Drug resistance analysis of Enterobacter cloacae isolated from blood samples in Hebei, 2016-2021 / 中国热带医学

@# Objective　To investigate the drug resistance of Enterobacter cloacae isolated from blood samples in 75 member units of the Bacterial Drug Resistance Monitoring Network in Hebei, 2016- 2021, so as to provide a basis for rational drug use in clinic. Methods　WHONET 5.6 software was used to retrospectively analyze drug susceptibility of Enterobacter cloacae isolated from 32 secondary hospitals and 43 tertiary hospitals. SPSS19.0 software was used for statistical analysis. Results After removing the duplicate strains, 1 225 strains of E. cloacae were isolated from blood samples of 75 hospitals during 6 years, including 157 strains from secondary hospitals and 1 068 strains from tertiary hospitals. In this study, the resistance of Enterobacter cloacae to 16 kinds of antibiotics was analyzed. The drug resistance rates to cefuroxime (52.4%-67.8%), piperacillin (27.4%-31.2%), ceftazidime (27.8%-35.5%), ceftriaxone (29.5%-45.0%), aztreonam (22.2%-32.3%), cotrimoxazole (21.6%-28.7%) were higher; the resistance rates to amikacin and tobramycin were lower than 15.0%. The resistance rates to imipenem and meropenem were 3.6%-12.3% and 5.1%-11.4%, respectively. The resistance rate to ciprofloxacin in tertiary hospitals was 22.4%, and the resistance rate to cotrimoxazole was 23.9%. Except for these two antimicrobials, the resistance rates to other antimicrobial drugs in tertiary hospitals were higher than that in secondary hospitals. A total of 121 carbapenem-resistant Enterobacter cloacae strains were detected in the past 6 years, with an increasing detection rate (χ2trend=6.305, P=0.012). Conclusions　Enterobacter cloacae has great differences in antimicrobial resistance to different antibiotics, and is sensitive to carbapenems. The drug resistance in tertiary hospitals is generally higher than that in secondary hospitals. Drug resistance monitoring and drug resistance mechanism research should be strengthened to better guide clinical drug use and curb the rise of drug resistance.

Diagnosis and Treatment of Klebsiella Pneumoniae Combined with Enterobacter Cloacae in Lumbar Intervertebral Space Infection / 中山大学学报(医学科学版)

ObjectiveTo explore the clinical diagnosis and treatment of rare primary lumbar intervertebral space infection with Klebsiella pneumoniae and Enterobacter cloacae， and provide clinical experience for the diagnosis and treatment of this rare spinal infection. MethodsAn elderly male patient with low back pain and numbness in the left lower extremity for more than 7 months， which aggravated for more than 1 week， was diagnosed with lumbar disc herniation after laboratory and imaging examinations. After admission， the symptoms became acutely aggravated， and re-examination of lumbar enhanced MRI showed local enhancement at the posterior edge of the L3/4 intervertebral space. The VAS score was 9 points， and the lumbar JOA score was 6 points. A posterior lumbar interbody fusion of L3-L5 was performed， and L3/4 intervertebral disc specimens were collected during the operation for bacterial culture. ResultsBacterial culture results showed Klebsiella pneumoniae and Enterobacter cloacae infection. The patient was treated with sensitive antibiotics for 6 weeks after the operation， and the patient was cured during the follow-up of half a year after the operation. ConclusionFor middle-aged and elderly patients with clinical manifestations of acute severe low back pain or lower extremity pain， the possibility of spinal infection should be considered when routine laboratory and imaging examinations suggest lumbar degenerative diseases.

