Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.274
Filtrar
1.
World J Microbiol Biotechnol ; 35(9): 134, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31432266

RESUMO

Shiga toxin-producing Escherichia coli (STEC) are zoonotic pathogens and may induce severe diarrheagenic diseases in humans and other animals. Non-O157 STEC have been emerging as important pathogens causing outbreaks worldwide. Bacterial resistance to antimicrobials has become a global public health problem, which involves different ecological spheres, including animals. This study aimed to characterize the resistance to antimicrobials, plasmids and virulence, as well as the serotypes and phylogenetic groups in E. coli isolated from sheep in Brazil. A total of 57 isolates were obtained and showed different antimicrobial resistance profiles. Nineteen isolates presented acquired antimicrobial resistance genes (ARGs) (blaCTX-M-Gp9, qnrB, qnrS, oqxB, oqxA, tetA, tetB, tetC, sul1 and sul2) and plasmid families (F, FIA, FIB, I1, K, HI1 and ColE-like). The stx1, stx2 and ehxA virulence genes were detected by PCR, being 50 isolates (87.7%) classified as STEC. A great diversity of serotypes was detected, being O176:HNM the most predominant. Phylogenetic group E was the most prevalent, followed by B1, A and B2. To the best of our knowledge, this is the first report in the world of blaCTX-M-Gp9 (O75, O114, O100, O128ac and O176 serogroups), qnrB and oqxB genes in non-O157 STEC in healthy sheep. The results obtained in the present study call attention to the monitoring of antimicrobial-resistant non-O157 STEC harboring acquired ARGs worldwide and indicate a zoonotic risk due to the profile of virulence, resistance and serotype found.


Assuntos
Infecções por Escherichia coli/veterinária , Fezes/microbiologia , Doenças dos Ovinos/microbiologia , Escherichia coli Shiga Toxigênica/isolamento & purificação , Animais , Brasil , Infecções por Escherichia coli/microbiologia , Genes Bacterianos , Variação Genética , Genótipo , Técnicas de Genotipagem , Testes de Sensibilidade Microbiana , Filogenia , Plasmídeos/análise , Reação em Cadeia da Polimerase , Sorogrupo , Ovinos , Escherichia coli Shiga Toxigênica/efeitos dos fármacos , Escherichia coli Shiga Toxigênica/genética , Escherichia coli Shiga Toxigênica/patogenicidade , Fatores de Virulência/genética
2.
Environ Pollut ; 254(Pt B): 113058, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31454571

RESUMO

Dairy cattle of different ages experience different living conditions and varied frequency of antibiotic administration that likely influence the distribution of microbiome and resistome in ways that reflect different risks of microbial transmission. To assess the degree of variance in these distributions, fecal and soil samples were collected from six distinct housing areas on commercial dairy farms (n = 7) in Washington State. 16S rRNA gene sequencing indicated that the microbiota differed between different on-farm locations in feces and soil, and in both cases, the microbiota of dairy calves was often distinct from others (P < 0.05). Thirty-two specific antibiotic resistance genes (ARGs) were widely distributed on dairies, of which several clinically relevant ARGs (including cfr, cfrB, and optrA) were identified for the first time at U.S. dairies. Overall, ARGs were observed more frequently in feces and soil from dairy calves and heifers than from hospital, fresh, lactation and dry pens. Droplet-digital PCR demonstrated that the absolute abundance of floR varied greatly across housing areas and this gene was enriched the most in calves and heifers. Furthermore, in an extended analysis with 14 dairies, environmental soils in calf pens had the most antibiotic-resistant Escherichia coli followed by heifer and hospital pens. All soil E. coli isolates (n = 1,905) are resistant to at least 4 different antibiotics, and the PFGE analysis indicated that florfenicol-resistant E. coli is probably shared across geographically-separated farms. This study identified a discrete but predictable distribution of antibiotic resistance genes and organisms, which is important for designing mitigation for higher risk areas on dairy farms.


Assuntos
Indústria de Laticínios , Resistência Microbiana a Medicamentos/genética , Antibacterianos/farmacologia , Monitoramento Ambiental , Escherichia coli/efeitos dos fármacos , Infecções por Escherichia coli/veterinária , Fazendas , Fezes , Habitação , Microbiota/efeitos dos fármacos , Prevalência , RNA Ribossômico 16S , Solo , Microbiologia do Solo , Washington
3.
BMC Vet Res ; 15(1): 227, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31277658

RESUMO

BACKGROUND: Antimicrobial resistance is a worldwide problem causing serious health threats. Escherichia coli is one of the most important bacteria that causes resistance problem. These bacteria produce an enzyme called extended-spectrum ß-lactamase (ESBL) that allows it to become resistant to a wide variety of penicillins and cephalosporins. Currently, no information or published studies on ESBL-producing E.coli in broilers are available in the Philippines. This cross-sectional study was conducted to determine the prevalence and distribution of extended-spectrum ß-lactamase (ESBL)-encoding genes, blaCTX-M, blaSHV, and blaTEM, among E. coli isolates from broiler farms in Luzon, Philippines. RESULTS: Results showed a farm prevalence of 66. 67%. A total of 69 (44.23%) ESBL-producing E. coli were isolated from boot swabs and cloacal swab samples from broiler farms. All major blaCTX-M groups except blaCTX-M-25 group were identified in the isolates. The most prevalent group was blaCTX-M-1, 72.46% (CI: 60.38-82.54%), followed by blaCTX-M-2, blaCTX-M-9 group and blaCTX-M-8. The blaTEM and blaSHV genes were identified in 57.97 and 27.54% of isolates, respectively. The blaCTX-M and blaTEM were the most common gene combinations (33.33%). Coexistence of blaCTX-M types was observed in 50 (73.53%) isolates. CONCLUSION: This study shows the high prevalence, diversity of patterns and coexistence of ESBL genes in the E. coli isolates from cloacal and boot swabs from broiler farms which pose risks of possible transmission to the environment, other animals and human.


