The waaL gene mutation compromised the inhabitation of Enterobacter sp. Ag1 in the mosquito gut environment
Abstract Background The mosquito gut harbors a variety of bacteria that are dynamically associated with mosquitoes in various contexts. However, little is known about bacterial factors that affect bacterial inhabitation in the gut microbial community. Enterobacter sp. Ag1 is a predominant Gram negat...
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| Format: | Article |
| Language: | English |
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BMC
2015-08-01
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| Series: | Parasites & Vectors |
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| Online Access: | https://doi.org/10.1186/s13071-015-1049-1 |
| _version_ | 1797811870716919808 |
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| author | Dong Pei Jinjin Jiang Wanqin Yu Phanidhar Kukutla Alejandro Uentillie Jiannong Xu |
| author_facet | Dong Pei Jinjin Jiang Wanqin Yu Phanidhar Kukutla Alejandro Uentillie Jiannong Xu |
| author_sort | Dong Pei |
| collection | DOAJ |
| description | Abstract Background The mosquito gut harbors a variety of bacteria that are dynamically associated with mosquitoes in various contexts. However, little is known about bacterial factors that affect bacterial inhabitation in the gut microbial community. Enterobacter sp. Ag1 is a predominant Gram negative bacterium in the mosquito midgut. Methods In a mutant library that was generated using transposon Tn5-mediated mutagenesis, a mutant was identified, in which the gene waaL was disrupted by the Tn5 insertion. The waaL encodes O antigen ligase, which is required for the attachment of O antigen to the outer core oligosaccharide of the lipopolysaccharide (LPS). Results The waaL − mutation caused the O antigen repeat missing in the LPS. The normal LPS structure was restored when the mutant was complemented with a plasmid containing waaL gene. The waaL − mutation did not affect bacterial proliferation in LB culture, the mutant cells grew at a rate the same as the wildtype (wt) cells. However, when waaL − strain were co-cultured with the wt strain or complemented strain, the mutant cells proliferated with a slower rate, indicating that the mutants were less competitive than wt cells in a community setting. Similarly, in a co-feeding assay, when fluorescently tagged wt strain and waaL − strain were orally co-introduced into the gut of Anopheles stephensi mosquitoes, the mutant cells were less prevalent in both sugar-fed and blood-fed guts. The data suggest that the mutation compromised the bacterial inhabitation in the gut community. Besides, the mutant was more sensitive to oxidative stress, demonstrated by lower survival rate upon exposure to 20 mM H2O2. Conclusion Lack of the O antigen structure in LPS of Enterobacter compromised the effective growth in co-culture and co-feeding assays. In addition, O-antigen was involved in protection against oxidative stress. The findings suggest that intact LPS is crucial for the bacteria to steadily stay in the gut microbial community. |
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| institution | Directory Open Access Journal |
| issn | 1756-3305 |
| language | English |
| last_indexed | 2024-03-13T07:29:08Z |
| publishDate | 2015-08-01 |
| publisher | BMC |
| record_format | Article |
| series | Parasites & Vectors |
| spelling | doaj.art-1cc26f77388c44899dd67728797c9ec62023-06-04T11:10:31ZengBMCParasites & Vectors1756-33052015-08-018111010.1186/s13071-015-1049-1The waaL gene mutation compromised the inhabitation of Enterobacter sp. Ag1 in the mosquito gut environmentDong Pei0Jinjin Jiang1Wanqin Yu2Phanidhar Kukutla3Alejandro Uentillie4Jiannong Xu5Biology Department, New Mexico State UniversityBiology Department, New Mexico State UniversityBiology Department, New Mexico State UniversityBiology Department, New Mexico State UniversityBiology Department, New Mexico State UniversityBiology Department, New Mexico State UniversityAbstract Background The mosquito gut harbors a variety of bacteria that are dynamically associated with mosquitoes in various contexts. However, little is known about bacterial factors that affect bacterial inhabitation in the gut microbial community. Enterobacter sp. Ag1 is a predominant Gram negative bacterium in the mosquito midgut. Methods In a mutant library that was generated using transposon Tn5-mediated mutagenesis, a mutant was identified, in which the gene waaL was disrupted by the Tn5 insertion. The waaL encodes O antigen ligase, which is required for the attachment of O antigen to the outer core oligosaccharide of the lipopolysaccharide (LPS). Results The waaL − mutation caused the O antigen repeat missing in the LPS. The normal LPS structure was restored when the mutant was complemented with a plasmid containing waaL gene. The waaL − mutation did not affect bacterial proliferation in LB culture, the mutant cells grew at a rate the same as the wildtype (wt) cells. However, when waaL − strain were co-cultured with the wt strain or complemented strain, the mutant cells proliferated with a slower rate, indicating that the mutants were less competitive than wt cells in a community setting. Similarly, in a co-feeding assay, when fluorescently tagged wt strain and waaL − strain were orally co-introduced into the gut of Anopheles stephensi mosquitoes, the mutant cells were less prevalent in both sugar-fed and blood-fed guts. The data suggest that the mutation compromised the bacterial inhabitation in the gut community. Besides, the mutant was more sensitive to oxidative stress, demonstrated by lower survival rate upon exposure to 20 mM H2O2. Conclusion Lack of the O antigen structure in LPS of Enterobacter compromised the effective growth in co-culture and co-feeding assays. In addition, O-antigen was involved in protection against oxidative stress. The findings suggest that intact LPS is crucial for the bacteria to steadily stay in the gut microbial community.https://doi.org/10.1186/s13071-015-1049-1Enterobacter sp. Ag1LipopolysaccharidewaaL geneO antigen ligaseInhabitationOxidative stress |
| spellingShingle | Dong Pei Jinjin Jiang Wanqin Yu Phanidhar Kukutla Alejandro Uentillie Jiannong Xu The waaL gene mutation compromised the inhabitation of Enterobacter sp. Ag1 in the mosquito gut environment Parasites & Vectors Enterobacter sp. Ag1 Lipopolysaccharide waaL gene O antigen ligase Inhabitation Oxidative stress |
| title | The waaL gene mutation compromised the inhabitation of Enterobacter sp. Ag1 in the mosquito gut environment |
| title_full | The waaL gene mutation compromised the inhabitation of Enterobacter sp. Ag1 in the mosquito gut environment |
| title_fullStr | The waaL gene mutation compromised the inhabitation of Enterobacter sp. Ag1 in the mosquito gut environment |
| title_full_unstemmed | The waaL gene mutation compromised the inhabitation of Enterobacter sp. Ag1 in the mosquito gut environment |
| title_short | The waaL gene mutation compromised the inhabitation of Enterobacter sp. Ag1 in the mosquito gut environment |
| title_sort | waal gene mutation compromised the inhabitation of enterobacter sp ag1 in the mosquito gut environment |
| topic | Enterobacter sp. Ag1 Lipopolysaccharide waaL gene O antigen ligase Inhabitation Oxidative stress |
| url | https://doi.org/10.1186/s13071-015-1049-1 |
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