-
Cell Host & Microbe Nov 2022Gut-microbiota membership is associated with diverse neuropsychological outcomes, including substance use disorders (SUDs). Here, we use mice colonized with Citrobacter...
Gut-microbiota membership is associated with diverse neuropsychological outcomes, including substance use disorders (SUDs). Here, we use mice colonized with Citrobacter rodentium or the human γ-Proteobacteria commensal Escherichia coli HS as a model to examine the mechanistic interactions between gut microbes and host responses to cocaine. We find that cocaine exposure increases intestinal norepinephrine levels that are sensed through the bacterial adrenergic receptor QseC to promote intestinal colonization of γ-Proteobacteria. Colonized mice show enhanced host cocaine-induced behaviors. The neuroactive metabolite glycine, a bacterial nitrogen source, is depleted in the gut and cerebrospinal fluid of colonized mice. Systemic glycine repletion reversed, and γ-Proteobacteria mutated for glycine uptake did not alter the host response to cocaine. γ-Proteobacteria modulated glycine levels are linked to cocaine-induced transcriptional plasticity in the nucleus accumbens through glutamatergic transmission. The mechanism outline here could potentially be exploited to modulate reward-related brain circuits that contribute to SUDs.
Topics: Mice; Humans; Animals; Cocaine; Proteobacteria; Citrobacter rodentium; Gastrointestinal Microbiome; Bacteria; Escherichia coli; Glycine
PubMed: 36323315
DOI: 10.1016/j.chom.2022.09.014 -
Current Opinion in Microbiology Feb 2022During their co-evolution with pathogens, hosts acquired defensive health strategies that allow them to maintain their health or promote recovery when challenged with... (Review)
Review
During their co-evolution with pathogens, hosts acquired defensive health strategies that allow them to maintain their health or promote recovery when challenged with infections. The cooperative defense system is a largely unexplored branch of these evolved defense strategies. Cooperative defenses limit physiological damage and promote health without having a negative impact on a pathogen's ability to survive and replicate within the host. Here, we review recent discoveries in the new field of cooperative defenses using the model pathogens Citrobacter rodentium and Salmonella enterica. We discuss not only host-encoded but also pathogen-encoded mechanisms of cooperative defenses. Cooperative defenses remain an untapped resource in clinical medicine. With a global pandemic exacerbated by a lack of vaccine access and a worldwide rise in antibiotic resistance, the study of cooperative defenses offers an opportunity to safeguard health in the face of pathogenic infection.
Topics: Citrobacter rodentium; Enterobacteriaceae Infections; Health Promotion; Host-Pathogen Interactions; Humans; Salmonella enterica
PubMed: 34847524
DOI: 10.1016/j.mib.2021.11.003 -
Microbiology Spectrum Dec 2022With the globally prevailing carbapenemase-producing (CP) spp., polymyxin antibiotics have been reconsidered as one of the last-resort treatment options. Our study was...
With the globally prevailing carbapenemase-producing (CP) spp., polymyxin antibiotics have been reconsidered as one of the last-resort treatment options. Our study was conducted to investigate the prevalence of in species. From October to November 2021, 650 fecal samples and 215 isolates were collected from healthy individuals and infected patients, respectively. Isolates were screened for the presence of the gene by the PCR method. -carrying strains were identified by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Due to the susceptibility to colistin, spp. isolates were first induced to increase the expression of on China blue agar plates containing colistin and were then subjected to conjugation experiments. Whole-genome sequencing was performed on the Illumina NovaSeq PE150 system. The prevalence of in the genus from healthy guts and infected patients was 0.62% and 1.86%, respectively. In all -positive strains, MICs of polymyxin B were observed at ≤2 μg/mL, displaying a nonresistant phenotype. As for conjugation experiments, only one isolate successfully transferred the gene to Escherichia coli C600. Whole-genome sequencing showed that eight -positive isolates carried and genes encoding resistance to beta-lactam antibiotics, including , , , , and . We also discovered that could be located on the pKPC-CAV1321 plasmid. Our study investigated the prevalence of - in spp. in both healthy individuals and infected patients and described the carriage of on the pKPC-CAV1321 plasmid for the first time. The emergence of homologues posed a serious threat to the therapeutic efficiency of polymyxin antibiotics. Citrobacter freundii is generally regarded as an opportunistic pathogen associated with a variety of nosocomial infections. In this study, we investigated the prevalence of in spp. isolates from healthy individuals and infected patients and highlighted the importance of the rational use of antibiotics. In addition, this epidemiological investigation is the first to describe the carriage of on plasmid pKPC-CAV1321 and confirms the horizontal transfer of this plasmid. Our research may shed new light on further studies of dissemination in humans.
