Prevalence of autism spectrum disorder in mainland china over the past 6 years: a systematic review and meta-analysis.

BACKGROUND: Coupled with its rising prevalence, Autism spectrum disorder (ASD) has become a globally recognized public health concern. Nevertheless, large-scale, multicenter studies that analyze the epidemiology of ASD in China are relatively scarce. METHODS: Literature searches were conducted in PubMed/Medline, Embase, the Cochrane Library, Wanfang Data Knowledge Service Platform, China Biology Medicine database (CBM), China Science and Technology Journal Database (CSTJ), and China National Knowledge Infrastructure (CNKI) to retrieve studies published before April 8, 2023, related to ASD prevalence among children aged 0 to 14 years in mainland China. Meta-analysis was conducted using RevMan 5.2 and Stata 14.0. RESULTS: Twenty-one articles were included. The ASD prevalence among children in mainland China has been 0.7% (95% confidence interval(CI): 0.006-0.008) since 2017. The prevalence of ASD among boys was 1.0% (95% CI: 0.008-0.011), which was significantly higher than that among girls at 0.2% (95% CI: 0.002-0.003), with a statistically significant difference (OR = 3.198, 95% CI: 2.489-4.109, P = 0.000). Among the included studies, 18 reported an ASD prevalence of 0.8% (95% CI: 0.007-0.010), while 3 studies reported an autistic disorder (AD) prevalence of 0.7% (95% CI: 0.006-0.008). The prevalence of autism among urban children was 23.9% (95% CI: 0.149-0.328), and in rural areas, it was 0.7% (95% CI: 0.002-0.013), with no statistically significant difference (OR = 1.342, 95% CI: 0.258-6.975, P = 0.727). Regression analysis showed that factors such as region (P = 0.000), age (P = 0.000), study period (P = 0.000), sample size (P = 0.000), sampling method (P = 0.002), population source (P = 0.000), disease type (P = 0.000), quality score of the study (P = 0.000), and diagnostic criteria (P = 0.000) might have contributed to the heterogeneity in ASD prevalence. CONCLUSION: The prevalence of ASD in China from 2017 to 2023 was 7/1000, showing an upward trend compared to that before 2017 (26.50/10,000). The male-to-female prevalence ratio was 5:1.The overall prevalence remained significantly lower than that reported in foreign countries.

Sleep initiation patterns and sleep quality among toddlers in the southeast of China: initial study results.

BACKGROUND: A large number of psychological consequences including sleep health emerged during the 2019 Coronavirus disease (COVID-19) pandemic. Sleep patterns in toddlers are vulnerable to negative environmental exposures, however, very few studies on this topic have been published so far. OBJECTIVES: In this paper, we aimed to investigate the sleep patterns and associated factors in toddlers from China confined at home in the context of COVID-19 pandemic. METHODS: From April to November 2021, a convenience sample of 493 parents of young children aged (12-35 months) were surveyed from Fuzhou, Sanming, Quanzhou, Nanping, and Longyan cities in the Fujian Province, China. A cross-sectional survey was conducted via Electronic questionnaires to collect parent and child social-demographic characteristics. The Brief Infant Sleep Questionnaire (BISQ) was used to collect data on sleep practices, sleep duration and patterns, as well as the number of nocturnal awaking . RESULTS: The mean age of toddlers was 2.11 years old, and 52.54% (259/493) were males. Among the 493 toddlers' sleep patterns, 331(67.1%) initiated sleep accompanied by parents, 67(13.6%) slept independently, 59 (12.0%) were breast fed/bottle fed to initiate sleep, 27 (5.5%) were held and 9 (1.8%) rocked. The clear longitudinal association between the duration of night-time sleep, the frequency of nighttime awakenings, and various sleep patterns remains clear (p < 0.05). Multiple linear regression analysis indicated that sleep initiation with bottle-feeding/breast-feeding and rocked significantly increased the frequency of nighttime awakenings and reduced the duration of nighttime sleep (p < 0.05), as held was dramatically only for increasing the number of nighttime awakenings (p < 0.05). Multi-variate logistic regression analysis demonstrated that toddlers with severe sleep difficulties had a higher probability of being rocked to initiate sleep (p < 0.05). Conversely, young children with minor sleep problems were more apt to be in bed alone to initiate sleep (p < 0.05). CONCLUSIONS: During the COVID-19 pandemic, most infants and toddlers initiated sleep accompanied by parents and tend to have electronic media exposure before bedtime. Increased waking at night may be associated with sleep initiation with breast-feeding/bottle-feeding. Therefore, pediatric practitioners in primary community hospitals should pay attention to the education and promotion of sleep hygiene and parenting knowledge of young children to avoid the formation of poor sleep hygiene habits.

