Campylobacter Bacteria Research Articles

Marked host specificity and lack of phylogeographic population structure of Campylobacter jejuni in wild birds

Zoonotic pathogens often infect several animal species, and gene flow among populations infecting different host species may affect the biological traits of the pathogen including host specificity, transmissibility and virulence. The bacterium Campylobacter jejuni is a widespread zoonotic multihost pathogen, which frequently causes gastroenteritis in humans. Poultry products are important transmission vehicles to humans, but the bacterium is common in other domestic and wild animals, particularly birds, which are a potential infection source. Population genetic studies of C. jejuni have mainly investigated isolates from humans and domestic animals, so to assess C. jejuni population structure more broadly and investigate host adaptation, 928 wild bird isolates from Europe and Australia were genotyped by multilocus sequencing and compared to the genotypes recovered from 1366 domestic animal and human isolates. Campylobacter jejuni populations from different wild bird species were distinct from each other and from those from domestic animals and humans, and the host species of wild bird was the major determinant of C. jejuni genotype, while geographic origin was of little importance. By comparison, C. jejuni differentiation was restricted between more phylogenetically diverse farm animals, indicating that domesticated animals may represent a novel niche for C. jejuni and thereby driving the evolution of those bacteria as they exploit this niche. Human disease is dominated by isolates from this novel domesticated animal niche.

Specific synthesis of neurostatin and gangliosides O-acetylated in the outer sialic acids using a sialate transferase.

Gangliosides are sialic acid containing glycosphingolipids, commonly found on the outer leaflet of the plasma membrane. O-acetylation of sialic acid hydroxyl groups is one of the most common modifications in gangliosides. Studies on the biological activity of O-acetylated gangliosides have been limited by their scarcity in nature. This comparatively small change in ganglioside structure causes major changes in their physiological properties. When the ganglioside GD1b was O-acetylated in the outer sialic acid, it became the potent inhibitor of astroblast and astrocytoma proliferation called Neurostatin. Although various chemical and enzymatic methods to O-acetylate commercial gangliosides have been described, O-acetylation was nonspecific and produced many side-products that reduced the yield. An enzyme with O-acetyltransferase activity (SOAT) has been previously cloned from the bacteria Campylobacter jejuni. This enzyme catalyzed the acetylation of oligosaccharide-bound sialic acid, with high specificity for terminal alpha-2,8-linked residues. Using this enzyme and commercial gangliosides as starting material, we have specifically O-acetylated the gangliosides’ outer sialic acids, to produce the corresponding gangliosides specifically O-acetylated in the sialic acid bound in alpha-2,3 and alpha-2,8 residues. We demonstrate here that O-acetylation occurred specifically in the C-9 position of the sialic acid. In summary, we present a new method of specific O-acetylation of ganglioside sialic acids that permits the large scale preparation of these modified glycosphingolipids, facilitating both, the study of their mechanism of antitumoral action and their use as therapeutic drugs for treating glioblastoma multiform (GBM) patients.

Comparison of immunochromatography, PCR and culture methods for the detection of Campylobacter bacteria

A total of 463 fecal specimens from human patients were tested for the presence of Camphylobacter by a commercial immunochromatography kit (ImmunoCard STAT! CAMPY), polymerase chain reaction (PCR) and conventional bacteriological (CB) methods. Using culture as the standard of reference, the ImmunoCard STAT! CAMPY assay had a sensitivity of 86% and a specificity of 100%. On the other hand, using PCR as the standard of reference, ImmunoCard STAT! CAMPY assay had a sensitivity of 90.5% and a specificity of 100%.

