Genotypic and phenotypic characteristics of Streptococcus pneumoniae from community-acquired pneumonia patients and healthy asymptomatic participants in Sichuan province, China.

BACKGROUND: Streptococcus pneumoniae (S. pneumoniae) is the common cause of community-acquired pneumonia (CAP) and is also found in the upper respiratory tract of healthy people. Hence, the study aimed to compare the serotypes, virulence/pili genes, and antibiotic susceptibility of S. pneumoniae from healthy asymptomatic participants and CAP patients. METHODS: Streptococcus pneumoniae were retrospectively collected from health asymptomatic participants and CAP patients in Sichuan, China. The serotypes were tested by multiplex polymerase chain reaction (PCR) or Quellung reaction. Antibiotic susceptibility testing was performed using the broth microdilution method. The molecular epidemiology of S. pneumoniae was analyzed by multilocus sequence typing (MLST). Additionally, the presence of virulence/pili genes were detected using PCR. RESULTS: A total of 83 pneumococcal isolates were collected in the current study. Of these, 52 and 31 isolates were from healthy asymptomatic participants and CAP patients, respectively. Most of S. pneumoniae were resistant to erythromycin (ERY), clindamycin (CLI), tetracycline (TET) and trimethoprim-sulfamethoxazole (SXT). 90.4% isolates were classified as multidrug resistant (MDR). The predominant serotypes were 3, 19F and 19A in the CAP carriers, whereas 3, 6 and 19F were the main serotypes among the asymptomatic carriers. The overall coverage rates of pneumococcal conjugate vaccine (PCV) 10 and PCV13 serotypes were 34.9% and 66.3%, respectively. The predominant sequence types (STs) were ST271, ST320, and ST3397. There were significant differences in some resistance and virulence characteristics between CAP patients and asymptomatic carriers. Additionally, clonal complex (CC) 271 strains had higher percentage in resistance to cefuroxime (CXM) and cefotaxime (CEF), meropenem (MER) and cefepime (CFP), which mainly carried the rlrA and sipA genes. CONCLUSIONS: High coverage rate of PCV13 and high prevalence of MDR indicated the necessity to expand immunization with PCV13 and rationally use the antibiotics in Sichuan, China. Importantly, long-term surveillance should be conducted to assess effectiveness brought by vaccines. Our findings may supply new guidance for developing new pneumococcal vaccines.

Incidence, Etiology, and Environmental Risk Factors of Community-Acquired Pneumonia Requiring Hospitalization in China: A 3-Year, Prospective, Age-Stratified, Multicenter Case-Control Study.

Background: Community-acquired pneumonia (CAP) is a leading infectious cause of hospitalization and death worldwide. Knowledge about the incidence and etiology of CAP in China is fragmented. Methods: A multicenter study performed at 4 hospitals in 4 regions in China and clinical samples from CAP patients were collected and used for pathogen identification from July 2016 to June 2019. Results: A total of 1674 patients were enrolled and the average annual incidence of hospitalized CAP was 18.7 (95% confidence interval, 18.5-19.0) cases per 10000 people. The most common viral and bacterial agents found in patients were respiratory syncytial virus (19.2%) and Streptococcus pneumoniae (9.3%). The coinfections percentage was 13.8%. Pathogen distribution displayed variations within age groups as well as seasonal and regional differences. The severe acute respiratory syndrome coronavirus 2 was not detected. Respiratory virus detection was significantly positively correlated with air pollutants (including particulate matter ≤2.5 µm, particulate matter ≤10 µm, nitrogen dioxide, and sulfur dioxide) and significantly negatively correlated with ambient temperature and ozone content; bacteria detection was opposite. Conclusions: The hospitalized CAP incidence in China was higher than previously known. CAP etiology showed that differences in age, seasons, regions, and respiratory viruses were detected at a higher rate than bacterial infection overall. Air pollutants and temperature have an influence on the detection of pathogens.

Reference Intervals for Reticulocyte Hemoglobin Content, Mean Reticulocyte Volume and Reticulocyte Count Percentage in Healthy Han Ethnic Adults of Chengdu.

BACKGROUND: The goals of this study are to determine the RIs of RHE, MRV, and reticulocyte count percentage (RET) in healthy Han ethnic adults of Chengdu. METHODS: A total of 691 Han adults without iron deficiency, aged 20 to 90 years were included in the study. The RIs were defined as mean ± 1.96 SD. RESULTS: After statistical analysis the RIs were 29.95 - 35.12 pg (RHE), 99.76 - 115.97 fL (MRV) in males and 29.77 - 34.52 pg (RHE), 98.72 - 113.83 fL (MRV) in females. RET reference interval was 0.485 - 1.504%. CONCLUSIONS: In our study, we established RHE, MRV, and RET RIs of the Han ethnic population in Chengdu for the first time.

Establishment of Reference Intervals for Serum Cytokeratin-19 Fragment and Neuron Specific Enolase by Indirect Method Using Data Obtained from Healthy Chinese Population in Chengdu.

BACKGROUND: In order to establish suitable reference intervals (RIs) of serum cytokeratin-19 fragment (Cyfra211) and neuron specific enolase (NSE) for the healthy Chinese population in Chengdu, China, an indirect method was developed using the data from the people presented for routine health check-up. METHODS: All results for 4,988 healthy persons serum cytokeratin-19 fragment and 3,293 healthy persons neuron specific enolase were collected in our laboratory information system between January 2016 and December 2018. Outliers were identified and excluded using the stem-and-leaf and box plot methods. Mann-Whitney U test was used to observe the difference between sexes. Spearman's rank correlation analysis was used to evaluate the correlation between serum results and age. The RIs were defined by nonparametric 95th percentile interval. RESULTS: After statistical analysis the indirect RIs were 0.0 - 3.70 ng/mL (Cyfra211) and 0 - 17.26 ng/mL (NSE) in males and 0.0 - 3.35 ng/mL (Cyfra211) and 0.0 - 16.29 ng/mL (NSE) in females. Cyfra211 and NSE levels in males and females had no correlation with age. Therefore, there was no need to establish RIs according to age group. RIs of Cyfra211 and NSE were verified and passed the verification in the end. CONCLUSIONS: Using health check-up persons' laboratory data values is a relatively easy and cheap method of establishing laboratory specific references. This method deserves to be promoted and applied by other clinical laboratories.

