Spatial exploration of Streptococcus pneumoniae clonal clustering in São Paulo, Brazil

Abstract

Objectives:To examine the spatial distribution of Streptococcus pneumoniae and its clonal patterns collected between 2002 and 2006 in São Paulo, Brazil. Methods: As part of an observational study in São Paulo city, Brazil, S. pneumoniae isolates routinely cultured from blood, respiratory specimens, or cerebrospinal and other profound fluids were selected. Additionally, only isolates with either penicillin (PEN) intermediate (I) or resistant (R) status on routine antibiogram were included, in order to obtain a higher probability of clonal isolates. A single I/R S. pneumoniae isolate per patient was included and submitted to genotypic determination by pulsed field gel electrophoresis (PFGE). Minimum inhibitory concentrations (MICs) were determined for the isolates by Etest® to PEN and other antimicrobials. Each isolate was geocoded in a digital map. The Kernel function and ratio methods between total isolates vs. clones were used in order to explore possible cluster formations. Results: Seventy-eight (78) S. pneumoniae community isolates from two major outpatient centers in São Paulo, Brazil, were selected from the databank according to their penicillin susceptibility profile, i.e. R or I to penicillin assessed by oxacillin disc diffusion. Of these, 69 were submitted to PFGE, 65 to MIC determination, and 48 to spatial analytical procedures. Preliminary spatial analysis method showed two possible cluster formation located in southwest and southeast regions of the city. Conclusion: Further analyses are required for precisely determining the existence of S. pneumoniae clusters and their related risk factors. Apparently there is a specific transmission pattern of S. pneumoniae clones within certain regions and populations. GIS and spatial methods can be applied to better understand epidemiological patterns and to identify target areas for public health interventions.

Susceptibility profiles and correlation with pneumococcal serotypes soon after implementation of the 10-valent pneumococcal conjugate vaccine in Brazil

“…20 Data from Brazil are still scarce and fragmented. Some studies have shown low 21,22 or no 23 rates of non-susceptibility to penicillin, whereas others have indicated rates around 20%; 24-25 serotypes 14, 23F, 6B, and 19F have been most commonly associated with this resistance in brazilian studies. 24,25 Full resistance (MIC >4.0 mg/ml) to penicillin was not found among the isolates included in this study.…”

Geospatial analysis of Helicobacter pylori infection in South Australia: Should location influence eradication therapy?

“…22,23 Geospatial analyses are underutilized for studying antimicrobial resistance and have not previously been applied to H. pylori. Globally, geospatial analyses have been useful for understanding the distribution of infection in antimicrobial-resistant Staphylococcus aureus, 24 Streptococcus pneumoniae, 25 and Escherichia coli. 26 Given the large variation in H. pylori resistance rates, a better understanding of the geospatial distribution of both infection and resistance, and its influence on risk factors for resistance, is needed to guide eradication therapy.…”

Geographic mapping of Enterobacteriaceae with extended-spectrum β-lactamase (ESBL) phenotype in Pereira, Colombia

“…KDE helps identify the presence of clusters and irregularities [ 29 ]. This tool requires a radius to determine the circular neighborhood around each point, where that point will have influence, otherwise speaking, KDE determines how the influence of a point extends in the given radius [ 14 , 16 , 19 ]. We arbitrarily assume that each home address of a given patient could have a radius of influence of 250 m.…”