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β-N-acetylglucosaminidase (NagZ), a cytosolic glucosaminidase, plays a pivotal role in peptidoglycan recycling. Previous research demonstrated that NagZ knockout significantly eradicated AmpC-dependent β-lactam resistance in Enterobacter cloacae. However, NagZ’s role in the virulence of E. cloacae remains unclear. Our study, incorporating data on mouse and Galleria mellonella larval mortality rates, inflammation markers, and histopathological examinations, revealed a substantial reduction in the virulence of E. cloacae following NagZ knockout. Transcriptome sequencing uncovered differential gene expression between NagZ knockout and wild-type strains, particularly in nucleotide metabolism pathways. Further investigation demonstrated that NagZ deletion led to a significant increase in cyclic diguanosine monophosphate (c-di-GMP) levels. Additionally, transcriptome sequencing and RT-qPCR confirmed significant differences in the expression of ECL_03795, a gene with an unknown function but speculated to be involved in c-di-GMP metabolism due to its EAL domain known for phosphodiesterase activity. Interestingly, in ECL_03795 knockout strains, a notable reduction in the virulence was observed, and virulence was rescued upon complementation with ECL_03795. Consequently, our study suggests that NagZ’s function on virulence is partially mediated through the ECL_03795→c-di-GMP pathway, providing insight into the development of novel therapies and strongly supporting the interest in creating highly efficient NagZ inhibitors.

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Raising prices of organic fertilizers, environmental relation of their usage and need for global foodstuff, placed a topic of universal interest in cultivation of legume plants for human nutrients and soil fertility supplementation. Three rates of N fertilizer were studied in the field: 0, 20 and 40 kg N/ha. Three bacterial strains were identified and inoculated in the experiment: Enterobacter asburiae (E. asburiae), Klebsiella quasipneumoniae (K. quasipneumoniae) and Enterobacter cloacae (E. cloacae). The soil samples were taken before and after experiment for chemical attributes analysis. The effect of N2 fertilizer and 3 bacterial strains was on soil chemical properties, yield components and yield of peanut plant. The results of present study showed that application of different N2 fertilizer rates was a little influence on the N2-fixing ability of rhizosphere bacteria, but high effect was significant at the peanut nodule number. In the 3 N fertilizer rates and 3 bacteria, which only had N2 fertilizer rate of 40 kg N/ha and E. asburiae significantly raised the maximum yield component and yield of peanut, while there was the lowest yield component and yield of peanut was observed in N fertilizer rate application of 0 kg N/ha and E. cloacae inoculation. The differences in rhizosphere bacterium strains between different N fertilizer rates was better than that caused by the nitrogen fertilizer amount. This could be due to the substantial improvement in soil chemical attributes at different soils, especially in, pH, OM and total N, as these significantly impacted the soil structure. [ABSTRACT FROM AUTHOR]

ABSTRACT Enterobacter cloacae is an emerging pathogen isolated in healthcare-associated infections. A major virulence factor of this bacterium is the type VI secretion system (T6SS). The genome of E. cloacae harbors two T6SS gene clusters (T6SS-1 and T6SS-2), and the functional characterization of both systems showed that these two T6SSs are not expressed under the same conditions. Here, we report that the major histone-like protein HU positively regulates the expression of both T6SSs and, therefore, the function that each T6SS exerts in E. cloacae. Single deletions of the genes encoding the HU subunits (hupA and hupB) decreased mRNA levels of both T6SS. In contrast, the hupA hupB double mutant dramatically affected the T6SS expression, diminishing its transcription. The direct binding of HU to the promoter regions of T6SS-1 and T6SS-2 was confirmed by electrophoretic mobility shift assay. In addition, single and double mutations in the hup genes affected the ability of inter-bacterial killing, biofilm formation, adherence to epithelial cells, and intestinal colonization, but these phenotypes were restored when such mutants were trans-complemented. Our data broaden our understanding of the regulation of HU-mediated T6SS in these pathogenic bacteria.IMPORTANCET6SS is a nanomachine that functions as a weapon of bacterial destruction crucial for successful colonization in a specific niche. Enterobacter cloacae expresses two T6SSs required for bacterial competition, adherence, biofilm formation, and intestinal colonization. Expression of T6SS genes in pathogenic bacteria is controlled by multiple regulatory systems, including two-component systems, global regulators, and nucleoid proteins. Here, we reported that the HU nucleoid protein directly activates both T6SSs in E. cloacae, affecting the T6SS-related phenotypes. Our data describe HU as a new regulator involved in the transcriptional regulation of T6SS and its impact on E. cloacae pathogenesis.

β-N-acetylglucosaminidase (NagZ), a cytosolic glucosaminidase, plays a pivotal role in peptidoglycan recycling. Previous research demonstrated that NagZ knockout significantly eradicated AmpC-dependent β-lactam resistance in Enterobacter cloacae . However, NagZ's role in the virulence of E. cloacae remains unclear. Our study, incorporating data on mouse and Galleria mellonella larval mortality rates, inflammation markers, and histopathological examinations, revealed a substantial reduction in the virulence of E. cloacae following NagZ knockout. Transcriptome sequencing uncovered differential gene expression between NagZ knockout and wild-type strains, particularly in nucleotide metabolism pathways. Further investigation demonstrated that NagZ deletion led to a significant increase in cyclic diguanosine monophosphate (c-di-GMP) levels. Additionally, transcriptome sequencing and RT-qPCR confirmed significant differences in the expression of ECL_03795, a gene with an unknown function but speculated to be involved in c-di-GMP metabolism due to its EAL domain known for phosphodiesterase activity. Interestingly, in ECL_03795 knockout strains, a notable reduction in the virulence was observed, and virulence was rescued upon complementation with ECL_03795. Consequently, our study suggests that NagZ's function on virulence is partially mediated through the ECL_03795→c-di-GMP pathway, providing insight into the development of novel therapies and strongly supporting the interest in creating highly efficient NagZ inhibitors.

