Drůbež a drůbeží produkty jsou považovány za potenciálně významný zdroj rezistentních kmenů E. coli a jejich determinant kódovaných mobilními elementy, jako jsou geny pro ESBL/AmpC betalaktamázy. Drůbež je také hostitelem kmenů s extraintestinální patogenitou (ExPEC). Podobnost drůbežích APEC s humánními kmeny vedla k zařazení ExPEC mezi bakterie se zoonotickým potenciálem. Populační diverzita různých patotypů E. coli, druhová specifita a cirkulace různých kmenů a genetických determinant mezi populacemi jsou však velmi složité a výše uvedená rizika nelze řešit odděleně jedno od druhého.

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• MeSH
• bakteriální zoonózy MeSH
• Escherichia coli * metabolismus   patogenita   MeSH
• extraintestinální patogenní Escherichia coli MeSH
• nemoci drůbeže ošetřování   prevence a kontrola   MeSH
• přenos infekční nemoci MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH

In poultry production conditions today, birds are surrounded by viral, bacterial, and parasitic agents. DCs are the main antigen-presenting cells located in tissues of the body, and their role involves recognizing antigen structures, engulfing and processing them, and subsequently presenting antigen peptides on their surface by major histocompatibility complex, where T cells and B cells are stimulated and can begin appropriate cellular and antibody immune response. This unique function indicates that these cells can be used in producing vaccines, but first it is necessary to culture DCs in vitro to identify the principles of their interactions with pathogens. The following review summarizes our current knowledge about avian dendritic cells and their interactions with pathogens. It provides a basis for future studies of these unique cells and their use in vaccine development.

• MeSH
• B-lymfocyty imunologie   MeSH
• dendritické buňky imunologie   MeSH
• drůbež imunologie   MeSH
• humorální imunita MeSH
• infekce imunologie   MeSH
• interakce hostitele a patogenu MeSH
• myši MeSH
• nemoci ptáků imunologie   MeSH
• prezentace antigenu MeSH
• ptáci imunologie   MeSH
• T-lymfocyty imunologie   MeSH
• vakcíny imunologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

The great plasticity and diversity of the Escherichia coli genome, together with the ubiquitous occurrence, make E. coli a bacterium of world-wide concern. Of particular interest are pathogenic strains and strains harboring antimicrobial resistance genes. Overlapping virulence-associated traits between avian-source E. coli and human extraintestinal pathogenic E. coli (ExPEC) suggest zoonotic potential and safety threat of poultry food products. We analyzed whole-genome sequencing (WGS) data of 46 mcr-1-positive E. coli strains isolated from retail raw meat purchased in the Czech Republic. The investigated strains were characterized by their phylogroup-B1 (43%), A (30%), D (11%), E (7%), F (4%), B2 (2%), C (2%), MLST type, and serotype. A total of 30 multilocus sequence types (STs), of which ST744 was the most common (11%), were identified, with O8 and O89 as the most prevalent serogroups. Using the VirulenceFinder tool, 3 to 26 virulence genes were detected in the examined strains and a total of 7 (15%) strains met the pathogenic criteria for ExPEC. Four strains were defined as UPEC (9%) and 18 (39%) E. coli strains could be classified as APEC. The WGS methods and available on-line tools for their evaluation enable a comprehensive approach to the diagnosis of virulent properties of E. coli strains and represent a suitable and comfortable platform for their detection. Our results show that poultry meat may serve as an important reservoir of strains carrying both virulence and antibiotic resistance genes for animal and human populations.

