Flagellin typing of Bordetella bronchiseptica strains originating from different host species

Bordetella bronchiseptica is a widespread Gram-negative pathogen occurring in different mammal species. It is known to play a role in the aetiology of infectious atrophic rhinitis of swine, canine kennel cough, respiratory syndromes of cats, rabbits and guinea pigs, and sporadic human cases have also been reported. In this study, ninety-three B. bronchiseptica strains were examined from a broad range of host species and different geographical regions using restriction fragment length polymorphism analysis of polymerase chain reaction products of flaA to reveal the possible host-specificity of the flagellin. Eight types (A-H) of flaA were identified, including five newly described ones (D-H). All but one of the twenty11 two B. bronchiseptica strains from swine showed type B fragment pattern. The eighteen Hungarian isolates of canine origin were uniform (type A) while in other countries type B and D were also present in dogs. The sequence and phylogenetic analysis of 36 representative strains of flaA types revealed four clusters. These clusters correlated with flaA PCR-RFLP types and host species, especially in pigs and dogs. The revealed diversity of the strains isolated from human cases indicated possible zoonotic transmissions from various animal sources

Antimicrobial susceptibility of Bordetella Avium and Ornithobacterium Rhinotracheale strains from wild and domesticated birds in Hungary

The antimicrobial susceptibility of 19 Bordetella avium and 36 Ornithobacterium rhinotracheale strains was tested by the Kirby-Bauer disk diffusion method, and the minimal inhibitory concentrations (MIC) of amoxicillin, doxycycline and erythromycin were also determined. Most O. rhinotracheale strains were resistant to nalidixic acid, sulphamethoxazole–trimethoprim and gentamicin, and were susceptible to ampicillin, chloramphenicol, spectinomycin and tilmicosin. All B. avium strains were resistant to ceftiofur and lincomycin and susceptible to doxycycline, gentamicin, polymyxin B, spectinomycin and sulphonamides. The MICs ranged widely for all three antibiotics tested against O. rhinotracheale strains, from 0.12 μg/ml to 32 μg/ml for amoxicillin and erythromycin, and from 0.6 μg/ml to 32 μg/ml for doxycycline. For B. avium isolates, the MIC values ranged from ≤ 0.03 μg/ml to 1 μg/ml for amoxicillin, from ≤ 0.03 μg/ml to 0.12 μg/ml for doxycycline and from 8 μg/ml to 16 μg/ml for erythromycin. These findings support the idea that the use of antibiotics in a region or a farm may affect antimicrobial resistance and underline the need for prudent application of antibiotic therapy based on proper antimicrobial susceptibility testing

Development of molecular biological tools for the rapid determination of antibiotic susceptibility of Mycoplasma hyopneumoniae isolates

Mycoplasma hyopneumoniae is the etiologic agent of porcine enzootic pneumonia, a contagious respiratory disease, causing significant economic losses worldwide. Antibiotic treatment is commonly utilised in the pig industry to control M. hyopneumoniae infection. Since the conventional antibiotic susceptibility test is time-consuming, taking up to weeks’ period, antibiotics are usually empirically chosen. Certain single nucleotide polymorphisms in the parC (C239A/T, G250A) and gyrA (G242C, C247 T, A260 G) genes show correlation with decreased fluoroquinolone susceptibility by the change of the target site. Furthermore, the nucleotide alteration A2059 G in the 23S rRNA sequence correlates with significantly decreased macrolide and lincosamide susceptibility of M. hyopneumoniae. Mismatch amplification mutation assays (MAMA) and high resolution melt (HRM) analysis, capable to detect the mentioned resistance markers, were developed in the present study, in order to provide susceptibility data in a considerably shorter time than the conventional methods. The results of the MAMA and HRM assays were congruent with the results of the conventional antibiotic susceptibility method of the tested M. hyopneumoniae field isolates. The sensitivity of the MAMAs was 103-104 copy numbers, while that of the HRM assay was 105-106 copy numbers. To the best of our knowledge this was the first time that MAMA and HRM assays were developed for the rapid detection of decreased fluoroquinolone, macrolide or lincosamide susceptibility in M. hyopneumoniae strains

