Deciphering the influence of Bacillus subtilis strain Ydj3 colonization on the vitamin C contents and rhizosphere microbiomes of sweet peppers.

Bacillus subtilis strain Ydj3 was applied to sweet peppers to understand the influence of this bacterium on the growth, fruit quality, and rhizosphere microbial composition of sweet pepper. The promotion of seed germination was observed for sweet pepper seeds treated with the Ydj3 strain, indicating that Ydj3 promoted seed germination and daily germination speed (131.5 ± 10.8 seeds/day) compared with the control (73.8 ± 2.5 seeds/day). Strain Ydj3 displayed chemotaxis toward root exudates from sweet pepper and could colonize the roots, which enhanced root hair growth. Following the one-per-month application of strain Ydj3 to sweet pepper grown in a commercial greenhouse, the yield, fruit weight, and vitamin C content significantly increased compared with those of the control. Additionally, the composition of the rhizosphere bacterial community of sweet pepper changed considerably, with the Bacillus genus becoming the most dominant bacterial genus in the treated group. These results suggested that B. subtilis Ydj3 promotes seed germination and enhances fruit quality, particularly the vitamin C content, of sweet pepper. These effects may be partly attributed to the B. subtilis Ydj3 colonization of sweet pepper roots due to Ydj3 chemotaxis toward root exudates, resulting in the modulation of the rhizosphere bacterial community.

A risk-prediction score for colorectal lesions on 12,628 participants at high risk of colorectal cancer.

BACKGROUND: The uptake of colonoscopy is low in individuals at risk of colorectal cancer (CRC). We constructed a risk-prediction score (RPS) in a large community-based sample at high risk of CRC to enable more accurate risk stratification and to motivate and increase the uptake rate of colonoscopy. METHODS: A total of 12,628 participants classified as high-risk according to positivity of immunochemical fecal occult blood tests or High-Risk Factor Questionnaire underwent colonoscopy. Logistic regression was used to derive a RPS and analysed the associations of the RPS with colorectal lesions, giving odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Of the participants, men (OR = 1.73, 95% CI = 1.58-1.90), older age (≥65 years; 1.41, 1.31-1.53), higher body mass index (≥28 kg/m2; 1.22, 1.07-1.39), ever smoking (1.47, 1.31-1.65), and weekly alcohol use (1.28, 1.09-1.52) were associated with a higher risk of colorectal lesions. We assigned 1 point to each of the above five risk factors and derived a RPS ranging from 0 to 5, with a higher score indicating a higher risk. Compared with a RPS of 0, a RPS of 1, 2, 3, and 4-5 showed a higher risk of colorectal lesions, with the OR (95% CI) being 1.50 (1.37-1.63), 2.34 (2.12-2.59), 3.58 (3.13-4.10), and 3.91 (3.00-5.10), respectively. The area under the receiver-operating characteristic curve of RPS in predicting colorectal lesions was 0.62. CONCLUSIONS: Participants with an increase in the RPS of ≥1 point had a significantly higher risk of colorectal lesions, suggesting the urgency for measuring colonoscopy in this very high-risk group. High-risk strategies incorporating RPS may be employed to achieve a higher colonoscopy-uptake rate.

Cost-effectiveness analysis of different screening strategies for colorectal cancer in Guangzhou, southern China: a Markov simulation analysis based on natural community screening results.

OBJECTIVES: To evaluate the cost-effectiveness of four different primary screening strategies: high-risk factor questionnaire (HRFQ) alone, single immunochemical faecal occult blood test (iFOBT), double iFOBT and HRFQ+double iFOBT for colorectal cancer (CRC) screening compared with no screening using the Markov model. METHODS: Treeage Pro V.2011 software was used to simulate the Markov model. The incremental cost-effectiveness ratio, which was compared with the willingness-to-pay (WTP) threshold, was used to reflect the cost-effectiveness of the CRC screening method. One-way sensitivity analysis and probabilistic sensitivity analysis were used for parameter uncertainty. RESULTS: All strategies had greater effectiveness because they had more quality-adjusted life years (QALYs) than no screening. When the WTP was ¥435 762/QALY, all screening strategies were cost-effective compared with no screening. The double iFOBT strategy was the best-buy option compared with all other strategies because it had the most QALYs and the least cost. One-way sensitivity analysis showed that the sensitivity of low-risk adenoma, compliance with colonoscopy and primary screening cost were the main influencing factors comparing single iFOBT, double iFOBT and HRFQ+double iFOBT with no screening. However, within the scope of this study, there was no fundamental impact on cost-effectiveness. Probabilistic sensitivity analysis showed that when the WTP was ¥435 762/QALY, the probabilities of the cost-effectiveness acceptability curve with HRFQ alone, single iFOBT, double iFOBT and HRFQ+double iFOBT were 0.0%, 5.3%, 69.3% and 25.4%, respectively. CONCLUSIONS: All screening strategies for CRC were cost-effective compared with no screening strategy. Double iFOBT was the best-buy option compared with all other strategies. The significant influencing factors were the sensitivity of low-risk polyps, compliance with colonoscopy and cost of primary screening.