Introduction: Carbapenemase-producing Gram-negative bacilli are a worldwide problem, which represent a health concern because most of their resistance mechanisms are encoded by plasmids and therefore easily transmissible in hospital settings. Many methods have been proposed to detect such resistance, but screening is still challenging. Recently, the modified carbapenem inactivation method has shown promising results; however, more studies need to be performed. Hence, this study aimed to evaluate the performance of the mCIM in carbapenem-resistant Enterobacteriaceae and non-fermenting Gram-negative bacilli isolates. Materials and methods: From a microbial collection with molecular characterization of carbapenemase genes previously conducted, 100 Gram-negative bacilli isolates were selected: fifty-two non-carbapenemase-producing and 48 carbapene- mase-producing isolates. The mCIM was performed according to the CLSI guidelines, and to assess the performance of the method, sensitivity and specifi- city were calculated. Results: The sensitivity of the mCIM observed in this study was 96% (46/48), and the specificity was 96,2% (50/52). Most of the Gram-negative bacilli carrying a carbapenemase gene were mCIM-positive. Moreover, in carbapenem-resistant isolates that do not produce a carbapenemase (En- terobacteriaceae and non-fermenters), the results of the mCIM were negative. Conclusion: Overall, the mCIM provides a good alternative for the screening of carbapenemase-producing Gram-negative bacilli. Our findings highlight that mCIM is a sensitive and specific method to assess carbapenemase production in non-fermenting Gram-negative bacilli and Enterobacteriaceae such as Enterobacter cloacae. [ABSTRACT FROM AUTHOR]

The emergence of pathogenic bacteria with β-lactam antibiotics-resistant profile has threatened the continued use of such antibiotics in the future. This research was conducted to investigate the antimicrobial activity of green tea ethanol extract (GTE) and its ability to improve the antibacterial action of several β-lactam antibiotics against Enterobacter cloacae clinical isolates. The simplicia of green tea was extracted by sonication for 30 minutes using 50% ethanol solvent, and the total phenolic content of the GTE was subsequently determined. Next, the GTE used in testing against two clinical isolates of E. cloacae was obtained from the Pathology Laboratory of Wahidin Sudiro Husodo Hospital in Makassar. The sensitivity of bacteria to GTE was confirmed using the agar diffusion method, the Vitek® rapid method, and the double-disk synergistic test. Antibacterial activity of antibiotics, GTE, and combination of antibiotics with GTE were then tested against clinical isolates of E. cloacae using the checkerboard microdilution assay. The results showed that GTE contained 51.64 ± 0.21 % measured as gallic acid equivalent and 37.95 + 5.17 % Epigallocatechin gallate (EGCG). The confirmatory test results indicated that one clinical isolate of E. cloacae (code 13/04) was resistant to amoxicillin-clavulanate but did not produce an extended-spectrum β-lactamase (ESBL). Another clinical E. cloacae isolate (code 275B/06) was indicated to produce ESBL and demonstrated to yield resistance to amoxicillin-clavulanate and cefotaxime. The minimum inhibitory concentration of GTE against the two clinical isolates of E. cloacae was >8000 ppm (8 mg/ml). In conclusion, GTE could not increase the antibacterial activity of amoxicillin and cefotaxime, but it was sufficient to improve the activity of imipenem against the tested isolates of E. cloacae.

Background: Colorectal cancer (CRC) is a gastrointestinal disease linked with GIT microbial dysbiosis. The present study has targeted the comparative analysis of virulent factor FadA from gut-associated bacteria of CRC patients ( F. nucleatum ) and healthy individuals ( E. cloacae ). Methods: For this purpose, FadA protein sequences of fifteen strains of F. nucleatum and four strains of E. cloacae , were retrieved from the UniProt database. These sequences were analysed through VirulentPred, PSLpred, ProtParam, PFP-FunDSeqE, PROTEUS Structure Prediction Server, SWISS-MODEL, SAVES validation server, MEME suite 5.5.0, CAVER Web tool, Webserver VaxinPAD, HPEPDOCK and HDOCK servers. Results: FadA protein from F. nucleatum was found to exhibit significant differences as compared to E. nucleatum i.e. it exhibited helical configuration, cytoplasmic, periplasmic, outer-membrane and extracellular localisation, 2D structure comprising of 70-96% helix, 0% beta-sheet, 4-30% coils and 17-20 signal peptide residues, hydrophilicity, strongly acidic character and smaller number of antigenic epitopes. In contrast, FadA protein from E. nucleatum was found to have globular 3D configuration, cytoplasmic localisation, 2D structure (30-56% helix, 12-21% beta-sheet, 33-50% coils and 43 signal peptide residues), highly hydrophobic, slightly acidic and more number of antigenic epitopes. Docking analyses of virulent factors revealed their high binding affinities with previously reported inhibitory peptide and FAD-approved drug COX2. Conclusion: The wide range of differences not only provided us the reason for the role of FadA protein as a virulent factor in F. nucleatum but also might help us in designing virulent FadA protein inhibiting strategies including peptide-based vaccine adjuvants and drugs designing, modification of tunnels and catalytic pockets to reduce substrate binding and FAD approved drugs selection. Inhibition of this virulent factor in CRC patients' gut bacteria might result in oncogenesis regression and reduced death rate., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

The genotypic characterization of some bacterial pathogens that were incriminated in disease outbreaks among Haffara seabream "Rhabdosargus haffara" and marbled spinefoot "Siganus rivulatus" was investigated in full through the current study. A total of 250 fish samples (125 of each species) were collected along the Red Sea coasts of Hurghada City, Egypt. Fish samples were inspected for clinical signs, post-mortem changes, and bacteriological examination. The investigated fishes displayed septicemic signs and external skin lesions characteristic for streptococcosis and tenacibaculosis. Enterococcus spp., Streptococcus spp., and Flavobacterium spp. were isolated from moribund fishes using selective media. These isolates were phenotypically and genetically identified and characterized. The identities of bacterial isolates were confirmed as Enterococcus fecalis, Streptococcus iniae, Enterobacter cloacae, and Tenacibaculum maritimum based on sequencing the 16S rRNA gene. Enterococcus fecalis was the most common pathogen isolated from S. rivulatus and R. haffara and accounted for 46.8% and 47.8% of the total isolates, respectively. Accordingly, the present study proved that Enterocoocus spp., Streptococcus spp., and T. maritimum are important pathogenic bacteria incriminated in wild fish outbreaks in the Red Sea in Egypt. These findings proved the importance of regular and permanent bacteriological examination of wild fish to overcome fish mortalities, which lead to economic losses. Finally, sequencing and phylogenetic relationship techniques proved their usefulness as an ideal assay to develop a reliable, accurate, and rapid detection method for bacterial pathogens in the aquatic environment. [ABSTRACT FROM AUTHOR]

Copyright of Experimed is the property of Experimed and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Infections caused by carbapenemase‐producing Enterobacteriaceae (CPE) are an emerging threat in both solid organ and stem cell transplant recipients. Invasive CPE infections in transplant recipients are associated with a high mortality, often due to limited therapeutic options and antibacterial toxicities. One of the most therapeutically challenging group of CPE are the metallo‐β‐lactamase (MBL)‐producing Gram‐negative bacteria, which are now found worldwide, and often need treatment with older, highly toxic antimicrobial regimens. Newer β‐lactamase inhibitors such as avibactam have well‐established activity against certain carbapenemases such as Klebsiella pneumoniae carbapenemases (KPC), but have no activity against MBL‐producing organisms. Conversely, aztreonam has activity against MBL‐producing organisms but is often inactivated by other co‐existing β‐lactamases. Here, we report four cases of invasive MBL‐CPE infections in transplant recipients caused by IMP‐4‐producing Enterobacter cloacae who were successfully treated with a new, mechanism‐driven antimicrobial combination of ceftazidime/avibactam with aztreonam. This novel antimicrobial combination offers a useful treatment option for high‐risk patients with CPE infection, with reduced drug interactions and toxicity. [ABSTRACT FROM AUTHOR]

