1
|
Salazar JK, Wang Y, Yu S, Wang H, Zhang W. Polymerase chain reaction-based serotyping of pathogenic bacteria in food. J Microbiol Methods 2015; 110:18-26. [DOI: 10.1016/j.mimet.2015.01.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 01/09/2015] [Accepted: 01/14/2015] [Indexed: 10/24/2022]
|
2
|
Pike BL, Guerry P, Poly F. Global Distribution of Campylobacter jejuni Penner Serotypes: A Systematic Review. PLoS One 2013; 8:e67375. [PMID: 23826280 PMCID: PMC3694973 DOI: 10.1371/journal.pone.0067375] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 05/16/2013] [Indexed: 11/30/2022] Open
Abstract
Penner serotyping has been the principal method for differentiating Campylobacter isolates since its inception. Campylobacter capsule polysaccharide (CPS), the principal serodeterminant on which Penner serotyping is based, is presently of interest as a vaccine component. To determine the required valency of an effective CPS-based vaccine, a comprehensive understanding of CPS distribution is needed. Because of the association between Penner serotype and CPS, we conducted a systematic review to estimate the frequency and distribution of Penner serotypes associated with cases of Campylobacteriosis. In total, more than 21,000 sporadic cases of C. jejuni cases were identified for inclusion. While regional variation exists, distribution estimates indicate that eight serotypes accounted for more than half of all sporadic diarrheal cases globally and three serotypes (HS4 complex, HS2, and HS1/44) were dominant inter-regionally as well as globally. Furthermore, a total of 17 different serotypes reached a representation of 2% or greater in at least one of the five regions sampled. While this review is an important first step in defining CPS distribution, these results make it clear that significant gaps remain in our knowledge. Eliminating these gaps will be critical to future vaccine development efforts.
Collapse
Affiliation(s)
- Brian L. Pike
- Enteric Diseases Department, Infectious Disease Directorate, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- * E-mail:
| | - Patricia Guerry
- Enteric Diseases Department, Infectious Disease Directorate, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Frédéric Poly
- Enteric Diseases Department, Infectious Disease Directorate, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| |
Collapse
|
3
|
Ling ZQ, Lv P, Lu XX, Yu JL, Han J, Ying LS, Zhu X, Zhu WY, Fang XH, Wang S, Wu YC. Circulating Methylated XAF1 DNA Indicates Poor Prognosis for Gastric Cancer. PLoS One 2013; 8:e67195. [PMID: 23826230 PMCID: PMC3695092 DOI: 10.1371/journal.pone.0067195] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 05/16/2013] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Methylated DNA in fluids may be a suitable biomarker for cancer patients. XAF1 has been shown to be frequently down-regulated in human gastric cancer (GC). Here, we investigated if XAF1 methylation in GC could be a useful biomarker. METHODS Real-time RT-PCR was used to detect XAF1 mRNA expression; immunohistochemistry and western blot were used to examine XAF1 protein expression in GC tissues (n = 202) and their corresponding para-cancerous histological normal tissues (PCHNTs). Real-time methylation specific-PCR was used to investigate XAF1 promoter methylation in the same panel of GC tissues, their PCHNTs and sera. RESULTS We confirmed frequent XAF1 down-regulation in both mRNA and protein levels in GC tissues as compared to normal controls and PCHNTs. XAF1 hypermethylation was evidenced in 83.2% (168/202) of GC tissues and 27.2% (55/202) of PCHNTs, while no methylation was detected in the 88 normal controls. The methylation level in GC tissues was significantly higher than that in PCHNTs (p<0.05). The hypermethylation of XAF1 significantly correlated with the down-regulation of XAF1 in GC tissues in both mRNA and protein levels (p<0.001 each). Moreover, we detected high frequency of XAF1 methylation (69.8%, 141 out of 202) in the sera DNAs from the same patients, while the sera DNAs from 88 non-tumor controls were negative for XAF1 methylation. The XAF1 methylation in both GC tissues and in the sera could be a good biomarker for diagnosis of GC (AUC = 0.85 for tissue and AUC = 0.91 for sera) and significantly correlated with poorer prognosis (p<0.001). In addition, after-surgery negative-to-positive transition of XAF1 methylation in sera strongly associated with tumor recurrence. CONCLUSIONS 1) Dysfunction of XAF1 is frequent and is regulated through XAF1 promoter hypermethylation; 2) Detection of circulating methylated XAF1 DNAs in the serum may be a useful biomarker in diagnosis, evaluating patient's outcome (prognosis and recurrence) for GC patients.