Assuntos
Escherichia coli/genética , Escherichia coli/isolamento & purificação , beta-Lactamases/genética , Criação de Animais Domésticos , Animais , Galinhas , Estudos Transversais , Farmacorresistência Bacteriana/genética , Escherichia coli/enzimologia , Infecções por Escherichia coli/veterinária , Filipinas , Doenças das Aves Domésticas/microbiologia
4.
Res Vet Sci ; 125: 279-284, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31326704

RESUMO

Mutation of the PhoP/Q two-component system decreases the expression of ybjX and pagP encoding outer membrane proteins, and mutation of ybjX or pagP attenuates avian pathogenic Escherichia coli (APEC) pathogenicity. However, whether ybjX/pagP mutation (double-deletion mutant) has a synergistic effect on pathogenicity remains unknown. Herein, electrophoresis mobility shift assay (EMSA) experiments showed that the PhoP/Q system regulated ybjX and pagP transcription indirectly. The APECΔybjX/pagP mutant strain, constructed using the Red recombination method, exhibited reduced invasion of chicken embryo fibroblast (DF-1) cells, but had no effect on virulence in a chicken model. Using RNA sequencing to identify differential mRNAs in APECΔybjXΔpagP and native strains, we revealed up-regulation of genes involved in the bacterial chemotaxis pathway. The ybjX/pagP mutant strain displayed significantly increased motility, suggesting that double deletion of ybjX and pagP enhances motility via the bacterial chemotaxis pathway.


Assuntos
Aciltransferases/metabolismo , Infecções por Escherichia coli/veterinária , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Aciltransferases/genética , Animais , Quimiotaxia , Embrião de Galinha , Galinhas , Escherichia coli/genética , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Proteínas de Membrana/genética , Movimento , Mutação , Doenças das Aves Domésticas/microbiologia , Virulência , Fatores de Virulência/genética
5.
Cell Prolif ; 52(5): e12663, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31347748

RESUMO

OBJECTIVE: Induction of secondary necrosis/pyroptosis contributes to the toxicity of chemotherapeutic drugs, in which gasdermin E (GSDME) plays critical roles. This study aimed to explore whether GSDME is involved in mediating the cytotoxic effects of cisplatin and doxorubicin on mouse macrophages. METHODS: RAW 264.7 cells and bone marrow-derived macrophages (BMDMs) were treated with cisplatin or doxorubicin. Propidium iodide staining was used to assay necrosis, and immunoblotting was performed to detect protein expression. GSDME was knocked down by using small interfering RNA. Mice were injected intraperitoneally to evaluate toxicity to macrophages in vivo. Flow cytometry and immunofluorescence microscopy were adopted to analyse phenotypes of peritoneal cells. Cytokine levels were assayed by cytometric bead array. RESULTS: Both cisplatin and doxorubicin dose-dependently induced necrosis in mouse RAW 264.7 macrophages and BMDMs. Accompanying this, multiple caspases were activated, concomitant with the cleavage of poly (ADP-ribose) polymerase. Consistent with caspase-3 activation, GSDME was cleaved to generate its N-terminal fragment (GSDME-NT), thus leading to secondary necrosis/pyroptosis. Inhibition of caspase-3 significantly attenuated the generation of GSDME-NT concurrently with decreased necrosis in macrophages. GSDME knockdown also evidently decreased the necrosis in RAW 264.7 and BMDMs. Besides, cisplatin administration depleted peritoneal macrophages in mice, which was associated with caspase-3 activation and GSDME-NT generation. Consistent with the macrophage depletion, cisplatin administration significantly decreased survival of mice with bacterial infection. CONCLUSION: Chemotherapeutic cisplatin and doxorubicin exerted their cytotoxicity on macrophages partly by inducing caspase-3/GSDME-mediated secondary necrosis.


