Research Articles (Medical Bioscience)

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Anaerobes and bacterial vaginosis in pregnancy: virulence factors contributing to vaginal colonisation
(Multidisciplinary Digital Publishing Institute, 2014) Africa, Charlene W.J.; Nel, Janske; Stemmet, Megan C.
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.
The association between gender and tooth loss in a small rural population of South Africa
(Science Publishing Group, 2013) Africa, Charlene W.J.; Reddy, Jairam
Periodontal disease, which attacks the gums and supporting structures of the tooth, is one of the major causes of tooth loss in adults. Few studies on general well-being have compared the differences in oral health between men and women with studies from Europe and USA reporting that there are more edentulous women than men.Among the many factors contributing to tooth loss are poverty, availability and accessibility to dental and other health care as well as cultural traditions. This study examined a population living in a high fluoride area near Cape Town. This isolated community has until recently been unexposed to the diets and habits of the western world and have inter-married for decades. The results of this study indicated that although women had better oral hygiene habits than men, tooth loss was associated with age rather than gender.
Bacterial morphotype grading for periodontal disease assessment
(Nature Publishing Group, 2017) Smeda-Pienaar, Kim; Kaambo, Eveline; Africa, Charlene W.J.
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.
BANA-positive plaque samples are associated with oral hygiene practices and not CD4+ T cell counts in HIV-positive patients
(Hindawi Publishing Corporation, 2012) John, Cathy N.; Stephen, Lawrence X.G.S.; Africa, Charlene W.J.
Background. The “red complex” microorganisms, namely, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia are considered as potential pathogens causing HIV-associated periodontal diseases. Moreover, it has been recognized that an association exists between CD4+ T cell counts and periodontal disease progression. Objective. To establish whether CD4+ T cell counts or oral hygiene plays a greater role in producing BANA-positive results in HIV-associated periodontal disease. Materials and Methods. One hundred and twenty HIV-positive patients participated in the study, and their CD4+ T cell counts were obtained from their medical records. The six Ramfjord teeth were used for evaluating periodontal clinical indices and subgingival plaque sampling. BANA test was used for the detection and prevalence of the “red complex” bacteria in plaque samples. Results.Amajority of 69.17% HIV-positive patients were BANA-positive. No significant associations were found between BANA and CD4+ T cell counts. A highly significant association was found between BANA with probing depth and clinical attachment level (P ≤ 0.0001) and between BANA and the use of interdental aids (P = 0.0168). Conclusion. HIV-associated periodontal diseases are strongly related to oral hygiene practices rather than the effect of CD4+ T cell counts, and the use of interdental aids was marked as a significant predictor of BANA-negative plaque samples.
Candida antifungal drug resistance in sub-Saharan African populations: A systematic review
(Science Navigation Group, 2017) Africa, Charlene W.J.; Abrantes, Pedro Miguel dos Santos
BACKGROUND: Candida infections are responsible for increased morbidity and mortality rates in at-risk patients, especially in developing countries where there is limited access to antifungal drugs and a high burden of HIV co-infection. OBJECTIVES: This study aimed to identify antifungal drug resistance patterns within the subcontinent of Africa. METHODS: A literature search was conducted on published studies that employed antifungal susceptibility testing on clinical Candida isolates from sub-Saharan African countries using Pubmed and Google Scholar. RESULTS: A total of 21 studies from 8 countries constituted this review. Only studies conducted in sub-Saharan Africa and employing antifungal drug susceptibility testing were included. Regional differences in Candida species prevalence and resistance patterns were identified. DISCUSSION: The outcomes of this review highlight the need for a revision of antifungal therapy guidelines in regions most affected by Candida drug resistance. Better controls in antimicrobial drug distribution and the implementation of regional antimicrobial susceptibility surveillance programmes are required in order to reduce the high Candida drug resistance levels seen to be emerging in sub-Saharan Africa.
