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1.
Nucleic Acids Res ; 51(7): 3240-3260, 2023 04 24.
Artículo en Inglés | MEDLINE | ID: mdl-36840716

RESUMEN

Actinobacillus pleuropneumoniae is the cause of porcine pleuropneumonia, a severe respiratory tract infection that is responsible for major economic losses to the swine industry. Many host-adapted bacterial pathogens encode systems known as phasevarions (phase-variable regulons). Phasevarions result from variable expression of cytoplasmic DNA methyltransferases. Variable expression results in genome-wide methylation differences within a bacterial population, leading to altered expression of multiple genes via epigenetic mechanisms. Our examination of a diverse population of A. pleuropneumoniae strains determined that Type I and Type III DNA methyltransferases with the hallmarks of phase variation were present in this species. We demonstrate that phase variation is occurring in these methyltransferases, and show associations between particular Type III methyltransferase alleles and serovar. Using Pacific BioSciences Single-Molecule, Real-Time (SMRT) sequencing and Oxford Nanopore sequencing, we demonstrate the presence of the first ever characterised phase-variable, cytosine-specific Type III DNA methyltransferase. Phase variation of distinct Type III DNA methyltransferase in A. pleuropneumoniae results in the regulation of distinct phasevarions, and in multiple phenotypic differences relevant to pathobiology. Our characterisation of these newly described phasevarions in A. pleuropneumoniae will aid in the selection of stably expressed antigens, and direct and inform development of a rationally designed subunit vaccine against this major veterinary pathogen.


Asunto(s)
Actinobacillus pleuropneumoniae , Variación de la Fase , Animales , Porcinos , Actinobacillus pleuropneumoniae/genética , Actinobacillus pleuropneumoniae/metabolismo , Metilasas de Modificación del ADN/genética , Metilasas de Modificación del ADN/metabolismo , Metilación de ADN , Metiltransferasas/genética , Metiltransferasas/metabolismo , Bacterias/genética , ADN/metabolismo
2.
Avian Pathol ; 53(1): 1-13, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37722832

RESUMEN

RESEARCH HIGHLIGHTS: High Campylobacter prevalence in chickens; C. jejuni more prevalent than C. coli.Susceptibility to macrolides but resistance to quinolones/tetracyclines in isolates.Homogeneous resistance patterns within farms; higher in broilers than in native birds.Partial association between phenotypic and genotypic resistance among isolates.


Asunto(s)
Infecciones por Campylobacter , Campylobacter coli , Campylobacter jejuni , Campylobacter , Animales , Pollos , Campylobacter jejuni/genética , Infecciones por Campylobacter/epidemiología , Infecciones por Campylobacter/veterinaria , Tailandia/epidemiología , Antibacterianos/farmacología , Campylobacter coli/genética , Farmacorresistencia Bacteriana/genética , Pruebas de Sensibilidad Microbiana/veterinaria
3.
PLoS Biol ; 16(5): e1002630, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29734341

RESUMEN

[This corrects the article DOI: 10.1371/journal.pbio.2003916.].

4.
Avian Pathol ; 50(1): 31-40, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32990455

RESUMEN

A total of 62 isolates of Riemerella-like organisms, originally isolated from Australian poultry (10 from chickens, 46 from ducks, five from unknown hosts and one vaccine strain), were included in this study. On the basis of two published polymerase chain reaction (PCR) assays that are reported to be specific for Riemerella anatipestifer, 51 of the isolates were identified as R. anatipestifer. Forty-six of these isolates had a detailed history and were sourced from ducks, while five were of unknown origin. The 11 remaining isolates failed to yield a positive reaction in either PCR with 10 originating from chickens and one from a duck. Amplification and sequencing of the 16S rRNA gene of these isolates identified the duck isolate as Moraxella lacunta. Phylogenetic analysis of the 10 chicken isolates identified one as R. columbina and the remaining nine isolates as Riemerella-like taxon 2. The 51 Australian R. anatipestifer isolates were assigned by gel diffusion test to serovars 1 (26 isolates), 6 (seven isolates), 8 (five isolates), 9 (two isolates), 13 (one isolate) and 14 (one isolate) while nine isolates gave no reaction to any antiserum. A commercial system was used to perform DNA fingerprinting using rep-PCR analysis, which revealed different clusters with a lack of a clear relationship between the clusters and the serovars.


