An isothermal CRISPR- based lateral flow assay for detection of Neisseria meningitidis.

BACKGROUND: Neisseria meningitidis can cause life-threatening meningococcal meningitis and meningococcemia. Old standard microbiological results from CSF/blood cultures are time consuming. This study aimed to combine the sensitivity of loop-mediated isothermal nucleic acid amplification (LAMP) with the specificity of CRISPR/Cas12a cleavage to demonstrate a reliable diagnostic assay for rapid detection of N. meningitidis. METHODS: A total of n = 139 samples were collected from patients with suspected meningococcal disease and were used for evaluation. The extracted DNA was subjected to qualitative real-time PCR, targeting capsular transporter gene (ctrA) of N. meningitidis. LAMP-specific primer pairs, also targeting the ctrA, were designed and the LAMP products were subjected to CRISPR/Cas12 cleavage reaction. the readout was on a lateral flow strip. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of LAMP-CRISPR/Cas was compared with real-time PCR assays. The limit of detection (LOD) was established with serial dilutions of the target N. meningitidis DNA and calculated by Probit regression analysis. RESULTS: Six LAMP assay-specific primers were developed targeting the ctrA gene of N. meningitidis, which is conserved in all meningococcal serogroups. The LAMP primers did not amplify DNA from other bacterial DNA tested, showing 100% specificity. The use of 0.4 M betaine increased the sensitivity and stability of the reaction. LAMP-CRISPR/Cas detected meningococcal serogroups (B, C, W). The assay showed no cross-reactivity and was specific for N. meningitidis. The LOD was 74 (95% CI: 47-311) N. meningitidis copies. The LAMP-CRISPR/Cas performed well compared to the gold standard. In the 139 samples from suspected patients, the sensitivity and specificity of the test were 91% and 99% respectively. CONCLUSION: This developed and optimized method can complement for the available gold standard for the timely diagnosis of meningococcal meningitis and meningococcemia.

Association between Bacteroides fragilis and Fusobacterium nucleatum infection and colorectal cancer in Vietnamese patients.

BACKGROUND: Colorectal cancer (CRC) is a significant global health concern, and understanding the role of specific bacterial infections in its development and progression is of increasing interest. This cross-sectional study investigated the associations between Bacteroides fragilis (B. fragilis) and Fusobacterium nucleatum (F. nucleatum) infections and Vietnamese CRC patients. METHODS: 192 patients with either polyps or CRC at varying stages were recruited from May 2017 to December 2020. Real-time PCR assessed infection rates and bacterial loads in CRC tissues. RESULTS: B. fragilis infection was notably higher in CRC tissues (51.6 %) than polyps (9.4 %), with a fivefold higher relative load. Positive associations were found in stages II and III, indicating a fivefold increase in CRC progression risk. F. nucleatum infection rates were significantly higher in CRC tissues (55.2 %) than in polyps (10.5 %). In stage II, the infection rate exceeded that in adjacent tissues. The relative load of F. nucleatum was higher in stage III than in stages I and II. Positive F. nucleatum patients had a 3.2 times higher risk of CRC progression. CONCLUSION: These findings suggest associations between loading of F. nucleatum or/and B. fragilis with the advanced stages of CRC.

Unfractionated heparin versus enoxaparin for venous thromboembolism prophylaxis in intensive care units: a propensity score adjusted analysis.

Venous thromboembolism (VTE) is a common complication in hospitalized patients. Pharmacologic prophylaxis is used in order to reduce the risk of VTE events. The main purpose of this study is to compare the prevalence of deep vein thrombosis (DVT) and pulmonary embolism (PE) in patients admitted to the intensive care unit (ICU) who received unfractionated heparin (UFH) versus enoxaparin as VTE prophylaxis. Mortality was evaluated as a secondary outcome. This was a Propensity Score Adjusted Analysis. Patients admitted to neurology, surgical, or medical ICUs and screened with venous doppler ultrasonography or computed tomography angiography for detection of VTE were included in the analysis. We identified 2228 patients in the cohort, 1836 (82.4%) patients received UFH and 392 (17.6%) patients received enoxaparin. Propensity score matching yielded a well-balanced cohort of 950 (74% UFH, 26% enoxaparin) patients. After matching, there was no difference in prevalence of DVT (RR 1.05; 95% CI 0.67-1.64, p = 0.85) and PE (RR 0.76; 95% CI, 0.44-1.30, p = 0.31). No significant differences in location and severity of DVT and PE between the two groups were detected. Hospital and intensive care unit stay was similar between the two groups. Unfractionated heparin was associated with a higher rate of mortality, (HR 2.04; 95% CI, 1.13-3.70; p = 0.019). The use of UFH as VTE prophylaxis in ICU patients was associated with a similar prevalence of DVT and PE compared with enoxaparin, and the site and degree of occlusion were similar. However, a higher mortality rate was seen in the UFH group.