A comparison of susceptibility patterns of oral Candida isolates from South African and Cameroonian HIV- positive populations
(The International Association for Dental Research (IADR), 2012) Abrantes, Pedro Miguel dos Santos; McArthur, Carole P.; Africa, Charlene W.J.
METHOD: In this study, Candida isolates were collected from the oral mucosa of 128 South African and 126 Cameroonian HIV-positive patients, by scraping the mouths of consenting patients using sterile cotton swabs. Ethics clearance for this project was granted by the University of the Western Cape. Confirmation of Candida species was done by growth on differential media, Gram staining and microscopy. The isolates were grown on selective media and differentiated using two commercial chromogenic agars and Tomato (V8) agar. Changes in colony colour, morphology and pseudohyphae/chlamydospore expression could then be observed, allowing for species differentiation. Isolates were also examined for antifungal susceptibility patterns using the TREK system. RESULT: The results from this study suggest that the prevalence of Candida species varies according to geographical region and HIV-subtype. Discrepancies in antifungal drug susceptibility patterns were also observed in the two populations. CONCLUSION: The emerging drug-resistance raises the need for increased species prevalence surveillance, as this information can have clinical implications in the choice of more appropriate and effective patient treatment.
Drug susceptibility profiles of Candida species isolated from the oral mucosa of HIV-positive West African patients using the TREK Sensititre system
(2013) McArthur, Carole P.; Abrantes, Pedro Miguel dos Santos; Awasom, Charles; Ayuk, L.; Africa, Charlene W.J.
BACKGROUND: Candida infections are a common cause of death in immunocompromised patients. The prevalence and anti-mycotic drug susceptibility profiles of Candida species from Cameroon in Africa are unavailable. This study was prompted by an increasing incidence of treatment failure. Drug susceptibility profiles, necessary to improve treatment outcomes, is particularly important in countries where the sale of antimicrobials and antifungals is uncontrolled and resistance may emerge due to the indiscriminate use. OBJECTIVE: The goal of this study was to characterize and determine drug susceptibility of oral Candida species in Cameroonian patients with HIV/AIDS. MATERIALS AND METHODS: Candida species were isolated from the oral cavity of 126 HIV-positive patients attending a local HIV/AIDS clinic in the Cameroon. Drug susceptibility to azoles and echinocandins was determined using the commercial TREK Sensititre® YeastOne™ platform that provides the minimal inhibitory concentration of amphotericin B, 5-flucytosine, anidulafungin, caspofungin, micafungin, fluconazole, itraconazole, posaconazole, and voriconazole. RESULTS: Ninety two isolates identified were Candida albicans. Remaining isolates were C. glabrata (24), C. tropicalis (4), C. krusei (3), C. parapsilopsis/lusitanreae/keyfr (2), and one isolate was C. dubliniensis. More than 50% of C. albicans isolated were resistant to azoles but 115 Candida species (87%) were susceptible to amphotericin B. Twenty one of the twenty four C.glabrata identified (88%) were resistant to micafungin. The majority of Cameroonian Candida species were sensitive to flucytosine (5-FC) (95%) and echinocandins (79%). CONCLUSIONS: The report of azole resistance in all Candida species isolated from immunocompromised patients in Cameroon is a new and important observation. We found the approach using a broad screening platform an effective means to obtain data rapidly. We propose confirmation of these data and regional surveillance of Candida species in other areas in Cameroon and surrounding countries to develop an effective public health management and treatment strategy.
Examination of maternal gingival crevicular fluid for the presence of selected periodontopathogens implicated in the pre-term delivery of low birthweight infants
(Landes Bioscience, 2010) Africa, Charlene W.J.; Kayitenkore, Janet; Bayingana, Claude
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. 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. 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 PC R 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.
Further evidence for periodontal disease as a risk indicator for adverse pregnancy outcomes
(Elsevier, 2017) Turton, Mervyn; Africa, Charlene W.J.
