Antibiotic susceptibility and serotype distribution in Streptococcus pneumoniae circulating in Italy: results of the SEMPRE surveillance study (2000-2002).

During 2000-2002, 20 clinical microbiology centres collected 1623 Streptococcus pneumoniae isolates. Susceptibility to penicillin, amoxicillin, amoxicillin/clavulanic acid, cefaclor, cefuroxime, cefotaxime, clarithromycin, ciprofloxacin, levofloxacin, rifampicin and teicoplanin was determined locally by the Etest and/or by the microdilution method by three co-ordinating centres. Total resistance to penicillin increased from 15.2% to 16.1% and macrolide resistance increased from 37.9% to 43.7%. Overall, the most effective drugs (>99% susceptible strains) were amoxicillin, amoxicillin/clavulanic acid, levofloxacin and rifampicin. The most frequent serotypes were: 23F (15.8%), 3 (10.8%) 14 (9.1%), 19F (9.1%), 6B (7.2%), 19A (6.9%) and 6A (4.8%). In conclusion, penicillin and macrolide resistance is increasing in Italy, whilst fluoroquinolone currently remains active. The most common serotypes circulating are included in the heptavalent conjugate vaccine, with the exception of type 3.

The Sentinel Project: an update on the prevalence of antimicrobial resistance in community-acquired respiratory Streptococcus pneumoniae and Haemophilus spp. in Italy.

A total of 460 Streptococcus pneumoniae and Haemophilus spp. collected from respiratory infections during 2000 was tested for their susceptibility to 15 selected antibiotics. Overall, penicillin resistance among pneumococci was 10.5%, while lack of susceptibility to macrolides, co-trimoxazole, tetracycline and chloramphenicol reached 35.2%, 26.2%, 22.6% and 6.0%, respectively. Amoxicillin/clavulanic acid and levofloxacin were the most potent compounds (100% and 99.9% susceptible strains, respectively). Among isolates of Haemophilus influenzae and Haemophilus parainfluenzae, beta-lactamase production (12.5% and 10%, respectively), and co-trimoxazole (19.9% and 40.0%) and clarithromycin (11.2% and 40.0%) resistance were the prevalent threats. This study confirms the trend observed in Italy since 1992: macrolide resistance among respiratory microorganisms is increasing, while several drugs including amoxicillin/clavulanic acid, third generation injectable cephalosporins and fluoroquinolones remain active on the great majority of these pathogens.

Serum levels of the interferon-gamma-inducing cytokine interleukin-18 are increased in individuals at high risk of developing type I diabetes.

AIMS/HYPOTHESIS: Interleukin (IL)-18 is a cytokine primarily produced by macrophages and capable of inducing T lymphocyte synthesis of interferon (IFN)-gamma. An up-regulated synthesis of IFN-gamma with consequential Type I cytokine dominance has been repeatedly shown in Type I (insulin-dependent) diabetes mellitus and thought to be involved in its pathogenesis. Because increased production of IFN-gamma could be secondary to a dysregulated synthesis of IL-18, we compared the circulating levels of IL-18 in patients with newly diagnosed Type I diabetes with those of non-diabetic first-degree relatives and healthy control subjects. METHODS: Serum samples were obtained from healthy control subjects, patients with newly diagnosed Type I diabetes, and their healthy first-degree relatives. The latter were subdivided into "low" and "high" risk prediabetics depending on whether they were negative or positive for two or more of the anti-pancreatic autoantibodies ICA, GAD, IA-2 and IAA. Serum levels of IL-18 were measured by solid-phase ELISA. RESULTS: Interleukin (IL)-18 was above the detection limit of 25 pg/ml in 7 of 40 (17%) healthy control subjects, in 5 of 35 (14%) patients and in 3 of 30 (10%) first-degree relatives at low risk of developing Type I diabetes. In contrast, IL-18 could be detected in 19 of 28 (68%; p < 0.0001) relatives at high risk. The mean serum level of IL-18 was higher in these individuals when compared with the low-risk relatives, patients and control subjects. CONCLUSIONS/INTERPRETATION: IL-18 serum levels are increased selectively during the early, subclinical stage of Type I diabetes.

Increased rate of survival in Streptococcus pneumoniae-infected rats treated with the new immunomodulator Pidotimod.

Wistar rats infected with Streptococcus pneumoniae (type III ATCC) rapidly develop an acute form of experimental lobar pneumonia (ELP) with death of 80-90% of the animals by 6 days after the infection. Prophylactic treatment of these animals with the novel immunomodulator Pidotimod, at the dose of 25 mg/kg bw, significantly increased their rate of survival as compared to the control group (50 vs. 90% respectively). Recovery from the infection appeared definitive since all the Pidotimod-treated survivors were alive and in good condition at the end of the observation period (45 days post infection). Prophylactic treatment with higher or lower doses of the drug was ineffective. Therapy with Pidotimod was not effective. This preliminary study suggests that Pidotimod may have contributed to activation of specific and non-specific immune effectors involved in the host response to S. pneumoniae infection.

