1
|
Kim J, Guk JH, Mun SH, An JU, Song H, Kim J, Ryu S, Jeon B, Cho S. Metagenomic analysis of isolation methods of a targeted microbe, Campylobacter jejuni, from chicken feces with high microbial contamination. MICROBIOME 2019; 7:67. [PMID: 31027515 PMCID: PMC6485176 DOI: 10.1186/s40168-019-0680-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 04/04/2019] [Indexed: 05/06/2023]
Abstract
BACKGROUND Originating from poultry, particularly chickens, Campylobacter jejuni is the leading foodborne pathogen worldwide and a major cause of campylobacteriosis. Isolating C. jejuni is difficult due to its specific growth requirements, the presence of viable but non-culturable bacteria, and because it is often masked by competing flora. Currently, there is no optimized method for isolating C. jejuni from chicken feces. Here, we evaluated the method for isolating C. jejuni from chicken feces using culture-independent sequence-based metagenomics and culture-dependent tools. Further, we assessed changes in microbial communities during microbe isolation to determine how the process can be improved. RESULTS Fourteen different variations of C. jejuni isolation procedures were applied to all 35 chicken fecal samples. These variations included using different enrichment broths (without enrichment or enrichment in Bolton or Preston broth), different ratios of sample-to-enrichment broth (1:101, 1:102, and 1:103), and different selective agars (modified charcoal-cefoperazone-deoxycholate agar (mCCDA) or Preston agar). Enrichment during isolation of C. jejuni was evaluated on the basis of microbial diversity and taxonomic composition using metagenomics tools. The effect of selective media was evaluated using a combination of metagenomics and culture-dependent tools. Microbial diversity significantly decreased during the enrichment process, regardless of the type of enrichment broth, with the most significant decrease observed at a feces-to-broth ratio of 1:103. Particularly, in 103-Preston broth, the relative abundance of Campylobacter increased, while extended-spectrum beta-lactamase-producing Escherichia coli, which interfere with Campylobacter isolation, decreased. Metagenomics results were validated by quantitative PCR and culture-dependent analysis. Additionally, selective media affected the isolation results, although microbes with high relative abundance during enrichment were also frequently isolated using culture-dependent methods. Significantly more C. jejuni was isolated from mCCDA than from Preston agar enriched in 103 Preston broth. CONCLUSIONS Enrichment in Preston broth at a ratio of 1:103 followed by spreading onto mCCDA was the most effective method for isolating C. jejuni. This is the first study to apply metagenomics to evaluate a method for isolating a targeted microbe, C. jejuni, from chicken feces, a source with high microbial contamination. Thus, metagenomics can be applied to improve methods for isolating bacteria that are difficult to separate.
Collapse
Affiliation(s)
- Junhyung Kim
- Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
| | - Jae-Ho Guk
- Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
| | - Seung-Hyun Mun
- Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
| | - Jae-Uk An
- Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
| | - Hyokeun Song
- Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
| | - Jinshil Kim
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, and Center for Food and Bioconvergence, Seoul National University, Seoul, Republic of Korea
| | - Sangryeol Ryu
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, and Center for Food and Bioconvergence, Seoul National University, Seoul, Republic of Korea
| | - Byeonghwa Jeon
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, and Center for Food and Bioconvergence, Seoul National University, Seoul, Republic of Korea
- School of Public Health, University of Alberta, Edmonton, Alberta Canada
| | - Seongbeom Cho
- Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
| |
Collapse
|
2
|
Chon JW, Kim YJ, Rashid F, Sung K, Khan S, Kim H, Seo KH. Improvement of Bolton broth by supplementation with tazobactam for the isolation of Campylobacter from chicken rinses. Poult Sci 2018; 97:289-293. [PMID: 29112760 DOI: 10.3382/ps/pex169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 10/19/2017] [Indexed: 11/20/2022] Open
Abstract
Overgrowth of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) on Campylobacter media prevents the latter's selective isolation, thereby making the improvement of Campylobacter-selective media necessary. We evaluated tazobactam (an ESBL inhibitor) to supplement Bolton enrichment broth (Tz-Bolton broth) for the selective isolation of Campylobacter in chicken carcass rinses. First, using 20 strains of ESBL-producing E. coli and 13 Campylobacter strains, we found 4 μg/mL of tazobactam to be optimal for inhibiting the ESBL-producing E. coli while allowing the growth of all tested Campylobacter strains. Next, 80 whole chicken carcasses were rinsed with buffered peptone water (BPW), and 25 mL of BPW rinse was mixed with 2 × blood-free Bolton broth (25 mL) with or without tazobactam followed by incubation at 42°C for 48 h under microaerobic conditions. A loopful of the incubated broth was inoculated on modified charcoal-cefoperazone-deoxycholate agar (mCCDA) and microaerobically incubated at 42°C for 48 h. The tazobactam supplemented Bolton broth showed a higher Campylobacter isolation rate (38.8%, p < 0.05) than normal Bolton broth (15%). Moreover, the number of mCCDA plates with non-Campylobacter was much lower (p < 0.05) after enrichment in Tz-Bolton broth (0%) than in the normal Bolton broth (80%), suggesting that selectivity of the modified broth was superior to normal Bolton broth.