Asunto(s)
Pollos/virología , Patos/virología , Infecciones por Flavobacteriaceae/veterinaria , Enfermedades de las Aves de Corral/virología , Riemerella/inmunología , Animales , Australia , Infecciones por Flavobacteriaceae/virología , Filogenia , Reacción en Cadena de la Polimerasa/veterinaria , ARN Ribosómico 16S/genética , Riemerella/clasificación , Riemerella/genética , Serogrupo
5.
Trop Anim Health Prod ; 53(3): 371, 2021 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-34173084

RESUMEN

Porcine circovirus type 2 (PCV2), an important pig viral pathogen, can cause porcine circovirus-associated disease (PCVAD), resulting in economic losses associated with decreased growth and mortalities. The diagnosis of PCVAD is complex requiring clinical, pathological and virological approaches. This study assessed PCV2 infection using histopathology and immunohistochemistry (IHC) on tissue samples and quantitative polymerase chain reaction (qPCR) on serum samples from 47 grower-finisher pigs allocated in three clinical groups in the Philippines. Typical PCV2 histopathological lesions were observed in mediastinal lymph nodes (MLN) of eight of 47 pigs. Lymphoid depletion was seen in all eight pigs and granulomatous inflammation in one of these pigs. Four of these eight pigs were PCV2 positive by both IHC and qPCR. IHC revealed PCV2 antigen in 8 pigs in at least one of the following tissues: MLN (5/8), spleen (3/8), tonsils (4/8) and lungs (5/8). PCV2 antigen was observed in 3/8 MLN with lymphoid depletion and in one MLN with depletion and granulomatous inflammation. The qPCR test showed that 33 sera had a non-detectable level, twelve had < 106 and two had > 106 PCV2 DNA copies/ml serum. One pig with lymphoid depletion had > 106 PCV2 DNA copies/ml serum, and another pig without MLN lesions also had > 106 PCV2 DNA copies/ml serum. These findings suggest that PCVAD is present in the Philippines and confirm the challenges of PCVAD diagnosis as different patterns of results were obtained from the different tests.


Asunto(s)
Infecciones por Circoviridae , Circovirus , Enfermedades de los Porcinos , Animales , Anticuerpos Antivirales , Infecciones por Circoviridae/veterinaria , Ganglios Linfáticos , Filipinas , Porcinos
6.
J Zoo Wildl Med ; 51(4): 771-779, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33480557

RESUMEN

A total of 22 Pasteurellaceae isolates obtained from the oral cavity of koalas (Phascolarctos cinereus) at different wildlife centers in Australia were investigated using amplification and sequencing of two housekeeping genes, rpoA and recN. The available sequences from the Lonepinella koalarum type strain (ACM3666T) and the recent isolates of Lonepinella-like bacteria obtained from human infected wounds associated with koala bites were also included. Phylogenetic analysis was performed on the concatenated rpoA-recN genes and genome relatedness was calculated based on the recN sequences. The oral cavity isolates, the koala bite wound isolates, and L. koalarum ACM3666T resulted in four clusters (Clusters 1-4). Clusters 1-3 were clearly not members of the genus Lonepinella. Cluster 1 was closely related to the genus Fredericksenia, and Clusters 2 and 3 appeared to be novel genera. Cluster 4 consisted of three subclusters: Cluster 4a with one koala bite wound isolate and L. koalarum ACM3666T, Cluster 4b with three oral cavity isolates and two Lonepinella-like wound isolates, and Cluster 4c with three nearly identical oral cavity isolates that may represent a different species within the genus Lonepinella. The rich Pasteurellaceae population, including potential novel taxa in the oral cavity of koalas supports an important role of these highly adapted microorganisms in the physiology of koalas. Moreover, the pathogenic potential of Lonepinella-like species is an important consideration when investigating infected koala bites in humans.