Normal Reference Intervals of Neutrophil-To-Lymphocyte Ratio, Platelet-To-Lymphocyte Ratio, Lymphocyte-To-Monocyte Ratio, and Systemic Immune Inflammation Index in Healthy Adults: a Large Multi-Center Study from Western China.

BACKGROUND: Numerous studies have shown that the hematological components of the systemic inflammatory response, including the neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR), the lymphocyte-to-monocyte ratio (LMR), and the systemic immune inflammation index (SII) are efficient prognostic indicators in patients with cancers. Most of the studies did not investigate the reference intervals (RIs) of these parameters in healthy controls. METHODS: A retrospective cohort study was performed on healthy ethnic Han population aged between 18 and 79 years of age by retrieving the data from a healthy routine examination center database and laboratory infor-mation system of four participating centers in western China. By following the Clinical and Laboratory Standards Institute (CLSI), RIs of each parameter was established and validated. RESULTS: The analysis included 5,969 healthy subjects. We found that the individual's gender can significantly influence PLR, LMR, and SII (all p < 0.05), but not NLR (p > 0.05). Surprisingly, we also found that with an increase in age, the PLR, LMR, and SII tend to decrease, while NLR remained stable. PLR, LMR, and SII values were significantly higher in the young adults (18 - 64 years) than in old adults (65 - 79 years) (p < 0.001). The RIs of NLR, PLR (adults), PLR (old adults), LMR and SII were 0.88 - 4.0, 49 - 198, 42 - 187, 2.63 - 9.9, 142 x 109/L - 804 x 109/L, respectively. CONCLUSIONS: Our study addresses possible variations and establishes consensus for the NLR, PLR, LMR, and SII RIs for healthy Han Chinese adults in western China. Further, established RIs can standardize clinical applications and promote the use of these indicators into the routine complete blood count report.

Identification of synthetic peptides that inhibit lipopolysaccharide (LPS) binding to myeloid differentiation protein-2 (MD-2).

Many studies have suggested that the synergic effect of myeloid differential protein-2 (MD-2) on bacterial lipopolysaccharide (LPS) stimulation of toll-like receptor 4 (TLR4) may be a critical step during the LPS-TLR4 response signaling pathway. We performed a bioinformatic analysis on the MD-2 protein and identified the amino acid sequence NH2-FSKGKYKCV-COOH (K128-132) as a possible key sequence involved in the binding between MD-2 and LPS. We then screened a random phage display peptide library using this sequence as bait in order to identify antagonistic peptides. After 3 rounds of selection, 3 positive clones were identified. All 3 peptides were shown to inhibit, in a dose-dependent manner the production of tumor necrosis factor-α and interleukin-6 in human U937 and THP-1 cell lines as well as human peripheral blood monocytes stimulated by LPS. Only 2 of the 3 peptides were able to bind MD-2 directly as shown by sulfo-SBED biotin label transfer experiments. BALB/C mice were used to estimate the protection of these peptides from LPS challenge, and 2 of the 3 peptides (Lys-Thr-Val-Pro-Asp-Asn-His and Ile-Gly-Lys-Phe-Leu-Tyr-Arg) reduced mortality of the challenged mice from 100% to 53.8%. This study has demonstrated that interfering with the binding between MD-2 and LPS might be a potential therapeutic strategy for treating LPS-induced sepsis, and in doing so has identified 2 potential peptide candidates.

[Heterogeneity changes in secretion ability of monocyte/macrophage and its significance after trauma hemorrhage in rat].

OBJECTIVE: To investigate the relationship between the heterogeneity in secretion ability of monocyte (Mo)/macrophage and the immune dysfunction after severe trauma. METHODS: Twenty-four healthy Wistar rats were randomly divided into normal control group and trauma hemorrhage 1, 4 and 7 days groups. The contents of interleukin-6 (IL-6) and IL-10 secretion of Mo/macrophage from different anatomical regions were determined by radioimmunoassay. RESULTS: (1)In normal rats, the ability to secrete IL-6 and IL-10 was different among alveolar macrophages (AM), peritoneal macrophages (PM) and Mo. PM showed the highest ability to secrete IL-10 while Mo had the highest ability to secrete IL-6. (2)After trauma hemorrhage, the secretion of IL-6 and IL-10 by AM were increased dramatically. On the contrary, the secretion of IL-6 by PM was declined from the 1st day to the 4th day, then increased even over that of the normal control group on the 7th day. However, the secretion of IL-10 by PM was significantly elevated on the 1st day after trauma hemorrhage, peaking on the 4th day, and only slight lowering was found on the 7th day. The secretion of IL-6 by Mo was declined gradually all the time, reaching the lowest point on the 7th day. On the contrary, the secretion of IL-10 by Mo was increasing, reaching its peak on the 7th day. CONCLUSION: The heterogeneity of secretion ability of Mo/macrophage obtained from different anatomical regions is present under normal condition, and is more obvious following a severe injury. This change may play an important role in the immune dysfunction and the development of complications after trauma.