Potential Mechanisms of Transmission of Tick-Borne Viruses at the Virus-Tick Interface.

Ticks (Acari; Ixodidae) are the second most important vector for transmission of pathogens to humans, livestock, and wildlife. Ticks as vectors for viruses have been reported many times over the last 100 years. Tick-borne viruses (TBVs) belong to two orders (Bunyavirales and Mononegavirales) containing nine families (Bunyaviridae, Rhabdoviridae, Asfarviridae, Orthomyxovirida, Reoviridae, Flaviviridae, Phenuviridae, Nyamiviridae, and Nairoviridae). Among these TBVs, some are very pathogenic, causing huge mortality, and hence, deserve to be covered under the umbrella of one health. About 38 viral species are being transmitted by <10% of the tick species of the families Ixodidae and Argasidae. All TBVs are RNA viruses except for the African swine fever virus from the family Asfarviridae. Tick-borne viral diseases have also been classified as an emerging threat to public health and animals, especially in resource-poor communities of the developing world. Tick-host interaction plays an important role in the successful transmission of pathogens. The ticks' salivary glands are the main cellular machinery involved in the uptake, settlement, and multiplication of viruses, which are required for successful transmission into the final host. Furthermore, tick saliva also participates as an augmenting tool during the physiological process of transmission. Tick saliva is an important key element in the successful transmission of pathogens and contains different antimicrobial proteins, e.g., defensin, serine, proteases, and cement protein, which are key players in tick-virus interaction. While tick-virus interaction is a crucial factor in the propagation of tick-borne viral diseases, other factors (physiological, immunological, and gut flora) are also involved. Some immunological factors, e.g., toll-like receptors, scavenger receptors, Janus-kinase (JAK-STAT) pathway, and immunodeficiency (IMD) pathway are involved in tick-virus interaction by helping in virus assembly and acting to increase transmission. Ticks also harbor some endogenous viruses as internal microbial faunas, which also play a significant role in tick-virus interaction. Studies focusing on tick saliva and its role in pathogen transmission, tick feeding, and control of ticks using functional genomics all point toward solutions to this emerging threat. Information regarding tick-virus interaction is somewhat lacking; however, this information is necessary for a complete understanding of transmission TBVs and their persistence in nature. This review encompasses insight into the ecology and vectorial capacity of tick vectors, as well as our current understanding of the predisposing, enabling, precipitating, and reinforcing factors that influence TBV epidemics. The review explores the cellular, biochemical, and immunological tools which ensure and augment successful evading of the ticks' defense systems and transmission of the viruses to the final hosts at the virus-vector interface. The role of functional genomics, proteomics, and metabolomics in profiling tick-virus interaction is also discussed. This review is an initial attempt to comprehensively elaborate on the epidemiological determinants of TBVs with a focus on intra-vector physiological processes involved in the successful execution of the docking, uptake, settlement, replication, and transmission processes of arboviruses. This adds valuable data to the existing bank of knowledge for global stakeholders, policymakers, and the scientific community working to devise appropriate strategies to control ticks and TBVs.

Type I IFNs: A Blessing in Disguise or Partner in Crime in MERS-CoV-, SARS-CoV-, and SARS-CoV-2-Induced Pathology and Potential Use of Type I IFNs in Synergism with IFN-γ as a Novel Antiviral Approach Against COVID-19.

Since the end of 2019, the emergence of novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has accelerated the research on host immune responses toward the coronaviruses. When there is no approved drug or vaccine to use against these culprits, host immunity is the major strategy to fight such infections. Type I interferons are an integral part of the host innate immune system and define one of the first lines of innate immune defense against viral infections. The in vitro antiviral role of type I IFNs against Middle East respiratory syndrome coronavirus (MERS-CoV) and SARS-CoV (severe acute respiratory syndrome coronavirus) is well established. Moreover, the involvement of type I IFNs in disease pathology has also been reported. In this study, we have reviewed the protective and the immunopathogenic role of type I IFNs in the pathogenesis of MERS-CoV, SARS-CoV, and SARS-CoV-2. This review will also enlighten the potential implications of type I IFNs for the treatment of COVID-19 when used in combination with IFN-γ.

Comparative Study of Protection against Newcastle Disease in Young Broilers Administered Natural Chicken Alpha Interferon via Oral and Intramuscular Routes.