How spatial accessibility to colonoscopy affects diagnostic adherences and adverse intestinal outcomes among the patients with positive preliminary screening findings.

BACKGROUND: Colonoscopy is an important procedure for early colorectal cancer (CRC) detection, however, patients with positive preliminary screening results in China may not seek for colonoscopy to confirm the diagnosis. We evaluated the spatial accessibility of colonoscopy among the residents with positive preliminary screening results in Guangzhou, China, and investigated how colonoscopy accessibility was associated with the population adherence and adverse intestinal outcomes. METHODS: This study was based on the Guangzhou community-based CRC screening program. Spatial accessibility was measured using three metrics including travel time from home to nearest colonoscopy hospital, physician-to-population ratio (PPR) and accessibility indicator estimated with enhanced two-step floating catchment area method (E2SFCA). We used Cox regression and logistic regression to assess the association of colonoscopy accessibility with population adherence and adverse intestinal outcomes, respectively. RESULTS: A total of 34 606 people were identified with positive preliminary screening findings. Central areas were reported with higher E2SFCA scores, higher PPR and less travel time. The model adjusting for potential individual level confounders found that PPR > 50 (Hazard Ratio (HR) = 1.88, 95% Confidence Interval (CI): 1.79-1.97) and higher scores of E2SFCA (HR = 3.78, 95% CI: 2.07-6.92) were associated with increased adherence, although estimates were not significant in the model adjusting for both individual and district-level confounders. For adverse intestinal outcomes, the final multilevel logistic model suggested a lower risk of intestinal lesions among the residents in areas with PPR > 50 (Odds Ratio (OR) = 0.49, 95% CI: 0.24-0.99) and higher scores of E2SFCA (OR = 0.20, 95% CI: 0.05-0.82). CONCLUSION: Significant inequality of colonoscopy accessibility was observed across Guangzhou. The increased incidence of intestinal lesions was associated with spatial inequalities of medical resources. Policies against the spatial inequality in medical resources should be developed.

Mass screening for colorectal cancer in a population of two million older adults in Guangzhou, China.

Screening is an effective measure to prevent and control colorectal cancer (CRC). A mass CRC screening programme was conducted in Guangzhou from 2015 to 2017. Public media and reminders from a mobile short message service were used to invite residents aged between 50 and 74 years. A high-risk factor questionnaire (HRFQ) and biennial faecal immunochemical testing (FIT) were chosen as the primary screening methods, and individuals with a positive test result were referred to a defined hospital for an assessment colonoscopy. During the 3 years, 350,581 residents of the total eligible population of 2,283,214 attended the free first stage of screening. In all, 91.0% of the participants finished the HRFQs and FITs. The total uptake rate was 15.4%, which increased with age, female sex, and rural location. There was 15.9% positivity in the first stage of screening, including 8.5% positive HRFQs, 6.2% positive FITs and 1.2% positive HRFQs and FITs. In total, 10,600 individuals with positive HRFQs/FITs completed an assessment colonoscopy. The total uptake rate of colonoscopies was 18.9%, which decreased with age and female sex. Three hundred fifty-one CRCs and 980 advanced adenomas (AAs) were diagnosed with positive predictive values (PPV) of 3.3% and 9.2%, respectively. The PPVs of CRCs in the exclusively FIT-positive population were 4.9%, which was 10 times greater than in the exclusively HRFQ-positive population (0.5%). The PPVs of CRCs and AAs increased with age and male sex. The detection ratio of localized CRCs (including stage I and stage II) increased 68.1% due to screening. Although the compliance rate was low, the PPVs for CRCs and AAs were high. More effective mobilization of the programme's needs and subsidies for colonoscopies should be taken into account to increase compliance.

Effectiveness of a short message service intervention to motivate people with positive results in preliminary colorectal cancer screening to undergo colonoscopy: A randomized controlled trial.

BACKGROUND: Colonoscopy adherence among populations at high risk for colorectal cancer (CRC) is crucial for the early diagnosis and treatment of CRC, but the adherence rate has been found to be poor. A short message service (SMS) is effective in promoting cancer screening, but its effectiveness in promoting colonoscopy among populations at high risk for CRC has not been well studied. METHODS: In this randomized controlled trial conducted in Guangzhou, China, participants who had tested positive during preliminary CRC screening (a high-risk factor questionnaire and/or an immunochemical fecal occult blood test) but had not undergone colonoscopy were randomized into low-frequency (monthly) intervention, high-frequency (biweekly) intervention, and control groups. The 2 intervention groups received behavioral theory-based SMS for 6 months. Data were obtained from the CRC screening database. The outcome was undergoing a colonoscopy examination. RESULTS: For the 1362 participants, the rates of colonoscopy adherence were 5.2%, 6.0%, and 10.5% at month 3 and 7.1%, 9.6%, and 13.7% at month 6 in the control, low-frequency intervention, and high-frequency intervention groups, respectively. After adjustments for potential confounders, the high-frequency intervention group was approximately twice as likely as the control group to undergo colonoscopy (adjusted hazard ratio, 1.99; 95% confidence interval, 1.32-3.01), whereas the difference between the low-frequency intervention and control groups was not statistically significant. The cost of SMS to increase colonoscopy uptake by 1 in the high-frequency intervention group was US $2.7. CONCLUSIONS: Text messages sent biweekly for 6 months to patients with positive preliminary screening results could increase colonoscopy adherence. SMS could be a prioritized intervention for promoting colonoscopy in large community-based populations.

