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1.
Pathogens ; 13(6)2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38921777

RESUMEN

This study aimed to enhance our understanding of the agreement between two sampling methods for the detection of bovine respiratory disease (BRD) pathogens in calves using high-throughput real-time qPCR (ht-RT-qPCR). In total, 233 paired nasal swab (NS) and non-endoscopic bronchoalveolar lavage (nBAL) samples were collected from 152 calves from 12 Danish cattle herds. In 202 of the observations, the calves were examined using a standardized clinical protocol. Samples were tested for three viruses (bovine respiratory syncytial virus, bovine corona virus, and influenza D virus) and six bacteria (Histophilus somni, Mannheimia haemolytica, Mycoplasma bovis, Mycoplasma species, Pasteurella multocida, and Truepurella pyogenes). The results showed age-related differences in disease and pathogen occurrence, with the highest detection rates in calves aged 35 days or older. Poor to moderate agreement was found between the NS and nBAL results. The presence of Mannheimia haemolytica in both NS and nBAL in younger calves and in nBAL in older calves was associated with clinical BRD. There was a potential link between BRD and influenza D virus in older calves, although it was only found in one herd in a small sample size. Overall, NS was a relatively poor predictor of pathogens in the lower respiratory tract. The present study confirms the complexity of pathogen detection in BRD, with marked influences of age and the sampling method on pathogen detection and disease associations.

2.
Porcine Health Manag ; 9(1): 33, 2023 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-37434248

RESUMEN

BACKGROUND: Recently, in-feed medicinal zinc has been phased out in pig production in the European Union. This makes updated knowledge about porcine post-weaning diarrhea (PWD) crucial. The objectives of the present study were to investigate (i) the clinical presentation of PWD in pigs housed in Danish herds that did not use medicinal zinc, specifically the prevalence of diarrhea and whether PWD was associated to clinical signs of dehydration or altered body temperature; (ii) which microorganism are associated to PWD; and iii) whether measurements of the fecal pH have a potential to be used diagnostically to differentiate between infectious etiologies in cases of PWD. RESULTS: The prevalence of diarrhea varied considerably between the outbreaks in the nine studied herds (median = 0.58, range = 0.10; 0.94). In a cross-sectional design (n = 923), diarrhea was associated with reduced rectal temperature and alkaline feces. Diarrhea was also associated with observably reduced skin elasticity, possibly indicating dehydration. In both diarrheic case pigs (n = 87) and control pigs (n = 86), the presence of Brachyspira pilosicoli, Clostridium perfringens, Cryptosporidium spp., Cystoisopora suis, enterotoxigenic Escherichia coli, Lawsonia intracellularis, porcine circovirus types 2 and 3, rotavirus A, B, C, and H, Samonella enterica spp. enterica, and Trichuris suis was described. PWD was associated with high levels of enterotoxigenic E. coli shedding (odds ratio versus no E. coli detection = 4.79 [CI 1.14; 12.62]). Diarrhea was associated with high levels of rotavirus A shedding (odds ratio versus no/low rotavirus A = 3.80 [CI 1.33; 7.97]). The association between microbiological findings in diarrheic pigs and fecal pH was negligible. CONCLUSIONS: Enterotoxigenic E. coli was confirmed to be a cause of PWD; however, cases of PWD where enterotoxigenic E. coli was not detected in high levels occurred commonly, and this adds to the increasing evidence suggesting that PWD is not necessarily a result of enteric colibacillosis. Rotaviral enteritis might be a differential diagnosis of PWD. pH-measurements cannot be used to differentiate between differential diagnoses for PWD.

3.
Acta Vet Scand ; 65(1): 30, 2023 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-37400879

RESUMEN

BACKGROUND: Post-weaning diarrhoea (PWD) is a multifactorial condition and the most well documented infectious cause is enterotoxigenic Escherichia coli. The objective of the study was to investigate possible associations between pathological manifestations and pathogens in pigs with and without PWD. The study was conducted as a case-control study and included a total of 173 pigs from 9 different commercial intensive indoor production herds in eastern Denmark. RESULTS: Based on clinical examination, a total of 89 piglets with PWD (cases) and 84 piglets without PWD (controls) were included. Most of the pigs (n = 105/173) presented gastric lesions, which were more frequently observed in the control group. The odds of gastric ulcers were lower among pigs with PWD compared to pigs without PWD with an odds ratio (OR) of 0.2 (0.0; 0.7). Abnormal content in the colon was associated with PWD, with an OR of 6.5 (3.2; 14.3). No apparent association was found between lesions and the various pathogens or a combination of these. The odds of neutrophilic granulocyte infiltration were lower in the jejunum among pigs with PWD (OR 0.3 [0.1; 0.6]) compared to pigs without PWD. The association between neutrophilic granulocyte infiltration in jejunum and PWD differed between the herds (P = 0.03). Furthermore, the associations between PWD and hyperleukocytosis (P = 0.04) or infiltration of eosinophilic granulocytes (P = 0.04) in ileum were also herd dependent. Histopathology revealed several lesions not relatable to PWD. CONCLUSION: The association between lesions and specific pathogens or PWD is more complex than anticipated.


