Enterobacter Aerogenes Isolates Research Articles

Evaluation of antibacterial activity of pomegranate (Punica granatum L. and Citrus lemon against urinary tract infection causing bacteria E. Coli, Enterococcus fecalis, Enterobacter aerogenes collected from various diagnostic laboratories of Khwazakhela,

E. Coli is one of the major gram-negative pathogens well known causative agent for almost all kind of UTIs, however Enterobacteriaceae such as Enterobacter aerogenes and Enterococci fecalis are responsible for UT infections. The present study was conducted to evaluate the in vitro antibacterial activity of ethanol and aqueous extract of pomegranate and lemon peels against (23 isolated stains) E. Coli, (16 isolated strains) Enterococcus faecalis and (9 isolated strain) of Enterobactor aerogenes recovered from the urine sample of patientsin Swat KPK-Pakistan. The Agar dilution and well method was applied for the antibacterial activity of pomegranate and lemon peelextracts. All of the three subject isolates were exposed to different concentrations of pomegranate and lemon peel. MIC of aqua extract of pomegranateagainst the subject isolates of E. Coli was 200 µl/mLand ethanol extract was 50 µl/mL. So the ethanol extract of pomegranate was found to be more effective as compared to the aqueous extract. On the other hand MIC of aqua extract lemon peel against the subject isolates of E. coli was100 µl/mL and ethanol extract was 25 µl/mL. So the ethanol extract of pomegranate was found to be more effective as compared to the aqueous extract. MIC of ethanol extract of pomegranate against the isolates of Enterococcus fecalis was found smaller (50 µl/mL) than that of water extract (100 µl/mL). So the ethanol extract of pomegranate was found to be more effective as compared to the aqueous extract. On the other hand. MIC of aqua lemon extract against the subject isolates of Enterococcus fecalis was 100 µl/mL and ethanol extract was 25 µl/mL. Mainly the ethanolic extract of lemon peel was more effective than the ethanolic extract of pomegranate against Enterococcus fecalis isolates. The MIC of the water and ethanolic extract of pomegranate against Enterobacter aerogenes was found 500 µl/mL and 200 µl/mL respectively. So the ethanol extract of pomegranate was found to be more effective as compared to the aqueous extract. On the other hand MIC of the ethanolic extract of lemon peel was 100 µl/mL, while the water extracts showed inhibition against the Enterobacter aerogenes isolates at the concentration of 250 µl/mL. So the ethanol extract of lemon was found to be more effective as compared to the aqueous extract.For the determination of antibacterial activity of both pomegranate and lemon extracts (in ethanol and water) method as described in Clinical and Laboratory Standard Guidelines (CLSI) was adopted. The subject isolate of E. Coli, Enterococcus fecali, and Enterobacter aerogenes were shown different sensitivities (sensitive >10mm zone inhibition or resistant <10mm zone inhibition t) for ciprofloxacin with a variable zone of inhibition.

Emergence of New Delhi metallo-β-lactamase-1 (NDM-1) producing Enterobacterales from water sources: An impending public health challenge in Adamawa-north senatorial zone, Nigeria

Background: The emergence of New Delhi metallo-beta-lactamase-1 (NDM-1) among Enterobacterales in water sources has raised a major public health concern and constitute critical threat to human health as these organisms exhibits high level of resistance to available potent antibiotics. The aim of this study is to detect the presence of NDM-1 gene among carbapenem resistant Enterobacterales (CRE) isolates from water sources.
 Methodology: A total of 256 water samples were collected from randomly selected hand-dug wells (128 samples) and river/stream (128 samples) for each of dry and rainy seasons in four out of the five local government areas (LGAs) of Adamawa-north senatorial zone, Nigeria. The water samples were filtered using membrane filtration technique and the filters introduced into appropriate bacteriologic media for bacterial growth. The bacterial isolates recovered were identified by both phenotypic and molecular protocols. Phenotypic carbapenem (imipenem) resistance was determined by disc diffusion test, blaNDM-1 gene was detected by specific polymerase chain reaction (PCR) test, and plasmid DNA was extracted and electrophoresed by standard procedure.
 Results: Of the 256 water samples analyzed for bacteria growth, 300 bacterial isolates of the order Enterobacterales were recovered. Of these, only 45 (12.6%) isolates were phenotypically resistant to carbapenem (imipenem) antibiotic and blaNDM-1 gene was detected in 30 (66.7%) of these. While blaNDM-1 gene was detected in all the isolates of Klebsiella oxytoca, Klebsiella variicola, Enterobacter aerogenes, Enterobacter hormaechei, Enterobacter asburiae, Citrobacter freundii, and Morganella morganii that were resistant to imipenem, other isolates harbored blaNDM-1 gene in varying proportion. Most of the isolates positive for blaNDM-1 also harbored R-plasmids.
 Conclusion: Emergence of carbapenem resistance mediated by NDM-1 gene in Enterobacterales isolated from water sources constitutes an emerging public health challenge with potential transmission to humans, thereby complicating the treatment of infections caused by these resistant pathogens in man. As such, the urgent need for antimicrobial surveillance and stewardship is of utmost importance.

