Phytochemical Screening and Antibacterial Activity of Chrysophyllum albidum Collected in Nsukka, South East Nigeria

Background: Chrysophyllum albidum is widely used by African people for the treatment of various types of diseases such as ear infection, sore throat, typhoid, cellulites, septicaemia, bactericemia, abscesses and tooth infections. Aim: The study was conducted to investigate the chemical components and antibacterial activity of the extract and fractions from the root bark of Chrysophyllum albidum from Nsukka, South-east Nigeria. Methodology: The fresh roots were collected, washed, cut into small pieces, air dried and pulverized to powder using mechanical grinder. Extraction and fractionation were done by cold maceration method and technique of liquid–liquid extraction respectively. The phytochemical analysis of the methanol extract and, n-hexane, butanol, aqueous and ethylacetate fractions of the plant part was carried out using standard method. The antibacterial activities were determined using cup-plate agar diffusion and agar dilution methods. Results: The phytochemical screening of the extract revealed the presence of tannins, flavonoids, saponins, terpenoids, alkaloids, reducing sugar and cardiac glycosides. The inhibition zone diameter (IZD) produced by the agents against some selected Gram positive bacteria (GPB) and Gram negative bacteria (GNB) pathogens ranged from 6 – 25 mm and 6 – 12 mm respectively. The MIC and MBC values produced by the extract and fractions of the plant’s part against the GPB ranged from 1.25 – 40 mg/ml and 5 – 80 mg/ml respectively Many of the GNB were not sensitive to the agents tested except Pseudomonas aeruginosa and Klebsiella spp that exhibited mild to moderate sensitivity to the agents. Conclusion: These agents, therefore, exhibited a potent antibacterial activity against all the GPB and a few GNB pathogens tested due to their potent phytochemicals. The results of this work have corroborated the trado-medical use of root of Chrysophyllum albidum for treating ear infection, sore throat, typhoid, cellulites, septicaemia, bactericemia, boils and tooth infection/decay.

Evaluation of the effects of Albizia lebbeck bark extracts on the cariogenic properties of Streptococcus mutans

Introduction: Oral diseases continue to be a major and common health problem worldwide and affect the quality of life by causing considerable pain and discomfort. While the mechanistic methods of caries prevention and treatment are in vogue, the concern about adverse effects of the constituents of these methods persists. Thus, there has always existed a need to develop effective and safe strategies to combat oral pathogens such as Streptococcus mutans (S. mutans). Aim: To examine the action of Albizia lebbeck (A. lebbeck) bark extracts on the growth and virulence factors of S. mutans such as- biofilm formation, surface adherence, cell surface hydrophobicity and acid production. Materials and Methods: Ethyl acetate, hexane, and chloroform extracts of the bark of A. lebbeck was prepared and tested for their activity against the ATCC 25175 S. mutans. The phytochemical constituents of the extracts were determined by biochemical assays and the MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) were obtained using the well diffusion assay. The effect of the sub-MIC concentrations of extracts on biofilm formation & eradication, microbial growth, adherence of the strain to glass surfaces, cell surface hydrophobicity and acid production were also determined. Results: All extracts inhibited the organism’s growth, and MIC was determined as 25 mg/ml. the sub-MIC concentrations of the extracts were found to- inhibit the formation of biofilms, eradicate formed biofilms and interfere with the adherence and acid production of S. mutans. Conclusion: The ethyl acetate and ethanolic extracts were found to be active at low concentrations (0.02mg/ml) and demonstrate a potential to be used in the formulation of anti-caries preparations.

Antibacterial and antifungal activity of methanolic extracts of Salix alba L. against various disease causing pathogens / Atividade antibacteriana e antifúngica de extratos metanólicos de Salix alba L. contra vários patógenos que causam doenças

Abstract The present study was aimed to manifest the antibacterial and antifungal activity of methanolic extracts of Salix alba L. against seven Gram-positive and Gram-negative bacterial pathogens e.g. Streptococcus pyogenes, Staphylococcus aureus (1), S. aureus (2), Shigella sonnei, Escherichia coli (1), E. coli (2) and Neisseria gonorrhoeae and three fungal isolates from the air such as Aspergillus terreus, A. ornatus, and Rhizopus stolonifer. Two different serotypes of S. aureus and E. coli were used. The agar well-diffusion method results showed the dose-dependent response of plant extracts against bacterial and fungal strains while some organisms were found resistant e.g. E. coli (1), S. sonnei, A. terreus and R. stolonifer. The highest antibacterial activity was recorded at 17.000±1.732 mm from 100 mg/mL of leaves methanolic extracts against S. pyogenes while the activity of most of the pathogens decreased after 24 h of incubation. The highest antifungal activity was reported at 11.833±1.0 mm against A. ornatus at 50 mg/mL after 48 h of the incubation period. These experimental findings endorse the use of S. alba in ethnopharmacological formulations and suggest the use of methanolic extracts of the said plant to develop drugs to control the proliferation of resistant disease causing pathogenic microbes.

