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1.
PLoS One ; 15(2): e0228388, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32045422

RESUMEN

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.


Asunto(s)
Cloranfenicol/farmacología , Farmacorresistencia Bacteriana , Infecciones por Escherichia coli/veterinaria , Escherichia coli/aislamiento & purificación , Enfermedades de los Porcinos/epidemiología , Animales , Antibacterianos/farmacología , China/epidemiología , Escherichia coli/efectos de los fármacos , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Porcinos , Enfermedades de los Porcinos/tratamiento farmacológico , Enfermedades de los Porcinos/microbiología
2.
Vet Q ; 40(1): 43-50, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31939335

RESUMEN

Background: The coinfection process of Escherichia coli, an etiological agent of clinical mastitis and Mycobacterium avium subsp. paratuberculosis (MAP), a non-mastitic etiological agent in the bovine mammary gland is not fully known.Objective: Verify the ability of MAP to interfere with the invasion and translocation of E. coli in bovine mammary epithelial cell line (MAC-T).Methods: For the invasion assay, MAC-T cells were challenged with MAP K10 for 2 h and then challenged with E. coli for 10, 30 and 120 min. For the translocation assay, the trans well plates were used and the challenge sequence was repeated as previously described. The amount of E. coli in the assays was determined by counting colony forming units (CFU) in Luria-Bertani medium. Quantitative real-time PCR was used to quantify MAP in MAC-T cells. To verify the viability of the MAC-T cells, the MTT assay was performed. MAP culture supernatant was also evaluated at different percentages for E. coli growth.Results: Previous MAP infection in MAC-T cells inhibited E. coli invasion in 10, 30 and 120 min. No significant interference of MAP in the translocation of E. coli from the apical-basal direction was verified. Quantity of MAP DNA inside the MAC-T cells was statistically similar. Neither reduction in MAC-T cells viability was detected during the experiment nor MAP-released factor in the supernatant inhibited E. coli invasion.Conclusion: These findings suggest that MAP-positive cows could be more resistant to E. coli infection, but when infected, could rapidly translocate E. coli to the subepithelial region.


Asunto(s)
Traslocación Bacteriana/fisiología , Coinfección/veterinaria , Células Epiteliales/microbiología , Escherichia coli/patogenicidad , Mastitis Bovina/microbiología , Mycobacterium avium subsp. paratuberculosis/patogenicidad , Animales , Bovinos , Línea Celular , Coinfección/microbiología , Modelos Animales de Enfermedad , Infecciones por Escherichia coli/veterinaria , Femenino , Glándulas Mamarias Animales/microbiología , Leche/microbiología , Paratuberculosis
3.
J Agric Food Chem ; 68(2): 441-450, 2020 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-31736308

RESUMEN

Absorption of glucose, via intestinal Na+/glucose cotransporter 1 (SGLT1), activates salt and water absorption and is an effective route for treating Escherichia coli (E. coli)-induced diarrhea. Activity and expression of SGLT1 is regulated by sensing of sugars and artificial/natural sweeteners by the intestinal sweet receptor T1R2-T1R3 expressed in enteroendocrine cells. Diarrhea, caused by the bacterial pathogen E. coli, is the most common post-weaning clinical feature in rabbits, leading to mortality. We demonstrate here that, in rabbits with experimentally E. coli-induced diarrhea, inclusion of a supplement containing stevia leaf extract (SL) in the feed decreases cumulative morbidity, improving clinical signs of disease (p < 0.01). We show that the rabbit intestine expresses T1R2-T1R3. Furthermore, intake of SL enhances activity and expression of SGLT1 and the intestinal capacity to absorb glucose (1.8-fold increase, p < 0.05). Thus, a natural plant extract sweetener can act as an effective feed additive for lessening the negative impact of enteric diseases in animals.


Asunto(s)
Diarrea/veterinaria , Células Enteroendocrinas/metabolismo , Infecciones por Escherichia coli/veterinaria , Escherichia coli/fisiología , Mucosa Intestinal/efectos de los fármacos , Edulcorantes no Nutritivos/administración & dosificación , Extractos Vegetales/administración & dosificación , Conejos/microbiología , Transportador 1 de Sodio-Glucosa/metabolismo , Stevia/química , Animales , Diarrea/tratamiento farmacológico , Diarrea/microbiología , Diarrea/mortalidad , Células Enteroendocrinas/efectos de los fármacos , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/mortalidad , Femenino , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiología , Masculino , Hojas de la Planta/química , Conejos/metabolismo , Transportador 1 de Sodio-Glucosa/genética
4.
Int J Food Microbiol ; 314: 108391, 2020 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-31689613