Asunto(s)
Mordeduras y Picaduras , Infecciones por Pasteurellaceae/microbiología , Pasteurellaceae/clasificación , Phascolarctidae/microbiología , Infección de Heridas/microbiología , Animales , Australia/epidemiología , Genoma Bacteriano , Humanos , Pasteurellaceae/genética , Pasteurellaceae/aislamiento & purificación , Filogenia , Infección de Heridas/epidemiología , Zoonosis
7.
PLoS Biol ; 15(11): e2003916, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29161268

RESUMEN

Nucleic acid amplification is a powerful molecular biology tool, although its use outside the modern laboratory environment is limited due to the relatively cumbersome methods required to extract nucleic acids from biological samples. To address this issue, we investigated a variety of materials for their suitability for nucleic acid capture and purification. We report here that untreated cellulose-based paper can rapidly capture nucleic acids within seconds and retain them during a single washing step, while contaminants present in complex biological samples are quickly removed. Building on this knowledge, we have successfully created an equipment-free nucleic acid extraction dipstick methodology that can obtain amplification-ready DNA and RNA from plants, animals, and microbes from difficult biological samples such as blood and leaves from adult trees in less than 30 seconds. The simplicity and speed of this method as well as the low cost and availability of suitable materials (e.g., common paper towelling), means that nucleic acid extraction is now more accessible and affordable for researchers and the broader community. Furthermore, when combined with recent advancements in isothermal amplification and naked eye DNA visualization techniques, the dipstick extraction technology makes performing molecular diagnostic assays achievable in limited resource settings including university and high school classrooms, field-based environments, and developing countries.


Asunto(s)
Bacterias/genética , Técnicas Genéticas , Ácidos Nucleicos/aislamiento & purificación , Plantas/genética , Animales , Arabidopsis/genética , Celulosa/química , ADN/análisis , ADN/aislamiento & purificación , Humanos , Técnicas de Amplificación de Ácido Nucleico , Ácidos Nucleicos/análisis , Oligonucleótidos/genética , Hojas de la Planta/genética , ARN/análisis , ARN/aislamiento & purificación
8.
Int J Syst Evol Microbiol ; 70(6): 3686-3692, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32416742

RESUMEN

Twenty-nine isolates of an unknown haemophilic organism were isolated from the lungs of pigs from 14 farms in Australia. Phylogenetic analyses based on the 16S rRNA gene, recN and rpoA showed a monophyletic group that was most closely related to Glaesserella parasuis and [Actinobacillus] indolicus. Whole genome sequence analysis indicated that the Glaesserella parasuis and this group, using the type strain HS4635T for comparison, showed a similarity of 30.9 % DNA-DNA renaturation. The isolates were Gram-stain-negative, NAD-dependent, CAMP-negative and were oxidase-positive, catalase-negative and produced indole but not urease. The isolates could be separated from all currently recognized haemophilic and non-haemophilic members of the family Pastuerellaceae. Key phenotypic properties were the production of indole, the lack of urease activity, production of ß-galactosidase but not α-fucosidase, acid formation from (-)-d-arabinose, (+)-d-galactose, maltose and trehalose and a failure to produce acid from (-)-d-mannitol. Taken together, these data indicate that the isolates belong to a novel species for which the name Glaesserella australis sp. nov. is proposed. The type strain is HS4635T (=CCUG 71931T and LMG 30645T).


Asunto(s)
Pulmón/microbiología , Pasteurellaceae/clasificación , Filogenia , Porcinos/microbiología , Animales , Australia , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Genes Bacterianos , Pasteurellaceae/aislamiento & purificación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
9.
Emerg Infect Dis ; 25(1): 153-156, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30561297

RESUMEN

We report 3 cases of koala bite wound infection with Lonepinella koalarum-like bacteria requiring antimicrobial and surgical management. The pathogens could not be identified by standard tests. Phylogenetic analysis of 16S rRNA and housekeeping genes identified the genus. Clinicians should isolate bacteria and determine antimicrobial susceptibilities when managing these infections.


