HIV/Candida co-infection in Sub-Saharan African women on ART

5th FIDSSA Congress 2013: Champagne Sports Resort Drakensberg, KwaZulu Natal, South Africa - Poster Presentations.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.National Research Foundation of South AfricaDepartment of HE and Training approved lis

Strengths and limitations of different Chromogenic Media for the identification of Candida species

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.National Research Foundation of South Afric

Proteomics of drug-resistant HIV-associated candidiasis

Candidiasis and HIV co-infection may cause increased patient morbidity and mortality due to oropharyngeal or systemic dissemination. Limited information exists on the prevalence, antifungal susceptibility profiles and drug resistance mechanisms of Candida species on the African continent, the highest HIV-affected region globally and home to new and emerging drug resistant Candida species. Candida species isolated from the oral mucosa of HIV-positive African patients were found to be resistant to many of the antifungals routinely used in HIV-associated candidiasis. Candida cell membrane fractions were examined using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and high performance liquid chromatography mass spectrometry (HPLC/MS) in order to elucidate the cell membrane proteins specifically expressed by antifungal drug resistant isolates. SDS-PAGE and HPLC/MS allowed for the identification of multi-drug resistance efflux transporter CDR2 proteins and the elucidation of Candida colonization mechanisms and pH-responsive proteins, with significant associations observed between specific drug resistance and the duration of antiretroviral (ARV) therapy. This study provided useful information on the mechanisms of antifungal resistance in Candida species. It also formed the basis for further studies to address the transfer of resistance between Candida species in an oral microbial biofilm

Proteomic mechanisms of drug resistance in Candida cell membrane fractions

Poster presented at the International Association for Dental Research, 92nd General Session, Cape Town, South Africa, 25-28 June 2014.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.National Research Foundation of South Africa (NRF

Antimicrobial resistant Gram-positive cocci in pregnant mothers with aerobic vaginitis

The vaginal microbiota of a healthy asymptomatic woman consists of an extensive diversity of anaerobic and aerobic bacterial genera and species dominated by the microaerophilic genus Lactobacillus , known to inhibit the growth of potentially pathogenic non-acid tolerant microorganisms. An imbalance of species within this biofilm may result in endogenous opportunistic infections such as aerobic vaginitis (AV) caused by S. agalactiae and E. faecalis, which have been implicated in neonatal and obstetric sepsis. The prevalence and antimicrobial susceptibility of E. faecalis and S. agalactiae in pregnant women with AV in the Western Cape, South Africa was determined using standard microbiological culture methods and the Sensititre TREK system. AV was detected in 26.13% of the 199 tested pregnant women, with S. agalactiae and E. faecalis isolated from 32 and 20 mothers respectively. S. agalactiae and E. faecalis showed resistance to 12 of the 17 antibiotics tested, including those recommended for prophylaxis according to the CDC guidelines. The resistance of S. agalactiae and E. faecalis to commonly administered antimicrobials highlights the need for alternative treatment regimens for AV during pregnancy to reduce the risk of AV-associated negative pregnancy outcomes.National Research Foundation of South Afric

Drug susceptibility profiles of Candida species isolated from the oral mucosa of HIV-positive West African patients using the TREK Sensititre system

Poster presented at ASM2013, 113th General Meeting, American Society of Microbiology, 18-21 May, Denver, ColoradoBACKGROUND: 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

Purely-long-range bound states of He(2s3S)+(2s ^3S)+He(2p3P)(2p ^3P)

We predict the presence and positions of purely-long-range bound states of $^4$He$(2s ^3S)+{}^4$He$(2p ^3P)$ near the $2s ^3S_1+2p ^3P_{0,1}$ atomic limits. The results of the full multichannel and approximate models are compared, and we assess the sensitivity of the bound states to atomic parameters characterizing the potentials. Photoassociation to these purely-long-range molecular bound states may improve the knowledge of the scattering length associated with the collisions of two ultracold spin-polarized $^4$He$(2s ^3S)$ atoms, which is important for studies of Bose-Einstein condensates.Comment: 16 pages, 5 figure

Qubits from Number States and Bell Inequalities for Number Measurements

Bell inequalities for number measurements are derived via the observation that the bits of the number indexing a number state are proper qubits. Violations of these inequalities are obtained from the output state of the nondegenerate optical parametric amplifier.Comment: revtex4, 7 pages, v2: results identical but extended presentation, v3: published versio

Noise Sources in Photometry and Radial Velocities

The quest for Earth-like, extrasolar planets (exoplanets), especially those located inside the habitable zone of their host stars, requires techniques sensitive enough to detect the faint signals produced by those planets. The radial velocity (RV) and photometric transit methods are the most widely used and also the most efficient methods for detecting and characterizing exoplanets. However, presence of astrophysical "noise" makes it difficult to detect and accurately characterize exoplanets. It is important to note that the amplitude of such astrophysical noise is larger than both the signal of Earth-like exoplanets and state-of-the-art instrumentation limit precision, making this a pressing topic that needs to be addressed. In this chapter, I present a general review of the main sources of noise in photometric and RV observations, namely, stellar oscillations, granulation, and magnetic activity. Moreover, for each noise source I discuss the techniques and observational strategies which allow us to mitigate their impact.Comment: 11 pages, 2 tables, Lecture presented at the IVth Azores International Advanced School in Space Sciences on "Asteroseismology and Exoplanets: Listening to the Stars and Searching for New Worlds" (arXiv:1709.00645), which took place in Horta, Azores Islands, Portugal in July 201

The use of heat and chemical penetration enhancers to increase the follicular delivery of erythromycin to the skin

Copyright © 2019. Published by Elsevier B.V.The effect of heat on the follicular absorption of drugs into the skin has not previously been investigated. In comparison to drug delivery across the continuous stratum corneum (SC), follicular absorption is known to be relatively rapid and therefore the use of short durations of heat may be particularly useful for enhancing drug delivery to the hair follicles, as well as being practical for patients to use. In this study erythromycin has been used as a model drug and the combined use of heat and chemical penetration enhancers was found to be able to synergistically increase the penetration of erythromycin into human skin via the follicular route. Moreover durations of heat application as short as 10 min in combination with particular enhancer systems were found to be sufficient to significantly increase erythromycin delivery to the skin. Overall the data indicate that the use of heat with chemical penetration enhancers offers a potentially valuable strategy for delivering drugs via the follicular route.Peer reviewedFinal Accepted Versio