# Guideline on Testing of Lower Respiratory Tract Specimens
Revised June, 2015
The purpose of this guideline is to provide physicians with clear and concise directions on testing and interpreting laboratory reports of pathogens from the lower respiratory tract for community-based patients.
Routine sputum cultures for the etiologic diagnosis of outpatients with community acquired pneumonia have limited value. Specimens should only be collected if individual antibiotic management will change based on the sputum culture results.
The following etiological agents of pneumonia are not detected in routine cultures: Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella, anaerobes, respiratory viruses, and Mycobacterium tuberculosis. If viral testing is required to confirm suspicion of a viral infection, the specimen should be forwarded in a proper viral collection kit directly to the Public Health Laboratory.
The quantity of the organisms present, source of culture, presence of a tracheostomy, immune status, and age of the patient may determine the significance of a pathogen.
Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis may be part of the normal respiratory flora and the presence of these organisms alone in a respiratory culture does not necessarily indicate infection.

# Specimen Collection Instructions
Appropriate specimens to identify pathogens causing pneumonia include expectorated and induced sputum.
Sputum specimens should not be submitted unless a good quality specimen can be obtained, therefore collections from non-hospitalized pediatric patients are discouraged. 1 Sputum specimens will be rejected unless they meet the laboratory's quality score system screening requirement (ratio of squamous cells to neutrophils). 2,3 Sputum samples should ideally be transported to the laboratory in less than 2 hours if at room temperature, otherwise the specimen must be refrigerated.
If an active infection with M. tuberculosis is suspected at least three sputum samples, preferably collected at one hour intervals, should be submitted for testing. 4 Suspicion of M. tuberculosis should be specified on the requisition.
Blood culture should be considered in patients with asplenia, severe chronic liver disease, active alcohol abuse, or severe community acquired pneumonia (such as patients with cavitary disease or pleural effusions).  The penicillin result may predict susceptibility to ampicillin, amoxicillin, 2nd or 3rd generation cephalosporins e.g., cefprozil, cefuroxime, cefpodoxime, cefaclor.
b) Susceptibility and resistance to azithromycin and clarithromycin may be predicted by erythromycin result. 6 Haemophilus influenzae -lactamase test Amoxicillin/ampicillin susceptibility is generally predicted by the results of -lactamase testing. Infections due to lactamase producing/amoxicillin resistant strains may be empirically treated with amoxicillin/clavulanate, trimethoprim/sulfamethoxazole, cefuroxime, cefixime, cefprozil, tetracycline, clarithromycin, azithromycin, or fluoroquinolones.

# Moraxella catarrhalis
The OAML gratefully acknowledges the contribution of the following experts:
Warning & Disclaimer This Guideline was prepared to assist clinicians who order tests from community laboratories. Users must ensure that their own practices comply with all specific government policies and specific legislative and accreditation requirements that apply to their organizations. The Guideline is not meant to be construed as legal advice or be all inclusive on this topic. Given the complexity of legal requirements, users are reminded that whenever there is uncertainty regarding whether some aspect of a Guideline is appropriate for their practice or organization, further direction should be obtained from the Laboratory Director, their own professional association, college and/or legal counsel or appropriate government ministry.