RESUMO
We conducted a retrospective cohort study to evaluate risk factors associated with clinical mastitis in dairy cows in southern Chile between the first milk test after calving to 200 d in milk (DIM). Data from 8,772 cows were collected from June 2017 to November 2019 on 10 dairy farms selected by convenience in southern Chile. Data were analyzed using a multivariable mixed logistic regression using a manual backward selection process with logit link function and farm as a random effect. The dependent variable was clinical mastitis between the first milking sample collected by monthly milk sampling program up to 200 DIM. Days in milk, fat, urea, parity, season, and somatic cell counts were statistically associated with clinical mastitis in the first 200 d in milk. Cows with higher than average milk yield, parity, urea, and somatic cell count were at greater odds of being diagnosed with clinical mastitis compared with their respective referents. In contrast, higher milk fat was associated with lower odds of clinical mastitis. Significant interactions between days in milk with season and parity were observed, where for every 5-d increase in DIM, the odds of clinical mastitis decreased by different proportions depending on the interaction. Identified risk factors for clinical mastitis using first monthly milk sampling data can help dairy farmers in Chile implement herd-level mastitis prevention and control measures.
Assuntos
Mastite Bovina , Animais , Bovinos , Contagem de Células/veterinária , Chile/epidemiologia , Indústria de Laticínios , Fazendas , Feminino , Humanos , Lactação , Mastite Bovina/tratamento farmacológico , Leite , Gravidez , Estudos Retrospectivos , Fatores de Risco , UreiaRESUMO
This research aims to investigate the presence and pathogenic potential of Arcobacter in poultry meat samples purchased in the retail market of Valdivia (South of Chile) as well as in faecal samples from backyard chickens from rural areas around this city. The isolates obtained were identified by molecular methods. Furthermore, putative virulence genes were assessed by PCR and the antimicrobial resistance was tested by phenotypic methods. Arcobacter was present in 41·6% of the samples, with the highest value in retail poultry meat (55·7%) followed by backyard production (28·0%). Arcobacter butzleri was the most prevalent species (75·6%) followed by Arcobacter skirrowii (14·8%) and Arcobacter cryaerophilus (9·6%). An 8·5% of A. butzleri strains from meat were resistant to both ciprofloxacin and tetracycline and 6·1% were resistant to erythromycin, while none was resistant to gentamycin, unlike strains from domestic chickens, which showed no resistance. Furthermore, A. butzleri strains from chicken meat presented a higher prevalence of virulence genes than strains from domestic chickens. In fact, in this last group, some genes (hecA, hecB and irgA) were completely absent. Therefore, this study provides insight on the epidemiology of Arcobacter in Chilean poultry and suggests that under traditional breeding conditions strains are, apparently, less pathogenic and drug resistant.
Assuntos
Antibacterianos/farmacologia , Arcobacter/efeitos dos fármacos , Galinhas/microbiologia , Farmacorresistência Bacteriana/genética , Infecções por Bactérias Gram-Negativas/veterinária , Animais , Arcobacter/isolamento & purificação , Chile/epidemiologia , Ciprofloxacina/farmacologia , Eritromicina/farmacologia , Fezes/microbiologia , Microbiologia de Alimentos , Gentamicinas/farmacologia , Infecções por Bactérias Gram-Negativas/epidemiologia , Carne/microbiologia , Reação em Cadeia da Polimerase , Aves Domésticas/microbiologia , Prevalência , Tetraciclina/farmacologia , Virulência , Fatores de Virulência/genéticaRESUMO
Although, antibiotics are effective in the treatment of bovine mastitis, they do not address the regeneration of mammary glandular tissue and have been associated to the increment in antimicrobial resistance worldwide. Considering the necessity of alternative therapies for this disease of high economic impact and the reported regenerative and antibacterial effects of mesenchymal stem cell (MSCs), we evaluated the safety and efficacy of an allogenic MSC-based intramammary therapy in dairy cows with experimentally induced Staphylococcus aureus clinical mastitis. In a safety trial, heifers were inoculated intramammarily with a 2.5 × 107-suspension of bovine fetal AT-MSCs on experimental days 1 and 10. Animals were evaluated clinically on a daily basis during a 20-day experimental period and blood samples were collected for hemogram determination and peripheral blood leukocytes (PBLs) isolation. In an efficacy trial, Holstein Friesian cows were inoculated with S. aureus and treated intramammarily with vehicle (NEG; days 4 and 10), antibiotics (ATB; days 4 and 5) or a suspension of 2.5 × 107 AT-MSCs (MSC; days 4 and 5). Cows were clinically evaluated daily and milk samples were collected for somatic cell count (SCC) and colony forming units (CFU). Blood samples were collected for serum haptoglobin and amyloid A determination. Intramammary administration of two doses of bovine fetal AT-MSCs in healthy cows did not induce changes in clinical or hematological variables, and gene expression profiles in PBLs associated to activation (CD4, CD8, CD25, CD62L and CD69) and proinflammatory cytokines (CCL2, CCL5, IL2, CXCL3, IFNγ, and TNFα). Quarters of MSC group of cows had similar SCC log/mL in milk compared to infected quarters of ATB or NEG cows. However, quarters of MSC cows had lower CFU log/mL in milk compared to quarters of NEG cows. Intramammarily inoculation of repeated doses of 2.5 × 107 allogenic AT-MSCs did not induce clinical or immunological response in healthy cows. Moreover, MSC-intramammary treatment reduced bacterial count in milk of cows with S. aureus clinical mastitis compared to untreated cows. This work provides initial evidence for the safety and efficacy of an allogenic MSC-based intramammary therapy for the treatment of bovine mastitis.
