Streptococcus pyogenes in Neonates and Postpartum Women: First Report on Prevalence, Resistance, emm Typing, and Risk Factors in Khyber Pakhtunkhwa

Streptococcus pyogenes is a significant pathogen in postpartum women and neonates. This study aimed to determine its prevalence, antibiotic susceptibility, clinical features, and associated risk factors in tertiary care hospitals in Khyber Pakhtunkhwa, Pakistan. A total of 384 clinical samples were collected from postpartum women (n = 192) and neonates (n = 192) in maternity wards. S. pyogenes isolates were identified using standard microbiological methods, and antibiotic susceptibility was assessed via the Kirby–Bauer disk diffusion assay. The emm typing was performed through PCR and sequencing. Clinical features and risk factors were analyzed statistically. The overall prevalence of S. pyogenes was 14.3% (55/384), with 16.7% in postpartum women and 11.9% in neonates. Isolates exhibited high sensitivity to β-lactams (penicillin ≥ 95%, ampicillin ≥ 91%) but moderate resistance to cephalosporins (cefepime ~12%) and macrolides (erythromycin 23.5–29.0%). Fluoroquinolones and tetracyclines showed the highest resistance rates (ciprofloxacin 38.7–43.5%, tetracycline 32.1–37.5%). Molecular typing revealed diverse emm types, with emm44, emm77, and emm12 being predominant. Fever and sepsis were common, with postpartum women experiencing more wound infections (33.3%) and neonates exhibiting respiratory distress (55.6%). Significant risk factors included prolonged labor (> 18 hours, p = 0.030) and premature rupture of membranes (p = 0.039) in mothers, preterm birth (p = 0.013), and neonatal resuscitation (p = 0.028) in neonates. The study highlights a substantial burden of S. pyogenes infections and increasing antibiotic resistance. Enhanced surveillance, antibiotic stewardship, and targeted infection control strategies are crucial to mitigating morbidity and mortality in these high-risk groups.