Staphylococcus lugdunensis Endophthalmitis: Case Series and Literature Review

Staphylococcus lugdunensis Peritoneal Dialysis-Related Peritonitis: A Matched Comparative Analysis

Rationale & Objective

Staphylococcus lugdunensis (S lugdunensis) is a coagulase-negative staphylococcus species that has been increasingly recognized to cause serious infections with virulence resembling Staphylococcus aureus (S aureus). No studies have evaluated the characteristics and outcomes of patients with S lugdunensis peritoneal dialysis-related peritonitis compared with those with S aureus peritonitis. We aim to evaluate the clinical course of peritonitis as caused by these organisms.

Study Design

A retrospective matched comparative analysis involving a single tertiary center from July 2000 to July 2020.

Setting & Participants

Forty-eight episodes of S aureus peritonitis were matched to 19 cases of S lugdunensis peritonitis.

Analytical Approach

The cases were individually matched for year of peritonitis, sex, age (±10 years), and Charlson Comorbidity Index (±3). A comparative analysis was performed between the 2 organisms. The outcome includes responses at day 5 of peritonitis and the rate of complete response.

Results

There is a higher predilection of diabetes in those with S aureus peritonitis than in those with S lugdunensis (64.6% vs 31.6%; P = 0.03). Patients with S aureus peritonitis also have a much higher total cell count at presentation (4,463.9 ± 5,479.5 vs 1,807.9 ± 3,322.7; P = 0.05); a higher prevalence of poor response at day 5 (50.0% vs 15.8%; P = 0.03); a lower rate of complete response (64.6% vs 94.7%; P = 0.01) and are more prone to relapse with the same organism (29.2% vs 0%, respectively; P = 0.01) as compared to those with S lugdunensis.

Limitations

The result of this small retrospective study involving a single center may not be generalizable to other centers. There is also no data for comparative analysis on other coagulase-negative staphylococci such as Staphylococcus epidermidis, which belongs to the same family as S lugdunensis.

Conclusions

Although S aureus peritonitis is more virulent with significant morbidity, S lugdunensis can cause similarly serious peritonitis. This largest case series of S lugdunensis peritonitis enabled better characterization of clinical features and outcomes of patients with S lugdunensis peritonitis.

Does corneal tattooing affect the conjunctival microbiota?

PURPOSE

This study aimed to investigate the effects of commercial tattoo inks used in corneal tattooing on conjunctival microbiota.

METHOD

This prospective case control study consisted of 125 participants divided in the following three groups: 35 patients with corneal tattoos, 40 patients with corneal leukoma, and 50 healthy subjects. Corneal tattooing was performed in all the cases in this study using a tattoo pen machine and commercial tattoo ink. A total of 500 cultures were taken from 250 eyes of 125 individuals on chocolate and sheep blood agar. Bacteriological samples were taken from the inferior eyelid conjunctiva using a sterile cotton swab. Without any contact elsewhere, the swabs were smeared on bedside chocolate agars and 5% sheep blood agar.

RESULTS

In tattooed eyes, bacterial growth was detected in 42.9% of the chocolate and sheep blood agar samples. In other healthy eyes of patients with corneal tattoos, 54.5% bacterial growth on chocolate agar and 57.1% on sheep blood agar were detected. No statistical difference was detected in the conjunctival microbiota of chocolate and sheep blood agar (p = 0.254, p = 0.134, respectively) in the tattooed eyes compared to the other eye of the individual. No statistically significant difference was found in terms of bacterial growth in tattooed, leukoma, or healthy eyes on chocolate and sheep blood agar (p = 0.408, p = 0.349). The growth rate of Staphylococcus epidermidis decreased by 33.3% (from 12 to 8) on chocolate agar in 35 tattooed eyes, and it decreased by 28.5% (from 14 to 10) on sheep blood agar, while gram-negative bacteria Brevundimonas diminuta, Acinetobacter lwoffii, and Psychrobacter faecalis were detected in three patients.

CONCLUSION

Corneal tattooing using commercial dye does not affect conjunctival microbiota. In the past 3 years, 120 patients have been tattooed with commercial tattoo ink in Istanbul Medeniyet University Göztepe Training and Research Hospital. No complications related to infection were found in the 3-year follow-up. The gram-negative bacteria detected in the healthy control group and tattooed eyes were bacteria found on normal skin or in the respiratory tract. Although some gram-negative bacteria do not cause infection, careful eye examination, follow-up, and culture are required in suspicious cases.

The Deadly Contaminant: A Case of Staphylococcus lugdunensis Endocarditis

The incidence of infective endocarditis (IE) has been on the rise since it was first reported a century ago, and the associated mortality remains unchanged despite advances in medical and surgical management. To diagnose IE, the modified Duke criteria are used, which rely on isolating the causative organism. However, this can be challenging if the micro-organism is considered a contaminant. Staphylococcus lugdunensis (SL) is one such organism. In this case, an elderly female presented with intermittent chest pain, palpitation, and diaphoresis, for which she underwent left heart catheterization. Her hospital course was complicated by persistent fever and night sweats, leading to blood cultures isolating methicillin sensitivity. It was initially reported as a contaminant. However, an extensive workup was unremarkable, and a transthoracic echocardiogram was done, which revealed tricuspid vegetations with moderate regurgitation. The patient was treated with cefazolin, repeat cardiac imaging at the end of treatment revealed no vegetation, and the patient remained asymptomatic. Despite being associated with fulminant IE with higher mortality than Staphylococcus aureus (S. aureus), which requires surgical management in most cases, SL is still often reported as a contaminant. Isolation of SL should warrant further investigation beyond mere contaminants, and prompt treatment should be initiated in the appropriate clinical scenario to avoid poor outcomes.