Assuntos
Terapia Baseada em Transplante de Células e Tecidos , Mastite Bovina/terapia , Células-Tronco Mesenquimais/citologia , Infecções Estafilocócicas/terapia , Animais , Bovinos , Feminino , Lactação/fisiologia , Glândulas Mamárias Animais/microbiologia , Glândulas Mamárias Animais/patologia , Mastite Bovina/microbiologia , Mastite Bovina/patologia , Transplante de Células-Tronco Mesenquimais , Leite/microbiologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/patologia , Staphylococcus aureus/patogenicidadeRESUMO
BACKGROUND: Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of paratuberculosis, a contagious infectious disease that affects domestic and wild ruminants causing chronic inflammation of the intestine. MAP has proven to be very resistant to both physical and chemical processes, making it difficult to control this pathogen. Based on the recognized antimicrobial properties of copper, the objective of this study was to evaluate the effectiveness of copper ions to reduce MAP numbers and/or MAP viability in a fluid matrix. Besides, methicillin-resistant Staphylococcus aureus (MRSA), and Escherichia coli were used as controls of the effectiveness of copper ions. MAP-spiked PBS was subjected to copper ions treatment at 24 V for 5 min and the PBS suspensions were sampled before and after treatment. MAP viability and quantification were determined using three complementary techniques: a phage amplification assay, MGIT culture and qPCR. RESULTS: Moderate numbers (103 CFU ml-1) of the two control bacteria were completely eliminated by treatment with copper ions. For MAP, copper ions treatment reduced both the viability and numbers of this pathogen. Phage assay information quickly showed that copper ions (24 V for 5 min) resulted in a significant reduction in viable MAP. MGIT culture results over time showed statistically significant differences in time-to-detection (TTD) values between PRE and POST treatment. MAP genome equivalent estimates for PBS suspensions indicated that MAP numbers were lower in samples POST-treatment with copper ions than PRE-treatment. CONCLUSIONS: The use of copper ions resulted in a significant reduction of MAP in a liquid matrix, although some MAP survival on some occasions was observed.
Assuntos
Cobre/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Mycobacterium avium subsp. paratuberculosis/efeitos dos fármacos , Bacteriófagos/efeitos dos fármacos , Bacteriófagos/genética , Soluções Tampão , Contagem de Colônia Microbiana , Escherichia coli/efeitos dos fármacos , Genoma Bacteriano/genética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Mycobacterium avium subsp. paratuberculosis/genética , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Paratuberculosis, an infectious disease of domestic and wild ruminants caused by Mycobacterium avium subsp. paratuberculosis (Map), is an economically important disease in dairy herds worldwide. In Chile the disease has been reported in domestic and wildlife animals. However, accurate and updated estimations of the herd-prevalence in cattle at national or regional level are not available. The objectives of this study were to determine the herd-level prevalence of dairy herds with Map infected animals of Southern Chile, based on two diagnostic tests: culture of environmental fecal samples and bulk-tank milk qPCR. Two composite environmental fecal samples and one bulk-tank milk sample were collected during September 2010 and September 2011 from 150 dairy farms in Southern Chile. Isolation of Map from environmental fecal samples was done by culture of decontaminated samples on a commercial Herrold's Egg Yolk Medium (HEYM) with and without mycobactin J. Suspicious colonies were confirmed to be Map by conventional IS900 PCR. Map detection in bulk-tank milk samples was done by real time IS900 PCR assay. PCR-confirmed Map was isolated from 58 (19.3%) of 300 environmental fecal samples. Holding pens and manure storage lagoons were the two more frequent sites found positive for Map, representing 35% and 33% of total positive samples, respectively. However, parlor exits and cow alleyways were the two sites with the highest proportion of positive samples (40% and 32%, respectively). Herd prevalence based on environmental fecal culture was 27% (true prevalence 44%) compared to 49% (true prevalence 87%) based on bulk-tank milk real time IS900 PC. In both cases herd prevalence was higher in large herds (>200 cows). These results confirm that Map infection is wide spread in dairy herds in Southern Chile with a rough herd-level prevalence of 28-100% depending on the herd size, and that IS900 PCR on bulk-tank milk samples is more sensitive than environmental fecal culture to detect Map-infected dairy herds.
