sRNA expression profile of KPC-2-producing carbapenem-resistant Klebsiella pneumoniae: Functional role of sRNA51.

The emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) has significant challenges to human health and clinical treatment, with KPC-2-producing CRKP being the predominant epidemic strain. Therefore, there is an urgent need to identify new therapeutic targets and strategies. Non-coding small RNA (sRNA) is a post-transcriptional regulator of genes involved in important biological processes in bacteria and represents an emerging therapeutic strategy for antibiotic-resistant bacteria. In this study, we analyzed the transcription profile of KPC-2-producing CRKP using RNA-seq. Of the 4693 known genes detected, the expression of 307 genes was significantly different from that of carbapenem-sensitive Klebsiella pneumoniae (CSKP), including 133 up-regulated and 174 down-regulated genes. Both the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment and Gene Ontology (GO) analysis showed that these differentially expressed genes (DEGs) were mainly related to metabolism. In addition, we identified the sRNA expression profile of KPC-2-producing CRKP for the first time and detected 115 sRNAs, including 112 newly discovered sRNAs. Compared to CSKP, 43 sRNAs were differentially expressed in KPC-2-producing CRKP, including 39 up-regulated and 4 down-regulated sRNAs. We chose sRNA51, the most significantly differentially expressed sRNA in KPC-2-producing CRKP, as our research subject. By constructing sRNA51-overexpressing KPC-2-producing CRKP strains, we found that sRNA51 overexpression down-regulated the expression of acrA and alleviated resistance to meropenem and ertapenem in KPC-2-producing CRKP, while overexpression of acrA in sRNA51-overexpressing strains restored the reduction of resistance. Therefore, we speculated that sRNA51 could affect the resistance of KPC-2-producing CRKP by inhibiting acrA expression and affecting the formation of efflux pumps. This provides a new approach for developing antibiotic adjuvants to restore the sensitivity of CRKP.

TLR2 regulates Moraxella catarrhalis adhesion to and invasion into alveolar epithelial cells and mediates inflammatory responses.

Moraxella catarrhalis is a major cause of chronic obstructive pulmonary disease. Toll-like receptor 2 (TLR2) plays an important role in the inflammatory response in host respiratory epithelial cells. M. catarrhalis induces an inflammatory immune response in respiratory epithelial cells that is mostly dependent on TLR2. However, the mechanisms by which this pathogen adheres to and invades the respiratory epithelium are not well understood. The present study aimed to reveal the role of TLR2 in M. catarrhalis adhesion to and invasion into alveolar epithelial cells, using molecular techniques. Pretreatment with the TLR2 inhibitor TLR2-IN-C29 enhanced M. catarrhalis adhesion to A549 cells but reduced its invasion, whereas the agonist Pam3CSK4 reduced both M. catarrhalis adhesion and invasion into A549 cells. Similarly, M. catarrhalis 73-OR strain adhesion and invasion were significantly reduced in TLR2-/- A549 cells. Moreover, the lung clearance rate of the 73-OR strain was significantly higher in TLR2-/- C57/BL6J mice than in wild-type (WT) mice. Histological analysis showed that inflammatory responses were milder in TLR2-/- C57/BL6J mice than in WT mice, which was confirmed by a decrease in cytokine levels in TLR2-/- C57/BL6J mice. Overall, these results indicate that TLR2 promoted M. catarrhalis adhesion and invasion of A549 cells and lung tissues and mediated inflammatory responses in infected lungs. This study provides important insights into the development of potential therapeutic strategies against M. catarrhalis and TLR2-induced inflammatory responses.

Characterization of Streptococcus pneumoniae Macrolide Resistance and Its Mechanism in Northeast China over a 20-Year Period.

