This study investigated the changes in colour, amino acids, and volatile flavour compounds in the enzymatic hydrolysates of chicken carcasses containing different types and amounts of reducing sugars (xylose, arabinose, glucose, and fructose), so as to develop a chicken-based flavouring agent. Before heat treatment at 100 °C for 60 min, the chosen reducing sugars were separately added to the chicken carcass hydrolysate at its natural pH. Pentoses decreased pH more significantly than hexoses in the chicken carcass hydrolysate. The browning degree followed the pattern of pH decline, as pentoses caused more intense browning than hexoses, with xylose dosage having the greatest effect on the colour changes (ΔE). Fructose addition notably reduced free amino acids (FAAs) and cystine contents. Furthermore, phenylalanine decreased with increasing dosages of arabinose, xylose, and fructose. Glutamic acid content decreased significantly with fructose addition but showed insignificant changes with xylose. At the same dosage, the addition of pentoses resulted in the production of more sulphur-containing volatile compounds like methional, 2-[(methylthio) methyl] furan, and dimethyl disulphide than hexoses. Methional and furfural, which provide a roasted, savoury flavour, were produced by adding more xylose. Heat treatment with xylose also removed hexanal, the main off-odourant.

Campylobacter is one of the most common causes of foodborne gastroenteritis. The objective of this study was to estimate the prevalence and risk factors associated with Campylobacter jejuni and Campylobacter coli species in fresh chicken carcasses for human consumption from farmers\' markets and small food stores in seven localities of Bogotá, Colombia. Ninety-one samples of fresh chicken carcasses were collected from farmers\' markets and small food stores at seven localities in Bogotá. Samples were tested for Campylobacter using the real-time polymerase chain reaction (real time PCR) and isolation by plating. To analyze possible risk factors associated with Campylobacter spp. contamination in retail chicken carcasses, information was collected using a structured questionnaire and a univariate logistic regression analysis (α = 0.05) was used. Forty-two positive samples were obtained for Campylobacter spp., given a prevalence of 46.2%, of which 54.8% were to C. jejuni, 9.52% to C. coli and 35.7% to joint contaminations. C. jejuni was the most prevalent species. Risk factors found included poor cleanliness, in frequency of disinfection, type of establishment, and direct contact of chickens with other food. This study is the first report in the country on the prevalence and risk factors of Campylobacter in retail chicken.

Animal and poultry processing generates significant volumes of by-products that can be further processed for other uses. In this study, we treated minced chicken carcasses with proteases to produce protein hydrolysates that can be used as nutritional and/or flavor-enhancing ingredients. Five different microbial proteases were investigated for their abilities to hydrolyse the minced chicken carcass: Flavourzyme, Protamex, PB01, PB02, and PB03, with PB02 demonstrating the highest degree of hydrolysis (DH) of the minced chicken carcass (43.95%) after 4 h of hydrolysis. The essential hydrolytic parameters were optimized using response surface methodology in conjunction with Box-Behnken design. The optimal conditions were found to be: enzyme/substrate ratio of 3:100 (w/w), temperature of 51.20°C, pH of 6.62 ± 0.05, and substrate/water ratio of 1:1 (w/v) for 4-h hydrolysis, which resulted in a maximum DH of 45.44%. The protein recovery was 50.45 ± 2.05%, and the protein hydrolysate was high in free amino acids (7,757.31 mg/100 mL), of which essential and taste-active amino acids accounted for 41.74% and 92.64%, respectively. The hydrolysate was comprised mainly of low molecular weight peptides (1-5 kDa, 0.5-1 kDa, and <0.5 kDa), which were potential taste substances and flavor precursors. The resulting hydrolysate might be employed as a nutritive product, an ingredient for flavoring generation or a component of fermentation media.

Escherichia albertii is an emerging enteropathogen. Several foodborne outbreaks of E. albertii have been reported in Japan; however, foods associated with most outbreaks remain unidentified. Therefore, polymerase chain reaction (PCR) assays detecting E. albertii specifically and sensitively are required. Primers and probe for real-time PCR assays targeting E. albertii-specific gene (EA-rtPCR) was designed. With 74 strains, including 43 E. albertii strains and several of its close relatives, EA-rtPCR specifically amplified E. albertii; therefore, the sensitivity of EA-rtPCR was then evaluated. The detection limits were 2.8 and 2.0-3.2 log colony-forming unit (CFU)/mL for E. albertii culture and enriched chicken culture inoculated with the pathogen, respectively. In addition, E. albertii was detected from 25 g of chicken meat inoculated with 0.1 log CFU of the pathogen by EA-rtPCR. The detection of E. albertii from chicken meat by EA-rtPCR was also evaluated by comparing with the nested-PCR assay, and 28 retail chicken meat and 193 dissected body parts from 21 chicken carcass were tested. One and three chicken meat were positive in the nested-PCR assay and EA-rtPCR, respectively. Fourteen carcasses had at least one body part that was positive for EA-rtPCR, and 36 and 48 samples were positive for the nested-PCR assay and EA-rtPCR, respectively. A total of 37 strains of E. albertii were isolated from seven PCR-positive samples obtained from six chicken carcass. All E. albertii isolates harbored eae gene, and were classified as E. albertii O-genotype (EAOg)3 or EAOg4 by EAO-genotyping. The EA-rtPCR developed in this study has potential to improve E. albertii detection in food and advance research on E. albertii infection.

