Sudden infant death due to Lactococcal infective endocarditis

Lactococcus lactis endocarditis and liver abscess in an immunocompetent patient: a case report and review of the literature

BACKGROUND

Over the last two decades, several cases of infections caused by Lactococcus lactis have been reported. This Gram-positive coccus is considered non-pathogenic for humans. However, in some rare cases, it can cause serious infections such as endocarditis, peritonitis, and intra-abdominal infections.

CASE PRESENTATION

A 56-year-old Moroccan patient was admitted to the hospital because of diffuse abdominal pain and fever. The patient had no past medical history. Five days before his admission, he developed abdominal pain in the right lower quadrant along with chills and feverish sensations. Investigations showed a liver abscess, which was drained, and the microbiological study of the pus revealed Lactococcus lactis subsp. cremoris. Three days after admission, control computed tomography objectified splenic infarctions. Cardiac explorations were performed and showed a floating vegetation on the ventricle side of the aortic valve. We retained the diagnosis of infectious endocarditis according to the modified Duke criteria. The patient was declared afebrile on day 5 and the evolution was clinically and biologically favorable. Lactococcus lactis subsp. cremoris, formerly known as Streptococcus cremoris, is a rare cause of human infections. The first case of Lactococcus lactis cremoris endocarditis was reported in 1955. This organism includes three subspecies: lactis, cremoris, and hordniae. A MEDLINE and Scopus search showed only 13 cases of infectious endocarditis due to Lactococcus lactis, with subsp. cremoris identified in four of the cases.

CONCLUSIONS

To our knowledge, this is the first case report of the co-occurrence of Lactococcus lactis endocarditis and liver abscess. Despite its reported low virulence and good response to antibiotic treatment, Lactococcus lactis endocarditis must be considered a serious disease. It is imperative for a clinician to suspect this microorganism of causing endocarditis when they notice signs of infectious endocarditis in a patient with a history of consumption of unpasteurized dairy products or contact with farm animals. The finding of a liver abscess should lead to an investigation of endocarditis, even in previously healthy patients without obvious clinical signs of endocarditis.

Lactococcus Species Central Line-Associated Bloodstream Infection in Pediatrics: A Case Series

Lactococcus spp. is typically thought to be of low virulence and seldom considered pathogenic. Few cases of significant infections in children have been reported, all outside of the United States. There is also limited data on antimicrobial susceptibility testing for Lactococcus spp. We present three pediatric patients with central line bloodstream infections due to Lactococcus spp. between 2018 and 2020, along with a review of the pediatric literature.

The role of endocarditis in sudden cardiac death: highlighting the value of the autopsy, pathological features and cardiac complications

OBJECTIVE

Endocarditis is increasing in incidence due to growing numbers of cardiac interventions, valve replacements and immunosuppressants. It can be difficult to diagnose clinically, has high mortality and can present as sudden cardiac death (SCD) with few/subtle preceding symptoms. True incidence of SCD related to endocarditis is unknown.

METHODS

Retrospective analysis of UK national database of 6000 cases of SCD, 1994-2020, for "endocarditis" as cause of death.

RESULTS

Of 30 cases (0.50%), 19(63%) were male and mean age was 36.2 ± 20.1 years. Postmortem examination showed the aortic valve was solely affected in 13 (43%), mitral in 9 (30%), tricuspid in 2(6.7%) and pulmonary in 1 (3.3%). Three cases (10%) had more than one valve affected and 2 (6.7%) were nonvalvular affecting the ascending aorta. Vegetations ranged from small easily missed irregularities to large fungating masses. Ten (33%) patients developed aortic abscesses, 2 of which had aneurysms, 13 (43%) had coronary artery septic emboli with micro-abscesses and myocardial microinfarction, and 2 (6.7%) were healed endocarditis with perforation and regurgitation with ventricular remodeling. Thirteen (43%) had an identifiable underlying valve abnormality or replacement, most common being a bicuspid aortic valve (7; 54%).