Collapse
Affiliation(s)
- Zhi-Qiang Ling
- Zhejiang Cancer Research Institute, Zhejiang Province Cancer Hospital, Zhejiang Cancer Center, Hangzhou, Zhejiang, China
| | - Ping Lv
- Zhejiang Cancer Research Institute, Zhejiang Province Cancer Hospital, Zhejiang Cancer Center, Hangzhou, Zhejiang, China
| | - Xiao-Xiao Lu
- Zhejiang Cancer Research Institute, Zhejiang Province Cancer Hospital, Zhejiang Cancer Center, Hangzhou, Zhejiang, China
| | - Jiang-Liu Yu
- Zhejiang Cancer Research Institute, Zhejiang Province Cancer Hospital, Zhejiang Cancer Center, Hangzhou, Zhejiang, China
| | - Jing Han
- Zhejiang Cancer Research Institute, Zhejiang Province Cancer Hospital, Zhejiang Cancer Center, Hangzhou, Zhejiang, China
| | - Li-Sha Ying
- Zhejiang Cancer Research Institute, Zhejiang Province Cancer Hospital, Zhejiang Cancer Center, Hangzhou, Zhejiang, China
| | - Xin Zhu
- Zhejiang Cancer Research Institute, Zhejiang Province Cancer Hospital, Zhejiang Cancer Center, Hangzhou, Zhejiang, China
| | - Wang-Yu Zhu
- Zhejiang Cancer Research Institute, Zhejiang Province Cancer Hospital, Zhejiang Cancer Center, Hangzhou, Zhejiang, China
| | - Xian-Hua Fang
- Department of Pathology, Zhejiang Province Cancer Hospital, Zhejiang Cancer Center, Hangzhou, Zhejiang, China
| | - Shi Wang
- Department of Endoscopy, Zhejiang Province Cancer Hospital, Zhejiang Cancer Center, Hangzhou, Zhejiang, China
| | - Yi-Chen Wu
- Zhejiang Cancer Research Institute, Zhejiang Province Cancer Hospital, Zhejiang Cancer Center, Hangzhou, Zhejiang, China
| |
Collapse
|
4
|
Carreira AC, Clemente L, Rocha T, Tavares A, Geraldes M, Barahona MJ, Botelho A, Cunha MV. Comparative genotypic and antimicrobial susceptibility analysis of zoonotic Campylobacter species isolated from broilers in a nationwide survey, Portugal. J Food Prot 2012; 75:2100-9. [PMID: 23212005 DOI: 10.4315/0362-028x.jfp-12-183] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Campylobacter is a major cause of human foodborne disease worldwide and has been associated with the consumption of contaminated poultry. The prevalence of Campylobacter species in broiler flocks from more than 200 producers widespread in mainland Portugal was assessed in 2008 in response to Commission Decision 2007/516/EC. Campylobacter isolates were obtained from 83.3% of 424 pooled cecal samples, with a higher prevalence of Campylobacter coli (61.2%) than Campylobacter jejuni (38.8%). Restriction fragment length polymorphism analysis of the flaA gene (flaA-RFLP) of 112 C. coli isolates and 67 C. jejuni isolates yielded 11 flaA-RFLP patterns with HinfI (Hunter Gaston diversity index [HGDI] = 0.62) and 48 flaA-RFLP patterns with DdeI (HGDI = 0.89), indicating a high level of genetic diversity. A wide geographic distribution of the most frequent restriction pattern was observed. MICs of five antimicrobials (ciprofloxacin, gentamicin, streptomycin, erythromycin, and tetracycline) were determined for 215 C. coli isolates and 136 C. jejuni isolates. The occurrence of non-wild-type isolates, exhibiting an acquired resistance phenotype, was higher for C. coli than C. jejuni for all antimicrobials tested. Sixty-three percent of C. jejuni and C. coli isolates were considered non-wild type based on their response to both ciprofloxacin and erythromycin, which are frequently used in the treatment of human infections. The high prevalence of antimicrobial-resistant Campylobacter strains detected supports the need for increased epidemiological surveillance and prevention in a country where large amounts of poultry meat are consumed.
Collapse
Affiliation(s)
- Ana Cláudia Carreira
- Instituto Nacional dos Recursos Biológicos, Laboratório Nacional de Investigação Veterinária, Laboratório de Bacteriologia, Estrada de Benfica 701, 1549-011 Lisboa, Portugal
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Guerry P, Poly F, Riddle M, Maue AC, Chen YH, Monteiro MA. Campylobacter polysaccharide capsules: virulence and vaccines. Front Cell Infect Microbiol 2012; 2:7. [PMID: 22919599 PMCID: PMC3417588 DOI: 10.3389/fcimb.2012.00007] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 01/24/2012] [Indexed: 12/11/2022] Open
Abstract
Campylobacter jejuni remains a major cause of bacterial diarrhea worldwide and is associated with numerous sequelae, including Guillain Barré Syndrome, inflammatory bowel disease, reactive arthritis, and irritable bowel syndrome. C. jejuni is unusual for an intestinal pathogen in its ability to coat its surface with a polysaccharide capsule (CPS). These capsular polysaccharides vary in sugar composition and linkage, especially those involving heptoses of unusual configuration and O-methyl phosphoramidate linkages. This structural diversity is consistent with CPS being the major serodeterminant of the Penner scheme, of which there are 47 C. jejuni serotypes. Both CPS expression and expression of modifications are subject to phase variation by slip strand mismatch repair. Although capsules are virulence factors for other pathogens, the role of CPS in C. jejuni disease has not been well defined beyond descriptive studies demonstrating a role in serum resistance and for diarrhea in a ferret model of disease. However, perhaps the most compelling evidence for a role in pathogenesis are data that CPS conjugate vaccines protect against diarrheal disease in non-human primates. A CPS conjugate vaccine approach against this pathogen is intriguing, but several questions need to be addressed, including the valency of CPS types required for an effective vaccine. There have been numerous studies of prevalence of CPS serotypes in the developed world, but few studies from developing countries where the disease incidence is higher. The complexity and cost of Penner serotyping has limited its usefulness, and a recently developed multiplex PCR method for determination of capsule type offers the potential of a more rapid and affordable method. Comparative studies have shown a strong correlation of the two methods and studies are beginning to ascertain CPS-type distribution worldwide, as well as examination of correlation of severity of illness with specific CPS types.
