Retail Raw Chicken Research Articles

Prevalence of Colistin Resistance in Escherichia coli in Eastern Turkey and Genomic Characterization of an mcr-1 Positive Strain from Retail Chicken Meat.

Colistin is one of the most effective antibiotics against multidrug resistant Gram-negative bacteria. However, the recent emergence of plasmid-borne mobilized colistin resistance (mcr) genes is considered a serious antimicrobial resistance challenge worldwide. In this study, we report detection of an mcr-1 carrying Escherichia coli isolate (named ATAVET mcr-1 Turkey) from retail raw chicken meat in Turkey. Of the 11 (from 500 total tested) phenotypically colistin-resistant isolates, 1 was shown to carry the mcr-1 gene by PCR. Whole-genome sequencing indicated that mcr-1 was located on a ∼13 kb-long contig that was almost identical to the corresponding part in pZJ1635, an IncI2 plasmid encoding mcr-1 in the same genetic context in another E. coli strain. In addition, ATAVET mcr-1 Turkey harbored blaCTX-M-8, qnrB19, mdf(A), tet(A), sul2, aph(3″)-Ib, aph(6)-Id, and floR resistance genes. Phylogenetic analysis based on whole genome and multilocus sequence typing indicated that ATAVET mcr-1 Turkey was more closely related to mcr-1 carrying E. coli isolates from food and human clinical samples previously reported from different parts of the world than to those from Turkey. These findings further emphasize the worldwide emergence and spread of mcr meditated colistin resistance in bacteria with zoonotic potential within animals and the food chain.

Comparative Analysis of Aerotolerance, Antibiotic Resistance, and Virulence Gene Prevalence in Campylobacter jejuni Isolates from Retail Raw Chicken and Duck Meat in South Korea.

Human infections with Campylobacter are primarily associated with the consumption of contaminated poultry meat. In this study, we isolated Campylobacter jejuni from retail raw chicken and duck meat in Korea and compared their aerotolerance, antibiotic resistance, and virulence gene prevalence. Whereas C. jejuni isolates from chicken dominantly belonged to multilocus sequence typing (MLST) clonal complex (CC)-21, CC-45 is the common MLST sequence type in duck meat isolates. C. jejuni strains from both chicken and duck meat were highly tolerant to aerobic stress. The prevalence of virulence genes was higher in C. jejuni strains from chicken than those from duck meat. However, antibiotic resistance was higher in duck meat isolates than chicken isolates. Based on the prevalence of virulence genes and antibiotic resistance, fluoroquinolone-resistant C. jejuni strains harboring all tested virulence genes except virB11 were predominant on retail poultry. Fluoroquinolone-resistant C. jejuni strains carrying most virulence genes were more frequently isolated in summer than in winter. The comparative profiling analysis in this study successfully demonstrated that antibiotic-resistant and pathogenic strains of C. jejuni are highly prevalent on retail poultry and that retail duck meat is an important vehicle potentially transmitting C. jejuni to humans in Korea.

Characterization of mcr-1-Harboring Plasmids from Pan Drug-Resistant Escherichia coli Strains Isolated from Retail Raw Chicken in South Korea.

A number of studies from different countries have characterized mcr-1-harboring plasmids isolated from food; however, nothing has been reported about it in South Korea. In this study, we report the characterization of mcr-1 plasmids from pan drug-resistant (PDR) Escherichia coli strains isolated from retail food in the country. Colistin-resistant E. coli strains were isolated from retail raw chicken, and PCR was carried out to detect the mcr-1 gene. Whole genome sequencing of the mcr-1-positive strains was performed for further characterization. The results of whole genome sequencing revealed that all mcr-1 plasmids belonged to the IncI2 type. In addition to the mcr-1 plasmids, all of the isolates also carried additional plasmids possessing multiple antibiotic resistance genes, and the PDR was mediated by resistant plasmids except for fluoroquinolone resistance resulting from mutations in gyrA and parC. Interestingly, the mcr-1 plasmids were transferred by conjugation to other pathogenic strains including enterohemorrhagic E. coli (EHEC), enterotoxigenic E. coli (ETEC), enteroaggregative E. coli (EAEC), Salmonella, and Klebsiella at the frequencies of 10−3−10−6, 10−2−10−5, 10−4−10−5, 10−4−10−6, and 10−5−10−6, respectively. The results showed that mcr-1 plasmids can be easily transmitted to pathogenic bacteria by conjugation.

