Characteristics of non-carbapenemase producing carbapenem-resistant Klebsiella pneumoniae from a tertiary hospital in China.

INTRODUCTION: The spread of carbapenem-resistant Klebsiella pneumoniae (CRKP) is a substantial severe global public health burden. Non-carbapenemase-producing CRKP (non-CP-CRKP) is increasingly recognized as the source of severe infections. METHODOLOGY: We analyzed the genotypic, and phenotypic profiles of non-CP-CRKP strains with the whole-genome sequences isolated between 2017 and 2019 and the clinical characterization of non-CP-CRKP infection. RESULTS: A total of 91 CRKP strains were collected, of which 5 (5.49%) strains were non-CP-CRKP. Four strains were from male patients; three strains were isolated from the bile of patients who underwent biliary interventional surgery and four had a history of antibiotic exposure. Three strains were sequence type (ST)11, one was ST1, and one was ST5523. The non-CP-CRKP strains were insusceptible to ertapenem. Three strains were susceptible to amikacin. All the strains were susceptible to imipenem, meropenem, tigecycline, ceftazidime/avibatam and polymyxin B. The ß-lactamases of non-CP-CRKP predominantly included blaCTX-M, blaSHV, and blaTEM subtypes. Two site mutations in ompK36 (p.A217S and p.N218H) and four in ompK37 (p.I70M, p.I128M, p.N230G, and m233_None234insQ) were detected accounting for carbapenem resistance. Plasmids IncFI and IncFII were found in most strains. Genes encoding aerobactin, yersiniabactin and allantoin utilization were not detected in several isolates, and all non-CP-CRKP strains did not carry rmpA gene. CONCLUSIONS: Non-CP-CRKP infected patients had a history of previous antibiotic exposure or invasive procedures. Non-CP-CRKP strains were insusceptible to ertapenem. The mechanism of resistance includes ß-lactamases production and the site mutations in ompK36 and ompK37. Several virulence genes were not detected in non-CP-CRKP.

Molecular Epidemiology and Virulence Gene Analysis of Methicillin-Resistant Staphylococcus aureus Associated with Skin and Soft Tissue Infections in the Shaoxing Region.

Objective: This study aimed to investigate the prevalence, molecular types, and virulence genes of methicillin-resistant Staphylococcus aureus (MRSA) causing skin and soft tissue infections (SSTIs) in the Shaoxing region. Methods: MRSA strains were collected from patients with SSTIs in Shaoxing People's Hospital from January 2019 to December 2019. We conducted SCCmec typing, Staphylococcus protein A (SPA) typing, multilocus sequence typing (MLST), and virulence gene analysis using whole-genome sequencing on all MRSA strains. Results: The detection rate of community-acquired MRSA (CA-MRSA) isolated from SSTI patients in our hospital was 33.3% (6/18). The primary SCCmec types of CA-MRSA strains were IV and V, with IVg(2B) and V(5C2&5) accounting for 16.7% each. Hospital-acquired MRSA (HA-MRSA) strains primarily exhibited SCCmec types IVa(2B) (25.0%), followed by II(2A) (16.7%), V(5C2) (16.7%), and V(5C2&5) (8.3%). SPA typing indicated that CA-MRSA strains causing SSTIs were predominantly t437 (14.3%), t034 (14.3%), t309 (14.3%), t4549 (14.3%), and t7637 (14.3%). The primary SPA type of HA-MRSA strains was t311 (16.7%). MLST typing revealed that the main sequence types (STs) of CA-MRSA strains causing SSTIs were ST22 (33.3%), followed by ST398, ST59, ST88, and ST630, each accounting for 16.7%. The principal STs of HA-MRSA strains were ST398 (16.7%), ST59 (16.7%), ST88 (16.7%), and ST5 (16.7%), followed by ST22, ST630, ST6, and ST188, each at 8.3%. The primary clones of CA-MRSA strains causing SSTIs were ST59-t437-IVg(2B) (16.7%) and ST630-t4549-V(5C2&5) (16.7%), while the primary clones of HA-MRSA strains were ST59-t437-IVa(2B), ST630-t4549-V(5C2&5), ST6-t304-IVa(2B), ST5-t311-II(2A), ST59-t172-IVa(2B), ST398-t571-V(5C2), ST398-t034-V(5C2), and ST5-t311-II(2A), each accounting for 8.3%. The detection rate of the lukSF-PV virulence gene was higher in CA-MRSA strains (50.0%) than in HA-MRSA strains (16.7%). Conclusions: The isolation rate of CA-MRSA strains causing SSTIs was high in Shaoxing People's Hospital, with ST59-t437-IVg(2B) and ST630-t4549-V(5C2&5) being the predominant clones. MRSA strains exhibited multiple virulence genes, with the lukSF-PV gene having a higher detection rate in CA-MRSA strains, signifying its importance as a virulence factor in CA-MRSA.

