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Pentamycin is a polyene antibiotic, registered in Switzerland for the treatment of vaginal candidiasis, trichomoniasis, and mixed infections. Chemical instability has hindered its widespread application and development as a drug. Here, we report the identification of Streptomycessp. S816, isolated from Philippine mangrove soil, as a pentamycin producer. Genome sequence analysis identified the putative pentamycin biosynthetic gene cluster, which shows a high degree of similarity to the gene cluster responsible for filipin III biosynthesis. The ptnJgene, which is absent from the filipin III biosynthetic gene cluster, was shown to encode a cytochrome P450 capable of converting filipin III to pentamycin. This confirms that the cluster directs pentamycin biosynthesis, paving the way for biosynthetic engineering approaches to the production of pentamycin analogues. Several other Streptomycesgenomes were found to contain ptnJorthologues clustered with genes encoding polyketide synthases that appear to have similar architectures to those responsible for the assembly of filipin III and pentamycin, suggesting pentamycin production may be common in Streptomycesspecies.

Group B Streptococcus(GBS) is a leading cause of neonatal bacterial infections. Early-onset infections have decreased in recent years but, despite considerable efforts poured into prevention, cases continue to occur.

Human herpesvirus 6 (HHV 6) has neurotropic and neuroinvasive properties. The virus has been found in the cerebrospinal fluid of many children with aseptic meningoencephalitis. Intrauterine transmission has been documented by HHV 6 DNA detection in cord blood specimens of apparently healthy newborns and in fetuses following spontaneous abortions. A patient is described with early neonatal afebrile seizures resulting from a congenital HHV 6 variant B infection disclosed by repeated detection of viral genome by polymerase chain reaction (PCR) in cerebrospinal fluid in the first days of life. At follow‐up, magnetic resonance imaging (MRI) studies disclosed hyperintensities in the periventricular white matter and basal ganglia, associated with cerebral atrophy. Further follow‐up at 18 months revealed poor neurological outcome with mild neurodevelopmental retardation, strabismus and hypertonia of legs. This report provides evidence of neurological involvement after HHV 6 vertical transmission, and the association with neurological sequelae. J. Med. Virol. 70:628–632, 2003. © 2003 Wiley‐Liss, Inc.

Risk factors affecting vertical hepatitis C virus (HCV) transmission are not completely known, if we exclude maternal HIV coinfection. We hypothesized that immunogenetic factors related to maternal or neonatal HLA profiles may affect HCV vertical transmission. HLA typing (microcytotoxicity assay on blood samples) was performed in 18 infants affected by vertically transmitted HCV infection and in 17 serum-reverted infants. (Serum-reversion is defined as antibody negative by 1 year of age and persistently HCV-RNA negative.) Moreover, HLA typing was performed in 20 mothers. Logistic regression analysis showed a significant negative association between children's HLA-DR13 antigens and risk of HCV vertical transmission (p < 0.01). This association persisted in a model including the maternal HIV status: HLA DR13 and maternal HIV coinfection showed a separate, opposite effect on vertical HCV infection (p < 0.01 and p < 0.001, respectively). The relative risk estimate for the ratio of not-infected to infected children in the presence of DR13 was 8.4 (95% confidence bounds, 1.1–60.8). Breast-feeding did not affect the risk of vertical HCV transmission. Maternal HLA profile did not relate to vertical infection. The present study reveals a significant association between HLA-DR13 and the likelihood of seroreversion in infants born to HCV-infected mothers. The findings of the present study could help in better understanding the pathogenesis of vertical HCV infection and in better identifying the cases at higher risk, which would be useful for the development of prevention strategies. It is possible that DR13 modulates the immune response to viruses, enhancing their clearance and, thus, in the case of HCV, exerting a protective role against the development of vertical infection.

Risk factors affecting vertical hepatitis C virus (HCV) transmission are not completely known, if we exclude maternal HIV coinfection. We hypothesized that immunogenetic factors related to maternal or neonatal HLA profiles may affect HCV vertical transmission. HLA typing (microcytotoxicity assay on blood samples) was performed in 18 infants affected by vertically transmitted HCV infection and in 17 serum-reverted infants. (Serum-reversion is defined as antibody negative by 1 year of age and persistently HCV-RNA negative.) Moreover, HLA typing was performed in 20 mothers. Logistic regression analysis showed a significant negative association between children’s HLA-DR13 antigens and risk of HCV vertical transmission (p< 0.01). This association persisted in a model including the maternal HIV status HLA DR13 and maternal HIV coinfection showed a separate, opposite effect on vertical HCV infection (p< 0.01 and p< 0.001, respectively). The relative risk estimate for the ratio of not-infected to infected children in the presence of DR13 was 8.4 (95 confidence bounds, 1.1–60.8). Breast-feeding did not affect the risk of vertical HCV transmission. Maternal HLA profile did not relate to vertical infection. The present study reveals a significant association between HLA-DR13 and the likelihood of seroreversion in infants born to HCV-infected mothers. The findings of the present study could help in better understanding the pathogenesis of vertical HCV infection and in better identifying the cases at higher risk, which would be useful for the development of prevention strategies. It is possible that DR13 modulates the immune response to viruses, enhancing their clearance and, thus, in the case of HCV, exerting a protective role against the development of vertical infection.