Bacteriemia por Enterobacter cancerogenus en un paciente con trauma pélvico / Enterobacter cancerogenus bacteremia in a patient with pelvic trauma

Resumen Existen escasas comunicaciones de infecciones por Enterobacter cancerogenus. Aunque ha sido aislado en heridas contaminadas asociadas a traumas, también ha sido reportado como agente etiológico en una amplia variedad de otras infecciones, siendo infrecuente la presencia de bacteriemia. Presentamos el primer caso reportado en Chile de una bacteriemia causada por este microorganismo, en un varón de 28 años con una fractura de pelvis estable debido a un accidente de tránsito de alta energía. Tuvo una buena respuesta clínica al tratamiento con ertapenem.

Abstract There are few cases reports of Enterobacter cancerogenus infections. Although it has been isolated in contaminated wounds associated with trauma, it has also been reported as an etiological agent in a wide variety of other infections, with the presence of bacteremia being infrequent. We present the first case reported in Chile of a bacteremia caused by this agent, in a 28-year-old patient with a stable pelvic fracture due a high-energy traffic accident. He had a good clinical response to treatment with ertapenem.

Genomic epidemiology analysis of Enterobacter hormaechei subsp. hoffmannii / 中华检验医学杂志

Objectives:To investigate the genetic characteristics of the blaNDM-1-carrying plasmid of the multidrug resistant Enterobacter hormaechei subsp. hoffmannii clinical isolate C37, and constructing a phylogenetic tree of the 66 publicly available genomes of the Enterobacter hormaechei subsp. hoffmannii to explore its global epidemic situation. Methods:Carbapenem-resistant Enterobacter cloacae complex (CRECC) strains isolated from the First Affiliated Hospital of Sun Yat-sen University from August 2014 to August 2021 were collected. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) and 16S rDNA Sanger sequencing were used for species identification. Micro broth dilution method was used for antibacterial susceptibility test. The polymerase chain reaction (PCR) was used to detect the β-lactamase resistance gene and plasmid-mediated quinolone resistance (PMQR) gene carried by the C37 strain. The conjugation experiment was used to confirm the conjugative metastasis of the resistance genes in C37 strain. Whole genome of the C37 strain was sequenced. Core genome was extracted and the phylogenetic analysis of 66 publicly available Enterobacter hormaechei subsp. hoffmannii was performed. Results:Enterobacter hormaechei subsp. hoffmannii C37 strain is resistant to third-generation cephalosporins, carbapenems, aminoglycosides and quinolones, and carries blaACT-5, blaNDM-1, qnrA1, aac(6′)-Ib-cr, oqxAB, fosA, dfrA15 and other resistance genes, as well as IncX3, IncX4, IncFIB and IncFII plasmids. Multilocus sequence typing (MLST) analysis showed that C37 strain belongs to the ST78 type of Enterobacter cloacae complex (ECC). Conclusions:ST78 type Enterobacter hormaechei subsp. hoffmannii is closely related to the spread of carbapenem resistance genes. It is a potential high-risk clone to spread carbapenem resistance genes. The prevalence and trends of ST78 type Enterobacter hormaechei subsp. Hoffmannii should be monitored.

Abordaje interdisciplinario de endoftalmitis endógena neonatal. Reporte de caso / Interdisciplinary approach to endogenous neonatal endophthalmitis. Case report

La endoftalmitis endógena neonatal es una patología poco frecuente que puede causar daño ocular grave. Puede manifestarse en pacientes con comorbilidades, como nacimiento pretérmino, bajo peso al nacer, complicaciones posquirúrgicas perinatales o sepsis.El presente reporte de caso documenta a una paciente pretérmino que fue sometida a múltiples cirugías abdominales. Durante su internación, desarrolló sepsis, meningitis y endoftalmitis endógena neonatal. La frecuencia extremadamente baja de la endoftalmitis endógena a esta edad, la importancia de preservar la salud visual del paciente y el abordaje interdisciplinario son puntos importantes de aprendizaje en este caso.

