Abdominal abscess due to leuconostoc species in a liver transplant recipient

A very rare case of bacteraemia in a 4-year-old girl with osteopetrosis with probable Leuconostoc lactis infection

Leuconostoc lactis (LLac) is a Gram-positive coccus of the family Leuconostocaceae . It can be found in a variety of vegetables and dairy products. LLac is an opportunistic pathogen with intrinsic resistance to vancomycin and teicoplanin. In this case report, we discuss a rare case of LLac-associated bacteraemia in a patient with osteopetrosis. A 4-year-old girl was admitted to the paediatric emergency department with acute fever without other signs. Blood culture revealed an infection with LLac. Using the streptococcus antibiogram, the isolate was resistant to vancomycin, teicoplanin, rifampicin and sulfamethoxazole-trimethoprim but sensitive to β-lactams, gentamicin, streptomycin, azithromycin, clarithromycin, lincomycin, clindamycin and erythromycin. The patient was treated with intravenous ceftriaxone and gentamicin, and subsequently with oral amoxicillin. After a favourable course, she was discharged from the hospital on the 10th day. The modes of transmission and physiopathology of LLac remain unknown. Factors associated with this infection include compromised immunity, previous antibiotic therapy especially with vancomycin, and application of a central venous catheter. In our patient, the risk factors for infection were pancytopenia and multiple transfusions used to treat bone marrow failure. The source of the bacteraemia could have been the cutaneous route, but it could also have been digestive due to the reservoir of the bacteria. LLac is known as an opportunistic bacterium. Further studies on its pathogenesis and other risk factors are needed to understand the true prevalence of this potentially fatal bacterium in compromised individuals, such as the case of our patient.

A Rare Case of Leuconostoc pseudomesenteroides Bacteremia and Refractory Septic Shock

Leuconostoc species are rare causes of bacteremia and are commonly mistaken for Streptococcus species. Due to their inherent resistance to commonly used drugs, they are often overlooked resulting in poor and sometimes lethal outcomes. While there are not many reported cases of this bacterial infection, Leuconostoc species are important to consider when faced with a highly drug-resistant bacterial strain. We present here a case of a 29-year-old male who presented with an out-of-hospital cardiac arrest, initially resuscitated but ultimately succumbing to his illness. This is a unique case in which our patient was subsequently found to have a rare bloodstream infection with Leuconostoc pseudomesenteroides.

The First Case of L. pseudomesenteroides Pulmonary Infection and Literature Review

L. pseudomesenteroides is a very rare bacterium that infects human beings, and it has been used as an industrial fermentation bacterium. At present, only a few cases have been reported about this bacterium infecting the human body, but most reports are mainly about sepsis. We will report on a woman with lymphoma who was successfully diagnosed by the use of transbronchial cryobiopsy (TBCB) with L. pseudomesenteroides pulmonary infection.

Endocarditis por Leuconostoc lactis en un lactante: reporte de caso

Introducción. Las infecciones por Leuconostoc lactis son raras y se asocian a múltiples factores de riesgo; además, de acuerdo con lo revisado en la literatura relevante, no hay reportes de endocarditis causada por este microorganismo en población pediátrica.Presentación del caso. Lactante con síndrome de intestino corto que fue llevado por sus padres al servicio de urgencias por desnutrición. Durante su estancia hospitalaria prolongada, el paciente presentó múltiples infecciones, por lo que requirió catéter venoso central (CVC), alimentación enteral prolongada y nutrición parenteral. En uno de los episodios infecciosos intrahospitalarios se tomaron hemocultivos periféricos y se realizó un ecocardiograma, lo que permitió diagnosticarlo con endocarditis por L. lactis y por lo cual se decidió iniciar manejo con linezolid. Luego de 21 días de tratamiento, la infección fue controlada, pero con el fin de mejorar su estado nutricional y debido a un nuevo episodio de bacteremia, se decidió prolongar su estancia hospitalaria. Finalmente, después de 112 días de hospitalización, fue dado de alta para continuar manejo integral ambulatorio.Conclusión. A pesar de ser una entidad poco frecuente en pediatría, la endocarditis por L. lactis debe sospecharse en pacientes con múltiples factores de riesgo y con infecciones polimicrobianas. Un tratamiento oportuno y específico como el usado en el presente caso puede evitar complicaciones futuras.

