Chemical Study and Comparison of the Biological Activities of the Essential Oils of Helichrysum petiolare, H. cymosum, and H. odoratissimum.

Helichrysum species are prominent South African medicinal plants. From the essential oils (EOs) of three Helichrysum species, H. petiolare, H. odoratissimum, and H. cymosum, sixty-three constituent components were identified, with hydrocarbons and oxygenated monoterpenes and sesquiterpenes as major components. The compounds were analyzed by gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) spectroscopy. In H. petiolare EO, the major components were faurinone (20.66%) and (E)-ß-ocimene (17.21%). Faurinone was isolated from this EO for the first time. In H. odoratissimum, 1,8-cineole (17.44%) and α-pinene, and γ-curcumene (15.76%) were the major components whereas, in H. cymosum, α-pinene (29.82%) and (E)-caryophyllene (19.20%) were the major components. In the antibacterial activity study, the EOs were tested against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The EOs were found to possess low antibacterial, anti-tyrosinase, and photoprotection activities and moderate antioxidant capacities, thus establishing these Helichrysum EOs as valuable antioxidant agents.

HPLC-MS identification and expression of Candida drug-resistance proteins from African HIV-infected patients.

The objective of this study was to elucidate the proteomic mechanisms of drug resistance in HIV-infected African patients. Cell membrane fractions from forty oral Candida isolates isolated from African HIV-positive patients were analysed using HPLC-MS with the aim of identifying proteins associated with their pathogenicity and drug resistance. Heat shock proteins that mediate the fungicidal activity of salivary peptides were found in all tested Candida fractions, with pH-responsive proteins associated with increased pathogenicity only being present in the three most commonly isolated species. ABC multidrug transporter efflux pumps and estrogen binding proteins were only found in C. albicans fractions, while ergosterol biosynthesis proteins were identified in four species. The combination of various adherence, invasion, upregulation and efflux pump mechanisms appear to be instrumental for the Candida host colonization and drug resistance emergence in HIV-infected individuals.

Chemical Composition and Cosmeceutical Potential of the Essential Oil of Oncosiphon suffruticosum (L.) Källersjö.

The South African medicinal plant Oncosiphon suffruticosum (L.) Källersjö is an important remedy used to treat chronic, respiratory, and skin ailments. From the essential oil (EO) extracted by the hydrodistillation, sixteen constituent components were identified with oxygenated monoterpenes: camphor (31.21%), filifolone (13.98%), chrysanthenone (8.72%), 1,8-cineole (7.85%), and terpinen-4-ol (7.39%) as predominant constituents. In the antibacterial activity study, the EO was found most susceptible against Pseudomonas aeruginosa with an MIC of 6.4 mg/mL; however, it showed the same activity against Staphylococcus aureus and Escherichia coli with an MIC value of 12.8 mg/mL. The sun protecting factor (SPF) of the EO was found to be 2.299 and thus establishing it as a potentially important cosmeceutical for sunscreen applications. This is the first report investigating the essential oil of O. suffruticosum for its chemical composition and skin-related in vitro biological activities viz antibacterial, antioxidant capacity, antityrosinase, and sun protection factor.

Biosynthesis, Characterization, and Biological Activities of Procyanidin Capped Silver Nanoparticles.

In this study, procyanidin dimers and Leucosidea sericea total extract (LSTE) were employed in the synthesis of silver nanoparticles (AgNPs) and characterized by ultraviolet-visible (UV-Visible) spectroscopy, high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), and dynamic light scattering (DLS) techniques. AgNPs of about 2-7 nm were obtained. DLS and stability evaluations confirmed that the AgNPs/procyanidins conjugates were stable. The formed nanoparticles exhibited good inhibitory activities against the two enzymes studied. The IC50 values against the amylase enzyme were 14.92 ± 1.0, 13.24 ± 0.2, and 19.13 ± 0.8 µg/mL for AgNPs coordinated with LSTE, F1, and F2, respectively. The corresponding values for the glucosidase enzyme were 21.48 ± 0.9, 18.76 ± 1.0, and 8.75 ± 0.7 µg/mL. The antioxidant activities were comparable to those of the intact fractions. The AgNPs also demonstrated bacterial inhibitory activities against six bacterial species. While the minimum inhibitory concentrations (MIC) of F1-AgNPs against Pseudomonas aeruginosa and Staphylococcus aureus were 31.25 and 15.63 µg/mL respectively, those of LSTE-AgNPs and F2-AgNPs against these organisms were both 62.50 µg/mL. The F1-AgNPs demonstrated a better bactericidal effect and may be useful in food packaging. This research also showed the involvement of the procyanidins as reducing and capping agents in the formation of stable AgNPs with potential biological applications.

