Community-Based Outbreaks in Vulnerable Populations of Invasive Infections Caused by Streptococcus pneumoniae Serotypes 5 and 8 in Calgary, Canada

BACKGROUND: Outbreaks of invasive pneumococcal disease (IPD) typically occur within institutions. Beginning in 2005, we detected an increase in serotype (ST) 5 and ST8 IPD cases, predominantly in homeless persons living in an open community. METHODOLOGY/PRINCIPAL FINDINGS: CASPER (Calgary Area S. pneumoniae Epidemiology Research) surveillance study of all IPD (sterile site isolates) in our region (pop ~1,100,000). Interviews and chart reviews of all cases and all isolates phenotypically analyzed and selected isolated tested by multi-locus sequence typing (MLST). CONCLUSIONS/SIGNIFICANCE: During 2005-2007, 162 cases of ST5 IPD and 45 cases of ST8 IPD were identified. The isolates demonstrated phenotypic and genotypic clonality. The ST5 isolates were sequence type (ST) 289 and demonstrated intermediate susceptibility to TMP-SMX. The ST8 isolates were predominantly ST1268, with a susceptible antimicrobial susceptibility profile. Individuals with ST5 IPD were more likely to be middle aged (OR 2.6), homeless (OR 4.4), using illicit drugs(OR 4.8), and asthmatic(OR 2.6). Those with ST8 were more likely to be male (OR 4.4), homeless (OR 2.6), aboriginal (OR7.3), and a current smoker (OR 2.5). Overlapping outbreaks of ST5 and ST8 IPD occurred in an open community in Calgary, Canada and homelessness was a predominant risk factor. Homelessness represents a unique community in which pneumococcal outbreaks can occur

Single-nucleotide polymorphisms of MMP-2 gene in stroke subtypes.

Matrix metalloproteinases (MMP) are expressed after ischemic stroke. These proteases are responsible for a higher incidence of hemorrhages, are correlated to size of infarction and influence the effects of recombinant tissue plasminogen activator treatment. We therefore evaluated single nucleotide polymorphisms (SNP) of MMP-2 in different subtypes of stroke patients in an association study using a case-control design. METHODS: 197 stroke patients were divided according to modified TOAST criteria (small vessel disease, large vessel disease, hemorrhagic stroke and asymptomatic carotid artery stenosis) and compared to 143 controls. Clinical data like age, sex, risk factors and diagnostic results including MRI or cranial CT scans and ultrasound evaluations of intra- and extracranial arteries were obtained. Genotypes of MMP-2 (12 SNP) were compared to controls and DNA samples were analyzed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) analysis. Logistic regression analysis was performed for small vessel disease to test for interactions between markers and defined clinical risk factors. Additionally, MMP-2 serum levels obtained in the first 24 h after stroke were measured. RESULTS: From the MMP-2 gene, 5 markers (rs1030868, rs2241145, rs2287074, rs2287076, rs7201) showed a significant association with small vessel infarcts (p < 0.05) and rs7201:g.C was identified as an independent risk factor by multivariable logistic regression analysis. MMP-2 protein levels were significantly lower in this group (174 +/- 48 ng/dl) versus controls (214 +/- 56 ng/dl). For other stroke subtypes, no significant association with MMP-2 SNP could be found. CONCLUSION: Our study demonstrates an association of the MMP-2 gene with the development of lacunar stroke, and no association of MMP-2 with other stroke subtypes