Molecular characterization of adult-colonizing Streptococcus agalactiae from an area-based surveillance study in Romania.

One hundred and forty-eight colonizing isolates from adult Romanian women were conventionally serotyped and screened for antibiotic resistance. Capsular type assignment by multiplex polymerase chain reaction (PCR) was performed for nonserotypeable isolates. Tetracycline and macrolide resistance genes (tetM, tetO, tetL, ermA, ermB, and mefA) including tetM gene association with conjugative elements of the Tn916 family were searched. Molecular typing included PCR screening for major surface protein antigen genes (bac, bca, alp1, alp2/3, alp4, and rib), mobile genetic elements (GBSi1 and IS1548), and rapid detection of hypervirulent clone ST-17. Genetic diversity was assessed by pulsed field gel electrophoresis (PFGE) analysis of SmaI macrorestriction patterns. Among the colonizing isolates studied, serotypes V and III predominated and high rates of tetracycline and macrolide resistance were observed. The tetM gene occurred in 140 tetracycline-resistant isolates and was associated with the int-Tn916 gene in 94 of them. Most of the isolates displayed a constitutive MLS(B) phenotype (38/46 isolates) and harbored the ermB gene. rib, alp2/3, and alp1 were the most common surface protein genes detected. Either IS1548 or GBSi1 intron were detected in almost half of the isolates and nine serotype III isolates belonged to clone ST-17. PFGE analysis of SmaI macrorestriction patterns, obtained from 118 isolates, revealed an apparent genetic diversity.

Prevalence of virulence genes in Escherichia coli strains isolated from Romanian adult urinary tract infection cases.

A total of 78 E. coli strains isolated from adults with different types of urinary tract infections were screened by polymerase chain reaction for prevalence of genetic regions coding for virulence factors. The targeted genetic determinants were those coding for type 1 fimbriae (fimH), pili associated with pyelonephritis (pap), S and F1C fimbriae (sfa and foc), afimbrial adhesins (afa), hemolysin (hly), cytotoxic necrotizing factor (cnf), aerobactin (aer). Among the studied strains, the prevalence of genes coding for fimbrial adhesive systems was 86%, 36%, and 23% for fimH, pap, and sfa/foc,respectively. The operons coding for Afa afimbrial adhesins were identified in 14% of strains. The hly and cnf genes coding for toxins were amplified in 23% and 13% of strains, respectively. A prevalence of 54% was found for the aer gene. The various combinations of detected genes were designated as virulence patterns. The strains isolated from the hospitalized patients displayed a greater number of virulence genes and a diversity of gene associations compared to the strains isolated from the ambulatory subjects. A rapid assessment of the bacterial pathogenicity characteristics may contribute to a better medical approach of the patients with urinary tract infections.

Genetic evidence of multiple transmissions of HIV type 1 subtype F within Romania from adult blood donors to children.

We studied the phylogeny of HIV-1 subtype F viruses from children and adults in Romania in order to (1) clarify whether the Romanian subtype F epidemic was caused by one or several virus introductions and (2) gain insight into the route of spread of the HIV-1 subtype F virus among children and adults in Romania. env (V3), gag (p17/half p24), and pol (prot/half RT) sequences were obtained from three districts in Romania: Tirgu Mures (n = 9, children), Craiova (n = 15, children), and Bucharest (n = 13, adults). Of 37 HIV V3 sequences from Romania, 35 belonged to the genetic subtype F in the neighbor-joining tree, whereas 2 sequences from adults clustered with subtypes A and C. Within the subtype F cluster, no bootstrap-supported subclusters were observed according to geographic area in Romania. Two of the adult V3 sequences that clustered with the children were obtained from individuals who tested HIV seropositive in 1989 and 1990, showing that the subtype F virus was present among adults when the HIV epidemic began among children in Romania. The HIV-1 subtype F viruses obtained from children showed a mean pairwise V3 nucleotide distance of 7.9% and maximum distances of between 18 and 19%; both are higher than previously described. The mean V3 distances (overall, synonymous, and nonsynonymous) were significantly higher for adults than for children. One V3 sequence from the Democratic Republic of Congo clustered within the Romanian sequences, suggesting that the subtype F virus in Romania may originate from this area. Our data also suggest that HIV-1 subtype F was present among Romanian adults before it appeared in 1989 among institutionalized children. The juvenile population was most likely infected with the HIV-1 subtype F virus on more than one occasion, presumably through HIV-contaminated blood (products) obtained from adults.

Investigation of the results obtained following repeated boosters with Di-Te vaccine in HIV positive children.

The paper is an attempt to study the effect of repeated boosters with Di-Te vaccine in positive children. The efficacy of their administration (vaccinal coverage degree, level of secreted antitoxins, the persistency of the immune response) and their influence upon the subsequent evolution of HIV infection are investigated.

Use of the presence of anti-protein gag antibodies as an evolution marker of HIV infection.

The paper studies the modifications occurring in the prevalence of anti-protein gag antibodies during the evolution of the infection in a paediatric population iatrogenically infected and not submitted to antiretroviral treatment. The study was performed by annual clinical examination of children and by laboratory determinations: western-blot, p24 Ag assay, determination of lymphocyte population by flowcytometry. The predictive capacity of p17 antibodies was revealed, their occurrence after seroconversion pointing to a favourable evolution, with a longer asymptomatic period; the disappearance of these antibodies during the disease indicates a more advanced stage of the disease. The disappearance of p24 and p55 antibodies during the evolution of the disease shows a more advanced stage of the disease, both clinically and as concerning the immunosuppression degree.

Characterization of the epidemiological process of HIV infection using some immunological markers.

In an attempt to elucidate the causes which led to the high percentage of HIV infection in the infantile population in Romania, the paper deals with the study of the evolution of the infection process, in the 0-6 years age group; the process was separately studied in children from closed collectivities (5,318 sera) and children living with their families (2,462). The study of the various patterns obtained with sera analysed by western-blot allowed of concluding that the massive spreading of the infection in both types of infantile population occurred in 1991-1992, the most intense process being reported in the 0-2 years age group (children from closed collectivities). The differences between the evolution of HIV infection epidemic in the above mentioned infantile populations and that noticed in adults are shown.