Resumo O presente estudo teve como objetivo manifestar a atividade antibacteriana e antifúngica de extratos metanólicos de Salix alba L. contra sete patógenos bacterianos Gram-positivos e Gram-negativos. Streptococcus pyogenes, Staphylococcus aureus (1), S. aureus (2), Shigella sonnei, Escherichia coli (1), E. coli (2) e Neisseria gonorrhoeae e três isolados de fungos do ar, como Aspergillus terreus, A. ornatus, e Rhizopus stolonifer. Dois sorotipos diferentes de S. aureus e E. coli foram usados. Os resultados do método de difusão em ágar mostraram a resposta dependente da dose de extratos de plantas contra cepas de bactérias e fungos, enquanto alguns organismos foram considerados resistentes, e.g. E. coli (1), S. sonnei, A. terreus e R. stolonifer. A maior atividade antibacteriana foi registrada em 17.000 ± 1.732 de 100 mg/mL de extratos metanólicos de folhas contra S. pyogenes, enquanto a atividade da maioria dos patógenos diminuiu após 24 h de incubação. A maior atividade antifúngica foi relatada em 11,833 ± 1,0 contra A. ornatus a 50 mg/mL após 48 h do período de incubação. Esses achados experimentais endossam o uso de S. alba em formulações etnofarmacológicas e sugerem o uso de extratos metanólicos da referida planta para o desenvolvimento de fármacos que controlem a proliferação de doenças resistentes que causam micróbios patogênicos.

Antibacterial and antifungal activity of methanolic extracts of Salix alba L. against various disease causing pathogens

Abstract The present study was aimed to manifest the antibacterial and antifungal activity of methanolic extracts of Salix alba L. against seven Gram-positive and Gram-negative bacterial pathogens e.g. Streptococcus pyogenes, Staphylococcus aureus (1), S. aureus (2), Shigella sonnei, Escherichia coli (1), E. coli (2) and Neisseria gonorrhoeae and three fungal isolates from the air such as Aspergillus terreus, A. ornatus, and Rhizopus stolonifer. Two different serotypes of S. aureus and E. coli were used. The agar well-diffusion method results showed the dose-dependent response of plant extracts against bacterial and fungal strains while some organisms were found resistant e.g. E. coli (1), S. sonnei, A. terreus and R. stolonifer. The highest antibacterial activity was recorded at 17.000±1.732 mm from 100 mg/mL of leaves methanolic extracts against S. pyogenes while the activity of most of the pathogens decreased after 24 h of incubation. The highest antifungal activity was reported at 11.833±1.0 mm against A. ornatus at 50 mg/mL after 48 h of the incubation period. These experimental findings endorse the use of S. alba in ethnopharmacological formulations and suggest the use of methanolic extracts of the said plant to develop drugs to control the proliferation of resistant disease causing pathogenic microbes.

Resumo O presente estudo teve como objetivo manifestar a atividade antibacteriana e antifúngica de extratos metanólicos de Salix alba L. contra sete patógenos bacterianos Gram-positivos e Gram-negativos. Streptococcus pyogenes, Staphylococcus aureus (1), S. aureus (2), Shigella sonnei, Escherichia coli (1), E. coli (2) e Neisseria gonorrhoeae e três isolados de fungos do ar, como Aspergillus terreus, A. ornatus, e Rhizopus stolonifer. Dois sorotipos diferentes de S. aureus e E. coli foram usados. Os resultados do método de difusão em ágar mostraram a resposta dependente da dose de extratos de plantas contra cepas de bactérias e fungos, enquanto alguns organismos foram considerados resistentes, e.g. E. coli (1), S. sonnei, A. terreus e R. stolonifer. A maior atividade antibacteriana foi registrada em 17.000 ± 1.732 de 100 mg/mL de extratos metanólicos de folhas contra S. pyogenes, enquanto a atividade da maioria dos patógenos diminuiu após 24 h de incubação. A maior atividade antifúngica foi relatada em 11,833 ± 1,0 contra A. ornatus a 50 mg/mL após 48 h do período de incubação. Esses achados experimentais endossam o uso de S. alba em formulações etnofarmacológicas e sugerem o uso de extratos metanólicos da referida planta para o desenvolvimento de fármacos que controlem a proliferação de doenças resistentes que causam micróbios patogênicos.

Inhibitory Activity of Ceiba' Honey against Escherichia Coli ATCC 33218

Escherichia coli is a type of bacteria that has evolved yearly, such as resistance to various antibiotics. Honey consumption can improve the quality of individual health. It has the potential to inhibit the growth of Escherichia coli. This study aimed to characterize the Escherichia coli ATCC 33218, and to investigate the inhibitory activity of Ceiba' honey against this strain. We obtained Ceiba' honey from the honey farm of Ceiba petandra. The antibiotic sensitivity tests revealed that the strain used in this study is not ESBL strain. Even it is resistant to Ampicillin, Amoxycillin, Penicillin, and Oxacillin and is sensitive to Cefotaxime. This study runs inhibition zone, MIC, MBC, and time-kill growth experiments to evaluate the inhibitory activity of Ceiba' honey. It showed a strong inhibition zone. Its MIC and MBC were 30 and 40%, respectively. The time-kill growth experiments revealed its inhibition by lowering the lag phase, slowing the growth rate, and decreasing the biomass yield of strain. In conclusion, Escherrichia coli ATCC 33218 is not an ESBL strain. Furthermore, Ceiba' honey has inhibitory and killing power against Escherichia coli ATCC 33218.