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 periodon- tal 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 peri- odontal disease is a risk indicator for adverse pregnancy outcomes.
HIV/Candida co-infection in Sub-Saharan African women on ART
(Infectious Diseases Society of Southern Africa, the Sexually Transmitted Diseases Society of Southern and the Public Health Association of South Africa., 2013) Abrantes, Pedro Miguel dos Santos; Africa, Charlene W.J.
INTRODUCTION: Sub-Saharan Africa has 23.5 million cases of HIV and is home to 92% of the world’s HIV-positive pregnant women of whom 24% die of pregnancy related complications. Oral candidiasis is a common condition in HIV-AIDS patients, caused by commensal yeasts which may colonise the mucous membranes of the mouth causing morbidity due to several factors including immunosuppression, smoking, poor nutrition and the use of antibiotics. Methods: One hundred and ninety-four South African and Cameroonian HIV-positive women participated in the study. Only subjects who had white pseudomembranous plaque on the tongue or visible oral candidiasis were included. Samples were collected by scraping the patient’s oral mucosa and tongue with a sterile swab. Candida species were differentiated using selective and chromogenic media and their susceptibility to antifungal drugs was tested using the TREK Sensititre system. Results and conclusion: One hundred and ninety-six isolates, representative of six Candida species were identified. C. albicans was the predominating species, with C. glabrata and C. dubliniensis being the more frequent of the non-albicans isolates. Azole drug resistance patterns were very high for C. albicans, while C. glabrata showed high resistance patterns to echinocandins drugs. The duration of ART could be associated with the presence of different Candida species but no concrete conclusions could be drawn concerning HIV/Candida co-infection when controlling for other risk factors such as HIV stage, pregnancy, age and treatment for tuberculosis. This may be a cause for concern, particularly in the case of pregnancy, where co-infection may pose a risk for maternal morbidity and mortality.
An in-vitro analysis of the antimicrobial efficacy of herbal toothpastes on selected primary plaque colonizers
(iMD Publishers, 2011) Peck, Mogammad T.; Africa, Charlene W.J.; Stephen, Lawrence X.G.S.; Marnewick, Johan; Majeed, Abdul
Plaque associated oral disease affects a considerable portion of the population and is considered one of the major causes of tooth loss. In most cases toothbrushing only removes a limited amount of dental plaque and other chemical agents are required to reduce the bacterial load. Aims & objectives: The purpose of study was to determine whether there was any significant difference in the antimicrobial activity of 4 herbal toothpastes against cultures of 3 primary plaque colonizers. Methods: A total of 5 toothpastes were tested for their antimicrobial efficacy against Streptococcus mutans (NCTC 10920), Streptococcus sanguinis (NCTC 10904) and a non-specific α-heamolytic streptococcus by agar diffusion method. The data were collected and analysed using one way ANOVA and Tukey’s multiple comparison test significant at p<0.05. Results: Dentazyme® herbal toothpaste showed the greatest ability to inhibit bacterial growth for all the tested organisms (p<0.05). Nature Fresh had the lowest potential for antimicrobial activity. Conclusions: Dentazyme® Herbal toothpaste was the only herbal toothpaste to inhibit the growth of all the bacteria tested and had similar antimicrobial efficacy to a triclosan containing toothpaste (Colgate® Total®).
Is human Immunodeficiency Virus (HIV) stage an independent risk factor for altering the periodontal status of HIV-positive patients? A South African study
(BioMed Central, 2013) John, Cathy N.; Stephen, Lawrence X.G.S.; Africa, Charlene W.J.
