Coagulase positive staphylococci, Staphylococcus aureus and Staphylococcus pseudintermedius, are important causes of infection in human beings and dogs respectively. The rapid increase in the incidence of methicillin resistant S. aureus (MRSA) in people and its emergence in dogs has raised the profile of this organism in the veterinary community. Similarly, human S. pseudintermedius infections have also been recognized as the awareness of bidirectional human-dog transmission increases. Antimicrobial resistance has been complicating the treatment of S. aureus infections since the first penicillin resistance was observed in the 1940s. Methicillin resistance (resistance to the majority of â-lactams), is particularly troublesome as the â-lactams are a safe and effective class of antimicrobials for treating susceptible staphylococcal infections in both human beings and dogs. Additionally, resistance to other antimicrobial classes such as the macrolides, tetracyclines, sulfonamides and chloramphenicol, further complicates the treatment of staphylococcal infections. Particularly in small animal private practice, infections are often treated empirically, requiring knowledge of locally prevalent susceptibility patterns. The emergence of resistance to commonly used drugs necessitates surveillance to monitor the dissemination of resistance, and to guide antimicrobial therapy. In the last decade there have been many studies attempting to address gaps in our knowledge of the ecology of S. aureus and S. pseudintermedius in dogs. In particular, the prevalence of colonization with methicillin resistant staphylococci has been documented in different dog populations. However, failing to sample all relevant sites of colonization, may have decreased the sensitivity of these studies. The sites where coagulase positive staphylococci colonize dogs have not been systematically evaluated. The clinical and infection control implications of S. aureus infections, or colonization in the case of MRSA, requires timely laboratory identification. The tube coagulase test is arguably the most important tool used for identifying of staphylococcal species. Studies dating from the 1970s and 1980s suggested that the use of rabbit plasma, which is the current standard, may not be the ideal media for all situations and that different plasmas may need to be considered in different diagnostic situations. In this thesis, the ecology of coagulase positive staphylococci in dogs was studied from start to finish including sample collection, bacterial identification, antimicrobial susceptibility testing and molecular epidemiological investigations. This thesis will serve as a template to be used for follow up studies or by investigators setting up a surveillance program in their region. We found that multiple sites of colonization (nares, pharynx and rectum), are involved in both S. aureus and S. pseudintermedius carriage in dogs. Single site colonized dogs were identified, suggesting that maximal screening sensitivity requires sampling multiple body sites. When canine and rabbit plasma were compared, the time until clot formation was found to be significantly shorter with canine plasma. Although, the availability of canine plasma may limit its use in the diagnostic laboratory, investigators should be aware that rabbit plasma may not be ideal for all applications of the tube coagulase test. Antimicrobial susceptibility testing of canine S. aureus and S. pseudintermedius and human S. aureus isolates was done. Consistent with previous reports from Saskatoon, the S. pseudintermedius isolates were found to be overwhelmingly susceptible: pan-susceptibility was the most common phenotype identified. Antimicrobial resistance was more common among S. aureus than S. pseudintermedius including resistance to drugs which all S. pseudintermedius were susceptible to. No resistance to vancomycin, linezolid, daptomycin or quinupristin/dalfopristin was found. All isolates remained susceptible to at least one of tetracycline, clindamycin, chloramphenicol or trimethoprim/sulfamethoxazole which are often used for treating infections caused by multidrug resistant staphylococci. Finally, DNA fingerprinting revealed that the canine and human S. aureus isolates tested did not belong to mutually exclusive populations. Using AFLP, IS-typing and spa typing, many human and canine isolates were indistinguishable suggesting a common population, supporting the hypothesis that interspecies transmission occurs. The complex and under-characterized ecology of S. aureus and S. pseudintermedius requires more study so that risk factors for infection can be defined and effective infection control measures implemented. Because multiple species are involved, collaboration between veterinarians and human health professionals is imperative, and will no doubt yield the most success in our efforts to understand these potential pathogens.

