Identification and ribotypes of Staphylococcus caprae isolates isolated as human pathogens and from goat milk

Abstract

We report five cases of human infection with Staphylococcus caprae. Two were community acquired (one case each of endocarditis and urinary tract infection); the other three were acquired in a hospital (two cases of bacteremia associated with intravenous access and one case of urinary tract infection). Analysis of human isolates and goat isolates from eight herds showed that they could be misidentified by some commercial identification systems but were clearly identified as S. caprae by ribotyping, according to their species-specific ribotype. Phylogenetic methods applied to the ribotypes did not reveal two distinct lineages corresponding to the goat and human origins of the isolates, although human ribotypes were clearly distinguishable by the presence of a core of four specific bands. The latter observation may reflect some degree of evolutionary change within the species between human and goat isolates.

Distribution of Staphylococcus Species among Human Clinical Specimens and Emended Description of Staphylococcus caprae

“…There is little possibility for geographic variation for biochemical traits of S. caprae human isolates. Our described biochemical traits (isolates from Japan) are almost identical to those in the report of Vandenesch et al (26), who used S. caprae isolated from humans in France and United Kingdom. Therefore, we believed that our described traits of S. caprae (Table 2) is useful not only for Japan but also for other countries.…”

“…In their report, all human and goat isolates produced acid from fructose, but 33% (5 of 15 strains) and 55% (8 of 15 strains) of goat isolates did not produce acid from mannitol and maltose, respectively, while all human isolates showed positive reactions for both tests. Moreover, these two different derivatives were clearly differentiated genetically by SmaI digestion of chromosomal DNA (13) or by ribotyping with an EcoRI enzyme and a 16S-23S rRNA probe (26). These observations and our DNA-DNA hybridization results suggest that the S. caprae species contains two different evolutionary groups.…”

“…S. caprae was originally isolated from goat milk in 1983 (7) and has been primarily associated with animal specimens. Only a few researchers have reported S. caprae strains isolated from human specimens (3,13,15,26), but from our data, it is clear that there are many S. caprae strains in human clinical specimens. We have not received the detailed report of the isolate site of S. caprae strains, but some strains were isolated from blood, skin abscess, and urine samples.…”

“…We could not find other animal-derived S. caprae strains (we tested about 150 isolates) and thus could not compare the biochemical traits of S. caprae isolated from humans and animals in Japan. However, Vandenesch et al (26) did report the biochemical traits of S. caprae from human and goat isolates. In their report, all human and goat isolates produced acid from fructose, but 33% (5 of 15 strains) and 55% (8 of 15 strains) of goat isolates did not produce acid from mannitol and maltose, respectively, while all human isolates showed positive reactions for both tests.…”

Identification of coagulase-negative staphylococci other than Staphylococcus epidermidis by automated ribotyping

“…The results of the present study show that automated ribotyping is highly reliable for CoNS identification, with a very high value for identification of CoNS isolates at the species level. Additionally, in some cases, automated ribotyping was able to detect polymorphisms below the species level, as shown previously for the manual ribotyping procedure [14,38,51], which could be helpful for epidemiological purposes. It should be emphasised that automated ribotyping did not result in any misidentifications in the present study.…”