: SMT, a nitric oxide synthase inhibitor, can significantly increase the content of glycosaminoglycan and proteoglycan synthesis, and computer-based image analysis is a reliable method for evaluating proteoglycan metabolism.