BACKGROUND: Leuconostoc spp. are facultatively anaerobic Gram-positive cocci involved in cases of hospital-acquired bacteremia, mainly in immunocompromised hosts. The available data is scarce due to its uncommon presentation.
METHODS: We describe all the episodes of Leuconostoc spp. bacteremia in a third level hospital in a 13-year period (2008-2021).
RESULTS: Four cases of clinically relevant bacteremia were detected. All cases were categorized as catheter-related. The following risk factors were found: previous glycopeptide therapy (75%), use of parenteral nutrition (100%) and cancer (75%). All isolates showed susceptibility to beta-lactams. Catheter removal was performed and wide spectrum antimicrobials were administered, with clinical response in all cases except one.
CONCLUSIONS: Apart from cancer and glycopeptide exposure, disruption of skin barrier and gastrointestinal conditions were identified as risk factors, as it was concordantly underlined in other case series. Susceptibility to beta-lactams is usually maintained. Catheter removal and administration of an active antibacterial therapy seem to be the best approach for Leuconostoc spp. catheter-related bacteremia.

The Kimoto-style fermentation starter is a traditional preparation method of sake brewing. In this process, specific microbial transition patterns have been observed within nitrate-reducing bacteria and lactic acid bacteria during the production process of the fermentation starter. We have characterized phylogenetic compositions and diversity of the bacterial community in a sake brewery performing the Kimoto-style fermentation. Comparing the time-series changes with other sake breweries previously reported, we found a novel type of Kimoto-style fermentation in which the microbial transition differed significantly from other breweries during the fermentation step. Specifically, the lactic acid bacteria, Leuconostoc spp. was a predominant species in the late stage in the preparation process of fermentation starter, on the other hand, Lactobacillus spp., which plays a pivotal role in other breweries, was not detected in this analysis. The discovery of this new variation of microbiome transition in Kimoto-style fermentation has further deepened our understanding of the diversity of sake brewing.

UNASSIGNED: and importance: Leuconostoc is a genus of gram-positive bacteria, this type of bacteria, which can be found in green vegetables and are used in wine, cheese, and sugar production, is an uncommon cause of disease in human beings.
UNASSIGNED: We report the case of a 60 years old male, with a medical history of nasopharyngeal carcinoma treated by chemotherapy and radiotherapy. The patient was admitted for total hematuria and episodic fever for the last 2 months. blood test found an anemia at 5g/dl, hyperleukocytosis at 18,000/ml,The transthoracic echocardiography showed, moderate mitral regurgitation, severe mitral stenosis with a valve area of 1.5cm2, and a mobile vegetation measuring 14 × 6 mm on A2 part of the anterior mitral valve. Transesophageal echocardiography (TEE) showed a 16 × 8 mm mitral vegetation. An empirical antibiotic therapy then adapted to the antibiogram.
UNASSIGNED: our patient is at an extremely elevated risk for infective endocarditis. This case is interesting because the pathogenic bacterial species for IE are typically staphylococci and streptococci, Two similar cases of Leuconostoc spp endocarditis were found in the literature, effective therapy of penicillin-resistant group viridians streptococci with combination therapy, our team opted for empiric treatment with ceftriaxone associated to gentamycin.
UNASSIGNED: It is critical for clinicians to be aware of the many pathogenic organisms, including Leuconostoc species. It is also clear that a higher index of suspicion must be maintained in patients with multiple predisposing factors such as the patient in the case presented.

OBJECTIVE: To report a case of delayed-onset endophthalmitis presenting 14 years after an uncomplicated cataract surgery.
METHODS: Case report.
RESULTS: An 89-year-old pseudophakic man complained of redness and reduced visual acuity in his right eye. He had no history of trauma or systemic infection, and his only surgery on the right eye was an uncomplicated cataract surgery 14 years before. On physical examination, he was found to have keratic precipitates and a white posterior capsular plaque in the right eye. He was treated with a right pars plana vitrectomy and intraocular lens removal. Microbiological classification of the samples revealed the presence of a Leuconostoc species within the vitreous humor and coagulase-negative staphylococci on the lens. Two months after placement of the intraocular lens, he achieved a best-corrected visual acuity of 20/200 in his right eye.
CONCLUSIONS: To the best of our knowledge, this is the first reported case of delayed-onset endophthalmitis occurring more than 10 years after an uncomplicated cataract surgery. This case highlights a highly unusual presentation of delayed-onset endophthalmitis and reports a potential novel microbiological cause of plaque formation.