Collapse
Affiliation(s)
- Patricia Guerry
- Enteric Diseases Department, Naval Medical Research Center Silver Spring, MD, USA.
| | | | | | | | | | | |
Collapse
|
6
|
Ridley AM, Allen VM, Sharma M, Harris JA, Newell DG. Real-time PCR approach for detection of environmental sources of Campylobacter strains colonizing broiler flocks. Appl Environ Microbiol 2008; 74:2492-504. [PMID: 18203857 PMCID: PMC2293161 DOI: 10.1128/aem.01242-07] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Accepted: 01/07/2008] [Indexed: 11/20/2022] Open
Abstract
Reducing colonization of poultry flocks by Campylobacter spp. is a key strategy in the control and prevention human campylobacteriosis. Horizontal transmission of campylobacters, from in and around the farm, is the presumed route of flock colonization. However, the identification and prioritization of sources are confounded by the ubiquitous nature of these organisms in the environment, their poor rates of recovery by standard culture methods, and the need for cost-effective and timely methods for strain-specific comparison. A real-time PCR screening test for the strain-specific detection of campylobacters in environmental samples has been developed to address this issue. To enable this approach, fluorescently labeled PCR oligonucleotide probes suitable for a LightCycler-based assay were designed to match a highly variable DNA segment within the flaA short variable region (SVR) of Campylobacter jejuni or C. coli. The capacity of such probes to provide strain-specific tools was investigated by using bacterial cultures and spiked and naturally contaminated poultry fecal and environmental samples. The sensitivity of two representative probes was estimated, by using two different C. jejuni strains, to be 1.3 x 10(2) to 3.7 x 10(2) CFU/ml in bacterial cultures and 6.6 x 10(2) CFU/ml in spiked fecal samples. The specificity of the SVR for C. jejuni and C. coli was confirmed by using a panel of strains comprising other Campylobacter species and naturally contaminated samples. The approach was field tested by sampling the environment and feces of chickens of two adjacently located poultry houses on a conventional broiler farm throughout the life of one flock. All environmental samples were enriched for 2 days, and then DNA was prepared and stored. Where feasible, campylobacter isolates were also recovered and stored for subsequent testing. A strain-specific probe based on the SVR of the strain isolated from the first positive chicken fecal sample was developed. This probe was then used to screen the stored environmental samples by real-time PCR. Pulsed-field gel electrophoresis was used to compare recovered environmental and fecal isolates to assess the specificity of the method. The results established the proof of principle that strain-specific probes, based on the SVR of flaA, can identify a flock-colonizing strain in DNA preparations from enriched environmental cultures. Such a novel strategy provides the opportunity to investigate the epidemiology of campylobacters in poultry flocks and allows targeted biosecurity interventions to be developed. The strategy may also have wider applications for the tracking of specific campylobacter strains in heavily contaminated environments.
Collapse
Affiliation(s)
- Anne M Ridley
- Veterinary Laboratories Agency, Woodham Lane, Addlestone, Surrey KT15 3NB, United Kingdom.
| | | | | | | | | |
Collapse
|
7
|
Lentzsch P, Rieksneuwöhner B, Wieler LH, Hotzel H, Moser I. High-resolution genotyping of Campylobacter upsaliensis strains originating from three continents. J Clin Microbiol 2004; 42:3441-8. [PMID: 15297481 PMCID: PMC497571 DOI: 10.1128/jcm.42.8.3441-3448.2004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ninety-six Campylobacter upsaliensis strains that originated from Australia, Canada, and Europe (Germany) and that were isolated from humans, dogs, and cats were serotyped for their heat-stable surface antigens. All of them were genotyped by enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR) profiling, and 83 strains were genotyped by macrorestriction analysis with the endonuclease XhoI. Eighty-four percent of the strains belonged to five different serotypes (serotypes OI, OII, OIII, OIV, and OVI), with the proportions of strains in each serotype being comparable among the groups of strains from all three continents. Two serotypes, OIII and OIV, were prevalent at rates of 35 to 40%. Serotypes OI, OII, and OVI were detected at rates of 1.5 to 15%. Between 10 and 17.7% of the strains did not react with the available antisera. Analysis of the ERIC-PCR profiles revealed two distinct genotypic clusters, which represented the German and the non-European strains, respectively. XhoI macrorestriction yielded two genotypic clusters; one of them contained 80.2% of the German strains and 34.6% of the non-European strains, and the second cluster consisted of 65.4% of the non-European strains and 19.8% of the German strains. Fourteen strains from all three continents were analyzed for their 16S rRNA gene sequences. Only two minor variations were detected in four of the strains. In conclusion, C. upsaliensis has undergone diverging processes of genome arrangement on different continents during evolution without segregating into different subspecies.
Collapse
Affiliation(s)
- P Lentzsch
- Centre for Agricultural Landscape and Land Use Research, Müncheberg, Germany
| | | | | | | | | |
Collapse
|
8
|
Harrington CS, Moran L, Ridley AM, Newell DG, Madden RH. Inter-laboratory evaluation of three flagellin PCR/RFLP methods for typing Campylobacter jejuni and C. coli: the CAMPYNET experience. J Appl Microbiol 2004; 95:1321-33. [PMID: 14633007 DOI: 10.1046/j.1365-2672.2003.02101.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS To compare typeability, discriminatory ability, and inter-laboratory reproducibility of three flagellin PCR/RFLP (fla typing) methods previously described for Campylobacter. METHODS AND RESULTS The sample set (n = 100) was diverse, including both C. jejuni (n = 85) and C. coli (n = 15). Two of the three flaA typing methods amplified flaA alone, whereas one, a multiplex assay, amplified flaB in addition to flaA. DdeI restriction enzyme was employed for all methods, but HinfI was also investigated. 98-100% typeability was obtained for flaA-based methods, but only 93% for the multiplex assay, due to inconsistent amplification of a non-specific product. In addition, there appeared to be selective amplification of flaA over flaB. More DdeI types were generated using a longer flaA PCR amplicon, whilst additional use of HinfI increased the number of types by ca 25%. Inter-laboratory reproducibility for both flaA-based methods was defined at 100%. CONCLUSIONS Fla typing requires standardization with respect to PCR primers and restriction enzymes. This study identified an assay, employing the full flaA gene and DdeI digestion, as an appropriate method on which to standardize. 100% inter-laboratory reproducibility was demonstrated using that method. SIGNIFICANCE AND IMPACT OF THE STUDY This work should facilitate progress towards inter-laboratory standardization of fla typing.
