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Bačić A, Milivojević V, Petković I, Kekić D, Gajić I, Medić Brkić B, Popadić D, Milosavljević T, Rajilić-Stojanović M. In Search for Reasons behind Helicobacter pylori Eradication Failure-Assessment of the Antibiotics Resistance Rate and Co-Existence of Helicobacter pylori with Candida Species. J Fungi (Basel) 2023; 9:328. [PMID: 36983496 PMCID: PMC10056355 DOI: 10.3390/jof9030328] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 02/24/2023] [Accepted: 03/01/2023] [Indexed: 03/10/2023] Open
Abstract
Helicobacter pylori eradication is characterized by decreasing successful eradication rates. Although treatment failure is primarily associated with resistance to antibiotics, other unknown factors may influence the eradication outcome. This study aimed to assess the presence of the antibiotics resistance genes in H. pylori and the presence of Candida spp., which are proposed to be endosymbiotic hosts of H. pylori, in gastric biopsies of H. pylori-positive patients while simultaneously assessing their relationship. The detection and identification of Candida yeasts and the detection of mutations specific for clarithromycin and fluoroquinolones were performed by using the real-time PCR (RT-PCR) method on DNA extracted from 110 gastric biopsy samples of H. pylori-positive participants. Resistance rate to clarithromycin and fluoroquinolone was 52% and 47%, respectively. Antibiotic resistance was associated with more eradication attempts (p < 0.05). Candida species were detected in nine (8.18%) patients. Candida presence was associated with older age (p < 0.05). A high rate of antibiotic resistance was observed, while Candida presence was scarce, suggesting that endosymbiosis between H. pylori and Candida may not be a major contributing factor to the eradication failure. However, the older age favored Candida gastric mucosa colonization, which could contribute to gastric pathologies and microbiome dysbiosis.
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Affiliation(s)
- Ana Bačić
- Department of Biochemical Engineering and Biotechnology, Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia
| | - Vladimir Milivojević
- Clinic for Gastroenterology and Hepatology, University Clinical Centre of Serbia, 11000 Belgrade, Serbia
- Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
| | - Isidora Petković
- Department of Biochemical Engineering and Biotechnology, Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia
| | - Dušan Kekić
- Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
- Institute for Microbiology and Immunology, Medical Faculty, University of Belgrade, 11000 Belgrade, Serbia
| | - Ina Gajić
- Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
- Institute for Microbiology and Immunology, Medical Faculty, University of Belgrade, 11000 Belgrade, Serbia
| | - Branislava Medić Brkić
- Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
- Institute for Pharmacology, Clinical Pharmacology and Toxicology, Medical Faculty University of Belgrade, 11000 Belgrade, Serbia
| | - Dušan Popadić
- Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
- Institute for Microbiology and Immunology, Medical Faculty, University of Belgrade, 11000 Belgrade, Serbia
| | | | - Mirjana Rajilić-Stojanović
- Department of Biochemical Engineering and Biotechnology, Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia
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Sánchez-Alonzo K, Arellano-Arriagada L, Bernasconi H, Parra-Sepúlveda C, Campos VL, Silva-Mieres F, Sáez-Carrillo K, Smith CT, García-Cancino A. An Anaerobic Environment Drives the Harboring of Helicobacter pylori within Candida Yeast Cells. BIOLOGY 2022; 11:biology11050738. [PMID: 35625466 PMCID: PMC9139145 DOI: 10.3390/biology11050738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 05/07/2022] [Indexed: 11/30/2022]
Abstract
