A prospective study of hearing changes after beginning zidovudine or didanosine in HIV-1 treatment-naïve people

BACKGROUND: While hearing loss in HIV-infected people after beginning nucleoside reverse transcriptase inhibitors (NRTIs) has been reported, there have been no prospective studies that measured hearing changes longitudinally in treatment-naïve HIV-infected subjects following initiation of regimens containing NRTIs. The goal of this study was to conduct a prospective assessment of the contribution of zidovudine (ZDV) and didanosine (ddI) to hearing loss METHODS/DESIGN: A prospective observational pilot study to determine whether ZDV or ddI, alone or in combination, are associated with sensorineural hearing loss in HIV-infected persons. Changes in hearing levels at all frequencies and in low and high frequency pure tone averages were measured at baseline, 16, and 32 weeks after initiating antiretroviral therapy. DISCUSSION: Treatment with ZDV and ddI did not result in loss of hearing, even after taking into account noise exposure, immune status and age. The results of this prospective pilot study do not support the notion that treatment with nucleoside antiretrovirals damages hearing

Novel P335-like Phage Resistance Arises from Deletion within Putative Autolysin <i>yccB</i> in <i>Lactococcus lactis</i>

Lactococcus lactis and Lactococcus cremoris are broadly utilized as starter cultures for fermented dairy products and are inherently impacted by bacteriophage (phage) attacks in the industrial environment. Consequently, the generation of bacteriophage-insensitive mutants (BIMs) is a standard approach for addressing phage susceptibility in dairy starter strains. In this study, we characterized spontaneous BIMs of L. lactis DGCC12699 that gained resistance against homologous P335-like phages. Phage resistance was found to result from mutations in the YjdB domain of yccB, a putative autolysin gene. We further observed that alteration of a fused tail-associated lysin-receptor binding protein (Tal-RBP) in the phage restored infectivity on the yccB BIMs. Additional investigation found yccB homologs to be widespread in L. lactis and L. cremoris and that different yccB homologs are highly correlated with cell wall polysaccharide (CWPS) type/subtype. CWPS are known lactococcal phage receptors, and we found that truncation of a glycosyltransferase in the cwps operon also resulted in resistance to these P335-like phages. However, characterization of the CWPS mutant identified notable differences from the yccB mutants, suggesting the two resistance mechanisms are distinct. As phage resistance correlated with yccB mutation has not been previously described in L. lactis, this study offers insight into a novel gene involved in lactococcal phage sensitivity

Audio-vestibular function in human immunodeficiency virus infected patients in India

Objective: As the acquired immunodeficiency syndrome (AIDS) epidemic shows no signs of abating, the impact of AIDS is felt more in the developing countries due to socioeconomic reasons. The possibility of drug-induced ototoxicity also adds to the risk of audio vestibular dysfunction. We sought to determine if there was a difference between the audio-vestibular function in the asymptomatic human immunodeficiency virus (HIV) infected patients and patients with AIDS. Study Design: A prospective, cross-sectional study Setting: A tertiary care center in South India Materials and Methods: The audio-vestibular system of 30 asymptomatic HIV positive subjects (group 1) and 30 subjects with AIDS (group 2), and age-matched 30 healthy controls (group 3) were assessed using pure tone audiometry and cold caloric test. Results: Sixteen patients each, in group 1 and group 2 and four subjects in the control group were detected to have a hearing loss indicating significantly more HIV infected individuals (group 1 and 2) were having hearing loss (P=0.001). Kobrak′s (modified) test showed 27% of patients in group 1 and 33% of patients in group 2 and none in the group 3 had a hypofunctioning labyrinth (P=0.001). Conclusion: It seems that the human immunodeficiency virus does affect the audio-vestibular pathway. There was a significant incidence of audio-vestibular dysfunction among the HIV infected patients, as compared to the control population (P=0.001) and no significant difference between the asymptomatic HIV seropositive patients and AIDS patients. Majority of the patients had no otological symptoms

In vitro assessment of antiretroviral drugs demonstrates potential for ototoxicity

Several studies have reported an increased incidence of auditory dysfunction among HIV/AIDS patients. We used auditory HEI-OC1 cells in cell viability, flow cytometry and caspases 3/7-activation studies to investigate the potential ototoxicity of fourteen HIV antiretroviral agents: Abacavir, AZT, Delavirdine, Didenosine, Efavirenz, Emtricitabine, Indinavir, Lamivudine, Nefinavir, Nevirapine, Tenofovir, Ritonavir, Stavudine and Zalcitabine, as well as combinations of these agents as used in the common anti-HIV cocktails Atripla™, Combivir™, Epzicom™, Trizivir™, and Truvada™. Our results suggested that most of the single assayed anti-HIV drugs are toxic for HEI-OC1 auditory cells. The cocktails, on the other hand, decreased auditory cells’ viability with high significance, with the following severity gradient: Epzicom ~ Trizivir ≫ Atripla ~ Combivir > Truvada. Interestingly, our results suggest that Trizivir- and Epzicom-induced cell death would be mediated by a caspase-independent mechanism. L-Carnitine, a natural micronutrient known to protect HEI-OC1 cells against some ototoxic drugs as well as to decrease neuropathies associated with anti-HIV treatments, increased viability of cells treated with Lamivudine and Tenofovir as well as with the cocktail Atripla, but had only minor effects on cells treated with other drugs and drug combinations. Altogether, these results suggest that some frequently used anti-HIV agents could have deleterious effects on patients hearing, and provide arguments in favor of additional studies aimed at elucidating the potential ototoxicity of current as well as future anti-HIV drugs