Tolerance to stress conditions associated with food safety in Campylobacter jejuni strains isolated from retail raw chicken

Campylobacter jejuni is a microaerophilic foodborne pathogen that is sensitive to stress conditions. However, it is not yet understood how this stress-sensitive pathogen may cause a significant number of cases of human gastroenteritis worldwide. In this study, we examined stress tolerance in 70 C. jejuni strains isolated from retail chicken under several stress conditions related to food safety. Compared to oxygen-sensitive (OS) strains of C. jejuni, C. jejuni strains with increased aerotolerance, such as hyper-aerotolerant (HAT) and aerotolerant (AT) strains, were more tolerant to peracetic acid, refrigeration and freeze-thaw stresses. However, the levels of thermotolerance and hyper-osmotolerance were not associated with the aerotolerance level of C. jejuni. The HAT and AT strains of C. jejuni exhibited significantly increased activities of catalase and superoxide dismutase (SOD), compared to the OS strains. Consistently, the HAT and AT strains were highly tolerant to oxidants, such as hydrogen peroxide, cumene hydroperoxide and menadione, compared to the OS strains. The AT and HAT strains that were tolerant to stresses, particularly peracetic acid and refrigeration, predominantly belonged to multilocus sequence typing (MLST) clonal complex (CC)-21. This study shows that oxidative stress resistance plays a role in determining the differential level of aerotolerance in C. jejuni and that AT and HAT strains of C. jejuni are more tolerant to oxidants and low temperatures than OS strains.

APPLICATION OF SALMONELLA PHAGE COCKTAIL TO CONTROL SALMONELLA TYPHIMURIUM IN VITRO

Members of the genus Salmonella are among the microbial pathogens associated with dangerous infection. The increased of Salmonella spp. antibiotic resistance has propelled the need of alternate therapeutic methods or strategies. Bacteriophage forms one of these alternate strategies. Six lytic bacteriophages infecting Salmonella Typhimurium were isolated from sewage drain water. Phages were purified biologically by single plaque assay and concentrated using the ultracentrifugation. The phage isolates were named O SM, O SF, O SG, O SP, O SA and O SD. Morphological characters of Salmonella phages showed that all the phage isolates belong to family Myoviridae. All phage isolates were highly stable at room temperature, storage at refrigerator temperature and had thermal inactivation point ranged from 90 to 98 °C. Phages were stable at pH conditions ranging from pH 4 to 12. Phages did not lose their infectivity after exposure to UV for 90 min. at 35 cm and 53 cm distance. The host range of the isolated phages was found that the phages had narrow host range. Phage cocktail with different MOI was used to control Salmonella Typhimurium in vitro. Data revealed that addition of phage cocktail at MOI 10 reduced the Salmonella cells with rate 98.2 % after 4 hrs. from addition. introduction Salmonella spp. belong to family Enterobacteriaceae and widely distributed in nature and often found in the intestinal tract of warm-blooded animals and humans,where they asymptomatically colonize and multiply (Newell & Fearnley, 2003 and Doyle & Erickson, 2006). More than 2,500 serotypes of Salmonella exist and the most prevalent and important Salmonella enterica serotypes reported worldwide are Enteritidis and Typhimurium. These are responsible for 99 % of Salmonellosis in humans and warm-blooded animals. The most common symptoms of Salmonella infection is non-bloody diarrhea and abdominal cramps (Bell and Kyriakides, 2002). Due to foodborne infections by Salmonella are obtained through ingesting contaminated food or water, (Abd El-Aziz, 2013 ) detected high incidence of Salmonella Typhimurium , one of the most frequently isolated serovars from food borne outbreaks throughout the world, in retail raw chicken meat and giblets in Egypt. Bacteriophages are considered an effective weapon against pathogenic bacteria. As a result of development resistant bacteria against antibiotics because of their repeated usage, bacteriophages are used as a safe alternative to control pathogenic bacteria (Abramia et al 2016). In addition, offer a great advantage over antibiotics. First, bacteriophages are specific and target only the pathogens of interest, so the normal gut microflora are not affected. Second, bacteriophages are self-replicating in the bacterial host and lyse bacteria. (Connerton and Connerton, 2005). This paper aims to investigate the incidence of lytic bacteriophages specific for Salmonella in sewage water and study the posibility of their application for controling the Salmonella in vitro.

