347 resultados para Campylobacter jejuni enterotoxin


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Campylobacter jejuni is a zoonotic bacterial pathogen of worldwide importance. It is estimated that 460,000 human infections occur in the United Kingdom per annum and these involve acute enteritis and may be complicated by severe systemic sequelae. Such infections are frequently associated with the consumption of contaminated poultry meat and strategies to control C. jejuni in poultry are expected to limit pathogen entry into the food chain and the incidence of human disease. Toward this aim, a total of 840 Light Sussex chickens were used to evaluate a Salmonella enterica serovar Typhimurium ΔaroA vaccine expressing the C. jejuni amino acid binding protein CjaA as a plasmid-borne fusion to the C-terminus of fragment C of tetanus toxin. Chickens were given the vaccine at 1-day-old and two weeks later by oral gavage, then challenged after a further two weeks with C. jejuni. Across six biological replicates, statistically significant reductions in caecal C. jejuni of c. 1.4 log10 colony-forming units/g were observed at three and four weeks post-challenge relative to age-matched unvaccinated birds. Protection was associated with the induction of CjaA-specific serum IgY and biliary IgA. Protection was not observed using a vaccine strain containing the empty plasmid. Vaccination with recombinant CjaA subcutaneously at the same intervals significantly reduced the caecal load of C. jejuni at three and four weeks post-challenge. Taken together these data imply that responses directed against CjaA, rather than competitive or cross-protective effects mediated by the carrier, confer protection. The impact of varying parameters on the efficacy of the S. Typhimurium ΔaroA vaccine expressing TetC-CjaA was also tested. Delaying the age at primary vaccination had little impact on protection or humoral responses to CjaA. The use of the parent strain as carrier or changing the attenuating mutation of the carrier to ΔspaS or ΔssaU enhanced the protective effect, consistent with increased invasion and persistence of the vaccine strains relative to the ΔaroA mutant. Expression in the ΔaroA strain of a TetC fusion to Peb1A, but not TetC fusions to GlnH or ChuA, elicited protection against intestinal colonisation by C. jejuni that was comparable to that observed with the TetC-CjaA fusion. Our data are rendered highly relevant by use of the target host in large numbers and support the potential of CjaA- and Peb1A-based vaccines for control of C. jejuni in poultry. © 2009 Elsevier Ltd. All rights reserved.

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Campylobacter jejuni and C. coli are the leading causes of human bacterial gastroenteritis in developed countries. Most human Campylobacter infections are sporadic and a seasonal peak in the distribution of infections can be seen in the summer months in several countries, including Finland. A variety of risk factors for Campylobacter infections have been identified; handling and eating poultry, drinking unpasteurized milk, contact with domestic animals, and travelling abroad. However, the relative importance of the different risk factors in sporadic cases of Campylobacter infection remains unknown. In most cases, the infection is self-limiting and no specific treatment is required. Campylobacter enteritis can cause a wide range of complications, including reactive arthritis (ReA) that is reported in 1-5% of the cases. Seven clinical microbiology laboratories serving different geographical areas of Finland, participated in this multi-centre study, conducted during a seasonal peak in 2002. In a matched case-control study, domestically-acquired sporadic Campylobacter infections from three geographical areas were collected. The final study comprised 100 cases and 137 controls. Risk factors for sporadic domestically-acquired Campylobacter infections were identified on the basis of a questionnaire; swimming in natural waters was found to be a novel risk factor for Campylobacter infection. Other independent risk factors were tasting or eating raw or undercooked meat and drinking untreated water from a dug well. The role of bacterial strain and host characteristics are not fully understood in Campylobacter infections. Exposure factors, demographical characteristics, and the serotype of the Campylobacter isolate may affect the severity of the enteritis. This cross-sectional study comprised 114 patients with C. jejuni enteritis, diagnosed in three clinical microbiology laboratories; most of the patients had participated in the previous case-control study. Swimming was associated with age ≤ 5 years and serotype Pen 6,7 was found significantly more often among patients reporting swimming. The geographical distribution among serotypes varied; serotype Pen 4-complex appeared more often in patients from urban areas and serotype Pen 21 among patients from more rural areas. Thus, risk factors and sources of infection for C. jejuni infection may vary among individuals depending on age and geographical location. The in vitro susceptibilities of C. jejuni and C. coli strains isolated from patients infected abroad (85 strains) or domestically (393 strains) revealed that susceptibility to erythromycin is still high, even among isolates of foreign origin. However, the novel antimicrobial agent telithromycin did not offer any advantage over erythromycin; isolates with high minimal inhibitory concentrations (MICs) for erythromycin also showed reduced susceptibility to telithromycin. Reduced susceptibility to fluoroquinolones was detected almost exclusively among isolates of foreign origin and half of these isolates with high MICs for fluoroquinolones also showed elevated MICs for doxycycline. Questionnaires concerning complications associated with C. jejuni enteritis were sent to patients two months after becoming ill; 201 patients from seven different geographical areas were included in the study. Musculoskeletal complications after C. jejuni infection were commonly reported by patients (39%). The incidence of classical ReA was 4% and that of Achilles enthesopathy and/or heel pain 9%. Other C. jejuni-associated reactive joint symptoms were commonly reported, however, due to their milder nature seldom seen and diagnosed by a physician. The severity of the enteritis may predict further complications; stomach ache during enteritis was connected to the development of later joint pain. Early antimicrobial treatment, within two days from the start of symptoms, shortened the duration of diarrhoea by two days but did not prevent later musculoskeletal complications. Campylobacter is an important human enteropathogen and causes a significant burden of illness. As the incidence of Campylobacter infections is high, the importance of the infection and the occurrence of complications will increase. This stresses the importance of understanding the risk factors for acquiring Campylobacter infection and how bacterial strain and host characteristics may affect the risk for infection. The role of antimicrobial treatment for acute Campylobacter enteritis seems to be marginal and should be used restrictively.