Simple Summary Helicobacter pylori is a pathogen that is associated with a number of gastric pathologies and has adapted to the gastric environment. Outside this organ, stress factors such as oxygen concentration affect the viability of this bacterium. This study aimed to determine if changes in oxygen concentration promoted the entry of H. pylori into the interior of yeast cells of the Candida genus. Co-cultures of H. pylori and Candida strains in Brucella broth plus 5% fetal bovine serum were incubated under microaerobic, anaerobic, or aerobic conditions. Bacteria-like bodies (BLBs) were detected within yeast cells (Y-BLBs) by optical microscopy, identified by molecular techniques, and their viability evaluated by SYTO-9 fluorescence. Co-cultures incubated under the three conditions showed the presence of Y-BLBs, but the highest Y-BLB percentage was present in H. pylori J99 and C. glabrata co-cultures incubated under anaerobiosis. Molecular techniques were used to identify BLBs as H. pylori and SYTO-9 fluorescence confirmed that this bacterium remained viable within yeast cells. In conclusion, although without apparent stress conditions H. pylori harbors within Candida yeast cells, its harboring increases significantly under anaerobic conditions. This endosymbiotic relationship also depends mostly on the H. pylori strain used in the co-culture. Abstract Helicobacter pylori protects itself from stressful environments by forming biofilms, changing its morphology, or invading eukaryotic cells, including yeast cells. There is little knowledge about the environmental factors that influence the endosymbiotic relationship between bacterium and yeasts. Here, we studied if oxygen availability stimulated the growth of H. pylori within Candida and if this was a bacterial- or yeast strain-dependent relationship. Four H. pylori strains and four Candida strains were co-cultured in Brucella broth plus 5% fetal bovine serum, and incubated under microaerobic, anaerobic, or aerobic conditions. Bacteria-like bodies (BLBs) within yeast cells (Y-BLBs) were detected by microscopy. H. pylori was identified by FISH and by PCR amplification of the 16S rRNA gene of H. pylori from total DNA extracted from Y-BLBs from H. pylori and Candida co-cultures. BLBs viability was confirmed by SYTO-9 fluorescence. Higher Y-BLB percentages were obtained under anaerobic conditions and using H. pylori J99 and C. glabrata combinations. Thus, the H. pylori–Candida endosymbiotic relationship is strain dependent. The FISH and PCR results identified BLBs as intracellular H. pylori. Conclusion: Stressful conditions such as an anaerobic environment significantly increased H. pylori growth within yeast cells, where it remained viable, and the bacterium–yeast endosymbiotic relationship was bacterial strain dependent with a preference for C. glabrata.
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Affiliation(s)
- Kimberly Sánchez-Alonzo
- Laboratory of Bacterial Pathogenicity, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepcion, Concepcion 4070386, Chile; (K.S.-A.); (L.A.-A.); (C.P.-S.); (F.S.-M.); (C.T.S.)
| | - Luciano Arellano-Arriagada
- Laboratory of Bacterial Pathogenicity, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepcion, Concepcion 4070386, Chile; (K.S.-A.); (L.A.-A.); (C.P.-S.); (F.S.-M.); (C.T.S.)
| | | | - Cristian Parra-Sepúlveda
- Laboratory of Bacterial Pathogenicity, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepcion, Concepcion 4070386, Chile; (K.S.-A.); (L.A.-A.); (C.P.-S.); (F.S.-M.); (C.T.S.)
| | - Víctor L. Campos
- Laboratory of Environmental Microbiology, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepcion, Concepcion 4070386, Chile;
| | - Fabiola Silva-Mieres
- Laboratory of Bacterial Pathogenicity, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepcion, Concepcion 4070386, Chile; (K.S.-A.); (L.A.-A.); (C.P.-S.); (F.S.-M.); (C.T.S.)
| | - Katia Sáez-Carrillo
- Department of Statistics, Faculty of Physical and Mathematical Sciences, Universidad de Concepcion, Concepcion 4070386, Chile;
| | - Carlos T. Smith
- Laboratory of Bacterial Pathogenicity, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepcion, Concepcion 4070386, Chile; (K.S.-A.); (L.A.-A.); (C.P.-S.); (F.S.-M.); (C.T.S.)
| | - Apolinaria García-Cancino
- Laboratory of Bacterial Pathogenicity, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepcion, Concepcion 4070386, Chile; (K.S.-A.); (L.A.-A.); (C.P.-S.); (F.S.-M.); (C.T.S.)