Neonatal endogenous endophthalmitis is a rare condition that can cause serious eye injuries. It can manifest in patients with comorbidities, such as preterm birth, low birth weight, post-surgical perinatal complications, or sepsis.This case report documents a preterm patient who underwent multiple abdominal surgeries. During her hospitalization, she developed sepsis, meningitis and neonatal endogenous endophthalmitis. The extremely low frequency of endogenous endophthalmitis at this age, the importance of preserving the patient's visual health, and the interdisciplinary approach are important learning points in this case.

Eosinophilic cystitis, a rare cause of persistent haematuria in a diabetic dog / Cistite eosinofílica, uma causa rara de hematúria persistente em um cão diabético

Eosinophilic cystitis is a rare inflammatory disorder characterized by eosinophilic infiltration of entire layers of the bladder wall. The condition has been described in adults, children, and dogs. However, there are no consensus guidelines for the treatment of eosinophilic cystitis. Although human and veterinary literature reviews show some effectiveness in management with corticosteroids, antihistamines, and antibiotics, a variety of serious and frequent side effects are associated with steroid therapy. As a result, steroids are relatively contraindicated for patients with diabetes mellitus and Cushing's syndrome. A five-year-old neutered male chow-chow with controlled diabetes was referred with an 18-month history of malodorous urine, gross haematuria, and dysuria that were nonresponsive to antibiotics. The findings on general examination were unremarkable except for abdominal suprapubic discomfort. The complete blood count and biochemical profile (such as urea and creatinine) were normal except for mild peripheral eosinophilia. Although ultrasonography, bladder contrast radiography, and urine cytology findings indicated malignancy, with the presence of atypical urothelial cells, histopathology confirmed eosinophilic cystitis. Management with cyclosporine was adequate with complete remission of haematuria. This case report presents the first reported successful use of cyclosporine for the treatment of eosinophilic cystitis in a dog with diabetes.(AU)

A cistite eosinofílica é uma doença inflamatória rara caracterizada por infiltração eosinofílica de todas as camadas da parede da bexiga. Essa enfermidade já foi descrita em adultos, crianças e cães. No entanto, não há um consenso de diretrizes sobre o seu tratamento. Mesmo que as literaturas humana e veterinária mostrem alguma eficácia no manejo com corticosteroides, anti-histamínicos e antibióticos, uma variedade de efeitos colaterais graves e frequentes está associada à terapia com esteroides. Dessa forma, o uso de esteroides é relativamente contraindicado para pacientes com diabetes mellitus e síndrome de Cushing, por exemplo. Um chow-chow, macho, castrado, de cinco anos e diabético estável foi encaminhado para atendimento com histórico de urina fétida, hematúria macroscópica e disúria não responsiva a antibióticos há 18 meses. A avaliação dos parâmetros físicos estava dentro dos padrões, exceto por desconforto abdominal suprapúbico à palpação. O hemograma e o perfil bioquímico (como a ureia e a creatinina) estavam dentro da normalidade para a espécie, exceto por eosinofilia periférica leve. Embora a ultrassonografia, a radiografia contrastada da bexiga e os achados da urinálise indicassem malignidade, com a presença de células uroteliais atípicas, a histopatologia confirmou o diagnóstico definitivo de cistite eosinofílica. O manejo com ciclosporina foi satisfatório, com ausência completa da hematúria. Este relato de caso apresenta o primeiro uso documentado de ciclosporina para o tratamento de cistite eosinofílica com sucesso em um cão com diabetes.(AU)

Chronic osteomyelitis in canine penile bone: case report / Osteomielite crônica em osso peniano canino: relato de caso

