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SUMMARYPig farmers and veterinarians have high prevalence of methicillin-resistantStaphylococcus aureus(MRSA) due to the occupational livestock exposure, while few reported this association on slaughterhouse workers. We conducted this cross-sectional study to explore the phenotypic and molecular characteristics ofS. aureusand MRSA in slaughterhouse pig-related workers and control workers in Guangdong Province, China. Participants were interviewed and provided two nasal swabs. Swabs were tested forS. aureus, and isolates were further tested for antimicrobial susceptibility, virulence genes and multi-locus sequence typing. Compared with control workers, pig-related workers have significantly higher prevalence of MRSA carriage (adjusted odd ratio (aOR) 3·70, 95% CI 1·63–8·40). The proportions of MRSA resistant to clindamycin, erythromycin, tetracycline or chloromycetin were significantly higher in pig-related workers than in control workers. The predominant phenotypes ofS. aureuswere resistant to penicillin, clindamycin, erythromycin and tetracycline. Three MRSA CC9 isolates with livestock-associated characteristics (resistance to tetracycline and absence of immune evasion cluster (IEC) genes) were detected in pig-related workers but not in control workers. For human-associated CCs (CC7, CC59, CC6, and CC188), there was no significant difference in IEC profile or antimicrobial resistance between the groups. These findings reveal that there may be a potential risk for livestock-to-human transmission of LA-MRSA and human-to-human transmission of human-associated MRSA.

Group B streptococcus (GBS) is a leading cause of morbidity and mortality in infants. This study aimed to estimate the prevalence, antimicrobial susceptibility and serotype distribution of GBS isolates in pregnant women worldwide. Studies were identified by searching several English and Chinese electronic databases and reviewing relevant articles. Effect estimates were pooled using fixed- or random-effects models. Twenty-eight studies were included in this systematic review. The pooled prevalence of GBS carriage in pregnant women was 10%, being significantly lower in Asia (7%) compared with non-Asian countries (19%). Most of the GBS isolates were susceptible to penicillin, ampicillin and vancomycin. The pooled rates of resistance to erythromycin and clindamycin were 25% and 27%, respectively, and were notably higher in Asia compared with non-Asian countries. The pooled rate of resistance to tetracycline was 73%, with similar high levels in Asia and non-Asian countries. The most prevalent serotypes of GBS isolates were serotypes III, V and Ia. These findings suggest that penicillin is still the first choice for intrapartum prophylaxis of GBS diseases and support growing concern about antibiotic use (especially erythromycin and clindamycin) in Asia.

Use of antimicrobials in industrial food animal production is associated with the presence of multidrug-resistant Staphylococcus aureus among animals and humans. The livestock-associated (LA) methicillin-resistant S. aureus (MRSA) clonal complex 9 (CC9) is associated with animals and related workers in Asia. This study aimed to explore the genotypic and phenotypic markers of LA-MRSA CC9 in humans. We conducted a cross-sectional study of livestock workers and controls in Guangdong, China. The study participants responded to a questionnaire and provided a nasal swab for S. aureus analysis. The resulting isolates were assessed for antibiotic susceptibility, multilocus sequence type, and immune evasion cluster (IEC) genes. Livestock workers had significantly higher rates of S. aureus CC9 (odds ratio [OR] = 30.98; 95% confidence interval [CI], 4.06 to 236.39) and tetracycline-resistant S. aureus (OR = 3.26; 95% CI, 2.12 to 5.00) carriage than controls. All 19 S. aureus CC9 isolates from livestock workers were MRSA isolates and also exhibited the characteristics of resistance to several classes of antibiotics and absence of the IEC genes. Notably, the interaction analyses indicated phenotype-phenotype (OR = 525.7; 95% CI, 60.0 to 4,602.1) and gene-environment (OR = 232.3; 95% CI, 28.7 to 1,876.7) interactions associated with increased risk for livestock-associated S. aureus CC9 carriage. These findings suggest that livestock-associated S. aureus and MRSA (CC9, IEC negative, and tetracycline resistant) in humans are associated with occupational livestock contact, raising questions about the potential for occupational exposure to opportunistic S. aureus . IMPORTANCE This study adds to existing knowledge by giving insight into the genotypic and phenotypic markers of LA-MRSA. Our findings suggest that livestock-associated S. aureus and MRSA (CC9, IEC negative, and tetracycline resistant) in humans are associated with occupational livestock contact. Future studies should direct more attention to exploring the exact transmission routes and establishing measures to prevent the spread of LA-MRSA.

