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1.
PLoS One ; 15(2): e0214267, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32106264

RESUMEN

The development of alternatives to antibiotics is crucial to limiting the incidence of antimicrobial resistance, especially in prophylactic and metaphylactic use to control post-weaning diarrhea (PWD). Feed additives, including bioactive compounds, could be a promising alternative. This study aimed to test two bioactive compounds, sodium salicylate (SA) and a chestnut extract (CE) containing hydrolysable tannins, on the occurrence of PWD. At weaning, 72 piglets were assigned to four treatments that combined two factors: CE supplementation (with 2% of CE (CE+) or without (CE-)) and SA supplementation (with 35 mg/kg BW of SA (SA+) or without (SA-)). Then, 4 days after weaning, all piglets were infected with a suspension at 108 CFU/ml of enterotoxigenic Escherichia coli (ETEC F4ac). Each piglet had free access to an electrolyte solution containing, or not, SA. This SA supplementation was administered for 5 days (i.e., from the day of infection (day 0) to 4 days post-infection (day 4). During the 2 weeks post-infection, supplementation with SA had no effect (P > 0.05) on growth performances nor on fecal scores. A significant SA × time interaction (P < 0.01) for fecal scores and the percentage of diarrhea indicated that piglets with SA did not recover faster and did have a second episode of diarrhea. In contrast to SA treatment, inclusion of CE increased (P < 0.05) growth performances and feed intake. In the first week post-infection, CE decreased (P < 0.001) the overall fecal scores, the percentage of piglets with diarrhea, the days in diarrhea, and ETEC shedding in the feces. There was a SA×CE interaction (P < 0.05) for ETEC shedding, suggesting a negative effect of combining SA with CE. This study highlighted that, in contrast to SA, CE could represent a promising alternative to antibiotics immediately after weaning for improving growth performance and reducing PWD.


Asunto(s)
Diarrea/veterinaria , Escherichia coli Enteropatógena/efectos de los fármacos , Extractos Vegetales/uso terapéutico , Salicilato de Sodio/uso terapéutico , Enfermedades de los Porcinos/tratamiento farmacológico , Animales , Derrame de Bacterias , Diarrea/tratamiento farmacológico , Diarrea/microbiología , Fagaceae/química , Extractos Vegetales/farmacología , Salicilato de Sodio/farmacología , Porcinos , Enfermedades de los Porcinos/microbiología
2.
PLoS One ; 15(1): e0228038, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31999733

RESUMEN

BACKGROUND: Leptospirosis, caused by pathogenic Leptospira spp., is a zoonotic infection that affects humans, dogs and many other mammalian species. Virtually any mammalian species can act as asymptomatic reservoir, characterized by chronic renal carriage and shedding of a host-adapted leptospiral serovar. Environmental contamination by chronic shedders results in acquisition of infection by humans and susceptible animals. METHODS: In this study, we investigated if clinically normal shelter dogs and cats harbor leptospires in their kidneys by screening urine samples for the presence of leptospiral DNA by a TaqMan based-quantitative PCR (qPCR) that targets pathogen-associated lipl32 gene. To identify the infecting leptospiral species, a fragment of leptospiral rpoB gene was PCR amplified and sequenced. Additionally, we measured Leptospira-specific serum antibodies using the microscopic agglutination test (MAT), a gold standard in leptospiral serology. RESULTS: A total of 269 shelter animals (219 dogs and 50 cats) from seven shelters located in the tri-state area of western Virginia, eastern Tennessee, and southeastern Kentucky were included in this study. All cats tested negative by both qPCR and MAT. Of the 219 dogs tested in the study, 26/198 (13.1%, 95% CI: 8.4-17.8%) were positive for leptospiral DNA in urine by qPCR and 38/211 (18.0%, 95% CI: 12.8-23.2%) were seropositive by MAT. Twelve dogs were positive for both qPCR and MAT. Fourteen dogs were positive by qPCR but not by MAT. Additionally, leptospiral rpoB gene sequencing from a sub-set of qPCR-positive urine samples (n = 21) revealed L. interrogans to be the leptospiral species shed by dogs. CONCLUSIONS: These findings have significant implications regarding animal and public health in the Cumberland Gap Region and possibly outside where these animals may be adopted.


Asunto(s)
Derrame de Bacterias , Enfermedades de los Perros/microbiología , Leptospira/fisiología , Leptospirosis/microbiología , Leptospirosis/veterinaria , Pruebas de Aglutinación , Animales , Región de los Apalaches , Perros , Geografía , Leptospirosis/orina , Prevalencia
3.
J Anim Sci ; 98(1)2020 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-31863091