Asunto(s)
Infecciones por Pasteurellaceae/diagnóstico , Pasteurellaceae/aislamiento & purificación , Phascolarctidae/microbiología , Infección de Heridas/diagnóstico , Anciano , Animales , Mordeduras y Picaduras , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infecciones por Pasteurellaceae/microbiología , Queensland , Infección de Heridas/microbiología
10.
J Clin Microbiol ; 55(1): 264-273, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27847372

RESUMEN

Currently, there is no agreed method available for broth microdilution susceptibility testing of Haemophilus parasuis, one of the most important bacterial pathogens in pig production. Therefore, the aim of this study was to develop a method that could be easily performed by diagnostic laboratories and that appears suitable for a harmonized susceptibility testing. Growth determinations using one type strain and three field isolates revealed no visible growth of H. parasuis in media which have proven to be suitable for susceptibility testing of fastidious organisms. Therefore, a new medium, cation-adjusted Mueller-Hinton broth (CAMHB) plus NADH and sterile filtered heat-inactivated chicken serum, was developed. The reproducibility of MICs obtained in this medium was evaluated and statistically analyzed, considering a model with two different variables (precondition of five identical MICs and MIC mode accepting a deviation of ±1 dilution step, respectively). No significant differences for both variables were seen between two time points investigated and between results obtained with the recently proposed test medium broth (TMB). Nearly all MICs of quality control strains were in the acceptable range. Subsequently, 47 H. parasuis isolates representing 13 serovars were tested with the newly developed medium and TMB. Statistical analysis of all isolates and 15 antimicrobial agents and antimicrobial combinations showed no significant difference between MICs obtained in supplemented CAMHB and TMB. Because of a simplified implementation in routine diagnostic and a lower chance of interference between medium components and antimicrobial agents, supplemented CAMHB is recommended with an incubation time of 24 h.


Asunto(s)
Antibacterianos/farmacología , Haemophilus parasuis/efectos de los fármacos , Pruebas de Sensibilidad Microbiana/métodos , Pruebas de Sensibilidad Microbiana/normas , Animales , Medios de Cultivo/química , Reproducibilidad de los Resultados , Porcinos
11.
J Clin Microbiol ; 53(2): 477-85, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25428149

RESUMEN

Pasteurella multocida is a Gram-negative bacterial pathogen that is the causative agent of a wide range of diseases in many animal species, including humans. A widely used method for differentiation of P. multocida strains involves the Heddleston serotyping scheme. This scheme was developed in the early 1970s and classifies P. multocida strains into 16 somatic or lipopolysaccharide (LPS) serovars using an agar gel diffusion precipitin test. However, this gel diffusion assay is problematic, with difficulties reported in accuracy, reproducibility, and the sourcing of quality serovar-specific antisera. Using our knowledge of the genetics of LPS biosynthesis in P. multocida, we have developed a multiplex PCR (mPCR) that is able to differentiate strains based on the genetic organization of the LPS outer core biosynthesis loci. The accuracy of the LPS-mPCR was compared with classical Heddleston serotyping using LPS compositional data as the "gold standard." The LPS-mPCR correctly typed 57 of 58 isolates; Heddleston serotyping was able to correctly and unambiguously type only 20 of the 58 isolates. We conclude that our LPS-mPCR is a highly accurate LPS genotyping method that should replace the Heddleston serotyping scheme for the classification of P. multocida strains.


Asunto(s)
Vías Biosintéticas/genética , Genotipo , Lipopolisacáridos/biosíntesis , Tipificación Molecular/métodos , Reacción en Cadena de la Polimerasa Multiplex/métodos , Pasteurella multocida/clasificación , Pasteurella multocida/genética , Animales , Humanos , Infecciones por Pasteurella/diagnóstico , Infecciones por Pasteurella/microbiología , Factores de Tiempo
13.
Avian Dis ; 58(1): 124-8, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24758124

