Report of a case of Streptococcus agalactiae mycotic aneurysm and review of the literature

A unique case of mycotic aneurysm of the abdominal aorta caused by Streptococcus agalactiae in an afebrile patient presenting with abdominal pain is described. Although this bacterium is associated with a variety of infections in human beings, aortitis is uncommon. Chronic alcoholism and diabetes mellitus are the 2 major predisposing conditions for group B Streptococci infection and both were present in this case. The abdominal pain and elevated inflammatory markers in the absence of fever were elusive in presentation; however, the diagnosis of mycotic aneurysm was established by abdominal computed tomography scan. The patient was treated successfully by resection of the diseased aorta and aortic allograft replacement. Culture of the excised tissue grew Streptococcus agalactiae sensitive to penicillin G and (other commonly tested antibiotics) fluoroquinolones. A prolonged course of moxifloxacin (for 6 months) was administered due to the persistence of elevated inflammatory markers and was remarkably well tolerated. Sixteen months after stopping the antibiotics, the patient is doing well, and the control imaging studies are satisfactory.     

Séroprévalence des marqueurs de l’infection chez les donneurs de sang à Niamey (Niger)

BackgroundThe study aimed to determine the seroprevalence of transfusion-transmitted infectious (TTI) markers for human immunodeficiency virus (HIV), hepatitis B and C viruses (HBV, HCV) and syphilis among blood donors in Niamey (Niger). The association between seroprevalence of ITT markers and sociodemographic characteristics of blood donors was investigated.MethodsA cross-sectional study was conducted in 2010 among 3213 blood donors. Data were collected from a pre-donation questionnaire and from laboratory tests results.ResultsThe male/female ratio was 4/1. Up to 18.1% of donations had at least one positive marker, in which 2.7% presented a positive test for two or more agents. A seroprevalence of 1.62% (95%CI: 1.21–2.12) was associated with HIV, 15.4% (13.9–16.7) with HBV, 1.18% (0.84–1.62) with HCV, and 0.47% (0.26–0.77) for blood samples reacted with RPR test for syphilis. The HIV seroprevalence was two-fold higher in family than in volunteer donors (OR = 2.15, 95%CI: 1.24–3.73). It was also higher in Rhesus D negative donors (OR = 2.40, 95%CI: 1.11–5.17). The hepatitis B surface antigen seroprevalence was significantly higher in males than females (OR = 1.85, 95%CI: 1.39–2.45) and in first time than in regular donors (P < 0.0001). The HCV seroprevalence was significantly higher in male donors (OR = 4.41, 95%CI: 1.06–18.4) and in donors from rural areas (OR = 4.09, 95%CI: 1.42–11.8). Syphilis marker was significantly associated with the marital status (higher seroprevalence in divorced donors, P = 0.0085).ConclusionPrevalence of TTI markers is high and national strategies for safe blood transfusion have to be strengthened. It is essential to recruit and maintain more volunteer donors, while females should be encouraged to donate blood.     

Phase I/II studies to evaluate safety and immunogenicity of a recombinant gp350 Epstein-Barr virus vaccine in healthy adults

Two double-blind randomised controlled studies (phase I and I/II) were performed to assess for the first time the safety and immunogenicity of a recombinant subunit gp350 Epstein-Barr virus (EBV) vaccine in 148 healthy adult volunteers. All candidate vaccine formulations had a good safety profile and were well tolerated, with the incidence of solicited and unsolicited symptoms within a clinically acceptable range. One serious adverse event was reported in the phase I trial which was considered to be of suspected relationship to vaccination. The gp350 vaccine formulations were immunogenic and induced gp350-specific antibody responses (including neutralising antibodies).     

Reciprocal regulation of protein tyrosine kinases p56lck and p59fyn, and altered tyrosine phosphorylation in murine AIDS

Murine AIDS (MAIDS), caused by a defective murine leukemia virus, is a severe lymphoproliferative disease associated with profound immunodeficiency and increased susceptibility to opportunistic infections. Most subsets of lymphocytes, including CD4+ and CD8+ T cells, are refractory to mitogen stimulation. As a first step to examine proximal signal transduction in the infected mice, Western and Northern blot analyses were performed, and showed that p56lck is dramatically decreased at the protein as well as the mRNA level in the lymph nodes (LN). In contrast, p59(fyn) and its mRNA were slightly increased in the LN of the same mice. Similar results were obtained with purified T cells. Interestingly, the thymus of the infected animals did not show any abnormality regarding p56(lck) or p59(fyn). Tyrosine phosphorylation was constitutively increased in the infected mice and was barely amplified by anti-CD3 mAb stimulation. A similar pattern was observed when tyrosine phosphorylation was selectively examined at the level of ZAP-70. Our results suggest that a reciprocal regulation of p56(lck) and p59(fyn) protein tyrosine kinases, previously described in various models of anergy, could also be involved in the pathogenesis of MAIDS.      

Organotypic culture of HPV-transformed keratinocytes: a model for testing lymphocyte infiltration of (pre)neoplastic lesions of the uterine cervix

 The aim of our study was to establish the relevance of an in vitro model for analysing the ability of human lymphocytes to infiltrate human papillomavirus (HPV)-associated (pre)neoplastic lesions of the uterine cervix. To mimic these lesions, we have used the organotypic raft culture of HPV-transformed keratinocytes (SiHa). The SiHa organotypic raft culture was co-cultured with resting or prestimulated (IL-2 or IL-2+anti-CD3 mAb) allogeneic peripheral blood mononuclear cells (PBMC) for 24 and 72 h. The majority of infiltrating cells were T lymphocytes. Occasional NK cells were also identified. The stimulation with IL-2+anti-CD3 mAb induced the highest number of infiltrating cells, with the maximum lymphocyte infiltration observed after 24 h of co-culture. The lymphocyte infiltration was associated with an increased number of apoptotic cells in the organotypic cultures. The ability of PBMC and purified T cell and NK cell populations to lyse HPV-transformed keratinocytes was also investigated on monolayer cultures. As expected in an allogenic model, the highest cytotoxicity was mediated by NK cells activated by IL-2 or IL-2+anti-CD3 mAb. The cytotoxic activity of T cells was weak but, interestingly, increased in the presence of phytohaemagglutinin A (PHA), assuming that T cells were able to kill HPV-infected keratinocytes when a bridge between T cells and keratinocytes was provided. In conclusion, the organotypic culture of HPV-transformed keratinocytes may provide an effective in vitro model for investigating novel T cell-based immunotherapy protocols for the treatment of HPV-associated lesions. Received: 1 September 1997 / Accepted: 9 December 1997