Highly Hydrophobic Gelatin Nanocomposite Film Assisted by Nano-ZnO/(3-Aminopropyl) Triethoxysilane/Stearic Acid Coating for Liquid Food Packaging.

Biodegradable gelatin (G) food packaging films are in increasing demand as the substitution of petroleum-based preservative materials. However, G packaging films universally suffer from weak hydrophobicity in practical applications. Constructing a hydrophobic micro/nanocoating with low surface energy is an effective countermeasure. However, the poor compatibility with the hydrophilic G substrate often leads to the weak interfacial adhesion and poor durability of the hydrophobic coating. To overcome this obstacle, we used (3-aminopropyl) triethoxysilane (APS) as an interfacial bridging agent to prepare a highly hydrophobic, versatile G nanocomposite film. Specifically, tannic acid (TA)-modified nanohydroxyapatite (n-HA) particles (THA) were introduced in G matrix (G-THA) to improve the mechanical properties. Micro/nanostructure with low surface energy composed of nanozinc oxide (Nano-ZnO)/APS/stearic acid (SA) (NAS) was constructed on the surface of G-THA film (G-THA/NAS) through one-step spray treatment. Consequently, as-prepared G-THA/NAS film presented excellent mechanics (tensile strength: 7.6 MPa, elongation at break: 292.7%), water resistance ability (water contact angle: 150.4°), high UV-shielding (0% transmittance at 200 nm), degradability (100% degradation rate after buried in the natural soil for 15 days), antioxidant (78.8% of 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity), and antimicrobial (inhibition zone against Escherichia coli: 15.0 mm and Staphylococcus aureus: 16.5 mm) properties. It should be emphasized that the bridging function of APS significantly improves the interfacial adhesion ability of the NAS coating with more than 95% remaining area after the cross-cut adhesion test. Meanwhile, the G-THA/NAS film could maintain stable and long-lasting hydrophobic surfaces against UV radiation, high temperature, and abrasion. Based on these multifunctional properties, the G-THA/NAS film was successfully applied as a liquid packaging material. To sum up, we provide a feasible and effective method to prepare high-performance green packaging films.

Development of two immunochromatographic test strips based on signal amplification and selenium nanoparticles for the rapid detection of T-2 mycotoxin.

Conventional immunochromatographic test strips (ICSs) based on gold nanoparticle (AuNP) probes offer limited sensitivity. Here, AuNPs were separately labeled with monoclonal or secondary antibodies (MAb or SAb). In addition, spherical, homogeneously dispersed, and stable selenium nanoparticles (SeNPs) were also synthesized. By optimizing the preparation parameters, two ICSs based on the dual AuNP signal amplification (Duo-ICS) or SeNPs (Se-ICS) were developed for the rapid detection of T-2 mycotoxin. The detection sensitivities of the Duo-ICS and Se-ICS assays for T-2 were 1 ng/mL and 0.25 ng/mL, respectively, which were 3-fold and 15-fold more sensitive, respectively, than a conventional ICS. Furthermore, the ICSs were applied in the detection of T-2 in cereals, which requires higher sensitivity. Our findings indicate that both ICS systems can be used for rapid, sensitive, and specific detection of T-2 toxin in cereals and potentially other sample types.