RESUMEN

Fowl cholera, caused by Pasteurella multocida, remains a major problem of poultry worldwide. In the current report, we describe an outbreak in free range organic broilers. In addition to culturing samples from dead broilers, we attempted to isolate P. multocida from feral cats trapped on the farm. The isolates were identified by PCR as P. multocida and then serotyped using the Heddleston scheme and genotyped using both a multilocus sequence typing (MLST) method and an enterobacterial repetitive intergenic consensus (ERIC)-PCR method. A total of 123 isolates of P. multocida were recovered from 12 broilers. All 123 isolates were examined by ERIC-PCR, and only one pattern was identified. A subset of seven broiler isolates were examined by MLST and all were typed as sequence type (ST) 20. A total of 28 isolates of P. multocida were recovered from 17 cats, and five ERIC-PCR genotypes were identified, with one genotype (E-1, shared by 19 isolates) being the same as the ERIC-PCR pattern associated with the broilers. One representative cat strain for each ERIC-PCR pattern was subjected to MLST. The cat isolate with the same ERIC-PCR genotype as the broiler isolates was confirmed as having the same MLST result, ST 20. The other five cat ERIC-PCR patterns were allocated to four STs: E-2 and E-5 to ST 265, E-3 to ST 30, E-4 to ST 20, and E-6 to ST 264. Both genotyping methods confirmed that isolates of P. multocida were common between the feral cats and the chickens. It was not clear whether the strain was transmitted from the cats to the chicken or whether the cats obtained the strain preying on chicken. The study has shown that cats can harbor P. multocida strains with the same genotype found in chickens affected with fowl cholera.


Asunto(s)
Enfermedades de los Gatos/epidemiología , Brotes de Enfermedades/veterinaria , Infecciones por Pasteurella/veterinaria , Pasteurella multocida/genética , Enfermedades de las Aves de Corral/epidemiología , Animales , Australia/epidemiología , Enfermedades de los Gatos/microbiología , Gatos , Recuento de Colonia Microbiana/veterinaria , ADN Intergénico/genética , ADN Intergénico/metabolismo , Genotipo , Tipificación de Secuencias Multilocus/veterinaria , Infecciones por Pasteurella/epidemiología , Infecciones por Pasteurella/microbiología , Infecciones por Pasteurella/patología , Pasteurella multocida/aislamiento & purificación , Reacción en Cadena de la Polimerasa/veterinaria , Enfermedades de las Aves de Corral/microbiología , Enfermedades de las Aves de Corral/patología
14.
Vet Microbiol ; 288: 109930, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38086163

RESUMEN

Mannheimia haemolytica is known as one of the major bacterial contributors to Bovine Respiratory Disease (BRD) syndrome. This study sought to establish a novel species-specific PCR to aid in identification of this key pathogen. As well, an existing multiplex PCR was used to determine the prevalence of serovars 1, 2 or 6 in Australia. Most of the 65 studied isolates originated from cattle with a total of 11 isolates from small ruminants. All problematic field isolates in the identification or serotyping PCRs were subjected to whole genome sequencing and bioinformatic analysis. The field isolates were also subjected to rep-PCR fingerprinting. A total of 59 out of the 65 tested isolates were conformed as M. haemolytica by the new species-specific PCR which is based on the rpoB gene. The confirmed M. haemolytica field isolates were assigned to serovars 1 (24 isolates), 2 (seven isolates) and 6 (26 isolates) while two of the isolates were negative in the serotyping PCR. The two non-typeable isolates were assigned to serovar 7 and 14 following whole genome sequencing and bioinformatic analysis. The rep-PCR typing resulted in five major clusters with serovars 1 and 6 often within the same cluster. The M. haemolytica-specific PCR developed in this work was species specific and should be a valuable support for frontline diagnostic laboratories. The serotyping results support the relative importance of serovars 1 and 6 in bovine respiratory disease.