RESUMEN

Salmonella in pigs is a concern for human foodborne salmonellosis. Dietary fungal fermented products, coated butyrate, and organic acids (OAs) may be promising control strategies. The objectives of this study were (i) to evaluate in vitro binding affinity of Salmonella enterica serovar Typhimurium (S. Typh) and Enteritidis (S. Ent), and enterotoxigenic Escherichia coli (ETEC) F4 or F18 to mannan-rich hydrolyzed copra meal (MCM) and fermented rye (FR) with Agaricus subrufescens; and (ii) to assess MCM and FR efficacy to control in vivo S. Typh shedding when combined with OAs and compared with coated butyrate strategy. A 31-d study included 32 pigs [6.29 ±â€…0.76 kg BW] individually housed and distributed into four dietary treatments: control diet; OA.BU, 4 kg/t OA plus 6 kg/t coated butyrate; OA.MCM, 4 kg/t OA plus 1 kg/t MCM; and OA.FR, 4 kg/t OA plus 2 kg/t FR. All pigs were challenged for 7 d with 1 mL S. Typh (109 colony forming units daily) at 10 d postweaning. Temperature and fecal samples were collected before and after challenge, and fecal Salmonella shedding quantified. Diarrhea scores were monitored daily and growth performance was evaluated weekly. In vitro, culture with MCM and FR showed significant (P < 0.01) binding affinity for both S. Typh and S. Ent, but not for ETEC F4 and F18. In vivo, pigs fed OA.MCM and OA.FR had lower (P < 0.05) shedding and day 3 peak shedding of S. Typh after infections than pigs fed control and OA.BU diets. Pigs fed OA.FR diet tended to have an 18% increase (P = 0.068) in BW on day 14 post first inoculation compared with control and OA.BU, and 19% increased (P = 0.093) final BW at day 21 compared with control. Diarrhea frequency post infection was overall lower (P = 0.006) for OA.FR (18.9%) than OA.BU (44.8%) and OA.MCM (41.7%) while control (28.7%) was not different. In conclusion, FR and MCM show in vitro-binding affinity to Salmonella enterica serovars Typh and Ent. Feeding FR or MCM combined with OA to nursery pigs reduces the peak and averages S. Typh shedding compared with control. Fermented rye with OA tends to improve pig performance after S. Typh challenge.


Asunto(s)
Alimentación Animal/análisis , Diarrea/veterinaria , Escherichia coli Enterotoxigénica/fisiología , Mananos/farmacología , Salmonelosis Animal/microbiología , Salmonella typhimurium/fisiología , Enfermedades de los Porcinos/microbiología , Animales , Derrame de Bacterias , Dieta , Heces/microbiología , Fermentación , Masculino , Porcinos
4.
PLoS Negl Trop Dis ; 13(12): e0007834, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31869324

RESUMEN

BACKGROUND: Trachoma, a conjunctivitis caused by repeated infections with Chlamydia trachomatis, remains a significant cause of blindness worldwide. While mass treatments with azithromycin decreases disease and infection, re-emergence occurs, indicating that elimination may require other sustainable interventions. Environmental changes largely focus on facial hygiene and latrines, but further work to identify other possible transmission targets are needed. We sought to determine, in a cross-sectional survey of households of children with active trachoma, if we could detect the presence of Chlamydia trachomatis on household objects and on family members based on sleeping and caretaking patterns. METHODS: In five villages in Kongwa, Tanzania, children

Asunto(s)
Derrame de Bacterias , Chlamydia trachomatis/aislamiento & purificación , Microbiología Ambiental , Composición Familiar , Mano/microbiología , Tracoma/microbiología , Preescolar , Estudios Transversales , Transmisión de Enfermedad Infecciosa , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Tanzanía
5.
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
6.
Vet Res ; 50(1): 85, 2019 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-31640784

RESUMEN

The causative agent of ileitis, Lawsonia intracellularis, is commonly associated with diarrhea and reduced weight gain in growing pigs. The effect of in-feed probiotics on L. intracellularis infection dynamics was evaluated. In brief, 70 2.5-week-old-pigs were randomly divided into six groups with 10-20 pigs each. All pigs were fed an age appropriate base ration for the duration of the study, which was supplemented with one of three Bacillus strains including B. amyloliquefaciens (T01), B. licheniformis (T02) and B. pumilus (T03). Another group was orally vaccinated with a commercial live L. intracellularis vaccine (VAC) at 3 weeks of age. At 7 weeks of age, T01-LAW, T02-LAW, T03-LAW, VAC-LAW and the POS-CONTROL groups were challenged with L. intracellularis while the NEG-CONTROL pigs were not challenged. All pigs were necropsied 16 days later. By the time of inoculation, all VAC-LAW pigs had seroconverted and at necropsy 10-65% of the pigs in all other challenged groups were also seropositive. The results indicate a successful L. intracellularis challenge with highest bacterial DNA levels in POS-CONTROL pigs, VAC-LAW pigs and T01-LAW pigs. There was a delay in onset of shedding in T02-LAW and T03-LAW groups, which was reflected in less severe macroscopic and microscopic lesions, reduced intralesional L. intracellularis antigen levels and a lower area under the curve for bacterial shedding. Under the study conditions, two of the probiotics tested suppressed L. intracellularis infection. The obtained findings show the potential of probiotics in achieving antibiotic-free control of L. intracellularis.