Toxicity of ciprofloxacin and ofloxacin to Moina macrocopa and investigation of p-value adjustments for (eco)toxicological studies.

Ciprofloxacin (CFX) and ofloxacin (OFX) are commonly found as residual contaminants in aquatic environments, posing potential risks to various species. To ensure the safety of aquatic wildlife, it is essential to determine the toxicity of these antibiotics and establish appropriate concentration limits. Additionally, in (eco)toxicological studies, addressing the issue of multiple hypothesis testing through p-value adjustments is crucial for robust decision-making. In this study, we assessed the no observed adverse effect concentration (NOAEC) of CFX and OFX on Moina macrocopa across a concentration range of 0-400 µg L-1. Furthermore, we investigated multiple p-value adjustments to determine the NOAECs. Our analysis yielded consistent results across seven different p-value adjustments, indicating NOAECs of 100 µg CFX L-1 for age at first reproduction and 200 µg CFX L-1 for fertility. For OFX treatment, a NOAEC of 400 µg L-1 was observed for both biomarkers. However, further investigation is required to establish the NOAEC of OFX at higher concentrations with greater certainty. Our findings demonstrate that CFX exhibits higher toxicity compared to OFX, consistent with previous research. Moreover, this study highlights the differential performance of p-value adjustment methods in terms of maintaining statistical power while controlling the multiplicity problem, and their practical applicability. The study emphasizes the low NOAECs for these antibiotics in the zooplanktonic group, highlighting their significant risks to ecological and environmental safety. Additionally, our investigation of p-value adjustment approaches contributes to a deeper understanding of their performance characteristics, enabling (eco)toxicologists to select appropriate methods based on their specific needs and priorities.

Two-stage revision for treatment of tuberculous prosthetic hip infection: an outcome analysis.

OBJECTIVES: Prosthetic joint infections (PJI) and especially tuberculosis (TB) PJI are rare diseases and hard to cure. The effectiveness of treatments for tuberculous PJI still remains a problem. The objective of this research was to indicate the success of two-stage revision replacement and also giving the associated criteria. METHODS: From 2015 to 2020, five patients with tuberculous PJI were treated with two-stage revision at Cho Ray hospital, Vietnam. We collected the dataset which included demographic data, the interval from the time of joint replacement to reported infection, records of tuberculous PJI, administration of anti-TB medications (duration, months), history of operation(s), duration of follow-up, and specific type(s) of antibiotics loaded in bone cement. The approval for this study was made by the institutional review board from Cho Ray Hospital, Vietnam. We conducted a literature review based on the keywords "PJI" and "TB" on PubMed. RESULTS: Five patients [median age 66 years (range 35-84)] had found tuberculous PJI. The median time from arthroplasty to diagnosis was 19 months (range 4-48). The diagnosis was confirmed by joint aspirates or synovial tissue. Positive PCR was also reported in all cases. The average duration of anti-tuberculosis polytherapy administration was 14.4 months. The operative techniques on five patients included debridement and using spacer loaded with 2 g streptomycin (and 2 g vancomycin if they got a coinfection) for 1 pack of bone cement, and revision arthroplasty. In most cases, the outcome of treatment using two-stage revision replacement was 80%. Overall, the auxiliary bacterial infections were recognized in three patients with tuberculous PJI and Staphylococcus aureus. Streptomycin and vancomycin were loaded in a cement spacer to increase the success rate, and tuberculous PJI was controlled for all patients. CONCLUSION: Tuberculous PJI can be controlled with two-stage revision replacement with an antibiotic-loaded cement spacer that is molded intraoperatively with custom mold and prolonged anti-tuberculosis treatment in all cases. LEVEL OF EVIDENCE: IV.

