Quality and safety of South African hand sanitisers during the COVID-19 pandemic.

Health agencies recommend using hand sanitisers as protection against the coronavirus. Thus far, the emphasis on hand sanitiser studies is limited to an analysis of disinfectant content only. This study aims to provide an extended analysis of 60 off-the-shelf alcohol-based hand sanitisers by using gas chromatography to report on alcohol content and the presence of impurities, a recombinant yeast estrogen screen to assess estrogenic activity, and an investigation into labelling compliance with the South African National Standard. Fifty hand sanitisers had an alcohol content of ≥60% v/v alcohol; however, most contained skin irritants and substances that could harm human and environmental health. Estrogenic activity was detected in 29 hand sanitisers and none of the products complied with all the labelling requirements. Since off-the-shelf hand sanitisers in South Africa are not regulated and monitored, evidence-based public awareness programmes on hand sanitiser quality and safety should become a priority.

Efficiency of selected wastewater treatment processes in removing estrogen compounds and reducing estrogenic activity using the T47D-KBLUC reporter gene assay.

The occurrence of endocrine-disrupting compounds (EDCs) consisting of natural and synthetic estrogens, namely estrone (E1), 17ß-estradiol (E2), estriol (E3) and 17α-ethinylestradiol (EE2) was quantified in wastewater samples. The aim of this study was to assess the removal efficiency for the selected estrogens (E1, E2, E3 and EE2) and reduction of estrogenic activity in wastewater samples from wastewater treatment plants (WWTPs) using different processes. Solid-phase extraction (SPE) followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods were used to quantify the selected estrogens in wastewater samples. Estrogenic activity was assessed using the T47D-KBluc gene reporter assay. Results revealed a decrease in estrogen concentrations observed in the effluents of all the WWTPs, except for E2 at Daspoort where no removal was noted. In general, the highest removal for total estrogens was observed at Phola (84%) combining three processes (AP, BF and wetland). The AS at Daspoort had a highest removal of 75% for E3; while at Zeekoegat the highest removal reached 61% for EE2. The PST at Daspoort had no removal recorded for all the compounds, except for the EE2 (33%). The AP and BF systems at Phola contributed to a higher removal of selected compounds. Downstream of the wetland at Phola no removal was recorded for E3; while the highest removal reached 61% for E1. The best performance in terms of the overall influent-to-effluent removal efficiency was observed at Phola WWTP, where E1 removal of 85% was recorded. The highest estrogenic activity in the effluent was reported at Phola, with an average estradiol equivalent (EEQ) value of 6.3 ± 6.7 ng/L. However, no anti-estrogenic activity was detected in any of the samples. The daily mass load discharged from the effluent of the three WWTPs was higher for E1 recorded at Zeekoegat (8002.3 ± 6416.3 mg/d), followed by Daspoort (3509.8 ± 849.0 mg/d) and finally Phola (176.1 ± 34.9).

Saturating mutagenesis and characterization of a herpesvirus genome using in vivo reconstitution of virus from cloned subgenomic regions.

The study of genome structure and gene function is pivotal in understanding the mechanisms of replication, pathogenesis, and virulence of herpesviruses. In this respect, mutagenesis and sequence analysis of genes encoded by the virus are of great importance. However, the herpesvirus genomes are large, with sizes ranging between 120 and over 200 kbp and encoding between 70 and 200 genes (see ref. 1 for a review). This large size hampers handling and systematic mutagenesis of the virus genome using standard modern molecular biology techniques. Most current methods of mutagenesis therefore do not rely on direct modification of the viral genome in vitro but depend on exchange in vivo, by homologous recombination, of a viral gene by a copy of the latter gene that is truncated in vitro by insertion of a marker gene. Mutant virus progeny can be screened or selected for, depending on the marker gene that is used. Commonly used marker genes are thymidine kinase and lacZ. This procedure is generally used, reliable, and has yielded a wealth of information on the function of herpers simplex virus type 1 (HSV-1) encoded genes. However, it requires prior mapping and cloning of every gene to be mutagenized and is therefore less feasible if the virus is a novel or less-well-known herpesvirus.

Live attenuated pseudorabies virus expressing envelope glycoprotein E1 of hog cholera virus protects swine against both pseudorabies and hog cholera.

To investigate whether live attenuated pseudorabies virus (PRV) can be used as a vaccine vector, PRV recombinants that expressed envelope glycoprotein E1 of hog cholera virus (HCV) were generated. Pigs inoculated with these recombinants developed high levels of neutralizing antibodies against PRV and HCV and were protected against both pseudorabies and hog cholera (classical swine fever).

Identification of two genes in the unique short region of pseudorabies virus; comparison with herpes simplex virus and varicella-zoster virus.

We have determined the nucleotide sequence of two genes in the unique short region of the genome of pseudorabies virus (PRV). Near the internal repeat, upstream of the gene encoding glycoprotein gX, we identified an open reading frame (ORF) encoding a protein of 390 amino acids. We designated this gene PK because the predicted protein contains most of the conserved motifs of a eukaryotic protein kinase. The protein shares amino acid homology with the protein kinases encoded by gene US3 of herpes simplex virus type 1 (HSV-1) and gene 66 of varicella-zoster virus. Near the terminal repeat, downstream of a gene encoding an 11K protein, we identified an ORF encoding a protein of 256 amino acids. We designated this gene 28K, the Mr of the predicted protein. Part of the amino acid sequence of 28K is homologous to the predicted US2 protein of HSV-1. Northern blot analysis revealed a 2.7 kb mRNA encoding the putative protein kinase and a 1.2 kb mRNA encoding the 28K protein in PRV-infected cells. The 5' ends of the mRNAs were mapped by primer extension. Two transcriptional start sites were identified for the PK mRNA: a minor start site immediately upstream of the ORF and a major start site (greater than 95% of the mRNA) within the ORF, 64 nucleotides upstream of an internal ATG codon. A single transcriptional start site was identified for the 28K mRNA immediately upstream of the ORF. Immunoblot analysis with anti-peptide sera revealed that, in cells infected with PRV, the PK gene was translated into two proteins with Mrs of 53K and 41K, and the 28K gene into a single protein with an Mr of 28K.

Regeneration of herpesviruses from molecularly cloned subgenomic fragments.

The ability to manipulate the genomes of herpesviruses is of eminent importance for obtaining insight into gene function and regulation of gene expression of these complex viruses. Here we report the use of in vivo overlap recombination to generate pseudorabies virus mutants. Cotransfection of up to five overlapping cloned subgenomic fragments, which together constitute the entire genomic information of pseudorabies virus, results in the efficient reconstitution of virus. This allows the efficient introduction of multiple well-defined mutations in herpesvirus genomes in a single step, without any selection or screening for a particular phenotype.