T-cell senescence: A crucial player in autoimmune diseases.

Senescent T cells are proliferative disabled lymphocytes that lack antigen-specific responses. The development of T-cell senescence in autoimmune diseases contributes to immunological disorders and disease progression. Senescent T cells lack costimulatory markers with the reduction of T cell receptor repertoire and the uptake of natural killer cell receptors. Senescent T cells exert cytotoxic effects through the expression of perforin, granzymes, tumor necrosis factor, and other molecules without the antigen-presenting process. DNA damage accumulation, telomere damage, and limited DNA repair capacity are important features of senescent T cells. Impaired mitochondrial function and accumulation of reactive oxygen species contribute to T cell senescence. Alleviation of T-cell senescence could provide potential targets for the treatment of autoimmune diseases.

Inhibition of AMPK-related kinase 5 (ARK5) enhances cisplatin cytotoxicity in non-small cell lung cancer cells through regulation of epithelial-mesenchymal transition.

Lung cancer incidence and mortality rates are amongst the highest of all malignant tumors worldwide. ARK5 is a member of the human AMP-activated protein kinase (AMPK) family which is implicated in tumor survival and progression. The current study was designed to explore the role of ARK5 in resistance of non-small cell lung cancer (NSCLC) to cisplatin. We studied the sensitivity of two NSCLC cell lines, NCI-H1229 and A549, to cisplatin by using proliferation and cell viability assays. We then examined expression of ARK5, Twist, and the epithelial to mesenchymal transition (EMT) biomarkers, E-cadherin and Vimentin, by Western blot and immunofluorescence. We found that ARK5 downregulation significantly increased the cisplatin chemosensitivity of NSCLC cells, and that NCI-H1299 cells, which express high levels of ARK5 and possess a mesenchymal phenotype, were more resistant to cisplatin than A549 cells, which show low expression ARK5. Furthermore, siRNA-mediated silencing of ARK5 resulted in altered EMT patterns in NSCLC cells. These data support a role for ARK5 in regulating EMT in NSCLC cells. Together, our findings suggest that ARK5 is a potential drug target for combating drug resistance and regulating EMT in NSCLC cells.

[Effect of eletroacupuncture for Z syndrome without organic lesion and serum leptin].

OBJECTIVE: To explore the effect and mechanism of electroacupuncture (EA) for Z syndrome without organic lesion (metabolic syndrome combined with obstructive sleep apnea hypopnea syndrome). METHODS: Fifty-eight patients with Z syndrome were divided into three groups according to mild,moderate and severe degree. Acupuncture and EA were used at Daimai (GB 26), Zhongwan (CV 12), Xiawan (CV 10), Zusanli ST 36), Qihai (CV 6) and Huaroumen (ST 24), etc., once a day and five times a week. The treatment of ten times was a course, and two courses were acquired continuously. Sleep respiration monitoring (PSG) was done before EA and in one week after treatment respectively. Triacylglycerol (TG) fasting blood glucose (FBG) fasting insulin (INS) and serum leptin (Lep) were tested before and after treatment in the three groups. RESULTS: After treatment apnea hypopnea index (AHI) and the percentage of the time of arterial oxygen saturation (SaO2) less than 90% taken in the total sleep time (SLT 90%) were improved apparently than those before treatment in the three groups (all P < 0.05). The levels of TG, FPG, INS and Lep were decreased after treatment in all groups (all P < 0.05). CONCLUSION: EA can improve AHI and nocturnal hypoxia of Z syndrome, and the mechanism may be related to decreasing the indices of metabolism syndrome and leptin.