Campylobacter sequence typing databases: applications and future prospects

Human campylobacteriosis, caused by the zoonotic bacteria Campylobacter jejuni and Campylobacter coli, remains a major cause of gastroenteritis worldwide. For many countries the implementation of effective interventions to reduce the burden of this disease is a high priority. Nucleotide sequence-based typing, including multilocus sequence typing (MLST) and antigen gene sequence typing (AGST), has provided unified, comprehensive, and portable Campylobacter isolate characterization, with curated databases of genotypes available (pubMLST.org/campylobacter). Analyses of large collections of isolates from various sources with these approaches have provided many insights into the epidemiology of these ubiquitous and diverse organisms. C. jejuni and C. coli populations are structured into clonal complexes, which reflect genealogy and are associated with specific phenotypes, e.g. the predisposition to infect particular animals, a property that has permitted the development of genetic means of attributing isolates from human disease to potential sources. This has identified retail meat, and especially chicken, as the likely cause of most human disease in many countries, although some human isolates have other likely origins. Such data have led directly to effective intervention studies and will be important in ongoing targeting of intervention strategies and the monitoring of their effectiveness. MLST and AGST data have also been employed in epidemiological investigations and studies of Campylobacter evolution and population biology. The sequence databases that have been established are compatible with the whole-genome sequencing (WGS) approaches likely to be implemented soon; indeed, the hierarchical approach adopted by MLST and AGST will be essential for the exploitation of WGS data.

Study and comparison of the bacterial contamination outbreak of chicken meat consumed in some cities of Mazandaran Province (Iran)

Since meat is the richest protein source and plays an important role in the transmission of bacteria, especially Zeonosis to humans, the pathogenic bacteria outbreaks such asSalmonella, Campylobacter, Yersinia, and Aeromonas in the packed and unpacked chicken meat supplied to some cities of Mazandaran province of Iran performed, which have not been examined and analyzed yet. 200 samples of chicken meat from the early summer of 2010 to late winter of the same year were prepared and tested for 9 months. Sampling was conducted in the places where the meat were packed as well as the suppliers which had no packing and sold their materials in bulk in different areas of the cities of Mazandaran (Amol, Tonekabon, and Noor cities). All needed tests done exactly based on the instructions No. 2394 of Iranian National Standards Institute. Among the 200 samples of chicken meat prepared from Amol, Tonekabon, and Noor, the contamination of 75 samples were positive. 33 cases of the chicken were contaminated with Salmonella(21.5%), 53 samples with Campylobacter (26.5%), 18 samples with Yersinia anterocolitica (9%) and 14 samples were contaminated with Aeromonas (7%). The observed differences among the samples taken from different areas of the given cities, both in packed and unpacked forms, were statistically significant (P<0.05) and also the unpacked and packed meat product supplying centers in Mazandaran were not significantly different for having some differences in the type of contaminations. Key words: Pathogenic microbes, chicken meat, Mazandaran province, Iran.

Examining Assumptions about Female Dominance in Autoimmune Disease

Examining Assumptions about Female Dominance in Autoimmune Disease

Survey of Belgian consumption patterns and consumer behaviour of poultry meat to provide insight in risk factors for campylobacteriosis

A survey was set-up using a web-application supplemented with a print-out questionnaire to gather knowledge on consumption patterns and consumer behaviour in the storage and preparation of poultry meat, in particular poultry meat preparations for Belgian adults. In total 1618 respondents were reached. The survey included questions on risk factors associated with campylobacteriosis i.e. storage conditions, potential for cross-contamination and undercooking. Almost 61% of the respondents have identified home freezing of fresh poultry meat as a common storage technique. Several cross-contamination routes in the kitchen are confirmed, e.g. putting cooked poultry meat at the same plate of the raw poultry meat (11.2%), not washing hands after handling raw poultry meat (11%), using the same knife (6.7%) or cutting board (8.2%) for the vegetables which was prior used for the poultry meat. Although the majority of the respondents indicated to eat their poultry meat well-cooked (96% for poultry meat preparations to 98.4% for broiler), 16% would eat not well-cooked poultry meat if served at a barbecue. Poultry parts not marinated or seasoned was ranked as eaten the most, followed by broiler and next meat preparations (with first the marinated/seasoned poultry cuts and second the minced poultry meat preparations). The gathered consumer data may now be incorporated into a retail to fork quantitative risk assessment model for poultry meat preparations to estimate the risk for campylobacteriosis to the Belgian consumer and to enable the evaluation of risk mitigation strategies (to support risk managers) in the consumer phase. A proper comparison of the contribution of the different pathways to consumers’ exposure (i.e. effect of freezing during storage, prevalence of undercooking and cross-contamination) to Campylobacter bacteria may now be performed.

