title: Antimicrobial susceptibilities and bacteriological characteristics of bovine Pseudomonas aeruginosa and Serratia marcescens isolates from mastitis.
abstract: The presence of metallo-β-lactamase (MBL)-producing and multidrug-resistant Pseudomonas aeruginosa (MDRP) strains among bovine isolates of Gram-negative bacilli, and O-serotypes of bovine Serratia marcescens and P. aeruginosa isolates have been reported rarely. The aims of this study were to (1) elucidate antimicrobial susceptibilities and O-serotypes of P. aeruginosa and S. marcescens isolates from bovine mastitis and the presence of MBL-producers and MDRP strains among them and (2) evaluate their relationships to human isolates. We investigated the MICs of 24 antimicrobials and O-serotypes for 116 P. aeruginosa and 55 S. marcescens isolates in Japan, primarily in 2006. A total of 171 isolates exhibited high antimicrobial susceptibilities with the exception of a partial drug. P. aeruginosa isolates exhibited high susceptibilities of ≥ 95.7% to ciprofloxacin, imipenem, meropenem, piperacillin, ceftazidime, cefepime, cefoperazone/sulbactam, amikacin, tobramycin, and gentamicin; however, they exhibited a susceptibility of only 69.8% to aztreonam. They exhibited substantial resistances to ceftriaxone, enrofloxacin, cefotaxime, and moxalactam. S. marcescens isolates exhibited high susceptibilities of ≥ 90.9% to kanamycin, ceftiofur, sulfamethoxazole-trimethoprim, and the 15 aforementioned drugs, but exhibited resistance to minocycline. Neither MBL-producers nor MDRP strains were detected among the 171 strains. The dominant serotypes of P. aeruginosa isolates were OG, OA, OB, OI, OF, OE, and OK; those of S. marcescens isolates were O6 and O5. Every S. marcescens isolate was pigmented. These findings suggest that bovine P. aeruginosa and S. marcescens isolates differ from human isolates from both antibiogram and phenotypic perspectives, and could help to evaluate differences in bacteriological characteristics between bovine and human isolates.
authors.affiliation: Veterinary Clinical Laboratory, Nemuro District Agricultural Mutual Aid Association, Nakashibetsu, Hokkaido 086-1105, Japan. monishi@kind.ocn.ne.jp
authors.forename: Mamoru
authors.initials: M
authors.lastname: Ohnishi
authors.forename: Takuo
authors.initials: T
authors.lastname: Sawada
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Hirose
authors.forename: Reiichiro
authors.initials: R
authors.lastname: Sato
authors.forename: Mizuki
authors.initials: M
authors.lastname: Hayashimoto
authors.forename: Eiji
authors.initials: E
authors.lastname: Hata
authors.forename: Chizuko
authors.initials: C
authors.lastname: Yonezawa
authors.forename: Hajime
authors.initials: H
authors.lastname: Kato
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002417:Cattle; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D007564:Japan / Q000453:epidemiology; D008414:Mastitis, Bovine / Q000453:epidemiology / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D008892:Milk / Q000382:microbiology; D011552:Pseudomonas Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D012703:Serotyping; D016868:Serratia Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary; D012706:Serratia marcescens / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents