Rickettsia africae and other unclassified Rickettsia species of the spotted fever group in ticks of the Western Ghats, India.

The spotted fever group (SFG) of Rickettsia are zoonotic disease-causing pathogens, commonly transmitted by hard ticks to a wide range of hosts, including humans. Rickettsia conorii is the common SFG recognised in India, whereas most of the infections due to other group species go undifferentiated at the species level. Hence, this study was conducted to screen host-seeking ticks in the Western Ghats region, India, for the DNA of SFG Rickettsia. The ticks were collected from Kerala, Goa, and Maharashtra states of India during a survey conducted between November 2017 and January 2018. In total, 288 tick pools were screened for Rickettsia spp. DNA using pan-Rickettsia real-time PCR, and conventional PCR targeting the gltA, OmpA and 17-kDa protein-coding genes. Nucleotide sequences were subjected to phylogenetic analysis using the NCBI BLAST tool to identify submitted sequences with higher homology. Neighbour-joining trees were constructed using the reference sequences of the GenBank database. Overall, Rickettsia spp. DNA was detected in 27.2% (62/228 pools) of host-seeking ticks across the Western Ghats region, with an estimated minimum infection rate of 0.057. Upon phylogenetic analysis, it was identified that the detected sequences were highly similar (> 99% sequence homology) to R. africae, Candidatus R. laoensis and an un-categorised Rickettsia species, and they were widely carried by Haemaphysalis ticks. The current study is the first report of R. africae and Candidatus R. laoensis in ticks in India. Although the pathogenicity of these species is not well documented, they may pose a potential threat to both animal and the human population in this geographical region.

Salivary microRNA profiling dysregulation in autism spectrum disorder: A pilot study.

Introduction: Autism spectrum disorders (ASD) are the most prevalent neurobiological disorders in children. The etiology comprises genetic, epigenetic, and environmental factors such as dysfunction of the immune system. Epigenetic mechanisms are mainly represented by DNA methylation, histone modifications, and microRNAs (miRNA). The major explored epigenetic mechanism is mediated by miRNAs which target genes known to be involved in ASD pathogenesis. Salivary poly-omic RNA measurements have been associated with ASD and are helpful to differentiate ASD endophenotypes. This study aims to comprehensively examine miRNA expression in children with ASD and to reveal potential biomarkers and possible disease mechanisms so that they can be used to improve faction between individuals by promoting more personalized therapeutic approaches. Materials and methods: Saliva samples were collected from 10 subjects: 5 samples of children with ASD and 5 from healthy controls. miRNAs were analyzed using an Illumina Next-Generation-Sequencing (NGS) system. Results: Preliminary data highlighted the presence of 365 differentially expressed miRNAs. Pathway analysis, molecular function, biological processes, and target genes of 41 dysregulated miRNAs were assessed, of which 20 were upregulated, and 21 were downregulated in children with ASD compared to healthy controls. Conclusion: The results of this study represent preliminary but promising data, as the identified miRNA pathways could represent useful biomarkers for the early non-invasive diagnosis of ASD.

Protective Effect of Resveratrol against Hypoxia-Induced Neural Oxidative Stress.

Oxidative stress plays an important role in brain aging and in neurodegenerative diseases. New therapeutic agents are necessary to cross the blood-brain barrier and target disease pathogenesis without causing disagreeable side effects. Resveratrol (RSV) may act as a neuroprotective compound, but little is known about its potential in improving the cognitive and metabolic aspects that are associated with neurodegenerative diseases. The objective of this study was to investigate the protective effects and the underlying mechanisms of RSV against hypoxia-induced oxidative stress in neuronal PC12 cells. For the induction of the hypoxia model, the cells were exposed to oxygen-deprived gas in a hypoxic chamber. Cell cycle and apoptosis were analyzed by a fluorescence activated cell sorting (FACS) analysis. The intracellular reactive oxygen species (ROS) level was analyzed by using dichlorodihydrofluorescein diacetate (DCFDA) and 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester (CM-H2DCFDA) tests. The expression of activated caspase-3, -9, Bcl-2, Bax, p53, and SOD was investigated by a Western blot analysis. We found that hypoxia reduced PC12 viability by inducing apoptosis, while RSV treatment attenuated the ROS-induced damage by reducing caspase-3, -9, and the Bax/Bcl-2 ratio. The RSV treated groups were found to improve cellular health, with a 7.41% increase in the S phase population in the 10 µM group, compared to the control. Hence, RSV has a protective effect in neuronal cells and may halt the cell cycle in the G1/S phase to repair the intracellular damage. Therefore, RSV could be a good candidate to act as an antioxidant and promising preventive therapeutic agent in neurodegenerative diseases for personalized medicine.