Construction of EF-G knockdown strain of Mycobacterium smegmatis and drug resistance analysis / 生物工程学报

As the only translational factor that plays a critical role in two translational processes (elongation and ribosome regeneration), GTPase elongation factor G (EF-G) is a potential target for antimicrobial agents. Both Mycobacterium smegmatis and Mycobacterium tuberculosis have two EF-G homologous coding genes, MsmEFG1 (MSMEG_1400) and MsmEFG2 (MSMEG_6535), fusA1 (Rv0684) and fusA2 (Rv0120c), respectively. MsmEFG1 (MSMEG_1400) and fusA1 (Rv0684) were identified as essential genes for bacterial growth by gene mutation library and bioinformatic analysis. To investigate the biological function and characteristics of EF-G in mycobacterium, two induced EF-G knockdown strains (Msm-ΔEFG1(KD) and Msm-ΔEFG2(KD)) from Mycobacterium smegmatis were constructed by clustered regularly interspaced short palindromic repeats interference (CRISPRi) technique. EF-G2 knockdown had no effect on bacterial growth, while EF-G1 knockdown significantly retarded the growth of mycobacterium, weakened the film-forming ability, changed the colony morphology, and increased the length of mycobacterium. It was speculated that EF-G might be involved in the division of bacteria. Minimal inhibitory concentration assay showed that inhibition of EF-G1 expression enhanced the sensitivity of mycobacterium to rifampicin, isoniazid, erythromycin, fucidic acid, capreomycin and other antibacterial agents, suggesting that EF-G1 might be a potential target for screening anti-tuberculosis drugs in the future.

Pyrazinamide-isoniazid hybrid: synthesis optimisation, characterisation, and antituberculous activity / Híbrido pirazinamida-isoniacida: optimización de síntesis, caracterización y actividad antituberculosa / Híbrido pirazinamida-isoniazida: otimização da síntese, caracterização e atividade antituberculose

Abstract Over time, the effective resistance mechanisms to various first- and second-line drugs against the disease of tuberculosis make its treatment extremely difficult. This work presents a new approach to synthesizing a hybrid of antituberculosis medications: isoniazid (INH) and pyrazinamide (PZA). The synthesis was performed using ultrasound-assisted synthesis to obtain an overall yield of 70%, minimizing the reaction time from 7 to 1 h. The evaluation of the biological activity of the hybrid (compound 2) was tested using the tetrazolium microplate assay (TEMA), showing inhibition in the growth of Mycobacterium tuberculosis H37Rv at a concentration of 0.025 mM at pH 6.0 and 6.7.

Resumen Debido a los grandes mecanismos de resistencia a lo largo del tiempo de diversos fármacos de primera y segunda línea contra la enfermedad de la tuberculosis, el tratamiento sigue dificultándose. Este trabajo presenta un nuevo enfoque para sintetizar un híbrido de fármacos antituberculosos: isoniazida (INH) y pirazinamida (PZA). La síntesis fue asistida por ultrasonido con el fin de obtener un rendimiento global del 70%, minimizando el tiempo de reacción de 7 a ' h. La evaluación de la actividad biológica del híbrido (compuesto 2) se probó usando el ensayo de microplaca de tetrazolio (TEMA), que mostró una inhibición en el crecimiento de Mycobacterium tuberculosis H37Rv a una concentración de 0,025 mM a pH 6,0 y 6,7.

Resumo Devido aos grandes mecanismos de resistência ao longo do tempo a diversos fármacos de primeira e segunda linha contra a tuberculose, o que torna seu tratamento extremamente difícil. Este trabalho apresenta uma nova abordagem para sintetizar um híbrido de fármacos antituberculose: isoniazida (INH) e pirazinamida (PZA) A síntese foi realizada utilizando a síntese assistida por ultrassom de forma a obter um rendimento global de 70%, minimizando o tempo de reação de 7 h para ' h. A avaliação da atividade biológica do híbrido (composto 2) foi testada utilizando o ensaio de microplaca de tetrazólio (TEMA), mostrando uma inibição no crescimento de Mycobacterium tuberculosis H37Rv na concentração de 0,025 mM em pH 6,0 e 6,7.

