FIB Concentrations Research Articles

Fibrinogen function indexes are potential biomarkers for evaluating the occurrence and severity of diabetic foot

Background and objectivesResearch suggests that fibrinogen (Fib) concentrations are used to assess the occurrence and severity of diabetic foot (DF) and to monitor the progression of diabetic foot in patients. However, its correlation with Fib function has not been reported. Here, angle α and k value, reflecting the Fib function, were used to analyse its correlation with DF, and their potential as biological indicators for evaluating the occurrence and severity of DF was explored.Subjects and methodsThis clinical study enrolled 163 type 2 diabetes mellitus (T2DM) patients, who were divided into the diabetes with DF (84 cases) group, diabetes with no DF (79 cases) group. Meanwhile, 90 healthy unrelated subjects were enrolled as controls.ResultsAngle α and fibrinogen levels increased greatly in subjects with DF compared with those without. The k value levels greatly decreased in subjects with DF compared with those without (P < 0.01). Spearman correlation analysis showed that angle α and fibrinogen were positively correlated with DF grading (r = 0.635, P < 0.01; r = 0.616, P < 0.01), k value was negatively correlated with DF (r= − 0.589, P < 0.01). ROC curve analysis showed that the optimal cut-off point for angle α to distinguish patients with DF from those without was 62.85 deg, with a sensitivity of 78.6% and specificity of 78.7%. The optimal cut-off point for k value was 1.75 min, with a sensitivity of 82.1% and specificity of 65.8%. The optimal cut-off point for fibrinogen was 3.85 g/l, with a sensitivity of 63.1% and specificity of 98.2%. The optimal cut-off point for angle α to evaluate the risk of diabetic foot progression was 70.20 deg, with a sensitivity of 73.2% and specificity of 90.7%. The optimal cut-off point for k value was 1.25 min, with a sensitivity of 67.9% and specificity of 90.8%. The optimal cut-off point for fibrinogen was 4.12 g/l, with a sensitivity of 85.7% and specificity of 93.5%.ConclusionAngle α, k-value and fibrinogen have clinical significance on the risk of occurrence and development of diabetic foot, which can contribute to early diagnosis and early clinical intervention in DF.

Fibrinogen function indexes are potential biomarkers of diabetic peripheral neuropathy

Background and objectivesResearch suggests that diabetic peripheral neuropathy (DPN) is related to plasma fibrinogen (Fib) concentrations, although its correlation with Fib function has not been reported. Here, the k value and angle α, reflecting the plasma Fib function, were used to analyse its correlation with DPN, and their potential as biological indicators for diagnosing DPN was explored.Subjects and methodsThis prospective observational clinical study enrolled 561 type 2 diabetes mellitus (T2DM) patients, who were divided into the diabetes with symptomatic neuropathy (161 cases), diabetes with asymptomatic neuropathy (132 cases) and diabetes with no neuropathy (268 cases) groups. Meanwhile, 160 healthy unrelated subjects were recruited as controls.ResultsFib levels increased slightly in diabetic subjects with neuropathy compared with those without. The angle α levels increased slightly in subjects with asymptomatic DPN compared with those with no neuropathy and increased greatly in subjects with symptomatic DPN compared with those without. The k value levels slightly decreased in subjects with asymptomatic DPN compared with those with no neuropathy and greatly decreased in subjects with symptomatic DPN compared with those without. The association of the k value and angle α with diabetic neuropathy was independent of the hyperglycaemic state and other potential confounders (odds ratio 0.080 [0.051–0.124], P < 0.001; odds ratio 1.131 [1.063–1.204], P < 0.001). The k value and angle α levels were closely correlated with neuropathy stage (r = − 0.686, P < 0.000; r = 0.314, P < 0.001). The optimal cut-off point for k value levels to distinguish patients with diabetic neuropathy from those without was 1.8 min, with a sensitivity of 73.7% and a specificity of 83.2% (AUC = 0.873). The optimal cut-off point for angle α levels was 60°, with a sensitivity of 41.0% and a specificity of 95.6% (AUC = 0.669).ConclusionsThe k value and angle α are closely associated with DPN. The levels of the k value and angle α may be helpful in the early diagnosis of DPN.