Enterobacter cloacae is an emerging pathogen isolated in healthcare-associated infections. A major virulence factor of this bacterium is the type VI secretion system (T6SS). The genome of E. cloacae harbors two T6SS gene clusters (T6SS-1 and T6SS-2), and the functional characterization of both systems showed that these two T6SSs are not expressed under the same conditions. Here, we report that the major histone-like protein HU positively regulates the expression of both T6SSs and, therefore, the function that each T6SS exerts in E. cloacae . Single deletions of the genes encoding the HU subunits ( hupA and hupB ) decreased mRNA levels of both T6SS. In contrast, the hupA hupB double mutant dramatically affected the T6SS expression, diminishing its transcription. The direct binding of HU to the promoter regions of T6SS-1 and T6SS-2 was confirmed by electrophoretic mobility shift assay. In addition, single and double mutations in the hup genes affected the ability of inter-bacterial killing, biofilm formation, adherence to epithelial cells, and intestinal colonization, but these phenotypes were restored when such mutants were trans -complemented. Our data broaden our understanding of the regulation of HU-mediated T6SS in these pathogenic bacteria., Importance: T6SS is a nanomachine that functions as a weapon of bacterial destruction crucial for successful colonization in a specific niche. Enterobacter cloacae expresses two T6SSs required for bacterial competition, adherence, biofilm formation, and intestinal colonization. Expression of T6SS genes in pathogenic bacteria is controlled by multiple regulatory systems, including two-component systems, global regulators, and nucleoid proteins. Here, we reported that the HU nucleoid protein directly activates both T6SSs in E. cloacae , affecting the T6SS-related phenotypes. Our data describe HU as a new regulator involved in the transcriptional regulation of T6SS and its impact on E. cloacae pathogenesis., Competing Interests: The authors declare no conflict of interest.

The study tested the hypothesis that harboring high levels of histo-blood group antigen-expressing Enerobactero cloacae is a risk factor for norovirus diarrhea. The fecal E. cloacae abundance in diarrheic norovirus positive (DNP), non-diarrheic norovirus negative (NDNN), diarrhea norovirus negative (DNN), and non-diarrhea norovirus positive (NDNP) infants was determined by qPCR, and the risk of norovirus diarrhea was assessed by logistical regression. DNP infants contained significantly higher counts of E. cloacae than NDNN and DNN infants, p = .0294, and 0.0001, respectively. The risk of norovirus diarrhea was significantly high in infants with higher counts of E. cloacae than those with lower counts, p = .009. Harboring higher counts of E. cloacae is a risk factor for norovirus diarrhea.

Wildlife has recently been pinpointed as one of the drivers of dissemination of genes conferring resistances to clinically important antimicrobials. The presence of both extended-spectrum beta-lactamase- (ESBL) and carbapenemase-encoding genes has notably been reported in wild birds, that can act as sentinels of antimicrobial resistance (AMR) contamination but also as long-distance spreaders in case of migratory birds. Here, 424 wild birds brought to a rescue center in France were sampled over a 6-month period. These birds encompassed 62 different sedentary or migratory species. A further 16 wild mammals present in the center were also investigated. No carbapenemase-producer was found, but we identified a surprisingly high proportion (24.1%) of ESBL-positive isolates. A total of 144 non-duplicate isolates were collected, including Escherichia coli (n = 88), Enterobacter cloacae (n = 51), and Citrobacter freundii (n = 5), of which 123 carried the blaCTX–M–9 gene. PFGE, phylogroup, and MLST revealed the presence of a limited number of ESBL-positive clones circulating in these animals, all presenting multiple associated resistances. Next-generation sequencing on a subset of isolates, followed by Southern blot hybridization, showed the wide dissemination of an IncHI2/ST1 plasmid carrying the blaCTX–M–9, blaSHV–12 and mcr-9 genes. In all, our results undoubtedly reflect cross transmissions of ESC-resistance (ESC-R) Enterobacteriaceae within the rescue center – similarly to nosocomial spreads observed at hospital, rather than the true bacterial flora of birds. We also showed that the spread of ESC-R in this rescue center did not only rely on clonal but also on a highly successful plasmidic transmission. Since most animals are intended to get back to nature after a few days or weeks, this is obviously an issue with regard to ESBL dissemination in natural environments.

Background and AimsIrritable bowel syndrome (IBS) and depression have high tendencies of comorbidity. In particular, diarrhea-predominant IBS (IBS-D) and depression exhibit similar fecal microbiota signatures, yet little is known about their pathogenic mechanism. Here, we propose that the differences in structure and composition of IBS-D and depression gut microbiota give rise to different downstream functions, which lead to distinct clinical phenotypes via host metabolism and further influence the interaction of brain–gut axis.MethodsWe performed multiomics study, including fecal metagenome-wide sequencing and serum metabolomics profiling in 65 individuals with IBS-D (n=22), depression (n=15), comorbid patients (n=13), and healthy controls (n=15). We analyzed functional genes contributed by the primary genus and evaluated their correlations with clinical indices and host metabolites.ResultsMetagenomic analysis revealed 26 clusters of orthologous groups of protein (COG) categories consisting of a total of 4,631 functional genes. Trehalose and maltose hydrolase (COG1554) and fucose permease (COG0738) were the most relevant and enriched functional genes in the IBS-D patients; urease accessory proteins UreE (COG2371) was that in the depression patients. Context based genome annotation suggest that an alteration of Escherichia coli and Enterobacter cloacae in IBS-D and depression respectively may be responsible for the enrichment described above. Correlation with host metabolites, such as maltotriose and isomaltose in carbohydrate metabolism and anandamide in neuroactive metabolism, drew further connections between these findings.ConclusionsThese changes led us to propose a connection between genomic signatures and clinical differences observed in IBS-D and depression. Our findings provide further insights into the involvement of gut microbiota in diseases related to brain–gut disorder.