Assuntos
Doenças dos Bovinos/epidemiologia , Mycobacterium avium subsp. paratuberculosis/isolamento & purificação , Paratuberculose/epidemiologia , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Chile/epidemiologia , Contagem de Colônia Microbiana/veterinária , Indústria de Laticínios , Fezes/microbiologia , Feminino , Leite/microbiologia , Paratuberculose/microbiologia , Prevalência , Reação em Cadeia da Polimerase em Tempo Real/veterináriaRESUMO
Selenium (Se) deficiency has been associated with lowered resistance to mastitis in dairy cattle. However, little published data exists on the effect of Se supplementation before calving on udder health of pastured dairy heifers. Further, the relative efficacy of injectable barium selenate and oral organic Se for improving udder health in cows has not previously been tested. The objectives of this study were to determine the effects of precalving Se supplementation and type of supplementation on the blood activity of glutathione peroxidase and measures of udder health immediately after calving and during the first month of lactation in pastured dairy heifers. One hundred forty pregnant Chilean Holstein-Friesian heifers were fed a basal diet containing, on average, 0.15 mg of Se/kg of dry matter. One month before predicted calving, heifers were allocated to 1 of 3 groups. Group 1 (n=49) received no supplementary Se, group 2 (n=46) received a single subcutaneous injection of Se (1 mg/kg of live weight, as barium selenate), and group 3 (n=45) was fed Se yeast (3 mg/heifer/d until calving). Heifers supplemented with barium selenate had a higher glutathione peroxidase activity from 14 d in milk onwards. Selenium supplementation, irrespective of source, tended to reduce the prevalence of intramammary infection (IMI) and decrease the prevalence of quarters with high somatic cell count (SCC) at calving. Overall, Se supplementation did not result in a reduction of the incidence of new IMI or clinical mastitis or in decreased SCC during the balance of the first month of lactation. However, in pasture-based heifers injected with barium selenate before calving, and fed diets with 1.3 and 2.5 mg of Se/d precalving and during lactation, respectively, no cases of clinical mastitis were observed in the first month of lactation.
Assuntos
Suplementos Nutricionais , Glutationa Peroxidase/sangue , Lactação/efeitos dos fármacos , Glândulas Mamárias Animais/efeitos dos fármacos , Selênio/farmacologia , Ração Animal , Animais , Bovinos , Contagem de Células/veterinária , Feminino , Glândulas Mamárias Animais/microbiologia , Mastite Bovina/prevenção & controle , Leite/citologia , Gravidez , Selênio/administração & dosagemRESUMO
In Chile, Mycobacterium avium subsp. paratuberculosis (Map) has been isolated on several occasions and clinical cases have been reported. Nevertheless, diagnostic tests have not yet been validated for this agent in the Chilean setting. The objective of the study was to validate a commercial ELISA to detect Map shedding dairy cows in management conditions, prevalence and stages of infection existing in Southern Chile, utilising different statistical approaches. Blood and faeces were collected from 1333 lactating cows in 27 dairy herds (both large commercial and smallholder dairy farms) between September 2003 and August 2004. Within the herds up to a maximum of 100 dairy cows were selected based on age (>or=3 years old) and, if present, clinical signs of a Map infection. In herds with less than 100 cows, all cows >or=3 years old were sampled. Blood samples were tested using a commercial ELISA kit (IDEXX Laboratories, Inc.). Faecal samples were cultured on Herrold's Egg Yolk Medium (HEYM). Latent class models (i.e. maximum likelihood (ML) methods and Bayesian inference) were used to determine the validity of the ELISA. Map was cultured from 54 (4.1%) cows and 10 (37.0%) herds, which were all large, commercial dairy herds. As a result of empty cells in the cross-tabulations, the ML model provided the same results as the validation with faecal culture as the gold-standard. In the Bayesian model, the Se and Sp of the ELISA were estimated to be 26% (95% CI: 18-35%) and 98.5% (95% CI: 97.4-99.4%), respectively. For faecal culture, the Se was 54% (95% CI: 46-62%) and the Sp was 100% (95% CI: 99.9-100%). Interestingly, the prevalence in the smallholder dairy farms was estimated to be 8% even though there were no faecal culture positive cows detected in those herds. There was no significant correlation between the two tests. The advantage of Bayesian inference is that the Se and Sp of both tests are obtained in one model relative to the (latent) true disease status, the model can handle small datasets and empty cells and the estimates can be corrected for the correlation between tests when the tests are not conditionally independent. Therefore, Bayesian analysis was the preferred method for Map that lacks a gold-standard and usually has low cow-level prevalence.
