Timing of Assessment of Humoral and Cell-Mediated Immunity after Influenza Vaccination.

Assessment of the immune response to influenza vaccines should include an assessment of both humoral and cell-mediated immunity. However, there is a lack of consensus regarding the timing of immunological assessment of humoral and cell-mediated immunity after vaccination. Therefore, we investigated the timing of immunological assessments after vaccination using markers of humoral and cell-mediated immunity. In the 2018/2019 influenza season, blood was collected from 29 healthy adults before and after vaccination with a quadrivalent inactivated influenza vaccine, and we performed serial measurements of humoral immunity (hemagglutination inhibition [HAI] and neutralizing antibody [NT]) and cell-mediated immunity (interferon-gamma [IFN-γ]). The HAI and NT titers before and after vaccination were strongly correlated, but no correlation was observed between the markers of cell-mediated and humoral immunity. The geometric mean titer and geometric mean concentration of humoral and cellular immune markers increased within 2 weeks after vaccination and had already declined by 8 weeks. This study suggests that the optimal time to assess the immune response is 2 weeks after vaccination. Appropriately timed immunological assessments can help ensure that vaccination is effective.

Evaluation of Serological Tests for the Diagnosis of Syphilis.

Background Syphilis remains a significant public health concern in India. Ensuring the accuracy of diagnostic tests is crucial for effectively managing this disease. Objectives This study aims to assess the detectability of syphilis using commercially available non-treponemal and treponemal tests due to observed discrepancies in test results, which can lead to confusion and anxiety among healthcare providers and patients. Materials and methods We analyzed 2312 serum samples using the rapid plasma reagin (RPR), Treponema pallidum hemagglutination assay (TPHA), enzyme-linked immunosorbent assay (ELISA), and modified TPHA rapid test, interpreting the results according to the manufacturers' instructions. We evaluated the diagnostic accuracy of all four tests. Concordance between the traditional and reverse algorithms was determined by calculating the percentage of agreement and the kappa (κ) coefficient. Results Of the 2312 samples tested, 34 (1.5%) were positive, and 2098 (90.7%) were negative across all four tests. Comparing the test results with clinical diagnosis, TPHA and TP-ELISA showed the highest sensitivity at 96.08%, while RPR demonstrated the highest specificity at 100%. The agreement between the traditional and reverse algorithms was moderate, with a 97.3% agreement and a κ value of 0.53. Conclusion Reliance on a single serological test for syphilis screening presents limitations. A combined approach using both RPR and TPHA tests can more accurately diagnose and confirm syphilis. This combination strategy is cost-effective and relatively simple to implement.

Indirect hemagglutination assay for diagnosing brucellosis: Past, present, and future.

Brucellosis is a zoonotic disease that causes enormous losses in livestock production worldwide and has a significant public health impact. None of the brucellosis-free countries is currently able to guarantee their ability to prevent the introduction of the pathogen due to the increase in tourism and the expansion of migration. The timely identification of infected animals is an effective means of preventing brucellosis and minimizing the epidemiological risk. The tube agglutination test, Rose Bengal plate test, complement fixation test, and enzyme-linked immunosorbent assay, which are routinely used to identify seropositive productive animals, have limitations and results that do not always correlate. The indirect hemagglutination assay (IHA) stands out among non-traditional methods because it is affordable, has a simple protocol, and is more reliable than classical serological tests, especially in cases of questionable and/or false-negative results. The diagnostic value of the IHA has long been studied by laboratories in several countries, but mostly by post-soviet research teams; therefore, the results continue to be published in Russian-language journals, ensuring that the local scientific community can access the results. In addition, the efficacy of this test for the diagnosis of brucellosis and other infectious diseases has not yet been reviewed. The purpose of this review was to summarize the results of studies on the development and use of IHA for the diagnosis of brucellosis and to determine the prospects for further improvement.

Back to the Basics of SARS-CoV-2 Biochemistry: Microvascular Occlusive Glycan Bindings Govern Its Morbidities and Inform Therapeutic Responses.

