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1.
Vet Parasitol Reg Stud Reports ; 21: 100435, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32862896

RESUMO

Faecal specimens from 36 scouring neonatal calves from two dairy farms located in the Al Ain region of the UAE were screened with pathogen-specific antigen ELISA for Cryptosporidium parvum, Escherichia coli K99, rotavirus, and coronavirus. Additionally, faecal smears were stained with modified-acid-fast for Cryptosporidium oocysts, and the VITEK 2 system plus Gram's stain used to identify bacteria isolated from the faecal samples. Farm management practices were also evaluated during a farm visit. Of the 36 calves, 29, 13, 5, and 6 were positive for C. parvum, E. coli K99, bovine coronavirus, and rotavirus antigens respectively, while 27 were positive for Cryptosporidium oocysts. In various combinations, mixed infections were detected in 20/36 calves. This is the first report of C. parvum, E. coli K99, Salmonella spp., rotavirus, and coronavirus in ≤14-days-old scouring neonatal dairy calves from the UAE. Molecular characterization of these pathogens and nationwide epidemiological calf scour studies are recommended.


Assuntos
Doenças dos Bovinos/epidemiologia , Criptosporidiose/epidemiologia , Cryptosporidium parvum , Animais , Animais Recém-Nascidos/microbiologia , Animais Recém-Nascidos/parasitologia , Bovinos , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/parasitologia , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/veterinária , Coronavirus Bovino , Indústria de Laticínios , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Feminino , Masculino , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/veterinária , Salmonelose Animal/epidemiologia , Emirados Árabes Unidos/epidemiologia
2.
Benef Microbes ; 11(5): 477-488, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32877228

RESUMO

Neonatal calf diarrhoea is one of the challenges faced by intensive farming, and probiotics are considered a promising approach to improve calves' health. The objective of this study was to evaluate the effect of potential probiotic lactobacilli on new-born dairy calves' growth, diarrhoea incidence, faecal score, cytokine expression in blood cells, immunoglobulin A (IgA) levels in plasma and faeces, and pathogen abundance in faeces. Two in vivo assays were conducted at the same farm in two annual calving seasons. Treated calves received one daily dose of the selected lactobacilli (Lactobacillus reuteri TP1.3B or Lactobacillus johnsonii TP1.6) for 10 consecutive days. A faecal score was recorded daily, average daily gain (ADG) was calculated, and blood and faeces samples were collected. Pathogen abundance was analysed by absolute qPCR in faeces using primers directed at Salmonella enterica, rotavirus, coronavirus, Cryptosporidium parvum and three Escherichia coli virulence genes (eae, clpG and Stx1). The faecal score was positively affected by the administration of both lactobacilli strains, and diarrhoea incidence was significantly lower in treated calves. No differences were found regarding ADG, cytokine expression, IgA levels and pathogen abundance. Our findings showed that oral administration of these strains could improve gastrointestinal health, but results could vary depending on the calving season, which may be related to pathogen seasonality and other environmental effects.


Assuntos
Doenças dos Bovinos/terapia , Diarreia , Lactobacillus johnsonii/metabolismo , Lactobacillus reuteri/metabolismo , Probióticos/uso terapêutico , Animais , Animais Recém-Nascidos , Bovinos , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/prevenção & controle , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/veterinária , Criptosporidiose/prevenção & controle , Citocinas/sangue , Indústria de Laticínios , Diarreia/prevenção & controle , Diarreia/terapia , Diarreia/veterinária , Infecções por Escherichia coli/prevenção & controle , Infecções por Escherichia coli/veterinária , Fezes/virologia , Trato Gastrointestinal/microbiologia , Imunoglobulina A/sangue , Infecções por Rotavirus/prevenção & controle , Infecções por Rotavirus/veterinária , Salmonelose Animal/prevenção & controle
3.
Int J Food Microbiol ; 324: 108589, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32442794

RESUMO

Shiga-toxigenic Escherichia coli (STEC) are important human pathogens associated with diarrhea and in some cases haemorrhagic colitis. Contaminated food derived from cattle and wildlife species are often associated with disease outbreaks. In this study, we report the prevalence, serogroup diversity and virulence profiles of STEC strains derived from cattle, rusa deer and pig. Of the 422 samples analyzed, STEC were detected in 40% (80/200) of cattle, 27.0% (33/122) of deer and 13.0% (13/100) of pigs. STEC isolates belonged to 38 O-serogroups whereby 5.2% (24/462) of the isolates belonged to clinically important EHEC-7 serogroups: O26 (n = 2), O103 (n = 1), O145 (n = 3) and O157 (n = 18). Fourteen serogroups (O26, O51, O84, O91, O100, O104, O110, O117, O145, O146, O156, O157, O177 and ONT) displayed multiple virulence profiles. We also identified two serovars (O117 and O119) in deer which are not well-documented in epidemiological surveys. 73.7% (28/38) of recovered O-serogroups are known to be associated with serious human illnesses including haemolytic uremic syndrome (HUS) and bloody diarrhea. STEC isolates harboring single genotypes stx1, stx2, eae and hlyA accounted for 3.0% (14/462), 9.1% (42/462), 47.6% (220/462) and 1.7% (8/462) of all STEC isolates screened, respectively. Virulence combinations stx1 and stx2 were harboured by 1.3% of isolates while strains with genetic profiles eae/hlyA were the second most prevalent amongst STEC isolates. The full known virulent genotypes (stx2/eae, stx1/stx2/eae, stx1/stx2/hlyA and stx2/eae/hlyA) were present in 22 of the 462 STEC strains. A total of 10 different virulence patterns were recovered amongst animal species. Phylogeny of the gnd gene showed that amongst STEC strains, serovar O100 outlined the main cluster. Fourteen (n = 14) different sequence types (STs) were identified from a panel of twenty (n = 20) STEC isolates. One of the isolate (PG007B) possessed a unique ST (adk 10, fumC 693, gyrB 4, icd 1, mdh 8, purA 8, recA 2) that could not be assigned using MLST databases. None of the ST's recovered in deer were observed in domestic species. Our findings shows that food associated animals found on the tropical island of Mauritius carry a diversity of STEC strains with many serovars known to be associated with human disease. This report indicates that increased awareness, surveillance and hygienic attention at critical stages of the human food chain are warranted.