Willingness to pay for colorectal cancer screening in Guangzhou.

AIM: To measure the willingness to pay for colorectal cancer screening in Guangzhou, and to identify those factors associated with it. METHODS: A face-to-face questionnaire survey for pre-screening population from free and non-free colonoscopy districts was used to collect information on demographic characteristics, health behaviours, the intention of the cancer screenings and willingness to pay for colorectal cancer screening. A total of 1243 participants who took part in the pre-screening for colorectal cancer in Guangzhou were collected in the study. Categorical data were compared using the χ2 test to analyse significant differences. Non-conditional logistic regression and multi-class logistic regression were also performed for multivariate analysis and to estimate the odds ratios. RESULTS: The percentage of participants willing to pay for colorectal cancer screening was 91.7%. "Unnecessary" was the dominant reason that participants gave for their unwillingness, accounting for 63.1%. Of those who were willing to pay, 29.2%, 20.7%, 14.8%, 13.0% and 22.4% of participants were willing to pay less than \100, \100-\199, \200-299, \300-\399 and more than \400, respectively. Non-logistic regression analysis showed that respondents who were male, had a high level of education, were from the family with more children/older to raise, and accepted colorectal cancer screening were willing to pay for this screening. Multi-class logistic regression analysis showed that respondents with higher annual household income per capita, from government and private enterprises, government agency/institution and peasants, and less family medical expenditure were willing to pay more. CONCLUSION: Willingness to pay for colorectal cancer screening in Guangzhou is high, but the amount of willing to pay is not much.

Spatio-temporal analysis of the incidence of colorectal cancer in Guangzhou, 2010-2014.

INTRODUCTION: Colorectal cancer (CRC) is a common type of neoplasm. This study examined the spatio-temporal distribution of the CRC incidence in Guangzhou during 2010-2014. METHODS: Colorectal cancer incidence data were obtained from the Guangzhou Cancer Registry System. Spatial autocorrelation analysis and a retrospective spatio-temporal scan were used to assess the spatio-temporal cluster distribution of CRC cases. RESULTS: A total of 14,618 CRC cases were registered in Guangzhou during 2010-2014, with a crude incidence of 35.56/100,000 and an age-standardized rate of incidence by the world standard population (ASRIW) of 23.58/100,000. The crude incidence increased by 19.70% from 2010 (32.88/100,000) to 2014 (39.36/100,000) with an average annual percentage change (AAPC) of 4.33%. The AAPC of ASRIW was not statistically significant. The spatial autocorrelation analysis revealed a CRC incidence hot spot in central urban areas in Guangzhou City, which included 25 streets in southwestern Baiyun District, northwestern Haizhu District, and the border region between Liwan and Yuexiu Districts. Three high- and five low-incidence clusters were identified according to spatio-temporal scan of CRC incidence clusters. The high-incidence clusters were located in central urban areas including the border regions between Baiyun, Haizhu, Liwan, and Yuexiu Districts. CONCLUSIONS: This study revealed the spatio-temporal cluster pattern of the incidence of CRC in Guangzhou. This information can inform allocation of health resources for CRC screening.

Possible increase in HIV and syphilis prevalence among men who have sex with men in Guangzhou, China: results from a respondent-driven sampling survey.

A respondent-driven sampling survey was conducted to investigate HIV related serological and behavioral characteristics of men who have sex with men (MSM) in Guangzhou, China, and to identify associated factors potentially driving the epidemic. Respondent-Driven Sampling Analysis Tool and SPSS were used to generate adjusted estimates and to explore associated factors. Three hundred seventy-nine eligible participants were recruited. The adjusted prevalence of HIV and current syphilis infection are 5.2% and 17.5% respectively. 60.3% have unprotected anal sex in the past 6 months. Unprotected anal sex, having receptive anal sex and current syphilis infection are significant factors associated with HIV infection. The potential for a rapid rise of HIV and syphilis infections among MSM in Guangzhou exists. Targeted interventions with voluntary counseling and testing (VCT) and sexually transmitted infection (STI) services are needed to address the epidemic, with a focus on such subgroups as those of with current syphilis, and non-official Guangzhou residence status.