Assuntos
Caspase 3/metabolismo , Cisplatino/farmacologia , Doxorrubicina/farmacologia , Piroptose/efeitos dos fármacos , Receptores Estrogênicos/metabolismo , Animais , Apoptose/efeitos dos fármacos , Citocinas/metabolismo , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/mortalidade , Infecções por Escherichia coli/patologia , Infecções por Escherichia coli/veterinária , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Células RAW 264.7 , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Receptores Estrogênicos/antagonistas & inibidores , Receptores Estrogênicos/genética , Taxa de Sobrevida
6.
BMC Vet Res ; 15(1): 268, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31357996

RESUMO

BACKGROUND: This study investigated changes over time in the epidemiology of extended-spectrum ß-lactamase (ESBL) producing Escherichia coli within a single equine referral hospital in the UK. Faecal samples were collected from hospitalised horses in 2008 and 2017, processed using selective media and standard susceptibility laboratory methods. A novel real-time PCR with high resolution melt analysis was used to distinguish blaCTX-M-1 and blaCTX-M-15 within CTX-M-1 group. RESULTS: In 2008, 457 faecal samples from 103 horses were collected, with ESBL-producing E. coli identified in 131 samples (28.7, 95% CI 24.6-33.1). In 2017, 314 faecal samples were collected from 74 horses with ESBL-producing E. coli identified in 157 samples (50.0, 95% CI 44.5-55.5). There were 135 and 187 non-duplicate ESBL-producing isolates from 2008 and 2017, respectively. In 2008, 12.6% of isolates belonged to CTX-M-1 group, all carrying blaCTX-M-1, whilst in 2017, 94.1% of isolates were CTX-M-1 group positive and of these 39.2 and 60.8% of isolates carried blaCTX-M-1 and blaCTX-M-15, respectively. In addition, the prevalence of doxycycline, gentamicin and 3rd generation cephalosporin resistance increased significantly from 2008 to 2017 while a decreased prevalence of phenotypic resistance to potentiated sulphonamides was observed. CONCLUSIONS: The real-time PCR proved a reliable and high throughput method to distinguish between blaCTX-M-1 and blaCTX-M-15. Furthermore, its use in this study demonstrated the emergence of faecal carriage of CTX-M-15 in hospitalised horses, with an increase in prevalence of ESBL-producing E. coli as well as increased antimicrobial resistance to frequently used antimicrobials.


Assuntos
Infecções por Escherichia coli/veterinária , Fezes/microbiologia , Doenças dos Cavalos/epidemiologia , Doenças dos Cavalos/microbiologia , beta-Lactamases/metabolismo , Animais , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Escherichia coli/genética , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Cavalos , Hospitais Veterinários/estatística & dados numéricos , Prevalência , Reino Unido/epidemiologia , beta-Lactamases/genética
7.
Arch Anim Nutr ; 73(5): 339-359, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31342760

RESUMO

This study aimed to evaluate the potential of two new fat-protected butyrate or heptanoate salts to improve gut health and control post-weaning colibacillosis in weaning piglets challenged with enterotoxigenic Escherichia coli (ETEC) F4+, particularly focusing on their impact on intestinal microbiota and fermentative activity along the gastrointestinal tract (GIT). Seventy-two 21-d-old pigs were fed a plain diet (CTR) or supplemented with sodium butyrate (BUT) or sodium heptanoate (HPT), both at 0.3%. After a week of adaptation, animals were orally challenged at days 8 and 9 with 5.8 · 109 and 6.6 · 1010 cfu, respectively, and were euthanised on d 4 and d 8 post-inoculation (PI) (n = 8) to collect blood, digesta and tissue samples and characterise microbial groups, pathogen loads (qPCR), fermentation, ileal histomorphometry and immune markers. Colonic microbiota was analysed by 16S rRNA gene MiSeq sequencing. Supplementing both acid salts did not compensate clinical challenge effects nor performance impairments and neither histomorphometry nor serum biomarkers. Changes in the gastric fermentative activity were registered, BUT reducing lactic acid concentrations (day 8 PI), and with HPT fewer animals presenting detectable concentrations of propionic, butyric and valeric acids. At ileum BUT increased acetic acid concentration (day 8 PI), and both additives reduced short-chain fatty acids (SCFA) in the colon. Increases in enterobacteria and coliforms counts in ileal digesta (day 4 PI, p < 0.10) and mucosa scrapes (p < 0.05) were registered although E. coli F4 gene copies were unaffected. Regarding changes in the colonic microbiota (day 4 PI), Prevotellaceae and Prevotella were promoted with BUT supplementation whereas only minor groups were modified in HPT-treated animals. Summarising, although the pathogen loads or inflammatory mediators remained unresponsive, butyrate and heptanoate showed a significant impact on microbial fermentation along the whole GIT, being able to modify different bacterial groups at the colon. It could be hypothesised that these effects might be mediated by a carry-over effect of the changes observed in gastric fermentation, but possibly also to a better nutrient digestion in the foregut as a result of the reduced colonic SCFA concentrations.


Assuntos
Ácido Butírico/metabolismo , Infecções por Escherichia coli/veterinária , Microbioma Gastrointestinal/efeitos dos fármacos , Heptanoatos/metabolismo , Intestino Grosso/efeitos dos fármacos , Doenças dos Suínos/prevenção & controle , Ração Animal/análise , Animais , Ácido Butírico/administração & dosagem , Colo/efeitos dos fármacos , Colo/microbiologia , Dieta/veterinária , Suplementos Nutricionais/análise , Escherichia coli Enterotoxigênica/fisiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/prevenção & controle , Fermentação/efeitos dos fármacos , Microbioma Gastrointestinal/fisiologia , Heptanoatos/administração & dosagem , Intestino Grosso/metabolismo , Intestino Grosso/microbiologia , Masculino , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Sódio/administração & dosagem , Sódio/metabolismo , Sus scrofa/metabolismo , Sus scrofa/microbiologia , Suínos , Doenças dos Suínos/microbiologia , Desmame
8.
Vet Ital ; 55(2): 169-172, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31274179