• Publikační typ
• časopisecké články MeSH

Blood feeding red poultry mites (RPM) serve as vectors of pathogenic bacteria and viruses among vertebrate hosts including wild birds, poultry hens, mammals, and humans. The microbiome of RPM has not yet been studied by high-throughput sequencing. RPM eggs, larvae, and engorged adult/nymph samples obtained in four poultry houses in Czechia were used for microbiome analyses by Illumina amplicon sequencing of the 16S ribosomal RNA (rRNA) gene V4 region. A laboratory RPM population was used as positive control for transcriptome analysis by pyrosequencing with identification of sequences originating from bacteria. The samples of engorged adult/nymph stages had 100-fold more copies of 16S rRNA gene copies than the samples of eggs and larvae. The microbiome composition showed differences among the four poultry houses and among observed developmental stadia. In the adults' microbiome 10 OTUs comprised 90 to 99% of all sequences. Bartonella-like bacteria covered between 30 and 70% of sequences in RPM microbiome and 25% bacterial sequences in transcriptome. The phylogenetic analyses of 16S rRNA gene sequences revealed two distinct groups of Bartonella-like bacteria forming sister groups: (i) symbionts of ants; (ii) Bartonella genus. Cardinium, Wolbachia, and Rickettsiella sp. were found in the microbiomes of all tested stadia, while Spiroplasma eriocheiris and Wolbachia were identified in the laboratory RPM transcriptome. The microbiomes from eggs, larvae, and engorged adults/nymphs differed. Bartonella-like symbionts were found in all stadia and sampling sites. Bartonella-like bacteria was the most diversified group within the RPM microbiome. The presence of identified putative pathogenic bacteria is relevant with respect to human and animal health issues while the identification of symbiontic bacteria can lead to new control methods targeting them to destabilize the arthropod host.

• MeSH
• Bacteria klasifikace   genetika   izolace a purifikace   MeSH
• bakteriální RNA genetika   MeSH
• Bartonella klasifikace   genetika   izolace a purifikace   MeSH
• druhová specificita MeSH
• mikrobiota * MeSH
• RNA ribozomální 16S genetika   MeSH
• roztoči růst a vývoj   mikrobiologie   MeSH
• taxonomické DNA čárové kódování MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

Natural variation in the presence or the absence of STM0517-0529 genes allowing allantoin utilisation has been described in field isolates of the multidrug resistant Salmonella enterica serovar Typhimurium belonging to the phage type DT104. Interestingly, S. enterica subspecies enterica serovar Typhimurium DT104 is quite frequent in pigs and cattle, but rarely present in egg-laying hens. Taking into account the different mode of allantoin metabolism in birds and mammals, we were interested in whether the absence of STM0517-0529 genes may disable this clone in poultry colonisation. We have therefore constructed the allB (also designated as STM0523) mutants in S. enterica subspecies enterica serovar Typhimurium and S. enterica subspecies enterica serovar Enteritidis, and with these, we infected mice, newly hatched chickens and adult egg-laying hens to show that the defect in allantoin utilisation does not influence S. enterica virulence for mice or adult hens, but slightly decreases virulence of S. enterica for chickens. The decrease in virulence of the allB mutant was relatively minor as it could be observed only after a mixed infection model, consistent with a lower prevalence, but not a total absence of such clones in poultry flocks.

• MeSH
• alantoin metabolismus   MeSH
• drůbež MeSH
• kyselina močová metabolismus   MeSH
• mnohočetná bakteriální léková rezistence MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• nemoci drůbeže mikrobiologie   patologie   MeSH
• Salmonella enteritidis genetika   metabolismus   patogenita   MeSH
• Salmonella typhimurium genetika   metabolismus   patogenita   MeSH
• salmonelová infekce u zvířat mikrobiologie   patologie   MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Thermotolerant Campylobacter spp., in particular Campylobacter jejuni, are among the most frequently identified pathogens, found to be causing human gastrointestinal infections in Europe, with the Czech Republic being no exception. The presented work aimed at assessing results of the first nationwide monitoring of prevalence and antibiotic resistance of Campylobacter spp. in broiler flocks in the Czech Republic, including a comparison of antibiotic resistance of C. jejuni isolates collected from poultry and the human community. The monitoring was carried out in poultry slaughterhouses in 2006 and 2007. From broilers, cloacal swabs were collected and examined. The human isolates of C. jejuni were acquired from rectal swabs in community patients with diarrhoeal diseases. Suspected isolates of both animal and human origin were confirmed by the PCR methods. Antibiotic resistance to selected anti-microbial agents was tested by the microdilution method. In the monitored period, the prevalence of thermotolerant Campylobacter spp. in broilers in the Czech Republic reached almost 50%. In 2006, C. jejuni was detected in 46% and Campylobacter coli in 3% of the tested samples. In 2007, C. jejuni was found in 43% and C. coli in 2% of the samples. The results of anti-microbial susceptibility testing of C. jejuni showed higher resistance in animals when compared with humans. The only exception was tetracycline with higher resistance in isolates of human origin. The highest resistance detected was to quinolone antibiotics. Resistance to oxolinic acid was 77% in animal and 60% in human isolates, to ciprofloxacin 72% in isolates from poultry and 55% in those from humans. In ampicillin, 26% of poultry isolates and 16% of human isolates were resistant. Moreover, 9% of animal isolates demonstrated resistance to streptomycin, undetected in human isolates. In erythromycin, resistance was found in 6% of poultry and 1% of human isolates.

