The laboratory diagnosis of Syphilis

Syphilis is a multisystem infection caused by the spirochaete Treponema pallidum. Currently, cases of possible syphilis are commonly investigated using the treponemal serological tests T. pallidum IgG chemiluminescence immunoassay (CLIA) and the T. pallidum particle agglutination (TPPA). The non-treponemal rapid plasma reagin (RPR) flocculation test is used to assess disease activity. There has been a resurgence of syphilis diagnoses in Australia. Large foci of infection have been identified in isolated communities. The remoteness of these locations, in conjunction with the particular socio-cultural characteristics of the population, pose unique challenges to the traditional diagnostic and treatment paradigms for syphilis. As a consequence of this increased incidence of syphilis, there has been interest in the utility of point of care tests (POCT), nucleic acid amplification tests (NAAT), the role of IgM testing in suspected congenital syphilis, and the laboratory investigation of possible neurosyphilis. This review looks at the current status of traditional serological assays and provides an update on more recent methods. It assesses the published literature in this area and makes recommendations for the rational use of pathology testing to aid in the diagnosis of the many facets of syphilis.

Syphilitic Balanitis of Follmann: Laboratory Pitfalls

We report a case of early syphilis, presenting as balanitis and papular syphilides in an HIV-infected patient, with a previous history of syphilis infection, which demonstrated a false negative VDRL testing due to a prozone phenomenon. This false negative response results from overwhelming antibody titers, which interfere with the proper formation of the antigen-antibody lattice network, necessary to visualize a positive flocculation test.

Effect of Bactericides on Control of Acidification Pollution and Spontaneous Combustion of Coal Gangue Dumps in China and Its Mechanism

Oxidation of pyrite in the coal gangue dumps usually results in acidification and spontaneous combustion, causing many environmental problems such as air, soil, and water pollution. The oxidizing bacteria exacerbate problems such as acidification, spontaneous combustion, and explosions. The bacterium Acidithiobacillus ferrooxidans was first separated and isolated from coal gangue samples. Bactericides such as Triclosan, Kathon (isothiazolinones), and sodium dodecyl sulfate (SDS) were selected for our study. Our findings indicated that the addition of bactericide effectively inhibited the oxidation of Fe2+, preventing pH decreases and oxidation-reduction potential increases. We also investigated the bactericidal mechanisms employed by the three bactericides against A. ferrooxidans by conducting a protein flocculation test, scanning electron microscopy, and time-of-flight mass spectrometry. We found that the specific inhibitory activities of the three bactericides differed. Kathon treatment caused A. ferrooxidans to release small amounts of proteins and lipids. A. ferrooxidans treated with Triclosan released small amounts of lipids and large amounts of plasmas. SDS caused the bacteria to release a large amount of proteins and lipids and degraded the surface structure of the cells, resulting in altered cell morphology.

Removal of multiple heavy metal ions using a macromolecule chelating flocculant xanthated chitosan

In this paper, the removal performance and mechanism of xanthated chitosan (XCTS) towards heavy metal ions are investigated. XCTS possesses both strong chelating abilities and excellent flocculation properties, which can effectively remove several kinds of heavy metal ions, such as Cr3+, Cu2+, Mn2+, Ni2+, Pb2+ and Zn2+. It has a good potential for practical application. In a flocculation test of a mixed component solution, the removal rates of Cr3+, Cu2+ and Cd2+ reach 100%, 100% and 99.1%, respectively. The removal rates are significantly greater than that of a single component solution. It indicates that there is a synergistic effect between different metal ions. Moreover, the selectivity of XCTS for Cr3+ and Cu2+ is obviously superior to that for Cd2+; XCTS is easier to combine with the heavy metal ions belonging to hard acids.

