RESUMO
Abstract This study investigated the synergy testing of penicillin, cephalosporin, amphenicols, and aminoglycoside in the camel milk (n=768 samples), subsequently used for isolation of MDR S. aureus targeting mecA gene. Antibiotic susceptibility of S. aureus showed >90% isolates were sensitive to ciprofloxacin and trimethoprim and resistant against oxacillin, ampicillin, and cefoxitin. Further, 50-85% of the S. aureus were sensitive to gentamicin, oxytetracycline, and chloramphenicol and resistant against cefotaxime, vancomycin, and cefixime. Minimum inhibitory concentration (MIC) of cefotaxime, (C) and ampicillin (A) in combination with gentamicin (G) was reduced by 99.34% and 70.46%, respectively, while with chloramphenicol (Ch), reduction was 57.49% and 60%, respectively. In addition, the Fractional Inhibitory Concentration Index (FICI) of G+A, Ch+C and Ch+G combinations showed synergy against 80%, 60%, and 30% of MDR S. aureus, respectively. Similarly, C+A and Ch+G displayed indifferent interaction against 70 % and 30% of isolates, respectively, while the later showed additive interaction against 10% of MDR S. aureus. Altogether, our results described effective combination of gentamicin and chloramphenicol with ampicillin and cefotaxime to combat MDR S. aureus
Assuntos
Penicilinas/agonistas , Staphylococcus aureus/patogenicidade , Cloranfenicol/agonistas , Sinergismo Farmacológico , Aminoglicosídeos/agonistas , Camelus/classificação , Testes de Sensibilidade Microbiana/instrumentação , Genes MDR , Leite/classificaçãoRESUMO
AIMS: This study aimed to evaluate in vitro individual and combined antifungal activity of propolis extract (PE) and oregano essential oil (OEO) against Penicillium allii, causal agent of blue mould disease. The chemical characterization of both products was also included. METHODS AND RESULTS: Chromatographic analysis of PE and OEO confirmed the presence of bioactive compounds. The antifungal susceptibility assays showed that PE and OEO were highly active against the mycelial growth and conidial germination of P. allii. PE and OEO MICs were 12·5 and 1·5 µl ml-1 , respectively. The MFCs of these products were 50 and 3·1 µl ml-1 , respectively. PE acted mainly through diffusion, while OEO acted by a mixed contribution of vapour and diffusion. Synergism and additive effect between both products were found in some combination ratios. CONCLUSION: PE and OEO, both natural products with different chemical composition, have a strong antifungal activity against P. allii and show a favourable interaction causing synergism. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study indicated the potential use of PE combined with OEO as a non-conventional strategy towards the formulation of a biofungicide to control blue mould disease in garlic seed-cloves.
Assuntos
Ascomicetos , Alho , Óleos Voláteis , Origanum , Penicillium , Própole , Syzygium , Óleos Voláteis/farmacologia , Extratos Vegetais/farmacologia , Própole/farmacologia , SementesRESUMO
A total of 15 Candida auris isolates from the SENTRY antimicrobial surveillance program between 2006 and 2019 were combined with 21 isolates from other collections for the evaluation of antifungal susceptibility and synergy against anidulafungin plus voriconazole or isavuconazole using the checkerboard method. Surveillance isolates were analyzed for genetic relatedness and resistance mechanisms. Applying the tentative statistical epidemiological cutoff values and the Centers for Disease Control tentative breakpoints, 32/36 isolates were resistant to fluconazole, 5/36 were resistant to amphotericin B, 5/36 were non-wild-type (NWT) to anidulafungin, 3/36 were NWT to micafungin, and 1/36 and 10/36 were NWT to isavuconazole and voriconazole, respectively. Of these, 10 isolates were multidrug resistant, which means that these isolates were resistant to 2 antifungal classes. Synergy or partial synergy was noted in 5/36 and 22/36, respectively, of the isolates with the combination of anidulafungin plus voriconazole, and 11/36 and 19/36 isolates, respectively, for the combination of anidulafungin plus isavuconazole. Multilocus sequence type (MLST) analysis of the 15 SENTRY isolates demonstrated that the isolates from the US were genetically related to, but different from, isolates from Latin America (Panama and Colombia) and Germany. Single nucleotide polymorphism (SNP) analysis showed that the 15 SENTRY isolates belonged to the described international clades and had associated Erg11 alterations, including 11 isolates displaying K143R, one displaying F126L, and one displaying Y501H alterations and a fluconazole MIC result of ≥64 mg/liter. Resistance mechanisms were not observed in the two isolates displaying fluconazole MIC values at 4 and 16 mg/liter. Isavuconazole displayed activity and greater synergy when tested with anidulafungin than seen with anidulafungin plus voriconazole against the C. auris clinical isolates that displayed resistance phenotypes.