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To H, Maldonado J, Tsutsumi N, Gottschalk M, Frey J, Nagai S. Characterization of Actinobacillus pleuropneumoniae biovar 2 isolates reportedly reacted with the serovar 4 antiserum, and development of a multiplex PCR for O-antigen typing. Vet Microbiol 2024; 291:110030. [PMID: 38428226 DOI: 10.1016/j.vetmic.2024.110030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 02/14/2024] [Accepted: 02/20/2024] [Indexed: 03/03/2024]
Abstract
We have analyzed the capsule (CPS) and the lipopolysaccharide O-Antigen (O-Ag) biosynthesis loci of twelve Spanish field isolates of Actinobacillus pleuropneumoniae biovar 2, eleven of them previously typed serologically as serovar 4 and one non-typable (NT) (Maldonado et al., 2009, 2011). These isolates have the common core genes of the type I CPS locus, sharing >98% identity with those of serovar 2. However, the former possesses the O-Ag locus as serovar 4, and the latter possesses the O-Ag locus as serovar 7. The main difference found between the CPS loci of the 11 isolates and that of serovar 2 reference strain S1536 are two deletions, one of an 8 bp sequence upstream of the coding sequence and one of 111 bp sequence at the 5' end of the cps2G gene. The deletion mutations mentioned lead to a defect in the production of CPS in these isolates, which contributed to their previous mis-identification. In order to complement the serotyping of A. pleuropneumoniae in diagnostics and epidemiology, we have developed a multiplex PCR for the comprehensive O-Ag typing of all A. pleuropneumoniae isolates.
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Affiliation(s)
- Ho To
- Nippon Institute for Biological Science, Tokyo, Japan; Faculty of Agriculture and Aquaculture, University of Cuu Long, Vinh Long, Viet Nam.
| | - Jaime Maldonado
- Diagnostic Laboratory, Laboratorios HIPRA S.A., Paratge Arbusset s/n, Girona 17170, Spain
| | | | - Marcelo Gottschalk
- Groupe de Recherche sur les Maladies Infectieuses en Production Animale, Faculty of Veterinary Medicine, University of Montreal, Québec, Canada
| | - Joachim Frey
- Vetsuisse Faculty, University of Bern, Bern 3012, Switzerland
| | - Shinya Nagai
- Nippon Institute for Biological Science, Tokyo, Japan
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2
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Tenk M, Tóth G, Márton Z, Sárközi R, Szórádi A, Makrai L, Pálmai N, Szalai T, Albert M, Fodor L. Examination of the Virulence of Actinobacillus pleuropneumoniae Serovar 16 in Pigs. Vet Sci 2024; 11:62. [PMID: 38393080 PMCID: PMC10892955 DOI: 10.3390/vetsci11020062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 01/20/2024] [Accepted: 01/23/2024] [Indexed: 02/25/2024] Open
Abstract
Different virulence variants of A. pleuropneumoniae are involved in the etiology of porcine pleuropneumonia. The purpose of the present trial was examination of the virulence of the Actinobacillus pleuropneumoniae A-85/14 strain, the type strain of serovar 16, in an animal challenge experiment. Thirty 12-week-old piglets seronegative for A. pleuropneumoniae were allocated into three trial groups each of 10 animals, and they were infected intranasally with 106, 107, or 108 colony forming units (cfu) of the strain, respectively. Clinical signs were recorded twice a day, and the animals were euthanized 6 days after the infection. Typical clinical signs and postmortem lesions of porcine pleuropneumonia were seen in the animals of each trial group; however, they were generally mild, and no significant differences could be seen between the three groups. Even 106 colony forming units of A. pleuropneumoniae A-85/14 strain could induce clinical signs and lesions. Based on these results, the type strain of serovar 16 of A. pleuropneumoniae must be regarded as a typical pathogenic strain of the species.
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Affiliation(s)
- Miklós Tenk
- CEVA-Phylaxia Veterinary Biologicals Co., Ltd., Szállás u. 5, H-1107 Budapest, Hungary; (M.T.); (Z.M.); (A.S.); (N.P.); (T.S.); (M.A.)
- Department of Microbiology and Infectious Diseases, University of Veterinary Medicine, Hungária Krt. 23-25, H-1143 Budapest, Hungary; (G.T.); (R.S.); (L.M.)
| | - Gergely Tóth
- Department of Microbiology and Infectious Diseases, University of Veterinary Medicine, Hungária Krt. 23-25, H-1143 Budapest, Hungary; (G.T.); (R.S.); (L.M.)
| | - Zsuzsanna Márton
- CEVA-Phylaxia Veterinary Biologicals Co., Ltd., Szállás u. 5, H-1107 Budapest, Hungary; (M.T.); (Z.M.); (A.S.); (N.P.); (T.S.); (M.A.)
| | - Rita Sárközi
- Department of Microbiology and Infectious Diseases, University of Veterinary Medicine, Hungária Krt. 23-25, H-1143 Budapest, Hungary; (G.T.); (R.S.); (L.M.)
| | - Alejandra Szórádi
- CEVA-Phylaxia Veterinary Biologicals Co., Ltd., Szállás u. 5, H-1107 Budapest, Hungary; (M.T.); (Z.M.); (A.S.); (N.P.); (T.S.); (M.A.)