Observational Study of the Prevalence and Antibiotic Resistance of Campylobacter spp. from Different Poultry Production Systems in KwaZulu-Natal, South Africa

Campylobacter bacteria are important foodborne pathogens that cause acute diarrheal illness, and infection is often associated with contaminated poultry. In a blind observational study, the prevalence and resistance profiles of thermophilic Campylobacter strains collected from different poultry production systems were tested against the clinically used antibiotics ciprofloxacin, tetracycline, erythromycin, gentamicin, and streptomycin. Campylobacter strains were isolated from chickens in rural production systems, a free-range commercial facility, and industrially raised broiler and egg-laying chickens all situated in KwaZulu-Natal, South Africa. Isolates were collected from the chicken cecae and were identified with conventional methods and tested for antibiotic resistance with the Clinical and Laboratory Standards Institute agar dilution method. The prevalence of Campylobacter spp. isolates in chickens was 68% (56 samples) in rural production, 47% (140 samples) in commercial free-range broilers, 47% (133 samples) in industrial broilers, and 94% (34 samples) in industrial layer hens. Isolates from the rurally raised chickens showed significantly (P < 0.01) less resistance against ciprofloxacin (7.9%), erythromycin (0%), and tetracycline (21.6%) than those from commercially produced chickens. Isolates from the commercially raised chickens (free range and industrial) were highly resistant to tetracycline (98.9 to 100%). The incidence of gentamicin and streptomycin resistance was 1.6 and 11.5%, respectively, in commercial free-range broilers, 1.7 and 16.4%, respectively, in industrially raised broilers, and 12.9 and 40%, respectively, in industrially raised layers. It is possible that variations among the poultry production systems, including antimicrobial usage, result in differences in antibiotic resistance profiles in Campylobacter.

Crystal structure of the multicopper oxidase from the pathogenic bacterium Campylobacter jejuniCGUG11284: characterization of a metallo-oxidase

Multicopper oxidases are a multi-domain family of enzymes that are able to couple oxidation of substrates with reduction of dioxygen to water. These enzymes are capable of oxidizing a vast range of substrates, varying from aromatic to inorganic compounds such as metals. This metallo-oxidase activity observed in several members of this family has been linked to mechanisms of homeostasis in different organisms. Recently, a periplasmic multicopper oxidase, encoded by Campylobacter jejuni, has been characterised and associated with copper homeostasis and with the protection against oxidative stress as it may scavenge metallic ions into their less toxic form and also inhibit the formation of radical oxygen species. In order to contribute to the understanding of its functional role, the crystal structure of the recombinant McoC (Campylobacter jejuni CGUG11284) has been determined at 1.95 Å resolution and its structural and biochemical characterizations undertaken. The results obtained indicate that McoC has the characteristic fold of a laccase having, besides the catalytic centres, another putative binding site for metals. Indeed, its biochemical and enzymatic characterization shows that McoC is essentially a metallo-oxidase, showing low enzymatic efficiency towards phenolic substrates.

Market surveillance for contamination with thermotolerant campylobacters on various categories of chicken meat in Switzerland.

