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Molecular characterisation of Leptospira strains in Pakistan
2016
Sohail, Muhammad Luqman | Khan, Muhammad Sarwar | Avais, Muhammad | Zahoor, Muhammad Yasir | Khattak, Irfan | Ashraf, Aqeela | Naseer, Omer
Introduction: Leptospirosis affects a wide range of mammals, humans, and even a few poikilothermic animal species. In Pakistan, serological studies of equine leptospirosis have reported a prevalence of over 40%, but no study has ever been conducted towards molecular detection of Leptospira in horses. Material and Methods: Blood samples from 128 horses were screened using ELISA and 41 positive samples were examined for the presence of leptospiral DNA using specific primers for 16S rRNA gene. Results: Out of 41 tested samples, 20 samples were found to be PCR-positive, revealing a fragment of 306 bp after gel electrophoresis. Sequencing and phylogenetic analysis of positive samples revealed circulation of pathogenic Leptospira spp. in Pakistani horses. No evidence of circulation of intermediate species was found in this study. Conclusion: This study reports the first molecular evidence of equine leptospirosis in Pakistan and lays ground for further research in this area. It also confirms the efficiency of 16S rRNA for the diagnosis of equine leptospirosis.
Mostrar más [+] Menos [-]Chlamydia psittaci reference genes for normalisation of expression data differ depending on the culture conditions and selected time points during the chlamydial replication cycle
2016
Van Lent, Sarah | Vanrompay, Daisy
Introduction: Chlamydia psittaci is a gram-negative obligate intracellular pathogen of birds. Poultry infections lead to economic losses and can be transmitted to humans. No vaccine is available and the bacterium-host cell interaction is not completely understood. Replicating bacteria cause pneumonia, but C. psittaci can also be non-replicating and persistent inside the cytoplasm of avian cells. RT-qPCR provides insight into the molecular pathogenesis of both active replicating and persistent Chlamydia psittaci in birds, but requires identification of stably expressed reference genes to avoid biases. Material and Methods: We investigated the expression stability of 10 C. psittaci candidate reference genes for gene expression analysis during normal growth and penicillin-induced persistence. C. psittaci Cal10 was cultured in HeLa229 and RNA was extracted. The expression level of each candidate was examined by RT-qPCR and Cq values were analysed using geNorm. Results: The genes tyrS, gidA, radA, and 16S rRNA ranked among the most stably expressed. The final selected reference genes differed according to the bacterial growth status (normal growth versus persistent status), and the time points selected during the duration of the normal chlamydial developmental cycle. Conclusion: The study data show the importance of systematic validation of reference genes to confirm their stability within the strains and under the conditions selected.
Mostrar más [+] Menos [-]Phenotypic diversity and potential virulence factors of the Shewanella putrefaciens group isolated from freshwater fish
2019
Paździor, Ewa | Pękala-Safińska, Agnieszka | Wasyl, Dariusz
The Shewanella putrefaciens group are ubiquitous microorganisms recently isolated from different freshwater fish species and causing serious health disorders. The purpose of the study was to characterise isolates of the S. putrefaciens group with special emphasis on elucidating serological diversity and determining putative virulence factors. Isolates collected from freshwater fish (n = 44) and reference strains were used. The identification of bacteria was carried out using biochemical kits and 16S rRNA sequencing. Polyclonal antibodies were prepared against the S. putrefaciens group. The bacterium’s susceptibility to antimicrobial agents, its enzymatic properties, and its adhesion ability to fish cell lines were also tested. Finally, selected isolates were used in challenge experiments in common carp and rainbow trout. Excluding six isolates undeterminable for species, the bacteria were classified to three species: S. putrefaciens, S. xiamenensis, and S. oneidensis, and showed some phenotypic diversity. Fourteen serological variants of the S. putrefaciens group were determined with the newly developed serotyping scheme. Serodiversity may play an important role in the virulence of particular isolates. Further, S. putrefaciens group members adhere to epithelial cells and produce enzymes which may contribute to their virulence. Challenge tests confirmed the pathogenicity of the S. putrefaciens group for fish.
Mostrar más [+] Menos [-]Occurrence of different strains of Babesia canis in dogs in eastern Poland
2016
Łyp, Paweł | Bartnicki, Michał | Staniec, Marta | Winiarczyk, Stanisław | Adaszek, Łukasz
Introduction: The aim of this study was to carry out a genetic analysis of Babesia canis isolates detected in dogs in eastern Poland and to study the correlation of the protozoa variant with a specific geographical region. Material and Methods: PCR was used to identify strains of B. canis from naturally infected animals (240 dogs from four provinces: Mazowieckie, Lublin, Podlasie, and Podkarpacie) by amplifying and sequencing a fragment of the 18S rRNA gene. Results: Sequencing the PCR products led to the identification of four variants of B. canis. Two previously described protozoa variants (18S rRNA-A and 18S rRNA-B) were observed in all provinces. Additionally, in the Mazowieckie and Lublin provinces a B. canis variant which contributed to the development of acute or atypical babesiosis was observed. The fourth variant of B. canis was detected only in dogs from the Lublin province, and the course of the disease was subclinical in all dogs infected with this variant. Conclusion: These results indicate the appearance of a new fourth B. canis genotype in Poland and confirm that it is still necessary to study the relationships between the genetic structure of protozoa, geographical distribution of the parasites, and clinical course of the disease.
