Beta-lactam resistant isolates
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ABSTRACT:
PROVIDER: PRJNA543210 | ENA |
REPOSITORIES: ENA
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Project description:P. aeruginosa isolates were grown in LB broth media. The bacterial media was then digested after incubation for 24 hours and analyzed to identify bacterial proteins related to beta-lactam drug resistance. Bottom-up proteomics analysis was performed.
2018-11-04 | PXD010588 | Pride
Project description:Pseudomonas aeruginosa is a predominant pathogen in chronic lung infections in individuals with cystic fibrosis (CF). Epidemic strains of P. aeruginosa, such as the Liverpool Epidemic Strain (LES), are capable of transferring between CF patients and have been associated with increased hospital visits and antibiotic treatments. We used label-free quantitative proteomics to compare the laboratory strain PAO1, beta-lactam resistant isolate LESB58, and beta-lactam susceptible isolate LESlike1 and their responses to three beta-lactams (aztreonam, carbenicillin, piperacillin), the aminoglycoside tobramycin, and hydrogen peroxide. Across all samples, we identified 3019 proteins with a minimum of two peptides. We found that LESB58 showed a large response to treatment with the beta-lactam carbenicillin, with 644 proteins significantly increased in abundance and 590 proteins significantly decreased in abundance (Students t-test, p≤0.05, FDR=0.05, S0=1). Proteomic characterization of an additional beta-lactam resistant isolate, LES431, exposed to carbenicillin showed that this response was shared by both isolates. Part of the response to carbenicillin in LESB58 included an increase in abundance in proteins involved in cell wall synthesis and division.
2023-08-23 | PXD034831 | Pride
Project description:Non-typeable Haemophilus influenzae (NTHi) is a common acute otitis media pathogen, with an incidence that is increased by previous antibiotic treatment. NTHi is also an emerging causative agent of other chronic infections in humans, some linked to morbidity, and all of which impose substantial treatment costs. In this study we explore the possibility that antibiotic exposure may stimulate biofilm formation by NTHi bacteria. We discovered that sub-inhibitory concentrations of beta-lactam antibiotic (i.e., amounts that partially inhibit bacterial growth) stimulated the biofilm-forming ability of NTHi strains, an effect that was strain and antibiotic dependent. When exposed to sub-inhibitory concentrations of beta-lactam antibiotics NTHi strains produced tightly packed biofilms with decreased numbers of culturable bacteria but increased biomass. The ratio of protein per unit weight of biofilm decreased as a result of antibiotic exposure. Antibiotic-stimulated biofilms had altered ultrastructure, and genes involved in glycogen production and transporter function were up regulated in response to antibiotic exposure. Down-regulated genes were linked to multiple metabolic processes but not those involved in stress response. Antibiotic-stimulated biofilm bacteria were more resistant to a lethal dose (10M-BM-5g/mL) of cefuroxime. Our results suggest that beta-lactam antibiotic exposure may act as a signaling molecule that promotes transformation into the biofilm phenotype. Loss of viable bacteria, increase in biofilm biomass and decreased protein production coupled with a concomitant up-regulation of genes involved with glycogen production might result in a biofilm of sessile, metabolically inactive bacteria sustained by stored glycogen. These biofilms may protect surviving bacteria from subsequent antibiotic challenges, and act as a reservoir of viable bacteria once antibiotic exposure has ended. 12 samples
2014-06-04 | E-GEOD-58213 | biostudies-arrayexpress
Project description:Whole genome sequencing of 20 clinical isolates resistant to beta-lactam antibiotics
| PRJEB4760 | ENA
Project description:Three types of phenotypic expression of ß-lactam resistance has been reported in MRSA: heterogeneous-, homogeneous-, and Eagle-type resistance. Heterogeneous to homogeneous (hetero-to-homo) conversion of ß-lactam resistance is postulated to be caused by a chromosomal mutation (chr*) together with mecA-gene expression. The Eagle-type resistance is a special pattern of chr* expression in the pre-MRSA strain N315 under the strong mecI-gene mediated repression of mecA gene transcription. Here, for the identification of chr*, experiments were conducted using an in-vitro derived homogeneously imipenem-resistant MRSA strain N315∆IPH5 (∆IPH5). The strain was selected with imipenem 8 mg/L from the heterogeneously imipenem-resistant MRSA strain N315∆IP (∆IP). The whole genome sequencing of ∆IPH5 revealed the presence of a unique mutation in the rpoB gene, rpoB(N967I), causing the amino-acid (AA) substitution of Asp by Ile at the 967th AA position of the RNA polymerase ß subunit. The effect of the mutation on the phenotypic change was confirmed by constructing and studying the phenotype of the strains H5rpoB(I967N), a ∆IPH5-derived strain cured of the rpoB mutation, and N315rpoB(N967I), a N315-derived strain introduced with the mutated rpoB gene. H5rpoB(I967N) regained the hetero-MRSA phenotype, and the mutant strain N315rpoB(N967I) showed an Eagle-type phenotype similar to that of N315h4. Furthermore, subsequent whole genome sequencing revealed that N315h4 also had a missense mutation in the rpoB gene rpoB(R644H). The rpoB mutations caused decreased autolysis, prolonged doubling-time, and tolerance to bactericidal concentrations of methicillin. We concluded that the certain rpoB mutations are chr* responsible for the hetero-to-homo phenotypic conversion of MRSA.
