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In this paper, a study of fungal and multi-mycotoxin contamination in 140 Camellia sinensis and 26 herbal teas marketed in Latvia is discussed. The analysis was performed using two-dimensional liquid chromatography with time-of-flight mass spectrometry (2D-LC-TOF-MS) and MALDI-TOF-MS. In total, 87% of the tea samples tested positive for 32 fungal species belonging to 17 genera, with the total enumeration of moulds ranging between 1.00 × 101 and 9.00 × 104 CFU g−1. Moreover, 42% of the teas (n = 70) were contaminated by 1 to 16 mycotoxins, and 37% of these samples were positive for aflatoxins at concentrations ranging between 0.22 and 41.7 µg kg−1. Deoxynivalenol (DON) and its derivatives co-occurred in 63% of the tea samples, with their summary concentrations reaching 81.1 to 17,360 µg kg−1. Ochratoxin A (OTA), enniatins, and two Alternaria toxins were found in 10–37% of the teas at low concentrations. The dietary exposure assessment based on the assumption of a probable full transfer of determined mycotoxins into infusions indicated that the analysed teas are safe for consumers: the probable maximum daily exposure levels to OTA and the combined DON mycotoxins were only 0.88 to 2.05% and 2.50 to 78.9% of the tolerable daily intake levels.
Ingars Reinholds; Estefanija Bogdanova; Iveta Pugajeva; Laura Alksne; Darta Stalberga; Olga Valcina; Vadims Bartkevics. Determination of Fungi and Multi-Class Mycotoxins in Camelia Sinensis and Herbal Teas and Dietary Exposure Assessment. Toxins 2020, 12, 555 .
AMA StyleIngars Reinholds, Estefanija Bogdanova, Iveta Pugajeva, Laura Alksne, Darta Stalberga, Olga Valcina, Vadims Bartkevics. Determination of Fungi and Multi-Class Mycotoxins in Camelia Sinensis and Herbal Teas and Dietary Exposure Assessment. Toxins. 2020; 12 (9):555.
Chicago/Turabian StyleIngars Reinholds; Estefanija Bogdanova; Iveta Pugajeva; Laura Alksne; Darta Stalberga; Olga Valcina; Vadims Bartkevics. 2020. "Determination of Fungi and Multi-Class Mycotoxins in Camelia Sinensis and Herbal Teas and Dietary Exposure Assessment." Toxins 12, no. 9: 555.
Rapid identification of methicillin-resistant Staphylococcus could ensure appropriate medical care. A total of 409 Staphylococcus spp. strains were used to develop a reliable MALDI-TOF method for species identification. We tested twelve S. aureus strains to compare three different sample preparation methods and the reproducibility of the methicillin-resistant m/z 2414±2 indicator peak with direct method in triplicate. A total of 65 Staphylococcus spp. strains (including 37 methicillin-resistant strains) from clinical and hospital environment isolates were used to confirm the presence of phenol-soluble modulin (PSM-mec) peptide. All 272 S. aureus strains from 409 samples were correctly identified at species level by MALDI-TOF. The samples prepared by three methods gave spectra with differences in the intensities and presence of certain peaks. The PSM-mec peak was not visible after the extraction method. The peak m/z 2414±2 was only detected in 61 % of the methicillin-resistant strains and in none of the methicillin-sensitive strains. The peak reproducibility for the five analyzed S. aureus strains showing the peak at m/z 2414±2 was 87%. The delta-toxin was observed in 49 out of 65 samples regardless of methicillin susceptibility, as well as in all the samples exhibiting the PSM-mec peak. The peak m/z 2414±2 is specific to methicillin-resistant strains carrying the mecA gene, but the absence of peak m/z 2414±2 does not exclude the possibility of resistance to methicillin. Thus, implementing MALDI-TOF analysis in routine laboratory work, especially with clinical samples, would in many cases provide rapid warning about the presence of methicillin-resistant strains.
Laura Alksne; Svetlana Makarova; Jeļena Avsejenko; Alla Cibrovska; Julija Trofimova; Olga Valciņa. Determination of methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis by MALDI-TOF MS in clinical isolates from Latvia. Clinical Mass Spectrometry 2020, 16, 33 -39.
AMA StyleLaura Alksne, Svetlana Makarova, Jeļena Avsejenko, Alla Cibrovska, Julija Trofimova, Olga Valciņa. Determination of methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis by MALDI-TOF MS in clinical isolates from Latvia. Clinical Mass Spectrometry. 2020; 16 ():33-39.
Chicago/Turabian StyleLaura Alksne; Svetlana Makarova; Jeļena Avsejenko; Alla Cibrovska; Julija Trofimova; Olga Valciņa. 2020. "Determination of methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis by MALDI-TOF MS in clinical isolates from Latvia." Clinical Mass Spectrometry 16, no. : 33-39.