RESUMO

The purpose of this study was to examine the prevalence of antimicrobial resistance among 180 Escherichia coli strains isolated from 200 wild pheasants caught in rural areas of the Czech Republic (Eastern Moravia) and Slovakia (Western Region). The isolates were also classified into phylogenetic groups by the multiplex PCR method. Our findings demonstrated that 130 strains were resistant to ampicillin (72%), 160 strains to cephalothin (89%), and 40 strains to tetracycline (22%). Ten strains were found to be resistant to chloramphenicol and sulfamethoxazole/trimethoprim (5.6%). In turn, all strains were sensitive to cefoperazone/sulbactam, ciprofloxacin, colistin, gentamicin, and piperacillin/tazobactam. Ten of the 180 isolates (5.6%) exhibited multi-resistant phenotypes, including resistances against beta-lactams, aminoglycosides, tetracyclines, sulphonamides, and chloramphenicol. As far as we know, this is the first report describing antimicrobial resistance in E. coli from pheasants.


Assuntos
Doenças das Aves/epidemiologia , Farmacorresistência Bacteriana , Infecções por Escherichia coli/veterinária , Escherichia coli/efeitos dos fármacos , Galliformes , Animais , Antibacterianos/farmacologia , Doenças das Aves/microbiologia , República Tcheca/epidemiologia , Farmacorresistência Bacteriana Múltipla , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Prevalência , Eslováquia/epidemiologia
9.
Vet Res ; 50(1): 48, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31221216

RESUMO

Enterotoxigenic Escherichia coli (ETEC) are an important cause of post-weaning diarrhea (PWD) in piglets. The IL-17 cytokine family is well known to play important roles in the host defense against bacterial infections at the mucosa. Previously, we reported the potential role of IL-17A in clearing an ETEC infection in piglets. IL-17C, another member of the IL-17 family, is highly expressed in the intestinal epithelium, however, its role during an ETEC infection is still unclear. In this study, we demonstrate that F4+ ETEC induce IL-17C mRNA and protein expression in intestinal tissues as well as in porcine intestinal epithelial cells (IPEC-J2). This IL-17C production is largely dependent on TLR5 signaling in IPEC-J2 cells. Both F4+ ETEC infection and exogenous IL-17C increased the expression of antimicrobial peptides and tight junction proteins, such as porcine beta-defensin (pBD)-2, claudin-1, claudin-2 and occludin in IPEC-J2 cells. Taken together, our data demonstrate that TLR5-mediated IL-17C expression in intestinal epithelial cells enhances mucosal host defense responses in a unique autocrine/paracrine manner in the intestinal epithelium against ETEC infection.


Assuntos
Escherichia coli Enterotoxigênica/fisiologia , Infecções por Escherichia coli/veterinária , Interleucina-17/genética , Doenças dos Suínos/genética , Receptor 5 Toll-Like/genética , Animais , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Interleucina-17/metabolismo , Mucosa Intestinal/fisiopatologia , Suínos , Doenças dos Suínos/metabolismo , Doenças dos Suínos/microbiologia , Receptor 5 Toll-Like/metabolismo
10.
Vet Microbiol ; 233: 52-60, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31176413

RESUMO

The spread of extended-spectrum ß-lactamases (ESBLs) in Escherichia coli is a major public health issue and ESBL-producing bacteria are frequently reported in livestock. For the assessment of the role of the foodborne transmission pathway in Germany, detailed data on the prevalence and characteristics of isolates of food origin are necessary. The objective of this study was to describe the prevalence of cefotaxime resistant E. coli as well as ESBL/pAmpC-producing E. coli and their characteristics in foods in Germany. Out of 2256 food samples, the highest prevalence of cefotaxime resistant E. coli was observed in chicken meat (74.9%), followed by turkey meat (40.1%). Prevalence in beef, pork and minced meat was considerably lower (4.2-15.3%). Whereas 18.0% of the raw milk samples, collected at farm level were positive, this was true only for few cheese samples (1.3%). In one out of 399 vegetable samples a cefotaxime-resistant E. coli was isolated. ESBL resistance genes of the CTX-M-group (10.1% of all samples) were most frequently detected, followed by genes of the pAmpC (2.6%), SHV (2.0%) and TEM (0.8%) families. Distribution of ESBL/AmpC-encoding E. coli resistance genes and E. coli phylogroups was significantly different between the chicken related food samples and all other food items. Our study results reflect that consumers might get exposed to ESBL/pAmpC-producing E. coli through several food chains. These results together with those collected at primary production and in the human population in other studies will allow more detailed analysis of the foodborne pathways, considering transmission from livestock populations to food at retail and to consumers in Germany.


