Extended-spectrum beta-lactamase-producing Escherichia coli harbouring sul and mcr-1 genes isolates from fish gut contents in the Mekong Delta, Vietnam.

This study investigated the existence of sulfonamides and colistin resistance genes among extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli recovered from fish gut in Vietnam and evaluated the susceptibility patterns of the ESBL-producing E. coli to relevant antimicrobials. A total of 88 ESBL-producing E. coli isolates were analysed for the presence of the ESBLs, sul (1, 2, 3) and mcr (1-3) genes by PCR. Antimicrobial resistance phenotypes of isolates were determined by disc diffusion. Results showed that: (i) A high prevalence of 94·3% of sulfonamide resistance was observed in 88 isolates. Moreover, the existence of 2·3% of ESBL-producing E. coli harbouring mcr-1 gene were detected; (ii) The phylogenetic types A and B1 were most frequent, and the blaCTX-M group1 and blaTEM genes encoding ESBL were detected in 47·7% of the isolates; (iii) ESBL-producing E. coli harbouring mcr-1 gene exhibited resistance to 11 antibiotics. The existence of mcr-1 and sul1,2,3 genes and the extremely high level of multiple drug resistance in all ESBL-producing E. coli isolates obtained from sampled fish in Vietnam is a major concern. Therefore, it is imperative to monitor ESBL-producing E. coli in the river waters of Vietnam.

Generating a high-confidence reference genome map of the Greater Duckweed by integration of cytogenomic, optical mapping, and Oxford Nanopore technologies.

Duckweeds are the fastest growing angiosperms and have the potential to become a new generation of sustainable crops. Although a seed plant, Spirodela polyrhiza clones rarely flower and multiply mainly through vegetative propagation. Whole-genome sequencing using different approaches and clones yielded two reference maps. One for clone 9509, supported in its assembly by optical mapping of single DNA molecules, and one for clone 7498, supported by cytogenetic assignment of 96 fingerprinted bacterial artificial chromosomes (BACs) to its 20 chromosomes. However, these maps differ in the composition of several individual chromosome models. We validated both maps further to resolve these differences and addressed whether they could be due to chromosome rearrangements in different clones. For this purpose, we applied sequential multicolor fluorescence in situ hybridization (mcFISH) to seven S. polyrhiza clones, using 106 BACs that were mapped onto the 39 pseudomolecules for clone 7498. Furthermore we integrated high-depth Oxford Nanopore (ON) sequence data for clone 9509 to validate and revise the previously assembled chromosome models. We found no major structural rearrangements between these seven clones, identified seven chimeric pseudomolecules and Illumina assembly errors in the previous maps, respectively. A new S. polyrhiza genome map with high contiguity was produced with the ON sequence data and genome-wide synteny analysis supported the occurrence of two Whole Genome Duplication events during its evolution. This work generated a high confidence genome map for S. polyrhiza at the chromosome scale, and illustrates the complementarity of independent approaches to produce whole-genome assemblies in the absence of a genetic map.

Air-breathing fishes in aquaculture. What can we learn from physiology?

During the past decade, the culture of air-breathing fish species has increased dramatically and is now a significant global source of protein for human consumption. This development has generated a need for specific information on how to maximize growth and minimize the environmental effect of culture systems. Here, the existing data on metabolism in air-breathing fishes are reviewed, with the aim of shedding new light on the oxygen requirements of air-breathing fishes in aquaculture, reaching the conclusion that aquatic oxygenation is much more important than previously assumed. In addition, the possible effects on growth of the recurrent exposure to deep hypoxia and associated elevated concentrations of carbon dioxide, ammonia and nitrite, that occurs in the culture ponds used for air-breathing fishes, are discussed. Where data on air-breathing fishes are simply lacking, data for a few water-breathing species will be reviewed, to put the physiological effects into a growth perspective. It is argued that an understanding of air-breathing fishes' respiratory physiology, including metabolic rate, partitioning of oxygen uptake from air and water in facultative air breathers, the critical oxygen tension, can provide important input for the optimization of culture practices. Given the growing importance of air breathers in aquaculture production, there is an urgent need for further data on these issues.

Low numbers of repeat units in variable number of tandem repeats (VNTR) regions of white spot syndrome virus are correlated with disease outbreaks.

