Archive for July 4, 2015

Postexposure Prophylactic Effect of Hepatitis B Virus (HBV)-Active Antiretroviral Therapy against HBV Infection

Antimicrob. Agents Chemother. February 2015 59:1292-1298

Tsunamasa Watanabe, Susumu Hamada-Tsutsumi, Yoshiyuki Yokomaku, Junji Imamura, Wataru Sugiura, and Yasuhito Tanaka

aDepartment of Virology and Liver Unit, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan

bDepartment of Infectious Diseases and Immunology Clinical Research Center, National Hospital Organization Nagoya Medical Center, Nagoya, Japan

Retrospective study indicates that hepatitis B virus (HBV)-active nucleoside (nucleotide) analogues (NAs) used for antiretroviral therapy reduce the incidence of acute HBV infections in human immunodeficiency virus (HIV)-infected patients.

Learning from HIV postexposure prophylaxis (PEP), we explored the possibility of using NAs in PEP following HBV exposure, if preexposure prophylaxis is feasible clinically.

Using freshly isolated primary human hepatocytes cultured in vitro, we analyzed the effect of HBV-active tenofovir and lamivudine in primary HBV infection and also the effect of treatment with these NAs after HBV infection. HBV-active NAs applied from 24 h before inoculation could not prevent the secretion of hepatitis B surface antigen into the culture medium, and cessation of the NAs after inoculation allowed the cells to establish an apparent HBV infection.

In contrast, hepatitis B immune globulin was able to prevent HBV infection completely. NA treatment before infection, however, can control the spread of HBV infection, as detected by immunohistochemistry.

Practically, starting NA treatment within 2 days of primary HBV infection inhibited viral spread effectively, as well as preexposure treatment. We demonstrated that preexposure NA treatment was not able to prevent the acquisition of HBV infection but prevented viral spread by suppressing the production of mature progeny HBV virions.

The effect of postexposure treatment within 2 days was similar to the effect of preexposure treatment, suggesting the possibility of HBV PEP using HBV-active NAs in HIV- and HBV-susceptible high-risk groups.



July 4, 2015 at 7:22 pm

Efficacy of Skin and Nasal Povidone-Iodine Preparation against Mupirocin-Resistant Methicillin-Resistant Staphylococcus aureus and S. aureus within the Anterior Nares

Antimicrob. Agents Chemother. May 2015 59:2765-2773

Michele J. Anderson, Maren L. David, Matt Scholz, Sally J. Bull, Dan Morse, Michelle Hulse-Stevens, and Marnie L. Peterson

aDepartment of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, Minnesota, USA

b3M Infection Prevention Division, 3M Company, St. Paul, Minnesota, USA

Mupirocin decolonization of nasal Staphylococcus aureus prior to surgery decreases surgical-site infections; however, treatment requires 5 days, compliance is low, and resistance occurs.

In 2010, 3M Company introduced povidone-iodine (PVP-I)-based skin and nasal antiseptic (Skin and Nasal Prep [SNP]). SNP has rapid, broad-spectrum antimicrobial activity.

We tested SNP’s efficacy using full-thickness tissue (porcine mucosal [PM] and human skin) explant models and human subjects.

Prior to or following infection with methicillin-resistant Staphylococcus aureus (MRSA) (mupirocin sensitive and resistant), explants were treated with Betadine ophthalmic preparation (Bet), SNP, or mupirocin (Bactroban nasal ointment [BN]) or left untreated.

One hour posttreatment, explants were washed with phosphate-buffered saline (PBS) plus 2% mucin. One, 6, or 12 h later, bacteria were recovered and enumerated.

Alternatively, following baseline sampling, human subjects applied two consecutive applications of SNP or saline to their anterior nares. One, 6, and 12 h after application of the preparation (postprep), nasal swabs were obtained, and S. aureus was enumerated.

We observed that treatment of infected PM or human skin explants with SNP resulted in >2.0 log10 CFU reduction in MRSA, regardless of mupirocin sensitivity, which was significantly different from the values for BN- and Bet-treated explants and untreated controls 1 h, 6 h, and 12 h after being washed with PBS plus mucin.

Swabbing the anterior nares of human subjects with SNP significantly reduced resident S. aureus compared to saline 1, 6, and 12 h postprep. Finally, pretreatment of PM explants with SNP, followed by a mucin rinse prior to infection, completely prevented MRSA infection.

We conclude that SNP may be an attractive alternative for reducing the bioburden of anterior nares prior to surgery.



July 4, 2015 at 7:18 pm


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