First detection of a colistin-resistant Klebsiella aerogenes isolate from a critically ill patient with septic shock in Bulgaria.

Colistin is considered as the last-line antibiotic for the treatment of infections caused by extensively drug-resistant Gram-negative pathogens belonging to the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) group. The present study aimed to explore the colistin resistance mechanisms of a Klebsiella aerogenes (formerly Enterobacter aerogenes) isolate (Kae1177-1bg) obtained from a Bulgarian critically ill patient with septic shock in 2020. Antimicrobial susceptibility testing and whole-genome sequencing using DNA nanoball technology were performed. The resulting read pairs were used for draft genome assembly, MLST analysis and mutation screening in the pmrA/B, phoP/Q, and mgrB genes. Kae1177-1bg demonstrated high-level resistance to colistin, resistance to 3rd generation cephalosporins and susceptibility to all other antibiotics tested. In our strain a CMY-2-type class C cephalosporinase was the only β-lactamase identified. No mobile colistin resistance (mcr) genes were detected. A total of three missense variants in the genes for the two-component PmrA/PmrB system were identified. Two of them were located in the pmrB (pR57K and pN275K) and one in the pmrA gene (pL162M). The pN275K variant emerged as the most likely cause for colistin resistance because it affected a highly conservative position and was the only nonconservative amino acid substitution. In conclusion, to the best of our knowledge, this is the first documented clinical case of a high-level colistin-resistant K. aerogenes in Bulgaria and the first identification of the nonconservative amino acid substitution pN275K worldwide. Colistin-resistant Gram-negative pathogens of ESKAPE group are serious threat to public health and should be subjected to infection control stewardship practices.

Prevalence of Extended-Spectrum Beta-Lactamases Enzymes in Enterobacter Aerogenes Isolated from Urinary Tract Infections in Shahrekord City

Introduction: Enterobacteriaceae produce the Extended-Spectrum Beta-Lactamases which is considered as an important resistant mechanism of beta-lactam antibiotics. The resistance to beta-lactam antibiotics is the main problem in the bacterial infections therapy. The prevalence of these enzymes changes in different geographical areas and with time. The present study aims to explore the frequency of the extended-spectrum blaSHV, blaCTX-M, blaTEM, in Enterobacter aerogenes isolated from urinary tract infections in Shahrekord City; the mentioned genes were investigated from the phenotypic and genotypic point of view.
 Methods: In this cross-sectional descriptive study, antibacterial susceptibility patterns of 50 isolates of Enterobacter aerogenes to Cefotaxim, Ceftazidim, Cefterixon and cephalotin were tested using disk diffusion (Kirby-Buer) method. In addition, confirmatory tests for detecting ESBLs phenotypes were performed using Ceftazidim-clavulanic acid and Cefotaxim- clavulanic acid combination disks. Then, the presence of blaSHV, blaCTX-M, blaTEM, genes in the broad-spectrum beta-lactamase producing strains was assessed in the presence of specific primers.
 Results: Out of 50 isolates of Enterobacter aerogenesis investigated in this study, 32 isolates (64%) were identified to produce broad-spectrum β-lactamases in the phenotypic study of ESBLS, and the prevalence of blaCTX-M, blaTEM and blaSHV was reported as 30%, 20% and 14%, respectively. In the statistical analysis, a statistically significant correlation was observed between resistance to the antibiotic ceftriaxone and the blaCTX-M, gene (p<0.05).
 Conclusion: The present study suggests that ESBL producing Enterobacter aerogenes isolates have a high prevalence. The increase in the number of these species is often caused due to the irrational prescription of antibiotics, which requires the use of new antimicrobial agents and limiting the unnecessary use of antimicrobial agents and increasing the use of infection control tools.