Collapse
Affiliation(s)
- Jung-Whan Chon
- Division of Microbiology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR, USA
| | - Young-Ji Kim
- KU center for One Health, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, Republic of Korea
| | - Farzana Rashid
- Department of Zoology, Lahore College for Women University, Jail Road, Lahore, Pakistan
| | - Kidon Sung
- Division of Microbiology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR, USA
| | - Saeed Khan
- Division of Microbiology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR, USA
| | - Hyunsook Kim
- Department of Food & Nutrition College of Human Ecology Hanyang University 222 Wangsimni-ro, Seongdong-gu, Seoul, Republic of Korea
| | - Kun-Ho Seo
- KU center for One Health, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, Republic of Korea
| |
Collapse
|
3
|
Jo Y, Oh HM, Yoon Y, Lee SY, Ha JH, Kim WI, Kim HY, Han S, Kim SR. Enrichment Broth for the Detection of Campylobacter jejuni and Campylobacter coli in Fresh Produce and Poultry. J Food Prot 2017; 80:1842-1850. [PMID: 28990821 DOI: 10.4315/0362-028x.jfp-16-450] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Accepted: 04/12/2017] [Indexed: 11/11/2022]
Abstract
Although campylobacteriosis caused by Campylobacter jejuni and Campylobacter coli has been increasingly reported worldwide owing to the consumption of contaminated poultry and fresh produce, the current detection protocols are not selective enough to inhibit unspecific microbes other than these pathogens. Five antibiotics were separately added to Bolton broth, and the survival rates of 18 Campylobacter spp. and 79 non-Campylobacter spp. were evaluated. The survival rate of the non-Campylobacter spp. was the lowest in Bolton broth with rifampin (6.3%), followed by cefsulodin (12.7%), novobiocin (16.5%), and potassium tellurite and sulfamethozaxole (both 17.7%). Also the most effective concentration of rifampin was found to be 12.5 mg/L, which markedly inhibited non-Campylobacter strains while not affecting the survival of Campylobacter strains. After the Campylobacter spp. were enriched in Bolton broth supplemented with 12.5 mg/L rifampin (R-Bolton broth), CampyFood Agar (CFA) was found to be better in selectively isolating the pathogens in the enrichment broth than the International Organization for Standardization method of using modified charcoal cefoperazone deoxycholate agar (mCCDA) for this step. When applied to natural food samples-here, romaine lettuce, pepper, cherry tomato, Korean leek, and chicken-the R-Bolton broth-CFA combination decreased the number of false-positive results by 50.0, 4.2, 20.8, 50.0, and 94.4%, respectively, compared with the International Organization for Standardization method (Bolton broth-mCCDA combination). These results demonstrate that the combination of R-Bolton broth and CFA is more efficient in detecting C. jejuni and C. coli in poultry and fresh produce and thus should replace the Bolton broth-mCCDA combination.