Background and Objectives: Legionella is one of the most important water-related pathogens. Inside the water supply systems and the biofilms, Legionella interact with other bacteria and free-living amoeba (FLA). Several amoebas may serve as hosts for bacteria in aquatic systems. This study aimed to investigate the co-occurrence of Legionella spp. and FLA in drinking water supply systems. Materials and Methods: A total of 268 water samples were collected from apartment buildings, hotels, and public buildings. Detection of Legionella spp. was performed in accordance with ISO 11731:2017 standard. Three different polymerase chain reaction (PCR) protocols were used to identify FLA. Results: Occurrence of Legionella varied from an average of 12.5% in cold water samples with the most frequent occurrence observed in hot water, in areas receiving untreated groundwater, where 54.0% of the samples were Legionella positive. The occurrence of FLA was significantly higher. On average, 77.2% of samples contained at least one genus of FLA and, depending on the type of sample, the occurrence of FLA could reach 95%. In the samples collected during the study, Legionella was always isolated along with FLA, no samples containing Legionella in the absence of FLA were observed. Conclusions: The data obtained in our study can help to focus on the extensive distribution, close interaction, and long-term persistence of Legionella and FLA. Lack of Legionella risk management plans and control procedures may promote further spread of Legionella in water supply systems. In addition, the high incidence of Legionella-related FLA suggests that traditional monitoring methods may not be sufficient for Legionella control.
Olga Valciņa; Daina Pūle; Artjoms Mališevs; Jūlija Trofimova; Svetlana Makarova; Genadijs Konvisers; Aivars Bērziņš; Angelika Krūmiņa. Co-Occurrence of Free-Living Amoeba and Legionella in Drinking Water Supply Systems. Medicina 2019, 55, 492 .
AMA StyleOlga Valciņa, Daina Pūle, Artjoms Mališevs, Jūlija Trofimova, Svetlana Makarova, Genadijs Konvisers, Aivars Bērziņš, Angelika Krūmiņa. Co-Occurrence of Free-Living Amoeba and Legionella in Drinking Water Supply Systems. Medicina. 2019; 55 (8):492.
Chicago/Turabian StyleOlga Valciņa; Daina Pūle; Artjoms Mališevs; Jūlija Trofimova; Svetlana Makarova; Genadijs Konvisers; Aivars Bērziņš; Angelika Krūmiņa. 2019. "Co-Occurrence of Free-Living Amoeba and Legionella in Drinking Water Supply Systems." Medicina 55, no. 8: 492.
Baiba Fogele; Rita Granta; Olga Valciņa; Aivars Bērziņš. Occurrence and diversity of Bacillus cereus and moulds in spices and herbs. Food Control 2018, 83, 69 -74.
AMA StyleBaiba Fogele, Rita Granta, Olga Valciņa, Aivars Bērziņš. Occurrence and diversity of Bacillus cereus and moulds in spices and herbs. Food Control. 2018; 83 ():69-74.
Chicago/Turabian StyleBaiba Fogele; Rita Granta; Olga Valciņa; Aivars Bērziņš. 2018. "Occurrence and diversity of Bacillus cereus and moulds in spices and herbs." Food Control 83, no. : 69-74.
An increasing number of bacteria have been described as benefiting from interaction with free-living amoeba. The most common association between free-living amoeba and microorganisms is interaction of various non-pathogenic and pathogenic bacterial species with amoeba. Various pathogenic bacterial species have capacity to resist digestion by free-living amoeba, which has been observed by many researchers. Also, several of these pathogens are able to resist digestion by macrophages. In addition, free-living amoeba have been associated with several diseases in humans. Acanthamniioeba castella is an important predator of bacteria. It is a ubiquitous organism in water, soil, and air. Attention from a public health perspective is needed by investigation of interaction of foodborne pathogens and free-living amoeba. Bacteria can use free-living amoeba as reservoirs, mediators or vehicles, an infection route, “biological gym” and evolutionary crib or interaction may result in a close endosymbiotic relationship. The purpose of this review is to describe the interaction mechanisms between free-living amoeba and common bacteria species that survive in host cells.
Ilze Rubeniņa; Muza Kirjušina; Aivars Bērziņš; Olga Valciņa; Inese Jahundoviča. Relationships between Free-Living Amoeba and their Intracellular Bacteria. Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences. 2017, 71, 259 -265.
AMA StyleIlze Rubeniņa, Muza Kirjušina, Aivars Bērziņš, Olga Valciņa, Inese Jahundoviča. Relationships between Free-Living Amoeba and their Intracellular Bacteria. Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences.. 2017; 71 (4):259-265.
