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Streptococcus suis is one of the most important swine bacterial pathogens causing economic losses. This report presents the serotype distribution of S. suis recovered from diseased pigs in Québec from January 2015 to June 2020. Serotypes 1/2 and 2 predominated, followed by serotypes 7, 3, 5, 4, 9, 1, and 14. Compared to previously reported data, very few changes could be observed concerning the serotype distribution, indicating a relative stability. Half of the untypable isolates did not belong to the species S. suis sensu stricto, as determined by recN polymerase chain reaction. Less than 10% of “real S. suis” isolates were untypable. The genetic diversity of S. suis serotypes 1, 2, and 14, as analyzed by multilocus sequence typing, was mainly represented by sequence type (ST)1, ST28, ST25, and ST94. All ST1 isolates (considered highly virulent) belonged to either serotype 1 or 14.

Actinobacillus pleuropneumoniae serotype 17, one of the two most recent serotypes described, has been isolated from diseased pigs in North America. Yet, no serological test for surveillance has been developed so far. An enzyme-linked immunosorbent assay (ELISA) using the long-chain lipopolysaccharide antigen (LC-LPS) of this serotype is described. As predicted by previous genetic data on the O-antigen locus, cross reactions were observed between this serotype and serotypes 3, 6, 8, and 15. Although animals infected by serotype 17 would be detected using the current serotype 3 LC-LPS ELISA, better results may be obtained when plates are coated with the antigen purified from the homologous serotype.

Highlights • Analysis of complete capsule loci in all 18 serovars of A. pleuropneumoniae. • Novel insights into evolution of capsule loci in A. pleuropneumoniae. • Development of two mPCRs for comprehensive capsule typing., Problems with serological cross-reactivity have led to development of a number of PCRs (individual and multiplex) for molecular typing of Actinobacillus pleuropneumoniae, the causative agent of porcine pleuropneumonia. Most of these assays were developed for detection of specific amplicons within capsule biosynthetic genes before the availability of complete sequences for the different serovars. Here we describe comparative analysis of the complete capsular loci for all 18 serovars of A. pleuropneumoniae, and development of two multiplex PCRs for comprehensive capsule typing of this important pig pathogen.

Highlights • Identification of two new serovars of Actinobacillus pleuropneumoniae. • Serological confirmation of specific reactivity with homologous antisera. • Characterization of the capsule loci of serovars 17 and 18. • Development of PCRs for molecular diagnostics., The aim of this study was to investigate isolates of Actinobacillus pleuropneumoniae previously designated serologically either as non-typable (NT) or as ‘K2:07’, which did not produce serovar-specific amplicons in PCR assays. We used whole genome sequencing to identify the capsule (CPS) loci of six previously designated biovar 1 NT and two biovar 1 ‘K2:O7’ isolates of A. pleuropneumoniae from Denmark, as well as a recent biovar 2 NT isolate from Canada. All of the NT isolates have the same six-gene type I CPS locus, sharing common cpsABC genes with serovars 2, 3, 6, 7, 8, 9, 11 and 13. The two ‘K2:O7’ isolates contain a unique three-gene type II CPS locus, having a cpsA gene similar to that of serovars 1, 4, 12, 14 and 15. The previously NT isolates share the same O-antigen genes, found between erpA and rpsU, as serovars 3, 6, 8, and 15. Whereas the ‘K2:O7’ isolates, have the same O-antigen genes as serovar 7, which likely contributed to their previous mis-identification. All of the NT and ‘K2:O7’ isolates have only the genes required for production of ApxII (apxIICA structural genes, and apxIBD export genes). Rabbit polyclonal antisera raised against representative isolates with these new CPS loci demonstrated distinct reactivity compared to the 16 known serovars. The serological and genomic results indicate that the isolates constitute new serovars 17 (previously NT) and 18 (previously ‘K2:O7’). Primers designed for amplification of specific serovar 17 and 18 sequences for molecular diagnostics will facilitate epidemiological tracking of these two new serovars of A. pleuropneumoniae.

Additional file 3. S. suis serotype 2 (S2) and serotype 9 (S9) AgI/II amino acid sequence alignment. Alignment was performed using Vector NTI 11.5. Conserved amino acids appear in light gray and identical amino acids in dark gray.

