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1.
J Microbiol ; 59(9): 854-860, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34382147

RESUMO

Extraintestinal pathogenic Escherichia coli (ExPEC) is an important zoonotic pathogen that places severe burdens on public health and animal husbandry. There are many pathogenic factors in E. coli. The type VI secretion system (T6SS) is a nano-microbial weapon that can assemble quickly and inject toxic effectors into recipient cells when danger is encountered. T6SSs are encoded in the genomes of approximately 25% of sequenced Gram-negative bacteria. When these bacteria come into contact with eukaryotic cells or prokaryotic microbes, the T6SS assembles and secretes associated effectors. In the porcine ExPEC strain PCN033, we identified four classic rearrangement hotspot (Rhs) genes. We determined the functions of the four Rhs proteins through mutant construction and protein expression. Animal infection experiments showed that the Δrhs-1CT, Δrhs-2CT, Δrhs-3CT, and Δrhs-4CT caused a significant decrease in the multiplication ability of PCN033 in vivo. Cell infection experiments showed that the Rhs protein is involved in anti-phagocytosis activities and bacterial adhesion and invasion abilities. The results of this study demonstrated that rhs1, rhs3, and rh4 plays an important role in the interaction between PCN033 and host cell. Rhs2 has contribution to cell and mice infection. This study helps to elucidate the pathogenic mechanism governing PCN033 and may help to establish a foundation for further research seeking to identify potential T6SS effectors.


Assuntos
Infecções por Escherichia coli/veterinária , Proteínas de Escherichia coli/metabolismo , Doenças dos Suínos/microbiologia , Animais , Aderência Bacteriana , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Escherichia coli Extraintestinal Patogênica/genética , Escherichia coli Extraintestinal Patogênica/metabolismo , Feminino , Intestinos/microbiologia , Camundongos , Família Multigênica , Suínos
2.
Front Cell Infect Microbiol ; 11: 690377, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34222051

RESUMO

Mastitis caused by Escherichia coli (E. coli) remains a threat to dairy animals and impacts animal welfare and causes great economic loss. Furthermore, antibiotic resistance and the lagged development of novel antibacterial drugs greatly challenge the livestock industry. Phage therapy has regained attention. In this study, three lytic phages, termed vB_EcoM_SYGD1 (SYGD1), vB_EcoP_SYGE1 (SYGE1), and vB_EcoM_SYGMH1 (SYGMH1), were isolated from sewage of dairy farm. The three phages showed a broad host range and high bacteriolytic efficiency against E. coli from different sources. Genome sequence and transmission electron microscope analysis revealed that SYGD1 and SYGMH1 belong to the Myoviridae, and SYGE1 belong to the Autographiviridae of the order Caudovirales. All three phages remained stable under a wide range of temperatures or pH and were almost unaffected in chloroform. Specially, a mastitis infected cow model, which challenged by a drug resistant E. coli, was used to evaluate the efficacy of phages. The results showed that the cocktails consists of three phages significantly reduced the number of bacteria, somatic cells, and inflammatory factors, alleviated the symptoms of mastitis in cattle, and achieved the same effect as antibiotic treatment. Overall, our study demonstrated that phage cocktail may be a promising alternative therapy against mastitis caused by drug resistant E. coli.


Assuntos
Bacteriófagos , Infecções por Escherichia coli , Mastite Bovina , Mastite , Preparações Farmacêuticas , Animais , Bovinos , Escherichia coli , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/veterinária , Feminino , Humanos , Mastite/tratamento farmacológico , Mastite/veterinária , Mastite Bovina/tratamento farmacológico
3.
Poult Sci ; 100(9): 101370, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34332223

RESUMO

The extended-spectrum cephalosporin resistant E. coli from food animals transferring to community settings of humans causes a serious threat to public health. Unlike phylogroup B2 E. coli strains, the clinical significance of isolates in phylogroup F is not well revealed. Here, we report on a collection (n = 563) of phylogroup F E. coli isolates recovered from chicken colibacillosis tissues and retail raw chicken meat samples in Eastern China. There was an overlapped distribution of MLST types between chicken colibacillosis-origin and meat-source phylogroup F E. coli, including dominant STs (ST648, ST405, ST457, ST393, ST1158, etc). This study further investigated the presence of extended-spectrum ß-lactamase (ESBL/pAmpC) producers in these chicken-source phylogroup F E. coli strains. The prevalence of extended-spectrum cephalosporin resistant strains in phylogroup F E. coli from chicken colibacillosis and raw meat separately accounted for 66.1 and 71.2%. The resistance genotypes and plasmid replicon types of chicken-source phylogroup F E. coli isolates were characterized by multiplex PCR. Our results revealed ß-lactamase CTX-M, OXA, CMY and TEM genes were widespread in chicken-source phylogroup F E. coli, and blaCTX-M was the most predominant ESBL gene. Moreover, there was a high prevalence of non-lactamase resistance genes in these ß-lactam-resistant isolates. The replicons IncB/O/K/Z, IncI1, IncN, IncFIC, IncQ1, IncX4, IncY, and p0111, associated with antibiotic-resistant large plasmids, were widespread in chicken-source phylogroup F E. coli. There was no obvious difference for the populations, resistance spectrums, and resistance genotypes between phylogroup F E. coli from chicken colibacillosis tissues and retail meats. This detail assessment of the population and resistance genotype showed chicken-source phylogroup F E. coli might hold zoonotic risk and contribute the spread of multidrug-resistant E. coli to humans.