Asunto(s)
Bacillus pumilus/química , Derrame de Bacterias/efectos de los fármacos , Infecciones por Desulfovibrionaceae/veterinaria , Lawsonia (Bacteria)/efectos de los fármacos , Probióticos/farmacología , Enfermedades de los Porcinos/tratamiento farmacológico , Alimentación Animal/análisis , Animales , Bacillus amyloliquefaciens/química , Bacillus licheniformis/química , Infecciones por Desulfovibrionaceae/tratamiento farmacológico , Infecciones por Desulfovibrionaceae/microbiología , Infecciones por Desulfovibrionaceae/patología , Dieta/veterinaria , Lawsonia (Bacteria)/fisiología , Distribución Aleatoria , Porcinos , Enfermedades de los Porcinos/microbiología , Enfermedades de los Porcinos/patología
7.
Prev Vet Med ; 170: 104727, 2019 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-31421493

RESUMEN

Leptospira infection in dairy cattle and leptospirosis in dairy farm workers were common in New Zealand prior to the introduction of dairy cattle vaccination in the 1980s. Despite widespread vaccination within the dairy industry, the long-term effectiveness of vaccination and current Leptospira exposure status remained unknown. A cross-sectional study was conducted from January-April 2016 to investigate the prevalence of pathogenic Leptospira spp. DNA in urine at cow and herd level, and its relationship to five Leptospira serovars known to be endemic. Two hundred dairy farms were randomly selected from the national database. Twenty paired blood and urine samples were collected on each farm from adult cows (n = 4000). Sera were tested using the Microscopic Agglutination Test against serovars Hardjobovis (termed Hardjo), Pomona, Copenhageni, Ballum and Tarassovi with titres ≥48 being considered positive. Urine was tested using quantitative real-time PCR (qPCR) that amplifies the gryB gene. All but one herd had been vaccinated with a bivalent Hardjo/Pomona or trivalent vaccine incorporating Copenhageni. In total, 2.4% of cows were urine qPCR positive and 27% of farms had at least one urine qPCR positive cow. Overall 63% of cows were seropositive to one or more serovars: 44% for Hardjo, 28% for Pomona, 15% for Copenhageni (in vaccinated herds), and for unvaccinated cows: 1% for Copenhageni, and 3% for Ballum and 17% for Tarassovi. Of the 94 qPCR urine-positive cows, 51 were seropositive to Tarassovi, 3 to Ballum, 3 to Copenhageni, 24 to Hardjo, and 17 to Pomona, the latter two presumably reflecting vaccination titres. A strong association was found between shedding and serology for Tarassovi. While there was no evidence that current vaccination programmes were ineffective in protecting against their target serovars, serovar Tarassovi has apparently emerged in NZ dairy cattle. As Tarassovi is currently not included in vaccines and is prevalent in notified leptospirosis cases in dairy workers, we concluded that this serovar poses a public health risk.


Asunto(s)
Derrame de Bacterias , Enfermedades de los Bovinos/epidemiología , Agricultores/estadística & datos numéricos , Leptospira/fisiología , Leptospirosis/veterinaria , Animales , Bovinos , Enfermedades de los Bovinos/microbiología , Estudios Transversales , Industria Lechera , Femenino , Humanos , Leptospirosis/epidemiología , Leptospirosis/microbiología , Leptospirosis/orina , Nueva Zelanda/epidemiología , Reacción en Cadena de la Polimerasa/veterinaria , Prevalencia , Medición de Riesgo , Estudios Seroepidemiológicos
8.
Vet Res ; 50(1): 58, 2019 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-31362780

RESUMEN

Human cases of salmonellosis are frequently liked with the consumption of contaminated table eggs. Recently, there has been an increase in consumer demand for cage-free eggs precipitating the need for a greater understanding of Salmonella dynamics in free-range production systems. A longitudinal study was conducted to determine the points in production where birds are most likely to be exposed to Salmonella and where the risk of egg contamination is highest. In this study, two free-range flocks were sampled from hatch to the end of production. At hatch, all chicks were Salmonella negative and remained negative during rearing. During production, the proportion of positive samples was low on both farms. Salmonella positive samples were detected intermittently for Flock A. Dust, nest box, and egg belt swabs had the highest proportion of positive samples and highest overall loads of Salmonella. The egg grading floor was swabbed at different points following the processing of eggs from Flock A. Only the suction cups that handle eggs prior to egg washing tested positive for Salmonella. Swabs collected from machinery handling eggs after washing were Salmonella negative. During production, positive samples from Flock B were observed at only single time point. Dust has been implicated as a source of Salmonella that can lead to flock to flock contamination. Bulk dust samples were collected and tested for Salmonella. The proportion of positive dust samples was low and is likely due to physical parameters which are not likely to support the survival of Salmonella in the environment.