CRISPR-Cas12a combination to alleviate the false-positive in loop-mediated isothermal amplification-based diagnosis of Neisseria meningitidis.

BACKGROUND: Loop isothermal amplification (LAMP) has recently been proposed as a point-of-care diagnostic tool to detect acute infectious pathogens; however, this technique embeds risk of generating false-positive results. Whereas, with abilities to accurately recognize specific sequence, the CRISPR/Cas12a can forms complexes with cognate RNA sensors and cleave pathogen's DNA targets complimerntary to its cognate RNA, afterward acquiring the collateral activity to unbiasedly cut nearby off-target fragments. Therefore, if relevant fluorescent-quencher-nucleic probes are present in the reaction, the non-specific cleavage of probes releases fluorescences and establish diagnostic read-outs. METHODS: The MetA gene of N. meningitidis was selected as target to optimize the LAMP reaction, whereas pseudo-dilution series of N. meningitidis gemonics DNA was used to establish the detection limit of LAMP/Cas12a combination assay. The diagnostic performance of established LAMP/Cas12a combination assay was validated in comparation with standard real-time PCR on 51 CSF samples (14 N. meningitidis confirmed patients and 37 control subjects). RESULTS: In relevant biochemical conditions, CRISPR-Cas12a and LAMP can work synchronously to accurately identify genetics materials of Nesseria menitigistis at the level 40 copies/reaction less than 2 h. CONCLUSIONS: In properly optimized conditions, the CRISPR-Cas12a system helps to alleviate false positive result hence enhancing the specificity of the LAMP assays.

Diagnosis of pathogens causing bacterial meningitis using Nanopore sequencing in a resource-limited setting.

AIM: The aim of the present study is to compare the performance of 16S rRNA Nanopore sequencing and conventional culture in detecting infectious pathogens in patients with suspected meningitis in a resource-limited setting without extensive bioinformatics expertise. METHODS: DNA was isolated from the cerebrospinal fluid (CSF) of 30 patients with suspected bacterial meningitis. The isolated DNA was subjected to 16S sequencing using MinION™. The data were analysed in real time via the EPI2ME cloud platform. The Nanopore sequencing was done in parallel to routine microbiological diagnostics. RESULTS: Nanopore sequencing detected bacterial pathogens to species level in 13 of 30 (43%) samples. CSF culture showed 40% (12/30) positivity. In 21 of 30 patients (70%) with suspected bacterial meningitis, both methods yielded concordant results. About nine of 30 samples showed discordant results, of these five were false positive and four were false negative. In five of the culture negative results, nanopore sequencing was able to detect pathogen genome, due to the higher sensitivity of the molecular diagnostics. In two other samples, the CSF culture revealed Cryptococcus neoformans and Streptococcus pneumoniae, which were not detected by Nanopore sequencing. Overall, using both the cultures and 16S Nanopore sequencing, positivity rate increased from 40% (12/30) to 57% (17/30). CONCLUSION: Next-generation sequencing could detect pathogens within six hours and could become an important tool for both pathogen screening and surveillance in low- and middle-income countries (LMICs) that do not have direct access to extensive bioinformatics expertise.

Design and Optimization for a New XYZ Micropositioner with Embedded Displacement Sensor for Biomaterial Sample Probing Application.

An XYZ compliant micropositioner has been widely mentioned in precision engineering, but the displacements in the X, Y, and Z directions are often not the same. In this study, a design and optimization for a new XYZ micropositioner are developed to obtain three same displacements in three axes. The proposed micropositioner is a planar mechanism whose advantage is a generation of three motions with only two actuators. In the design strategy, the proposed micropositioner is designed by a combination of a symmetrical four-lever displacement amplifier, a symmetrical parallel guiding mechanism, and a symmetrical parallel redirection mechanism. The Z-shaped hinges are used to gain motion in the Z-axis displacement. Four flexure right-circular hinges are combined with two rigid joints and two flexure leaf hinges to permit two large X-and-Y displacements. The symmetrical four-lever displacement amplifier is designed to increase the micropositioner's travel. The displacement sensor is built by embedding the strain gauges on the hinges of the micropositioner, which is developed to measure the travel of the micropositioner. The behaviors and performances of the micropositioner are modeled by using the Taguchi-based response surface methodology. Additionally, the geometrical factors of the XYZ micropositioner are optimized by teaching-learning-based optimization. The optimized design parameters are defined with an A of 0.9 mm, a B of 0.8 mm, a C of 0.57 mm, and a D of 0.7 mm. The safety factor gains 1.85, while the displacement achieves 515.7278 µm. The developed micropositioner is a potential option for biomedical sample testing in a nanoindentation system.