Due to the resistance of Streptococcus pneumoniae to ß-lactams, macrolides, and tetracyclines, treatment alternatives have become increasingly limited worldwide. We aim to describe the characterization of erythromycin-resistant S. pneumoniae (ERSP) strains in northeastern China over a period of 20 years. A total of 1,240 ERSP strains were collected and classified into five groups based on the ages of the patients. Etest strips and Kirby-Bauer disk diffusion were performed for drug susceptibility testing. The capsule swelling test was used for capsule typing. The phenotype of drug resistance was detected by the erythromycin and clindamycin double-disk method. The ermB, ermTR, mefA, and tetM genes were detected by PCR. Among the 1,240 ERSP strains, 510 were invasive isolates, and 730 were noninvasive isolates. The results of drug susceptibility testing showed that the rates of resistance to penicillin, amoxicillin, cefotaxime, ceftriaxone, meropenem, tetracycline, trimethoprim-sulfamethoxazole, and chloramphenicol varied among the different age groups. 19F, 19A, 23F, 14, and 6B were the serotypes that were commonly found among ERSP strains. Among all strains, 99.03% (1,228/1,240) exhibited an MLSB (macrolide-lincosamide-streptogramin B) resistance phenotype, of which 1,221 strains displayed a constitutive MLSB (cMLSB) phenotype and 7 strains showed an inducible MLSB (iMLSB) phenotype. All of these strains carried the ermB gene. In contrast, only 0.97% of strains of M phenotypes were found to carry the mefA gene. Both the ermB and mefA genes were detected in 704 strains that exhibited multidrug resistance, whereas the ermTR gene was not detected. Furthermore, 1,185 tetracycline-resistant strains were found to carry the tetM gene. Macrolide antimicrobial drugs should be used cautiously for the empirical treatment of S. pneumoniae infections. IMPORTANCE This study presents a retrospective analysis using 1,240 clinical erythromycin-resistant Streptococcus pneumoniae (ERSP) isolates collected in northeastern China between January 2000 and December 2019. The serotype distribution, corresponding vaccine coverage, as well as resistance phenotypes, genes, and mechanisms to macrolide and tetracycline of these isolates were systematically described, analyzed, and discussed. We hope that this study will inform clinicians in their respective regions when selecting antimicrobial agents. We also hope that this study is useful for researchers in related fields. Finally, we emphasize in this study that vaccination is the best preventive measure for S. pneumoniae infection considering its resistance to commonly used antibiotics. The determination of the S. pneumoniae serotype distribution also provides valuable empirical evidence for local health authorities when introducing appropriate vaccines in a specific area.

Seroepidemiology of TORCH Infections among 1.7 Million Women of Childbearing Age in Rural China: A Population-Based Cross-Sectional Study.

We conducted a national seroepidemiological study of the TORCH (Toxoplasma gondii [TOX], Rubella [RV], Cytomegalovirus [CMV], and Herpes Simplex Virus) in rural women to provided updated baseline data on TORCH prevalence. A total of 1,541,329 women of childbearing age were gathered from 2010 to 2012 in China. Of these, 858,072 women were tested positive for anti-RV IgG antibodies, 602,251 women were tested positive for anti-CMV antibodies, and 40,055 women were tested positive for anti-TOX antibodies. TORCH prevalence was highest among young adults (aged 25-34 years; P < 0.0001). A total of 69,220 women (4.49%) had received RV vaccination, of whom 49,988 (72.2%) had vaccine-acquired immunity. Of 1,541,329 women, 6,107 (0.40%) tested positive for anti-TOX IgM antibodies and 6,646 (0.43%) tested positive for anti-CMV IgM antibodies, suggesting the presence of TOX and CMV infections. TORCH markers were all more prevalent in the eastern region of China than in the central or western regions (all P < 0.0001). Prevalence rates related to all recent infection markers of TOX and CMV increased with increasing age in all regions (P < 0.0001). TORCH prevalence rates were found to be lower than previously published rates. This may be attributed to improvements in living standards and health habits in China. However, considering that the decrease in prevalence has led to an increase in the number of susceptible people, and the partial immunity caused by some pathogenic infections still leave infected people at risk of reinfection, strengthened vaccination and health education is essential to improve the quality of life of the Chinese population.