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Campylobacter is an important food borne pathogen, mainly associated with poultry. A lack of through-chain quantitative Campylobacter data has been highlighted within quantitative risk assessments. The aim of this study was to quantitatively and qualitatively measure Campylobacter and Escherichia coli concentration on chicken carcasses through poultry slaughter. Chickens (n = 240) were sampled from each of four flocks along the processing chain, before scald, after scald, before chill, after chill, after packaging and from individual caeca. The overall prevalence of Campylobacter after packaging was 83% with a median concentration of 0.8 log10 CFU/mL. The processing points of scalding and chilling had significant mean reductions of both Campylobacter (1.8 and 2.9 log10 CFU/carcase) and E. coli (1.3 and 2.5 log10 CFU/carcase). The concentration of E. coli and Campylobacter was significantly correlated throughout processing indicating that E. coli may be a useful indicator organism for reductions in Campylobacter concentration. The carriage of species varied between flocks, with two flocks dominated by Campylobacter coli and two flocks dominated by Campylobacter jejuni. Current processing practices can lead to significant reductions in the concentration of Campylobacter on carcasses. Further understanding of the variable effect of processing on Campylobacter and the survival of specific genotypes may enable more targeted interventions to reduce the concentration of this poultry associated pathogen.

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The reported incidence of human campylobacteriosis in Finland is higher than in most other European countries. A high annual percentage of sporadic infections is of foreign origin, although a notable proportion of summer infections is domestically acquired. While chickens appear to be a major source of campylobacters for humans in most countries, the prevalence of campylobacters is very low in chicken slaughter batches in Finland. Data on other potential animal reservoirs of human pathogenic campylobacters in Finland are scarce. Consequently, this study aimed to investigate the status of Finnish cattle as a potential source of thermophilic Campylobacter spp. and antibiotic-resistant Campylobacter jejuni for human sporadic campylobacter infections of domestic origin. A survey of the prevalence of thermophilic Campylobacter spp. in Finnish cattle studied bovine rectal faecal samples (n=952) and carcass surface samples (n=948) from twelve Finnish slaughterhouses from January to December 2003. The total prevalence of Campylobacter spp. in faecal samples was 31.1%, and in carcass samples 3.5%. Campylobacter jejuni, the most common species, was present in 19.5% of faecal samples and in 3.1% of carcasses. In addition to thermophilic Campylobacter spp., C. hyointestinalis ssp. hyointestinalis was present in bovine samples. The prevalence of campylobacters was higher among beef cattle than among dairy cattle. Using the enrichment method, the number of positive faecal samples was 7.5 times higher than that obtained by direct plating. The predominant serotypes of faecal C. jejuni, determined by serotyping with a set of 25 commercial antisera for heat-stable antigens (Penner), were Pen2 and Pen4-complex, which covered 52% of the samples. Genotyping with pulsed-field gel electrophoresis (PFGE) using SmaI restriction yielded a high diversity of C. jejuni subtypes in cattle. Determining the minimum inhibitory concentrations of ampicillin, enrofloxacin, erythromycin, gentamicin, nalidixic acid, and oxytetracycline among bovine C. jejuni isolates using a commercial broth microdilution method yielded 9% of isolates resistant to at least one of the antimicrobials examined. No multiresistant isolates were found among the bovine C. jejuni strains. The study of the shedding patterns of Campylobacter spp. among three Finnish dairy cattle herds included the examination of fresh faecal samples and tank milk samples taken five times, as well as samples from drinking troughs taken once during the one-year study. The semiquantitative enrichment method detected C. jejuni in 169 of the 340 faecal samples, mostly at low levels. In addition, C. jejuni was present in one drinking trough sample. The prevalence between herds and sampling occasions varied widely. PFGE, using SmaI as restriction enzyme, identified only a few subtypes in each herd. In two 2 