Highly pathogenic avian influenza (H5N1) infection in crows through ingestion of infected crow carcasses.

The present study was aimed to investigate the role of cannibalism in transmission of H5N1 avian influenza virus to house crows (Corvus splendens). Four crows were intranasally inoculated with 108.0 EID50 (A/crow/India/01CA249/2021) H5N1 highly pathogenic avian influenza (HPAI) virus and were observed for 14 days for any overt signs of illness. Two of the infected crows showed signs of wing paralysis, incoordination, and torticollis. For cannibalism experiment, two crows showing clinical signs were euthanized on 14th day post-infection (dpi) and were kept in the isolator and four naïve healthy crows were introduced along with the euthanized crows. The viscera from the infected carcasses were eaten by all the four crows. Oropharyngeal and cloacal swabs were collected up to 14 days to assess virus excretion. All four crows showed clinical signs viz., dullness, reluctance to move with ruffled feathers on 6th day post cannibalism along with neurological signs including incoordination and paralysis of the wings. All the crows gradually recovered after showing clinical signs and were euthanized on 21st day of observation period. Virus excretion was observed from 3rd to 11th day post cannibalism through both oropharyngeal and cloacal routes with maximum shedding through oropharyngeal route. The virus was isolated from lungs and trachea of one the infected crows at 21st day after euthanasia. All the four crows seroconverted against H5N1 virus infection at 14th day post cannibalism. Our study confirms the transmission of H5N1 virus in crows through cannibalism and highlights how H5N1 virus might circulate in a crow colony once they become infected.

Experimental Infection and In-Contact Transmission of H9N2 Avian Influenza Virus in Crows.

This study aimed to investigate the potential of H9N2 avian influenza virus to cause disease and intra-species transmission in house crows (Corvus splendens). A group of six crows were intranasally inoculated with 106.0 EID50 of H9N2 virus (A/chicken/India/07OR17/2021), and 24 h post-inoculation six naïve crows were co-housed with infected crows. Crows were observed for 14 days for any overt signs of illness. Oropharyngeal and cloacal swabs were collected up to 14 days to assess virus excretion. No apparent clinical signs were observed in either infected or in-contact crows. Virus excretion was observed only in infected birds up to 9 days post-infection (dpi) through both oropharyngeal and cloacal routes. All six infected crows seroconverted to H9N2 virus at 14 dpi, whereas all in-contact crows remained negative to H9N2 virus antibodies. No virus could be isolated from tissues viz., lung, liver, kidney, pancreas, small intestine and large intestine. Although crows became infected with the H9N2 virus, transmission of the virus was inefficient to the in-contact group. However, virus excretion through oral and cloacal swabs from infected crows suggests a potential threat for inter-species transmission, including humans. Crows, being a common synanthrope species, might have some role in influenza virus transmission to poultry and humans, which needs to be explored further.

Antimicrobial Efficacy of Acacia nilotica, Murraya koenigii L. Sprengel, Eucalyptus hybrid, Psidium guajava extracts and their combinations on Fusobacterium nucleatum and Porphyromonas gingivalis.

BACKGROUND: The herbal extracts have been effectively tried in the treatment and prevention of many oral diseases. AIM: The aim is to assess the antimicrobial efficacy of Acacia nilotica, Murraya koenigii L. Sprengel, Eucalyptus hybrid, Psidium guajava extracts and their combinations on Fusobacterium nucleatum (Fn) and Porphyromonas gingivalis (Pg). MATERIALS AND METHODS: The extraction process was carried out by Soxhlet apparatus using ethanol as solvent. The combinations of the four plant extracts were prepared by combining an equal quantity of 10% solution of each of the four plant extracts. The antimicrobial efficacy testing of the plant extracts and their combinations on Fn and Pg was performed using agar well diffusion method. Columbia 5% of sheep blood agar plates were used for antimicrobial efficacy testing under anaerobic conditions. The qualitative assay was carried out to identify the various phytochemical constituents. Dimethyl sulfoxide and 0.2% chlorhexidine acted as negative and positive controls, respectively. The mean diameter of inhibition zone between different categories was compared using one-way analysis of variance. RESULTS: All the individual plant extracts and their double, triple, and quadruple combinations were effective in inhibiting the growth of these bacteria. However, 0.2% chlorhexidine produced the highest mean diameter of inhibition zone. CONCLUSION: The plant extracts in combinations offer enhanced antimicrobial efficacy due to their synergistic action besides slowing the development of bacterial resistance. Hence, these extracts in combinations could be used tried as effective alternates to chlorhexidine.