| | - László Makrai
- Department of Microbiology and Infectious Diseases, University of Veterinary Medicine, Hungária Krt. 23-25, H-1143 Budapest, Hungary; (G.T.); (R.S.); (L.M.)
| | - Nimród Pálmai
- CEVA-Phylaxia Veterinary Biologicals Co., Ltd., Szállás u. 5, H-1107 Budapest, Hungary; (M.T.); (Z.M.); (A.S.); (N.P.); (T.S.); (M.A.)
| | - Tamás Szalai
- CEVA-Phylaxia Veterinary Biologicals Co., Ltd., Szállás u. 5, H-1107 Budapest, Hungary; (M.T.); (Z.M.); (A.S.); (N.P.); (T.S.); (M.A.)
| | - Mihály Albert
- CEVA-Phylaxia Veterinary Biologicals Co., Ltd., Szállás u. 5, H-1107 Budapest, Hungary; (M.T.); (Z.M.); (A.S.); (N.P.); (T.S.); (M.A.)
| | - László Fodor
- Department of Microbiology and Infectious Diseases, University of Veterinary Medicine, Hungária Krt. 23-25, H-1143 Budapest, Hungary; (G.T.); (R.S.); (L.M.)
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Morreale DP, Porsch EA, Kern BK, St Geme JW, Planet PJ. Acquisition, co-option, and duplication of the rtx toxin system and the emergence of virulence in Kingella. Nat Commun 2023; 14:4281. [PMID: 37460464 DOI: 10.1038/s41467-023-39939-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 07/04/2023] [Indexed: 07/20/2023] Open
Abstract
The bacterial genus Kingella includes two pathogenic species, namely Kingella kingae and Kingella negevensis, as well as strictly commensal species. Both K. kingae and K. negevensis secrete a toxin called RtxA that is absent in the commensal species. Here we present a phylogenomic study of the genus Kingella, including new genomic sequences for 88 clinical isolates, genotyping of another 131 global isolates, and analysis of 52 available genomes. The phylogenetic evidence supports that the toxin-encoding operon rtxCA was acquired by a common ancestor of the pathogenic Kingella species, and that a preexisting type-I secretion system was co-opted for toxin export. Subsequent genomic reorganization distributed the toxin machinery across two loci, with 30-35% of K. kingae strains containing two copies of the rtxA toxin gene. The rtxA duplication is largely clonal and is associated with invasive disease. Assays with isogenic strains show that a single copy of rtxA is associated with reduced cytotoxicity in vitro. Thus, our study identifies key steps in the evolutionary transition from commensal to pathogen, including horizontal gene transfer, co-option of an existing secretion system, and gene duplication.
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Affiliation(s)
- Daniel P Morreale
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Division of Infectious Diseases, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Eric A Porsch
- Division of Infectious Diseases, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Brad K Kern
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Division of Infectious Diseases, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Joseph W St Geme
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Division of Infectious Diseases, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Paul J Planet
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
- Division of Infectious Diseases, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
- Comparative Genomics, American Museum of Natural History, New York, NY, USA.
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Vereecke N, Vandekerckhove A, Theuns S, Haesebrouck F, Boyen F. Whole genome sequencing to study antimicrobial resistance and RTX virulence genes in equine Actinobacillus isolates. Vet Res 2023; 54:33. [PMID: 37020296 PMCID: PMC10074821 DOI: 10.1186/s13567-023-01160-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 03/03/2023] [Indexed: 04/07/2023] Open
Abstract
Actinobacillus equuli is mostly associated with disease in horses and is most widely known as the causative agent of sleepy foal disease. Even though existing phenotypic tools such as biochemical tests, 16S rRNA gene sequencing, and Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) can be used to identify members of the Actinobacillus genus, these methods struggle to differentiate between certain species and do not allow strain, virulence, and antimicrobial susceptibility typing. Hence, we performed in-depth analysis of 24 equine Actinobacillus isolates using phenotypic identification and susceptibility testing on the one hand, and long-read nanopore whole genome sequencing on the other hand. This allowed to address strain divergence down to the whole genome single nucleotide polymorphism (SNP) level. While lowest resolution was observed for 16S rRNA gene classification, a new multi-locus sequence typing (MLST) scheme allowed proper classification up to the species level. Nevertheless, a SNP-level analysis was required to distinguish A. equuli subspecies equuli and haemolyticus. Our data provided first WGS data on Actinobacillus genomospecies 1, Actinobacillus genomospecies 2, and A. arthritidis, which allowed the identification of a new Actinobacillus genomospecies 1 field isolate. Also, in-depth characterization of RTX virulence genes provided information on the distribution, completeness, and potential complementary nature of the RTX gene operons within the Actinobacillus genus. Even though overall low prevalence of acquired resistance was observed, two plasmids were identified conferring resistance to penicillin-ampicillin-amoxicillin and chloramphenicol in one A. equuli strain. In conclusion our data delivered new insights in the use of long-read WGS in high resolution identification, virulence gene typing, and antimicrobial resistance (AMR) of equine Actinobacillus species.
