Antibacterial activities of plant leaf extracts against multi-antibiotic resistant Staphylococcus aureus associated with skin and soft tissue infections.

BACKGROUND: The antibacterial activities of aqueous leaf extracts of Moringa oleifera, Vernonia amygdalina, Azadirachta indica and Acalypha wilkesiana against multidrug resistance (MDR) Staphylococcus aureus associated with skin and soft tissue infections were investigated. METHODS: Staphylococcus aureus (n = 183) from the skin and soft tissue infections with evidence of purulent pus, effusions from aspirates, wounds, and otorrhea were biotyped, and evaluated for biofilm production. The phenotypic antibiotic resistance and MDR strains susceptibility to plant leaves extract were determined using disc diffusion and micro-broth dilution assays respectively. The correlation of plant extract bioactive components with inhibitory activities was determined. RESULTS: High occurrence rate of S. aureus were recorded among infant and adult age groups and 13.2% mild biofilm producers from the wound (p < 0.05). Of 60.2% MDR strains with overall significant MARI of more than 0.85 (p < 0.05), high resistant rates to linozidine (92.7%; 95% CI:7.27-10.52), ofloxacin (94.2%; 95% CI:6.09-8.15), chloramphenicol (91.2%; 95% CI:6.11-8.32), gentamicin (97.3%; 95% CI:6.20-8.22), ciprofloxacin (92.7%; 95% CI: 5.28-7.99) and vancomycin (86.6%; 95% CI:6.81-9.59) were observed. Vernonia amygdalina and Azadirachta indica showed significant antimicrobial activity at 100 mg/ml and 75 mg/ml, with low susceptibility of less than 10% to 25 mg/ml, 50 mg/ml, and 75 mg/ml Moringa oleifera. Alkaloids, saponin and terpenoids were significant in Moringa oleifera, Acalypha wilkesiana, Azadirachta indica and Vernonia amygdalina leaves extracts (p < 0.05). High inhibitory concentrations at IC50; 3.23, 3.75 and 4.80 mg/ml (p = 0.02, CI: - 0.08 - 11.52) and IC90; 12.9, 7.5, and 9.6 mg/ml (p = 0.028, CI: 2.72-23.38) were shown by Acalypha wilkesiana, Vernonia amygdalina and Moringa oleifera respectively. Comparative outcome of the plant extracts showed Acalypha wilkesiana, Vernonia amygdalina and Moringa oleifera to exhibit significant inhibition activities (p < 0.05) compared to other extracts. Significant median inhibitory concentration (15.3 mg/ml) of Azadirachta indica were observed (p < 0.01) and strong associations of phytochemical compounds of Azadirachta indica (eta = 0.527,p = 0.017), Vernonia amygdalina (eta = 0.123,p = 0.032) and Acalypha wilkesiana (eta = 0.492,p = 0.012) with their respective inhibitory values. CONCLUSION: Observed high occurrence rate of skin and soft tissue infections caused by biofilm-producing MDR S. aureus requires alternative novel herbal formulations with rich bioactive compounds from Moringa oleifera, Acalypha wilkesiana, Azadirachta indica and Vernonia amygdalina as skin therapeutic agents.

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.

The bacteriology of chronic suppurative otitis media.

Specimens obtained directly from the middle ear under direct vision from 40 patients with chronic suppurative otitis media (CSOM) were investigated quantitatively and qualitatively for aerobes and anaerobes. Twenty one of the 40 specimens yielded aerobes only, 17 yielded a mixed flora of anaerobes and aerobes while only one yielded anaerobes only and the remaining one was sterile. Bacteroides fragilis was the commonest anaerobe and the second single most common bacteria generally present in CSOM. Pseudomonas aeruginosa and Staphylococcus aureus were the dominant aerobic flora appearing in 17 and 14 out of 40 specimens respectively. All pathogens isolated were present in very high counts averaging 10(8) ml of the exudate. The use of systemic anti-anaerobic drug combined with an anti-aerobic drug is worthy of a clinical trial.

Nasopharyngeal carriage of Neisseria meningitidis among school children at Ijede, Lagos State, Nigeria.