Antimicrobial efficacy of the combinations of Acacia nilotica,Murrayakoenigii (Linn.) Sprengel, Eucalyptus, and Psidiumguajava on primary plaque colonizers: An in vitro study.

BACKGROUND: The rise in disease incidence, increased resistance of pathogenic bacteria to currently used antibiotics and chemotherapeutics, opportunistic infections in immunocompromised individuals, and financial considerations in developing countries necessitates alternate preventive and treatment strategies for oral diseases. OBJECTIVE: The objective of the study is to assess the antimicrobial efficacy of triple and quadruple combinations of Acacia nilotica (AN), Murraya koenigii (Linn.) (MKL) Sprengel, Eucalyptus (Euca), and Psidium guajava (PS) on primary plaque colonizers. MATERIALS AND METHODS: The phytochemicals in four plants were extracted using Soxhlet apparatus. The dried extracts were diluted with dimethyl sulfoxide (DMSO) to prepare stock solutions (100 mg/ml) of each plant. The triple and quadruple combinations were prepared after mixing equal quantities of stock solutions from each plant extracts. The antimicrobial efficacy testing was done on Streptococcus mutans, Streptococcus sanguis, and Streptococcus salivarius using agar well diffusion method. Chlorhexidine of 0.2% composition and DMSO were used as positive and negative controls, respectively. The mean diameter of inhibition zone between different categories was compared using one-way analysis of variance. RESULTS: The combination of AN + MKL Sprengel + Euca + PS produced the highest mean diameter of inhibition zone (23.5 ± 2.17 mm) against S. mutans. The combination of AN + MKL Sprengel + Euca produced the maximum antimicrobial efficacy against S. sanguis (19.83 ± 1.33). CONCLUSION: All the triple and quadruple combinations of the plant extracts offered antimicrobial benefits either superior or comparable to 0.2% chlorhexidine against S. mutans, S. sanguis, and S. salivarius.

Antimicrobial efficacy of Acacia nilotica, Murraya koenigii (L.) Sprengel, Eucalyptus hybrid, Psidium guajava extracts and their combination on Streptococcus mutans and Lactobacillus acidophilus.

BACKGROUND: The aim of this in vitro study was to assess antimicrobial efficacy of Acacia nilotica, Murraya koenigii (L.) Sprengel, Eucalyptus hybrid, Psidium guajava extracts, and their combination on Streptococcus mutans and Lactobacillus acidophilus. MATERIALS AND METHODS: The branches of four plants were collected, identified, and authenticated by a taxonomist. The plants were rinsed in water, healthy leaves were separated and shade dried over a period of 3-4 weeks. Soxhlet apparatus using ethanol was employed for extraction procedure. The combinations of plant extracts were prepared by mixing equal quantities of 10% solutions of each of these extracts. 0.2% chlorhexidine and dimethyl sulfoxide were used as positive and negative controls, respectively. The antimicrobial efficacy testing was done using agar well-diffusion method under anaerobic conditions. The mean diameter of inhibition zone was computed and compared between different categories using one-way analysis of variance and Tukey's post-hoc test. A qualitative assay was carried out to identify the various phytochemical constituents in the plants. The data was assessed by SPSS version 20. The statistical significance was fixed at 0.05. RESULTS: All the plants extracts and their combinations inhibited S. mutans and L. acidophilus. However, the quadruple combination of A. nilotica + M. koenigii (L.) Sprengel + Eucalyptus hybrid + P. guajava produced the maximum inhibition zone (23.5 ± 2.2 mm) against S. mutans. Although, 0.2% chlorhexidine produced the highest inhibition zone against L. acidophilus (18.8 ± 1.2 mm), A. nilotica extract produced maximum inhibition among the various plant extracts and their combinations (14.1 ± 1.8 mm). CONCLUSION: All the individual plant extracts and their combinations were effective against S. mutans and L. acidophilus. These could be tried as herbal alternates to chlorhexidine. However, these in vitro results have to be further evaluated for any toxicity of the polyherbal combinations in animal models and effectiveness has to be assessed using in vivo studies on humans.

Antimicrobial efficacy of Acacia nilotica, Murraya koenigii L. Sprengel, Eucalyptus hybrid, and Psidium guajava on primary plaque colonizers: An in vitro comparison between hot and cold extraction process.