Molecular detection of blaCTX-M gene to predict phenotypic cephalosporin resistance and clinical outcome of Escherichia coli bloodstream infections in Vietnam.

BACKGROUND: Blood stream infections (BSI) caused by Extended Spectrum Beta-Lactamases (ESBLs) producing Enterobacteriaceae is a clinical challenge leading to high mortality, especially in developing countries. In this study, we sought to describe the epidemiology of ESBL-producing Escherichia coli strains isolated from Vietnamese individuals with BSI, to investigate the concordance of genotypic-phenotypic resistance, and clinical outcome of ESBL E. coli BSI. METHODS: A total of 459 hospitalized patients with BSI were screened between October 2014 and May 2016. 115 E. coli strains from 115 BSI patients were isolated and tested for antibiotic resistance using the VITEK®2 system. The ESBL phenotype was determined by double disk diffusion method following the guideline of Clinical and Laboratory Standards Institute. Screening for beta-lactamase (ESBL and carbapenemase) genes was performed using a multiplex-PCR assay. RESULTS: 58% (67/115) of the E. coli strains were ESBL-producers and all were susceptible to both imipenem and meropenem. Resistance to third-generation cephalosporin was common, 70% (81/115) were cefotaxime-resistant and 45% (52/115) were ceftazidime-resistant. blaCTX-M was the most common ESBL gene detected (70%; 80/115) The sensitivity and specificity of blaCTX-M-detection to predict the ESBL phenotype was 87% (76-93% 95% CI) and 54% (39-48% 95% CI), respectively. 28%% (22/80) of blaCTX-M were classified as non-ESBL producers by phenotypic testing for ESBL production. The detection of blaCTX-M in ESBL-negative E. coli BSI was associated with fatal clinical outcome (27%; 6/22 versus 8%; 2/26, p = 0.07). CONCLUSION: A high prevalence of ESBL-producing E. coli isolates harbouring blaCTX-M was observed in BSI patients in Vietnam. The genotypic detection of blaCTX-M may have added benefit in optimizing and guiding empirical antibiotic therapy of E. coli BSI to improve clinical outcome.

Upregulation of Enzymes involved in ISGylation and Ubiquitination in patients with hepatocellular carcinoma.

Background: ISGylation is the conjugation of ISG15 with target proteins. ISGylation occurs through an enzymatic cascade, which is similar to that of ubiquitination. Through ISGylation, ISG15 can bind to proteins involved in cell proliferation and differentiation, thus promoting genesis and progression of malignancies. The present study aims to investigate expression of genes involved in ISGylation and ubiquitination in patients with hepatocellular carcinoma and to correlate gene expression with clinical laboratory parameters of these patients. Methods: mRNA expression of genes encoding enzymes involved in the ISGylation process (EFP, HERC5, UBA1, UBC and USP18) was evaluated by quantitative real-time PCR in 38 pairs of tumour and adjacent non-tumour tissues from patients with hepatocellular carcinoma and correlated with distinct clinical laboratory parameters. Results: Relative mRNA expression of EFP, HERC5, UBA1 and USP18 was significantly higher in tumour tissues compared to adjacent non-tumour tissues (P=0.006; 0.012; 0.02 and 0.039, respectively). The correlation pattern of mRNA expression between genes in the tumours differed from the pattern in adjacent non-tumour tissues. Relative expression of EFP, HERC5 and UBA1 in adjacent non-tumour tissues was positively associated with direct bilirubin levels (Spearman's rho=0.31, 0.33 and 0.45; P=0.06, 0.05 and 0.01, respectively) and relative expression of USP18 in adjacent non-tumour tissues correlated negatively with ALT levels (Spearman's rho= -0.33, P=0.03). Conclusions: EFP, HERC5, UBA1, and USP18 genes are upregulated in tumour tissues of patients with HCC and, thus, may be associated with the pathogenesis of hepatocellular carcinoma.

