Pathogens

• To determine the distribution of emm types and the association between specific emm types and disease severity in order to guide vaccine development
• To track antimicrobial resistance among invasive GAS isolates
• To identify potentially modifiable risk factors for community-acquired GAS infections
• To identify potentially preventable GAS infections, such as nosocomial (postpartum and post-surgical) infections or invasive infections in closed facilities (e.g., nursing homes)

Whole-genome sequencing (WGS)1 based characterization for all isolates, which includes deduction of:

1. emm types and T types
2. Resistance mechanisms and all minimum inhibitory concentrations (MICs) on panel (and others); penicillin-binding protein 2x (PBP2x) amino acid sequence types to monitor for possible emergence of beta lactam nonsusceptibility
3. Multilocus sequence type (MLST)2
4. Presence/absence of key surface proteins, exotoxins, virulence markers
5. Strategic subset targeted for conventional MIC determination
6. Phylogenetic clustering within clonal types to detect potential ongoing disease clusters

• To assess the impact and implementation of current perinatal GBS disease prevention guidelines and update the evidence base available for policy decisions related to GBS prevention
• To monitor the impact of intrapartum prophylaxis on GBS resistance and non-GBS neonatal sepsis
• To characterize trends in invasive GBS disease epidemiology in other age groups, particularly late-onset neonatal disease and adult disease
• To identify serotypes responsible for disease in order to guide vaccine development

From select surveillance areas, whole-genome sequencing (WGS)1 based characterization for all isolates, which includes deduction of:

1. Capsular serotype
2. Minimum inhibitory concentration (MIC) predictions, including penicillin-binding protein 2x (PBP2x) typing to detect decreased beta-lactam susceptibility
3. Multilocus sequence type (MLST)
4. Strategic subset targeted for conventional MIC determination
5. Presence or absence of various surface proteins, including certain vaccine candidates
6. Phylogenetic clustering within clonal types to detect potential transmission events

• To evaluate progress in the elimination of serotype b disease
• To detect possible emergence of disease due to other capsular types
• To determine appropriate verification and validation criteria for current and potential serotyping methods

Real-time polymerase chain reaction (rt-PCR) for confirmation of isolate species and capsular genogrouping.

Note: CDC may perform conventional microbiological methods, slide agglutination, and whole-genome sequencing (WGS)1 as needed to resolve any discrepancies. CDC will perform WGS for molecular typing of isolates as part of special projects or requests.

• To document the epidemiology of meningococcal disease in the United States and monitor trends over time
• To evaluate the effectiveness of meningococcal vaccines and impact on disease burden
• To monitor the molecular epidemiology of serogroup B meningococcal vaccine antigens using isolates of serogroup B N. meningitidis collected through ABCs

Whole-genome sequencing (WGS)1 for isolate species confirmation, capsular genotyping, and molecular typing

Note: CDC may perform conventional microbiological methods, real-time polymerase chain reaction (rt-PCR), and slide agglutination as needed to resolve any discrepancies.

• To track emerging antimicrobial resistance in pneumococcal isolates
• To evaluate the impact of pneumococcal conjugate vaccines on disease burden in children and on antimicrobial resistance among children
• To evaluate the impact of a pneumococcal conjugate vaccine (PCV13), as well as the existing polysaccharide vaccine (PPSV23), on disease burden and on antimicrobial resistance among adults

Whole-genome sequencing (WGS)1 based characterization of all isolates, which includes deduction of:

1. Capsular serotype
2. Minimum inhibitory concentration (MIC) predictions, including penicillin-binding protein (PBP) typing system for determining beta-lactam antibiotic MICs
3. Multilocus sequence type (MLST)
4. Pilus types
5. Conventional MIC testing of selected strains
6. Phylogenetic clustering within clonal types to detect potential transmission events