of the herds, two subtypes persisted throughout the sampling. Individual animals presented various shedding patterns during the study. Comparison of C. jejuni isolates from humans, chickens and cattle included the design of primers for four new genetic markers selected from completely sequenced C. jejuni genomes 81-176, RM1221 and NCTC 11168, and the PCR examination of domestic human isolates from southern Finland in 1996, 2002 and 2003 (n=309), chicken isolates from 2003, 2006 and 2007 (n=205), and bovine isolates from 2003 (n=131). The results revealed that bovine isolates differed significantly from human and chicken isolates. In particular, the - glutamyl transpeptidase gene was uncommon among bovine isolates. The PFGE genotyping of C. jejuni isolates, using SmaI and KpnI restriction enzymes, included a geographically representative collection of isolates from domestic sporadic human infections, chicken slaughter batches, and cattle faeces and carcasses during the seasonal peak of campylobacteriosis in the summer of 2003. The study determined that 55.4% of human isolates were indistinguishable from those of chickens and cattle. Temporal association between isolates from humans and chickens was possible in 31.4% of human infections. Approximately 19% of the human infections may have been associated with cattle. However, isolates from bovine carcasses and human cases represented different PFGE subtypes. In conclusion, this study suggests that Finnish cattle is a notable reservoir of C. jejuni, the most important Campylobacter sp. in human enteric infections. Although the concentration of these organisms in bovine faeces appeared to be low, excretion can be persistent. The genetic diversity and presence or absence of marker genes support previous suggestions of host-adapted C. jejuni strains, and may indicate variations in virulence between strains from different hosts. In addition to chickens, Finnish cattle appeared to be an important reservoir and possible source of C. jejuni in domestic sporadic human infections. However, sources of campylobacters may differ between rural and urban areas in Finland, and in general, the transmission of C. jejuni of bovine origin probably occurs via other routes than food.

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354 p. (Bibliogr. 271-303) - Correo electrónico de la autora: andrea.guridi@gmail.com

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Aims: To compare pressure resistance between strains of Campylobacter jejuni, Campylobacter coli, Campylobacter lari and Campylobacter fetus, and to investigate the effect of suspending medium on pressure resistance of sensitive and more resistant strains. Methods and Results: Six strains of C. jejuni and four each of C. coli, C. lari and C. fetus were pressure treated for 10 min at 200 and 300 MPa. Individual strains varied widely in pressure resistance but there were no significant differences between the species C. jejuni, C. coli and C. lari. Campylobacter fetus was significantly more pressure sensitive than the other three species. The pressure resistance of C. jejuni cultures reached a maximum at 16-18 h on entry into stationary phase then declined to a minimum at 75 h before increasing once more. Milk was more baroprotective than water, broth or chicken slurry but did not prevent inactivation even of a resistant strain at 400 MPa. Conclusions: Pressure resistance varies considerably between species of Campylobacter and among strains within a species, and survival after a pressure challenge will be markedly influenced by culture age and food matrix. Significance and Impact of the Study: Despite the strain variation in pressure resistance and protective effects of food, Campylobacter sp. do not present a particular problem for pressure processing.

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Phenotypic and phylogenetic studies were performed on four Campylobacter-like organisms recovered from three seals and a porpoise. Comparative 16S rRNA gene sequencing studies demonstrated that the organisms represent a hitherto unknown subline within the genus Campylobacter, associated with a subcluster containing Campylobacter jejuni, Campylobacter coli and Campylobacter lari. DNA-DNA hybridization studies confirmed that the bacteria belonged to a single species, for which the name Campylobacter insulaenigrae sp. nov. is proposed. The type strain of Campylobacter insulaenigrae sp. nov. is NCTC 12927(T) (= CCUG 48653(T)).