A 10-year-old male mixed-breed dog was admitted for recurrent signs of urinary tract infection (UTI). Urinary bladder ultrasonography revealed decreased thickness of its wall with floating hyperopic particles within its lumen. Ultrasonography revealed a structure invading the dorsal wall of the penile urethral lumen, located in a segment distal to the bladder. Radiographies showed bone resorption with proliferation at the caudal aspect of the penile bone, stricture of the final aspect of the penile urethra, and no radiopaque images compatible with a urethrolith. Computed tomography showed bone proliferation causing stricture of the urethral lumen at two different sites. Presumptive diagnosis of penile neoplasia was considered more likely and the dog underwent penectomy along with orchiectomy and scrotal urethrostomy. Enterobacter spp. was cultured from the urine sample and antibiotic sensitivity tests revealed that the bacterium was susceptible to amikacin, imipenem, and meropenem. Histopathology revealed severe suppurative urethritis, bone resorption, and hyperostosis, suggestive of osteomyelitis of the penile bone. Neoplastic cells were not observed at any part of the examined tissue. The findings in the present case suggest that osteomyelitis of the penile bone should be included in differential diagnosis for partial and complete urethral obstruction in dogs with recurrent UTI.(AU)

Um cão mestiço, com 10 anos, foi admitido por sinais recorrentes de infecção do trato urinário (ITU). A ultrassonografia da bexiga urinária revelou diminuição da espessura de sua parede com partículas flutuantes dentro de seu lúmen. A ultrassonografia demonstrou estrutura invadindo a parede dorsal do lúmen da uretra peniana, localizada em segmento distal à bexiga. Radiografias evidenciaram reabsorção óssea com proliferação no aspecto caudal do osso peniano, estenose do aspecto final da uretra peniana e ausência de imagens radiopacas compatíveis com uretrólito. Pela tomografia computadorizada, observou-se proliferação óssea causando estreitamento da luz uretral em dois locais diferentes. Diagnóstico presuntivo de neoplasia peniana foi considerado mais provável e o cão foi submetido à penectomia, juntamente com orquiectomia e uretrostomia escrotal. Enterobacter spp. foi cultivada da amostra de urina e testes de sensibilidade revelaram susceptibilidade ao amicacina, imipenem e ao meropenem. A histopatologia revelou uretrite supurativa grave, reabsorção óssea e hiperostose compatível com osteomielite do osso peniano. Células neoplásicas não foram observadas em nenhuma parte do tecido examinado. Os achados do presente caso sugerem que a osteomielite do osso peniano deve ser incluída no diagnóstico diferencial de obstrução uretral parcial e completa em cães com ITU recorrente.(AU)

Enterobacter endophthalmitis: Clinical settings, susceptibility profile, and management outcomes across two decades

Purpose: To describe the clinical presentation and management of Enterobacter endophthalmitis and compare with previous in-house published literature. Methods: This was a retrospective interventional comparative case series involving 44 cases with culture proven Enterobacter endophthalmitis from April 2006 to August 2018 who underwent vitrectomy/vitreous biopsy, intravitreal antibiotics with or without additional procedures as appropriate. The current outcomes were compared to the outcomes previously reported a decade back from our center. The mean age at presentation, predisposing factor, number of interventions, interval between inciting event and presentation, type of intravitreal antibiotic used, anatomic, and the functional outcomes were analyzed and compared to the previous series. Results: There were 30 males. Mean age was 22.73 � 21.35 years (median 14 years). Inciting event was open globe injury in 34 (77.27%) eyes, 4 (9.09%) eyes following cataract surgery, 3 (6.81%) eyes with endogenous endophthalmitis, 2 (4.54%) eyes following keratoplasty, and 1 eye (2.27%) following trabeculectomy. Presenting visual acuity was favorable (?20/400) in 2 eyes (4.54%), at the final visit it was in 11 eyes (25%). The organisms were most sensitive to ciprofloxacin (95.12%), amikacin (90.47%), and ceftazidime (85.36%). A comparison of the current study with previous in-house study showed that number of eyes with presenting vision ?20/400 as well as final vision ?20/400 were comparable. Susceptibility was highest to ciprofloxacin 39 (95.12%) (previous series) and 33 (92%) (current series). Conclusion: Enterobacter organisms show susceptibility to ciprofloxacin, amikacin, and ceftazidime. Susceptibility profile, clinical presentations, and management remain largely similar over many years. Final outcome is unfavorable.