Assuntos
Infecções por Escherichia coli , Escherichia coli , Animais , Antibacterianos/farmacologia , Galinhas , Farmacorresistência Bacteriana/genética , Escherichia coli/genética , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/veterinária , Carne , Tipagem de Sequências Multilocus/veterinária
4.
Animal ; 15(8): 100310, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34311191

RESUMO

This study was undertaken to determine the effect of a yeast (Candida famata) and a bacterium (Lactobacillus plantarum), administered alone or in combination in the drinking water, on the population of yeast, Lactobacillus sp. and coliforms, and the prevalence of antimicrobial resistance (AMR) and virulence genes in Escherichia coli (E. coli) isolated from digesta samples taken throughout the life of broiler chickens. Male (Ross 308) day-old chicks (220) were used. C. famata (isolated from a chicken) and L. plantarum (isolated from a pig) were administered via the drinking water. Water was provided either untreated or with C. famata (CF; 108/ml), L. plantarum (LP; 105-108/ml), or a combination of CF and LP (106-108/ml) in water hoppers on 2 days each week for 35 days. Administering probiotics did not affect the growth performance in broiler chickens. No significant interactions were observed between main effects, and neither CF nor LP had any effect on the population size of Lactobacillus sp. or coliforms. The administration of C. famata increased the population density of yeasts in the small intestine at these ages. The population density of coliforms, Lactobacillus sp. and yeast decreased with age (P < 0.001). There was no significant effect of probiotics on the prevalence of phenotypic AMR and virulence genes in these studies. The prevalence of E. coli that was resistant to ampicillin and tetracycline, as well as carrying ≥3 virulence-associated genes, was greatest at the end of the starter phase (around 8 days old), before declining through the grower and finisher phases. There was only limited evidence that administering either CF or LP affected either the AMR or the virulence of E. coli in the bird. However, tetracycline resistance in E. coli was associated (P < 0.001, P < 0.01, P < 0.05, and P < 0.05) with the carriage of the iron uptake systems of E. coli D, iron-repressible protein, increased serum survival and temperature-sensitive haemagglutinin genes respectively, suggesting that the accumulation of iron and the genetic element conferring tetracycline resistance may be intertwined.


Assuntos
Infecções por Escherichia coli , Lactobacillus plantarum , Doenças dos Suínos , Animais , Antibacterianos/farmacologia , Candida , Galinhas , Resistência Microbiana a Medicamentos , Escherichia coli/genética , Infecções por Escherichia coli/veterinária , Masculino , Suínos , Virulência
5.
Can Vet J ; 62(6): 608-610, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34219768

RESUMO

Antimicrobial resistance surveillance targeting agricultural animals is practiced in many countries but does not often include media selective for cephalosporin resistance. Here, we compared the frequency of recovery of resistant Escherichia coli using selective and non-selective media from the cecal contents of 116 chickens collected by the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS). Third generation cephalosporin resistance was detected in 24 samples including 12, 10, and 2 on selective, non-selective, and both media, respectively. Isolates producing the CTX-M-1 ESBL were grown from 11 samples, 10 on selective medium only. Our results suggest that current surveillance approaches underestimate the true prevalence of resistance to critically important antimicrobials.


Assuntos
Farmacorresistência Bacteriana , Infecções por Escherichia coli , Doenças das Aves Domésticas , Animais , Antibacterianos/farmacologia , Anti-Infecciosos , Canadá , Galinhas , Escherichia coli , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/veterinária , Doenças das Aves Domésticas/tratamento farmacológico , Doenças das Aves Domésticas/microbiologia , beta-Lactamases
6.
Int J Mol Sci ; 22(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200743

RESUMO

Mastitis is a common disease in dairy cows that is mostly caused by E. coli, and it brings massive losses to the dairy industry. N6-Methyladenosine (m6A), a methylation at the N6 position of RNA adenine, is a type of modification strongly associated with many diseases. However, the role of m6A in mastitis has not been investigated. In this study, we used MeRIP-seq to sequence the RNA of bovine mammary epithelial cells treated with inactivated E. coli for 24 h. In this in vitro infection model, there were 16,691 m6A peaks within 7066 mRNA transcripts in the Con group and 10,029 peaks within 4891 transcripts in the E. coli group. Compared with the Con group, 474 mRNAs were hypermethylated and 2101 mRNAs were hypomethylated in the E. coli group. Biological function analyses revealed differential m6A-modified genes mainly enriched in the MAPK, NF-κB, and TGF-ß signaling pathways. In order to explore the relationship between m6A and mRNA expression, combined MeRIP-seq and mRNA-seq analyses revealed 212 genes with concomitant changes in the mRNA expression and m6A modification. This study is the first to present a map of RNA m6A modification in mastitis treated with E. coli, providing a basis for future research.