Collapse
|
9
|
Ziprin RL, Sheffield CL, Hume ME, Drinnon DLJ, Harvey RB. Cecal Colonization of Chicks by Bovine-Derived Strains of Campylobacter. Avian Dis 2003; 47:1429-33. [PMID: 14708992 DOI: 10.1637/7014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Campylobacter jejuni and Campylobacter coli strains were isolated from feces of dairy cattle at farms with no known problem due to campylobacteria. Farms were located in the northeast, desert southwest, and Pacific west. Twenty isolates were identified by ribotyping with a RiboPrinter. The ability of these bovine isolates to colonize the ceca of chicks was determined by challenge inoculation and reisolation of the challenge strain from the ceca at 1 and 2 wk after challenge. Isolates recovered from chick ceca were examined by ribotyping to assure they matched the challenge strain. One hundred percent of the bovine-derived challenge strains were capable of colonizing chicks. These results indicate that dairy cattle may be asymptomatic Campylobacter carriers and potential sources of campylobacteria contamination of poultry facilities.
Collapse
Affiliation(s)
- Richard L Ziprin
- Food and Feed Safety Research Unit, Southern Plains Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, 2881 F & B Road, College Station, TX 77845, USA
| | | | | | | | | |
Collapse
|
10
|
Sails AD, Swaminathan B, Fields PI. Clonal complexes of Campylobacter jejuni identified by multilocus sequence typing correlate with strain associations identified by multilocus enzyme electrophoresis. J Clin Microbiol 2003; 41:4058-67. [PMID: 12958226 PMCID: PMC193858 DOI: 10.1128/jcm.41.9.4058-4067.2003] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) with SmaI were used to subtype 55 isolates of Campylobacter jejuni from a diverse range of human and animal sources previously characterized by multilocus enzyme electrophoresis (MEE). MEE and MLST targeted 11 and 7 loci, respectively, and all loci were unique to each method. MEE, MLST, and PFGE identified 40, 37, and 48 discrete subtypes, respectively, with many of the subtypes occurring only once within the data set. Simpson's indices of diversity were calculated to be 0.979, 0.966, and 0.994 for MEE, MLST, and PFGE, respectively, demonstrating that MEE and MLST had similar discriminatory powers but that PFGE was more discriminatory. Allele diversity was higher in the MLST loci; individual single-locus diversities for the 11 MEE loci and the 7 MLST loci were 0.491 and 0.854, respectively. The clonal complexes recognized by MLST correlated with the strain associations previously recognized by MEE and contained some isolates indistinguishable by PFGE. Many clusters contained isolates from diverse geographical regions and from both humans and animals. These results demonstrate the usefulness of MLST for investigation of the global epidemiology of this important pathogen and illustrate its potential to identify indistinguishable strains or clones in geographically distinct regions.
Collapse
Affiliation(s)
- Andrew D Sails
- Foodborne and Diarrheal Diseases Branch, Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
| | | | | |
Collapse
|
11
|
Khan AA, McCarthy S, Wang RF, Cerniglia CE. Characterization of United States outbreak isolates of Vibrio parahaemolyticus using enterobacterial repetitive intergenic consensus (ERIC) PCR and development of a rapid PCR method for detection of O3:K6 isolates. FEMS Microbiol Lett 2002; 206:209-14. [PMID: 11814665 DOI: 10.1111/j.1574-6968.2002.tb11011.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Outbreaks of Vibrio parahaemolyticus gastroenteritis in the United States (Texas, New York and Pacific Northwest) in 1997-98 emphasized the need to develop molecular methods for identification and differentiation of these organisms. When outbreak isolates were analyzed for the enterobacterial repetitive intergenic consensus sequences, the Texas and New York outbreak isolates had a specific 850-bp DNA fragment that was absent in Pacific Northwest isolates. The 850-bp polymerase chain reaction (PCR) product was found in isolates of serovar O3:K6, which have an unusual potential to spread and cause infections. To develop a specific molecular detection method for serovar O3:K6, the nucleotide sequence of the 850-bp product was determined. The GenBank blast analysis did not show homology with any known Vibrio spp. gene sequences. Two PCR primers were designed to specifically amplify the unique sequences from serovar O3:K6 isolates. Genomic DNA from 10 Texas, eight New York, and seven Pacific Northwest outbreak isolates of V. parahaemolyticus was assayed by PCR. Texas and New York isolates were positive in the PCR assay, giving a 327-bp PCR product as predicted; however, Pacific Northwest isolates were negative, indicating the absence of the target gene. Texas and New York isolates were all serovar O3:K6; the Pacific Northwest isolates were not. The primers were tested with other Vibrio spp. and other closely related species and no amplification of the 327-bp PCR product was found. The PCR method can be used to specifically identify O3:K6 V. parahaemolyticus isolates in less than 6 h.
Collapse
Affiliation(s)
- Ashraf A Khan
- Division of Microbiology, US Food and Drug Administration, NCTR, Jefferson, AR 72079, USA.