Antimicrobial susceptibility of Riemerella anatipestifer strains isolated from geese and ducks in Hungary

Riemerella anatipestifer causes anatipestifer disease in many avian species. A total of 185 R. anatipestifer strains isolated in Hungary between 2000 and 2014 from geese and ducks were tested against 13 antibiotics (ampicillin, doxycycline, enrofloxacin, erythromycin, florfenicol, flumequine, gentamicin, penicillin, spectinomycin, streptomycin, sulphamethoxazole—trimethoprim, sulphonamide compounds, and tetracycline) by the Kirby-Bauer disk diffusion method. The majority of the strains were susceptible to florfenicol (97.9%), ampicillin (95.1%), penicillin (93%), sulphamethoxazole—trimethoprim (92.4%), and spectinomycin (86.5%). The highest resistance rates were observed for flumequine, tetracycline, erythromycin and streptomycin (94%, 91.4%, 75.1% and 71.4% resistance, respectively). The resistance patterns showed some variation depending on the geographical origin of the strains. The average rate of extensive drug resistance was 30.3%, and its proportion tended to increase in the period examined

Heterogeneity of Bordetella bronchiseptica adenylate cyclase (cyaA) RTX domain

Bordetella bronchiseptica is a widespread pathogen, with a broad host range, occasionally including humans. Diverse virulence factors (adhesins, toxins) allow its adaptation to its host, but this property of the adenylate cyclase (cyaA) toxin is not well understood. In this study, we analyzed the repeats-in-toxin domain of B. bronchiseptica cyaA with PCR, followed by restriction fragment length analysis. Of ninety-two B. bronchiseptica strains collected from different hosts and geographic regions, 72 (78.3%) carried cyaA and four RFLP types (A-D) were established using NarI and SalI. However, in 20 strains, cyaA was replaced with a peptide transport protein operon. A phylogenetic tree based on partial nucleotide sequences of cyaA revealed that group 2 contains strains of specifically human origin, whereas subgroup 1a contains all but one of the strains from pigs. The human strains showed many PCR-RFLP and sequence variants, confirming the clonal population structure of B. bronchiseptica

Riemerella anatipestifer caused disease of poultry - Literature review

SUMMARY Riemerella anatipestifer is prevalent throughout the world, including Hungary as well. Primarily, it causes disease in young ducklings and goslings, but it may induce heavy losses in turkey flocks too. The authors summarize the literature data on the history of the anatipestifer disease and the characteristics of R. anatipestifer. They describe the epidemiology, the clinical sings and the pathological lesions of anatipestifer disease. Isolation, identification and the methods of classification of R. anatipestifer are also discussed. Finally, they summarize the aspects of treatment and prevention of the disease

A baromfi Riemerella anatipestifer okozta megbetegedése

A Riemerella anatipestifer világszerte, így hazánkban is elterjedt kórokozó, elsősorban növendék kacsákban és libákban okoz betegséget, de súlyos veszteségeket idézhet elő pulykaállományokban is. A szerzők szakirodalmi adatok alapján összegzik az anatipestifer-betegség történetét és a R. anatipestifer baktérium tulajdonságait. Összefoglalják a betegség járványtanával kapcsolatos ismereteket,bemutatják az anatipestifer-betegség klinikai tüneteit, kórbonctani elváltozásait. Ismertetik a kórjelzéshez szükséges vizsgálatokat, a kórokozó jellemzésére szolgáló módszereket és összefoglalják a betegség gyógykezelésének, megelőzésének lehetőségeit

Detection of urease-negative Bordetella bronchiseptica from the field

Four urease-negative Bordetella bronchiseptica isolates originating from pigs were examined by phenotypic and molecular methods. The phenotypic properties of the isolates were in harmony with the data of the literature, except for the lack of urease activity in conventional tube test, API 20 NE and Diatabs™ assays. Using genotypic methods, the urease-negative isolates did not differ from the urease-positive reference strain. They were positive in species-specific and ureC PCR, and all strains showed uniform bands in PCR-RFLP studies of flaA genes. The reason for the lack of urease activity, a characteristic considered speciesspecific for B. bronchiseptica, needs to be studied further. The finding underlines the significance of genotyping when the phenotypic identification of B. bronchiseptica seems questionable