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

Abstract INTRODUCTION: 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. METHODS: We analyzed 29 E. aerogenes clinical isolates resistant to aminoglycosides. AMEs genes were investigated by PCR and sequencing. RESULTS: 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. CONCLUSIONS: The results highlight the importance in establishing rigorous methods for the surveillance of resistance genes, especially in colonized patients.

Detection of virulence and ß-lactamase encoding genes in Enterobacter aerogenes and Enterobacter cloacae clinical isolates from Brazil

ABSTRACT Enterobacter cloacae and E. aerogenes have been increasingly reported as important opportunistic pathogens. In this study, a high prevalence of multi-drug resistant isolates from Brazil, harboring several β-lactamase encoding genes was found. Several virulence genes were observed in E. aerogenes, contrasting with the E. cloacae isolates which presented none.

Detection of virulence and -lactamase encoding genes in Enterobacter aerogenes and Enterobacter cloacae clinical isolates from Brazil

ABSTRACT Enterobacter cloacae and E. aerogenes have been increasingly reported as important opportunistic pathogens. In this study, a high prevalence of multi-drug resistant isolates from Brazil, harboring several -lactamase encoding genes was found. Several virulence genes were observed in E. aerogenes, contrasting with the E. cloacae isolates which presented none.

Histamine production by Enterobacter aerogenes in chub mackerel (Scomber japonicus) at various storage temperatures

Abstract Growth of Enterobacter aerogenes and accumulation of histamine in chub mackerel (Scomber japonicus) were investigated through measuring bacterial count, histidine decarboxylase (HDC) activity and histamine content in fish samples stored at various temperatures from 4 to 37 °C. Results showed that bacterial count and HDC activity rapidly increased in chub mackerel inoculated with E. aerogenes at storage temperature above 20 °C and reached the highest values (8.64 log CFU/g and 31.68 U/g) at 37 °C. Meanwhile, fish samples stored at 25 and 37 °C for 18 h, formed histamine at above 50 mg/100 g of the potential hazard level. In contrast, bacterial growth and histamine formation were controlled for 36 h by cold storage at low temperature (4 °C). Therefore, strict temperature control was necessary for preservation and processing of chub mackerel in order to assure this marine fish safety.

Isolamento e determinação de sensibilidade e resistência a antimicrobianos de cepas bacterianas presentes na cloaca de Trachemys scripta elegans (Wied, 1839) criadas em cativeiro em Petrolina, PE / Isolation and determination of antimicrobials sensitivity and resistance of bacterial strains present in the cloaca Trachemys scripta elegans (Wied, 1839) raised in captivity in Petrolina/PE, Brazil

Este estudo isolou e determinou o perfil de sensibilidade e de resistência a antimicrobianos de cepas bacterianas isoladas da cloaca de Trachemys scripta elegans (T. s. elegans) criadas em cativeiro. Após 120 dias de adaptação, amostras de swab cloacal obtidas de 20 animais adultos foram cultivadas e, após a identificação dos patógenos através de testes bioquímicos, submetidas ao teste de suscetibilidade a nove antimicrobianos. Enterobacter aerogenes (85%); Shigella spp. (10%) e Edwadsiella spp. (5%) foram isolados e identificados. Os isolados de E. aerogenes foram sensíveis à gentamicina (86%), enrofloxacina (79%), estreptomicina (50%), sulfazotrim (36%) e ampicilina (29%) e resistentes a penicilina (100%), eritromicina (93%), cefalexina (86%) ampicilina (71%) e sulfazotrim (64%). Isolados de Shigella spp. apresentaram sensibilidade à gentamicina (100%), enrofloxacina (50%), doxicilina (50%), estreptomicina (50%), ampicilina (50%), penicilina (50%) e sulfazotrim (50%) e resistência a doxicilina (50%), estreptomicina (50%), ampicilina (50%), penicilina (100%), cefalexina (50%) e sulfazotrim (50%), enquanto que os de Edwardsiella spp. foram sensíveis apenas à gentamicina (100%) e altamente resistentes (100%) aos demais antimicrobianos. Os resultados sugerem a participação de T. s. elegans na cadeia epidemiológica, como reservatório de patógenos importantes, como E. aerogenes, Shigella spp. e Edwardisiella spp., tornando importante a adoção de medidas preventivas pelo risco zoonótico que apresentam e corretas de tratamento e de controle em cativeiros e domicílios, assim como de estudos que enfoquem as características de sensibilidade e de resistência antimicrobiana dos isolados cloacais, pois a multirresistência a drogas pode ser transmitida aos humanos e comprometer o tratamento de indivíduos com doenças graves.(AU)