Asunto(s)
Crianza de Animales Domésticos , Derrame de Bacterias , Pollos , Enfermedades de las Aves de Corral/epidemiología , Salmonelosis Animal/epidemiología , Salmonella/fisiología , Crianza de Animales Domésticos/métodos , Animales , Australia/epidemiología , Estudios Longitudinales , Óvulo/microbiología , Enfermedades de las Aves de Corral/microbiología , Prevalencia , Factores de Riesgo , Salmonelosis Animal/microbiología
9.
Vet Immunol Immunopathol ; 214: 109890, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31378218

RESUMEN

Bovine mastitis is a significant cause of economic losses in the dairy industry. Staphylococcus aureus is one of the most common contagious mastitis pathogens, whereas Staphylococcus chromogenes increasingly became a significant cause of subclinical mastitis in dairy cows. Current mastitis control measures are not effective on all mastitis pathogens. There is no effective vaccine to control Staphylococcal mastitis in dairy cows. The objective of this study was to evaluate the immune responses and protection in dairy cows vaccinated with S. aureus surface proteins (SASP) or S. chromogenes surface proteins (SCSP). We divided eighteen Holstein dairy cows randomly into three groups of 6 animals each. We vaccinated group 1 and 2 animals with SASP and SCSP with Emulsigen-D adjuvant, respectively. We injected control (group 3) animals with PBS (pH 7.2) in Emulsigen®-D. We vaccinated animals three times at 28 and 14 days before drying off, and at dry off. Two weeks after the third vaccination, we challenged each animal by dipping all teats in S. aureus culture suspension once daily for 14 consecutive days. We evaluated milk or mammary secretion and serum antibody titers during vaccination and challenge periods. We evaluated milk samples for the number of bacteria shedding and somatic cell counts (SCC). Out of six cows vaccinated with SASP, one cow was removed from the study due to injury, two were infected clinically, another two were infected subclinically, and the remaining cow was not infected. No SCSP vaccinated cows developed clinical or subclinical mastitis. Out of six control cows, two developed clinical mastitis whereas four were infected subclinically. The SCSP vaccine cross-protected against S. aureus mastitis and reduced number of S. aureus shedding in milk. We concluded that the SCSP is a promising vaccine to control Staphylococcal mastitis in dairy cows.


Asunto(s)
Mastitis Bovina/prevención & control , Proteínas de la Membrana/inmunología , Infecciones Estafilocócicas/veterinaria , Vacunas Estafilocócicas/inmunología , Staphylococcus aureus/inmunología , Animales , Derrame de Bacterias , Bovinos , Recuento de Células , Industria Lechera , Femenino , Proteínas de la Membrana/administración & dosificación , Leche/microbiología , Infecciones Estafilocócicas/inmunología , Infecciones Estafilocócicas/prevención & control , Vacunación
10.
J Dairy Sci ; 102(10): 9117-9137, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31378491

RESUMEN

Mycobacterium avium ssp. paratuberculosis (MAP) is the etiological agent of paratuberculosis, a disease that affects ruminants worldwide. Despite global interest in the control of this disease, gaps exist in our knowledge of fecal shedding patterns and concurrent serological patterns. This longitudinal study in dairy cattle herds with high MAP seroprevalence in France aimed at accurately describing fecal shedding patterns over 1 year; relating those shedding patterns to individual animal characteristics (age, breed, parity); and exploring the association between fecal shedding patterns and serological patterns. To describe temporal fecal shedding patterns and continuity of shedding, along with the standard quantitative PCR (qPCR) threshold cycle we used a cutoff value that related to low or nonculturable fecal shedding. We also defined a threshold cycle indicative of shedding in high quantities to describe infection progression patterns. Twenty-one herds completed the study, and 782 cows were tested 4 times each. We obtained 4 sets of paired fecal qPCR and serum ELISA results from 757 cows. Although we targeted highly likely infectious animals, we found a large diversity of shedding patterns, as well as high variability between herds in the proportion of animals showing a given pattern. The fecal qPCR results of almost 20% of the final study sample were positioned at least once in the range that indicated low or nonculturable fecal shedding (between the adjusted and the standard cutoff value). Although these animals would typically be classified as non-shedders, they could be important to infection dynamics on the farm. Animals that shed at least twice consecutively and animals that shed in high quantities rarely reverted to negativity. Repeated fecal qPCR can be used to detect temporal fecal shedding traits, and the decision to cull an animal could practically be based on temporal, semiquantitative results. Overall, we found a mismatch between fecal shedding and ELISA seropositivity (637 animals were ELISA-negative 4 times, but only 13% of those animals were qPCR-negative 4 times). We found that having more than 2 ELISA-positive samples was strongly related to persistent and continuous shedding. We suggest that although serological testing is much less sensitive than qPCR, it can also be used, particularly over the course of multiple testing events, to identify animals that are most likely to contribute to the contamination of the farm environment.