Measuring Streptococcus mutans, Streptococcus sanguinis and Candida albicans biofilm formation using a real-time impedance-based system.

Candida albicans and streptococci are amongst the most common fungal and bacterial organisms present in the oral cavity, with a growing body of evidence implicating C. albicans in increased caries severity and in the formation of the cariogenic biofilm. However, the interactive mechanisms between cariogenic streptococci and Candida are yet to be elucidated. In this study, the real-time biofilm formation of C. albicans, S. mutans and S. sanguinis was assessed individually and in combination using the xCELLigence system, an impedance-based microbial biofilm monitoring system. The impedance signal was the highest for C. albicans, followed by S. mutans and S. sanguinis. Although the streptococcal mixed adhesion was found to follow a similar trend to that of S. sanguinis, the introduction of C. albicans resulted in higher adhesion patterns, with the combined growth of S. sanguinis and C. albicans and the combination of all three species resulting in higher biofilm formation than any of the individual organisms over time. This study, the first to use impedance for real-time monitoring of interkingdom biofilms, adds to the body of evidence that C. albicans and oral streptococcal adhesion are interlinked and suggests that interkingdom interactions induce changes in the oral biofilm dynamics over time.

K21 Compound, a Potent Antifungal Agent: Implications for the Treatment of Fluconazole-Resistant HIV-Associated Candida Species.

Background/Objectives: With mucocutaneous candidiasis being highly prevalent in HIV patients, the emergence of fluconazole-resistant Candida species forms a major challenge in treating and eradicating these infections. The objective of this study was to establish the antifungal activity of K21, a membrane-rupturing antimicrobial compound derived from a silica quaternary ammonium compound (SiQAC) with tetraethoxysilane (TEOS). Methods: The study sample included 81 Candida species of which 9 were type strains and 72 were clinical isolates. Minimum inhibitory concentrations, synergy, fractional inhibitory concentration index (FICI), and time kill assays were determined by broth microdilution. Electron microscopy (EM) was used to determine the qualitative changes brought about after treatment with K21. Results: K21 inhibited the growth of all fluconazole-resistant and susceptible Candida strains with only 2 h of exposure required to effectively kill 99.9% of the inoculum, and a definite synergistic effect was observed with a combination of K21 and fluconazole. EM demonstrated the presence of two forms of extracellular vesicles indicative of biofilm formation and cell lysis. Conclusion: The study established the efficacy of K21 as an antifungal agent and with fluconazole-resistant candidiasis on the increase, the development of K21 can provide a promising alternative to combat acquired drug resistance.

Oral Health Status and Treatment Needs of Pregnant Women Attending Antenatal Clinics in KwaZulu-Natal, South Africa.

During pregnancy, the oral cavity is characterised by an acidic environment and an inflammatory response brought about by vomiting and changes in hormonal levels, respectively, thereby increasing the mother's risk of developing caries. Although evidence exists to support an association between pregnancy-associated periodontal disease and adverse pregnancy outcomes, there is a paucity of studies which focus on the caries prevalence and other oral manifestations of pregnant women. The aim of this study was to assess the oral health status and treatment needs of pregnant women attending antenatal clinics in KwaZulu-Natal, South Africa. Randomly selected mothers (n=443) attending a maternal obstetrics unit participated in the study. A questionnaire elicited demographic information about the participants, while the measurement of decayed, missing, and filled indices (DMFT) determined their caries status. Oral lesions were noted if present. Descriptive statistics for independent variables described frequencies in the various categories of race, location, pregnancy stage, etc., with the association between 2 independent variables tested by chi-square. Dependent variables such as DMFT were expressed as means and standard deviations, and ANOVA was used to examine whether independent variables significantly influenced the DMFT. The mean DMFT was 7.18 (±4.22) with significant correlations observed between DMFT, D, M, and age. F scores differed significantly between races, location, and educational levels and showed a significant correlation with pregnancy stage. Pregnancy epulis was diagnosed in 38 (8.5%), oral lesions in 65 (14.7%), and tooth mobility in 26 (5.9%) mothers. Early oral health screening during pregnancy can ensure the overall well-being of both the mother and the foetus.

