Molecular Differentiation of Lactococcus lactis Subspecies lactis and cremoris Strains by Ribotyping and Site Specific-PCR

Basaran, Pervin; Basaran, Nese; Çakır, İbrahim

doi:10.1007/s002840010176

Cited by 13 publications

(9 citation statements)

References 17 publications

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“…cremoris and L lactis ssp. lactis biovar diacetylactis are used for the production of fermented dairy products and production of cheddar cheese 6. Therefore, exposure to unpasteurised dairy products has been suggested as a risk factor of L lactis cremoris infection.…”

Section: Discussionmentioning

confidence: 99%

Lactococcus lactis cremorisinfection: not rare anymore?

2013

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SUMMARYA middle-aged female patient with diabetes was admitted with a right neck abscess. Ultrasound scan revealed a necrotic abscess suspicious of malignancy and biopsy showed evidence of chronic inflammation. In order to isolate the primary source of malignancy, we performed MRI and positron emission tomography scans but neither had conclusive results. Subsequently, we performed an incision and drainage of the mass in order to alleviate pressure symptoms. The ensuing histological examination revealed that the mass was caused by Lactococcus lactis cremoris. As such, the patient was treated with antibiotics and made a complete recovery. This report reinforces the scarce existing evidence that L lactis cremoris is a potential pathogen in adults. The case shows that atypical organisms should always be considered in the working diagnosis of an atypical neck abscess especially due to the rise in popularity of organic farming. BACKGROUND

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Section: Discussionmentioning

confidence: 99%

Lactococcus lactis cremorisinfection: not rare anymore?

2013

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“…The classification of L. lactis subspecies based on phenotypic characteristics is of primary importance in the dairy industry, as phenotypes directly reveal the abilities required in milk fermentation. It has been reported that PCR analysis with oligonucleotide primers designed for the rrnB-rrnC region correlates with phenotypic characterization (2).…”

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confidence: 99%

Rapid PCR-Based Method Which Can Determine Both Phenotype and Genotype of Lactococcus lactis Subspecies

Nomura

Kobayashi

Okamoto

2002

Appl Environ Microbiol

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A highly efficient, rapid, and reliable PCR-based method for distinguishing Lactococcus lactis subspecies (L. lactis subsp. lactis and L. lactis subsp. cremoris) is described. Primers complementary to positions in the glutamate decarboxylase gene have been constructed. PCR analysis with extracted DNA or with cells of different L. lactis strains resulted in specific fragments. The length polymorphism of the PCR fragments allowed a clear distinction of the L. lactis subspecies. The amplified fragment length polymorphism with the primers and the restriction fragment length polymorphism of the amplified products agreed perfectly with the identification based on genotypic and phenotypic analyses, respectively. Isolates from cheese starters were investigated by this method, and amplified fragments of genetic variants were found to be approximately 40 bp shorter than the typical L. lactis subsp. cremoris fragments.Lactococcal strains are essential to milk fermentation, especially in the cheese-making process, providing optimal conditions for curd formation and for the development of texture and flavor. It is important to the dairy industry to identify new strains of Lactococcus lactis for cheese manufacture. Dairy lactococcal strains are subdivided into L. lactis subsp. lactis and L. lactis subsp. cremoris based on a few phenotypic tests: growth in 4% NaCl, pH 9.2, at 40°C; the ability to hydrolyze arginine (7); and sensitivity to lithium chloride (1).Recently, a novel criterion for distinguishing L. lactis subsp. lactis from L. lactis subsp. cremoris has been reported: glutamate decarboxylase (GAD; EC 4.1.1.15) activity, which has been observed in L. lactis subsp. lactis and not in L. lactis subsp. cremoris (8). GAD catalyzes the irreversible decarboxylation of glutamate to ␥-aminobutyric acid (GABA). GAD constitutes a glutamate-dependent acid resistance mechanism with a glutamate-GABA antiporter (12). The gadB gene encoding L. lactis subsp. cremoris GAD was apparently inactivated by a frameshift mutation resulting from an adenine deletion or a thymine insertion and encoded a nonfunctional protein (10).It has been discovered in recent years that L. lactis strains can be divided into two phylogenetic groups based on genotypic analysis (6,11,13), and it has been proposed that the subspecies diagnoses be redefined to reflect these natural relationships (6). The new taxonomic system requires the transfer of several strains across subspecies lines, from L. lactis subsp. lactis to L. lactis subsp. cremoris and vice versa.As classification according to phenotypic criteria is complicated and requires skill, simple, fast, and reliable molecular methods have been developed (3,5). Classification based on these methods, however, coincides with genotypic identification and does not always correlate with phenotypic characterization. The classification of L. lactis subspecies based on phenotypic characteristics is of primary importance in the dairy industry, as phenotypes directly reveal the abilities required in milk fermentation. ...

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“…lactis biovar diacetylactis are used for the production of fermentated dairy products. L. lactis cremoris is particularly preferred for the production of chedar cheese (13). As a result, exposure to unpasteurized dairy products has been suggested as a risk factor of L. lactis cremoris infection.…”

Section: Discussionmentioning

confidence: 99%

Liver Abscess and Empyema due toLactococcus lactis cremoris

et al. 2010

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Lactococcus lactis cremoris infections are very rare in humans. We experienced liver abscess and empyema due to L. lactis cremoris in an immunocompetent adult. A 42-yr-old man was admitted with fever and abdominal pain. Abdominal computed tomography (CT) revealed a liver abscess and chest CT showed loculated pleural effusion consistent with empyema. L. lactis cremoris was isolated from culture of the abscess material and blood. The patient was treated with pus drainage from liver abscess, video-assisted thoracoscopic decortications for empyema, and antibiotics including cefotaxime and levofloxacin. The patient was completely recovered with the treatment. To our knowledge, this is the first report of a L. lactis cremoris infection in Korea.

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Molecular Differentiation of Lactococcus lactis Subspecies lactis and cremoris Strains by Ribotyping and Site Specific-PCR

Cited by 13 publications

References 17 publications

Lactococcus lactis cremorisinfection: not rare anymore?

Lactococcus lactis cremorisinfection: not rare anymore?

Rapid PCR-Based Method Which Can Determine Both Phenotype and Genotype of Lactococcus lactis Subspecies

Liver Abscess and Empyema due toLactococcus lactis cremoris

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