Studies on some clinical bacteria resistance to some antibiotics

SUMMARYFor many years methicillin resistant Staphylococcus aureus (MRSA) infections had been considered a problems for hospitals and other health care facilities, in recent years the emergence and spread of multidrug resistant Gram positive bacteria represent a The prevalence of MRSA increasing with infections caused by MRSA became one the most commonly acquired types of nosocomial infections due to excessive use of antibacterial agents.Due to increasing prevalence of antibiotics resistant staphylococci has prompted the need for antibacterial controls other than antibiotics, thus during last years a large number of essential oils and their constituents have been investigated for their anThe present investigation was carried out in an effort to open a new area for the possibility of making use of some plant extracts as antibacterial agents for this purpose, by using eight essential oils as marjoram, cumin, peppermint, clove, caraway, anisThis study carried out in the Microbiology Department Faculty of Medicine, Zagaizg University in period from May 2001 to March 2003. This work aims to isolate the MRSA strains from different hospital departments (surgery, orthopedic, and gynecology obstet(A) Antibiotic susceptibility:The obtained results are summarized as follows:1- The number of MRSA isolates among inpatients were higher than that of outpatients2- The percentage of MRSA isolates were higher in male with (65.45%) than that of female isolates (34.55%).3-The data illustrated that the isolated MSSA strains were susceptible to most tested antibiotics, as ciprofloxacin and gentamicin (100%), cephradine (90.1%), cefotaxime sodium (83.1%), chloramphenicol (76.1%) and erythromycin (57.7%), but less sensitive 4- The MRSA isolates were multidrug resistant to most chosen used antibiotics in this study; ciprofloxacin (quinolones) was the only antibiotic that effect on MRSA isolates.5- The minimum inhibitory concentration of ciprofloxacin antibiotic was highly to more resistant MRSA isolates (No. 17 and 20) which recorded 16 and 64 g/ml respectively.6- The results revealed that the more resistant MRSA isolates, (No. 17 and 20) resistant to high concentration of sodium chloride reach to 18% and combination with ciprofloxacin antibiotic at 14 and 62g/ml.(B) Antibacterial activity of plant extracts and essential oils:1- The plant extracts (water and alcoholic) of spearmint, caraway and anise have no effect against two MRSA isolates (No. 17 and 20).2- The alcoholic extracts from clove, rosemary, nigella, thyme, cardamom, liquorice and coriander were most effective on MRSA isolates (No. 17 and 20) but alcoholic extracts from black mustard and ammivisnaga have effect only on isolate (No. 17).3- The essential oils from thyme cinnamon and clove were the most inhibitory effect at 0.1 and 0.2ml against more resistant MRSA isolates (No. 17 and 20).4- Caraway oil has less effect at 0.1 and 0.2ml against selected MRSA isolates.5- The anise oil has no effect at 0.1 and 0.2ml against MRSA isolate (No, 17) while has antibacterial activity against MRSA isolates (No. 20).6- Peppermint oil has low effect at 0.1 and 0.2ml against MRSA isolates (No. 17), while 0.1 ml of oil not affected on isolate (No.20) but at 0.2ml has antibacterial effect.7- The marjoram and cumin essential oils showed no antibacterial activity against MRSA isolates (No. 17 and 20).8- The antibacterial activity of oils increased with increasing the concentration of tested oils.9- The combination between eight essential oils showed varied antibacterial activity but these combinations were not active than oil only against selected MRSA isolates.10-The thyme oil has the highest antibacterial activity against tested MRSA isolates followed by clove and cinnamon had less effective when applied by fumigation method.11-The combination between thyme oil, ciprofloxacin, methicillin, sodium chloride and calcium chloride were increased the antibacterial activity against tested MRSA isolates (No. 17 and 20).12- The thyme oil with ciprofloxacin and thyme oil with methicillin were have the same results of using thyme oil only against tested MRSA isolates.13- The mixture of the thyme oil with sodium chloride and thyme oil with calcium chloride showed antibacterial activity against tested MRSA isolates but the results of these combinations were not active than thyme oil alone.14- The inhibitory action of the thyme oil showed bactericidal effect at 0.2 ml, after 24, 48 and 72 hours against tested MRSA isolates, while at 0.1ml thyme oil has bacteriostatic after 72 hours only.