Group B Streptococcus Serotypes in Pregnant Women From the Western Cape Region of South Africa.

Background: Maternal colonization of Group B streptococci (GBS) during pregnancy is an important risk factor for neonatal morbidity and mortality. The aim of this study was to determine the prevalence and serotype distribution of GBS isolated from a cohort of pregnant women in the Western Cape, South Africa. Methods: Two ano-vaginal swabs were collected from 301 women at 28-37 weeks of gestation. Participants were recruited from four different antenatal clinics in the Western Cape, South Africa. GBS were detected by culture and PCR and serotypes confirmed by latex agglutination tests. Antibiotic sensitivity was performed using disc diffusion. Results: The GBS colonization rate was 16.6%. Serotype distribution revealed serotype V as the predominant serotype (66.67%) followed by serotype III (21.05%). Serotypes Ia, II, IV, and IX constituted 1.75% each and 3 GBS isolates were non-typeable. Serotype V demonstrated resistance to most of the antibiotics tested, while serotype III demonstrated better susceptibility, except for tetracycline. No significant differences were observed for GBS colonization or serotype distribution according to HIV status. Conclusion: Predominating serotypes differed from those previously reported from other regions in South Africa. Global surveillance of serotype distribution plays an important role in informing vaccine development and antibiotic prophylaxis.

Bacterial morphotype grading for periodontal disease assessment.

BACKGROUND: Listgarten and Hellden (1978) used darkfield microscopy of wet mounts to differentiate between healthy and periodontally diseased sites in the mouth by expressing the different bacterial morphotypes observed as a percentage of the total number of bacteria counted. This method of periodontal disease assessment gained favour as a diagnostic tool but presented with the limitation of immediate examination to determine the number of motile rods present and an inability to distinguish between gingivitis and periodontitis. Grading of bacterial morphotypes into several distinct categories of health or disease (Ison and Hay, 2002), simplified the scoring system of Gram-stained smears for the diagnosis of bacterial vaginosis (Nugent et al. 1991). The application of a similar grading system using stained smears rather than wet mounts could be advantageous to the diagnosis of periodontal disease. OBJECTIVES/AIMS: This study tested the hypothesis that stained smears of dental plaque collected from the gingival crevice of individuals with varying probing pocket depths (PD) may provide a grading system for periodontal disease assessment. MATERIALS AND METHODS: Subgingival plaque samples were collected from 49 patients, stained with a silver stain and the proportions of each bacterial morphotype graded relative to their respective PD measurements. RESULTS: This technique allowed for a grading system of I-IV, with grade I indicating health and grade IV indicating severe periodontal disease. DISCUSSION: Stained smear examination eliminates the time restriction for motile rod enumeration and allows for storage of smears for future reference. CONCLUSION: Standardization of the microscopic areas to be evaluated or examined will facilitate the agreement of cut-off values for the diagnosis of periodontal disease.

The Threat of Aerobic Vaginitis to Pregnancy and Neonatal Morbidity.

Aerobic vaginitis (AV) is an endogenous opportunistic infection brought about by the disruption of the normal vaginal microbiota. Its early diagnosis and treatment during pregnancy may reduce the risk of negative pregnancy outcomes. The aim of this review was to report on the aerobic bacteria most prevalent in AV and to provide evidence of the threat of untreated AV on pregnancy outcomes. More than 300 papers on preterm delivery were extracted from several research domains and filtered to include only AV-associated bacteria such as Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Group B streptococci and their association with adverse pregnancy outcomes. Due to the diverse sample groups, study techniques and outcomes, a meta-analysis was not conducted. The review revealed that the association of AV with adverse pregnancy outcomes has not been as widely researched as bacterial vaginosis (BV) and needs further investigation. Furthermore, the frequent misdiagnosis of AV coupled with the emerging antimicrobial resistance associated with bacteria implicated in AV and neonatal nosocomial infections pose a problem for prophylaxis and treatment to reduce the risk of maternal and neonatal morbidity and mortality.

