Provinces of Vietnam.

<p>Provinces (coloured) from which sampled pig originated are located in the south of Vietnam and surrounding Ho Chi Minh City.</p

Pulse field gel electrophoresis (PFGE) of <i>Streptococcus suis</i> serotype 2 strains isolated from tonsils of healthy pigs.

<p>Six <i>S. suis</i> serotype 2 strains isolated from patients with meningitis in southern Vietnam whose PFGE patterns represent the dominant PFGE patterns across <i>S. suis</i> serotype 2 strains isolated from humans (labeled A–F), were included for comparison purpose. A dendrogram was generated by Dice analysis (band tolerance, 1.3%) and cluster analysis with unweighted pair group method with arithmetic mean, using Bionumerics software (Applied Maths, Belgium). Bars indicate 95% confidence intervals. Columns: Cls: PFGE cluster; Pro: province of pig's origin or patients' residence; Date: date of tonsil collection or patients' admission; SH: slaughterhouse ID; WS: Whole sale seller ID; ST: sequence type, Res: tetracycline and erythromycin resistance gene detected by PCR and sequencing, ef: <i>epf</i> or <i>epf*</i> gene detected by PCR. CC: Cu Chi- HCMC; LA: Long An; HM: Hoc Mon – HCMC; HCM: Ho Chi Minh City; BD: Binh Duong; BTr: Ben Tre; DN: Dong Nai; BTh: Binh Thuan. O: amplicons of <i>tet</i>(O) gene detected. M: amplicons of <i>tet</i>(M) gene detected. B: amplicons of <i>erm</i>(B) gene detected. L: amplicons of <i>tet</i>(L) gene detected *: amplicons of mosaic tetracyclin resistance encoding gene <i>tet</i>(O/W/32/O) detected in these strains. #: no amplicons of <i>erm</i>(A), <i>erm</i>(B) or <i>mef</i>(A) were detected in these erythormycine resistant strains. 0: no amplicons of <i>epf</i> or <i>epf*</i> gene detected. 1: amplicons of <i>epf</i> gene detected. 2: amplicons of <i>epf</i>* gene detected.</p

Serotype distribution across <i>Streptococcus suis</i> strains isolated from pig tonsils.

<p>@ Serotyping was repeated three times; additional analysis of 7 representative strains by MLST and 16S rDNA sequencing confirmed that these strains are S. suis.</p><p>*Includes serotype 5, 8, 9,10, 11, 12, 13, 15, 19, 20, 22, 23, 25, 26, 27, 28, 29, 30, 31, 33.</p><p>**Strains reacting with antisera against two or three different serotypes.</p><p>#23 strains were auto-agglutinating, 16 strains could not be assigned to any serotype after agglutination with polyvalent antisera, and 6 strains reacted negatively with all poly-valent antisera.</p

Sampling of tonsils and associated culture results.

<p>*Pigs sampled in slaughterhouse I originated from (number of samples): Ben Tre province (25), Binh Duong province (31), Dong Nai province (75); slaughterhouse II: Binh Duong province (55), Binh Thuan province (83), Ho Chi Minh City (Hoc Mon) (12), Long An province (30), Tien Giang province (34); slaughterhouse III: Binh Duong province (50), Ho Chi Minh City (Cu Chi) (84), Long An province (37).</p