Topics: Humans; Anti-Bacterial Agents; beta-Lactamases; Citrobacter; Colistin; Drug Resistance, Bacterial; Escherichia coli; Microbial Sensitivity Tests; Plasmids
PubMed: 36374095
DOI: 10.1128/spectrum.01346-22 -
Future Microbiology Oct 2018Members of the genus Citrobacter are important opportunistic pathogens responsible for high mortality rate. Therefore, in this study, we aimed to develop efficient and...
AIM
Members of the genus Citrobacter are important opportunistic pathogens responsible for high mortality rate. Therefore, in this study, we aimed to develop efficient and accurate Citrobacter typing schemes for clinical detection and epidemiological surveillance.
MATERIALS & METHODS
Using genomic and experimental analyses, we located the O-antigen biosynthesis gene clusters in Citrobacter genome for the first time, and used comparative genomic analyses to reveal the specific genes in different Citrobacter serotypes.
RESULTS
Based on the specific genes in O-antigen biosynthesis gene clusters of Citrobacter, we established experimental and in silico serotyping systems for this bacterium.
CONCLUSION
Both serotyping tools are reliable, and our observations are biologically and clinically relevant for understanding and managing Citrobacter infection.
Topics: Animals; Citrobacter; Computer Simulation; Enterobacteriaceae Infections; Epidemiological Monitoring; Genome, Bacterial; Humans; Molecular Typing; O Antigens; Sequence Deletion; Serotyping; Whole Genome Sequencing
PubMed: 30099919
DOI: 10.2217/fmb-2018-0187 -
Current Opinion in Microbiology Oct 2021Citrobacter rodentium is a mouse-specific pathogen commonly used to model infection by human Enteropathogenic Escherichia coli, an important cause of infant diarrhea and... (Review)
Review
Citrobacter rodentium is a mouse-specific pathogen commonly used to model infection by human Enteropathogenic Escherichia coli, an important cause of infant diarrhea and mortality worldwide. In the early phase of infection, C. rodentium overcomes competition by the gut microbiota for successful replication. Then, the pathogen uses a type three secretion system (T3SS) to inject effector proteins into intestinal epithelial cells and induce metabolic and inflammatory conditions that promote colonization of the intestinal epithelium. C. rodentium also elicits highly coordinated innate and adaptive immune responses in the gut that regulate pathogen colonization and eradication. In this review, we highlight recent work on the regulation and function of the C. rodentium T3SS, the mechanisms employed by the pathogen to evade competition by the microbiota, and the function of the host immune response against infection.
Topics: Animals; Citrobacter rodentium; Enterobacteriaceae Infections; Enteropathogenic Escherichia coli; Immunity; Mice; Microbiota; Virulence
PubMed: 34352594
DOI: 10.1016/j.mib.2021.07.003 -
Current Opinion in Microbiology Dec 2021Citrobacter rodentium is a mouse-specific extracellular enteropathogen, commonly used as a small animal model for studying human enteropathogenic Escherichia coli... (Review)
Review
Citrobacter rodentium is a mouse-specific extracellular enteropathogen, commonly used as a small animal model for studying human enteropathogenic Escherichia coli infections. Both pathogens share a core set of virulence factors, including a type III secretion system, which enables translocation of effector proteins into infected cells to subvert host antimicrobial responses. Notably, these bacterial effectors have been reported to specifically target components of the apoptotic, necroptotic and pyroptotic signaling cascades in vivo, resulting in compromised immune cell recruitment and impaired mucosal homeostasis. Identifying the contributions of each cell death modality to bacterial control in a physiological model represents a crucial step in furthering our understanding of host-pathogen evolution and may provide insight into the host evasion strategies utilised by other enteric pathogens.
