Jornal de Agentes Antimicrobianos

Owing to the prevalence of antimicrobial resistance and its arising threat rendered by the ineffectiveness of existing antibiotics, the present work was aimed to generate new 5/6 substituted quinoxalinyl chalcones derivatives. A total of 16 compounds were synthesized and characterized by IR, 1H NMR, 13C NMR and mass spectral studies. The antimicrobial activity against resistant pathogens was by micro-dilution assay method. The result revealed that compounds bearing 2,4-dichloro benzylidine and 4-fluoro benzylidine moiety demonstrated promising antibacterial and antifungal activities against the selected pathogenic bacteria and fungi. It was observed that chalcones of 3,4- dihydroquinoxalin-2(1H)-one exhibited better activity (MIC: 2.57 ÃŽ¼M) as compared to the chalcones of quinoxalin-2,3(1H,4H)-dione. The ClogP values of the synthesized compounds were in good agreement with antifungal activity indicated the significance of lipid solubility better cell wall penetration. Overall quinoxalinyl chalcones exhibited broad spectrum antimicrobial activity.Owing to the prevalence of antimicrobial resistance and its arising threat rendered by the ineffectiveness of existing antibiotics, the present work was aimed to generate new 5/6 substituted quinoxalinyl chalcones derivatives. A total of 16 compounds were synthesized and characterized by IR, 1H NMR, 13C NMR and mass spectral studies. The antimicrobial activity against resistant pathogens was by micro-dilution assay method. The result revealed that compounds bearing 2,4-dichloro benzylidine and 4-fluoro benzylidine moiety demonstrated promising antibacterial and antifungal activities against the selected pathogenic bacteria and fungi. It was observed that chalcones of 3,4- dihydroquinoxalin-2(1H)-one exhibited better activity (MIC: 2.57 ÃŽ¼M) as compared to the chalcones of quinoxalin-2,3(1H,4H)-dione. The ClogP values of the synthesized compounds were in good agreement with antifungal activity indicated the significance of lipid solubility better cell wall penetration. Overall quinoxalinyl chalcones exhibited broad spectrum antimicrobial activity.

Objective: Antimicrobial materials are used as a possible approach to improve hygienic conditions in the food industry. The aim of this study was the investigation of the antimicrobial activity of the homopolymer of poly((tertbutyl- amino)-methyl-styrene) (poly(TBAMS)) and of the copolymer poly(TBAMS:acrylonitrile) [1:1] against microorganism present on meat processing equipment. Method: Antimicrobial polymers were characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry analysis. The antimicrobial activity against various pathogenic and spoilage bacteria (S. aureus, E. coli, L. monocytogenes, Salmonella spp., Pseudomonas spp., B. thermosphacta) was determined using a modified test method based on the Japanese Industrial Standard JIS Z 2801: 2000. Furthermore, the influence of high initial bacterial counts (up to 8.9 log10 cfu/ml) as well as the exposure of bacteria in mixed cultures on the antimicrobial activity was evaluated. Results: Spectroscopy identified the homopolymer poly(TBAMS) as well as a successful copolymerization with acrylonitrile. Results of antimicrobials tests showed significant reductions of bacterial counts on both polymers compared with the reference material of microorganisms in pure culture after 2 hour at 35°C. L. monocytogenes, E. coli and S. aureus were reduced to the detection limit (>4.2 log10-units). P. fluorescens was less sensitive to poly(TBAMS)-based films, especially to the copolymer. The homopolymer offers slightly higher activity than the copolymer, but glass transition temperature was lower. Tests with mixed cultures affirmed the dependency of activity on bacteria species. A tendency of higher antimicrobial activity against gram-positive was observed, if high initial counts were used; however, significant reduction of gram-negative were still determined. Conclusion: Poly(TBAMS)-films show excellent antimicrobial properties against microorganisms relevant in meat processing facilities, and the implementation of those surfaces could contribute to improving the hygienic conditions during production and processing.

The intestinal flora called the intestinal microbiota, consists of different bacteria and other microorganisms which occur naturally in the gastrointestinal tract organs components. These tract bacteria are present in their millions and help the functioning of the body in particular allowing aid to degradation of certain molecules into absorbable substrates. They also protect against invasion of the gut by other pathogenic bacteria, that is to say which may be responsible for disease. Factors like stress, antibiotics and diet can affect the balance of intestinal flora and in case of imbalance, digestive disorders type bloating, diarrhoea or vomiting may occur. Rattus norvegicus of weights 100 kg, from Algerian West Firm are scarified and isolation of their ileum and colon respectively. Two strains of bacteria, Escherichia coli and Lactobacillus are then purified and identified.