RESUMEN

Poultry production is the fastest growing meat sector worldwide. In the last five years, growing concerns have been expressed by international health agencies and consumers about the transmission of antibiotic-resistant bacteria from poultry meat to human. Consequently, poultry producers have adopted alternative production systems based on reduced antibiotic usage, including organic and antibiotic-free (AF) production. However, the effect of these production systems on the antibiotic resistance of the gut flora in slaughtered poultry has been poorly investigated. We hypothesized that organic and AF production systems reduce the risk of antibiotic resistance in the commensal Escherichia coli of broilers at slaughter compared with conventional production. Cecal content from broilers raised in conventional (292), AF (291), or organic (272) flocks (855 broilers in total) belonging to the same company was sampled. E. coli loads [colony-forming units (CFU/g)] and numbers of E. coli resistant to nalidixic acid (E. colinal) were determined for each sample. Antibiotic susceptibility of one isolate per sample was evaluated using the disc diffusion method; colistin resistance was determined by using the broth microdilution method. The differences in bacterial loads from the three production types were evaluated using one-way ANOVA. Differences in the proportion of resistant isolates in the three production lines were evaluated using Pearson's χ2 or Fisher's test. The strength of the association was evaluated by using odds ratio (OR), with the conventional production type as a reference (OR = 1). Overall, the analysis revealed a high level of resistance (50% or higher) to ampicillin, cefazolin, sulfonamides, nalidixic acid, and tetracycline, independently of the production type. High proportion of ciprofloxacin resistance (52%) was observed, with 4.5% isolates resistant to cefotaxime and 1.8% resistant to colistin. The average loads (log CFU/g cecal content) of E. colinal were determined as 6.84 for AF, 6.38 for organic type, and 7.27 for conventional type. The difference was significant (p < 0.00001). Interestingly, broilers from AF flocks had higher E. colinal loads than broilers from organic flocks. This trend (conventional > AF > organic) was confirmed by qualitative data. However, the magnitude of the effect, measured as a reduced risk of resistance, varied broadly for the antibiotics tested. These findings suggest that poultry production systems alternative to the conventional broiler production are associated with reduced frequency of antibiotic-resistant E. coli among the commensal gut flora, posing a lower risk to the environment and the consumer.


Asunto(s)
Agricultura/métodos , Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Infecciones por Escherichia coli/veterinaria , Escherichia coli/efectos de los fármacos , Escherichia coli/aislamiento & purificación , Aves de Corral/microbiología , Animales , Antibacterianos/administración & dosificación , Ciego/microbiología , Pollos/microbiología , Escherichia coli/crecimiento & desarrollo , Infecciones por Escherichia coli/microbiología , Pruebas de Sensibilidad Microbiana
5.
J Dairy Sci ; 103(1): 852-857, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31733863

RESUMEN

We performed a survey aimed at analyzing milk samples collected from cows with mastitis for the presence of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli. Single-quarter mastitic milk samples obtained from 400 cows in 23 Greek dairy herds with a history of E. coli mastitis were processed for the selective isolation of ESBL-producing E. coli. The antimicrobial susceptibility of the ESBL-producing isolates was analyzed using agar disk diffusion, and minimum inhibitory concentrations of colistin were determined by broth microdilution. We used PCR followed by DNA sequencing to characterize the ß-lactamases and mcr-1 (colistin resistance) genes, and for phylotyping and multilocus sequence typing. We found a total of 89/400 (22.25%) E. coli isolates from 12/23 (52%) farms. Six isolates originating from 6 cows on a single farm were ESBL producers and were resistant to cefquinome, amoxicillin-clavulanic acid, aztreonam, ampicillin, and colistin. Five of these isolates were resistant to trimethoprim-sulfamethoxazole, and 5 to streptomycin. The 6 ESBL producers were mcr-1-positive and carried blaTEM-1 genes; 3 also carried blaCTX-M genes, and 3 carried blaSHV genes. All of the ESBL producers belonged to phylogroup A, multilocus sequence type ST666 (n = 5), or a single locus variant of ST666 (n = 1). To our knowledge, this is the first report of endemic bovine mastitis caused by mcr-1-positive, ESBL-producing E. coli. These results highlight the value of active surveillance of antimicrobial resistance not commonly tested by diagnostic laboratories for the early detection of novel resistant strains.


Asunto(s)
Colistina/farmacología , Infecciones por Escherichia coli/veterinaria , Escherichia coli/aislamiento & purificación , Mastitis Bovina/microbiología , Animales , Antibacterianos/farmacología , Bovinos , Cefalosporinas/farmacología , Industria Lechera , Farmacorresistencia Bacteriana , Escherichia coli/efectos de los fármacos , Escherichia coli/enzimología , Escherichia coli/genética , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/biosíntesis , Granjas , Femenino , Grecia , Pruebas de Sensibilidad Microbiana , Leche , Tipificación de Secuencias Multilocus , beta-Lactamasas/biosíntesis , beta-Lactamasas/genética
6.
Vet Res ; 50(1): 109, 2019 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-31831050

RESUMEN

The function of Autoinducer-2 (AI-2) which acts as the signal molecule of LuxS-mediated quorum sensing, is regulated through the lsr operon (which includes eight genes: lsrK, lsrR, lsrA, lsrC, lsrD, lsrB, lsrF, and lsrG). However, the functions of the lsr operon remain unclear in avian pathogenic Escherichia coli (APEC), which causes severe respiratory and systemic diseases in poultry. In this study, the presence of the lsr operon in 60 APEC clinical strains (serotypes O1, O2, and O78) was investigated and found to be correlated with serotype and has the highest detection rate in O78. The AI-2 binding capacity of recombinant protein LsrB of APEC (APEC-LsrB) was verified and was found to bind to AI-2 in vitro. In addition, the lsr operon was mutated in an APEC strain (APEC94Δlsr(Cm)) and the mutant was found to be defective in motility and AI-2 uptake. Furthermore, deletion of the lsr operon attenuated the virulence of APEC, with the LD50 of APEC94Δlsr(Cm) decreasing 294-fold compared with wild-type strain APEC94. The bacterial load in the blood, liver, spleen, and kidneys of ducks infected with APEC94Δlsr(Cm) decreased significantly (p < 0.0001). The results of transcriptional analysis showed that 62 genes were up-regulated and 415 genes were down-regulated in APEC94Δlsr(Cm) compared with the wild-type strain and some of the down-regulated genes were associated with the virulence of APEC. In conclusion, our study suggests that lsr operon plays a role in the pathogenesis of APEC.