Antibacterial Activity of Zinc Oxide Nanoparticles in Self- Curing Acrylic Resin Against Streptococcus mutans

ABSTRACT: Antibacterial activity of zinc oxide nanoparticles in self-curing acrylic resin against Streptococcus mutans. The main objective of this study was to investigate whether nanoparticles of zinc oxide (ZnO) in self-curing acrylic resin, hav e antimicrobial properties against Streptococcus mutans, one of the microorganisms involved in the development of caries. Self- cured acrylic resin samples were prepared by incorporating ZnO nanoparticles at different concentrations based on the minimum inhibitory concentration (MIC) for Streptococcus mutans ATCC 25175. Antibacterial activity against a biofilm was evaluated in samples that were aged in artificial saliva for different times using spectral confocal laser microscopy and scanning electron microscopy. Kruskal-Wallis test using IBM SPSS Statistics version 23.0 software (SPSS Inc. ®, Chicago, IL, United States) were used, establishing the value of p <0.05 for statistical significance. The volume of the total biomass that formed in the samples aged for one day was significantly lower than the volume of the total biomass that was formed in those aged for additional days (p <0.001). Electron microscopy analysis revealed high porosity surfaces in all samples. Bacterial clusters wer e located next to large pores and irregular surfaces, while smooth surfaces had defined and linear organization cocci or simple chains. Considering the limitations of this study, the results suggest that the antibacterial activity of ZnO nanoparticles add ed to self-curing acrylic (ALIKE) is effective, mainly in fresh 1-day samples, independent of their concentration, and in samples with 16 MIC aged for 14 days, indicating it does not lose its antibacterial activity despite setting for more days. In addition, the ZnO nanoparticles added to ALIKE have the ability to inhibit the formation of biofilms, although they do not minimize the number of viable bacteria.

RESUMEN: El objetivo principal de este estudio fue investigar si nanopartículas de óxido de zinc (ZnO), incorporadas a acrílico acrilico de autocurado, tienen propiedades antimicrobianas contra Streptococcus mutans, uno de los microorganismos implicados en el desarrollo de caries. Se prepararon muestras de resina acrílica autopolimerizada mediante la incorporación de nanopartículas de ZnO a diferentes concentraciones basadas en la concentración mínima inhibitoria (MIC) para Streptococcus mutans ATCC 25175. Se evaluó la actividad antibacteriana contra una biopelícula en muestras envejecidas en saliva artificial para diferentes tiempos utilizando espectros microscopía láser confocal y microscopía electrónica de barrido. Se utilizó la prueba de Kruskal-Wallis utilizando el software IBM SPSS Statistics versión 23.0 (SPSS Inc. ®, Chicago, IL, Estados Unidos), estableciendo el valor de p <0,05 para la significancia estadística. El volumen de la biomasa total que se formó en las muestras envejecidas durante un día fue significativamente menor que el volumen de la biomasa total que se formó en las envejecidas durante días adicionales (p <0,001). El análisis de microscopía electrónica reveló superficies de alta porosidad en todas las muestras. Los cúmulos bacterianos se ubicaron junto a poros grandes y superficies irregulares, mientras que las superficies lisas tenían cocos o cadenas simples de organización lineal y definida. Considerando las limitaciones de este estudio, los resultados sugieren que la actividad antibacteriana de las nanopartículas de ZnO agregadas al acrílico autopolimerizable (ALIKE) es efectiva, principalmente en muestras frescas de 1 día, independientemente de su concentración, y en muestras con 16 MIC envejecidas para 14 días, lo que indica que no pierde su actividad antibacteriana a pesar de estar fraguada durante más días. Además, las nanopartículas de ZnO añadidas a ALIKE tienen la capacidad de inhibir la formación de biopelículas, aunque no minimizan el número de bacterias viables.

Antimicrobial properties of heterocyclic compounds against clinical mastitis isolates / Propriedades antimicrobianas de compostos heterocíclicos contra isolados de mastite clínica

Mastitis causes significant economic losses to the dairy cattle industry. The present study aimed to evaluate the antibacterial properties of 39 heterocyclic derivatives (1,3-thiazoles and 4-thiazolidinones) against clinical mastitis isolates from dairy cows. Milk samples were collected from cows with clinical mastitis and the bacterial species were identified by PCR. Antibacterial activity was assessed using the broth microdilution method. First, 39 heterocyclic compounds were tested against four bacterial isolates (Staphylococcus aureus, Streptococcus agalactiae, Corynebacterium bovis and Escherichia coli) randomly chosen from those recovered from the milk samples (Study 1). Subsequently, the compounds with the strongest antibacterial activity were tested against all the bacterial isolates recovered from the milk samples (Study 2). 1,3-thiazoles showed the strongest antibacterial activity, specially compounds 30 and 38, which also showed bactericidal properties according to their minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values. Corynebacterium spp. and Enterobacteriaceae isolates were the most susceptible to compounds 30 and 38. Compounds 30 and 38 are promising targets for new antimicrobial agents.(AU)

A mastite causa significativas perdas econômicas à indústria leiteira bovina. O presente estudo teve como objetivo avaliar as propriedades antibacterianas de 39 derivados heterocíclicos (1,3-tiazóis e 4-tiazolidinonas) contra isolados clínicos de mastite em vacas leiteiras. Amostras de leite foram coletadas de vacas com mastite clínica e as espécies bacterianas isoladas foram identificadas por PCR. A atividade antibacteriana foi avaliada pelo método de microdiluição em caldo. Primeiramente, os 39 compostos heterocíclicos foram testados contra quatro isolados bacterianos (Staphylococcus aureus, Streptococcus agalactiae, Corynebacterium bovis e Escherichia coli) escolhidos aleatoriamente dentre os recuperados das amostras de leite (Estudo 1). Posteriormente, compostos com atividade antibacteriana mais forte foram testados contra todos os isolados bacterianos recuperados das amostras de leite (Estudo 2). Os compostos 1,3-tiazóis apresentaram a maior atividade antibacteriana, principalmente os compostos 30 e 38, que também apresentaram propriedades bactericidas de acordo com seus valores de concentração inibitória mínima (CIM) e concentração bactericida mínima (CBM). Os isolados Corynebacterium spp. e Enterobacteriaceae foram os mais suscetíveis aos compostos 30 e 38. Os compostos 30 e 38 mostraram-se promissores como novos agentes antimicrobianos.(AU)