From April 2009 to April 2010, 1,132 samples of different types of chicken meat were tested qualitatively and quantitatively for thermotolerant campylobacters. Samples were recovered at retail in shops from the entire territory of Switzerland and comprised imported meat and meat from domestic production. The meat categories covered by the study were refrigerated and frozen meat, meat with and without skin, and meat preparations. Overall, 38.4% of the samples were positive, and in 27.8%, Campylobacter bacteria could be quantified. Counts ranged from ≥10 to <10(4) CFU/g with a maximum value of 8 × 10(3) CFU/g in a sample of refrigerated chicken meat with skin. The contamination frequencies were 45.2% in meat with skin, 40.8% in meat without skin, and 27.4% in meat preparations. Refrigerated meat was contaminated with Campylobacter bacteria more often than frozen meat (53.9 versus 20.0%). The study also showed considerable differences between the contamination rates found for samples from different large retail chains. In 2010, a further study with 120 samples of refrigerated and sliced chicken meat and fresh chicken liver was carried out in order to test a possible seasonal variation of the occurrence of Campylobacter bacteria. The contamination frequency of sliced meat increased from 10.0% in the period from February to March to 36.7% during July to August. In both sampling periods, the counts remained in the range of ≥10 to <100 CFU/g with a maximum value of 30 CFU/g. For chicken liver, a 10.0% contamination rate was observed in the period from December to January, which rose to 100% in the period from August to October. Contrary to the results for sliced meat, not only did the frequency of contamination increase but so did the Campylobacter counts, with the highest recorded value being 2.2 × 10(4) CFU/g.

Ciliate Ingestion and Digestion: Flow Cytometric Measurements and Regrowth of a Digestion‐Resistant Campylobacter jejuni

We measured ingestion and digestion rates of the pathogenic bacterium Campylobacter jejuni by a freshwater ciliate Colpoda sp. to determine whether Campylobacter is able to resist protist digestion. Campylobacter and the nonpathogenic bacterium Pseudomonas putida LH1 were labeled with a 5-chloromethylfluorescein diacetate, which fluoresces in intact and active cells but fades when exposed to low pH environments, such as protistan food vacuoles. Ingestion and digestion rates were measured via flow cytometry as the change in ciliate fluorescence over time, which corresponded to the quantity of intracellular bacteria. The rate of Campylobacter ingestion exceeded the digestion rate. Ciliates retained labeled Campylobacter 5h after ingestion was stopped. In contrast, ciliates grazing upon P. putida returned to baseline fluorescence within 5h, indicating that P. putida were completely digested. The ability of intracellular Campylobacter to remain viable after ingestion was tested by sorting individual ciliates and bacterial cells into Campylobacter-selective media. Campylobacter growth occurred in 15% (±5 SE) of wells seeded with highly fluorescent ciliates, whereas only 4% (±1) of wells seeded with free-living Campylobacter exhibited growth. A key advantage of this approach is that it is rapid and should be applicable to other phagocytotis studies.

International Committee on Systematics of Prokaryotes Subcommittee on the taxonomy of Campylobacter and related bacteria

International Committee on Systematics of Prokaryotes Subcommittee on the taxonomy of Campylobacter and related bacteria

Treatment of fresh poultry carcases with emulsions of glycerol monocaprate (monocaprin) to reduce contamination with Campylobacter and psychrotrophic bacteria

1. A previous study has shown that emulsions of monocaprin in citrate lactate buffer at pH 4·1–4·3 are highly active in killing Campylobacter in water, where they reduce viable bacterial counts by more than 6 log10 colony forming units (cfu) in 1 min at a concentration of 1·25 mM (0·03%). 2. The present study was carried out to evaluate whether monocaprin emulsions could be used to kill Campylobacter on raw poultry. 3. It was shown that immersion of naturally contaminated chicken legs in 20 mM (0·5%) monocaprin emulsion at pH 4·1 for 1 min at 20°C reduced the number of Campylobacter by 2·0 to 2·7 log10 cfu. Pre-chill dipping of whole carcases into 20 mM monocaprin emulsion in the slaughterhouse also caused a significant reduction in Campylobacter contamination. 4. Immersion in monocaprin emulsions at pH 4·1 was also assessed as a means to reduce the number of psychrotrophic spoilage bacteria. There were lower psychrotrophic bacteria counts on treated chicken parts than on untreated controls after storage at 3°C for up to 14 d. 5. Immersion in emulsions of monocaprin, which is a natural lipid classified as GRAS, may be a feasible method to reduce the number of Campylobacter and spoilage bacteria on raw poultry. This method could reduce the risk of human exposure to Campylobacter, and at the same time increase the shelf-life of poultry products.