Perfil de tolerancia al triclosán y detección de los genes MexA, MexC, AcrB y oqxA relacionados con la expresión de bombas de expulsión en aislados clínicos del género Enterobacter aerogenes y Enterobacter cloacae

Introducción: La resistencia a los antimicrobianos y la tolerancia a biocidas está dada por mecanismos comunes, generados por su uso en diferentes ambientes; mecanismos como la expresión de bombas de expulsión presentes en bacterias del género Enterobacter circulantes amenaza la eficacia de los antimicrobianos limitando las opciones de terapia antibiótica. Objetivos: Determinar el perfil de tolerancia al triclosán y detección de genes asociados a bombas de expulsión en aislados clínicos de Enterobacter aerogenes y Enterobacter cloacae. Materiales y Métodos: Se realizó un estudio observacional, descriptivo y de corte transversal, se determinaron perfiles de tolerancia al triclosán por microdilución, de susceptibilidad antimicrobiana, confirmación fenotípica de mecanismos de resistencia, por reacción en cadena de la polimerasa, se identificó la presencia de genes que codifican para bombas de expulsión. Resultados: El 17% correspondió a Enterobacter cloacae y el 6% Enterobacter aerogenes. El 93,7% de los aislados clínicos del género Enterobacter presentó el fenotipo de resistencia BLEE y AmpC. En el 81,3% de los aislamientos se obtuvo la presencia de al menos un gen relacionado con las expresión de bombas de expulsión, siendo frecuentes MexC y AcrB; no identificó presencia del gen oqxA. Conclusiones: La resistencia a diferentes grupos de antibióticos se identifica en especies de Enterobacter circulante, así la presencia de enzimas BLEE y AmpC, la presencia de genes relacionados con bombas de expulsión y la alta tolerancia al triclosán.

Quinolone resistance mechanisms among third-generation cephalosporin resistant isolates of Enterobacter spp. in a Bulgarian university hospital.

Background: There have been no reports in Bulgaria about quinolone resistance determinants among Enterobacter spp.Aims: To investigate plasmid and chromosomal quinolone resistance rates among 175 third-generation cephalosporin resistant Enterobacter spp. isolates (167 Enterobacter cloacae complex and eight Enterobacter aerogenes isolates) collected at a university hospital in Varna, Bulgaria, as well as to reveal their association with ESBL/AmpC production and a carriage of specific plasmid replicon types.Methods: PCR, isoelectric focusing, replicon typing, sequencing, and epidemiology typing were carried out.Results: A high level of combined third-generation cephalosporin and quinolone resistant Enterobacter spp. was found − 79.4%. The ESBL production rate was 87%, consisting mainly of CTX-M-15 among E. cloacae complex (in 76%) and CTX-M-3 among E. aerogenes (in 88%). Plasmid mediated quinolone resistance (PMQR) determinants were identified in 57% of the isolates. The most commonly detected PMQR determinants were qnrB (90%), consisting mainly of qnrB1 (in 61%), and qnrB9 (in 27%) of the isolates. Both alleles were transferred with CTX-M-15 genes; transconjugants showed HI2 replicons (for qnrB1 positive transconjugants) and were non-typeable (for qnrB9). One Enterobacter spp. isolate produced qnrB4. QnrA1, qnrS1, and aac(6ʹ)-Ib-cr were detected in single isolates only. QnrC, qnrD, qepA, and oqxAB genes were not found. QnrB was associated with CTX-M-15 production, and qnrS1 was linked to CTX-M-3. Alterations in 83 and 87 positions of gyrB in quinolone-resistance determining regions, and 80 position of parC were detected in high level quinolone resistant isolates. Among all the Enterobacter spp. isolates tested, one predominant clone A was identified (53%).Conclusion: Our data showed the necessity of more prudent use of quinolones and third-generation cephalosporins, because of the risk of promoting dissemination, and selection of multiple resistance determinants (ESBL, PMQR) among Enterobacter spp. isolates in Bulgaria.

