Objective: Group B streptococcus (GBS, Streptococcus agalactiae) is an important cause of neonatal sepsis. Prevention is possible by intrapartum screening for maternal GBS carriership and antimicrobial treatment of colonized women with risk factors during labor. The conflicting results of diagnostic performance are reported both for the newly developed rapid GBS antigen tests and Gram's stain.
Methods: The value of Gram's stain in GBS screening was investigated prospectively in 1,020 women. Intrapartum Gram's stains of the cervix from these women and of the introitus from 510 of them were compared with cultures of the cervix, introitus, and anorectum in a semiquantitative way.
Results: The sensitivities of the cervical and introital Gram's stains were 25% and 31%, respectively, and the specificities 99% and 98%, respectively. Higher sensitivities (52% and 44%, respectively) were found in heavily colonized parturients. No significant influence of rupture of the membranes was detected. There was a poor correlation between the number of gram-positive cocci in the Gram's stain and the growth density.
Conclusions: We do not recommend the routine use of the Gram's stain for intrapartum GBS detection because of both the limited sensitivity and positive predictive value.
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http://dx.doi.org/10.1155/S1064744995000421 | DOI Listing |
Sci Adv
January 2025
Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095, USA.
Gram staining has been a frequently used staining protocol in microbiology. It is vulnerable to staining artifacts due to, e.g.
View Article and Find Full Text PDFMicrobiol Spectr
October 2024
Department of Chemistry, SUNY College of Environmental Science and Forestry, Syracuse, New York, USA.
Unlabelled: The Gram staining method differentiates bacteria based on their cell envelope structure, with the monoderm and diderm cell envelope types traditionally being synonymous with Gram-positive and Gram-negative stain results, respectively. Monoderms have a single phospholipid membrane surrounded by a thick layer of peptidoglycan, while diderms have a lipopolysaccharide outer membrane exterior to a thin peptidoglycan layer. The (formerly ) phylum has members with both cell wall types, and recent phylogenetic analyses have shown that monoderm evolved from diderm ancestors on multiple occasions.
View Article and Find Full Text PDFMicrobiol Spectr
October 2024
Department of Microbiology, Japanese Red Cross Maebashi Hospital, Maebashi, Japan.
Rapid and accurate identification of (SA) in blood culture specimens is crucial for timely clinical intervention. Traditional Gram staining methods, although widely accessible and cost-effective, exhibit variable sensitivities and specificities in the BACTEC system. We aimed to develop and validate the "STAPH score," a novel semi-quantitative scoring system that integrates Gram stain morphology and time to positivity to differentiate SA from coagulase-negative staphylococci (CoNS) in blood cultures.
View Article and Find Full Text PDFInfect Dis (Lond)
December 2024
Department of Internal Medicine, division of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
Background: Diagnosis of urinary tract infections (UTIs) is a frequent challenge at the emergency department (ED). The clinical usefulness of the urine Gram stain (GS) is uncertain.
Objective: We studied the GS performance to clarify its clinical utility at the ED.
J Med Microbiol
August 2024
Hamad Medical Corporation, Doha, Qatar.
The frequency of multidrug-resistant organisms (MDROs) in hospitals and the risk of delaying effective treatment result in the culture of respiratory secretions for nearly all patients with suspected pneumonia. Culture delays contribute to over prescribing and use of broader spectrum antibiotics. The need for improved rapid diagnostics for early assessment of suspected hospital pneumonia.
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