Collapse
Affiliation(s)
- Youmi Jo
- Microbial Safety Team, Department of Agro-Food Safety & Crop Protection, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Republic of Korea.,Present address: Agromaterial Assessment Division, Department of Agro-Food Safety & Crop Protection, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Republic of Korea
| | - Hye-Min Oh
- Department of Food and Nutrition, Sookmyung Women's University, Seoul 04310, Republic of Korea
| | - Yohan Yoon
- Department of Food and Nutrition, Sookmyung Women's University, Seoul 04310, Republic of Korea
| | - Sun-Young Lee
- Department of Food Science and Technology, Chung-Ang University, Anseong 47262, Republic of Korea
| | - Ji-Hyoung Ha
- Microbial Safety Team, Department of Agro-Food Safety & Crop Protection, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Republic of Korea.,Present address: Hygienic Safety and Analysis Center, World Institute of Kimchi, Gwangju 61755, Republic of Korea
| | - Won-Il Kim
- Microbial Safety Team, Department of Agro-Food Safety & Crop Protection, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Republic of Korea
| | - Hwang-Yong Kim
- Microbial Safety Team, Department of Agro-Food Safety & Crop Protection, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Republic of Korea
| | - Sanghyun Han
- Microbial Safety Team, Department of Agro-Food Safety & Crop Protection, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Republic of Korea
| | - Se-Ri Kim
- Microbial Safety Team, Department of Agro-Food Safety & Crop Protection, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Republic of Korea
| |
Collapse
|
4
|
Chon JW, Kim HS, Kim DH, Kim YJ, Sung K, Kim H, Seo KH. Efficacy of Syringe Filtration for the Selective Isolation of Campylobacter from Chicken Carcass Rinse. J Food Prot 2017; 80:1050-1053. [PMID: 28513216 DOI: 10.4315/0362-028x.jfp-16-470] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We investigated the efficacy of syringe filtration for selective isolation of Campylobacter from chicken carcass rinse by combining syringe filtration with the conventional culture method. Whole chicken carcass rinses were incubated in Bolton enrichment broth, set aside or subjected to syringe filtration, and streaked on Campy-Cefex agar with or without cefoperazone antibiotic supplement. Compared with the conventional method without filtration, 0.65-μm-pore-size syringe filtration resulted in a significantly higher number of Campylobacter-positive samples (23.8 to 37.5% versus 70.0 to 72.5%; P < 0.05), a lower number of plates contaminated with non-Campylobacter (93.8% versus 6.3 to 26.3%), and a lower growth index (1 = growth of a few colonies; 2 = growth of colonies on about half of the plate; and 3 = growth on most of the plate) for competing microbiota (2.9 to 3.0 versus 1.2 to 1.4). When syringe filtration was applied, agar plates containing the antibiotic had significantly less contamination (6.3% versus 26.3%; P < 0.05) and a lower growth index (1.2 versus 1.4) compared with plates without the antibiotic, although the Campylobacter isolation rate was similar (P > 0.05). Syringe filtration combined with conventional enrichment improved the rate and selectivity of Campylobacter isolation from chicken carcasses.
Collapse
Affiliation(s)
- Jung-Whan Chon
- 1 U.S. Food and Drug Administration, National Center for Toxicological Research, Division of Microbiology, Jefferson, Arkansas 72079, USA
| | - Hong-Seok Kim
- 2 Center for One Health, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, Republic of Korea
| | - Dong-Hyeon Kim
- 2 Center for One Health, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, Republic of Korea
| | - Young-Ji Kim
- 2 Center for One Health, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, Republic of Korea
| | - Kidon Sung
- 1 U.S. Food and Drug Administration, National Center for Toxicological Research, Division of Microbiology, Jefferson, Arkansas 72079, USA
| | - Hyunsook Kim
- 3 Department of Food & Nutrition, College of Human Ecology, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, Republic of Korea
| | - Kun-Ho Seo
- 2 Center for One Health, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, Republic of Korea
| |
Collapse
|
5
|
Hazeleger WC, Jacobs-Reitsma WF, den Besten HMW. Quantification of Growth of Campylobacter and Extended Spectrum β-Lactamase Producing Bacteria Sheds Light on Black Box of Enrichment Procedures. Front Microbiol 2016; 7:1430. [PMID: 27672384 PMCID: PMC5018479 DOI: 10.3389/fmicb.2016.01430] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/29/2016] [Indexed: 11/13/2022] Open
Abstract
Campylobacter is well recognized as the leading cause of bacterial foodborne diarrheal disease worldwide, and is routinely found in meat originating from poultry, sheep, pigs, and cattle. Effective monitoring of Campylobacter contamination is dependent on the availability of reliable detection methods. The method of the International Organization for Standardization for the detection of Campylobacter spp. in food (ISO 10272-1:2006) recommends the use of Bolton broth (BB) as selective enrichment medium, including a pre-enrichment step of 4–6 h at 37°C to revive sublethally damaged cells prior to incubation for 2 days at 41.5°C. Recently the presence of abundantly growing extended spectrum β-lactamase producing Enterobacteriaceae (ESBL bacteria) has become one of the most important factors that interfere with the isolation of Campylobacter, resulting in false-negative detection. However, detailed growth dynamics of Campylobacter and its competitors remain unclear, where these would provide a solid base for further improvement of the enrichment procedure for Campylobacter. Other enrichment broths, such as Preston broth (PB) and BB plus clavulanic acid (BBc) have been suggested to inhibit competitive flora. Therefore, these different broths were used as enrichments to measure the growth kinetics of several strains of Campylobacter jejuni and ESBL bacteria separately, in co-culture and of strains in chicken samples. The maximum cell numbers and often the growth rates of Campylobacter in mixed culture with ESBL bacteria were significantly lower than in single cultures, indicating severe suppression of Campylobacter by ESBL bacteria, also in naturally contaminated samples. PB and BBc successfully diminished ESBL bacteria and might therefore be a better choice as enrichment medium in possibly ESBL-bacteria contaminated samples. The efficacy of a pre-enrichment step in the BB ISO-procedure was not supported for cold-stressed and non-stressed cells. Therefore, omission of this step (4–6 h at 37°C) might be advised to obtain a less troublesome protocol.