Assuntos
Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Microbiologia de Alimentos , Escherichia coli Shiga Toxigênica/isolamento & purificação , Animais , Animais Domésticos , Animais Selvagens , Bovinos , Cervos , Infecções por Escherichia coli/epidemiologia , Proteínas de Escherichia coli/genética , Genótipo , Maurício/epidemiologia , Filogenia , Prevalência , Sorogrupo , Escherichia coli Shiga Toxigênica/classificação , Escherichia coli Shiga Toxigênica/genética , Suínos , Fatores de Virulência/genética
4.
PLoS One ; 15(5): e0232890, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32392237

RESUMO

Diarrhea caused by Escherichia coli in calves is an important problem in terms of survivability, productivity and treatment costs. In this study, 88 of 150 diarrheic animals tested positive for E. coli. Of these, 54 samples had mixed infection with other bacterial and/or parasitic agents. There are several diarrheagenic E. coli pathotypes including enteropathogenic E. coli (EPEC), Shiga-toxin producing E. coli (STEC), enterotoxigenic E. coli (ETEC) and necrotoxigenic E. coli (NTEC). Molecular detection of virulence factors Stx2, Cdt3, Eae, CNF2, F5, Hly, Stx1, and ST revealed their presence at 39.7, 27.2, 19.3, 15.9, 13.6, 9.0, 3.4, and 3.4 percent, respectively. As many as 13.6% of the isolates lacked virulence genes and none of the isolate had LT or CNF1 toxin gene. The odds of isolating ETEC from male calves was 3.6 times (95% CI: 1.1, 12.4; P value = 0.042) that of female calves, whereas the odds of isolating NTEC from male calves was 72.9% lower (95% CI: 91.3% lower, 15.7% lower; P value = 0.024) than that in females. The odds of isolating STEC in winter was 3.3 times (95% CI: 1.1, 10.3; P value = 0.037) that of spring. Antibiograms showed 48 (54.5%) of the isolates to be multi-drug resistant. The percent resistance to tetracycline, streptomycin, ampicillin, and trimethoprim-sulfamethoxazole was 79.5, 67.0, 54.5, and 43.0, respectively. Ceftazidime (14.8%), amoxicillin-clavulanic acid (13.6%) and aztreonam (11.3%) showed the lowest resistance, and none of the isolates was resistant to imipenem. The results of this study can help improve our understanding of the epidemiological aspects of E. coli infection and to devise strategies for protection against it. The prevalence of E. coli pathotypes can help potential buyers of calves to avoid infected premises. The antibiograms in this study emphasizes the risks associated with the random use of antibiotics.


Assuntos
Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Diarreia/veterinária , Infecções por Escherichia coli/veterinária , Criação de Animais Domésticos , Animais , Búfalos , Bovinos , Diarreia/epidemiologia , Diarreia/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/epidemiologia , Proteínas de Escherichia coli/genética , Feminino , Masculino , Testes de Sensibilidade Microbiana , Fatores de Risco , Estações do Ano , Fatores de Virulência/genética
5.
J Anim Sci ; 98(5)2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32300795

RESUMO

The objective of this experiment was to investigate the impact of an F18 enterotoxigenic Escherichia coli (ETEC) challenge on growth performance, aspects of intestinal function, and selected immune responses of piglets, as well as to evaluate potential protective effects of direct-fed microbial (DFM) blends. Seventy-two weaned piglets (6.4 ± 0.2 kg body weight [BW]; ~21 d of age) were assigned to one of four treatments: 1) NC: Nonchallenged (n = 10), 2) positive challenged control (PC): F18 ETEC-challenged (n = 10), 3) PC + DFM1 (n = 8; three strains of Bacillus amyloliquefaciens; 7.5 × 105 colony-forming units [cfu]/g), or 4) PC + DFM2 (n=8; 2 strains of B. amyloliquefaciens and one strain of Bacillus subtilis; 1.5 × 105 cfu/g). Feed intake and BW were recorded on day 0, 7, and 17. Pigs were sham-infected either with 6 mL phosphate-buffered saline or inoculated with 6 mL F18 ETEC (~1.9 × 109 cfu/mL) on day 7 (0 d postinoculation [dpi]). All ETEC-challenged pigs were confirmed to be genetically susceptible to F18. Pigs had ad libitum access to feed and water throughout the 17-d trial. Fecal scores were visually ranked and rectal temperatures were recorded daily. To evaluate ETEC shedding, fecal swabs were collected on dpi 0, 1, 2, 3, 5, 7, and 10. Blood samples were collected on dpi 0, 1, 2, 4, 7, and 10. Ileal tissues were collected at necropsy on dpi 10. All challenged treatments had lower final BW, decreased average daily gain (ADG), and average daily feed intake (ADFI) during the 10-d postchallenge period (P < 0.01). The DFM2 treatment increased E. coli shedding on dpi 2 and decreased iton dpi 7 (P < 0.05) compared with the PC. Rectal temperature decreased across all challenged treatments (P < 0.01). Ileal mRNA abundance of occludin (OCLN) and zonula occludens-1 (ZO-1) decreased in PC and DFM1 compared with NC (P < 0.05). Pigs fed DFM2 had intermediate ileal mRNA abundance of OCLN and increased ZO-1 mRNA compared with pigs in PC (P < 0.05). Interleukin 8 (IL-8) increased in the plasma of PC and DFM2 on dpi 2 compared with NC (P < 0.05). Mucosal IL-8 increased in PC compared with NC (P < 0.05). All challenged treatments tended to have elevated tumor necrosis factor-α (TNF-α) mRNA abundance compared with NC (P < 0.10). Challenged pigs had reduced secretory immunoglobulin A and villus height compared with NC pigs (P < 0.05). The impact of an ETEC challenge on intestinal function and the immune system has been revealed, information critical to developing improved treatment regimes.


