Detection of Streptococcus suis in Bioaerosols of Swine Confinement Buildings

Abstract

Streptococcus suis is an important swine pathogen that can cause septicemia, meningitis, and pneumonia. Also recognized as an emerging zoonotic agent, it is responsible for outbreaks of human infections in Asian countries. Serotype 2 is the predominant isolate from diseased animals and humans. The aerosolization of S. suis in the air of swine confinement buildings (SCB) was studied. The presence of S. suis in bioaerosols was monitored in SCB where cases of infection had been reported and in healthy SCB without reported infections. Using a quantitative-PCR (qPCR) method, we determined the total number of bacteria (1 × 10(8) to 2 × 10(8) airborne/m(3)), total number of S. suis bacteria (4 × 10(5) to 10 × 10(5) airborne/m(3)), and number of S. suis serotype 2 and 1/2 bacteria (1 × 10(3) to 30 × 10(3) airborne/m(3)) present in the air. S. suis serotypes 2 and 1/2 were detected in the air of all growing/finishing SCB that had documented cases of S. suis infection and in 50% of healthy SCB. The total number of bacteria and total numbers of S. suis and S. suis serotype 2 and 1/2 bacteria were monitored in one positive SCB during a 5-week period, and it was shown that the aerosolized S. suis serotypes 2 and 1/2 remain airborne for a prolonged period. When the effect of aerosolization on S. suis was observed, the percentage of intact S. suis bacteria (showing cell membrane integrity) in the air might have been up to 13%. Finally S. suis was found in nasal swabs from 14 out of 21 healthy finishing-SCB workers, suggesting significant exposure to the pathogen. This report provides a better understanding of the aerosolization, prevalence, and persistence of S. suis in SCB.

Bioaerosols in the Barcelona subway system

“…The concentrations obtained for the NTC were subtracted from each series. The chosen protocol for bioaerosols quantification has been used in different type of environments with no inhibition observed …”

TREM-1 Signaling Promotes Host Defense during the Early Stage of Infection with Highly Pathogenic Streptococcus suis

“…In addition, S. suis has also been identified as the third most common cause of community-acquired bacterial meningitis in Hong Kong and as the leading and second most common cause of adult meningitis in Vietnam and Thailand, respectively (3,7,8). S. suis is known to constitute a high risk of infection for occupationally exposed people (9)(10)(11), but it could also cause severe infection in people who lack contact with swine and pork-derived products (12,13). Human S. suis isolates showed high adhesion to intestinal epithelial cells, suggesting that it should be considered a foodborne pathogen (14).…”

Reinfection with Streptococcus suis analysed by whole genome sequencing

“…Current evidence suggests that carriage of S. suis by humans in general is very rare (Nghia et al, ). Whilst potential carriage of S. suis due to continuous professional exposure to pigs (Bonifait, Veillette, Letourneau, Grenier, & Duchaine, ), combined with skin lesions related to his chronic dermatitis, cannot be ruled out in this patient, the genomic analysis does not suggest that infections occurred due to long‐term carriage of a single strain as the estimated substitution rate would be too high.…”