This study isolated and determined the profile of susceptibility and antimicrobials resistance of bacterial strains isolated from the cloaca Trachemys scripta elegans (T. s. elegans) raised in captivity. After 120 days of adaptation, cloacal swab samples obtained from 20 adults animals were grown and, after the pathogens identification through biochemical tests, submitted to the test of susceptibility to nine antimicrobials. Enterobacter aerogenes (85%); Shigella spp. (10%) and Edwadsiella spp. (5%) were isolated and identified. Isolates from E. aerogenes were sensitive to gentamicin (86%), enrofloxacin (79%), streptomycin (50%), sulfazotrim (36%) and ampicillin (29%) and resistant to penicillin (100%), erythromycin (93%), cephalexin (86%), ampicillin (71%) and sulfazotrim (64%). Isolates from Shigella spp. showed sensitivity to gentamicin (100%), enrofloxacin (50%), doxycycline (50%), streptomycin (50%), ampicillin (50%), penicillin (50%) and sulfazotrim (50%) and resistance to doxycycline (50 %), streptomycin (50%), ampicillin (50%), penicillin (100%), cephalexin (50%) and sulfazotrim (50%), while the Edwardsiella spp. were sensitive only to gentamicin (100%) and were highly resistant (100%) to other antibiotics. The results suggest the participation of T. s. elegans in the epidemiological chain, as reservoir of important pathogens, such as E. aerogenes, Shigella spp. and Edwardisiella spp., making it important to adopt preventive measures for zoonotic risk that present and correct treatment and control in captivity and households, as well as studies that address the sensitivity characteristics and antimicrobial resistance of isolates from cloaca, as it multidrug resistance to drugs can be transmitted to humans and compromise the treatment of patients with serious diseases.(AU)

The aerogenes infection in NICU and sensitivity analysis / 中国新生儿科杂志

Objective To study the risk factors,clinical manifestations,drug sensitivity and outcomes of preterm infants with aerogenes infection in NICU.Method Preterm infants diagnosed to have infection of aerogenes in our NICU during July 2014 to October 2014 were selected as the infection group in our study.Uninfected preterm infants whose gestational age and birth weight were similar to the infants in infection group were selected as the control group.The ratio of number of infants in infection group and control group was 1 ∶ 2.The basic situation,clinical application of antibiotics before infection,defecation times,invasive manipulations,and parenteral nutrition time of the two groups were retrospectively collected.The clinical manifestations,drug sensitivity and outcomes of preterm infants with aerogenes infection were analyzed.Result There were 8 infants in infection group (male:female =3∶5).The birth weight ranged from 780 to 2 760 g;and gestational age from 28 to 33 w.There were 16 infants in the control group (male:female =1 ∶ 1).The birth weight ranged from 1 070 to 1 780 g,and gestational age,from 29 to 33 w.The incidence of prenatal infection in infection group was higher than that in the control group (3/8 vs.4/16,P ＜ 0.05).Comparing the two study groups,there were statistical differences between them in the following aspects (all P ＜ 0.05):non-invasive respiratory support time [11 (6,36) d vs.4 (0,6) d] and invasive mechanical ventilation time [(1 (0,6) d vs.0 (0,0) d].All the 8 infants in infection group had pneumonia,3 of them with sepsis (1 case was extremely low birth weight infant,and 2 cases were very low birth weight infants),and one of them died from septic shock.Drug sensitivity analysis showed that aerogenes were resistant to all the third generation cephalosporins,and were sensitive to Meropenem and Piperacillin/Tazobactam.The resistance rates of Imipenem were 1/6 in the first month,2/6 in the second month,9/11 in the third month,and 2/4 in the fourth month,respectively.Conclusion Avoidance of prenatal infection and shortening of the application of ventilator may reduce the incidence of aerogenes infection.Most of infants with aerogenes infection have favourable prognosis.The resistance rate of third generation cephalosporins is very high.Aerogenes could develop resistance quickly to the antibiotics which is sensitive initially.