- Correspondence: ; Tel.: +56-41-2204144; Fax: +56-41-2245975
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Temperatures Outside the Optimal Range for Helicobacter pylori Increase Its Harboring within Candida Yeast Cells. BIOLOGY 2021; 10:biology10090915. [PMID: 34571792 PMCID: PMC8472035 DOI: 10.3390/biology10090915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 09/03/2021] [Accepted: 09/07/2021] [Indexed: 12/23/2022]
Abstract
Simple Summary Helicobacter pylori is associated with the development of diverse gastric pathologies. This bacterium has been shown to invade yeast to protect itself from environmental factors such as changes in pH, the presence of antibiotics or variations in nutrients that affect their viability. However, intra-yeast H. pylori has been reported from other sources, including food, or when the storage temperature is outside the optimal growth range for H. pylori, which is 30–37 °C. It is necessary to continue investigating the environmental factors that participate in the entry of the bacteria into yeast. In this work, it was evaluated whether temperature changes promote the entry of H. pylori into Candida and whether this endosymbiosis favors bacterial viability. It was observed that H. pylori significantly increased its invasiveness to yeast when these two microorganisms were co-cultured under 40 °C. The results support that H. pylori invades yeasts to protect itself from stressful environments, favoring its viability in these environments. In addition, it can be suggested that this microorganism would use yeast as a transmission vehicle, thereby contributing to its dissemination in the population. However, the latter still needs to be confirmed. Abstract Helicobacter pylori is capable of entering into yeast, but the factors driving this endosymbiosis remain unknown. This work aimed to determine if temperatures outside the optimal range for H. pylori increase its harboring within Candida. H. pylori strains were co-cultured with Candida strains in Brucella broth supplemented with 5% fetal bovine serum and incubated at 4, 25, 37 or 40 °C. After co-culturing, yeasts containing bacteria-like bodies (Y-BLBs) were observed by optical microscopy, and the bacterium were identified as H. pylori by FISH. The H. pylori 16S rRNA gene was amplified from the total DNA of Y-BLBs. The viability of intra-yeast H. pylori cells was confirmed using a viability assay. All H. pylori strains were capable of entering into all Candida strains assayed. The higher percentages of Y-BLBs are obtained at 40 °C with any of the Candida strains. H pylori also increased its harboring within yeast in co-cultures incubated at 25 °C when compared to those incubated at 37 °C. In conclusion, although H. pylori grew significantly at 40 °C, this temperature increased its harboring within Candida. The endosymbiosis between both microorganisms is strain-dependent and permits bacterial cells to remain viable under the stressing environmental conditions assayed.
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Sánchez-Alonzo K, Silva-Mieres F, Arellano-Arriagada L, Parra-Sepúlveda C, Bernasconi H, Smith CT, Campos VL, García-Cancino A. Nutrient Deficiency Promotes the Entry of Helicobacter pylori Cells into Candida Yeast Cells. BIOLOGY 2021; 10:426. [PMID: 34065788 PMCID: PMC8151769 DOI: 10.3390/biology10050426] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/02/2021] [Accepted: 05/04/2021] [Indexed: 12/14/2022]
Abstract
Helicobacter pylori, a Gram-negative bacterium, has as a natural niche the human gastric epithelium. This pathogen has been reported to enter into Candida yeast cells; however, factors triggering this endosymbiotic relationship remain unknown. The aim of this work was to evaluate in vitro if variations in nutrient concentration in the cultured medium trigger the internalization of H. pylori within Candida cells. We used H. pylori-Candida co-cultures in Brucella broth supplemented with 1%, 5% or 20% fetal bovine serum or in saline solution. Intra-yeast bacteria-like bodies (BLBs) were observed using optical microscopy, while intra-yeast BLBs were identified as H. pylori using FISH and PCR techniques. Intra-yeast H. pylori (BLBs) viability was confirmed using the LIVE/DEAD BacLight Bacterial Viability kit. Intra-yeast H. pylori was present in all combinations of bacteria-yeast strains co-cultured. However, the percentages of yeast cells harboring bacteria (Y-BLBs) varied according to nutrient concentrations and also were strain-dependent. In conclusion, reduced nutrients stresses H. pylori, promoting its entry into Candida cells. The starvation of both H. pylori and Candida strains reduced the percentages of Y-BLBs, suggesting that starving yeast cells may be less capable of harboring stressed H. pylori cells. Moreover, the endosymbiotic relationship between H. pylori and Candida is dependent on the strains co-cultured.
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Affiliation(s)
- Kimberly Sánchez-Alonzo
- Laboratory of Bacterial Pathogenicity, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepcion, Concepción 4070386, Chile; (K.S.-A.); (F.S.-M.); (L.A.-A.); (C.P.-S.); (C.T.S.)
| | - Fabiola Silva-Mieres
- Laboratory of Bacterial Pathogenicity, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepcion, Concepción 4070386, Chile; (K.S.-A.); (F.S.-M.); (L.A.-A.); (C.P.-S.); (C.T.S.)
| | - Luciano Arellano-Arriagada
- Laboratory of Bacterial Pathogenicity, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepcion, Concepción 4070386, Chile; (K.S.-A.); (F.S.-M.); (L.A.-A.); (C.P.-S.); (C.T.S.)
| | - Cristian Parra-Sepúlveda
- Laboratory of Bacterial Pathogenicity, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepcion, Concepción 4070386, Chile; (K.S.-A.); (F.S.-M.); (L.A.-A.); (C.P.-S.); (C.T.S.)
| | | | - Carlos T. Smith
- Laboratory of Bacterial Pathogenicity, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepcion, Concepción 4070386, Chile; (K.S.-A.); (F.S.-M.); (L.A.-A.); (C.P.-S.); (C.T.S.)
| | - Víctor L. Campos
- Laboratory of Environmental Microbiology, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción 4070386, Chile;
| | - Apolinaria García-Cancino
- Laboratory of Bacterial Pathogenicity, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepcion, Concepción 4070386, Chile; (K.S.-A.); (F.S.-M.); (L.A.-A.); (C.P.-S.); (C.T.S.)
