BACKGROUND: Streptococcus pneumoniae causes pneumonia, sepsis, and meningitis. This study aimed to investigate the clinical characteristics of mucoid and non-mucoid isolates of S. pneumoniae, and to explore the relationship between the isolate phenotypes and their antibiotic susceptibility. METHODS: Clinical isolates from 3,453 non-repetitive S. pneumoniae (189 mucoid and 3,264 non-mucoid) infections obtained between January 2008 and December 2012 from outpatients at the Kimitsu-Central Hospital were evaluated. RESULTS: Compared to the non-mucoid isolates, the mucoid phenotypes were more susceptible to certain antibiotics such as erythromycin, clarithromycin, and tetracycline as opposed to clindamycin, chloramphenicol, and rifampicin. The mucoid phenotype was isolated more frequently from schoolchildren, adults, and elderly adults in a variety of clinical sites, including otorrhea, genitalia, pus, and eye discharge than the non-mucoid phenotype. This suggested that mucoid isolates are more likely to be involved than non-mucoid isolates in various local infections. Systemic infection, which indicates invasiveness, was not associated with the mucoid or non-mucoid phenotype. CONCLUSIONS: The results of this study suggest that mucoid isolates tend to have higher susceptibility than non-mucoid isolates to antibiotics. To the best of our knowledge, mucoid and non-mucoid S. pneumoniae isolates considerably differ in terms of clinical isolation site and age-specific prevalence.
Adult ; Aged ; Anti-Bacterial Agents ; Chloramphenicol ; Clarithromycin ; Clindamycin ; Erythromycin ; Genitalia ; Humans ; Meningitis ; Outpatients* ; Phenotype ; Pneumonia ; Prevalence ; Rifampin ; Sepsis ; Streptococcus pneumoniae* ; Suppuration ; Tetracycline

OBJECTIVEThe aim of this study was to establish reference concentrations of urinary strontium by inductively coupled plasma atomic emission spectrometry (ICP-AES).

METHODSFor the determination of strontium, urine samples were collected from healthy Japanese (n=146; 115 males, 31 females; mean age, 33±9 years; age range, 18 to 58 years). The urine samples stored at or below -20°C were thawed with incubation at 40°C for 30 min and sediments were dissolved by vigorous shakings. Then, the samples were centrifuged at 3000 g for 5 min, and the supernatant was directly aspired into a P-5200-3600/1200 ICP-AES system from Hitachi Ltd., Tokyo, Japan.

RESULTSA steeper increase in the S/N ratio and a good effective linearity of the calibration line was obtained at 407.771 nm in the range of 0-300 μg/L strontium standard solution. Urine samples having the same background signal as that of 18 MΩ cm ultrapure blank water, a good correspondence of the single peak pattern of the spectra, accuracy and precision of spike recovery were also confirmed. Urinary strontium concentrations showed a log-normal distribution and a geometric mean concentration of 143.9 μg/L, with 5-95% confidential interval of 40.9-505.8 μg/L.

CONCLUSIONThe results of this study will be useful as guidelines for the biological monitoring of strontium in normal subjects and in individuals therapeutically or environmentally exposed to strontium.