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Affiliation(s)
- Nick Vereecke
- Department of Translational Physiology, Infectiology and Public Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium.
- PathoSense BV, Lier, Belgium.
| | - Arlette Vandekerckhove
- Department of Pathobiology, Pharmacology and Zoological Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | | | - Freddy Haesebrouck
- Department of Pathobiology, Pharmacology and Zoological Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Filip Boyen
- Department of Pathobiology, Pharmacology and Zoological Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
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Comparative Efficacy in Challenge Dose Models of a Toxin Expressing Whole-Cell Vaccine against Eight Serovars of Actinobacillus pleuropneumoniae in Pigs. Animals (Basel) 2022; 12:ani12233244. [PMID: 36496765 PMCID: PMC9740876 DOI: 10.3390/ani12233244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 11/19/2022] [Accepted: 11/20/2022] [Indexed: 11/24/2022] Open
Abstract
Actinobacillus pleuropneumoniae is a major economically significant bacterial respiratory pig pathogen, and whole cell vaccines are used to prevent disease. However, there is little data available on multi-serovar whole cell vaccine protection. Therefore, we determined the protective efficacies of a whole-cell A. pleuropneumoniae serovar 1 and 2 vaccine comprising ApxI-III toxins (C-vaccine, Coglapix®, Ceva, France) against serovars 1, 2, 4, 5, 6, 7, 9/11, and 13. The infection doses used induced disease representative of endemic field conditions, and standard protocols were used for all studies. Protection against homologous serovars 1 and 2 significantly reduced lung lesion scores (LLS) compared to positive controls: p = 0.00007 and p = 0.00124, respectively. The protection against heterologous serovars 4, 5, 6, 7, 9/11, and 13 also significantly reduced LLS: range p = 2.9 × 10-10 to p = 0.00953. As adjudged by the estimated random effect, reproducibility between studies was high. A highly significant serovar-independent reduction of pathological lung lesions by the C-vaccine was found for all the serovars tested (1, 2, 4, 5, 6, 7, 9/11, and 13). We conclude that the C-vaccine gives high serovar-independent protection against disease and is suitable for this use in the field.
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Outer Membrane Vesicles of Actinobacillus pleuropneumoniae Exert Immunomodulatory Effects on Porcine Alveolar Macrophages. Microbiol Spectr 2022; 10:e0181922. [PMID: 36040198 PMCID: PMC9602539 DOI: 10.1128/spectrum.01819-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Outer membrane vesicles (OMVs) are spontaneously released by Gram-negative bacteria, including Actinobacillus pleuropneumoniae, which causes contagious pleuropneumonia in pigs and leads to considerable economic losses in the swine industry worldwide. A. pleuropneumoniae OMVs have previously been demonstrated to contain Apx toxins and proteases, as well as antigenic proteins. Nevertheless, comprehensive characterizations of their contents and interactions with host immune cells have not been made. Understanding the protein compositions and immunomodulating ability of A. pleuropneumoniae OMVs could help illuminate their biological functions and facilitate the development of OMV-based applications. In the current investigation, we comprehensively characterized the proteome of native A. pleuropneumoniae OMVs. Moreover, we qualitatively and quantitatively compared the OMV proteomes of a wild-type strain and three mutant strains, in which relevant genes were disrupted to increase OMV production and/or produce OMVs devoid of superantigen PalA. Furthermore, the interaction between A. pleuropneumoniae OMVs and porcine alveolar macrophages was also characterized. Our results indicate that native OMVs spontaneously released by A. pleuropneumoniae MIDG2331 appeared to dampen the innate immune responses by porcine alveolar macrophages stimulated by either inactivated or live parent cells. The findings suggest that OMVs may play a role in manipulating the porcine defense during the initial phases of the A. pleuropneumoniae infection. IMPORTANCE Owing to their built-in adjuvanticity and antigenicity, bacterial outer membrane vesicles (OMVs) are gaining increasing attention as potential vaccines for both human and animal use. OMVs released by Actinobacillus pleuropneumoniae, an important respiratory pathogen in pigs, have also been investigated for vaccine development. Our previous studies have shown that A. pleuropneumoniae secretes OMVs containing multiple immunogenic proteins. However, immunization of pigs with these vesicles was not able to relieve the pig lung lesions induced by the challenge with A. pleuropneumoniae, implying the elusive roles that A. pleuropneumoniae OMVs play in host-pathogen interaction. Here, we showed that A. pleuropneumoniae secretes OMVs whose yield and protein content can be altered by the deletion of the nlpI and palA genes. Furthermore, we demonstrate that A. pleuropneumoniae OMVs dampen the immune responses in porcine alveolar macrophages stimulated by A. pleuropneumoniae cells, suggesting a novel mechanism that A. pleuropneumoniae might use to evade host defense.
