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First human case report of sepsis due to infection with Streptococcus suis serotype 31 in Thailand.

Hatrongjit R, Kerdsin A, Gottschalk M, Takeuchi D, Hamada S, Oishi K, Akeda Y - BMC Infect. Dis. (2015)

Bottom Line: The absence of a capsule was confirmed by transmission electron microscopy.The isolate was confirmed to be sequence type 221, with 13 putative virulence genes that are usually found in serotype 2 strains.Laboratory capacity to identify S. suis in the hospital is needed in developing countries, which can contribute to enhanced surveillance, epidemiological control, and prevention strategies in the prevalent area.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Science and Engineering, Kasetsart University Chalermphrakiat Sakon Nakhon Province Campus, Muang, Sakon Nakhon Province, 47000, Thailand. h_rujirat@hotmail.com.

ABSTRACT

Background: Streptococcus suis is a zoonotic pathogen that causes invasive infections in humans and pigs. It has been reported that S. suis infection in humans is mostly caused by serotype 2. However, human cases caused by other serotypes have rarely been reported. This is the first report of a human case of infection with S. suis serotype 31 in Thailand.

Case presentation: A 55-year-old male alcohol misuser with liver cirrhosis was admitted with sepsis to a hospital in the Central Region of Thailand. He had consumed a homemade, raw pork product prior to the onset of illness. He was alive after treatment with ceftriaxone and no complication occurred. An isolate from blood culture at the hospital was suspected as viridans group Streptococcus. It was confirmed at a reference laboratory as S. suis serotype 31 by biochemical tests, 16S rDNA sequencing, and multiplex polymerase chain reaction for serotyping, but it was untypable by the co-agglutination test with antisera against recognized S. suis serotypes, suggesting loss of capsular material. The absence of a capsule was confirmed by transmission electron microscopy. The isolate was confirmed to be sequence type 221, with 13 putative virulence genes that are usually found in serotype 2 strains.

Conclusion: We should be aware of the emergence of S. suis infections caused by uncommon serotypes in patients with predisposing conditions. Laboratory capacity to identify S. suis in the hospital is needed in developing countries, which can contribute to enhanced surveillance, epidemiological control, and prevention strategies in the prevalent area.

No MeSH data available.


Related in: MedlinePlus

An eBURST analysis of the entire S. suis MLST database (accessed on May 15, 2015). Clonal complexes relevant to human infection in Thailand are circled and labeled. S. suis serotype 31 (ST221) in this study belonged to CC221/234 (bold circle). Clonal complexes and the predicted founders STs are indicated by blue dots. The size of the dots is relative to the number of isolates with the respective ST present in the database
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Fig2: An eBURST analysis of the entire S. suis MLST database (accessed on May 15, 2015). Clonal complexes relevant to human infection in Thailand are circled and labeled. S. suis serotype 31 (ST221) in this study belonged to CC221/234 (bold circle). Clonal complexes and the predicted founders STs are indicated by blue dots. The size of the dots is relative to the number of isolates with the respective ST present in the database

Mentions: Multilocus sequence typing (MLST) analysis of this isolate showed that it belonged to sequence type (ST) 221 of clonal complex (CC) 221/234 (Fig. 2) [11]. PCR and sequencing were used to study the presence of 29 genes previously associated with S. suis serotype 2 virulence. These genes include the muramidase-released protein gene (mrp), the extracellular factor gene (epf), the suilysin gene (sly), the arginine deaminase gene (arcA) [12], the factor H-binding surface protein gene (fhb) [13], the fibronectin-binding protein gene (fbps) [14], an infection-related factor gene (trag) [15], the serum opacity factor gene (ofs) [16], the S-ribosylhomocysteinase gene (luxS) [17], the hyaluronate lyase gene (hyl) [18], the glutamine synthetase gene (glnA) [19], an amylopullulanase gene (apuA) [20], an enolase gene (eno) [21], an IgA protease gene [22], the subtilisin-like protease gene (sspA) [23], the sortase A gene (srtA) [24], the sortase BCD gene (srtBCD), the sortase E gene (srtE), the sortase F gene (srtF), the sortase G gene (srtG) [25], the zinc uptake regulator gene (zur) [26], the transcriptional regulator gene (rgg) [27], orphan response regulator genes including covR and revS [28, 29], the two-component regulatory system gene (ciaRH) [30], the divalent-cation-related ABC transporter genes (adcR and fur) [31], an iron-transporter gene (feoB) [32], and the virulence-related gene (virA) [33]. Our analysis of this isolate revealed the presence of 13 genes found in virulent serotype 2 strains. The IgA protease gene, arcA, luxS, glnA, apuA, eno, sspA, srtA, covR, zur, fur, adcR and feoB were present in this isolate; however, the well-recognized virulence markers (epf/mrp/sly) were absent.Fig. 2


First human case report of sepsis due to infection with Streptococcus suis serotype 31 in Thailand.