Enterobacter cloacae has emerged as an opportunistic pathogen in healthcare-associated infections. Analysis of the genomic sequences of several E. cloacae strains revealed the presence of genes that code for expression of at least one type VI secretion system (T6SS). Here, we report that E. cloacae strain ATCC 13047 codes for two functional T6SS named T6SS-1 and T6SS-2. T6SS-1 and T6SS-2 were preferentially expressed in tryptic soy broth and tissue culture medium (DMEM), respectively. Mutants in T6SS-1-associated genes clpV1 and hcp1 significantly affected their ability of inter- and intra-bacterial killing indicating that T6SS-1 is required for bacterial competition. In addition, the Hcp effector protein was detected in supernatants of E. cloacae cultures and a functional T6SS-1 was required for the secretion of this protein. A clpV2 mutant was impaired in both biofilm formation and adherence to epithelial cells, supporting the notion that these phenotypes are T6SS-2 dependent. In vivo data strongly suggest that both T6SSs are required for intestinal colonization because single and double mutants in clpV1 and clpV2 genes were defective in gut colonization in mice. We conclude that the two T6SSs are involved in the pathogenesis scheme of E. cloacae with specialized functions in the interaction with other bacteria and with host cells.

Species of the Enterobacter cloacae complex (ECC) represent an increasing cause of hospital-acquired infections and commonly exhibit multiple antibiotic resistances. In order to identify genes that may play a role in its ability to colonize the host, we used the transposon-sequencing (Tn-seq) approach. To this end, a high-density random transposon insertion library was obtained from E. cloacae subsp. cloacae ATCC 13047, which was used to analyze the fitness of ca. 300,000 mutants in Galleria mellonella colonization model. Following massively parallel sequencing, we identified 624 genes that seemed essential for the optimal growth and/or the fitness within the host. Moreover, 63 genes where mutations resulted in positive selection were found, while 576 genes potentially involved in the in vivo fitness were observed. These findings pointed out the role of some transcriptional regulators, type VI secretion system, and surface-associated proteins in the in vivo fitness of E. cloacae ATCC 13047. We then selected eight genes based on their high positive or negative fold changes (FCs) and tested the corresponding deletion mutants for their virulence and ability to cope with stresses. Thereby, we showed that ECL_02247 (encoding the NAD-dependent epimerase/dehydratase) and ECL_04444 (coding for a surface antigen-like protein) may correspond to new virulence factors, and that the regulator ECL_00056 was involved in in vivo fitness. In addition, bacterial cells lacking the flagellum-specific ATP synthase FliI (ECL_03223) and the hypothetical protein ECL_01421 were affected for mobility and resistance to H2O2, respectively. All these results yield valuable information regarding genes important for infection process and stress response of E. cloacae ATCC 13047 and participate to a better understanding of the opportunistic traits in this bacterial pathogen.

Enterobacter cloacae is the most common pathogenic species of the genus Enterobacter, identified in hospitalized and enfeebled patients as the etiologic agent of many infections and considered as a significant bacterial pathogen in recent years. E. Cloacae are typical gram negative opportunistic forms of bacteria that cause illness after another infection or injury has influenced the host immune system and are related with nosocomial infections. The infection may be caused by GIT, UTI or cross contamination of the blood. The present study focused on the existence of the main curli biogenesis gene (csgA) and the role of pH as an environmental factor in the gene expression (csgA) for curli biogenesis. In this study, urine samples from 75 patients.In Baghdad city clinically diagnosed with urinary tract infection,for gram staining, Api20System and gene expression (csgA) gene in Standardized pH7 and acid pH4 RT-PCR was performed with specific primers. Conventional gram staining techniques, agricultural methods and System API 20E showed good results for E. Cloacae. For the 75 patients, 10 (13.3%) the findings find the highest gene expression fold values for the (csgA)gene in pH7 while the lowest fold value for (csgA) at acid pH4 (0.1577) thus the modify conditions growth such as pH of bacteria E. Cloacae triggers gene expression changes for biogenesis process. the findings of rpoB gene expression, which was used as a control gene, indicated that this gene was good as a housekeeping gene. [ABSTRACT FROM AUTHOR]

Wildlife has recently been pinpointed as one of the drivers of dissemination of genes conferring resistances to clinically important antimicrobials. The presence of both extended-spectrum beta-lactamase- (ESBL) and carbapenemase-encoding genes has notably been reported in wild birds, that can act as sentinels of antimicrobial resistance (AMR) contamination but also as long-distance spreaders in case of migratory birds. Here, 424 wild birds brought to a rescue center in France were sampled over a 6-month period. These birds encompassed 62 different sedentary or migratory species. A further 16 wild mammals present in the center were also investigated. No carbapenemase-producer was found, but we identified a surprisingly high proportion (24.1%) of ESBL-positive isolates. A total of 144 non-duplicate isolates were collected, including Escherichia coli (n = 88), Enterobacter cloacae (n = 51), and Citrobacter freundii (n = 5), of which 123 carried the bla CTX–M–9 gene. PFGE, phylogroup, and MLST revealed the presence of a limited number of ESBL-positive clones circulating in these animals, all presenting multiple associated resistances. Next-generation sequencing on a subset of isolates, followed by Southern blot hybridization, showed the wide dissemination of an IncHI2/ST1 plasmid carrying the bla CTX–M–9, bla SHV–12 and mcr-9 genes. In all, our results undoubtedly reflect cross transmissions of ESC-resistance (ESC-R) Enterobacteriaceae within the rescue center – similarly to nosocomial spreads observed at hospital, rather than the true bacterial flora of birds. We also showed that the spread of ESC-R in this rescue center did not only rely on clonal but also on a highly successful plasmidic transmission. Since most animals are intended to get back to nature after a few days or weeks, this is obviously an issue with regard to ESBL dissemination in natural environments. [ABSTRACT FROM AUTHOR]

Background and Aims: Irritable bowel syndrome (IBS) and depression have high tendencies of comorbidity. In particular, diarrhea-predominant IBS (IBS-D) and depression exhibit similar fecal microbiota signatures, yet little is known about their pathogenic mechanism. Here, we propose that the differences in structure and composition of IBS-D and depression gut microbiota give rise to different downstream functions, which lead to distinct clinical phenotypes via host metabolism and further influence the interaction of brain–gut axis. Methods: We performed multiomics study, including fecal metagenome-wide sequencing and serum metabolomics profiling in 65 individuals with IBS-D (n=22), depression (n=15), comorbid patients (n=13), and healthy controls (n=15). We analyzed functional genes contributed by the primary genus and evaluated their correlations with clinical indices and host metabolites. Results: Metagenomic analysis revealed 26 clusters of orthologous groups of protein (COG) categories consisting of a total of 4,631 functional genes. Trehalose and maltose hydrolase (COG1554) and fucose permease (COG0738) were the most relevant and enriched functional genes in the IBS-D patients; urease accessory proteins UreE (COG2371) was that in the depression patients. Context based genome annotation suggest that an alteration of Escherichia coli and Enterobacter cloacae in IBS-D and depression respectively may be responsible for the enrichment described above. Correlation with host metabolites, such as maltotriose and isomaltose in carbohydrate metabolism and anandamide in neuroactive metabolism, drew further connections between these findings. Conclusions: These changes led us to propose a connection between genomic signatures and clinical differences observed in IBS-D and depression. Our findings provide further insights into the involvement of gut microbiota in diseases related to brain–gut disorder. [ABSTRACT FROM AUTHOR]