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Genetic Diversity of Actinobacillus pleuropneumoniae Serovars in Hungary. Vet Sci 2022; 9:vetsci9100511. [PMID: 36288125 PMCID: PMC9607985 DOI: 10.3390/vetsci9100511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/12/2022] [Accepted: 09/16/2022] [Indexed: 11/25/2022] Open
Abstract
Simple Summary Actinobacillus pleuropneumoniae causes severe pneumonia in pigs, resulting in high economic losses. A total of 114 isolates from pneumonia were characterized by the examination of biotype, serovar, antibiotic resistance genes, and genes of toxin production. Analyzing their genetic relationship, 16 groups of related isolates were found. The genetic diversity was different in the different groups, however. It was remarkably small in the case of serovar 13, which was unusually frequent in Hungary. Therefore, representative isolates of serovar 13 were subjected to whole-genome sequencing, confirming low diversity. Antibiotic resistance was frequently found in isolates of serovar 13 but was less frequent in other serovars. The unusually high frequency and low diversity of serovar 13 suggest a clonal spread in Hungary, which may have been facilitated by a high frequency of resistance to beta-lactams and tetracyclines. Abstract A total of 114 Actinobacillus pleuropneumoniae isolates from porcine hemorrhagic necrotic pleuropneumonia were characterized by the examination of biotype, serovar, antibiotic resistance genes, and genes of toxin production. Pulsed-field gel electrophoresis was used to analyze their genetic relationship, which identified 16 clusters. Serovar 2 (50 isolates), serovar 13 (25 isolates), serovar 9 (11 isolates), and serovar 16 (7 isolates) were the most frequent serovars. Serovar 2 formed nine distinguishable clusters; serovar 13 and serovar 16 were less diverse, exhibiting two potentially related subclusters; serovar 9 was represented by a single cluster. Remarkably small differences were seen in the core genome when nine representative isolates of serovar 13 were subjected to whole-genome sequencing. Tetracycline resistance was relatively frequent in the two clusters of serovar 13; one of them was also frequently resistant against beta-lactams. Resistance in other serovars was sporadic. All isolates carried the apxIV gene. The toxin profiles of serovar 2 were characterized by the production of ApxII and ApxIII toxins, except for a small cluster of three isolates: serovar 9 and serovar 16 isolates produced ApxI and ApxII toxins. Serovar 13 carried apxII and apxIBD genes, indicating the production of the ApxII toxin, but not of ApxI or ApxIII. The unusually high frequency and low diversity of serovar 13 are not explained by its virulence properties, but the high frequency of resistance to beta-lactams and tetracyclines may have played a role in its spread. The emergence of serovar 16 may be facilitated by its high virulence, also explaining its high clonality.
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Stancheva SG, Frömbling J, Sassu EL, Hennig-Pauka I, Ladinig A, Gerner W, Grunert T, Ehling-Schulz M. Proteomic and immunoproteomic insights into the exoproteome of Actinobacillus pleuropneumoniae, the causative agent of porcine pleuropneumonia. Microb Pathog 2022; 172:105759. [PMID: 36087692 DOI: 10.1016/j.micpath.2022.105759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 10/31/2022]
Abstract
Porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae affects pig health status and the swine industry worldwide. Despite the extensive number of studies focused on A. pleuropneumoniae infection and vaccine development, a thorough analysis of the A. pleuropneumoniae exoproteome is still missing. Using a complementary approach of quantitative proteomics and immunoproteomics we gained an in-depth insight into the A. pleuropneumoniae serotype 2 exoproteome, which provides the basis for future functional studies. Label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed 593 exoproteins, of which 104 were predicted to be virulence factors. The RTX toxins ApxIIA and ApxIIIA -were found to be the most abundant proteins in the A. pleuropneumoniae serotype 2 exoproteome. Furthermore, the ApxIVA toxin was one of the proteins showing the highest abundance, although ApxIVA is commonly assumed to be expressed exclusively in vivo. Our study revealed several antigens, including proteins with moonlight functions, such as the elongation factor (EF)-Tu, and proteins linked to specific metabolic traits, such as the maltodextrin-binding protein MalE, that warrant future functional characterization and might present potential targets for novel therapeutics and vaccines. Our Ig-classes specific serological proteome analysis (SERPA) approach allowed us to explore the development of the host humoral immune response over the course of the infection. These SERPAs pinpointed proteins that might play a key role in virulence and persistence and showed that the immune response to the different Apx toxins is distinct. For instance, our results indicate that the ApxIIIA toxin has properties of a thymus-independent antigen, which should be studied in more detail.
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Affiliation(s)
- Stelli G Stancheva
- Institute of Microbiology, Department for Pathobiology, University of Veterinary Medicine Vienna, Austria
| | - Janna Frömbling
- Institute of Microbiology, Department for Pathobiology, University of Veterinary Medicine Vienna, Austria
| | - Elena L Sassu
- University Clinic for Swine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Austria
| | - Isabel Hennig-Pauka
- Field Station for Epidemiology, University of Veterinary Medicine Hannover, Bakum, Germany
| | - Andrea Ladinig
- University Clinic for Swine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Austria
| | - Wilhelm Gerner
- Institute of Immunology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Tom Grunert
- Institute of Microbiology, Department for Pathobiology, University of Veterinary Medicine Vienna, Austria
| | - Monika Ehling-Schulz
- Institute of Microbiology, Department for Pathobiology, University of Veterinary Medicine Vienna, Austria.