Rapid, low cost and sensitive detection of Calreticulin mutations by a PCR based amplicon length differentiation assay for diagnosis of myeloproliferative neoplasms.

BACKGROUND: Calreticulin (CALR) gene mutations are currently recommended as biomarkers in diagnosis of patients with myeloproliferative neoplasms (MPN) with Jak2 V617F negative phenotype. Our aim was to establish a rapid, low cost and sensitive assay for identification of CALR gene mutations and to validate the diagnostic performance of the established assay in a patient cohort with different clinical MPN phenotypes. METHODS: One hundred five Philadelphia-negative MPN patients, including polycythemia vera (PV), essential thrombocythaemia (ET), and primary myelofibrosis (PMF) were initially screened for JAK2 mutations by amplification-refractory mutation system (ARMS-PCR) methodology and were further subjected to detection of CALR gene mutations by our in-house assay, a PCR based amplicon length differentiation assay (PCR-ALDA). The PCR-ALDA methodology was compared with real time PCR and Sanger sequencing methods. Furthermore, the analytical sensitivity of the assay was established. RESULTS: PCR - ALDA approach was able to detect and discriminate the pseudo-positive samples containing more than 1% CALR mutant alleles. CALR mutations were not detected in 63 Jak2 V617F positive cases in all three methods. In contrast, amongst 42 Jak2 V617F negative cases, both PCR-ALDA and Sanger sequencing coherently identified 12 CALR mutants compared to 10 CALR mutants detected by real-time PCR method. CONCLUSION: PCR-ALDA can be utilized as an easy-to-use, rapid, low cost and sensitive tool in the detection of CALR mutations in Philadelphia-negative MPN patients.

Soluble fibrinogen-like protein 2 levels in patients with hepatitis B virus-related liver diseases.

BACKGROUND: Clinical progression of HBV-related liver diseases is largely associated with the activity of HBV-specific T cells. Soluble fibrinogen-like protein 2 (sFGL2), mainly secreted by T cells, is an important effector molecule of the immune system. METHODS: sFGL2 levels were determined by ELISA assays in sera of 296 HBV patients clinically classified into the subgroups of acute hepatitis B (AHB), chronic hepatitis B (CHB), liver cirrhosis (LC), hepatocellular carcinoma (HCC) and patients with LC plus HCC. As control group, 158 healthy individuals were included. FGL2 mRNA was quantified by qRT-PCR in 32 pairs of tumor and adjacent non-tumor liver tissues. RESULTS: sFGL2 levels were elevated in HBV patients compared to healthy controls (P <  0.0001). In the patient group, sFGL2 levels were increased in AHB compared to CHB patients (P = 0.017). sFGL2 levels were higher in LC patients compared to those without LC (P = 0.006) and were increased according to the development of cirrhosis as staged by Child-Pugh scores (P = 0.024). Similarly, HCC patients had increased sFGL2 levels compared to CHB patients (P = 0.033) and FGL2 mRNA was up-regulated in tumor tissues compared to adjacent non-tumor tissues (P = 0.043). In addition, sFGL2 levels were positively correlated with HBV-DNA loads and AST (Spearman's rho = 0.21, 0.25 and P = 0.006, 0.023, respectively), but reversely correlated with platelet counts and albumin levels (Spearman's rho = - 0.27, - 0.24 and P = 0.014, 0.033, respectively). CONCLUSIONS: sFGL2 levels are induced by HBV infection and correlated with the progression and clinical outcome of HBV-related liver diseases. Thus, sFGL2 may serve as a potential indicator for HBV-related liver diseases.

Effects of nutrient ratios and carbon dioxide bio-sequestration on biomass growth of Chlorella sp. in bubble column photobioreactor.