Consistent with the biochemistry of coronaviruses as well established over decades, SARS-CoV-2 makes its initial attachment to host cells through the binding of its spike protein (SP) to sialylated glycans (containing the monosaccharide sialic acid) on the cell surface. The virus can then slide over and enter via ACE2. SARS-CoV-2 SP attaches particularly tightly to the trillions of red blood cells (RBCs), platelets and endothelial cells in the human body, each cell very densely coated with sialic acid surface molecules but having no ACE2 or minimal ACE2. These interlaced attachments trigger the blood cell aggregation, microvascular occlusion and vascular damage that underlie the hypoxia, blood clotting and related morbidities of severe COVID-19. Notably, the two human betacoronaviruses that express a sialic acid-cleaving enzyme are benign, while the other three-SARS, SARS-CoV-2 and MERS-are virulent. RBC aggregation experimentally induced in several animal species using an injected polysaccharide caused most of the same morbidities of severe COVID-19. This glycan biochemistry is key to disentangling controversies that have arisen over the efficacy of certain generic COVID-19 treatment agents and the safety of SP-based COVID-19 vaccines. More broadly, disregard for the active physiological role of RBCs yields unreliable or erroneous reporting of pharmacokinetic parameters as routinely obtained for most drugs and other bioactive agents using detection in plasma, with whole-blood levels being up to 30-fold higher. Appreciation of the active role of RBCs can elucidate the microvascular underpinnings of other health conditions, including cardiovascular disease, and therapeutic opportunities to address them.

Novel Anti-Viral Properties of the Herbal Extract of Davallia mariesii against Influenza A Virus.

Gu-Sui-Bu, the dried rhizome of Davallia mariesii, is a traditional Chinese herbal remedy with a significant history of treating osteoporosis and inflammatory conditions. However, its potential as an anti-influenza agent and its underlying mechanisms of action remain unexplored. To obtain a more potent extract from D. mariesii and gain insights into its mechanism of action against influenza A virus (IAV), we utilized a partitioning process involving organic solvents and water, resulting in the isolation of butanolic subfractions of the D. mariesii extract (DMBE). DMBE exhibited a broad anti-viral spectrum, effectively inhibiting IAV, with an EC50 of 24.32 ± 6.19 µg/mL and a selectivity index of 6.05. We subsequently conducted a series of in vitro assays to evaluate the antiviral effects of DMBE and to uncover its mechanisms of action. DMBE was found to inhibit IAV during the early stages of infection by hindering the attachment of the virus onto and its penetration into host cells. Importantly, DMBE was observed to hinder IAV-mediated cell-cell fusion. It also inhibited neuraminidase activity, plaque size, and the expression levels of phospho-AKT. In summary, this study provides evidence for the effectiveness of D. mariesii as a complementary and alternative herbal remedy against IAV. Specifically, our data highlight DMBE's capabilities in inhibiting viral entry and the release of virions.

In vitro immune analysis of serum from the hemolymph of the anomuran crab Albunea symmysta (Linnaeus, 1758) displayed diversified reactions.

The present investigation aims to substantiate that serum from the hemolymph of anomuran crab Albunea symmysta encompasses multiple immunological reactions in in vitro condition. The serum highly agglutinated human O erythrocytes in the presence of Ba2+. Distinct and unique sugar binding capacity of serum towards laminarin, N-acetyl sugars and higher binding specificity towards a glycoprotein, fetuin was inferred. In vitro enhancement of melanin synthesis due to enhanced oxidation of 3, 4-dihydroxy-dl-phenylalanine (dl-DOPA) by preincubation of nonself molecules with serum phenoloxidase (PO) was documented. Similarly, dl-DOPA oxidation by serum PO was reduced when preincubated with chemical inhibitors and copper chelators. Further, the crab serum lysed the vertebrate erythrocytes with maximum hemolysis against chicken and it unveiled dependency on divalent cation, serum concentration, ionic strength, pH, temperature and time interval. Occurrence of maximum hemolysis at a concentration of 30 µl, pH 8.0, temperature 37 °C and time interval of 60 min in the presence of Ba2+ were documented. Interestingly, serum hemolysis was reduced by different osmoprotectants suggesting a colloid-osmotic mechanism involving in hemolysis. It was observed that A. symmysta serum had antimicrobial activity against Gram-positive Staphylococcus aureus and fungal pathogen Candida albicans. The serum showed higher glycan content, potent lysozyme and free radical scavenging activity suggesting the existence of potential immune molecules of therapeutic use. These results clearly demonstrated the diversified immunogenicity of A. symmysta serum confirming a highly conserved non-specific immunity of crustaceans.