Assuntos
Anticorpos Antibacterianos/sangue , Doenças dos Bovinos/diagnóstico , Ensaio de Imunoadsorção Enzimática/veterinária , Paratuberculose/diagnóstico , Animais , Teorema de Bayes , Bovinos , Doenças dos Bovinos/epidemiologia , Chile/epidemiologia , Ensaio de Imunoadsorção Enzimática/normas , Fezes/microbiologia , Feminino , Funções Verossimilhança , Mycobacterium avium subsp. paratuberculosis/imunologia , Mycobacterium avium subsp. paratuberculosis/isolamento & purificação , Paratuberculose/epidemiologia , Prevalência , Sensibilidade e EspecificidadeRESUMO
Background: Consanguinity plays an important role in the genetic etiology of congenital malformations. In Easter Island the degree of consanguinity could be higher than in continental Chile. Therefore the study of the prevalence of congenital malformations in this island seems worthwhile. Aim: To study the prevalence of congenital malformations at birth in Easter Island. Material and methods: A review of personal and family features of all children born alive between 1988 and 1998 in the Rapa Nui Hospital of Easter Island. Results: During the study period, 772 newborns were reviewed and 22 were found to have congenital malformations. Among the latter, birth weight fluctuated between 3001 and 4000 g and the male/female ratio was 0.54. No differences in maternal age between children with and without malformations was observed. Heart and circulatory malformations, hemangiomas and Down syndrome were the predominant malformations. Conclusions: The prevalence of congenital malformations at birth in Easter Island is similar to that of continental Chile. No neural tube defects were detected in this sample
Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Aberrações Cromossômicas/etnologia , Anormalidades Múltiplas/etnologia , Peso ao Nascer , Idade Materna , Consanguinidade , Síndrome de Down/epidemiologia , Síndrome de Down/etnologiaRESUMO
UNLABELLED: To facilitate the estimation of acromegalic activity a prospective study was done comparing, against a clinical score, the effectiveness of serum IGF-I, IGFBP3 and the IGF-I/IGFBP3 molar ratio. Sixty nine observations were distributed in three groups: Group I=patients before surgery; group II=patients improved but still clinically active; group III=patients clinically inactive. Suppression of serum GH levels one hour after an oral glucose load was in agreement with the clinical score in 21/22 observations. Increases in serum IGF-I and IGFBP3 levels were similarly frequent: both 100% in group I, 80% and 95% in group II, 9% and 36% in group III, respectively. The frequency of abnormal molar ratios was 95%, 40% and 0% in the same groups. Log IGF-I, log IGFBP3, and log molar ratio correlated significantly with the clinical scores (r=0.873, r=0.692, and r=0.829, respectively). CONCLUSIONS: The IGF-I/IGFBP3 molar ratio was not better than either IGF-I or IGFBP3 in detecting activity in the three groups of patients studied. Both IGF-I and IGFBP3 appear comparably useful for the diagnosis and follow-up of acromegalic patients. Since IGF-I is a more biologically meaningful parameter it might be preferable.
