Antibodies to human herpes virus type 8 (HHV8) in general population and in individuals at risk for sexually transmitted diseases in Western Sicily.

BACKGROUND: Human herpes virus 8 (HHV8) appears to be the primary aetiologic agent of Kaposi sarcoma (KS). To study the distribution of HHV8, a seroepidemiological study was carried out in western Sicily, where a high incidence rate of classical KS is well documented. METHODS: A total of 970 sera of healthy human immunodeficiency virus (HIV) negative individuals of general population (1-70 years old) and 742 sera of individuals in different risk groups for HIV infection were evaluated by means of an indirect immunofluorescence assay able to detect antibodies to lytic and latent HHV8 antigens. RESULTS: Crude seroprevalence to HHV8 antigens was 11.5% in the general population, and it increased significantly with age from 6% under age 16 to 22% after age 50. Significantly higher HHV8 seroprevalence rates were detected among HIV positive and negative homosexual men (62% and 22%, respectively), men who had sex with prostitutes (40% and 29%, respectively); female prostitutes (42% and 30%, respectively), and clients at a sexually transmitted disease clinic (male: 60% and 33%, respectively, female: 63% and 43%, respectively). In contrast, heterosexual intravenous drug users had seroprevalence rates comparable to those found in the general population. CONCLUSIONS: The results suggest that HHV8 infection is widespread in Western Sicily. The high seroprevalence in individuals with high risk sexual activity point to the role of sexual behaviour in the transmission of the infection in adults, whereas the detection of antibodies in younger population (under 16 years old) is suggestive of a non-sexual route of transmission, probably occurring during childhood by close personal contact.

Inhibition of human immunodeficiency virus 1 (HIV-1) by variant B of human herpesvirus 6 (HHV-6).

Four HHV-6 strains were initially isolated during attempts to observe HIV-1 replication in cultured primary lymphocytes from 48 patients with AIDS. HHV-6 DNA from each strain was extracted from primary cell cultures and amplified using specific primers in a nested polymerase chain reaction (PCR) assay. All HHV-6 strains were classified as B variants by submitting the PCR products to the digestion of two restriction enzymes (Hind III and Bgl II). Since in primary cultures, the appearance of HHV-6 cytopathic effect was followed by a progressive reduction of HIV-1 replication, we tried to reproduce the observed inhibition in vitro. Two HHV-6 strains, used throughout the experiments, showed their ability to suppress HIV-1 replication when the viruses co-infected CD4+T lymphocyte cultures. While the intrinsic mechanism of this finding still remains unclear, the inhibition of HIV-1 replication was observed only when a high multiplicity of infection (m.o.i.) of HHV-6 and a low m.o.i. of HIV-1 were used in dually infected cell cultures. By using a semiquantitative determination of HIV-1 cDNA by PCR, it appears that the inhibition begins in infected cell cultures and, once established, does not allow any further HIV-1 replication.

Distribution of hepatitis C virus genotypes among intravenous drug users. A ten-year study in Palermo, Sicily.

A cross-sectional study was carried out on the sera of 88 active intravenous drug users (IVDU) collected between 1985 and 1986 to evaluate the circulation of HCV genotypes in Western Sicily. The patients were grouped by age and classified by their HIV status. Genotype 3a (48.8% of all cases) was most frequently detected, followed by genotype 1a (20.4%) and type 1b (17.0%). No significant differences in HCV genotype distribution were observed between HIV positive and negative individuals. Next, the HCV genotype distribution found in sera samples of IDVUs drawn between 1985 and 1986 was studied and divided into three age groups. The genotype distribution in the younger group was then compared with samples collected ten years later, between 1995 and 1996, from young HIV negative IVDU individuals. A different distribution between HCV genotypes 3a and 1a was found with a relative, though not significant, increase in the detection of genotype 1a (38%). Finally, sera from six IVDUs obtained at three different times over a ten-year period were genotyped for HCV. None of the subjects showed any change in the genotype found at the first sampling throughout the ten years. The results suggest that a) genotype 1a and 3a are the most common among IVDUs in Western Sicily, b) concurrent HIV infection does not seem to influence HCV genotype and c) infected IVDUs harbor almost exclusively one genotype.

Human herpesvirus type 8 DNA sequences in biological samples of HIV-positive and negative individuals in Sicily.

