Multilocus sequence types of Finnish bovine Campylobacter jejuni isolates and their attribution to human infections

Abstract

BackgroundCampylobacter jejuni is the most common bacterial cause of human gastroenteritis worldwide. Due to the sporadic nature of infection, sources often remain unknown. Multilocus sequence typing (MLST) has been successfully applied to population genetics of Campylobacter jejuni and mathematical modelling can be applied to the sequence data. Here, we analysed the population structure of a total of 250 Finnish C. jejuni isolates from bovines, poultry meat and humans collected in 2003 using a combination of Bayesian clustering (BAPS software) and phylogenetic analysis.ResultsIn the first phase we analysed sequence types (STs) of 102 Finnish bovine C. jejuni isolates by MLST and found a high diversity totalling 50 STs of which nearly half were novel. In the second phase we included MLST data from domestic human isolates as well as poultry C. jejuni isolates from the same time period. Between the human and bovine isolates we found an overlap of 72.2%, while 69% of the human isolates were overlapping with the chicken isolates. In the BAPS analysis 44.3% of the human isolates were found in bovine-associated BAPS clusters and 45.4% of the human isolates were found in the poultry-associated BAPS cluster. BAPS reflected the phylogeny of our data very well.ConclusionsThese findings suggest that bovines and poultry were equally important as reservoirs for human C. jejuni infections in Finland in 2003. Our results differ from those obtained in other countries where poultry has been identified as the most important source for human infections. The low prevalence of C. jejuni in poultry flocks in Finland could explain the lower attribution of human infection to poultry. Of the human isolates 10.3% were found in clusters not associated with any host which warrants further investigation, with particular focus on waterborne transmission routes and companion animals.

A Longitudinal 6-Year Study of the Molecular Epidemiology of Clinical Campylobacter Isolates in Oxfordshire, United Kingdom

“…These findings have been strongly supported by source attribution models that have employed MLST data to estimate the contribution made by different potential infection sources to the burden of human disease (41,42). While emphasizing the importance of contaminated poultry in this regard, these analyses also support a role for bovine, ovine, and other sources (7,41,42).…”

“…This pattern has been reported previously for ST-45 (22,29,44) and ST-283 complexes (29) but not for the ST-42 complex. The ST-45 and ST-283 complexes have both been identified as chicken associated (7,21,41), and the ST-45 complex has additionally been identified from a wide range of wild animal sources (27), but the ST-42 complex has been predominantly associated with ruminant hosts (6,13,21). While MLST data for isolates belonging to ST-45 and ST-283 complexes confirms a recent common ancestor (29), no similarity in genotype or host association was observed between these two complexes and isolates belonging to the ST-42 complex.…”

Quo vadis? — MonitoringCampylobacterin Germany

“…The contribution of Campylobacter from wild birds, pigs, and the environment as causative agent for human infection was also predicted to be low. In a Finnish study, Campylobacter from poultry were supposed to be equally responsible for human campylobacteriosis as Campylobacter from cattle [18]. The authors explained this phenomenon as due to the low prevalence of Campylobacter in Finnish poultry primary production, which is exceptional in Europe.…”

Incidence of zoonotic Campylobacter jejuni in fast meal meat, grill chickens and symptomatic Egyptians

“…Due to the varieties of cooking methods which differ in temperature degrees and courses, in addition to varied pH and salt concentration. So, the temperature within core parts along with short cooking time could be sustain the favorable media for Campylobacter persistence and survival and may be multiplied with lowering heating degrees (Haan et al, 2010). The current study established this concept through verified dissimilar incidence of C. jejuni in different types of examined quick meat meals; offal and liver sausage, hamburger, kofta and shawarma were recorded with varied values: 18.2, 15.2, 20.4, 13.2 and 14.5%, respectively, while the overall rate of isolation was 16% (Table 3 and Figure 1).…”