Enhanced percentage of Leu M3+DR+ and Leu M3+CD25+ cells in newly diagnosed IDDM patients.

The percentage of Leu M3+DR+ and of Leu M3+CD25+ cells was determined by means of immunofluorescence analysis in a group of patients with insulin dependent diabetes mellitus (IDDM). Our results show that an increased percentage of these cells may occur in the early stage of the disease. These data provide evidence for a "phenotypical" activation of Leu M3+ cells at the onset of the disease and warrant future studies to evaluate the potential role of these cells in the pathogenesis of IDDM.

Further characterization of the in vitro and in vivo activity of ciprofloxacin against mycoplasmas.

The aim of this study was the evaluation of some parameters which might better characterize ciprofloxacin: the influence of inoculum, serum and medium. Resistance development, hamster protection and mycoplasmacidal concentrations were also investigated. Ciprofloxacin showed moderate antimycoplasmal activity, both in vitro and in vivo. The minimum inhibitory concentrations (MICs) for Ureaplasma urealyticum, if compared to those shown by erythromycin, are lower, but higher than those obtained with tetracyclines. Unlike the macrolides, ciprofloxacin suffers from change of inoculum size, but no single step resistance induction was reported both in ureaplasmas and mycoplasmas. If Mycoplasma pneumoniae pneumonia or genital infections due to U. urealyticum carry out gram-negative rod isolation, ciprofloxacin can be considered a valid therapeutic agent for these mixed infections.

[ABAC, a closed system: problems and solutions, currency and perspectives]. / L'ABAC, un sistema chiuso: problemi e soluzioni, attualità e prospettive.

The ABAC System, as it is currently configured, uses pre-determined panels of antibiotics. This form of presentation is a limit for the use of the large number of new molecules, mainly active on Gram-negative bacteria. Therefore, the introduction of a new disposable, called "Gram-negative bacteria--new molecules" is suggested. Such a device will contain those additional and more widely tested antibiotics. According to recent studies concerning the pathology of Gram-positive organisms and the chemotherapeutic treatment for such pathology, changes in the disposable formulations for staphylococci and streptococci are proposed.

In vitro synergistic activity of some chinolinic compounds combined with beta-lactam antibiotics against gram-positive and gram-negative clinical isolates.

The antimicrobial activities of nalidixic acid-cephalexin (ratio 1:1) and cinoxacin-cefadroxil (ratio 1:2) combinations have been evaluated against 396 clinical isolates; many of them were nalidixic acid- or cinoxacin-resistant organisms (MIC greater than or equal to 100 micrograms/ml). We have also tested the nalidixic acid-amoxicillin combination (ratio 1:1) against 225 amoxicillin-resistant bacterial strains (MIC greater than or equal to 800 micrograms/ml). Synergy was found for 62-70% of the Enterobacteriaceae and nonfermenter bacilli tested and for 85-92% of the gram-positive bacterial strains. The 225 clinical isolates resistant to amoxicillin (MIC greater than or equal to 800 micrograms/ml) were synergistically inhibited by the nalidixic acid-amoxicillin combination.

Incidence and antibiotic susceptibility of Haemophilus influenzae in clinical specimens.

Recent data report increasing Haemophilus influenzae ampicillin- and chloramphenicol-resistant strains. Authors report the results of one year investigation in Sicily. In 281 clinical specimens tested, Haemophilus influenzae has been isolated in 60 cases. From antibiotic susceptibility tests it can be observed that 58 strains show ampicillin-resistance.

Comparative susceptibilities of organisms isolated in Sicily to cefotetan and other antibiotics.

In recent years there has been a gradual increase in the number of infections caused by Klebsiella, Enterobacter and Serratia and non-fermentative bacilli such as Pseudomonas, Alcaligenes and Acinetobacter. The object of this investigation was to evaluate the antibacterial properties of the cephalosporins cefoxitin, cefoperazone, cefotaxime and of gentamicin, in comparison with cefotetan, a new cephamycin with a high degree of stability to beta-lactamases. The cefotetan MIC was not affected either by size of the bacterial inoculum, or the culture medium and the serum protein binding of cefotetan was 85%. Cefotetan showed only moderate antibacterial activity, similar to that of the other cephalosporins tested, against the Gram-positive cocci, whereas it was very active against fermentative and non-fermentative Gram-negative bacilli, except for Pseudomonas aeruginosa. The remarkable activity of cefotetan against Klebsiella, Enterobacter and Serratia is of particular interest.