Mostrar más [+] Menos [-]Identification of bacterial pathogens and determination of their antibacterial resistance profiles in some cultured fish in Turkey
2016
Ture, Mustafa | Alp, Hüseyin
Introduction: In the present study, some of the commercial fish farms located in the Black Sea region of Turkey, were screened for bacteria between 2012 and 2014.Material and Methods: The bacterial agents isolated from fish were identified by classical biochemical tests and the rapid diagnostic tests (API 20 E and API 20 Strep). All strains were further identified by sequencing of the 16S rRNA genes. The strains were also investigated for resistance to different antimicrobials by the disc diffusion method. Antibiotic resistance genes, including tetracycline (B), β-lactam (ampC, blaTEM, blaPSE), florfenicol (floR), erythromycine (ereA, ereB), sulphonamide (sulI, sulII), and trimethoprim (dhfr1) genes, were determined by the PCR method.Results:Vibrio anguillarum, Vibrio fluvialis, Photobacterium damselae subsp. piscicida, Pseudomonas luteola, Lactococcus garvieae, Streptococcus iniae, Aeromonas hydrophila, and Yersinia ruckeri were isolated from marine and freshwater cultured fish. According to the results of disc diffusion, all isolates were sensitive to florfenicol, trimethoprim+sulfamethoxazole, oxitetracycline, and enrofloxacin, and resistant to lincomycin, penicillin G, and amoxicillin. Also, sulI, sulII, and floR resistance genes were detected in the bacteria.Conclusion: The results of the study open up the opportunity to perform further investigations which could determine the possible role of ARGs in fish pathogens.
Mostrar más [+] Menos [-]Nasal bacterial microbiota during an outbreak of equine herpesvirus 1 at a farm in southern Ontario
2021
Gomez, Diego E. | Arroyo, Luis G. | Lillie, Brandon | Weese, J Scott
The objective of this study was to investigate the nasal bacterial microbiota of healthy horses and horses infected with equine herpesvirus 1 (EHV-1). The nasal bacterial microbiota of 10 horses infected with EHV-1 and 11 control horses from a farm experiencing an outbreak was characterized using the Illumina MiSeq platform targeting the V4 region of the 16S ribosomal RNA gene. The nasal bacterial microbiota of healthy horses and EHV-1 horses was significantly different in community membership and structure. Horses shedding EHV-1 had lower bacterial richness (P = 0.002), evenness (P = 0.008), and diversity (P = 0.026) than healthy horses. Healthy horses had a higher relative abundance of Firmicutes and Bacteroidetes, but lower Proteobacteria than horses with EHV-1 (P < 0.05). This study provides the basis for generating hypotheses and investigations on the role of bacterial-viral interactions in the health and diseases of adult horses.
Mostrar más [+] Menos [-]Investigation of effects of omeprazole on the fecal and gastric microbiota of healthy adult horses
2019
Tyma, Jesse F. | Epstein, Kira L. | Whitefield-Cargile, Canaan M. | Cohen, Noah D. | Giguère, S. (Steeve)
OBJECTIVE To determine the effects of oral omeprazole administration on the fecal and gastric microbiota of healthy adult horses. ANIMALS 12 healthy adult research horses. PROCEDURES Horses were randomly assigned to receive omeprazole paste (4 mg/kg, PO, q 24 h) or a sham (control) treatment (tap water [20 mL, PO, q 24 h]) for 28 days. Fecal and gastric fluid samples were collected prior to the first treatment (day 0), and on days 7, 28, 35, and 56. Sample DNA was extracted, and bacterial 16S rRNA gene sequences were amplified and sequenced to characterize α and β diversity and differential expression of the fecal and gastric microbiota. Data were analyzed by visual examination and by statistical methods. RESULTS Composition and diversity of the fecal microbiota did not differ significantly between treatment groups or over time. Substantial variation in gastric fluid results within groups and over time precluded meaningful interpretation of the microbiota in those samples. CONCLUSIONS AND CLINICAL RELEVANCE Results supported that omeprazole administration had no effect on fecal microbiota composition and diversity in this group of healthy adult horses. Small sample size limited power to detect a difference if one existed; however, qualitative graphic examination supported that any difference would likely have been small and of limited clinical importance. Adequate data to evaluate potential effects on the gastric microbiota were not obtained. Investigations are needed to determine the effects of omeprazole in horses with systemic disease or horses receiving other medical treatments.