White spot syndrome virus (WSSV) is the most important pathogen in shrimp farming systems worldwide including the Mekong Delta, Vietnam. The genome of WSSV is characterized by the presence of two major 'indel regions' found at ORF14/15 and ORF23/24 (WSSV-Thailand) and three regions with variable number tandem repeats (VNTR) located in ORF75, ORF94 and ORF125. In the current study, we investigated whether or not the number of repeat units in the VNTRs correlates with virus outbreak status and/or shrimp farming practice. We analysed 662 WSSV samples from individual WSSV-infected Penaeus monodon shrimp from 104 ponds collected from two important shrimp farming regions of the Mekong Delta: Ca Mau and Bac Lieu. Using this large data set and statistical analysis, we found that for ORF94 and ORF125, the mean number of repeat units (RUs) in VNTRs was significantly lower in disease outbreak ponds than in non-outbreak ponds. Although a higher mean RU number was observed in the improved-extensive system than in the rice-shrimp or semi-intensive systems, these differences were not significant. VNTR sequences are thus not only useful markers for studying WSSV genotypes and populations, but specific VNTR variants also correlate with disease outbreaks in shrimp farming systems.

Determination and kinetics of enrofloxacin and ciprofloxacin in Tra catfish (Pangasianodon hypophthalmus) and giant freshwater prawn (Macrobrachium rosenbergii) using a liquid chromatography/mass spectrometry method.

Determination and kinetics of enrofloxacin and ciprofloxacin in Tra catfish (Pangasianodon hypophthalmus) and giant freshwater prawn (Macrobrachium rosenbergii) using a liquid chromatography/mass spectrometry method. J. vet. Pharmacol. Therap. 34, 142-152. The fluoroquinolones enrofloxacin (EF) and ciprofloxacin (CF) residues were investigated in the edible tissues of two important Asian aquacultured species such as Tra catfish (Pangasianodon hypophthalmus) and giant freshwater prawn (Macrobrachium rosenbergii) using a sensitive liquid chromatography-electrospray ionization-tandem mass spectrometry method. Fish and prawn were treated with medicated feed with multiple doses of EF, in field conditions. A validation study of the analytical method was realized in terms of linearity, specificity, precision (repeatability and within-laboratory reproducibility), recovery and decision limit (CCα). The time needed before the antibiotic disappears from animal tissues or reach the maximum residue limit (MRL, 100µg/kg) was assessed. The concentration values of EF detected in Tra catfish tissue were between the MRL and 2×MRL concentrations, according to the fish density, 7days following the end of the enrofloxacin treatment (20mg/kg body weight per day, for seven consecutive days). The concentration value of ER in prawn tissue was lower than the MRL and the limit of quantification (LOQ, 14µg/kg) 5 and 7days after the stop of the EF treatment (50mg/kg body weight per day, for five consecutive days), respectively. The mean detected levels of CF was much lower in comparison with that of EF, indicating that only a small part of EF is metabolized into CF (<5%) in both Tra catfish and prawn.

Allergen sensitisation among chronic respiratory diseases in urban and rural areas of the south of Viet Nam.

OBJECTIVE: To evaluate the prevalence of and risk factors for allergen sensitisation among patients with chronic respiratory disease (CRD) in southern Viet Nam. DESIGN: An environmental questionnaire and skin prick tests for airborne and food allergens were administered to patients with CRD, defined as individuals with respiratory symptoms and lung function defects. RESULTS: Of 610 CRD patients, 56% had chronic obstructive pulmonary disease and 31% were asthma patients; 80% were males. The most frequent sensitisers were dust mites (Dermatophagoides farinae 22%, Blomia tropicalis 19%, D. pteronyssinus 18%) and cockroach droppings (13%). Among study participants, 37% were from rural settings and 36% from urban areas, whereas 27% had migrated from rural to urban areas. Compared with people from rural areas, being born in an urban area was a risk factor for sensitisation to mites (OR 1.56, 95%CI 1.11-2.20, P < 0.02). In multivariate analysis, place of birth remained a risk factor for mite sensitisation. Compared with the native urban population, the risk of mite sensitisation was not significantly different among patients born in rural areas and those migrating to urban areas. CONCLUSION: Dust mites and cockroach droppings were the most frequent allergens among people with CRD in the south of Viet Nam. Compared with the urban population, being native to a rural area was protective against mite sensitisation, but this effect ceased to be significant after migration from rural to urban areas.