Asunto(s)
Proteínas Portadoras/metabolismo , Infecciones por Escherichia coli/veterinaria , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Homoserina/análogos & derivados , Lactonas/metabolismo , Enfermedades de las Aves de Corral/microbiología , Percepción de Quorum , Animales , Biopelículas , Proteínas Portadoras/genética , China/epidemiología , Escherichia coli/genética , Escherichia coli/patogenicidad , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica/fisiología , Homoserina/genética , Homoserina/metabolismo , Aves de Corral , Enfermedades de las Aves de Corral/epidemiología , Serogrupo
7.
Ann Agric Environ Med ; 26(4): 532-537, 2019 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-31885224

RESUMEN

Infections caused by extra-intestinal pathogenic Escherichia coli (ExPEC) are a serious public health problem worldwide. The most troublesome are urinary tract infections, severe neonatal meningitis, serious intraabdominal infections, and more rarely, pneumonia, intravascular-device infections, osteomyelitis, soft-tissue infections or sometimes bacteraemia. These strains are also able cause significant economic losses in animal husbandry. A thorough understanding of ExPEC ecology, reservoirs, chains and dynamics of transmission can greatly contribute to a reduction in the burden of ExPEC-associated disease. The ability of E. coli (including ExPEC) to exist and survive in various ecological niches impedes the precise recognition and indication of transmission routes most important for individual infections cases. Among many identified ExPEC reservoirs, animal companion and animals providing food seem to be important sources of infection for human; however, the real level of risk connected with potential transmission of these bacteria remains unclear. Food is indicated as one of potential ways of transmission. Despite a quite high number of reports, many of the uncertainties are expected to be reliably elucidated. This review presents most important data on the current state of knowledge concerning the potential role of food in ExPEC transmission. The possible consequences of ExPEC infections in human and animals are briefly described.


Asunto(s)
Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli/fisiología , Enfermedades Transmitidas por los Alimentos/microbiología , Enfermedades Transmitidas por los Alimentos/veterinaria , Animales , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/transmisión , Contaminación de Alimentos/análisis , Humanos
8.
Vet Microbiol ; 239: 108445, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31767071

RESUMEN

Avian pathogenic E. coli (APEC) and human uropathogenic E. coli (UPEC) harbour common virulence factors in spite of being associated with disease in different hosts. APEC strains have been shown to have zoonotic potential. In contrast, it is not known whether UPEC strains can cause infection in immunologically competent hens. The objective of the current study was to compare the ability of the well-characterized UPEC strain, UTI89, and the APEC strain, F149H1S2, to infect human and avian cells in culture and to cause salpingitis in an infection model in adult laying hens. In vitro characterization showed that the strains grew equally well in human urine, and both were able to infect human intestinal (Int407) and bladder (J82) epithelial cell lines, and they survived in avian macrophages (HD11) to the same extent. Groups of adult birds were inoculated with 108 bacteria directly into the oviduct using a surgical procedure. After an infection period of 48 h, bacterial load in the oviduct was determined by dilution series, and pathology was determined based on gross lesions and histological observations. Similar counts of UPEC UTI89 (ST95) and the APEC strain F149H1S2 (ST117) were obtained from tissues of infected birds, and salpingitis as evaluated by clinical score and histopathology was observed to a similar extent after infection with the two strains. Together, the results showed that UPEC UTI89 and APEC F149H1S2 have a similar potential for causing salpingitis in laying hens in the model used. No infection differences were observed between the UPEC UTI89 wild type and a mutant strain with knock-out of the well-known virulence gene, fimH, (UPEC UTI89ΔfimH), showing that the salpingitis model is not suitable for the detection of all UPEC virulence factors.


Asunto(s)
Infecciones por Escherichia coli/veterinaria , Escherichia coli/patogenicidad , Enfermedades de las Aves de Corral/microbiología , Infecciones del Sistema Genital/veterinaria , Adhesinas de Escherichia coli/genética , Animales , Línea Celular , Pollos , Infecciones por Escherichia coli/microbiología , Proteínas Fimbrias/genética , Humanos , Mutación , Enfermedades de las Aves de Corral/patología , Infecciones del Sistema Genital/microbiología , Infecciones del Sistema Genital/patología , Especificidad de la Especie , Factores de Virulencia/genética
9.
Vet Microbiol ; 239: 108446, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31767080

RESUMEN

Plasmid-mediated extended-spectrum ß-lactamase and AmpC ß-lactamase (ESBL/pAmpC) producing bacteria are present at all levels of the broiler production pyramid. Young birds can be found positive for ESBL/pAmpC-producing Escherichia coli shortly after arrival at farm. The aim of this study was to determine the effect of different challenge doses of ESBL/pAmpC-producing E. coli on time-until-colonization and the level of excretion in young broilers. One-day-old broilers (specific-pathogen free (SPF) and conventional Ross 308) were housed in isolators and challenged with 0.5 ml ESBL/pAmpC-producing E. coli strains of varying doses (101-105 CFU/ml). Presence and concentration (CFU/gram feces) of ESBL/pAmpC-producing E. coli and total E. coli were determined longitudinally from cloacal swabs, and in cecal content 72 h after challenge. Higher challenge doses resulted in shorter time-until-colonization. However, even the lowest dose (101 CFU/ml) resulted in colonization of the broilers which excreted >106 CFU/gram feces 72 h after inoculation. Conventional broilers were colonized later than SPF broilers, although within 72 h after challenge all broilers were excreting ESBL/pAmpC-producing E. coli. A probabilistic model was used to estimate the probability of colonization by initial inoculation or transmission. The higher the dose the higher the probability of excreting ESBL/pAmpC-producing E. coli as a result of inoculation. In conclusion, low initial doses of ESBL/pAmpC-producing E. coli can result in rapid colonization of a flock. Interventions should thus be aimed to eliminate ESBL/pAmpC-producing bacteria in the environment of the hatchlings and measures focusing at reducing colonization and transmission of ESBL/pAmpC-producing E. coli should be applied shortly after hatching.