Characteristics and blaNDM-1 genetic environment of plasmid from Enterobacter aerogenes / 中国感染控制杂志

Objective To study plasmid-mediated transfer,plasmid replicon typing,and genetic environment of blaNDM-1 gene in Enterobacteraerogenes(E.aerogenes).Methods E.aerogenes HN-NDM0711 was used as the subject of this research,the transferable properties of plasmid were analyzed by conjugation testing,conjugant was performed stability testing,plasmid type was determined by PCR-based replicon typing (PBRT),downstream and upstream of blaNDM-1 were sequenced using chromosome walking method,genetic context was analyzed by BLASTN and BALSTP,as well as annotated using Vector NTI 11.5.1 software,sequence pipeline graph was made,the sequence was submitted to Genbank through software Banklt.Results The conjugation testing of E.aerogenes pHN-NDM0711 was positive,after positive conjugant was conducted 4-day passage,minimal inhibitory concentrations (MICs) of imipenem and meropenem to all the cloned strains didn't change,blaNDM-1 were all positive.The replicon type was IncA/C;blaNDM-1 gene was localized between ISAba14 and IS91,at upstream of the blaNDM-1,class 1 integron and Tn3 transposon were identified,class 1 integron contained a new mosaic structure of a drug-resistant resistance gene cassette.Conclusion E.aerogenes pHN-NDM071 1,bearing blaNDM-1 gene in IncA/C plasmid,derived from gene recombination under different antimicrobial selection pressure.Antimicrobial use in clinical,industrial and agricultural area should be strictly controlled,so as to reduce the emergence of such bacteria.

Cistitis enfisematosa: una inusual forma de presentación de la infección del tracto urinario bajo / Emphysematous cystitis: Report of one case

Emphysematous cystitis is found in diabetic patients and in individuals with urinary stasis and immunosuppression. We report a 58-year-old male with hypertension, type 2 Diabetes on insulin treatment and central nervous system vasculitis on immunosuppressive therapy. He was admitted with weight loss and gait instability. A PET-CT showed a circumscribed image of air in the bladder contour without involving the upper urinary tract, suggesting emphysematous cystitis. Re-interrogated, the patient referred pneumaturia, dysuria and febrile sensation one week before admission. Urine culture showed Enterobacter aerogenes. He was treated with a urinary catheter, metabolic control and parenteral antimicrobials. The patient was discharged without symptoms 21 days after admission, with the bladder catheter.

Production of humic substances through coal-solubilizing bacteria

In this paper, the production of humic substances (HS) through the bacterial solubilization of low rank coal (LRC) was evaluated. The evaluation was carried out by 19 bacterial strains isolated in microenvironments with high contents of coal wastes. The biotransformed LRC and the HS produced were quantified in vitro in a liquid growth medium. The humic acids (HA) obtained from the most active bacterial strain were characterized via elemental composition (C, H, N, O), IR analyses, and the E4/E6 ratio; they were then compared with the HA extracted chemically using NaOH. There was LRC biotransformation ranged from 25 to 37%, and HS production ranged from 127 to 3100 mg.L-1. More activity was detected in the isolated strains of Bacillus mycoides, Microbacterium sp, Acinetobacter sp, and Enterobacter aerogenes. The HA produced by B. mycoides had an IR spectrum and an E4/E6 ratio similar to those of the HA extracted with NAOH, but their elemental composition and their degree of aromatic condensation was different. Results suggest that these bacteria can be used to exploit the LRC resulting from coal mining activities and thus produce HS in order to improve the content of humified organic matter in soils.