The dissemination of members of the Enterobacteriaceae family with extended spectrum beta-lactamases (ESBLs) and metallo-beta-lactamases (MBLs) has become a global concern. ESBLs and MBLs have been reported in humans, domestic animals, wildlife and the environment, and their isolation frequencies are increasing rapidly worldwide.  Most studies have been performed in developed countries and quite few in developing countries, where the antibiotic consumption is often poorly controlled. To explore the environmental contamination of antibiotic resistance in Bangladesh, and of ESBLs and MBLs in particular, fecal samples from poultry and wild birds were studied in this thesis. Samples were collected from both sick birds (poultry having Escherichia coli infections) and healthy birds (free-range poultry, seagulls and crows) residing in different environmental niches. Samples from patients and fresh/sea water were included, to follow the chain of antibiotic resistance in bacteria from humans to the environment. Information regarding the antibiotic usage in poultry production was also collected. The susceptibility of avian E. coli isolates cultured with and without selective pressure was tested against antibiotics commonly used in human and veterinary medicine in Bangladesh. Special attention was paid to ESBL-producing isolates, which were further characterized genetically. The results of the studies showed that E. coli isolates from commercial poultry, free-range poultry, gulls and crows were resistant to several classes of antibiotics, and that the level and spectrum of antibiotic resistance varied between different bird populations. There was no NDM-producer found among the birds, but ESBL-producing Enterobacteriaceae could be found in up to 59% of the crows, the birds with the highest carriage rate of multiresistant  Enterobacteriaceae of all bird species studied. The most common ESBL-type was CTX-M-15, which also is the most common in the human population in Bangladesh. Birds also shared clinically important sequence types with humans, including E. coli clone O25b-ST131. In conclusion, ESBL-producing bacteria with multiresistance are easily spread to wild birds. Their opportunistic feeding behavior at poorly managed hospital waste dumps and nearby water bodies makes them into both reservoirs and active spreaders. The high level of antibiotic resistant and ESBL-producing bacteria in the bird population of Bangladesh is worrying, and there is no easy solution in sight. Nationwide programs are necessary to both improve the management of hospital waste and sewage and the control of the antibiotic usage to prevent further environmental contamination. / <p>Time of defence has been changed to 09:00 am on 2013-05-27</p>

Coagulase positive staphylococci, Staphylococcus aureus and Staphylococcus pseudintermedius, are important causes of infection in human beings and dogs respectively. The rapid increase in the incidence of methicillin resistant S. aureus (MRSA) in people and its emergence in dogs has raised the profile of this organism in the veterinary community. Similarly, human S. pseudintermedius infections have also been recognized as the awareness of bidirectional human-dog transmission increases. Antimicrobial resistance has been complicating the treatment of S. aureus infections since the first penicillin resistance was observed in the 1940s. Methicillin resistance (resistance to the majority of â-lactams), is particularly troublesome as the â-lactams are a safe and effective class of antimicrobials for treating susceptible staphylococcal infections in both human beings and dogs. Additionally, resistance to other antimicrobial classes such as the macrolides, tetracyclines, sulfonamides and chloramphenicol, further complicates the treatment of staphylococcal infections. Particularly in small animal private practice, infections are often treated empirically, requiring knowledge of locally prevalent susceptibility patterns. The emergence of resistance to commonly used drugs necessitates surveillance to monitor the dissemination of resistance, and to guide antimicrobial therapy. In the last decade there have been many studies attempting to address gaps in our knowledge of the ecology of S. aureus and S. pseudintermedius in dogs. In particular, the prevalence of colonization with methicillin resistant staphylococci has been documented in different dog populations. However, failing to sample all relevant sites of colonization, may have decreased the sensitivity of these studies. The sites where coagulase positive staphylococci colonize dogs have not been systematically evaluated. The clinical and infection control implications of S. aureus infections, or colonization in the case of MRSA, requires timely laboratory identification. The tube coagulase test is arguably the most important tool used for identifying of staphylococcal species. Studies dating from the 1970s and 1980s suggested that the use of rabbit plasma, which is the current standard, may not be the ideal media for all situations and that different plasmas may need to be considered in different diagnostic situations. In this thesis, the ecology of coagulase positive staphylococci in dogs was studied from start to finish including sample collection, bacterial identification, antimicrobial susceptibility testing and molecular epidemiological investigations. This thesis will serve as a template to be used for follow up studies or by investigators setting up a surveillance program in their region. We found that multiple sites of colonization (nares, pharynx and rectum), are involved in both S. aureus and S. pseudintermedius carriage in dogs. Single site colonized dogs were identified, suggesting that maximal screening sensitivity requires sampling multiple body sites. When canine