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The aim of this work was to evaluate the conformity of intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT), and verify the accuracy of the planning and delivery system used in this work based on the AAPM TG-119 protocol. The Eclipse 13.6 treatment planning system (TPS) was used to plan the TG-119 test suite, which included four test cases: MultiTarget, Prostate, Head/Neck, and C-Shape for IMRT and VMAT techniques with 6 MV and 10 MV acceleration voltages. The results were assessed and discussed in terms of the TG-119 protocol and the results of previous studies. In addition, point dose and planar dose measurements were done using a semiflex ion chamber and an electronic portal imaging device (EPID), respectively. The planned doses of all test cases met the criteria of the TG-119 protocol, except those for the spinal cord of the C-Shape hard case. There were no significant differences between the treatment planning doses and the doses given in the TG-119 report, with p-values ranging from 0.974 to 1 (p > 0.05). Doses to the target volumes were similar in the IMRT and VMAT plans, but the organs at risk (OARs) doses were different depending on the test case. The planning results showed that IMRT is more conformal than VMAT in certain cases. For the point dose measurements, the confidence limit (CL point ) of 0.030 and 0.021 were better than the corresponding values of 0.045 and 0.047 given in the TG-119 report for high-dose and low-dose areas, respectively. Regarding the planar dose measurements, the CL planar value of 0.38 obtained in this work was lower than that given in the TG-119 report (12.4). It is concluded that the dosimetry measurements performed in this study showed better confidence limits than those provided in the TG 119 report. IMRT remains more conformal in certain circumstances than the more progressive VMAT. When selecting the method of delivering a dose to the patient, several factors must be considered, including the radiotherapy technique, energy, treatment site, and tumour geometry., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: Maternal disorders are the third leading cause of sepsis globally, accounting for 5.7 million (12%) cases in 2017. There are increasing concerns about the emergence of antimicrobial resistance (AMR) in bacteria commonly causing maternal sepsis. Our aim is to describe the protocol for a clinical and microbiology laboratory study to understand risk factors for and the bacterial etiology of maternal sepsis in a tertiary Obstetrics and Gynaecology Hospital., Methods: This case-control study aims to recruit 100 cases and 200 controls at Tu Du Hospital in Ho Chi Minh City, Vietnam, which had approximately 55,000 births in 2022. Women aged ≥ 18 years and ≥ 28 weeks gestation having a singleton birth will be eligible for inclusion as cases or controls, unless they have an uncomplicated localised or chronic infection, or an infection with SARS-CoV-2. Cases will include pregnant or recently pregnant women with sepsis recognised between the onset of labour and/or time of delivery/cessation of pregnancy for up to 42 days post-partum. Sepsis will be defined as suspected or confirmed infection with an obstetrically modified Sequential Organ Failure Assessment score of ≥ 2, treatment with intravenous antimicrobials and requested cultures of any bodily fluid. Controls will be matched by age, location, parity, mode of delivery and gestational age. Primary and secondary outcomes are risk factors associated with the development of maternal sepsis, the frequency of adverse outcomes due to maternal sepsis, bacterial etiology and AMR profiles of cases and controls., Discussion: This study will improve understanding of the epidemiology and clinical implications of maternal sepsis management including the presence of AMR in women giving birth in Vietnam. It will help us to determine whether women in this setting are receiving optimal care and to identify opportunities for improvement., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Thompson et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Methicillin-resistant Staphylococcus aureus (MRSA) is a critical pathogen responsible for a wide variety of serious infectious diseases in humans. The accelerated phenomena of drug tolerance, drug resistance, and dysbacteriosis provoked by antibiotic misuse are impeding the effectiveness of contemporary antibiotic therapies primarily used to treat this common worldwide pathogen. In this study, the antibacterial activity of 70% ethanol extract and multiple polar solvents of Ampelopsis cantoniensis were measured against the clinical MRSA isolate. The agar diffusion technique was employed to determine the zone of inhibition (ZOI), accompanied by the use of a microdilution series to identify the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Our results revealed that the ethyl acetate fraction exhibited the most significant antibacterial activity, which was determined to be bacteriostatic based on the MBC/MIC ratio 8. A list of compounds isolated from A. cantoniensis was computationally studied to further investigate the mechanism of action with the bacterial membrane protein PBP2a. The combination of molecular docking and molecular dynamics methods showed that the main compound, dihydromyricetin (DHM), is expected to bind to PBP2a at allosteric site. In addition, DHM was identified as the major compound of ethyl acetate fraction, which accounts for 77.03 ± 2.44% by high performance liquid chromatography (HPLC) analysis. As a concluding remark, our study addressed the antibacterial mechanism and suggested the prioritization of natural products derived from A. cantoniensis as a potential therapy for MRSA.Communicated by Ramaswamy H. Sarma.