Globin-mediated nitric oxide detoxification in the foodborne pathogenic bacterium Campylobacter jejuni proceeds via a dioxygenase or denitrosylase mechanism

Nitric oxide (NO ) is a toxin, but bacteria have evolved various strategies to detoxify this harmful radical to nitrate, the best known mechanism being the dioxygenase reaction of bacterial flavohaemoglobins. In addition, globins can form oxoferryl (Fe(IV) O) species through the reaction of the ferric haem with hydrogen peroxide: these species can also detoxify NO to nitrite and nitrate. During infection, Campylobacter is exposed to both NO and hydrogen peroxide. A question therefore arises: does Campylobacter jejuni utilize its single domain globin (Cgb) to detoxify NO via the oxoferryl route, or via the more conventional dioxygenase or denitroxylase routes? The data herein demonstrate that the reaction between Cgb and hydrogen peroxide is much slower than for other globins, and subsequent reaction between the oxoferryl species and NO is unfavourable. Furthermore, NO may bind to Cgb in the oxyferrous, ferrous and ferric states. The ample opportunity for NO to interact with ferrous and ferric Cgb, and the unfavourable reaction of ferric Cgb with hydrogen peroxide, suggests that NO detoxification in C. jejuni proceeds via a dioxygenase or denitroxylase route requiring the haem iron to exist only in the Fe(II) or Fe(III) redox states.

Prevalence and antimicrobial resistance of Campylobacter in raw milk in the selected areas of Poland

During the recent years, an immense increase in the number of food poisoning cases in people caused by Campylobacter (C.) species has occurred. Raw milk, next to poultry meat, is considered the most frequent cause of food poisoning in people caused by the subject bacteria, although it is not always possible to isolate Campylobacter cells from the incriminated milk. Most probably this difficulty is caused by low concentration of the pathogen in milk at the level of 2/3 cells/ml although even such low concentration represents risk to human health. The present study was aimed at determining the occurence of Campylobacter bacteria in milk originating from selected regions of Poland. The isolation method applied in this work was effective in recovering as few as 0.1 cell of Campylobacter per g of food. Among 150 bulk milk samples tested, Campylobacter spp. was isolated from 7 (4.6%) ones. The biochemical identification of the isolated strains conducted by means of conventional biochemical tests as well as by applying the API - Campy tests revealed that all the isolates belonged to the C. jejuni species. Determination of resistance to antibiotics was performed by means of the diffusion disks method for the following antibiotics: gentamicin, ciprofloxacin, ampicillin, chloramphenicol, erythromycin, doxycyclin and tetracycline. Among 7 isolates tested, all were susceptible to ampicillin, chloramphenicol, erythromycin and gentamicin, 28.5% to doxycyclin and 14.2% to tetracycline and ciprofloxacin.

Interaction of Bdellovibrio bacteriovorus with bacteria Campylobacter jejuni and Helicobacter pylori

Interaction of Bdellovibrio bacteriovorus 100NCJB with bacteria Campylobacter jejuni (strains 1, 2, 3, 4, and 5) and Helicobacter pylori, strain TX30a, was confirmed. The results indicate that lytic activity of bdellovibrios both in liquid media and cells attached to a surface was observed. The potential use of the antimicrobial activity of predatory bacteria for environmental bioprotection and public health is discussed.

Causes and Prevention of Foodborne Illness

Foodborne illness is caused by eating or drinking contaminated foods or beverages. According to the U.S. Department of Agriculture (USDA; 2006) and the Centers for Disease Control and Prevention (CDC; 2005), 76 million persons get sick, 325,000 are hospitalized, and 5,000 die annually from foodborne infection and illness in the United States. A century ago, typhoid fever, tuberculosis, and cholera were the common foodborne diseases (CDC, 2005). As a result of improvements in food safety (pasteurization of milk, safe canning, and disinfection of water), the food supply in the United States is among the safest in the world; nevertheless, food and beverages are still sources of bacteria and viruses that can cause foodborne illnesses, sometimes also referred to as food poisoning (CDC, 2005). The most commonly recognized foodborne infections are those caused by the bacteria Campylobacter jejuni, Salmonella, and Escherichia coli O157:H7 and by a group of viruses called Noroviruses (and other calciviruses; CDC, 2005). See Table 1 for a list of the major pathogens that cause foodborne illnesses.