S. suis strains used in this study; serotypes and accession numbers for reference capsule type sequences used in this study; information and pipeline results of S. suis strains downloaded from the Sequence Read Archive and comparison of cps loci of selected S. suis strains This supplementary file contains: 1) three supplementary Tables, 2) 26 supplementary Figures. (PDF 7086 kb)

Made available in DSpace on 2022-04-29T07:26:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-10-01 Streptococcus suis is an important pathogen in the swine industry. This article is the first to report the occurrence, risk factors, serotype distribution, and antimicrobial susceptibility of S. suis recovered from employees and environmental samples of swine slaughterhouses in Brazil. Tonsillar swabs from all 139 pig-slaughtering employees and 261 environmental swabs were collected for detection of S. suis and serotyping by monoplex and multiplex polymerase chain reaction, respectively. Antimicrobial susceptibility was determined by the disk-diffusion method. Although S. suis was not detected in any of the tested employees, it was isolated from 25% of the environmental samples. Significant differences (P < 0.05) in the occurrence of S. suis were observed between slaughterhouses and between areas of low, medium, and high risk. The most frequent serotypes were 4 and 29, each accounting for 12% of the isolates, followed by 5, 12, 21, and 31, each accounting for 6%. High rates of susceptibility to the antimicrobials doxycycline (100%), ceftiofur (94%), ampicillin (81%), and cephalexin (75%) were observed. However, multidrug resistance was observed in all the isolates. Because S. suis is present in the environment of swine slaughterhouses, on carcasses and knives, as well as on the hands of employees in all areas, all employees are at risk of infection. Departamento de Higiene Veterinária e Saúde Pública Universidade Estadual Paulista Júlio de Mesquita Filho, Distrito de Rubião Júnior, s/no Centre de recherche en infectiologie porcine et avicole Université de Montréal, 3200, rue Sicotte Departamento de Parasitologia Instituto de Biociências de Botucatu Universidade Estadual Paulista Júlio de Mesquita Filho, Distrito de Rubião Júnior, s/no Departamento de Higiene Veterinária e Saúde Pública Universidade Estadual Paulista Júlio de Mesquita Filho, Distrito de Rubião Júnior, s/no Departamento de Parasitologia Instituto de Biociências de Botucatu Universidade Estadual Paulista Júlio de Mesquita Filho, Distrito de Rubião Júnior, s/no

The characteristics of 29 Chilean field strains of Streptococcus suis recovered between 2007 and 2011 from pigs with clinical signs at different farms were studied. Serotyping with use of the coagglutination test revealed that all but 1 strain belonged to serotype 6; the remaining strain was serotype 22. All the serotype-6 strains were suilysin (hemolysin)-negative; in addition, they were found to be genotypically homogeneous by enterobacterial repetitive intergenic consensus sequence-based polymerase chain reaction (ERIC-PCR) and sensitive to ampicillin, ceftiofur, penicillin, and trimethoprim/sulfamethoxazole. The results indicate that, in contrast to what is generally observed in other countries, a single clone of S. suis was isolated from diseased pigs in the central region of Chile.Les caractéristiques de 29 souches de

Les porcs sauvages (Sus scrofa) sont largement distribués aux États-Unis. En 2011 et 2012, aux États-Unis des échantillons de sérum et d’amygdales furent obtenus de 162 et 37 porcs sauvages, respectivement, afin d’évaluer l’exposition à d’importants agents pathogènes porcins endémiques. Des anticorps contre le virus du syndrome reproducteur et respiratoire porcin (VSRRP) et le circovirus porcin de type 2 (CVP2) furent détectés chez 2,5 % et 25,3 % des sérums testés, respectivement. Des réactions sérologiques positives envers Mycoplasma hyopneumoniae et Actinobacillus pleuropneumoniae ont été détectées chez 19,7 % et 69,7 % des animaux. Plus de 15 % des animaux avaient des anticorps contre ces deux agents pathogènes simultanément. La plupart des animaux étaient également séropositifs pour Lawsonia intracellularis. Les porcs sauvages peuvent également être impliqués dans la transmission d’agents zoonotiques. Près de 50 % des animaux avaient des anticorps contre Salmonella. De plus, 94,4 % des animaux étaient porteurs de Streptococcus suis dans leurs amygdales. En conclusion, les porcs sauvages peuvent être considérés comme des réservoirs potentiels de différentes maladies endémiques des porcs domestiques, aussi bien que d’agents zoonotiques importants., Feral swine (Sus scrofa) are widely distributed in the United States. In 2011 and 2012, serum samples and tonsils were recovered from 162 and 37 feral swine, respectively, in the US to evaluate exposure to important swine endemic pathogens. Antibodies against porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) were found in 2.5% and 25.3% of tested sera, respectively. Positive serological reactions against Mycoplasma hyopneumoniae and Actinobacillus pleuropneumoniae have been detected in 19.7% and 69.7% of animals. More than 15% of animals presented antibodies against these 2 pathogens simultaneously. Most animals were also seropositive for Lawsonia intracellularis. Feral swine can also be involved in transmission of zoonotic agents. Almost 50% of animals possessed antibodies against Salmonella. In addition, 94.4% of animals were carriers of Streptococcus suis in their tonsils. In conclusion, feral swine may be considered as a potential reservoir for different endemic diseases in domestic pigs, as well as for important zoonotic agents.