Despite extensive vaccination approaches, Newcastle disease (ND) remains a permanent threat to the poultry industry worldwide. Besides vaccination, there is a burgeoning demand for new antivirals for use in interventions to control ND. One strategy is to strengthen the host innate immunity via host-derived innate immune proteins. Type I interferons define one of the first lines of innate immune defense against viral infections. Chicken interferon alpha (chIFN-α) is one of the potent cytokines that trigger antiviral responses. In the current study, we investigated the therapeutic effect of natural chIFN-α administered via oral and intramuscular (i.m.) routes against ND in broiler chickens. Our results showed that the level of protection against ND in response to chIFN-α therapy was dependent on the route and dose of IFN administration. A better therapeutic effect was observed in chickens treated with chIFN-α via the oral route than in those treated via the i.m. route. Regardless of the administration route, double-dose chIFN-α (2,000-U) treatments provided better protection than single-dose (1,000-U) treatments. However, complete protection against ND was achieved in birds treated with repeated doses of chIFN-α via the oral route. Histopathology of trachea, proventriculus, spleen, and liver showed a significant improvement in ND-induced degenerative changes in double-dose IFN-treatment groups compared to single-dose groups. Results of the hemagglutination test demonstrated a decrease in ND virus (NDV) titer in IFN-treated groups. Also, double doses of chIFN-α via oral route resulted in early recovery in weight gain. We propose that chIFN-α therapy via oral route could be an important therapeutic tool to control NDV infection in chicken.IMPORTANCE Newcastle disease (ND) is an economically important contagious disease of wild and domestic birds worldwide. The disease causes severe economic losses in terms of production due to high mortality and morbidity in nonvaccinated chickens. Despite extensive vaccination approaches, Newcastle disease (ND) remains a permanent threat to the poultry industry worldwide. In the current study, we used natural chicken IFN-α as an innate immune modulator to counteract ND in chickens. We report that chIFN-α is effective in protecting the chickens against ND and also prevents shedding of the virus, which can then prevent further spread of the disease. We propose that in addition to vaccination, chIFN-α therapy could be an effective option for controlling ND in areas of endemicity.

Anti-chicken type I IFN countermeasures by major avian RNA viruses.

Chicken type I interferons (type I IFNs) are key antiviral players of the chicken innate immune system and are considered potent antiviral agents against avian viral pathogens. Chicken type I IFNs are divided into three subtypes namely, chIFN-α, chIFN-ß, and chIFN-κ. Viral pathogen-associated molecular patterns (PAMPs) recognized by their corresponding specific PRRs (pattern recognition receptors) induce the expression of chicken type I IFNs. Interaction of chicken type I IFNs with their subsequent IFN receptors results in the activation of the JAK-STAT pathway, which in turn activates hundreds of chicken interferon-stimulated genes (chISGs). These chISGs establish an antiviral state in neighboring cells and prevent the replication and dissemination of viruses within chicken cells. Chicken type I IFNs activate different pathways that constitute major antiviral innate defense mechanisms in chickens. However, evolutionary mechanisms in viruses have made them resistant to these antiviral players by manipulating host innate immune pathways. This review focuses on the underlying molecular mechanisms employed by avian RNA viruses to counteract chicken type I IFNs and chISGs through different viral proteins. This may help to understand host-pathogen interactions and the development of novel therapeutic strategies to control viral infections in poultry.

Novel Coronavirus disease 2019 (COVID-19): new challenges and new responsibilities in developing countries.

Novel coronavirus disease 2019 (COVID-19) is caused by the SARS-CoV-2 virus, which belongs to the genus Coronaviridae with its high mutation rate. From the current perspective, we discuss the current status of COVID-19, new challenges, and potential interventions to control the pandemic in developing counties such as Pakistan.

Enhancement in humoral response against inactivated Newcastle disease vaccine in broiler chickens administered orally with plant-derived soyasaponin.

The present study aimed to evaluate the immunopotentiating effect of plant-derived soyasaponin and its immunogenicity in chickens challenged with Newcastle disease virus (NDV). Soyasaponin was extracted from soybean seeds and detected using the phytochemical tests, followed by quantification through the dry-weight method. One-day-old broiler chicks (n = 90) were divided into 3 groups, named as A, B, and C. Group A birds were orally administrated with soyasaponin (5 mg/kg), followed by immunization with inactivated ND vaccine intramuscularly (IM), whereas group B birds were vaccinated with inactivated ND vaccine alone. Group C birds were kept unvaccinated. A booster dose on day 21 was also administered IM to group A and B birds. At day 35, all 3 groups were challenged with NDV. To determine the immunogenicity potential of soyasaponin, antibody titer was measured using the hemagglutination inhibition test before and after the NDV challenge. Histochemical examination was performed to determine the pathological changes associated with NDV infection. Foam formation and hemolytic activity confirmed the presence of saponin in soya bean extract. Group A birds showed a higher antibody response compared with group B and C birds. The disease challenge study showed that soyasaponin-adjuvanted NDV vaccine provided complete protection to group A birds against ND. Moreover, no side effects of soyasaponin were observed on the growth performance of birds during the experiment. Therefore, we can conclude that soyasaponin is a potential immunogenic agent and therefore could be a promising candidate to launch a protective humoral response against ND in chickens.

Web of interferon stimulated antiviral factors to control the influenza A viruses replication.