Hatrongjit R, Kerdsin A, Gottschalk M, Takeuchi D, Hamada S, Oishi K, Akeda Y - BMC Infect. Dis. (2015)

An eBURST analysis of the entire S. suis MLST database (accessed on May 15, 2015). Clonal complexes relevant to human infection in Thailand are circled and labeled. S. suis serotype 31 (ST221) in this study belonged to CC221/234 (bold circle). Clonal complexes and the predicted founders STs are indicated by blue dots. The size of the dots is relative to the number of isolates with the respective ST present in the database
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4588491&req=5

Fig2: An eBURST analysis of the entire S. suis MLST database (accessed on May 15, 2015). Clonal complexes relevant to human infection in Thailand are circled and labeled. S. suis serotype 31 (ST221) in this study belonged to CC221/234 (bold circle). Clonal complexes and the predicted founders STs are indicated by blue dots. The size of the dots is relative to the number of isolates with the respective ST present in the database
Mentions: Multilocus sequence typing (MLST) analysis of this isolate showed that it belonged to sequence type (ST) 221 of clonal complex (CC) 221/234 (Fig. 2) [11]. PCR and sequencing were used to study the presence of 29 genes previously associated with S. suis serotype 2 virulence. These genes include the muramidase-released protein gene (mrp), the extracellular factor gene (epf), the suilysin gene (sly), the arginine deaminase gene (arcA) [12], the factor H-binding surface protein gene (fhb) [13], the fibronectin-binding protein gene (fbps) [14], an infection-related factor gene (trag) [15], the serum opacity factor gene (ofs) [16], the S-ribosylhomocysteinase gene (luxS) [17], the hyaluronate lyase gene (hyl) [18], the glutamine synthetase gene (glnA) [19], an amylopullulanase gene (apuA) [20], an enolase gene (eno) [21], an IgA protease gene [22], the subtilisin-like protease gene (sspA) [23], the sortase A gene (srtA) [24], the sortase BCD gene (srtBCD), the sortase E gene (srtE), the sortase F gene (srtF), the sortase G gene (srtG) [25], the zinc uptake regulator gene (zur) [26], the transcriptional regulator gene (rgg) [27], orphan response regulator genes including covR and revS [28, 29], the two-component regulatory system gene (ciaRH) [30], the divalent-cation-related ABC transporter genes (adcR and fur) [31], an iron-transporter gene (feoB) [32], and the virulence-related gene (virA) [33]. Our analysis of this isolate revealed the presence of 13 genes found in virulent serotype 2 strains. The IgA protease gene, arcA, luxS, glnA, apuA, eno, sspA, srtA, covR, zur, fur, adcR and feoB were present in this isolate; however, the well-recognized virulence markers (epf/mrp/sly) were absent.Fig. 2

Bottom Line: The absence of a capsule was confirmed by transmission electron microscopy.The isolate was confirmed to be sequence type 221, with 13 putative virulence genes that are usually found in serotype 2 strains.Laboratory capacity to identify S. suis in the hospital is needed in developing countries, which can contribute to enhanced surveillance, epidemiological control, and prevention strategies in the prevalent area.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Science and Engineering, Kasetsart University Chalermphrakiat Sakon Nakhon Province Campus, Muang, Sakon Nakhon Province, 47000, Thailand. h_rujirat@hotmail.com.

ABSTRACT

Background: Streptococcus suis is a zoonotic pathogen that causes invasive infections in humans and pigs. It has been reported that S. suis infection in humans is mostly caused by serotype 2. However, human cases caused by other serotypes have rarely been reported. This is the first report of a human case of infection with S. suis serotype 31 in Thailand.

Case presentation: A 55-year-old male alcohol misuser with liver cirrhosis was admitted with sepsis to a hospital in the Central Region of Thailand. He had consumed a homemade, raw pork product prior to the onset of illness. He was alive after treatment with ceftriaxone and no complication occurred. An isolate from blood culture at the hospital was suspected as viridans group Streptococcus. It was confirmed at a reference laboratory as S. suis serotype 31 by biochemical tests, 16S rDNA sequencing, and multiplex polymerase chain reaction for serotyping, but it was untypable by the co-agglutination test with antisera against recognized S. suis serotypes, suggesting loss of capsular material. The absence of a capsule was confirmed by transmission electron microscopy. The isolate was confirmed to be sequence type 221, with 13 putative virulence genes that are usually found in serotype 2 strains.

Conclusion: We should be aware of the emergence of S. suis infections caused by uncommon serotypes in patients with predisposing conditions. Laboratory capacity to identify S. suis in the hospital is needed in developing countries, which can contribute to enhanced surveillance, epidemiological control, and prevention strategies in the prevalent area.

No MeSH data available.


Related in: MedlinePlus