| | | | | | | |
Collapse
|
12
|
Fitzgerald C, Helsel LO, Nicholson MA, Olsen SJ, Swerdlow DL, Flahart R, Sexton J, Fields PI. Evaluation of methods for subtyping Campylobacter jejuni during an outbreak involving a food handler. J Clin Microbiol 2001; 39:2386-90. [PMID: 11427543 PMCID: PMC88159 DOI: 10.1128/jcm.39.7.2386-2390.2001] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In October 1998, the Centers for Disease Control and Prevention (CDC) assisted in an investigation of an outbreak of campylobacteriosis at a school in Salina, Kansas. Twenty-two isolates were submitted from the Kansas state public health laboratory to CDC, 9 associated with the outbreak and 13 epidemiologically unrelated sporadic isolates. Pulsed-field gel electrophoresis (PFGE) using SmaI and SalI was initially used to validate the epidemiologic data. We then tested the ability of other subtyping techniques to distinguish the outbreak-associated isolates from unrelated sporadic isolates. The methods employed were somatic O serotyping, PCR-restriction fragment length polymorphism (RFLP) analysis of flaA, DNA sequence analysis of 582 bp of flaA that included the short variable region (SVR), and sequencing of the entire flaA gene. PFGE was the most discriminatory technique, yielding 11 SmaI and 10 SalI restriction profiles. All outbreak isolates were indistinguishable by PFGE, somatic O serotyping, and sequencing of the 582-bp region of the flaA gene. fla typing by PCR-RFLP grouped one sporadic isolate with the outbreak strain. Analysis of the DNA sequence of a 582-bp segment of flaA produced strain groupings similar to that generated by PCR-RFLP but further differentiated two flaA PCR-RFLP types (with a 1-bp difference in the 582-bp region). Two sporadic strains were distinct by flaA PCR-RFLP but differed only by a single base substitution in the 582-bp region. The entire flaA gene was sequenced from strains differing by a single base pair in the 582-bp region, and the data revealed that additional discrimination may in some cases be obtained by sequencing outside the SVR. PFGE was superior to all other typing methods tested for strain discrimination; it was crucial for understanding the Kansas outbreak and, when SmaI was used, provided adequate discrimination between unrelated isolates.
Collapse
Affiliation(s)
- C Fitzgerald
- Foodborne and Diarrheal Diseases Branch, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Moser I, Rieksneuwöhner B, Lentzsch P, Schwerk P, Wieler LH. Genomic heterogeneity and O-antigenic diversity of Campylobacter upsaliensis and Campylobacter helveticus strains isolated from dogs and cats in Germany. J Clin Microbiol 2001; 39:2548-57. [PMID: 11427567 PMCID: PMC88183 DOI: 10.1128/jcm.39.7.2548-2557.2001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A serotyping scheme based on heat-stable surface antigens was established for 101 Campylobacter upsaliensis and 10 Campylobacter helveticus strains isolated from 261 dogs and 46 cats of different ages originating from two geographically distinct regions in Germany. The prevalence of C. upsaliensis varied between 27.8% in juvenile dogs (<12 months of age) and 55.4% in adult dogs (P < 0.05). Of the cats, 19.6% harbored C. upsaliensis, whereas 21.7% carried C. helveticus. Of the C. upsaliensis isolates from both host species, 93.1% belonged to five different serogroups, two of them being prevalent at rates of 47.5 and 27.7%, with different frequencies in both regions. Six (54.6%) of the C. helveticus isolates also belonged to serotypes found among C. upsaliensis strains, whereas five (45.4%) possessed an O antigen unique for C. helveticus. In contrast, a considerable degree of genomic diversity of the isolates was assessed by macrorestriction analyses with the endonucleases SmaI and XhoI, using pulsed-field gel electrophoresis as well as enterobacterial repetitive intergenic consensus sequence PCR (ERIC PCR). Restriction with SmaI pointed towards the existence of clonal groups associated to some extent with serotypes, while restriction with XhoI disintegrated these groups to smaller noncoherent subgroups. Analysis of ERIC PCR profiles did not exhibit any associations with serotypes. In conclusion these data demonstrate the genomic heterogeneity among C. upsaliensis strains and indicate that the combination of SmaI restriction with serotyping is a useful tool to investigate the expansion of clonal groups of C. upsaliensis.
Collapse
MESH Headings
- Animals
- Antigenic Variation
- Base Sequence
- Campylobacter/classification
- Campylobacter/genetics
- Campylobacter/immunology
- Campylobacter/isolation & purification
- Campylobacter Infections/epidemiology
- Campylobacter Infections/microbiology
- Campylobacter Infections/veterinary
- Cat Diseases/epidemiology
- Cat Diseases/microbiology
- Cats
- DNA, Bacterial/analysis
- DNA, Bacterial/genetics
- DNA, Ribosomal/analysis
- DNA, Ribosomal/genetics
- Dog Diseases/epidemiology
- Dog Diseases/microbiology
- Dogs
- Electrophoresis, Gel, Pulsed-Field
- Genetic Variation
- Germany/epidemiology
- Molecular Sequence Data
- O Antigens/genetics
- O Antigens/immunology
- Polymerase Chain Reaction/methods
- Polymorphism, Restriction Fragment Length
- Prevalence
- RNA, Ribosomal, 16S/genetics
- Sequence Analysis, DNA
- Serotyping
Collapse
Affiliation(s)
- I Moser
- Institut für Mikrobiologie und Tierseuchen, Freie Universität, Berlin, Germany.
| | | | | | | | | |
Collapse
|
14
|
Fitzgerald C, Stanley K, Andrew S, Jones K. Use of pulsed-field gel electrophoresis and flagellin gene typing in identifying clonal groups of Campylobacter jejuni and Campylobacter coli in farm and clinical environments. Appl Environ Microbiol 2001; 67:1429-36. [PMID: 11282587 PMCID: PMC92751 DOI: 10.1128/aem.67.4.1429-1436.2001] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although campylobacters have been isolated from a wide range of animal hosts, the association between campylobacters isolated from humans and animals in the farm environment is unclear. We used flagellin gene typing and pulsed-field gel electrophoresis (PFGE) to investigate the genetic diversity among isolates from animals (cattle, sheep, and turkey) in farm environments and sporadic cases of campylobacteriosis in the same geographical area. Forty-eight combined fla types were seen among the 315 Campylobacter isolates studied. Six were found in isolates from all four hosts and represented 50% of the total number of isolates. Seventy-one different SmaI PFGE macrorestriction profiles (mrps) were observed, with 86% of isolates assigned to one of 29 different mrps. Fifty-seven isolates from diverse hosts, times, and sources had an identical SmaI mrp and combined fla type. Conversely, a number of genotypes were unique to a particular host. We provide molecular evidence which suggests a link between campylobacters in the farm environment with those causing disease in the community.