Cancer-elicited inflammation attenuates response and outcome in tyrosine kinase inhibitor naive patients with advanced NSCLC

ObjectiveCancer elicited inflammation is the main environmental cause leading to carcinogenesis and metastasis of non-small cell lung cancer (NSCLC). Roles of the inflammatory biomarker in predicting the clinical efficacy of tyrosine kinase inhibitor (TKI) and prognosis of naive patients with advanced NSCLC need to be determined, and the best inflammatory predicted biomarker remains unknown. MethodsA total of 178 eligible advanced NSCLC patients (124 and 54 cases within discovery and validation cohorts, respectively) who received first-line EGFR-TKI between July of 2014 and October of 2020 were enrolled in the present study. We detected circulating immune cell counting, albumin (Alb), pre-albumin (pAlb), ALP, AST, LDH, GGT, HDL-c, and fibrinogen (Fib) concentrations, and calculated 22 inflammatory ratios and scores. Logistic regression and Cox proportional hazards models were used to assess the impact of these ratios and scores on objective response and disease control rate (ORR and DCR) as well as progression-free survival (PFS) in these patients. ResultsTwenty-five percentage and 24.07% of NSCLC patients were observed objective response to the treatment of first-line EGFR-TKI in discovery and validation cohort, respectively. Univariate and multivariate Cox regression showed that high PLR, NPS, SII, SIS, mSIS, GLR and FPR as well as low PNI were significantly associated with poor PFS in discovery cohort. However, only high SII and FPR were found to be associated with unsatisfactory outcome in validation cohort. Time-dependent areas under ROC of FPR were 0.702 (0.517–0.888) in discovery cohort, and 0.767 (0.613–0.921) in validation cohort, which were extremely higher than the other biomarkers. The patients with FPR-SII combined score 2 harbored worse prognosis compared to the combined score 0 in discovery (plog-rank = 0.003, adjusted HR = 2.888, 95%CI = 1.500–5.560) and validation cohort (plog-rank = 0.001, adjusted HR = 3.769, 95%CI = 1.676–8.478) as well as overall population (plog-rank < 0.001, adjusted HR = 3.109, 95%CI = 1.878–5.147), and its time-dependent AUCs were 0.747 (0.594–0.900) and 0.815 (0.688–0.942) in the two cohorts, respectively, which were significantly higher than the single biomarker in the two cohorts. The patients with high FPR and FPR-SII score harbored worse DCR than the low patients in the two cohorts and overall population, respectively. Moreover, the similar poor survival was observed in advanced high-FPR NSCLC patients with different treatment options, however, the survival of low-FPR patients with treatment of single TKI, radiotherapy or chemotherapy or radio-chemotherapy combined TKI was good compared to the high-FPR patients with radio-chemotherapy combined TKI, and the survival differences were observed between TKI (plog-rank < 0.001) or radiotherapy combined TKI (plog-rank = 0.014) treated low-FPR patients and the high FPR patients. Additionally, FPR-SII combined score could monitor the progression of the disease in real-time, and the median month of the positive score appearance was significantly earlier than CT/MRI detection (p < 0.001 for 3 months vs. 13 months). ConclusionsHigh-grade cancer elicited inflammation could attenuates response and outcome in tyrosine kinase inhibitor naive patients with advanced NSCLC. FPR-SII combined score was the best inflammatory biomarker to monitor and predict the progression of advanced NSCLC patients with treatment of TKI.