Molecular, biochemical, and phenotypic characterization of a newly isolated Enterobacter hormaechei subsp. xiangfangensis strain associated with diarrhea cases in Iraq

Aims@#The current study aimed to isolate and characterize bacterial strains associated diarrhea with the focus on Enterobacter species strains and test for susceptibility to antibiotics.@*Methodology and results@#A total of 400 stool samples from inpatients suffering from diarrhea in Al-Qasim Hospital at Al-Hilla City of Iraq were screened form January 2018 to January 2019. Phenotypic, molecular, and biochemical methods were used to identify the isolated bacteria. A new strain of Enterobacter hormaechei was obtained from two stool samples of inpatients suffering from diarrhea for more than two weeks. This strain is Gram negative, rod shaped, and facultative anaerobic. Multiple sequence alignment analysis and phylogenetic tree construction of the sequenced 16S rRNA gene of the isolated strain suggested that this strain can be identified as E. hormaechei subsp. xiangfangensis, named as E. hormaechei subsp. xiangfangensis strain AA1. This strain was resistant to augmentin, ampicillin, cephalothin, cefoxitin, ceftazidime, cefixime, ticracillin/clavulanic acid, cefotaxime, streptomycin, erythromycin, amikacin, ciprofloxacin, and chloramphenicol, while it was susceptible to meropenem along with imipenem. @*Conclusion, significance and impact of study@# In the present study, E. hormaechei subsp xiangfangensis was isolated for the first time in Iraq and was resistant to most of the tested antibiotics, making it an etiologic agent that is not easy to be treated.

Risk factors for healthcare-associated pneumonia caused by carbapenem-resistant Enterobacter cloacae in patients in intensive care unit / 中国感染控制杂志

Objective To explore risk factors for healthcare-associated pneumonia (HAP) caused by carbapenemresistant Enterobacter cloacae (CREC) in patients in intensive care unit (ICU).Methods From July 2013 to June 2017, 64 patients with CREC-HAP in ICU of a hospital were collected as case group, and 64 patients with carbapenem-sensitive Enterobacter cloacae HAP (CSEC-HAP) were as control group, risk factors for the occurrence of CREC-HAP were analyzed retrospectively by 1∶1 matched case-control study.Results Univariate analysis showed that APACHE II score≥20, long length of ICU stay, use of ventilator, long length of ventilator use, use of carbapenems, long duration of antimicrobial use, and at least 2 kinds of antimicrobial agents combined use were associated with the occurrence of CREC-HAP (all P＜0.05).Multivariate logistic regression analysis showed that APACHE II score≥20, use of ventilator, long length of ventilator use, use of carbapenems, and long duration of antimicrobial use were independent risk factors for occurrence of CREC-HAP (all P＜0.05).Conclusion Risk factors for occurrence of CREC-HAP in ICU patients include the use of carbapenems, long length of ventilator use, long duration of antimicrobial use, and APACHE II score≥20.Effective preventive and control measures can be formulated and taken in view of the above risk factors.

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.

Matricaria Recutita Extract (Chamomile) to reduce Candida Albicans and Entrobacter Cloacae biofilms: in vitro study / Extrato de Matricaria recutita (camomila) para redução do biofilme de Candida albicans e Entrobacter cloacae: estudo in vitro