OBJECTIVE: To evaluate the circulation of a new human herpesvirus (HHV), HHV-8 or Kaposi's sarcoma (KS)-associated herpesvirus in a geographical area where a high incidence rate of classical KS was already present before the appearance of the AIDS epidemic. DESIGN AND METHODS: The study was carried out by analysing: (i) bioptic samples from classic, AIDS-associated KS, and controls; (ii) peripheral blood mononuclear cells (PBMC) from classic KS, HIV-positive subjects with and without KS and healthy HIV-negative individuals; (iii) semen samples from heterosexual HIV-positive and HIV-negative individuals affected or not by KS; and (iv) cervical swabs from HIV-negative healthy heterosexual females. All specimens were tested for the presence of HHV-8 DNA sequences by a two-step polymerase chain reaction. RESULTS: Positive results were obtained in 90% of bioptic samples of classic KS and in 100% of AIDS-associated KS. Viral sequences were also present in 50% of PBMC of subjects with classic KS and AIDS-associated KS, in 10% of AIDS patients without the angiosarcoma and in 11% of healthy HIV-negative individuals. Finally, HHV-8 DNA was detected in 13% of semen of HIV-negative heterosexual individuals and in 10% of AIDS patients without KS. Both PBMC and ejaculates from the same individual gave positive results. No HHV-8 sequences were found in cervical swabs. CONCLUSIONS: HHV-8 is widespread in the general population in Sicily since it was detected in PBMC and semen of heterosexual HIV-negative individuals and is not found only in high-risk groups. The viral load appears to be more elevated in a high-risk population and it may be ascribed to a viral reactivation. The higher incidence rates of KS in Sicily compared with northern Italy and other European countries might be related to the presence of HHV-8 in the general population.

Rare association of human herpesvirus 6 DNA with human papillomavirus DNA in cervical smears of women with normal and abnormal cytologies.

We investigated by nested PCR the possible association of human herpesvirus 6 (HHV-6) and human papillomavirus (HPV) genomes in the cervixes of 109 women with normal and abnormal cytological smears. HPV DNA was detected in 8.33% of 24 women with normal cytologies and in 41.1% of 85 women with abnormal cytologies; the proportion of HPV DNA was directly related to the severity of the lesions. HHV-6 DNA was found in only one patient, who had a cytological pattern of koilocytosis. The HHV-6 genome was classified by restriction enzyme analysis as variant B. The study indicates that detection of the HHV-6 genome in the cervixes of women with a wide spectrum of gynecological complaints is a rare event and rules out the possible association between HHV-6 and HPV genomes in cervical cancer lesions.

Epidemiology of Salmonella typhimurium: ribosomal DNA analysis of strains from human and animal sources.

Salmonella typhimurium is the most frequently identified serovar of Salmonella in Italy. This serovar is characterized by the widespread dissemination among human and non-human sources of phenotypically and genetically well-differentiated clones. In this study 457 strains of S. typhimurium isolated in Italy in the years 1982-91 from human and animal sources were submitted to characterization by the rDNA fingerprinting technique. Application of this typing method, after digestion of chromosomal DNA with HincII endonuclease, confirmed the greatest genetic differentiation of clones of S. typhimurium, allowing reliable identification of 45 rDNA patterns linked into 9 major clusters. rDNA pattern clusters or ribotypes specific to man were not recognized, whereas some rDNA patterns were characteristically related to ducks, pigeons and pet birds. The ribotyping results for isolates from animal hosts suggest that pig and cattle are the main source of human infection.

rDNA fingerprinting as a tool in epidemiological analysis of Salmonella typhi infections.

Characterization of 169 strains of Salmonella typhi of phage types C1, C4, D1 and D9 isolated in 1975-88 was carried out by rDNA gene restriction pattern analysis. Twenty-four isolates had been recovered during four large waterbone outbreaks in the last 20 years in Sicily; 145 strains, isolated from apparently sporadic cases of infection in Southern Italy in the same period of time, were also examined. Application of rRNA-DNA hybridization technique after digestion of chromosomal DNA with Cla I showed the identity of patterns of the epidemic strains of phage types C1 and D1, confirming attribution of the outbreaks to single bacterial clones. Patterns of the two available strains of lysotype D9 were slightly different, whilst the 12 epidemic strains of phage type C4 could be assigned to two distinct patterns scarcely related to each other and, consequently, to two different clones. A considerable heterogeneity was detected among all apparently sporadic isolates of the four phage types under study. This fingerprinting method appears a reliable tool to complement phage typing in characterizing isolates of S. typhi. In particular, epidemiological features of spread of this salmonella serovar in areas, where simultaneous circulation of indigenous and imported strains occurs, can be elucidated.

Reemergence of Shigella dysenteriae type 2 in Sicily: an epidemiological evaluation.