• MeSH
• antibakteriální látky terapeutické užití   MeSH
• bakteriální léková rezistence MeSH
• Campylobacter coli účinky léků   MeSH
• Campylobacter jejuni účinky léků   MeSH
• financování organizované MeSH
• kampylobakterové infekce epidemiologie   farmakoterapie   mikrobiologie   veterinární   MeSH
• kur domácí MeSH
• lidé MeSH
• mikrobiální testy citlivosti MeSH
• mnohočetná bakteriální léková rezistence MeSH
• nemoci drůbeže epidemiologie   farmakoterapie   mikrobiologie   MeSH
• počet mikrobiálních kolonií MeSH
• prevalence MeSH
• rizikové faktory MeSH
• veřejné zdravotnictví MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zoonózy MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Geografické názvy
• Česká republika MeSH

Salmonella Enteritidis is the main serovar of poultry origin in humans, but its complex interaction with certain avian cells is still not fully understood. Previously we identified several genes significantly induced in chicken embryo fibroblasts (CEFs) by the wild-type strain S. Enteritidis 11 (SE 11). In the present study, we raised the question whether virulence-attenuated mutants of this strain would induce altered expression of the newly identified fibroblast genes associated with immune and non-immune functions of CEFs. Gene expression was evaluated by real-time PCR following challenge by the parental strain SE 11 and its virulence attenuated mutants lacking flagellin gene fliD only or fliD and the serovar-specific virulence plasmid pSEV. As a result, deletion mutants induced a lower expression of all immune genes, but an increased expression of the non-immune genes G0S2 and ENO2 relative to the parental strain. Our data indicate the importance of flagella and pSEV in modulation of virulence and host response in this model. We demonstrated, for the first time ever, an increased induction of survival genes G0S2 and ENO2 by virulence-attenuated mutants of S. Enteritidis.

• MeSH
• bakteriální proteiny genetika   MeSH
• fibroblasty mikrobiologie   MeSH
• flagella genetika   MeSH
• interakce hostitele a patogenu MeSH
• kuřecí embryo MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• nemoci drůbeže imunologie   mikrobiologie   MeSH
• plazmidy genetika   MeSH
• Salmonella enteritidis genetika   patogenita   MeSH
• salmonelová infekce u zvířat imunologie   mikrobiologie   MeSH
• virulence genetika   MeSH
• zvířata MeSH
• Check Tag
• kuřecí embryo MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The present multicenter study aimed at assessing the performance of air sampling as a novel method for monitoring Campylobacter in biosecure poultry farms. We compared, using a harmonized procedure, the bacteriological isolation protocol (ISO 10272-1:2017) and a real-time PCR method used on air filter samples. Air samples and boot swabs were collected from 62 biosecure flocks from five European countries during the summer of 2019. For air filters, the frequency of PCR-positive findings was significantly higher (n = 36; 58%) than that obtained with the cultivation methods (P < 0.01; standardized residuals). The cultivation protocols (one with Bolton enrichment and one with Preston enrichment) were comparable to each other but returned fewer positive samples (0 to 8%). The association between type of sample and frequency of PCR-positive findings was statistically confirmed (P < 0.01; Fisher´s exact test), although no culture-positive air filters were detected using direct plating. For the boot swabs, the highest number of positive samples were detected after enrichment in Preston broth (n = 23; 37%), followed by direct plating after homogenization in Preston (n = 21; 34%) or Bolton broth (n = 20; 32%). It is noteworthy that the flocks in Norway, a country known to have low Campylobacter prevalence in biosecure chicken flocks, tested negative for Campylobacter by the new sensitive approach. In conclusion, air sampling combined with real-time PCR is proposed as a multipurpose, low-cost, and convenient screening method that can be up to four times faster and four times more sensitive than the current boot-swab testing scheme used for screening biosecure chicken production.IMPORTANCECampylobacter bacteria are the cause of the vast majority of registered cases of foodborne illness in the industrialized world. In fact, the bacteria caused 246,571 registered cases of foodborne illness in 2018, which equates to 70% of all registered cases in Europe that year. An important tool to prevent campylobacters from making people sick is good data on where in the food chain the bacterium is present. The present study reports a new test method that quadruples the likelihood of identifying campylobacter-positive chicken flocks. It is important to identify campylobacter-positive flocks before they arrive at the slaughterhouse, because negative flocks can be slaughtered first in order to avoid cross-contamination along the production line.