Collapse
Affiliation(s)
- C Fitzgerald
- Department of Biological Sciences, Lancaster University, Lancaster LA1 4YQ, United Kingdom.
| | | | | | | |
Collapse
|
15
|
Affiliation(s)
- T M Wassenaar
- Institute of Medical Microbiology and Hygiene, Johannes Gutenberg University, D-55101 Mainz, Germany
| | | |
Collapse
|
16
|
|
17
|
Marshall S, Clark CG, Wang G, Mulvey M, Kelly MT, Johnson WM. Comparison of molecular methods for typing Vibrio parahaemolyticus. J Clin Microbiol 1999; 37:2473-8. [PMID: 10405387 PMCID: PMC85259 DOI: 10.1128/jcm.37.8.2473-2478.1999] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An outbreak of Vibrio parahaemolyticus gastroenteritis on Canada's west coast in 1997 emphasized the need to develop molecular methods for differentiation and typing of these organisms. Isolates were analyzed by enterobacterial repetitive intergenic consensus sequence (ERIC) PCR, detection of restriction fragment length polymorphisms (RFLP) in rRNA genes (ribotyping), pulsed-field gel electrophoresis (PFGE), and RFLP analysis of the genetic locus encoding the polar flagellum (Fla locus RFLP analysis). ERIC PCR and ribotyping were the most informative typing methods, especially when used together, while Fla locus RFLP analysis was the least discriminatory. PFGE exhibited good discrimination but suffered from a high incidence of DNA degradation. ERIC PCR and ribotyping will be useful for the evaluation of genetic and epidemiological relationships among V. parahaemolyticus strains.
Collapse
Affiliation(s)
- S Marshall
- National Laboratory for Outbreak Investigations and Antibiotic Resistance, Laboratory Centre for Disease Control, Health Canada, Ottawa, Ontario
| | | | | | | | | | | |
Collapse
|
18
|
Owen RJ, Leeton S. Restriction fragment length polymorphism analysis of the flaA gene of Campylobacter jejuni for subtyping human, animal and poultry isolates. FEMS Microbiol Lett 1999; 176:345-50. [PMID: 10427717 DOI: 10.1111/j.1574-6968.1999.tb13682.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
233 strains of Campylobacter jejuni were subtyped by PCR-RFLP analysis of the flagellin (flaA) gene by double digestion with EcoRI and PstI (EP flaA-profiling). The strains represented a variety of common Penner heat stable (HS) serotypes and comprised isolates of human, bovine, ovine, chicken and canine origin. FlaA amplicons were obtained directly from DNA in cell lysates of most strains. RFLP analysis showed considerable allelic variation and nine EP flaA-types were identified of which the most common were type 2 (32%), type 3 (20%), type 4 (12%) and type 6 (12%). Other flaA-profiles each represented less than 10% of strains. C. jejuni strains of each serotype generally had one or two specifically associated flaA-types although some were features of several serotypes. Strains with the same flaA-type were found in different hosts. EP flaA-profiles were reproducible, clear and simple to record, and laboratory protocols were rapid and low cost with high throughput capacity. The EP flaA-profiling scheme provided an excellent molecular subtyping method to supplement HS serotyping, and reference strains are recommended to facilitate its use in future epidemiological investigations.
Collapse
Affiliation(s)
- R J Owen
- Laboratory of Enteric Pathogens, Central Public Health Laboratory, London, UK.
| | | |
Collapse
|
19
|
Hänninen ML, Hakkinen M, Rautelin H. Stability of related human and chicken Campylobacter jejuni genotypes after passage through chick intestine studied by pulsed-field gel electrophoresis. Appl Environ Microbiol 1999; 65:2272-5. [PMID: 10224037 PMCID: PMC91334 DOI: 10.1128/aem.65.5.2272-2275.1999] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/1998] [Accepted: 03/03/1999] [Indexed: 11/20/2022] Open
Abstract
The genomic stability of 12 Campylobacter jejuni strains consisting of two groups of human and chicken isolates was studied by analysis of their PFGE (pulsed-field gel electrophoresis) patterns after passage through newly hatched chicks' intestines. The patterns of SmaI, SalI, and SacII digests remained stable after intestinal passage, except for those of two strains. One originally human strain, FB 6371, changed its genotype from II/A (SmaI/SacII) to I/B. Another strain, BTI, originally isolated from a chicken, changed its genotype from I/B to a new genotype. The genomic instability of the strains was further confirmed by SalI digestion and ribotyping of the HaeIII digests. In addition, heat-stable serotype 57 of strain FB 6371 changed to serotype 27 in all isolates with new genotypes but remained unchanged in an isolate with the original genotype. Serotype 27 of strain BTI remained stable. Our study suggests that during intestinal colonization, genomic rearrangement, as demonstrated by changed PFGE and ribopatterns, may occur.