A mixed infection of Leuconostoc lactis and vancomycin-resistant Enterococcus in a liver transplant recipient

Bacterial infection in patients who have undergone liver transplantation is a major complication of the procedure. Leuconostoc spp. are important pathogenic bacteria in individuals with poor immune function, especially transplant patients. In this report, we describe the case of a 45-year-old Asian male liver transplant recipient who was initially preliminarily diagnosed with infection with Leuconostoc pseudomesenteroides by using the microbial tests of the VITEK 2 system and the aesculin hydrolysis test, and with vancomycin-resistant Enterococcus. Subsequently, the Leuconostoc isolate was identified as Leuconostoc lactis by 16S rRNA gene partial sequencing. In this paper, we discuss our identification of L. lactis based on physiological characteristics and molecular methodology. Accurate identification of these infections is important for the outcome; use of 16S rRNA gene sequence analysis offers a rapid and precise diagnostic approach. Administration of the drug linezolid may be useful for the treatment of both Leuconostoc spp. and vancomycin-resistant Enterococcus infections. We suggest that clinical analysts should use molecular methods in addition to biochemical tests in order to identify Leuconostoc at the species level more accurately.

Successful treatment of Leuconostoc bacteremia in a neutropenic patient with tigecycline

Leuconostoc lactis is a recognised cause of infection in immunocompromised hosts. It is intrinsically resistant to multiple antibiotics and treatment options may be limited. We report a case of safe and effective use of tigecycline in the treatment of Leuconostoc catheter-related line sepsis in a neutropenic patient. To our knowledge, this is the first reported case of successful use of tigecycline for Leuconostoc bacteremia.

Accuracies of Leuconostoc phenotypic identification: a comparison of API systems and conventional phenotypic assays

Background

Commercial diagnostics are commonly used to identify gram-positive bacteria. Errors have been reported mostly at the species level. We have found certain phenotypic criteria used in API systems which significantly misidentify Leuconostoc, an emerging human pathogen, at the genus level. We also attempt to find practical, conventional phenotypic assays for accurate identification of this group of bacteria.

Methods

Clinical isolates of catalase-negative, gram-positive coccoid or coccobacillary bacteria with non-β hemolysis in our institute during 1997–2004 were subject to an identification aid by API 20 STREP, following the instruction manual, as an aid to conventional phenotypic tests. Those identified as Leuconostoc by API 20 STREP were re-examined by the same kit and also by API 50 CHL according to the instruction manuals, by our Leuconostoc conventional phenotypic assays, by Leuconostoc- and Lactobacillus-specific PCR's, and, where possible, by 16S rDNA sequence analysis. In addition, catalase-negative gram-positive isolates during 2005–2006 which were resistant to vancomycin at high levels were also evaluated by the same phenotypic and genotypic assays.

Results

Out of several thousands of clinical gram-positive isolates, 26 catalase negative gram-positive isolates initially identified as Leuconostoc by API 20 STREP and 7 vancomycin-resistant gram-positive catalase-negative bacteria entered the study. 11 out of the 26 isolates and all the 7 isolates were identified as Leuconostoc by API 20 STREP. Only 5 isolates, however, were confirmed by both genotypic and all defined conventional phenotypic criteria. API 50 CHL also failed to reliably provide accurate identification of Leuconostoc. We have identified key problem tests in API 20 STREP leading to misidentification of the bacteria. A simple, conventional set of phenotypic tests for Leuconostoc identification is proposed.

Conclusion

The current API systems cannot accurately identify Leuconostoc. Identification of vancomycin-resistant, catalase-negative gram-positive bacteria should be performed by a few practical phenotypic assays, with assistance of genotypic assays where available.

Molecular identification of Leuconostoc mesenteroides as a cause of brain abscess in an immunocompromised patient

Leuconostoc species are emerging pathogens that can cause severe infections, particularly in immunocompromised patients. Using molecular methods, we identified Leuconostoc mesenteroides as the cause of a brain abscess which was successfully treated by surgery and antimicrobial treatment. This is the first report of brain abscess caused by this species.

Leuconostoc Osteomyelitis

Leuconostoc spp. is a variety of streptococcus that can cause disease in humans, most notably those with HIV infection or other causes of immunodepression. We report the case of a patient who had Leuconostoc osteomyelitis in an area of lymphedema.

Multiple liver abscesses associated with bacteremia due to Leuconostoc lactis

Leuconostoc species, which are members of the family Streptococcacae, have only recently been recognized as potential pathogens. We describe a patient with type II diabetes mellitus who had multiple liver abscesses associated with bacteremia due to Leuconostoc lactis. To our knowledge, this is the first case of this association to be reported in the literature.