Assuntos
Adenosina/análogos & derivados , Metilação de DNA , Células Epiteliais/metabolismo , Infecções por Escherichia coli/veterinária , Regulação da Expressão Gênica , Glândulas Mamárias Animais/metabolismo , Mastite Bovina/genética , Adenosina/química , Animais , Bovinos , Células Epiteliais/imunologia , Células Epiteliais/microbiologia , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/imunologia , Feminino , Perfilação da Expressão Gênica , Glândulas Mamárias Animais/imunologia , Glândulas Mamárias Animais/microbiologia , Mastite Bovina/imunologia , Mastite Bovina/microbiologia
7.
Zool Res ; 42(4): 461-468, 2021 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-34156173

RESUMO

During a 2018 antimicrobial resistance surveillance of Escherichia coli isolates from diarrheal calves in Xinjiang Province, China, an unexpectedly high prevalence (48.5%) of fosfomycin resistance was observed. This study aimed to reveal the determinants of fosfomycin resistance and the underlying transmission mechanism. Polymerase chain reaction (PCR) screening showed that all fosfomycin-resistant E. coli carried the fosA3 gene. Pulsed-field gel electrophoresis (PFGE) and southern blot hybridization revealed that the 16 fosA3-positive isolates belonged to four different PFGE patterns (i.e., A, B, C, D). The fosA3 genes of 11 clonally related strains (pattern D) were located on the chromosome, while others were carried by plasmids. Whole-genome and long-read sequencing indicated that the pattern D strains were E. coli O101: H9-ST10, and the pattern C, B, and A strains were O101: H9-ST167, O8: H30-ST1431, and O101: H9 with unknown ST, respectively. Among the pattern C strains, the bla CTX-M-14 gene was co-localized with the fosA3 gene on the F18: A-: B1 plasmids. Interestingly, phylogenetic analysis based on core genome single nucleotide polymorphisms (cgSNPs) showed that the O101: H9-ST10 strains were closely related to a Australian-isolated Chroicocephalus-origin E. coli O101: H9-ST10 strain producing CTX-M-14 and FosA3, with a difference of only 11 SNPs. These results indicate possible international dissemination of the high-risk E. coli clone O101: H9-ST10 by migratory birds.


Assuntos
Doenças dos Bovinos/microbiologia , Charadriiformes/microbiologia , Diarreia/veterinária , Infecções por Escherichia coli/veterinária , Proteínas de Escherichia coli/metabolismo , Escherichia coli/classificação , Migração Animal , Animais , Antibacterianos/farmacologia , Austrália , Bovinos , Doenças dos Bovinos/epidemiologia , China/epidemiologia , Diarreia/epidemiologia , Diarreia/microbiologia , Farmacorresistência Bacteriana , Escherichia coli/genética , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , beta-Lactamases/genética
8.
J Zoo Wildl Med ; 52(2): 755-762, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34130423

RESUMO

A multiparous pygmy hippopotamus (Choeropsis liberiensis) dam produced three consecutive calves that died acutely at 13-15 wk of age from bacterial sepsis, for which diagnostic and therapeutic intervention was not possible. Streptococcus iniae (Cases 1 and 3), Escherichia coli (Case 2), and an unidentified member of the family Pasteurellaceae (Case 1) were identified in postmortem tissues through bacterial culture followed by standard and molecular identification methods. After the loss of two calves, a series of vaccinations were administered to the dam during the third pregnancy to enhance transplacental and colostral transfer of antibodies to the calf. The third calf did not survive, and the source of the bacterial infection in these three calves was undetermined. Prior to and after the birth of the fourth calf, nutritional and nutraceutical supplements were provided to the dam and calf. Additionally, pest control around the barn was enhanced. The fourth calf survived. Pygmy hippopotamus calves at the age of 13-15 wk may have increased susceptibility to bacterial infection, possibly due to waning maternally derived immunity. The findings in these cases, combined with a previous association of S. iniae in pygmy hippopotamus deaths, suggest that this bacterium is an especially important pathogen of the endangered pygmy hippopotamus.


Assuntos
Artiodáctilos , Infecções Bacterianas/veterinária , Endotoxemia/veterinária , Infecções por Escherichia coli/veterinária , Sepse/veterinária , Infecções Estreptocócicas/veterinária , Criação de Animais Domésticos , Animais , Animais de Zoológico , Infecções Bacterianas/prevenção & controle , Vacinas Bacterianas/imunologia , Endotoxemia/microbiologia , Escherichia coli , Infecções por Escherichia coli/patologia , Feminino , Masculino , Sepse/microbiologia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/patologia , Streptococcus iniae
9.
Poult Sci ; 100(8): 101230, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34171653