LRP1B Polymorphisms Are Associated with Multiple Myeloma Risk in a Chinese Han Population.

Multiple myeloma (MM) is an extremely complex plasma cell malignancy that is genetically heterogeneous. A recent Genome-wide association study (GWAS) indicated that variation at 2q22 (rs61070260) influences MM risk. This association has not been validated to date in a Chinese Han population. In this study, we evaluated the association between rs61070260 in LRP1B and MM risk in a Chinese Han population involving 739 MM patients and 592 healthy controls. Our results indicated that rs61070260 in LRP1B was significantly associated with MM susceptibility (P=3.937×10-37). Furthermore, the linkage disequilibrium (LD) analysis of rs61070260 revealed an LD block encompassing exons 26, 27 and 28 of the LRP1B gene, and a subsequent sequencing analysis identified three SNPs (rs762074421, rs756168629, rs113600691) in exons 26 and 28 of LRP1B. For the SNP rs756168629 in exon 26, a missense mutation which results in a transition from arginine to histidine at position 1661 of the LRP1B protein, has not been found in Chinese populations according to the Chinese Millionome Database and Genome Aggregation Database (EAS), and this mutation was predicted to be deleterious or damaging by SIFT and PolyPhen. These findings firmly establish the role of LRP1B in contributing to MM susceptibility. In addition, the identification of a rare coding mutation (p.R1661H) in LRP1B detected in MM individuals was suggested to be harmful to the encoded protein, which was characterized as a candidate tumour suppressor; thus, LRP1B is likely to be a disease-associated gene that is implicated in the development and progression of MM.

Urine markers of renal tubular injury in idiopathic membranous nephropathy: A cross sectional study.

INTRODUCTION: Idiopathic membranous nephropathy (IMN) is a primary glomerular disease and a major cause of adult nephrotic syndrome. Presently, little is known about the capabilities of the urine markers to reflect the severity of IMN. We aimed at establishing whether urinary N-acetyl-ß-glucosaminidase (NAG), Retinol binding protein (RBP), Kidney injury molecule-1 (KIM-1) and Neutrophil gelatianse-associated lipocalin (NGAL) are related with renal parameters and the histological grades tubular injury. METHODS: The levels of urinary NAG, RBP, KIM-1 and NGAL were determined in 165 biopsy-proven patients and 64 healthy controls. Their levels were then compared between patients and healthy subjects, and between patients with and without nephrotic syndrome. Their linearity with renal parameters and associations with histological grades of renal tubular injury were also assessed. RESULTS: All biomarkers were significantly increased in patients (p < .001). However, no significant increase was observed between patients exhibiting moderate and severe grades tubular injury and those exhibiting mild histological grade. With exception of RBP, all biomarkers were higher in patients with nephrotic syndrome (p < .001) and significantly correlated with majority of renal parameters including proteinuria. CONCLUSION: Our findings suggest that although urine markers of tubular injury are increased in IMN, they may not offer a reflection of histological grades.

Serum phospholipase A2 receptor antibodies and immunoglobulin G subtypes in adult idiopathic membranous nephropathy: Clinical value assessment.

