Point-of-care cerebrospinal fluid Gram stain for the management of acute meningitis in adults: a retrospective observational study

The role of gram stain in reducing broad-spectrum antibiotic use: A systematic literature review and meta-analysis

The number of studies that verify whether Gram stain can help to reduce the use of broad-spectrum antibiotics is relatively limited compared to those evaluating its concordance with culture test results. Thereby, we aimed to evaluate the effectiveness of Gram staining in the reduction of broad-spectrum antibiotics and its impact on clinical outcomes. We systematically reviewed studies having used Gram stain to guide antibiotic selection and evaluated performance measures between 1996 and 2022. We extracted available data on broad-spectrum antibiotic use as a primary outcome of the studies in view of an exploratory meta-analysis designed to estimate the clinical effect of Gram stain. We also evaluated the clinical response and coverage rates of the initial antibiotic therapy. One randomized study and four non-randomized studies were eligible, all of which were conducted in tertiary care hospitals in Japan. Gram stain was associated with reduced broad-spectrum antibiotic use, including antipseudomonal antibiotics (odds ratio [OR], 0.05; 95% confidence interval [CI], 0.01-0.34), anti-methicillin-resistant Staphylococcus aureus antibiotics (OR, 0.21; 95% CI, 0.07-0.63), and carbapenems (OR, 0.07; 95% CI, 0.02-0.19), without impairing clinical outcomes, including clinical response rate (OR, 1.48; 95% CI, 0.95-2.31) and coverage rate of initial antibiotic therapy (OR, 0.70; 95% CI, 0.40-1.22) using random-effects models in our meta-analysis. In conclusion, Gram stain may be useful in guiding initial antibiotic selection without apparent adverse clinical outcomes. However, currently available studies evaluating the clinical usefulness of Gram stain are limited to specific clinical settings.

[Experience with the Biofire FilmArray® for infectious meningitis/encephalitis in a high complexity institution in Bogota, Colombia]

INTRODUCTION

Infectious meningoencephalitis (IME) is a neurological emergency with a significant rate of morbidity and mortality. The Biofire FilmArray® meningitis/encephalitis (FAME) panel for testing in cerebrospinal fluid (CSF) has proven to be a valuable tool for the aetiological diagnosis of IME, facilitating targeted antimicrobial therapy. The aim is to determine the impact of the FAME panel on antimicrobial therapeutic decisions in patients with suspected IME in the first 24 hours of clinical assessment.

PATIENTS AND METHODS

This is a descriptive observational study that comments on the clinical manifestations, the neuroimaging and paraclinical findings, and the antibiotic therapy of patients with suspected IME. An analysis was performed to determine the impact of FAME on antimicrobial therapy in the first 24 hours of the clinical assessment of patients.

RESULTS

Altogether 44 patients were included. The average time required to obtain the result of the FAME panel for testing in CSF was nine hours, with 20.4% (9/44) of tests yielding positive results. Within 24 hours of clinical assessment, their outcome had an impact on antimicrobial treatment decisions in 75% (33/44) of cases. In patients with a high clinical suspicion of IME, the result of FAME made it possible to change the initial empirical therapy to a targeted therapy in 15% (3/20) of cases and to discontinue the initial empirical therapy in 35% (7/20) of the subjects. In patients with low clinical suspicion of IME, their result allowed 25% (6/24) to have their suspicion confirmed and they were started on targeted antibiotic therapy; in contrast, 70.8% (17/24) had their diagnosis ruled out and were not started on treatment.

CONCLUSIONS

The result of the FAME panel for testing in CSF has a high impact on antimicrobial therapeutic decisions within 24 hours of clinical assessment. However, it must be interpreted with the clinical context, local epidemiology and other diagnostic studies.

Can Gram staining be a guiding tool for optimizing initial antimicrobial agents in bacterial infections?

The emergence of multidrug-resistant organisms poses a significant threat to global public health, making the optimization of antimicrobial use crucial. Antimicrobial therapy is often initiated in emergency rooms (ERs) and intensive care units (ICUs), where patients are at high risk of infection. Prompt antimicrobial selection is essential in these facilities, and point-of-care testing can guide the appropriate initial antimicrobial therapy. Gram staining, a quick and inexpensive method, was previously used for point-of-care testing by physicians in the 1980s but was discontinued in 1988 in the United States. However, in Japan, the clinical practice of Gram stain-based antimicrobial therapy by physicians has continued in a limited number of hospitals. Several studies undertaken in Japan have shown that Gram staining carried out by trained physicians can reduce the overuse of broad-spectrum antimicrobial agents in ERs and ICUs without worsening patients' outcomes. Gram stain-based antimicrobial therapy reduced unnecessary use of carbapenems in the ER. Furthermore, Gram staining has been shown to significantly reduce the overuse of broad-spectrum antimicrobials without worsening clinical cure and mortality for patients with ventilator-associated pneumonia in the ICU. The classic technique of Gram staining has regained its usefulness through persistent clinical practice in Japan. It is hoped that Japanese researchers in this field will demonstrate to the world the efficacy of the classic technique of Gram staining in addressing this critical problem. Gram staining carried out by trained physicians could serve as a valuable means of optimizing antimicrobial treatment in ERs and ICUs.