High prevalence of blaCTX-M-14 among genetically diverse Escherichia coli recovered from retail raw chicken meat portions in Japan

Global widespread of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, especially Escherichia coli poses a greater threat in healthcare and community settings of humans. Raw meats from food animals colonized with ESBL producers may be one of important transmission routes for those bacteria in the community. This study investigated the presence of ESBL-producing E. coli in retail raw chicken and pork meats in Japan. ESBL producers were detected from the 59 of 150 (39.3%) chicken samples, but none were from all the 50 pork samples tested. The blaCTX-M-14 (17; 24.3%) was most frequently identified, followed by blaCTX-M-2 (16; 22.9%), blaSHV-12 (11; 15.7%), and blaCTX-M-55 (10; 14.3%) among a total of 70 ESBL-producing E. coli isolates from 59 chicken samples. The isolates with blaCTX-M-14 were often combined with phylogroup B1 (9/17) mainly composed of ST162 (7/9), and phylogroup F (5/17) with diverse STs. The blaCTX-M-14 was basically associated with the common elements ISEcp1 and ΔIS903 or IS903 in all 17 isolates. In 6 isolates, comprising 5 phylogroup B1-ST162 and a nontypeable-ST162 isolates, an IS26-truncated ISEcp1 was identified upstream of the blaCTX-M-14, and a fosA3 was further located downstream of ΔIS903. Furthermore, some mobile genetic elements mediating blaCTX-M-14 unique to raw chicken meat portions were identified. The blaCTX-M-2 gene was preceded by ISEcp1 or ISCR1 in 16 isolates, whereas the presence of Δorf3 downstream of blaCTX-M-2 was limited only in 6 isolates from Brazilian samples though they exhibited diverse phylogroups and STs. The blaCTX-M-55 and blaCTX-M-1 shared classical flanking structures, ISEcp1-blaCTX-M-orf477, although the length of spacer sequences between ISEcp1 and the start codon of blaCTX-M was 45 bp and 80 bp for blaCTX-M-55 and blaCTX-M-1, respectively. Among blaSHV-12-harboring isolates, ST38 was frequently detected (6/11) though their phylogroup distribution varied.In conclusion, besides transmission of bla gene-harboring E. coli lineages which have adaptability to both human and chicken, spread of mobile genetic elements associated with bla genes from E. coli lineages adapted to chicken to those adapted to human is highly suggested. Our results provide important information to gain a better understanding of the transmission risk of bla genes from retail chicken meats to human.

Characterization of Toxin Genes and Antimicrobial Susceptibility of Staphylococcus aureus from Retail Raw Chicken Meat

The aim of this study was to investigate the toxin gene profile and antimicrobial resistance of Staphylococcus aureus isolates from raw chicken in the People's Republic of China. In total, 289 S. aureus isolates were characterized by antimicrobial susceptibility testing, and genes encoding enterotoxins, exfoliative toxins, Panton-Valentine leukocidin, and toxic shock syndrome toxin were revealed by PCR. Overall, 46.0% of the isolates were positive for one or more toxin genes. A high proportion of toxin genes were pvl (26.6%), followed by sej (12.5%), sea (9.0%), seh (8.3%), seb (6.9%), sec (6.9%), sed (4.8%), sei (3.1%), and see (2.4%). None of the isolates harbored seg, tsst-1, or exfoliative toxin genes. In total, 29 toxin gene profiles were obtained, and pvl (10.7%) was the most frequent genotype, followed by sea (5.9%), seb (4.8%), and sej (4.2%). Furthermore, 99.7% of the strains were resistant to at least one of the tested antimicrobial agents, and 87.2% of them displayed multidrug resistance. Resistance was most frequently observed to trimethoprim-sulfamethoxazole and erythromycin (86.2% for each), followed by tetracycline (69.9%), amoxicillin-clavulanic acid (45.0%), and ampicillin (42.6%). None of the strains were resistant to vancomycin. This study indicates that S. aureus isolates from raw chicken harbored multiple toxin genes and exhibited multiple antimicrobial resistance, which represents a potential health hazard for consumers.

Prevalence of Virulence Genes in Extended-Spectrum β-lactamases (ESBLs)-Producing Salmonella in Retail Raw Chicken in China.