Mostrar más [+] Menos [-]Comparative molecular analysis of fecal microbiota of bobcats (Lynx rufus) and domestic cats (Felis catus)
2019
Eshar, D. | Lee, C. | Weese, J. S.
The goal of this study was to explore and describe fecal microbiota of captive and wild bobcats (Lynx rufus) and compare the results to those of domestic cats (Felis catus). Fecal samples from 27 bobcats (8 wild, 19 zoo-kept) were used for novel bacterial deoxyribonucleic acid (DNA) identification using next-generation sequencing of the V4 region of the bacterial 16S ribosomal ribonucleic acid (rRNA) gene, analyzed by Illumina sequencing, and then compared to data obtained from a colony of 10 domestic cats. In this study, the microbiota of both species was dominated by Firmicutes, followed by Proteobacteria, Actinobacteria, Bacteroidetes, and Verrucomicrobia. When compared, fecal samples from bobcats harbored more Proteobacteria and Actinobacteria than fecal samples from domestic cats. There was a remarkable inter-bobcat variation in the relative abundances of the main bacterial genera. There were no significant differences, however, between the main phyla of the microbiota of the wild and domestic bobcats. Proteobacteria in wild bobcats (P = 0.079) and Firmicutes in zoo-kept bobcats (P = 0.079) approached significance. There were no differences in predominant genera between wild and captive bobcats. The results of this study showed that there are notable differences in fecal bacterial communities between domestic cats and both captive and wild bobcats. The lack of significant differences in bacterial communities between wild and zoo-kept bobcats suggests that the varied diet provided for these felids can result in a fecal microbiota resembling that generated by a wild diet.
Mostrar más [+] Menos [-]Staphylococcus spp., Streptococcus canis, and Arcanobacterium phocae of healthy Canadian farmed mink and mink with pododermatitis
2015
Chalmers, Gabhan | McLean, John | Hunter, D Bruce | Brash, Marina | Slavic, Durda | Pearl, David L. | Boerlin, Patrick
Pododermatitis is a disease of concern for mink breeders in Canada and worldwide, as it causes discomfort and lowers the breeding rates on farms affected by the disease. Unfortunately, the etiology and pathogenesis of pododermatitis are still unknown. In this study, we compared Staphylococcus spp. and Streptococcus canis isolates from healthy mink with isolates from animals with pododermatitis on 2 farms in Ontario. Almost all hemolytic Staphylococcus spp. isolated were shown to be Staphylococcus delphini Group A by 16S ribosomal ribonucleic acid (rRNA) sequence analysis and polymerase chain reaction (PCR). Pulsed-field gel electrophoresis (PFGE) did not reveal any S. delphini or S. canis clonal lineages specifically associated with pododermatitis, which suggests that these bacteria do not act as primary pathogens, but does not dismiss their potential roles as opportunistic pathogens. While S. delphini and S. canis were the most prevalent bacterial pathogens in mink pododermatitis, they were also present in samples from healthy mink. Arcanobacterium phocae is occasionally isolated from pododermatitis cases, but is difficult to recover with conventional culture methods due to its slow growth. A quantitative real-time PCR was developed for the detection of A. phocae and was tested on 138 samples of footpad tissues from 14 farms. The bacterium was detected only in pododermatitis-endemic farms in Canada and was at higher concentrations in tissues from infected footpads than in healthy tissues. This finding suggests that A. phocae is involved in the pathogenesis of pododermatitis.
Mostrar más [+] Menos [-]Evaluation of factors associated with the risk of infection with Cryptosporidium parvum in dairy calves
2012
Szonyi, Barbara | Chang, Yung-Fu | Wade, Susan E. | Mohammed, Hussni O.
Objective-To identify risk factors associated with Cryptosporidium parvum infection in dairy calves. Animals-108 case animals and 283 control animals. Procedures-Case animals were calves infected with C parvum, and controls were infected with Cryptosporidium bovis (n = 67) or calves not infected with Cryptosporidium spp. Fecal samples were tested via the flotation concentration method for Cryptosporidium spp. Samples were genotyped by sequencing of the 18s rRNA gene. Associations between host, management, geographic, and meteorologic factors and Cryptosporidium genotype were assessed. Results-Younger calves and calves housed in a cow barn were more likely to be infected with both genotypes. Herd size and hay bedding were associated with an increased risk of infection with C parvum, and Jersey breed was a risk factor for C bovis infection. Compared with a flat surface, a steeper slope was significantly associated with a decreased likelihood of infection with both genotypes, and precipitation influenced the risk of C parvum infection only. Conclusions and Clinical Relevance-Risk factors for calf infection with C parvum differed from those for infection with C bovis. Results may be useful to help design measures that reduce animal exposure and decrease public health risk and economic losses associated with C parvum infection in cattle.
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