Lung cancer is a major health burden accounting for 1.59 million deaths worldwide. For both sub-types of lung cancer (NSCLC and SCLC), chemotherapy is an option. However, success is limited and side effects are detrimental to an individuals’ overall quality of life. To complicate matters further, cancer cells can develop resistance to chemotherapeutic agents due to the presence of membrane associated proteins such as P-glycoprotein and Multidrug resistance-associated protein. Thus it is, imperative that new drug treatments are developed that have neither the toxicity nor mechanisms of resistance associated with conventional chemotherapy. In recent years, antimicrobial peptides (AMPs) have attracted attention as potential anti-cancer drugs due to reports that they can selectively target and kill cancer cells while leaving normal healthy cells unaffected. This review summaries several studies and discusses whether AMPs could be a viable treatment option in the fight against lung cancer.

In this study we determined that Geobacillus sp. 15 strain secretes antibacterial compound-bacteriocin. Only few bacteriocin producing thermophilic bacteria of this genus have been identified to the date. Also, we optimized medium composition for the better cell growth of this strain and increased the yield of secreted bacteriocin. In this work we showed that some particular salts or their combinations may have impact on higher growth of Geobacillus sp. 15 strain bacteria or their produced bacteriocins. These results can facilitate research on this strain and its secreted bacteriocin. These antibacterial proteins and peptides are promising natural agents as an alternative to antibiotics in medicine or veterinary and to traditional preservatives in food industry. Optimized composition of the growth medium can be very useful for studies of other Geobacillus spp. strains and their produced bacteriocins. Furthermore, these data may be used to increase the biomass of Geobacillus bacteria and the yield of protein when it is dependent on bacterial cell yield.

The antibacterial assay of the seed of Vigna subterranea (Bambara Groundnut) on certain clinical isolates: Proteus mirabilis, Escherichia coli, Klebsiella aerogenes, Klebsiella ozaenae, Staphylococcus aureus and Pseudomonas aeruginosa was determined using the agar diffusion technique to investigate its potential use as antibacterial agent. The antimicrobial activity of the test organisms to the seed extract was screened by using the agar-well diffusion method. An inoculum suspension was swabbed uniformly to solidified 20 ml Mueller-Hinton Agar (MHA) and the inoculum was allowed to dry for 5 minutes. Holes of 5 mm in diameter were made in the seeded agar using sterile cork-borer. Aliquot of 50 μl from each seed extract was added into each well on the seeded medium and allowed to stand on the bench for 1 hour for proper diffusion and thereafter incubated at 37°C for 24 hour. The resulting inhibition zones were measured in millimeters (mm). Negative controls using 50 μl PBS were also run in the same manner and parallel to the treatments. These studies were performed in duplicate. The seed extracts of V. subterranea showed varying antimicrobial activities against the test organisms. Antimicrobial screening indicated that V. subterranea showed the highest (39 ± 2.55 mm) inhibition against E. coli and K. ozanae at dilutions 1 and 2 respectively. The least activity was observed at dilutions 2 while P. mirabilis and E. coli both had zones of inhibition of 8 ± 0.00 mm and 8 ± 1.41 mm respectively. Susceptibility testing using standard antibiotics (positive control) was also carried out. P. mirabilis, E. coli and K. aerogenes were susceptible to the entire tested antibiotics except Augumentin (AUG) and Amoxicillin (AMX). The diameters of the clear zones of inhibitions were measured and the result recorded to the nearest millimeters (mm). The diameter of the zone was used as a measure of the susceptibility of the isolate and the diffusion rate of the seed extracts/antibiotics through the agar medium. The result of the study suggests that seed extract of V. subterranea can be used for the treatment of infections caused by the test organisms.

Despite the many advances in the treatment of systemic lupus erythematous (SLE), infection remains one of the leading causes of morbidity and mortality of patients. The reasons for the high incidence of infection are immunosuppressive therapy and immune disturbances of lupus itself. Bacterial infections are most frequent, followed by viral and fungal infections. Vaccination is the most important tool in the prevention of infections specially influenza and Streptococcus pneumonia infections. Prophylaxis of tuberculosis and pneumocystosis are also recommended to prevent those deadly infections. In this review, we aim to give an overview of the prevention means of infections in SLE.