Comparative evaluation of rapid plasma reagin and ELISA with Treponema pallidum hemagglutination assay for the detection of syphilis in blood donors: a single center experience.

INTRODUCTION: The prime responsibility of blood transfusion services in India is to provide safe blood. The donated blood is tested for human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), malaria and syphilis. In India, the screening of donated blood for syphilis is performed by rapid plasma reagin (RPR) or venereal disease research laboratory (VDRL), whereas the World Health Organization (WHO) recommends screening of syphilis in blood donors by enzyme-linked immunosorbent assay (ELISA). Therefore, the aim of this study was to evaluate the performance of RPR and ELISA with the Treponema pallidum hemagglutination assay (TPHA - the gold standard) for the detection of syphilis in blood donors. METHODS: In this cross-sectional study, 1524 consecutive whole blood donors were screened from April to October 2022. All blood samples collected during the study period were tested by RPR, ELISA and the TPHA and the results obtained were compared. RESULTS: The seroprevalence of syphilis in blood donors in this study was 0.06% by RPR and 0.72% by ELISA and TPHA. On considering ELISA and the TPHA as the gold standard, ELISA had comparable sensitivity (100%), a higher specificity (100% vs. 99.34%), a higher positive predictive value (PPV - 100% vs. 9.1%) and no biological false positive/false negative results (0 vs. 10 false negatives) when compared to RPR. CONCLUSION: ELISA performed better as a screening assay than RPR in the detection of syphilis in blood donors, which is in agreement with the WHO recommendations for syphilis testing in blood donors with low prevalence.

Hemagglutination inhibition antibody titers mediate influenza vaccine efficacy against symptomatic influenza A(H1N1), A(H3N2), and B/Victoria infections.

BACKGROUND: The hemagglutination inhibition antibody (HAI) titer mediates only a part of vaccine-induced protection against influenza virus infections. Using causal mediation analysis, we quantified the proportion of vaccine efficacy mediated by post-vaccination HAI titers. METHODS: Causal mediation analyses were conducted using data collected for a randomized, active-comparator controlled, phase 3 trial of a candidate inactivated, split-virion seasonal quadrivalent influenza vaccine (QIV) in children aged 3 to 8 years conducted from October 2010 to December 2011 in eight countries. Vaccine efficacy was estimated with a weighted Cox proportional hazards regression model. Estimates were decomposed into the direct and indirect effects mediated by post-vaccination HAI titers. RESULTS: The proportions of vaccine efficacy mediated by post-vaccination HAI titers were estimated to be 22% (95% CI: 18%, 47%) for influenza A(H1N1), 20% (95% CI: 16%, 39%) for influenza A(H3N2), and 37% (95% CI: 26%, 85%) for influenza B/Victoria. CONCLUSIONS: HAI titers partially mediate influenza vaccine efficacy against influenza A(H1N1), A(H3N2), and B/Victoria. Our estimates were lower than previous studies, possibly reflecting expected heterogeneity in antigenic similarity between vaccine and circulating viruses across seasons. Data from more influenza seasons are needed to understand better the mediating effects of HAI titers on vaccine efficacy.

Recent H9N2 avian influenza virus lost hemagglutination activity due to a K141N substitution in hemagglutinin.