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Aims: In view of recent findings that a multidrug efflux pump CmeABC exists in Campylobacter jejuni, 391 C. jejuni and 52 Campylobacter coli of human and animal origin were examined for a multidrug resistance phenotype. Materials and methods: The MICs of ampicillin, chloramphenicol, ciprofloxacin, erythromycin, kanamycin, tetracycline, cetrimide, triclosan, acridine orange, paraquat and ethidium bromide were determined. Resistance to organic solvents and the effect of salicylate (known inducer of the marRAB operon in Escherichia coli and Salmonella) were also examined. Results: Two C. coli and 13 C. jejuni isolates, mainly from pigs or poultry, were resistant to three or more antibiotics and 12 of these strains had reduced susceptibility to acridine orange and/or ethidium bromide. Strains (n=20) that were less susceptible to acridine orange, ethidium bromide and triclosan were significantly more resistant (P<0.05) to ampicillin, chloramphenicol, ciprofloxacin, erythromycin, nalidixic acid and tetracycline, with two- to four-fold increases in MIC values compared with strains (n=20) most susceptible to acridine orange, ethidium bromide and triclosan. Growth of strains with 1 mM salicylate caused a small (up to two-fold) but statistically significant (Pless than or equal to0.005) increase in the MICs of chloramphenicol, ciprofloxacin, erythromycin and tetracycline. Conclusions: These data indicate that multiple antibiotic resistant (MAR)-like Campylobacter strains occur and it may be postulated that these may overexpress cmeABC or another efflux system.

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Um total de 200 suínos (1 - 21 semanas de idade), originários de cinco criações localizadas no Estado de São Paulo, Brasil foi dividido em dois grupos de 100 animais caracterizando-se o grupo G1 de animais com diarréia e G2, sem diarréia. Campylobacter foi isolado em 43% das amostras provenientes de G1 e 34% de G2. O microrganismo foi mais frequentemente encontrado em leitões na faixa de 0 a 4 semanas de idade. Campylobacter coli foi a espécie mais comumente observada em G1 (44,2%) e em G2 (32,4%), seguido por Campylobacter jejuni/ coli com 16,3% em G1 e 23,5% em G2. As contagens de Campylobacter foram significativamente maiores (p < 0,01) em G1 ( £ 108 UFC/g) do que em G2 (£ 104 UFC/g), fato que sugere que o microrganismo pode, pelo menos, atuar no agravamento do processo diarréico.