RESUMO

The transmission of antimicrobial resistance bacteria from animals to humans has become an important concern. The extended-spectrum beta-lactamase (ESBL) -AmpC- producing Escherichia coli (ESBL-AmpC EC) and quinolones resistant E. coli are of particular interest. The present study aimed to evaluate the load and prevalence of antibiotic-resistant commensal E. coli along the goose production cycle on 2 free-range farms in central Italy. On A farm, oxytetracycline was administered, while the B farm did not use antibiotics during the geese productive cycle. One hundred geese of 1-day-old from the same batch were divided into the two farms. At hatching, the animals showed an average of E. coli loads was 6.83 ± 0.48 log CFU/g, and 0.28 ± 0.28, 0, 5.12 ± 0.54 log CFU/g for E. coli resistant to nalidixic acid (E. colinal), to cefotaxime (E. colicef) and to tetracyclines (E. colitet), respectively. The loads of E. coli, E. colinal, E. colicef and E. colitet on 224 environmental faecal pools were determined at 8 time points. Antimicrobial susceptibility and molecular characterization of E. colicef isolates were performed. The ANOVA was used to assess the difference in bacterial loads between the two farms. We described more than 50% of resistances for tetracyclines in both farms, and sulphonamides and cephazolin in the A farm. The loads of E. coli and E. colinal in faeces were estimated at approximately 6-7 log (CFU/g) and 5-6 log (CFU/g) in the two farms, respectively. The average load of extended-spectrum beta-lactamase Escherichia coli (ESBL EC) in goose faeces varied broadly along the production cycle: in the first weeks, a sharp increase was observed in both farms, while later on A farm, the burden of ESBL EC remained steady until the end of the production cycle and on B farm the load dramatically decreased from 6 wk of age onward. An increase in the proportion of E. colinal was observed on A farm shortly after the antibiotic administration. Our study shows that the dynamics of antibiotic-resistant E. coli in farmed geese are similar to the ones observed in broilers. However, the risk of the emergence of antibiotic-resistant commensal E. coli, might be mitigated by the adoption of good management practices, including prudent use of antibiotics.


Assuntos
Infecções por Escherichia coli , Escherichia coli , Animais , Antibacterianos/farmacologia , Galinhas , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/veterinária , Gansos , Itália , Estudos Longitudinais , beta-Lactamases
10.
Poult Sci ; 100(8): 101250, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34182220

RESUMO

Fluoroquinolones (FQs) have been used effectively antimicrobial agents of choice for treatment of various infections caused by E. coli and FQs-resistance of E. coli from broiler breeders has been implicated in its vertical transmission to their offspring. The objective of this study investigated the phenotypic and genotypic characteristics of FQ-resistant E. coli isolates from broiler breeder farms in Korea. A total of 106 FQ-resistant E. coli isolates were tested in this study and all isolates had mutations in quinolone resistance determining regions; all (100%) had mutations in gyrA, 89 (84.0%) had mutations in parE, 8 (7.5%) isolates showed the mutations with parC and parE, and none had mutations in gyrB. The predominant mutation type was double mutation in gyrA (S83L and D87N), and all FQ-resistant E. coli isolates that had mutations in parC or parE also had double mutations in gyrA. Especially, FQ-resistant E. coli isolates which possessed double mutations in gyrA in combination with double mutations in parC or single mutations in both parC and parE were shown high levels of minimum inhibitory concentrations rage. Of the 23 plasmid-mediated quinolone resistance (PMQR)-positive E. coli isolates, qnrS was detected in 10 (9.4%) isolates, and followed by qnrA (7 isolates, 6.6%), qnrB (4 isolates, 3.8%), and aac(6')-Ib-cr (2 isolates, 1.9%). Sixteen (69.6%) of the 23 PMQR-positive E. coli isolates harbored class 1 integrons with four different gene cassette arrangements and total of 9 plasmid replicon types were also identified in 23 PMQR-positive E. coli isolates. This is the first study to investigate the prevalence and characteristics of FQ-resistant and PMQR-positive E. coli isolated from the broiler breeder in Korea; it supports that constant monitoring and studies at the broiler breeder level are required to prevent the pyramidal transmission of FQ-resistant E. coli.


Assuntos
Infecções por Escherichia coli , Fluoroquinolonas , Animais , Antibacterianos/farmacologia , Galinhas , DNA Girase/genética , Farmacorresistência Bacteriana/genética , Escherichia coli/genética , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/veterinária , Fazendas , Fluoroquinolonas/farmacologia , Testes de Sensibilidade Microbiana/veterinária , Mutação , República da Coreia/epidemiologia
11.
Ann Agric Environ Med ; 28(2): 271-276, 2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34184510