Integrating culture and molecular quantification of microbial contaminants into a predictive modeling framework in a low-lying, tidally-influenced coastal watershed

Examinations of stormwater delivery in the context of tidal inundation are lacking. Along the coastal plains of the southeastern United States, tidal inundation is increasing in frequency and severity, often with dramatic adverse impacts on timely stormwater discharge, coastal flooding hazards, and even “sunny day flooding”. Therefore, a comprehensive study was conducted to examine tidally-influenced stormwater outfalls discharging to Taylor's Creek, an estuary proximal to Beaufort, NC used regularly for recreation and tourism. Over a wide range of meteorological conditions, water samples were collected and analyzed for fecal indicator bacteria (FIB, used for water quality management) and previously published quantitative microbial source tracking (qMST) markers. Nineteen sampling events were conducted from July 2017–June 2018 with samples classified according to tidal state and defined as either inundated, receding, or transition. A first-of-its-kind multiple linear regression model was developed to predict concentrations of Enterococcus sp. by tidal cycle, salinity and antecedent rainfall. We demonstrated that the majority of variability associated with the concentration of Enterococcus sp. could be predicted by E. coli concentration and tidal phase. FIB concentrations were significantly (<0.05) influenced by tide with higher concentrations observed in samples collected during receding (low) tides (EC: log 3.12 MPN/100 mL; ENT: 2.67 MPN/100 mL) compared to those collected during inundated (high) (EC: log 2.62 MPN/100 mL; ENT: 2.11 MPN/100 mL) or transition (EC: log 2.74 MPN/100 mL; ENT: 2.53 MPN/100 mL) tidal periods. Salinity, was also found to significantly (<0.05) correlate with Enterococcus sp. concentrations during inundated (high) tidal conditions (sal: 17 ppt; ENT: 2.04 MPN/100 mL). Tide, not precipitation, was shown to be a significant driver in explaining the variability in Enterococcus sp. concentrations. Precipitation has previously been shown to be a driver of Enterococcus sp. concentrations, but our project demonstrates the need for tidal parameters to be included in the future development of water quality monitoring programs.

Urban inputs of fecal bacteria to the coastal zone of Libreville, Gabon, Central Western Africa

Libreville, the largest city in Gabon, adversely impacts the Komo Estuary and the Akanda National Park aquatic ecosystems through discharge of domestic and industrial waste. Fecal Indicator Bacteria (FIB: Escherichia coli and fecal streptococci) were enumerated using culture-based methods in water from 40 sites between 2017 and 2019 including coastal outlets, mangrove channels, open bays and littoral rivers. Contamination levels were high in discharge waters from small urban rivers in Libreville agglomeration, frequently exceeding international safety guidelines, whereas FIB concentrations decreased downstream from the city in main mangrove channels. Littoral forest rivers were significantly impacted by fecal contamination despite the absence of settlements in the watersheds. Protected areas are not effective in avoiding FIB contamination, indicating inefficient waste management. Dedicated management policies should be implemented to reduce both the sanitary concern and global pollution, poorly assessed in a context of demographic increase in tropical littoral zones.

Highly Sensitive Electrochemical Impedance- Based Biosensor for Label-Free and Wide Range Detection of Fibrinogen Using Hydrothermally Grown AlFeO3 Nanospheres Modified Electrode

We report an ultra-selective biosensor for detection of fibrinogen (fib) using AlFeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> nanospheres modified screen-printed carbon electrode (AFO/SPCE) via electrochemical impedance spectroscopy (EIS). The orthorhombic phase and nanospheres-like morphology of hydrothermally grown AlFeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> are confirmed via X-Ray diffraction (XRD) and scanning electron microscopy (SEM) imaging, respectively. The sensor exhibits excellent selectivity, sensitivity and low limit of detection (LOD) of 14 ng mL <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> with a wide dynamic range from 3 μg mL <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> to 340 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> μg mL <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> which is more suitable for detecting both the deficiency and excess level of fib in the human blood. The decrease in charge transfer resistance (Rct) with an increase in fib concentrations can be attributed to the strong interaction and electrooxidation of fib molecules forming protein carbonyl groups at the surface of the electrode with enhanced electrical conductivity. This is a report on the low-cost, simple electrochemical impedance sensor using perovskite AlFeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> for reliable and rapid sensing of fib which shows great potential for developing biosensors for healthcare.