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Two hundred and four stools of 102 diarrheic (0-12 months of age) and 102 non-diarrheic dogs coming from kennel and ambulatory, respectively, were assayed for the presence of Campylobacter. From the diarrhetic group, 46% of the samples yelded positive Campylobacter isolation mainly found in young animals until 5 months of age (72%), whereas those with age ranging from 6-12 months showed either a lower frequence of the organisms (28%) and a trend of the younger animals to be more charged than the older. 47 Campylobacter strains isolated from the diarrheic group were: C. jejuni biotype 1 (49%); C. jejuni biotyp 2 (11%); C. jejuni/coli (19%); C. coli (8,5%); Campylobacter NARTC group (8,5%) and C. sputoruns (4%). In the non-diarrhetic group, 27 (28%) Campylobacter strains were classified as: C. jejuni biotype 1 (34%) and biotype 2 (28%); C. jejuni/coli (24%) and C. coli (14%). According the biochemical tests, the 1% glycine tolerance test was not taking in account for the differentiation of C. jejuni because 45% of the strains failed in showing characteristic and 3 strains did not reduce the sodium selenite. The biochemical studies also showed phenotipical cross reactions between two Campylobacter NARTC-group strains with the C. jejuni strains, as well as two thermophilic species grew also at 25°C. All the 76 isolates were sensitive to gentamicin, nitrofurantoin and neomycin and resistant to oxacillin and penicillin. Furthermore, for the remaining 16 drugs the populational resistance ranged from 8% to 73% of strains. The presence of Campylobacter in dogs as well their close contact which man makes possible the occurrence of infections as also confirm the campylobacteriosis as an important zoonosis.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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As infecções de origem alimentar no homem, causadas por Campylobacter spp., resultam em grandes perdas econômicas e estão relacionadas à produção e o abate de frangos, etapas importantes na disseminação dessas bactérias. Baseando-se na importância do Campylobacter spp. na saúde pública e tendo em vista os dados constantes na literatura de que as aves comercializadas estão constantemente contaminadas com esse agente, sentiu-se a necessidade de realizar um estudo envolvendo a criação e o abate de frangos na região amazônica para que medidas profiláticas e de controle possam ser adotadas. O trabalho teve como objetivo estudar a ocorrência de Campylobacter spp. em granjas e abatedouro avícolas na mesorregião metropolitana de Belém – PA; isolar e identificar as espécies de Campylobacter spp. e identificar as fontes de contaminação nas granjas e os pontos críticos no abate. Foi coletado um total de 120 amostras em três granjas avícolas: 30 amostras de “swab” cloacal, 30 amostras de cama de frango, 30 amostras de ração e 30 amostras de água dos bebedouros. No abatedouro, foram colhidas 126 amostras: 36 amostras de água em 12 pontos diferentes da linha de abate e mais 30 amostras de pele do conjunto peito/ pescoço, 30 amostras de fígado e 30 amostras de moela. As amostras foram colhidas entre os meses de janeiro e maio de 2007 para o isolamento e identificação das espécies de Campylobacter spp. As amostras foram processadas na Seção de Bacteriologia e Micologia do Instituto Evandro Chagas – IEC da Secretaria de Vigilância em Saúde (SVS), Ministério da Saúde, Ananindeua – PA. Campylobacter spp. foi isolado em 33,3% (40/120) das amostras das granjas. Não houve diferença significativa (p>0,05) entre os percentuais de isolamentos positivos entre as três granjas pesquisadas. Ao analisar as freqüências dos isolados de Campylobacter spp. para cada tipo de amostra das granjas, observou-se que 96,6% (29/30) das amostras de “swab” cloacal, 33,3% (10/30) das amostras de cama e 3,3% (1/30) das amostras de água foram positivas para Campylobacter spp. Não foi isolada a bactéria nas amostras de ração. Campylobacter jejuni foi identificado bioquimicamente em 82,5% (33/40) das cepas isoladas nas granjas. No abatedouro, todas as cepas isoladas foram identificadas como C. jejuni., sendo isolado a bactéria em 8,73% (11/126) das amostras provenientes da linha de abate. Ao analisar as freqüências dos isolados de C. jejuni para cada tipo de amostra do abatedouro, observou-se que 27,8% (10/36) das amostras de água foram positivas para C. jejuni, seguido pela moela com 3,3% (1/30) das amostras positivas. Não foi isolado Campylobacter spp. nas amostras de fígado e de pele do conjunto peito/ pescoço. Houve diferença significativa (p<0,0001) entre os isolamentos positivos, negativos e os tipos de amostras processadas nas granjas e no abatedouro. As principais fontes de contaminação nas granjas foram o “swab” cloacal, a cama e, em menor escala, a água. Os principais pontos críticos observados no abatedouro foram a água, seguido pela moela. C. jejuni foi identificado em elevado percentual entre as cepas isoladas nas granjas e em todas as cepas do abatedouro.

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Pós-graduação em Microbiologia Agropecuária - FCAV

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To obtain genetic information about Campylobacter jejuni and Campylobacter coli from broilers and carcasses at slaughterhouses, we analyzed and compared 340 isolates that were collected in 2008 from the cecum right after slaughter or from the neck skin after processing. We performed rpoB sequence-based identification, multilocus sequence typing (MLST), and flaB sequence-based typing; we additionally analyzed mutations within the 23S rRNA and gyrA genes that confer resistance to macrolide and quinolone antibiotics, respectively. The rpoB-based identification resulted in a distribution of 72.0% C. jejuni and 28.0% C. coli. The MLST analysis revealed that there were 59 known sequence types (STs) and 6 newly defined STs. Most of the STs were grouped into 4 clonal complexes (CC) that are typical for poultry (CC21, CC45, CC257, and CC828), and these represented 61.8% of all of the investigated isolates. The analysis of 95 isolates from the cecum and from the corresponding carcass neck skin covered 44 different STs, and 54.7% of the pairs had matching genotypes. The data indicate that cross-contamination from various sources during slaughter may occur, although the majority of Campylobacter contamination on carcasses appeared to originate from the slaughtered flock itself. Mutations in the 23S rRNA gene were found in 3.1% of C. coli isolates, although no mutations were found in C. jejuni isolates. Mutations in the gyrA gene were observed in 18.9% of C. jejuni and 26.8% of C. coli isolates, which included two C. coli strains that carried mutations conferring resistance to both classes of antibiotics. A relationship between specific genotypes and antibiotic resistance/susceptibility was observed.