Three strains of Shigella dysenteriae type 2 were isolated from a small household outbreak which occurred in Palermo, Sicily, during summer 1990. Two isolates were recovered from hospitalized patients and one from an asymptomatic carrier. The infection could not be associated with travel to foreign countries or contact with travellers returned from abroad. Since 1953 S. dysenteriae has been never isolated in Southern Italy. The isolates from dysentery cases were susceptible to antibiotics and carried a plasmid of 120 MDa associated with a small cryptic plasmid; in contrast, the strain isolated from the healthy carrier contained an additional plasmid of approximately 40 MDa, which codified for resistance to ampicillin, streptomycin, sulfamethoxazole and trimethoprim. All strains showed some atypical biochemical properties, but their rRNA-DNA patterns of hybridization were closely similar to that of the reference strains of type 2 and easily distinguishable from those of the other types of non-Shiga bacillus reference strains. Epidemiological isolation features of these strains suggest a possible circulation of this Shigella species in Sicily. Genetic characterization of these strains may be useful for surveillance of infections by this organism.

Epidemiological evaluation by rRNA-DNA hybridization of strains of Salmonella enterica subsp. enterica serovar Abortusovis isolated in southern Italy in the years 1981-1989.

Salmonella enterica subsp. enterica serovar Abortusovis is a major agent of abortion of the sheep and is firmly established, although at low prevalence, in Sicily. This paper describes the application rDNA gene restriction pattern fingerprinting to investigate relatedness among 7 serovar Abortusovis strains isolated at the "Istituto Zooprofilattico Sperimentale" of Sicily and 29 isolates identified at the Southern Italy Centre of Enterobacteriaceae between 1981 and 1989. Although Abortusovis serovar has exhibited a remarkable degree of homogeneity, genomic DNA polymorphisms, that have emerged, suggest possible importation of bacterial clones from different geographic areas.

rRNA probing of chromosomal DNA of epidemic and sporadic isolates of Salmonella enterica subsp. enterica serovar Kottbus from northern and southern Italy.

Fifty-two strains of Salmonella enterica subsp. enterica serovar Kottbus, identified at the Centres of Enterobacteriaceae of Northern and Southern Italy, were investigated by molecular genetic methods. Thirteen isolates were recovered during two food-poisoning outbreaks that occurred in May 1987 in Lombardy. The rDNA gene restriction patterns, obtained by probing endonuclease cleaved chromosomal DNA with photobiotin labeled Escherichia coli rRNA, revealed some heterogeneity among strains isolated from Southern Italy, whereas Northern Italy isolates exhibited virtually identical banding patterns.

Molecular analysis of strains of Shigella boydii isolated in northern and southern Italy.

In the years 1981-1988, Shigella boydii played a very limited role in the aetiology of diarrhoeal disease in Italy. However, between September and November, 1985, 19 isolates of serotype 2 were recovered in northern Italy from a dysentery outbreak which occurred in a geriatrics hospital in Abbiategrasso (Milan, Lombardy) and seven were identified in southern Italy during the period January-July, 1986 from apparently unrelated infection cases occurring in Brindisi (Apulia). These isolates were compared by molecular methods to seven strains of S. boydii of serotype 2 isolated since 1981 from the same geographic areas. Plasmid DNA analysis showed a large variety of patterns, whereas hybridization of chromosomal DNA with E. coli rRNA identified only two different profiles, one of which was exclusively found in all isolates from the hospital outbreak. No differences were detected among rDNA patterns of the remaining strains of S. boydii, irrespective of their geographic origin. These findings are consistent with the hypothesis that the infrequent cases of infection from S. boydii of serotype 2 which occurred during the years under study could probably be attributed to two different bacterial clones. Hybridization procedure and detection of hybrids were simplified by replacement of radioactive labelling of rRNA by the use of photobiotin.

Characterization of strains of Salmonella enterica subsp. enterica serovar Wien isolated in Italy: an epidemiological evaluation.

In the years 1987-1988, 110 strains of Wien serovar were isolated from a gastroenteritis outbreak in a neonatal unit in Palermo (Sicily). These strains showed different drug resistance patterns and plasmid profiles. Analysis of endonuclease restriction fragments of chromosomal DNA by hybridization with E. coli rRNA has demonstrated that a single bacterial clone or its derivatives were responsible for the outbreak. Furthermore, the study of 139 strains, isolated since 1970 from different geographic locations of the Mediterranean area, has confirmed a notable degree of homogeneity within Wien serovar, even though the detection of genetic polymorphisms in some isolates suggests that a number of distinct bacterial strains contributes to maintain the circulation of Wien serovar.

Salmonella serovars identified at the Centre for Enterobacteriaceae of Palermo over the 5-year period 1983-87.

Salmonellosis is become an increasing public health problem in many countries. Serotyping and assessment of antibiotic resistance are useful tools, which assist in understanding the epidemiology of Salmonella infections. In this respect, the Centre of Enterobacteriaceae of Southern Italy provides helpful information on the changing pattern of Salmonella serovars in this geographic area. This paper reports the distribution of serovars and their antibiotic susceptibility in the years 1983-1987. In particular, because of their peculiar trends during this 5-year period, epidemiological features of Mbandaka, Corvallis, Dublin, Infantis and Wien serovars are described.