The H9N2 avian influenza virus (AIV) represents a significant risk to both the poultry industry and public health. Our surveillance efforts in China have revealed a growing trend of recent H9N2 AIV strains exhibiting a loss of hemagglutination activity at 37°C, posing challenges to detection and monitoring protocols. This study identified a single K141N substitution in the hemagglutinin (HA) glycoprotein as the culprit behind this diminished hemagglutination activity. The study evaluated the evolutionary dynamics of residue HA141 and studied the impact of the N141K substitution on aspects such as virus growth, thermostability, receptor-binding properties, and antigenic properties. Our findings indicate a polymorphism at residue 141, with the N variant becoming increasingly prevalent in recent Chinese H9N2 isolates. Although both wild-type and N141K mutant strains exclusively target α,2-6 sialic acid receptors, the N141K mutation notably impedes the virus's ability to bind to these receptors. Despite the mutation exerting minimal influence on viral titers, antigenicity, and pathogenicity in chicken embryos, it significantly enhances viral thermostability and reduces plaque size on Madin-Darby canine kidney (MDCK) cells. Additionally, the N141K mutation leads to decreased expression levels of HA protein in both MDCK cells and eggs. These findings highlight the critical role of the K141N substitution in altering the hemagglutination characteristics of recent H9N2 AIV strains under elevated temperatures. This emphasizes the need for ongoing surveillance and genetic analysis of circulating H9N2 AIV strains to develop effective control and prevention measures.IMPORTANCEThe H9N2 subtype of avian influenza virus (AIV) is currently the most prevalent low-pathogenicity AIV circulating in domestic poultry globally. Recently, there has been an emerging trend of H9N2 AIV strains acquiring increased affinity for human-type receptors and even losing their ability to bind to avian-type receptors, which raises concerns about their pandemic potential. In China, there has been a growing number of H9N2 AIV strains that have lost their ability to agglutinate chicken red blood cells, leading to false-negative results during surveillance efforts. In this study, we identified a K141N mutation in the HA protein of H9N2 AIV to be responsible for the loss of hemagglutination activity. This finding provides insight into the development of effective surveillance, prevention, and control strategies to mitigate the threat posed by H9N2 AIV to both animal and human health.

Alpha-sitosterol: a new antiviral agent produced by Streptomyces misakiensis and its potential activity against Newcastle disease virus.

BACKGROUND: Newcastle Disease Virus (NDV) causes severe economic losses in the poultry industry worldwide. Hence, this study aimed to discover a novel bioactive antiviral agent for controlling NDV. Streptomyces misakiensis was isolated from Egyptian soil and its secondary metabolites were identified using infrared spectroscopy (IR), gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) spectroscopy. The inhibitory activity of bioactive metabolite against NDV were examined. Three experimental groups of 10-day-old specific pathogen-free embryonated chicken eggs (SPF-ECEs), including the bioactive metabolite control group, NDV control positive group, and α-sitosterol and NDV mixture-treated group were inoculated. RESULTS: α-sitosterol (Ethyl-6-methylheptan-2-yl]-10,13-dimethyl-dodecahydro-1H-cyclopenta[a]phenanthren-3-ol), a secondary metabolite of S. misakiensis, completely inhibited hemagglutination (HA) activity of the NDV strain. The HA activity of the NDV strain was 8 log2 and 9 log2 for 0.5 and 0.75% RBCs, respectively. The NDV HA activity for the two concentrations of RBCs was significantly (P < 0.0001) inhibited after α-sitosterol treatment. There was a significant (P < 0.0001) decrease in the log 2 of HA activity, with values of - 0.500 (75%, chicken RBCs) before inoculation in SPF-ECEs and - 1.161 (50%, RBCs) and - 1.403 (75%, RBCs) following SPF-ECE inoculation. Compared to ECEs inoculated with NDV alone, the α-sitosterol-treated group showed improvement in histological lesion ratings for chorioallantoic membranes (CAM) and hepatic tissues. The CAM of the α-sitosterol- inoculated SPF-ECEs was preserved. The epithelial and stromal layers were noticeably thicker with extensive hemorrhages, clogged vasculatures, and certain inflammatory cells in the stroma layer in the NDV group. However, mild edema and inflammatory cell infiltration were observed in the CAM of the treated group. ECEs inoculated with α-sitosterol alone showed normal histology of the hepatic acini, central veins, and portal triads. Severe degenerative alterations, including steatosis, clogged sinusoids, and central veins, were observed in ECEs inoculated with NDV. Mild hepatic degenerative alterations, with perivascular round cell infiltration, were observed in the treated group. CONCLUSION: To the best of our knowledge, this is the first study to highlight that the potentially bioactive secondary metabolite, α-sitosterol, belonging to the terpene family, has the potential to be a biological weapon against virulent NDV. It could be used for the development of innovative antiviral drugs to control NDV after further clinical investigation.

