an-affordable-hiv-1-drug-resistance-monitoring-method-for-resource

An Affordable HIV-1 Drug Resistance Monitoring Method for Resource Limited Settings

HIV-1 drug resistance has the potential to seriously compromise the effectiveness and impact of antiretroviral therapy (ART). As ART programs in ...

University of KwaZulu-Natal, Durban, South Africa

We quantified the relationship between human immunodeficiency virus (HIV) RNA shedding in breast milk, cumulative RNA exposure, and postnatal transmission, relating timing of infection in the infant to estimated total volume of milk exposure.

Cumulative exposure to cell-free HIV in breast milk, rather than feeding pattern per se, identifies postnatally infected infants.

Transmission through breastfeeding remains important for mother-to-child transmission (MTCT) in resource-limited settings. We quantify the relationship between cell-free (RNA) and cell-associated (DNA) shedding of HIV-1 virus in breastmilk and the risk of postnatal HIV-1 transmission in the first 6 months postpartum.

Cell-free (RNA) and cell-associated (DNA) HIV-1 and postnatal transmission through breastfeeding.

Organized bacterial communities, or biofilms, provide an important reservoir for persistent cells that are inaccessible or tolerant to antibiotics. Curli pili are cell-surface structures produced by certain bacteria and have been implicated in biofilm formation in these species. In order to determine whether these structures, which were suggested to be encoded by the Rv3312A (mtp) gene, have a similar role in Mycobacterium tuberculosis, we generated a Δmtp mutant and a mtp-complemented strain of a clinical isolate of M. tuberculosis and analyzed these strains for their ability to produce pili in comparison to the wild-type strain. Phenotypic analysis by transmission electron microscopy proved the essentiality of mtp for piliation in M. tuberculosis. We then compared biofilm formation of the derived strains in detergent-free Sauton's media. Biofilm mass was quantified spectrophotometrically using crystal violet. Furthermore, we examined mtp gene expression by quantitative real-time PCR in wild-type cells grown under biofilm versus planktonic growth conditions. We found a 68.4 % reduction in biofilm mass in the mutant compared to the wild-type strain (P = 0.002). Complementation of the mutant resulted in a restoration of the wild-type biofilm phenotype (P = 0.022). We, however, found no significant difference between mtp expression in cells of the biofilm to those growing planktonically. Our findings highlight a crucial, but non-specific, role of pili in the biofilm lifestyle of M. tuberculosis and indicate that they may represent an important target for the development of therapeutics to attenuate biofilm formation, thereby potentially reducing persistence.

Pili contribute to biofilm formation in vitro in Mycobacterium tuberculosis.

Substantial amounts of data have been generated from patient management and academic exercises designed to better understand the human immunodeficiency virus (HIV) epidemic and design interventions to control it. A number of specialized databases have been designed to manage huge data sets from HIV cohort, vaccine, host genomic and drug resistance studies. Besides databases from cohort studies, most of the online databases contain limited curated data and are thus sequence repositories. HIV drug resistance has been shown to have a great potential to derail the progress made thus far through antiretroviral therapy. Thus, a lot of resources have been invested in generating drug resistance data for patient management and surveillance purposes. Unfortunately, most of the data currently available relate to subtype B even though >60% of the epidemic is caused by HIV-1 subtype C. A consortium of clinicians, scientists, public health experts and policy markers working in southern Africa came together and formed a network, the Southern African Treatment and Resistance Network (SATuRN), with the aim of increasing curated HIV-1 subtype C and tuberculosis drug resistance data. This article describes the HIV-1 data curation process using the SATuRN Rega database. The data curation is a manual and time-consuming process done by clinical, laboratory and data curation specialists. Access to the highly curated data sets is through applications that are reviewed by the SATuRN executive committee. Examples of research outputs from the analysis of the curated data include trends in the level of transmitted drug resistance in South Africa, analysis of the levels of acquired resistance among patients failing therapy and factors associated with the absence of genotypic evidence of drug resistance among patients failing therapy. All these studies have been important for informing first- and second-line therapy. This database is a free password-protected open source database available on www.bioafrica.net. Database URL: http://www.bioafrica.net/regadb/

Southern African Treatment Resistance Network (SATuRN) RegaDB HIV drug resistance and clinical management database: supporting patient management, surveillance and research in southern Africa.

Siva Danaviah

Africa Centre for Health and Population Studies,
College of Health Sciences,
Africa Centre for Health and Population Studies, College of Health Sciences

University of KwaZulu-Natal, Durban, South Africa

An Affordable HIV-1 Drug Resistance Monitoring Method for Resource Limited Settings

Siva Danaviah

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University of KwaZulu-Natal, Durban, South Africa

An Affordable HIV-1 Drug Resistance Monitoring Method for Resource Limited Settings

Africa Centre for Health and Population Studies,
College of Health Sciences,
Africa Centre for Health and Population Studies, College of Health Sciences