In 2000, a protein–polysaccharide pneumococcal conjugate vaccine was recommended for use in infants and young children. Surveillance data show that from 1998 to 2001 the rate of invasive disease ...declined by 69 percent among children less than two years of age. There were also smaller but significant reductions in pneumococcal disease in adults.
Pneumococcal sepsis and meningitis are less frequent in infants and young children.
In early 2000, a 7-valent protein–polysaccharide pneumococcal conjugate vaccine (Prevnar, Wyeth Lederle Vaccines) was licensed for use in infants and young children in the United States. This was the first vaccine that promised efficacy against pneumococcal disease for this high-risk group. In the second half of 2000, recommendations for routine use of the vaccine in all infants and children under two years of age and in high-risk children two through four years of age were published,
1
,
2
and distribution of the vaccine through public programs began. By August 2001, a shortage was reported.
3
Controlled clinical trials have shown that the . . .
This study assesses a novel bile solubility test and MALDI-TOF for the differentiation of Streptococcus pneumoniae from other mitis group streptococci, including differentiation of S. pneumoniae from ...Streptococcus pseudopneumoniae. Eighty-four species verified mitis group isolates were subjected to our bile solubility test (which measures and calculates the differences of absorbance in the test tube containing 10% sodium deoxycholate versus a blank control tube, after incubation for 10 minutes at 36 °C using a spectrophotometer) and MALDI-TOF MS (both the standard result output and by visual spectra evaluation). Applying a calculated optimal cut-off absorbance-value of 2.1, differentiated S. pneumoniae from all but one other mitis group streptococci (one S. mitis isolate generated an OD-value above 2.1). MALDI-TOF score value identification identified correctly 46 S. pneumoniae and 4 S. pseudopneumoniae but misidentified 16 other mitis group strains. Visual spectra evaluation correctly identified all S. pneumoniae and S. pseudopneumoniae strains but misidentified 13 other mitis group strains. The bile solubility test based on spectrophotometric reading described in this study can differentiate S. pneumoniae from other Streptococcus species. Combining the bile solubility test and the MALDI-TOF spectra results provide a correct identification of all S. pneumoniae and S. pseudopneumoniae isolates.
CONTEXT Historically, incidence of pneumococcal disease in the United States
has been higher among blacks than among whites. Following recommendation of
a new 7-valent pneumococcal conjugate vaccine ...for children in October 2000,
the incidence of invasive pneumococcal disease has declined dramatically,
but the impact of vaccination on racial disparities in incidence of pneumococcal
disease is unknown. OBJECTIVE To assess the effect of conjugate vaccine introduction on rates of pneumococcal
disease among whites and blacks in the United States. DESIGN, SETTING, AND PATIENTS Analysis of data from the Active Bacterial Core Surveillance (ABCs)/Emerging
Infections Program Network, an active, population-based surveillance system
in 7 states. Patients were 15 923 persons with invasive pneumococcal
disease occurring between January 1, 1998, and December 31, 2002. MAIN OUTCOME MEASURES Age- and race-specific pneumococcal disease incidence rates (cases per
100 000 persons), rate ratios, and rate differences. RESULTS Between 1998 and 2002, annual incidence rates for invasive pneumococcal
disease decreased from 19.0 to 12.1 cases per 100 000 among whites and
from 54.9 to 26.5 among blacks. Due to these declines, 14 730 fewer cases
occurred among whites and 8780 fewer cases occurred among blacks in the United
States in 2002, compared with 2 prevaccine years, 1998 and 1999. Before vaccine
introduction, incidence among blacks was 2.9 times higher than among whites
(95% confidence interval CI, 2.7-3.0); in 2002, the black-white rate ratio
had been reduced to 2.2 (95% CI, 2.0-2.4). Incidence among black children
younger than 2 years went from being 3.3 times higher (95% CI, 3.0-3.7) than
among white children in the prevaccine period to 1.6 times higher (95% CI,
1.1-2.2) in 2002. By 2002, 74% of white children and 68% of black children
aged 19 to 35 months in the 7 states had received at least 1 dose of pneumococcal
conjugate vaccine; 43% of white and 39% of black children received 3 or more
doses. CONCLUSION Although blacks remain at higher risk of invasive pneumococcal disease,
introduction of childhood pneumococcal vaccination has reduced the racial
disparity in incidence of pneumococcal disease.