Asunto(s)
Infecciones por Escherichia coli , Enfermedades de los Porcinos , Animales , Porcinos , Infecciones por Escherichia coli/veterinaria , Estudios de Casos y Controles , Diarrea/veterinaria , Diarrea/patología , Tracto Gastrointestinal , Yeyuno , Enfermedades de los Porcinos/patología
4.
Porcine Health Manag ; 9(1): 26, 2023 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-37264473

RESUMEN

BACKGROUND: Diagnosing and treatment of diseases in pigs are important to maintain animal welfare, food safety and productivity. At the same time antimicrobial resistance is increasing, and therefore, antibiotic treatment should be reserved for individuals with a bacterial infection. The aim of the study was to investigate gross and histological lesions and related pathogens in pigs that died during the nursery period in five Danish farms. In addition, high throughput, real-time qPCR monitoring of specific porcine pathogens in fecal sock and oral fluid samples were carried out to investigate the between-farm and between-batch variation in the occurrence of pathogens. RESULTS: Twenty-five batches of nursery pigs from five intensive, indoor herds were followed from weaning (approximately four weeks) to the end of nursery (seven to eight weeks post weaning). Gross and histological evaluation of 238 dead and 30 euthanized pigs showed the highest prevalence of lesions in the skin, respiratory system, gastrointestinal tract, and joints. Gross and histological diagnoses of lung and joint lesions agreed in 46.5% and 62.2% of selected pigs, respectively. Bacteriological detection of Escherichia coli, Streptococcus suis or Staphylococcus aureus infections in joints, lungs and livers was confirmed as genuine infection on immunohistochemical staining in 11 out of 70 tissue sections. The real-time qPCR analysis of pooled samples showed that most pathogens detected in feces and in oral fluid in general followed the same shedding patterns in consecutive batches within herds. CONCLUSIONS: Gross assessment should be supplemented with a histopathological assessment especially when diagnosing lesions in the lungs and joints. Moreover, microbiological detection of pathogens should optimally be followed up by in situ identification to confirm causality. Furthermore, routine necropsies can reveal gastric lesions that may warrant a change in management. Real-time qPCR testing of fecal sock samples and oral fluid samples may be used to monitor the infections in the individual herd and testing one batch seems to have a good predictive value for subsequent batches within a herd. Overall, optimal diagnostic protocols will provide a more substantiated prescription of antibiotics.

5.
Porcine Health Manag ; 8(1): 49, 2022 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-36503595

RESUMEN

BACKGROUND: Post weaning diarrhoea is expected to become an increasing problem in pig herds following the outphasing of medicinal Zinc Oxide. Currently, no equally effective substitute has been found and an increase in metaphylactic batch medication with antibiotics is expected. However, prudent use of antibiotics is needed to mitigate antibiotic resistance development and one option could be pre-treatment diagnostics. Employing a point-of-care test in a herd could provide fast diagnostics and help guide antibiotic treatment. Hence, the aim of this study was to evaluate the diagnostic performance of a commercially available point-of-care test for enterotoxigenic Escherichia coli (ETEC) F4, ETEC F18 and rotavirus in weaned pigs. RESULTS: In total 115 diarrheic samples from two conventional herds were included in the evaluation of the Rainbow Piglet Scours test, which was compared to microbiological PCR analyses. The comparison yielded a diagnostic sensitivity, diagnostic specificity, positive and negative predictive value of 0.28, 0.99, 0.92 and 0.70 for ETEC F4, 0.40, 0.92, 0.91 and 0.45 for ETEC F18 and 0.67, 0.88, 0.91 and 0.61 for rotavirus. CONCLUSIONS: The point-of-care test yielded a low diagnostic sensitivity and a high diagnostic specificity for ETEC F4, ETEC F18 and rotavirus. Due to the high level of false negatives, the test cannot be recommended for individual diagnostics on pig-level.