Prevalence of latent tuberculous infection among adults in the general population of Ca Mau, Viet Nam.

SETTING: The study was conducted in a randomly selected sample of persons aged 15 years living in Ca Mau Province, southern Viet Nam. OBJECTIVE: To estimate the prevalence of latent tuberculous infection (LTBI) in the general adult population of this province of Viet Nam. The secondary objective was to examine age and sex differences in prevalence. DESIGN: A cross-sectional survey was conducted in a cluster-random sample of the population. Clusters were subcommunes. The presence of LTBI was assessed using the QuantiFERON®-TB Gold In-Tube test system. RESULTS: QuantiFERON tests were performed among 1319 persons aged 15 years (77.7% of those selected). The overall prevalence of positive tests was 36.8% (95%CI 33.4-40.3). The prevalence of a positive test was lower in females than in males (31.0% vs. 44.7%, OR 0.57, 95%CI 0.45-0.72, P < 0.0001). The prevalence of positive tests increased with increasing age quintile (P < 0.0001). CONCLUSION: More than one third of the general adult population in a province in southern Viet Nam have evidence of LTBI. Although LTBI prevalence is higher in males, the sex difference is not as great as that for TB notification rates.

Economic burden of multidrug-resistant tuberculosis: a multicenter study across Vietnamese regions.

SETTING: Multidrug-resistant tuberculosis (MDR-TB) has become a major worldwide health problem. Various studies have been conducted on the cost of MDR-TB treatment; however, this has remained largely unexplored in Viet Nam. OBJECTIVE: To estimate the total cost of MDR-TB treatment at several health care facilities in Viet Nam. DESIGN: A prospective, prevalence-based study was conducted at three selected centers from March to June 2016 in 204 patients, 102 of whom were treated for 9 months and 102 for 20 months. Direct medical costs were calculated using electronic hospital databases, while a questionnaire was used to interview participants for evaluating direct non-medical and indirect costs. Total costs were estimated from a societal perspective in 2017 USD. RESULTS: Patients were mostly males aged 25-44 years. The average length of hospitalization in the 9-month treatment group was 168 ± 127 days; in the 20-month group, it was 671 ± 119 days. The average treatment cost for MDR-TB was respectively US$1480.34 ± 211.61 and US$2695.58 ± 294.98 for the 9- and 20-month treatment groups. Direct medical costs generally accounted for the highest proportion of the total costs, while the cost of pharmaceuticals and materials comprised the highest direct cost. CONCLUSION: There was a significant difference in total costs among the three hospitals in the 9- and 20-month treatment groups.

Management and treatment outcomes of patients enrolled in MDR-TB treatment in Viet Nam.

SETTING: The programmatic management of drug-resistant tuberculosis (TB) in Viet Nam has been rapidly scaled up since 2009. OBJECTIVES: To document the annual numbers of patients enrolled for multidrug-resistant tuberculosis (MDR-TB) treatment during 2010-2014 and to determine characteristics and treatment outcomes of patients initiating treatment during 2010-2012. DESIGN: A retrospective cohort study using national reports and data from the national electronic data system for drug-resistant TB. RESULTS: The number of patients enrolled annually for MDR-TB treatment increased from 97 in 2010 to 1522 in 2014. The majority of patients were middle-aged men who had pulmonary disease and had failed a retreatment regimen; 77% had received ⩾2 courses of TB treatment. Favourable outcomes (cured and treatment completed) were attained in 73% of patients. Unfavourable outcomes included loss to follow-up (12.5%), death (8%) and failure (6.3%). Having had ⩾2 previous treatment courses and being human immunodeficiency virus-positive were associated with unfavourable outcomes. CONCLUSION: Increasing numbers of patients are being treated for MDR-TB each year with good treatment outcomes under national programme management in Viet Nam. However, there is a need to increase case detection-currently at 30% of the estimated 5100 MDR-TB cases per year, reduce adverse outcomes and improve monitoring and evaluation.

