Investigations of clostridium perfringens in turkey and layer flocks in Germany

AuszugThe Enteric health is an important concern to the poultry industry, as any changes, due to mechanical, chemical or biological disturbance of digestive system (enteric disorders), leading to sever economical losses. Enteric disorders can cause decreased productivity, increased feed conversion ratio, downgraded carcasses, increased medication costs and reduced welfare of birds, in addition to the zoonotic importance of some enteric pathogens through contaminated poultry products in the food chain. One of the important enteric diseases in poultry is necrotic enteritis (NE) caused by Clostridium perfringens, which occurs both in clinical (CNE) as well as in the subclinical form (SNE). Both forms significantly affect the performance and egg production of the birds (Kaldhusdal and Løvland 2002). Economically NE costs the worldwide poultry industry an estimated US $ 2 billion annually (McReynolds et al., 2004). In the last decades, antibiotics have been supplemented to animal and poultry feed to improve growth performance and efficiency as well as to established the intestinal flora and protect the birds from adverse effects of pathogenic enteric microorganisms (Ferket et al., 2002). It was concluded that excessive use of antimicrobial growth promoters (AGPs) in animal feeds imposes a selection pressure for bacteria that are resistant to antibiotics (JETACAR, 1999). Because of the potential development of antibiotic-resistant human pathogenic bacteria after prolonged use of AGPs and increased consumer concerns about antibiotic resistance, the EU decided the ban all AGPs in a gradual process begin with Avoparcin in 1997 and ending with Avilamycin in 2006 (EC, 2003). Except are compounds, which are used as anticoocidial drugs. Some of these not only have an effect against coccidia, but also against several intestinal bacteria including C. perfringens (Elwinger et al., 1998; Engberg et al., 2000). A ban of anticoccidials is anticipated in the near future. Since AGPs are not used in poultry rations, there is a remarkable increase in NE cases in poultry flocks. This was recorded at first in Scandinavian countries, which banned the use of AGPs earlier (Løvland and Kaldhusdal 1999). The EU ban of AGPs has had a marked effect on the incidence of NE in poultry (Hermans and Morgan, 2007, Svobodová et al., 2007). In regard of the above mentioned managemental and regulatory changes in poultry husbandry in the last decades, the objectives of this study were: To monitor and provid data about: 1) Prevalence of Clostridium perfringens in commercial turkey and layer flocks reared in various locations in Germany as well as to determination of the distribution of the different toxinotype of C. perfringens and the presences of some important minor toxins (Publication No. 1). 2) Determination of antibiotic sensitivities of Clostridium perfringens isolates from commercial turkeys in Germany in vitro using minimum inhibitory concentrations (MIC) test (Publication 2). 3) In vitro determination of antibiotic sensitivities of Clostridium perfringens isolates from commercial layer flocks in Germany (Publication 3).