RESUMO

INTRODUCTION: The article discusses the antimicrobial resistance of poultry-isolated bacteria in the Wielkopolska region of Poland. MATERIAL AND METHODS: From August 2014 - June 2016, antibiotic resistance screening tests were performed involving 4,496 samples of Escherichia coli and 84 samples of Klebsiella spp., and the following antibiotics: amoxicillin, amoxicillin with clavulanic acid, colistin, doxycycline, enrofloxacin, florfenicol, neomycin, norfloxacin, spectinomycin, and trimethoprim with sulfamethoxazole. The research used broth the microdilution method and CLSI standards. RESULTS: During the investigation period of 22 months a growing percentage of E. coli isolates showed antibiotic resistance to amoxicillin, amoxicillin with clavulanic acid, colistin, enrofloxacin, neomycin, norfloxacin, spectinomycin, and trimethoprim with sulfamethoxazole. Resistance to doxycycline and florfenicol decreased. The most efficient antibiotics against E. coli were colistin (84.64 %), neomycin (80.62 %), and amoxicillin with clavulanic acid (73.05 %). Klebsiella samples were the most susceptible to neomycin (85.71 %), colistin (84.52 %), and trimethoprim with sulfamethoxazole (73.81 %). CONCLUSIONS: Antibiotic resistance of pathogenic micro-organisms, such as Escherichia coli and Klebsiella spp., is a serious problem both for poultry producers and for public health protection. Low efficiency of numerous antibiotic groups forces reflection on limiting the use of medicines in food-producing animals.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Infecções por Enterobacteriaceae/veterinária , Infecções por Escherichia coli/veterinária , Escherichia coli/efeitos dos fármacos , Klebsiella/efeitos dos fármacos , Doenças das Aves Domésticas/microbiologia , Animais , Galinhas/microbiologia , Infecções por Enterobacteriaceae/microbiologia , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Klebsiella/genética , Klebsiella/isolamento & purificação , Testes de Sensibilidade Microbiana , Polônia
12.
Appl Environ Microbiol ; 87(14): e0312120, 2021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-33962981

RESUMO

Enterotoxigenic Escherichia coli (ETEC) and Shiga toxin-producing E. coli (STEC) strains are the causative agents of severe foodborne diseases in both humans and animals. In this study, porcine pathogenic E. coli strains (n = 277) as well as porcine commensal strains (n = 188) were tested for their susceptibilities to 34 bacteriocin monoproducers to identify the most suitable bacteriocin types inhibiting porcine pathogens. Under in vitro conditions, the set of pathogenic E. coli strains was found to be significantly more susceptible to the majority of tested bacteriocins than commensal E. coli. Based on the production of bacteriocins with specific activity against pathogens, three potentially probiotic commensal E. coli strains of human origin were selected. These strains were found to be able to outcompete ETEC strains expressing F4 or F18 fimbriae in liquid culture and also decreased the severity and duration of diarrhea in piglets during experimental ETEC infection as well as pathogen numbers on the last day of in vivo experimentation. While the extents of the probiotic effect were different for each strain, the cocktail of all three strains showed the most pronounced beneficial effects, suggesting synergy between the tested E. coli strains. IMPORTANCE Increasing levels of antibiotic resistance among bacteria also increase the need for alternatives to conventional antibiotic treatment. Pathogenic Escherichia coli represents a major diarrheic infectious agent of piglets in their postweaning period; however, available measures to control these infections are limited. This study describes three novel E. coli strains producing antimicrobial compounds (bacteriocins) that actively inhibit a majority of toxigenic E. coli strains. The beneficial effect of three potentially probiotic E. coli strains was demonstrated under both in vitro and in vivo conditions. The novel probiotic candidates may be used as prophylaxis during piglets' postweaning period to overcome common infections caused by E. coli.


Assuntos
Toxinas Bacterianas , Bacteriocinas/uso terapêutico , Infecções por Escherichia coli/prevenção & controle , Escherichia coli , Probióticos/uso terapêutico , Doenças dos Suínos/prevenção & controle , Animais , Toxinas Bacterianas/metabolismo , Bacteriocinas/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Fezes/microbiologia , Suínos , Doenças dos Suínos/microbiologia , Fatores de Virulência/genética
13.
Ecotoxicol Environ Saf ; 220: 112317, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34049228

RESUMO

There are rising concerns about microbes harboring antibiotic resistance genes (ARGs) and virulence-associated genes (VAGs) in humans and food-producing animals. Moreover, ARGs are considered as emerging environmental pollutants, posing probable life-threatening complications in humans and animals. Commensal Escherichia coli (E. coli) strain can carry a large number of VAGs, which may become opportunistic pathogen. The objective of this study was to determine the prevalence and possible association of ARGs and VAGs in E. coli isolates from clinically healthy waterfowls in China's tropical island, Hainan. For this purpose, 311 non-repeating E. coli isolates were evaluated for phenotypic drug resistance linked with ARGs. Additionally, strains were examined for subsequent resistance and virulence genes by uniplex or multiplex PCR and sequencing. Overall, 89 types of antibiotic resistance patterns were analysed, while 25 ARGs and 23 VAGs were observed, of which qnrS (99.4%) and iucD (99.7%) were the most commonly found genes, respectively. Significant positive associations were observed among ARGs and VAGs (p<0.05, OR>1). The strongest association between resistance and virulence gene was observed for qnrS and iss (OR, 76.25; 95% CI, 4.02-1445.42). Our results propose that waterfowls serve as a reservoir of E. coli carrying multi ARGs and various ExPEC associated VAGs. Therefore, this study provides necessary information on the occurrence and possible associations of ARGs and VAGs in healthy waterfowls, which may act as a reference for the regulatory use of antibiotics to stop the direct or indirect spread of these resistant and potential virulent microbes to natural environment.


