Search

Aim of study is the determination of concentrations of two important cytokines: TNF alfa and IL8 in children with bacterial meningitis to establish a correlation between infection, CSF concentration of cytokines and neurological sequelae. TNF alfa and IL8 concentrations in CSF have been measured by quantitative immunometric enzyme assay during the course of the disease. In the purulent meningitis we observed that CSF concentrations of these cytokines decreased to undectable values 24 to 48 hours after beginning of the antibiotic therapy. Conversely, in the 3 patients with mycobacterial meningitis (TBM) the concentrations of IL8 were higher for a longer period, being detectable in the CSF between 4 and 8 weeks after the beginning of the specific treatment. We found no significant differences of the values of IL8 in children with neurological sequelae compared with children without sequelae.

To evaluate the incidence of bacterial colonization in the throat and in urines of children admitted to a paediatric ward in the year 1994. To test the sensitivity of isolates on the most common antibiotics used in therapy.The investigation was carried out on a group of 270 children (125 male and 145 female), aged between 3 months and 12 years, hospitalized with feverish infectious pathology in the department of infectious and Tropical Diseases of the University "La Sapienza" of Rome. The cultures of the throat swabs and on urines were performed on the admission of the children before the beginning of the therapy.The throat-swab cultures showed pathogenous microrganisms in 232 samples (85.9%) with a slight prevalence of Gram-negative bacteria (122) with respect to Gram-positive (110) and saprophytic microbial flora (38). The urine cultures proved to be positive in 81 cases (30%) with a prevalence of Gram-negative (56) above Gram-positive isolates (25).The two/thirds of paediatric patients hospitalized in an Infectious Diseases Department appeared to be colonized in the upper respiratory tract, whereas in about 10% of them a marked bacteriuria was clearly evident, often in the absence of specific symptoms. A few isolates either from the throat or from urines, showed resistance to the common antibacterial agents.

The relationship between the interleukin-2 (IL-2) system and the humoral response against human immunodeficiency virus type-I (HIV-1) is important in understanding the immune reaction before the development of AIDS. Levels of IL-2 and soluble IL-2 receptor (sIL-2R) in serum and cerebrospinal fluid (CSF) samples from 31 asymptomatic HIV-1 seropositive individuals were measured and correlated with levels of anti-1 IgG and IgM antibodies. High IL-2 levels were detected in the CSF of 20 (65%) subjects, 18 (90%) of whom had evidence of intrathecal synthesis of HIV-1-specific IgM antibodies. Similarly, IgG antibodies were detected in 10 subjects who had elevated IL-2 levels in the CSF. Moreover, intrathecal levels of IL-2 and sIL-2R correlated with intrathecal synthesis of both IgG and IgM antibodies. Local release of IL-2 seems to play an important role in the initiation of the antibody response against HIV-1 in early stages of infection and may be utilised in devising effective therapeutic strategies.

HIV infection is thought to exacerbate the virulence of normal saprophytic vaginal microflora. We studied the vaginal ecosystem of HIV patients to detect the quantitative and qualitative variation of vaginal microorganisms. 15 patients (5 with AIDS and 10 with ARC) were investigated. Vaginal candidiasis was more frequent in this group than in the control groups. Gardnerella was present in 60% of patients generally in association with anaerobic bacteria and Mycoplasma. Among anaerobia, Bacteroides sp and other Gram-negative rods were the most common bacteria. Neisseria gonorrhoeae was absent in all patients tested. Chlamydia trachomatis was recovered in two out of the 15 HIV-positive patients. Aerobic Gram-negative flora was 100-fold that of the control group and anaerobic Gram-negative flora 10-fold.

Clavulanic acid was tested for in vitro synergistic activity with Ampicillin and Amoxycillin against 41 Gram-negative strains beta-lactamase positive or negative. Clavulanic acid provides progressive inhibition of the beta-lactamases of many bacteria. The better protective effect of CA on AM or AMX is at concentration of 100 mcg. Some synergy was seen against E. coli, Klebsiella and Proteus. Enterobacter and Pseudomonas remained resistant to the combination of AMX and AM with clavulanic acid. We have seen no synergistic effect when non beta-lactamase producing organisms were tested. Although CA alone has a broad antibacterial spectrum, the degree of activity is generally rather poor.

To estimate the antibacterial activity of sub-MIC concentrations of Erythromycin and Miocamycin in the mucosal surfaces, we studied the adhesivity of Gram-positive pathogenic strains (S. pyogenes, S. aureus) towards oral and urinary epithelial cells. Erythromycin strongly inhibits the adhesivity of Staphylococci to oral cells (50% of inhibition) and to a lesser extent the adhesivity of Streptococci (21%), while Miocamycin reduced the adhesivity of Staphylococci by about 16%. In some cases, an increase in the adhesivity on urinary cells was found mainly for Miocamycin. Therefore Erythromycin, at sub-MIC concentrations, is able to induce a marked reduction in the adhesivity of Staphylococci and Streptococci; this may interfere with the invasivity and subsequent pathogenicity of these bacteria. As far as phagocytosis is concerned, one strain of enterotoxic coagulase + S. aureus bearing A-protein on its surface but lacking the capsule was taken into consideration. The presence of A-protein induces resistance to phagocytosis and opsonization by normal serum. The addition of antibiotics which inhibit protein biosynthesis, such as Clindamycin, Miocamycin and Erythromycin, increases either uptake of this strain or intracellular killing. In particular Clindamycin and Erythromycin, at sub-MIC concentrations, are able to affect the interaction of Staphylococcus with phagocytic cells.

The antigenemia and the patterns of antibodies to core protein (p24) and envelope glycoproteins (gp41, gp120) have been investigated in 81 patients with Human Immunodeficiency Virus (HIV) infection followed prospectively for 24 months. HIV antigen was detectable in 23 (28.4%) patients at entry to the study (13/13 with AIDS and 10/23 with ARC) and in 33 (40.7%) at the end (25/28 with AIDS, 5/12 with ARC e 3/14 with LAS). Anti-p24 were positive in 51 (63.0%) patients at the entry (26/30 symptomless, 13/15 with LAS e 12/23 with ARC) and in 41 (50.6%) at the end of the study (23/27 symptomless, 9/14 with LAS, 7/12 with ARC e 2/28 with AIDS). All patients were positive for anti-gp41 and showed no significant changes in the antibody titers during the two years of follow-up; by contrast, anti-gp120 was undetectable in most patients (26/28) with AIDS. Clinical progression in a high proportion of patients was associated with the appearance of HIV antigen, with the decline of anti-p24 titers and with no antibody reactivity to gp120 glycoprotein.

An A-protein positive strain of Staphylococcus aureus was grown in varying concentrations of erythromycin, clindamycin and miocamycin at sub-MIC levels and incubated in purified human polymorphonuclear leukocytes (PMNs). The presence of A-protein produced resistance of the above strain to phagocytosis and killing by PMNs and a slight resistance to opsonization by normal serum. The addition of antibiotics, which inhibit protein biosynthesis, caused significant changes in the ability of this bacterium to resist opsonization by serum complement. The antimicrobial agents produced a significant enhancement of bacterial killing and phagocytosis. In particular, clindamycin and erythromycin, at sub-MIC concentrations, modified the hair-like structure of S. aureus, which contains A-protein, and were able to affect the interaction of the strain with phagocytic cells.