Robert E. Gertz

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BACKGROUND The introduction of the 7-valent conjugate pneumococcal vaccine (PCV7) in children may result in serotype replacement. We estimated the rate of increase of invasive pneumococcal disease (IPD) caused by serotype 19A in children <5 years old and determined the genetic composition of these isolates. METHODS Cases of IPD between July 1999 and June(More)
Monitoring of serotypes and their clonal associations is critical as pneumococci adapt to the selective pressures exerted by the pneumococcal seven-valent conjugate vaccine (PCV7). We genotyped 1,476 invasive isolates from the Active Bacterial Core surveillance (705 [89.8%] of the isolates were obtained from children <5 years of age, and 771 [18.4%] of the(More)
Beta-lactam antibiotics (BLAs) are the first-line agents used against group B streptococci (GBS) infection. A clonal set of four independent, invasive GBS isolates with elevated MICs to BLAs were identified that shared a pbp2x mutation (Q557E) corresponding to a resistance-conferring pneumococcal mutation. BLA sensitivity was restored through allelic(More)
Streptococcus pneumoniae ('pneumococcus') causes an estimated 14.5 million cases of serious disease and 826,000 deaths annually in children under 5 years of age(1). The highly effective introduction of the PCV7 pneumococcal vaccine in 2000 in the United States(2,3) provided an unprecedented opportunity to investigate the response of an important pathogen to(More)
We performed culture-based and PCR-based tests for pneumococcal identification and serotyping from carriage specimens collected in rural and urban Kenya. Nasopharyngeal specimens from 237 healthy children <5 years old (C-NPs) and combined nasopharyngeal/oropharyngeal specimens from 158 adults (A-NP/OPs, 118 HIV-positive) were assessed using pneumococcal(More)
Monitoring antibiotic-resistant pneumococcal strains not covered by the 7-valent conjugate vaccine is an important priority. The Centers for Disease Control and Prevention's Active Bacterial Core Surveillance identified 68 invasive penicillin-nonsusceptible serotype 35B (PN35B) isolates recovered from 1995 to 2001 from patients residing in the states of(More)
Late-onset group B streptococcal (GBS) infection affecting identical twins is described. Although exhibiting similar signs and symptoms at presentation, twin A suffered fulminant fatal meningitis while twin B recovered completely. The GBS isolates proved to be genetically identical and possessed equivalent abilities to invade and injure cells of the human(More)
UNLABELLED β-Lactam antibiotics are the drugs of choice to treat pneumococcal infections. The spread of β-lactam-resistant pneumococci is a major concern in choosing an effective therapy for patients. Systematically tracking β-lactam resistance could benefit disease surveillance. Here we developed a classification system in which a pneumococcal isolate is(More)
Streptococcus equi subsp. zooepidemicus is a known zoonotic pathogen. In this public health investigation conducted in Virginia, USA, in 2013, we identified a probable family cluster of S. zooepidemicus cases linked epidemiologically and genetically to infected guinea pigs. S. zooepidemicus infections should be considered in patients who have severe(More)
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