Extended-spectrum β-lactamases (ESBLs)-producing Salmonella is a tremendous hazard to food safety and public health. The objective of this study was to determine the prevalence of 30 virulence genes (avrA, sipA, sseC, marT, rhuM, siiE, pipA, pipD, envR, gogB, gtgA, sodC1, sseI, irsA, sopE2, spvC, rck, spvR, fhuA, msgA, pagK, srfj, stkc, fimA, lpfD, pefA, stcC, steB, stjB, and tcfA) in 156 ESBLs-producing Salmonella isolates that belonged to 21 serotypes. These isolates were recovered from retail raw chicken samples collected from 5 provinces and 2 national cities in China between 2007 and 2012. The results indicated that 154 (98.7%) ESBLs-producing Salmonella isolates carried at least 1 virulence gene, 138 (88.5%) simultaneously carried at least 5 virulence genes, 107 (68.6%) carried 10 or more, and 20 (12.8%) carried 15 or more virulence genes. The most frequently detected virulence genes were marT (n = 127, 81.4%), siiE (n = 126, 80.8%), msgA (n = 121, 77.6%), and sipA (n = 121, 77.6%). Significant difference was identified between detection percentages of virulence genes of rhuM, pipD, envR, sopE2, pagK, lpfD, steB, and stjB in S. Indiana, S. Thompson, S. Enteritidis, S. Typhimurium, S. Shubra, S. Edinburg, and S. Agona isolates. Distribution of virulence genes were significantly influenced by sampling districts (P<0.01), especially for sodC1 and pipD, and then were msgA and sopE2. The heatmap showed the frequencies of virulence genes in ESBLs-producing isolates from retail chickens in southern, central, and northern regions of China were completely different from each other. Based on our findings, ESBLs-producing Salmonella of retail chicken origin were common carriers of multiple virulence genes and were regionally distributed.

Prevalence and Antibiotic Resistance of Non-typhoidal Salmonella Isolated from Raw Chicken Carcasses of Commercial Broilers and Spent Hens in Tai'an, China.

The present study was aimed to determine the prevalence and characteristics of Salmonella isolated from meat samples of commercial broilers (CB) and spent hens (SH). Between March and June 2016, 200 retail raw chicken carcasses (100 from CB and 100 from SH) were obtained from local supermarkets in Tai’an city of China, and Salmonella isolates were then analyzed for antibiotic resistance, serotype, β-lactamase genes, and the presence of class 1 integron. Forty Salmonella strains were obtained in this study (CB: 21/100, 21%; SH: 19/100, 19%). Three serotypes were identified in 40 Salmonella, and S. Enteritidis (CB: 15/21, 71.4%; SH: 10/19, 52.6%) was the dominant serotype, followed by S. Typhimurium (CB: 4/21, 19%; SH: 6/19, 31.6%) and S. Derby (CB: 2/21, 9.5%; SH: 3/19, 15.8%). Among 21 Salmonella isolated from CB, high antibiotic resistance rates were found for ampicillin (20/21, 95.2%), nalidixic acid (18/21, 85.7%), cefotaxime (17/21, 81%), and tetracycline (13/21, 61.9%); class 1 integron was observed in seven isolates (7/21, 33.3%), and gene cassettes included an empty integron (0.15 kb, n = 1), aadA2 (1.2 kb, n = 3), drfA1-aadA1 (1.4 kb, n = 1), and drfA17-aadA5 (1.7 kb, n = 2); blaTEM-1 was the dominant β-lactamase gene (21/21, 100%), followed by blaCTX-M-55 (7/21, 33.3%). Among 19 Salmonella isolated from SH, high antibiotic resistance rates were found for nalidixic acid (19/19, 100%), tetracycline (19/19, 100%), ampicillin (18/19, 94.7%), and ciprofloxacin (13/19, 68.4%); class 1 integron was observed in two isolates (2/19, 10.5%), and gene cassettes included drfA17-aadA5 (1.7 kb, n = 1) and drfA1-aadA1 (1.4 kb, n = 1); blaTEM-1 was the dominant β-lactamase gene (19/19, 100%), followed by blaCTX-M-55 (2/19, 10.5%) and blaCMY-2 (1/19, 5.3%). Collectively, antibiotic-resistant Salmonella can be widely detected in retail raw chicken carcasses of CB and SH, and therefore can pose a serious risk to public health.