Background: The immunosuppresion in HIV patients makes them highly susceptible to microbial infections. The aim of the study was to establish whether HIV stage (as depicted by CD4+ T lymphocyte counts) could independently be associated with periodontal status (as revealed by the measurement of clinical indices). Methods: One hundred and twenty HIV-infected patients attending an infectious diseases clinic in the Western Cape, South Africa were included in the study. The periodontal clinical indices such as plaque index, gingival index, pocket probing depth and clinical attachment levels were measured on the mesial aspect of the six Ramfjord teeth. The CD4 + T cell counts were taken from the patients’ medical records and patients’ HIV stage determined and grouped according to their CD4+ T cell counts into A (<200 cells /mm3), B (200–500 cells /mm3) and C (>500 cells /mm3). Results: The mean age of 120 HIV-positive patients was 33.25 years and the mean CD4 + T cell count was 293.43 cells/mm3. The probing depth and clinical attachment loss were found to be significantly associated with the total CD4 + T cell counts but not with HIV stage. Significant correlations were found between age and all clinical indices except for clinical attachment loss. No correlation was found between age and HIV stage of the patients. The use of antiretroviral therapy was significantly associated with probing depth and clinical attachment loss, but not with plaque nor gingival index. Significant associations were observed between smoking and all of the clinical indices except for the gingival index. A significant association was observed between the use of interdental aids and all the clinical indices except for probing depth, while brushing was significantly associated with plaque index only. CD4 + T cell counts were significantly associated with brushing frequency (p = 0.0190) and the use of interdental aids (p = 0.0170). Conclusion: The findings of this study conclude that HIV stage, ART and age are not independent risk factors for changes in the periodontal status of HIV-positive subjects but rather that smoking and oral hygiene habits determine their susceptibility to disease.
Metronidazole in the Prophylaxis and treatment of Anaerobic Infection
(Health and Medical Publishing Group, 1978) Applebaum, P.C.; Moodley, J.; Chatterton, S.A.; Cowan, D.B.; Africa, Charlene W.J.
The influence of prophylactic metronidazole on vaginal carriage rates of anaerobes and the development of postoperative anaerobic infection was studied in 104 women who underwent abdominal hysterectomy. Metronidazole prophylaxis in 54 patients led to a decrease in the anaerobe vaginal carriage rate from 65% pre-operatively to 17% and 28% on the 3rd and 7th postoperative days respectively. In the control group (50 patients) no significant decrease in anaerobe yield was noted, corresponding percentages being 72%, 64%, and 74%. Postoperative infection occurred in 36 patients (28 controls; 8 on prophylactic metronidazole). Wound swabs from all 8 patients in the latter group yielded aerobes, and in 1 patient mixed infection (aerobes/anaerobes) occurred. In 7 of these patients (including the patient with mixed infection), the infection resolved spontaneously, while the 8th patient responded to therapy with metronidazole, kanamycin and ampicillin. In the control patients, 21 cases of postoperative wound infection and 4 of vault infection were seen; wound swabs from patients in the former group yielded aerobes in only 6 cases, and mixed growth of aerobes/ anaerobes in 10 cases. Postoperative wound/vault infections in control patients cleared spontaneously in 18 cases and responded to imidazole therapy, with or without ampicillin and kanamycin, in 7 cases.
Multi-drug resistant (MDR) oral Candida species isolated from HIV-positive patients in South Africa and Cameroon
(Elsevier, 2014) Abrantes, Pedro Miguel dos Santos; McArthur, Carole P.; Africa, Charlene W.J.