Pandemic COVID-19, an update of current status and new therapeutic strategies.

The global COVID-19 pandemic is underway. In recent weeks, several countries throughout the globe, and particularly in Europe, have experienced an exponential increase in the number of individuals infected with COVID-19, probably induced by a new variant of SARS-CoV-2, called the "Omicron variant." Mass vaccination against COVID-19 continues worldwide. Are authorized mRNA vaccines effective against the new Omicron variant? Recently, several pharmaceutical companies have developed oral antiviral pills against SARS-CoV-2, i.e., molnupiravir and paxlovid, that inhibit SARS-CoV-2 viral replication by acting on the RNA polymerase of SARS-CoV. In pre-registration clinical trials, molnupiravir and paxlovid have shown excellent clinical efficacy results, but what impact will these new oral antiviral agents have against pandemic COVID-19? In what specific clinical situations are they preferred over other antivirals such as remdesivir? In this brief review, we explore these important aspects.

Advances in the Omicron variant development.

Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 has spread worldwide, leading the World Health Organization (WHO) to declare a pandemic, on 11 March 2020. Variants of concern have appeared at regular intervals-Alpha, Beta, Gamma, Delta, and now Omicron. Omicron variant, first identified in Botswana in November 2021, is rapidly becoming the dominant circulating variant. In this review, we provide an overview regarding the molecular profile of the Omicron variant, epidemiology, transmissibility, the impact on vaccines, as well as vaccine escape, and finally, we report the pharmacological agents able to block the endocellular entry of SARS-CoV-2 or to inhibit its viral replication. The Omicron has more than 50 mutations, of which the spike protein has 26-35 amino acids different from the original SARS-CoV-2 virus or the Delta, some of which are associated with humoral immune escape potential and greater transmissibility. Omicron has a significant growth advantage over Delta, leading to rapid spread with higher incidence levels. The disease so far has been mild compared to the Delta. The two vaccination doses offer little or no protection against Omicron infection while the booster doses provide significant protection against mild illness and likely offer even greater levels of protection against serious illness. Recently, new oral antiviral agents such as molnupiravir and paxlovid have been approved and represent important therapeutic alternatives to antiviral remdesivir. In addition, monoclonal antibodies such as casirivimab/imdevimab bind different epitopes of the spike protein receptor; is this class of drugs effective against the Omicron variant? However, more research is needed to define whether Omicron is indeed more infectious and whether the vaccines, monoclonal antibodies, and antivirals currently available are effective.

Spatial distribution of Haemaphysalis species ticks and human Kyasanur Forest Disease cases along the Western Ghats of India, 2017-2018.

Kyasanur Forest Disease (KFD) is a viral haemorrhagic fever, transmitted to humans and other hosts by a tick vector of genus Haemaphysalis. It affects 400-500 people annually in the Western Ghats region of India through spring to summer season. To understand the species composition, distribution, and abundance of Haemaphysalis ticks in endemic taluks (sub-districts) of India, a surveillance for ticks was conducted between October 2017 and January 2018. In total 105 sites were selected based on grid sampling from five taluks representing five KFD endemic states in south India. A sum of 8373 ticks were collected by using standard flagging method. The study showed a wide distribution of host seeking tick species among the selected taluks, wherein Haemaphysalis spinigera was predominant in 3/5 taluks, Haemaphysalis bispinosa in 1/5 taluks, and both the species in 1/5 taluks. Further, the H. spinigera abundance was categorised and compared with the incidence of human cases during the same season. The grids with very high and high H. spinigera abundance had 70% of the 205 human cases reported. This method of tick surveillance could be efficiently used as a standard model for KFD transmission risk assessment and prediction of impending outbreaks.

HSV susceptibility to acyclovir - genotypic and phenotypic characterization.

BACKGROUND: Infections due to drug-resistant herpes simplex viruses (HSV) represent an important clinical concern, especially in immunocompromised patients. The present study was aimed at detecting acyclovir (ACV) susceptibility in HSV clinical samples. METHODS: A total of 13 HSV-positive clinical samples (5 HSV-1 and 8 HSV-2) recovered from patients (1 immunocompromised and 12 of unknown immune status) were included in the study. The genotypic analysis involved an initial UL23 (thymidine kinase) gene sequencing, followed by a confirmatory phenotypic assay using plaque reduction technique. RESULTS: Two novel amino acid changes, A37V and H283N, were detected in HSV-1 positive clinical samples, which were found to be susceptible to acyclovir (half maximal effective concentration = 1.5 µM) by plaque reduction assay. CONCLUSIONS: These two novel amino acid changes could be therefore considered as natural polymorphisms, a phenomenon widely associated with the HSV-UL23 gene.