Enterobacter cloacae has emerged as an opportunistic pathogen in healthcare-associated infections. Analysis of the genomic sequences of several E. cloacae strains revealed the presence of genes that code for expression of at least one type VI secretion system (T6SS). Here, we report that E. cloacae strain ATCC 13047 codes for two functional T6SS named T6SS-1 and T6SS-2. T6SS-1 and T6SS-2 were preferentially expressed in tryptic soy broth and tissue culture medium (DMEM), respectively. Mutants in T6SS-1-associated genes clpV1 and hcp1 significantly affected their ability of inter- and intra-bacterial killing indicating that T6SS-1 is required for bacterial competition. In addition, the Hcp effector protein was detected in supernatants of E. cloacae cultures and a functional T6SS-1 was required for the secretion of this protein. A clpV2 mutant was impaired in both biofilm formation and adherence to epithelial cells, supporting the notion that these phenotypes are T6SS-2 dependent. In vivo data strongly suggest that both T6SSs are required for intestinal colonization because single and double mutants in clpV1 and clpV2 genes were defective in gut colonization in mice. We conclude that the two T6SSs are involved in the pathogenesis scheme of E. cloacae with specialized functions in the interaction with other bacteria and with host cells. [ABSTRACT FROM AUTHOR]

Species of the Enterobacter cloacae complex (ECC) represent an increasing cause of hospital-acquired infections and commonly exhibit multiple antibiotic resistances. In order to identify genes that may play a role in its ability to colonize the host, we used the transposon-sequencing (Tn-seq) approach. To this end, a high-density random transposon insertion library was obtained from E. cloacae subsp. cloacae ATCC 13047, which was used to analyze the fitness of ca. 300,000 mutants in Galleria mellonella colonization model. Following massively parallel sequencing, we identified 624 genes that seemed essential for the optimal growth and/or the fitness within the host. Moreover, 63 genes where mutations resulted in positive selection were found, while 576 genes potentially involved in the in vivo fitness were observed. These findings pointed out the role of some transcriptional regulators, type VI secretion system, and surface-associated proteins in the in vivo fitness of E. cloacae ATCC 13047. We then selected eight genes based on their high positive or negative fold changes (FCs) and tested the corresponding deletion mutants for their virulence and ability to cope with stresses. Thereby, we showed that ECL_02247 (encoding the NAD-dependent epimerase/dehydratase) and ECL_04444 (coding for a surface antigen-like protein) may correspond to new virulence factors, and that the regulator ECL_00056 was involved in in vivo fitness. In addition, bacterial cells lacking the flagellum-specific ATP synthase FliI (ECL_03223) and the hypothetical protein ECL_01421 were affected for mobility and resistance to H2O2, respectively. All these results yield valuable information regarding genes important for infection process and stress response of E. cloacae ATCC 13047 and participate to a better understanding of the opportunistic traits in this bacterial pathogen. [ABSTRACT FROM AUTHOR]

Chronic infections caused by gram negative bacteria are the mains reasons to have morbidity and death in patients, despite using high doses of antibiotics applied to cure diseases producing by them. This study was designed to identify the role of flagella in biofilm formation Ten pure strains were collected from our lab. Morphological variation and motility assays led us to study two strains in detail. They were characterized biochemically, physiologically and genetically. Biofilm formation analysis was performed using test tube assay, congo red assay and liquid-interface coverslip assay. In order to disrupt flagella of studied strains, blending was induced for 5, 10 and 15 minutes followed by centrifugation and observing motility using motility test. Biofilm quantification of wild type (parental) and blended strains was done using test tube and liquid interface coverslip assays. 16S rRNA sequencing identified strains as Pseudomonas aeroginosa and Enterobacter cloacae. Significant biofilm formation (p>0.05) by was observed after 72 and 18 hours using test tube and liquid-interface coverslip assays respectively. Flagellar disruption showed that 15 minutes blending caused significant reduction in both strains, hence demonstrated that flagellar mediated motility could be a potent strategy to stabilize aggregate and invest resources for biofilm formation in P. aeruginosa and E. cloacae. [ABSTRACT FROM AUTHOR]

One of the most important macronutrients to plants is phosphorus, which increases the biological activities in plants. Phosphorus is found as insoluble and unavailable form for plant. Some microbes of the soil can transform insoluble phosphate shape to a more suitable shape for plants' requirements. The current study used some microorganisms as bacteria and fungus that had the ability to convert phosphorus. Different phosphate microorganisms have been isolated, screened, identified; and the intrinsic antibiotic resistance was tested. One hundred bacterial isolates were isolated from Curcuma, Ocimum and rhizospheres of Eruca plants and tested for phosphate solubilization. The results showed nine bacterial isolates (R1B2, R2W22, R3B28, R4B31, R5C33, R6B34, R7 C35, R8 B40, and C15) out of 100 investigated bacterial isolates, which had a potential of phosphate solubilization ability based on Pikovasky (PVK) and National Botantial Research Institute Phosphate (NBRIP). The media was based on clear halo zone, and the nine isolates of the bacteria were determined using biochemical (API 20) test. Based on the results, the identified isolates of bacteria were: Enterobacter cloacae (R1B2, R2W22, R3B28, R4B31, R5C33, R6B34, R6 C35, R7 C35 and R8 B40), Klebsiella pneumonia (C15), Bacillus cereus (R2W22) and Bacillus megaterium (R3B28). We found eight selected bacteria (R1B2, R2W22, R3B28, R4B31, R5C33, R6B34, R7C35 and R8B40 and C15) which were confirmed by 16S rRNA sequence. These sequences were submitted to the NCBI GeneBank under accession number MK064178 for E. cloacae R1B2, (MK064181) for E. cloacae R4B31, (MK064182) for E. cloacae R5C33 (MK064183) for E. cloacae R6B34, (MK064184) for E. cloacae R7C35, (MK064185) for E. cloacae B40R8, MK064179 for B. cereus R2W22 and MK064180 for B. megaterium R3B28. Intrinsic antibiotic resistance test was carried out for 8 phosphate solubilizing bacteria (R5C33, R7C35, R2W22, R8B40, R3B28, and C15) using 9 antibiotics. The obtained data revealed that B. cereus (R2W22), E. cloacae (R5C33, R7C35, and R6B34), were resistant against six antibiotics. While E. cloacae (R8B40 and R1B2) was resistance against eight antibiotics. B. megaterium (R3B28) had resistance for three antibiotics. Seven isolates of fungi were isolated from soil samples and screened for phosphate solubilization. The data showed Aspergillus niger (LA) had high phosphate solubilization and identified based on 18S rRNA sequencing. The sequence data were submitted to Gene Bank. Isolates of bacteria and fungi could be used as potent bio-fertilizer for phosphate. [ABSTRACT FROM AUTHOR]

