Inactivation of Herpesvirus hominis Types 1 and 2 by Silver Nitrate In Vitro and In Vivo

Abstract

Herpes simplex virus (HSV) types 1 and 2 (two strains each) were inactivated at different rates in vitro by 40 The present striking increase in the incidence of venereal diseases in the United States has been accompanied by a marked increase in observed genital infections caused by herpesviruses, mostly Herpesvirus hominis (herpes simplex virus [HSVJ) type 2. This rise in genital herpetic infections can be expected to produce an increasing exposure of newborns to the virus during passage through the birth canal, with a possible risk of serious illness (6, 7). The eyes of the neonate are one of the highly susceptible potential sites for infection with herpesviruses. However, immediately after delivery, 1% silver nitrate is instilled into the eyes of all newborns. This "Crede prophylaxis" is highly effective in controlling ocular infection due to gonococci acquired from the mother's genital tract (3). The question arises whether this silver nitrate prophylaxis might also have an effect on herpesvirus eye infection of the neonate acquired during passage through the birth canal. Cell culture. Vero (African green monkey kidney) cells were used in all culture procedures and for the preparation of infective pools of virus. The growth medium was Eagle's minimal essential medium (MEM) with the addition of 5% heat-inactivated fetal calf serum, nonessential amino acids, penicillin (100 units/ml), and streptomycin (100 ug/m4. When confluent monolayers were formed, the growth medium was replaced with maintenance medium (MM) consisting of MEM with 2% heat-inactivated fetal calf serum, nonessential amino acids, penicillin, and streptomycin.For plaque assays, the cells were grown in 16-oz (0.47-liter) prescription bottles. The cell sheets were removed with a mixture of 0.05% pancreatin, 0.05% ethylenediaminetetraacetate, and 0.05% trypsin in phosphate-buffered saline, and were resuspended in growth medium to a concentration of 1.5 million cells/5 ml. This volume was seeded into plastic tissue culture dishes (60 by 15 mm) and incubated at 37 C in 5% CO2 for 2 to 3 days. The medium was removed from confluent monolayers, and plates were inoculated with 0.2 ml of the material to be assayed. After a 2-to 2.5-h adsorption period at on May 12, 2018 by guest http://aac.asm.org/ Downloaded from

Inactivation of Herpes Simplex Virus by Thiosemicarbazones and Certain Cations

“…It can be seen that Me-IBT inactivated strains of both type 1 and type 2 HSV, including a strain of HSV type 2 which transforms hamster cells in vitro. The rates of inactivation of the type 1 and 2 strains appear to be quite similar in contrast to previous findings from this laboratory and others (4,6,11,12) with other compounds such as silver nitrate, cytosine arabinoside, and iododeoxyuridine.…”

“…Not all viruses are susceptible; however, vaccinia virus, Newcastle disease virus, reovirus, vesicular stomatitis virus, poliovirus, and poliovirus infectious RNA are not affected despite the fact that some of these possess a virion transcriptase (9). This lack of susceptibility may be a function of the ability of the drug to penetrate the virion, for we have demonstrated that the DNA-dependent RNA polymerase activity of the vaccinia virus core is markedly inhibited by exposure to 40,uM Me (4) and two strains of HSV type 2, the MS strain (4) and a strain (HSV-2-333) which transforms hamster cells in vitro (5) (kindly supplied by Fred Rapp), were used. The cytopathic effect of these viruses was determined on Vero cells.…”

Copper as a Biocidal Tool

“…In 1974, Totsuka and Ohtaki [55] showed that the effect of copper sulphate on poliovirus RNA is proportional to its concentration, and that most amino acids except cysteine had a protective effect against copper as did Fe 2+ and Al 3+ . In 1974, Coleman and colleagues [56] reported that herpes simplex virus (HSV) type I was sensitive to silver. In 1992, Sagripanti and colleagues [57,58] found that cupric and ferric ions were by themselves able to inactivate five enveloped or nonenveloped, single-or double-stranded DNA or RNA viruses (phi X174, T7, phi 6, Junin, and HSV).…”

Specific Inactivation of Herpes Simplex Virus by Silver Nitrate at Low Concentrations and Biological Activities of the Inactivated Virus

“…Thus, in vitro and in vivo effects of compounds such as silver nitrate (5) or silver sulfadiazine (3) on HSV infection have recently been investigated to evaluate them as local chemotherapeutic agents.…”