BACKGROUND: Idiopathic membranous nephropathy (IMN) is widely considered as an organ-specific autoimmune disorder. Implicated in its pathogenesis are the phospholipase A2 receptors (PLA2R) expressed on glomerular podocytes against which serum antibodies are formed. In this study we quantified and assessed the clinical value of total serum PLA2R antibodies and the subtype antibodies in IMN. METHODS: We measured serum levels of total PLA2R antibodies and IgG subtype antibodies by Enzyme Linked Immunosorbent Assay (ELISA) in 146 biopsy-proven IMN patients, 51 non-IMN patients and 62 healthy controls. We went ahead and determined the diagnostic potential of total serum PLA2R antibodies and assessed if a relationship exists between the dominat subtype antibody and the clinical parameters. RESULTS: The diagnostic sensitivity and specificity of total serum PLA2R antibody for IMN were found at 69.9% and 100% respectively. Significant differences in systolic blood pressure, serum Cystatin C, serum albumin and estimated glomerular filtration rate (eGFR) were found between the antibody-positive and antibody-negative groups of IMN patients. Subtype antibody 4 and 1 exhibited the highest positive rates of 94.4% and 91.6% respectively. The mean serum proportion of subtype antibodies was 65.4, 12.7, 7.6 and 4.6% for subtype 4, 1, 3 and 2 respectively. Serum levels of total protein and albumin were significantly decreased among patients with high serum titres of antibody subtype 4. CONCLUSION: Our findings underscore the diagnostic potential of total serum PLA2R antibodies and highlight the importance of antibody subtype 4 over other subtype antibodies in IMN.

A review of urinary angiotensin converting enzyme 2 in diabetes and diabetic nephropathy.

Urinary angiotensin converting enzyme 2 (ACE2) is significantly increased in diabetes and diabetic nephropathy. While studies on its clinical significance are still underway, its urinary expression, association with metabolic and renal parameters has been in the recent past considerably studied. The recent studies have demystified urine ACE2 in many ways and suggested the roles it could play in the management of diabetic nephropathy. In all studies the expression of urinary ACE2 was determined by enzyme activity assay and/with the quantification of ACE2 protein and mRNA by methods whose reliability are yet to be evaluated. This review summarizes recent findings on expression of urinary ACE2, examines its relationship with clinical parameters and highlights possible applications in management of diabetic nephropathy.

Risk alleles for IgA nephropathy-associated SNPs conferred completely opposite effects to idiopathic membranous nephropathy in Chinese Han.

The coexistence of immunoglobulin A nephropathy (IgAN) and idiopathic membranous nephropathy (IMN) in a few cases suggested that there could be existed a similar mechanism in pathogenesis of these two types of primary glomerulonephritis. In order to verify this hypothesis, a total of 23 reported IgAN-associated SNPs were genotyped in a cohort of 485 IMN patients and 569 healthy controls with Chinese Han origin. After Cochran-Armitage test for trend analysis, seven IgAN-associated SNPs located in the major histocompatibility complex (MHC) region were found to be significantly associated with the susceptibility of IMN, with rs9275596 as the top one (p = 1.97E-43, OR = 3.977). It was worth mentioning that the minor alleles of the SNPs conferred completely opposite effects on the pathogenesis of IMN and IgAN, suggesting quite different roles played by these SNPs for these two kinds of primary glomerulonephritis. Conditional logistic regression analysis displayed that SNPs protective from IMN (odds ratio < 1.00) were still significantly associated with IMN (p = 3.67E-4 for rs660895 and p = 1.26E-4 for rs9275224) with the most significant SNP rs9275596 as a covariate. Haplotype-based analysis showed that the seven SNPs were mapped to independent linkage disequilibrium (LD) blocks. Moreover, three out of these seven SNPs, including rs9275224, rs660895, and rs9357155, were found to be potential expression quantitative trait loci (eQTLs) for HLA-DQ molecules. Out of the purpose of identifying the causal variants for IMN within the MHC region, imputation analysis was performed using genotype data of Chinese Han released by the 1000 Genome Project and identified hundreds of SNPs potentially associated with the disease. In brief, our analysis revealed a significant association with the susceptibility of idiopathic membranous nephropathy for the IgAN-correlated SNPs. These SNPs conferred a completely different role for the pathogenesis of these two kinds of diseases.

The Association of rs1047763 and rs1008898 of C1GALT1 with IgA Nephropathy Risk: A Global Meta-Analysis.