Co-doping is one of the most facile and efficient strategies for boosting the photocatalytic performance of g-C _3 N _4 . Herein, a series of Ti and O co-doped g-C _3 N _4 (Ti/OCN) composites with excellent photocatalytic inactivation activity of Enterobacter cloacae ( E. cloacae ) were successfully synthesized by simple calcination of urea/formic acid/TiCl _4 precursor. The obtained Ti/OCN-3 possessed the optimal photocatalytic capability with complete inactivation of 6.20 log CFU·ml ^−1 E. cloacae under 60 min of visible light irradiation. The improved photocatalytic disinfection performance was probably attributed to the synergistic effect of Ti and O co-doping, which led to an extended visible light response and accelerated charge transport efficiency. Furthermore, scavenger trapping and electron spin resonance (ESR) experiments revealed that ·O _2 ^− , h ^+ and ·OH were responsible for the enhanced inactivation activity. Overall, this research provided a promising strategy for fabricating g-C _3 N _4 -based catalysts to efficiently deal with the hazards of pathogenic microorganisms.

Carbapenem-resistant Enterobacteriaceae (CRE) has been considered a serious global threat, but carbapenem resistance remains relatively uncommon in E. cloacae, especially in China. The aim of this study was to characterize carbapenem-resistant E. cloacae (CR-ECL) isolates from 2012 to 2016 in Southwest China. Our study revealed that 20 (15.2%) of the 132 CR-ECL isolates obtained from patients were identified as NDM-1, with most isolates carrying the IncFIIA plasmids. Notably, we initially observed that the E. cloacae strain co-harbored NDM-1 and IMP-8 carbapenemases simultaneously. Analysis of the genetic environment of these two genes has revealed that the highly conserved regions (blaNDM-1-bleMBL-trpF-tat) are associated with the dissemination of NDM-1, while IS26, intI1, and tniC could be involved in the spread of IMP-8. Molecular epidemiology studies showed the nosocomial outbreak caused by NDM-1-producing E. cloacae ST88. Transferring from another hospital and previous carbapenem exposure were identified as independent risk factors for the acquisition of NDM-1-producing E. cloacae. These findings emphasize the need for intensive surveillance and precautions to monitor the further spread of NDM-1 in China.

In this study, Enterobacter cloacae bacterium was isolated from curd and its antibacterial potential against the pathogen Plesiomonas shigelloides was evaluated using the freshwater ornamental fish Kenyi cichlid (Maylandia lombardoi). Among the bacterial isolates, E. cloacae exhibited tolerance to acidic pH 2 and demonstrated the highest antibacterial activity against P. shigelloides in various in vitro assays. Dietary supplementation of E. cloacae with prebiotic supplement 2% mannan oligosaccharide improved the growth performance and reduced the toxic metabolites such as nitrite in culture tank water of Kenyi cichlid. In vivo application of E. cloacae with mannan oligosaccharide significantly elevated (p < 0.05) white blood cell counts (88.47 ± 2.15 103 mm−3) and respiratory burst activity (0.243 ± 0.007) of Kenyi cichlid when challenged with P. shigelloides. Intestinal morphology of Kenyi cichlid fish treated with probiotic and prebiotic combinations showed improved intestinal architectures. The present findings confirm that the isolated bacterium E. cloacae is a potential probiotic and can be used effectively to prevent infection of P. shigelloides in freshwater ornamental fish culture. [ABSTRACT FROM AUTHOR]

Carbapenem-resistant Enterobacteriaceae (CRE) has been considered a serious global threat, but carbapenem resistance remains relatively uncommon in E. cloacae, especially in China. The aim of this study was to characterize carbapenem-resistant E. cloacae (CR-ECL) isolates from 2012 to 2016 in Southwest China. Our study revealed that 20 (15.2%) of the 132 CR-ECL isolates obtained from patients were identified as NDM-1, with most isolates carrying the IncFIIA plasmids. Notably, we initially observed that the E. cloacae strain co-harbored NDM-1 and IMP-8 carbapenemases simultaneously. Analysis of the genetic environment of these two genes has revealed that the highly conserved regions (blaNDM-1-bleMBL-trpF-tat) are associated with the dissemination of NDM-1, while IS26, intI1, and tniC could be involved in the spread of IMP-8. Molecular epidemiology studies showed the nosocomial outbreak caused by NDM-1-producing E. cloacae ST88. Transferring from another hospital and previous carbapenem exposure were identified as independent risk factors for the acquisition of NDM-1-producing E. cloacae. These findings emphasize the need for intensive surveillance and precautions to monitor the further spread of NDM-1 in China. [ABSTRACT FROM AUTHOR]

Objective To establish a domestic database of Enterobacteria cloacae (E. cloacae) , and improve the identification efficiency using peptide mass fingerprinting. Methods Peptide mass fingerprinting was used for the identification and subtyping of E. cloacae . Eighty-seven strains, identified based on hsp60 genotyping, were used to construct and evaluate a new reference database. Results Compared with the original reference database, the identification efficiency and accuracy of the new reference database was greatly improved at the species level. The first super reference database for E. cloacae identification was also constructed and evaluated. Based on the super reference database and the main spectra projection dendrogram, E. cloacae strains were divided into two clades. Conclusion Peptide mass fingerprinting is a powerful method to identify and subtype E. cloacae , and the use of this method will allow us to obtain more information to understand the heterogeneous organism E. cloacae . [ABSTRACT FROM AUTHOR]

To grapple with multidrug resistant bacterial infections, implementations of antibacterial nanomedicines have gained prime attention of the researchers across the globe. Nowadays, zinc oxide (ZnO) at nano‐scale has emerged as a promising antibacterial therapeutic agent. Keeping this in view, ZnO nanostructures (ZnO‐NS) have been synthesised through reduction by P. aphylla aqueous extract without the utilisation of any acid or base. Structural examinations via scanning electron microscopy (SEM) and X‐ray diffraction have revealed pure phase morphology with highly homogenised average particle size of 18 nm. SEM findings were further supplemented by transmission electron microscopy examinations. The characteristic Zn–O peak has been observed around 363 nm using ultra‐violet–visible spectroscopy. Fourier‐transform infrared spectroscopy examination has also confirmed the formation of ZnO‐NS through detection of Zn–O bond vibration frequencies. To check the superior antibacterial activity of ZnO‐NS, the authors' team has performed disc diffusion assay and colony forming unit testing against multidrug resistant E. coli, S. marcescens and E. cloacae. Furthermore, protein kinase inhibition assay and cytotoxicity examinations have revealed that green fabricated ZnO‐NS are non‐hazardous, economical, environmental friendly and possess tremendous potential to treat lethal infections caused by multidrug resistant pathogens. [ABSTRACT FROM AUTHOR]

