Ninety-five colonizing isolates and 74 invasive isolates of Streptococcus agalactiae from Kenyan adults were characterized by using capsular serotyping and multilocus sequence typing. Twenty-two sequence types clustering into five clonal complexes were found. Data support the view that S. agalactiae isolates belonging to a limited number of clonal complexes are invasive in adults worldwide.Streptococcus agalactiae, or group B streptococcus (GBS), regarded mainly as a pathogen of neonates and pregnant women (15), is increasingly affecting nonpregnant adults (19). In adults, S. agalactiae causes skin and soft tissue infections, bacteremia, urinary tract infections, pneumonia, osteomyelitis, meningitis, endocarditis, and streptococcal toxic shock syndrome (2,6,18,20). Risk factors associated with invasive GBS in adults are old age, diabetes mellitus, neurologic diseases, cirrhosis or other liver diseases, stroke, breast cancer, and renal failure (7,22,23). S. agalactiae colonizes the lower gastrointestinal and genitourinary tracts of 30 to 50% of healthy adults (26), and an estimated 20 to 30% of all pregnant women are carriers (25). S. agalactiae can be isolated from vaginal or rectal swabs, and prenatal screening for colonization of pregnant women is recommended (27). The objective of this study was to analyze the epidemiology of GBS in East African adults by using multilocus sequence typing (MLST) (13) and capsular serotyping (10), with a focus on investigating possible correlations between clonal complexes of GBS in invasive or colonizing isolates.The Aga Khan University Hospital in Nairobi (AKUH,N) is a tertiary care, referral university hospital in Nairobi, Kenya. GBS were cultivated at the Division of Microbiology of AKUH,N from specimens derived from both inpatients and outpatients between January 2007 and June 2010. Swabs from outreach collection points were transported in Stuart's transport medium to the hospital. Blood cultures were routinely performed using Plus-aerobic/F, Plus-anaerobic/F, and Peds Plus Bactec 9120 media (Becton Dickinson) in combination with commercially available biphasic culture medium bottles (Roche Diagnostics, France). Single GBS colonies were picked from 5% sheep blood agar plates (Oxoid, United Kingdom), and identification of GBS was performed using colony morphology, Gram staining, CAMP test, the API Streptococcus identification kit (Bio-Merieux, France), and the latex agglutination test using a bacterial meningitis kit with specific group B latex (Wellcogen kit from Remel Europe Ltd.). Antimicrobial susceptibility testing was performed, and results were interpreted according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI) (5). Streptococcus pneumoniae ATCC 49619 was used for quality control. All GBS isolates were found to be susceptible to penicillin and cephalosporin. GBS isolates analyzed here were selected according to availability of stocked isolates and accessibility of patient files. One isolate per patient was included in this study. Clinica...

Microcystins produced by freshwater cyanobacteria pose serious threats to human health and are a growing problem in drinking water supplies worldwide. Toxin detection and identification in water reservoirs when cyanobacterial density is still low is a key step to predict harmful algal blooms and to allow the safe use of the resource. For this purpose, developing sensitive and rapid methods of analysis is crucial. Adopting a strategy that couples the use of a filter-feeder organism (Unio elongatulus, Pfeiffer 1825 (Bivalvia: Unionidae)) with matrixassisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) technology, effective microcystin detection was achieved. The performances of MALDI-TOF MS, high-liquid-performance chromatography with diode array detector (HPLC-DAD) and enzyme-linked immunosorbent assays (ELISA) test were compared. The results obtained in this study suggest that the exploitation of an efficient bioaccumulator organism, coupled with a rapid and sensitive analytical method, can be a very useful strategy in monitoring programs for early and prompt risk management.

Abstract. We assess the benefits of offline laserdesorption/ionization mass spectrometry in understanding ambient particulate matter (PM) sources. The technique was optimized for measuring PM collected on quartz-fiber filters using silver nitrate as an internal standard for m/z calibration. This is the first application of this technique to samples collected at nine sites in central Europe throughout the entire year of 2013 (819 samples). Different PM sources were identified by positive matrix factorization (PMF) including also concomitant measurements (such as NO x , levoglucosan, and temperature). By comparison to reference mass spectral signatures from laboratory wood burning experiments as well as samples from a traffic tunnel, three biomass burning factors and two traffic factors were identified. The wood burning factors could be linked to the burning conditions; the factors related to inefficient burns had a larger impact on air quality in southern Alpine valleys than in northern Switzerland. The traffic factors were identified as primary tailpipe exhaust and most possibly aged/secondary traffic emissions. The latter attribution was supported by radiocarbon analyses of both the organic and elemental carbon. Besides these sources, factors related to secondary organic aerosol were also separated. The contribution of the wood burning emissions based on LDI-PMF (laser-desorption/ionization PMF) correlates well with that based on AMS-PMF (aerosol mass spectrometer PMF) analyses, while the comparison between the two techniques for other components is more complex.

Abstract. We assess the benefits of offline laser-desorption/ionization mass spectrometry (LDI-MS) in understanding ambient particulate matter (PM) sources. The technique was optimized for measuring PM collected on quartz-fiber filters using silver nitrate as an internal standard for m/z calibration. This is the first application of this technique to samples 20 collected at nine sites in central Europe throughout the entire year 2013 (819 samples). Different PM sources were identified by positive matrix factorization (PMF) including also concomitant measurements (such as NO x , levoglucosan, and temperature). By comparison to reference mass spectral signatures from laboratory wood burning experiments as well as samples from a traffic tunnel, three biomass-burning factors and two traffic factors were identified. The wood-burning factors could be linked to the burning conditions; the factors related to inefficient burns had a larger impact on air quality in 25 southern Alpine valleys than in northern Switzerland. The traffic factors were identified as primary tailpipe exhaust and most possibly aged/secondary traffic emissions, respectively. The latter attribution was supported by radiocarbon analyses of both the organic and elemental carbon. Besides these sources, also factors related to secondary organic aerosol were separated.

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