[The E test and quinolone-resistant Campylobacter jejuni].

BACKGROUND

The E-Test is a quantitative technique for the determination of antimicrobial sensitivity. The system is based on the diffusion of a predefined exponential gradient in a determined antibiotic, using an inert plastic support which is applied to a solid culture medium and it is an alternative method for antibiotic sensitivity testing. Of the series published, some specifically include microorganisms considered fastidious or difficult to grow, such as Campylobacter jejuni. In recent years a progressive increase in the resistance of these microorganisms to antibiotics, such as the fluoroquinolone group, has been observed. The aim of the present study was to compare in 10 antimicrobial agents the results of E-Test with those of the dilution-agar technique in 57 strains of ciprofloxacine-resistant Campylobacter jejuni.

METHODS

In this serie we studied 57 ciprofloxacine-resistant strains of Campylobacter jejuni using the E-Test and comparing the results with those obtained in a parallel study employing the agar dilution technique.

RESULTS

The two methods coincided in the classification of the isolates as sensitive or resistant, except in the case of clindamycine (1 strain) and tetracycline (8 strains). The MIC's values obtained were similar (+/- 1 log2 dilution) in near of 90% of isolates for ciprofloxacine and erythromycine. However, for ampicilline, amoxycilline/clavulanic acid and gentamicin these results were obtained in less than 30%.

CONCLUSIONS

In general, the E-Test may be considered a valid alternative in the follow-up and control of resistant strains of Campylobacter jejuni, isolated with increasing frequency in clinical microbiology laboratories, although the correlation with agar-dilution techniques was only discrete and its relatively high cost could limit their general use.