Influenza viruses cause mild to severe infections in animals and humans worldwide with significant morbidity and mortality. Infection of eukaryotic cells with influenza A viruses triggers the induction of innate immune system through the interaction between pattern recognition receptors (PRRs) and pathogen associated molecular patterns (PAMPs), which culminate in the induction of interferons (IFNs). Consequently, IFNs bind to their cognate receptors on the cellular membrane and activate the signaling pathway for transcriptional regulation of interferon-stimulated genes (ISGs) through Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway. Cumulative actions of these ISGs establish an antiviral state of the host. Several ISGs have been described, which play critical roles to inhibit the infection and replication of influenza A viruses at multiple steps of virus life cycle. In this review, the dynamics and redundancy of these ISGs against influenza A viruses are discussed. Additionally, current understanding and molecular mechanisms that are underlying the roles of ISGs in pathogenesis of influenza virus are critically reviewed.

Comprehensive network map of transcriptional activation of chicken type I IFNs and IFN-stimulated genes.

Chicken type I interferons (type I IFNs) are key antiviral players of the chicken immune system and mediate the first line of defense against viral pathogens infecting the avian species. Recognition of viral pathogens by specific pattern recognition receptors (PRRs) induce chicken type I IFNs expression followed by their subsequent interaction to IFN receptors and induction of a variety of IFN stimulated antiviral proteins. These antiviral effectors establish the antiviral state in neighboring cells and thus protect the host from infection. Three subtypes of chicken type I IFNs; chIFN-α, chIFN-ß, and a recently discovered chIFN-κ have been identified and characterized in chicken. Chicken type I IFNs are activated by various host cell pathways and constitute a major antiviral innate defense in chicken. This review will help to understand the chicken type 1 IFNs, host cellular pathways that are involved in activation of chicken type I IFNs and IFN stimulated antiviral effectors along with the gaps in knowledge which will be important for future investigation. These findings will help us to comprehend the role of chicken type I IFNs and to develop different strategies for controlling viral infection in poultry.

Isolation and antibiotic sensitivity pattern of drug resistant bacteria in ulcerative foot of type 2 diabetic patients.

The present study aimed to decipher the bacterial infections in diabetic foot human patients in Pakistan and the anti-microbial susceptibility for clinical relevance. A total of 30 samples were collected from hospitalized type 2 diabetic patients (men and women) having foot ulcers. The collected samples were cultured on mannitol salt agar, Blood agar and MacConkey's agar and cetrimide agar. Gram staining and specific biochemical tests were performed to identify the invading bacteria. Antibiotic sensitivity and resistance pattern was performed for isolated bacteria by Kirby-Bauer disc diffusion method. In diabetic foot ulcers, most prevalent bacteria were S. aureus with percent positivity of 83% followed by E. coli (66%), K. pneumoniae (40%) and P. aeruginosa (16%). The infected ulcer with poly-microorganisms was 83.4% and the infected ulcer with single isolates was 16.6%. Imipenem was found to be most sensitive antibiotic against Gram positive as well as Gram negative bacterial isolates from diabetic foot ulcer human patients. Gram negative isolates from diabetic foot showed resistance to ampicillin, sulfamethoxazole/trimethoprim, cefotaxime/clavulanate, metronidazole. The diabetic foot ulcers of human patients revealed high prevalence of S. aureus followed by E. coli, K. pneumoniae and P. aeruginosa respectively. Imipenem was found to be the most sensitive antibiotic for all the bacterial isolates from foot ulcers of type 2 diabetic patients. This study suggests imipenem as effective antibiotic for treatment of diabetic foot ulcers against bacteria.

Antimicrobial profiling and molecular characterization of antibiotic resistant genes of Proteus vulgaris isolated from tertiary care hospital, Islamabad, Pakistan.

Urinary tract infections (UTIs) are among the most common bacterial infections acquired from hospitals and community. Pseudomonas and Proteus species are the common cause of these UTIs. Generally, UTIs are self-limiting but have potential to re-occur. Extensive treatment therapy with antibiotics lead to the development of resistance in uropathogens. The development of antibiotic resistance is leading to the failure of currently available antibiotic based therapies thus making the situation worse. The objective of the present study was to access antimicrobial sensitivity and to characterize antibiotic resistant genes of Proteus vulgaris (P. vulgaris) isolated from patients suffering with UTIs. A total of 150 urine samples were collected and cultured on MacConkey agar medium followed by isolation and identification on blood agar medium. Biochemical characterization of all presumptive Proteus isolates was done using Remel Rap ID one kit. Antibiotic sensitivity for P. vulgaris isolates was performed by disc diffusion method. Presence of blaTEM and qnr antibiotic resistant genes was determined by PCR. The results showed that the overall prevalence of P. vulgaris in clinical samples was 11.3%. It showed maximum resistance (94%) to three antibiotics i.e. ampicillin, tigecycline and chloramphenicol, while least resistance was observed against imipenem (12%). Statistical analysis depicted that imipenem had a significantly larger zone of inhibition (P=.01), while ampicillin had significantly smaller zone of inhibition (P=.0004) followed by chloramphenicol (p-value = 0.002). Imipenem should be considered as an effective antibiotic to treat urinary tract infections associated with P. vulgaris. Both blaTEM and qnr genes were found to be involved in conferring resistance to ß-lactam and quinolones antibiotics.