CHINET 2012 surveillance of antibiotic resistance in Enterobacter spp .in China / 中国感染与化疗杂志

Objective To investigate the distribution and antibiotic resistance of clinical Enterobacter isolates .Methods A total of 3 031 clinical strains of Enterobacter were collected from 15 hospitals from January 1 through December 31 , 2012 . Antimicrobial susceptibility testing was performed with Kirby-Bauer or minimum inhibitory concentration method .The results were analyzed according to CLSI 2012 breakpoints .Results Enterobacter cloacae and Enterobacter aerogenes accounted for 73 .0% (2 212/3 031) and 23 .9% (725/3 031) of all the Enterobacter strains .The isolates of other Enterobacter species accounted for 3 .1% (94/3 031 ) . The main source of the isolates was respiratory tract specimen , accounting for 53 .2% (1 612/3 031) .Most (> 89% ) of the Enterobacter strains were resistant to cefazolin and cefoxitin . Generally ,54 .4% ,47 .5% and 34 .3% of the strains were resistant to cefuroxime ,cefotaxime and cefazidime ,respectively . About 6 .6% to 26 .3% of the strains were resistant to amikacin ,gentamicin ,piperacillin-tazobactam ,cefepime ,cefoperazone-sulbactam ,ciprofloxacin and trimethoprim-sulfamethoxazole .Imipenem ,meropenem and ertapenem showed the highest activity , to which only 3 .5% ,3 .7% and 10 .3% of the strains were resistant ,respectively .About 8 .9% (269/3 031) of the strains were resistant to at least imipenem ,meropenem or ertapenem .Four Enterobacter strains were extensive-drug resistant (XDR) .Conclusions The prevalence of antibiotic resistance in Enterobacter isolates decreased slightly in 2012 compared to the data in 2011 ,but the situation is still very serious .We should continue to take effective measures to control the resistant strains .

Statistical optimization of culture conditions by response surface methodology for synthesis of lipase with Enterobacter aerogenes

Optimization of lipase production by Enterobacter aerogenes was carried out using response surface methodology (RSM) where the statistical model was obtained by fractional factorial central composite design. The influence of various physico-chemical parameters, viz. temperature, oil concentration, inoculum volume, pH and incubation period on lipase production was examined. Optimization of physico-chemical parameters resulted 1.4- fold increase in lipase activity. The optimum levels of parameters were 34°C, oil concentration 3 percent, inoculum volume 7 percent, pH 7 and incubation time 60 h for obtaining a maximum lipase activity of 27.25 U/ml.

Ventilator-associated pneumonia caused by carbapenem-resistant Enterobacteriaceae carrying multiple metallo-beta-lactamase genes.

Context: Ventilator-associated pneumonia (VAP) is a leading nosocomial infection in the intensive care unit (ICU). Members of Enterobacteriaceae are the most common causative agents and carbapenems are the most commonly used antibiotics. Metallo-beta-lactamase (MBL) production leading to treatment failure may go unnoticed by routine disc diffusion susceptibility testing. Moreover, there is not much information on association of MBL-producing Enterobacteriaceae with ICU-acquired VAP. Therefore, a study was undertaken to find out the association of MBL-producing Enterobacteriaceae with VAP. Settings: This study was conducted in a large tertiary care hospital of North India with an eight-bed critical care unit. Materials and Methods: The respiratory samples (bronchoalveolar lavage, protected brush catheter specimens and endotracheal or transtracheal aspirates) obtained from VAP patients (during January 2005-December 2006) were processed, isolated bacteria identified and their antibiotic susceptibilities tested as per standard protocols. The isolates of Enterobacteriaceae resistant to carbapenem were subjected to phenotypic and genotypic tests for the detection of MBLs. Results: Twelve of 64 isolates of Enterobacteriaceae were detected as MBL producers, bla IMP being the most prevalent gene. Additionally, in three strains, simultaneous coexistence of multiple MBL genes was detected. Conclusion: The coexistence of multiple MBL genes in Enterobacteriaceae is an alarming situation. As MBL genes are associated with integrons that can be embedded in transposons, which in turn can be accommodated on plasmids thereby resulting in a highly mobile genetic apparatus, the further spread of these genes in different pathogens is likely to occur.

