Genomic characterization of Aeromonas spp. isolates from striped catfish with motile Aeromonas septicemia and human bloodstream infections in Vietnam.

Aeromonas spp. are commonly found in the aquatic environment and have been responsible for motile Aeromonas septicemia (MAS) in striped catfish, resulting in significant economic loss. These organisms also cause a range of opportunistic infections in humans with compromised immune systems. Here, we conducted a genomic investigation of 87 Aeromonas isolates derived from diseased catfish, healthy catfish and environmental water in catfish farms affected by MAS outbreaks in eight provinces in Mekong Delta (years: 2012-2022), together with 25 isolates from humans with bloodstream infections (years: 2010-2020). Genomics-based typing method precisely delineated Aeromonas species while traditional methods such as aerA PCR and MALDI-TOF were unable identify A. dhakensis. A. dhakensis was found to be more prevalent than A. hydrophila in both diseased catfish and human infections. A. dhakensis sequence type (ST) 656 followed by A. hydrophila ST251 were the predominant virulent species-lineages in diseased catfish (43.7 and 20.7 %, respectively), while diverse STs were found in humans with bloodstream infections. There was evidence of widespread transmission of ST656 and ST251 on striped catfish in the Mekong Delta region. ST656 and ST251 isolates carried a significantly higher number of acquired antimicrobial resistance (AMR) genes and virulence factors in comparison to other STs. They, however, exhibited several distinctions in key virulence factors (i.e. lack of type IV pili and enterotoxin ast in A. dhakensis), AMR genes (i.e. presence of imiH carbapenemase in A. dhakensis), and accessory gene content. To uncover potential conserved proteins of Aeromonas spp. for vaccine development, pangenome analysis has unveiled 2202 core genes between ST656 and ST251, of which 78 proteins were in either outer membrane or extracellular proteins. Our study represents one of the first genomic investigations of the species distribution, genetic landscape, and epidemiology of Aeromonas in diseased catfish and human infections in Vietnam. The emergence of antimicrobial resistant and virulent A. dhakensis strains underscores the needs of enhanced genomic surveillance and strengthening vaccine research and development in preventing Aeromonas diseases in catfish and humans, and the search for potential vaccine candidates could focus on Aeromonas core genes encoded for membrane and secreted proteins.

Waterpipe tobacco smoking and risk of all-cause mortality: a prospective cohort study.

BACKGROUND: Despite an increasing proportion of smokers who use non-cigarette products, the harmfulness of these is inconsistent. This study aimed to evaluate the impact of waterpipe tobacco (WTP) smoking on all-cause mortality. METHODS: A prospective cohort study followed up on 35 646 participants from 2007 to 2019 in Northern Viet Nam. Data for each type of cigarette and WTP smoking were collected based on demographic lifestyle and semi-quantitative food frequency questionnaires. Smokers were categorized as current smokers and former smokers who were lifetime ever smokers but stopped smoking >6 months before the interview. Data on all-cause mortality (2449 deaths) were obtained from medical records at the state health facilities. The hazard ratios (HRs) and 95% CIs for mortality were estimated using a Cox proportional-hazards model. RESULTS: Compared with non-smokers, ever smokers had a higher all-cause mortality risk (HR = 1.29, 95% CI = 1.16-1.43). Current WTP (HR = 1.37, 95% CI = 1.19-1.57), current cigarette (HR = 1.40, 95% CI = 1.22-1.60) and former WTP smokers (HR = 1.39, 95% CI = 1.10-1.76) showed an elevated risk of dying. The mortality risk was significantly elevated in dual smokers using WTP and cigarettes (HR = 1.55, 95% CI = 1.35-1.79) and exclusive WTP smokers (HR = 1.38, 95% CI = 1.21-1.57). Elevated risk was observed for the main targeted attractions of cancer, diabetes and heart diseases. Smoking cessation of >10 years decreased the risk of all-cause mortality (HR = 0.61, 95% CI = 0.44-0.85) and cancer (HR = 0.24, 95% CI = 0.11-0.52). CONCLUSIONS: WTP smoking increases the risk of all-cause mortality. A unique programme to control exposure to WTP should be a high priority in Viet Nam and other countries.

Calcium Intake Contributed by Whole Foods and Gastric Cancer in Viet Nam: A Case­Control Study.

