Campylobacter enteritis in Portugal: epidemiological features and biological markers.

From 1984 to 1989, stool samples from 2811 gastroenteritis cases were examined for the presence of Campylobacter jejuni and C. Coli, Salmonella, Shigella and Yersinia species. Isolation rates were: Campylobacter jejuni and C. Coli, 5.3%, Salmonella spp., 14.8%, Shigella spp., 4.6% and Yersinia enterocolitica, 1.1%. Age group distribution analysis shows a higher Campylobacter isolation rate in children under one year of age. Seasonal distribution revealed a peak incidence in winter as in other Mediterranean countries. Predominant biotypes were C. jejuni I (51%), C. jejuni II (21.5%) and C. coli I (18.8%). Antimicrobial susceptibility testing did not reveal resistance to erythromycin. Thirty of the strains harboured plasmids with 7 different profiles.

In-vitro evaluation of antibiotic combinations against Campylobacter fetus.

We evaluated the in-vitro activity of 16 antibiotics against 22 clinical isolates of Campylobacter fetus. The interaction of these antibiotics was also tested by chequer-board titration and time-kill assay. Eight antibiotic combinations were evaluated. Antagonism was not found with any of the combinations tested. The highest synergistic effect was obtained with a combination of ampicillin and cefazolin or ampicillin and gentamicin.

Modified selective medium for isolation of Campylobacter spp. from feces: comparison with Preston medium, a blood-free medium, and a filtration system.

Our previously described (H. Goossens, M. De Boeck, and J. P. Butzler, Eur. J. Clin. Microbiol. 2:389-393, 1983) selective medium, consisting of cefoperazone (15 mg/liter), rifampin (10 mg/liter), colistin (10,000 IU/liter), and amphotericin B (2 mg/liter) (medium M1), for the isolation of Campylobacter jejuni and Campylobacter coli from stool specimens was modified as follows: cefoperazone (30 mg/liter), rifampin (10 mg/liter), and amphotericin B (2 mg/liter) (medium M2). A comparative study of the isolation of Campylobacter spp. from stool specimens was carried out with medium M1; medium M2; a selective blood-free medium consisting (per liter) of charcoal (4 g), ferrous sulfate (0.25 g), sodium pyruvate (0.25 g), casein hydrolysate (3 g), sodium deoxycholate (1 g), nutrient broth no. 2 (25 g), agar (12 g), and cefoperazone (32 mg) (medium M3); and Preston medium containing (per liter) trimethoprim (10 mg), rifampin (10 mg), polymyxin B (5,000 IU), and cycloheximide (100 mg) (medium M4). We also included a filtration system in which membrane filters were applied directly to the surface of the nonselective blood-free medium distributed in small petri dishes. A total of 5,276 stool specimens were tested: 2,788 stool specimens were tested on M1 and M3 in study 1; 2,488 stool specimens were inoculated on the four selective media in study 2, and the last 986 specimens of the 2,488 were tested in parallel with the filtration system. In study 2, 128 Campylobacter strains were isolated from 126 different patients; 85.0, 88.3, 82.5, and 66.6% of these strains were isolated on M1, M2, M3, and M4, respectively. No contaminating fecal flora was found on 65.4, 70.7, 62.4, and 40.3% of the M1, M2, M3, and M4 plates, respectively. Furthermore, C. coli was found to be more susceptible to antibiotics present in the selective media, particularly colistin and polymyxin B, than was C. jejuni. We therefore recommend M2 for the isolation of Campylobacter spp. Finally, the filtration method was found to be easy and cheap; although the sensitivity was low, this method allowed the isolation of new Campylobacter spp. which seem to be associated with diarrhea.

Comparative in vitro activities of aztreonam, ciprofloxacin, norfloxacin, ofloxacin, HR 810 (a new cephalosporin), RU28965 (a new macrolide), and other agents against enteropathogens.