Candida species are a common cause of infection in immune-compromised HIV-positive individuals, who are usually treated with the antifungal drug, fluconazole in public hospitals in Africa. However, information about the prevalence of drug resistance to fluconazole and other antifungal agents on Candida species is very limited. This study examined 128 Candida isolates from South Africa and 126 Cameroonian Candida isolates for determination of species prevalence and antifungal drug susceptibility. The isolates were characterized by growth on chromogenic and selective media and by their susceptibility to nine antifungal drugs tested using the TREK™ YeastOne9 drug panel (Thermo Scientific). Eighty three percent (82.8%) of South African isolates were C. albicans (106 isolates), 9.4% were C. glabrata (12 isolates) and 7.8% were C. dubliniensis (10 isolates). Of the Cameroonian isolates, 73.02% were C. albicans (92 isolates); 19.05% C. glabrata (24 isolates); 3.2% C. tropicalis (4 isolates); 2.4% C. krusei (3 isolates); 1.59% either C. kefyr, C. parapsilopsis or C. lusitaneae (2 isolates); and 0.79% C. dubliniensis (1 isolate). Widespread C. albicans resistance to azoles was detected phenotypically in both populations. Differences in drug resistance were seen within C. glabrata found in both populations. Echinocandin drugs were more effective on isolates obtained from the Cameroon than in South Africa. A multiple drug resistant (MDR) C. dubliniensis strain isolated from the South African samples was inhibited only by 5-flucytosine in vitro on the YO9 panel. Drug resistance among oral Candida species is common among African HIV patients in these two countries. Regional surveillance of Candida species drug susceptibility should be undertaken to ensure effective treatment for HIV-positive patients.
Oral colonization of Gram-negative anaerobes as a risk factor for preterm birth
(Landes Bioscience, 2011) Africa, Charlene W.J.
Preterm birth significantly impacts on neonatal morbidity and mortality and is apparently increasing worldwide. 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 Gramnegative 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.
Proteomic mechanisms of drug resistance in Candida cell membrane fractions
(International Association for Dental Research, 2014) Abrantes, Pedro Miguel dos Santos; Bouic, Patrick J.D.; Africa, Charlene W.J.
INTRODUCTION: The African continent has the highest burden of HIV infection, accounting for approximately 65% of new infections globally. Oral candidiasis is a major cause of increased morbidity in HIV-infected individuals and is usually treated with fluconazole, an antifungal drug which interferes with ergosterol synthesis in the fungal cell membrane. The increased resistance of Candida species to antifungal drugs leads to treatment failure and an increase in untreatable Candida infections. OBJECTIVES/METHODS: Drug susceptibility patterns were determined for Candida species isolated from oral swabs of 254 patients from two HIV-positive African populations. Forty cell membrane fractions isolated from the clinical isolates were analyzed using High Performance Liquid Chromatography – Mass Spectrometry (HPLC-MS) and the results compared to the UniProt protein database for the identification of Candida peptides known to be involved in colonization and drug resistance strategies within the host. RESULTS: Fluconazole-susceptible and –resistant C. albicans isolates were found to express oxidoreductases that bind mammalian estrogens with high affinity. Peptides that confer resistance to formaldehyde were found in C. albicans, C. glabrata and C. dubliniensis in both susceptible and resistant cell fractions. Multidrug resistance proteins (CDR1 and CDR2) were seen in C. albicans cell fractions. CONCLUSION: The combination of different drug resistance mechanisms and binding abilities to salivary histatins and estrogen seem to be instrumental in the colonisation and retention of Candida in these immunocompromised patients. The results also suggest the presence of differences in efflux transporter protein expression in fluconazole-susceptible and –resistant isolates within the HIV population.
Risk factors of preterm delivery of low birth weight (plbw) in an African population
(Academic Journals, 2010) Bayingana, Claude; Muvunyi, Claude Mambo; Africa, Charlene W.J.
More than 20 million infants in the world (15.5% of all births) are born with low birth weight. Ninety-five percent of them are in developing countries. The objective of this study was to examine different factors which may contribute to preterm delivery of low birth weight (PLBW) in a recent sample of Rwandan birth. The study sample included 200 randomly selected women admitted to the department of obstetrics-gynecology of the teaching hospital of Butare in Rwanda. Mothers were asked to complete a questionnaire and obstetrics records were used in order to identify factors which might pose a health risk to them and their infants. Maternal weight, height, history of previous preterm and healthy conditions of the children in the family showed a significant relationship with PLBW. Maternal level of education, number of pregnancies of the mother, urinary tract infection, sexually transmitted disease, antibiotic administration, diabetes, history of heart disease, alcohol consumption and smoking showed a relationship with PLBW but the relationship was not significant. More studies are required for a better understanding of the mechanism leading to preterm delivery of low birth infants.
