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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

Genetic organization of the cps locus in unencapsulated S. suis serotype 31 isolate no. 43640 and reference S. suis serotype 31 strain 92-4172. Gray arrows indicate low similarity of amino acid sequences. Black arrows show high similarity of amino acid sequences
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Fig3: Genetic organization of the cps locus in unencapsulated S. suis serotype 31 isolate no. 43640 and reference S. suis serotype 31 strain 92-4172. Gray arrows indicate low similarity of amino acid sequences. Black arrows show high similarity of amino acid sequences

Mentions: The entire cps locus of the unencapsulated serotype 31 strain 43640 (accession number KM576773) as well as cpsA and cpsB of five encapsulated S. suis serotype 31 strains (p523, p346, p369, p567 and p559; accession numbers KM884773–KM884777) isolated from slaughtered pigs were amplified and sequenced [see Additional file 1: Table S1 and Additional file 2: Table S2]. Our isolate showed an intact cpsA-cpsO (Fig. 3) as described for serotype 31 reference strain 92–4172 (accession number AB737835). No insertions, deletions, or frameshifts were found in the genes of the cps locus. In addition, the nucleotide sequence of cpsA-cpsO in this isolate showed a high identity (97 %) with the reference serotype 31. Comparison of the CpsA–CpsO protein sequences of both strains also revealed high identities (97.75–100 %), except for the CpsA and CpsB proteins, which had lower identities (93.11 and 84.71 %, respectively) with proteins of the reference strain (Fig. 3).Fig. 3


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)

Genetic organization of the cps locus in unencapsulated S. suis serotype 31 isolate no. 43640 and reference S. suis serotype 31 strain 92-4172. Gray arrows indicate low similarity of amino acid sequences. Black arrows show high similarity of amino acid sequences
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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

Fig3: Genetic organization of the cps locus in unencapsulated S. suis serotype 31 isolate no. 43640 and reference S. suis serotype 31 strain 92-4172. Gray arrows indicate low similarity of amino acid sequences. Black arrows show high similarity of amino acid sequences
Mentions: The entire cps locus of the unencapsulated serotype 31 strain 43640 (accession number KM576773) as well as cpsA and cpsB of five encapsulated S. suis serotype 31 strains (p523, p346, p369, p567 and p559; accession numbers KM884773–KM884777) isolated from slaughtered pigs were amplified and sequenced [see Additional file 1: Table S1 and Additional file 2: Table S2]. Our isolate showed an intact cpsA-cpsO (Fig. 3) as described for serotype 31 reference strain 92–4172 (accession number AB737835). No insertions, deletions, or frameshifts were found in the genes of the cps locus. In addition, the nucleotide sequence of cpsA-cpsO in this isolate showed a high identity (97 %) with the reference serotype 31. Comparison of the CpsA–CpsO protein sequences of both strains also revealed high identities (97.75–100 %), except for the CpsA and CpsB proteins, which had lower identities (93.11 and 84.71 %, respectively) with proteins of the reference strain (Fig. 3).Fig. 3

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