Extracellular protease activity of different Pseudomonas strains: dependence of proteolytic activity on culture conditions.

AIMS: This study investigated the effect of growth conditions on proteolytic activity of a Pseudomonas strain, named Pseudomonas sp. LBSA1, isolated from bulk raw milk. It was compared with three Pseudomonas chlororaphis and one Pseudomonas fluorescens strain from culture collections. METHODS AND RESULTS: Bacteriae were grown in a minimal salt medium. For all the strains, addition of 1% (v/v) skim milk to the growth medium was sufficient to induce protease production in 48-h culture. Addition of 1 mmol l(-1) calcium chloride permitted the detection of proteolytic activity of four strains in 48-h cultures but not for Pseudomonas sp. LBSA1. The five strains presented two patterns of proteolytic activity when grown in the minimal salt medium supplemented with 2% (v/v) skim milk at various temperatures for 48 h. Two electrophoretic protease patterns were also obtained from the zymogram of extracellular medium for the five strains. CONCLUSIONS: The growth conditions permitting protease production are variable and do not depend on the genus of the producing strain. SIGNIFICANCE AND IMPACT OF THE STUDY: For the first time a study on proteolytic activity of P. chlororaphis strains is reported. Among the tested criteria, zymograms of extracellular medium were the only ones that permitted distinguishing the P. chlororaphis strains from the P. fluorescens strain.

A non-comparative, multicentre study of cefepime in the treatment of serious bacterial infections.

Multi-resistant strains of Gram-negative bacteria are rapidly emerging as a frequent cause of serious bacterial infection in the hospital environment. Effective treatment must include an antibiotic with activity against these organisms. In an open multicentre study, cefepime was evaluated as empirical therapy in 156 hospitalized patients (mean age 57 years) with serious infection of the urinary tract (n = 43), lower respiratory tract (n = 101) and skin and soft tissue (n = 12). In 18 patients, septicaemia/bacteraemia was also diagnosed. Cefepime, 2 g bd, was administered for a maximum of 16 days (mean 8). Of 98 pathogens isolated, 75 were Gram-negative and 23 were Gram-positive species. Ninety-four of the pathogens were susceptible to cefepime, including multi-resistant isolates such as Pseudomonas aeruginosa and Enterobacter cloacae. The overall clinical cure rate, excluding septicaemia/bacteraemia, was 92% (94/102); the corresponding bacterial eradication rate was 95% (52/55). In patients with septicaemia/bacteraemia, the clinical cure rate was 87% (13/15) despite eradication of 100% (11/11) of the assessable pathogens. Cefepime was well-tolerated, although 14 (9%) patients experienced local intolerance at the infusion site. Other drug-related adverse events were reported in six (4%) patients and included diarrhoea, pruritus, rash and urticaria. Cefepime is safe and effective as empirical treatment for serious infections commonly found in the hospital setting. Clinical cure and bacterial eradication can be achieved with a convenient bd dosing schedule.

Triple combination penicillin-vancomycin-gentamicin for experimental endocarditis caused by a highly penicillin-and glycopeptide-resistant isolate of Enterococcus faecium.

A combination of low-dose penicillin (75,000 IU/kg twice daily [b.i.d.]) vancomycin (30 mg/kg b.i.d.) and gentamicin (6 mg/kg b.i.d.) has been shown to be as effective as a combination of high-dose penicillin (500,000 IU/kg b.i.d.) and gentamicin (6 mg/kg b.i.d.) in the treatment of rabbit endocarditis caused by an Enterococcus faecium strain moderately resistant to beta-lactams and highly resistant to glycopeptides. The same regimens were evaluated against an E. faecium strain highly resistant to both penicillin (MIC, 128 micrograms/mL) and vancomycin (MIC, 512 micrograms/mL). High doses of penicillin-gentamicin and vancomycin-gentamicin had no effect in in vitro killing-curve studies or in rabbits after treatment for 5 days. High doses of penicillin-vancomycin were only bacteriostatic in killing curves and provided a small reduction in the bacterial titers of the vegetations. In contrast, high-dose penicillin-vancomycin-gentamicin was bactericidal in vitro and highly effective in treating rabbits. However, the emergence of a bacterial subpopulation resistant to the synergistic effect of penicillin and vancomycin could reduce the clinical utility of this combination.

French consensus on antibiotherapy of urinary tract infections. The French Society for Infectious Diseases.

We report on a recent French Consensus Conference on antimicrobial therapy of urinary tract infections (UTI). These guidelines were limited to questions on which a consensus seemed possible, namely lower uncomplicated urinary tract infections, bacteriuria in pregnancy and in the elderly, acute pyelonephritis and prostatitis.

[Pseudomonas aeruginosa meningitis treated with azlocillin. 5 cases]. / Méningites à Pseudomonas aeruginosa traitées par l'azlocilline. Cinq observations.

Prior to the introduction of new beta-lactam antibiotics, such as ureidopenicillins and some third generation cephalosporins, the choice of antibiotics for the treatment of meningitis caused by Ps. aeruginosa was limited, and even now, this infection remains of poor prognosis. Five patients with meningitis, aged from 18 to 75 years, were treated with azlocillin. The strains of Ps. aeruginosa isolated were all sensitive to azlocillin, the zones of inhibition being greater than 20 mm in diameter with bacteriostatic concentrations. Azlocillin was administered 8-hourly by intravenous injection in doses of 30 g/day in 3 cases and 15 g/day in 2 cases. The mean duration of treatment was 33 days (range 23-50 days). In addition to azlocillin 4 patients received an aminoglycoside (tobramycin or amikacin) parenterally and, in one case, intrathecally. Four patients underwent a surgical operation on the focus of infection between the 9th and 13th days of treatment. In 3 of these 4 patients surgery was necessary to obtain apyrexia, but in all cases the CSF was already sterile when it was performed. The outcome was favourable in all 5 cases. One patient relapsed on 4 occasions due to persistent petrous bone fistula; each time, the azlocillin treatment was reinstituted and brought about clinical and bacteriological cure. The germ was eradicated in CSF on the 3rd day of treatment in 3 patients and on the 7th day in one. One patient developed transient eosinophilia and another, transient neutropenia after 30 days. It is concluded that azlocillin, associated with an aminoglycoside, is an active and effective antibiotic for the treatment of Ps. aeruginosa meningitis.

Furosemide, mithramycin, and salmon calcitonin in hypercalcemia.

Twenty-nine patients with acute hypercalcemia secondary to carcinoma, myeloma and parathyroid adenoma have been treated with large doses of furosemide, mithramycin, or salmon calcitonin perfusion. With furosemide administration the treatment was successful in 6 of 10 patients. Furosemide was injected intravenously at the rate of 125 mg every 3 hours. With mithramycin perfusion only 2 of 8 patients have a return of the serum calcium levels to normal. With salmon thyrocalcitonin 3 of 10 patients obtained a good result. It can be interesting to suggest the association of furosemide and salmon calcitonin infusion to treat hypercalcemia of myeloma.