Asunto(s)
Infecciones por Escherichia coli/veterinaria , Enfermedades de las Aves de Corral/microbiología , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Pollos , Escherichia coli/enzimología , Escherichia coli/genética , Infecciones por Escherichia coli/enzimología , Infecciones por Escherichia coli/genética , Infecciones por Escherichia coli/microbiología , Plásmidos/genética , Enfermedades de las Aves de Corral/enzimología , Enfermedades de las Aves de Corral/genética , Enfermedades de las Aves de Corral/transmisión , Tiempo , beta-Lactamasas/genética , beta-Lactamasas/metabolismo
10.
Vet Microbiol ; 239: 108479, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31767081

RESUMEN

Worldwide infections by Shiga toxin-producing Escherichia coli (STEC) in humans have been reported after consumption of mainly beef, but also deer meat. Not only the consumption of contaminated deer meat represents a risk, but also the transmission of STEC between deer and domestic animals should be considered. Within the framework of a telemetry study of roe deer (Capreolus capreolus) the aim was to analyse the occurrence of STEC. Due to the chance to sample some animals several times it was possible to obtain data on the repeated shedding of STEC in roe deer. In total 124 faeces or rectal swabs of 77 live trapped roe deer were collected. The isolates obtained were characterized for stx subtypes, different virulence genes, the so-called top-five serogroups, phylogenetic groups, PFGE-types and antimicrobial susceptibilities. The majority of roe deer were stx-positive whenever sampled. Twenty-eight animals were sampled more than once and were used to examine the duration of shedding STEC. The time interval of 6 persistently stx-negative tested animals was between 6 and 440d (median 49d, interquartile range (IQR) 17-258d). Ten animals excreted undistinguishable STEC strains in intervals between 4 and 778d (median 42d, IQR 22-79d). Most of the isolates were stx2b-positive, eae-negative and frequently ehlyA-positive. None of the isolates belonged to serogroup O26, O103, O111, O145 and O157, respectively. All isolates were sensitive to the antimicrobial substances tested. Although the duration of each shedding event could not be determined the results indicate long-term excretion of STEC in roe deer. This is an important consideration for the observance of good hygiene practice while field dressing of deer and preparing deer meat.


Asunto(s)
Ciervos , Infecciones por Escherichia coli/veterinaria , Escherichia coli Shiga-Toxigénica/fisiología , Animales , Antibacterianos/farmacología , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Heces/microbiología , Pruebas de Sensibilidad Microbiana , Prevalencia , Recto/microbiología , Serogrupo , Escherichia coli Shiga-Toxigénica/clasificación , Escherichia coli Shiga-Toxigénica/efectos de los fármacos , Escherichia coli Shiga-Toxigénica/genética , Factores de Virulencia/genética
11.
Res Vet Sci ; 127: 27-32, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31670090

RESUMEN

Bovines are the primary reservoir of enterohemorrhagic Escherichia coli (EHEC) O157:H7 and the main source of its transmission to humans. Here, we present a one-year longitudinal study of fecal shedding of E. coli O157. E. coli O157 obtained from recto-anal mucosal samples were characterized by multiplex PCR. The E. coli O157 prevalence ranged from 0.84% in July to 15.25% in November. The confinement within pens resulted in prevalence of 11%. Most animals (61.86%; 75/118) shed E. coli O157 at least in one sampling occasion. Of the positive animals, 82.19%, 16.44%, and 1.37% were stx positive on one, two and three sampling occasions, respectively. All the E. coli O157 isolated strains carried the genes eae and rfbO157, whereas 11%, 33% and 56% contained stx1, stx2 and stx1/stx2, respectively. The stx1/stx2 and stx2 types were significantly higher during the grazing and finishing periods, respectively, in comparison with the rearing and grazing periods. The presence of stx2a subtype was evident in four isolates, whereas stx2c was present in at least seven. However, both subtypes were present simultaneously in two isolates. The stx1/stx2c, stx1/stx2d and stx1/stx2NT genotypes occurred in 24, 2 and 15 isolates, respectively. The simultaneous occurrence of stx1 and stx2c significantly increased during grazing. Some cases of within-pen and between-pen transmission occurred throughout the study. Contagion levels during in-field grazing were higher than during permanent confinement in the pens. Thus, the individual patterns of shedding varied depending on the proportion of animals shedding the bacteria within pens and the time of shedding.