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Sarkar R, Roychoudhury P, Kumar S, Dutta S, Konwar N, Subudhi PK, Dutta TK. Rapid detection of Actinobacillus pleuropneumoniae targeting the apxIVA gene for diagnosis of contagious porcine pleuropneumonia in pigs by Polymerase Spiral Reaction. Lett Appl Microbiol 2022; 75:442-449. [PMID: 35616177 DOI: 10.1111/lam.13749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 11/29/2022]
Abstract
Actinobacillus pleuropneumoniae is the primary etiological agent of contagious porcine pleuropneumonia associated with serious economic impact on pig husbandry worldwide. Diagnosis of the disease by existing techniques including isolation and identification bacteria followed by serotyping, serological techniques, conventional PCR, real-time PCR and LAMP assays are cumbersome, time consuming, costly and not suitable for rapid field application. A novel isothermal polymerase chain reaction (PSR) technique is standardized for all the reagents, incubation time and incubation temperature against A. pleuropneumoniae. Sensitivity of the assay was determined against various dilutions of purified DNA and total bacterial count. Specificity of the assay was determined against 11 closely related bacterial isolates. The relative sensitivity and specificity was compared with bacterial isolation, conventional PCR and real-time PCR assays. The PSR assay for specific detection was standardized at 64o C for 30 minutes incubation in a water bath. The result was visible by the naked eye after centrifugation of the reaction mixture or after incorporation of SYBR Green dye as yellow-green fluorescence. The technique was found to be 100% specific and equally sensitive with real-time PCR and 10 times more sensitive than conventional PCR. The PSR assay could be applicable in detection of the organisms in porcine nasal swabs spiked with A. pleuropneumoniae. This is the first ever report on development of PSR for specific detection of A. pleuropneumoniae and can be applied for early diagnosis at field level.
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Affiliation(s)
- R Sarkar
- Department of Veterinary Microbiology, Central Agricultural University, Selesih, Aizawl, Mizoram-796 014, India
| | - P Roychoudhury
- Department of Veterinary Microbiology, Central Agricultural University, Selesih, Aizawl, Mizoram-796 014, India
| | - S Kumar
- Department of Veterinary Microbiology, Central Agricultural University, Selesih, Aizawl, Mizoram-796 014, India
| | - S Dutta
- Department of Veterinary Microbiology, Central Agricultural University, Selesih, Aizawl, Mizoram-796 014, India
| | - N Konwar
- Department of Veterinary Microbiology, Central Agricultural University, Selesih, Aizawl, Mizoram-796 014, India
| | - P K Subudhi
- Department of Veterinary Microbiology, Central Agricultural University, Selesih, Aizawl, Mizoram-796 014, India
| | - T K Dutta
- Department of Veterinary Microbiology, Central Agricultural University, Selesih, Aizawl, Mizoram-796 014, India
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Isolation of Biotype 1 Serotype 12 and Detection of Actinobacillus pleuropneumoniae from Wild Boars. Pathogens 2022; 11:pathogens11050505. [PMID: 35631027 PMCID: PMC9142963 DOI: 10.3390/pathogens11050505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/21/2022] [Accepted: 04/22/2022] [Indexed: 02/04/2023] Open
Abstract
Actinobacillus pleuropneumoniae is a major pathogen of swine, which can cause severe pleuropneumonia in pigs, but sometimes the disease can be generalized. Diseases caused by A. pleuropneumoniae are frequent all over the world, resulting in high losses among domestic pigs. However, our knowledge on the occurrence of A. pleuropneumoniae in wild boars and feral pigs is limited. We aimed to examine the carriage of A. pleuropneumoniae by hunted wild boars. The presence of A. pleuropneumoniae was examined in tonsils of 68 hunted wild boars collected at a game processing unit. An in-house designed species-specific PCR test was used to detect the gene of Apx IV toxin, and the samples were inoculated on a modified selective agar. A. pleuropneumoniae was detected in 10 animals (14.7%) by PCR and one A. pleuropneumoniae serotype 12 strain was isolated. The antibiotic resistance pattern of the strain resembled field strains that were isolated from farmed pigs in Hungary. This is the first case for the detection of A. pleuropneumoniae not only using PCR or ELISA, but also its isolation, identification, and serotyping.