Risk factors of preterm delivery of low birth weight (plbw) in an African population
(Academic Journals, 2010) Bayingana, Claude; Muvunyi, Claude Mambo; Africa, Charlene W.J.
More than 20 million infants in the world (15.5% of all births) are born with low birth weight. Ninety-five percent of them are in developing countries. The objective of this study was to examine different factors which may contribute to preterm delivery of low birth weight (PLBW) in a recent sample of Rwandan birth. The study sample included 200 randomly selected women admitted to the department of obstetrics-gynecology of the teaching hospital of Butare in Rwanda. Mothers were asked to complete a questionnaire and obstetrics records were used in order to identify factors which might pose a health risk to them and their infants. Maternal weight, height, history of previous preterm and healthy conditions of the children in the family showed a significant relationship with PLBW. Maternal level of education, number of pregnancies of the mother, urinary tract infection, sexually transmitted disease, antibiotic administration, diabetes, history of heart disease, alcohol consumption and smoking showed a relationship with PLBW but the relationship was not significant. More studies are required for a better understanding of the mechanism leading to preterm delivery of low birth infants.
A simple point of care test can indicate the need for periodontal therapy to reduce the risk for adverse pregnancy outcomes in mothers attending antenatal clinics
(Taylor & Francis Group, 2017) Turton, Mervyn Sydney; Africa, Charlene W.J.; Henkel, Ralf; Africa, Charlene W.J.
INTRODUCTION: Although the association between periodontal disease (PD) and adverse pregnancy outcomes has gained recognition amongst antenatal healthcare workers, not much has changed in practice to address it. This prospective study tested the hypothesis that BANA (N-benzoyl-DL-arginine- 2-naphthylamide), a diagnostic test for PD, may inform obstetricians and other antenatal healthcare practitioners, of the risk of adverse pregnancy outcomes in mothers attending antenatal clinics. METHODS: At first visit, the presence of suspected periodontopathogens was assessed by BANA testing of dental plaque from 443 mothers attending antenatal clinics in KwaZulu-Natal, South Africa and an association later sought with pregnancy outcomes. The accuracy of BANA to predict adverse pregnancy outcomes was evaluated by the calculation of likelihood ratios. The study complied with the Declaration of Helsinki. RESULTS: Significant differences were found between pregnancy outcomes of BANA-negative and BANA-positive mothers (p<0.0001). BANA showed sensitivity and negative predictive values of 87% and 91%; 75% and 78%; 87% and 94% in detecting low birth weight, preterm delivery, and preterm low birth weight delivery respectively. CONCLUSION: This study confirms that BANA may indicate the need for periodontal therapy to reduce the risk of adverse pregnancy outcomes and could form part of the routine antenatal examination.
Strengths and limitations of different Chromogenic Media for the identification of Candida species
(Scientific & Academic Publishing, 2012) Messeir, Ilze; Abrantes, Pedro Miguel dos Santos; Africa, Charlene W.J.
The treatment of invasive candidiasis and other Candida infections with the appropriate antifungal agent is assisted by the identification of Candida isolates to the species level. Rapid and accurate methods of differentiation are therefore imperative if treatment is to be effective, particularly in HIV-positive patients and in pregnant mothers where intervention may be necessary to reduce the risk for preterm delivery. The time used for isolation, identification and detection of mixed cultures may be reduced with the help of available chromogenic media. In this study, five commercial chromogenic media were evaluated for the differentiation of Candida species. Six type-strains of Candida species were streaked onto each of five different chromogenic media and incubated for up to 4 days at the different temperatures recommended by the manufacturers. This comparative evaluation demonstrated the strengths and weaknesses of each medium employed and found CHROMagar™ Candida and Chromogenic Candida Agar to be the most effective for distinguishing between different Candida species.

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