and rabbit plasma were compared, the time until clot formation was found to be significantly shorter with canine plasma. Although, the availability of canine plasma may limit its use in the diagnostic laboratory, investigators should be aware that rabbit plasma may not be ideal for all applications of the tube coagulase test. Antimicrobial susceptibility testing of canine S. aureus and S. pseudintermedius and human S. aureus isolates was done. Consistent with previous reports from Saskatoon, the S. pseudintermedius isolates were found to be overwhelmingly susceptible: pan-susceptibility was the most common phenotype identified. Antimicrobial resistance was more common among S. aureus than S. pseudintermedius including resistance to drugs which all S. pseudintermedius were susceptible to. No resistance to vancomycin, linezolid, daptomycin or quinupristin/dalfopristin was found. All isolates remained susceptible to at least one of tetracycline, clindamycin, chloramphenicol or trimethoprim/sulfamethoxazole which are often used for treating infections caused by multidrug resistant staphylococci. Finally, DNA fingerprinting revealed that the canine and human S. aureus isolates tested did not belong to mutually exclusive populations. Using AFLP, IS-typing and spa typing, many human and canine isolates were indistinguishable suggesting a common population, supporting the hypothesis that interspecies transmission occurs. The complex and under-characterized ecology of S. aureus and S. pseudintermedius requires more study so that risk factors for infection can be defined and effective infection control measures implemented. Because multiple species are involved, collaboration between veterinarians and human health professionals is imperative, and will no doubt yield the most success in our efforts to understand these potential pathogens.

In this study, 59 epidemiologically unrelated Salmonella strains isolated from foods in T&uuml / rkiye and 49 Salmonella strains obtained from National Salmonella Reference Laboratories of Germany were analysed. For the characterization of strains, analyses such as serotyping, phage typing, antibiotyping and molecular biological characterization were done. The strains exhibited 17 different serotypes with S. Enteritidis serotype and PT21 phage type being the most prevalent in Turkish isolates. The highest antimicrobial resistance was observed against NAL for Turkish strains, whereas it was against SUL for strains from German origin. Molecular typing of all strains exhibited different plasmid profiles and PFGE patterns. There were 1-4 plasmids/profile for Turkish strains and 1-7 plasmids/profile for German strains. The PFGE patterns revealed 42 different subgroups, having two major clusters with 44,3% arbitrary homology. Among 72 resistant strains, the most prevalent resistance genotypes were observed as blatem-1 (%56, AMP resistance) / floR (%100, CHL and FFC resistance) / aphA1 (%100, KAN and NEO resistance) / tet(A) (%53, TET resistance) / aadA1 (%82, SPE and STR resistance) / sulI (%78, SUL resistance). The class I integron variable region analyses exhibited 700 bp (1 strain), 1000 bp (37 strain), 1200 bp (16 strain) and 1600 bp (3 strain) integrons.

Bovine respiratory disease (BRD) is the principal cause of morbidity and mortality among feedlot cattle. Mannheimia haemolytica is consistently implicated in this condition, but treatment options are diminishing with the rise of antimicrobial resistance and intensifying consumer pressure to reduce reliance on conventional therapies. Thus, sustainable alternatives like vaccination are required. In this study, the phenotypic and genotypic diversity of BRD pathogens were examined with the objective to identify vaccine targets using reverse vaccinology, an innovative approach to identify antigens via genomic sequence. Preliminary surveillance confirmed M. haemolytica serotype 2 isolates were predominant in healthy animals (75.5%) while serotypes 1 (70.7%) and 6 (19.5%) were common in diseased animals. Pathogens of BRD, including M. haemolytica, Pasteurella multocida and Histophilus somni were also isolated from North American BRD mortalities, and compared using pulsed-field gel electrophoresis and antimicrobial susceptibility. Concurrently, polymerase chain reaction detection of bacterial and viral agents confirmed that M. haemolytica with bovine viral diarrhea virus were the most prevalent. Whereas isolates from live cattle were found to have a relatively low level of resistance, several pathogens from the mortalities were found to contain integrative conjugative elements (ICE) conferring resistance to seven antimicrobial classes. These ICEs were transferred via conjugation to other bacterial species, emphasizing the need for alternative antimicrobial therapies. Collectively, data from these investigations informed the selection of 11 diverse M. haemolytica strains for whole genome sequencing and comparative analyses. Several bacteriophage associated genes and CRISPR-Cas regulated gene expression systems were identified and are likely contributing to virulence in M. haemolytica. Coding sequences across all genomes were screened using pan-genome analysis, identifying 291 candidates with cell-surface associated signatures. Using a cell-free translation system and enzyme-linked immunosorbent assay the candidates were screened against serum from cattle challenged with serovar 1, 2 or 6 of M. haemolytica, and ranked according to immunogenicity. The top five vaccine candidates included Ssa1, ComE, a solute binding protein, an outer membrane protein, and the periplasmic component of an ABC transporter. With further characterization, these unique antigenic candidates could be developed into a vaccine to effectively reduce the dependence on antimicrobial therapies.