Asunto(s)
Derrame de Bacterias , Enfermedades de los Bovinos/microbiología , Mycobacterium avium subsp. paratuberculosis , Paratuberculosis/microbiología , Animales , Bovinos , Ensayo de Inmunoadsorción Enzimática/veterinaria , Heces/microbiología , Femenino , Francia , Estudios Longitudinales , Mycobacterium avium subsp. paratuberculosis/inmunología , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Estudios Seroepidemiológicos
11.
J Anim Sci ; 97(9): 3636-3647, 2019 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-31260524

RESUMEN

It was shown previously that high dietary fiber (DF) and immune system stimulation (ISS) with systemic Escherichia coli lipopolysaccharide independently increased the threonine (Thr) requirement to maximize growth performance and protein deposition (PD). However, no additive effects on the Thr requirement were observed when both DF and ISS were present. The objective of the present study was to investigate whether supplementing Thr to meet previously estimated requirements for high DF and systemic immune challenge would maintain performance of pigs exposed to an enteric immune challenge when fed high DF. A total of 128 pigs (22.6 ± SD = 1.6 kg initial BW) were assigned to 1 of 4 dietary treatments in a 2 × 2 factorial arrangement in a randomized complete block design (n = 8 pens/treatment and 4 pigs/pen) for 28 d. Treatments were a low-fiber (LF; 13% total DF) or high-fiber (HF; 20% total DF) diet with either a standard (STD; 0.65% SID) or supplemental (SUP; 0.78% SID) Thr level. After a 7-d adaptation, pigs were orally inoculated with 2 mL (2.3 × 109 CFU/mL) of Salmonella typhimurium (ST). Blood samples and rectal swabs were obtained and rectal temperature recorded to determine clinical responses and ST shedding. On day 7 postinoculation, 1 pig/pen was euthanized and mesenteric lymph nodes, spleen, and digesta (ileum, cecum, and colon) were sampled to assess ST colonization and translocation. Body weight and feed intake were recorded on day 0, 7, and 21 postinoculation to calculate ADG, ADFI, and G:F. Rectal temperature increased (P < 0.05) 24 h postinoculation and remained elevated at day 6. Serum albumin concentration decreased (P < 0.05), whereas haptoglobin concentration increased (P < 0.05) postinoculation. There was no fiber or Thr effect (P > 0.05) on ST counts in the ileum and cecum, but a fiber × Thr interaction (P < 0.05) was observed in the colon. Supplemental Thr improved (P < 0.05) growth performance in LF- and HF-fed challenged pigs. However, performance of supplemented HF challenged pigs was less than (P < 0.05) supplemented LF challenged pigs. These results suggest that Thr supplemented to meet requirements for high DF and systemic immune challenge was not sufficient to maintain growth performance of pigs fed HF diets and challenged with an enteric pathogen.


Asunto(s)
Fibras de la Dieta/metabolismo , Suplementos Dietéticos , Salmonella typhimurium/fisiología , Porcinos/crecimiento & desarrollo , Treonina/farmacología , Animales , Derrame de Bacterias/efectos de los fármacos , Dieta/veterinaria , Tracto Gastrointestinal/metabolismo , Salmonella typhimurium/inmunología , Porcinos/inmunología , Porcinos/microbiología
12.
Can J Vet Res ; 83(3): 177-180, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31308589

RESUMEN

The objective of this study was to assess the impact of in-feed flavophospholipol on Salmonella shedding and antibody response in nursery pigs. Weaned pigs were fed either a diet containing 4 ppm flavophospholipol (n = 16) or a non-medicated feed (n = 16) for 36 d. All pigs were orally challenged with a 2-mL dose of 108 colony-forming units (CFUs)/mL of Salmonella Typhimurium on Days 7 and 8 of the trial. On Day 36, all pigs were euthanized and samples were collected from the liver, spleen, and ileocecal lymph nodes. Fecal and tissue samples were quantitatively cultured for Salmonella and serum samples were tested for the presence of the Salmonella antibody by enzyme-linked immunosorbent assay (ELISA). There was no difference between the 2 groups in antibody response and the presence of Salmonella in feces and tissue (P > 0.05). Medicating nursery diets with flavophospholipol at 4 ppm did not appear to reduce Salmonella infection in nursery pigs.


Asunto(s)
Alimentación Animal/análisis , Derrame de Bacterias/efectos de los fármacos , Bambermicinas/farmacología , Salmonelosis Animal/prevención & control , Salmonella typhimurium , Enfermedades de los Porcinos/microbiología , Animales , Dieta/veterinaria , Porcinos , Enfermedades de los Porcinos/prevención & control
13.
BMC Vet Res ; 15(1): 195, 2019 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-31186019

RESUMEN

BACKGROUND: MicroRNAs are involved in a broad range of biological processes and are known to be differentially expressed in response to bacterial pathogens. RESULTS: The present study identified microRNA responses in porcine peripheral blood after inoculation with the human foodborne pathogen Salmonella enterica serovar Typhimurium strain LT2. We compared the microRNA transcriptomes of the whole blood of pigs (Duroc × Landrace × Yorkshire) at 2-days post inoculation and before Salmonella infection. The analysis identified a total of 29 differentially expressed microRNAs, most of which are implicated in Salmonella infection and immunology signaling pathways. Joint analysis of the microRNA and mRNA transcriptomes identified 24 microRNAs with binding sites that were significantly enriched in 3' UTR of differentially expressed mRNAs. Of these microRNAs, three were differentially expressed after Salmonella challenge in peripheral blood (ssc-miR-146a-5p, ssc-miR-125a, and ssc-miR-129a-5p). Expression of 23 targets of top-ranked microRNA, ssc-miR-146a-5p, was validated by real-time PCR. The effects of miR-146a, IFN-γ, and IL-6 on the regulation of fecal bacteria shedding counts in pigs were investigated by in vivo study with a Salmonella challenge model. CONCLUSIONS: The results indicated that induction of miR-146a in peripheral blood could significantly increase the fecal bacterial load, whereas IFN-γ had the reverse effect. These microRNAs can be used to identify targets for controlling porcine salmonellosis.