Burkholderia cepacia infection in children without cystic fibrosis: a clinical analysis of 50 cases.

Background: Burkholderia cepacia (B. cepacia) is an emerging pathogen of nosocomial infection in pediatric patient carrying cystic fibrosis. The clinical diagnosis and treatment of B. cepacia infection remains poorly studied. This study outlined the risk factors, antimicrobial susceptibility, and clinical characteristics aiming to improve the treatment of B. cepacia infection. Methods: A retrospective study was conducted based on the 50 cases infection caused by B. cepacia in children without cystic fibrosis, which were diagnosed in the First Affiliated Hospital of Xiamen University, from January 1st, 2011 to December 31st, 2021. Results: A total of 50 children were infected with B. cepacia, of whom 68% had an underlying health condition, such as cardiovascular disease (23.5%), respiratory disease (17.6%), nervous system disease (14.7%), and neoplastic disease (14.7%). At the onset of B. cepacia infection, 42 (84%) pediatric patients were in an intensive care unit (ICU), 33 (66%) underwent endotracheal intubation, and 32 (64%) had a central venous catheter (CVC). In addition, hospital-acquired cases were 46 (92%), and healthcare-acquired cases were 4 (12%). The most common infectious sites of B. cepacia were the respiratory tract (68%), followed by the blood (20%), and the urinary tract (12%). It indicated that B. cepacia was the most sensitive to ceftazidime (95.65%), followed by trimethoprim-sulfamethoxazole (88.68%), meropenem (82.98%), cefepime (77.78%), and levofloxacin (55.85%). The drug resistance rate of piperacillin-tazobactam, minocycline, aztreonam, cefoperazone-sulbactam and ceftriaxone was higher than 55%. 38 cases were cured or improved, eight had treatment terminated, and four died. Conclusion: B. cepacia is an opportunistic pathogen normally found in immunocompromised pediatric patients and highly likely to lead to drug resistance. Nosocomial B. cepacia infections occurred mostly in patients in the ICU based on our observations. The surveillance of B. cepacia infections including changing epidemiology and increasing resistance of the microorganism is still very important. Treatment with effective antibiotics such as ceftazidime, meropenem, trimethoprim-sulfamethoxazole is associated with a favorable prognosis.

Brain metabolite profiles provide insight into mechanisms for behavior sexual dimorphisms in zebrafish (Danio rerio).

The zebrafish (Danio rerio) has historically been a useful model for research in genetics, ecology, biology, toxicology, and neurobehavior. Zebrafish have been demonstrated to have brain sexual dimorphism. However, the sexual dimorphism of zebrafish behavior demands our attention, particularly. To evaluate the behavior and brain sexual dimorphisms in zebrafish, this study assessed sex differences in adult D. rerio in four behavioral domains, including aggression, fear, anxiety, and shoaling, and further compared with metabolites in the brain tissue of females and males. Our findings showed that aggression, fear, anxiety and shoaling behaviors were significantly sexually dimorphic. Interestingly, we also show through a novel data analysis method, that the female zebrafish exhibited significantly increased shoaling behavior when shoaled with male zebrafish groups and, for the first time, we offer evidence that male shoals are beneficial in dramatically alleviating anxiety in zebrafish. In addition, there were significant changes in metabolites in zebrafish brain tissue between the sexes. Furthermore, zebrafish behavioral sexual dimorphism may be associated with brain sexual dimorphism, with significant differences in brain metabolites. Therefore, to prevent the influence or even bias of behavioral sex differences on results, it is suggested that behavioral studies or behavioral-based other relevant investigations consider sexual dimorphism of behavior and brain.

Metabolic Engineering of Escherichia coli for High-Level Production of (R)-Acetoin from Low-Cost Raw Materials.