This thesis is an investigation of two common skin conditions of pigs: exudative epidermitis (EE) and ear necrosis (EN). The cause of exudative epidermitis and risk factors are well understood, however the study was prompted because of reports of treatment failure. A survey of veterinary practitioners (n=15) and pork producers (n=58) was conducted to determine which treatments are commonly used. Amongst farmer respondents topical treatments were often used and in serious cases injectable penicillin G was administered. Thirty farms with a history of EE were visited and skin samples taken from affected pigs. The antimicrobial resistance pattern for isolates of Staphylococcus hyicus and Staphylococcus aureus revealed that almost all isolates were resistant to penicillin G and ampicillin. In addition, certain isolates of S. hyicus as well as S. aureus were shown to possess the mecA gene which is associated with resistance to methicillin. The presence of widespread resistance to penicillin G among staphylococci isolates suggests a reason for poor treatment response. The presence of the mecA gene in staphylococci other than S. aureus recovered from pigs has not been reported before and is of interest from a public health standpoint. A second study investigated EN. The causative agent(s) and the associated risk factors are not well understood. Eleven case farms were visited and skin biopsies and oral swabs taken from pigs in early, mid and late stages of the disease. Bacteriological culturing was performed for staphylococci and spirochetes as well as histological examination of the biopsy samples. Farm-level risk factors were assessed on 14 case farms and 9 control farms. Staphylococci were generally recovered in abundance from the majority of samples but spirochetes were not cultured and only identified microscopically in a small number of tissue samples. Histology revealed that the disease appeared to occur first as a lesion on the epidermal surface that caused tissue damage and led to subsequent invasion of the dermis. This pathogenesis was consistent with the hypothesis that staphylococci colonize the skin surface and produce exfoliating toxins. Ear biting was noted to be commonly present and may be an important contributing factor. / Ontario Pork Animal Health Strategic Initiative Fund Ontario Ministry of Agriculture, Food and Rural Affairs(OMAFRA) Ontario Veterinary College, University of Guelph

A cross-sectional study investigated the shedding of zoonotic organisms (Campylobacter, Giardia, and Salmonella) and antimicrobial resistant generic E. coli in dogs that visited dog parks in southern Ontario. Logistic regression models were constructed to identify risk factors. Factors for the shedding of Campylobacter spp. included consumption of a commercial dry diet, exposure to compost, and age. Factors for the shedding of C. upsaliensis included outdoor water access and age. A risk factor for ampicillin resistance was attending a dog day care. For resistance to at least one antimicrobial, factors included attending a dog day care, breed size, consumption of a commercial dry diet and consumption of a homemade cooked diet. For multiclass resistance, exposure to compost, breed size, and consumption of a commercial dry diet were identified. Park was not significant in any model. Dogs that visit dog parks shed organisms that may pose a human health risk. / Canadian Institutes of Health Research (CIHR) Institute of Population and Public Health/ Public Health Agency of Canada Applied Public Health Research Chair awarded to J. M. Sargeant; Public Health Agency of Canada; Ontario Veterinary College Pet Trust Fund; and a grant to D. L. Pearl from the Canada Foundation for Innovation and the Ontario Research Fund.

