Susceptibility of cariogenic Streptococcus mutans to extracts of Garcinia kola, Hibiscus sabdariffa, and Solanum americanum.

BACKGROUND: The elimination of cariogenic bacteria from the oral cavity using antibacterial agents is one of the primary strategies for the prevention of dental caries. Avariety of plants with potent activity are known to be used in indigenous communities for dental hygiene worldwide. OBJECTIVE: To determine if Hibiscus sabdariffa, Solanum americanum and Garcinia kola can inhibit the growth of cariogenic bacteria in the mouth. METHODS: Methanol and aqueous extracts obtained from three plants, Hibiscus sabdariffa, Solanum americanum and Garcinia kola were studied for their antibacterial activity against cariogenic Streptococcus mutans obtained from patients with clinically identified carious lesions, using the agar dilution method. The sources of extracts for Garcinia, Hibiscus and Solanum were respectively fruits and leaves for the latter two. RESULTS: The extracts (both methanol and aqueous) from Garcinia kola showed the most intensive activity and completely inhibited the growth of the primary cariogenic Streptococcus mutans at 1.25 mg/ml. Hibiscus sabdariffa was also active at a minimum inhibitory concentration (MIC) of 2.5mg/ml while Solanum americanum did not show any direct effect on S. mutans. CONCLUSION: The result of this study showed that G. kola and H. sabdariffa have direct antibacterial effect on Streptococcus mutans.

Susceptibility profile of Enterococcus faecalis isolated at the Lagos University Teaching Hospital, Nigeria.

Enterococcus faecalis is the most common of the Enterococcus genus causing infection, particularly urinary tract infections, worldwide. It is also a common cause of nosocomial infections and resistance to various antibiotics is on the increase worldwide. Thirty-five strains of E. Faecalis isolated from various clinical specimens (blood, wound swabs endocervical swabs but mostly urine) were screened for high-level aminoglycoside resistance. Their susceptibility nine antibiotics (ampicillin, gentamicin, streptomycin, vancomycin, tetracycline cotrimoxazole and chloramphenicol, ciprofloxacin and erthromycin) was also determined. All isolates were susceptible to Ampicillin and Vancomycin with MIC90 of 4microg/ml but resistant to Nalidixic acid with an MIC90>256microg/ml. Four (11%) of the isolates showed high-level resistance to Gentamicin while 11(32%) exhibited high-level resistance streptomycin after 24 hours incubation. It will appear that Ampicillin in combination with gentamicin but not streptomycin, can still be used empirically for the treatment of Enterococcal infections.

Significance of antibiotics resistance amongst clinical bacterial isolates in Lagos.

In vitro susceptibility of several strains of six different species of clinical facultative pathogens involved in nosocomial infections in our hospital was investigated by a series of disc diffusion, broth dilution and Chequerboard titration testing. With disc diffusion method all the test strains, except Streptococcus pyogenes, were resistant to penicillin. 46% of the Klebsiella aerogenes and 73% of the Pseudomonas strains were generally resistant to cefotaxime. The minimum inhibitory concentration (MIC) of the antibiotics correlated well with the results of the disc diffusion tests. Synergistic effects were demonstrated by various combinations of gentamicin, ampicillin, clindamycin, colistin, cefoxitin, and ceftriazone against resistant strains of S. aureus, Pseudomonas aeruginosa, Escherichia coli and Klebsiella aerogenes. Against S. aureus the effect of gentamicin/clindamycin demonstrated indifference. The need for stringent caution is strongly advocated in the selection of combination therapy for serious infections caused by some hospital bacterial strains particularly in acute care units. The clinical microbiologist should be consulted at all times during the process of selection of an appropriate combined therapy for expert guidance.