The aim of this study was to determine the frequency of biocide resistant genes, qacA, qacE and cepA in multidrug resistant (MDR) bacteria: Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii and to correlate the presence or absence of resistant genes with biocides susceptibility. The study included 44 MDR K. pneumoniae, P. aeruginosa and A. baumannii microorganisms. The bacteria were screened for the presence of biocide resistant genes by the polymerase chain reaction (PCR) method. The test organisms were isolated from various clinical specimens in the Qassim region, Saudi Arabia. The in vitro susceptibility tests of the three biocides (benzalkonium chloride, cetrimide and chlorhexidine gluconate) were studied against the test isolates by broth microdilution method following Clinical and Laboratory Standards Institute guidelines. With the distribution of biocide resistant genes in K. pneumoniae, all 9 isolates (100%) possessed cepA; 4 (44.4%) and 1 (11.1%) isolate contained qacA and qacE genes respectively. Among 24 isolates of A. baumannii tested, cepA, qacA and qacE genes were found in 54.2%, 16.7% and 33.3% of isolates respectively. Among 11 P. aeruginosa isolates, 63.6% contained cepA gene, 18.2% contained qacE genes, and none of the isolates harboured qacA gene. There was no significant correlation between presence or absence of biocide resistant genes and high MIC values of the test isolates (p≥0.2). Our observations imply that there was no significant correlation between presence or absence of biocide resistant genes and MICs observed in MDR K. pneumoniae, P. aeruginosa and A. baumannii. Further studies are required to find to confirm the trend of reduced susceptibility to biocides of problematic nosocomial pathogens.

Background: Human papillomavirus (HPV), one of the most frequently transmitted viruses, causes several malignancies, including cervical cancer. Aim: Owing to its unique pathogenicity, the HPV virus can persist in the host organism for a longer duration than other viruses to complete its lifecycle. During its association with the host, HPV causes various pathological conditions affecting the immune system by evading the host's immune mechanisms, thereby leading to the progression of various diseases, including cancer. Method: To date, ~ 150 serotypes have been identified, and certain high-risk HPV types are known to be associated with genital warts and cervical cancer. As of now, two prophylactic vaccines are in use for the treatment of HPV infection; however, no effective antiviral drug is available for HPVassociated disease/infections. Numerous clinical and laboratory studies have been conducted to formulate an effective and specific vaccine against HPV infections and associated diseases. Result: As the immunological basis of HPV infection and associated disease progress persist indistinctly, deeper insights into immune evasion mechanism and molecular biology of disease would aid in developing an effective vaccine. Conclusion: Thus, this systematic review focuses on the immunological aspects of HPV-associated cervical cancer by uncovering immune evasion strategies adapted by HPV.

SARS-CoV-2 encodes eight accessory proteins, one of which, ORF8, has a poorly conserved sequence with SARS-CoV and its role in viral pathogenicity has recently been identified. ORF8 in SARS-CoV-2 has a unique functional feature that allows it to form a dimer structure linked by a disulfide bridge between Cys20 and Cys20 (S-S). This study provides structural characterization of natural mutant variants as well as the identification of potential drug candidates capable of binding directly to the interchain disulfide bridge. The lead compounds reported in this work have a tendency to settle in the dimeric interfaces by direct interaction with the disulfide bridge. These molecules may disturb the dimer formation and may have an inhibition impact on its potential functional role in host immune evasion and virulence pathogenicity. This work provides detailed insights on the sequence and structural variability through computational mutational studies, as well as potent drug candidates with the ability to interrupt the intermolecular disulfide bridge formed between Cys20 and Cys20. Furthermore, the interactions of ORF8 peptides complexed with MHC-1 is studied, and the binding mode reveals that certain ORF8 peptides bind to MHC-1 in a manner similar to other viral peptides. Overall, this study is a narrative of various computational approaches used to provide detailed structural insights into SARS-CoV-2 ORF8 interchain disulfide bond disruptors.

The present study was conducted to isolate and identify the Acanthamoeba species from various water sources such as drinking water, tap water, swimming pool, and other recreational water. During the study period, 57 water samples were collected from various sources such as tap water, drinking water, swimming pool, and recreational water. All samples were processed and cultured on non-nutrient agar medium (NNA) with Escherichia coli overlay for the isolation of Acanthamoeba species. Organism identified based on the microscopic morphology of cyst and trophozoites forms. The pathogenicity of Acanthamoeba was analyzed by thermotolerance and osmotolerance assays. Acanthamoeba were detected in 10 out of 57 (17.5%) examined water samples. The high percentage of positivity was observed in bore well water stored in tanks (37.5%) and in recreational water samples (26.7%). All processed drinking water samples were free from Acanthamoeba. Based on pathogenicity test assays, four (40%) were pathogenic and three (30%) were non-pathogenic. The observed frequency of Acanthamoeba spp. was compared with available literature worldwide. This study is the first report showing the distribution of Acanthamoeba in various water sources in the central region of Saudi Arabia and confirms that the high percentage presence of pathogenic strains in recreational water could threat contact lens wearers. Further research works are required to identify the prevalence of pathogenic Acanthamoeba from various water sources in Saudi Arabia.

The impact of sandstorm dust events affects local air quality and public health. These issues are becoming of greater concern in Saudi Arabia. There is a significant lack of research on airborne endotoxin exposure and analysis in the Middle East countries and no coherent body of research exists focusing on sandstorm dust in worldwide. In this study, we used a novel design of an aluminum foil plate (AFP) electrostatic dust cloth (EDC) for the passive air sampling of sandstorm dust. A total of 38 sandstorm dust samples were collected during sandstorm episodes occurring between January and April 2020 in both indoor (7 days, n = 20) and outdoor environments (24 h, n = 18). After exposure, and following an extraction procedure, bacterial endotoxin levels were measured using the Limulus Amoebocyte Lysate (LAL) gel clot method. The study highlights that the airborne endotoxin level observed was between 10 and 200 EU/m2 in both indoor and outdoor environments, during a sandstorm event. Agricultural activities and farmhouses observed higher airborne endotoxin levels. In general, increased endotoxin levels were related to the severity of the sandstorms. Given that the observed values were high as per existing guidelines for respiratory health, we recommend the setting an occupational airborne exposure limit for bacterial endotoxin. This is the first report and further studies across various sandstorm-hit regions will need to be undertaken, together with various sampling methods, in order to assess for seasonal and geographic trends.