Yes, Multiple Bacteria Besides Group A Streptococcus Cause Throat Infections
While Group A β-hemolytic Streptococcus (Streptococcus pyogenes) is the most common bacterial cause of pharyngitis, other bacteria including Groups C and G streptococci, Neisseria gonorrhoeae, Arcanobacterium haemolyticum, Corynebacterium diphtheriae, Fusobacterium necrophorum, and several others can cause throat infections, though they are far less common and most do not require routine antibiotic treatment. 1, 2
Primary Bacterial Causes
Group A Streptococcus (Most Important)
- Group A β-hemolytic streptococci cause 15-30% of pediatric pharyngitis cases and are the only bacterial cause requiring routine antibiotic treatment to prevent acute rheumatic fever and other complications 1, 2
- This organism accounts for 5-15% of adult pharyngitis cases 3
Groups C and G Streptococci (Common but Less Significant)
- These organisms can cause pharyngitis but antibiotic benefit is unproven, and they do not lead to complications like acute rheumatic fever 2, 4
- Pharyngitis from Group C streptococcus typically remains localized and does not progress to bacteremia 4
Rare but Serious Bacterial Pathogens
The following bacteria require consideration in specific clinical contexts 2:
- Corynebacterium diphtheriae - causes diphtheria with characteristic pseudomembrane formation 2, 5
- Neisseria gonorrhoeae - consider in sexually active patients with pharyngeal exposure 2, 6
- Fusobacterium necrophorum - can cause Lemierre's syndrome (suppurative thrombophlebitis of internal jugular vein) 2
- Arcanobacterium haemolyticum - causes pharyngitis particularly in adolescents and young adults, sometimes with scarlatiniform rash 2, 6
- Francisella tularensis - causes oropharyngeal tularemia 2
- Yersinia enterocolitica - rare cause of pharyngitis 2
- Mixed anaerobic infections - can occur in specific clinical settings 2
Atypical Bacterial Pathogens
- Mycoplasma pneumoniae and Chlamydia pneumoniae are uncommon causes of acute pharyngitis and typically present with other systemic symptoms 1, 7, 6
Critical Clinical Pitfall
The signs and symptoms of bacterial and viral pharyngitis overlap so broadly that accurate diagnosis on clinical grounds alone is impossible - even experienced physicians overdiagnose streptococcal pharyngitis by 80-95% 1, 8, 6. This leads to massive antibiotic overuse, contributing to resistance and unnecessary side effects 1.
Diagnostic Approach
- Laboratory confirmation with rapid antigen detection test or throat culture is required when bacterial infection is suspected 1, 2
- Testing should be reserved for patients without clear viral features (conjunctivitis, coryza, cough, diarrhea) 1, 2
- Rapid antigen tests have 79-88% sensitivity and 90-96% specificity for Group A Streptococcus 6
The Viral Reality
Viruses are the most common cause of acute pharyngitis overall, including adenovirus, influenza, parainfluenza, rhinovirus, respiratory syncytial virus, coxsackievirus, echoviruses, herpes simplex virus, and Epstein-Barr virus 1, 2. Most patients seeking care for sore throat have viral infections - fewer than 10% of adults and 30% of children actually have bacterial pharyngitis 6.