Molecular analysis of Salmonella wien strains isolated from a neonatal unit outbreak.

One hundred and thirteen S. wien strains, isolated in Palermo from August 1987 to May 1988 during an enteritis outbreak in a neonatal care unit, were investigated. Genetic and phenotypic characteristics of isolates suitable for epidemiological studies are reported.

An enteric infection by Salmonella typhimurium: a multiple typing study.

A multiple typing analysis was carried out on 14 apparently heterogeneous Salmonella typhimurium strains recovered during a 3 week period from an enteritis case. Conjugational transfer of resistance determinants and restriction endonuclease fingerprinting of plasmids allowed the different isolates of S. typhimurium to be attributed to a single clone.

Molecular study on nosocomial Pseudomonas aeruginosa strains.

Nosocomial Pseudomonas aeruginosa isolates were typed by DNA fingerprinting techniques. Chromosomal DNA banding patterns, after endonuclease digestion, of six isolates from a neonatal care unit confirmed the results of O-serotyping and antimicrobial susceptibility pattern analysis. In contrast, the characterization by chromosomal DNA fingerprinting of P. aeruginosa strains isolated from patients treated in a burn unit disagreed with the two classic typing methods: in fact, isolates that varied in serotype and antibiograms showed identical restriction endonuclease profiles, whereas two indistinguishable isolates cultured from individual patients were easily and reproducibly differentiated by molecular analysis.

Multiple typing of strains of Salmonella enterica subsp. bongori ser. 48:Z35:- isolated in southern Italy.

In 1984-87, 10 isolates of Salmonella enterica subsp. bongori ser. 48:Z35:-, 9 of human source, were identified at the Southern Italy Centre of Enterobacteriaceae. This serotype had never been identified in Southern Italy before 1984. The combined use of different typing methods, with particular reference to restriction enzyme fingerprinting of plasmid and chromosomal DNA, supports the hypothesis that all Bongor serovars derive from a single strain.

Multiple typing of Salmonella typhimurium isolates: an epidemiological study.

An epidemiological study was carried out on sixty-four Salmonella typhimurium strains isolated in Palermo during the period January-July 1987 and identified at the Southern Italy Center of Enterobacteriaceae. These included 5 isolates from a small food-poisoning outbreak, which resulted antibiotic susceptible, not colicinogenic and untypable by the phage-type scheme of Anderson. Plasmid profile analysis was not a reliable method to differentiate them from non epidemic strains. The 5 epidemic isolates, belonging to biotype 25a, were assigned into NT 2 phage-type by an accessory set of phages developed in this laboratory. Such biotype/phage-type association was never detected in the remaining Salmonella typhimurium strains isolated during the first 7 months of 1987. Chromosomal DNA analysis provided additional information on the relationships among Salmonella typhimurium isolates.

Molecular study on Salmonella enteritidis strains from a nosocomial gastroenteritis outbreak.

A molecular epidemiological analysis was carried out on S. enteritidis isolates identified at the Central Italy Enterobacteriaceae Center during 1986. 26 of these were from a diarrhoeal disease outbreak, which occurred in the period April-June at the "S. Chiara" Hospital, Pisa. All S. enteritidis strains harboured a virulence-encoding 39 MDa plasmid. The nosocomial isolates made in June 1986 carried an additional non-conjugative plasmid of 75 MDa, associated with the streptomycin-resistance. In contrast, the nosocomial S. enteritidis strains isolated during the period April-May and 16 isolates from the same geographic area were susceptible to antibiotics and showed a different plasmid pattern. According to the plasmid profile and antibiotic resistance pattern analysis, it could be argued that the hospital cases of S. enteritidis infection occurring after May 1986 are attributable to a strain having different origin from the strain circulating in April-May 1986.

Molecular relationship among Salmonella dublin isolates identified at the Center for Enterobacteriaceae of Palermo during the years 1971-85.

A molecular epidemiological study was carried out on 60 Salmonella dublin isolates identified at the Southern Italy Enterobacteriaceae Center between 1971 and 1985. These included 23 isolates from children with diarrhoea in Palermo obtained during 1984. All isolates from the outbreak of gastroenteritis in children were resistant to chloramphenicol and streptomycin and harboured two plasmids of 50 MDa and 3 MDa molecular weight, whereas the majority of the isolates identified before 1984 were susceptible to these antibiotics and carried only a 50 MDa molecular weight plasmid. Four S. dublin strains successively identified from cattle (Palermo, Foggia, Portici) and from a child (Palermo) were shown to possess similar antibiotic resistance patterns and plasmid profiles to S. dublin isolates from the outbreak of gastroenteritis in children. The 50 MDa plasmid was shown to be associated with virulence in mice, while it was not possible to assign any genetic function to the 3 MDa plasmid.