Emergence of aph(3')-VI and accumulation of aminoglycoside modifying enzyme genes in KPC-2-possessing Enterobacter aerogenes isolates from infections and colonization in patients from Recife-PE, Brazil.

The objective of this study was to characterize genes of aminoglycoside modifying enzymes (AMEs) in colonizing and infecting isolates of E. aerogenes harboring bla KPC from patients at a public hospital in Recife-PE, Brazil. We analyzed 29 E. aerogenes clinical isolates resistant to aminoglycosides. AMEs genes were investigated by PCR and sequencing. Colonizing and infecting isolates mainly presented the genetic profiles aac(3)-IIa/aph(3')-VI or ant(2")-IIa/aph(3')-VI. This is the first report of aph(3')-VI in E. aerogenes harboring bla KPC in Brazil. The results highlight the importance in establishing rigorous methods for the surveillance of resistance genes, especially in colonized patients.

Modulation of antimicrobial resistance in clinical isolates of Enterobacter aerogenes: A strategy combining antibiotics and chemosensitisers.

The main focus of this study was to evaluate the antimicrobial susceptibility profiles of a number of human clinical isolates of Enterobacter aerogenes isolates and to explore the effects of selected chemosensitisers on reversal of the resistant phenotype of these isolates. This study design was accomplished by: (i) characterising several multidrug-resistant (MDR) E. aerogenes clinical isolates; (ii) evaluating the contribution of target gene mutations to the resistance phenotype, focusing on fluoroquinolones and chloramphenicol only; (iii) evaluating the contribution of membrane permeability and efflux to the MDR phenotype; (iv) assessing the combined action of selected antimicrobials and chemosensitisers in order to identify combinations with synergistic effects able to reduce the minimum inhibitory concentration (MIC); and (v) understanding how these combinations can modulate the permeability or efflux of these isolates. Resistance to ciprofloxacin could not be totally reversed owing to pre-existing mutations in target genes. Chloramphenicol susceptibility was efficiently restored by the addition of the selected chemosensitisers. From the modulation kinetics it was clear that phenothiazines were able to increase the accumulation of Hoechst dye. Modulation of permeability and efflux in the presence of chemosensitisers can help us to propose more appropriate chemotherapeutic combinations that can set the model to be used in the treatment of these and other MDR infections.

Antibacterial activity of <i>Terminalia glaucescens</i>, <i>Mangifera indica</i> and <i>Mitracarpus villosus</i> on carbapenem-resistant enterobacteriaceae

The root of Terminalia glaucescens , stem-bark of Mangifera indica and leaves of Mitracarpus villosus were screened for antibacterial activities against 23 carbapenem-resistant Enterobacteriaceae (CRE) isolates. The phyto-constituents of the plants were extracted by cold maceration. Disc-diffusion and broth microdilution methods were used to determine the antibacterial activity and the minimum inhibitory concentration, respectively. The sensitivity of the isolates to the methanol extracts of the plant parts was between four to eight isolates (10 – 26.5 mm) including Enterobacter aerogenes , Proteus mirabilis and Escherichia coli , with the highest activity shown by Mitracarpus villosus . An overall higher activity was however observed with the ethanol extracts of the plant parts with potency on twelve to fifteen isolates (9 – 18.5 mm) including Enterobacter aerogenes , Proteus mirabilis , Escherichia coli and Klebsiella pneumoniae . Generally for all methanol extracts, a constant MIC value 100 mg/ml was observed for the susceptible isolates except two Enterobacter aerogenes isolates with MIC of 1 mg/ml while the MIC value of the ethanol extracts ranged from ≤ 0.1 – 100 mg/ml. Ethanol extracts of stem-bark of Mangifera indica and leaves of Mitracarpus villosus exhibited considerably higher activities compared to other extracts with low MIC values. The phytochemical screening showed that the extracts contained at least five bioactive metabolites with alkaloids, tannin and flavonoids present in all. The plants used in this study show promising antibacterial activity that can be explored in the treatment of multi-drug resistant Enterobacteriaceae infections.