Asunto(s)
Derrame de Bacterias/inmunología , MicroARNs/metabolismo , Salmonelosis Animal/inmunología , Enfermedades de los Porcinos/inmunología , Animales , Heces/microbiología , Femenino , Interferón gamma/metabolismo , Interleucina-6/metabolismo , Masculino , ARN Mensajero/metabolismo , Salmonelosis Animal/microbiología , Salmonella typhimurium/inmunología , Transducción de Señal , Sus scrofa , Porcinos , Enfermedades de los Porcinos/microbiología , Transcriptoma
14.
Zoonoses Public Health ; 66(6): 618-621, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31187579

RESUMEN

The objectives of this study were to determine the prevalence and characteristics of Clostridium difficile shedding in owned dogs in Nigeria and Malawi. Clostridium difficile was isolated from 31/120 (26%) dogs in Nigeria and 11/92 (12%) dogs in Malawi (p = 0.012). Overall, 22/42 (52%) isolates were toxigenic; 17/31 (55%) from Nigeria and 5/11 (45%) from Malawi. All toxigenic isolates possessing tcdA and tcdB, and only one also possessed cdtA/B. Sixteen different ribotypes were found, ten (63%) of which were non-toxigenic. Most isolates corresponded to ribotypes that have been previously identified in humans or livestock. The role of dogs in transmission of C. difficile and the clinical implications of C. difficile shedding in dogs remain unclear. These data indicate that dogs could act as a source of C. difficile for exposure of other species, including humans; however, the true risk is unknown. Further study of the ecology of C. difficile and the role of dogs in disease of humans and other domestic animals is indicated.


Asunto(s)
Derrame de Bacterias , Clostridium difficile/aislamiento & purificación , Perros/microbiología , Animales , Clostridium difficile/clasificación , Heces/microbiología , Malaui , Nigeria
15.
Zoonoses Public Health ; 66(6): 562-578, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31179637

RESUMEN

Livestock meat and offal contribute significantly to human nutrition as sources of high-quality protein and micronutrients. Livestock products are increasingly in demand, particularly in low- and middle-income settings where economies are growing and meat is increasingly seen as an affordable and desirable food item. Demand is also driving intensification of livestock keeping and processing. An unintended consequence of intensification is increased exposure to zoonotic agents, and a contemporary emerging problem is infection with Campylobacter and Salmonella spp. from livestock (avian and mammalian), which can lead to disease, malabsorption and undernutrition through acute and chronic diarrhoea. This can occur at the farm, in households or through the food chain. Direct infection occurs when handling livestock and through bacteria shed into the environment, on food preparation surfaces or around the house and surroundings. This manuscript critically reviews Campylobacter and Salmonella infections in animals, examines the factors affecting colonization and faecal shedding of bacteria of these two genera as well as risk factors for human acquisition of the infection from infected animals or environment and analyses priority areas for preventive actions with a focus on resource-poor settings.


Asunto(s)
Derrame de Bacterias , Infecciones por Campylobacter/veterinaria , Campylobacter/aislamiento & purificación , Infecciones por Salmonella/microbiología , Salmonella/aislamiento & purificación , Zoonosis , Animales , Infecciones por Campylobacter/microbiología , Humanos , Infecciones por Salmonella/transmisión
16.
J Immunoassay Immunochem ; 40(4): 419-438, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31154897

RESUMEN

Brucellosis constitutes an infectious re-emerging zoonosis. Spread of diseases could be exacerbated by stress-induced immunosuppression. This study evaluated relationship between Brucella melitensis infection, shedding dynamics, dexamethasone-induced stress, pathological alterations and resveratrol ameliorative effects in goats. Twelve nonpregnant goats were divided into four groups A, B, C, and D of three animals each. Groups A and B were administered 107 CFU/mL of B. melitensis ocularly, 21 days prior to 7 days consecutive administration of dexamethasone (2 mg/kg). Group A was further administered resveratrol (5 mg/kg) intravenously for 5 consecutive days from day 31 post B. melitensis inoculation. Group C was administered similar dose of B. melitensis while group D was inoculated normal saline. Blood, nasal, ocular, and vaginal swabs were collected at intervals for analysis. The does were sacrificed at day 42 post inoculation (pi). Tissues were collected for tissue bacterial load determination, histopathology, and immunohistochemistry. Dexamethasone administration from day 21 pi increased the frequency in the shedding dynamics, tissue bacterial load, pathological alterations (frequency of microgranuloma and intensity of immunostaining) in group B while 5 days treatment with resveratrol following dexamethasone administration significantly reduced tissue bacterial load, decline in shedding dynamics, and ameliorate damage by dexamethasone administration/B. melitensis infection.