Assuntos
Proteínas de Bactérias/genética , Escherichia coli/genética , Microbiologia de Alimentos , Carne/microbiologia , beta-Lactamases/genética , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/biossíntese , Cefotaxima/farmacologia , Farmacorresistência Bacteriana , Escherichia coli/enzimologia , Infecções por Escherichia coli/transmissão , Infecções por Escherichia coli/veterinária , Proteínas de Escherichia coli/biossíntese , Proteínas de Escherichia coli/genética , Alemanha , Gado/microbiologia , Aves Domésticas/microbiologia , Prevalência , Carne Vermelha/microbiologia , Verduras/microbiologia , beta-Lactamases/biossíntese
11.
Vet Microbiol ; 233: 61-67, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31176414

RESUMO

The incidence of infections with extended spectrum ß-lactamase producing Escherichia coli (ESBL-E) is increasing both in humans and animals. There is a paucity of data about the rate of faecal carriage of ESBL-E in pets. In this study, faecal swabs collected from 586 pets (225 cats; 361 dogs) in Auckland, New Zealand, were analysed for the presence of ESBL-E by culture, and a questionnaire was delivered to the owners. The ESBL-E were characterised and data elicited by the questionnaires were used for a multivariable analysis, to investigate the factors associated with faecal ESBL-E carriage. The prevalence of ESBL-E in faecal swabs was 6.4%. The ß-lactamase genes detected in the ESBL-E were the blaCTX-M-14 (n = 2) and blaCMY-2 (n = 34). Several isolates displayed multilocus sequence types (ST) associated with human and animal infections. Multiple isolates sharing the same ST displayed different antibiograms and ß-lactamase genes, reflecting horizontal gene transfer between and within ST. Variables independently associated with increased odds of ESBL-E carriage were: animal received systemic antimicrobial treatment in the six months before the sampling; presence of household members working in veterinary clinics; presence of household members travelling overseas in the six months before the sampling. We conclude that pets are colonised by ESBL-E which are genotypically similar to the bacteria found to infect humans and animals. The statistical analysis suggested a number of eco-epidemiological factors associated with ESBL-E carriage. In particular, they suggest veterinary clinics may represent hot-spots of antimicrobial resistance.


Assuntos
Portador Sadio/veterinária , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Escherichia coli/veterinária , Escherichia coli/genética , Animais de Estimação/microbiologia , beta-Lactamases/genética , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Portador Sadio/epidemiologia , Gatos/microbiologia , Cães/microbiologia , Escherichia coli/enzimologia , Infecções por Escherichia coli/epidemiologia , Fezes/microbiologia , Feminino , Transferência Genética Horizontal , Genética Populacional , Genótipo , Hospitais Veterinários , Humanos , Masculino , Tipagem de Sequências Multilocus , Nova Zelândia/epidemiologia , Prevalência , beta-Lactamases/biossíntese
12.
Microb Pathog ; 135: 103570, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31158492

RESUMO

Escherichia coli can cause severe, acute hemorrhagic pneumonia and systemic infection in farmed foxes, raccoon dogs and minks, leading to considerable economic losses to the farmers. It is well established that the htrA-encoded serine protease HtrA is critical for bacterial growth and survival under stress, and HtrA has been determined to be a potential vaccine target. However, the roles of HtrA in E. coli pathogenesis remain unknown. In this study, we generated an htrA-deletion mutant of the E. coli protype strain HBCLE-12 that causes pneumonia in silver foxes and then evaluated the changes in bacterial physiological characteristics in the absence of HtrA. The data show that knockout of the htrA gene did not affect growth and biochemical characteristics but led to impaired virulence of the strain. Increased susceptibility to environmental stresses, impaired survival in serum, and reduced biofilm formation may contribute to the virulence attenuation of the mutant. Furthermore, the HtrA-deficient mutant was subjected to RNA-seq analysis, and 16 differentially expressed genes were determined. This study provided insight that HtrA plays a definitive role in E. coli-induced infection.


Assuntos
Infecções por Escherichia coli/veterinária , Escherichia coli/enzimologia , Escherichia coli/genética , Raposas/microbiologia , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Proteínas Periplásmicas/genética , Proteínas Periplásmicas/metabolismo , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Doenças dos Animais/microbiologia , Animais , Proteínas de Bactérias , Biofilmes/crescimento & desenvolvimento , Proteínas e Peptídeos de Choque Frio/genética , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/patogenicidade , Regulação Bacteriana da Expressão Gênica , Técnicas de Inativação de Genes , Camundongos , Pneumonia/microbiologia , Pneumonia/veterinária , Deleção de Sequência , Estresse Fisiológico/genética , Transcriptoma , Virulência/genética , Fatores de Virulência/genética
13.
Vet Microbiol ; 234: 61-71, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31213273

RESUMO

Anti-phage activity of serum is of importance in repeated phage therapy. Higher serum anti-phage activity has been associated with greater susceptibility of phages to neutralisation and phage therapy failure. In this study, in vivo and in vitro survivability and immunogenicity of four coliphages (TM1, TM2, TM3 and TM4) were investigated in naive chickens and chickens pre-immunised with phage TM1. Furthermore, two phages that displayed different survivability and immunogenicity (TM1 and TM3) were compared with respect to their efficacy in treating naive or pre-immunised (TM1) chickens suffering from colibacillosis. The efficacy of the treatments was evaluated based on body weight, relative organ weights, mortality, E. coli counts in the lungs as well as severity and frequency of internal organ lesions. At the end of the experiment, both naive and pre-immunised chickens treated with TM3 showed significantly lower mortality and higher body weights than untreated chickens and those treated with TM1. The same trend was observed in incidence and severity of organ lesions as well as relative spleen weight. However, naive chickens treated with TM1 also showed a shortened inflammation period as indicated by spleen weights. E. coli counts in the lungs of chicken treated with TM3 were lower than those of chickens treated with TM1 on days 3 and 10 post challenge. These data indicate that the outcome of phage therapy and the impact of serum anti-phage activity are highly phage-type dependent in broilers.