Evaluation of the Rapid Polymyxin NP test for detection of colistin susceptibility in Enterobacteriaceae isolated from Thai patients

Development and evaluations of the Rapid Polymyxin NP test for detection of colistin resistance in Enterobacteriaceae have been recently reported. In this study, we evaluated the performance of the test using a larger number of Enterobacteriaceae, and a larger proportion of isolates with a colistin MIC close to the breakpoint. Out of 339 isolates, the Rapid Polymyxin NP test detected colistin resistance in 13 isolates of Escherichia coli, 213 isolates of Klebsiella pneumoniae, 9 isolates of Enterobacter aerogenes, and 10 isolates of the other Enterobacteriaceae species. Sensitivity and specificity of the test for detecting colistin resistance were 100% and 95.9%, respectively. Positive predictive value and negative predictive value were 98.3% and 100%, respectively.

Porin Deficiency in Carbapenem-Resistant Enterobacter aerogenes Strains.

The more frequent reports of carbapenem-resistant Enterobacteriaceae have raised the alarm for public health. Apart from the production of carbapenemases, deficiency (decreased or loss of expression) of outer membrane proteins (OMPs) has been proposed as a potentially important mechanism of carbapenem resistance. The aim of the present study was to evaluate the contribution of the major OMPs to carbapenem resistance in Enterobacter aerogenes (CREA) isolates and also investigate the role of small RNAs (sRNAs) in inducing porin-associated permeability defects. The differential expression of OMPs was analyzed in four clinical CREA isolates. omp35 and omp36 genes were further investigated by whole-genome sequencing, induction of meropenem resistance, sRNA overexpression, OMP complementation assays, and reverse transcription-quantitative PCR. All four isolates examined were deficient in omp35 and omp36. Functional restoration of these two genes confirmed their contribution to carbapenem resistance. The meropenem induction assay further revealed that porin deficiency plays a role in carbapenem resistance under antibiotic selection pressure. Single-point mutations in omp36 leading to premature stop codons were detected in two of the isolates. Elevated expression levels of the sRNAs micF and micC were detected in the other two porin-deficient isolates, which were predicted to be potential porin regulators from whole-genome sequencing. Overexpression of micF and micC downregulated the expression of Omp35 and Omp36, respectively. Porin deficiency plays an important role in carbapenem resistance among clinical E. aerogenes isolates under regulation of the sRNAs micC and micF. Furthermore, overexpression of micC and micF had a minor to no impact on carbapenem minimum inhibitory concentrations, and thus, the regulatory mechanism is likely to be complex.

Screening, nutritional optimization and purification for phytase produced by Enterobacter aerogenes and its role in enhancement of hydrocarbons degradation and biofilm inhibition

In this study, a novel isolate of Enterobacter aerogenes isolated from contaminated soils with hydrocarbons had extracellular phytate-degrading activity. Enterobacter aerogenes isolates were identified by biochemical tests and confirmed by16S rRNA gene products (amplified size 211bp) for genotypic detection. The phytase activity was reached to maximum activity when this isolate was cultivated under the optimal conditions which consisted of using minimal salt medium containing 1%(w/v) rice bran as a sole source for carbon and 2% (w/v) yeast extract at pH 5.5 and temperature of 50°C for 48 h. The phytase had purified to homogeneity by 50% ammonium sulphate precipitation, ion exchange and gel filtration chromatography with 75.7 fold of purification and a yield of 30.35%. The purified phytase is a single peptide with approximate molecular mass of 42 kDa as assessed by SDS-PAGE. The highest degradative ability by Enterobacter aerogenes of black oil, white oil and used engine oil had observed after 72 h of incubation. Rapid degradation of black oil and used engine oil had also observed while slow degradation of white oilat all time of incubation. The purified phytase inhibited biofilm formation ability in a dose-dependent manner for all Gram-negative and Gram-positive biofilm-forming bacteria and a significant difference in cell surface hydrophobicity was observed after exposure of planktonic cells to phytase for hour. The hydrolyzing effect of phytase released by Enterobacter aerogenes for complex salts of phosphorus that are insoluble in the soil led to increase of phosphorus concentrations and enhanced the ability of Enterobacter aerogenes to degrade a specific hydrocarbon in contaminated soil so that the phytase has a promising application in bioremediation of contaminated soils with hydrocarbons.

