Screening of crude extracts of six medicinal plants used in South-West Nigerian unorthodox medicine for anti-methicillin resistant Staphylococcus aureus activity

BACKGROUND: Six Nigerian medicinal plants Terminalia avicennioides, Phylantus discoideus, Bridella ferruginea, Ageratum conyzoides, Ocimum gratissimum and Acalypha wilkesiana used by traditional medical practitioners for the treatment of several ailments of microbial and non-microbial origins were investigated for in vitro anti-methicillin Resistant Staphylococcus aureus (MRSA) activity. METHODS: Fresh plant materials were collected from the users. Water and ethanol extracts of the shredded plants were obtained by standard methods. The Bacterial cultures used were strains of MRSA isolated from patients. MRSA was determined by the reference broth microdilution methods using the established National Committee for Clinical Laboratory Standards break points. Staphylococcus aureus NCIB 8588 was used as a standard strain. Susceptibility testing and phytochemical screening of the plant extracts were performed by standard procedures. Controls were maintained for each test batch. RESULTS: Both water and ethanol extracts of T. avicennioides, P. discoideus, O. gratissimum, and A. wilkesiana were effective on MRSA. The Minimum Inhibition Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the ethanol extracts of these plants range from 18.2 to 24.0 mcg/ml and 30.4 to 37.0 mcg/ml respectively. In contrast, MIC range of 30.6 to 43.0 mcg/ml and 55.4 to 71.0 mcg/ml were recorded for ethanol and water extracts of B. ferruginea, and A. conyzoides respectively. Higher MBC values were obtained for the two plants. These concentrations were too high to be considered active in this study. All the four active plants contained at least trace amount of anthraquinones. CONCLUSION: Our results offer a scientific basis for the traditional use of water and ethanol extracts of A. wilkesiana, O. gratissimum, T. avicennioides and P. discoideus against MRSA-associated diseases. However, B. ferruginea and A. conyzoides were ineffective in vitro in this study; we therefore suggest the immediate stoppage of their traditional use against MRSA-associated diseases in Lagos, Nigeria

Trends of Multiple Drug Resistance in Salmonella Enterica Serovar Typhi in Lagos, Nigeria.

Background: The frequent treatment failures with empirical therapy observed in some hospitalized typhoid fever patients in the last decade is of great concerned to both public and private physicians owing to the wide spread and circulation of antibiotic resistant strains of S. typhiMethods: This study assessed the trends in antibiotic resistance in 235 Salmonella typhi stains isolated by standard procedures from blood and/stool samples of hospitalized patients from 1997 to 2003. All the isolates were subjected to antimicrobial susceptibility testing using the following antibiotics: chloramphenicol, Ampicillin, cotrimoxazole, tetracycline, nalidixic acid, ciprofloxacin and ofloxacin. Susceptibility and resistance were determined by standard methods.Results: From 1997 through 2003, 188 (80%) of 235 isolates were multiple drug resistant (MDR), chloramphenicol being the most resisted antibiotic (83.0%) followed by Ampicillin (81.7%). Only one strain was resistant to both ciprofloxacin and ofloxacin. Also the prevalence of chloramphenicol resistant isolates increased gradually from 72.4% in 1997 to 89.2% in 2003. Similar trends were recorded for other four antibiotics tested, even for single drug resistance S. typhi isolates. Our study confirmed increased in circulation of MDR-S. typhi isolates over relatively short period.Conclusion: We hereby suggest for a while the immediate stoppage of prescription of chloramphenicol and other first line antibiotics used in the treatment of typhoid fever in Nigeria. The use of more effective drugs such as ofloxacin and ciprofloxacin would go a long way in stemming the prevalence of persons with chronic infections as well as reducing the widespread of MDR-S. typhi strains in our environment, but our fear is that resistance is likely to develop unless these valuable drugs are used prudentl

Trends of Multiple Drug Resistance in Salmonella Enterica Serovar Typhi in Lagos, Nigeria.

Background: The frequent treatment failures with empirical therapy observed in some hospitalized typhoid fever patients in the last decade is of great concerned to both public and private physicians owing to the wide spread and circulation of antibiotic resistant strains of S. typhi Methods: This study assessed the trends in antibiotic resistance in 235 Salmonella typhi stains isolated by standard procedures from blood and/stool samples of hospitalized patients from 1997 to 2003. All the isolates were subjected to antimicrobial susceptibility testing using the following antibiotics: chloramphenicol, Ampicillin, cotrimoxazole, tetracycline, nalidixic acid, ciprofloxacin and ofloxacin. Susceptibility and resistance were determined by standard methods. Results: From 1997 through 2003, 188 (80%) of 235 isolates were multiple drug resistant (MDR), chloramphenicol being the most resisted antibiotic (83.0%) followed by Ampicillin (81.7%). Only one strain was resistant to both ciprofloxacin and ofloxacin. Also the prevalence of chloramphenicol resistant isolates increased gradually from 72.4% in 1997 to 89.2% in 2003. Similar trends were recorded for other four antibiotics tested, even for single drug resistance S. typhi isolates. Our study confirmed increased in circulation of MDR-S. typhi isolates over relatively short period. Conclusion: We hereby suggest for a while the immediate stoppage of prescription of chloramphenicol and other first line antibiotics used in the treatment of typhoid fever in Nigeria. The use of more effective drugs such as ofloxacin and ciprofloxacin would go a long way in stemming the prevalence of persons with chronic infections as well as reducing the widespread of MDR-S. typhi strains in our environment, but our fear is that resistance is likely to develop unless these valuable drugs are used prudently