Antimicrobial properties of heterocyclic compounds against clinical mastitis isolates

ABSTRACT: Mastitis causes significant economic losses to the dairy cattle industry. The present study aimed to evaluate the antibacterial properties of 39 heterocyclic derivatives (1,3-thiazoles and 4-thiazolidinones) against clinical mastitis isolates from dairy cows. Milk samples were collected from cows with clinical mastitis and the bacterial species were identified by PCR. Antibacterial activity was assessed using the broth microdilution method. First, 39 heterocyclic compounds were tested against four bacterial isolates (Staphylococcus aureus, Streptococcus agalactiae, Corynebacterium bovis and Escherichia coli) randomly chosen from those recovered from the milk samples (Study 1). Subsequently, the compounds with the strongest antibacterial activity were tested against all the bacterial isolates recovered from the milk samples (Study 2). 1,3-thiazoles showed the strongest antibacterial activity, specially compounds 30 and 38, which also showed bactericidal properties according to their minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values. Corynebacterium spp. and Enterobacteriaceae isolates were the most susceptible to compounds 30 and 38. Compounds 30 and 38 are promising targets for new antimicrobial agents.

RESUMO: A mastite causa significativas perdas econômicas à indústria leiteira bovina. O presente estudo teve como objetivo avaliar as propriedades antibacterianas de 39 derivados heterocíclicos (1,3-tiazóis e 4-tiazolidinonas) contra isolados clínicos de mastite em vacas leiteiras. Amostras de leite foram coletadas de vacas com mastite clínica e as espécies bacterianas isoladas foram identificadas por PCR. A atividade antibacteriana foi avaliada pelo método de microdiluição em caldo. Primeiramente, os 39 compostos heterocíclicos foram testados contra quatro isolados bacterianos (Staphylococcus aureus, Streptococcus agalactiae, Corynebacterium bovis e Escherichia coli) escolhidos aleatoriamente dentre os recuperados das amostras de leite (Estudo 1). Posteriormente, compostos com atividade antibacteriana mais forte foram testados contra todos os isolados bacterianos recuperados das amostras de leite (Estudo 2). Os compostos 1,3-tiazóis apresentaram a maior atividade antibacteriana, principalmente os compostos 30 e 38, que também apresentaram propriedades bactericidas de acordo com seus valores de concentração inibitória mínima (CIM) e concentração bactericida mínima (CBM). Os isolados Corynebacterium spp. e Enterobacteriaceae foram os mais suscetíveis aos compostos 30 e 38. Os compostos 30 e 38 mostraram-se promissores como novos agentes antimicrobianos.

Antibacterial and Antibiofilm Activities of Crude Extract of Lasiodiplodia pseudotheobromae IBRL OS-64 against Foodborne Bacterium, Yersinia enterocolitica

The antibacterial and antibiofilm activities of crude extract of Lasiodiplodia pseudotheobromaeIBRL OS-64 was studied and tested against a foodborne pathogenic bacterium, Yersinia enterocolitica. The ethylacetate extract exhibited favorable antibacterial activity with the zone of inhibition was 20.3±0.6 mm compared to dichloromethane (15.0±0.3 mm) and butanol (9.0±0.3 mm) extracts. Minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) values of the extract were 125 and 250 μg/mL, respectively. Structural degeneration studies through scanning electron microscopy (SEM) and transmission electron microscope (TEM) micrographs exhibited major abnormalities that occurred on thebacterial cells after exposureto the extract were complete alterations in their morphology and collapsed of the cells beyond repair. The findings showed that the extract possesses antibiofilm activity against the initial and preformed biofilm of Y. enterocoliticawith the highest inhibition value of 69.12% and 58.70%, respectively The results also revealed the initial biofilm was more susceptible to the extract as compared to pre-formed biofilm. The light microscopy (LM) and SEM photomicrographs proved that thefungal extract significantly eliminates extracellular polysaccharide (EPS) matrices and hinder the attachment of the bacterial cells for biofilm formation. Therefore, the current study suggested the ethyl acetate crude extract from an endophytic fungus, L. pseudotheobromae IBRL OS-64 may be an effective antibacterial and anti-biofilm agent to treat foodborne pathogens

Effect of Methanolic Extract of Securigera securidaca as Antioxidant and Antibacterial Activities

In the present work, the phytochemical screening, polyphenolic content, antibacterial activity and antioxidant activity of Securigera securidacaseeds in methanol were carried out. Phytochemical analysis of seeds showed the presence of alkaloids, flavonoids, saponins, terpenoids, steroids and glycosides. Total phenolic content was estimated by Folin Ciocalteau method and the result showed the highest phenolic content of 62.28 mg/g. Methanolic extract was screened for antibacterial activity by disc diffusion method and it found to be potent. The MIC of methanol extract identified by broth dilution method showed a MIC value of 0.25 mg/ml for both E. coliand Kl. Oxytoca, and also 0.5 mg/ml for both S. aureusand S. epidermis.The antioxidant effect of the seeds was tested by DPPH scavenging activity as in vitro assay. The extract had potent inhibitory activity (IC50) value of 0.057mg/ml. The finding experimental results showed that methanolic extract of Securigera securidacais important as a source of antibacterial activity and polyphenolic antioxidants.