BACKGROUND: The potential drawbacks of the existing antiplaque agents call for innovative strategies that are safe, effective, and easily available. OBJECTIVE: The objective was to assess and compare antimicrobial efficacy of four plant extracts derived using hot and cold extraction methods against Streptococcus mutans, Streptococcus sanguis, and Streptococcus salivarius. MATERIALS AND METHODS: The leaves of Acacia nilotica, P. guajava, Eucalyptus hybrid, and Murraya konigii L. Sprengel were collected from the surrounding areas, identified and authenticated by a taxonomist. The leaves were washed, shade-dried, and hand crushed to obtain coarse powder. This was subsequently ground into a fine powder and extracted using ethanol by cold infusion and hot extraction process. The antimicrobial efficacy testing was done on American Type Culture Collection strains of S. mutans, S. sanguis, and S. salivarius using agar well diffusion method. 0.2% chlorhexidine and dimethyl sulfoxide were used as positive and negative controls. The mean inhibition zone using 10% concentration of these extracts was compared using independent sample t-test and one-way analysis of variance. RESULTS: All the four plant extracts inhibited the growth of S. mutans, S. sanguis, and S. salivarius irrespective of the method of extraction. The extracts of A. nilotica, P. guajava, and E. hybrid derived from both the methods of extraction exhibited a significantly higher inhibition zone against S. mutans in comparison with Murraya koenigii L. Sprengel and chlorhexidine. The cold extracts of A. nilotica and E. hybrid exhibited higher zone of inhibition against S. sanguis while the hot extracts of M. koenigii L. Sprengel exhibited a higher zone of inhibition against S. mutans. CONCLUSION: All the four plant extracts derived using either hot or cold extraction were effective against these bacteria and have the potential to be used as antiplaque agents.

Evaluation of antibacterial activity of Prosopis juliflora (SW.) DC. leaves.

BACKGROUND: The ethnobotanical importance of Prosopis juliflora is well-known in the folkloric system of medicine for the treatment of various ailments. Although, the study related to the antibacterial potential of this plant, from Central India is scanty. MATERIAL AND METHODS: The in vitro antibacterial activity of Prosopis juliflora leaves collected from the local area was evaluated against ten bacterial type cultures by agar well diffusion assay. The crude extracts prepared by two methods separately with three different solvents were examined for the preliminary antibacterial activity and phytochemical screening, the results of which were used for the choice of solvent and mass extraction of crude extract. Solvent fractionation of crude extract was done employing two sets of solvents namely Set-PCE and Set-HDB which resulted in total, six organic and two aqueous fractions, which were finally subjected to antibacterial activities. RESULTS: Varying degrees of growth inhibition was shown by all the fractions against tested microorganisms. The highest antibacterial activity was observed in aqueous fractions as compared to solvent fractions. CONCLUSION: Isolation and characterization of the bioactive components can be further done by systematic screening of the most active solvent fraction which could lead to the possible source of new antibacterial agents.

Antimicrobial efficacy of the combinations of Acacia nilotica, Murraya koenigii L. sprengel, Eucalyptus hybrid and Psidium guajava on primary plaque colonizers.

BACKGROUND: There is an urgent need for innovative strategies to combat the two most common dental diseases of mankind namely dental caries and periodontitis. OBJECTIVE: The aim was to assess the antimicrobial efficacy of the double combinations of Acacia nilotica (AN), Murraya koenigii L. Sprengel (MKL), Eucalyptus hybrid and Psidium guajava on primary plaque colonizers. MATERIALS AND METHODS: The plant extracts of AN, MKL. Sprengel, Eucalyptus hybrid and P. guajava were prepared using Soxhlet apparatus. The stock solutions of individual plant extracts (100 mg/ml) were prepared. Equal quantities of stock solutions were mixed to obtain six double combinations of herbal extracts. The antimicrobial efficacy testing was done against three primary plaque colonizers using agar well-diffusion method. 0.2% chlorhexidine and dimethyl sulfoxide were used as positive and as negative controls. The mean inhibition zone between the categories was compared using one-way Analysis of Variance and Tukey's post hoc test. RESULTS: The combination of AN and P. guajava produced the highest mean diameter of inhibition zone (21.08 mm ± 2.11) against Streptococcus mutans. The chlorhexidine produced the least inhibition zone against S. mutans (14.50 ± 2.07). The combination of AN and P. guajava produced the maximum antimicrobial efficacy against Streptococcus sanguis (19.67 ± 1.03) and Streptococcus salivarius (20.33 ± 1.86). CONCLUSION: All the combinations of plant extracts have the potential to be used as antiplaque and anticaries agents. The combinations of herbal extracts offer enhanced antimicrobial efficacy due to the synergistic effects besides slowing the development of resistance.