Changes of acute-phase proteins during different physiological conditions in dairy Saanen goats

A wide range of physiologic and metabolic changes occur during late pregnancy to parturition and lactation because of increased fetal growth and colostrum and milk production. This study was aimed to investigate the changes of acute-phase proteins (APPs) during important physiological condition (late pregnancy and early lactation) in dairy Saanen goats. Twenty clinically healthy Saanen does with an age of 3 ± 0.5 years were used for the study. They were randomly selected from a larger herd according to singleton pregnancy. Samples were collected from jugular vein at three different physiological times which included T1, non-pregnancy non-lactation (before pregnancy); T2, late pregnancy (4-month pregnancy); and T3, early lactation (1 month after parturition). The assessment of the serum concentrations of haptoglobin (Hp), serum amyloid A (SAA), ceruloplasmin (Cp), and plasma fibrinogen (Fib) were measured. The serum concentrations of Hp at T1 were significantly lower than T2 (P < 0.001) and also at T2 significantly lower than T3 (P < 0.01). The Cp levels were significantly higher at T2 compared with other times of sampling (P < 0.05). There were no significant differences in SAA and Fib concentrations at different times of study. The determination of changes in serum concentrations of APPs can be helpful in monitoring animal health, finding the causes of physiological stress, and making a differential diagnosis from the pathological conditions.

Quantitative PCR Detection of Enteric Viruses in Wastewater and Environmental Water Sources by the Lisbon Municipality: A Case Study

Current regulations and legislation require critical revision to determine safety for alternative water sources and water reuse as part of the solution to global water crisis. In order to fulfill those demands, Lisbon municipality decided to start water reuse as part of a sustainable hydric resources management, and there was a need to confirm safety and safeguard for public health for its use in this context. For this purpose, a study was designed that included a total of 88 samples collected from drinking, superficial, underground water, and wastewater at three different treatment stages. Quantitative Polimerase Chain Reaction (PCR) detection (qPCR) of enteric viruses Norovirus (NoV) genogroups I (GI) and II (GII) and Hepatitis A (HepA) was performed, and also FIB (E. coli, enterococci and fecal coliforms) concentrations were assessed. HepA virus was only detected in one untreated influent sample, whereas NoV GI/ NoV GI were detected in untreated wastewater (100/100%), secondary treated effluent (47/73%), and tertiary treated effluent (33/20%). Our study proposes that NoV GI and GII should be further studied to provide the support that they may be suitable indicators for water quality monitoring targeting wastewater treatment efficiency, regardless of the level of treatment.

Implementation of an automated beach water quality nowcast system at ten California oceanic beaches

Fecal indicator bacteria like Escherichia coli and entercococci are monitored at beaches around the world to reduce incidence of recreational waterborne illness. Measurements are usually made weekly, but FIB concentrations can exhibit extreme variability, fluctuating at shorter periods. The result is that water quality has likely changed by the time data are provided to beachgoers. Here, we present an automated water quality prediction system (called the nowcast system) that is capable of providing daily predictions of water quality for numerous beaches. We created nowcast models for 10 California beaches using weather, oceanographic, and other environmental variables as input to tuned regression models to predict if FIB concentrations were above single sample water quality standards. Rainfall was used as a variable in nearly every model. The models were calibrated and validated using historical data. Subsequently, models were implemented during the 2017 swim season in collaboration with local beach managers. During the 2017 swim season, the median sensitivity of the nowcast models was 0.5 compared to 0 for the current method of using day-to-week old measurements to make beach posting decisions. Model specificity was also high (median of 0.87). During the implementation phase, nowcast models provided an average of 140 additional days per beach of updated water quality information to managers when water quality measurements were not made. The work presented herein emphasizes that a one-size-fits all approach to nowcast modeling, even when beaches are in close proximity, is infeasible. Flexibility in modeling approaches and adaptive responses to modeling and data challenges are required when implementing nowcast models for beach management.