Acetoin is an important four-carbon platform chemical with versatile applications. Optically pure (R)-acetoin is more valuable than the racemate as it can be applied in the asymmetric synthesis of optically active α-hydroxy ketone derivatives, pharmaceuticals, and liquid crystal composites. As a cytotoxic solvent, acetoin at high concentrations severely limits culture performance and impedes the acetoin yield of cell factories. In this study, putative genes that may improve the resistance to acetoin for Escherichia coli were screened. To obtain a high-producing strain, the identified acetoin-resistance gene was overexpressed, and the synthetic pathway of (R)-acetoin was strengthened by optimizing the copy number of the key genes. The engineered E. coli strain GXASR-49RSF produced 81.62 g/L (R)-acetoin with an enantiomeric purity of 96.5% in the fed-batch fermentation using non-food raw materials in a 3-L fermenter. Combining the systematic approach developed in this study with the use of low-cost feedstock showed great potential for (R)-acetoin production via this cost-effective biotechnological process.

Biosynthesis of Quercetin-Loaded Melanin Nanoparticles for Improved Antioxidant Activity, Photothermal Antimicrobial, and NIR/pH Dual-Responsive Drug Release.

Quercetin (QCT) is a promising dose-dependent nutraceutical that usually suffers from poor water solubility and low bioavailability issues. In this work, a novel QCT-loaded nanoscale delivery system was constructed based on the oxidative self-polymerization of melanin (Q@MNPs). The FT-IR, XRD, and Zeta potential analyses confirmed that QCT was successfully absorbed on the melanin nanoparticles (MNPs) via Π-Π and hydrogen bonding interactions. The encapsulation efficiency and particle size of Q@MNPs were 43.78% and 26.68 nm, respectively. Q@MNPs improved the thermal stability of QCT and the antioxidant properties in comparison to MNPs. Meanwhile, Q@MNPs presented fantastic photothermal conversion capacity and stability triggered by the NIR laser, which significantly enhanced the antibacterial capability with a sterilization rate of more than 98% against E. coli and S. aureus. More importantly, Q@MNPs exhibited NIR/pH dual-responsive drug release behavior and good biocompatibility (at concentrations of < 100 µg/mL). Thus, Q@MNPs show promising prospects for flavonoid delivery.

Validation of the sleep disturbance scale for children (SDSC) in infants and toddlers from mainland China.

The sleep disturbance scale for children (SDSC) has been validated in the population of Chinese children (aged 5-16 years) and has good psychometric properties. However, valid assessment tools for sleep problems in the population of infants and young children from mainland China are relatively scarce, and rates of screening and management for pediatric sleep problems are low. Objective: This study is to evaluate the reliability and validity of SDSC among infants (aged 6-36 months), and to provide a reference for expanding the application of the SDSC for Chinese infants (SDSC-I). Materials and methods: From April to November 2021, parents of infants from Fuzhou, Quanzhou, Longyan, Sanming, and Nanping cities in Fujian Province, China completed the SDSC-I. Several factor analyses were performed to evaluate the reliability and validity of the scale. Results: Of note, 432 out of 469 samples were valid. After item selections and exploratory factor analyses, the SDSC-I concluded six dimensions (disorders of initiating sleep, disorders of maintaining sleep, sleep hyperhidrosis, sleep breathing disorders, parasomnias, and non-restorative sleep and excessive somnolence) with 23 items. The Cronbach's α coefficient of the scale was 0.863, and those for the six dimensions were within 0.576-0.835. The values of parameters for content validity of the scale were: IR = 0.87, I-CVI > 0.78, Kappa value > 0.74, S-CVI/UA = 0.87, S-CVI/Ave = 0.98. Principal component analysis revealed that the Kaiser-Meyer-Olkin (KMO) value was 0.84, and the factor loading of items ranged from 0.328 to 0.849, with six factors of eigenvalue more than one, which could explain 58.274% of the total variance. The confirmatory factor analysis results showed that χ2/DF was 3.556, root-mean-square error of approximation (RMSEA) was 0.077, comparative fit index (CFI) was 0.809, and standardized RMR (SRMR) was 0.070. Conclusion: Our study provides evidence that the SDSC-I is reliable and valid, and it is effective for the screening and management of sleep disturbances among infants (aged 6-36 months). Compared with other questionnaires such as the Brief Infant Sleep Questionnaire (BISQ), it is worthy of popularization and application in pediatric primary care.

