Current Issue : October - December Volume : 2019 Issue Number : 4 Articles : 6 Articles
Microbial resistance to currently available antibiotics is a public health problem in the\nfight against infectious diseases. Most antibiotics are characterized by numerous side effects that\nmay be harmful to normal body cells. To improve the efficacy of these antibiotics and to find an\nalternative way to minimize the adverse effects associated with most conventional antibiotics, piperine\nand piperlongumine were screened in combination with conventional rifampicin, tetracycline, and\nitraconazole to evaluate their synergistic, additive, or antagonistic interactions against Staphylococcus\naureus, Pseudomonas aeruginosa, and Candida albicans. The fractional inhibitory concentration index\nwas used to estimate the synergistic effects of various combination ratios of the piperamides and\nantibiotics against the bacterial and fungal strains. Both piperine and piperlongumine showed\nsynergistic effects against S. aureus when combined at various ratios with rifampicin. Synergistic\ninteraction was also observed with piperine in combination with tetracycline against S. aureus, while\nantagonistic interaction was recorded for piperlongumine and tetracycline against S. aureus. All the\npiperamide/antibacterial combinations tested against P. aeruginosa showed antagonistic effects, with\nthe exception of piperine and rifampicin, which recorded synergistic interaction at a ratio of 9:1\nrifampicin/piperine. No synergistic interaction was observed when the commercial compounds were\ncombined with itraconazole and tested against C. albicans. The results showed that piperine and\npiperlongumine are capable of improving the effectiveness of rifampicin and tetracycline. Dosage\ncombinations of these bioactive compounds with the antibiotics used may be a better option for the\ntreatment of bacterial infections that aims to minimize the adverse effects associated with the use of\nthese conventional antibacterial drugs....
The aim of present work was to study the comparative antimicrobial activity of extract of Tinospora cordifolia (T. cordifolia), Merremia emarginata (M. emarginata) against different microbial species. The physiochemical parameter extractive values of both the drugs were determined for the selection of solvent by using chloroform, ethyl acetate and ethanol by soxhlet extraction. Extract of both individual drugs and combined drugs were prepared. Culture of microbial species of Salmonella typhi (S. typhi), Staphylococcus aureus (S. aureus) and Bacillus subtilis (B. subtilis) were prepared and zone of inhibition were checked by using individual extract of drug and combined extract drug. Both drugs shows antimicrobial activity against different microbial species as well as extract of combined drugs also showed good antimicrobial activity. Combined extract of T. cordifolia and M. emarginata showed more zone of inhibition against S. typhi. The obtained experimental data serve as useful guide for antimicrobial activity of combined effect of T. cordifolia and M. emarginata against S. typhi, S. aureus and B. subtilis. The combination of extract of two drugs shows optimal antimicrobial activity against S. typhi....
Antibiotic susceptibility testing (AST) specifies effective antibiotic dosage and formulates\na profile of empirical therapy for the proper management of an individual patientâ??s health against\ndeadly infections. Therefore, rapid diagnostic plays a pivotal role in the treatment of bacterial infection.\nIn this article, the authors review the socio-economic burden and emergence of antibiotic resistance.\nAn overview of the phenotypic, genotypic, and emerging techniques for AST has been provided\nand discussed, highlighting the advantages and limitations of each. The historical perspective on\nconventional methods that have paved the way for modern AST like disk diffusion, Epsilometer\ntest (Etest), and microdilution, is presented. Several emerging methods, such as microfluidic-based\noptical and electrochemical AST have been critically evaluated. Finally, the challenges related with\nAST and its outlook in the future are presented....