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Hennig-Pauka I, Hartmann M, Merkel J, Kreienbrock L. Coinfections and Phenotypic Antimicrobial Resistance in Actinobacillus pleuropneumoniae Strains Isolated From Diseased Swine in North Western Germany-Temporal Patterns in Samples From Routine Laboratory Practice From 2006 to 2020. Front Vet Sci 2022; 8:802570. [PMID: 35155648 PMCID: PMC8831912 DOI: 10.3389/fvets.2021.802570] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 12/14/2021] [Indexed: 11/13/2022] Open
Abstract
Actinobacillus pleuropneumoniae (APP) is one major bacterial porcine respiratory tract pathogen causing disease outbreaks worldwide, although effective commercial vaccines are available. Due to frequent failure of this preventive measure, treatment with antimicrobials is indispensable to prevent animal losses within an outbreak situation. To preserve the effectivity of antimicrobial substances to fight APP should therefore be the primary aim of any interventions. In this study, the temporal development of antimicrobial resistance in APP was analyzed retrospectively in the time period 2006-2020 from a routine diagnostic database. In parallel, frequent coinfections were evaluated to identify most important biotic cofactors as important triggers for disease outbreaks in endemically infected herds. The proportion of APP serotype 2 decreased over time but was isolated most often from diseased swine (57% in 2020). In ~1% of the cases, APP was isolated from body sites outside the respiratory tract as brain and joints. The lowest frequencies of resistant isolates were found for cephalothin and ceftiofur (0.18%), florfenicol (0.24%), tilmicosin (2.4%), tiamulin (2.4%), enrofloxacin (2.7%), and spectinomycin (3.6%), while the highest frequencies of resistant isolates were found for gentamicin (30.9%), penicillin (51.5%), and tetracycline (78.2%). For enrofloxacin, tiamulin, tilmicosin, and tetracycline, significantly lower frequencies of resistant isolates were found in the time period 2015-2020 compared to 2006-2014, while gentamicin-resistant isolates increased. In summary, there is only a low risk of treatment failure due to resistant isolates. In maximum, up to six coinfecting pathogens were identified in pigs positive for APP. Most often pigs were coinfected with Porcine Circovirus 2 (56%), Streptococcus suis (24.8%), or the Porcine Reproductive and Respiratory Syndrome Virus (23.3%). Potential synergistic effects between these pathogens published from experimental findings can be hypothesized by these field data as well. To prevent APP disease outbreaks in endemically infected herds more efficiently in the future, next to environmental trigger factors, preventive measures must also address the coinfecting agents.
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Affiliation(s)
- Isabel Hennig-Pauka
- Field Station for Epidemiology, University of Veterinary Medicine Hannover, Bakum, Germany
| | - Maria Hartmann
- Department of Biometry, Epidemiology and Information Processing, WHO Collaborating Centre for Research and Training for Health at the Human-Animal-Environment Interface, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Jörg Merkel
- Department of Infectious Diseases, Institute for Microbiology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Lothar Kreienbrock
- Department of Biometry, Epidemiology and Information Processing, WHO Collaborating Centre for Research and Training for Health at the Human-Animal-Environment Interface, University of Veterinary Medicine Hannover, Hannover, Germany
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12
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Proposal of a subtype of serovar 4, K4b:O3, of Actinobacillus pleuropneumoniae based on serological and genotypic analysis. Vet Microbiol 2021; 263:109279. [PMID: 34798366 DOI: 10.1016/j.vetmic.2021.109279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 11/02/2021] [Accepted: 11/08/2021] [Indexed: 11/22/2022]
Abstract
The aim of this study was to investigate an isolate of Actinobacillus pleuropneumoniae, named 14-760, which was serologically not classifiable among the recognised serovars of A. pleuropneumoniae. It reacted with the antisera raised against serovars 3, 6, 8, 15 and 17 in the agar gel precipitation (AGP) test, and was positive in the capsular serovar 4-specific PCR (cps4B PCR) assay. The isolate contains a type II capsule locus similar to serovar 4 but with variations in the length of four intergeneric regions (modF-cpxA, cpxD-cpsA, cpsC-a 114 bp orf, and lysA-ydeN), and three gene sequences (modF, cpsC and ydeN). The main difference found between the K4 and K4b cps genes is the additional 35 AAs found in type 4b due to a 4 bp insert in cps4bC. The LPS O-Ag locus is highly similar to that of reference strains of serovars 3, 6, 8, 15, 17 and 19. Isolate 14-760 is biovar 1 and contains solely the structural genes required for toxin ApxII production (apxIICA), and the type I secretion system (apxIBD) for the export of ApxII. Antiserum against isolate 14-760 adsorbed with antigen prepared from serovars 8, 15 or 17 reference strains remained reactive with isolate 14-760, but not with antigens prepared from serovars 1-18. Taken together, our results indicate the existence of a subtype of A. pleuropneumoniae, serovar 4, that we called "K4b:O3″, and we propose isolate 14-760 as the reference strain.
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13
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Komaniecki G, Lin H. Lysine Fatty Acylation: Regulatory Enzymes, Research Tools, and Biological Function. Front Cell Dev Biol 2021; 9:717503. [PMID: 34368168 PMCID: PMC8339906 DOI: 10.3389/fcell.2021.717503] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 06/30/2021] [Indexed: 11/19/2022] Open
Abstract
Post-translational acylation of lysine side chains is a common mechanism of protein regulation. Modification by long-chain fatty acyl groups is an understudied form of lysine acylation that has gained increasing attention recently due to the characterization of enzymes that catalyze the addition and removal this modification. In this review we summarize what has been learned about lysine fatty acylation in the approximately 30 years since its initial discovery. We report on what is known about the enzymes that regulate lysine fatty acylation and their physiological functions, including tumorigenesis and bacterial pathogenesis. We also cover the effect of lysine fatty acylation on reported substrates. Generally, lysine fatty acylation increases the affinity of proteins for specific cellular membranes, but the physiological outcome depends greatly on the molecular context. Finally, we will go over the experimental tools that have been used to study lysine fatty acylation. While much has been learned about lysine fatty acylation since its initial discovery, the full scope of its biological function has yet to be realized.