Asunto(s)
Derrame de Bacterias , Enfermedades de los Bovinos/microbiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli O157/fisiología , Adhesinas Bacterianas/análisis , Animales , Argentina , Bovinos , Infecciones por Escherichia coli/microbiología , Escherichia coli O157/genética , Escherichia coli O157/patogenicidad , Proteínas de Escherichia coli/análisis , Heces/microbiología , Genotipo , Estudios Longitudinales , Masculino , Toxina Shiga/análisis , Virulencia
12.
PLoS Pathog ; 15(10): e1008003, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31581229

RESUMEN

Specific Escherichia coli isolates lysogenised with prophages that express Shiga toxin (Stx) can be a threat to human health, with cattle being an important natural reservoir. In many countries the most severe pathology is associated with enterohaemorrhagic E. coli (EHEC) serogroups that express Stx subtype 2a. In the United Kingdom, phage type (PT) 21/28 O157 strains have emerged as the predominant cause of life-threatening EHEC infections and this phage type commonly encodes both Stx2a and Stx2c toxin types. PT21/28 is also epidemiologically linked to super-shedding (>103 cfu/g of faeces) which is significant for inter-animal transmission and human infection as demonstrated using modelling studies. We demonstrate that Stx2a is the main toxin produced by stx2a+/stx2c+ PT21/28 strains induced with mitomycin C and this is associated with more rapid induction of gene expression from the Stx2a-encoding prophage compared to that from the Stx2c-encoding prophage. Bacterial supernatants containing either Stx2a and/or Stx2c were demonstrated to restrict growth of bovine gastrointestinal organoids with no restriction when toxin production was not induced or prevented by mutation. Isogenic strains that differed in their capacity to produce Stx2a were selected for experimental oral colonisation of calves to assess the significance of Stx2a for both super-shedding and transmission between animals. Restoration of Stx2a expression in a PT21/28 background significantly increased animal-to-animal transmission and the number of sentinel animals that became super-shedders. We propose that while both Stx2a and Stx2c can restrict regeneration of the epithelium, it is the relatively rapid and higher levels of Stx2a induction, compared to Stx2c, that have contributed to the successful emergence of Stx2a+ E. coli isolates in cattle in the last 40 years. We propose a model in which Stx2a enhances E. coli O157 colonisation of in-contact animals by restricting regeneration and turnover of the colonised gastrointestinal epithelium.


Asunto(s)
Enfermedades de los Bovinos/transmisión , Células Epiteliales/microbiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli O157/efectos de los fármacos , Íleon/microbiología , Organoides/microbiología , Toxina Shiga II/farmacología , Animales , Bovinos , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/microbiología , Células Epiteliales/citología , Células Epiteliales/metabolismo , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/microbiología , Escherichia coli O157/aislamiento & purificación , Íleon/citología , Íleon/metabolismo , Masculino , Organoides/crecimiento & desarrollo , Organoides/metabolismo , Virulencia
13.
Vet Microbiol ; 238: 108429, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31648721

RESUMEN

Viral haemorrhagic disease (VHD) and colibacillosis are common diseases in rabbits that cause economic losses worldwide. The effect of colibacillosis on the immune response of vaccinated rabbits against rabbit haemorrhagic disease virus (RHDV) was studied. Four groups (G1-G4) were included. G1 was the negative control group; G2 was the RHDV vaccine group; G3 was the E. coli-infected group; and G4 was the E. coli-infected + RHDV vaccine group. The E. coli infection and RHDV vaccination were simultaneously performed, with another previous infection, 3 days before vaccination. At 28 days post-vaccination (PV), the rabbits (G2-G4) were challenged intramuscularly with 0.5 ml of RHDV at a dose of 103 50% median lethal dose (LD50)/rabbit. The rabbits were observed for clinical signs, body weight gain and mortality rates. Tissue, blood, serum, and faecal samples and rectal swabs were collected at 3, 5, 7, 14, 21 and 28 days PV. Significant clinical signs and mortality and a decrease in BW were observed in the infected + RHDV vaccine group. On the 3rd day post-infection (PI), compared with all the other groups, the vaccinated group (G2) had significantly upregulated hepatic tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels; however, the infected + RHDV vaccine group had significantly higher intestinal levels of TNF-α and IL-6 than the other groups. Furthermore, E. coli infection in vaccinated rabbits led to immunosuppression, as shown by significant decreases (P < 0.05) in heterophil phagocytic activity, the CD4+/CD8+ ratio, and HI antibody responses to RHDV and a significant increase in the heterophil to lymphocyte (H/L) ratio. In conclusion, colibacillosis leads to immunosuppression involving a shift in the equilibrium of cytokines and reduced weight gain and mortality in vaccinated rabbits and could be a contributing factor in RHDV vaccination failure in rabbit farming.


Asunto(s)
Infecciones por Caliciviridae/veterinaria , Infecciones por Escherichia coli/veterinaria , Conejos/inmunología , Vacunación/veterinaria , Vacunas Virales/inmunología , Animales , Infecciones por Caliciviridae/inmunología , Infecciones por Caliciviridae/mortalidad , Citocinas/genética , Infecciones por Escherichia coli/inmunología , Infecciones por Escherichia coli/mortalidad , Infecciones por Escherichia coli/fisiopatología , Regulación de la Expresión Génica/inmunología , Virus de la Enfermedad Hemorrágica del Conejo/inmunología , Conejos/microbiología , Conejos/virología , Vacunación/normas
14.
J Dairy Sci ; 102(12): 11449-11452, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31629516

