This study was conducted to compare the presence and antimicrobial susceptibility of Campylobacter, Salmonella spp., and other enteric bacteria between chickens and guinea fowls. Birds were reared on enclosed concrete floor housing covered with pine wood shavings litter material. Chicken (n = 40) and guinea fowl (n = 40) carcasses, drinking water (10 mL; n = 40), and litter (10 g; n = 40) were aseptically collected randomly from a poultry farm and analyzed within 1 h of collection. Individual pens served as experimental units and were replicated twice. Campylobacter spp., Salmonella spp., and other enterobactericeae were isolated and identified using standard selective media and biochemical tests. Isolates were tested for sensitivity to tetracycline, ampicillin, streptomycin, kanamycin, nalidixic acid, gentamicin, erythromycin, ciprofloxacin, cefoxitin, and colistin using the Kirby-Bauer disk diffusion test. Campylobacter spp. and Salmonella spp. were isolated from 28 and 35% of whole carcass rinses of chickens and from 18 and 23% of whole carcass rinses of guinea fowl, respectively. Although only Salmonella spp. were recovered from drinking water, both Salmonella and Campylobacter spp. were recovered from litter material. Campylobacter upsaliensis was recovered only in the guinea fowl, whereas Klebsiella oxytoca and Enterobacter sakazakii were recovered only in chickens. Although no antibiotic resistance was determined in Campylobacter upsaliensis, most Campylobacter, Salmonella, and Escherichia coli isolates from both chickens and guinea fowl were resistant to antibiotics such as ampicillin, kanamycin, erythromycin, and nalidixic acid.

The feasibility of using an ATP bioluminescence assay for assessing microbial contamination of home refrigerators was evaluated and compared with the standard culture methods. Samples of refrigerator surfaces were collected from 123 households by swabbing an area of 100 cm2 on three locations in the refrigerator with premoisturized sterile swabs. Microbial contaminations were determined by aerobic plate count (APC; incubated at 35 degrees C for 48 h) and psychrotrophic plate count (PPC; incubated at 7 degrees C for 10 days) on plate count agar. The results were compared to the readings from the microbial ATP (mATP) bioluminescence assay. The correlation coefficient (r) between mATP and PPC (r = 0.851) was slightly higher than that between mATP and APC (r = 0.823). Our results indicated a potential discrepancy in the population of mesophilic and psychrotrophic bacteria in the refrigerator samples. Nevertheless, mATP appeared to be a reliable indication of the average of APC and PPC (r = 0.895). The mATP bioluminescence assay would provide a rapid and convenient test for researchers in field studies to assess microbial contamination in refrigerators.

The aim of this investigation was to study the efficacy of UV-C light emitting diode system (LED) operating at 263 nm for the inactivation of Listeria monocytogenes and Escherichia coli O157:H7. Specified concentrations of bacteria were inoculated in apple juice and irradiated at the designated UV doses of 0 to 15 mJ/cm-2. In addition, UV irradiation doses ranging from 0 to 160 mJ/cm-2 were also delivered to apple juice and polyphenols and vitamins were profiled. LC-MS/MS analysis was conducted to assess the stability of polyphenols or vitamins in UV-C exposed apple juice. The polyphenol and vitamin results demonstrated that UV-C irradiation in apple juices at relevant commercial UV doses induced significant reductions in the concentrations of selected polyphenols and vitamins, p<0.05. Ascorbic acid was reduced to 32%, at 160 mJ/cm2 whereas 17% reduction was observed at 40 mJ/cm2. Riboflavin was observed to be relatively stable. Epicatechin and chlorogenic was significantly reduced at high exposure doses. In contrast minor changes were observed at 40 mJ/cm2. Results show that UV-C irradiation effectively inactivated pathogenic microbes in apple juice. The log reduction kinetics of microorganisms followed log-linear and with higher R2 (>0.95) and low RMSE values. The D10 values of 4.16 and 3.84 mJ/cm-2 were obtained from the inactivation of Escherichia coli, and Listeria monocytogenes in apple juice. The results from this study imply that adequate log reduction of pathogens is achievable in apple juice and suggest significant potential for UV-C treatment of other liquid foods.

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A monoclonal antibody-based sandwich enzyme-linked immunosorbent assay (ELISA) was developed for the sensitive detection of porcine skeletal muscle in raw and heat-processed meat and feed products. Heat treatment of meat samples up to 132 °C for 2 h did not affect the assay performance. The assay uses a pair of monoclonal antibodies (MAbs 8F10 and 5H9) specific to skeletal muscle troponin I (TnI). MAb 8F10, reacting to mammalian TnI, is the capture antibody and the biotin-conjugated MAb 5H9, specific to porcine TnI, the detection antibody. The sandwich ELISA is able to detect 0.05% (w/w) of laboratory-adulterated pork in chicken, 0.1% (w/w) pork in beef mixtures, 0.05% (w/w) pork meal in soy-based feed, and 1% commercial meat and bone meal (MBM), containing an unknown amount of pork, in soy-based feed. This new assay provides a rapid and reliable means to detect the contamination of meat and feed products with trace amounts of porcine muscle tissue to ensure product quality and safety.