Asunto(s)
Enfermedades de los Bovinos , Mannheimia haemolytica , Enfermedades Respiratorias , Bovinos , Animales , Bacterias/genética , Serotipificación/métodos , Serotipificación/veterinaria , Enfermedades de los Bovinos/microbiología , Rumiantes , Reacción en Cadena de la Polimerasa Multiplex/veterinaria , Enfermedades Respiratorias/veterinaria
15.
Microbiol Spectr ; 12(4): e0380523, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38426766

RESUMEN

Pasteurella multocida is an upper respiratory tract commensal in several mammal and bird species but can also cause severe disease in humans and in production animals such as poultry, cattle, and pigs. In this study, we performed whole-genome sequencing of P. multocida isolates recovered from a range of human infections, from the mouths of cats, and from wounds on dogs. Together with publicly available P. multocida genome sequences, we performed phylogenetic and comparative genomic analyses. While isolates from cats and dogs were spread across the phylogenetic tree, human infections were caused almost exclusively by subsp. septica strains. Most of the human isolates were capsule type A and LPS type L1 and L3; however, some strains lacked a capsule biosynthesis locus, and some strains contained a novel LPS outer-core locus, distinct from the eight LPS loci that can currently be identified using an LPS multiplex PCR. In addition, the P. multocida strains isolated from human infections contained novel mobile genetic elements. We compiled a curated database of known P. multocida virulence factor and antibiotic resistance genes (PastyVRDB) allowing for detailed characterization of isolates. The majority of human P. multocida isolates encoded a reduced range of iron receptors and contained only one filamentous hemagglutinin gene. Finally, gene-trait analysis identified a putative L-fucose uptake and utilization pathway that was over-represented in subsp. septica strains and may represent a novel host predilection mechanism in this subspecies. Together, these analyses have identified pathogenic mechanisms likely important for P. multocida zoonotic infections.IMPORTANCEPasteurella multocida can cause serious infections in humans, including skin and wound infections, pneumonia, peritonitis, meningitis, and bacteraemia. Cats and dogs are known vectors of human pasteurellosis, transmitting P. multocida via bite wounds or contact with animal saliva. The mechanisms that underpin P. multocida human predilection and pathogenesis are poorly understood. With increasing identification of antibiotic-resistant P. multocida strains, understanding these mechanisms is vital for developing novel treatments and control strategies to combat P. multocida human infection. Here, we show that a narrow range of P. multocida strains cause disease in humans, while cats and dogs, common vectors for zoonotic infections, can harbor a wide range of P. multocida strains. We also present a curated P. multocida-specific database, allowing quick and detailed characterization of newly sequenced P. multocida isolates.


Asunto(s)
Infecciones por Pasteurella , Pasteurella multocida , Humanos , Gatos , Bovinos , Animales , Porcinos , Perros , Pasteurella multocida/genética , Filogenia , Lipopolisacáridos/metabolismo , Infecciones por Pasteurella/veterinaria , Antibacterianos/farmacología , Antibacterianos/metabolismo , Zoonosis , Mamíferos
16.
Poult Sci ; 103(4): 103485, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38335668

RESUMEN

Chickens are the primary reservoirs of Campylobacter spp., mainly C. jejuni and C. coli, that cause human bacterial gastrointestinal infections. However, genomic characteristics and antimicrobial resistance of Campylobacter spp. in low- to middle-income countries need more comprehensive exploration. This study aimed to characterize 21 C. jejuni and 5 C. coli isolates from commercial broilers and native chickens using whole genome sequencing and compare them to 28 reference Campylobacter sequences. Among the 26 isolates, 13 sequence types (ST) were identified in C. jejuni and 5 ST in C. coli. The prominent ST was ST 2274 (5 isolates, 19.2%), followed by ST 51, 460, 2409, and 6455 (2 isolates in each ST, 7.7%), while all remaining ST (464, 536, 595, 2083, 6736, 6964, 8096, 10437, 828, 872, 900, 8237, and 13540) had 1 isolate per ST (3.8%). Six types of antimicrobial resistance genes (ant(6)-Ia, aph(3')-III, blaOXA, cat, erm(B), and tet(O)) and one point mutations in the gyrA gene (Threonine-86-Isoleucine) and another in the rpsL gene (Lysine-43-Arginine) were detected. The blaOXA resistance gene was present in all isolates, the gyrA mutations was in 95.2% of C. jejuni and 80.0% of C. coli, and the tet(O) resistance gene in 76.2% of C. jejuni and 80.0% of C. coli. Additionally, 203 virulence-associated genes linked to 16 virulence factors were identified. In terms of phenotypic resistance, the C. jejuni isolates were all resistant to ciprofloxacin, enrofloxacin, and nalidixic acid, with lower levels of resistance to tetracycline (76.2%), tylosin (52.3%), erythromycin (23.8%), azithromycin (22.2%), and gentamicin (11.1%). Most C. coli isolates were resistant to all tested antimicrobials, while 1 C. coli was pan-susceptible except for tylosin. Single-nucleotide polymorphisms concordance varied widely, with differences of up to 13,375 single-nucleotide polymorphisms compared to the reference Campylobacter isolates, highlighting genetic divergence among comparative genomes. This study contributes to a deeper understanding of the molecular epidemiology of Campylobacter spp. in Thai chicken production systems.