ABSTRACT Objective: This research study aimed at evaluating the inhibitory activity of Matricaria recutira (chamomile) hydroalcoholic extract on Candida albicans and Enterobacter cloacae biofilms. Methods: C. albicans and E. cloacae biofilms with thirty-hour formation were submitted, for five minutes, to 100, 200 and 300 mg / mL of M. recutita hydroalcoholic extract, chlorhexidine digluconate 0.12% (Periogard® - inhibition control) or sterile distilled water (growth control). Subsequently, they were washed and divided into two groups to determine the microbial viability: G/UFC - counting of colony forming units (cfu) in agar and G/DNA - quantification of viable DNA with violet crystal dye by spectrophotometry. Results: M. recutita extract at 300 mg/mL reduced significantly (p <0.01) the E. cloacae cfu/mL number in biofilm with results similar to chlorhexidine 0.12%, while extracts at 100 and 200 mg/mL did not have the same effectiveness. The amount of E. cloacae viable DNA was reduced (p <0.05) in all the M. recutita extract concentrations and chlorhexidine. There was no significant difference (p = 0.565) in the cfu/mL number or in the amount of viable DNA (p = 0.8094) in C. albicans biofilm when compared to untreated biofilm (control) or, even, between the extracts when compared to each other or to chlorhexidine 0.12%. Conclusion: 300 mg/mL M. recutita extract reduced significantly the E. cloacae biofilm but not the C. albicans, both with a similar result to chlorhexidine 0.12% (Periogar®).

RESUMO Objetivo: Avaliar a atividade inibitória do extrato hidroalcoólico de Matricaria recutira (camomila) sobre biofilme de Candida albicans e Enterobacter cloacae. Métodos: Biofilmes de C. albicans e E. cloacae com trinta horas de formação foram submetidos por cinco minutos a 100, 200 e 300 mg/mL de extrato hidroalcoólico de M. recutita, digluconato de clorexidina 0,12% (Periogard® - controle de inibição) ou água destilada esterilizada (controle do crescimento). Depois foram lavados e divididos em dois grupos para determinação da viabilidade microbiana: G1 - contagem de unidades formadoras de colônia (ufc) em ágar e G2 - quantificação de DNA viável com corante cristal violeta por espectrofotometria. Resultados: O extrato de M. recutita a 300 mg/mL reduziu significativamente (p < 0,01) o número de ufc/mL de E. cloacae em biofilme com resultados semelhantes a clorexidina 0,12%, enquanto os extratos a 100 e 200 mg/mL não tiveram a mesma efetividade. Já a quantidade de DNA viável de E. cloacae foi reduzida (p < 0,05) em todas as concentrações do extrato de M. recutita testadas e clorexidina. Não houve diferença significativa (p=0,565) no número de ufc/mL ou na quantidade de DNA viável (p=0,8094) no biofilme de C. albicans quando comparado ao biofilme sem tratamento (controle) ou mesmo entre as concentrações do extrato quando comparados entre si ou com a clorexidina 0,12%. Conclusão: O extrato de M. recutita 300 mg/mL reduziu significativamente o biofilme de E. cloacae mas não de C. albicans, ambos com resultado semelhante à clorexidina 0,12% (Periogar®).

Clonal relation and antimicrobial resistance pattern of extended-spectrum ß-lactamase- and AmpC ß-lactamase-producing Enterobacter spp. isolated from different clinical samples in Tehran, Iran

Abstract INTRODUCTION: Here, we determined the genes encoding antibiotic resistance enzymes and virulence factors and evaluated the genetic relationship between Enterobacter spp. isolated from different clinical samples. METHODS: A total of 57 clinical isolates of Enterobacter spp. were tested for the production of extended-spectrum β-lactamases (ESBLs), carbapenemase, and AmpC using phenotypic and genotypic methods. RESULTS: The most common ESBLs and AmpC β-lactamases were bla TEM (63.3%) and bla EBC (57.7%), respectively. The most prevalent virulence gene was rpos (87.7%). The random amplified polymorphic DNA (RAPD) patterns of strains were genetically unrelated. CONCLUSIONS: RAPD polymerase chain reaction analysis revealed high genetic diversity among isolates.