Serological Evidence for Circulation of Influenza D Virus in the Ovine Population in Italy.

Influenza D virus (IDV) is a novel orthomyxovirus initially isolated from pigs exhibiting influenza-like disease in the USA. Since then, IDV has been detected worldwide in several host species, including livestock animals, whilst specific antibodies have been identified in humans, raising concerns about interspecies transmission and zoonotic risks. Few data regarding the seroprevalence of IDV in small ruminants have been available to date. In this study, we assessed the prevalence of antibodies against IDV in ovine serum samples in Sicily, Southern Italy. Six hundred serum samples, collected from dairy sheep herds located in Sicily in 2022, were tested by haemagglutination inhibition (HI) and virus neutralization (VN) assays using reference strains, D/660 and D/OK, representative of two distinct IDV lineages circulating in Italy. Out of 600 tested samples, 168 (28.0%) tested positive to either IDV strain D/660 or D/OK or to both by HI whilst 378 (63.0%) tested positive to either IDV strain D/660 or D/OK or to both by VN. Overall, our findings demonstrate that IDV circulates in ovine dairy herds in Sicily. Since IDV seems to have a broad host range and it has zoonotic potential, it is important to collect epidemiological information on susceptible species.

Controlled expression of avian pre-migratory fattening influences indices of innate immunity.

While immunity is frequently dampened when birds engage in strenuous migratory flights, whether and how immunity changes during the rapid accumulation of energy stores in preparation for migration remains largely unknown. Here we induced pre-migratory fattening through controlled changes of daylight in common quails (Coturnix coturnix) and regularly assessed changes in three markers of constitutive innate immunity (leukocyte coping capacity or LCC, hemagglutination and hemolysis titres) and measures of body composition (lean and fat mass). All the three markers showed similar changes over the pre-migratory fattening process. LCC responses, hemagglutination titres, and hemolysis titres, were on average higher in the mid-fattening phase compared to the peak-fattening phase, when values were similar to those observed prior the start of pre-migratory fattening. At mid-fattening, we found that the birds that showed a larger accumulation of fat mass (as % of body mass) had lower LCC peak responses and hemolysis titres. Reversibly, at mid-fattening, we also found that the birds that kept a higher proportion of lean mass (as % of body mass) had the highest LCC peaks. Our results indicate that migratory birds undergo changes in immune indices (over 8 weeks) as they accumulate energy stores for migration and propose that this could be due to competing or trade-off processes between metabolic remodelling and innate immune system function.

Experimental investigation of the effect of tebuconazole on three biomarkers of innate immunity in the house sparrow (Passer domesticus).

Triazoles are among the most widely used fungicides in the world due to their efficacy against fungal crop diseases and their broad spectrum of action. Intensive use of triazoles has resulted in residual contamination in different compartments of agroecosystems and exposes non-target species to potential sublethal effects. Triazoles are known to be immunomodulators in medicine and therapeutic treatments, but very little data is available on their potential effect on immune parameters of non-target vertebrate species living in agroecosystems. In this study, we experimentally examined the impact of tebuconazole on three immune biomarkers (haemagglutination titre (HA), haemolysis titre (HL), and haptoglobin concentration (Hp)), as well as on the body condition of house sparrows (Passer domesticus). Our results suggest that tebuconazole had very little, if any, effect on the studied immune parameters. However, further studies are needed to better assess the effect of tebuconazole on bird immunity because (1) experimental individuals were kept under optimal conditions and the impact of tebuconazole on immunity may occur under suboptimal conditions, (2) only one concentration of tebuconazole was tested and its effect could be dose-dependent and (3) other complementary immunological biomarkers should be studied, given the complexity of the vertebrate immune system. Current knowledge on the potential effects of triazoles on the immunity of wild farmland vertebrates is still largely insufficient. Further physiological and immune studies should be conducted to better understand the effect of triazole fungicides on farmland birds.