Topics: Animals; Cell Death; Citrobacter rodentium; Enterobacteriaceae Infections; Escherichia coli Infections; Mice; Type III Secretion Systems; Virulence Factors
PubMed: 34601305
DOI: 10.1016/j.mib.2021.09.005 -
Journal of Microbiological Methods Sep 2022The CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR associated proteins) system is a useful tool to edit genomes quickly and efficiently....
The CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR associated proteins) system is a useful tool to edit genomes quickly and efficiently. However, the use of CRISPR/Cas9 to edit bacterial genomes has been limited to select microbial chassis primarily used for bioproduction of high value products. Thus, expansion of CRISPR/Cas9 tools to other microbial organisms is needed. Here, our aim was to assess the suitability of CRISPR/Cas9 for genome editing of the Citrobacter freundii type strain ATCC 8090. We evaluated the commonly used two plasmid pCas/pTargetF system to enable gene deletions and insertions in C. freundii and determined editing efficiency. The CRISPR/Cas9 based method enabled high editing efficiency (~91%) for deletion of galactokinase (galk) and enabled deletion with various single guide RNA (sgRNA) sequences. To assess the ability of CRISPR/Cas9 tools to insert genes, we used the fluorescent reporter mNeonGreen, an endopeptidase (yebA), and a transcriptional regulator (xylS) and found successful insertion with high efficiency (81-100%) of each gene individually. These results strengthen and expand the use of CRISPR/Cas9 genome editing to C. freundii as an additional microbial chassis.
Topics: CRISPR-Cas Systems; Citrobacter freundii; Gene Editing; Genome, Bacterial
PubMed: 35779647
DOI: 10.1016/j.mimet.2022.106533 -
Journal of the American Veterinary... Dec 2019
Topics: Alligators and Crocodiles; Animals; Citrobacter; Dermatitis; Male; Mycobacterium avium
PubMed: 31793839
DOI: 10.2460/javma.255.12.1349 -
MSphere Dec 2021The spread of Klebsiella pneumoniae carbapenemase (KPC)-producing is a public health concern. KPC-encoding is predominantly spread by strains of a particular...
Molecular Analysis of -Harboring Plasmids: Tn Interplasmid Transposition and Tn-Carrying ColRNAI Plasmid Mobilization from Klebsiella pneumoniae to Citrobacter europaeus and Morganella morganii in a Single Patient.
The spread of Klebsiella pneumoniae carbapenemase (KPC)-producing is a public health concern. KPC-encoding is predominantly spread by strains of a particular phylogenetic lineage, clonal group 258, but can also be spread by horizontal transfer of -carrying plasmids. Here, we report the transfer of a -harboring plasmid via mobilization from K. pneumoniae to Citrobacter freundii complex and Morganella morganii strains in a single patient. We performed draft whole-genome sequencing to analyze 20 carbapenemase-producing strains (15 of K. pneumoniae, two of C. freundii complex, and three of M. morganii) and all K. pneumoniae strains using MiSeq and/or MinION isolated from a patient who was hospitalized in New York and Montreal before returning to Japan. All strains harbored -containing Tn. The 15 K. pneumoniae strains each belonged to sequence type 258 and harbored a Tn-carrying multireplicon-type plasmid, IncN and IncR (IncN+R). Three of these K. pneumoniae strains also possessed a Tn-carrying ColRNAI plasmid, suggesting that Tn underwent interplasmid transposition. Of these three ColRNAI plasmids, two and one were identical to plasmids harbored by two Citrobacter europaeus and three M. morganii strains, respectively. The Tn-carrying ColRNAI plasmids were each 23,753 bp long and incapable of conjugal transfer via their own genes alone, but they mobilized during the conjugal transfer of Tn-carrying IncN+R plasmids in K. pneumoniae. Interplasmid transposition of Tn from an IncN+R plasmid to a ColRNAI plasmid in K. pneumoniae and mobilization of Tn-carrying ColRNAI plasmids contributed to the acquisition of in and M. morganii. Plasmid transfer plays an important role in the interspecies spread of carbapenemase genes, including the Klebsiella pneumoniae carbapenemase (KPC)-coding gene, . We conducted whole-genome sequencing (WGS) analysis and transmission experiments to analyze -carrying mobile genetic elements (MGEs) between the -harboring K. pneumoniae, Citrobacter europaeus, and Morganella morganii strains isolated from a single patient. was contained within an MGE, Tn. WGS of -carrying K. pneumoniae, , and M. morganii strains isolated from one patient revealed that Tn-carrying ColRNAI plasmids were generated by plasmid-to-plasmid transfer of Tn from a multireplicon-type IncN and IncR (IncN+R) plasmid in K. pneumoniae strains. Tn-carrying ColRNAI plasmids were incapable of conjugal transfer in and M. morganii but mobilized from K. pneumoniae to a recipient Escherichia coli strain during the conjugal transfer of Tn-carrying IncN+R plasmid. Therefore, Tn-carrying ColRNAI plasmids contributed to the acquisition of in and M. morganii.