Coagulase-negative staphylococci: a 20-year study on the antimicrobial resistance profile of blood culture isolates from a teaching hospital

ABSTRACT The increasing rates of nosocomial infection associated with coagulase-negative staphylococci (CoNS) were the rationale for this study, aiming to categorize oxacillin-resistant CoNS species recovered from blood culture specimens of inpatients at the UNESP Hospital das Clínicas in Botucatu, Brazil, over a 20-year period, and determine their sensitivity to other antimicrobial agents. The mecA gene was detected in 222 (74%) CoNS samples, and the four types of staphylococcal chromosomal cassette mec (SCCmec) were characterized in 19.4%, 3.6%, 54.5%, and 14.4% of specimens, respectively, for types I, II, III, and IV. Minimal inhibitory concentration (MIC) values to inhibit 50% (MIC50) and 90% (MIC90) of specimens were, respectively, 2 and >256 µL/mL for oxacillin, 1.5 and 2 µL/mL for vancomycin, 0.25 and 0.5 µL/mL for linezolid, 0.094 and 0.19 µL/mL for daptomycin, 0.19 and 0.5 µL/mL for quinupristin/dalfopristin, and 0.125 and 0.38 µL/mL for tigecycline. Resistance to oxacillin and tigecycline and intermediate resistance to quinupristin/dalfopristin were observed. Eight (2.7%) of all 300 CoNS specimens studied showed reduced susceptibility to vancomycin. Results from this study show high resistance rates of CoNS to antimicrobial agents, reflecting the necessity of using these drugs judiciously and controlling nosocomial dissemination of these pathogens.

Dosificación empírica de vancomicina en neonatos: relación entre recomendación de dosis iniciales y relación área bajo la curva en 24 h/concentración inhibitoria mínima / Empiric vancomycin dosing in neonates: relationship between initial dose and 24 h area under the curve/minimum inhibitory concentration ratio

Resumen Introducción: Vancomicina es un antimicrobiano ampliamente utilizado para infecciones por Staphylococcus coagulasa negativa en neonatos; sin embargo, no existe claridad sobre la dosis empírica que asegure su eficacia terapéutica. Objetivo: Evaluar la relación entre las dosis iniciales de vancomicina utilizadas en una Unidad de Cuidado Intensivo Neonatal (UCIN) con la eventualidad de alcanzar el objetivo terapéutico de área bajo la curva sobre concentración inhibitoria mínima (ABC/CIM) mayor a 400 µg/h/mL. Materiales y Método: Estudio descriptivo y retrospectivo, realizado entre febrero 2016 y marzo 2018. Se incluyeron neonatos en tratamiento con vancomicina por sospecha/confirmación de infección por cocáceas grampositivas y medición de concentraciones plasmáticas de vancomicina al inicio del tratamiento. La probabilidad de alcanzar el objetivo terapéutico se evaluó mediante re-muestreo de valores de ABC y CIM. Resultados: Se incluyeron 38 pacientes con 49 concentraciones plasmáticas de vancomicina. Los aislados microbiológicos se confirmaron en 94,7% de los pacientes (n = 36). Los valores de ABC/CIM en dos grupos (según niveles valle de vancomicina < 10 µg/mL y ≥ 10 µg/mL), fueron de una mediana de 327 (IQ 25-75 = 174-395) y 494 (IQ 25-75 = 318-631), respectivamente (p = 0,035). Las dosis empíricas utilizadas logran logran un objetivo terapéutico (ABC/CIM > 400) de sólo 47,7% considerando CIMs en nuestra institución. Conclusiones: Teniendo en cuenta las sensibilidades institucionales, no es posible asegurar alcanzar ABC/CIM > 400 µg/h/mL. Se debe seguir investigando para replantear las actuales estrategias de dosificación y así determinar la más apropiada para neonatos.