Experimental Theileria lestoquardi infection in sheep: Biochemical and hematological changes

Malignant theileriosis (Theileria lestoquardi infection) is a hemoparasitic tick-borne disease that affects both wild and domestic small ruminants. The aim of this study was to evaluate biochemical and hematological characteristics of sheep after being experimentally infected by T. lestoquardi. T. lestoquardi infection was induced in seven Baluchi sheep of six-to-eight months old via experimentally-infected Hyalomma anatolicum adult ticks. Biochemical and hematological parameters were measured twice a week during the three weeks’ post infection. Twenty-three biochemical analytes and seven hematological ones were measured. After three to four days infection, body temperature rose above 40°C. Maximum and minimum parasitaemia were 3.3% and 0.28%, respectively. Piroplasms and schizont were seen on average from days 7.2 and 4 post infection, respectively. The concentrations and activities of Alb, HDL, ALT, T3, T4, Ca, Fe, Mg, iP, WBC, RBC, PCV, Hb, Plt, neutrophil and lymphocytes significantly decreased (P≤0.05) during experimental infection. However, concentrations and activities of BT, GGT, Glu, BUN, Crea, FIB and Cu significantly increased (P≤0.05). There was no significant change in the serum amounts of Chol, LDL, TG, VLDL and Zn. The observed hypoalbuminemia and increase of FIB concentrations referred to pro-inflammatory cytokines production. Moreover, the raising of GGT activity indicates liver damage, cholestatic disorders or schizont infiltration. The disease stress and corticosteroids are suspected to cause the Glu concentration increase. The present study is aimed at improving the knowledge of malignant theileriosis.

Head-to-head comparison of statins versus fibrates in reducing plasma fibrinogen concentrations: A systematic review and meta-analysis

BackgroundSeveral studies suggest differences between fibrates and statins in lowering plasma fibrinogen (Fib) concentrations, but the evidence is not definitive. Therefore, the aim of this meta-analysis of head-to-head randomized trials was to compare the efficacy of statins and fibrates on plasma Fib concentrations. MethodsThe literature search included Medline, Scopus, and Web of Science up to February 1st, 2015, to identify head-to-head comparative randomized trials investigating the efficacy of fibrates vs statins on plasma Fib concentrations. ResultsIn total 22 trials with 2762 participants were included to the meta-analysis. Random-effect meta-analysis suggested a significantly greater effect of fibrates vs statins in lowering plasma Fib concentrations (weighted mean difference [WMD]: −40.7mg/dL, 95% confidence interval [CI]: −55.2, −26.3, p<0.001). When the analysis was stratified according to the type of fibrate administered, there were significant Fib-lowering effects with both bezafibrate (n=8 treatment arms; WMD: −23.7mg/dL, 95% CI: −41.8, −5.7, p=0.01) and fenofibrate (n=15 treatment arms; WMD: −43.7mg/dL, 95% CI: −61.3, −26.2, p<0.001). Overall, there was a numerically greater effect in the subgroup of trials with ≥12 weeks duration (n=17 treatment arms; WMD: −42.7mg/dL, 95% CI: −60.3, −25.1, p<0.001) compared with the subgroup of trials lasting <12 weeks (n=7 treatment arms; WMD: −36.7mg/dL, 95% CI: −52.0, −21.4, p<0.001). ConclusionsMonotherapy with either fibrates or statins suggested a significantly greater effect of fibrates in lowering plasma Fib concentrations. According to these findings, mechanisms associated with fibrinogen metabolism might be responsible for the distinct effects of statins and fibrates in reducing cardiovascular endpoints.

Hemostatic analysis of dogs naturally envenomed by the African puffadder (Bitis arietans) and snouted cobra (Naja annulifera).

