Upper Respiratory Culture, Routine

Throat swab, nasopharynx swab, nares swab, ear swab

One swab or aspirated material

Bacterial culture transport swab

Isolate and identify potentially pathogenic organisms from throat, sinus etc; evaluate pharyngitis; evaluate nares for staph

Interpretation requires a significant level of experience and technical proficiency in order to avoid false-positives and false-negatives.¹ Many other etiologic agents can be responsible for pharyngitis.² Note: This procedure does not include screening for Neisseria gonorrhoeae or Corynebacterium diphtheriae. Anaerobic organisms that are frequently implicated in chronic infection of the tonsils and adenoids are not recovered by aerobic culture methods.

Culture

Routine respiratory flora present or no growth

Thrush, oral candidiasis, and Candida esophagitis frequently complicate antineoplastic therapy, hyperalimentation, transplantation immunosuppression, pregnancy, and the acquired immunodeficiency syndrome (AIDS). In addition to a fungal culture, a saline wet preparation, Gram stain, or KOH preparation demonstrating yeast cells or pseudohyphae may also be useful in rapidly establishing the diagnosis of oral or mucocutaneous candidiasis.

Streptococcus pyogenes: (group A β-hemolytic strep) and other β-hemolytic streptococci in groups B, C, D, and G are generally susceptible to penicillin and its derivatives, therefore, susceptibility need not be routinely determined. The principal reason for considering an alternative drug for individual patients is allergy to penicillin. Erythromycin, a cephalosporin, or clindamycin might be substituted in these cases. Patients allergic to penicillins may also be allergic to cephalosporins.

In the late 1980s a resurgence of serious Streptococcus pyogenes infection was observed. Complications including rheumatic fever, sepsis, severe soft tissue invasion, and toxic shock-like syndrome (TSLS) are reported to be most common with the M1 serotype and a unique invasive clone has become the predominant cause of severe streptococcal infections.³

Ear: Normal flora of the skin of the healthy ear includes Staphylococcus epidermidis, Corynebacterium sp, and Staphylococcus aureus. Correlation of nasopharyngeal cultures with results of tympanocentesis culture is poor and lacks predictive value in identification of the causative agent of otitis media. In decreasing order of frequency, the following organisms have been recovered from tympanocentesis: S pneumoniae (50% to 75%), H influenzae (10% to 30%), Moraxella (Branhamella) catarrhalis (5% to 10%), Streptococcus pyogenes (5% to 10%), Staphylococcus aureus (1% to 5%), Pseudomonas aeruginosa (0.1% to 1%). E coli, Klebsiella pneumoniae, Pseudomonas aeruginosa may be isolated from neonates. In therapeutic failures, S aureus, and P aeruginosa are most frequently recovered. Tympanocentesis is not usually performed in primary infections. It is to be considered in treatment failures and neonates. Candida superinfection may complicate therapy for recurring ear infections and may be a cause of persistent otorrhea. Otitis externa is frequently caused by P aeruginosa and less frequently by Candida sp, Proteus sp, S aureus, and Trichophyton sp.