RESUMEN

Antimicrobial residues in milk have been discussed as a possible selector for Enterobacteriaceae that produce extended-spectrum ß-lactamases (ESBL) in dairy herds. Such residues are found in waste milk after antibiotic treatment of mastitis, but antibiotic dry cow therapy might also lead to antibiotic residues in colostrum and in milk during early lactation. While it is known that feeding of waste milk selects ESBL bacteria in calves, this was not investigated for colostrum yet, which is supposed to contain much lower antibiotic concentrations than waste milk. In this observational prospective case study on 2 farms, we hypothesized that blanket dry cow treatment with ß-lactams would have more selective (here: increasing) effects on ESBL concentrations than selective (here: individually chosen) antibiotic dry cow therapy. Thus, we compared concentrations of ESBL-producing Enterobacteriaceae in feces of calves (n = 50) at 2 dairy farms with different management of antibiotic dry cow therapy. Considerably higher concentrations of ESBL-producing Escherichia coli were observed in blanket antibiotic dry cow therapy on d 3 of the calf's life (7.6 vs. 5.3 log cfu/g of calf feces). Both farms used narrow-spectrum penicillin combined with aminoglycosides for drying off, and the majority of ESBL isolates (93%) were co-resistant to aminoglycosides. No waste milk was fed to calves and no calf was treated with ß-lactam antibiotics or aminoglycosides during the first 3 d of life, thus differences were most likely associated with different frequency of antibiotic dry cow therapy on farms (19 of 25 mother cows on farm A, 9 of 25 on farm B). Even though the presumable selection effect of antibiotics used for drying off decreased within the next 3 wk, this result further emphasizes the need for the reduction and prudent use of antibiotic dry cow therapy on farms.


Asunto(s)
Antibacterianos/uso terapéutico , Calostro/química , Infecciones por Escherichia coli/veterinaria , Escherichia coli/enzimología , Leche/química , beta-Lactamasas/metabolismo , Animales , Antiinfecciosos/análisis , Bovinos , Estudios de Cohortes , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/microbiología , Granjas , Heces/microbiología , Femenino , Embarazo , Estudios Prospectivos
15.
J Dairy Sci ; 102(12): 11476-11482, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31629523

RESUMEN

The objective of this study was to describe weekly quarter-level somatic cell count (QSCC) after occurrence of nonsevere clinical mastitis (CM) that was diagnosed as culture negative, or caused by Escherichia coli or Klebsiella pneumoniae. All cases occurred in cows enrolled in negatively, controlled randomized clinical trials. We hypothesized that after occurrence of CM, QSCC patterns would vary among etiologies and this effect would not be mitigated by treatment using intramammary (IMM) ceftiofur. Data from two previously published randomized clinical trials performed on 3 Wisconsin dairy farms were used. Only cases confirmed as culture negative (NG) or E. coli or Kleb. pneumoniae (GRAMNEG) were used for analysis. In NG, cows were assigned to no antimicrobial treatment (negative control, n = 44) or 5 d of once daily IMM (n = 41) infusions with an approved product containing ceftiofur hydrochloride. In GRAMNEG, cows were assigned to IMM treatment with the same ceftiofur product for 2 different durations (2 d, n = 36; or 8 d, n = 38) or no antimicrobial treatment (negative control, n = 36). For quarters enrolled in NG, no significant differences were identified for weekly QSCC between quarters in the treated or negative control groups (5.4 log10SCC for both groups). For quarters enrolled in GRAMNEG, no significant differences were identified for QSCC between quarters that received the 2-d (6.2 log10SCC) or 8-d (6.3 log10SCC) IMM treatment or were in the negative control group (6.0 log10SCC). At the pathogen level, regardless of treatment, QSCC varied among pathogens and log10SCC were 5.4 (culture negative), 5.8 (E. coli), and 6.2 (Kleb. pneumoniae). Patterns of QSCC of CM diagnosed as culture negative and E. coli were similar in magnitude and time to resolution of the inflammatory response. In conclusion, as compared to CM diagnosed as culture negative or caused by E. coli, CM caused by Kleb. pneumoniae was associated with poorer outcomes. Regardless of IMM ceftiofur treatment, the immune response of the cow resulted in rapid reduction of SCC of quarters diagnosed as culture negative and quarters with CM caused by E. coli. In contrast, the SCC remained elevated for quarters with CM caused by Kleb. pneumoniae and a greater proportion of those cases remained chronically infected.


Asunto(s)
Antibacterianos/uso terapéutico , Cefalosporinas/uso terapéutico , Infecciones por Escherichia coli/veterinaria , Infecciones por Klebsiella/veterinaria , Klebsiella pneumoniae , Mastitis Bovina/tratamiento farmacológico , Animales , Bovinos , Recuento de Células/veterinaria , Escherichia coli , Infecciones por Escherichia coli/tratamiento farmacológico , Femenino , Infecciones por Klebsiella/tratamiento farmacológico , Estudios Longitudinales , Glándulas Mamarias Animales/patología , Mastitis Bovina/epidemiología , Mastitis Bovina/microbiología , Leche/citología
16.
Emerg Microbes Infect ; 8(1): 1524-1527, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31631781

RESUMEN

The recent emergence of plasmid-mediated tigecycline resistance genes, tet(X3) and tet(X4), in animals and humans in China would pose a foreseeable threat to public health. To illustrate this paradigm shift in tigecycline resistance, here, covering the period 2008-2018, we retrospectively analysed a national strain collection of Escherichia coli (n = 2254), obtained from chickens and pigs, in six representative provinces of China. The gene tet(X4) was identified in five pig isolates collected in 2016 and 2018 from the provinces of Sichuan (3/15, 2018), Henan (1/25, 2018) and Guangdong (1/28, 2016), but not in the isolates prior to 2016. None of the isolates was detected harbouring tet(X3). All tet(X4)-positive E. coli exhibited high levels of tigecycline resistance (MICs, 16-64 mg/L), and two were confirmed as colistin resistant, harbouring chromosome-borne mcr-1 gene. The gene tet(X4) was detected on a plasmid in all five isolates, whereas a co-location of tet(X4) on the chromosome of one isolate was observed. Diverse host strains and novel plasmids related to the tet(X4) gene were observed. Our timely findings of the recent emergence of tet(X4) gene in food animal support the rapid surveillance and eradication of this gene before it is established.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Infecciones por Escherichia coli/veterinaria , Proteínas de Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Enfermedades de las Aves de Corral/microbiología , Enfermedades de los Porcinos/microbiología , Tigeciclina/farmacología , Animales , Pollos , China , Colistina/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Escherichia coli/metabolismo , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/metabolismo , Plásmidos/genética , Plásmidos/metabolismo , Estudios Retrospectivos , Porcinos
17.
J Vet Emerg Crit Care (San Antonio) ; 29(6): 696-701, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31642173