Campylobacter jejuni and Salmonella typhimurium are the leading causes of bacterial food contamination in chicken carcasses. Contamination is particularly associated with the slaughtering process. The present study isolated C. jejuni and S. typhimurim from fifty chicken carcass samples, all of which were acquired from different companies in Riyadh, Saudi Arabia. The identification of C. jejuni was performed phenotypically by using a hippurate test and genetically using a polymerase chain reaction with primers for 16S rRNA and hippurate hydrolase (hipO gene). For the dentification of S. typhimurim, a serological Widal test was carried out using serum anti-S. typhimurium antibodies. Strains were genetically detected using invA gene primers. The positive isolates for C. jejuni showed a specific molecular size of 1448 bp for 16S rRNA and 1148 bp for hipO genes. However, the positive isolates of the invA gene exhibited a specific molecular size at 244 bp using polymerase chain reaction (PCR). Comparing sequencing was performed with respect to the invA gene and the BLAST nucleotide isolates that were identified as Salmonella enterica subsp. enterica serovar typhimurium strain ST45, thereby producing a similarity of 100%. The testing identified C.jejuni for hippuricase, GenBank: Z36940.1. While many isolates of Salmonella spp. that contained the invA gene were not necessarily identified as S. typhimurim, the limiting factor for the Widal test used antiS. typhimurum antibodies. The multidrug resistance (MDR) of C. jejuni isolates in chickens was compared with the standard C. jejuni strain ATCC 22931. Similarly, S. typhimurium isolates were compared with the standard S. typhimurium strain ATCC 14028.

The currently most utilized antimicrobial agent in poultry processing facilities is peracetic acid, a chemical increasingly recognized as hazardous to human health. We evaluated the efficacy of mixtures of natural antimicrobial compounds, namely reuterin, microcin J25, and lactic acid, for reducing the viability of Salmonella enterica and total aerobes on broiler chicken carcasses. The compounds were compared singly and in combination with water and 0.1% peracetic acid. The minimum inhibitory concentrations of reuterin, lactic acid, and microcin J25 against S. enterica serovar Enteritidis were respectively 2 mM, 0.31%, and 0.03 μM. In vitro, the combinations of reuterin + lactic acid and reuterin + microcin J25 were synergic, making these compounds effective at four times lower concentrations than those used alone. Salmonella viable counts fell to zero within 10 min of contact with reuterin + lactic acid at 10 times the concentrations used in combination, compared to 18 h in the case of reuterin + microcin J25. Sprayed onto chilled chicken carcasses, this reuterin + lactic acid mixture reduced Salmonella spp. counts by 2.02 Log CFU/g, whereas reuterin + microcin J25 and peracetic acid reduced them by respectively 0.83 and 1.13 Log CFU/g. The synergy of reuterin with lactic acid or microcin J25 as inhibitors of bacterial growth was significant. Applied as post-chill spray, these mixtures could contribute to food safety by decreasing Salmonella counts on chicken carcasses.

Chicken meat is one of the most widely consumed meats worldwide. The microbiota on the whole body of chicken is a potential source of foodborne pathogens that can be transmitted to humans during the preparation of raw meat. However, to date, there have been no studies comparing the microbiota of packaged chicken products and those of raw chicken carcasses from butcher shops, although such information could be useful for identifying sources of contamination in cases of food poisoning. We addressed this in the present study by analyzing the microbiota of 80 chicken meat samples collected from various butcher shops and processing plants in South Korea with the Illumina MiSeq system based on the 16S rRNA gene sequence. The bacterial amounts in chicken samples were estimated by quantitative real-time PCR. Although different microbial members were present in unpackaged meat from butcher shops as compared to those in packaged products from commercial sources, seasonal differences (sample obtained in January vs. July) in microbiota were more significant even in the packaged products from the same company. We also investigated the influence of contaminated foodborne pathogen on the indigenous microbiota (64 chicken samples) by artificially inoculated with Salmonella enterica serotype Virchow on chicken carcasses under various conditions, and carrying out 16S rRNA gene and whole metagenome sequencing. The amount of contaminated Salmonella in chicken meat samples was the highest and lowest in samples stored at 27 °C and 4 °C after washing, respectively. Additionally, the relative abundance of virulence genes was detected lower in samples stored at 4 °C after washing in both butcher shop and commercial samples. These results could be useful for reducing the risk of foodborne illness caused by cross-contamination during the preparation of chicken meat.