Further evidence for periodontal disease as a risk indicator for adverse pregnancy outcomes.

BACKGROUND: Although there is increasing evidence to suggest an association between periodontal disease and adverse pregnancy outcomes, the issue remains controversial. STUDY OBJECTIVE: This study tested the hypothesis that periodontal disease is a risk indicator for preterm delivery of low-birthweight infants. MATERIALS AND METHODS: The study sample comprised 443 pregnant women with a mean (± standard deviation) age of 24.13 (±5.30) years. At first visit, maternal oral health status was assessed by the measurement of probing pocket depth and clinical attachment loss, and periodontal status was graded as absent, mild, moderate or severe. An association was sought between pregnancy outcomes and maternal periodontal status. RESULTS: While controlling for other factors, significant associations were found between pregnancy outcomes and maternal periodontal index scores. CONCLUSION: This study provides further evidence that periodontal disease is a risk indicator for adverse pregnancy outcomes.

Anaerobes and bacterial vaginosis in pregnancy: virulence factors contributing to vaginal colonisation.

The aetiology and pathogenesis of bacterial vaginosis (BV) is unclear but it appears to be associated with factors that disrupt the normal acidity of the vagina thus altering the equilibrium between the normal vaginal microbiota. BV has serious implications for female morbidity, including reports of pelvic inflammatory disease, adverse pregnancy outcomes, increased susceptibility to sexually transmitted infections and infertility. This paper reviewed new available information regarding possible factors contributing to the establishment of the BV vaginal biofilm, examined the proposed role of anaerobic microbial species recently detected by new culture-independent methods and discusses developments related to the effects of BV on human pregnancy. The literature search included Pubmed (NLM), LISTA (EBSCO), and Web of Science. Because of the complexity and diversity of population groups, diagnosis and methodology used, no meta-analysis was performed. Several anaerobic microbial species previously missed in the laboratory diagnosis of BV have been revealed while taking cognisance of newly proposed theories of infection, thereby improving our understanding and knowledge of the complex aetiology and pathogenesis of BV and its perceived role in adverse pregnancy outcomes.

Efficacy of methods used for the diagnosis of bacterial vaginosis.

INTRODUCTION: Bacterial vaginosis (BV) has been associated with pelvic inflammatory disease, adverse pregnancy outcomes, increased susceptibility to sexually transmitted infections and infertility. Diagnosis of BV should be rapid, reliable and safe. This is especially vital in pregnant women where intervention may be necessary for the well-being of both the mother and the foetus. AREAS COVERED: This paper consulted PUBMED, LISTA and Web of Science for point-of-care and laboratory-based tests commonly used for the diagnosis and management of BV in pregnant women. An overview of strengths and weaknesses of the methods used may partially explain why treatment plans have failed. Differences in sampling and detection methods, time of gestation, inter-examiner variability and interpretation of data, and the use of different reference tests, amongst many other factors, complicated a meta-analysis of the data. EXPERT OPINION: Inconsistencies found in clinical and laboratory detection methods used for the monitoring of treatment have a direct impact on success rates. With current advances in technology, the diagnosis of BV is taking on a new perspective. New information implicating specific vaginal biofilms in adverse pregnancy outcomes through the application of advanced technology promises to change the way we view the aetiology, diagnosis and management of BV.

Oral colonization of Gram-negative anaerobes as a risk factor for preterm delivery.

BACKGROUND: Preterm birth significantly impacts on neonatal morbidity and mortality and is apparently increasing world-wide. Several studies have attempted to define a causative role for periodontal disease in adverse pregnancy outcomes but few have focused on the microbiology of periodontal disease in relation to these outcomes. RESULTS: The evidence for a positive correlation is strong, supported by microbiological and immunological findings. Conflicting results are often associated with uncontrolled confounding factors. MATERIALS AND METHODS: A literature search was conducted in order to establish whether or not a role exists for oral Gram-negative bacteria in adverse pregnancy outcomes. Association and intervention studies are summarized along with pathogenic potential of the Gram-negative bacteria most frequently implicated in periodontal disease.