BACKGROUND: Recent studies revealed the potential tumor-suppressive effects of calcium. We aimed to investigate the association between dietary calcium intake contributed by whole foods and gastric cancer. METHODS: 466 gastric cancer cases and 1531 controls were extracted from the completed case-control studies in hospitals in Hanoi from 2017 to 2019. A validated semi-quantitative food frequency questionnaire was used to obtain data via face-to-face interviews with the trained interviewer. Calcium intake was calculated based on the food frequency intake per year. Adjusted odds ratios (OR) and 95% confidence intervals (95% CI) were calculated. RESULTS: The study participants consumed less than 50% of 700 mg/day compared to the recommended calcium intake. With increasing calcium intake, we found a reduction in gastric cancer in both genders, men and women (adjusted OR and 95%CI, 5th vs. 1st quintile: 0.50 (0.36, 0.70), p_trend 0.000; 0.62 (0.42, 0.92), p_trend 0.019; and 0.30 (0.16, 0.57), p_trend 0.000, respectively). The inverse association remained in the subgroups of never-smokers and those with positive H. pylori infection. CONCLUSION: We observed substantial benefits of calcium intake from whole foods against gastric cancer in the Vietnamese population with a low nutritious status.

A prospective cohort study on the association between waterpipe tobacco smoking and gastric cancer mortality in Northern Vietnam.

Tobacco consumption, as a worldwide problem, is a risk factor for several types of cancer. In Vietnam, tobacco consumption in the form of waterpipe tobacco smoking is common. This prospective cohort study aimed to study the association between waterpipe tobacco smoking and gastric cancer mortality in Northern Vietnam. A total of 25,619 eligible participants were followed up between 2008 and 2019. Waterpipe tobacco and cigarette smoking data were collected; semi-quantitative food frequency and lifestyle questionnaires were also utilized. Gastric cancer mortality was determined via medical records available at the state health facilities. A Cox proportional hazards model was used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI). During 314,992.8 person-years of follow-up, 55 men and 25 women deaths due to gastric cancer were identified. With never-smokers as the reference, the risk of gastric cancer mortality was significantly increased in participants who were ever-smoking (HR = 2.43, 95% CI = 1.35-4.36). The positive risk was also observed in men but was not significantly increased in women. By types of tobacco use, exclusive waterpipe smokers showed a significantly increased risk of gastric cancer mortality (HR = 3.22, 95% CI = 1.67-6.21) but that was not significantly increased in exclusive cigarette smokers (HR = 1.90, 95% CI = 0.88-4.07). There was a significant positive association between tobacco smoking and gastric cancer death for indicators of longer smoking duration, higher frequency per day, and cumulative frequency of both waterpipe and cigarette smoking. Waterpipe tobacco smoking would significantly increase the risk of gastric cancer mortality in the Vietnamese population. Further studies are required to understand the waterpipe tobacco smoking-driven gastric cancer burden and promote necessary interventions.

Waterpipe Tobacco Smoking and Risk of Stomach Cancer: A Case-Control Study in Vietnamese Men.

OBJECTIVE: This study investigated the impacts of waterpipe tobacco (WTP) and cigarette smoking on stomach cancer development in Vietnamese men. METHODS: A total of 80 stomach cancer cases and 146 controls were recruited in a hospital-based case-control study. Data on sociodemographic, anthropometric characteristics, tobacco smoking, and the dietary pattern was obtained based on a semi-quantitative food frequency and demographic lifestyle questionnaire; and venous anti-Helicobacter pylori IgG antibodies were tested by ELISA. Unconditional logistic regression analysis with adjustments for potential confounding was performed to estimate the association between target exposures and stomach cancer. RESULTS: Compared to the never tobacco smokers, the risk of stomach cancer significantly increased among tobacco smokers (OR 2.95, 95%CI 1.26-6.90, p=0.013). Those who early started tobacco smoking before 26 years old had a high risk of SC (OR 3.04, 95%CI 1.29-7.20, p for trend=0.011). For types of tobacco, It was increased risk in exclusively cigarette smokers (OR 2.85, 95%CI 1.19-6.85, p=0.019) and in WPT smokers (OR 3.09, 95%CI 1.24-7.68, p=0.015). The daily frequency and longer duration of exclusively WPT or cigarette smoking tended to be significantly higher SC risk. CONCLUSIONS: The findings suggest that tobacco smoking, particularly water pipe tobacco smoking, dramatically and independently increased the risk of stomach cancer.