MARIMON J, GOMARIZ M, IDIGORAS P, MONTES M, VICENTE D, PEREZ-TRALLERO E; Interscience Conference on Antimicrobial Agents and Chemotherapy (43rd: 2003: Chicago, Ill.).
Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2003 Sep 14-17; 43: abstract no. C2-103.
Hospital Donostia, Donostia-San Sebatian, Spain.
BACKGROUND: In our area, Yersinia enterocolitica is a common bacterial pathogen isolated from stools of patients with gastroenteric disease. METHODS: Nalidixic acid (NA) susceptibility of all Y. enterocolitica clinical isolates between 1998-2002 was studied by disk diffusion. All NA-resistant (NA-R) and a sample of NA-susceptible (NA-S) isolates were restudied by agar dilution (NCCLS guidelines). E. coli ATCC 25922 and S. aureus ATCC 29213 were included as controls. Quinolone-resistance determining region (QRDR) of the gyrA gene was studied by a PCR-RFLP assay based on the Yersinia pestis QRDR sequence (GenBank AF 282314) and the enzyme HhaI to detect the presence of point mutations at codon Ser-83. The QRDR of NA-R isolates with no mutation at Ser-83 by PCR-RFLP and of a sample of NA-R with mutation at Ser-83 and NA-S isolates were sequenced. RESULTS: From 1998 to 2002, 591 Y. enterocolitica were isolated from 495 different patients. NA-R isolates represented 22.4% (109/486) of the isolates studied (annual range: 16.5% to 28.6%). NA MIC[50] of NA-R isolates was >128 microg/ml (range 32- >128) while MIC[50] of 145 NA-S isolates was <4 microg/ml (range <4- 8). The 73 NA-R isolates studied had point mutations in the gyrA gene. Mutation at Ser-83 and Asp-87 were the only mutations found. By PCR-RFLP 71/73 NA-R isolates had a point mutation at Ser-83. QRDR sequencing revealed that 12 of these isolates had a substitution at Ser-83 (AGC) changing into Arg (7 to AGG, 4 to AGA and 1 to CGC) and 3 into Ile (ATC). The 2 remaining NA-R isolates had a substitution at Asp-87 changing into Tyr (TAC) and Asn (AAC). By PCR-RFLP no point mutation at Ser-83 was found among the 51 NA-S isolates studied and no mutation was found in the QRDR of the 7 NA-S isolates sequenced. CONCLUSIONS: The overall resistance among Y. enterocolitica from human isolates was 22.4% in the last 5 years. All NA-R strains studied had point mutations in the gyrA gene. Substitutions at Ser-83 were the mutation most frequently found.
Publication Types:
Keywords:
- Animals
- Base Sequence
- Humans
- Microbial Sensitivity Tests
- Mutation
- Nalidixic Acid
- Point Mutation
- Polymerase Chain Reaction
- Polymorphism, Restriction Fragment Length
- Spain
- Yersinia enterocolitica
- genetics
Other ID:
UI: 102265103
From Meeting Abstracts