A Comparison of Three Methods for the Isolation of Arcobacter spp. from Retail Raw Poultry in Northern Ireland

Abstract

Recent evidence suggests that arcobacters, especially Arcobacter butzleri, are potential foodborne pathogens, but standardized detection methods have yet to be established. A study was undertaken to determine which of three isolation methods was the most effective for the isolation of Arcobacter spp. from fresh raw poultry. Methods 1 was microaerobic and involved a membrane filtration step followed by plating onto blood agar. Method 2 was also microaerobic and involved enrichment and plating media containing a five-antibiotic cocktail. Method 3 was aerobic and was based on enrichment in a charcoal-based broth containing two antibiotics. Retail poultry samples (n = 50) were obtained from supermarkets in Northern Ireland; the European Community license number was recorded to ensure sample diversity. Presumptive arcobacters were identified using genus-specific and species-specific primers. Methods 1 resulted in the lowest recovery of arcobacters (28% of samples positive). The detection rate for method 2 (68%) was higher than that for method 3 (50%), but the difference was not significant (P > 0.05). Modification of method 3 by plating the enrichment broth at 24 h, as well as at 48 h, increased recovery to 68%. Use of methods 2 and 3 together increased the number of positive samples detected by approximately 25% compared with use of either method alone. A. butzleri was the most commonly isolated species using all methods. Method 3 detected Arcobacter cryaerophilus in more samples (n = 3) than did method 1 and 2 (n = 1). Arcobacter skirrowii was detected by only method 3 (n = 1). In terms of sensitivity, ease of use, and diversity of species recovered, modified method 3 was the overall method of choice.

Prevalence of Arcobacter spp. on chicken meat at retail markets and in farm chickens in Selangor, Malaysia

“…A. cryaerophilus and A. skirowii are slow growing species and may need more than 72 h to produce visible colonies on the agar plates; thus, with longer incubation period which in some studies up to 8 days incubation (Atabay, Wainø, & Madsen, 2006;Aydin, Gümüssoy, Atabay, Ica, & Abay, 2006), it may be possible to isolate these and other species of Arcobacter. The use of more than one isolation method is also recommended as this would allow for maximum recovery of arcobacters from naturally contaminated chicken meat (Scullion, Harrington, & Madden, 2004). Another possible explanation could be that A. cryaerophilus may not compete well with A. butzleri during enrichment as suggested by Houf, De Zutter, Van Hoof, and Vandamme (2002) who had isolated only A. butzleri from neck skin samples after enrichment but were able to isolate both A. cryaerophilus and A. butzleri by direct plating.…”

Prevalence of Arcobacter species in market-weight commercial turkeys

“…Previous reports have described protocols to estimate Arcobacter prevalence in live birds or poultry meat (DeBoer et al 1996;Eifert et al 2003;Houf et al 2001;Johnson et al 1991;Lerner et al 1994;Phillips 2001;Ridsdale et al 1998;Scullion et al 2004;Son et al 2006). Because of its complexity, few studies have evaluated Ellinghausen-…”

“…The serogroup identity of A. butzleri isolates from poultry and clinical cases of diarrhoeal illness suggested that poultry are possible reservoir of infection (Marinescu et al 1996). Poultry, including up to 97% of chicken carcasses (Atabay et al 2003;DeBoer et al 1996;Kabeya et al 2003;Lammerding et al 1996), retail products (Scullion et al 2006), and up to 80% of ground poultry (Manke et al 1998;Rivas et al 2004;Scullion et al 2004) are often contaminated with Arcobacter spp., primarily A. butzleri. In one study, A. cryaerophilus was the only Arcobacter species recovered from poultry transport crates (Houf et al 2002).…”

Taxonomy, Epidemiology, and Clinical Relevance of the Genus Arcobacter

“…However, it has been reported that the enrichment step reduces the diversity of Arcobacter species recovered in the plating medium in comparison with direct plating (68,71). In summary, it can be said that the methods for recovering Arcobacter are very diverse (Table 4) and that there is a lack of consensus about which of them is the most useful (depending on the type of sample), because few comparative studies have been performed (6,85,134) and, to our knowledge, there is no study in which they were all compared simultaneously. Some of the recovery problems reported include the inhibition of some Arcobacter species when using certain antibiotics (11,72) and insufficient inhibition of the accompanying microbiota (6,44).…”