Gonorrhea is caused by the human pathogen Neisseria gonorrhoeae. More than 106 million new cases of N. gonorrhoeae infections occur each year worldwide. There is no vaccine available against gonococcal infections and treatment of gonorrhea with antibiotics is the only way to eradicate infection. The high prevalence of antibiotic resistance (AMR) in this microorganism makes the effective treatment of gonococcal infections increasingly problematic. The emergence of AMR, especially to extended spectrum cephalosporins (i.e. cefixime and ceftriaxone) which are the last possibilities for single dose treatment options for gonococcal infections, is a serious concern. Gonorrhea may become an untreatable infection in the near future. Saskatchewan (SK) has one of the highest rates of gonorrhea in Canada. In order to better characterize the gonorrhea epidemic in SK, the objectives of the present research were to determine the prevalence and trends of AMR and emerging AMR mechanisms in N. gonorrhoeae isolates. AMR mechanisms were ascertained for the first time in SK in order to identify genetic causes of resistance. This was completed by determining and analyzing the DNA sequences of various genes - penA, mtrR, porB ponA, gyrA, parC mtrR, 23S rRNA alleles and erm –implicated in gonococcal AMR. The population dynamics of the N. gonorrhoeae isolates in SK was investigated by DNA based molecular methods to determine strain distribution, evolution of AMR phenotypes, and association between strain types (STs) and AMR genotypes and phenotypes. N. gonorrhoeae isolates (n=427) from Saskatchewan (2003-2011) were susceptible to antibiotics now recommended for treatment - cefixime, ceftriaxone and spectinomycin. Over 95% of the isolates tested were also susceptible to penicillin (96%) and ciprofloxacin (95.5%), antibiotics no longer recommended for treatment, and azithromycin (99.4%). Tetracycline resistance was also high (50.1%). N. gonorrhoeae isolates that were resistant to the antibiotics tested and also those isolates with MICs ≥0.003 mg/L to cefixime and ceftriaxone were analyzed (n=146) to determine their resistance mechanisms. This analysis revealed that reduced susceptibility to ceftriaxone and cefixime and resistance to penicillin is mediated by specific mutations in penicillin binding protein 2 (PBP2), in the promoter and dimerization domains of MtrR and porin protein (PorB). Novel mutations and combinations of mutations were noted. Ciprofloxacin resistant N. gonorrhoeae isolates carried double mutations in GyrA (S91F and D95G/N) and a S87R or S88P substitution in ParC. Isolates resistant to azithromycin had specific mutations in all the four alleles of 23S rRNA as well as in the DNA binding domain of MtrR. Most resistance was chromosomally mediated while plasmid-mediated resistance to penicillin (0.93% of penicillin resistant isolates) and tetracycline (3.3%) was low. DNA based strain typing methods such as porB-DNA sequencing, N. gonorrhoeae multi-antigen sequence typing (NG-MAST) and multilocus sequence typing (MLST) showed that the gonococcal population in SK differs appreciably from both other Canadian provinces and from strains reported internationally. MLST analysis, which ascertains the evolution of isolates over time, demonstrated that penicillin and tetracycline resistant isolates in SK evolved through spontaneous mutations in established lineages. Ciprofloxacin and azithromycin resistant N. gonorrhoeae isolates, on the other hand, were introduced into SK from outside the province. Significant associations between particular mutation pattern combinations in resistance determining genes and specific NG-MAST STs were identified e.g. NG-MAST ST 25 was associated with specific combined mutation patterns in PBP2, MtrR and PorB and antibiotic susceptibility; and, NG-MAST ST 3654 was associated with another PBP2/MtrR/PorB mutation pattern, chromosomal resistance to penicillin and tetracycline and elevated MICs to cefixime. This research shows the importance of regional antimicrobial susceptibility monitoring. In the context of SK, this means that local surveillance of gonococcal AMR may be used to develop policies for regional treatment guidelines which promote the prudent use of antimicrobials for treatment, including those antibiotics which may no longer be used in other regions due to higher AMR rates. Further, the significant association between particular AMR mutation pattern combinations and specific STs indicates that AMR might be predicted. These results should assist in the development of non-culture-based tests for the diagnosis of gonococcal AMR similar to nucleic acid amplification tests used to diagnose N. gonorrhoeae infections.