N-Linked glycoengineering for human therapeutic proteins in bacteria

Approx. 70% of human therapeutic proteins are N-linked glycoproteins, and therefore host cells for production must contain the relevant protein modification machinery. The discovery and characterisation of the N-linked glycosylation pathway in the pathogenic bacterium Campylobacter jejuni, and subsequently its functional transfer to Escherichia coli, presents the opportunity of using prokaryotes as cell factories for therapeutic protein production. Not only could bacteria reduce costs and increase yields, but the improved feasibility to genetically control microorganisms means new and improved pharmacokinetics of therapeutics is an exciting possibility. This is a relatively new concept, and progress in bacterial N-glycosylation characterisation is reviewed and metabolic engineering targets revealed.

A link between the assembly of flagella and lipooligosaccharide of the Gram-negative bacterium Campylobacter jejuni.

Campylobacter jejuni is the leading cause of acute bacterial diarrhea worldwide and is implicated in development of Guillain-Barré syndrome. Two major surface features, the outer membrane lipooligosaccharide and flagella, are highly variable and are often targets for modification. Presumably, these modifications provide a competitive advantage to the bacterium. In this work, we identify a gene encoding a phosphoethanolamine (pEtN) transferase (Cj0256) that serves a dual role in modifying not only the lipooligosaccharide lipid anchor lipid A with pEtN, but also the flagellar rod protein FlgG. Generation of a mutant in C. jejuni 81-176 by interruption of cj0256 resulted in the absence of pEtN modifications on lipid A as well as FlgG. The cj0256 mutant showed a 20-fold increase in sensitivity to the cationic antimicrobial peptide, polymyxin B, as well as a decrease in motility. Transmission EM of the cj0256 mutant revealed a population (approximately 95%) lacking flagella, indicating that, without pEtN modification of FlgG, flagella production is hindered. Most intriguing, this research identifies a pEtN transferase showing preference for two periplasmic substrates linking membrane biogenesis and flagellar assembly. Cj0256 is a member of a large family of mostly uncharacterized proteins that may play a larger role in the decoration of bacterial surface structures.

Effects of polyphosphate additives on Campylobacter survival in processed chicken exudates.

Campylobacter spp. are responsible for a large number of the bacterial food poisoning cases worldwide. Despite being sensitive to oxygen and nutritionally fastidious, Campylobacter spp. are able to survive in food processing environments and reach consumers in sufficient numbers to cause disease. To investigate Campylobacter persistence on processed chicken, exudates from chickens produced for consumer sale were collected and sterilized. Two types of exudates from chicken products were collected: enhanced, where a marinade was added to the chickens during processing, and nonenhanced, where no additives were added during processing. Exudates from enhanced chicken products examined in this study contained a mixture of polyphosphates. Exudate samples were inoculated with Campylobacter jejuni or Campylobacter coli strains and incubated under a range of environmental conditions, and viable bacteria present in the resultant cultures were enumerated. When incubated at 42 degrees C in a microaerobic environment, exudates from enhanced chicken products resulted in increased survival of C. jejuni and C. coli compared with that in nonenhanced exudates in the range of <1 to >4 log CFU/ml. Under more relevant food storage conditions (4 degrees C and normal atmosphere), the exudates from enhanced chicken products also demonstrated improved Campylobacter survival compared with that in nonenhanced exudates. Polyphosphates present in the enhanced exudates were determined to be largely responsible for the improved survival observed when the two types of exudates were compared. Therefore, polyphosphates used to enhance chicken quality aid in sustaining the numbers of Campylobacter bacteria, increasing the opportunity for disease via cross-contamination or improperly cooked poultry.