Antibacterial Activity of Ethyl Acetate the Extract of Noni Fruit (Morinda citrifolia L.) Against Bacterial Spoilage in Fish

Noni fruit (Morinda citrifolia L.) contains compounds that have potential as antibacterial agent. Antibacterial compounds produced noni fruit (M. citrifolia L.) can inhibit bacterial growth. This study was conducted to test the antibacterial activity of ethyl acetate extract of noni fruit (M. citrifolia L.) against spoilage bacterial in fish. Pseudomonas aeruginosa, Bacillus cereus, Escherichia coli, Klebsiella oxytoca, and Enterobacter aerogenes isolates and examine antibacterial phytochemical profile. Extraction of noni compounds was done by maceration, followed by partition with ethyl acetate to obtain the soluble and insoluble ethyl acetate fraction. Previews result show that the ethyl acetate extract had very strong activity. Extraction process continued by separation and isolation used preparative thin layer chromatography method, so that obtained five isolates and mark them as A, B, C, D and E. Antibacterial activity assay performed on isolates A, B, C, D, and E with 20 and 30% concentration. The test results showed that isolates A could not be inhibit the growth of bacteria, isolates B, C, D, and E has antibacterial activity with weak to strong inhibition. Isolate B had the greatest inhibition activity against the B. cereus, whereas isolates E had the greatest inhibition activity against P. aeroginosa. MIC (Minimum Inhibitor Concentration) and MBC (Minimum Bactericidal Concentration) test result showed that MIC and MBC values could not be determined. Analysis of compounds by TLC showed that isolate B suspected contains coumarin or flavonoids compounds that have antibacterial activity.

Donor-derived infections among Chinese donation after cardiac death liver recipients

AIMTo investigate blood cultures of deceased donors and report the confirmed transmission of bacterial infection from donors to liver recipients.METHODSWe retrospectively studied the results of blood cultures among our donation after cardiac death (DCD) donors and calculated the donor-derived bacterial infection rates among liver recipients. Study participants underwent liver transplantation between January 1, 2010 and February 1, 2017. The study involved a total of 67 recipients of liver grafts from 67 DCD donors. We extracted the data of donors’ and patients’ characteristics, culture results and clinical outcomes, especially the post-transplant complications in liver recipients, from electronic medical records. We analyzed the characteristics of the donors and the corresponding liver recipients with emphasis put on donor-derived infections.RESULTSHead trauma was the most common origin of death among our 67 DCD donors (46.3%). Blood taken prior to the procurement operation was cultured for 53 of the donors, with 17 episodes of bloodstream infections developing from 13 donors. The predominant organism isolated from the blood of donors was Gram-positive bacteria (70.6%). Only three (4.5%) of 67 liver recipients developed confirmed donor-derived bacterial infections, with two isolates of multidrug-resistant Klebsiella pneumoniae and one isolate of multidrug-resistant Enterobacter aerogenes. The liver recipients with donor-derived infections showed relation to higher crude mortality and graft loss rates (33.3% each) within 3 mo post transplantation, as compared to those without donor-derived infections (9.4% and 4.7%, respectively). All three liver recipients received appropriate antimicrobial therapy.CONCLUSIONLiver recipients have high occurrence of donor-derived infections. The liver recipients with donor-derived multidrug-resistant Enterobacteriaceae infections can have good outcome if appropriate antimicrobial therapy is given.

The differential importance of mutations within AmpD in cephalosporin resistance of Enterobacter aerogenes and Enterobacter cloacae