Abstract Background: Vancomycin is used for treating coagulase-negative staphylococcus infections in neonates. However, concerns about the appropriate empirical dosing required for optimal efficacy, still remain. Aim: To assess the relationship between the initial doses of vancomycin used in a Neonatal Intensive Care Unit (NICU) with the possibility of achieving therapeutic target of AUC024h/MIC > 400 µg/h/mL. Methods: Retrospective and descriptive study carried out between February 2016 and March 2018. All neonates treated with vancomycin for suspected/proven Gram-positive infection and with at least one trough serum concentration level were included. Probability of target attainment (PTA) was evaluated through resampling of AUC and MIC values. Results: Final dataset included 38 patients and 49 trough vancomycin levels; 94.7% of these cases (n = 36) were confirmed Gram-positive infections. The median AUC/MIC values for the trough values vancomycin < 10 µg/mL group and for the ≥ 10 µg/mL group were 327 (IQR 174-395) and 494 (IQR 318-631) respectively (p = 0.035). Current empirical dosing strategy has a 47.7% PTA (AUC/MIC > 400) when taking institutional MICs into account. Conclusions: It is not possible to assure achieving a AUC/MIC > 400 µg/h/mL when considering institutional sensibilities. Current empiric dosing strategies should be reconsidered and further investigation needs to be done to help determine the appropriate empirical dosing required for optimal efficacy in neonates.

Manifestaciones clínicas de la insensibilidad congénita al dolor con anhidrosis / Clinicai manifestations of congenital Insensitivity to pain with anhidrosis

RESUMEN Introducción: La insensibilidad congénita al dolor con anhidrosis (HSAN IV o CIPA) es una enfermedad rara con sintomatologia multisistémica, que impacta el funcionamiento cognitivo, y afecta negativamente la calidad de vida los pacientes y sus familias. Se estima que la mayoría de los individuos que padecen esta enfermedad mueren antes de los tres años por las complicaciones que esta genera. Objetivo: Realizar una revisión de la sintomatologia clinica de la enfermedad y las alteraciones neurocognitivas reportadas en 145 casos de pacientes con insensibilidad congénita al dolor con anhidrosis reportados en la literatura cientifica entre 2000 y 2017. Desarrollo: La revisión permitió identificar los sintomas clínicos más frecuentes en los pacientes con insensibilidad congénita al dolor con anhidrosis IV: fiebres, anhidrosis, osteomielitis, fracturas, artropatias y necrosis avascular. Conclusiones: La insensibilidad congénita al dolor con anhidrosis como enfermedad multisistémica tiene implicaciones cognitivas en pacientes que la padecen; sin embargo, se desconoce el nivel de impacto de esta enfermedad en el comportamiento y las funciones superiores de los pacientes afectados.

ABSTRACT Introduction: The congenital insensitivity to pain with anhidrosis (HSAN IV) is a rare disease, which results in different with multisystem symptoms, impacting cognitive functions that affect negatively the quality of life not only in patients but also in relatives. It is estimated that most individuals suffering from this disease die before turning three years of age due to the complications that arise from this condition. Objective: Review the clinical symptomatology of this disease and the neurocognitive alterations that occurred in 145 cases of patients with HSAN IV reported in the scientific literature between 2000 and 2017. Findings: Te review allowed to identify the most frequent clinical symptoms in patients with HSAN IV: fever, anhidrosis, osteomyelitis, fractures, arthropathies and avascular necrosis. Conclusions: There is a scientific ignorance of the impact of HSAN IV on the behavior and superior functions in patients affected by this disease.

Partial Purification and Characterization of Albain 1, a Triterpene with Antimicrobial Activity, from the Wood Extract of Avicennia alba Blume

Secondary metabolites of plants are important resources for development of new drugs. Mangrove plants are very well known sources of wide variety of secondary metabolites. Many of these secondary metabolites from mangroves have been found to possess significant biological activities where human health is concerned. Avicennia albaBlume is one such mangrove plant with reports of having many such secondary metabolites of clinical and commercial interests.Aim:To evaluate antimicrobial activity potential of A. albawood extract and to isolate new bioactive constituent(s) responsible for such biological activity.Methodology: Preliminary screenings of antimicrobial activities in different organic solvent extracts of A. albawood tissue were done by TLC-bioautography method and phytochemical nature of the antimicrobial constituent(s) in the extracts have been studied. One compound exhibiting significant antimicrobial activity, named as Albain 1, has been isolated. MIC value has been determined for Albain 1. The purity and structure of Albain 1 have been determined by HPLC, 1HNMR, FTIR and HRMS etc. analysis.Results: 1HNMR, FTIR and HRMS analysis have found out that the isolated compound Albain1 is a triterpene and the molecular formula is C30H48O4.It has exhibited remarkable antimicrobial activity against Bacillus cereus, Bacillus polymyxa, Bacillus pumilas (MIC 125μg / ml).Conclusion:The observed antimicrobial activity of the isolated fraction of A. albaoffer great potentials in pharmaceutical industries.

Antibacterial Activity Of Desiccated Cyanobacterium Anabaena Sp. Isolated From Terracotta Monuments Of Bishnupur, West Bengal

Anabaena sp. are the dominant cyanobacterial species on terracotta monuments of Bishnupur which exposed to high solar radiation, ultraviolet and in a desiccated condition in most part of the year. In the present study three Anabaena species were isolated from crust samples and its antibacterial activities were evaluated against pathogenic bacteria Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus, Salmonella typhimurium, Escherichia coli. We observed good antibacterial activity in ethyl acetate and ethanol extract of Anabaena sp. (VBCCA 052002) which having highest antibacterial activity against Staphylococcus aureus, Salmonella typhimurium, Staphylococcus aureus and E. coli respectively. We have validated the antibacterial assay by using resazurin based antimicrobial assay in microtiter plates and calculated the MIC value of ethyl acetate extract of Anabaena sp. (VBCCA 052002) which is found to be 100 µg/ml against Staphylococcus aureus and 150 µg/ml against Salmonella typhimurium.