Assuntos
Bacillus amyloliquefaciens/fisiologia , Bacillus subtilis/fisiologia , Escherichia coli Enterotoxigênica/imunologia , Infecções por Escherichia coli/veterinária , Imunidade Inata , Probióticos/análise , Doenças dos Suínos/prevenção & controle , Animais , Derrame de Bactérias , Dieta/veterinária , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/prevenção & controle , Fezes/microbiologia , Feminino , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/microbiologia , Trato Gastrointestinal/fisiologia , Masculino , Distribuição Aleatória , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/microbiologia , Desmame
6.
Res Vet Sci ; 131: 24-30, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32278961

RESUMO

Two-component systems (TCSs) are widespread regulatory systems which can help bacteria to control their cellular functions and respond to a diverse range of stimuli. The KdpD/KdpE system had been well studied for regulating potassium transport and identified as an adaptive regulator involved in the virulence of some pathogenic bacteria, but its role in avian pathogenic Escherichia coli (APEC) was still unknown. In this study, the mutant strain AE17ΔKdpDE was obtained successfully of a clinical APEC isolation AE17 using the lambda Red recombinase system and performed the transcriptional sequencing of the wild type strain AE17 and the mutant strain AE17ΔKdpDE. The transcriptional sequencing results revealed that the KdpD/KdpE two-component system mainly influenced the expression of the genes covering metabolic pathways, flagellar assembly, global transcription regulator. The expression of some flagellar-related genes detecting by quantitative real-time PCR was consistent with the results of transcriptional sequencing. Importantly, fewer flagellum of the mutant strain AE17ΔKdpDE was observed than AE17 using the transmission electron microscope and a decreased motility circle of AE17ΔKdpDE appeared in the semisolid medium. In addition, the serum bactericidal assay was carried out with the specific-pathogen-free chicken in different dilution and the survival ability in the serum of AE17ΔKdpDE was also obviously lower than that of AE17. These results suggested that in APEC, the KdpD/KdpE two-component system mainly influenced the expression of flagella-related genes, the flagellum formation, the motility and antiserum bactericidal activity.


Assuntos
Galinhas/microbiologia , Infecções por Escherichia coli/veterinária , Proteínas de Escherichia coli/metabolismo , Escherichia coli/genética , Escherichia coli/patogenicidade , Proteínas Quinases/metabolismo , Transativadores/metabolismo , Animais , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Feminino , Doenças das Aves Domésticas/microbiologia , Proteínas Quinases/genética , Transativadores/genética , Virulência
7.
Vet Res ; 51(1): 49, 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32234079

RESUMO

Bacterial exopolysaccharides (EPSs) are known to modulate immunity. To date, a plethora of studies have reported the effect of EPSs on intestinal cells; however few works have revealed a complete picture of the signalling events in intestinal epithelial cells induced by bacterial EPSs. Here, using transcriptomics, we comprehensively mapped the biological processes in porcine intestinal epithelial cells challenged with EPS derived from Lactobacillus reuteri alone, enterotoxigenic Escherichia coli (ETEC) or ETEC after pretreatment with EPS. The Gene Ontology analysis of differentially expressed genes (DEGs) showed that ETEC is able to evoke biological processes specifically involved in cell junction reorganization, extracellular matrix degradation, and activation of the innate immune response through the activation of pattern recognition receptors, such as TLRs and CTRs. A total of 495 DEGs were induced in ETEC-challenged cells. On the other hand, EPS pretreatment was able to attenuate overexpression of the genes induced by ETEC infection. The most relevant finding of this study is that EPS has a suppressive effect on the inflammatory response evoked by ETEC infection. On the basis of high-throughput RNA-seq, this report is the first to describe the effects of EPSs derived from L. reuteri used as a pretreatment of global gene expression in porcine epithelial cells.


Assuntos
Escherichia coli Enterotoxigênica/fisiologia , Infecções por Escherichia coli/veterinária , Mucosa Intestinal/fisiopatologia , Lactobacillus reuteri/fisiologia , Polissacarídeos Bacterianos/administração & dosagem , Doenças dos Suínos/fisiopatologia , Animais , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/fisiopatologia , Mucosa Intestinal/microbiologia , Polissacarídeos Bacterianos/classificação , Suínos , Doenças dos Suínos/microbiologia
8.
Poult Sci ; 99(4): 1875-1887, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32241467

RESUMO

The present study was undertaken to investigate the effect of aqueous Withania somnifera root (WSR) extract in broiler chicks experimentally infected with Escherichia coli O78 @ 107 CFU/0.5 ml intraperitoneally. Clinical signs and mortality due to colibacillosis observed in infected chicks were mild and lasted for short duration in WSR extract supplemented group as compared with the nonsupplemented group. A significant increase in serum alanine transaminase, aspartate transaminase, lactate dehydrogenase, and creatine phosphokinase activities and a decrease in total protein and albumin concentrations were observed in the infected groups, though these changes were of lower magnitude in WSR extract supplemented group. A significantly higher activity of oxidative blood parameters such as superoxide dismutase, catalase, glutathione reductase, and glutathione-S-transferase enzymes were noticed in WSR extract supplemented group. The WSR extract supplemented group revealed significantly higher E. coli-specific antibody titer and enhanced lymphocyte proliferation response as compared with the nonsupplemented group. The gross and histopathological lesions of colibacillosis were mild in the WSR extract-supplemented infected group as compared with the nonsupplemented infected group. Withania somnifera root extract supplementation produced 31.48 and 34.38% protection in the gross and histopathological lesions in E. coli infected chicks, respectively. It is concluded that supplementation of 20% WSR extract @ 20 ml/L of water caused a reduction in the severity, mortality, and recovery period of E. coli infection and enhanced the humoral and cellular immune responses suggesting its protective effect on limiting the pathology of E. coli infection in broiler chickens.