Phenotypic and molecular detection of multi-drug resistant Salmonella Enteritidis, Salmonella Typhimurium and Salmonella species in retail raw beef and chicken

Phenotypic and molecular detection of multi-drug resistant Salmonella Enteritidis, Salmonella Typhimurium and Salmonella species in retail raw beef and chicken

Microbiological Qualityassessment and Detection of Fecal Escherichia Coli (Coliform) in Foods of Animal Origin Sold in The Open Markets of Kolkata City in India

The present investigation was undertaken to estimate the microbiological quality of marketed foods of animal origin in the city of Kolkata. A total 300 various categories of food samples comprising of retail raw beef (n=75), goat meat (n=75), chicken (n=75) and unpasteurized poultry eggs (n=75) were collected from different open domestic market of Kolkata. The aerobic bacterial contamination load were estimated in retail raw beef ranging from 1.2x105 to 4.1x107 cfu/g, goat meat 2.9x105 to 5.3x106 cfu/g, chicken 3.3x104 to 5x106 cfu/g and unpasteurized eggs <1 to 2.1x107 cfu/ml. The fecal Escherichia coli (Coliform) was detected in 41 of 75(54.66%) raw beef, 47 of 75 (62.66%) goat meat, 53 of 75(70.66%) chicken and 3 of 75(04.00%) unpasteurized poultry eggs. These findings indicate substantial presence of microbial contaminants in foods of animal origin in open markets of Kolkata, where dearth of proper sanitation in the market places prevails.

Prevalence of the Antibiotic Resistance Genes in Coagulase-Positive-and Negative-Staphylococcus in Chicken Meat Retailed to Consumers.

The use of antibiotics in farm management (growing crops and raising animals) has become a major area of concern. Its implications is the consequent emergence of antibiotic resistant bacteria (ARB) and accordingly their access into the human food chain with passage of antibiotic resistance genes (ARG) to the normal human intestinal microbiota and hence to other pathogenic bacteria causative human disease. Therefore, we pursued in this study to unravel the frequency and the quinolone resistance determining region, mecA and cfr genes of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), methicillin-resistant coagulase-negative staphylococci (MRCNS) and methicillin-susceptible coagulase-negative staphylococci (MSCNS) isolated from the retail trade of ready-to-eat raw chicken meat samples collected during 1 year and sold across the Great Cairo area. The 50 Staphylococcus isolated from retail raw chicken meat were analyzed for their antibiotic resistance phenotypic profile on 12 antibiotics (penicillin, oxacillin, methicillin, ampicillin-sulbactam, erythromycin, tetracycline, clindamycin, gentamicin, ciprofloxacin, chloramphenicol, sulfamethoxazole-trimethoprim, and vancomycin) and their endorsement of the quinolone resistance determining region, mecA and cfr genes. The isolation results revealed 50 isolates, CPS (14) and CNS (36), representing ten species (S. aureus, S. hyicus, S. epidermedius, S. lugdunensis, S. haemolyticus, S. hominus, S. schleiferi, S. cohnii, S. intermedius, and S. lentus). Twenty seven isolates were methicillin-resistant. Out of the characterized 50 staphylococcal isolates, three were MRSA but only 2/3 carried the mecA gene. The ARG that bestows resistance to quinolones, β-lactams, macrolides, lincosamides, and streptogramin B [MLS(B)] in MRSA and MR-CNS were perceived. According to the available literature, the present investigation was a unique endeavor into the identification of the quinolone-resistance-determining-regions, the identification of MRSA and MR-CNS from retail chicken meat in Egypt. In addition, these isolates might indicate the promulgation of methicillin, oxacillin and vancomycin resistance in the community and imply food safety hazards.

Antimicrobial susceptibility, virulence gene and pulsed-field gel electrophoresis profiles of Salmonella enterica serovar Typhimurium recovered from retail raw chickens, China

A total of 138 Salmonella enterica serovar Typhimurium isolates recovered from retail raw chickens in seven provinces of China from 2007 to 2012 were characterized for antimicrobial susceptibility, genotype and presence of virulence genes. Resistance was most frequently detected to sulfisoxazole (90.6%), tetracycline (73.2%), nalidixic acid (65.9%), ceftiofur (59.4%), ampicillin (54.3%) and kanamycin (34.8%). Resistance to cefoxitin (6.5%), amikacin (5.8%) and ceftriaxone (3.6%) was less frequently detected. One hundred and thirty seven (99.3%) isolates were resistant to at least one antibiotic, and 82 (59.4%) to more than five antibiotics. Pulsed-field gel electrophoresis (PFGE) subtyping generated 66 PFGE patterns and 12 clusters. Isolates with similar PFGE patterns in the same cluster were all resistant to similar categories and numbers of antibiotics and harbored similar virulence genes. Among 30 virulence genes we screened for, the top five genes were pagK (82.6%), sodC1 (66.7%), siiE (58.7%), pefA (58.7%) and marT (50.7%). All isolates were identified harboring at least one virulence gene, 80 (58.0%) and 16 (11.6%) were simultaneously positive for at least nine and seventeen virulence genes, respectively. Twenty four (17.4%) isolates harbored at least ten virulence genes and exhibited resistance to at least ten antibiotics. Our results revealed that S. Typhimurium isolates in retail raw chickens were not only genotype multiform, but majority of them were multidrug resistant and co-carried multiple virulence genes, which may pose great potential hazard to public health.