Lentinus arcularius (=Polyporus arcularius) is a medicinal polypore mushroom recorded in Vietnam based on morphological observation. In this study, three L. arcularius isolates were identified using molecular and morphological methods. Furthermore, the antimicrobial and antioxidant activities of their intracellular and/or extracellular metabolites were investigated. The ethyl acetate and n-butanol fractions were the most active extracts against Gram-positive and Gram-negative bacteria (Escherichia coli VTCC 12014, Pseudomonas aeruginosa VTCC 12273, and Staphylococcus aureus VTCC 10658) and fungi (Candida albicans VTCC 20568, Saccharomyces cerevisiae VTCC 20146, and Aspergillus niger VTCC 30001). These fractions also showed the highest antioxidant activity by α,α-diphenyl-β-picryl-hydrazyl as a free-radical agent or the highest percentage at 75-100% inhibition. These results suggest that L. arcularius might be a potential medicinal mushroom with antimicrobial and antioxidant effects.

Vaccines against Salmonella Typhi, the causative agent of typhoid fever, are commonly used by travellers, however, there are few examples of national immunization programs in endemic areas. There is therefore a paucity of data on the impact of typhoid immunization programs on localised populations of S. Typhi. Here we have used whole genome sequencing (WGS) to characterise 44 historical bacterial isolates collected before and after a national typhoid immunization program that was implemented in Thailand in 1977 in response to a large outbreak; the program was highly effective in reducing typhoid case numbers. Thai isolates were highly diverse, including 10 distinct phylogenetic lineages or genotypes. Novel prophage and plasmids were also detected, including examples that were previously only reported in Shigella sonnei and Escherichia coli. The majority of S. Typhi genotypes observed prior to the immunization program were not observed following it. Post-vaccine era isolates were more closely related to S. Typhi isolated from neighbouring countries than to earlier Thai isolates, providing no evidence for the local persistence of endemic S. Typhi following the national immunization program. Rather, later cases of typhoid appeared to be caused by the occasional importation of common genotypes from neighbouring Vietnam, Laos, and Cambodia. These data show the value of WGS in understanding the impacts of vaccination on pathogen populations and provide support for the proposal that large-scale typhoid immunization programs in endemic areas could result in lasting local disease elimination, although larger prospective studies are needed to test this directly., Competing Interests: The authors have declared that no competing interests exist.

Objectives: We aimed to quantify the impact of fluoroquinolone resistance on the clinical outcome of paediatric shigellosis patients treated with fluoroquinolones in southern Vietnam. Such information is important to inform therapeutic management for infections caused by this increasingly drug-resistant pathogen, responsible for high morbidity and mortality in young children globally., Methods: Clinical information and bacterial isolates were derived from a randomized controlled trial comparing gatifloxacin with ciprofloxacin for the treatment of paediatric shigellosis. Time-kill experiments were performed to evaluate the impact of MIC on the in vitro growth of Shigella and Cox regression modelling was used to compare clinical outcome between treatments and Shigella species., Results: Shigella flexneri patients treated with gatifloxacin had significantly worse outcomes than those treated with ciprofloxacin. However, the MICs of fluoroquinolones were not significantly associated with poorer outcome. The presence of S83L and A87T mutations in the gyrA gene significantly increased MICs of fluoroquinolones. Finally, elevated MICs and the presence of the qnrS gene allowed Shigella to replicate efficiently in vitro in high concentrations of ciprofloxacin., Conclusions: We found that below the CLSI breakpoint, there was no association between MIC and clinical outcome in paediatric shigellosis infections. However, S. flexneri patients had worse clinical outcomes when treated with gatifloxacin in this study regardless of MIC. Additionally, Shigella harbouring the qnrS gene are able to replicate efficiently in high concentrations of ciprofloxacin and we hypothesize that such strains possess a competitive advantage against fluoroquinolone-susceptible strains due to enhanced shedding and transmission., (© The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.)

