Prevalence and mechanism of resistance against macrolides and lincosamides in Streptococcus suis isolates.
Eighty-seven Streptococcus suis isolates recovered in 1999-2000 from diseased pigs, all from different farms, were screened for resistance against macrolide and lincosamide antibiotics by the disk diffusion and agar dilution test and a PCR assay, amplifying the ermB gene and the mefA/E gene. Seventy-one percent of the isolates showed constitutive resistance to macrolide and lincosamide antibiotics (MLS(B)-phenotype). All these isolates were positive for the ermB gene in the PCR, but negative for the mefA/E gene. For all strains minimum inhibitory concentrations (MIC) against five other antimicrobial agents were determined. All strains were susceptible to penicillin. Ninety-nine percent of the isolates were susceptible to enrofloxacin and tiamulin. Eighty-five percent of the strains were resistant to doxycycline. A 540bp fragment of the ermB genes of eight S. suis strains was sequenced and compared with ermB genes of five S. pneumoniae and five S. pyogenes strains of human origin. A 100% homology was found between these fragments in seven S. suis, one S. pneumoniae and three of the S. pyogenes isolates. This study demonstrates that resistance against macrolides, lincosamides and streptogramin B is widespread in S. suis and mediated by ribosome methylation, encoded by the ermB gene.
Martel
A
A
Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium. an.martel@rug.ac.be
Baele
M
M
Devriese
L A
LA
Goossens
H
H
Wisselink
H J
HJ
Decostere
A
A
Haesebrouck
F
F
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D024901:Drug Resistance, Multiple, Bacterial / Q000502:physiology; D055231:Lincosamides; D018942:Macrolides; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008745:Methylation; D008780:Methyltransferases / Q000235:genetics* / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000662:veterinary; D015995:Prevalence; D012703:Serotyping / Q000662:veterinary; D013290:Streptococcal Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000235:genetics; D013297:Streptococcus pyogenes / Q000187:drug effects / Q000235:genetics; D017011:Streptococcus suis / Q000145:classification / Q000187:drug effects* / Q000235:genetics; D013552:Swine; D013553:Swine Diseases / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D055231:Lincosamides; D018942:Macrolides; C117866:MefA protein, Streptococcus; C431304:MefE protein, Streptococcus pneumoniae; D008565:Membrane Proteins; D008780:Methyltransferases; C035181:rRNA (adenosine-O-2'-)methyltransferase