Assuntos
Antibacterianos/farmacologia , Doenças das Aves/microbiologia , Farmacorresistência Bacteriana , Patos , Infecções por Escherichia coli/veterinária , Escherichia coli/genética , Gansos , Animais , Animais Selvagens , China , Escherichia coli/efeitos dos fármacos , Escherichia coli/patogenicidade , Escherichia coli/fisiologia , Infecções por Escherichia coli/microbiologia , Virulência/genética
14.
Res Vet Sci ; 137: 174-185, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34000648

RESUMO

The antimicrobial resistance (AMR) in human and animal pathogens is a global concern, and antimicrobial use (AMU) is considered the most important driver for its increase. The aim of this study was to assess AMR in Escherichia coli and Enterococcus spp. in faecal samples of pigs subjected to four different AMU protocols from birth to finishing: G1, no in-feed antimicrobials; G2: a total average dose 6018 mg antimicrobials/pig; G3: a total average dose 8127 mg antimicrobials/pig; and G4: a total average dose 15,678 mg antimicrobials/pig. Faecal samples were collected at six time points and AMR was assessed in both bacteria. The microbiota composition was assessed by 16S rRNA sequencing. Minor differences on the microbiota profile was observed among groups, but a lower Firmicutes:Bacteroidetes ratio was noted in G4. Escherichia coli and Enterococcus spp. strains isolated from all groups showed a high level of multi-drug resistance (MDR). The amount of antimicrobials used was significantly positively associated with the probability of MDR in both bacteria. Approximately 43% of the variation in MIC90 for colistin could be explained by AMU, and a one-day increase in administration of colistin increased MIC90 by 0.05 µg mL-1. In conclusion, the results suggest that the higher the use of antimicrobials in farms, the higher the MDR frequency and resistance to the highest priority critically important antimicrobials for humans in commensal gut bacteria of pigs.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Enterococcus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Doenças dos Suínos/microbiologia , Animais , Antibacterianos/administração & dosagem , Revisão de Uso de Medicamentos , Enterococcus/genética , Enterococcus/isolamento & purificação , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/veterinária , Fezes/microbiologia , RNA Ribossômico 16S , Suínos
15.
Poult Sci ; 100(6): 101094, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33989952

RESUMO

The study was carried out to estimate the burden and pattern of antibiotic resistance and to identify antibiotic resistance genes with focus on ESBL producers, plasmid mediated quinolone resistance, and tetracycline efflux genes, in faecal bacterial isolates collected from poultry farms of coastal Southern Karnataka, India. High resistance to fluoroquinolones was observed with 94% Escherichia coli and 80% Klebsiella pneumoniae being resistant to both ciprofloxacin and levofloxacin. All the Escherichia coli strains were resistant to tetracycline (100%). qnrB (38%) was the most common gene detected followed by qnrS (27%) and qnrA (21.5%). All Klebsiella pneumoniae isolates resistant to tetracycline harbored tetA gene. Most of the isolates in our study had high MAR indices indicating rampant use of antibiotics.


Assuntos
Infecções por Escherichia coli , Klebsiella pneumoniae , Animais , Antibacterianos/farmacologia , Galinhas , Farmacorresistência Bacteriana/genética , Escherichia coli/genética , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/veterinária , Índia , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana/veterinária , Fenótipo
16.
Int J Med Microbiol ; 311(4): 151511, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33975122

RESUMO

Super-shed (SS) Escherichia coli O157 (E. coli O157) demonstrate a strong, aggregative, locus of enterocyte effacement (LEE)-independent adherence phenotype on bovine recto-anal junction squamous epithelial (RSE) cells, and harbor polymorphisms in non-LEE-adherence-related loci, including in the type 1 fimbriae operon. To elucidate the role of type 1 fimbriae in strain- and host-specific adherence, we evaluated the entire Fim operon (FimB-H) and its adhesion (FimH) deletion mutants in four E. coli O157 strains, SS17, SS52, SS77 and EDL933, and evaluated the adherence phenotype in bovine RSE and human HEp-2 adherence assays. Consistent with the prevailing dogma that fimH expression is genetically switched off in E. coli O157, the ΔfimHSS52, ΔfimB-HSS52, ΔfimB-HSS17, and ΔfimHSS77 mutants remained unchanged in adherence phenotype to RSE cells. In contrast, the ΔfimHSS17 and ΔfimB-HSS77 mutants changed from a wild-type strong and aggregative, to a moderate and diffuse adherence phenotype, while both ΔfimHEDL933 and ΔfimB-HEDL933 mutants demonstrated enhanced binding to RSE cells (p < 0.05). Additionally, both ΔfimHSS17 and ΔfimHEDL933 were non-adherent to HEp-2 cells (p < 0.05). Complementation of the mutant strains with their respective wild-type genes restored parental phenotypes. Microscopy revealed that the SS17 and EDL933 strains indeed carry type 1 fimbriae-like structures shorter than those seen in uropathogenic E. coli. Taken together, these results provide compelling evidence for a strain and host cell type-dependent role of fimH and the fim operon in E. coli O157 adherence that needs to be further evaluated.