Shigella sonnei is a major contributor to the global burden of diarrhoeal disease, generally associated with dysenteric diarrhoea in developed countries but also emerging in developing countries. The reason for the recent success of S. sonnei is unknown, but is likely catalysed by its ability to acquire resistance against multiple antimicrobials. Between 2011 and 2013, S. sonnei exhibiting resistance to fluoroquinolones, the first-line treatment recommended for shigellosis, emerged in Bhutan. Aiming to reconstruct the introduction and establishment of fluoroquinolone-resistant S. sonnei populations in Bhutan, we performed whole-genome sequencing on 71 S. sonnei samples isolated in Bhutan between 2011 and 2013.We found that these strains represented an expansion of a clade within the previously described lineage III, found specifically in Central Asia. Temporal phylogenetic reconstruction demonstrated that all of the sequenced Bhutanese S. sonnei diverged from a single ancestor that was introduced into Bhutan around 2006. Our data additionally predicted that fluoroquinolone resistance, conferred by mutations in gyrA and parC , arose prior to the introduction of the founder strain into Bhutan. Once established in Bhutan, these S. sonnei had access to a broad gene pool, as indicated by the acquisition of extended-spectrum β-lactamase-encoding plasmids and genes encoding type IV pili. The data presented here outline a model for the introduction and maintenance of fluoroquinolone-resistant S. sonnei in a new setting. Given the current circulation of fluoroquinolone-resistant S. sonnei in Asia, we speculate that this pattern of introduction is being recapitulated across the region and beyond.

Azithromycin is an effective treatment for uncomplicated infections with Salmonella enterica serovar Typhi and serovar Paratyphi A (enteric fever), but there are no clinically validated MIC and disk zone size interpretative guidelines. We studied individual patient data from three randomized controlled trials (RCTs) of antimicrobial treatment in enteric fever in Vietnam, with azithromycin used in one treatment arm, to determine the relationship between azithromycin treatment response and the azithromycin MIC of the infecting isolate. We additionally compared the azithromycin MIC and the disk susceptibility zone sizes of 1,640 S. Typhi and S. Paratyphi A clinical isolates collected from seven Asian countries. In the RCTs, 214 patients who were treated with azithromycin at a dose of 10 to 20 mg/ml for 5 to 7 days were analyzed. Treatment was successful in 195 of 214 (91%) patients, with no significant difference in response (cure rate, fever clearance time) with MICs ranging from 4 to 16 μg/ml. The proportion of Asian enteric fever isolates with an MIC of ≤ 16 μg/ml was 1,452/1,460 (99.5%; 95% confidence interval [CI], 98.9 to 99.7) for S. Typhi and 207/240 (86.3%; 95% CI, 81.2 to 90.3) (P < 0.001) for S. Paratyphi A. A zone size of ≥ 13 mm to a 5-μg azithromycin disk identified S. Typhi isolates with an MIC of ≤ 16 μg/ml with a sensitivity of 99.7%. An azithromycin MIC of ≤ 16 μg/ml or disk inhibition zone size of ≥ 13 mm enabled the detection of susceptible S. Typhi isolates that respond to azithromycin treatment. Further work is needed to define the response to treatment in S. Typhi isolates with an azithromycin MIC of >16 μg/ml and to determine MIC and disk breakpoints for S. Paratyphi A., (Copyright © 2015, Parry et al.)