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Affiliation(s)
- Garrison Komaniecki
- Graduate Field of Biochemistry, Molecular, and Cell Biology, Cornell University, Ithaca, NY, United States.,Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, United States
| | - Hening Lin
- Graduate Field of Biochemistry, Molecular, and Cell Biology, Cornell University, Ithaca, NY, United States.,Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, United States.,Howard Hughes Medical Institute, Cornell University, Ithaca, NY, United States
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14
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Loy JD, Hille M, Maier G, Clawson ML. Component Causes of Infectious Bovine Keratoconjunctivitis - The Role of Moraxella Species in the Epidemiology of Infectious Bovine Keratoconjunctivitis. Vet Clin North Am Food Anim Pract 2021; 37:279-293. [PMID: 34049659 DOI: 10.1016/j.cvfa.2021.03.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Infectious bovine keratoconjunctivitis (IBK) involves multiple factors and opportunistic pathogens, including members of the genus Moraxella, specifically M bovis. The causal role of M bovis is clear, where the presence of virulence factors that facilitate colonization (pili) and host cytotoxicity (RTX toxins) are well characterized, and IBK has been reproduced in many models. Experimental infection with M bovoculi has failed to reproduce IBK-typical lesions in cattle thus far. However, recent work using genomics and mass spectrometry have found genomic diversity and recombination within these species, making species differentiation complex and challenging the ability to assign IBK causality to these organisms.
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Affiliation(s)
- John Dustin Loy
- Nebraska Veterinary Diagnostic Center, School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, 4040 East Campus Loop North 115Q NVDC, Lincoln, NE 68583-0907, USA.
| | - Matthew Hille
- Nebraska Veterinary Diagnostic Center, School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, 4040 East Campus Loop North 115Q NVDC, Lincoln, NE 68583-0907, USA
| | - Gabriele Maier
- Department of Population Health & Reproduction, School of Veterinary Medicine, University of California Davis, 1 Shields Avenue, VM3B, Davis, CA 95616, USA
| | - Michael L Clawson
- US Meat Animal Research Center, USDA Agriculture Research Service, Clay Center, 844 Road 313, Clay Center, NE 68933, USA
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15
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Stringer OW, Bossé JT, Lacouture S, Gottschalk M, Fodor L, Angen Ø, Velazquez E, Penny P, Lei L, Langford PR, Li Y. Proposal of Actinobacillus pleuropneumoniae serovar 19, and reformulation of previous multiplex PCRs for capsule-specific typing of all known serovars. Vet Microbiol 2021; 255:109021. [PMID: 33667982 DOI: 10.1016/j.vetmic.2021.109021] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 02/22/2021] [Indexed: 02/01/2023]
Abstract
Two serologically and molecularly non-typeable isolates of the porcine lung pathogen Actinobacillus pleuropneumoniae have been identified from diseased swine in two different continents. Genome sequencing was carried out to identify their diagnostically relevant genotypes. Both isolates are biovar 1 and encode genes for production of ApxIV and ApxII (apxIICA structural genes, and apxIBD export genes). They both possess the same novel type II capsule locus (most similar to serovar 1, but with two capsule genes not previously found in A. pleuropneumoniae) but differ in their O-Ag loci. Strain 7213384-1 from Denmark, which we propose as the reference strain for serovar 19, has a serogroup 3/6/8/15 O-Ag locus; the Canadian isolate A08-013 has a serogroup 4/7 O-Ag locus. We have expanded the second of our two previously described A. pleuropneumoniae mPCRs to include capsule gene-specific primers for definitive detection of serovars 13-14 and 16-19.
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Affiliation(s)
- Oliver W Stringer
- Section of Paediatric Infectious Disease, Department of Infectious Disease, Imperial College London, UK
| | - Janine T Bossé
- Section of Paediatric Infectious Disease, Department of Infectious Disease, Imperial College London, UK.
| | - Sonia Lacouture
- Groupe de Recherche sur les Maladies Infectieuses du Porc, Faculté de Médecine Vétérinaire, Université de Montréal, Québec, Canada
| | - Marcelo Gottschalk
- Groupe de Recherche sur les Maladies Infectieuses du Porc, Faculté de Médecine Vétérinaire, Université de Montréal, Québec, Canada
| | - László Fodor
- Department of Microbiology and Infectious Diseases, University of Veterinary Medicine, Budapest, Hungary
| | - Øystein Angen
- Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark
| | | | | | - Liancheng Lei
- College of Veterinary Medicine, Jilin University, Changchun, PR China
| | - Paul R Langford
- Section of Paediatric Infectious Disease, Department of Infectious Disease, Imperial College London, UK.
