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.