Photobioreactor technology, especially bubble column configuration, employing microalgae cultivation (e.g., Chlorella sp.), is an ideal man-made environment to achieve sufficient microalgae biomass through its strictly operational control. Nutrients, typically N and P, are necessary elements in the cultivation process, which determine biomass yield and productivity. Specifically, N:P ratios have certain effects on microalgae's biomass growth. It is also attractive that microalgae can sequester CO2 by using that carbon source for photosynthesis and, subsequently, reducing CO2 emission. Therefore, this study aims to investigate the effect of N:P ratios on Chlorella sp.'s growth, and to study the dynamic of CO2 fixation in the bubble column photobioreactor. According to our results, N:P ratio of 15:1 could produce the highest biomass yield (3568 ±â€¯158 mg L-1). The maximum algae concentration was 105 × 106 cells mL-1, receiving after 92 h. Chlorella sp. was also able to sequester CO2 at 28 ±â€¯1.2%, while the specific growth rate and carbon fixation rate were observed at 0.064 h-1 and 68.9 ±â€¯1.91 mg L-1 h-1, respectively. The types of carbon sources (e.g., organic and inorganic carbon) possessed potential impact on microalgae's cultivation.

Differential release of manure-borne bioactive phosphorus forms to runoff and leachate under simulated rain.

Limited information exists on the unhindered release of bioactive phosphorus (P) from a manure layer to model the partitioning and transport of component P forms before they reach an underlying soil. Rain simulations were conducted to quantify effects of intensity (30, 60, and 90 mm h-1) on P release from an application of 60 Mg ha-1 of dairy manure. Runoff contained water-extractable- (WEP), exchangeable and enzyme-labile bioactive P (TBIOP), in contrast to the operationally defined "dissolved-reactive P" form. The released P concentrations and flow-weighed mass loads were described by the log-normal probability density function. At a reference condition of 30 mm h-1 and maintaining the surface at a 5% incline, runoff was minimal, and WEP accounted for 20.9% of leached total P (TP) concentrations, with an additional 25-30% as exchangeable and enzyme-labile bioactive P over the 1-h simulation. On a 20% incline, increased intensity accelerated occurrence of concentrationmax and shifted the skewed P concentration distribution more to the left. Differences in trends of WEP, TBIOP, or net enzyme-labile P (PHPo) cumulative mass released per unit mass of manure between intensities were attributable to the higher frequency of raindrops striking the manure layer, thus increasing detachment and load of colloidal PHPo of the water phases. Thus, detailed knowledge of manure physical characteristics, bioactive P distribution in relation to rain intensity, and attainment of steady-state of water fluxes were critical factors in improved prediction of partitioning and movement of manure-borne P under rainfall.

Enrichment of bacterial DNA for the diagnosis of blood stream infections.

BACKGROUND: Blood cultures are commonly employed to identify bacterial pathogens causing sepsis. PCR assays to diagnose septicemia require extraction of bacterial DNA from blood samples and thus, delay the initiation of appropriate antimicrobial treatment. The presence of abundant human DNA may hamper the sensitivity of PCR in the detection of bacteria. METHODS: We used serial dilutions of E. Coli spiked pseudo-blood-sepsis samples to develop a simple method that combines the use of a polar detergent solvent and adjustment of the basic pH to remove human DNA. A 16S rRNA gene-based screening algorithm was established to differentiate Gram-positive and Gram-negative groups of bacteria and the family of Enterobacteriaceae. A stringent validation with appropriate controls was implemented. The method of human DNA removal was then applied on 194 sepsis blood samples and 44 cerebrospinal fluid (CSF) samples by real-time PCR. RESULTS: This uncomplicated and straightforward approach allows to remove up to 98 % of human DNA from peripheral blood of septic patients. The inhibitory effect of human DNA is efficiently prevented and the detection limit of real-time PCR is increased to 10 E. Coli CFUs/ml. This sensitivity is 10 times higher compared to conventional real-time PCR assays. The classical blood culture detected 58/194 (30 %) of sepsis and 9/44 (21 %) of CSF samples. Out of the 194 blood samples tested, the conventional real-time PCR targeting 13 common sepsis causing pathogens correctly detected the bacterial DNA in 16/194 (8 %) only and 14/44 (32 %) in cerebrospinal fluid samples. Our newly established approach was able to provide correct diagnoses in 78 (40 %) of the 194 blood samples and in 14 (32 %) of the CSF samples. The combination of both blood cultures and our technique raised the rate of sepsis diagnoses to 112/194 (58 %). Of the total group tested positive, 46 (24 %) cases showed overlap with the classical methodology. CONCLUSION: We report a simple optimized in-house protocol for removal of human DNA from blood sepsis samples as a pre-analytical tool to prepare DNA for subsequent PCR assays. With the detection increase of our in-house DNA removal approach, subsequent PCR assays can reach detection limits of 10 E. coli CFUs/ml and significantly improve the diagnostic rate in blood sepsis cases.

