30 research outputs found
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
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.This material is based upon work partially supported financially by the National Research Foundation of South Africa [Grant number TTK2008052700013]
Enhanced oxidative stress by alcohol use in HIV+ patients: possible involvement of cytochrome P450 2E1 and antioxidant enzymes
BACKGROUND: Alcohol consumption is prevalent amongst HIV positive population. Importantly, chronic alcohol use is reported to exacerbate HIV pathogenesis. Although alcohol is known to increase oxidative stress, especially in the liver, there is no clinical evidence that alcohol increases oxidative stress in HIV positive patients. The mechanism by which alcohol increases oxidative stress in HIV positive patients is also unknown. METHODS: To examine the effects of alcohol use on oxidative stress we recruited HIV+ patients who reported mild-to-moderate alcohol use. Strict inclusion and exclusion criteria were applied to reduce the effect of other therapeutic drugs metabolized via the hepatic system as well as the effect of co-morbidities such as active tuberculosis on the interaction between alcohol and HIV infection, respectively. Blood samples were collected from HIV-negative alcohol-users and HIV positive alcohol-users followed by collection of plasma and isolation and fractionation of monocytes from peripheral blood. We then determined oxidative DNA damage, glutathione level, alcohol level, transcriptional level of cytochrome P450 2E1 (CYP2E1) and several antioxidant enzymes, and plasma level of cytokines. RESULTS: Compared to HIV-negative alcohol users, HIV-positive alcohol users demonstrated an increase in oxidative DNA damage in both plasma and CD14+ monocytes, as well as, a relative increase in oxidized/reduced glutathione (GSSG/GSH) in plasma samples. These results suggest an increase in oxidative stress in HIV-positive alcohol users compared with HIV-negative alcohol users. We also examined whether alcohol metabolism, perhaps by CYP2E1, and antioxidant enzymes are involved in alcohol-mediated increased oxidative stress in HIV-positive patients. The results showed a lower plasma alcohol level, which was associated with an increased level of CYP2E1 mRNA in monocytes, in HIV-positive alcohol users compared with HIV-negative alcohol users. Furthermore, the transcription of major antioxidants enzymes (catalase, SOD1, SOD2, GSTK1), and their transcription factor, Nrf2, were reduced in monocytes obtained from HIV positive alcohol users compared to the HIV-negative alcohol user group. However, no significant change in levels of five major cytokines/chemokines were observed between the two groups. CONCLUSIONS: The data suggests that alcohol increases oxidative stress in HIV+ patients, perhaps through CYP2E1- and antioxidant enzymes-mediated pathways. The enhanced oxidative stress is accompanied by a failure of cellular antioxidant mechanisms to maintain redox homeostasis. Overall, the enhanced oxidative stress in monocytes may exacerbate HIV pathogenesis in HIV positive alcohol users
Stelleninhaber geht – Wissen bleibt!
In Deutschland nimmt der Anteil älterer Arbeitnehmerinnen und Arbeitnehmer tendenziell zu. Deshalb muss sich die Bibliotheksleitung verstärkt auf das altersbedingte Ausscheiden älterer Arbeitnehmer einstellen. Eine langjährige Fachkraft verfügt über spezielles Erfahrungswissen im direkten Aufgabenfeld. Die Bibliotheksleitung muss den Transfer allen relevanten Wissens, dazu gehört das Erfahrungswissen, vom Stelleninhaber auf seinen Nachfolger ermöglichen und unterstützen. Am Beispiel der Universitätsbibliothek der Bergakademie Freiberg wird untersucht, wie das Wissensmanagement im Rahmen eines Stellenwechsels derzeit geregelt ist. Das geschieht mit Hilfe von Tiefeninterviews in verschiedenen Abteilungen. Die Auswertung der Interviews bildet die Basis für ein Konzept für das Wissensmanagement beim Stellenwechsel an der UB Freiberg. Das Konzept benennt u. a. Maßnahmen zur Identifikation des stellenbezogenen Wissens, Maßnahmen zur Dokumentation des relevanten Wissens und Instrumente zur Wissensweitergabe beim Stellenwechsel
Role of CCL3L1-CCR5 Genotypes in the Epidemic Spread of HIV-1 and Evaluation of Vaccine Efficacy
Polymorphisms in CCR5, the major coreceptor for HIV, and CCL3L1, a potent CCR5 ligand and HIV-suppressive chemokine, are determinants of HIV-AIDS susceptibility. Here, we mathematically modeled the potential impact of these genetic factors on the epidemic spread of HIV, as well as on its prevention.Ro, the basic reproductive number, is a fundamental concept in explaining the emergence and persistence of epidemics. By modeling sexual transmission among HIV+/HIV- partner pairs, we find that Ro estimates, and concordantly, the temporal and spatial patterns of HIV outgrowth are highly dependent on the infecting partners' CCL3L1-CCR5 genotype. Ro was least and highest when the infected partner possessed protective and detrimental CCL3L1-CCR5 genotypes, respectively. The modeling data indicate that in populations such as Pygmies with a high CCL3L1 gene dose and protective CCR5 genotypes, the spread of HIV might be minimal. Additionally, Pc, the critical vaccination proportion, an estimate of the fraction of the population that must be vaccinated successfully to eradicate an epidemic was <1 only when the infected partner had a protective CCL3L1-CCR5 genotype. Since in practice Pc cannot be >1, to prevent epidemic spread, population groups defined by specific CCL3L1-CCR5 genotypes might require repeated vaccination, or as our models suggest, a vaccine with an efficacy of >70%. Further, failure to account for CCL3L1-CCR5-based genetic risk might confound estimates of vaccine efficacy. For example, in a modeled trial of 500 subjects, misallocation of CCL3L1-CCR5 genotype of only 25 (5%) subjects between placebo and vaccine arms results in a relative error of approximately 12% from the true vaccine efficacy.CCL3L1-CCR5 genotypes may impact on the dynamics of the HIV epidemic and, consequently, the observed heterogeneous global distribution of HIV infection. As Ro is lowest when the infecting partner has beneficial CCL3L1-CCR5 genotypes, we infer that therapeutic vaccines directed towards reducing the infectivity of the host may play a role in halting epidemic spread. Further, CCL3L1-CCR5 genotype may provide critical guidance for optimizing the design and evaluation of HIV-1 vaccine trials and prevention programs
Games of Incomplete Information and Myopic Equilibria
A new concept of an equilibrium in games is introduced that solves an open
question posed by A. Neyman
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Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.
Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707
Contribution of HIV Infection, AIDS, and Antiretroviral Therapy to Exocrine Pathogenesis in Salivary and Lacrimal Glands
The structure and function of exocrine glands are negatively affected by human immunodeficiency virus (HIV) infection and its co-morbidities, including innate and adaptive immune responses. At the same time, exocrine function may also be influenced by pharmacotherapies directed at the infectious agents. Here, we briefly review the role of the salivary glands and lacrimal glands in normal physiology and exocrine pathogenesis within the context of HIV infection and acquired immune deficiency syndrome (AIDS), including the contribution of antiretroviral therapies on both. Subsequently, we discuss the impact of HIV infection and the types of antiretroviral therapy on disease management and therapy development efforts