Contexte : La prise en charge de la tuberculose (TB) pharmacorésistante au Viet Nam a bénéficié d'une accélération considérable depuis 2009.Objectifs : Documenter le nombre annuel de patients enrôlés pour un traitement de TB multirésistante (TB-MDR) entre 2010 et 2014, et déterminer les caractéristiques et les résultats du traitement des patients qui l'out commencé entre 2010 et 2012.Schéma : Etude rétrospective de cohorte basée sur les rapports nationaux et les données du système national de données électroniques pour la TB pharmacorésistante.Résultats : Le nombre de patients enrôlés chaque année pour traitement de TB-MDR a augmenté de 97 en 2010 à 1522 en 2014. La majorité des patients étaient des hommes d'âge moyen qui avaient une atteinte pulmonaire et chez qui un protocole de retraitement avait échoué ; 77% d'entre eux avaient reçu au moins deux traitements de TB. De bons résultats (guérison et achèvement du traitement) ont été obtenus chez 73% des patients. Les résultats défavorables incluaient les sujets perdus de vue (12,5%), les décès (8%) et les échecs (6,3%). Avoir eu plus de deux traitements préalables et être positif pour le virus de l'immunodéficience humaine étaient associés à des résultats défavorables.Conclusion : Un nombre croissant de patients est traité pour TB-MDR chaque année dans le cadre du programme national de prise en charge au Viet Nam, avec de bons résultats. Cependant, il est nécessaire d'augmenter la détection des cas (actuellement seulement 30% des 5100 cas de TB-MDR estimés par an), de réduire la proportion de résultats défavorables et d'améliorer le suivi et l'évaluation.

Marco de referencia: Desde el 2009, se ha ampliado rápidamente la escala del tratamiento de la tuberculosis (TB) farmacorresistente en el marco del programa nacional de Viet Nam.Objetivos: Documentar el número de pacientes inscritos cada año en el tratamiento de la TB multidrogorresistente (TB-MDR) del 2010 al 2014 y determinar los desenlaces terapéuticos y sus características en los pacientes que iniciaron tratamiento del 2010 al 2012.Método: Fue este un estudio retrospectivo de cohortes a partir de los registros y los datos del sistema electrónico nacional de datos sobre la TB farmacorresistente.Resultados: El número de pacientes incorporados cada año al tratamiento de la TB-MDR aumentó de 97 en el 2010 a 1522 en el 2014. En su mayoría, se trató de hombres de mediana edad con afectación pulmonar, en quienes había fracasado una pauta de retratamiento y de los cuales el 77% había recibido dos o más ciclos de tratamiento antituberculoso. El 73% de pacientes alcanzó desenlaces favorables (curación y compleción del tratamiento). Los desenlaces desfavorables observados fueron la pérdida durante el seguimiento (12,5%), la muerte (8%) y el fracaso terapéutico (6,3%). El hecho de haber recibido dos o más ciclos de tratamiento antituberculoso y la positividad frente al virus de la inmunodeficiencia humana se asociaron con los desenlaces desfavorables.Conclusión: Cada año, un mayor número de pacientes recibe tratamiento por TB-MDR en el marco del programa nacional contra la TB y alcanza desenlaces terapéuticos favorables en Viet Nam. Sin embargo, es preciso aumentar la detección de casos (que alcanza actualmente el 30% de los 5100 casos estimados de TB-MDR por año), disminuir los desenlaces desfavorables y mejorar el seguimiento y la evaluación.

Prospective case-control study of encephalopathy in children with dengue hemorrhagic fever.

We present a prospective case-control study of 27 serologically confirmed dengue hemorrhagic fever (DHF) patients with severe central nervous system symptoms. Dengue associated encephalopathy accounted for 0.5% of 5,400 patients admitted with DHF. The mortality rate among children with encephalopathy was 22%, with the survivors experiencing a complete recovery. Liver enzymes and bilirubin were significantly elevated in the study group. In analysis of the cerebrospinal fluid (CSF), reverse transcriptase-polymerase chain reaction revealed dengue-3-specific RNA in one evaluated case. Dengue-specific immunoglobulin M was detected in CSF in 14 of 22 assessable patients, indicating a localized infection. Magnetic resonance imaging scans showed cerebral edema in the majority of patients, although encephalitis-like changes were less common. There was an equal distribution of primary and secondary infections. On the basis of previous reports and of the findings of our study, DHF probably encompasses an expanding clinical spectrum that infrequently involves encephalitis due to a direct neurotropic effect of dengue virus.

