With the advancement of DNA-based biosensors and automation for bacterial detection, enrichment broths could be screened for the presence of Campylobacter spp. in a shorter time, with greater sensitivity and without the generation of any microaerobic condition. In addition, food microbiology laboratories interested in establishing techniques
for the isolation of Campylobacter from retail meat will have access to a cost-effective enrichment procedure without the need to invest in systems to generate microaerobiosis. Reference documents from the FDA and FSIS USDA should eventually be updated to provide for an alternative, simplified protocol that yields similar number of GSK2118436 clinical trial Campylobacter positive samples as the current
reference protocols. Methods Sample preparation, incubation and Campylobacter isolation Retail broiler meat samples (total = 108 samples; 49 breasts and 59 thighs) were purchased from local stores (Auburn, AL) from April 2009 to October 2010. Samples were selleck chemical tested in batches of three to five samples per week. Each meat package was considered one sample, and from each package ~1-inch pieces were cut aseptically and mixed thoroughly. For all samples, 25 g of meat was weighed two times (two subsamples) in individual, sterile Whirl-Pak® (Nasco, Fort Atkinson, WI). Each subsample was enriched in 100 ml of Bolton’s broth (with antimicrobial supplements) and 5% (v/v) of lysed horse blood [17]. The control subsamples (microaerobic
Crizotinib subsamples) were incubated in anaerobic jars gassed with a microaerobic gas mix (85% N2, 10% CO2, 5% O2; Airgas, Radnor, PA) using the evacuation-replacement system MACSmics Jar Gassing System (Microbiology International, Frederick, MD). The other subsamples (aerobic subsamples) were incubated without the addition of microaerobic gas mix, by closing the bags after removing the remaining air manually. All subsamples were incubated at 42°C for 48 h. After incubation and for all subsamples, 0.1 ml of the enriched broth was transferred Bupivacaine to modified charcoal cefoperazone deoxycholate agar [10] through a 0.65 μm membrane filter as described elsewhere [33]. All agar plates were incubated under microaerobic conditions at 42°C for 48 h. Presumptive Campylobacter colonies were observed under phase contrast microscopy (Olympus BX51, Olympus America Inc., Center Valley, P) for spiral morphology and darting motility. Presumptive isolates were stored at -80°C in tryptic soy broth (Difco, Detroit, MI) supplemented with 20% glycerol (v/v) and 5% (v/v) lysed horse blood for further analysis. Identification of presumptive Campylobacter isolates by mPCR assays Campylobacter isolates were recovered from frozen stocks by transferring to Brucella agar plates supplemented with 5% horse blood and through 0.6 μm membrane filters as described above. Plates were incubated at 42°C under microaerobic conditions for 24 h.