Gemella morbillorum as a source bacteria for necrotising fasciitis of the torso

Bacterial pathogens in pediatric appendicitis: a comprehensive retrospective study

Background

Appendicitis is a frequent condition, with peak incidences in the second decade of life. Its pathogenesis is under debate, but bacterial infections are crucial, and antibiotic treatment remains essential. Rare bacteria are accused of causing complications, and various calculated antibiotics are propagated, yet there is no comprehensive microbiological analysis of pediatric appendicitis. Here we review different pre-analytic pathways, identify rare and common bacterial pathogens and their antibiotic resistances, correlate clinical courses, and evaluate standard calculated antibiotics in a large pediatric cohort.

Method

We reviewed 579 patient records and microbiological results of intraoperative swabs in standard Amies agar media or fluid samples after appendectomies for appendicitis between May 2011 and April 2019. Bacteria were cultured and identified via VITEK 2 or MALDI-TOF MS. Minimal inhibitory concentrations were reevaluated according to EUCAST 2022. Results were correlated to clinical courses.

Results

Of 579 analyzed patients, in 372 patients we got 1330 bacterial growths with resistograms. 1259 times, bacteria could be identified to species level. 102 different bacteria could be cultivated. 49% of catarrhal and 52% of phlegmonous appendices resulted in bacterial growth. In gangrenous appendicitis, only 38% remained sterile, while this number reduced to 4% after perforation. Many fluid samples remained sterile even when unsterile swabs had been taken simultaneously. 40 common enteral genera were responsible for 76.5% of bacterial identifications in 96.8% of patients. However, 69 rare bacteria were found in 187 patients without specifically elevated risk for complications.

Conclusion

Amies agar gel swabs performed superior to fluid samples and should be a standard in appendectomies. Even catarrhal appendices were only sterile in 51%, which is interesting in view of a possible viral cause. According to our resistograms, the best in vitro antibiotic was imipenem with 88.4% susceptible strains, followed by piperacillin-tazobactam, cefuroxime with metronidazole, and ampicillin-sulbactam to which only 21.6% of bacteria were susceptible. Bacterial growths and higher resistances correlate to an elevated risk of complications. Rare bacteria are found in many patients, but there is no specific consequence regarding antibiotic susceptibility, clinical course, or complications. Prospective, comprehensive studies are needed to further elicit pediatric appendicitis microbiology and antibiotic treatment.

Necrotizing Soft Tissue Infection Secondary to Streptococcus constellatus, Actinomyces odontolyticus, and Gemella morbillorum in an Intravenous Drug User: A Case Report and Literature Review

A 53-year-old male with active IV heroin use presented with left upper extremity pain, erythema, swelling, and purulent foul-smelling drainage. Rapid diagnosis of necrotizing soft tissue infection (NSTI) was made based on clinical and radiologic findings. He was taken to the operating room for wound washouts and surgical debridements. The early microbiologic diagnosis was made based on intraoperative cultures. Successful treatment of NSTI in the setting of rare pathogens was achieved. The wound was ultimately treated with wound vac therapy, followed by primary delayed closure of the upper extremity and skin grafting of the forearm. We present a case of NSTI secondary to Streptococcus constellatus, Actinomyces odontolyticus, and Gemella morbillorum in an intravenous (IV) drug user, successfully treated with early surgical intervention.

Impact of different oral treatments on the composition of the supragingival plaque microbiome

Background

Dental plaque consists of a diverse microbial community embedded in a complex structure of exopolysaccharides. Dental biofilms form a natural barrier against pathogens but lead to oral diseases in a dysbiotic state.

Objective

Using a metaproteome approach combined with a standard plaque-regrowth study, this pilot study examined the impact of different concentrations of lactoperoxidase (LPO) on early plaque formation, and active biological processes.

Design

Sixteen orally healthy subjects received four local treatments as a randomized single-blind study based on a cross-over design. Two lozenges containing components of the LPO-system in different concentrations were compared to a placebo and Listerine®. The newly formed dental plaque was analyzed by mass spectrometry (nLC-MS/MS). 

Results

On average 1,916 metaproteins per sample were identified, which could be assigned to 116 genera and 1,316 protein functions. Listerine® reduced the number of metaproteins and their relative abundance, confirming the plaque inhibiting effect. The LPO-lozenges triggered mainly higher metaprotein abundances of early and secondary colonizers as well as bacteria associated with dental health but also periodontitis. Functional information indicated plaque biofilm growth.

Conclusion

In conclusion, the mechanisms on plaque biofilm formation of Listerine® and the LPO-system containing lozenges are different. In contrast to Listerine®, the lozenges led to a higher bacterial diversity.

Gemella morbillorum mitral valve endocarditis in a patient with a history of mitral valve annuloplasty

A woman with a history of congenital heart disease status post multiple valve operations including mitral valve repair presented with 2 months of low back pain and general malaise. Blood cultures returned positive for Gram-positive cocci. While transthoracic echocardiography did not identify vegetations, transoesophageal echocardiography visualised vegetations on the patient's mitral valve, which had previously undergone repair with annuloplasty. The patient was found to have infectious endocarditis (IE), caused by Gemella morbillorum The patient was treated with over 6 weeks of intravenous antibiotics. Cases of Gemella-associated IE are rare and largely relegated to case reports. This report aims to contribute to the literature regarding this subject, and to further characterise the presentation and treatment of Gemella-associated IE. Additionally, this report emphasises the importance of maintaining a high suspicion of IE in a patient with non-specific malaise in the setting of prior cardiac valve operation.