BACKGROUND The usefulness of sputum Gram stain in patients with community-acquired pneumonia (CAP) is controversial. There has been no study to evaluate the diagnostic value of this method in patients with healthcare-associated pneumonia (HCAP). The purpose of this study was to evaluate the usefulness of sputum Gram stain in etiological diagnosis and pathogen-targeted antibiotic treatment of CA...

Gram stains remain the cornerstone of diagnostic testing in the microbiology laboratory for the guidance of empirical treatment prior to availability of culture results. Incorrectly interpreted Gram stains may adversely impact patient care, and yet there are no comprehensive studies that have evaluated the reliability of the technique and there are no established standards for performance. In t...

Cerebrospinal fluid (CSF) access device placement in the pediatric population presents challenges due to the development of infections following placement, access or revision, and/or shunt malfunctions. Here we report an unusual pediatric case of L. monocytogenes ventriculitis/VP shunt (VPS) infection and associated pseudocyst with an emphasis on the importance of VPS removal in clearing the in...

The Gram stain method was applied to the photometric characterization of aquatic bacterial populations with a charge-coupled device camera and an image analyzer. Escherichia coli and Bacillus subtilis were used as standards of typical gram-negative and gram-positive bacteria, respectively. A mounting agent to obtain clear images of Gram-stained bacteria on Nuclepore membrane filters was develop...

INTRODUCTION Campylobacter species are recognized as a major cause of acute gastroenteritis in humans throughout the world. The diagnosis is mainly based on stool culture. This study was done to evaluate the effectiveness of staining methods (Gram stain using 0.3% carbol fuchsin as counter stain and 1% carbol fuchsin direct stain) versus culture as the gold standard. METHODS A total of 300 ch...

Group A beta-haemolytic streptococci were isolated from 51 (9.8%) of 519 patients with pharyngitis. Throat culture results showed the mean sensitivity, specificity and predictive value of a positive Gram-stained smear of pharyngeal secretions as 70%, 89% and 69%. The data suggest that Gram staining of a smear directly from the swab is as accurate as and more speedy than a culture from the phary...

INTRODUCTION Acinetobacter baumannii and Brucella species are Gram-negative organisms that are vulnerable to misinterpretation as Gram-positive or Gram-variable in blood cultures. OBJECTIVE We assess the random errors in gram stain interpretation to reduce the likelihood of such errors and therefore patient harm. METHODOLOGY Aerobic and anaerobic blood cultures from two patients in an acute...

Dark blue rings and circles emerged when the non-specific polysaccharide stain lactophenol cotton blue was added to Gram stained slides. The dark blue staining is attributable to the presence of capsular polysaccharides and bacterial slime associated with clumps of Gram-negative bacteria. Since all bacterial cells are glycosylated and concentrate polysaccharides from the media, the majority of...

Bartholomew and Mittwer (1951) presented photographic evidence that the gram-positive staining area of bacterial cells could be fitted internally to the area demonstrated by the Dyar cell wall stain. Their conclusion was that the bacterial cell wall was not included in the grampositive area. Lamanna and Mallette (1954) explained Gram differentiation of intact cells on the basis that crystal vio...

There exist many methods for the application of the Gram stain to histological sections, and with all of them there is generally no difficulty in recognising Gram-positive organisms. However, with most of the well-recognised methods Gram-negative bacteria are difficult to distinguish from the background. Twort's method distinguishes Gram-negative bacteria from the background but is relatively t...