Asunto(s)
Antiinflamatorios/farmacología , Derrame de Bacterias/efectos de los fármacos , Brucella melitensis/efectos de los fármacos , Brucelosis/tratamiento farmacológico , Dexametasona/farmacología , Resveratrol/farmacología , Animales , Antiinflamatorios/administración & dosificación , Brucelosis/patología , Dexametasona/administración & dosificación , Femenino , Cabras , Inyecciones Intravenosas , Resveratrol/administración & dosificación
17.
Microb Pathog ; 134: 103577, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31176881

RESUMEN

In the present study, the spectrum of bacterial pathogens in the nasal shedding during disease process and in pneumonic lungs of dead animals was studied. A total of 288 clinical samples from cattle and buffaloes comprising of nasal swabs, blood, tracheal swabs, heart blood and lung tissue samples were collected from diseased (n = 190) and dead animals (n = 98). The recovered bacterial isolates were characterized by biochemical reactions, Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI TOF-MS) and the 16S rRNA sequence analysis. The predominant bacterial isolates associated were Pasteurella multocida, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus. The emerging pathogens causing bovine pneumonia identified were Leclercia spp., Stenotrophononas maltophila and Staphylococcus sciuri. Bacteriological examination of pneumonic lungs samples revealed 96.9% samples to be positive for polymicrobial isolation. Macroscopical lesions of lungs exhibited various stages and types of pneumonia with variable degree of haemorrhages, oedema and emphysema. Histopathologically, the fibrinous bronchopneumonia was observed to be the most frequent lesions seen in bovine pneumonia. Multi-drug resistance (MDR) was observed in 10% of P. multocida isolates. The resistance was seen for penicillin, cephalosporins and fluoroquinolones. Multi-drug resistance was seen in 90% of the E.coli tested. K. pneumoniae, E. hormaechei, E. cloacae, P. putida and Leclercia spp. identified were found to be multi-drug resistant. Understanding the etiological diversity of bacterial pathogens of bovine pneumonia may provide information for the better choice of therapeutics and health management.


Asunto(s)
Bacterias/clasificación , Bacterias/crecimiento & desarrollo , Bacterias/aislamiento & purificación , Enfermedades de los Bovinos/microbiología , Pulmón/microbiología , Microbiota , Neumonía/microbiología , Animales , Antibacterianos/farmacología , Bacterias/genética , Derrame de Bacterias/efectos de los fármacos , Técnicas de Tipificación Bacteriana , Búfalos , Bovinos , Farmacorresistencia Bacteriana Múltiple , Pulmón/patología , Pruebas de Sensibilidad Microbiana , Microbiota/genética , Filogenia , ARN Ribosómico 16S/genética
18.
mBio ; 10(3)2019 06 18.
Artículo en Inglés | MEDLINE | ID: mdl-31213554

RESUMEN

Host-to-host transmission is a necessary but poorly understood aspect of microbial pathogenesis. Herein, we screened a genomic library of mutants of the leading respiratory pathogen Streptococcus pneumoniae generated by mariner transposon mutagenesis (Tn-Seq) to identify genes contributing to its exit or shedding from the upper respiratory tract (URT), the limiting step in the organism's transmission in an infant mouse model. Our analysis focused on genes affecting the bacterial surface that directly impact interactions with the host. Among the multiple factors identified was the dlt locus, which adds d-alanine onto lipoteichoic acids (LTA) and thereby increases Toll-like receptor 2-mediated inflammation and resistance to antimicrobial peptides. The more robust proinflammatory response in the presence of d-alanylation promotes secretions that facilitate pneumococcal shedding and allows for transmission. Expression of the dlt locus is controlled by the CiaRH system, which senses cell wall stress in response to antimicrobial activity, including in response to lysozyme, the most abundant antimicrobial along the URT mucosa. Accordingly, in a lysM-/- host, there was no longer an effect of the dlt locus on pneumococcal shedding. Thus, our findings demonstrate how a pathogen senses the URT milieu and then modifies its surface characteristics to take advantage of the host response for transit to another host.IMPORTANCE Streptococcus pneumoniae (the pneumococcus) is a common cause of respiratory tract and invasive infection. The overall effectiveness of immunization with the organism's capsular polysaccharide depends on its ability to block colonization of the upper respiratory tract and thereby prevent host-to-host transmission. Because of the limited coverage of current pneumococcal vaccines, we carried out an unbiased in vivo transposon mutagenesis screen to identify pneumococcal factors other than its capsular polysaccharide that affect transmission. One such candidate was expressed by the dlt locus, previously shown to add d-alanine onto the pneumococcal lipoteichoic acid present on the bacterial cell surface. This modification protects against host antimicrobials and augments host inflammatory responses. The latter increases secretions and bacterial shedding from the upper respiratory tract to allow for transmission. Thus, this study provides insight into a mechanism employed by the pneumococcus to successfully transit from one host to another.