Assuntos
Anti-Infecciosos/metabolismo , Galinhas , Infecções por Escherichia coli/veterinária , Escherichia coli/fisiologia , Extratos Vegetais/metabolismo , Doenças das Aves Domésticas/tratamento farmacológico , Withania/química , Ração Animal/análise , Animais , Anti-Infecciosos/administração & dosagem , Anti-Infecciosos/química , Dieta/veterinária , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Raízes de Plantas/química , Doenças das Aves Domésticas/microbiologia , Distribuição Aleatória
9.
Res Vet Sci ; 130: 144-152, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32179292

RESUMO

Avian pathogenic Escherichia coli (APEC) can lead to extraintestinal disease in avian species via respiratory tract infection. However, the regulatory mechanism of APEC on the pathogenicity of chicken trachea epithelium remains unknown. In this study, we examined pathological changes in chicken trachea at different infection times (4, 8, 12 and 24 h). The RNA sequencing of APEC infection group and the PBS group (negative control) of chicken trachea epithelium were analysed. Our studies revealed that the oedema, heterophil infiltration and hyperaemia appeared at 8 and 12 h post APEC infection. And the hyperaemia phenomenon and heterophilic granulocyte infiltration disappeared at 24 h post infection. Then RNA sequencing showed many genes were dynamically expressed in the APEC infection group. At 4, 8 and 12 h post infection, the mRNA of differentially expressed genes were enriched by cytokine-cytokine receptor interaction and the toll-like receptor signalling pathway. The cell cycle pathway was enriched at 24 h post infection. Altogether, these findings suggest that APEC infection induces pathological change in the chicken trachea, the mRNA of differentially expressed genes participating in inflammation and hyperplasia signalling pathways. Which not only provide more evidence for regulatory mechanism of APEC on the pathogenicity of chicken trachea epithelium, but also facilitate the effective management of APEC infections in poultry through trachea.


Assuntos
Proteínas Aviárias/metabolismo , Galinhas , Citocinas/metabolismo , Infecções por Escherichia coli/veterinária , Doenças das Aves Domésticas/patologia , Receptores de Citocinas/metabolismo , Doenças da Traqueia/veterinária , Animais , Ciclo Celular , Escherichia coli/fisiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/patologia , Infecções por Escherichia coli/fisiopatologia , Feminino , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/fisiopatologia , RNA Mensageiro/metabolismo , Traqueia/patologia , Traqueia/fisiopatologia , Doenças da Traqueia/microbiologia , Doenças da Traqueia/patologia , Doenças da Traqueia/fisiopatologia
10.
Vet Microbiol ; 242: 108566, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32122581

RESUMO

Antimicrobial resistance reported in bacteria of animal origin is considered a major challenge to veterinary public health. In this study, the genotypic and phenotypic characterisation of twelve Escherichia coli isolates of bovine origin is reported. Twelve bacterial isolates of animal origin were selected from a previous study based on their multidrug resistant (MDR) profile. Efflux pump activity was measured using ethidium bromide (EtBr) and the biofilm forming ability of the individual strains was assessed using a number of phenotypic assays. All isolates were resistant to tetracyclines and a number of isolates expressed resistance to fluoroquinolones which was also confirmed in silico by the presence of these resistance markers. Amino acid substitutions in the quinolone resistance-determining regions were identified in all isolates and the presence of several siderophores were also noted. Whole genomesequence (WGS) data showed different STs that were not associated with epidemic STs or virulent clonal complexes. Seven isolates formed biofilms in minimal media with some isolates showing better adaptation at 25 °C while others at 37 °C. The capacity to efflux EtBr was found to be high in 4 isolates and impaired in 4 others. The pathogenicity of three selected isolates was assessed in zebrafish embryo infection models, revealing isolates CFS0355 and CFS0356 as highly pathogenic. These results highlight the application of NGS technologies combined with phenotypic assays in providing a better understanding of E. coli of bovine origin and their adaptation to this niche environment.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Escherichia coli/veterinária , Proteínas de Escherichia coli/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Animais , Biofilmes/crescimento & desenvolvimento , Bovinos/microbiologia , Simulação por Computador , DNA Girase/genética , Embrião não Mamífero , Infecções por Escherichia coli/virologia , Testes de Sensibilidade Microbiana , Virulência , Peixe-Zebra/virologia
11.
Poult Sci ; 99(3): 1591-1597, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32111325