Collapse
Affiliation(s)
- M L Hänninen
- Department of Food and Environmental Hygiene, The Haartman Institute, 00231 Helsinki, Finland.
| | | | | |
Collapse
|
20
|
RFLP and Sequence Analysis of and PCR Products Amplified Directly from Environmental Samples. Lebensm Wiss Technol 1998. [DOI: 10.1006/fstl.1998.0410] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
21
|
Jackson CJ, Fox AJ, Jones DM, Wareing DR, Hutchinson DN. Associations between heat-stable (O) and heat-labile (HL) serogroup antigens of Campylobacter jejuni: evidence for interstrain relationships within three O/HL serovars. J Clin Microbiol 1998; 36:2223-8. [PMID: 9665996 PMCID: PMC105019 DOI: 10.1128/jcm.36.8.2223-2228.1998] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
A comparative examination of the heat-stable (O) and heat-labile (HL) serogrouping results for 9,024 sporadic human isolates of Campylobacter jejuni revealed conserved associations between specific O and HL antigens (O/HL serovars). Forty-nine percent of the isolates which grouped for both O and HL antigens belonged to one of three serovars: O 4 complex/HL 1 (17.9%), O 1/HL 2 (16.8%), or O 50/HL 7 (14.5%). Other common serovars were O 2/HL 4 (8.3%), O 6/HL 6 (8.1%), O 53/HL 11 (4.5%), O 19/HL 17 (3.3%), O 5/HL 9 (3.3%), O 9/HL 9 (3.2%), and O 23/HL 5 (3.1%). These 10 serovars accounted for 83.1% of the serogroupable isolates. A large number of strains (41.3%) could be typed by only one of the two methods or could not be serogrouped (11%). Strains belonging to three serovars, O 2/HL 4, O 50/HL 7, and O 23/HL 5, were further characterized by combining data from expressed features (O/HL serogroups, phage groups, and biotypes) with restriction fragment length polymorphism genotypes. These polyphasic data demonstrated that within each serovar, individual isolates showed substantial conservation of both genomic and phenotypic characteristics. The essentially clonal nature of the three serovars confirmed the potential of combined O and HL serogrouping as a practical and phylogenetically valid method for investigating the epidemiology of sporadic C. jejuni infection.
Collapse
Affiliation(s)
- C J Jackson
- Public Health Laboratory, Withington Hospital, Manchester, United Kingdom.
| | | | | | | | | |
Collapse
|
22
|
Janvier B, Constantinidou C, Aucher P, Marshall ZV, Penn CW, Fauchère JL. Characterization and gene sequencing of a 19-kDa periplasmic protein of Campylobacter jejuni/coli. Res Microbiol 1998; 149:95-107. [PMID: 9766213 DOI: 10.1016/s0923-2508(98)80025-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In order to study a 19-kDa protein (p19) of Campylobacter jejuni, we purified this protein to homogeneity from C. jejuni strain 81,176 by anion exchange chromatography. The molecular weight of the native protein is 19,000 daltons. P19 was found to be acidic with an isoelectric point of 4.8 and was located in the periplasmic space of the bacteria. The 20 N-terminal amino acids were sequenced and no significant similarities with known proteins were shown. A monoclonal antibody showed that p19 is conserved in the 2 species C. jejuni and C. coli. Analysis of sera from 23 patients with a Campylobacter-related infection indicated that p19 is not immunogenic during natural infection in man. The gene encoding p19 was cloned and no strong homologies with known sequences were identified. The preparation of a knockout mutant in p19 will enable the investigation of the function of this cell wall component of Campylobacter.
Collapse
MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Monoclonal
- Bacterial Proteins/chemistry
- Bacterial Proteins/genetics
- Bacterial Proteins/isolation & purification
- Base Sequence
- Blotting, Western
- Campylobacter Infections/immunology
- Campylobacter coli/chemistry
- Campylobacter coli/genetics
- Campylobacter jejuni/chemistry
- Campylobacter jejuni/genetics
- Child
- Chromatography, High Pressure Liquid
- Cloning, Molecular
- DNA, Bacterial/chemistry
- Electrophoresis, Gel, Two-Dimensional
- Electrophoresis, Polyacrylamide Gel
- Female
- Humans
- Isoelectric Point
- Membrane Proteins/chemistry
- Membrane Proteins/genetics
- Membrane Proteins/isolation & purification
- Mice
- Mice, Inbred BALB C
- Molecular Sequence Data
- Molecular Weight
- Periplasm/chemistry
- Periplasmic Proteins
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
Collapse
Affiliation(s)
- B Janvier
- Microbiologie A, CHU la Milétrie, Poitiers, France
| | | | | | | | | | | |
Collapse
|
23
|
Meinersmann RJ, Helsel LO, Fields PI, Hiett KL. Discrimination of Campylobacter jejuni isolates by fla gene sequencing. J Clin Microbiol 1997; 35:2810-4. [PMID: 9350739 PMCID: PMC230067 DOI: 10.1128/jcm.35.11.2810-2814.1997] [Citation(s) in RCA: 181] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Comparison of the entire coding sequence of flaA (1,764 nucleotides) from 15 isolates of Campylobacter jejuni showed two regions of high variability, one region approximately from base positions 700 to 1,450 and a short variable region (SVR) from base positions 450 to 600. Parsimony analysis of the SVR sequences yielded a dendrogram similar to that which was derived by analysis of the entire gene. PCR was used to generate templates, and the SVR was sequenced with primers constructed to hybridize to conserved flanking sequences. The SVRs of 22 isolates of C. jejuni from four outbreaks that have been well characterized and a larger panel of isolates from three additional outbreaks were sequenced. Analysis of the nucleotide sequences produced results that grouped the isolates very similarly to other subtyping techniques. Sequence data were also generated for isolates from three additional outbreaks. Categorizing the isolates by fla SVR DNA sequence placed them in epidemiologically relevant groups. Sequence analysis of the C. jejuni flaA SVR may be a useful tool for epidemiologic investigations and could complement or replace serotyping and other subtyping methods.