Background: Clinical breakpoints and epidemiological cut-off values for N. gonorrhoeae azithromycin antimicrobial susceptibility testing have not been established. This study utilized existing minimum inhibitory concentration (MIC) data from CDC’s Gonococcal Isolate Surveillance Project (GISP) to establish epidemiological cut-off values for azithromycin and N. gonorrhoeae as determined by agar dilution. Methods: MIC distributions for the pooled dataset and each data year (2005-2012) were constructed. Epidemiological cut-off values were calculated using two methods. Method 1 considers the wild-type MIC distribution, the modal MIC for the distribution, and the inherent variability of the test (±1 twofold-dilution). Method 2 defines the epidemiological cut-off value as two twofold-dilutions higher than the MIC50. Results: Taking into consideration the wild-type MIC distributions and the inherent variability of the test, the epidemiological cut-off value chosen for the pooled dataset and each data year using Method 1 was ≤1.0 µg/mL. The MIC50 for the pooled dataset and each data year was 0.25 µg/mL. Two twofold-dilutions higher than the MIC50 (0.25 µg/mL) for the pooled dataset and each data year was 1.0 µg/mL. Discussion: The epidemiological cut-off values chosen using Methods 1 and 2 (≤1.0 µg/mL) were identical for the pooled dataset and each data year, indicating the epidemiological cut-off value has not changed from 2005-2012. The epidemiological cut-off value for N. gonorrhoeae azithromycin agar dilution antimicrobial susceptibility testing established during this study can be used to help set clinical breakpoints and identify isolates with reduced susceptibility to azithromycin.

Tyrimo tikslas – disertaciniame darbe suplanuotų atlikti tyrimų tikslas buvo įvertinti broilerių pulkų ir mažmeninėje prekyboje parduodamos paukštienos (broilerių sparnelių ir blauzdelių) užkrėstumo kampilobakterijomis sąsajas su žmonių susirgimais kampilobakterioze bei kampilobakterijų atsparumą antimikrobinėms medžiagoms Lietuvoje. Darbo tikslui pasiekti buvo atlikti tyrimai pagal šiuos numatytus uždavinius: 1. Nustatyti broilerių pulkų ir šviežios paukštienos produktų – sparnelių ir blauzdelių užkrėstumą kampilobakterijomis. 2. Įvertinti sąsajas tarp kampilobakterijų paplitimo paukštienos gamybos grandinėje ir žmonių susirgimų kampilobakterioze atsižvelgiant į išskirtų kampilobakterijų padermių genetinius panašumus ar skirtumus. 3. Palyginti iš skirtingų šaltinių išskirtų kampilobakterijų padermių atsparumą antimikrobinėms medžiagoms. 4. Įvertinti broilerių užsikrėtimo intensyvumo kampilobakterijomis įtaką galimam skerdenėlių užkrėstumui skerdimo metu. Tyrimai, kurių metu buvo išskiriamos kampilobakterijos iš broilerių pulkų, paukštienos produktų, bei žmonių klinikinių išmatų mėginių, atlikti vienerių metų (2009–2010) laikotarpiu. Tyrimų metu buvo įvertintas broilerių pulkų bei prekybos vietose parduodamų paukštienos produktų užkrėstumas kampilobakterijomis bei atliktas C. coli ir C. jejuni padermių, išskirtų iš broilerių pulkų, paukštienos produktų ir žmonių išmatų mėginių, genetinis charakterizavimas taikant RFIP metodą. Tokie tyrimai Lietuvoje atlikti pirmą kartą ir... [toliau žr. visą tekstą] / Aim of the study: the aim of the research was to estimate the level of contamination with Campylobacter spp., of poultry meat sold at retail (broiler wings and drumsticks) in connection with human campylobacteriosis cases in Lithuania, as well as antimicrobial resistance of Campylobacters isolated from both sources. To achieve the aim, research under the followings objectives has been carried out: 1. To evaluate the rate of contamination with Campylobacter spp. of broiler flocks and poultry products – wings and drumsticks. 2. To estimate the links between prevalence of Campylobacter spp. in poultry meat production chain and human cases of campylobacteriosis with regard to genetic diversity of Campylobacter spp. isolates. 3. To compare the antimicrobial resistance of Campilobacter spp. strains isolated from poultry meat production chain and human campylobacteriosis cases. 4. To evaluate the influence of quantitative load of Campylobacter spp. in broilers gastrointestinal tract to likely contamination of broiler carcasses during processing. The research, at which Campylobacter spp. were isolated from broiler flocks, poultry products and human stool samples, was conducted in a period of one year (2009–2010). With this study we evaluated the contamination of broiler flocks and poultry meat sold at retail with Campylobacter spp., genetic characterisation of C. coli and C. jejuni isolates from broiler flocks, poultry meat and human stool samples was made using the RFLP method... [to full text]