CONCLUSIONS

This study highlights that although rare, endocarditis is an important cause of SCD in those with normal valves, valvular disease and valve replacement surgery. Absence of a premortem diagnosis in 70% of our cohort highlights the need for detailed analysis of the heart and cardiac valves at autopsy. Gross appearance of vegetations varies widely and can be missed. Awareness of associated cardiac complications is required for elucidation of the cause of death and will provide valuable lessons for clinicians.

Characterization and Antimicrobial Susceptibility of Lactococcus lactis Isolated from Endodontic Infections in Ouagadougou, Burkina Faso

Background: This study aimed to characterize and test the antimicrobial susceptibility of Lactococcus lactis isolated in endodontic infections in Burkina Faso. Material and methods: This was a prospective study conducted at the Municipal Oral Health Center of Ouagadougou, Burkina Faso, from June to October 2014. Clinical data were collected using a questionnaire form. The method of streaking on selective medium was used to isolate bacteria. Identification was made using the API 20 Strep gallery. Antibiotic susceptibility was performed by the diffusion method on solid medium. Results: One hundred and twenty-five (125) patients were received with a significant proportion from the age group of 19 to 40 years (55.2%). Apical periodontitis accounted for 50.4% and cellulitis for 49.6% of cases. Lactococcus lactis ssp. lactis was identified in five exudate samples. Isolates were 100% resistant to cefixime and metronidazole, 80% to ceftriaxone, cefuroxime, cefotaxime, chloramphenicol and 60% to penicillin G, amoxicillin, amoxicillin clavulanic acid. A multidrug resistance of more than three families of antibiotics was noticed. No strains produced extended spectrum ß-lactamases. Conclusion: Lactococcus lactis is part of endodontic biofilm. The reported strong antibiotic resistance involving endodontic therapy will focus on the effect of the disinfectant solution and the mechanical action of the canal instruments.

Infective endocarditis caused by Lactococcus lactis subsp. lactis and Pediococcus pentosaceus: A case report and literature review

RATIONALE

Lactococcus lactis and Pediococcus pentosaceus are rare pathogens which rarely caused infections in humans. Several cases with L. lactis endocarditis have been reported in the literature, among them few were caused by L. lactis subsp. Lactis. Opportunistic P. pentosaceus infections were rarely reported.

PATIENT CONCERNS

A 66-year-old man presented to our hospital due to persistent fever for 15 days. A physical checking revealed a grade II holosystolic murmur at the heart apex. A chest computed tomography (CT) scan suggested bronchitis. L. lactis subsp. lactis was identified in blood cultures. Transthoracic and transesophageal echocardiography revealed the presence of a large hyperechogenic mass in the left atrium, and a large floating vegetation on the mitral valve with a severe mitral regurgitation.

DIAGNOSIS

Infectious endocarditis caused by L. lactis subsp. Lactis was diagnosed.

INTERVENTIONS

Levofloxacin (0.5 g/day) was used for 20 days; however, L. lactis subsp. lactis remained to be isolated from blood culture. Therefore, vancomycin (2 g/day) was used to replace levofloxacin. Six days after the treatment with vancomycin, the blood culture revealed no L. lactis subspecies lactis, but yielded a growth of gram-positive and non-spore forming cocci; and P. pentosaceus was identified. Antimicrobial susceptibility test revealed P. pentosaceus was sensitive to penicillin and levofloxacin. Vancomycin was discontinued, and levofloxacin (0.5 g/day) was restarted and treated for another 7 days. The patient recovered with negative blood culture results, and discharged from the hospital.

OUTCOMES

The patient recovered with negative blood culture results, and discharged from the hospital.

LESSONS

Our patient had a long-period of antibiotic treatment with strategy alterations. Standard interpretation criteria of Clinical and Laboratory Standards Institute (CLSI) for L. lactis should be established, and molecular tests will increase the identification rate of L. lactis infections.

Infective Endocarditis in a Young Adult due to Lactococcus lactis: A Case Report and Review of the Literature

Infective endocarditis (IE) is a condition mainly associated with valvular disease or prosthetic valve and intravenous drug use as a risk factor. Here, we describe a rare case of a previously healthy patient with endocarditis due to Lactococcus lactis associated with cattle contact, where antibiotic treatment resulted in full recovery.

