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Aim: The nasopharyngeal carriage of Streptococcus pneumoniae is an important risk factor for pneumococcal diseases. Data regarding prevalence and serotype distribution of this pathogen are lacking in our population., Experimental Design: longitudinal observational cohort study., Setting: healthy children aged 1-7 years attending day-care centers and schools of a district of a Southern Italy city., Measures: the nasopharyngeal colonization rate of Streptococcus pneumoniae as well as its antibiotic susceptibility was determined., Results: Of 317 nasopharyngeal cultures obtained, 18.29% of the cultures were positive for Streptococcus pneumoniae; 60.34% of the isolates were serotypes 19A, 19F, 14, 6B, or 23F; 8.62% of the strains were intermediately resistant to penicillin. Erythromycin-resistance was observed in 65.51% of the micro-organisms isolated and particularly serotypes 19, 14, and 6 were more erythromycin-resistant than organisms of other serotypes. Co-trimoxazole resistance was detected in 17.24% of the strains. All the strains resulted uniformly susceptible to cefotaxime and ceftriaxone., Conclusion: The high rate of nasopharyngeal carriage of Streptococcus pneumoniae, along with the resistance to antibiotics widely used in the community, suggests the importance of an epidemiological surveillance as well as the application of new vaccine strategies.

Introduction: The medical treatment (i.e. antibiotic therapy) of orofacial infections sometimes proves inadequate for the recovery of the patients. Therefore, aside the antibacterial treatment, both incision and drainage are necessary to remove the causal factors., Clinical Case: In our report we show that in case of failure of classic antibacterial therapy, surgical treatment alone does not allow by itself the recovery of the patient if microorganisms developed resistance to antibiotics., Conclusion: Recent studies have demonstrated a prevalence of anaerobes in orofacial abscesses. On this basis it appears important that in the analysis of the bacterial flora the handling of samples is carried out in the proper way in order to ensure the isolation of both aerobic and anaerobic species as well as the antibiotic sensitivity.

The AA. report the personal contributions and the recent findings of other investigators dealing with the toxic activities of Legionella pneumophila, the causative agent of Legionnaires' Disease. From the results of some tests (particularly Limulus endotoxin assay, pyrogenic reaction, skin Shwartzman reaction) there is an increasing evidence that Legionella pneumophila possesses some of the in vitro and in vivo biological properties associated with endotoxins of Gram negative bacteria, even if to a different of potency in different strains. However, the exact roles of an endotoxin and other bacterial products (e.g. haemolysins) as a pathogenetic mediators of the pathophysiological events of the disease remain to be determined.

In most recent papers some Authors have demonstrated that several bacteriocins are able to markedly inhibit the division of various neoplastic mammalian cell lines; also in vivo the inhibition of tumor growth or even regression relative to controls are statistically significant. Since such preparations are "crude" and it's possible that contaminating agents may represent a possible source of variability in the results, mostly in vivo; we have examined a preparation of Pyocin employed in this study for the possible endotoxin contamination using the Limulus assay. Such test was positive in triplicate and semiquantitative determination has shown and endotoxin amount of 5 to 10 microgram/ml. This level is, in vitro, not anough to give cytotoxic effect, but in vivo is able to influence experimental results. In addition, since some bacteriocins and enterotoxins are produced under exactly identical conditions, there is this a possibility that the enterotoxin are coproduced in these preparations and are causing some of the cytotoxic effects on experimental tumors. A more complete separation and purification of preparations will be required before definitive comments.

In a previous report it has been shown that enterotoxin preparations (cholera and E. Coli) able to activate adenylatecyclase system, abrogated platelet aggregation induced by ADP. In the present study the same experimental model has been applied to some purified filtrates from Salmonella typhimurium strains. Preparations from 986 and TLM (invasive strains causing also fluid secretion) interfere with platelet aggregation, while 1027 strain (invasive but not evoking fluid secretion) didn't show such effect. It has been argued, as Sandefur and Peterson have demonstrated with different experimental models, that the system of platelet aggregation induced by ADP is valid for some strains of Salmonella typhimurium, which act with a mechanism partially involving adenylatecyclase system (i.g. cholera-like).

The capacity of a strain of Mycoplasma pneumoniae to induce the production of procoagulant activity by human mononuclear cells is described. This finding could contribute to the understanding of the pathogenetic mechanism(s) involved in the thromboembolic complications often associated with fatal cases of Mycoplasma pneumoniae infection.

A detailed critical review on the role of endotoxins from gram-negative bacteria in the pathogenesis of most of the intestinal experimental models of surgical interest is presented. Data of an investigation on 10 cases of acute appendicitis and 2 cases of intestinal occlusion associated with toxaemia are then presented: in all these cases the Limulus test significatively revealed the presence of endotoxin in the blood and in the peritoneal fluid, also in absence of bacteria in the blood. The implications of these results and the use of the test in clinical practice are discussed.

Some culture filtrates or enterotoxin preparations from enterobacteria that activate the adenylate cyclase system (vibrio cholerae, LT fraction from escherichia coli and klebsiella pneumoniae, shigella dysenteriae type 1) exibit an inhibiting effect on ADP-induced platelet aggregation, while other enterotoxin preparations not effective on adenylate cyclase system, don't interfere with this model. The A. propose the platelet aggregation as cellular assay to detect enterotoxin fractions effective upon adenylate cyclase system.

The A.A. have examined by Limulus endotoxin assay some LPS preparations from R. typhi, R. slovaka, C. burnetti phase I and II, as a demonstration of endotoxicity. All the preparations tested were able to gel the Limulus amoebocyte lysates, even if to a different degree of reactivity. The results add credibility to the hypothesis that LPS from Rickettsiaceae can represent at least in part the pathogenetic mediators of some manifestations described in Rickettsiosis; however, without endotoxin assay in the blood of patients, one cannot assume to this be true.

Administration of E. coli LPS prior to 3.5 mg/Kg dose of thiourea has been reported to protect rats against pulmonary edema and pleural effusion. However, LPS of Shigella sonnei (either in phase I or II) did not show any protective effect. These data might suggest a different mechanism of endotoxins on membranes.

The injection in the peritoneum of Limulus amebocyte lysate at the same time of inoculation of lethal dose of E. coli LPS is able to protect the rats against endotoxin lethality.

Lipoglycans represent a special type of lipopoly-saccharide that differs in structure from the well-known gram-negative bacteria lipopolysaccharide. After briefly describing their most important characteristics, the authors take into consideration the in vitro interaction between lipoglycans from Acholeplasma granularum, Acholeplasma oculi, and Acholeplasma axanthum and human leukocytes in terms of production of procoagulant activity. The results obtained show that the examined lipoglycans possess, similarly to lipopolysaccharides, the capacity to induce the production of procoagulant activity, thromboplastin-like, from human mononuclear cells. However, the pathophysiological significance of this endotoxin-like activity remains to be established.

Protection against endotoxin challenge. The AA. have summarized shortly some experimental data dealing with trials of protection against endotoxin challenge pointing out, mostly, the effects of phosphate-containing compounds, as well as dextrane, anticoagulants, platelets, polymyxin B, and serum antiendotoxin and Lipid A antiserum. They have reported some experiments carried out by means of Limulus amebocyte lysate.