To investigate hemostatic changes in dogs envenomed by cytotoxic (African puffadder) and neurotoxic snakes (snouted cobra) using thromboelastography (TEG) and plasma-based coagulation assays. Prospective observational clinical study. University teaching hospital. Eighteen client-owned dogs; 9 envenomed by African puffadder (Bitis arietans) and 9 by snouted cobra (Naja annulifera). Ten healthy dogs served as controls. None. Blood was collected at presentation and 24 hours post envenomation. Platelet count, TEG, prothrombin time, activated partial thromboplastin time (aPTT), antithrombin activity, and fibrinogen (Fib) and C-reactive protein (CRP) concentrations were measured. Outcomes were analyzed using linear mixed models at 5% significance. At presentation, R time was significantly prolonged in the puffadder group compared to the cobra (P = 0.01) and control groups (P = 0.05). Platelet count was significantly lower in the puffadder compared to the cobra (P = 0.04) and control groups (P = 0.001), respectively. Antithrombin activity was significantly decreased in the puffadder (P = 0.002) and cobra groups (P = 0.004) compared to the control group. Both prothrombin time and activated partial thromboplastin time were significantly prolonged in the cobra group compared to the control group (P = 0.03 for both). The TEG variables, maximum amplitude (MA) and G, were significantly increased 24 hours post envenomation in the puffadder group compared to their values at presentation (P = 0.05 for both). Fib and CRP concentrations were significantly increased 24 hours post envenomation in both snake-envenomed groups. Prolonged clot initiation was a common feature in puffadder-envenomed dogs at presentation and this was likely venom induced. Snouted cobra-envenomed dogs were normo- to hypercoagulable at presentation. Dogs from both puffadder and cobra groups progressed to a more hypercoagulable by 24 hours post envenomation, most likely due to marked inflammation as indicated by the increased Fib and CRP concentrations. TEG proved a sensitive tool for detecting abnormal hemostasis in snake-envenomed dogs.

Influence of the uterine inflammatory response after insemination with frozen–thawed semen on serum concentrations of acute phase proteins in mares

The aim of this study was to investigate the clinical relevance of measuring blood concentrations of serum amyloid A (SAA), haptoglobin (Hp) and fibrinogen (Fib) in horse reproductive management, and changes in response to artificial insemination (AI) with frozen–thawed semen. Standardbred mares (n=18) with different reproductive status (eight healthy mares in first postpartum oestrus, five healthy barren mares and five mares with endometritis) were inseminated with frozen–thawed semen. Endometritis was evaluated during oestrus by bacteriological culture, cytology and presence of ultrasonically visible intrauterine fluid during oestrus. Concentrations of SAA, Hp and Fib were analysed in the blood in every 48h during oestrus and until 5, 6 or 7 days after AI. The day of sampling and number of blood samples varied between mares because of length of the oestrus and time of AI. Changes in concentrations of SAA, Hp and Fib were evaluated based on the day of sampling regard to AI and classification of the mares. There were no differences in SAA, Hp and Fib concentrations over time before or after AI or between the groups of mares. The insemination of mares with frozen–thawed semen did not increase the plasma concentrations of SAA, Hp and Fib above clinical threshold concentration and there were no differences between susceptible or healthy mares.

Water Quality Conditions Associated with Cattle Grazing and Recreation on National Forest Lands

There is substantial concern that microbial and nutrient pollution by cattle on public lands degrades water quality, threatening human and ecological health. Given the importance of clean water on multiple-use landscapes, additional research is required to document and examine potential water quality issues across common resource use activities. During the 2011 grazing-recreation season, we conducted a cross sectional survey of water quality conditions associated with cattle grazing and/or recreation on 12 public lands grazing allotments in California. Our specific study objectives were to 1) quantify fecal indicator bacteria (FIB; fecal coliform and E. coli), total nitrogen, nitrate, ammonium, total phosphorus, and soluble-reactive phosphorus concentrations in surface waters; 2) compare results to a) water quality regulatory benchmarks, b) recommended maximum nutrient concentrations, and c) estimates of nutrient background concentrations; and 3) examine relationships between water quality, environmental conditions, cattle grazing, and recreation. Nutrient concentrations observed throughout the grazing-recreation season were at least one order of magnitude below levels of ecological concern, and were similar to U.S. Environmental Protection Agency (USEPA) estimates for background water quality conditions in the region. The relative percentage of FIB regulatory benchmark exceedances widely varied under individual regional and national water quality standards. Relative to USEPA’s national E. coli FIB benchmarks–the most contemporary and relevant standards for this study–over 90% of the 743 samples collected were below recommended criteria values. FIB concentrations were significantly greater when stream flow was low or stagnant, water was turbid, and when cattle were actively observed at sampling. Recreation sites had the lowest mean FIB, total nitrogen, and soluble-reactive phosphorus concentrations, and there were no significant differences in FIB and nutrient concentrations between key grazing areas and non-concentrated use areas. Our results suggest cattle grazing, recreation, and provisioning of clean water can be compatible goals across these national forest lands.