Morganella morganii: An unusual analysis of 11 cases of pediatric urinary tract infections.

BACKGROUND: The increase in rare opportunistic microbial infections caused by Morganella morganii is alarming across the globe. It has been reported that in cases of urinary tract infections (UTIs) caused by M. morganii, however, few studies investigated children. Our study aimed to analyze the risk factors, antimicrobial susceptibility, and clinical characteristics, so as to improve the clinical diagnosis and therapy of M. morganii infection. METHODS: Between April 1, 2017 and April 1, 2021, 11 cases of pediatric UTIs caused by M. morganii were included in this retrospective study. Medical records were reviewed and analyzed. RESULTS: The study population included 10 males and one female between 11 months and 13 years old (mean age: 4 years 9 months). The most common comorbidity was nephrotic syndrome (72.7%, 8/11). Six patients (54.5%) were in the immunosuppressed state due to chemotherapy or immunosuppressant therapy. Ten cases defined as lower UTIs with no specific clinical manifestations had normal or slightly elevated leukocyte counts and procalcitonin (PCT) levels, and normal C-reactive protein (CRP) levels. One child diagnosed upper UTIs accompanied with fever, high level of leukocyte counts, CRP, and PCT. The M. morganii presented 100% susceptibility to aztreonam, ertapenem, meropenem, piperacillin/tazobactam, cefepime, ceftazidime, cefotetan, ticarcillin/clavulanic acid, and cefoperazone/sulbactam. Almost all patients had good responses to third-generation cephalosporins antibiotic therapy. CONCLUSION: Clinical vigilance for the possibility of M. morganii in pediatric UTIs in combination with underlying disease or immunosuppression is warranted. Treatment strategies should be proposed according to the clinical condition and the antibiotic susceptibility results.

An Investigation of the Properties of Expanded Polystyrene Concrete with Fibers Based on an Orthogonal Experimental Design.

Expanded polystyrene (EPS) concrete is commonly used as the core material of commercial sandwich panels (CSPs). It is environmentally friendly and lightweight but has poor strength. Adding fibers can improve the microstructure of EPS concrete and reduce the weakening effect of EPS beads on the mechanical properties of concrete. An orthogonal experimental design (OED) was used in this paper to analyze the influence of length and content of polypropylene fiber (PF), glass fiber (GF), and carbon fiber (CF) on the physical and mechanical properties and micromorphology of EPS concrete. Among them, CFs have the most apparent impact on concrete and produce the most significant improvements in all properties. According to the requirements of the flexural performance of CSPs, the splitting tensile strength was taken as the optimization index, and the predicted optimal combination (OC) of EPS concrete with fibers was selected. The variations in the material properties, mechanical properties, and microstructure with age were analyzed. The results show that with increasing age, the dry density, compressive strength, and splitting tensile strength of concrete are markedly improved relative to those of the CSP core material and the control case (CC), and even the degree of hydration is improved.

Development of an immunochromatographic test strip for the rapid detection of aristolochic acid A in herbal medicinal materials.