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Intracellular Presence of Helicobacter pylori and Its Virulence-Associated Genotypes within the Vaginal Yeast of Term Pregnant Women. Microorganisms 2021; 9:microorganisms9010131. [PMID: 33430099 PMCID: PMC7827377 DOI: 10.3390/microorganisms9010131] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/18/2020] [Accepted: 11/20/2020] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND
Helicobacter pylori transmission routes are not entirely elucidated. Since yeasts are postulated to transmit this pathogen, this study aimed to detect and genotype intracellular H. pylori harbored within vaginal yeast cells. METHODS A questionnaire was used to determine risk factors of H. pylori infection. Samples were seeded on Sabouraud Dextrose Agar and horse blood-supplemented Columbia agar. Isolated yeasts were identified using and observed by optical microscopy searching for intra-yeast H. pylori. Total yeast DNA, from one random sample, was extracted to search for H. pylori virulence genes by PCR and bacterial identification by sequencing. RESULTS 43% of samples contained yeasts, mainly Candida albicans (91%). Microscopy detected bacteria such as bodies and anti-H. pylori antibodies binding particles in 50% of the isolated yeasts. Total DNA extracted showed that 50% of the isolated yeasts were positive for H. pylori 16S rDNA and the sequence showed 99.8% similarity with H. pylori. In total, 32% of H. pylori DNA positive samples were cagA+ vacAs1a vacAm1 dupA-. No relationship was observed between possible H. pylori infection risk factors and vaginal yeasts harboring this bacterium. CONCLUSION
H. pylori having virulent genotypes were detected within vaginal yeasts constituting a risk for vertical transmission of this pathogen.
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Siavoshi F, Saniee P. Candida accommodates non-culturable Helicobacter pylori in its vacuole - Koch's postulates aren't applicable. World J Gastroenterol 2018; 24:310-314. [PMID: 29375217 PMCID: PMC5768950 DOI: 10.3748/wjg.v24.i2.310] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 12/08/2017] [Accepted: 12/13/2017] [Indexed: 02/06/2023] Open
Abstract
The following are the responses to the "letter to the editor" ("Helicobacter is preserved in yeast vacuoles! Does Koch's postulates confirm it?") authored by Nader Alipour and Nasrin Gaeini that rejected the methods, results, discussions and conclusions summarized in the review article authored by Siavoshi F and Saniee P. In the article, 7 papers, published between 1998 and 2013, were reviewed. The 7 papers had been reviewed and judged very carefully by the assigned expertise of the journals involved, including the reviewers of the World Journal of Gastroenterology (WJG), before publication. In the review article, 121 references were used to verify the methods, results and discussions of these 7 papers. The review article was edited by the trustworthy British editor of the (WJG), and the final version was rechecked and finally accepted by the reviewers of (WJG). None of the reviewers made comments like those in this "letter to the editor", especially the humorous comments, which seem unprofessional and nonscientific. Above all, the authors' comments show a lack of understanding of basic and advanced microbiology, e.g. bacterial endosymbiosis in eukaryotic cells. Accordingly, their comments all through the letter contain misconceptions. The comments are mostly based on personal conclusions, without any scientific support. It would have been beneficial if the letter had been reviewed by the reviewers of the article by Siavoshi and Saniee.