Background: Carbapenems resistance in Enterobacter spp. has increased in the last decade, few studies, however, described the mechanisms of resistance in this bacterium. This study evaluated clonality and mechanisms of carbapenems resistance in clinical isolates of Enterobacter spp. identified in three hospitals in Brazil (Hospital A, B and C) over 7-year. Methods: Antibiotics sensitivity, pulsed-field gel electrophoresis (PFGE), PCR for carbapenemase and efflux pump genes were performed for all carbapenems-resistant isolates. Outer-membrane protein (OMP) was evaluated based on PFGE profile. Results: A total of 130 isolates of Enterobacter spp were analyzed, 44/105 (41, 9%) E. aerogenes and 8/25 (32,0%) E. cloacae were resistant to carbapenems. All isolates were susceptible to fosfomycin, polymyxin B and tigecycline. KPC was present in 88.6% of E. aerogenes and in all E. cloacae resistant to carbapenems. The carbapenems-resistant E. aerogenes identified in hospital A belonged to six clones, however, a predominant clone was identified in this hospital over the study period. There is a predominant clone in Hospital B and Hospital C as well. The mechanisms of resistance to carbapenems differ among subtypes. Most of the isolates co-harbored blaKPC, blaTEM and /or blaCTX associated with decreased or lost of 35-36KDa and or 39 KDa OMP. The efflux pump AcrAB-TolC gene was only identified in carbapenems-resistant E. cloacae. Conclusions: There was a predominant clone in each hospital suggesting that cross-transmission of carbapenemsresistant Enterobacter spp. was frequent. The isolates presented multiple mechanisms of resistance to carbapenems including OMP alteration. [ABSTRACT FROM AUTHOR]

Although biofilm formation is a very effective mechanism to sustain bacterial life, it is detrimental in medical and industrial sectors. Current strategies to control biofilm proliferation are typically based on biocides, which exhibit a negative environmental impact. In the search for environmentally friendly solutions, nanotechnology opens the possibility to control the interaction between biological systems and colonized surfaces by introducing nanostructured coatings that have the potential to affect bacterial adhesion by modifying surface properties at the same scale. In this work, we present a study on the performance of graphene and hexagonal boron nitride coatings (h-BN) to reduce biofilm formation. In contraposition to planktonic state, we focused on evaluating the efficiency of graphene and h-BN at the irreversible stage of biofilm formation, where most of the biocide solutions have a poor performance. A wild Enterobacter cloacae strain was isolated, from fouling found in a natural environment, and used in these experiments. According to our results, graphene and h-BN coatings modify surface energy and electrostatic interactions with biological systems. This nanoscale modification determines a significant reduction in biofilm formation at its irreversible stage. No bactericidal effects were found, suggesting both coatings offer a biocompatible solution for biofilm and fouling control in a wide range of applications.

• Enterobacter cloacae clinical isolates were exposed to cefepime, meropenem and ceftazidime-avibactam • Increases in minimum inhibitory concentrations were greater for cefepime and meropenem than for ceftazidime-avibactam • Alterations in AmpC, OmpC and efflux proteins were observed in only 4/13 mutants • Isolates had alterations in genes not commonly associated with β-lactam resistance Five Enterobacter cloacae isolates were subjected to 10-day serial passage in broth microdilution with cefepime, meropenem, or ceftazidime-avibactam to evaluate increases in minimum inhibitory concentration (MIC) and resistance mechanisms after exposure. Post-exposure isolates displaying >2-fold changes from the parent isolate were analysed alongside the parent isolate. Increases in MIC were 4- to 256-fold (median: 16-fold) after cefepime exposure, 16- to 128-fold (64-fold) after meropenem, and 2- to 32-fold (8-fold) after ceftazidime-avibactam. Post-exposure isolates had diverse mechanisms, identified using a combination of short and long whole-genome sequencing. All agents selected for AmpC alterations in one isolate set. OmpC and TetA/AcrR regulator alterations were noted in meropenem and ceftazidime-avibactam post-exposure isolates of the same set. Other mutations in AmpC were noted when isolates were exposed to cefepime or ceftazidime-avibactam. A premature stop codon in the cell division inhibitor protein, MioC was observed when one parent isolate was exposed to any of the agents, indicating a cell persistence mechanism. Mutations in less common transporter systems and protein synthesis components were also noted. All agents showed cross-resistance to other β-lactams and resistance mechanisms were diverse, with some not usually associated with β-lactam resistance in Enterobacterales. This initial evaluation indicates that cefepime and meropenem select for isolates with higher MIC values compared to ceftazidime-avibactam. Further studies evaluating these findings should be performed for other species for which the primary β-lactam resistance mechanism is not gene acquisition. These studies should evaluate these observations in vivo to assess their translation into patient treatment policies. [ABSTRACT FROM AUTHOR]

The overuse of N fertilizers has caused serious environmental problems (e.g., soil acidification, excessive N 2 O in the air, and groundwater contamination) and poses a serious threat to human health. Improving N fertilizer utilization efficiency and plant uptake is an alternative for N fertilizers overuses. Enterobacter cloacae is an opportunistic pathogen, also used as plant growth-promoting rhizobacteria (PGPR), has been widely presented in the fields of bioremediation and bioprotection. Here we developed a new N fixation-release model by combining biochar with E. cloacae. The efficiency of the model was evaluated using a greenhouse pot experiment with maize (Zea mays L.) as the test crop. The results showed that biochar combined with E. cloacae significantly increased the N content. The application of biochar combined with E. cloacae increased total N in soil by 33% compared with that of N fertilizers application. The N-uptake and utilization efficiency (NUE) in plant was increased 17.03% and 14.18%, respectively. The activities of urease, dehydrogenase and fluorescein diacetate hydrolase (FDA) was improved, the catalase (CAT) activity decreased. Analysis of the microbial community diversity revealed the abundance of Proteobacteria, Actinobacteria, Firmicutes, and Gemmatimonadetes were significantly improved. The mechanism under the model is that E. cloacae acted as N-fixation by capturing N 2 from air. Biochar served as carrier, supporting better living environment for E. cloacae , also as adsorbent adsorbing N from fertilizer and from fixed N by E. cloacae , the adsorption in turn slower the N release. Altogether, the model promotes N utilization by plants, improves the soil environment, and reduces N pollution. • N is fixed and slowly released to plants through a green sustainability model. • N fixation release model promotes N uptake by plants and improves N utilization. • Soil enzyme and microorganisms were positive effect via a N fixation-release model. • Controlling the slow release of N can reduce environmental pollution due to N loss. [ABSTRACT FROM AUTHOR]