INTRODUCTION: Plants containing aristolochic acid and its derivatives are nephrotoxic, mutagenic, and carcinogenic to humans; chronic diet poisoning caused by the aristolochic acid is the cause of endemic (Balkan) nephropathy and related cancers. OBJECTIVE: To develop a colloidal gold immunochromatographic test strip (ICS) based on the competitive format for the rapid detection of aristolochic acid A (AA-A) in herbal medicinal materials. MATERIALS AND METHODS: For the ICS based on gold nanoparticles (AuNPs), the antigen [AA-A-bovine serum albumin (BSA)], and goat anti-mouse IgG were drawn on the nitrocellulose membrane as the test line (T line) and the control line (C line), respectively. Monoclonal antibody (MAb)-AuNP conjugates were sprayed onto the conjugate pad. The sensitivity of the ICS was 6 ng/mL, and the test was completed in 10 min. The analysis of AA-A in traditional Chinese medicine samples showed that the ICS results were in good agreement with those obtained by high-performance liquid chromatography methods. CONCLUSION: These results demonstrated that the ICS test could be used as a reliable, rapid, cost-effective, and convenient qualitative tool for on-site screening techniques to detect AA-A in herbal medicinal materials without any special instrumentation.

[Clinical and genetic analysis of a case with Thiamine metabolism dysfunction syndrome 5].

OBJECTIVE: To report the clinical manifestation and genetic characteristics of a child with Thiamine metabolism dysfunction syndrome 5. METHODS: Clinical data and genetic results were collected and analyzed. Peripheral blood samples of the child and their parents were collected for whole exome sequencing, and the functional effect of the variants on the TPK1 enzyme activity was verified by an in vitro assay. RESULTS: A four-year-old boy presented with preschool onset of ataxia were characterized. High-throughput sequencing identified a novel homozygous variant of TPK1 gene c.382G>A (p.Leu128Phe). His father and mother were both found carrying the variant. The variant protein showed a 30.9% reduction in TPK1 enzyme activity compared with the wildtype. CONCLUSION: A novel pathogenic variant has been identified in a boy with thiamine metabolic dysfunction syndrome type 5.

The prevalence of sleep problems among children in mainland China: a meta-analysis and systemic-analysis.

BACKGROUND: We conducted a meta-analysis and systematic review to identify a reliable estimate of sleep problems prevalence among children in mainland China and to describe its epidemiological characteristics. METHODS: Relevant studies were searched thoroughly via electronic databases included China National Knowledge Infrastructure, Wanfang, Weipu, PubMed, Embase and Medline databases from inception until December 2020. Prevalence estimates were calculated by random-effects models. The sources of heterogeneity were explored using subgroup analyses and Meta-regression analysis, and publication bias was estimated by funnel plots and Egger's Test. RESULTS: Overall, 66 studies were included in this meta-analysis, which revealed that the pooled prevalence of sleep problems was 37.6% (95%CI: 34.3-40.9%) with high heterogeneity (I2 = 99.6%,P < 0.001). The incidence of snoring was 7.7%, choking or gasping was 0.9%, apnea was 1.5%, restless sleep was 11.3%, mouth breathing was 4.7%, hyperhidrosis was 17.2%, leg movements was 2.7%, bruxism was 9.6%, sleep talking was 0.7%, sleep-walking was 0.8%, nightmare was 5.1%, enuresis was 3.4%, night awakening was 6.7% and trouble falling asleep was 11.1%. The prevalence rate of sleep problems among males was higher than females (OR:1.01,95%CI:1.05-1.13). In all age groups, the prevalence rates of sleep problems increased with age, including infancy or early childhood group (33.3%), pre-school group (38.9%), school-age group (43.7%). The prevalence rate in South China (30.4%, 95%CI: 23.9-36.8%) was the lowest, and the highest prevalence rate was in West China (47.4%,95%CI:35.9-58.9%), which than any other region in China. The point estimate for sleep disorders prevalence obtained using the CSHQ criterion was higher than other criteria. Meta-regression indicated that age group could influence prevalence estimation (P = 0.011). CONCLUSIONS: Over the past two decades, the prevalence rate of sleep problems among children in mainland China has increased, significantly affecting two-fifth of the school-age children. The incidence of hyperhidrosis, restless sleep and trouble falling asleep were significantly higher than other sleep prombles. The prevalence rate of sleep problems in west China was significantly higher than in any other area. There is still a lack of guidelines on children's sleep problems in mainland China, so future research should pay special attention to the sleep problems of school-age children and children in economically backward areas.