RESUMO

Antimicrobial resistance (AMR) is an important threat to public health worldwide. Furthermore, different studies have demonstrated a close association between antibiotic use in animal production and AMR in humans. It is well known that it is necessary to reduce antibiotic administration in farms by finding effective alternative treatments, using more resistant breeds and improving animal welfare. However, to be able to assess the alternatives proposed, it is essential to study the epidemiology of AMR under production conditions. Hence, the aim of this study was to investigate the AMR dynamic in 2 genetic poultry breeds during the growing period. The study was performed in 2 experimental poultry houses to simulate real production conditions, and no antibiotics were administered during the growing period. In addition, 2 poultry breeds were used, fast-growing and slow-growing. To evaluate AMR evolution, Escherichia coli was selected as indicator bacterium. To this end, animals from each experimental group were sampled at different times: on day of arrival, at mid-period, and at slaughter day. In the laboratory, cecal content was removed and inoculated in selective media. Then, biochemical tests were performed to confirm E. coli. Finally, antibiotic susceptibility was assessed according to Decision 2013/653. At the onset of the cycle, significant differences were observed between breeds, as the E. coli strains isolated from fast-growing 1-day-old-chicks showed higher AMR rates. However, at the end of the period, no significant differences were found between breeds and their presence of resistant bacteria (above 95%). Therefore, although no antibiotics were administered during the growing period, a high level of AMR at slaughter day was demonstrated. Further studies are necessary to determine the main risk factors that increase the level of AMR throughout the productive cycle in broiler chickens. In conclusion, it is important to highlight that although it is crucial to control both antibiotic use and animal welfare during the growing period, measures should be taken at all levels of the production chain.


Assuntos
Galinhas , Resistência Microbiana a Medicamentos , Farmacorresistência Bacteriana Múltipla , Infecções por Escherichia coli/veterinária , Escherichia coli/fisiologia , Doenças das Aves Domésticas/genética , Animais , Galinhas/genética , Infecções por Escherichia coli/genética , Feminino , Masculino , Distribuição Aleatória
12.
Trop Anim Health Prod ; 52(5): 2721-2724, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32125596

RESUMO

Nomadic populations do not have permanent settlements as they move their livestock between grazing areas in different seasons; such movements may have great impact on dissemination of food-borne pathogens in various regions. The aim of this study was to characterize Shiga toxin-producing Escherichia coli (STEC) strains as a food-borne pathogen in sheep and goats of Bakhtiari pastoral tribe in Iran. In the present study, 72 fecal samples were obtained from 26 sheep and 46 goats. First, all recovered E. coli isolates were screened for stx gene. After detection of stx-positive isolates, the virulence genes including stx1, stx2, eae, ehly, saa, astA, subAB, terD, and the genetic markers of O Island 57 (Z2098 and Z2099) were investigated. Also fifteen important STEC O-serogroups were determined using PCR assays. Results showed that 27 animals (27/72; 37.5%) carried STEC strains including 16/26 (61.6%) sheep and 11/46 (23.9%) goats. All STECs were eae-negative but 81.4% (22/27) were positive for saa. The most prevalent virulence profile was stx1/stx2/ehly/saa/subAB (37%; 10/27). Most STECs (24/27) were positive for at least one of the selected OI-57 markers. The O91 (n = 6), O5 (n = 3), O113 (n = 1), O128 (n = 1), and O104 (n = 1) were the detected O-serogroups in this study. It is concluded that such moving animal populations could have public health concerns which have to be addressed in the future.


Assuntos
Infecções por Escherichia coli/veterinária , Cabras/microbiologia , Ovinos/microbiologia , Escherichia coli Shiga Toxigênica/genética , Fatores de Virulência/genética , Animais , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Fezes/microbiologia , Feminino , Irã (Geográfico)/epidemiologia , Masculino , Reação em Cadeia da Polimerase/veterinária , Saúde Pública , Sorogrupo , Sorotipagem/veterinária , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/microbiologia , Toxina Shiga/genética , Escherichia coli Shiga Toxigênica/isolamento & purificação , Migrantes , Virulência/genética
13.
BMC Vet Res ; 16(1): 33, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32005239

RESUMO

BACKGROUND: In dairy herds, mastitis causes detrimental economic losses. Genetic selection offers a sustainable tool to select animals with reduced susceptibility towards postpartum diseases. Studying underlying mechanisms is important to assess the physiological processes that cause differences between selected haplotypes. Therefore, the objective of this study was to establish an in vivo infection model to study the impact of selecting for alternative paternal haplotypes in a particular genomic region on cattle chromosome 18 for mastitis susceptibility under defined conditions in uniparous dairy cows. RESULTS: At the start of pathogen challenge, no significant differences between the favorable (Q) and unfavorable (q) haplotypes were detected. Intramammary infection (IMI) with Staphylococcus aureus 1027 (S. aureus, n = 24, 96 h) or Escherichia coli 1303 (E. coli, n = 12, 24 h) was successfully induced in all uniparous cows. This finding was confirmed by clinical signs of mastitis and repeated recovery of the respective pathogen from milk samples of challenged quarters in each animal. After S. aureus challenge, Q-uniparous cows showed lower somatic cell counts 24 h and 36 h after challenge (P < 0.05), lower bacterial shedding in milk 12 h after challenge (P < 0.01) and a minor decrease in total milk yield 12 h and 24 h after challenge (P < 0.01) compared to q-uniparous cows. CONCLUSION: An in vivo infection model to study the impact of genetic selection for mastitis susceptibility under defined conditions in uniparous dairy cows was successfully established and revealed significant differences between the two genetically selected haplotype groups. This result might explain their differences in susceptibility towards IMI. These clinical findings form the basis for further in-depth molecular analysis to clarify the underlying genetic mechanisms for mastitis resistance.