Assessment of Humoral Immune Responses to Repeated Influenza Vaccination in a Multiyear Cohort: A 5-Year Follow-up.

The long-term effects of host factors on vaccine-elicited immune responses have not been well studied, and the interactions of host factors with annual influenza vaccinations are yet to be explored. We analyzed data from a cohort of 386 individuals who received the standard-dose influenza vaccine and enrolled in ≥2 seasons from 2016 to 2020. Our analyses indicated disparate vaccine-elicited immune responses between males and females in adults when they were repeatedly vaccinated for at least 2 seasons. Notably, we found interactive effects between age and body mass index (BMI) on overall immune responses, and between sex at birth and BMI in adults.

Improved in vitro Hemagglutination Assays Utilizing P-Type and Type 1 Uropathogenic Escherichia coli to Evaluate Bacterial Anti-Adhesion Activity of Cranberry Products.

Cranberries have a long history of use in the prevention of urinary tract infections. Cranberry products vary in proanthocyanidin content, a compound implicated in preventing the adhesion of uropathogenic Escherichia coli (E. coli) to uroepithelial cells. Testing is routinely done by cranberry product formulators to evaluate in vitro bacterial anti-adhesion bioactivity, shelf-life, and potential efficacy of cranberry products for consumer use to maintain urinary tract health. Hemagglutination assays evaluate the anti-adhesion bioactivity of cranberry products by determining how effectively the products prevent agglutination of specific red blood cells with E. coli expressing P-type and Type 1 fimbriae. The current study sought to improve upon an established anti-adhesion assay method by expanding the number of E. coli strains used to broaden potential in vivo efficacy implications and presenting results using photomicrographic data to improve accuracy and build databases on products that are routinely tested. Different lots of cranberry powder ingredient and two formulated products were tested independently for anti-adhesion activity using the established method and the improved method. Positive harmonization of results on the same samples using rigorous controls was achieved and provides the substantiation needed for the cranberry industry to utilize the improved, rapid in vitro testing method to standardize cranberry products for sufficient anti-adhesion bioactivity and maintain consumer confidence.

Difficulty in Serologic Screening for Subclinical Rubella during Pregnancy.

In Japan, rubella antibodies are tested in all pregnant women to detect subclinical infections. This study aimed to assess the validity of measuring rubella antibodies for detecting subclinical rubella among pregnant women in Japan. This single-center retrospective study measured rubella hemagglutination inhibition (HI) titers and rubella-specific IgM antibody index (IgM) values. IgM values were measured by conducting enzyme immunoassay, and IgM-values >1.2 were considered positive. Of 14,965 included pregnant women, 186 (1.2%) were IgM-positive. Only one patient was clinically diagnosed with rubella (HI titer, 1:2,048; IgM value, 10) and developed fever and skin rash. She decided to terminate her pregnancy without undergoing repeated blood tests. Of the IgM-positive patients, 136 (73.1%) had rubella HI titers of < 1:256. The correlation coefficient between rubella HI and IgM titers was weakly positive (0.2527; P < 0.0001). This study showed that a single combination of rubella HI and rubella-specific IgM measurements alone could not detect subclinical rubella. Creating awareness among pregnant women by informing them that almost all rubella-specific IgM-positive individuals without symptoms are not acutely infected could decrease their anxiety and prevent unnecessary pregnancy termination.