Examination of maternal gingival crevicular fluid for the presence of selected periodontopathogens implicated in the pre-term delivery of low birthweight infants.

BACKGROUND: Reports show that more than 20 million infants world-wide are born prematurely with 95% of all pre-term births occurring in developing countries. Oral colonization of gram-negative anaerobes has been implicated as a risk factor for preterm delivery of low birth weight infants. MATERIALS AND METHODS: This study comprised 200 women admitted to the department of obstetrics and gynecology of the teaching hospital of Butare in Rwanda. Gingival crevicular fluid was collected from each quadrant of the mother's mouth (using paper points) within 24 hours of delivery. A dichotomous score of presence or absence of gingival inflammation was recorded for each patient along with demographic data such as age, marital status etc. Samples were examined by PCR for the presence of Aggregatibacter actinomycetemcomitans and selected members of the red and orange complexes described by Socransky et al., (1998), and their presence associated with age, gingival inflammation and pregnancy outcomes. RESULTS: Association of bacterial species with the risk of periodontal disease and thus the risk of preterm delivery was only observed when they occurred in pairs or groups of three or more. Aa appeared to be a necessary co-factor for significant associations of bacterial groups with the variables recorded.

The use of Perioscan as a potential screening test for mothers at risk for delivery of pre-term and low birth-weight infants.

Increased levels of oestrogen and progesterone during pregnancy may lead to periodontal disease. The anaerobic Gram-negative bacteria classified as the "red complex" (Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola) are frequently associated with periodontal disease. Periodontopathogens produce toxins and enzymes that can enter the bloodstream and cross the placenta to harm the foetus. The response of the mother's immune system to infection by these periodontopathogens brings about the release of inflammatory mediators which may trigger preterm labour or result in low birth-weight infants. The purpose of this study was to examine the use of Perioscan as a potential screening test for mothers at risk for pre-term delivery of low birth weight infants due to periodontal disease. Subgingival plaque samples were obtained from pregnant women between the ages of 17 to 45 years attending an ante-natal clinic in the Western Cape in South Africa. Plaque samples were analyzed by the enzymatic Perioscan test for detection of the red complex in 372 sites from 66 women. Results were confirmed by polymerase chain reaction (PCR) detection of the three species of the red complex. Seventeen (25.75%) of the population group tested positive with Perioscan but only 27 (7.25%) of the 372 sites were positive. Of the 66 mothers examined, we managed to retrieve 29 records post-delivery. In all the mothers examined, Perioscan results showed an association with the indices used to diagnose periodontal disease, and could also be associated with preterm delivery of low birth-weight infants in two of the 29 maternal records recovered.

Salivary gland disease in HIV/AIDS and primary Sjögren's syndrome: analysis of collagen I distribution and histopathology in American and African patients.

BACKGROUND: Salivary gland disease (SGD) in HIV/AIDS is clinically and histopathologically very similar to Sjögren's Syndrome (SS), although the mechanism of tissue damage is unknown. The aim of this study is to determine the prevalence of SGD in primary SS and in HIV/AIDS in USA and in West African patients, and to seek distinguishing histopathologic features that may help to elucidate underlying mechanisms. METHODS: Histologic sections of minor salivary glands from 164 HIV-positive and -negative patients from Cameroon and the US, and from 17 US patients with primary SS, were evaluated following salivary gland biopsy for inflammatory changes. To confirm the presence of fibrosis, collagen I, which is the most abundant collagen type, was assessed immunohistochemically in H&E-stained sections. RESULTS: Forty-eight per cent of patients with HIV from Cameroon had severe SGD, while it was only in 6% of patients from the US. Patients with HIV in the US had less fibrosis and collagen I deposits than Cameroonians. Seventy-six per cent of US HIV-positive patients had received anti-retroviral therapy, while none of the African patients had. SS and AIDS patients had a tendency for lymphocytes to locate in a perivascular rather than in a periductal distribution. CONCLUSIONS: The prevalence of SGD and the presence of fibrosis and collagen I in Cameroonians with HIV is significantly higher than in HIV-positive American patients, and is similar to US patients with primary SS. The impact of patient selection, anti-retroviral therapy, and pathogenic mechanisms on salivary gland pathology is discussed.