Mechanisms leading to carbapenem and cephalosporin resistance were sought in Enterobacter aerogenes isolates that were highly resistant to carbapenems but had no known carbapenemase. Results were compared with recent work examining carbapenem-resistant Enterobacter cloacae. Eighteen carbapenem-resistant E. aerogenes were screened for known β-lactamase and carbapenemase genes, and novel carbapenemases were sought in whole-genome sequencing (WGS) data of the three most resistant isolates. For all isolates, ampC, ampR, ampD and the porin genes omp35 and omp36 were investigated by Sanger sequencing or from available WGS data. Expression of ampC and porin genes was measured in comparison with cephalosporin- and carbapenem-susceptible control strains by reverse transcriptase PCR, with porin translation also detected by SDS-PAGE. Loss of Omp35, primarily due to decreased transcription (up to 250×), was observed in ertapenem-resistant isolates (MICs ≥ 2 mg/L), whereas meropenem resistance (MICs ≥ 4 mg/L) was observed in those isolates also showing decreased or no production of Omp36. Loss of Omp36 was due to combinations of premature translation termination or reduced transcription. In contrast to E. cloacae, cephalosporin resistance in E. aerogenes was not associated with lesions in AmpD. High-level cefepime resistance (MIC = 32 mg/L) was caused by a novel modification in the H-10 helix of AmpC in one isolate. The differential importance of AmpD lesions in cephalosporin resistance in E. cloacae and E. aerogenes underlines the differences between these contrasting members of the Enterobacter genus. Porin loss resulted in high-level carbapenem resistance with gradual loss of Omp36, which led to high-level meropenem resistance.

Detection of New Delhi Metallo-Beta-Lactamase (Encoded by blaNDM-1 ) in Enterobacter aerogenes in China.

The increase in blaNDM-1 in Enterobacteriaceae has become a major concern worldwide. In previous study, we investigated clonal dissemination and mechanisms of resistance to carbapenem in China. We carried out retrospective surveillance for blaNDM-1 among carbapenem-resistant enterobacter strains, which were isolated from patients at our hospital by bacterial strains selection, antimicrobial susceptibility testing, species identification, and molecular detection of resistance gene. We found three blaNDM-1 -positive isolates which were identified as Enterobacter aerogenes in clinical patients in China. The blaNDM-1 -positive Enterobacter aerogenes isolates were first found. It is important to mandate prudent usage of antibiotics and implement infection control measures to control the spread of these resistant blaNDM-1 -positive strains.

Hygienic quality, adulteration of pork and histamine production by Raoultella ornithinolytica in milkfish dumpling

Ten milkfish dumpling products purchased from retail stores in southern Taiwan were collected to determine the occurrence of biogenic amines, histamine-forming bacteria, and adulteration of pork. This study showed the high contents of aerobic plate count (APC), total coliforms (TC) and Escherichia coli in tested milkfish dumpling samples, whereas the average content of various biogenic amines in all tested samples was < 1.6 mg/100 g (< 0.05 to 1.54 mg/100 g). Three histamine-producing bacterial strains (2 isolates of Raoultella ornithinolytica and 1 isolate of Enterobacter aerogenes) isolated from tested samples produced 276.6 ppm to 561.8 ppm of histamine in trypticase soy broth supplemented with 1.0% L-histidine (TSBH). Assay of multiplex polymerase chain reaction (PCR) revealed that the adulteration rates were 50% (5/10) for pork in milkfish dumplings. In addition, milkfish dumpling stuffing was inoculated with R. ornithinolytica at 5.0 log colony forming units (CFU)/g and stored at various temperatures from 4°C to 37°C to investigate bacterial growth and formation of histamine. The histamine contents quickly increased to higher than 50 mg/100 g in samples stored at 37°C and 25°C within 24 hours and 36 hours, respectively, as well as stored at 15°C within 48 hours. Therefore, bacterial growth and histamine formation were controlled by cold storage of the samples at 4°C.

Assessment of Antibiogram of Multidrug-Resistant Isolates of Enterobacter aerogenes after Biofield Energy Treatment

Assessment of Antibiogram of Multidrug-Resistant Isolates of Enterobacter aerogenes after Biofield Energy Treatment

Assessment of Antibiogram of Multidrug-Resistant Isolates of Enterobacter aerogenes after Biofield Energy Treatment

Assessment of Antibiogram of Multidrug-Resistant Isolates of Enterobacter aerogenes after Biofield Energy Treatment

Assessment of Antibiogram of Multidrug-Resistant Isolates of Enterobacter aerogenes after Biofield Energy Treatment

Assessment of Antibiogram of Multidrug-Resistant Isolates of Enterobacter aerogenes after Biofield Energy Treatment