Epidemiology and antibiogram of Riemerella anatipestifer isolated from waterfowl slaughterhouses in Taiwan

Abstract

Introduction: Laryngeal swab samples collected from three waterfowl slaughterhouses in central Taiwan were cultured and suspected isolates of Riemerella anatipestifer were identified by API 20NE and 16S rDNA PCR. Material and Methods: Serum agglutination was used for serotyping, and antimicrobial susceptibility was tested. Results: Seventy-six R. anatipestifer isolates were detected, and the prevalences in the ducks and geese were 12.3% (46/375) and 8.0% (30/375), respectively. The positive isolation rates were 65.6% for all arriving waterfowl, 76.0% for birds in the holding area, 1.6% for defeathered carcasses, but zero for degummed carcasses. A PCR examination detected R. anatipestifer in the slaughtering area frequently. Serotype B was dominant in both duck (34.8%) and goose (46.7%) isolates, but the wide serotype distribution may very well impede vaccination development. All isolates were resistant to colistin, and 79.7% were resistant to more than three common antibiotics. Conclusion: The results proved that most ducks had encountered antibiotic-resistant R. anatipestifer in rearing, which suggests that the bacterium circulates in asymptomatic waterfowl. It is worth noting that most waterfowl farms were found to harbour R. anatipestifer, and contaminated slaughterhouses are a major risk factor in its spread. Effective prevention and containment measures should be established there to interrupt the transmission chain of R. anatipestifer.

Identification by MALDI-TOF MS and Antibiotic Resistance of Riemerella anatipestifer, Isolated from a Clinical Case in Commercial Broiler Chickens

“…Gyuris et al [ 19 ] found that more than one half of the RA isolates from geese and ducks in Hungary had developed resistance against gentamicin. The high prevalence of colistin resistance in the isolates was also reported in previous studies [ 35 , 38 ]. According to the same results, more than 70% of the isolates were resistant to lincomycin as well [ 35 , 39 ].…”

“…The high prevalence of colistin resistance in the isolates was also reported in previous studies [ 35 , 38 ]. According to the same results, more than 70% of the isolates were resistant to lincomycin as well [ 35 , 39 ]. Colistin and lincomycin are approved for use in feed treatments for bacterial infections in poultry.…”

“…All three RA isolates displayed a clear sensitivity profile to amoxicillin, ceftiofur and sulphamethoxazole-trimethoprim. Chang et al [ 35 ] reported a high percentage (97.4%) of the tested RA isolates which were susceptible to amoxicillin. Ceftiofur, is an approved third generation cefalosporin for food animal use in the United States and Europe [ 36 ].…”

“…Studies in duck isolates in Taiwan also approved that the ceftiofur is among the most effective antibiotics. Chang et al [ 35 ] found that sulphamethoxazole-trimethoprim showed 57% and 50% efficacy RA isolates from geese and ducks, respectively. Sun et al [ 37 ] noted that Chinese ducks’ RA isolates, were resistant to sulphonamide, while 75% of the strains were susceptible to sulphamethoxazole-trimethoprim.…”

“…According to our results, all the RA isolates displayed an expanding resistance pattern to eight antibiotics: colistin sulfate, spectinomycin, gentamicin, lincomycin, neomycin, oxytetracycline, spectinomycin, tetracycline and tylosin. Chang et al [ 35 ] examined antibiotic resistant of RA in ducks and geese, demonstrated that 50% or more of the isolates had developed resistance against commonly used antibiotics. Gyuris et al [ 19 ] found that more than one half of the RA isolates from geese and ducks in Hungary had developed resistance against gentamicin.…”