Asunto(s)
Antiinfecciosos , Infecciones por Campylobacter , Campylobacter coli , Campylobacter jejuni , Campylobacter , Animales , Humanos , Pollos/genética , Tailandia/epidemiología , Infecciones por Campylobacter/epidemiología , Infecciones por Campylobacter/veterinaria , Infecciones por Campylobacter/microbiología , Tilosina , Farmacorresistencia Bacteriana/genética , Campylobacter/genética , Antibacterianos/farmacología , Secuenciación Completa del Genoma/veterinaria , Pruebas de Sensibilidad Microbiana/veterinaria
17.
J Bacteriol ; 195(21): 4854-64, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23974032

RESUMEN

Pasteurella multocida is a Gram-negative multispecies pathogen and the causative agent of fowl cholera, a serious disease of poultry which can present in both acute and chronic forms. The major outer membrane component lipopolysaccharide (LPS) is both an important virulence factor and a major immunogen. Our previous studies determined the LPS structures expressed by different P. multocida strains and revealed that a number of strains belonging to different serovars contain the same LPS biosynthesis locus but express different LPS structures due to mutations within glycosyltransferase genes. In this study, we report the full LPS structure of the serovar 4 type strain, P1662, and reveal that it shares the same LPS outer core biosynthesis locus, L3, with the serovar 3 strains P1059 and Pm70. Using directed mutagenesis, the role of each glycosyltransferase gene in LPS outer core assembly was determined. LPS structural analysis of 23 Australian field isolates that contain the L3 locus revealed that at least six different LPS outer core structures can be produced as a result of mutations within the LPS glycosyltransferase genes. Moreover, some field isolates produce multiple but related LPS glycoforms simultaneously, and three LPS outer core structures are remarkably similar to the globo series of vertebrate glycosphingolipids. Our in-depth analysis showing the genetics and full range of P. multocida lipopolysaccharide structures will facilitate the improvement of typing systems and the prediction of the protective efficacy of vaccines.


Asunto(s)
Regulación Bacteriana de la Expresión Génica/fisiología , Lipopolisacáridos/biosíntesis , Pasteurella multocida/clasificación , Pasteurella multocida/metabolismo , Secuencia de Aminoácidos , Variación Genética , Lipopolisacáridos/genética , Datos de Secuencia Molecular , Pasteurella multocida/genética
18.
Avian Pathol ; 42(6): 581-5, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24224551

RESUMEN

Pasteurella multocida was isolated from poultry on six farms (one free-range duck farm, one free-range turkey farm, one conventional enclosed turkey farm, and three free-range layer farms) suffering fowl cholera outbreaks. In addition, historical isolates from previous outbreaks were available for the conventional turkey farm and the three free-range layer farms. The isolates were serotyped using the Heddleston scheme and genotyped using multi-locus sequencing typing. In the current outbreaks, two of the farms had two different sequence types (STs) of P. multocida in the investigated outbreak (the free-range turkey farm and one of the free-range layer farms). The remaining four farms had one ST within the investigated outbreak. In looking at the historical isolates, two of the four farms had multiple genotypes involved. On the four farms with historical isolates from previous outbreaks, at least one new genotype was present in the investigated outbreak as compared with the historical isolates. On one layer farm, one genotype persisted over a 10-year period. Serotyping revealed the presence of multiple serovars in the current and historical outbreaks, with serovars sometimes changing over time. This study has shown that several STs of P. multocida can be present during some outbreaks of fowl cholera, although other outbreaks involve a single ST. Also, the STs present on a property suffering repeated fowl cholera can both persist and change over time.