Asunto(s)
Proteínas Bacterianas/genética , Derrame de Bacterias , Inflamación , Infecciones Neumocócicas/inmunología , Infecciones Neumocócicas/transmisión , Sistema Respiratorio/microbiología , Streptococcus pneumoniae/genética , Alanina/metabolismo , Animales , Animales Recién Nacidos , Elementos Transponibles de ADN , Modelos Animales de Enfermedad , Biblioteca Genómica , Interacciones Huésped-Patógeno/inmunología , Lipopolisacáridos/metabolismo , Ratones , Ratones Endogámicos C57BL , Mutagénesis , Streptococcus pneumoniae/inmunología , Ácidos Teicoicos/metabolismo
19.
Vet Res ; 50(1): 45, 2019 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-31215485

RESUMEN

Field studies on Salmonella infection in suckling piglets are scarce due to the intrinsic difficulties of collecting proper samples (i.e. tonsils or mesenteric lymph nodes), and most of them rely on the analysis of rectal swabs that limit their accuracy. We used 495 slaughtered 4-weeks-old male piglets intended for human consumption from 5 Salmonella-seropositive breeding farms to collect gastrointestinal packages and perform a thorough detection of Salmonella on mesenteric lymph nodes and intestinal content. The overall prevalence of both infection and shedding was high (≈ 36%) indicating that piglets played an active role in Salmonella maintenance in the farms. Major serotypes found in piglets included 4,[5],12:i: (35.4%), Rissen (17.1%), Derby (10.9%) and Bovismorbificans (10.3%). In most of the infected animals (72.8%) the same serotype was found in mesenteric lymph nodes and feces. Significant higher ELISA OD% values were found in meat juice samples from non-infected piglets compared to infected ones (median OD% of 12.0 and 17.3, respectively; P = 0.002) suggesting some protective effect of sow's colostrum. Salmonella was also isolated from feces from weaned sows contemporary of the slaughtered piglets, and 89% of the serotypes identified in sows were also detected in piglets. Pulsed field gel electrophoresis analyses showed that 75% of the piglet isolates that were compared to those of sows were related to them, suggesting the circulation of Salmonella strains between sows and piglets. It appears that improving piglet colostrum intake along with the reduction of the shedding in sows may favor the control of Salmonella infection in breeding farms.


Asunto(s)
Derrame de Bacterias , Salmonelosis Animal/epidemiología , Salmonella/fisiología , Enfermedades de los Porcinos/epidemiología , Destete , Animales , Intestinos/microbiología , Ganglios Linfáticos/microbiología , Masculino , Prevalencia , Salmonelosis Animal/prevención & control , Salmonelosis Animal/transmisión , Estudios Seroepidemiológicos , España/epidemiología , Sus scrofa , Porcinos , Enfermedades de los Porcinos/prevención & control , Enfermedades de los Porcinos/transmisión
20.
Vet Microbiol ; 231: 1-6, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30955794

RESUMEN

Neonatal porcine diarrhea (NPD) is a current problem on pig farms and is caused by several enteropathogens. Among them, Clostridioides difficile stands out due to its importance in piglets and zoonotic potential. A non-toxigenic strain of C. difficile (NTCD), named Z31, was previously tested in hamster and piglet experimental models as a strategy to prevent C. difficile infection (CDI). To evaluate the capacity of the strain Z31 to prevent CDI and NPD in one-day-old piglets on a commercial farm, 90 piglets from 16 litters received 1 × 106 spores of Z31 while 84 animals from the same litters served as controls. Animals were clinically evaluated, and fecal samples were collected 24 h after administration and submitted to A/B toxin detection and isolation of C. difficile. Stool samples were also submitted to rotavirus, Escherichia coli, and Clostridium perfringens detection. Administration of Z31 reduced the incidence of CDI in treated animals (7.8%) when compared to the control group (25.0%; P = 0.003). In animals that developed CDI, the intensity of diarrhea was lower in those that received Z31 than in the control group. Neonatal porcine diarrhea was reduced in treated animals when compared to untreated animals (P < 0.001). The present study suggests that Z31 can potentially be used to prevent CDI in piglets on commercial farms.


Asunto(s)
Infecciones por Clostridium/prevención & control , Clostridium difficile/fisiología , Clostridium difficile/patogenicidad , Diarrea/veterinaria , Enfermedades de los Porcinos/microbiología , Animales , Animales Recién Nacidos , Derrame de Bacterias , Infecciones por Clostridium/microbiología , Clostridium perfringens/aislamiento & purificación , Diarrea/microbiología , Diarrea/prevención & control , Escherichia coli Enterotoxigénica/aislamiento & purificación , Granjas , Heces/microbiología , Porcinos , Enfermedades de los Porcinos/prevención & control
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