RESUMEN
The effect of high N-acetylcysteine (NAC) concentrations (10 and 50 mM) on antibiotic activity against 40 strains of respiratory pathogens was investigated. NAC compromised the activity of carbapenems (of mostly imipenem and, to lesser extents, meropenem and ertapenem) in a dose-dependent fashion. We demonstrated chemical instability of carbapenems in the presence of NAC. With other antibiotics, 10 mM NAC had no major effects, while 50 mM NAC sporadically decreased (ceftriaxone and aminoglycosides) or increased (penicillins) antibiotic activity.
Asunto(s)
Acetilcisteína/farmacología , Antibacterianos/farmacología , Imipenem/farmacología , Tienamicinas/farmacología , beta-Lactamas/farmacología , Aminoglicósidos/antagonistas & inhibidores , Aminoglicósidos/farmacología , Ceftriaxona/antagonistas & inhibidores , Ceftriaxona/farmacología , Combinación de Medicamentos , Interacciones Farmacológicas , Enterobacter cloacae/efectos de los fármacos , Enterobacter cloacae/crecimiento & desarrollo , Enterobacter cloacae/aislamiento & purificación , Ertapenem , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Escherichia coli/aislamiento & purificación , Humanos , Imipenem/antagonistas & inhibidores , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/crecimiento & desarrollo , Klebsiella pneumoniae/aislamiento & purificación , Meropenem , Pruebas de Sensibilidad Microbiana , Penicilinas/agonistas , Penicilinas/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/crecimiento & desarrollo , Pseudomonas aeruginosa/aislamiento & purificación , Infecciones del Sistema Respiratorio/microbiología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Staphylococcus aureus/aislamiento & purificación , Streptococcus pneumoniae/efectos de los fármacos , Streptococcus pneumoniae/crecimiento & desarrollo , Streptococcus pneumoniae/aislamiento & purificación , Streptococcus pyogenes/efectos de los fármacos , Streptococcus pyogenes/crecimiento & desarrollo , Streptococcus pyogenes/aislamiento & purificación , Tienamicinas/antagonistas & inhibidores , beta-Lactamas/antagonistas & inhibidoresRESUMEN
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