Assuntos
Mastite Bovina/genética , Mastite Bovina/microbiologia , Herança Paterna , Animais , Bovinos , Indústria de Laticínios , Escherichia coli , Infecções por Escherichia coli/veterinária , Feminino , Haplótipos , Masculino , Leite/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus
14.
Poult Sci ; 99(2): 1150-1155, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32036966

RESUMO

Plasmid-mediated quinolone resistance (PMQR) genes located on conjugative plasmids can be transferred to other bacteria in the absence of antimicrobial selective pressure. To elucidate the prevalence of resistance, including PMQR in an egg-producing commercial layer farm in western Japan where no antimicrobials were used, minimum inhibitory concentrations (MIC) for a total of 375 Escherichia coli isolates obtained from chicken houses in the farm between 2012 and 2017 were determined using the agar dilution methods. Eighty-seven isolates resistant to oxytetracycline (OTC) accounted for 23.0% of the tested isolates, followed by isolates resistant to dihydrostreptomycin (DSM) (18.4%), sulfisoxazole (18.1%), ampicillin (AMP) (14.4%), trimethoprim (TMP) (14.4%), and nalidixic acid (10.1%). The prevalence rate of multidrug-resistant (MDR) isolates-which are resistant to 3 or more antimicrobial classes, including ß-lactams, aminoglycosides, quinolones, folate pathway inhibitors, tetracyclines, and phenicols-was inversely related to the age of chickens at the time of bacterial examination. Probably, the prevalence of MDR isolates in layer chickens may have decreased with age owing to the absence of selective pressure. Furthermore, 45 isolates exhibiting enrofloxacin MICs of more than 0.25 µg/mL were examined for PMQR genes. The transfer of PMQR genes was tested by conjugation analysis. Southern blot analysis of genomic DNA revealed that the qnrS1 (5 isolates), qnrS2 (1 isolate), and qnrS13 genes (1 isolate) were located on plasmids with sizes ranging from approximately 60 to 120 kpb. In 1 of the 5 qnrS1-positive isolates and in an isolate with qnrS13, the qnrS genes were transferred to recipient strains. The plasmid harboring the qnrS1 gene was typed as IncF by PCR-based replicon typing. On this plasmid, the blaTEM, aadA, tetA, and dfrA1 genes responsible for resistance to AMP, DSM, OTC, and TMP, respectively, were detected. The tetA gene was detected in the plasmid harboring the qnrS13 gene, which was typed as IncI1. These results suggest that despite the low prevalence of quinolone resistance in this farm, various PMQR genes, located on diverse plasmids, exist.


Assuntos
Galinhas , Farmacorresistência Bacteriana , Infecções por Escherichia coli/veterinária , Escherichia coli/efeitos dos fármacos , Abrigo para Animais , Doenças das Aves Domésticas/prevenção & controle , Quinolonas/farmacologia , Criação de Animais Domésticos , Animais , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/prevenção & controle , Plasmídeos/efeitos dos fármacos , Doenças das Aves Domésticas/microbiologia
15.
Poult Sci ; 99(2): 763-771, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32036976

RESUMO

Suboptimal animal welfare may affect natural immunity, rendering animals more susceptible to environmentally conditioned diseases, including those requiring antimicrobial treatment, which may promote antimicrobial resistance (AMR) in bacterial populations. Herewith, we tested the hypothesis that conventionally raised turkeys have higher levels of AMR in indicator Escherichia coli bacteria, but lower levels of natural immunity, as compared to turkeys reared under organic conditions. Litter and serum samples were collected from 28 conventional and 4 organic turkey farms: E. coli isolates from litter were tested for resistance to 14 antimicrobials, while 3 parameters of natural immunity (i.e., lysozyme, hemolytic complement levels, and serum bactericidal activity) were assessed in the sera. Resistant E. coli isolates were identified in both conventional and organic farms but generally more frequently in conventional farms. High rates of resistance to ampicillin (96%), tetracycline (95%), streptomycin (82%), sulfamethoxazole (80%), ciprofloxacin (73%), and trimethoprim (71%), as well as high rates of multiresistance, were observed in conventional farms. Organically raised turkeys had significantly higher levels of lysozyme and serum bactericidal activity than conventional turkeys, and these levels were also higher in turkeys housed in farms where AMR frequency was lower. Findings support the hypothesis that conventional farming conditions may affect turkeys' natural immunity, rendering the animals more susceptible to environmentally conditioned diseases requiring antimicrobial treatment, which would in turn promote AMR. Reducing AMR in turkey farming is therefore more likely to be successful when considering animal welfare as an option to reduce the need of antimicrobial use.


Assuntos
Criação de Animais Domésticos/métodos , Farmacorresistência Bacteriana , Infecções por Escherichia coli/veterinária , Imunidade Inata , Perus , Animais , Escherichia coli/efeitos dos fármacos , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Feminino , Itália , Masculino , Testes de Sensibilidade Microbiana/veterinária , Agricultura Orgânica
16.
BMC Genomics ; 21(1): 102, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32000686

RESUMO

BACKGROUND: Neutrophils are the first effectors of inflammatory response triggered by mastitis infection, and are important defense cells against pathogenic Escherichia coli (E. coli). DNA methylation, as a critical epigenetic mechanism for regulating gene function, is involved in bovine mastitis. RESULTS: In this study, we sequenced the blood neutrophils of healthy and E. coli-infected mastitic half-sib cows for the overall DNA methylation levels using transcriptome sequencing and reduced representation bisulfite sequencing. The methylation levels in the mastitis cows (MCs) were decreased compared with healthy cows (HCs). A total of 494 differentially methylated regions were identified, among which 61 were up-methylated and 433 were down-methylated (MCs vs. HCs). The expression levels of 1094 differentially expressed genes were up-regulated, and 245 genes were down-regulated. Twenty-nine genes were found in methylation and transcription data, among which seven genes' promoter methylation levels were negatively correlated with expression levels, and 11 genes were differentially methylated in the exon regions. The bisulfite sequencing PCR and quantitative real-time PCR validation results demonstrated that the promoter methylation of CITED2 and SLC40A1 genes affected differential expression. The methylation of LGR4 exon 5 regulated its own alternative splicing. The promoter methylation of bta-miR-15a has an indirect effect on the expression of its target gene CD163. The CITED2, SLC40A1, and LGR4 genes can be used as candidates for E. coli-induced mastitis resistance. CONCLUSIONS: This study explored the roles of DNA methylation in affecting transcription of protein-coding genes and miRNAs in E. coli-induced mastitis, thereby helping explain the function of DNA methylation in the pathogenesis of mastitis and provided new target genes and epigenetic markers for mastitis resistance breeding in dairy cattle.