Isothermal titration calorimetry (ITC) is a label-free technique that allows the direct determination of the heat absorbed or released in a reaction. Frequently used to determining binding parameters in biomolecular interactions, it is very useful to address enzyme-catalyzed reactions as both kinetic and thermodynamic parameters can be obtained. Since calorimetry measures the total heat effects of a reaction, it is important to consider the contribution of the heat of protonation/deprotonation that is possibly taking place. Here, we show a case study of the reaction catalyzed by the glucose-6-phosphate dehydrogenase (G6PD) from Leuconostoc mesenteroides. This enzyme is able to use either NAD(+) or NADP(+) as a cofactor. The reactions were done in five buffers of different enthalpy of protonation. Depending on the buffer used, the observed calorimetric enthalpy (ΔH(cal)) of the reaction varied from -22.93 kJ/mol (Tris) to 19.37 kJ/mol (phosphate) for the NADP(+)-linked reaction, and -11.67 kJ/mol (Tris) to 7.32 kcal/mol or 30.63 kJ/mol (phosphate) for the NAD(+) reaction. We will use this system as an example of how to extract proton-independent reaction enthalpies from kinetic data to ensure that the reported accurately represent the intrinsic heat of reaction.

A three week old extremely low birth weight (ELBW) infant infected by vancomycin-resistant Leuconostoc spp is presented. Treatment with appropriate antibiotics was successful after the percutaneous inserted central catheter (PICC) was removed. The infection with Leuconostoc spp is rare but should be suspected when vancomycin-resistant organisms resembling streptococci are isolated. Previous pediatric case reports are also summarized and reviewed.

Although Leuconostoc species are rarely pathogenic for humans, they may sometimes give rise to serious infections. In this report, a case of meningitis caused by vancomycin resistant Leuconostoc spp. was reported. Fifty-seven years old female patient was admitted to the hospital with the complaints of headache and sudden onset of unconsciousness and hospitalized in the neurosurgery department because of subarachnoidal hemorrhage. Patient was followed up with dexamethasone treatment and daily lumbar puncture without any surgical intervention. The findings of hemorrhage were receded in the cerebrospinal fluid (CSF) and the consciousness of the patient improved gradually. However, on the ninth day of the hospitalization, the patient became febrile and confused; white blood cell count was 7920/mm3, protein level was 1952 mg/l in the CSF examination. Nosocomial meningitis was diagnosed and empirical treatment with ceftazidime (3 x 2 g/day) and vancomycin (4 x 500 mg/day) was started. CSF culture revealed growth of gram-positive cocci which were identified as Leuconostoc spp. by VITEK 2 Compact (Biomerieux, France) and Phoenix Instrument (Becton-Dickinson, USA) systems. Since the isolate was found susceptible to penicillin, ampicillin, cefotaxime, cefepime, chloramphenicol, clindamycin, erythromycin and linezolid, and resistant to vancomycin by disk diffusion and miniAPI ATB STREP 5 (Biomerieux, France) methods, the treatment was switched to linezolid (2 x 600 mg/day). Vancomycin and teicoplanin resistance was confirmed by E-test. The treatment was continued with linezolid and the patient\'s clinical condition improved after 14 days of treatment. The possible way of Leuconostoc transmission in this case was thought to be the lumbar punctures performed during the follow-up of subarachnoid hemorrhage. This presentation which demonstrated that Leuconostoc spp. might rarely lead to meningitis, also pointed out that when a vancomycin resistant gram-positive coccus was identified, Leuconostoc spp. should always be kept in mind.

We report the case of a 26-day-old premature infant born at 24 weeks\' gestation who developed septicemia while receiving vancomycin therapy. The blood isolate initially identified as a vancomycin-resistant Streptococcous viridans was found to be Leuconostoc spp. Her condition improved with parenteral ampicillin and gentamicin therapy and removal of the intravenous central catheter. Prematurity is a recognized risk factor for Leuconostoc disease. Clinicians need to consider Leuconostoc spp. when vancomycin-resistant pathogens are identified and provide appropriate therapy.

BACKGROUND: Infections caused by Leuconostoc species are rare with most reported cases occurring in immunocompromised patients. This article presents 6 new cases of pediatric patients with short bowel syndrome who developed Leuconostoc bacteremia, and compares these cases with those previously reported in the literature.
METHODS: This is a retrospective, descriptive study (January 2001 to May 2007) performed in a tertiary care teaching center. Hospitalized patients younger than 18 years of age, with multiple positive blood cultures for Leuconostoc spp. were evaluated. The collected data were compared with 10 similar previously reported cases.
RESULTS: Six new cases of pediatric patients with short bowel syndrome who developed Leuconostoc bacteremia were identified. All 6 patients had received total parenteral nutrition and had central venous access, while 3 of these patients also received enteral nutrition. These results are similar to those reported in the literature. Only one of the newly reported patients had received vancomycin therapy before detection of Leuconostoc in the blood, whereas all prior reported cases had previously received this antimicrobial agent. Molecular analysis identified Leuconostoc mesenteroides as the most common species (4 cases) detected.
CONCLUSIONS: This report expands on the number of cases of Leuconostoc bacteremia in pediatric patients with short bowel syndrome and shows that prior vancomycin is not a required risk factor for the development of this infection. As previously reported in the literature, the presence of a central venous catheter and disrupted bowel mucosa are risk factors for Leuconostoc bacteremia.

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