Dynamics of cyanobacteria and cyanobacterial toxins and their correlation with environmental parameters in Tri An Reservoir, Vietnam.

This study evaluates the water quality from Tri An Reservoir, a drinking water supply for several million people in southern Vietnam, in terms of cyanobacterial biomass and their potent toxins, microcystins (MCs). Cyanobacteria, their toxins and environmental parameters were monitored monthly for 1 year (April 2008-March 2009) at six stations covering a transect through the reservoir. Dynamics of cyanobacterial abundance in relation to cyanobacterial biomass, toxins and environmental factors were investigated. Environmental variables from Tri An Reservoir favored algal and cyanobacterial development. However, cyanobacterial biomass and proportion varied widely, influenced by physical conditions, available nutrients and nutrient competition among the phytoplankton groups. Cyanobacterial biomass correlated slightly positively to temperature, pH and biochemical oxygen demand (BOD5), but negatively to total inorganic nitrogen concentrations. During most of the sampling times, MC concentrations in the reservoir were quite low (≤0.07 µg L(-1) MC-LR equivalent), and presented a slight positive correlation to BOD5, total nitrogen:total phosphorus ratio and cyanobacterial biomass. However, in cyanobacterial scum samples, which now and then occurred in the reservoir, MC concentrations reached up to 640 µg g(-1) DW(-1). The occurrence of MC in the reservoir poses a risk to local residents who use the water daily for domestic purposes.

Prevalence of Opisthorchis viverrini-Like Fluke Infection in Ducks in Binh Dinh Province, Central Vietnam.

Following the first report of Opisthorchis viverrini infection in a domestic duck in Phu My District of Binh Dinh Province, Central Vietnam, many other cases were observed in the province. We determined the infection rate and intensity of O. viverrini infection in ducks in 4 districts of the province. A total of 178 ducks were randomly selected from 34 farms for examination of flukes in the liver and gall bladder. An infection rate of 34.3% (range 20.7-40.4% among districts) was found; the intensity of infection was 13.8 worms per infected duck (range 1-100). These findings show the role of ducks as a host for O. viverrini, duck genotype, which is sympatric with the human O. viverrini genotype in this province. It also stresses the need for investigations on the zoonotic potential and the life cycle of this parasite.

Investigation of antibiotics in health care wastewater in Ho Chi Minh City, Vietnam.

Hospital wastewater contains huge amounts of hazardous pollutants which are being discharged daily to environment with or without treatment. Antibiotics were among the important group of pharmaceuticals considered as a potential source of health risk for human and other living creatures. Although the investigations about the existence of antibiotics in hospital wastewater have gained concern for researchers in many countries, there is only one research conducted in Hanoi-Vietnam. Hence, in this study, investigations have been done to fulfill the requirement of real situation in Vietnam by accomplishing survey for 39 health care facilities in Ho Chi Minh City. As results, seven popular antibiotics were detected to exist in all samples such as sulfamethoxazole (2.5 ± 1.9 µg/L), norfloxacin (9.6 ± 9.8 µg/L), ciprofloxacin (5.3 ± 4.8 µg/L), ofloxacin (10.9 ± 8.1 µg/L), erythromycin (1.2 ± 1.2 µg/L), tetracycline (0.1 ± 0.0 µg/L), and trimethoprim (1.0 ± 0.9 µg/L). On the other hand, survey also showed that only 64% of health care facilities using conventional activate sludge (AS) processes in wastewater treatment plants (WWTPs). As a consequence, basic environmental factors (BOD5, COD, TSS, NH4+-N, or total coliforms) were not effectively removed from the hospital wastewater due to problems relating to initial design or operational conditions. Therefore, 18% effluent samples of the surveyed WWTPs have exceeded the national standard limits (QCVN 28:2010, level B).