Bovine tuberculosis (bTB) is a highly transmissible infection and remains of great concern as a zoonosis. The worldwide incidence\nof bTB is in rise, creating potential reservoir and increased infection risk for humans and animals. In attempts to identify novel\nsurface antigens of Mycobacterium bovis as a proof-of-concept for potential inducers of protective immunity, we investigated\nsurface proteome of M. bovis BCG strain that was cultured under the granuloma-like condition. We also demonstrated that the\npathogen exposed to the biologically relevant environment has greater binding and invasion abilities to host cells than those of\nbacteria incubated under regular laboratory conditions. A total of 957 surface-exposed proteins were identified for BCG cultured\nunder laboratory condition, whereas 1,097 proteins were expressed under the granuloma-like condition. The overexpression of\nMb1524, Mb01_03198, Mb1595_p3681 (PhoU1 same as phoY1_1), and Mb1595_p0530 (HbhA) surface proteins in Mycobacterium\nsmegmatis leads to increased binding and invasion to mucosal cells. We also examined the immunogenicity of purified\nrecombinant proteins and tested M. smegmatis overexpressing these surface antigens for the induction of protective immunity in\nmice. Significantly high levels of specific IgA and IgG antibodies were observed in recombinant protein immunized groups by\nboth inhalation and intraperitoneal (IP) routes, but only IP delivery induced high total IgA and IgG levels. We did not detect\nmajor differences in antibody levels in the M. smegmatis group that overexpressed surface antigens. In addition, the bacterial load\nwas significantly reduced in the lungs of mice immunized with the combination of inhaled recombinant proteins. Our findings\nsuggest that the activation of the mucosal immunity can lead to increased ability to confer protection upon M. bovis\nBCG infection....
Plant-mediated synthesis of nanomaterials has been increasingly gaining popularity due to its eco-friendly nature and costeffectiveness.\nIn the present study, we synthesized silver (Ag) nanoparticles using aqueous extracts of fresh leaves of Impatiens\nbalsamina and Lantana camara medicinal plants as bioreducing agents. This method allowed the synthesis of nanoparticles, which\nwas confirmed by ultraviolet-visible (UV-Vis) spectrophotometry and transmission electron microscopy (TEM). UV-Vis spectra\nand visual observation showed that the color of the fresh leaf extracts of L. camara and I. balsamina turned into grayish brown and\nbrownish yellow, respectively, after treatment with Ag precursors. In addition, TEM analysis confirmed that AgNO3 solutions for\nall concentrations produced Ag nanoparticles and their average size was less than 24 nm. Moreover, aqueous leaf extracts of\nI. balsamina and L. camara were separately tested for their antimicrobial activity against Gram-positive Staphylococcus aureus and\nGram-negative Escherichia coli bacteria. The results showed that the bacterial growth was inhibited by the extracts containing Ag\nnanoparticles. Statistical calculation performed using the Tukey test showed that zones of inhibition for the two bacteria produced\nby the aqueous leaf extracts of L. camara containing 3mM and 5mM Ag precursors were not significantly different from that by\nciprofloxacin as positive control. On the contrary, there was significant difference between the zone of inhibition for E. coli by\nciprofloxacin and that by the extracts of I. balsamina leaves containing 3mM and 5mM Ag precursors. A similar result was\nobserved on the zone of inhibition for S. aureus by the extracts of I. balsamina leaves containing 3mMAg precursor. It was shown\nthat the aqueous extracts of fresh L. camara leaves containing Ag nanoparticles were comparable to ciprofloxacin in inhibiting\nbacterial growth....
Since conventional culture-based antibiotic susceptibility testing (AST) methods are too\ntime-consuming (typically 24-72 h), rapid AST is urgently needed for preventing the increasing\nemergence and spread of antibiotic resistant infections. Although several phenotypic antibiotic\nresistance sensing modalities are able to reduce the AST time to a few hours or less, concerning the\nbiological heterogeneity, their accuracy or limit of detection are limited by low throughput. Here,\nwe present a rapid AST method based on whole slide imaging (WSI)-enabled high-throughput\nsensing antibiotic resistance at single-bacterium level. The time for determining the minimum\ninhibitory concentration (MIC) was theoretically shortest, which ensures that the growth of each\nindividual cell present in a large population is inhibited. As a demonstration, our technique was\nable to sense the growth of at least several thousand bacteria at single-cell level. Reliable MIC of\nEnterobacter cloacae against gentamicin was obtained within 1 h, while the gold standard broth dilution\nmethod required at least 16 h for the same result. In addition, the application of our method prevails\nover other imaging-based AST approaches in allowing rapid and accurate determination of antibiotic\nsusceptibility for phenotypically heterogeneous samples, in which the number of antibiotic resistant\ncells was negligible compared to that of the susceptible cells. Hence, our method shows great promise\nfor both rapid AST determination and point-of-care testing of complex clinical bacteria isolates....
Loading....