Faecal carriage of oxyiminocephalosporin-resistant Enterobacteriaceae among paediatric units in different hospitals in the south of France.

The aim of this study was to determine the presence of oxyiminocephalosporin-resistant (OCR) Gram-negative bacilli and extended-spectrum ß-lactamase (ESBL)-producing isolates in stool specimens obtained from paediatric patients hospitalised for acute diarrhoea. We conducted a prospective, multicentre study over a period of 6 months in seven hospitals in the south of France. Samplings were carried out from infants admitted for acute diarrhoea with no previous antibiotic treatment in the last week. Bacteria in stool specimens were screened for the presence of OCR Gram-negative bacilli on Drigalski agar supplemented with ceftazidime and ESBL CHROMagar® media, and confirmed by the Rosco tablets test. Genetic detection was performed by the Check MDR® microarray and by polymerase chain reaction (PCR) and sequencing with bacterial DNA extracted from isolates. The presence of OCR enterobacteria was markedly high (177/1,118 patients, 15.2 %), with an important community origin (66.1 %). The majority of multidrug-resistant (MDR) bacteria were Enterobacter cloacae (106, 59.9 %) and Escherichia coli (61, 34.5 %). The prevalence of ESBL and CTX-M producers represented 5.2 and 4.3 % of the isolates, respectively. The main proportion of these ESBL carriers was found in children less than 1 year of age (53.4 %). One carbapenemase (IMP-1) was detected. The study revealed the wide dissemination of MDR bacteria in infants attending hospitals in the south of France during a non-outbreak situation, in particular, the spread of cefotaximase and the detection of a carbapenemase. This worrisome situation must reinforce the use of hygiene procedures and appropriate antibiotics to control the emergence and spread of OCR organisms.

[Statistical study of the SIRSCAN computerised camera]. / Etude statistique de la caméra informatisée SIRSCAN.

The antibiograms of 1162 bacterial strains, including references, have been performed within four centres. They have been read manually and by the SIRSCAN camera, which yields to 30936 couples of diameters values. A non-concordance, at a 3 mm level, was observed fot 11.14% of the diameters. The mean of difference is 0.82 mm and the standard deviation 3.34 mm. Round Petri dishes gave results less reliable than those obtained with square dishes. A deviation in function of the centres is obtained for wild-strains as for the references. For the whole population a S/R discordance (sensible/résistant confusion) is obtained for 1.76% of the diameters. This value drops to 0.93% for enterobacteriaceae, P. aeruginosa and S. aureus (968 strains).

[Determination of the isoelectric point of beta-lactamases isolated from 67 Klebsiella oxytoca strains and phenotype behaviour against eight beta-lactam antibiotics]. / Détermination du point isoélectrique des bêtalactamases extraites de 67 souches de Klebsiella oxytoca et comportement phénotypique vis-a-vis de huit bêtalactamines.

Klebsiella oxytoca is naturally resistant to aminopenicillins and carboxypenicillins by production of a chromosomal beta-lactamase but susceptible to third generation cephalosporins. The third generation cephalosporins activity may be reduced by: overproduction of the chromosomally encoded beta-lactamase or an extended-spectrum beta-lactamase. These activity modification are rarely found in the hospital of Aix-en-Provence (France). The activity modification rate of K. oxytoca resistant by one of these mechanisms between 1986 and 1991 are 3.6% for chromosomally encoded beta-lactamase overproduction and 0.7% for acquisition of an extended-spectrum beta-lactamase. We have determined the isoelectric point (pI) by isoelectrofocusing of the beta-lactamases isolated from 67 K. oxytoca and the activity of 8 beta-lactams has been studied by disk-diffusion. 51 wild strains, 14 overproducing strains (including 2 in vitro mutants) and 2 strains with extended-spectrum beta-lactamase were studied. For every wild strain, we observed only one band except for two strains with two bands (pl 5.4 + 6.3 and pl 5.6 + 7.7). The isoelectric points for the other strains are comprised between pl 5.25 and pl 8.2: 22 pl 7.7; 13 pl 5.25; 4 pl 5.6; 4 pl 6.3; 2 pl 6.6; 2 pl 8.1 and 2 pl 8.2. In the strains with chromosomally encoded beta-lactamase overproduction we observed several bands in each extract and only the major band was considered. The isoelectric point of in vitro mutant strains with beta-lactamase overproduction was the same that the wild strains. We observed 3 pl: 5.25 - 1 pl: 5.6 - 3 pl 6.3 and 5 pl 7.7.(ABSTRACT TRUNCATED AT 250 WORDS)

[In vitro effect of cefixime against 200 strains of Branhamella catarrhalis. Comparison with cefotaxime]. / Activité in vitro du céfixime sur 200 souches de Branhamella catarrhalis. Comparaison au céfotaxime.

The in vitro activity of cefixime was tested against 200 strains of Branhamella catarrhalis. Of these strains, 146 had been collected during 1987 from 15 different "Centres hospitaliers généraux", through a multicenter collaborative investigation organized by the "Collège de Bactériologie-Virologie-Hygiène des hôpitaux généraux". The remaining 54 strains were isolated at the "Centre hospitalier", of Aix-en-Provence. The strains originated from: bronchopulmonary collections: 80.2 per cent, sinusitis: 5.6 per cent, conjunctivitis: 4.6 per cent, otitis: 3.5 per cent, blood cultures: 0.5 per cent, miscellaneous: 5.6 per cent. Seventy-three per cent of the strains produced beta-lactamases. MIC determination was performed according to the agar dilution procedure on non-enriched Mueller-Hinton agar (30 hours incubation at 37 degrees C without CO2). The inoculum was 10(5) CFU per spot. Non beta-lactamase producing strains displayed the following MIC 50 and MIC 90 values (mg/l): amoxicillin: 0.03 - 0.125; cefotaxime: 0.06 - 1; cefixime: 0.06 - 0.5. Beta-lactamase producing strains were generally more resistant: amoxicillin: 32 - 128; cefotaxime: 1 - 2, and cefixime: 0.5 - 1.

[In vitro comparative activity of five macrolides against 190 Branhamella catarrhalis strains]. / Activité comparée in vitro de cinq macrolides sur 190 souches de Branhamella catarrhalis.

We compared the in vitro activity of 5 macrolides against 190 strains of Branhamella catarrhalis; 48 strains were isolated at Centre Hospitalier, Aix-en-Provence, the 142 others were isolated during 1987, in 15 different Centres-Hospitaliers-Généraux in France. 153 strains were betalactamase producing strains; no difference in susceptibility to erythromycin was observed on betalactamase producing and non producing strains. Three active macrolides against 100% of strains were: erythromycin (MIC 50 = 0.25 mg/l - MIC 90 = 0.50 mg/l), roxithromycin (MIC 50 = 0.50 mg/l - MIC 90 = 0.50 mg/l) and josamycin (MIC 50 = 0.50 mg/l - MIC 90 = 1 mg/l); A lower activity was noted on midecamycin (mic 50 = 2 mg/l - MIC 90 = 2 mg/l) and spiramycin (MIC 50 = 4 mg/l - MIC 90 = 8 mg/l).