There has been little focus on the possible association between second-hand smoke (SHS) exposure and depressive symptoms among adolescents. Thus, this study aimed to explore the dose–response relationships between SHS exposure and depressive symptoms among adolescents and differentiate these associations in setting-specific exposure and severity-specific outcomes. A cross-sectional study was conducted using a stratified cluster sampling method to obtain a representative sample of high school students in Guangzhou, China. Depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale. Univariable and multivariable logistic regression models were used to explore the potential associations between SHS exposure and depressive symptoms. Among 3575 nonsmoking students, 29.6% were classified as having probable depressive symptoms and 9.6% had severe depressive symptoms. There were monotonically increasing dose–response relationships between setting-specific (public places, homes, or indoor/outdoor campuses) SHS exposure and severity-specific (probable or severe) depressive symptoms. When examining these relations by source of exposure, we also observed similar dose–response relationships for SHS exposure in campuses from smoking teachers and from smoking classmates. Our findings suggest that regular SHS exposure is associated with a significant, dose-dependent increase in risk of depressive symptoms among adolescents, and highlight the need for smoke-free environments to protect the health of adolescents.

Single treatment and staged treatments in vertical wells are widely applied in sandstone and mudstone thin interbedded (SMTI) reservoir to stimulate the reservoir. The keys and difficulties of stimulating this category of formations are to avoid hydraulic fracture propagating through the interface between shale and sand as well as control the fracture height. In this paper, the cohesive zone method was utilized to build the 3-dimensional fracture dynamic propagation model in shale and sand interbedded formation based on the cohesive damage element. Staged treatments and single treatment were simulated by single fracture propagation model and double fractures propagation model respectively. Study on the changes of fracture vicinity stress field during propagation is to compare and analyze the parameters which influence the interfacial induced stresses between two different fracturing methods. As a result, we can prejudge how difficult it is that the fracture propagates along its height direction. The induced stress increases as the pumping rate increasing and it changes as a parabolic function of the fluid viscosity. The optimized pump rate is 4.8 m3/min and fluid viscosity is 0.1 Pa⋅s to avoid the over extending of hydraulic fracture in height direction. The simulation outcomes were applied in the field to optimize the treatment parameters and the staged treatments was suggested to get a better production than single treatment.

This study aimed to explore the association between occupational pig contact and human methicillin-resistant coagulase-negative staphylococci (MRCoNS) carriage. We conducted a cross-sectional study of pig exposed participants and controls in Guangdong, China, using a multi-stage sampling design. Participants provided a nasal swab for MRCoNS analysis and resulting isolates were tested for antibiotic susceptibility. The dose-response relation was examined using log binomial regression or Poisson regression models. The adjusted prevalence of MRCoNS carriage in pig exposed participants was 1.67 times (95% CI: 1.32-2.11) higher than in controls. The adjusted average number of resistance to different antibiotic classes of MRCoNS isolates from pig exposed participants was 1.67 times (95% CI: 1.46-1.91) higher than those from controls. Notably, we found the frequency and duration of occupational pig contact was associated with increased prevalence and increased number of resistance to different antibiotic classes of MRCoNS in a dose-response manner. When examining these relations by MRCoNS species, there was still evidence of similar exposure-response relations. Additionally, the proportion of tetracycline-resistant and tet(M)-containing MRCoNS isolates was significantly higher in pig exposed participants than in controls. These findings suggested a potential transmission of MRCoNS from livestock to humans by occupational livestock contact, and the presence of phenotypic and genotypic tetracycline resistance may aid in the differentiation of animal origins of MRCoNS isolates.

Maternal colonization with group B Streptococcus (GBS) during pregnancy increases the risk of neonatal infection by vertical transmission. However, it remains unclear whether treating all colonized women during labor exposes a large number of their neonates to possible adverse effects without benefit. We performed a meta-analysis to assess the effect of intrapartum antibiotic prophylaxis on neonatal adverse outcomes. We identified studies by searching several English and Chinese electronic databases and reviewing relevant articles. Data were pooled using fixed-effects or random-effects meta-analysis, and for each outcome both risk ratio (RR) and 95% confidence intervals (95% CIs) were calculated. Fourteen studies (2,051 pregnant women and 2,063 neonates) were included, comprising 13 randomized clinical trials and 1 cohort study. Antibiotic prophylaxis is associated with a significant reduced risk of all cause infections (RR = 0.28, 95% CI = 0.18–0.42), GBS infection (RR = 0.24, 95% CI = 0.13–0.44), early-onset GBS infection (RR = 0.24, 95% CI = 0.13–0.45), non-GBS infections (RR = 0.34, 95% CI = 0.20–0.59), and GBS colonization (RR = 0.10, 95% CI = 0.06–0.16). But no significant reduction was observed in late-onset GBS infection, mortality from early-onset GBS infection or from non-GBS infections. Notably, no significant differences were found between ampicillin and penicillin prevention for neonatal adverse outcomes. Our findings suggest that antibiotic prophylaxis is effective in reducing neonatal GBS colonization and infection.

