Combined analysis of transcriptomics and metabolomics provide insights into the antibacterial mechanism of bacteriocin XJS01 against multidrug-resistant Staphylococcus aureus

Multidrug-resistant (MDR) bacteria are widespread in the environment and pose a serious threat to public health. It has been shown that bacteriocins have a great potential in controlling MDR pathogens, including Staphylococcus aureus. A previously reported Lactobacillus salivarius bacteriocin XJS01 exhibited good antibacterial activity against MDR S. aureus 2612:1606BL1486 (henceforth referred to as S. aureus_26), but its molecular mechanism remains unknown. Herein, we investigated the antibacterial mechanism of XJS01 on S. aureus_26 using an approach combining transcriptomics and metabolomics. The results showed that XJS01 induced significant changes at both transcriptional and metabolic levels in S. aureus_26. In total, 231 differentially expressed genes (DEGs) and 206 differentially abundance metabolites (DAMs) were identified in S. aureus_26 treated with 1 × MIC (minimum inhibition concentration) XJS01 compared with untreated (XJS01-free) cells (control). Functional analysis revealed that these DEGs and DAMs, alone with the related pathways and biological processes, were typically involved in stress response, being primarily related to metal uptake, cell virulence, self-help mechanism, amino acid and energy metabolism, bacterial stress response (e.g., two-component system), and membrane transport (e.g., phosphotransferase system). Overall, this study uncovered the multi-target effects of bacteriocins against MDR S. aureus at the genome-wide transcriptional and metabolic levels. These findings might be useful in the development of bacteriocins for the control of MDR S. aureus and other drug-resistant bacteria.

Honeybee (Apis mellifera) resistance to deltamethrin exposure by Modulating the gut microbiota and improving immunity

Honeybees (Apis mellifera) are important economic insects and play important roles in pollination and maintenance of ecological balance. However, the use of pesticides has posed a substantial threat to bees in recent years, with the more widely used deltamethrin being the most harmful. In this study, we found that deltamethrin exposure significantly reduced bee survival in a dose-dependent manner (p = 0.025). In addition, metagenomic sequencing further revealed that DM exposure significantly reduced the diversity of the bee gut microbiota (Chao1, p < 0.0001; Shannon, p < 0.0001; Simpson, p < 0.0001) and decreased the relative abundance of core species of the gut microbiota. Importantly, in studies of GF-bees, we found that the colonization of important gut bacteria such as Gilliamella apicola and Lactobacillus kunkeei significantly increased bee resistance to DM (survival rate increased from 16.7 to 66.7%). Interestingly, we found that the immunity-genes Defensin-2 and Toll were significantly upregulated in bees after the colonization of gut bacteria. These results suggest that gut bacteria may protect against DM stress by improving host immunity. Our findings provide an important rationale for protecting honeybees from pollutants from the perspective of gut microbes.

P1880Entropy-based algorithm for atrial fibrillation detection using photoplethysomgraphic signal recorded by a smart watch

Background

Atrial fibrillation (AF) is the most common arrhythmia, and its paroxysmal and short duration nature makes its detection challenging. The most important limitation of current smartwatches is that patients need to touch to the sensor of the watch to record signals when patients feel discomfort. We developed a wearable smart watch and evaluated its accuracy to differentiate AF from sinus rhythm, which can continuously detecting heart rhythm without hand touching the device.

Methods and results

A wearable smart watch with PPG sensor and electrocardiogram (ECG) recording function was used for signal acquisition. A total 399 patients with a mean age of 67 years old were enrolled in the study, of whom 237 (81.5%) were male, and 101 have been diagnosed with AF. Pulse wave extracted from the green light spectrum of the signal and ECG were recorded for about 10 minutes for each patient. Pulse-to-pulse intervals (PPI) were automatically identified. All ECG signals were verified by two cardiologists. The correlation between R-to-R interval on ECG and PPI were excellent, with a correlation coefficient R >0.99 (p<0.05). An entropy-based algorithm which combined Shannon entropy of successive difference of PPI and sample entropy of PPI was used to discriminate between AF and sinus rhythm. This method had high sensitivity and specificity (96% and 98%, respectively), the area under receiver operating characteristic curve reached 0.98.