RESUMEN

OBJECTIVE: To describe a case of successful management of epidural-subdural abscess and severe meningitis with secondary brain herniation in a dog. CASE SUMMARY: A rhino-sinusotomy was performed in a 3-year-old mixed-breed dog for management of refractory sinonasal aspergillosis. Initial recovery was good, but the dog became acutely stuporous 36 hours after surgery. Evidence of increased intracranial pressure with brain herniation and midline shift secondary to an epidural abscess was observed on magnetic resonance imaging. Decompressive craniectomy and drainage of the abscess was performed. Intensive nursing care and physiologic support was performed with consciousness returning 7 days after initial stupor. The dog was discharged 14 days after craniectomy and was ambulatory with support. NEW/UNIQUE INFORMATION PROVIDED: Intracranial abscesses are rarely described in dogs and few had a successful outcome reported. All previous reports have been of brain abscesses or empyema, rather than a combination of epidural and subdural abscessation. Additionally, the process of sino-rhinotomy for management of aspergillosis has not been previously linked to intracranial abscess formation. To the authors' knowledge, this is the first report of successful management of an epidural-subdural abscess and suggests that even with cases with low modified Glasgow Coma Scale scores outcome may be positive.


Asunto(s)
Enfermedades de los Perros/etiología , Empiema Subdural/veterinaria , Absceso Epidural/veterinaria , Infecciones por Escherichia coli/veterinaria , Escherichia coli/aislamiento & purificación , Animales , Antibacterianos/uso terapéutico , Enfermedades de los Perros/microbiología , Perros , Empiema Subdural/microbiología , Empiema Subdural/terapia , Absceso Epidural/microbiología , Absceso Epidural/terapia , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/patología , Infecciones por Escherichia coli/terapia , Masculino , Complicaciones Posoperatorias/microbiología , Complicaciones Posoperatorias/veterinaria
18.
J Dairy Sci ; 102(12): 11233-11249, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31606213

RESUMEN

Vaccination against coliform mastitis has become part of mastitis control programs in the past 3 decades, as a means of reducing the severity of clinical mastitis. Our study objective was to evaluate the effect of 2 commercially available vaccines on clinical, behavioral, and antibody response following Escherichia coli intramammary challenge in cows near peak lactation. Cows (n = 12 per group) were vaccinated with vaccine 1 (V1) or vaccine 2 (V2) at dry-off, 21 d pre-calving, and 14 d post-calving. Twelve cows served as unvaccinated controls (CTL). Cows were challenged with E. coli in a rear quarter at approximately 100 d in milk. Milk samples were collected pre- and post-challenge to enumerate E. coli and determine somatic cell count. Serum was collected before each vaccination and at d 0, 1, 2, 3, 6, 30, and 60 relative to challenge, to study antibody response. Milk IgA and tumor necrosis factor-α concentrations were determined in whey. Vaginal temperature, cow activity, and milk yield and components were monitored post-challenge. Bacterial count, somatic cell score, milk yield and component decline, vaginal temperature, activity measures, and antibody and cytokine response were analyzed for treatment differences. The effects of parity, breed, and a repeated measure of time were also tested. Seven cows had to be removed from the study post-challenge for antibiotic treatment (CTL and V1, n = 3 each; V2, n = 1), 2 of which were euthanized (both CTL). Vaccinated cows exhibited fever (vaginal temperature ≥39.4°C) 3 h earlier than CTL cows, but we found no differences between treatments for bacterial count, somatic cell score, or milk yield reduction. Vaccinated cows spent more time lying per rest bout 2 d post-challenge, but total daily lying time was not different from CTL cows during the 7 d post-challenge. The vaccines differed in antibody response: V1 cows had greater serum IgG1 and IgG2 post-challenge. A parity effect was also evident: primiparous cows had lower bacterial counts, somatic cell score and a smaller milk yield decline than multiparous cows, but also had lower antibody production. Immunization with either J5 bacterin did not reduce clinical signs of mastitis in cows challenged at 100 d in milk, demonstrating that the effects of J5 vaccination had diminished at peak lactation.


Asunto(s)
Infecciones por Escherichia coli/veterinaria , Vacunas contra Escherichia coli/inmunología , Inmunogenicidad Vacunal , Mastitis Bovina/prevención & control , Animales , Anticuerpos Antibacterianos/sangre , Bovinos , Recuento de Células/veterinaria , Escherichia coli/inmunología , Vacunas contra Escherichia coli/administración & dosificación , Femenino , Humanos , Inmunoglobulina G/sangre , Lactancia , Mastitis Bovina/inmunología , Mastitis Bovina/microbiología , Leche/citología , Leche/microbiología , Paridad , Embarazo , Vacunación/veterinaria
19.
J Dairy Sci ; 102(11): 10587-10598, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31477304