A Green Route for High-Yield Production of Tetramethylpyrazine From Non-Food Raw Materials.

2,3,5,6-Tetramethylpyrazine (TMP) is an active pharmaceutical ingredient originally isolated from Ligusticum wallichii for curing cardiovascular and cerebrovascular diseases and is widely used as a popular flavoring additive in the food industry. Hence, there is a great interest in developing new strategies to produce this high-value compound in an ecological and economical way. Herein, a cost-competitive combinational approach was proposed to accomplish green and high-efficiency production of TMP. First, microbial cell factories were constructed to produce acetoin (3-hydroxy-2-butanone, AC), an endogenous precursor of TMP, by introducing a biosynthesis pathway coupled with an intracellular NAD+ regeneration system to the wild-type Escherichia coli. To further improve the production of (R)-AC, the metabolic pathways of by-products were impaired or blocked stepwise by gene manipulation, resulting in 40.84 g/L (R)-AC with a high optical purity of 99.42% in shake flasks. Thereafter, an optimal strain designated GXASR11 was used to convert the hydrolysates of inexpensive feedstocks into (R)-AC and achieved a titer of 86.04 g/L within 48 h in a 5-L fermenter under optimized fermentation conditions. To the best of our knowledge, this is the highest (R)-AC production with high optical purity (≥98%) produced from non-food raw materials using recombinant E. coli. The supernatant of fermentation broth was mixed with diammonium phosphate (DAP) to make a total volume of 20 ml and transferred to a high-pressure microreactor. Finally, 56.72 g/L TMP was obtained in 3 h via the condensation reaction with a high conversion rate (85.30%) under optimal reaction conditions. These results demonstrated a green and sustainable approach to efficiently produce high-valued TMP, which realized value addition of low-cost renewables.

Neonatal septicemia caused by a rare pathogen: Raoultella planticola - a report of four cases.

BACKGROUND: Raoultella planticola(R.planticola) is a very rare opportunistic pathogen and sometimes even associated with fatal infection in pediatric cases. Recently,the emergence of carbapenem resistance strains are constantly being reported and a growing source of concern for pediatricians. CASE PRESENTATION: We reported 4 cases of neonatal septicemia caused by Raoultella planticola. Their gestational age was 211 to 269 days, and their birth weight was 1490 to 3000 g.The R. planticola infections were detected on the 9th to 27th day after hospitalization and occured between May and June. They clinically manifested as poor mental response, recurrent cyanosis, apnea, decreased heart rate and blood oxygen, recurrent jaundice, fever or nonelevation of body temperature. The C-reactive protein and procalcitonin were elevated at significantly in the initial phase of the infection,and they had leukocytosis or leukopenia. Prior to R.planticola infection,all of them recevied at least one broad-spectrum antibiotic for 7-27d.All the R.planticola strains detected were only sensitive to amikacin, but resistant to other groups of drugs: cephalosporins (such as cefazolin, ceftetan,etc) and penicillins (such as ampicillin-sulbactam,piperacillin,etc),and even developed resistance to carbapenem. All the infants were clinically cured and discharged with overall good prognosis. CONCLUSION: Neonatal septicemia caused by Raoultella planticola mostly occured in hot and humid summer, which lack specific clinical manifestations. Pediatricians should keep in mind that R. planticola can be a potential source of neonatal sepsis and even has the potential to acquire carbapenem-resistance. Preventing outbreaks of epidemics requires early detection, timely diagnosis and treatment, and active isolation.

Enhanced production of optical (S)-acetoin by a recombinant Escherichia coli whole-cell biocatalyst with NADH regeneration.