Campylobacter jejuni and C. coli are the leading causes of enteric infections in many developed countries. Healthy chickens are considered to act as reservoirs of campylobacters, as the organisms colonize the intestinal tract. Once infected birds enter a processing plant, contamination of chicken carcasses with campylobacters occurs over the entire skin during defeathering and evisceration due to leakage of crop and/or intestinal contents. Although the role of feather follicles in the contamination of chicken carcasses by campylobacters during processing is still debatable, it has been considered that the microorganisms would be entrapped and retained in the follicles due to the morphological changes resulting from defeathering and chilling. In the present study, we observed the morphology of feather follicles in chicken carcasses after defeathering and chilling. A total of 3,133 feather follicles were examined for morphological changes before and after chilling. Shortly after defeathering, most (91.5%) of the follicles were closed, whereas after chilling they were either closed (85.5%) or open (6%), although a small proportion of enlarged follicles became smaller or closed (2.6%). Moreover, 5.9% of the follicles that were slightly open became further enlarged after chilling. Furthermore, the proportion of enlarged feather follicles that became closed after chilling showed no discernible relationship with the degree of campylobacter contamination in different areas of the carcass skin, suggesting that campylobacters may not be confined to feather follicles as a result of the morphological changes attributable to defeathering and chilling.

OBJECTIVE: The objective of this study was to genetically characterize the antimicrobial resistance mechanisms of Salmonella enterica serotype Indiana C629 isolated from a chicken carcass in China in 2014.
METHODS: Antimicrobial susceptibility against a panel of 23 antimicrobial agents was carried out on Salmonella enterica serotype Indiana C629 and assessed according to CLSI standards. Whole-genome sequencing of this isolate was conducted to obtain the complete genome of S. Indiana.
RESULTS: Salmonella Indiana C629 expressed an XDR phenotype being resistant to more than 20 antimicrobial agents, including imipenem and meropenem. From the analysis of the resistance mechanisms, two mutations were identified in subunit A of DNA gyrase within the quinolone resistance determining region, in addition to the acquisition of mobile efflux pumps encoding oqxA/B/R. Additionally, four beta-lactamases resistance genes (blaCTX-M-65, blaTEM-1, blaOXA-1, and blaNDM-1), five aminoglycosides resistance genes (aac(3)-IV, aac(6\')-Ib-cr, aadA2, aadA5, and aph(4)-Ia), two phenicol resistance genes (catB3 and floR), and five trimethoprim/sulfamethoxazole resistance genes (sul1/2/3 and dfrA12/17) were also identified. A total of 191 virulence genes were identified. Among them, 57 belonged to type-three secretion system (T3SS) encoding genes, 55 belonged to fimbrial adherence encoding genes, and 39 belonged to flagella-encoding genes CONCLUSIONS: This study demonstrated that multi-resistance mechanisms consistent with an XDR-phenotype, along with various virulence encoding genes of a S. Indiana strain in China These findings highlight the importance of cooperation among different sectors in order to monitor the spread of resistant pathogens among food animal, foods of animal origin and human beings that might further take measures to protect consumers\' health.

The bla NDM-1 gene in Salmonella species is mostly reported in clinical cases, but is rarely isolated from red and white meat in China.
A Salmonella Indiana (S. Indiana) isolate was cultured from a chicken carcass procured from a slaughterhouse in China. Antimicrobial susceptibility was tested against a panel of agents. Whole-genome sequencing of the isolate was carried out and data was analyzed.
A large plasmid, denoted as plasmid pC629 (210,106 bp), containing a composite cassette, consisting of IS26-bla NDM-1-ble MBL -△trpF-tat-cutA-ISCR1-sul1-qacE△1-aadA2-dfrA12-intI1-IS26 was identified. The latter locus was physically linked with bla OXA-1, bla CTX-M-65, bla TEM-1-encoding genes. A mercury resistance operon merACDEPTR was also identified; it was flanked on the proximal side, among IS26 element and the distally located on the bla NDM-1 gene. Plasmid pC629 also contained 21 other antimicrobial resistance-encoding genes, such as aac(6\')-Ib-cr, aac(3)-VI, aadA5, aph(4)-Ia, arr-3, blmS, brp, catB3, dfrA17, floR, fosA, mph(A), mphR, mrx, nimC/nimA, oqxA, oqxB, oqxR, rmtB, sul1, sul2. Two virulence genes were also identified on plasmid pC629.
To the best of our knowledge, this is the first report of bla NDM-1 gene being identified from a plasmid in a S. Indiana isolate cultured from chicken carcass in China.