Group B Streptococcal Bacteremia in Adults in the 21st Century: Review of 132 Episodes Over a 10-Year Period in a Large Community Teaching Hospital

Clinical Disease and Outcomes of Group B Streptococcus Bloodstream Infections at a Teaching Hospital in Saudi Arabia From 2015 to 2022

Background Invasive disease due to group B Streptococcus (GBS) infection in adult males and nonpregnant females can cause various diseases, such as primary bacteremia, endocarditis, skin and soft tissue infection (SSTI), and meningitis. Especially in older people, invasive GBS infection has a high case fatality rate. In Saudi Arabia, little is known about the clinical signs and symptoms of GBS bacteremia and the associated risk factors and mortality rate. Methodology We performed a retrospective study at King Abdulaziz University Hospital in Jeddah, Saudi Arabia, a large tertiary hospital, to investigate clinical disease, potential risk factors, susceptibility patterns, and mortality related to GBS in adult males and nonpregnant females diagnosed with GBS bacteremia. All patients ≥14 years of age with GBS-positive blood cultures from January 1, 2015, until December 31, 2022, were included. Patient data such as age, sex, comorbidities, hospital ward, length of hospital stay, monomicrobial versus polymicrobial bloodstream infection, antimicrobials used for treatment, complications, whether an infectious disease specialist had seen them, and outcomes were extracted from the electronic health records. Results A total of 50 patients with GBS bacteremia met the inclusion criteria. The mean age of these patients was 57.0 years (SD = 16.0), and 27 (54%) were female. The 90-day mortality was 11 (22%). In total, 34 (68%) patients had a monomicrobial infection, and among those with polymicrobial infection, methicillin-resistant Staphylococcus aureus was the most common co-infection (56%, n = 9/16). The most common source of infection was SSTI and wound infection in 24 (48%) patients. Most patients had one or more comorbidities; the mean Charlson comorbidity index was 3.8 (SD = 2.4). The most prevalent comorbidity was diabetes mellitus in 35 (70%) patients. Of all variables analyzed, only age was significantly associated with mortality (p = 0.016), and age had a predictive value for mortality (p = 0.035). Conclusions In Saudi Arabia, as in other countries, GBS is an important pathogen, especially in older people, that should be considered when encountering a patient with bacteremia. In addition, in patients over 65 years old, GBS bacteremia carries a high risk for mortality.

Prevalence of group B streptococcus colonization in pregnant women in Jiangsu, East China

Background

Group B streptococcus (GBS) is the leading cause of early-onset neonatal sepsis. However, GBS was infrequently reported in the developing world in contrast to western countries. This study assessed the prevalence of GBS colonization among pregnant women in Jiangsu, East China, and revealed the difference of GBS infection between culture and PCR.

Methods

A total of 16,184 pregnant women at 34 to 37 weeks’ gestation aged 16–47 years were recruited from Nanjing Kingmed Center for Clinical Laboratory. Nine thousand twenty-two pregnant women received GBS screening by PCR detection only. Seven thousand one hundred sixty-two pregnant women received GBS screening by bacterial culture and GBS-positive samples were tested for antibiotic resistance.

Results

The overall GBS positive rate was 8.7% by PCR and 3.5% by culture. Colonization rate was highest in the “25–29 years” age group. The 249 GBS-positive samples which detected by culture were all sensitive to penicillin. The prevalence of resistance to erythromycin, clindamycin, and levofloxacin was 77.5, 68.3, and 52.2%, respectively.

Conclusions

This study revealed the data on the prevalence of GBS colonization in pregnant women at 34 to 37 weeks’ gestation in Jiangsu, East China. It compared the difference of the sensitivity to detect GBS between PCR and culture. PCR was expected to become a quick method in pregnancy women conventional detection of GBS infection.

Immune Responses to Invasive Group B Streptococcal Disease in Adults

Antibodies to capsular polysaccharides and pilus proteins develop in recovering adults.

Immunization of nonpregnant adults could help prevent invasive group B Streptococcus (GBS) infections, but adult immune responses have not been investigated. We defined capsular polysaccharide (CPS) and pilus island (PI) surface antigen distribution and expression and immune responses to GBS infection in nonpregnant adults. Prospective surveillance from 7 hospitals in Houston, Texas, USA, identified 102 adults with GBS bacteremia; 43% had skin/soft tissue infection, 16% bacteremia without focus, and 12% osteomyelitis. CPS-specific IgG was determined by ELISA and pilus-specific IgG by multiplex immunoassay. CPS types were Ia (24.5%), Ib (12.7%), II (9.8%), III (16.7%), IV (13.7%), and V (12.7%); 9.8% were nontypeable by serologic methods. Pili, expressed by 89%, were most often PI-2a. CPS and pilus-specific IgG increased during convalescence among patients with strains expressing CPS or PI. All GBS expressed CPS or PI; 79% expressed both. Increased antibodies to CPS and PI during recovery suggests that GBS bacteremia in adults is potentially vaccine preventable.