RESUMEN

In 2 epidemiological studies, we evaluated the effect of mastitis induced by gram-positive Streptococcus and gram-negative Escherichia coli on impaired reproductive performance in lactating Holstein cows. In the first study, 52,202 cows from 178 dairy farms throughout Israel were divided into groups based on infection before first artificial insemination (AI) with Streptococcus or E. coli, 3 groups with elevated somatic cell count (SCC) without infection by those pathogens [low SCC (200-400) × 103 cell/mL; medium SCC (401-1,000) × 103 cell/mL; high SCC, >1,000 × 103 cell/mL], and uninfected controls. Pregnancy per first AI (P/1stAI) and pregnancy rate at 300 d in milk (PREG 300) were analyzed by the GLIMMIX procedure (SAS); number of AI per pregnancy (AI/P), days open, and rest days (calving to first AI) were analyzed by the MIXED procedure (SAS Institute Inc., Cary, NC). Values of P/1stAI were similarly low for Streptococcus and E. coli (27-28%) versus 42% in controls; PREG 300 was lower for Streptococcus (76%) than for E. coli (79%) versus 88% for uninfected controls and a mean 83% for the elevated SCC groups. Days open and number of AI/P were higher than in controls and similar in Streptococcus and E. coli groups. The second study included 778 cows on 6 dairy farms; the cows were infected before first AI by Streptococcus or E. coli or uninfected. Resumption of cyclicity was determined by an automated activity-monitoring system, and data were sorted by time of infection before or after cyclicity resumed. The Streptococcus group had lower P/1stAI before and after cyclicity (26 and 27%, respectively) than the E. coli group (31 and 34%, respectively) and uninfected controls (42%). Notably, PREG 300 in the Streptococcus group before (73%) and after (67%) cyclicity was much lower than for the E. coli group (85 and 93%, respectively) and the controls (95%). A marked rise in day of cyclicity resumption (∼80 d) was observed in cows that were infected early on. Number of AI/P was higher in the mastitic groups than in uninfected controls. Uterine disease postpartum, although more prevalent among Streptococcus cows, did not substantially alter the larger reduction in P/1stAI and PREG 300 in Streptococcus versus E. coli cows. Thus, long-term Streptococcus-induced mastitis disrupted fertility more than short-term acute E. coli-induced mastitis, resulting in a much higher percentage of Streptococcus cows in late lactation that did not conceive due to reproduction failure.


Asunto(s)
Infecciones por Escherichia coli/veterinaria , Mastitis Bovina/fisiopatología , Reproducción , Infecciones Estreptocócicas/veterinaria , Animales , Bovinos , Escherichia coli , Infecciones por Escherichia coli/fisiopatología , Femenino , Fertilidad , Inseminación Artificial/veterinaria , Israel , Lactancia , Mastitis Bovina/microbiología , Leche , Embarazo , Índice de Embarazo , Infecciones Estreptocócicas/fisiopatología , Streptococcus
20.
J Anim Sci ; 97(11): 4503-4508, 2019 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-31545364

RESUMEN

An infection model with enterotoxigenic Escherichia coli (ETEC) harboring the F4 fimbriae can be used to assess the impacts that various challenges associated with weaning (e.g., dietary, psychological, environmental) have on the expression of postweaning diarrhea. The objective of this study was to develop a novel inoculation method for administering an ETEC culture that would induce a higher proportion of ETEC-F4 diarrhea, in pigs that genetically showed ETEC-F4 susceptibility or resistance. The study was designed as a factorial arrangement of treatments with the factors being 1) partially susceptible or resistant to ETEC-F4 based on genetic testing, and 2) 4 challenge treatments, being a) a conventional liquid broth method using a drenching gun [Positive control (PC)], b) a Syringe method, c) a Capsule method, and d) Negative control [pigs not challenged (NC)]. At 21 ± 3 d of age (mean ± SEM), 48 male castrate pigs (Large White × Landrace) weighing approximately 7.0 ± 1.18 kg were allocated to 4 treatment groups in 2 replicate pens (6 pigs per pen). Initial ETEC-F4 susceptibility was based on a DNA marker test and each treatment group had 9 partially susceptible and 3 resistant pigs. On days 7 and 8 after weaning, pigs were challenged with ETEC (serotype O149:K88; toxins LT1, ST1, ST2, and EAST). On each inoculation day the PC pigs were orally dosed with 9 mL 7.12 × 109 colony-forming unit (CFU), the Syringe pigs with 0.8 mL 6.72 × 109 CFU, the Capsule pigs were orally administered 2 capsules containing 0.8 mL 3.28 × 109 CFU, and the NC pigs 1 mL of phosphate-buffered saline (PBS) solution. Approximately 72 h after infection, 44, 22, 78, and 0% of partially susceptible pigs in the PC, the Syringe, the Capsule, and the NC group had developed ETEC-F4 diarrhea (P = 0.007). Partially susceptible pigs had a higher diarrhea index (DI) compared to resistant pigs (31.5 vs. 4.8, P < 0.001). The NC group had a lower DI compared to the PC and Capsule pigs (3.9, 38.1, and 40.3, respectively, P < 0.005). Following infection, genetically resistant pigs in the Capsule group had a DI of zero and the partially susceptible pigs had a DI of 55.6 (P = 0.014). This study showed that genetically screening pigs and using a Capsule to deliver ETEC-F4 can increase cases of diarrhea and the efficiency of the challenge model. Taken together, these methods have the potential to reduce the number of pigs needed in future experimental infection studies.


Asunto(s)
Diarrea/veterinaria , Modelos Animales de Enfermedad , Escherichia coli Enterotoxigénica/fisiología , Infecciones por Escherichia coli/veterinaria , Enfermedades de los Porcinos/microbiología , Porcinos , Animales , Infecciones por Escherichia coli/microbiología , Sitios Genéticos , Masculino , Destete
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