Collapse
Affiliation(s)
- R J Meinersmann
- Agricultural Research Service, U.S. Department of Agriculture, Athens, Georgia 30604, USA.
| | | | | | | |
Collapse
|
24
|
Harrington CS, Thomson-Carter FM, Carter PE. Evidence for recombination in the flagellin locus of Campylobacter jejuni: implications for the flagellin gene typing scheme. J Clin Microbiol 1997; 35:2386-92. [PMID: 9276421 PMCID: PMC229973 DOI: 10.1128/jcm.35.9.2386-2392.1997] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The flagellin subunit of the flagellar filament in Campylobacter jejuni is encoded by two highly homologous tandem genes, flaA and flaB. The flaA gene was sequenced in 18 strains of C. jejuni, including isolates from three outbreak groups. Sequences obtained were compared with flaA sequences available in the GenBank database, and all were analyzed for mosaic gene structure by using recently described statistical tests for detecting gene conversion among aligned sets of sequences. Strong evidence was found supporting recombination between flaA genes of different strains (i.e., intergenomic recombination). Intragenomic recombination between the flaA and flaB genes of C. jejuni TGH9011 was also demonstrated. Both mechanisms of recombination may act as a potential means by which pathogenic strains can generate increased antigenic diversity, so allowing them to escape the immunological responses of the host. Furthermore, demonstration of recombination within and between flagellin loci of natural strains suggests that flagellin gene typing (restriction fragment length polymorphism analysis of PCR-amplified flagellin genes) cannot be considered a stable method for long-term monitoring of pathogenic Campylobacter populations.
Collapse
Affiliation(s)
- C S Harrington
- Department of Medical Microbiology, University of Aberdeen, Scotland, United Kingdom.
| | | | | |
Collapse
|
25
|
Jackson CJ, Fox AJ, Wareing DR, Hutchinson DN, Jones DM. The application of genotyping techniques to the epidemiological analysis of Campylobacter jejuni. Epidemiol Infect 1996; 117:233-44. [PMID: 8870620 PMCID: PMC2271704 DOI: 10.1017/s0950268800001400] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Campylobacter jejuni serogroup reference strains and collections of sporadic and outbreak-associated isolates were examined for restriction fragment length polymorphisms (RFLPs), using C. jejuni random chromosomal and 16S rRNA gene probes. A collection of 48 Penner (HS) and 14 Lior (HL) serogroup reference strains, plus 10 clinical isolates, generated 35 RFLP and 26 ribotype patterns. In combination the two loci generated 48 distinct genotypes. Both probes were able to differentiate between certain random isolates of the same HS/HL serogroups but greater discrimination was obtained with RFLP than with ribotyping. Genotyping distinguished accurately between related and unrelated strains when applied to several outbreaks. Genotypic analysis of C. jejuni by restriction fragment length polymorphisms is a valuable technique for epidemiological typing. Chromosomal variation detected by the two unlinked probe loci provides some information about the genetic relationship between isolates.
Collapse
Affiliation(s)
- C J Jackson
- Public Health Laboratory, Withington Hospital, Manchester
| | | | | | | | | |
Collapse
|
26
|
Santesteban E, Gibson J, Owen RJ. Flagellin gene profiling of Campylobacter jejuni heat-stable serotype 1 and 4 complex. Res Microbiol 1996; 147:641-9. [PMID: 9157491 DOI: 10.1016/0923-2508(96)84021-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Flagellin gene (flaA) sequence polymorphisms were used to discriminate amongst 167 strains of Campylobacter jejuni serotype HS1 and the HS4 complex. Direct PCR of cell suspensions provided a rapid method for analysing DNase-negative strains, whereas purified DNA was necessary for the DNase-positive strains. Nine different PCR-RFLP patterns (genotypes) were identified by analysis with Hinfl and 12 with Ddel, giving a total of 19 combined flaA profile types. The most common combined fla types were H1D1 (35%) and H1D2 (20%) for serotype HS1, and H1D2 (23%) and H4D7 (43%) for serotype HS4. Comparison of flaA typing with other key subtyping methods for C. jejuni showed it to be less discriminatory than pulsed field gel electrophoretic (PFGE) profiling, but more so than ribotyping. Fla types provided a useful indication of strain diversity, but as some were conserved across different serotypes, ribotypes and PFGE types, the same fla type could not be used as the sole basis for grouping strains. We provide evidence for several distinct subgroups based on conserved multiple genomic criteria within the HS1 and HS4 strains, and conclude that monitoring of such subgroups could provide a novel basis for future epidemiological surveillance of C. jejuni.
Collapse
Affiliation(s)
- E Santesteban
- Laboratory of Enteric Pathogens, Central Public Health Laboratory, London, United Kingdom
| | | | | |
Collapse
|
27
|
Burnens AP, Wagner J, Lior H, Nicolet J, Frey J. Restriction fragment length polymorphisms among the flagellar genes of the Lior heat-labile serogroup reference strains and field strains of Campylobacter jejuni and C. coli. Epidemiol Infect 1995; 114:423-31. [PMID: 7781730 PMCID: PMC2271288 DOI: 10.1017/s0950268800052134] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Several typing systems have been described for Campylobacter jejuni and C. coli, to assess the complex epidemiology of these important enteric pathogens. In the present study two typing methods, slide agglutination according to the Lior scheme, and the demonstration of restriction-fragment length polymorphisms (RFLP) of flagellar genes, have been used in parallel on a set of 194 strains. This set comprised 118 sero-reference strains of C. jejuni and C. coli of the Lior scheme, as well as 76 clinical isolates. All isolates were serotyped and subjected to PCR for amplification of flagellar genes, and the PCR product was restricted with Alu I. Flagellar genes could be amplified in 152 strains. Among 85 seroreference strains, 74 different RFLP patterns were observed, and among 67 clinical isolates, there were 36 patterns. There was only limited correlation between flagellar RFLP and the Lior serogroup, and the variability of patterns in serogroups HL2 and HL4 were as marked as the variability between serogroups. Flagellar gene RFLP patterns are shown to be stable, highly discriminatory epidemiologic markers.
Collapse
Affiliation(s)
- A P Burnens
- National Reference Laboratory for Foodborne Diseases, University of Berne, Switzerland
| | | | | | | | | |
Collapse
|