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Affiliation(s)
- Farideh Siavoshi
- Department of Microbiology, School of Biology, University College of Sciences, University of Tehran, Tehran 14176-14411, Iran
| | - Parastoo Saniee
- Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University G.C., Tehran 19839-4716, Iran
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Alipour N, Gaeini N, Taner A, Yıldız F, Masseret S, Malfertheiner P. Retracted: Vacuoles ofAcanthamoeba castellaniiBehave as a Specialized Shelter (host) forHelicobacter pylori. Helicobacter 2015. [DOI: 10.1111/hel.12233] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/28/2023]
Affiliation(s)
- Nader Alipour
- Department of Biotechnology; METU; Ankara Turkey
- Department of Medical Microbiology; Faculty of Medicine; Giresun university; Giresun Turkey
| | - Nasrin Gaeini
- Department of Radiology; Trakya University; Edirne Turkey
| | - Abbas Taner
- Department of Medical Microbiology; Yuksek ihtisas university; Ankara Turkey
| | - Fatih Yıldız
- Department of Biotechnology; METU; Ankara Turkey
| | - Sadegh Masseret
- Digestive Disease Research Center of Tehran Medical Science university; Shariati hospital; Tehran IRAN
| | - Peter Malfertheiner
- Digestive Disease Department; Otto von Guarig Clinical University; Magdeburg Germany
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Siavoshi F, Saniee P. Vacuoles of Candida yeast as a specialized niche for Helicobacter pylori. World J Gastroenterol 2014; 20:5263-5273. [PMID: 24833856 PMCID: PMC4017041 DOI: 10.3748/wjg.v20.i18.5263] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 01/09/2014] [Accepted: 02/26/2014] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori (H. pylori) are resistant to hostile gastric environments and antibiotic therapy, reflecting the possibility that they are protected by an ecological niche, such as inside the vacuoles of human epithelial and immune cells. Candida yeast may also provide such an alternative niche, as fluorescently labeled H. pylori were observed as fast-moving and viable bacterium-like bodies inside the vacuoles of gastric, oral, vaginal and foodborne Candida yeasts. In addition, H. pylori-specific genes and proteins were detected in samples extracted from these yeasts. The H. pylori present within these yeasts produce peroxiredoxin and thiol peroxidase, providing the ability to detoxify oxygen metabolites formed in immune cells. Furthermore, these bacteria produce urease and VacA, two virulence determinants of H. pylori that influence phago-lysosome fusion and bacterial survival in macrophages. Microscopic observations of H. pylori cells in new generations of yeasts along with amplification of H. pylori-specific genes from consecutive generations indicate that new yeasts can inherit the intracellular H. pylori as part of their vacuolar content. Accordingly, it is proposed that yeast vacuoles serve as a sophisticated niche that protects H. pylori against the environmental stresses and provides essential nutrients, including ergosterol, for its growth and multiplication. This intracellular establishment inside the yeast vacuole likely occurred long ago, leading to the adaptation of H. pylori to persist in phagocytic cells. The presence of these bacteria within yeasts, including foodborne yeasts, along with the vertical transmission of yeasts from mother to neonate, provide explanations for the persistence and propagation of H. pylori in the human population. This Topic Highlight reviews and discusses recent evidence regarding the evolutionary adaptation of H. pylori to thrive in host cell vacuoles.
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Flahou B, De Baere T, Chiers K, Pasmans F, Haesebrouck F, Ducatelle R. Gastric Infection with Kazachstania heterogenica influences the outcome of a Helicobacter suis infection in Mongolian gerbils. Helicobacter 2010; 15:67-75. [PMID: 20302592 DOI: 10.1111/j.1523-5378.2009.00736.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
BACKGROUND The Mongolian gerbil model is often used to investigate the interactions between different gastric Helicobacter species and the gastric tissue. A preliminary screening of a gerbil population intended for use in Helicobacter suis infection studies revealed a natural yeast infection in the stomach of these animals. After identification, we have investigated the effect of the gastric yeast infection on the outcome of an experimental H. suis infection in Mongolian gerbils. MATERIALS AND METHODS Yeast cells were isolated from the stomachs of Mongolian gerbils. Identification was done by Internally Transcribed rRNA Spacer 2 Region PCR fragment length analysis. To investigate a possible pathologic role of this yeast, Mongolian gerbils were infected experimentally with this yeast. Co-infection with the newly isolated H. suis was performed to investigate possible interactions between both micro-organisms. RESULTS Kazachstania heterogenica was found colonizing the stomach of Mongolian gerbils, mainly in the antrum. Few pathologic changes were seen in the stomachs of infected animals. Experimental co-infection of gerbils with this yeast and the newly isolated H. suis showed a significant increase in inflammation in animals infected with both micro-organisms compared to animals infected only with H. suis. CONCLUSIONS K. heterogenica colonizes the stomach of Mongolian gerbils in exactly the same regions as gastric Helicobacter species. The uncontrolled presence of this yeast in the gerbil stomach can lead to an overestimation of the inflammation caused by Helicobacter in this animal model.
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Affiliation(s)
- Bram Flahou
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
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