[Localization of antigenes in the pig aorta by immunofluorescence with antisera against aortic fractions (author's transl)]. / Localisation par immunofluorescence, d'antigenes d'aorte de porc à l'aide de serums anti-fractions aortiques

Immunization of rabbits with pig aorta homogenates and with aortic fractions (endothelial cells; media; "microsomal" and "soluble" fractions) yielded specific circulating anti-aortic tissue antibodies. Localization of these antibodies in frozen sections, by the indirect immunofluorescence technique, disclosed cross-reactions between endothelium and media, but no reaction was observed with elastic fibers.

Determination of PCDD/Fs in breast milk of women living in the vicinities of Da Nang Agent Orange hot spot (Vietnam) and estimation of the infant's daily intake.

Seventeen toxic congeners of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in breast milks using the high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) method. Twenty seven breast milk samples were collected from primiparae who have lived over 5 years in wards namely Chinh Gian, An Khe, Khue Trung, and Hoa Thuan Tay which are located near the Da Nang Agent Orange hot spot (the AO/Dioxin hot spot). The samples were then analyzed for PCDD/F residues in order to assess the human exposure to dioxins from the AO/Dioxin hot spot, especially health risk to the breast-fed infants. The average TEQ levels in the four studied cohorts ranged from 8.1 to 26 pg/g lipid, with the highest level up to 51 pg TEQ/g lipid found in the An Khe ward. The TEQ level was correlated with geographical position and ranking in the order of Khue Trung, Hoa Thuan Tay, Chinh Gian and An Khe. The mean estimated PCDD/Fs infant's daily intake in the cohort of Khue Trung, Hoa Thuan Tay, Chinh Gian and An Khe was about 41, 122, 124, and 134 pg TEQ/kg bw/day, respectively, which are much higher than the tolerable daily intake proposed by the World Health Organization (4 pg TEQ/kg bw/day).

Association of streptomycin resistance mutations with level of drug resistance and Mycobacterium tuberculosis genotypes.

OBJECTIVES: To determine 1) the relationship between specific streptomycin (SM) resistance mutations and the minimum inhibitory concentration (MIC), and 2) whether these mutations are preferentially associated with the Beijing genotype in Viet Nam. METHODS: A total of 131 consecutive Mycobacterium tuberculosis isolates resistant to either isoniazid (INH) or rifampicin (RMP), collected previously, were tested for SM resistance, spoligotyped and sequenced in the rpsL, rrs and gidB genes. The MIC for 50 mutants was also determined. RESULTS: Overall, 116/131 isolates were SM-resistant. The three most frequently occurring mutation sites in rpsL and rrs were at codon 43 of rpsL (72/116, 62.1%), rpsL88 (22/116, 18.9%) and rrs514 (8/116, 6.9%). Mutations in the rrs910 region were found in two isolates (1.7%), and three isolates had mutations in both rpsL and rrs (2.6%). gidB mutations were found in both resistant and susceptible strains. Among SM-resistant isolates resistant to INH/RMP, the Beijing genotype was strongly associated with rpsL43 mutation (aOR 23.6, 95%CI 2.9-193.4, P = 0.002). The median MIC for each mutation was as follows: rpsL43 = 256 µg/ml, rpsL88 = 16 µg/ml, 515 loop = 4 µg/ml, 910 region = 8 µg/ml, and double mutation = 256 µg/ml. We found a strong association between rpsL43 and high drug resistance levels, with all rpsL43 mutants having an MIC >256 µg/ml (P < 0.001).

Population dynamics of shrimps in littoral marine waters of the Mekong Delta, south of Viet Nam.

The population dynamics of eight commercial species of shrimp (Haliporoides sibogae, Harpiosquilla harpax, Metapenaeus affinis, Metapenaeus brevicornis, Metapenaeus tenuipes, Parapenaeopsis cultrirostris, Parapenaeopsis gracillima and Parapenaeus maxilipedo) distributed in littoral marine zone of the Mekong Delta were investigated. Length-based stock assessment using FiSAT II software package was used to assess the growth and mortality parameters: Asymptotic size (L8), growth coefficient (K), total (Z) and natural (M) mortality, exploitation rate (E), recruitment pattern, current probability of capture and selectivity of fishing gears. Yield-per-recruit analyses were carried out showing different levels of the exploitation. Results showed that the maximum sustainable yield would be reached for an exploitation rate higher than the current one for each population. However, the size of first capture should be increased for every population. The findings indicated that the current exploitations of shrimp populations distributed in littoral marine zone of the Mekong Delta are under exploitation level for maximum sustainable yield; however, all the shrimp populations are subject to growth over-exploitation.