Microbiological quality assessment of sand and water from three selected beaches of South Coast, São Paulo State, Brazil

This study aimed to assess the sanitary quality of water, and wet and dry sand from three beaches located in the South Coast region of São Paulo State, Brazil, selected taking into account the frequency of tourists and the water quality (good, fair and poor). Thirty-six water samples each of wet and dry sand and seawater were collected monthly over a period of one year and analyzed for fecal indicator bacteria (FIB: thermotolerant coliforms, Escherichia coli, and enterococci), presumptive Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and dermatophytes. The results revealed FIB concentrations more elevated in dry sand followed by wet sand and water. P. aeruginosa and presumptive S. aureus were detected with a similar frequency in water and sand samples, but maximum concentrations and geometric means were higher in dry sand. C. albicans was detected only in water samples whereas the dermatophyte Microsporum sp. was isolated exclusively from dry and wet sand samples. This evaluation showed also that the environment had a significant influence on P. aeruginosa but not on presumptive S. aureus concentrations. According to threshold values proposed in the literature for E. coli and enterococci dry sand densities, none of the beaches would be considered of sufficient quality for recreational activities.

An assessment of fecal indicator and other bacteria from an urbanized coastal lagoon in the City of Los Angeles, California, USA

A study was performed in Del Rey Lagoon, City of Los Angeles, to determine if the lagoon was as a source or sink for fecal indicator bacteria (FIB: total coliforms, Escherichia coli, enterococci) and to screen for the presence of other potentially pathogenic bacteria. The lagoon receives tidal flows from the adjacent Ballona Estuary whose water usually is contaminated with FIB originating from the highly urbanized Ballona Creek Watershed. During 16 sampling events from February 2008 through March 2009, replicate water samples (n = 3) were collected 1h prior to the high tide and 1h prior to the following low tide. FIB concentrations were measured by the defined substrate method (IDEXX, Westbrook, Me) followed by culturing of bacterial isolates sampled from positive IDEXX Quanti-Tray wells and were identified using the Vitek 2 Compact (bioMérieux, Durham, NC). Mean concentrations of FIB often differed by an order of magnitude from flood to ebb flow conditions. The lagoon tended to act as a sink for total coliforms based on the ratio of mean flood to ebb densities (R (F/E)) >1.0 during 56% of the sampling events and during ebb flows, as a source for E. coli and enterococci (R (F/E) <1.69% of events). Approximately 54 species were identified from 277 isolates cultured from the IDEXX Quanti-Trays. Of these, 54% were species known to include pathogenic strains that can be naturally occurring, introduced in runoff, or originated from other sources. Diversity and cluster analyses indicated a dynamic assemblage that changes in species composition with day-to-day fluctuations as well as tidal action. The concept of monitoring the lagoon and estuary as a sentinel habitat for pathogenic assemblages is discussed.

Addressing uncertainty in fecal indicator bacteria dark inactivation rates

Assessing the potential threat of fecal contamination in surface water often depends on model forecasts which assume that fecal indicator bacteria (FIB, a proxy for the concentration of pathogens found in fecal contamination from warm-blooded animals) are lost or removed from the water column at a certain rate (often referred to as an “inactivation” rate). In efforts to reduce human health risks in these water bodies, regulators enforce limits on easily-measured FIB concentrations, commonly reported as most probable number (MPN) and colony forming unit (CFU) values. Accurate assessment of the potential threat of fecal contamination, therefore, depends on propagating uncertainty surrounding “true” FIB concentrations into MPN and CFU values, inactivation rates, model forecasts, and management decisions. Here, we explore how empirical relationships between FIB inactivation rates and extrinsic factors might vary depending on how uncertainty in MPN values is expressed. Using water samples collected from the Neuse River Estuary (NRE) in eastern North Carolina, we compare Escherichia coli (EC) and Enterococcus (ENT) dark inactivation rates derived from two statistical models of first-order loss; a conventional model employing ordinary least-squares (OLS) regression with MPN values, and a novel Bayesian model utilizing the pattern of positive wells in an IDEXX Quanti-Tray®/2000 test. While our results suggest that EC dark inactivation rates tend to decrease as initial EC concentrations decrease and that ENT dark inactivation rates are relatively consistent across different ENT concentrations, we find these relationships depend upon model selection and model calibration procedures. We also find that our proposed Bayesian model provides a more defensible approach to quantifying uncertainty in microbiological assessments of water quality than the conventional MPN-based model, and that our proposed model represents a new strategy for developing robust relationships between environmental factors and FIB inactivation rates, and for reducing uncertainty in water resource management decisions.