Collapse
Affiliation(s)
- Wilma C Hazeleger
- Laboratory of Food Microbiology, Wageningen University Wageningen, Netherlands
| | | | | |
Collapse
|
6
|
Kim J, Oh E, Banting GS, Braithwaite S, Chui L, Ashbolt NJ, Neumann NF, Jeon B. An Improved Culture Method for Selective Isolation of Campylobacter jejuni from Wastewater. Front Microbiol 2016; 7:1345. [PMID: 27617011 PMCID: PMC4999441 DOI: 10.3389/fmicb.2016.01345] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 08/15/2016] [Indexed: 01/30/2023] Open
Abstract
Campylobacter jejuni is one of the leading foodborne pathogens worldwide. C. jejuni is isolated from a wide range of foods, domestic animals, wildlife, and environmental sources. The currently available culture-based isolation methods are not highly effective for wastewater samples due to the low number of C. jejuni in the midst of competing bacteria. To detect and isolate C. jejuni from wastewater samples, in this study, we evaluated a few different enrichment conditions using five different antibiotics (i.e., cefoperazone, vancomycin, trimethoprim, polymyxin B, and rifampicin), to which C. jejuni is intrinsically resistant. The selectivity of each enrichment condition was measured with Ct value using quantitative real-time PCR, and multiplex PCR to determine Campylobacter species. In addition, the efficacy of Campylobacter isolation on different culture media after selective enrichment was examined by growing on Bolton and Preston agar plates. The addition of polymyxin B, rifampicin, or both to the Bolton selective supplements enhanced the selective isolation of C. jejuni. The results of 16S rDNA sequencing also revealed that Enterococcus spp. and Pseudomonas aeruginosa are major competing bacteria in the enrichment conditions. Although it is known to be difficult to isolate Campylobacter from samples with heavy contamination, this study well exhibited that the manipulation of antibiotic selective pressure improves the isolation efficiency of fastidious Campylobacter from wastewater.
Collapse
Affiliation(s)
- Jinyong Kim
- School of Public Health, University of Alberta, Edmonton, AB Canada
| | - Euna Oh
- School of Public Health, University of Alberta, Edmonton, AB Canada
| | - Graham S Banting
- School of Public Health, University of Alberta, Edmonton, ABCanada; Provincial Laboratory for Public Health, Alberta Health Services, Edmonton, ABCanada
| | - Shannon Braithwaite
- School of Public Health, University of Alberta, Edmonton, ABCanada; Provincial Laboratory for Public Health, Alberta Health Services, Edmonton, ABCanada
| | - Linda Chui
- Provincial Laboratory for Public Health, Alberta Health Services, Edmonton, ABCanada; Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, ABCanada
| | - Nicholas J Ashbolt
- School of Public Health, University of Alberta, Edmonton, ABCanada; Provincial Laboratory for Public Health, Alberta Health Services, Edmonton, ABCanada
| | - Norman F Neumann
- School of Public Health, University of Alberta, Edmonton, ABCanada; Provincial Laboratory for Public Health, Alberta Health Services, Edmonton, ABCanada
| | - Byeonghwa Jeon
- School of Public Health, University of Alberta, Edmonton, AB Canada
| |
Collapse
|
7
|
Comparative performance of isolation methods using Preston broth, Bolton broth and their modifications for the detection of Campylobacter spp. from naturally contaminated fresh and frozen raw poultry meat. Int J Food Microbiol 2016; 234:60-64. [PMID: 27391222 DOI: 10.1016/j.ijfoodmicro.2016.06.040] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 06/27/2016] [Accepted: 06/28/2016] [Indexed: 12/26/2022]
Abstract
The performance of different isolation methods was evaluated for the detection of Campylobacter from naturally contaminated raw poultry meat. Therefore, fresh and frozen poultry meat samples were analysed using the standard procedure (ISO 10272-1:2006), enrichment in Preston broth, and enrichment in modified Bolton broth (supplemented with (i) potassium clavulanate (C-BB), (ii) triclosan (T-BB), (iii) polymyxin B (P-BB)). The enrichment cultures were streaked onto both modified charcoal cefoperazone deoxycholate agar (mCCDA) and RAPID'Campylobacter agar (RCA). Moreover, direct plating on mCCDA and RCA was performed to quantify Campylobacter. In total, 33 out of 59 fresh retail meat samples (55.9%) were Campylobacter positive. For both fresh and frozen poultry meat samples, enrichment in Bolton broth (ISO 10272-1:2006) resulted in a higher number of positive samples than enrichment in Preston broth. Supplementation of Bolton broth with potassium clavulanate (C-BB) and triclosan (T-BB) enhanced the Campylobacter recovery from fresh poultry meat compared to non-supplemented Bolton broth, although the use of C-BB was less applicable than T-BB for Campylobacter recovery from frozen samples. Additionally, the use of RCA resulted in a higher isolation rate compared to mCCDA. The present study demonstrates the impact of culture medium on the recovery of Campylobacter from fresh and frozen naturally contaminated poultry meat samples and can support laboratories in choosing the most appropriate culturing method to detect Campylobacter.
