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Antibiotic-resistance is widely spread phenomenon in the environment because of uncontrolled discharge of urban and animal wastewaters. Sewage treatment can significantly reduce the number of both sensitive and resistant bacteria. A reduction of about 1.5 logarithmic units in faecal coliforms was observed during biological treatment (3, 7), but a simultaneous increase in the percentage of resistant strains occurred because of not well understood selection phenomena. The above reported bacterial reduction is not always sufficient to meet the quality standards of Italian legislation required to discharge the treated effluents into surface waters, and so, chlorination become a compulsory additional treatment whose impact on both sensitive and resistant microflora must be evaluated. The results obtained in the present research have demonstrated that chlorine concentrations in the range of 0.5-2 ppm are able to reduce significantly the faecal coliforms concentrations and, in particular, treatment with 1 ppm of chlorine for 1 hour reduces the concentration of the above reported bacteria to the extent of 2 logarithmic units, so that their final concentration are of the about 10(2)/100 ml. The surviving chlorine tolerant bacteria seem to be antibiotic resistant in higher percentage than the chlorine sensitive ones and so, as a consequence, a significant increase in the antibiotic resistance and multiresistance was observed in the chlorinated effluents. In this context it is interesting to underline the larger variety of resistance patterns observed in the chlorine-resistant bacteria in comparison with the uniformity in the resistance patterns observed in isolated from unchlorinated effluents. The selected chlorine-tolerant strains seem to be less able to transfer their resistances under laboratory conditions, not because of curing effect of chlorine on the plasmids but, probably, because of the damage to cellular cell envelopes.

The urinary excretion of proteins, N-acetyl-3-glucosaminidase and leucine aminopeptidase, was measured in 50 patients with rheumatoid arthritis (RA), of whom 20 subjects were on nonsteroidal anti-inflammatory drugs (NSAIDs) and 30 on gold salts. No pathological changes of the above-mentioned urinary parameters have been observed in the group of RA patients, in comparison with control subjects and patients suffering from osteoarthritis treated with NSAIDs.

The Authors have analyzed the complex problems of the possible binding between uric acid and plasma proteins using two methods consisting of serum ultrafiltration at 22 degrees C or electrophoresis on different supports with successive specific coloration of the free and bound uric acid. The percentage of free and bound uric acid was established in serum from normal subjects, patients with primary gout, patients with renal insufficiency treated by dialysis and subjects with type IV dyslipidemia. The Authors discuss the results obtained as regards the possible role played by urate-plasma proteins binding in the interpretation of a genetic defect present in gouty patients involving a diminished uric acid binding capacity of plasma proteins.

The emission of phenols from a European car working with leaded and unleaded fuels with different percentage of aromatics has been considered. Fuels having the same aromatic content, but with a different composition of aromatic fraction, have also been taken into account. The results obtained showed that the emission of phenols increases with the increase of the aromatic content of fuel and also when unleaded instead of leaded fuels are used. The type of aromatic present in fuels was found to be important in forming the amount of both total and individual phenols emitted in the exhaust gas and in determining the number of phenolic compounds formed during combustion, although the phenol and isomer cresols were produced by combustion of all the fuels tested. The quantitative determination of individual phenols has been carried out on the benzene extract of the aqueous condensate and of the particulate matter of exhaust gas by the NaOH-extraction-GC-chromatographic method.

The toxic effect of the metal ions of cadmium, zinc, nickel and mercury and their tetracyanide salt complexes, on the activated sludge not previously acclimated, has been studied. The evaluation of the effect was carried out using both the Warburg and TTC-method. The results obtained have shown that the toxicity of the cadmium and zinc complexes is higher than that of the corresponding metals, while the toxicity of Ni(CN)4(2-) is lower than that of the corresponding metals. No differences have been found between the effect of mercury and the corresponding tetracyanide complex. From the data obtained it appears that it is not possible to generalize about the biological effect of complexation with the CN- group, but it should be stated that, generally, there are substantial differences between metals and their cyanide complexes as far as toxicity for activated sludge is concerned.

The tests commonly used for bacterial identification, especially in the field of microbial environmental analyses frequently do not provide a sufficient strain differentiation. Considering the importance that accurate characterization of bacterial pollution indicators could have as epidemiological tools, this study used a resistogram subtyping method for Escherichia coli as a tentative method of effecting a good monitoring of the environmental spread of this microorganism. The resistance of 313 E. coli strains of different origin (human, animal, sewage), previously identified by standard biochemical reactions, to 8 chemical compounds (inorganic, organic and dyes) and to 7 antibiotics was tested. The results indicated this method has a higher discriminatory power for chemicals than for drugs. Some typical resistotype patterns for E. coli from various sources are described.