Topics: Bacterial Proteins; Citrobacter; Enterobacteriaceae Infections; Gene Transfer, Horizontal; Humans; Klebsiella Infections; Klebsiella pneumoniae; Microbial Sensitivity Tests; Morganella morganii; Plasmids; Whole Genome Sequencing; beta-Lactamases
PubMed: 34730375
DOI: 10.1128/mSphere.00850-21 -
Applied and Environmental Microbiology Apr 2022Klebsiella pneumoniae carbapenemase (KPC) producers are an emerging threat to global health, and the hospital water environment is considered an important reservoir of...
Klebsiella pneumoniae carbapenemase (KPC) producers are an emerging threat to global health, and the hospital water environment is considered an important reservoir of these life-threatening bacteria. We characterized plasmids of KPC-2-producing Citrobacter freundii and Klebsiella variicola isolates recovered from hospital sewage in Japan. Antimicrobial susceptibility testing, whole-genome sequencing analysis, bacterial conjugation, and transformation experiments were performed for both KPC-2 producers. The gene was located on the Tn transposon-related region from an IncP-6 replicon plasmid that could not be transferred via conjugation. Compared to the -encoding plasmid of the C. freundii isolate, alignment analysis of plasmids with showed that the -encoding plasmid of the K. variicola isolate was a novel IncP-6/IncF-like hybrid plasmid containing a 75,218-bp insertion sequence composed of IncF-like plasmid conjugative transfer proteins. Carbapenem-resistant transformants harboring were obtained for both isolates. However, no IncF-like insertion region was found in the K. variicola donor plasmid of the transformant, suggesting that this IncF-like region is not readily functional for plasmid conjugative transfer and is maintained depending on the host cells. The findings on the KPC-2 producers and novel genetic content emphasize the key role of hospital sewage as a potential reservoir of pathogens and its linked dissemination of through the hospital water environment. Our results indicate that continuous monitoring for environmental emergence of antimicrobial-resistant bacteria might be needed to control the spread of these infectious bacteria. Moreover, it will help elucidate both the evolution and transmission pathways of these bacteria harboring antimicrobial resistance. Antimicrobial resistance is a significant problem for global health, and the hospital environment has been recognized as a reservoir of antimicrobial resistance. Here, we provide insight into the genomic features of -harboring isolates of Citrobacter freundii and Klebsiella variicola obtained from hospital sewage in Japan. The findings of carbapenem-resistant bacteria containing this novel genetic context emphasize that hospital sewage could act as a potential reservoir of pathogens and cause the subsequent spread of via horizontal gene transfer in the hospital water environment. This indicates that serial monitoring for environmental bacteria possessing antimicrobial resistance may help us control the spread of infection and also lead to elucidating the evolution and transmission pathways of these bacteria.
Topics: Anti-Bacterial Agents; Carbapenems; Citrobacter freundii; Hospitals; Japan; Klebsiella; Plasmids; Sewage; Water
PubMed: 35380451
DOI: 10.1128/aem.00019-22