Staphylococcus au reus (MSSA) and MRSA (ST398) isolated from post-mortem samples from pigs

In 2003 a new strain of methicillin resistant Staphylococcus aureus (MRSA), now called livestock-associated MRSA (LA-MRSA), was found in humans and in pigs. Pigs were found to be carriers of this strain of MRSA. So far, only one publication reported LA-MRSA being involved in pathological lesions in pigs: a case of exudative dermatitis in which LA-MRSA was found

Differences in the Population Structure of Invasive Streptococcus suis Strains Isolated from Pigs and from Humans in the Netherlands

Streptococcus suis serotype 2 is the main cause of zoonotic S. suis infection despite the fact that other serotypes are frequently isolated from diseased pigs. Studies comparing concurrent invasive human and pig isolates from a single geographical location are lacking. We compared the population structures of invasive S. suis strains isolated between 1986 and 2008 from human patients (N = 24) and from pigs with invasive disease (N = 124) in the Netherlands by serotyping and multi locus sequence typing (MLST). Fifty-six percent of pig isolates were of serotype 9 belonging to 15 clonal complexes (CCs) or singleton sequence types (ST). In contrast, all human isolates were of serotype 2 and belonged to two non-overlapping clonal complexes CC1 (58%) and CC20 (42%). The proportion of serotype 2 isolates among S. suis strains isolated from humans was significantly higher than among strains isolated from pigs (24/24 vs. 29/124; P<0.0001). This difference remained significant when only strains within CC1 and CC20 were considered (24/24 vs. 27/37,P = 0.004). The Simpson diversity index of the S. suis population isolated from humans (0.598) was smaller than of the population isolated from pigs (0.765, P = 0.05) indicating that the S. suis population isolated from infected pigs was more diverse than the S. suis population isolated from human patients. S. suis serotype 2 strains of CC20 were all negative in a PCR for detection of genes encoding extracellular protein factor (EF) variants. These data indicate that the polysaccharide capsule is an important correlate of human S. suis infection, irrespective of the ST and EF encoding gene type of S. suis strains

Staphylococcus au reus (MSSA) and MRSA (ST398) isolated from post-mortem samples from pigs

In 2003 a new strain of methicillin resistant Staphylococcus aureus (MRSA), now called livestock-associated MRSA (LA-MRSA), was found in humans and in pigs. Pigs were found to be carriers of this strain of MRSA. So far, only one publication reported LA-MRSA being involved in pathological lesions in pigs: a case of exudative dermatitis in which LA-MRSA was found.</p

Differences in the Population Structure of Invasive Streptococcus suis Strains Isolated from Pigs and from Humans in the Netherlands

Streptococcus suis serotype 2 is the main cause of zoonotic S. suis infection despite the fact that other serotypes are frequently isolated from diseased pigs. Studies comparing concurrent invasive human and pig isolates from a single geographical location are lacking. We compared the population structures of invasive S. suis strains isolated between 1986 and 2008 from human patients (N = 24) and from pigs with invasive disease (N = 124) in the Netherlands by serotyping and multi locus sequence typing (MLST). Fifty-six percent of pig isolates were of serotype 9 belonging to 15 clonal complexes (CCs) or singleton sequence types (ST). In contrast, all human isolates were of serotype 2 and belonged to two non-overlapping clonal complexes CC1 (58%) and CC20 (42%). The proportion of serotype 2 isolates among S. suis strains isolated from humans was significantly higher than among strains isolated from pigs (24/24 vs. 29/124; P<0.0001). This difference remained significant when only strains within CC1 and CC20 were considered (24/24 vs. 27/37,P = 0.004). The Simpson diversity index of the S. suis population isolated from humans (0.598) was smaller than of the population isolated from pigs (0.765, P = 0.05) indicating that the S. suis population isolated from infected pigs was more diverse than the S. suis population isolated from human patients. S. suis serotype 2 strains of CC20 were all negative in a PCR for detection of genes encoding extracellular protein factor (EF) variants. These data indicate that the polysaccharide capsule is an important correlate of human S. suis infection, irrespective of the ST and EF encoding gene type of S. suis strains

Distribution of <i>Streptococcus suis</i> isolates among patients and pigs in the Netherlands, according to serotype and genotype.

<p>Distribution of <i>Streptococcus suis</i> isolates among patients and pigs in the Netherlands, according to serotype and genotype.</p

Phylogenetic analyses of concatenated sequences of seven housekeeping gene fragments of <i>Streptococcus suis</i> strains isolated from human patients and pigs in the Netherlands.

<p>The tree was constructed using Neighbor-Joining algorithm in SplitsTree4 using MLST allelic profiles. Distance matrix was obtained from allelic profiles using the SplitsTree program at <a href="http://pubmlst.org/analysis/" target="_blank">http://pubmlst.org/analysis/</a>. ST’s comprising the different clonal complexes are circled. Serotypes are indicated by coloured dots with a diameter corresponding to the number of strains. The horizontal line indicates the scale for genetic distance in arbitrary units.</p