Acetoin is an important platform chemical with a variety of applications in foods, cosmetics, chemical synthesis, and especially in the asymmetric synthesis of optically active pharmaceuticals. It is also a useful breath biomarker for early lung cancer diagnosis. In order to enhance production of optical (S)-acetoin and facilitate this building block for a series of chiral pharmaceuticals derivatives, we have developed a systematic approach using in situ-NADH regeneration systems and promising diacetyl reductase. Under optimal conditions, we have obtained 52.9 g L-1 of (S)-acetoin with an enantiomeric purity of 99.5% and a productivity of 6.2 g (L h)-1. The results reported in this study demonstrated that the production of (S)-acetoin could be effectively improved through the engineering of cofactor regeneration with promising diacetyl reductase. The systematic approach developed in this study could also be applied to synthesize other optically active α-hydroxy ketones, which may provide valuable benefits for the study of drug development.

Microbial Routes to (2R,3R)-2,3-Butanediol: Recent Advances and Future Prospects.

(2R,3R)-2,3-Butanediol has many industrial applications, such as it is used as an antifreeze agent and low freezing point fuel. In addition, it is particularly important to provide chiral groups in drugs. In recent years, this valuable bio-based chemical has attracted increasing attention, and significant progress has been made in the development of microbial cell factories for (2R,3R)-2,3-butanediol production. This article reviews recent advances and challenges in microbial routes to (2R,3R)-2,3- butanediol production, and highlights the metabolic engineering and synthetic biological approaches used to improve titers, yields, productivities, and optical purities. Finally, a systematic and integrative strategy for developing high-performance microbial cell factories is proposed.

Regulation of general amino acid permeases Gap1p, GATA transcription factors Gln3p and Gat1p on 2-phenylethanol biosynthesis via Ehrlich pathway.

In Saccharomyces cerevisiae, when l-phenylalanine (l-Phe) is used as the sole nitrogen source, 2-phenylethanol (PE) is mainly synthesized via the Ehrlich pathway. General amino acid permease Gap1p is response of aromatic amino acids transportation, and GATA transcription factors Gln3p and Gat1p regulate the transcription of permease gene and catabolic enzyme genes for nitrogen sources and aromatic amino acids utilization. In this study, it was demonstrated that over-expressing GLN3 gene from industrial yeast strain MT2 or S. cerevisiae haploid strain YS58, 2-PE synthesis levels of recombinant strains increased 54% or 40% than that of the control strain, which suggested that higher Gln3p activity in yeast has positive regulation effect on 2-PE biosynthesis via Ehrlich pathway. The recombinant strains with over-expression of GAT1 gene from MT2 or YS58 also up-regulated Ehrlich pathway for 2-PE biosynthesis and increased 2-PE production. Similarly, when GAP1 gene respectively from MT2 or YS58 was over-expressed, 2-PE yield was improved obviously, suggesting that GAP1 over-expressing in yeast also promoted Ehrlich pathway to produce 2-PE. The synergistic regulation of GLN3/GAT1 or GLN3/GAP1 over-expression was similar to that of single factor over-expression. Among these regulatory factors, Gln3p of industrial yeast strain MT2 caused stronger regulation on target genes than that of haploid strain YS58, which might be due to the differences in translational efficiency or nuclear localization of each Gln3p, or due to their different spatial structures and binding domains. Further results showed that efficient Gln3p expression in MT2 brought about higher 2-PE, 3.59gL-1, which was of potential significant for commercial exploitation.

[Advances in biosynthesis of 2-phenylethanol by yeasts].

2-Phenylethanol (2-PE) is an aromatic alcohol with a pleasant rose-like fragrance. It has been widely used in food, cosmetic, and pharmaceutical industry. Most of 2-PE is produced by chemical synthesis, but the use of chemically synthesized product is restricted in some fields. 2-PE from plant extraction is natural but its production is very low. Microbial biotransformation is a promising process to produce natural 2-PE. In this paper, we review recent research progress in the synthetic metabolic pathways and regulatory processes of 2-PE in yeast, and strategies for improving 2-PE production. Moreover, we discuss the limitation of current progress and future research directions.