Genotyping of 353 Staphylococcus aureus bloodstream isolates collected between 2004 and 2009 at a Norwegian university hospital and potential associations with clinical parameters

Abstract

We analyzed 353 Staphylococcus aureus bloodstream isolates from 2004 to 2009 to identify dominant genotypes, changes over time, and associations between genotype, phenotype, and clinical parameters. The isolates were genotyped with regard to spa type and presence of Panton-Valentine leukocidin and toxic shock syndrome toxin 1-encoding genes. A high level of genetic diversity was detected. All but three isolates were methicillin sensitive. Interestingly, spa clonal complex 021 showed a weak association with higher all-cause hospital mortality.

Fig 1

spa clonal complexes of the 353 S. aureus bacteremia isolates after Based Upon Repeat Pattern (BURP) analysis show genetic heterogeneity. spa CCs without founder, singletons, and 20 isolates not fulfilling the BURP analysis criteria (8) are not included in the figure. Clusters of linked isolates correspond to spa CCs. The spa type with the highest founder score is defined as the founder of the cluster and is marked in dark gray. Light gray indicates subfounders, which are the spa types with the second highest founder score. If two spa types have an equally high founder score, both are colored dark gray. Only the spa CCs are labeled. The size of the circles indicates the number of isolates that were assigned to that spa type. Note that the spacing between linked and unlinked spa types and spa CCs does not provide information about the genetic distance between them. The different clonal complexes consist of the following spa types. spa CC 021: t012, t017, t018, t019, t021, t037, t046, t122, t238, t318, t342, t486, t582, t584, t726, t840, t869, t1298, t1347, t1414, t2303, t3222, t3611, t4033, t6360, t6361, t6362; spa CC 133: t015, t050, t116, t133, t230, t295, t331, t722, t728, t908, t1078, t1081, t1510, t1996, t2519, t3537, t4604, t5025, t6259, t6368, t6414; spa CC 084: t084, t085, t120, t279, t328, t346, t491, t774, t853, t1034, t1116, t1492, t1877, t3603, t4714; spa CC 304/024: t008, t024, t190, t304, t594, t648, t701, t2842, t5160, t6269, t6363; spa CC 065: t004, t040, t065, t123, t130, t330, t370, t715, t880, t6413; spa CC 359: t044, t127, t177, t189, t224, t267, t359, t1381, t6367, t6369; spa CC 166: t089, t136, t153, t166, t414, t2103, t3631, t5741; spa CC 005: t005, t223, t309, t474, t490, t1139, t6265; spa CC 002: t002, t010, t045, t067, t214, t1265; spa CC 280/140: t140, t167, t258, t280, t1541, t3188; spa CC 160: t156, t160, t213, t771, t1137; spa CC 316/216: t172, t216, t316, t471; spa CC 159: t159, t171, t284.