Conclusions

We developed an entropy-based algorithm for AF detection with PPG signal recorded by a wearable smart watch. This algorithm discriminates AF from sinus rhythm accurately. This advance in technology overcomes an important clinical obstacle and can increase the AF detection rate tremendously.

Optimization of pressurized liquid extraction for Z-ligustilide, Z-butylidenephthalide and ferulic acid in Angelica sinensis

Pressurized liquid extraction, one of the most promising and recent sample preparation techniques, offers the advantages of reducing solvent consumption and allowing for automated sample handling. It is being exploited in diverse areas because of its distinct advantages. However, because the extraction is performed at elevated temperatures using PLE, thermal degradation could be a concern. Z-ligustilide, one of the biologically active components in Angelica sinensis, is an unstable compound, which decomposes rapidly at high temperature. In this study, we carried out a comparative study to evaluate PLE as a possible alternative to current extraction methods like Soxhlet and sonication for simultaneous extraction of Z-ligustilide, Z-butylidenephthalide and ferulic acid in A. sinensis. The operating parameters for PLE including extraction solvent, particle size, pressure, temperature, static extraction time, flush volume and numbers of extraction were optimized by using univariate approach coupled with central composite design (CCD) in order to obtain the highest extraction efficiency. Determination of Z-ligustilide, Z-butylidenephthalide and ferulic acid were carried out by means of high performance liquid chromatography with diode-array detector. The results showed that PLE was a simple, high efficient and automated method with lower solvent consumption compared to conventional extraction methods such as Soxhlet and sonication. PLE could be used for simultaneous extraction of Z-ligustilide, Z-butylidenephthalide and ferulic acid in A. sinensis.

[Determination of naoning pian by multi-wavelength linear regression method]

Assay of naoning pian was reported by multi-wavelength linear regression method in this paper. The program was edited by BASIC. The recoveries and RSD of pyramidon and caffeine were 98.03%-100.9%, 1.0% and 97.77%-99.39%, 0.61%, respectively. This method could be used for the determination of two components in naoning pian without separation. The method was simple, rapid, and results were satisfactory.

Accuracy of birth certificate data regarding the amount, timing, and adequacy of prenatal care using prenatal clinic medical records as referents

This study compared birth certificate data on the amount, timing, and adequacy of prenatal care with the same data abstracted from the prenatal clinic records of 2,032 women who attended a health department prenatal clinic in northeast Georgia from 1980 to 1988. Overall accuracy was poor. Only 14.3% (n = 291) of the records completely agreed on the total number of visits, while approximately 36% (n = 738) and 53% (n = 1,081) agreed within one visit and two visits, respectively. Complete agreement for month and trimester prenatal care began was 31.1% (n = 632) and 50.6% (n = 1,202), respectively. Because of the small geographic region included in the current study, the generalizability of these findings to other populations may be limited.

Proportionate mortality study of golf course superintendents

A proportionate mortality study of a cohort of golf course superintendents was conducted using death certificates for 686 deceased members of the Golf Course Superintendents Association of America who died from 1970 to 1992. White males were included in the study population from all 50 states. The study objective was to compare mortality from this cohort to the general U.S. white male population. The proportionate mortality ratio (PMR) for all types of cancer was 136 (CI: 121, 152). Significant excess mortality from smoking-related diseases was observed. The PMR for arteriosclerotic heart disease was 140, which was significantly elevated (CI: 127, 155). In addition, the PMR for all respiratory diseases was 176 (CI: 135,230), while the PMR for emphysema was 186 (CI: 101,342). The PMR for lung cancer was 117 (CI: 93, 148). Mortality for four cancer types--brain, lymphoma (non-Hodgkin's lymphoma, NHL), prostate, and large intestine--occurred at elevated levels within this cohort: brain cancer PMR = 234 (CI: 121,454), non-Hodgkin's lymphoma (NHL) PMR = 237 (CI: 137,410), prostate cancer PMR = 293 (CI: 187,460), and large intestine cancer PMR = 175 (CI: 125,245). The PMR for diseases of the nervous system was 202 (CI: 123,333). A similar pattern of elevated NHL, brain, and prostate cancer mortality along with excess deaths from diseases of the nervous system has been noted among other occupational cohorts exposed to pesticides.