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Antibiotic resistance crisis occasioned by sporadic appearance of multi-drug resistance (MDR) in human pathogens to clinically applied antimicrobials is a serious threat to global health. In this study, we investigated the drug resistant phenotype of Gram-positive cocci isolates from environment. Staphylococcus capitis and Staphylococcus haemolyticus colonies were isolated on mannitol-salt agar plates supplemented with tetracycline. Antibiotic susceptibility profile of the isolates via minimum inhibitory concentration (MIC) determination was examined. Isolates showed decreased sensitivity to clinically applied antimicrobial agents: tetracycline, kanamycin, erythromycin, norfloxacin, teicoplanin, and ampicillin. Genomic analysis demonstrated the presence of multiple antibiotic resistant genes in these bacteria, suggesting the origin of the multiple antimicrobials resistant phenotype. Tetracycline resistance of these isolates was transduced to Staphylococcus aureus-RN4220 strain. These findings indicate the presence of multiple antimicrobials resistant S. capitis and S. haemolyticus strain in a nonhospital setting. Moreover, the presence of plethora of genes responsible for MDR suggest that these strains could present potential threat to human health by serving as reservoir for lateral transference of antimicrobial resistance conferring foreign genetic elements to other clinically relevant pathogens. [ABSTRACT FROM AUTHOR]

A new class of 10 novel quinoxaline hydrazones was synthesized to examine their antimicrobial activity. The structures of the compounds were confirmed by IR, 1H-NMR, and MS spectral data and elemental analyses. Antimicrobial activity of the compounds was evaluated against 3 fungal and 7 bacterial strains by Micro-broth dilution assay. All of the synthesized compounds showed significant antibacterial activity against Pseudomonas aeruginosa. Furthermore, antibacterial activity of the 2,4- difluoro substituted compound 4b displayed two fold better activity than chloramphenicol against this bacterial strain. [ABSTRACT FROM AUTHOR]