Assuntos
Metilação de DNA , Infecções por Escherichia coli/veterinária , Perfilação da Expressão Gênica/veterinária , Mastite Bovina/genética , Neutrófilos/química , Sequenciamento Completo do Genoma/veterinária , Animais , Estudos de Casos e Controles , Bovinos , Epigênese Genética , Infecções por Escherichia coli/genética , Feminino , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Mastite Bovina/microbiologia , MicroRNAs/genética , Regiões Promotoras Genéticas , Análise de Sequência de RNA/veterinária
17.
Arch Anim Nutr ; 74(4): 271-295, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32108496

RESUMO

Short and medium-chain fatty acids (SCFA and MCFA, respectively) are commonly used as feed additives in piglets to promote health and prevent post-weaning diarrhoea. Considering that the mechanism and site of action of these fatty acids can differ, a combined supplementation could result in a synergistic action. Considering this, it was aimed to assess the potential of two new in-feed additives based on butyrate or heptanoate, protected with sodium salts of MCFA from coconut distillates, against enterotoxigenic Escherichia coli (ETEC) F4+ using an experimental disease model. Two independent trials were performed in 48 early-weaned piglets fed a control diet (CTR) or a diet supplemented with MCFA-protected sodium butyrate (BUT+; Trial 1) or sodium heptanoate (HPT+; Trial 2). After 1 week of adaptation, piglets were challenged with a single oral inoculum of ETEC F4+ (minimum 1.4 · 109 cfu). One animal per pen was euthanised on days 4 and 8 post-inoculation (PI) and the following variables assessed: growth performance, clinical signs, gut fermentation, intestinal morphology, inflammatory mediators, pathogen excretion and colon microbiota. None of the additives recovered growth performance or reduced diarrhoea when compared to the respective negative controls. However, both elicited different responses against ETEC F4+. The BUT+ additive did not lead to reduce E. coli F4 colonisation but enterobacterial counts and goblet cell numbers in the ileum were increased on day 8 PI and this followed higher serum TNF-α concentrations on day 4 PI. The Firmicutes:Bacteroidetes ratio was nevertheless increased. Findings in the HPT+ treatment trial included fewer animals featuring E. coli F4 in the colon and reduced Enterobacteriaceae (determined by 16S RNA sequencing) on day 4 PI. In addition, while goblet cell numbers were lower on day 8 PI, total SCFA levels were reduced in the colon. Results indicate the efficacy of MCFA-protected heptanoate against ETEC F4+ and emphasise the potential trophic effect of MCFA-protected butyrate on the intestinal epithelium likely reinforcing the gut barrier.


Assuntos
Ácido Butírico/metabolismo , Ácidos Graxos/metabolismo , Microbioma Gastrointestinal/fisiologia , Trato Gastrointestinal/efeitos dos fármacos , Heptanoatos/metabolismo , Sus scrofa/fisiologia , Ração Animal/análise , Animais , Ácido Butírico/administração & dosagem , Cocos/química , Colo/efeitos dos fármacos , Colo/microbiologia , Dieta/veterinária , Suplementos Nutricionais/análise , Escherichia coli Enterotoxigênica/fisiologia , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Ácidos Graxos/administração & dosagem , Fermentação/efeitos dos fármacos , Trato Gastrointestinal/anatomia & histologia , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/metabolismo , Heptanoatos/administração & dosagem , Masculino , Sus scrofa/crescimento & desenvolvimento , Sus scrofa/microbiologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/microbiologia
18.
BMC Vet Res ; 16(1): 37, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32013971

RESUMO

BACKGROUND: Since 2011, antibiotic usage has decreased continuously in livestock in Germany. Whether this is accompanied by a reduction in bacterial antimicrobial resistance has not been proven so far. In this study 3054 Escherichia coli (E. coli) isolates from pigs which had suffered from disease on 2161 farms in North Western Germany were evaluated retrospectively from 2006 to 2017 for trends in their antimicrobial resistance pattern. Data were substantially related to the "pre-reduction period" and were therefore suggested as a basis for this task. Minimal inhibitory concentrations for selected antimicrobial substances were evaluated for E. coli strains isolated from different organs of diseased swine sampled for routine diagnostic. In total, 81% of E. coli were isolated from faeces or the gastrointestinal tract, 11% from the genito-urinary tract and 8% from other organs. Susceptibility testing and classification of isolates in accordance with clinical cut-offs followed the Clinical and Laboratory Standards Institute (CLSI). If no clinical cut-offs were available for the respective combination of species, substance and organ, other published clinical cut-offs were used. RESULTS: Differences in susceptibility patterns between isolates from the gastrointestinal and genito-urinary tract were found for most substances. Isolates from the genito-urinary tract were less frequently resistant to ampicillin, apramycin, colistin, neomycin, spectinomycin and tetracycline and more frequently resistant to enrofloxacin and florfenicol. A multifactorial logistic regression model revealed time-dependent decreases in frequency of resistant isolates for neomycin, spectinomycin and tetracycline. For colistin, the highest percentage of resistant isolates with 16.0% was found in 2015 followed by a decrease to the level of 2009-2010 in 2017. A decrease in frequencies of ampicillin-resistant isolates was dependent on the age-group and time period. Irrespective of the year, less than 15% E. coli isolates were resistant to apramycin, cephalosporins, colistin, enrofloxacin, florfenicol, gentamicin and neomycin. CONCLUSION: An overall time-dependent decrease in the percentage of resistant E. coli isolates was found for some substances. These data from diseased animals indicate an impact of a general reduction in antibiotic usage on development of bacterial antimicrobial resistance in the field and can support the decision-making of swine practitioners for treatment options in swine.