Asunto(s)
Brotes de Enfermedades/veterinaria , Infecciones por Pasteurella/veterinaria , Pasteurella multocida/genética , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/microbiología , Animales , Australia/epidemiología , Genotipo , Reacción en Cadena de la Polimerasa/veterinaria , Aves de Corral , Serotipificación/veterinaria
19.
Biomedicines ; 11(8)2023 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-37626783

RESUMEN

The COVID-19 pandemic caused much illness, many deaths, and profound disruption to society. The production of 'safe and effective' vaccines was a key public health target. Sadly, unprecedented high rates of adverse events have overshadowed the benefits. This two-part narrative review presents evidence for the widespread harms of novel product COVID-19 mRNA and adenovectorDNA vaccines and is novel in attempting to provide a thorough overview of harms arising from the new technology in vaccines that relied on human cells producing a foreign antigen that has evidence of pathogenicity. This first paper explores peer-reviewed data counter to the 'safe and effective' narrative attached to these new technologies. Spike protein pathogenicity, termed 'spikeopathy', whether from the SARS-CoV-2 virus or produced by vaccine gene codes, akin to a 'synthetic virus', is increasingly understood in terms of molecular biology and pathophysiology. Pharmacokinetic transfection through body tissues distant from the injection site by lipid-nanoparticles or viral-vector carriers means that 'spikeopathy' can affect many organs. The inflammatory properties of the nanoparticles used to ferry mRNA; N1-methylpseudouridine employed to prolong synthetic mRNA function; the widespread biodistribution of the mRNA and DNA codes and translated spike proteins, and autoimmunity via human production of foreign proteins, contribute to harmful effects. This paper reviews autoimmune, cardiovascular, neurological, potential oncological effects, and autopsy evidence for spikeopathy. With many gene-based therapeutic technologies planned, a re-evaluation is necessary and timely.

20.
J Wildl Dis ; 59(3): 398-406, 2023 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-37170426

RESUMEN

We describe two cases of wound infections of koalas (Phascolarctos cinereus), one wild and one captive, in which Lonepinella-like organisms were involved. The wild adult koala was captured with bite wound injuries, as part of a koala population management program in Queensland, Australia. In both cases, there was evidence of physical trauma causing the initial wound. The captive koala suffered injury from the cage wire, and the wild koala had injuries suggestive of intermale fighting. Gram-negative bacteria isolated from both cases proved to be challenging to identify using routine diagnostic tests. The wound in the captive koala yielded a pure culture of an organism shown by whole genome sequence (WGS) analysis to be a member of the genus Lonepinella, but not a member of the only formally described species, L. koalarum. The wound of the wild koala yielded a mixed culture of Citrobacter koseri, Enterobacter cloacae and an organism shown by WGS analysis to be Lonepinella, but again not Lonepinella koalarum. Both cases were difficult to treat; the captive koala eventually had to have the phalanges amputated, and the wild koala required removal of the affected claw. The two Lonepinella isolates from these cases have a close relationship to an isolate from a human wound caused by a koala bite and may represent a novel species within the genus Lonepinella. Wound infections in koalas linked to Lonepinella have not been reported previously. Wildlife veterinarians need to be aware of the potential presence of Lonepinella-like organisms when dealing with wound infections in koalas, and the inability of commercial kits and systems to correctly identify the isolates.


Asunto(s)
Infecciones por Chlamydia , Phascolarctidae , Infección de Heridas , Animales , Humanos , Phascolarctidae/microbiología , Australia/epidemiología , Animales Salvajes , Queensland/epidemiología , Infección de Heridas/veterinaria , Infecciones por Chlamydia/veterinaria
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