A total of 639 school children ranging in age from 5 to 15 years were investigated for nasopharyngeal carriage of Neisseria meningitidis in Ijede, Lagos-State, Nigeria. The carriage rate was found to be 6.2%. Of the 40 children from whom meningococci were isolated, 25 (62.5%) were males and 15 (37.5%) were females. Serogrouping of the isolates showed that serogroup C Neisseria meningitidis was isolated with the highest frequency 40%, while serogroups A, B, and W135 had isolation rates of 25.5%, 17.5% and 7.5% respectively. This study has shown that group C Neisseria meningitidis is the prevalent serogroup among school children in the area, which is south of the meningitis belt in Nigeria.

Direct Gram's stain of vaginal discharge as a means of diagnosing bacterial vaginosis.

The diagnosis of bacterial vaginosis (BV) by direct gram-stained smear of vaginal discharge was evaluated in 90 consecutive patients. Vaginal secretions from 20 healthy female volunteers were also examined. All specimens were examined by culture for growth of Gardnerella vaginalis and Lactobacillus spp. Only 35 (38.9%) of the patients with vaginal discharge satisfied the clinical diagnosis of BV. The vaginal gram-stained smear from all these 35 patients contained typical gardnerella morphotypes characteristic of BV and G. vaginalis was isolated from all of them as well as from a further 10 patients who did not satisfy the criteria for diagnosis of BV. The semi-quantitative assessment of gardnerella morphotypes was found to correlate positively with the semi-quantitative assessment of G. vaginalis growth by culture (p less than 0.0001). There was a strong inverse relationship between the quantity of lactobacillus and gardnerella morphotypes. Direct gram-staining of smears should facilitate the diagnosis of BV for clinicians with minimum need for confirmation by culture, particularly in a third world setting with few or no laboratory facilities.

Randomised comparative efficacy of clindamycin, metronidazole, and lincomycin, plus gentamicin in chronic suppurative otitis media.

Chronic suppurative otitis media is major health problem seen frequently in the ENT clinics in Nigeria and the outcome of most medical management in the past have been disappointing. A comparative randomised clinical trial involving combination therapies with systemic clindamycin, metronidazole, lincomycin, each with gentamicin, was conducted on a total of 14 patients. At the end of one week, and three-week, follow-up end points the clinical response with bacteriological cure were, for clindamycin and gentamicin 21%, metronidazole and gentamicin 33%, lincomycin and gentamicin 22%, and the control (aural toilet alone) 14%. However, when the clinical response was measured only by the ceasation of discharge, the outcome was more impressive. By this assessment the clinical response with clindamycin and gentamicin was 52% of the 140 patients, metronidazole and gentamicin 69%, lincomycin and gentamicin 47%, and the control 24%. The metronidazole and gentamicin regime was significantly more effective than the other regimes and it is suggested for use in prophylactic treatment of CSOM patients undergoing surgical procedures.

The anaerobic and aerobic bacterial flora of leg ulcers in patients with sickle-cell disease.

Leg ulcers in 26 patients with sickle-cell disease (SCD) were studied bacteriologically over a period of 6 months. The average age of the patients was 20.92 years and the mean duration of the ulcers was 3.43 years. In order of frequency, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacteroides melaninogenicus were the predominant organisms. Anaerobes were isolated from 14 (54%) of 26 patients and represent 21% of the total 77 isolates. The presence of anaerobes correlated well with odorous ulcers. Isolation of anaerobes from leg ulcers of patients with SCD has added to knowledge of bacterial infection in SCD.

Effect of cariogenic food exposure on prevalence of dental caries among fee and non-fee paying Nigerian schoolchildren.

Dental caries status, frequency of sweet consumption and method of toothcleaning of 180 Nigerian elementary schoolchildren aged 8-15 yr were investigated by clinical examination and questionnaire technique. The highest frequency of sweet consumption was recorded for the fee-paying pupils, who also had statistically significantly higher caries prevalence than in non-fee paying schools (P less than 0.001). About 48% and 24% of the fee and non-fee paying pupils respectively had dental caries. There was no significant difference in the sex distribution of the disease (P greater than 0.05). However, there was a significant difference (P less than 0.001) between methods of cleaning the teeth in the two types of schools. The majority (95%) of the fee-paying pupils used only a toothbrush while 51% of the non-fee paying pupils used a chewing stick. Methods for restricting the use of sweet snacks in addition to oral hygiene instruction are discussed as important means to reduce the increasing caries prevalence in schoolchildren in developing countries.