| | - Yanwen Li
- Section of Paediatric Infectious Disease, Department of Infectious Disease, Imperial College London, UK
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16
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Hille MM, Clawson ML, Dickey AM, Lowery JH, Loy JD. MALDI-TOF MS Biomarker Detection Models to Distinguish RTX Toxin Phenotypes of Moraxella bovoculi Strains Are Enhanced Using Calcium Chloride Supplemented Agar. Front Cell Infect Microbiol 2021; 11:632647. [PMID: 33796479 PMCID: PMC8007961 DOI: 10.3389/fcimb.2021.632647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 03/01/2021] [Indexed: 11/16/2022] Open
Abstract
Moraxella bovoculi is the bacterium most often cultured from ocular lesions of cattle with infectious bovine keratoconjunctivitis, also known as bovine pinkeye. Some strains of M. bovoculi contain operons encoding for a repeats-in-toxin (RTX) toxin, which is a known virulence factor of multiple veterinary pathogens. We explored the utility of MALDI-TOF MS and biomarker detection models to classify the presence or absence of an RTX phenotype in M. bovoculi. Ninety strains that had undergone whole genome sequencing were classified by the presence or absence of complete RTX operons and confirmed with a visual assessment of hemolysis on blood agar. Strains were grown on Tryptic Soy Agar (TSA) with 5% sheep blood, TSA with 5% bovine blood that was supplemented with 10% fetal bovine serum, 10 mmol/LCaCl2, or both. The formulations were designed to determine the influence of growth media on toxin production or activity, as calcium ions are required for toxin secretion and activity. Mass spectra were obtained for strains grown on each agar formulation and biomarker models were developed using ClinProTools 3.0 software. The most accurate model was developed using spectra from strains grown on TSA with 5% bovine blood and supplemented with CaCl2, which had a sensitivity and specificity of 93.3% and 73.3%, respectively, regarding RTX phenotype classification. The same biomarker model algorithm developed from strains grown on TSA with 5% sheep blood had a substantially lower sensitivity and specificity of 68.0% and 52.0%, respectively. Our results indicate that MALDI-TOF MS biomarker models can accurately classify strains of M. bovoculi regarding the presence or absence of RTX toxin operons and that agar media modifications improve the accuracy of these models.
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Affiliation(s)
- Matthew M Hille
- School of Veterinary Medicine and Biomedical Sciences, Institute for Agriculture and Natural Resources, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Michael L Clawson
- U.S. Meat Animal Research Center, United States Department of Agriculture, Agricultural Research Service, Clay Center, NE, United States
| | - Aaron M Dickey
- U.S. Meat Animal Research Center, United States Department of Agriculture, Agricultural Research Service, Clay Center, NE, United States
| | - Justin H Lowery
- School of Veterinary Medicine and Biomedical Sciences, Institute for Agriculture and Natural Resources, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - John Dustin Loy
- School of Veterinary Medicine and Biomedical Sciences, Institute for Agriculture and Natural Resources, University of Nebraska-Lincoln, Lincoln, NE, United States
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17
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Motlova L, Klimova N, Fiser R, Sebo P, Bumba L. Continuous Assembly of β-Roll Structures Is Implicated in the Type I-Dependent Secretion of Large Repeat-in-Toxins (RTX) Proteins. J Mol Biol 2020; 432:5696-5710. [PMID: 32860773 DOI: 10.1016/j.jmb.2020.08.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/22/2020] [Accepted: 08/24/2020] [Indexed: 01/10/2023]
Abstract
Repeats-in-Toxin (RTX) proteins of Gram-negative bacteria are excreted through the type I secretion system (T1SS) that recognizes non-cleavable C-terminal secretion signals. These are preceded by arrays of glycine and aspartate-rich nonapeptide repeats grouped by four to eight β strands into blocks that fold into calcium-binding parallel β-roll structures. The β-rolls are interspersed by linkers of variable length and sequence and the organization of multiple RTX repeat blocks within large RTX domains remains unknown. Here we examined the structure and function of the RTX domain of Bordetella pertussis adenylate cyclase toxin (CyaA) that is composed of five β-roll RTX blocks. We show that the non-folded RTX repeats maintain the stability of the CyaA polypeptide in the Ca2+-depleted bacterial cytosol and thereby enable its efficient translocation through the T1SS apparatus. The efficacy of secretion of truncated CyaA constructs was dictated by the number of retained RTX repeat blocks and depended on the presence of extracellular Ca2+ ions. We further describe the crystal structure of the RTX blocks IV-V of CyaA (CyaA1372-1681) that consists of a contiguous assembly of two β-rolls that differs substantially from the arrangement of the RTX blocks observed in RTX lipases or other RTX proteins. These results provide a novel structural insight into the architecture of the RTX domains of large RTX proteins and support the "push-ratchet" mechanism of the T1SS-mediated secretion of very large RTX proteins.
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Affiliation(s)
- Lucia Motlova
- Faculty of Sciences, Charles University, Vinicna 5, 128 44 Prague 2, Czech Republic
| | - Nela Klimova
- Faculty of Sciences, Charles University, Vinicna 5, 128 44 Prague 2, Czech Republic.; Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague 4, Czech Republic
| | - Radovan Fiser
- Faculty of Sciences, Charles University, Vinicna 5, 128 44 Prague 2, Czech Republic
| | - Peter Sebo
- Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague 4, Czech Republic
| | - Ladislav Bumba
- Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague 4, Czech Republic..
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18
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Abstract
RTX-Toxins (Repeats in ToXin) are members of a rapidly expanding family of proteins [...].
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Affiliation(s)
- Roland Benz
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Campusring 1, 28759 Bremen, Germany;
- Rudolf-Virchow-Center for Experimental Biomedicine, University of Würzburg, Versbacher Str. 9, 97078 Würzburg, Germany
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