Preparation and Investigation of Silver Nanoparticle–Antibody Bioconjugates for Electrochemical Immunoassay of Tick-Borne Encephalitis

A new simple electrochemical immunosensor approach for the determination of antibodies to tick-borne encephalitis virus (TBEV) in immunological products was developed and tested. The assay is performed by detecting the silver reduction signal in the bioconjugates with antibodies (Ab@AgNP). Here, signal is read by cathodic linear sweep voltammetry (CLSV) through the detection of silver chloride reduction on a gold–carbon composite electrode (GCCE). Covalent immobilization of the antigen on the electrode surface was performed after thiolation and glutarization of the GCCE. Specific attention has been paid to the selection of conditions for stabilizing both the silver nanoparticles and their Ab@AgNP. A simple flocculation test with NaCl was used to select the concentration of antibodies, and the additional stabilizer bovine serum albumin (BSA) was used for Ab@AgNP preparation. The antibodies to TBEV were quantified in the range from 50 IU·mL−1 to 1600 IU·mL−1, with a detection limit of 50 IU·mL−1. The coefficient of determination (r2) is 0.989. The electrochemical immunosensor was successfully applied to check the quality of immunological products containing IgG antibodies to TBEV. The present work paves the path for a novel method for monitoring TBEV in biological fluids.

Coagulant dose as an operating parameter in a solid contact clarifier

The objective of this study was to determine the applicability of the laboratory flocculation test (Jar Test) for a solid contact clarifier. Cohesivity, a parameter characterizing the sludge blanket can be established by determining the Sludge Cohesion Coefficient (SCC) by conducting a Sludge Cohesion Test (SCT). A series of laboratory tests were performed using the Jar Test and SCT. Considering the large number of variable parameters involved with natural raw water, sludge samples were prepared using synthetic raw water with varying turbidity and coagulant dose combinations. A comparison was made between the optimum coagulant dose obtained using the two tests. Highest SCC observed at the optimum coagulant dose was within the range of 0.6–3.3 m/hr. Low SCC values indicate a light and fragile sludge blanket whereas high SCC values indicate a quick settling consistent blanket. With increasing raw water turbidity, the optimum coagulant dose given by SCT is lower than that of the Jar Test. Hence, at higher raw water turbidity occurrences, it may be possible to operate the upward flow solid contact clarifiers with lower coagulant dose. A significant quadratic relationship is observed between the optimum coagulation doses with R2 = 0.9 and α < 0.05.

An Effective Flocculation Method to the Kaolin Wastewater Treatment by a Cationic Polyacrylamide (CPAM): Preparation, Characterization, and Flocculation Performance

P(AM-DMC) (PAD) was synthesized by ultraviolet- (UV-) initiated copolymerization with methacryloxyethyl trimethyl ammonium chloride (DMC) and acrylamide (AM) as the monomers and initiator 2,2-azobis [2-(2-imidazolin-2-yl) propane] dihydrochloride (VA-044) as the photoinitiator. Parameters that affect the molecular weight were reviewed by using the single-factor approach. The results showed that the molecular weight (MW) of PAD could come to 7.88 × 106 Da with the optimum polymerization conditions as follows: monomer concentration of 30%, monomer mass ratio m(AM) : m(DMC) of 3 : 1, initiator concentration of 0.6‰, illumination time of 80 min, solution pH value of 4.5, and incident light intensity of 1000 μW cm−2. The PAD was represented by several instruments. The results of FTIR and 1H NMR showed that PAD was indeed polymerized by AM and DMC. The results of TGA showed that PAD was very stable at room temperature while the result of SEM revealed that PAD had a porous structure and rough surface. For PAD used as flocculant in kaolin wastewater treatment, the results confirmed that, at optimal conditions, the turbidity and the floc size d50 could reach to 5.9 NTU and 565.936 μm, respectively, at the optimal conditions (pH = 7.0 and dosage = 2 mg l−1). Kaolin wastewater flocculation test outcome reveals that the PAD with high cationic degree and intrinsic viscosity could boost the charge neutralization and bridging capability. Consequently, the result is an excellent flocculation performance of treating kaolin wastewater.