IgA nephropathy (IgAN) is a globally common primary glomerulonephritis characterized by an elevated level of serum IgA and immune complex deposition in the mesangial area. In the serum of patients with IgAN, the hinge region of IgA1 immunoglobulin contains aberrantly glycosylated O-glycans deficient in galactose, which is normally added to the core 1 O-glycan structure by core 1 synthase, glycoprotein-N-acetylgalactosamine 3-beta-galactosyltransferase 1 (C1GALT1), the key enzyme in the process of glycosylation. It is unknown if single-nucleotide polymorphisms rs1047763 and rs1008898 of C1GALT1 increase the risk of IgAN. We enrolled 5 subjects in this meta-analysis, including a total of 1693 IgAN patients and 1864 control subjects. We performed meta-analysis on associations between rs1047763, rs1008898, and IgAN using the allele model, dominant model, recessive model, and additive model. We found that there was no relationship between rs1047763 and rs1008898 in C1GALT1 and susceptibility to IgAN.

NCOA1 is a novel susceptibility gene for multiple myeloma in the Chinese population: A case-control study.

Multiple myeloma (MM) is an incurable malignancy of mature B-lymphoid cells, and its pathogenesis is only partially understood. Previous studies have demonstrated that a number of Non-Hodgkin Lymphoma (NHL) associated genes also show susceptibility to MM, suggesting malignancies originating from B cells may share similar genetic susceptibility. Several recent large-scale genome-wide association studies (GWAS) have identified HLA-I, HLA-II, CXCR5, ETS1, LPP and NCOA1 genes as genetic risk factors associated with NHL, and this study aimed to investigate whether these genes polymorphisms confer susceptibility with MM in the Chinese Han population. In 827 MM cases and 709 healthy controls of Chinese Han, seven single nucleotide polymorphisms (SNPs) in the HLA-I region (rs6457327), the HLA-II region (rs2647012 and rs7755224), the CXCR5 gene (rs4938573), the ETS1 gene (rs4937362), the LPP gene (rs6444305), and the NCOA1 region (rs79480871) were genotyped using the Sequenom platform. Our study indicated that genotype and allele frequencies of rs79480871 showed strong associations with MM patients (pa = 3.5×10-4 and pa = 1.5×10-4), and the rs6457327 genotype was more readily associated with MM patients than with controls (pa = 4.9×10-3). This study was the first to reveal the correlation between NCOA1 gene polymorphisms and MM patients, indicating that NCOA1 might be a novel susceptibility gene for MM patients in the Chinese Han population.

Development of gestation-specific reference intervals for thyroid hormones in normal pregnant Northeast Chinese women: What is the rational division of gestation stages for establishing reference intervals for pregnancy women?

BACKGROUND: A laboratory- and region-specific trimester-related reference interval for thyroid hormone assessment of pregnant women was recommended. Whether the division by trimester is suitable requires verification. Here, we tried to establish appropriate reference intervals of thyroid-related hormones and antibodies for normal pregnant women in Northeast China. METHODS: A total of 947 pregnant women who underwent routine prenatal care were grouped via two methods. The first method entailed division by trimester: stages T1, T2, and T3. The second method entailed dividing T1, T2, and T3 stages into two stages each: T1-1, T1-2, T2-1, T2-2, T3-1, and T3-2. Serum levels of TSH, FT3, FT4, Anti-TPO, and Anti-TG were measured by three detection systems. RESULTS: No significant differences were found in TSH values between T1-1 group and the non-pregnant women group. However, the TSH value of the T1-1 group was significantly higher than that of T1-2 group (P<0.05). The TSH values in stage T3-2 increased significantly compared to those in stage T3-1 measured by three different assays (P<0.05). FT4 and FT3 values decreased significantly in the T2-1 and T2-2 stages compared to the previous stage (P<0.05). The serum levels of Anti-TPO and Anti-TG were not having significant differences between the six stages. CONCLUSION: The diagnosis and treatment of thyroid dysfunction during pregnancy should base on pregnancy- and method-specific reference intervals. More detailed staging is required to assess the thyroid function of pregnant women before 20 gestational weeks.