This paper analyses and compares different methodologies for supporting system frequency in low inertia power systems using HVDC interconnectors. Reduced system inertia, caused by the massive integration of converter-interfaced renewables and the displacement of conventional synchronous generation, can result in high values of rate of change of frequency (ROCOF), increasing the risk of frequency stability problems. In this paper, HVDC interconnections are analysed to determine their capability to provide support to the frequency stability between the Great British (GB) power system and the Continental Europe (CE) power system. Different frequency support control schemes (including droop control and the exchange of Frequency Control Reserves) are modelled and compared for a variety of cases. HVDC interconnector constraints including maximum power ramp rates and available capacity for frequency support have been derived by analysing historical operational data and incorporated into the analysis. Probabilistic uncertainty analysis considering variations in system inertia and the availability of interconnector capacity for frequency support has been performed. Studies are performed on a simplified frequency-based model of the future GB power system. The findings illustrate that droop control provides the best frequency support mechanism.

Tobacco smoking and depression are strongly associated, but the possible association between second-hand smoke (SHS) exposure and depression is unclear. This study aimed to examine the possible relation between SHS exposure and depressive symptoms among pregnant women. A cross-sectional survey was conducted in Shenzhen, China, using a multistage sampling method. The univariable and multivariable logistic regression models were used to explore the associations between SHS exposure and depressive symptoms. Among 2176 pregnant women, 10.5% and 2.0% were classified as having probable and severe depressive symptoms. Both binary and multinomial logistic regression revealed that there were significantly increased risks of severe depressive symptoms corresponding to SHS exposure in homes or regular SHS exposure in workplaces using no exposure as reference. In addition, greater frequency of SHS exposure was significantly associated with the increased risk of severe depressive symptoms. Our findings suggest that SHS exposure is positively associated with depressive symptoms in a dose-response manner among the pregnant women.

Background To investigate the status of antibiotics use in acute appendicitis patients who undergo appendectomy in a Chinese tertiary care hospital. Methods A retrospective analysis of 93 patients who underwent appendectomy from June 1, 2011 to May 30, 2012 and had recorded use of intravenous antibiotics. We defined simple appendicitis and suppurative appendicitis as mild appendicitis. Gangrenous appendicitis and perforated appendicitis were classified as advanced appendicitis. The occurrence of advanced appendicitis, postoperative complications and length of hospital stay were the three major end points for outcomes analysis. Results 100 % of the patients received antibiotics therapy before and after operation. 45 patients received Fluoroquinolones (48.4 %), 41 patients received Cephalosporins (44.1 %) and 7 patients received Carbapenems (7.5 %). We found no statistical difference between antibiotics selection and the occurrence of advanced appendicitis (P = 0.3337). Both the monovariate analysis and multivariate analysis showed no statistical difference between antibiotics selection and the postoperative complications (P > 0.05). The average stay of patients receiving Fluoroquinolones was 2.6 days shorter than patients who received Cephalosporins (P = 0.0085). Conclusion It is a lack of a standardized guideline for antibiotics selection in our hospital. All the antibiotics prescription were empirical. We tended to choose high levels of antibiotics, pay insufficient attention to the anaerobic bacteria and have a long duration of antibiotics therapy. We also found that antibiotics selection bore no relationship with the occurrence of advanced appendicitis and postoperative complications. Fluoroquinolones may lead to a shorter hospital stay, but this result may also be affected by the fewer underlying diseases and lower severity of the patients.

Leukemia relapse and nonrecurrence mortality (NRM) due to leukemia stem cells (LSCs) represent major problems following hematopoietic stem cell transplantation (HSCT). To eliminate LSCs, the sensitivity of LSCs to chemotherapeutic agents used in conditioning regimens should be enhanced. Curcumin (CUR) has received considerable attention as a result of its anticancer activity in leukemia and solid tumors. In this study, we investigated the cytotoxic effects and underlying mechanisms in leukemia stem-like KG1a cells exposed to busulfan (BUS) and CUR, either alone or in combination. KG1a cells exhibiting BUS-resistance demonstrated by MTT and annexin V/propidium iodide (PI) assays, compared with HL-60 cells. CUR induced cell growth inhibition and apoptosis in KG1a cells. Apoptosis of KG1a cells was significantly enhanced by treatment with CUR+BUS, compared with either agent alone. CUR synergistically enhanced the cytotoxic effect of BUS. Seven apoptosis-related proteins were modulated in CUR- and CUR+BUS-treated cells analyzed by proteins array analysis. Importantly, the antiapoptosis protein survivin was significantly downregulated, especially in combination group. Suppression of survivin with specific inhibitor YM155 significantly increased the susceptibility of KG1a cells to BUS. These results demonstrated that CUR could increase the sensitivity of leukemia stem-like KG1a cells to BUS by downregulating the expression of survivin.