Antibiotic Susceptibility and Molecular Screening of Class I Integron in Salmonella Isolates Recovered from Retail Raw Chicken Carcasses in China.

Salmonella is one of the leading causes for foodborne diseases. Foods, particularly those of animal origin, act as an important role for Salmonella transmission. In this study, the antibiotic susceptibility of 743 Salmonella isolates recovered from retail raw chicken carcasses in eight provinces was tested, and the isolates were also screened for the presence of class I integron and drug-resistant gene cassettes. One hundred thirteen (15.21%) isolates were harboring class I integron. A higher percentage of integron-positive Salmonella isolates were found in retail chicken in Sichuan Province (29.33%), followed by Beijing (22.14%), Shaanxi (19.15%), Guangxi (14.13%), Henan (12.50%), Shanghai (7.25%), Fujian (8.22%), and Guangdong (6.25%) Provinces. The respective prevalence of class I integron in Salmonella isolates recovered from retail chickens in large, free, and small markets was 16.31%, 14.04%, and 15.27%. Moreover, 20.13%, 14.02%, and 13.74% of Salmonella isolates recovered from retail chickens stored in frozen, chilled, and ambient conditions, respectively, were positive for class I integron. Subsequent sequencing of class I integron revealed the presence of 10 gene cassettes harboring resistance genes (dfrA17-aadA5, dfrA17-aadA5, dfrA1-aadA1, dfrA12-aadA2, dfrA17-aadA5-aadA4, dfrA1-aadA1-aadA2, dfrA1, dfrA5, aadA2, aacA4-catB8-aadA1-dfrA1-(aac6-II)-(blaCARB-8), blaPSE-1-blaP1). The most prevalent gene cassette was dfrA17-aadA5 (59.62%). Class I integron-positive isolates were significantly more resistant to multiple antibiotics, and they commonly exhibited corresponding antibiotic resistance profiles to the antibiotic resistance gene cassettes harbored in their class I integron. The results indicated that class I integron with different antibiotic resistance gene cassettes that were prevalent in Salmonella isolates differed from provinces, marketplaces, and chicken storage conditions.

Prevalence and Characterization of Antibiotic Resistance Food Borne Pathogens Isolated from Locally Produced Chicken Raw Meat and their Handlers

The present study was undertaken to determine the prevalence and the potential public health significance of Salmonella (S.)serovars, Escherichia coli (E.coli), and Staphylococcus aureus (S. aureus) in raw chicken meat which is available in domestic retail shops as well as their handlers in Mansoura City, Dakahlia Governorate, Egypt. Samples of retail raw chicken meat (n = 200) as well as equal sized samples of hand swabs and stool specimens (n = 50) from retail handlers were bacteriologically tested E.coli, Staph. aureus and Salmonellaspp., wererecovered from the raw chicken meat at the following percentages: (35, 22 and 5%, respectively) using conventional biochemical identification methods. Serotyping of the obtained Salmonella spp., revealed that Salmonella Kentuckypresented at the highest rate of isolation followedby Salmonella Enteritidis, Salmonella Infantis and Salmonella Typhimurium.High frequency of S. aureus were found to colonize the skin (40%) and the stool specimens (30%) of chicken meat handlers; whereas four out of 50 stool samples (8%) and one out of 50 hand swabs (2%) from handlers were found to be contaminated with Salmonella spp.E.coli was also detected in 40% of the stool samples and in 24% of handlers hand swabs. Serological identification of E. coli isolates revealed the presence of E. coli(O26: H11, O103:H2, O128:H2, O111:H2 andO78) in the examined raw meat, O26: H11, O2:H4 and O128:H2 in stool samples and O26: H11,O103:H2 and O125:H21 in hand swabs.All recovered isolates showed various degree of antibiotic resistance. It becomes apparent that retail chicken raw meat sold at the respective shops at Mansoura city is highly contaminated with food-borne pathogens which is considered a potential vehicle for transmitting food-borne diseases. Hence there is an urgent need for increased implementation of consumer food safety education efforts.