Assuntos
Anticorpos Antivirais/sangue , Colífagos/imunologia , Infecções por Escherichia coli/veterinária , Terapia por Fagos/efeitos adversos , Doenças das Aves Domésticas/terapia , Animais , Galinhas , Escherichia coli , Infecções por Escherichia coli/terapia , Imunidade Humoral , Imunização , Imunoglobulina M/sangue , Imunoglobulinas/sangue , Inflamação , Pulmão/microbiologia , Pulmão/patologia , Terapia por Fagos/métodos , Doenças das Aves Domésticas/microbiologia , Soro , Baço/microbiologia , Baço/patologia
14.
Comp Immunol Microbiol Infect Dis ; 64: 163-167, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31174693

RESUMO

In the last few years, antimicrobial resistant (AMR) Escherichia coli have been detected in newborn chickens suggesting their vertical transmission from breeding birds to their offspring. However, little is known about the presence of AMR E. coli in the reproductive organs of broiler breeders. The aim of this study was to investigate the presence of E. coli in the ovaries of healthy broiler breeders and to study their antimicrobial resistance. Samples from broiler breeders (n = 80) collected from 80 different broiler breeder flocks were included in this study. Antibiotic susceptibility testing was performed using disk diffusion method according to Clinical and Laboratory Standards Institute guidelines. Minimal inhibitory concentrations (MICs) of five antimicrobial agents were determined by Etest. PCR and sequencing were used to detect the blaESBL genes. E. coli were detected in the ovaries of thirty seven out of 80 (46.25%) sampled flocks. High levels of resistance to various first-line antimicrobial agents were recorded in E. coli isolates. This study showed that 89.18% of E. coli isolates were multidrug resistant (MDR). Furthermore, MDR extended-spectrum ß-lactamases (ESBL)-producing E. coli were detected in the ovaries of four different broiler breeder flocks. Molecular characterization revealed that three isolates harboured blaCTX-M-1 gene and one isolate expressed blaSHV-12 gene. In addition, one blaCTX-M-1 -producing E. coli co-harboured the blaTEM-1 gene. These findings would contribute to a better epidemiological understanding of MDR E. coli for improve existing preventive strategies in order to reduce the dissemination of antimicrobial resistance in the broiler production system.


Assuntos
Farmacorresistência Bacteriana Múltipla , Infecções por Escherichia coli/veterinária , Escherichia coli/isolamento & purificação , Ovário/microbiologia , Doenças das Aves Domésticas/microbiologia , Argélia , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Cefalosporinas/farmacologia , Galinhas/microbiologia , Escherichia coli/enzimologia , Feminino , Testes de Sensibilidade Microbiana , beta-Lactamases/genética
15.
J Vet Diagn Invest ; 31(4): 611-615, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31184286

RESUMO

Calf diarrhea is a common cause of pre-weaning morbidity and mortality in cattle operations. We evaluated the role of Escherichia coli by assessing the frequency of genes encoding virulence factors (virotypes) in E. coli from feces or intestinal contents, and the association of these virotypes or other diarrheagenic pathogens with intestinal morphologic changes in calves with or without diarrhea. E. coli was isolated from 408 feces and 105 intestines of calves with diarrhea and compared to those isolated from 635 feces and 100 intestines of calves without diarrhea, from 2002 to 2016. Virotype EAST1:F17, in combination with minor virotypes, was the most commonly detected type, but without differences in frequency between the 2 groups of calves. No significant intestinal morphologic changes were observed with the different E. coli virotypes in either group of calves, except for bacterial attachment to enterocytes for virotype STa:F5, which was detected only in calves with diarrhea. These observations suggest that E. coli, excluding virotype STa:F5, is not a significant diarrhea-causing agent in calves. However, the intestinal lesions observed in ~82% of calves with diarrhea were attributed to other diarrheagenic pathogens that include bovine coronavirus, Clostridium perfringens, Cryptosporidium spp., Eimeria spp., rotavirus, and Salmonella spp.


Assuntos
Doenças dos Bovinos/microbiologia , Diarreia/veterinária , Infecções por Escherichia coli/veterinária , Escherichia coli/patogenicidade , Animais , Bovinos , Diarreia/microbiologia , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Fezes/microbiologia , Intestinos/microbiologia , Virulência , Fatores de Virulência
16.
BMC Vet Res ; 15(1): 159, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31118039