2013-08-27 | GSE42218 | GEO
Project description:Carbapenem-resistant Acinetobacter baumannii (CRAb) is an urgent public health threat, according to the CDC. This pathogen has few treatment options and causes severe nosocomial infections with >50% fatality rate. Although previous studies have examined the proteome of CRAb, there have been no focused analyses of dynamic changes to β-lactamase expression that may occur due to drug exposure. Here, we present our initial proteomic study of variation in β-lactamase expression that occurs in CRAb with different β-lactam antibiotics. Briefly, drug resistance to Ab (ATCC 19606) was induced by the administration of various classes of β-lactam antibiotics, and the cell-free supernatant was isolated, concentrated, separated by SDS-PAGE, digested with trypsin, and identified by label-free LC-MS-based quantitative proteomics. Thirteen proteins were identified and evaluated using a 1789 sequence database of Ab β-lactamases from UniProt, the majority of which were Class C β-lactamases (≥80%). Importantly, different antibiotics, even those of the same class (e.g. penicillin and amoxicillin), induced non-equivalent responses comprising various isoforms of Class C and D serine-β-lactamases, resulting in unique resistomes. These results open the door to a new approach of analyzing and studying the problem of multi-drug resistance in bacteria that rely strongly on β-lactamase expression.
2023-07-20 | PXD042336 | Pride
Project description:Non-typeable Haemophilus influenzae (NTHi) is a common acute otitis media pathogen, with an incidence that is increased by previous antibiotic treatment. NTHi is also an emerging causative agent of other chronic infections in humans, some linked to morbidity, and all of which impose substantial treatment costs. In this study we explore the possibility that antibiotic exposure may stimulate biofilm formation by NTHi bacteria. We discovered that sub-inhibitory concentrations of beta-lactam antibiotic (i.e., amounts that partially inhibit bacterial growth) stimulated the biofilm-forming ability of NTHi strains, an effect that was strain and antibiotic dependent. When exposed to sub-inhibitory concentrations of beta-lactam antibiotics NTHi strains produced tightly packed biofilms with decreased numbers of culturable bacteria but increased biomass. The ratio of protein per unit weight of biofilm decreased as a result of antibiotic exposure. Antibiotic-stimulated biofilms had altered ultrastructure, and genes involved in glycogen production and transporter function were up regulated in response to antibiotic exposure. Down-regulated genes were linked to multiple metabolic processes but not those involved in stress response. Antibiotic-stimulated biofilm bacteria were more resistant to a lethal dose (10µg/mL) of cefuroxime. Our results suggest that beta-lactam antibiotic exposure may act as a signaling molecule that promotes transformation into the biofilm phenotype. Loss of viable bacteria, increase in biofilm biomass and decreased protein production coupled with a concomitant up-regulation of genes involved with glycogen production might result in a biofilm of sessile, metabolically inactive bacteria sustained by stored glycogen. These biofilms may protect surviving bacteria from subsequent antibiotic challenges, and act as a reservoir of viable bacteria once antibiotic exposure has ended.
2014-06-04 | GSE58213 | GEO
Project description:Mutations in the gdpP gene are a clinically relevant mechanism for β-lactam resistance in methicillin resistant Staphylococcus aureus lacking mec determinants
| PRJEB41705 | ENA
Project description:Resistant isolates of methicillin-resistant Staphylococcus aureus (MRSA) often cause infections with high rates of mortality. Antimicrobial peptides are source of molecules for new antimi-crobials development, such as melittin, a fraction of venom from Apis mellifera bee. The aims of this work were to evaluate antibacterial and antibiofilm activity of melittin and its association with oxa-cillin (meltoxa) on MRSA isolates and to investigate mechanisms of action on MRSA by using proteomic analysis.
2023-05-25 | MSV000092035 | MassIVE
Project description:beta-lactam resistant isolate from reservoir water in Singapore
| PRJEB41995 | ENA