High Prevalence of Hyper-Aerotolerant Campylobacter jejuni in Retail Poultry with Potential Implication in Human Infection.

Campylobacter jejuni is a leading cause of foodborne illnesses around the world. Since C. jejuni is microaerophilic and sensitive to oxygen, aerotolerance is important in the transmission of C. jejuni to humans via foods under aerobic conditions. In this study, 70 C. jejuni strains were isolated from retail raw chicken meats and were subject to multilocus sequence typing (MLST) analysis. In the aerotolerance testing by aerobic shaking at 200 rpm, 50 (71.4%) isolates survived after 12 h (i.e., aerotolerant), whereas 20 (28.6%) isolates did not (i.e., aerosensitive). Interestingly, further aerobic cultivation showed that 25 (35.7%) isolates still survived even after 24 h of vigorous aerobic shaking (i.e., hyper-aerotolerant). Compared to aerosensitive strains, the hyper-aerotolerant strains exhibited increased resistance to oxidative stress, both peroxide and superoxide. A mutation of ahpC in hyper-aerotolerant strains significantly impaired aerotolerance, indicating oxidative stress defense plays an important role in hyper-aerotolerance. The aerotolerant and hyper-aerotolerant strains were primarily classified into MLST clonal complexes (CCs)-21 and -45, which are known to be the major CCs implicated in human gastroenteritis. Compared to the aerosensitive strains, CC-21 was more dominant than CC-45 in aerotolerant and hyper-aerotolerant strains. The findings in this study revealed that hyper-aerotolerant C. jejuni is highly prevalent in raw chicken meats. The enhanced aerotolerance in C. jejuni would impact human infection by increasing possibilities of the foodborne transmission of C. jejuni under aerobic conditions.

Salmonella on Raw Poultry in Retail Markets in Guatemala: Levels, Antibiotic Susceptibility, and Serovar Distribution

The objective of this study was to determine Salmonella numbers on retail raw chicken carcasses in Guatemala and to phenotypically characterize the isolates (serotyping and antibiotic susceptibility). In total, 300 chicken carcasses were collected from seven departments in Guatemala. Salmonella numbers were determined using the most-probable-number method following the U.S. Department of Agriculture’s Food Safety and Inspection Service protocol. In total, 103 isolates were obtained, all of which were tested for antibiotic susceptibility, whereas 46 isolates were serotyped. Overall, Salmonella prevalence and mean number (mean log most probable number per carcass) was 34.3% and 2.3 (95% confidence interval: 2.1 to 2.5), respectively. Significant differences (P < 0.05) in Salmonella prevalence were found by storage condition (refrigerated or ambient temperature), market type (wet markets, supermarkets, and independent poultry stores), chicken production system (integrated or nonintegrated production company), and chicken skin color (white or yellow). Chickens produced by integrated companies had lower Salmonella numbers (P < 0.05) than nonintegrated companies, and white-skin carcasses had lower numbers (P < 0.05) than yellow-skin carcasses. Among 13 different Salmonella serovars identified, Paratyphi B (34.8%) was most prevalent, followed by Heidelberg (16.3%) and Derby (11.6%). Of all the Salmonella isolates, 59.2% were resistant to one to three antibiotics and 13.6% to four or more antibiotics. Among all the serovars obtained, Salmonella Paratyphi B and Heidelberg were the most resistant to the antibiotics tested. Salmonella levels and antibiotic resistant profiles among isolates from raw poultry at the retail market level were high relative to other reports from North and South America. These data can be used by Guatemalan stakeholders to develop risk assessment models and support further research opportunities to control transmission of Salmonella spp. and antibiotic-resistant isolates from chicken meat to humans.

Virulence characteristics of hcp (+) Campylobacter jejuni and Campylobacter coli isolates from retail chicken.