RESUMO

BACKGROUND: Avian pathogenic Escherichia coli (APEC) is the principle cause of colibacillosis affecting poultry. The main challenge to the poultry industry is antimicrobial resistance and the emergence of multidrug resistant bacteria that threaten the safety of the food chain. Risk factors associated with emergence of antimicrobial resistance among avian pathogenic E. coli were correlated with the inappropriate use of antimicrobials along with inadequate hygienic practices, which encourages the selection pressure of antimicrobial resistant APEC. The aim of this study was to isolate, identify, serogroup and genotype APEC from broilers, assess their antibiotic resistance profile, expressed genes and the associated risk factors. RESULTS: APEC was isolated from the visceral organs of sick chickens with a prevalence of 53.4%. The most prevalent serotypes were O1, O2, O25 and O78, in percentage of 14.8, 12.6, 4.4 and 23.7%, respectively. Virulence Associated Genes; SitA, iss, iucD, iucC, astA, tsh cvi and irp2 were detected in rate of 97.4, 93.3, 75, 74, 71, 46.5, 39 and 34%, respectively and 186 (69.2%) isolates possess > 5-10 genes. The highest resistance was found against sulphamethoxazole-trimethoprim, florfenicol, amoxicillin, doxycycline and spectinomycin in percentage; 95.5, 93.7, 93.3, 92.2 and 92.2%, respectively. Sixty-eight percent of APEC isolates were found to have at least 5 out of 8 antimicrobial resistant genes. The most predominant genes were Int1 97%, tetA 78.4%, bla TEM 72.9%, Sul1 72.4%, Sul2 70.2%. Two risk factors were found to be associated with the presence of multi-drug resistant APEC in broiler chickens, with a P value ≤0.05; the use of ground water as source of drinking water and farms located in proximity to other farms. CONCLUSIONS: This study characterized the VAGs of avian pathogenic E. coli and establish their antimicrobial resistance patterns. The widespread of antimicrobial resistance of APEC isolates and detection of ARGs highlighted the need to monitor the spread of ARGs in poultry farms and the environment in Jordan. Use of ground water and closely located farms were significant risk factors associated with the presence of MDR APEC in broiler chickens in Jordan.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Infecções por Escherichia coli/veterinária , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Doenças das Aves Domésticas/microbiologia , Criação de Animais Domésticos , Animais , Galinhas , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Água Subterrânea/microbiologia , Jordânia/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Fatores de Risco
17.
Vet Res ; 50(1): 40, 2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31126325

RESUMO

Systemic infections caused by avian pathogenic Escherichia coli (APEC) are economically devastating to poultry industries worldwide and are also potentially threatening to human health. Pathogens must be able to precisely modulate gene expression to facilitate their survival and the successful infection. The Cpx two-component signal transduction system (TCS) regulates surface structure assembly and virulence factors implicated in Gram-negative bacterial pathogenesis. However, the roles of the Cpx TCS in bacterial fitness and pathogenesis during APEC infection are not completely understood. Here, we show that the Cpx TCS response regulator CpxR is critical to the survival and virulence of APEC. Inactivation of cpxR leads to significant defects in the interbacterial competition activity, invasion and survival of APEC in vitro and in vivo. Moreover, activation of CpxR positive regulates the expression of the APEC type VI secretion system 2 (T6SS2). Further investigations revealed that phosphorylated CpxR directly bound to the T6SS2 hcp2B promoter region. Taken together, our results demonstrated that CpxR contributes to the pathogensis of APEC at least through directly regulating the expression and function of T6SS2. This study broadens understanding of the regulatory effect of Cpx TCS, thus elucidating the mechanisms through which Cpx TCS involved in bacterial virulence.


Assuntos
Proteínas de Bactérias/metabolismo , Infecções por Escherichia coli/veterinária , Escherichia coli/patogenicidade , Regulação Bacteriana da Expressão Gênica/fisiologia , Doenças das Aves Domésticas/microbiologia , Animais , Aderência Bacteriana , Proteínas de Bactérias/genética , Patos , Ensaio de Desvio de Mobilidade Eletroforética , Infecções por Escherichia coli/microbiologia , Mutação , Regiões Promotoras Genéticas , Virulência , beta-Galactosidase/metabolismo
18.
Vet Res Commun ; 43(2): 131-142, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31055768

RESUMO

In this study, we investigated the effects of probiotic, acidifier and synbiotic supplementation on growth performance, mortality rate, intestinal gene expressions, fecal shedding, and organs colonization induced by Escherichia coli in broiler chickens. Six experimental groups were included; negative control group (NC), positive control group (PC), probiotic group (PR), acidifier group (AC), synbiotic group (SY) and colistin sulfate group (CS). Chickens in groups NC and PC were fed a basal diet, while chickens in groups PR, AC, SY, and CS were fed a basal diet containing probiotic, acidifier, synbiotic and colistin sulfate, respectively from the 1st day to the 28th day of age. At 7 days of age, all groups (not NC) were orally challenged with 0.5 ml (1.0 × 109 CFU/ml) E. coli O78. The dietary supplementation of acidifier and synbiotic were sufficient to quell the devastating effects of E. coli infection in broilers. Growth performances represented by body weight gain, feed intake and feed conversion ratio were significantly improved as well as, mortalities were prevented whilst the ileal pro-inflammatory gene expressions (IL-6, IL-8, IL-13, TLR-4, IFN-γ, LITAF, AvBD-2, and AvBD-9) were significantly downregulated and the anti-inflammatory cytokine (IL-10) was significantly increased. In addition, E. coli fecal shedding and organs colonization was significantly diminished. It was concluded that the addition of both acidifier and synbiotic to the diet of broilers infected with E. coli could modulate the intestinal inflammatory responses induced by E. coli infection and minimized the inflammation-induced damage which resulted in improvement in growth performance, prevention of mortalities and reduction of E. coli environmental contamination.