Antimicrobial, Antioxidant and Antibiofilm Potential of Peppermint (Mentha piperita) Essential Oil for Application in Meat Products

The current study was carried out to examine in-vitro antimicrobial, antioxidant and antibiofilm efficacy of Peppermint essential oil (PEO) for its potential application in meat products. Antimicrobial activity was measured by using zone inhibition assay (ZOI) and Minimum Inhibitory Concentration (MIC) against ten food borne pathogens including four Gram-positive viz. Listeria monocytogenes, Enterococcus faecalis, Bacillus cereus and Staphylococcus aureus and six Gram-negative viz. Proteus mirabilis, Salmonella enterica serovar Typhi, Klebsiella pneumonia, Shigella flexneri, Escherichia coli and Pseudomonas aeruginosa whereas antioxidant assay was measured using 1,1 diphenyl-2 picrylhydrazyl (DPPH) and 2-2- azinobis-3 ethylbenthiazoline-6-sulphonic acid (ABTS) radical scavenging activity. Maximum zone size was observed for Proteus mirabilis whereas, MIC values ranged from 5000-20000 ppm for all tested organisms. The oil was found to be more effective against Pseudomonas aeruginosa and Salmonella enterica serovar Typhi. Antibiofilm activity (%) was also performed against pure cultures of two pathogens i.e. Listeria monocytogenes and Proteus mirabilis as positive control. The results exhibited that with application of PEO, biofilm formation of both Listeria monocytogenes and Proteus mirabilis was inhibited by 45.80% and 73.01%, respectively in contrast to their respective controls. ABTS and DPPH radical scavenging activity of PEO was measured at five different concentrations and values were ranging from 17.24-49.07% for ABTS whereas 35.16 – 60.70% for DPPH under investigation. It can be concluded that peppermint essential oil possesses potent antimicrobial, antioxidant and antibiofilm activity and can be further used as a natural alternative for preservation in meat industry

Formulation Evaluation And Optimization Of Chitosan Coated Ceftriaxone Loaded Microparticles

Ceftriaxone, a third generation cephalosporin antibiotic is an important antibiotic used in the treatment of invasive infections caused by the certain bacteria such as the penicillin-resistant microorganisms like Staphyloccocus aureus, strains of S. pneumonia, S. aureus and Enterobacteriaceae , particularly among E. coli. There is increasing antimicrobial resistance of Ceftriaxone in particular against these strains of bacteria. This study has been conducted to formulate, evaluate and optimize chitosan coated ceftriaxone loaded microparticles with better efficacy and also observes the MIC against strains of bacteria. Emulsion crosslinking method was used for the formulation of microparticles of ceftriaxone by using chitosan as a polymer and glutraldehyde as a cross linking agent which is optimized by using Box-Behnken Design. Three independent variables were taken; effect of drug and the polymer ratio, effect of the stirring speed and effect of crosslinking agent and dependent variables were microparticles entrapment efficiency and the In vitro drug release. Following optimization of the formulations, physical characterization as well as entrapment efficiency and ultimately in-vitro evaluation was performed. Physical characterization include optical microscopy, SEM and DLS to check there physical properties. The method used for the formulation of microparticle had the optimum entrapment efficiency of 61.7% which was increase with the increase in the addition of the more amount of chitosan and glutraldehyde and method also achieved the good in vitro release. MIC studies of microparticles were done against Klebsiella pneumonia, Staphylococcus aureus, Streptococcus mutans, Escherichia coli and it was found that the formulations showed decrease in MIC.

Antimicrobial Activity of Bacterial Intracellular and Extracellular Pigment Extract Against Potent Pathogens

A strain of pigmented Pseudomonas aeruginosa was isolated from soil and was analyzed for its pigment’santimicrobial properties. The isolated bacteriaum was able to produce two types of pigments viz,extracellulat and intracellular. The extracellular pigment was green and was water soluble andintracellular pigment was dark red and was not diffusible in water. Both these pigments were extractedand extracted pigments were used for antimicrobial studies. Many potent pathogens were used for thisstudy. Both Gram positive, negative and fungal pathogens were used in this study. The antimicrobialproperties were explored by using well diffusion method. MIC values for extracellular pigment againstmany pathogens were also determined. The extracellular pigment showed notable antimicrobial activityagainst C. albicans ATCC10231 followed by M. luteus ATCC9341, S. aureus ATCC 6538, E.coli ATCC8739 and P. aeruginosa ATCC9027. The lowest MIC value was recorded forC.albicans (360±00 µg/mL), E. coli ATCC8739 (433.3±0.4 µg/mL). The results of this studyshowed that the bacterium produces extracellular pigment as a protective weapon against manypathogens and competitors on the other hand the intracellular pigment’s role is different fromextracellular pigment.