Characteristic Analysis of Cooperation Hydrogen Production Using Rhodopseudomonas sp. DT and Enterobacter Aerogenes / 微生物学通报

Cooperation hydrogen production was carried out using Rhodopseudomonas sp. DT and Enterobacter aerogenes. The effects of the initial ratio of Rhodopseudomonas sp. DT and E. aerogenes, culture temperature, and carbon source on the cooperation hydrogen production were investigated. The results suggested that cooperation hydrogen production rate was highly affected by the initial ratio of Rhodopseudomonas sp. DT and E. aerogenes. The mixed bacteria of Rhodopseudomonas sp. DT and E. aerogenes with 1:1 initial ratio benefited to the cooperation hydrogen production, which led the hydrogen production rate and duration of gas production to 3.1 mol H2/mol glucose and 81 h, respectively. The pH dynamics analysis of culture medium further discovered that the pH of the mixed bacteria with 1:1 initial ratio changed from 6 to 7 smaller than other conditions, which was probably fitted to produce hydrogen. Furthermore, the mixed bacteria with 1:1 initial ratio had the higher hydrogen production efficiency at temperatures of 28?C and 37?C than at 20?C, and without any hydrogen production at temperature of 50?C. The carbon sources of glucose, succinate acid, malic acid could be used to produce hydrogen by the mixed bacteria. Even the soluble starch, unused by Rhodopseudomonas sp. DT, was also decomposed by the mixed bacteria to produce hydrogen with the conversion efficiency of 8.22%. The glucose was the optimal carbon resource, and the conversion efficiency could reach to 36.11%. The results, further, implied that the cooperation hydrogen production could enlarge the use of the carbon sources.

Atividade antimicrobiana do extrato bruto etanólico de raízes e partes aéreas de Ottonia martiana Miq. (Piperaceae) / Antimicrobial activity of crude ethanolic extracts of Ottonia martiana Miq. (Piperaceae) roots and aerial parts

Ottonia martiana Miq., Piperaceae, conhecida na medicina popular brasileira como "anestésia", é um arbusto característico da Floresta Atlântica. Devido à ação anestésica sobre a mucosa oral, raízes e partes aéreas são popularmente utilizadas em dores de dente, na forma de alcoolaturas (bochechos) ou pela mastigação de fragmentos de partes da planta. Como os microrganismos estão adquirindo resistência aos antibióticos tradicionais, a procura por novos agentes antimicrobianos, a partir de plantas, vem sendo intensificada. Nesta perspectiva, avaliou-se o efeito antimicrobiano do extrato bruto etanólico dos órgãos totais desta espécie (EBEtOH) frente às bactérias Enterococcus faecium (ATCC 6569), Enterobacter aerogenes (ATCC 13048) e Pseudomonas aeruginosa (ATCC 15442), utilizando-se os métodos de difusão em ágar e bioautografia. Os resultados obtidos por difusão em ágar mostraram que o EBEtOH de O. martiana apresenta potencial antibacteriano contra E. faecium, evidenciado pelo aparecimento de zonas de inibição de crescimento no respectivo bioautograma e não demonstraram ação antimicrobiana contra as outras cepas testadas.

Ottonia martiana Miq., Piperaceae, known in Brazilian folk medicine as "anestésia", is an herbaceous shrub found in Atlantic Tropical Forest. Due to its anesthetic action on the mucous membranes of the mouth, roots and aerial parts are commonly used to relief toothache, usually as alcoholic macerates (mouth washing) or by chewing parts of the plant. As most microorganisms are acquiring resistance to traditional antibiotics, the search for new antimicrobials agents, specially from plants, is being intensified. Based on this, the activity of the crude ethanolic extract from roots and aerial parts (EBEtOH) of O. martiana against Enterococcus faecium (ATCC 6569), Enterobacter aerogenes (ATCC 13048) and Pseudomonas aeruginosa (ATCC 15442) was evaluated using the agar difusion and bioautographic methods. Results from the agar diffusion assay showed that O. martiana EBEtOH has a potencial effect against E. faecium, which was corroborated by the presence of inhibition zones in the bioautographic test, whereas no inhibitory action against the other assayed bacteria was observed.

STUDY ON FERMENTATION CONDITIONS OF A 1.3-PD HIGH-PRODUCTION STRAIN FROM E. AEROGENES / 微生物学通报

The fermentation conditions of high 1.3 -propanediol-producing strain E. aero-N-56 were determined in this Paper. The optimum conditions of producing 1.3-PD were: initial pH 7.0, temperature 30℃, culture time 48 h, inoculum size 9% . Under the optimum conditions: the 1.3-PD productivity reached up to 23.68 g/L?d; the 1,3-PD yield of E. aero-N-56 up to 47.36 g/L in 30 L fermentor.