Streptococcus suis remains an important challenge for the worldwide swine industry. Considering that Brazil is a major pork producer and exporter, proper monitoring of the pathogen and resistance rates are required. We present here the characterization of Brazilian S. suis strains isolated over a 15 year period by pulsed-field gel electrophoresis (PFGE) typing, capsular, virulence, and antimicrobial resistance profiling. Serotype prevalence revealed a predominance of serotype 2/ 1 2 followed by 3, 7, 1/14, 6, 8, 18, 28, and 27; the latter had not yet been reported in Brazil. Resistance profiling enabled the differentiation of nine profiles presenting resistance to three and up to eight antimicrobial classes. Even though an association between the most resistant strains and isolation year starting from 2009 was observed, a high frequency of multidrug-resistant strains isolated from 2001 to 2003 was also detected. This suggests that despite the isolation period, S. suis strains already presented high resistance selection pressure. A slight association of serotype 2/ 1 2 with some virulence profiles and PFGE pulsotypes was also identified. Nevertheless, no clonal dispersion or persistency of clones over the analyzed years and herds was detected.Pathogens 2020, 9, 31 2 of 15 shown that serotypes 20, 22, 26, 32, 33, and 34 do not belong to this species and should be classified as other bacterial species [6,7]. Moreover, novel nine capsular polysaccharide synthesis (cps) loci (NCLs) of non-typable S. suis strains have been identified based on DNA sequencing. Therefore, strict S. suis species currently comprise 38 serotypes [8].Among the virulence factors that have already been characterized in S. suis, most studied so far are the capsule, muramidase-released protein (MRP), the extracellular factor (EF), hemolysins including suilysin (SLY), plasminogen receptors, and arginine deiminase (arcA) [9].Considering antimicrobial susceptibility of S. suis strains, recent studies have described increases in resistance rates to some antimicrobial classes. Resistance to lincosamides and macrolides has been increasing, both for pigs and human strains, and resistance to sulfonamides and tetracycline showed high prevalence [8]. Resistance to cephalosporin was already described in Europe and China, but resistance prevalence to penicillin, ampicillin, and ceftiofur remains low in most countries [8,10].Emergence of multidrug resistant S. suis strains has also been described in humans and pigs, including asymptomatic animals, with highlight for the Asian epidemic clones [8]. Phenotypic and genetic studies suggest that swine may be reservoirs for the spread of antibiotic-resistant S. suis strains, which demands attention for the public health risk [8].Brazil is a major producer and exporter of pork, occupying for several years the fourth place as producer and exporter in the world [4]. This position demands attention to swine health issues. Currently, special efforts are required to reduce antimicrobial usage and monitor resistance rates ...

Artificial insemination is the foundation of Brazilian intensive pig farming and the semen quality is a key point for the success of the productive chain. Several bacteria have already been reported as semen contaminants and may cause morphological and functional changes in sperm, decreasing male fertility, in addition to predisposing females to reproductive failures. The objective of this study was to perform a bacteriological examination of boar semen (Sus scrofa) obtained from an Artificial Insemination Centre in the southwestern region of Paraná. One hundred semen samples were assessed for volume, colour, smell, motility, agglutinated sperm cells and for bacterial contamination. Bacterial species were further identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. The results revealed positive bacterial isolation in 43% of the samples, with predominance of Gram-negative pathogens. The identified species were: Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli, Kerstersia gyiorum, Aerococcus viridans, Brevibacterium casei, Providencia stuartii, Citrobacter koseri and Staphylococcus pasteuri. The E. coli contamination was associated with decreased sperm motility (p < 0.01) and vigour (p = 0.002). Despite the frequent usage, the antimicrobial resistance tests showed that few isolates were resistant to gentamycin or neomycin, drugs that are commonly used to extend semen viability in Brazil.

Introduction: Vagococcus spp. is known for its importance as a systemic and zoonotic bacterial pathogen even though it is not often reported in pigs. This is related to the pathogen misidentification due to the lack of usage of more discriminatory diagnostic techniques. Here we present the first report of Vagococcus lutrae in swine and the characterization of Vagococcus fluvialis and Vagococcus lutrae isolated from diseased animals. Methodology: Between 2012 and 2017, 11 strains with morphological characteristics similar to Streptococcus spp. were isolated from pigs presenting different clinical signs. Bacterial identification was performed by matrix assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry and confirmed by 16S rRNA sequencing and biochemical profile. Strains were further genotyped by single-enzyme amplified fragment length polymorphism (SE-AFLP). Broth microdilution was used to determine the minimal inhibitory concentration of the antimicrobials of veterinary interest. Results: Ten strains were identified as V. fluvialis and one was identified as V. lutrae. The SE-AFLP analysis enabled the species differentiation with specific clustering of all V. fluvialis separately from the V. lutrae strain. Most strains presented growth in the maximum antibiotic concentration values tested for eight of the 10 analyzed antimicrobial classes. Conclusions: The observed resistance pattern can represent a problem for veterinary and producers in the treatment of diseases associated Vagococcus spp. in swine production. Vagococcus species may also be a risk for pig industry workers. The data described here will be of great value in further understanding the behavior of this pathogen in animal production.

Caracterização do perfil de resistência aos antimicrobianos de estirpes de Salmonella enterica isoladas nas distintas fases de criação de um sistema de produção integrado de suínos