Antimicrobial susceptibility of Campylobacter jejuni and Campylobacter fetus subsp. fetus to eight cephalosporins with special reference to species differentiation

To determine whether employing antibiograms is useful to separate Campylobacterjejuni and Campylobacter coli, we determined the MICs of 12 antibiotics for 104 human clinical strains and 74 swine strains. Of 74 swine strains, 5 (7%) were hippurate positive, as were 93 (89%) of 104 human strains. The 12 antimicrobial agents tested were ampicillin, amoxicillin, clindamycin, chloramphenicol, erythromycin, furazolidone, norfloxacin, nalidixic acid, rosoxacin, rosaramicin, tetracycline, and Sch 32063. Isolates from humans were significantly (P <0.001) more susceptible than swine strains to clindamycin, erythromycin, rosaramnicin, and Sch 32063. Of 11 human hippurate-negative strains, 3 (27%) were resistant to clindamycin, erythromycin, rosaramicin, and Sch 32063, compared with 1 of 93 (1%) hippurate-positive strains. Nearly all human and swine strains were susceptible to furazolidone and nalidixic acid. Campylobacter isolates from humans and swine have different antibiograms, and the susceptibility to certain antibiotics, such as clindamycin, may be helpful for differentiation of C. jejuni from C. coli.

Section: Resultsmentioning

confidence: 99%

Comparison of antimicrobial susceptibility patterns of Campylobacter jejuni and Campylobacter coli

Wang¹,

Reller²,

Blaser³

1984

“…fetus by their susceptibility to <40 p.g of nalidixic acid per ml (12,24,25). CLO type 1 and 2 strains were susceptible to cefazolin but strains of C. jejuni that are susceptible to this antimicrobial agent have not been reported (11,15).…”

Section: Resultsmentioning

confidence: 99%

In vitro susceptibilities of Campylobacter-like organisms to twenty antimicrobial agents

Flores¹,

Fennell²,

Holmes³

et al. 1985

We determined MICs of 20 antimicrobial agents for 50 representative strains of four subgroups of Campylobacter-like organisms (CLOs) by agar dilution. Ampicillin, gentamicin, doxycycline, tetracycline, ceftriaxone, rifampin, spectinomycin, nalidixic acid, and chloramphenicol were active against all strains of CLOs. Most CLO strains (83%) were inhibited by 4 ,ug of sulfamethoxazole per ml and by 8 ,Ig of trimethoprim-sulfamethoxazole per ml. Of type 1 strains, 28% were resistant to 8 ,g of erythromycin per ml. In addition, cross resistance between erythromycin and clindamycin was always present. Type 1 strains exhibited a broad distribution of MICs of metronidazole and streptomycin, whereas all type 2 strains were uniformly susceptible to metronidazole and resistant to streptomycin. Unlike type 1 and 3 strains, type 2 CLOs were susceptible to cephalothin and penicillin G and highly resistant to streptomycin. The type 3 strain was uniquely resistait to cefazolin. The majority of strains were not inhibited by cefoperazone; and all were resistant to trimethoprim. In contrast to Campylobacterjejuni and Campylobacterfetus subsp. fetus, ail CLOs tested were susceptible to 0.5 ,ug of rifampin per ml.Increased awareness of the role of Campylobacter spp. in human disease and the development of improved selective media have resulted in recent isolation of several novel Campylobacter spp. from humans (7,8,10,13,14,(16)(17)(18). Among these, we isolated Campylobacter-like organisms (CLOs) from symptomatic and asymptomatic homosexual nmen being evaluated for enteritis, proctitis, and proctocolitis in a sexually transmitted diseases clinic. These organisms were isolated by using, a selective medium containing vancomycin, polymyxin B, trimethoprim, and amphotericin B supplemented with 10%o sheep blood (2) after incubation at 37°C in a microaerophilic environment. The classification of these CLOs within the genus Campylobacter and their phenotypic characterization into three subgroups were recently described by Fennell et al. (8). Further studies revealed four genetically distinct CLO subgroups (types 1A, 1B, 2, and 3), two of which (types 1A and 1B) were phenotypically identical (21a). The spectrum of diseases associated with CLO infection includes asymptomatic gastrointestinal colonization (17), proctocolitis (17)

“…Figure 2 shows that the derived amino acid sequence of the aacA4 allele from Campylobacter demonstrated 100% homology to the AAC(6Ј)-Ib 7 enzyme, which has been shown to confer characteristics resulting in higher kanamycin and tobramycin MICs but only slightly increased resistance to gentamicin (5). To evaluate the phenotype conferred by the AAC(6Ј)-Ib 7 enzyme in C. jejuni, four of the isolates containing aacA4 were assayed for tobramycin and gentamicin resistance, using agar dilution on Mueller-Hinton agar containing 5% washed sheep red blood cells (19). Table 1 shows that for the int ϩ aacA4 ϩ strains tested, tobramycin MICs were 25 to 50 g/ml and gentamicin MICs were 10 to 50 g/ml.…”

mentioning

confidence: 99%

Class 1 Integron-Associated Tobramycin-Gentamicin Resistance in Campylobacter jejuni Isolated from the Broiler Chicken House Environment

Lee¹,

Sánchez

Zimmer

et al. 2002

Using PCR, we screened 105 isolates of poultry-associated Campylobacter jejuni for the presence of class 1 integrons. Of those isolates, 21% (22 of 105) possessed the integrase gene, but only 5 isolates produced an amplicon in a 5-3 conserved sequence PCR directed toward amplification of the resistance cassettes. DNA sequencing demonstrated that all five isolates possessed the aminoglycoside resistance gene, aacA4.