CONTEXT Macrolide antibiotics, including erythromycin, clarithromycin, and azithromycin,
are the mainstays of empirical pneumonia therapy. Macrolide resistance among Streptococcus pneumoniae, the ...most common cause of community-acquired
pneumonia, is increasing in the United States. Whether resistance is a significant
problem or whether macrolides remain useful for treatment of most resistant
strains is unknown. OBJECTIVE To examine the epidemiology of macrolide-resistant pneumococci in the
United States. DESIGN AND SETTING Analysis of 15 481 invasive isolates from 1995 to 1999 collected
by the Centers for Disease Control and Prevention's Active Bacterial Core
surveillance system in 8 states. MAIN OUTCOME MEASURES Trends in macrolide use (1993-1999) and resistance and factors associated
with resistance, including examination of 2 subtypes, the M phenotype, associated
with moderate minimum inhibitory concentrations (MICs), and the MLSB phenotype, associated with high MICs and clindamycin resistance. RESULTS From 1993 to 1999, macrolide use increased 13%; macrolide use increased
320% among children younger than 5 years. Macrolide resistance increased from
10.6% in 1995 to 20.4% in 1999. M phenotype isolates increased from 7.4% to
16.5% (P<.001), while the proportion with the
MLSB phenotype was stable (3%-4%). The median erythromycin MIC
(MIC50) of M phenotype isolates increased from 4 µg/mL to
8 µg/mL. In 1999, M phenotype strains were more often from children
than persons 5 years or older (25.2% vs 12.6%; P<.001)
and from whites than blacks (19.3% vs 11.2%; P<.001). CONCLUSIONS In the setting of increasing macrolide use, pneumococcal resistance
has become common. Most resistant strains have MICs in the range in which
treatment failures have been reported. Further study and surveillance are
critical to understanding the clinical implications of our findings.
1 Department of Pediatrics and the World Health Organization Collaborating Center for Reference and Research on Streptococci, University of Minnesota, Minneapolis, MN 55455, USA
2 Centers for Disease ...Control and Prevention, Division of Bacterial and Mycotic Diseases, Respiratory Diseases Branch, 1600 Clifton Rd, Mailstop CO2, Atlanta, GA 30333, USA
Correspondence Edward L. Kaplan kapla001{at}umn.edu
Received 1 July 2005
Accepted 23 September 2005
Strain characterization of group A streptococci (GAS) has traditionally been based on serological identification of M protein. Additional tests to determine T-protein serotype and production of streptococcal serum opacity factor (SOF) provide important information both to aid in and to supplement M-protein serotyping. Advances in DNA-sequencing technology in the late twentieth century resulted in the development of a method for determining the M type of GAS from the sequence of the gene encoding M protein, the emm gene. Although emm -sequence typing has largely replaced M typing in many laboratories, information provided by T typing and SOF determination continues to provide valuable supplementary information for strain characterization. A comprehensive summary of the correlation of T pattern and SOF production with M type was last published in 1993, several years before emm typing became widely available. Since then, the ease of M-type identification afforded by emm typing has resulted in an increase in the number of confirmed M/ emm types of more than 50 %. However, comprehensive information about T-protein serotype and the correlation of SOF production with these new M/ emm types is not widely available. This report presents a comprehensive summary of this information, not only for newly described types, but also updated information for previously described types. This information was extracted from combined records from streptococcal reference laboratories at the University of Minnesota and at the Centers for Disease Control and Prevention in Atlanta. Data from more than 40 000 strains (representing uncomplicated GAS infections, systemic invasive infections and strains associated with non-suppurative sequelae, collected from the US and diverse locations worldwide) were analysed.
Abbreviations: CDC, Centers for Disease Control and Prevention; GAS, group A streptococci; SOF, serum opacity factor; UMN, University of Minnesota.
Limited data are available about the impact of antimicrobial resistance on clinical outcomes in cases of pneumococcal pneumonia. This was studied in 146 persons hospitalized with invasive pneumonia ...due to Streptococcus pneumoniae (minimum inhibitory concentration of cefotaxime, ⩾.25 μg/mL) who were identified through population-based active surveillance for the period of November 1994 through April 1996. Compared with matched control subjects who had infection with more-susceptible S. pneumoniae, the proportion of subjects who died or who were admitted to an intensive care unit did not differ significantly. Multivariable analysis showed no significant contribution of antimicrobial resistance to mortality or the requirement for care in an intensive care unit. The ability to detect an effect of antimicrobial resistance on these important outcome measures may have been influenced by aggressive multidrug empirical therapy in this group of hospitalized patients. Factors other than resistance, such as severity of illness at presentation and advance directive status (“do not resuscitate” orders), appear to have a stronger influence on pneumococcal pneumonia outcomes.
One hundred one isolates of nutritionally variant streptococci from 97 patients were phenotypically characterized and compared with the type strains of Granulicatella adiacens (formerly Abiotrophia ...adiacens) (ATCC 49175(T)) Abiotrophia defectiva (ATCC 49176(T)), and Granulicatella elegans (formerly Abiotrophia elegans) (DSM 11693(T)). Of the isolates, 55 and 43 resembled G. adiacens and A. defectiva, respectively, while 3 strains resembled G. elegans. Phenotypic characteristics useful in differentiating between species within the genera Granulicatella and Abiotrophia (G. adiacens, G. elegans, Granulicatella balaenopterae, and A. defectiva) were production of alpha- and beta-galactosidase; production of beta-glucuronidase; hippurate hydrolysis; arginine dihydrolase activity; and acid production from trehalose, sucrose, pullulan, and tagatose. From the reports submitted with the specimens, the clinical diagnosis was endocarditis in 58% of patients and septicemia or bacteremia in 26% of patients.
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