Assuntos
Suplementos Nutricionais , Infecções por Escherichia coli/veterinária , Regulação da Expressão Gênica/efeitos dos fármacos , Doenças das Aves Domésticas/fisiopatologia , Probióticos/farmacologia , Animais , Galinhas , Colistina/farmacologia , Ingestão de Alimentos/efeitos dos fármacos , Escherichia coli , Infecções por Escherichia coli/fisiopatologia , Intestinos/efeitos dos fármacos , Simbióticos , Ganho de Peso/efeitos dos fármacos
19.
Res Vet Sci ; 124: 417-425, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31078789

RESUMO

This study reports on the influence of experimentally-induced uterine inflammation on chemical phenotypes, number and distribution of neurons in the dorsal root ganglia (DRGs) innervating the uterus in sexually mature gilts. On day 17 of the first studied estrous cycle, the uterine horns were injected with retrograde tracer Fast Blue (FB). After 28 days (on an expected day 3 of third studied estrous cycle), 50 ml of either saline (group SAL) or Escherichia coli (E. coli) suspension (109 colony-forming units/ml, group E. coli) were injected into each uterine horn. In the control pigs (group CON), only laparotomy was performed. Eight days later DRGs and uteri were collected. All infected gilts developed severe form of acute endometritis. By use of double immunofluorescence labelling the numbers of uterine perikarya expressing substance P (SP), calcitonin gene-related peptide (CGRP), neurokinin A (NKA), galanin (GAL) and pituitary adenylate cyclase-activating polypeptide (PACAP) were analyzed. Injection of E. coli decreased the total number of the FB positive perykaria in the Th10-S4 DRGs. We revealed an increase in the populations of uterine perikarya coded SP+/CGRP-, SP+/NKA-, SP-/NKA+, SP+/GAL+, SP+/GAL-, SP-/GAL+, SP+/PACAP+ and SP-/PACAP+. Our results suggest that uterine inflammation affects both the spatial and neurochemical organization pattern of uterine sensory innervation. Additionally, the inflammation may affect the transmission of sensory information from uterus to spinal cord.


Assuntos
Endometrite/veterinária , Gânglios Espinais/fisiologia , Sus scrofa/fisiologia , Doenças dos Suínos/fisiopatologia , Útero/inervação , Animais , Endometrite/fisiopatologia , Escherichia coli , Infecções por Escherichia coli/fisiopatologia , Infecções por Escherichia coli/veterinária , Feminino , Gânglios Espinais/fisiopatologia , Distribuição Aleatória , Suínos/fisiologia , Útero/fisiopatologia
20.
Res Vet Sci ; 124: 426-432, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31082572

RESUMO

Having sensitive serum biomarkers able to determine the structural changes of the small intestine suffering from bacterial digestive diseases could be a valuable tool particularly in piglets at weaning, when intestinal infections are highly prevalent. We evaluated the usefulness of three inflammatory and gut-wall-integrity biomarkers to assess the degree of intestinal histo-morphological damage in piglets. Piglets were orally challenged with Salmonella Typhimurium or enterotoxigenic Escherichia coli (ETEC) to get a variable range of response according to individual variability. Forty-eight piglets were challenged with Salmonella Typhimurium and seventy-two with enterotoxigenic Escherichia coli K88. Clinical signs and faecal score were recorded. At Days 4 and 8 post-inoculation, blood was sampled, animals euthanised and distal ileum dissected. Morphological measures were obtained from the gut tissue, and serum tumour necrosis factor-alpha (TNF-α), pig major acute-phase protein (Pig-MAP) and intestinal fatty acid-binding protein (I-FABP) were determined. Animals developed mild-to-severe diarrhoea after the challenge. When analysing the complete set of analytical results, a high correlation was found among the three serum biomarkers. The most representative morphological indicator was the villus:crypt ratio (V:C), which showed a strong negative correlation with all three biomarkers. Regression analyses between faecal score and the previous variable showed linear relations. When the range of V:C was analysed, based on the quartile distribution of each serum variable, a marked increase in their concentration was observed with greater villus damage. Summarising, the combination of I-FABP, Pig-MAP and TNF-α may be useful for determining the intestinal injury degree and barrier integrity in recently weaned pigs.


Assuntos
Proteínas da Fase Aguda/metabolismo , Infecções por Escherichia coli/veterinária , Proteínas de Ligação a Ácido Graxo/metabolismo , Salmonelose Animal/fisiopatologia , Doenças dos Suínos/fisiopatologia , Fator de Necrose Tumoral alfa/metabolismo , Animais , Biomarcadores/metabolismo , Diarreia/microbiologia , Diarreia/fisiopatologia , Modelos Animais de Doenças , Escherichia coli Enterotoxigênica/fisiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/fisiopatologia , Intestinos/microbiologia , Masculino , Salmonelose Animal/microbiologia , Salmonella typhimurium/fisiologia , Sus scrofa , Suínos , Doenças dos Suínos/microbiologia , Desmame
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA