Characterization of Clostridium perfringens isolates from healthy turkeys and from turkeys with necrotic enteritis

Abstract

Clostridium perfringens is an important bacterial pathogen, especially in poultry, where it can lead to both subclinical and clinical disease. The aim of this study was to present data on pathological findings at outbreaks of necrotic enteritis (NE) in turkey production in Finland during the period from 1998 to 2012. Furthermore, C. perfringens isolates from healthy and diseased turkeys were characterized and their genetic diversity was investigated using pulsed-field gel electrophoresis (PFGE). Isolates (n = 212) from birds with necrotic gut lesions and from healthy flocks of 30 commercial turkey farms were characterized for the presence of cpa, cpb, iA, etx, cpb2, and cpe and netB genes. A total of 93 C. perfringens isolates, including 55 from birds with necrotic gut lesions and 38 from healthy birds from 13 different farms, were analyzed with PFGE. All contract turkey farmers (n = 48) of a turkey company that produces 99% of domestic turkey meat in Finland were interviewed about background information, management at the farm, and stress factors related to NE outbreaks. Pulsed-field gel electrophoresis analysis with SmaI restriction enzyme resulted in 30 PFGE patterns among the 92 C. perfringens isolates of high diversity. Out of all isolates, 212 (100%) were α-toxin-positive and one isolate (0.5%) was both α- and β2 toxin-positive. Fourteen isolates (6.6%) were necrotic enteritis toxin B (NetB) positive; all were recovered from turkeys with NE. In none of the isolates obtained from healthy turkeys was the netB toxin identified. In conclusion, a high diversity of C. perfringens isolates from turkeys with different health status was shown. All isolates produced α toxin, whereas only low percentages of isolates carried the netB toxin gene. The role of the netB toxin in NE in turkeys needs to be further investigated.

Genotyping and antimicrobial susceptibility of Clostridium perfringens isolated from Tinamidae, Cracidae and Ramphastidae species in Brazil

“…Recent studies have shown a high correlation between the detection of the NetB-encoding gene and the occurrence of NE in broiler chickens and in turkeys (KEYBURN et al, 2008;ALLAART et al, 2012;LYHS et al, 2013). In the present study, there were no C. perfringens strains positive for of the 18 Clostridium perfringens strains isolated from Ramphastidae, Tinamidae and Cracidae species in Brazil.…”

Genome analysis of Clostridium perfringens isolates from healthy and necrotic enteritis infected chickens and turkeys

“…Both chickens and turkeys were from conventionally raised indoor flocks. The samples were collected on 14 different Danish chicken farms between 1997 and 2002 [12], and seven different Finnish turkey farms between 1997 and 2010 [8]. The samples were primarily from the intestine, but six chicken isolates were obtained from liver samples (Additional file 1).…”

“…Colonization of the intestine by netB -positive type A strains is known to be the main cause of necrotic enteritis (NE) in broilers [4, 5], which constitutes a considerable burden to the animal welfare and production yield in the international poultry industry [6]. NetB is essential in the pathogenesis of NE in chickens [4, 5], whereas the prevalence of netB is low among diseased turkeys [7, 8]. Few studies of the virulence gene content in strains from turkeys with NE and enteric diseases have been carried out [9] and to our knowledge, there are no reports on whole-genome sequencing of C. perfringens isolates from turkeys.…”

Clostridium perfringens: a review of the disease in pigs, horses and broiler chickens

“…In addition, it was demonstrated that the NetB-encoding gene (netb) is common in C. perfringens type A isolates from NE birds, whereas it is rare in healthy birds (KEYBURN et al, 2008). A similar association was recently reported in turkeys: netb was identified in 6.6% of the C. perfringens strains isolated from turkeys with NE but in none of the strains isolated from healthy animals (LYHS et al, 2013). Because reports have indicated that C. perfringens netbnegative strains can cause NE, it appears that there are other virulence factors involved (LEE et al, 2011).…”