Assuntos
Farmacorresistência Bacteriana , Infecções por Escherichia coli/veterinária , Escherichia coli/efeitos dos fármacos , Doenças dos Suínos/microbiologia , Animais , Antibacterianos/uso terapêutico , Infecções por Escherichia coli/microbiologia , Fezes/microbiologia , Trato Gastrointestinal/microbiologia , Alemanha/epidemiologia , Testes de Sensibilidade Microbiana , Estudos Retrospectivos , Suínos , Doenças dos Suínos/tratamento farmacológico , Sistema Urogenital/microbiologia
19.
Appl Environ Microbiol ; 86(8)2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32033947

RESUMO

A nationwide study on the occurrence of extended-spectrum ß-lactamase (ESBL)/AmpC in nonhospitalized horses in the Netherlands was performed. Molecular characterization was done, and questionnaires were analyzed to identify factors associated with carriage. In total, 796 horse owners were approached; 281 of these submitted a fecal sample from their horse(s), resulting in 362 samples. All samples were cultured qualitatively in Luria-Bertani (LB) broth and subsequently on MacConkey agar, both supplemented with 1 mg/liter cefotaxime (LB+ and MC+). Positive samples were subsequently cultured quantitatively on MC+. Initial extended-spectrum-ß-lactamase (ESBL)/AmpC screening was performed by PCR, followed by whole-genome sequencing on selected strains. Associations between ESBL/AmpC carriage and questionnaire items were analyzed using a univariate generalized estimating equation (GEE) regression analysis, followed by a multiple GEE model for relevant factors. In total, 39 of 362 samples (11%) were determined to be positive for ESBL/AmpC. bla CTX-M-1-carrying isolates were obtained from 77% of positive samples (n = 30). Other ESBL/AmpC genes observed included bla CTX-M-2, bla CTX-M-14, bla CTX-M-15, bla CTX-M-32, bla SHV-12, bla CMY-2, and bla ACT-10 A high association between the presence of bla CTX-M-1 and IncHI1 plasmids was observed (46% of samples; n = 18). Based on core genome analysis (n = 48 isolates), six Escherichia coli clusters were identified, three of which represented 80% of the isolates. A negative association between ESBL/AmpC carriage and horses being in contact with other horses at a different site was observed. The presence of a dog on the premises and housing in a more densely human-populated region were positively associated.IMPORTANCE Extended-spectrum ß-lactamases (ESBLs) are widespread in human and animal populations and in the environment. Many different ESBL variants exist. The dissemination of ESBLs within and between populations and the environment is also largely influenced by genetic mobile elements (e.g., plasmids) that facilitate spread of these ESBLs. In order to identify potential attributable ESBL sources for, e.g., the human population, it is important to identify the different ESBL variants, the bacteria carrying them, and the potential risk factors for ESBL carriage from other potential sources. This nationwide study focuses on ESBL carriage in the open horse population and investigated the molecular characteristics, geographical distribution throughout the Netherlands, and potential risk factors for fecal ESBL carriage in horses. These data can be used for future attribution studies in order to reduce potential transmission of ESBL-producing bacteria between sources.


Assuntos
Infecções por Escherichia coli/veterinária , Fezes/microbiologia , Doenças dos Cavalos/epidemiologia , Animais , Proteínas de Bactérias/metabolismo , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/metabolismo , Doenças dos Cavalos/microbiologia , Cavalos , Países Baixos/epidemiologia , beta-Lactamases/metabolismo
20.
PLoS One ; 15(2): e0228388, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32045422

RESUMO

BACKGROUND: Amphenicols have been widely used in the pig industry in China, leading to varying degrees of drug resistance. METHODS: The systematic review was performed according to PRISMA (Preferred Reported Items for Systematic Reviews and Meta-Analysis) recommendations on studies investigating the prevalence of amphenicol-resistant Escherichia coli (E. coli) isolated from pig in mainland China from 2000 to 2018, a random-effects model was selected, then followed by meta-analysis. RESULTS: A total of 103 articles were included in the study. The results of the meta-analysis revealed that the pooled summarized prevalence of resistance to chloramphenicol (CAP) was 72.31% (95% confidence interval (95% CI) = 67.12%-77.23%) and to florfenicol (FF) was 58.64% (95% CI = 52.48%-64.67%). During the past 18 years, the resistance rate to CAP remained high initially but then declined rapidly after 2012, whereas the resistance rate to FF plateaued (54.13%-59.60%) from 2000-2018. In different parts of China, the rate of resistance to amphenicols among E. coli isolates was fairly consistent, with the exception of the north and northwest regions. CONCLUSIONS: In 2002, the veterinary use of CAP was prohibited and its resistance levels in E. coli isolated from pigs was initially maintained at a high level but then showed an obvious downward trend in recent years. Resistance to commonly used FF remained at a high but stable level.


Assuntos
Cloranfenicol/farmacologia , Farmacorresistência Bacteriana , Infecções por Escherichia coli/veterinária , Escherichia coli/isolamento & purificação , Doenças dos Suínos/epidemiologia , Animais , Antibacterianos/farmacologia , China/epidemiologia , Escherichia coli/efeitos dos fármacos , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Suínos , Doenças dos Suínos/tratamento farmacológico , Doenças dos Suínos/microbiologia
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