Assuntos
Acromegalia/sangue , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Acromegalia/cirurgia , Adolescente , Adulto , Idoso , Hormônio do Crescimento Humano/sangue , Humanos , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
The biosynthesis of met-enkephalin in human pituitary and human pituitary adenomas is still not well known. In this work, we studied the processing of proenkephalin-derived peptides in postmortem human pituitary (PMHP), ACTH-producing adenomas (ACTH-PA), nonfunctioning adenomas (NFA), and GH-producing adenomas (GH-PA). ACTH-PA contained at least 10 times more proenkephalin-derived peptides than PMHP, NFA,and GH-PA. Proenkephalin processing was different in the four tested tissues. In ACTH-PA, proenkephalin was processed to high-, intermediate-, and low-mol-wt products. The highest met-enkephalin-containing peptides levels corresponded to intermediate and low-mol-wt materials, although met-enkephalinArg-Phe and synenkephalin immunoreactivity appeared only in high-mol-wt peptides. In PMHP and NFA, met-enkephalin-Arg-Phe immunoreactivity was detected in intermediate- and low-mol-wt materials, and it was absent in GH-PA. Immunoblotting of ACTH-PA showed that met-enkephalin-Arg-Phe immunoreactivity corresponded to peptides of 44, 32-30, 27, and 17 kDa. The 32-30 and 17-kDa molecules were localized in the nuclear fraction where they were extracted after enzymatic digestion with DNase I. Plasmatic met-enkephalin levels did not increase in patients with Cushing's disease, suggesting that the pentapeptide stored in ACTH-PA was not released to the general circulation. In conclusion, we demonstrated that only ACTH-PA contained high levels of proenkephalin peptides, which were stored in cytoplasm organelles and in the nucleus, probably bound to chromatin. These results suggest an adenoma-specific physiological role of proenkephalin products.
Assuntos
Adenoma/metabolismo , Hormônio Adrenocorticotrópico/metabolismo , Encefalinas/metabolismo , Neoplasias Hipofisárias/metabolismo , Precursores de Proteínas/metabolismo , Adulto , Idoso , Carboxipeptidase B , Carboxipeptidases/metabolismo , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Desoxirribonuclease I/metabolismo , Encefalina Metionina/metabolismo , Feminino , Hormônio do Crescimento Humano/metabolismo , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Peso Molecular , Hipófise/metabolismo , Processamento de Proteína Pós-Traducional , Tripsina/metabolismoRESUMO
Against a clinical score we compared the effectiveness of three biochemical markers of acromegalic activity: a) growth hormone response to i.v. thyrotropin-releasing hormone, b) growth hormone suppression one hour after an oral glucose load, c) basal plasma IGF-I levels. In 21 patients we obtained 39 observations comprising the four parameters. According to the clinical score, patients were divided into three groups: group I = patients before surgery; group II = improved but still clinically active; group III = clinically inactive. After i.v. thyrotropin-releasing hormone, abnormal observations increased although the patients improved clinically, so that this test was excluded from statistical analysis. Abnormalities in plasma IGF-I levels and in GH suppression after oral glucose were similarly frequent in the groups studied: both 100% in group I, both 71.4% in group II, 27.3% vs. 18.2% in group III (p > 0.05). Both tests made exactly the same contribution to the other's capacity to detect acromegalic activity: 3 out of 39 observations (5.1%). We conclude that basal plasma IGF-I is the single best biochemical marker to detect acromegalic activity, since it is statistically at least as useful as growth hormone suppression, and is far more simple for the patient and the laboratory.
Assuntos
Acromegalia/diagnóstico , Fator de Crescimento Insulin-Like I/análise , Hormônio Liberador de Tireotropina , Acromegalia/sangue , Biomarcadores/sangue , Seguimentos , Teste de Tolerância a Glucose , Hormônio do Crescimento/efeitos dos fármacos , Humanos , Estudos Prospectivos , Fatores de TempoRESUMO
Against a clinical score we compared the effectiveness of three biochemical markers of acromegalic activity: a) growth hormone response to i.v. thyrotropin-releasing hormone, b) growth hormone suppression one hour after an oral glucose load, c) basal plasma IGF-I levels. In 21 patients we obtained 39 observations comprising the four parameters. According to the clinical score, patients were divided into three groups: group I = patients before surgery; group II = improved but still clinically active; group III = clinically inactive. After i.v. thyrotropin-releasing hormone, abnormal observations increased although the patients improved clinically, so that this test was excluded from statistical analysis. Abnormalities in plasma IGF-I levels and in GH suppression after oral glucose were similarly frequent in the groups studied: both 100
in group I, both 71.4
in group II, 27.3
vs. 18.2
in group III (p > 0.05). Both tests made exactly the same contribution to the others capacity to detect acromegalic activity: 3 out of 39 observations (5.1
). We conclude that basal plasma IGF-I is the single best biochemical marker to detect acromegalic activity, since it is statistically at least as useful as growth hormone suppression, and is far more simple for the patient and the laboratory.