• MeSH
• Campylobacter izolace a purifikace   MeSH
• kampylobakterové infekce diagnóza   mikrobiologie   veterinární   MeSH
• kur domácí * MeSH
• nemoci drůbeže diagnóza   mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Dánsko MeSH
• Itálie MeSH
• Norsko MeSH
• Polsko MeSH

This study documents the clinical signs, necropsy findings and viral antigen distribution of the highly pathogenic avian influenza (HPAI) H5N1 virus infection in domestic poultry (a backyard farm) and the phylogenetic analysis of the virus. On January 29, 2015, an outbreak of HPAI H5N1 in domestic poultry was reported on a backyard farm in Bulgaria. Out of the twenty-two chickens with clinical signs, twenty died while the remaining two were destroyed. The morbidity was 100%, whereas the overall mortality and lethality were 90.91%. The clinical observations made were sudden death, high mortality, weakness, and recumbency. Although multisystemic lesions were observed occasionally, the main pathologic findings were observed in the nervous, circulatory, respiratory, and gastrointestinal systems. An influenza virus nucleocapsid protein was identified by an immunohistochemical analysis in all the analysed organs: brain 3/3, trachea 3/3, lung 3/3, intestine 3/3, heart 3/3, which confirmed the systemic infection. The phylogenetic analyses of the virus showed a close genetic relationship with the H5N1 viruses of Asian origin, isolated in 2012 and 2013, belonging to the clade 2.3.2.1c. The HA-gene genetically clusters with HPAI H5N1 viruses isolated from wild pelicans in Romania and Bulgaria, thereby demonstrating the link between wild and domestic birds in the epidemiology of avian influenza. The contact between the affected chickens and migrating water birds over Bulgaria’s territory was suspected as a reason for the outbreak in the backyard farm. In addition, the detection of the virus in wild bird populations in Bulgaria three days earlier strongly supports the hypothesis of migrating wild birds spreading HPAI H5N1.

Infections associated with Escherichia coli are responsible for immense losses in poultry production; moreover, poultry products may serve as a source of pathogenic and/or resistant strains for humans. As early as during the first hours of life, commercially hatched chickens are colonized with potentially pathogenic E. coli from the environment of hatcheries. The source of contamination has not been quite elucidated and the possibility of vertical spread of several avian pathogenic E. coli (APEC) lineages has been suggested, making the hatcheries an important node where cross-contamination of chicken of different origin can take place. The recent technological progress makes the method of whole-genome sequencing (WGS) widely accessible, allowing high-throughput analysis of a large amount of isolates. Whole-genome sequencing offers an opportunity to trace APEC and extended-spectrum/plasmid-encoded AmpC beta-lactamases-producing E. coli (ESBL/pAmpC-E.coli) along the poultry processing chain and to recognize the potential pathways of “epidemicˮ sequence types. Data from WGS may be used in monitoring antimicrobial resistance, comparative pathogenomic studies describing new virulence traits and their role in pathogenesis and, above all, epidemiologic monitoring of clonal outbreaks and description of different transmission routes and their significance. This review attempts to outline the complexity of poultry-associated E. coli issues and the possibility to employ WGS in elucidating them.

• MeSH
• bakteriální léková rezistence genetika   MeSH
• bakteriální zoonózy klasifikace   přenos   MeSH
• drůbež mikrobiologie   MeSH
• epidemiologické monitorování veterinární   MeSH
• Escherichia coli * patogenita   MeSH
• nemoci drůbeže * epidemiologie   klasifikace   přenos   MeSH
• plazmidy genetika   MeSH
• sekvenování celého genomu klasifikace   metody   přístrojové vybavení   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• klinická studie MeSH
• práce podpořená grantem MeSH