Biology and population dynamics of the goby Pseudapocryptes elongatus in the coastal mud flat areas of the Mekong Delta, Vietnam.

This study describe the reproductive biological characteristics and population parameters of the goby, Pseudapocryptes elongatus (Cuvier, 1816), in the coastal mud flat areas of the Mekong Delta, Vietnam. A total of 1058 specimens was collected from January 2004 to June 2005 and results showed that the breeding season occurred with two spawning peaks in July and October. Length at first maturity (L(m)) was 15.4 and 16.3 cm for females and males, respectively. The batch fecundity estimates ranged from 2,652 to 29,406 hydrated oocytes per ovary in the fish ranging from 12.8 to 22.4 cm TL. Length frequency data of the goby ranging from 9.0 to 24.0 cm TL were analyzed using the FiSAT II software. The von Bertalanffy growth parameters were determined as L8 = 25.9 cm, K = 0.66 year(-1) and t(o) = - 0.26 year(-1). The longevity (t(max)) of the goby was estimated to be 4.55 years. There were two recruitment peaks with very different magnitudes and the means of these two peaks were separated by an interval of 5 months. Length at first capture (L(c)) was 10.05 cm, the instantaneous fishing mortality rate (F = 1.38 year(-1)) and natural mortality rate (M = 1.46 year(-1)) accounted for 49 and 51% of the total mortality (Z = 2.84 year(-1)), respectively. Relative yield-per-recruit and biomass-per-recruit analyses gave E(max) = 0.65, E0.1 = 0.55 and E0.5 = 0.33. Results show that the fish stock is subjected to growth overexploitation.

[Influence of chlormadinone acetate on hypothalamic differentiation in male rats]. / Einfluss von Chlormadinonazetat auf die Hypothalamusdifferenzierung männlicher Ratten.

PIP: The effect of chlormadinone acetate on adult male rats during the hypothalamic differentiation phase was studied. Psychic intersexuality with increased male and increased female sexual behavior was observed both before and after postpuberal castration and sex hormone replacement. Organ weights of testes, seminal vesicles, and ventral prostrates were normal, but penis and adrenal gland weights were significantly smaller. Body growth was also significantly reduced compared with control animals. The effects of chlormadinone acetate on androgen-dependent brain differentiation are discussed and compared with analogous effects of cyproterone acetate and orchidectomy.^ieng

Dioxin levels in adipose tissues of hospitalized women living in the south of Vietnam in 1984-89 with a brief review of their clinical histories.

Agent Orange, a phenoxyherbicide consisting of 50% 2,4-D and 50% 2,4,5-T, the latter contaminated in the parts per million range with the highly toxic dioxin, 2,3,7,8-TCDD, was sprayed in the south of Vietnam from 1962 to 1971. The chemicals are of concern because of their potential to be causally involved in cancer, adverse reproductive outcomes, immune deficiency and other illness. Because exposed women would be especially involved in the adverse reproductive outcomes, specifically spontaneous abortions and congenital malformations, as well as developmental deficiencies in children, we elected to conduct a pilot study in Vietnam to determine whether elevated 2,3,7,8-tetrachloro-p-dioxin-(TCDD), the dioxin characteristic of Agent Orange could still be found in some women between one and two decades after exposure, and whether the types of illness characteristic of dioxins was present in women with elevated dioxin levels. We were easily able to find some women with increased TCDD from Agent Orange, A surprisingly high level of dioxins from industrial sources was also found in these women in the south. Much lower levels of all dioxins were found in patients in the north of Vietnam. No obvious relation between elevated dioxins and disease was noted in this pilot study, which is meant to precede epidemiology studies which will test the hypotheses that elevated dioxins in humans may lead to an increase in adverse reproductive outcomes and in rates of certain cancers.