Antimicrobials are used extensively in chicken production in Vietnam, but to date no quantitative data are available. A 2012-2013 survey of 208 chicken farms in Tien Giang province, stratified by size (10-200 chickens; >200-2000), was carried out to describe and quantify the use of antibacterial antimicrobials (usage per week per chicken and usage per 1000 chickens produced) in the Mekong Delta and to investigate factors associated with usage. Twenty-eight types of antimicrobial belonging to 10 classes were reported. Sixty-three per cent of all commercial formulations contained at least two antimicrobials. On 84% occasions, antimicrobials were administered with a prophylactic purpose. The overall adjusted quantities of antimicrobials used/week/chicken and per 1000 chickens produced (g) were 26.36 mg (SE ± 3.54) and 690.4 g (SE ± 203.6), respectively. Polypeptides, tetracyclines, penicillins and aminoglycosides were the antimicrobials used by most farms (18.6% farms, 17.5%, 11.3% and 10.1% farms, respectively), whereas penicillins, lincosamides, quinolones, and sulphonamides/trimethoprim were quantitatively the most used compounds (8.27, 5.2, 3.16 and 2.78 mg per week per chicken, respectively). Factors statistically associated with higher levels of usage (per week per chicken) were meat farms (OR = 1.40) and farms run by a male farmer (OR = 2.0). All-in-all-out farming systems (correlated with medium farms) were associated with reduced levels of antimicrobial usage (OR = 0.68). Usage levels to produced meat chickens were considerably higher than those reported in European countries. This should trigger the implementation of surveillance programmes to monitor sales of antimicrobials that should contribute to the rational administration of antimicrobials in order to preserve the efficacy of existing antimicrobials in Vietnam., (© 2014 The Authors. Zoonoses and Public Health Published by Blackwell Verlag GmbH.)

Visceral leishmaniasis (also known as kala-azar) is classified as one of the most neglected tropical diseases. It is becoming a growing health problem in Ethiopia, with endemic areas that are continually spreading. The annual burden of visceral leishmaniasis (VL) in Ethiopia is estimated to be between 4,500 and 5,000 cases, and the population at risk is more than 3.2 million. There has been a change in the epidemiology of VL in Ethiopia. Over the last decades, almost all cases and outbreaks of VL were reported from arid and semi-arid parts of the country; however, recent reports indicated the introduction of this disease into the highlands. Migration of labourers to and from endemic areas, climatic and environmental changes, and impaired immunity due to HIV/AIDS and malnutrition resulted in the change of VL epidemiology. HIV spurs the spread of VL by increasing the risk of progression from asymptomatic infection towards full VL. Conversely, VL accelerates the onset of AIDS. In Ethiopia, VL epidemiology remains complex because of the diversity of risk factors involved, and its control is becoming an increasing challenge. This paper reviews the changes in epidemiology of VL in Ethiopia and discusses some of the possible explanations for these changes. The prospects for novel approaches to VL control are discussed, as are the current and future challenges facing Ethiopia's public health development program.

Bacteriocins are ribosomally synthesized antimicrobial peptides, which have been found in diverse bacterial species of terrestrial origins and some from the sea. New bacteriocins with new characteristics, new origins and new applications are likely still awaiting discovery. The present study screened bacteria isolated from marine animals of interest to the aquaculture industry for antimicrobial and bacteriocin-like activities in order to uncover biodiversity of bacteriocin producers, and explore the potential application in aquaculture. In total, 24 of 100 screened isolates showed antimicrobial activities and 7 of these exerted bacteriocin-like activities. Sequencing of 16S rRNA genes identified the isolates as members of the six genera Proteus, Providencia, Klebsiella, Alcaligenes, Bacillus and Enterococcus. In some cases, further analysis of housekeeping genes, rpoB for Proteus and recA for Klebsiella, as well as biochemical tests was necessary for identification to species level, and some of the Proteus isolates may represent novel species. The seven bacteriocinogenic isolates showed a wide antimicrobial spectrum against foodborne and animal pathogens, which opens the way to their potential use as marine drugs and probiotics in food, aquaculture, livestock and clinical settings. As a case study, the protective effect of shortlisted bacteriocinogenic isolates were tested in aquaculture-raised spiny lobster (Panulirus ornatus) juveniles. A single-strain (Bacillus pumilus B3.10.2B) and a three-strain (B. pumilus B3.10.2B, Bacillus cereus D9, Lactobacillus plantarum T13) probiotic preparation were added to the feed of Panulirus ornatus juveniles, which were subsequently challenged with the pathogen Vibrio owensii DY05. Juveniles in the probiotic treatments displayed increased growth and reduced feed conversion rates after 60 days, and increased survival rate after pathogen challenge relative to the control. This study represents the first evidence of bacteriocin production by bacteria associated with lobster, tiger shrimp, snubnose pompano and cobia and the first description of V. owensii as a pathogen in P. ornatus juveniles., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Background: Close contacts of tuberculosis (TB) patients are at increased risk of developing tuberculosis. Although passive contact screening guidelines are incorporated in the national TB control program, currently it is unknown how frequent close contacts are screened for TB in Vietnam. This study assesses current contact screening practices in Vietnam and determines the proportion of household contacts screened of newly registered TB patients., Method: Survey of household contacts of smear-positive TB patients (index patients) registered for treatment in 2008 in three Vietnamese cities. Households were interviewed in 2010 about screening for TB since treatment registration date of the index patient., Results: We interviewed 4,118 household contacts of 1,091 identified index cases. Contact screening mainly relied on self-referral by household contacts. Of the 4,118 household contacts, 474 (11.5%) self-referred for TB screening, while this screening proportion was only 5.5% among contacts under 5 years old (16/293). Sputum examinations were performed in 374 (78.9%) of the screened contacts. Contact screening identified 27 cases of pulmonary TB (0.7%; or 656 cases/100,000 contacts), of which 20 were detected by sputum smear., Conclusions: The low proportion of household TB contacts screened for TB illustrates the limitations of passive contact screening as currently practiced in Vietnam. Children under 5 years of age are particularly neglected with this approach. Active contact screening with fixed follow-up times of close contacts of newly diagnosed TB patients should be considered in Vietnam, particularly in case of young children and drug-resistant TB.