6.
J Appl Microbiol ; 133(4): 2516-2527, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35858716

RESUMEN

AIMS: Diarrhoea is a common health problem in calves and a main reason for use of antimicrobials. It is associated with several bacterial, viral and parasitic pathogens, most of which are commonly present in healthy animals. Methods, which quantify the causative agents, may therefore improve confidence in associating a pathogen to the disease. This study evaluated a novel commercially available, multiplex quantitative polymerase chain reaction (qPCR) assay (Enterit4Calves) for detection and quantification of pathogens associated with calf-diarrhoea. METHODS AND RESULTS: Performance of the method was first evaluated under laboratory conditions. Then it was compared with current routine methods for detection of pathogens in faecal samples from 65 calves with diarrhoea and in 30 spiked faecal samples. The qPCR efficiencies were between 84%-103% and detection limits of 100-1000 copies of nucleic acids per sample were observed. Correct identification was obtained on 42 strains of cultured target bacteria, with only one false positive reaction from 135 nontarget bacteria. Kappa values for agreement between the novel assay and current routine methods varied between 0.38 and 0.83. CONCLUSION: The novel qPCR method showed good performance under laboratory conditions and a fair to good agreement with current routine methods when used for testing of field samples. SIGNIFICANCE AND IMPACT OF STUDY: In addition to having fair to good detection abilities, the novel qPCR method allowed quantification of pathogens. In the future, use of quantification may improve diagnosis and hence treatment of calf diarrhoea.


Asunto(s)
Reacción en Cadena de la Polimerasa Multiplex , Ácidos Nucleicos , Animales , Bacterias/genética , Bovinos , Diarrea/diagnóstico , Diarrea/microbiología , Diarrea/veterinaria , Heces/microbiología , Reacción en Cadena de la Polimerasa Multiplex/métodos , Sensibilidad y Especificidad
7.
Ann Intern Med ; 174(3): 335-343, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33205991

RESUMEN

BACKGROUND: Observational evidence suggests that mask wearing mitigates transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It is uncertain if this observed association arises through protection of uninfected wearers (protective effect), via reduced transmission from infected mask wearers (source control), or both. OBJECTIVE: To assess whether recommending surgical mask use outside the home reduces wearers' risk for SARS-CoV-2 infection in a setting where masks were uncommon and not among recommended public health measures. DESIGN: Randomized controlled trial (DANMASK-19 [Danish Study to Assess Face Masks for the Protection Against COVID-19 Infection]). (ClinicalTrials.gov: NCT04337541). SETTING: Denmark, April and May 2020. PARTICIPANTS: Adults spending more than 3 hours per day outside the home without occupational mask use. INTERVENTION: Encouragement to follow social distancing measures for coronavirus disease 2019, plus either no mask recommendation or a recommendation to wear a mask when outside the home among other persons together with a supply of 50 surgical masks and instructions for proper use. MEASUREMENTS: The primary outcome was SARS-CoV-2 infection in the mask wearer at 1 month by antibody testing, polymerase chain reaction (PCR), or hospital diagnosis. The secondary outcome was PCR positivity for other respiratory viruses. RESULTS: A total of 3030 participants were randomly assigned to the recommendation to wear masks, and 2994 were assigned to control; 4862 completed the study. Infection with SARS-CoV-2 occurred in 42 participants recommended masks (1.8%) and 53 control participants (2.1%). The between-group difference was -0.3 percentage point (95% CI, -1.2 to 0.4 percentage point; P = 0.38) (odds ratio, 0.82 [CI, 0.54 to 1.23]; P = 0.33). Multiple imputation accounting for loss to follow-up yielded similar results. Although the difference observed was not statistically significant, the 95% CIs are compatible with a 46% reduction to a 23% increase in infection. LIMITATION: Inconclusive results, missing data, variable adherence, patient-reported findings on home tests, no blinding, and no assessment of whether masks could decrease disease transmission from mask wearers to others. CONCLUSION: The recommendation to wear surgical masks to supplement other public health measures did not reduce the SARS-CoV-2 infection rate among wearers by more than 50% in a community with modest infection rates, some degree of social distancing, and uncommon general mask use. The data were compatible with lesser degrees of self-protection. PRIMARY FUNDING SOURCE: The Salling Foundations.


Asunto(s)
COVID-19/prevención & control , Máscaras , Pandemias/prevención & control , Adulto , COVID-19/diagnóstico , COVID-19/transmisión , Prueba de Ácido Nucleico para COVID-19 , Prueba Serológica para COVID-19 , Dinamarca/epidemiología , Transmisión de Enfermedad Infecciosa/prevención & control , Humanos , Persona de Mediana Edad , Distanciamiento Físico , SARS-CoV-2
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