BackgroundRecently the Type VI secretion system (T6SS), which can play a significant role in bacterial survival and pathogenesis, was reported in Campylobacter spp., having the hcp gene as a key component.MethodsCampylobacteriosis is associated with the consumption of infected chicken meat. Our study aimed to explore the presence of T6SS in C. jejuni (n = 59) and C. coli (n = 57) isolates, from retail raw chicken and to investigate their pathogenic potential. The hcp gene was used as an indicator for the T6SS presence.ResultsUsing multiplex PCR we have identified a significantly higher prevalence of hcp in C. coli isolates (56.1%) than in C. jejuni (28.8%) and AFLP analysis of the isolates showed a high degree of genetic similarity between the isolates carrying the hcp gene. Genome sequencing data showed that 84.3% of the C. coli and 93.7% of the C. jejuni isolates had all 13 T6SS open reading frames. Moreover, the virulence characteristics of hcp + isolates, including motility and the ability to invade human intestinal epithelial cells in vitro, were significantly greater than in the control strain C. jejuni 12502; a human isolate which is hcp positive.ConclusionOverall, it was discovered that hcp+C. coli and C. jejuni isolated from retail chicken isolates posses genetic and phenotypic properties associated with enhanced virulence. However, since human infections with C. coli are significantly less frequent than those of C. jejuni, the relationship between virulence factors and pathogenesis requires further study.

Quantitative surveys of Salmonella and Campylobacter on retail raw chicken in Yangzhou, China

To assess the risks to consumers from Salmonella and Campylobacter in whole raw chickens sold in Yangzhou City, 12-month quantitative surveys were performed in succession. In this study, 480 samples were collected from supermarkets and wet markets from 2011 to 2013. The examination method of Salmonella was optimized from the most probable number (MPN), and the level of Campylobacter contamination was tested using the direct plating method. These results showed that the positive rates of Salmonella and Campylobacter were 33.8% and 51.3%, respectively, and the corresponding mean values of enumeration were 0.524 MPN/g and 1473.49 colony-forming units/g. For prevalence and loads of Salmonella, there was no significant difference between supermarkets and wet markets. However, for Campylobacter, the contamination level of wet markets was greater compared to supermarkets. Seasonality was observed in both qualitative and quantitative studies for both pathogens, with summer being the high-incidence season. Diversity among Salmonella isolates was high in terms of serovar, and the dominant serotypes were Salmonella Typhimurium (34.6%) and Salmonella Enteritidis (16.7%). Diversity of Campylobacter isolates demonstrated that Campylobacter jejuni (45.5%) and Campylobacter coli (30.9%) were the most common species, except for the mixed contamination. Survey results indicated that there was a need for more interventions to minimize the exposure of consumers to Salmonella and Campylobacter.

Emergence of β-lactamases and extended-spectrum β-lactamases (ESBLs) producing Salmonella in retail raw chicken in China.

β-Lactamases and extended-spectrum β-lactamases (ESBLs) producing pathogenic bacteria were widely studied previously in China, but were seldom focused on foodborne Salmonella. In this study, an investigation concerning β-lactamases and ESBLs producing Salmonella recovered from retail raw chickens was performed. Sixty of 699 foodborne Salmonella isolates were detected as β-lactamases and ESBLs-producing ones that covered 12 Salmonella serotypes and exhibited different pulsed-field gel electrophoresis genotypes. Forty-four of 60 β-lactamases and ESBLs-producing strains were simultaneously resistant to ampicillin, amoxicillin/clavulanic acid, ceftiofur, ceftriaxone, and cefoxitin. The most commonly detected β-lactamases and ESBLs-encoding gene was bla(TEM-1) (n = 44), followed by bla(OXA-1) (n = 38), bla(CMY-2) (n = 29), bla(PSE-1-like) (n = 1), bla(CTX-M-3) (n = 16), and bla(CTX-M-15) (n = 1), respectively. Fourteen, 24, 21, and 1 isolates were detected simultaneously positive for 1, 2, 3, and 4 of the detected β-lactamases and ESBLs-encoding genes, respectively. A Salmonella strain simultaneously co-carrying bla(TEM-1), bla(OXA-1), bla(CMY-2), and bla(CTX-M-3) was first reported in the present study. Amino acid substitution of Trp244Cys/His247Leu was detected in PSE-1, Val218Asp in CMY-2, and Asp242Gly in CTX-M-15 enzymes, respectively. A difference was found among the amino acid sequences of the detected OXA-1, CMY-2, CTX-M, PSE-1, and TEM-1. The results demonstrated that β-lactamases and ESBLs were emerging and prevalent in foodborne Salmonella.