An antimicrobial activity of oil extracted from Saara hardwickii

Abstract Present research work represents antiviral and antibacterial value of body fat of Saara hardwickii commonly called as spiny tailed lizard. Oil was extracted from body fats located in the ventral region of this animal using hydrocarbons e.g., n-hexane, methanol, butanol and ethyl acetate as a solvent. The antibacterial activity of lizard oil was tested against standard as well as multi-resistant lines ofEscherichia coli, Styphalococcus aureus, Pseudomonas aeruginosa and Proteus vulgaris alone and with antibiotic ampicillin. For antibacterial potential, Ethyl acetate and Butanol solvent extract showed best zone of inhibition (7mm) with P. aeruginosa and S. aureus respectively. For antiviral potential, Butanol and Methanol extract showed best HA (Hemagglutination) titer of 04 with NDV and IBV viral strain respectively. It is concluded that lizard oil has antimicrobial potential against different pathogens strains (virus, bacteria).

Resumo O presente trabalho de pesquisa apresenta a importância antiviral e antibacteriana da gordura corporal de Saara hardwickii, comumente chamado de lagarto de cauda espinhosa. O óleo foi extraído de gorduras corporais localizadas na região ventral desse animal usando hidrocarbonetos, por exemplo, n-hexano, metanol, butanol e acetato de etila, como solvente. A atividade antibacteriana do óleo do lagarto foi testada em linhagens padrão e multirresistentes de Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa e Proteus vulgaris, de forma isolada e com antibiótico ampicilina. Para o potencial antibacteriano, acetato de etila e extrato de butanol apresentaram melhor zona de inibição (7 mm) com P. aeruginosa e S. aureus, respectivamente. Para o potencial antiviral, o extrato de butanol e o extrato de metanol apresentaram melhor título de hemaglutinação de 4 com as cepas virais NDV e IBV, respectivamente. Conclui-se que o óleo do lagarto possui potencial antimicrobiano contra diferentes cepas de patógenos (vírus e bactérias).

An antimicrobial activity of oil extracted from Saara hardwickii / Atividade antimicrobiana do óleo extraído de Saara hardwickii

Present research work represents antiviral and antibacterial value of body fat of Saara hardwickii commonly called as spiny tailed lizard. Oil was extracted from body fats located in the ventral region of this animal using hydrocarbons e.g., n-hexane, methanol, butanol and ethyl acetate as a solvent. The antibacterial activity of lizard oil was tested against standard as well as multi-resistant lines ofEscherichia coli, Styphalococcus aureus, Pseudomonas aeruginosa and Proteus vulgaris alone and with antibiotic ampicillin. For antibacterial potential, Ethyl acetate and Butanol solvent extract showed best zone of inhibition (7mm) with P. aeruginosa and S. aureus respectively. For antiviral potential, Butanol and Methanol extract showed best HA (Hemagglutination) titer of 04 with NDV and IBV viral strain respectively. It is concluded that lizard oil has antimicrobial potential against different pathogens strains (virus, bacteria).

O presente trabalho de pesquisa apresenta a importância antiviral e antibacteriana da gordura corporal de Saara hardwickii, comumente chamado de lagarto de cauda espinhosa. O óleo foi extraído de gorduras corporais localizadas na região ventral desse animal usando hidrocarbonetos, por exemplo, n-hexano, metanol, butanol e acetato de etila, como solvente. A atividade antibacteriana do óleo do lagarto foi testada em linhagens padrão e multirresistentes de Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa e Proteus vulgaris, de forma isolada e com antibiótico ampicilina. Para o potencial antibacteriano, acetato de etila e extrato de butanol apresentaram melhor zona de inibição (7 mm) com P. aeruginosa e S. aureus, respectivamente. Para o potencial antiviral, o extrato de butanol e o extrato de metanol apresentaram melhor título de hemaglutinação de 4 com as cepas virais NDV e IBV, respectivamente. Conclui-se que o óleo do lagarto possui potencial antimicrobiano contra diferentes cepas de patógenos (vírus e bactérias).