With the exponential growth of the global population, the agricultural sector is bound to use ever larger quantities of fertilizers to augment the food supply, which consequently increases food production costs. Urea, when applied to crops is vulnerable to losses from volatilization and leaching. Current methods also reduce nitrogen use efficiency (NUE) by plants which limits crop yields and, moreover, contributes towards environmental pollution in terms of hazardous gaseous emissions and water eutrophication. An approach that offsets this pollution while also enhancing NUE is the use of controlled release urea (CRU) for which several methods and materials have been reported. The physical intromission of urea granules in an appropriate coating material is one such technique that produces controlled release coated urea (CRCU). The development of CRCU is a green technology that not only reduces nitrogen loss caused by volatilization and leaching, but also alters the kinetics of nitrogen release, which, in turn, provides nutrients to plants at a pace that is more compatible with their metabolic needs. This review covers the research quantum regarding the physical coating of original urea granules. Special emphasis is placed on the latest coating methods as well as release experiments and mechanisms with an integrated critical analyses followed by suggestions for future research., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: Recent guidelines have acknowledged that thrombolysis decreases mortality from acute myocardial infarction (AMI) independently of age. The purpose of this study was to determine the age-related rates of thrombolytic administration and in-hospital mortality and the variables related to the use of thrombolytic therapy for patients with AMI., Methods: A prospective cohort analysis involved a registry of 44 acute care Quebec hospitals that enrolled 3741 patients with AMI between January 1995 and May 1996. The main outcomes of interest were crude and adjusted age-related in-hospital mortality rates and rates of use of thrombolytic therapy., Results: In-hospital mortality rates increased dramatically with age from 2.1% in patients with AMI who were less than 55 years of age to 26.3% in those who were 85 years of age or older. Overall, 35.8% of the patients received thrombolysis. There was a pronounced inverse gradient in the use of thrombolysis with age, ranging from 46.2% in the youngest age group (< 55 years) to 9.5% in the oldest group (> or = 85 years). After adjustment for potential confounders, the older patients remained significantly less likely to receive thrombolytic therapy. Compared with patients who were less than 55 years of age, the odds ratio of receiving thrombolytic therapy was 0.68 (95% confidence interval [CI] 0.52-0.89) for patients aged 65-74 years, 0.48 (95% CI 0.35-0.65) for patients aged 75-84 years and 0.13 (95% CI 0.06-0.26) for patients aged 85 years or more. Other variables related to thrombolytic therapy were diabetes (odds ratio [OR] 0.77, 95% CI 0.59-1.00), cerebrovascular disease (OR 0.46, 95% CI 0.30-0.72), angina (OR 0.73, 95% CI 0.56-0.95), typical chest pain (OR 2.56, 95% CI 1.88-3.47); ST elevation (OR 8.93, 95% CI 7.24-11.00), Q wave MI (OR 5.26, 95% CI 4.20-6.60) and increased length of time between onset of symptoms and arrival at hospital., Interpretation: Age is an important independent predictor of in-hospital mortality and lower thrombolytic use following AMI. Other studies are required to further evaluate the appropriateness of thrombolytic therapy for elderly patients.