Sputum gram stain assessment in community-acquired bacteremic pneumonia

Abstract

A prospective study was performed over a 4.5-year period to determine the ability of a sputum Gram stain to predict the cause of community-acquired bacterial pneumonia. A blood culture isolate, rather than a sputum culture, served as the reference standard to provide precise identification of the etiologic agent. The study population comprised 59 bacteremic adults who expectorated a valid sputum sample. Data are presented that indicate that a physician, aided by the morphology of the stained sputum, could theoretically select appropriate monotherapy approximately 94% of the time when selective, defined criteria for the microbiology of valid sputum are met. Three of the five patients with pneumonia caused by Haemophilus injluenzae, however, had sputum stains that suggested alternative pathogens. This study reaffirms that the Gram-stained sputum is a reliable, but not infallible, guide to direct initial antibiotic therapy in adults with community-acquired bacterial pneumonia.

Practice Guidelines for the Management of Community-Acquired Pneumonia in Adults

“…Some studies, although uncontrolled, do suggest benefit of these diagnostic studies [71][72][73][74][75][76]. For example, Boerner and Zwadyk [64] reported that a positive early diagnosis by sputum Gram staining correlated with more rapid resolution of fever after initiation of antimicrobial therapy.…”

Diagnostic test for etiologic agents of community-acquired pneumonia

“…Culture results may be an inadequate comparison, however, because of its inherent problems, including quality control in specimen collection, delays in plating, and erroneous results because of previous antibiotic use [27]. Better comparators are used in studies involving patients with positive blood cultures [28] and patients with transtracheal aspirates [1]. Both studies showed gram staining to have highly favorable results.…”

JAID/JSC Guidelines for the Treatment of Respiratory Infectious Diseases: The Japanese Association for Infectious Diseases/Japanese Society of Chemotherapy – The JAID/JSC Guide to Clinical Management of Infectious Disease/Guideline-preparing Committee Respiratory Infectious Disease WG

“…Concerning examination, Gram staining and culture of sputum are used to identify causative microorganisms and select subsequent treatment strategies [6,7] (AII). Kits for rapid diagnosis with urine or nasal swab are also used for auxiliary diagnosis [8,9] (AII).…”

“…-ST combination drug (SMX at 400 mg/TMP at 80 mg), oral administration, 2 tablets/twice a day or intravenous drip, 960 mg/twice a day -CLDM, intravenous drip, 600 mg/2e4 times a day (The results of drug susceptibility testing must be confirmed). Refer to the section "2.1 Community-acquired pneumonia---2.1.2 Definitive therapy--- [3] H. influenza (ABPCsusceptible), [4] H. influenza (b-lactamase-producing), [5] H. influenza (b-lactamase-negative ampicillin-resistant (BLNAR), and [6] H. influenza (b-lactamase-positive amoxicillin clavulanate-resistant (BLPACR)" (p. 6e7).…”