Chicago/Turabian StyleIlze Rubeniņa; Muza Kirjušina; Aivars Bērziņš; Olga Valciņa; Inese Jahundoviča. 2017. "Relationships between Free-Living Amoeba and their Intracellular Bacteria." Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences. 71, no. 4: 259-265.
Continuous environmental exposure of humans to Legionella may induce immune responses and generation of antibodies. The aim of this study was to investigate the seroprevalence of Legionella pneumophila serogroups (SG) 1–6 in the general healthy population and identify the associated host-related and environmental risk factors. L. pneumophila SG 1–6 seroprevalence among a total of 2007 blood samples collected from healthy donors was 4.8%. Seroprevalence was higher in women (5.9%) than men (3.3%) and in areas with a larger number of inhabitants, ranging from 3.5% in rural regions to 6.8% in the capital, Riga. Blood samples from inhabitants of apartment buildings tested positive for L. pneumophila in more cases (5.8%) compared to those from inhabitants of single-family homes (2.7%). Residents of buildings with a municipal hot water supply system were more likely to be seropositive for L. pneumophila (OR = 3.16, 95% CI 1.26–7.91). Previous episodes of fever were additionally identified as a risk factor (OR = 2.42, 95% CI 1.43–4.1). In conclusion, centralized hot water supply, female gender and previous episodes of fever were determined as the main factors associated with L. pneumophila seropositivity in our study population.
Olga Valciņa; Daina Pūle; Irina Lucenko; Dita Krastiņa; Žanete Šteingolde; Angelika Krumina; Aivars Berzins. Legionella pneumophila Seropositivity-Associated Factors in Latvian Blood Donors. International Journal of Environmental Research and Public Health 2015, 13, 58 .
AMA StyleOlga Valciņa, Daina Pūle, Irina Lucenko, Dita Krastiņa, Žanete Šteingolde, Angelika Krumina, Aivars Berzins. Legionella pneumophila Seropositivity-Associated Factors in Latvian Blood Donors. International Journal of Environmental Research and Public Health. 2015; 13 (1):58.
Chicago/Turabian StyleOlga Valciņa; Daina Pūle; Irina Lucenko; Dita Krastiņa; Žanete Šteingolde; Angelika Krumina; Aivars Berzins. 2015. "Legionella pneumophila Seropositivity-Associated Factors in Latvian Blood Donors." International Journal of Environmental Research and Public Health 13, no. 1: 58.
Vita Strazdina; Margarita Terentjeva; Olga Valcina; Inga Eizenberga; Aleksandr Novoslavskij; Jevgenija Osmjana; Aivars Berzins. The Microflora of Gills, Gut and Skin of European Eels (Anguilla anguilla) in Lakes of Latvia. Journal of Food Science and Engineering 2015, 5, 1 .
AMA StyleVita Strazdina, Margarita Terentjeva, Olga Valcina, Inga Eizenberga, Aleksandr Novoslavskij, Jevgenija Osmjana, Aivars Berzins. The Microflora of Gills, Gut and Skin of European Eels (Anguilla anguilla) in Lakes of Latvia. Journal of Food Science and Engineering. 2015; 5 (3):1.
Chicago/Turabian StyleVita Strazdina; Margarita Terentjeva; Olga Valcina; Inga Eizenberga; Aleksandr Novoslavskij; Jevgenija Osmjana; Aivars Berzins. 2015. "The Microflora of Gills, Gut and Skin of European Eels (Anguilla anguilla) in Lakes of Latvia." Journal of Food Science and Engineering 5, no. 3: 1.
Margarita Terentjeva; Inga Eizenberga; Aleksandr Novoslavskij; Vita Strazdiņa; Olga Valciņa; Jevgenija Ošmjana; Aivars Berzins. Bacterial microflora of freshwater fish originated from Usmas Lake in Latvia. Journal of Microbiology, Biotechnology and Food Sciences 2015, 4, 74 -77.
AMA StyleMargarita Terentjeva, Inga Eizenberga, Aleksandr Novoslavskij, Vita Strazdiņa, Olga Valciņa, Jevgenija Ošmjana, Aivars Berzins. Bacterial microflora of freshwater fish originated from Usmas Lake in Latvia. Journal of Microbiology, Biotechnology and Food Sciences. 2015; 4 ():74-77.
Chicago/Turabian StyleMargarita Terentjeva; Inga Eizenberga; Aleksandr Novoslavskij; Vita Strazdiņa; Olga Valciņa; Jevgenija Ošmjana; Aivars Berzins. 2015. "Bacterial microflora of freshwater fish originated from Usmas Lake in Latvia." Journal of Microbiology, Biotechnology and Food Sciences 4, no. : 74-77.