| Abstract: |
Summary, Conclusions & RecommendationsThe rapidly growing problem of antibiotic-resistant Streptococcus pneumoniae is increasing from day to day. The problem is exacerbated by the tendency of these strains to spread throughout the community and throughout the world. This study was carried out to determine the percentage of penicillin and erythromycin resistant Streptococcus pneumoniae on 600 outpatients from May 2002 to April 2004. Cases suffering from different clinical conditions, presented with (100) nasopharngitis, (50) cases of sinusitis, (80) cases with acute otitis media, (300) cases of COPD, (50) cases of pneumonia, (14) cases with conjunctivitis and (6) cases with meningitis.All of the collected specimens were subjected to direct Gram staining, cultivation on gentamycin sheep blood agar in CO2 incubation conditions. Optochin disc sensitivity was done to ?-hemolytic colonies to differentiate between Streptococcus pneumoniae and Streptococcus viridans, intraperitoneal injection of the suspected growth filtrate was inoculated in mice in controversial cases. 30 Streptococcus pneumoniae strains were isolated with the following distribution and percentage: 6 strains from cases of nasopharyngitis (6%), 6 strains from cases of sinusitis (12%), 18 strains from cases of COPD and pneumonia (5.14%).Antibiotic susceptibility testing was done to the isolated 30 Streptococcus pneumoniae strains against 16 antibiotics belonged to different antibiotic groups. E-test strips to both penicillin and erythromycin were used for MIC determination for all isolates. S. pneumoniae ATCC (700905) was used as a quality control strain for accurate results.22 (73.3%) of the isolates were resistant to penicillin, while 18 (60%) were erythromycin-resistant. 14 (46.7%) of the collected isolates were multidrug resistant. 30 (100%) of the isolates were sensitive to impinem, vancomycin and gatifloxacin. The most resistant antibiotic was tetracycline 25 (83.3%).There was highly significant association between previous antibiotic intake and the isolation of erythromycin-resistant strains. Allergy followed by smoking was also significant risk factors. However, age, sex and educational level were not significant risk factors. There was significant association between recovery of erythromycin-resistant strains with autumn followed by winterPCR was done for detection of erythromycin-resistant determinants searching for ermB and mef E genes. DNA extraction to erythromycin-resistant strains was done by three different methods: by freezing and boiling, phenol-chloroform extraction and DNA extraction kit with nearly almost similar results regarding to DNA purity. The cheapest and the most rapid method was freezing and boiling. The most pure DNA was obtained from extraction by phenol-chloroform extraction.DNA amplification was done using primers designed for ermB and mef E genes. Ready to go beads PCR beads were used. MefE gene was detected in 18 (100%) of erythromycin-resistant strains while 12 (66.7%) of these strains contain ermB gene. No erythromycin-resistant strain was free from these determinants.From the previous summary, we can conclude that:1- The percentage of penicillin and erythromycin resistant Streptococcus pneumoniae is the highest among all studies dealt with this topic (72.3%) and (60%) respectively.2- Cases with sinusitis are risky patients for development of penicillin and erythromycin-resistant Streptococcus pneumoniae.3- There is a strong association between resistance to certain group of antibiotics and development of resistance to others.4- There is a strong association between recent antibiotic intake and development of erythromycin resistant Streptococcus pneumoniae.5- Autumn followed by winter is significantly associated with development of erythromycin resistant Streptococcus pneumoniae.Although appropriate antimicrobial-drug use has unquestioned benefit, the following recommendations should be followed:1. No antibiotic prescription except when it is highly indicated, if it is made sure that it is bacterial infection.2. The patient should be asked about the antibiotics that he had given during the last months, or the best is to make a special file for each patient to avoid losing of more antibiotics and so generation of resistant strains.3. The patient should be instructed to complete the course of antibiotic to maximize bacterial eradication.4. Utilization of the PK-PD of the antibiotic should be done with respection of drug interactions and keeping the site of infection. in mind5. Creation of general awareness about importance of antibiotics and its policy should be available to the general population6. Written regulations and periodic review for ideal antibiotics should be available for the medical stuff in all hospital departements.7. Surveillance for the general prescribing practice with basic principles and approved guidelines.8. Regular monitoring of culture and sensitivity results of prevalent nosocomial infections should be done.9. Regular evaluation of the success/ failure rate of these guidelines by the infection control committee should be followed.
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