Enterobacter cloacaewas originally isolated from soil irrigated with wastewater on the basis of its ability to grow with linear alkylbenzene sulfonate (LAS) as the sole source for carbon and energy. The isolated bacterium was grown in batch cultures using a 2-chlorobenzoic acid (2-CBA)-containing minimal salt medium (MSM). 2-CBA was found to be the sole source for carbon and energy. 2-CBA inhibited the growth rate with a maximum concentration of 10 mM, after which no growth occurred. The Haldane model was used to predict the specific growth rate concentration data. 2-CBA degradation by starvedE. cloacacells was faster than that of nonstarved cells. The maximum growth rates on 2-CBA (2 mM) for starved and nonstarved cells reached only 0.34 and 0.28 h−1, respectively. Glucose, lactose, sucrose, maltose, succinic acid, and mannitol as additional carbon sources at a fixed concentration (0.2%) caused the degradation rate of 2-CBA to proceed faster at ranges between 1.08- and 1.5-fold higher than that of the control. In contrast, using only fructose and sorbitol as the carbon sources showed catabolic repression of the degradation activity of 2-CBA byE. cloacacells, although their cell mass was improved. All nitrogen sources supplied caused an increase in cell mass, whereas only lysine, alanine, glutamine, casein, and yeast extract caused a decrease in the degradation rate of 2-CBA, with a range between 12% and 28%. The activity of C120 could be detected in a crude extract ofE. cloacaecells, indicating that the chloroaromatic ring fission occurs through theorthopathways, not through themetapathways. The data showed that different initial cell (inocula) densities did not affect the induction time for 2-CBA degradation. However, doubling the initial cell densities reduced the time required for reaching the complete degradation. 2-CBA degradation was optimally achieved at a 37°C incubation temperature and a pH of 7.5. [ABSTRACT FROM AUTHOR]

Abstract: Enterobacter cloacae was isolated from the gut of the wood feeding termite, Heterotermes indicola, and a 2.25-kb fragment conferring cellulase activity was cloned in Escherichia coli. The cloned fragment contained a 1083-bp ORF which could encode a protein belonging to glycosyl hydrolase family 8. The cellulase gene was introduced into Zymomonas mobilis strain Microbial Type Culture Collection centre (MTCC) on a plasmid and 0.134filter paper activity unit (FPU)/ml units of cellulase activity was observed with the recombinant bacterium. Using carboxymethyl cellulose and 4% NaOH pretreated bagasse as substrates, the recombinant strain produced 5.5% and 4% (V/V) ethanol respectively, which was threefold higher than the amount obtained with the original E. cloacae isolate. The recombinant Z. mobilis strain could be improved further by simultaneous expression of cellulase cocktails before utilizing it for industrial level ethanol production. [ABSTRACT FROM AUTHOR]

Abstract: Fertilizer costs are a major component of corn production. The use of biofertilizers may be one way of reducing production costs. In this study we present isolation and identification of three plant growth promoting bacteria that were identified as Enterobacter cloacae (CR1), Pseudomonas putida (CR7) and Stenotrophomonas maltophilia (CR3). All bacterial strains produced IAA in the presence of 100mgl−1 of tryptophan and antifungal metabolites to several soilborne pathogens. S. maltophilia and E. cloacae had broad spectrum activity against most Fusarium species. The only strain that was positive for nitrogen fixation was E. cloacae and it, and P. putida, were also positive for phosphate solubilization. These bacteria and the corn isolate Sphingobacterium canadense CR11, and known plant growth promoting bacterium Burkholderia phytofirmans E24 were used to inoculate corn seed to examine growth promotion of two lines of corn, varieties 39D82 and 39M27 under greenhouse conditions. When grown in sterilized sand varieties 39M27 and 39D82 showed significant increases in total dry weights of root and shoot of 10–20% and 13–28% and 17–32% and 21–31% respectively. Plants of the two varieties grown in soil collected from a corn field had respective increases in dry weights of root and shoot of 10–30% and 12–35% and 11–19% and 10–18%. In sand, a bacterial mixture was highly effective whereas in soil individual bacteria namely P. putida CR7 and E. cloacae CR1 gave the best results with 39M27 and 39D82 respectively. These isolates and another corn isolate, Azospirillum zeae N7, were tested in a sandy soil with a 55 and 110kgha−1 of nitrogen fertility at the Delhi research Station of Agriculture and Agri-Food Canada over two years. Although out of seven bacterial treatments, no treatment provided a statistically significant yield increase over control plots but S. canadense CR11 and A. zeae N7 provided statistically significant yield increase as compared to other bacteria. The 110kg rate of nitrogen provided significant yield increase compared to the 55kg rate in both years. [Copyright &y& Elsevier]

It is well known that gut microbiota imbalance can promote the development of metabolic disease. Enterobacter cloacae (E. cloacae) is a kind of opportunistic pathogen in the intestine. Therefore, we hypothesized that E. cloacae accelerated the development of metabolic disease. To answer this question, we used E. cloacae to induce disease in guinea pigs. We used H&E staining to detect the pathological changes of liver and aorta and used Oil Red O staining to evaluate the lipid accumulation in the liver. And that we used a kit to detect AST content and used Western blot to detect protein levels in the liver. We found that E. cloacae could induce liver pathological changes and lipid accumulation as well as aortic wall pathological changes in guinea pigs. And E. cloacae increased the liver index to 5.94% and the serum AST level to 41.93 U/L. Importantly, E. cloacae activated liver high mobility group protein (HMGB1)/toll-like receptor 4 (TLR4)/myeloiddifferentiationfactor88 (MYD88)/nuclear factor-kappa B (NF-κB) signal and sterol regulatory element-binding protein 1c (SREBP-1c) and inhibited AMP-activated protein kinase (AMPK). We conclude that E. cloacae promote nonalcoholic fatty liver disease (NAFLD) by inducing inflammation and lipid accumulation, and E. cloacae also promote atherosclerosis. These findings are important for study on the pathogenesis and drug screening of NAFLD and atherosclerosis. [Display omitted] • E. cloacae aggravated NAFLD by activating HMGB1/TLR4/MyD88/NF-κB signal. • E. cloacae aggravated NAFLD by activating SREBP-1c and inhibiting AMPK. • E. cloacae accelerated the development of atherosclerosis. [ABSTRACT FROM AUTHOR]