High yield of blood cultures in the etiologic diagnosis of cellulitis, erysipelas, and cutaneous abscess in elderly patients

Background

Cellulitis is a common disease in the elderly, and detecting etiologic organisms with blood cultures is difficult because of the low positive rate and occasional skin contamination. Therefore, routine blood cultures are not recommended for uncomplicated cellulitis. However, it is unclear whether blood culture collection for the diagnosis of cellulitis in elderly patients is useful.

Methods

This single hospital–based observational study was performed between April 2012 and March 2015 in Okinawa, Japan. All enrolled patients were aged 15 years or older and admitted to the Division of Infectious Diseases with suspected cellulitis, erysipelas, and cutaneous abscess. Two routine sets of blood cultures were obtained.

Results

Two hundred and twenty-one patients were enrolled. The median age was 77 years. The proportion of bacteremia was 21.7% for all patients (48/221), 8.5% (4/47) for those <65 years, and 25.3% (44/174) for those ≥65 years old (P = .013). The skin contamination rate was 0.9% (2/221). The most common pathogen was Streptococcus dysgalactiae (62.5%). Gram-negative bacteremia not susceptible to cefazolin was detected in 8.3%. Cefazolin and ampicillin were the first- and second-most commonly used therapies. Anti–methicillin-resistant Staphylococcus aureus therapy was required in 3.6% of patients. In addition to age and severe infection, shaking chills and white blood count ≥13 000 cells/µL were independent risk factors of bacteremia.

Conclusions

Two routine sets of blood cultures are recommended for the precise diagnosis and appropriate treatment of cellulitis in elderly patients, especially in patients with shaking chills or leukocytosis.

Point-of-care urine Gram stain led to narrower-spectrum antimicrobial selection for febrile urinary tract infection in adolescents and adults

Background

Febrile urinary tract infections (fUTIs), which include pyelonephritis, prostatitis, and urosepsis, are the most common cause of sepsis. However, the treatment has become more complex because of the worldwide increase in antimicrobial resistance (AMR). The objective of this study was to clarify whether point-of-care Gram stain (PCGS) of urine contributed to fUTI diagnosis and treatment in adults.

Methods

This hospital-based observational study was undertaken between January 2013 and March 2015 in Okinawa, Japan. All enrolled patients were adults who had been admitted to the Division of Infectious Diseases with suspected fUTI. The usefulness of PCGS results were compared for urinalysis (U/A) and urine cultures (U/Cs). The targeted therapy type and its susceptibility based on PCGS were analyzed, and each was investigated in two groups: the uncomplicated pyelonephritis group and the complicated pyelonephritis/prostatitis group.

Results

Two hundred and sixty-six patients were enrolled. The results of PCGS were closely correlated with those of U/A for pyuria and bacteriuria, and moderately correlated with the results of U/C for bacterial types. In the uncomplicated group, narrow-spectrum antimicrobials such as cefotiam were initially selected in 97.9% (47/48) of patients, and their susceptibility was 97.9% (47/48). In the complicated group, the susceptibility was 84.2% (186/221) (p = 0.009) despite frequent AMRs (14.7%; 32/218) and low use of broad-spectrum antimicrobials such as carbapenems (7.7%; 17/221).

Conclusion

Urine PCGS led to a more precise fUTI diagnosis and prompted clinicians to select narrower-spectrum antibiotics with high susceptibility.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07194-9.

Infectious Meningitis and Encephalitis

Infectious meningitis and encephalitis are associated with significant morbidity and mortality worldwide. Acute bacterial meningitis is rapidly fatal and early recognition and institution of therapy are imperative. Viral meningitis is typically a benign self-limited illness. Chronic meningitis (defined as presenting with >4 weeks of symptoms) is most often caused by tuberculosis and fungal infection. Because the diagnostic testing for tuberculous meningitis is insensitive and cultures often take weeks to grow, therapy is often initiated empirically when the diagnosis is suspected. Human simplex virus encephalitis is the most common cause of encephalitis and requires prompt treatment with intravenous acyclovir.