Collapse
|
8
|
Yoo JH, Choi NY, Bae YM, Lee JS, Lee SY. Development of a selective agar plate for the detection of Campylobacter spp. in fresh produce. Int J Food Microbiol 2014; 189:67-74. [DOI: 10.1016/j.ijfoodmicro.2014.07.032] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 07/17/2014] [Accepted: 07/24/2014] [Indexed: 11/29/2022]
|
9
|
Chon JW, Kim YJ, Kim HS, Kim DH, Kim H, Song KY, Seo KH. Supplementation of Bolton broth with triclosan improves detection of Campylobacter jejuni and Campylobacter coli in chicken carcass rinse. Int J Food Microbiol 2014; 181:37-9. [DOI: 10.1016/j.ijfoodmicro.2014.04.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Revised: 03/28/2014] [Accepted: 04/04/2014] [Indexed: 10/25/2022]
|
10
|
Ugarte-Ruiz M, Wassenaar TM, Gómez-Barrero S, Porrero MC, Navarro-Gonzalez N, Domínguez L. The effect of different isolation protocols on detection and molecular characterization of Campylobacter from poultry. Lett Appl Microbiol 2013; 57:427-35. [PMID: 23837671 DOI: 10.1111/lam.12130] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 05/30/2013] [Accepted: 07/01/2013] [Indexed: 12/19/2022]
Abstract
We determined whether different methods to isolate Campylobacter (including the ISO standard 10272:2006-1) affected the genotypes detectable from poultry, at three points during slaughter: caecal content, neck skin and meat. Carcasses from 28 independent flocks were thus sampled (subset A). In addition, ten neck skin samples from four flocks, ten caecal samples from ten different flocks and ten unrelated meat samples obtained from local supermarkets were collected (subset B). Campylobacter was isolated using eight different protocols: with and without enrichment using Bolton broth, Preston broth or Campyfood broth (CFB), followed by culture on either modified Charcoal Cefoperazone Deoxycholate Agar (mCCDA) or Campyfood agar (CFA). All obtained isolates were genotyped for flaA-SVR, and over half of the isolates were also typed by MLST. The strain richness, as a measure of number of detected fla-genotypes, obtained from subset A neck skin and caecal samples was higher than that of meat samples. In half of the cases, within a flock, at least one identical fla-genotype was obtained at all three slaughter stages, suggestive of autologous contamination of carcasses. Enrichment reduced the observed richness of isolates, while CFA plates increased richness compared to mCCDA plates, irrespective of inclusion of an enrichment step. Because the isolation protocol used influences both the yield and the fla-genotype richness obtained from poultry, this variable should be taken into account when different studies are being compared.
Collapse
Affiliation(s)
- M Ugarte-Ruiz
- Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Universidad Complutense de Madrid, 28040 Madrid, Spain
| | | | | | | | | | | |
Collapse
|
11
|
Improvement of modified charcoal-cefoperazone-deoxycholate agar by addition of potassium clavulanate for detecting Campylobacter spp. in chicken carcass rinse. Int J Food Microbiol 2013; 165:7-10. [DOI: 10.1016/j.ijfoodmicro.2013.04.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 04/08/2013] [Accepted: 04/10/2013] [Indexed: 11/22/2022]
|