Francisella tularensis and other bacteria in hares and ticks in North Rhine-Westphalia (Germany)

Tularemia is a zoonotic disease caused by the bacterium Francisella tularensis. The disease can be transmitted to humans through contact with infected animals such as the European brown hare (Lepus europaeus) and ticks as vectors. The aim of this study was to isolate F. tularensis from ticks and hares in North Rhine-Westphalia using cysteine heart agar to determine their genetic relatedness and to identify other bacteria that grow on this medium. 848 European brown hares and 1556 questing ticks (all Ixodes ricinus) from forests were tested using cultivation and MALDI-TOF mass spectrometry or partial 16S rRNA gene sequencing. The majority of F. tularensis isolates from hares (n=24; 96%) and genomic F. tularensis DNA recovered from ticks belonged to the basal genetic clade IV and subclade B.18. These isolates were sensitive to erythromycin and were assigned to biovar I. Only a single strain isolated from a hare was assigned to basal clade I (B.12/B.35). All isolates were sensitive to tetracycline, doxycycline, streptomycin, gentamicin, chloramphenicol, and ciprofloxacin. Only 4 tick pools were positive for F. tularensis and cultivation was not successful in any of the pools. Most of the other isolated bacteria belonged to the order Bacillales with 36 Staphylococcus isolates, 9 Bacillus isolates and 8 Paenibacillus isolates. Prominent members of Enterobacterales were represented by different genera like Pantoea, Erwinia, Raoultella etc. Several of the bacterial species were soil or plant-associated, but some of the bacterial species were found in I. ricinus for the first time. Our results showed that F. tularensis was detected only in few ticks of an endemic area, but ticks were also infected by several other bacteria with zoonotic potential. Therefore, a wider spectrum of pathogens should be considered if a patient was bitten by a tick.

Scientific Opinion on the update of the list of QPS-recommended biological agents intentionally added to food or feed as notified to EFSA

EFSA is requested to assess the safety of a broad range of biological agents in the context of notification for market authorisation as sources of food and feed additives, food enzymes and plant protection products. The qualified presumption of safety (QPS) assessment was developed to provide a harmonised generic pre-assessment to support safety risk assessments performed by EFSA's scientific Panels. The safety of unambiguously defined biological agents (at the highest taxonomic unit appropriate for the purpose for which an application is intended), and the completeness of the body of knowledge are assessed. Identified safety concerns for a taxonomic unit are, where possible and reasonable in number, reflected as 'qualifications' in connection with a recommendation for a QPS status. The list of QPS recommended biological agents was reviewed and updated in the current opinion and therefore becomes the valid list. The 2016 update reviews previously assessed microorganisms including bacteria, yeasts and viruses used for plant protection purposes following an Extensive Literature Search strategy. The taxonomic units related to the new notifications received since the 2013 QPS opinion, were periodically evaluated for a QPS status and the results published as Statements of the BIOHAZ Panel. Carnobacterium divergens, Lactobacillus diolivorans, Microbacterium imperiale, Pasteuria nishizawae, Pediococcus parvulus, Bacillus flexus, Bacillus smithii, Xanthomonas campestris and Candida cylindracea were recommended for the QPS list. All taxonomic units previously recommended for the 2013 QPS list had their status reconfirmed as well their qualifications with the exception of Pasteuria nishizawae for which the qualification was removed. The exclusion of filamentous fungi and enterococci from the QPS evaluations was reconsidered but monitoring will be maintained and the status will be re-evaluated in the next QPS Opinion update. Evaluation of bacteriophages should remain as a case-by-case procedure and should not be considered for QPS status.

A Case of Infective Endocarditis and Pulmonary Septic Emboli Caused by Lactococcus lactis

Infective endocarditis is a rare condition in children with normal hearts. We present here a case of previously healthy eleven-year-old girl with infective endocarditis and pulmonary septic emboli caused by a very rare bacterial etiology (Lactococcus lactis). Identification of this pathogen was only made by polymerase chain reaction.