Using guinea pig as a model for evaluation of equine influenza vaccine

Equine influenza is a highly contagious viral disease, specially among 1-5 years old naive horses. Vaccination is considered the best way to control the disease spread and outbreaks. Although foals are the main animal used for evaluation of equine influenza vaccines, guinea pigs were chosen as an alternative model in the present work, as they have a negligible antibody titer against equine influenza virus and are cheaper and easier to handle than foals. Five equine influenza vaccine batches were evaluated in two animal models, foals and guinea pigs, by injection of two doses/animal with 4 weeks apart using 2 mL/animal/dose and evaluation of immune responses by hemagglutination inhibition test and enzyme-linked immunosorbent assay. On the 7th week post vaccination, equine influenza antibodies titers reached maximum values of 9-10.2 and 8.7-10 hemagglutination inhibition units for foals and guinea pigs, respectively; sample/negative ratios were 0.126-0.464 and 0.128-0.445 for both animals, respectively. The use of guinea pigs as an animal model for the evaluation of equine influenza vaccines could be recommended instead of foals.

La gripe equina es una enfermedad viral muy contagiosa, especialmente entre los caballos jóvenes de 1 a 5 años de edad. La vacunación se considera la mejor forma de controlar la propagación y los brotes de la enfermedad. Aunque los potros son el principal animal utilizado para la evaluación de vacunas contra la gripe equina, en el presente trabajo se eligieron cobayos como modelo alternativo, ya que tienen un título insignificante de anticuerpos contra el virus de la gripe equina y son más baratos y fáciles de manejar que los potros. Se evaluaron cinco lotes de vacunas contra la gripe equina en dos modelos animales, potros y cobayos, mediante la inyección de dos dosis/animal con 4 semanas de intervalo utilizando 2 mL/animal/dosis y la evaluación de las respuestas inmunitarias mediante la prueba de inhibición de la hemaglutinación y el ensayo inmunoenzimático. En la 7ª semana posvacunación, los títulos de anticuerpos contra la gripe equina alcanzaron valores máximos de 9-10,2 y 8,7-10 unidades de inhibición de la hemaglutinación para potros y cobayos, respectivamente; las relaciones muestras/negativos fueron de 0,126-0,464 y 0,128-0,445 para ambos animales, respectivamente. Podría recomendarse el uso de cobayos como modelo animal para la evaluación de vacunas contra la gripe equina, en lugar de potros.

Spectroscopic and thermodynamic characterization of the interaction between sugar-stabilised silver nanoparticles and wheat germ agglutinin (WGA), a chitin binding lectin.

Nanomaterials have lately been investigated in agriculture as eco-friendly and effective antifungal agents. Many nanomaterials, notably metal nanoparticles, have strong antifungal properties. Among metal nanoparticles, Ag nanoparticles have received the most attention as antifungal agents. Many plant lectins have been identified as antifungal agents. Conjugating AgNPs with antifungal lectins is thus expected to improve Ag nanoparticle antifungal efficacy. Understanding the molecular interactions and physical features of lectin-sugar-stabilised nanoparticle conjugates is critical for future applications. WGA has traditionally been used as an anti-tumor and antifungal agent. To investigate the prospect of developing an effective biocompatible antifungal system with applications in medicine and agriculture, fluorescence spectroscopy was used to investigate the interaction between sugar-stabilised silver nanoparticles and WGA. During the association, protein intrinsic fluorescence emission is suppressed by about ∼15 % at saturation, with no significant shift in fluorescence emission maxima. Binding tests reveal a strong bond. Stern-Volmer analysis of the quenching data indicates that the interaction happens via a static quenching process that induces complex formation. The study of hemagglutination activity and interaction experiments in the presence of particular sugar shows that the lectin's sugar-binding site is separate from the nanoparticle-binding site, and cell recognition is conserved in the lectin-nanoparticle complex. The Van't Hoff plot thermodynamic parameters suggest that the contact is hydrophobic. The fact that ΔGo is negative shows that the binding is a spontaneous process. CD spectroscopy experiments reveal that the lectin's secondary structure is not affected while binding to the nanoparticle. Our findings suggest that a stable WGA-silver nanoparticle combination may emerge for a variety of applications.