The in vitro activity of drugs currently used in the treatment of diarrhea against 595 enteropathogens from worldwide sources was compared with that of six newly developed antibiotics, ciprofloxacin; norfloxacin; ofloxacin; aztreonam; HR810, an expanded-spectrum cephalosporin; and RU28965, a new macrolide. In contrast with ampicillin and chloramphenicol, trimethoprim-sulfamethoxazole showed an excellent activity against all of the enteropathogens tested, except Campylobacter species. Ciprofloxacin had the highest activity, with an overall 90% MIC of less than or equal to 0.097 micrograms/ml, except for Campylobacter species (0.39 micrograms/ml). Unlike other cephalosporins, HR810 showed a satisfactory activity against Campylobacter species (90% MIC of 3.12 micrograms/ml). RU28965 was three times less active than erythromycin against Campylobacter species.

Susceptibility pattern of Campylobacter jejuni from human and animal origins to different antimicrobial agents.

The in vitro antimicrobial activities of different antimicrobial agents on Campylobacter jejuni from human and animal origins were compared by using a Dynatech MIC 2000 system. In general, the minimal inhibitory concentration distributions for the human strains were very comparable with those of the animal strains. The animal strains had a bimodal distribution for ampicillin, clindamycin, and tetracycline.

In-vitro activity of 21 antimicrobial agents against Neisseria gonorrhoeae in Brussels.

The minimum inhibitory concentrations (MIC) of 21 antimicrobial agents was measured for 80 strains of Neisseria gonorrhoeae isolated in Brussels in 1978. Bimodal distributions were found for penicillin G, ampicillin, amoxycillin, carbenicillin, and cephalexin. Of the strains, 17.5% were relatively resistant to penicillin G (MIC greater than 0.08 microgram/ml) 27.5% to ampicillin (MIC greater than 0.16 microgram/ml), 23.8% to amoxycillin, and 43.3% to carbenicillin. Cefotaxime was the most active antibiotic, with MICs in the nanogram range; 3.8% and 5% of the strains were relatively resistant to cephaloridine and cephalexin respectively, but no strains were resistant to cefazolin, cefuroxime, or cefotaxime. Resistance to tetracycline, doxycycline, minocycline, erythromycin, and spiramycin (MIC greater than 1 microgram/ml) was found in 6.3%, 2.5%, 5%, and 51.3% of the strains respectively. A very good correlation was present between chloramphenicol and thiamphenicol, with 16.3% and 10% of relatively resistant strains respectively. Only two isolates showed an MIC greater than 1.25 microgram/ml for rifampicin, and 10% of the strains needed greater than or equal to 12 microgram/ml of spectinomycin for complete inhibition of growth. A very high energy was found for the 20 : 1 combination of sulphamethoxazole and trimethoprim, with only one isolate resistant to this combination. None of the strains tested produced beta-lactamase.

The in-vitro activity of ceftazidime: comparison with other beta-lactam antibiotics.

We have compared the in-vitro bacteriostatic and bactericidal activity of ceftazidime against cephalothin-resistant Gram-negative bacteria, Haemophilus influenzae and Gram-positive bacteria. Comparison was made with cefaperazone, cefuroxime, moxalactam, cefotaxime, cefamandole, cefoxitin, cephalothin, cefazolin, azlocillin, carbenicillin, ticarcillin, ampicillin and oxacillin. In general ceftazidime was one of the most active compounds with low MIC and MBC values.

Bacteriostatic and bactericidal activities of 24 antimicrobial agents against Campylobacter fetus subsp. jejuni.

The bacteriostatic and bactericidal activities of 24 antimicrobial agents were tested with the Dynatech MIC 2000 system against 86 strains of Campylobacter fetus subsp. jejuni from human sources. The penicillins (penicillin G, ampicillin, amoxycillin, carbenicillin) had poor activity. Ampicillin and amoxycillin were equally active. Cefotaxime revealed a rather good activity. Erythromycin, gentamicin, tobramycin, amikacin, and furazolidone were the most active compounds. Two strains (2.3%) were resistant to erythromycin. One strain (1.2%) was completely resistant to tobramycin. The tetracyclines (tetracyline, doxycycline, minocycline) were generally effective, but 8% of the strains were totally resistant to them. Minocycline was the most active. Chloramphenicol, thiamphenicol, and clindamycin had good activity. The bacteriostatic and bactericidal distributions for colistin, nalidixic acid, and metronidazole were broad.