Sources of Nutrients and Fecal Indicator Bacteria to Nearshore Waters on the North Shore of Kaua`i (Hawai`i, USA)

Water quality monitoring in Hanalei Bay, Kaua`i (Hawai`i, USA) has documented intermittent high concentrations of nutrients (nitrate, phosphate, silica, and ammonium) and fecal indicator bacteria (FIB, i.e., enterococci and Escherichia coli) in nearshore waters and spurred concern that contaminated groundwater might be discharging into the bay. The present study sought to identify and track sources of nutrients and FIB to four beaches in Hanalei Bay and one beach outside the bay, together representing a wide range of land uses. 223Ra and 224Ra activity, salinity, nutrient and FIB concentrations were measured in samples from the coastal aquifer, the nearshore ocean, springs, the Hanalei River, and smaller streams. In addition, FIB concentrations in beach sands were measured at each site, and the enterococcal surface protein (esp) gene assay was used to investigate whether the observed FIB originated from a human source. Nutrient concentrations in groundwater were significantly higher than in nearshore water, inversely correlated to salinity, and highly site specific, indicating local controls on groundwater quality. Fluxes of groundwater into Hanalei Bay were calculated using a mass-balance approach and represented at least 2–10% of river discharges. However, submarine groundwater discharge (SGD) may provide 2.7 times as much nitrate + nitrite to Hanalei Bay as does the Hanalei River. It may also provide significant fluxes of phosphate and ammonium, comprising 15% and 20% of Hanalei River inputs, respectively. SGD-derived silica inputs to the bay comprised less than 3% of Hanalei River inputs. FIB concentrations in groundwater were typically lower than those in nearshore water, suggesting that significant FIB inputs from SGD are unlikely. Positive esp gene assays suggested that some enterococci in environmental samples were of human fecal origin. Identifying how nutrients and FIB enter nearshore waters will help environmental managers address pressing water quality issues, including exceedances of the state Enterococcus water quality standard and nutrient loading to coral reefs.

Effect of Antihypertensive Treatment on PlasmaFibrinogen and Serum HDL Levelsin Patients with Essential Hypertension

The influence of hypertension, and its treatment, on circulating lipid and fibrinogen (Fib) concentrations in patients with essential hypertension was investigated. The lipid profile and Fib levels were measured in 353 patients (131 men) with essential hypertension. Their median age was 60 years (range: 18-85 years). All patients had normal results from liver, renal, and thyroid function tests. There were 162 patients (45.9%) who were not receiving antihypertensive treatment. Of the remaining patients, 117 were taking 'lipid-hostile' beta-blockers, thiazide diuretics) antihypertensives and 74 were taking 'lipid-neutral' (angiotensin-converting enzyme inhibitors, calcium channel blockers, angiotensin-II receptor blockers) agents. Patients who were taking 'lipid-hostile' antihypertensive drugs had significantly higher plasma Fib concentrations when compared with those taking 'lipid-neutral' antihypertensives or those not receiving antihypertensive treatment. These differences were not attributable to established factors that influence plasma Fib levels, since when smokers and patients with diabetes mellitus and/or vascular disease were excluded, the difference remained significant. In addition, in these more homogeneous groups, patients receiving 'lipid-neutral' treatment had significantly higher serum high-density lipoprotein (HDL) cholesterol levels when compared with both those taking 'lipid-hostile' antihypertensives and untreated ones. There were no significant differences in the other lipid variables, independently of the presence/absence or the type of antihypertensives. These results suggest that antihypertensive drugs have additional effects, beyond lowering blood pressure, on other vascular risk factors, like Fib and HDL. These effects may depend on the type of drug used.