Assuntos
Infecções por Escherichia coli , Escherichia coli O157 , Proteínas de Escherichia coli , Animais , Aderência Bacteriana , Bovinos , Proteínas de Ligação a DNA , Infecções por Escherichia coli/veterinária , Escherichia coli O157/genética , Proteínas de Escherichia coli/genética , Fímbrias Bacterianas/genética , Humanos , Integrases , Fenótipo
17.
Int J Food Microbiol ; 347: 109196, 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-33906045

RESUMO

Due to the recent outbreaks of Salmonella and Escherichia coli in fresh produce in the United States, the transfer of foodborne pathogens between animal feeding operations and fresh produce continues to be a considerable risk. The purpose of this study was to determine if the establishment of a vegetation barrier (VB) on small-scale sustainable farms could prevent the transmission of Salmonella and E. coli to nearby fresh produce fields. A 5-layer VB (31 × 49 m) was constructed between a dairy farm, a poultry farm, and a nearby produce field. Fresh produce (i.e., romaine lettuce and tomato), animal feces, and environmental (i.e., air, soil, and barrier) samples were collected for 15 months from 2018 to 2019. Four replicates of soil and fresh produce samples were taken from three plots located 10 m, 61 m, and 122 m away from the respective animal locations and processed for Salmonella and E. coli. Air and vegetative strip samples were sampled at 15-day intervals. Multiple colonies were processed from each positive sample, and a total of 143 positive Salmonella (n = 15) and E. coli (n = 128) isolates were retrieved from the soil, produce, air, and fecal samples. Interestingly, 18.2% of the Salmonella and E. coli isolates (n = 26) were recovered from fresh produce (n = 9) samples. Surprisingly, Salmonella isolates (n = 9) were only found in fecal (n = 3) samples collected from the dairy pasture. Data analysis suggests that the VB is an effective tool at reducing the transmission of E. coli and Salmonella from animal farms to fresh produce fields. However, based on phenotypic and genotypic testing, it is clear that fecal samples from animal farms are not the only source of pathogen contamination. This indicates that the environment (e.g., soil and wind), as well as the initial setup of the farm (e.g., proximity to service roads and produce plot placement), can contribute to the contamination of fresh produce. Our study recommends the need for more effective bioremediation and prevention control measures to use in conjunction with VBs to reduce pathogen transmission.


Assuntos
Infecções por Escherichia coli/transmissão , Escherichia coli/isolamento & purificação , Alface/microbiologia , Lycopersicon esculentum/microbiologia , Salmonelose Animal/transmissão , Salmonella/isolamento & purificação , Animais , Bovinos , Indústria de Laticínios , Escherichia coli/crescimento & desenvolvimento , Infecções por Escherichia coli/veterinária , Fazendas , Fezes/microbiologia , Aves Domésticas/microbiologia , Salmonella/crescimento & desenvolvimento
18.
J Anim Sci ; 99(6)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33928383

RESUMO

This study was conducted to investigate the effects of early supplementation during 4 to 18 d of age with Lactobacillus plantarum (LP) in liquid diets on intestinal innate immune response in young piglets infected with enterotoxigenic Escherichia coli (ETEC) K88. Seventy-two barrow piglets at 4 d old were assigned to basal or LP-supplemented liquid diet (5 × 1010 CFU·kg-1). On day 15, piglets from each group were orally challenged with either ETEC K88 (1 × 108 CFU·kg-1) or the same amount of phosphate-buffered saline. The intestinal mucosa, mesenteric lymph node (MLN), and spleen samples were collected on day 18. Here, we found that LP pretreatment significantly decreased the mRNA relative expression of inflammatory cytokines (interleukin [IL]-1ß, IL-8, and tumor necrosis factor-α), porcine ß-defensin 2 (pBD-2), and mucins (MUC1 and MUC4) in the jejunal mucosa in piglets challenged with ETEC K88 (P < 0.05). Moreover, LP significantly decreased the ileal mucosa mRNA relative expression of IL-8 and MUC4 in young piglets challenged with ETEC K88 (P < 0.05). Furthermore, the piglets of the LP + ETEC K88 group had lower protein levels of IL-8, secretory immunoglobulin A, pBD-2, and MUC4 in the jejunal mucosa than those challenged with ETEC K88 (P < 0.05). Besides, LP supplementation reduced the percentage of gamma/delta T cells receptor (γδTCR) and CD172a+ (SWC3+) cells in MLN and the percentage of γδTCR cells in the spleen of young piglets after the ETEC K88 challenge. Supplementation with LP in liquid diets prevented the upregulated protein abundance of toll-like receptor (TLR) 4, phosphorylation-p38, and phosphorylation-extracellular signal-regulated protein kinases in the jejunal mucosa induced by ETEC K88 (P < 0.05). In conclusion, LP supplementation in liquid diet possesses anti-inflammatory activity and modulates the intestinal innate immunity during the early life of young piglets challenged with ETEC K88, which might be attributed to the suppression of TLR4-mediated mitogen-activated protein kinase signaling pathways. Early supplementation with LP in liquid diets regulates the innate immune response, representing a promising immunoregulation strategy for maintaining intestinal health in weaned piglets.


