BACTERIUM WITH LEUCONOSTOC PSEUDOMESENTEROIDES

– erythrocyte sedimentation rate, ALT – alanine aminotransferase;


INTRODUCTION
Streptococcus-like bacteria of the genus L. (Leuconostoc) were isolated in humans for the first time by Handwerger in the mid-80s of the last century. Leuconostoc spp. are facultativeanaerobic, gram-positive, catalase-negative, nonspore-forming, motile, heterofermentative cocci widely distributed in the environment, including soil and plants (1).
The genus Leuconostoc includes the "typical representative" L. mesenteroides and 8 "minor" species, including L. pseudomesenteroides. Members of the genus Leuconostoc are more of an economic importance, as they are used in the manufacture of dairy products and wine. The first suspected case of human infection with Leuconostoc spp. was recorded in 1985 (2). Until then, Leuconostoc species were considered nonpathogenic for humans. Since 1985, infections caused by Leuconostoc have been reported more frequently (3)(4)(5), becoming more and more important as opportunistic pathogens of immunodeficiency states (6)(7)(8). For example, a South Korean study describes 6 cases of bacteremia with Leuconostoc in patients over 60 years old, with aggravating underlying diseases. Within 30 days of the identification of the bacteria, four of these 6 patients died (9). At the same time, cases have also been described in immunocompetent patients. For example, secondary infection with Leuconostoc spp. following the application of a patch with plant components on the wound of a patient with amputation (10), or purulent meningitis caused by Leuconostoc spp. in a previously healthy patient (4), or bacteremia with the same pathogen in an immunocompetent patient suffering from Chagas disease (11), etc.
Leuconostoc infections often occur in patients whose underlying diseases are treated with vancomycin (12,14). There are described cases of isolation of Leuconostoc spp. from the blood of patients with malignant neoplasms and longterm catheterization, as well as from the removal of infected wounds, in postoperative infections and in odontogenic abscesses (4,12,(15)(16)(17). Pulmonary infection with Leuconostoc in a patient with lymphoma is also described (18). Xinfeng Lin and co-authors (19) in his paper associated hemophagocytic syndrome with Leuconostoc pseudomesenteroides infection in an adult patient.
Central Nervous System (CNS) infections caused by Leuconostoc spp. are extremely rare. Most often they are associated with a deficient immune field, such as, for example, purulent meningitis with Leuconostoc spp. in newborns (20,21). A case of nosocomial meningitis caused by Leuconostoc spp. has been described in connection with the use of a catheter with an extraventricular drainage system due to the presence of a thalamic hematoma with ventricular extension (2). Ventriculitis and brain abscess have also been described in CNS infections with Leuconostoc spp (22,23).
Several cases of L. mesenteroides bacteremia associated with the use of oral dietary supplements for children have been reported (3). Other additional factors that predispose to infection are: prolonged treatment in the hospital, the use of devices that violate the integrity of the skin and mucous membranes (venous catheters, gastro-or tracheostomy, drainage fistulas), extensive surgical interventions, decreased intestinal barrier function, antibiotic therapy with drugs that are not sufficiently active against Leuconostoc spp. (3,(5)(6)(7)24).
It must be recognized that infectious diseases caused by Leuconostoc spp. are rare. This is also due to the lack of practice of its isolation. Leuconostoc spp. can be taken into consideration only in the case of isolation from obviously sterile sources (blood, cerebrospinal fluid, peritoneal and joint fluids), ob serving all the rules of asepsis. If Leuconostoc is found in material with a high risk of external contamination (for example, in the wound exudate), its presence is significant only if no other more virulent microorganisms are found or if Leuconostoc is isolated in large quantities in several analysis of the sampled material (5,6).
The complexity of identifying the microorganism is associated with the similarity of some of its properties with other, more frequently detected bacteria -pneumococci, streptococci and lactobacilli. These similarities can cause misidentification (25). The natural resistance of Leuconostoc spp. to vancomycin allows its rapid differentiation from most other streptococcal bacteria, except Pediococcus spp. and certain vancomycinresistant strains of Enterococci. At the same time, carrying out tests using leucine aminopeptidase and pyrrodonylarylamidase allows the differentiation of Leuconostoc spp. with Pediococcus spp. and vancomycin-resistant Enterococci (26). In recent years, automated microbiological analyzers have been successfully used to confirm Leuconostoc bacteremia (27).
Leuconostoc is one of the few Gram-positive bacteria, including Pediococcus spp., Lactobacillus spp., Erysipelothrix, enterococci, naturally resistant to glycopeptide antibiotics -vancomycin and teicoplanin. However, despite resistance to glycopeptides, Leuconostoc spp. is sensitive to most antibiotics active against streptococci. Thus, Leuconostoc is usually sensitive to penicillin, ampicillin, clindamycin, erythromycin and fosfomycin. Moderate activity is shown by imipenem, cephalosporins, tetracyclines and chloramphenicol (6,25). Clinical data, extremely limited in number, indicate that apparently the antibiotics of choice for the treatment of infections caused by Leuconostoc spp. are penicillin and ampicillin (5,25).

CASE PRESENTATION
Patient V.D., 11 months old, was admitted to PMSI IDCH "Toma Ciorba" on 05.01.2022. When the patient was admitted, the following anamnestic data were found: The antibiotic treatment was continued with ceftriaxone, the pathogenetic one included dexamethasone. In continuation, the improvement 2020 of the general condition of the child, the normal ization of the body temperature was confirmed.