Association between HIV and other DNA viruses in vitro.

To investigate the association of human immunodeficiency virus (HIV) with various DNA viruses, including hepatitis B virus (HBV), cytomegalovirus (CMV) and Epstein-Barr virus, (EBV), simultaneous detection of HIV p24 antigen, HBV surface antigen and DNA, CMV-DNA and EBV-DNA expression was performed in phytohemagglutinin-stimulated peripheral blood mononuclear (PBMC) culture supernatants obtained from 54 individuals at risk for HIV infection. HIV expression in PBMC culture supernatants never occurred alone; expression of other viruses was always detected in the 24 samples expressing HIV antigen in vitro. Furthermore, in 16 patients expression of other viruses was detected without HIV expression, and in 14 patients none of the tested viruses were detected. These results indicate a strong association between the presence of HIV antibody and expression of DNA viruses in vitro (p = 0.0001). The coexpression of these viruses could be related to the evolution of HIV infection and AIDS.

Conjugal transfer of R plasmids to and from Enterobacteriaceae isolated from sewage.

The potential of the transfer of natural plasmids between sewage strains has been studied. In vitro transfer was conducted at 37 degrees C in tryptone soya broth and sterile raw sewage as mating media. In situ transfer was carried out in sterile raw sewage within membrane diffusion chambers at 10.6 degrees C. When the recipient was a laboratory strain of Escherichia coli K-12, the in situ frequency values were significantly lower (P less than 0.001) than those obtained in vitro for the same mating pair. When the laboratory recipient was replaced with recipients from the same sewage source, frequency values decreased progressively from the optimum conditions to the most adverse. However, in situ frequency values were higher than those for the same donors mated with a laboratory recipient.

[Antimicrobial resistance in strains of Salmonella enterica isolated in the Hospital de Basurto (Bilbao) from 1987 to 1990]. / Resistencia antimicrobiana en cepas de Salmonella enterica aisladas en el Hospital de Basurto (Bilbao) desde 1987 hasta 1990.

BACKGROUND: Rate development of antimicrobial resistance of Salmonella strains in Hospital Basurto of Bilbao from 1987 to 1990 and to study their resistance mechanism. METHODS: The antimicrobial resistance for all strains isolated (1201 strains) was performed by means of a agar-diffusion test. We selected 32 multi-resistant strains for additional study (MIC, conjugation, IEF, and plasmid profile). RESULTS: The most frequent isolated serotypes were S. enteritidis (79.01%), S. typhimurium (8.5%) and Salmonella serogroup C1 (6.9%). The resistance to one or more of 17 antimicrobial rose significantly: 9.6% in 1987; 10.25% in 1988; 16.45% in 1989 and 13.73% in 1990. The percentage of resistant serotypes were: S. typhimurium (40.2%); Salmonella serogroup B (31.8%); Salmonella serogroup C1 (16.8%); Salmonella serogroup D1 (13.04%); Salmonella serogroup C2 (9.09%) and S. enteritidis (8.4%). In 27 multi-resistant strains and their transconjugants, beta-lactamase bands with a pl: 5.4 and/or 5.6 compatible with TEM-1 and/or TEM-2 were observed. Also, these strains carried a plasmid of high molecular weight (125 MD). CONCLUSIONS: Although, the resistance of Salmonella is not a serious problem in our environment this situation is raising progressively with a greater number of strains with plasmid mediated beta-lactamases. So, the antimicrobial policy will be more severe and righ in both hospital and extrahospital surrounding.

[Detection of hepatitis B virus DNA in peripheral blood mononuclear cells from patients with various hepatopathies using in situ hybridization]. / Detección del DNA del virus de la hepatitis B en células mononucleares de sangre periférica de pacientes con distintas hepatopatías mediante hibridación "in situ".

We have investigated, by "in situ" hibridisation, the presence of hepatitis B virus (HBV) DNA in peripheral blood mononuclear cells (PBMC) from 45 patients with acute and chronic hepatic disorders directly related with HBV or with some seric HBV marker. Results has been related with serological markers and the different types of hepatopaties. The HBV-DNA was detected in PBMC more frequently in patients with hepatic alterations more prolongated (chronic active hepatitis, chronic persistent hepatitis and cirrhosis) than in acute hepatitis patients. It was not detected in any asymptomatic patient with HBV serological markers. As regards HBV serological markers, HBV-DNA was detected in PBMC in 8/11 HBsAg positive patients and in 11/34 HBsAg negative patients: 3 antiHBc positive, 5 antiHBc and antiHBs positive and 3 without conventional seric markers. The detection of HBV-DNA in antiHBc and/or antiHBs positive subjects means the virus may persist after recovery of infection and suggests PMBC could serve as additional reservoirs for reinfection of hepatocytes leading to a reactivation of the liver disease. Our results suggest that HBV infection of PBMC is a frequent event during HBV infection and can have important consequences fundamentally with respect to pathogenic mechanisms of HBV induced liver disease and to the transmission of the virus.

[Detection and antigenic distribution of hepatitis B virus in liver tissue and its relation to other serological markers of viral replication]. / Detección y distribución antigénica del virus de la hepatitis B en tejido hepático y su relación con otros marcadores serológicos de replicación viral.

The aim of this work has been the production of specific monoclonal antibodies against HBV-antigens and their utilisation in order to study their distribution on liver tissue. The monoclonal antibodies anti-HBc and anti-HBs were obtained by the modified hybridoma technique. This study was performed on 50 patients affected by several chronic hepatopathies. For the detection of the antigens, avidin-biotin-peroxidase complex immunostaining was used. Both cytoplasmic and membranous HBsAg were detected in 15 out of 16 HBsAg+ patients; 8 of 12 HBsAg-/anti-HBc+ patients and 1 HBsAg-/antiHBc- patient. Cytoplasmic and nuclear HBcAg was observed in 12 of 16 HBsAg+ patients and 4 of 20 HBsAg- patients. Although the presence of serum HBsAg is an index of liver infection, in some HBsAg-/antiHB+ patients (20%) with undetectable levels of HBsAg, hepatic injury may be disclosed by the detection of other markers of active viral replication.

[Presence of HBsAg in lymphocyte cultured from patients infected with human immunodeficiency virus (HIV)]. / Presencia de HBsAg en cultivos de linfocitos de pacientes infectados por el virus de la inmunodeficiencia humana (VIH).

The behavior of the hepatitis B virus was investigated in mononuclear cell cultures in nine patients infected by the human immunodeficiency virus. Although only one of them was a carrier of HBsAg and four had anti-HBs in their sera, HBsAg was detected in the supernatant of the cultures from all patients. These results suggest that mononuclear cells might act as a reservoir for hepatitis B virus, and that the concomitant infection by this virus and human immunodeficiency virus may alter the natural evolution of any of both conditions.