Assuntos
Escherichia coli Enterotoxigênica , Infecções por Escherichia coli , Lactobacillus plantarum , Animais , Dieta/veterinária , Suplementos Nutricionais , Infecções por Escherichia coli/prevenção & controle , Infecções por Escherichia coli/veterinária , Imunidade Inata , Mucosa Intestinal , Proteínas Quinases Ativadas por Mitógeno , Suínos , Receptor 4 Toll-Like/genética
19.
J Dairy Sci ; 104(7): 8243-8255, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33814154

RESUMO

Escherichia coli is a leading cause of bovine mastitis worldwide. The bacteria can rapidly grow in milk and elicit a strong lipopolysaccharide (LPS)/toll-like receptor-4 (TLR4)-dependent inflammatory response. Recently, the long polar fimbriae (LPF) were identified as a promising virulence factor candidate widely distributed in mammary pathogenic E. coli (MPEC) strains. Mammary pathogenic E. coli possess 2 lpf loci encoding LPF1 and LPF2, respectively. By deleting the major fimbrial subunit gene, lpfA, we found that both LPF1 and LPF2 contribute to MPEC adhesion, invasion, and biofilm formation in vitro. The lpf1A and lpf2A mutants showed reduced cytotoxicity in our in vitro cell infection model. Furthermore, we observed that LPF2 induced a mild TLR4-independent proinflammatory response. The median lethal dose (LD50) of both ∆lpf2A and ∆lpf1A∆lpf2A mutants to BALB/c mice increased by 0.38 and 0.15 logs, respectively, whereas that of wild-type strain MPJS13 was 8.69 logs. In contrast, LPF1 deficiency significantly enhanced the LPS/TLR4-mediated inflammatory response in mammary epithelial cells, and the LD50 of the mutant decreased to 8.18 logs. In conclusion, our data suggested that LPF are important in MPEC colonization of mammary cells and may provide a benefit to bacterial intracellular survival that induces persistent bovine mastitis.


Assuntos
Doenças dos Bovinos , Infecções por Escherichia coli , Proteínas de Escherichia coli , Doenças dos Roedores , Animais , Bovinos , Escherichia coli , Infecções por Escherichia coli/veterinária , Feminino , Fímbrias Bacterianas , Camundongos , Camundongos Endogâmicos BALB C
20.
Int J Mol Sci ; 22(8)2021 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-33920239

RESUMO

Post-weaning diarrhea due to enterotoxigenic Escherichia coli (ETEC) is a common disease of piglets and causes great economic loss for the swine industry. Over the past few decades, decreasing effectiveness of conventional antibiotics has caused serious problems because of the growing emergence of multidrug-resistant (MDR) pathogens. Various studies have indicated that antimicrobial peptides (AMPs) have potential to serve as an alternative to antibiotics owing to rapid killing action and highly selective toxicity. Our previous studies have shown that AMP GW-Q4 and its derivatives possess effective antibacterial activities against the Gram-negative bacteria. Hence, in the current study, we evaluated the antibacterial efficacy of GW-Q4 and its derivatives against MDR ETEC and their minimal inhibition concentration (MIC) values were determined to be around 2~32 µg/mL. Among them, AMP Q4-15a-1 with the second lowest MIC (4 µg/mL) and the highest minimal hemolysis concentration (MHC, 256 µg/mL), thus showing the greatest selectivity (MHC/MIC = 64) was selected for further investigations. Moreover, Q4-15a-1 showed dose-dependent bactericidal activity against MDR ETEC in time-kill curve assays. According to the cellular localization and membrane integrity analyses using confocal microscopy, Q4-15a-1 can rapidly interact with the bacterial surface, disrupt the membrane and enter cytosol in less than 30 min. Minimum biofilm eradication concentration (MBEC) of Q4-15a-1 is 4× MIC (16 µg/mL), indicating that Q4-15a-1 is effective against MDR ETEC biofilm. Besides, we established an MDR ETEC infection model with intestinal porcine epithelial cell-1 (IPEC-1). In this infection model, 32 µg/mL Q4-15a-1 can completely inhibit ETEC adhesion onto IPEC-1. Overall, these results suggested that Q4-15a-1 may be a promising antibacterial candidate for treatment of weaned piglets infected by MDR ETEC.


Assuntos
Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Escherichia coli Enterotoxigênica/efeitos dos fármacos , Infecções por Escherichia coli/tratamento farmacológico , Proteínas Citotóxicas Formadoras de Poros/farmacologia , Doenças dos Suínos/tratamento farmacológico , Animais , Antibacterianos/efeitos adversos , Antibacterianos/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli Enterotoxigênica/patogenicidade , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Testes de Sensibilidade Microbiana , Suínos/microbiologia , Doenças dos Suínos/microbiologia , Doenças dos Suínos/patologia
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