Research on interaction between Coptidis Rhizoma extracts and intestinal bacteria / 中草药

Objective To investigate the interaction between Coptidis Rhizoma extracts and intestinal bacteria. Methods The metabolites of Coptidis Rhizoma extracts by human gut microbiota were identified by UPLC-Q-TOF/MS. Furthermore, the effects of Coptidis Rhizoma extracts on the growth of Bifiobactderia, Lactobacilli, Enterobacter, and Enterococcus were evaluated by the colorimetric method. Results Alkaloids in Coptidis Rhizoma were mainly degraded by reduction and demethoxy, among which berberine and coptisine were converted to reductive products and palmatine was metabolized to a demethoxyl product. Additionally, pathogens such as Enterobacter and Enterococcus were obviously inhibited and probiotics such as Lactobacilli and Bifiobactderia were notably promoted by Coptidis Rhizoma extracts. Conclusion Gut microflora can metabolize alkaloids from Coptidis Rhizoma by multiple ways, and Coptidis Rhizoma extracts can improve the intestinal microecology.

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.

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.

Biological and Genetic Characteristics of Clinically Isolated Enterobacter cloacae with Multidrug Resistance

BACKGROUND: From January 2014 to December 2015, 69 clones of Enterobacter cloacae showing multidrug resistance to six classes of antimicrobial agents were collected from two medical centers in Korea. METHODS: Minimum inhibitory concentrations were determined using the E-test method, and 17 genes were detected using polymerase chain reaction (PCR). The epidemiological relatedness of the strains was identified using repetitive element sequence-based PCR and multilocus sequence typing. RESULTS: The 69 E. cloacae clones produced extended spectrum β lactamase (ESBL) and AmpC and showed multidrug resistance to cefotaxime, ceftazidime, and aztreonam. We identified the following sequence types: ST56 of type VI for ESBL SHV (N=12, 17.4%); ST53, ST114, ST113, and ST550 of types I, IV, VI, and VII, respectively, for CTX-M (N=11, 15.9%); and ST668 of type III for the carbapenemase NDM gene (N=1, 1.5%). The AmpC DHA gene (N=2, 2.89%) was confirmed as ST134, although its type was not identified, whereas EBC (MIR/ACT; N=18, 26.1%) was identified as ST53, ST24, ST41, ST114, ST442, ST446, ST484, and ST550 of types V, I, III, IV, VII, and VI, respectively. The formed subclasses were bla CTX-M-3 and bla CTX-M-22 by CTX-M-1, bla CTX-M-9 and bla CTX-M-125 by CTX-M-9, bla DHA-1 by DHA, and bla MIR-7 and bla ACT-15,17,18,25,27,28 by EBC (MIR/ACT). CONCLUSIONS: There were no epidemiological relationships between the gene products and the occurrence of resistance among the strains.

Analysis of Clinical Distribution and Drug Resistance of Non-sputum Specimen AmpC Enzyme-producing Enterobacter cloacae in a Hospital during 2011-2017 / 中国药房

OBJECTIVE:To provide reference for rational drug use and hospital infection control. METHODS:AmpC enzyme-producing Enterobacter cloacae were isolated from non-sputum specimen of a hospital during Jan. 2011-Oct. 2017. Drug sensitivity test was conducted by using MIC. The situation of AmpC enzyme production was confirmed by three dimensional test, and that of ESBLs-producing stain was detected with double-disk synergy test. RESULTS:There were 546 strains of AmpC enzyme-producing E. cloacae isolated from non-sputum specimen of the hospital,accounting for 4.80% of non-sputum specimen (546/11 375)and 38.97% of E. cloacae(546/1 401). Top 3 non-sputum samples in the list of detection rate were wound secretion (27.29%),midstream urine(25.82%)and blood(21.79%),and the departments with high detection rate were ICU(22.89%), neurosurgery department(18.68%)and general surgery department(16.67%). Resistance rate of AmpC enzyme-producing E. cloacae to most commonly used antibiotics was higher than 40%. There was statistical significance in resistant rate of the bacteria to ceftriaxone, cefotaxime, gentamicin, nitrofurantoin, levofloxacin, piperacillin/tazobactam, cefoperazone, ceftazidime,cefepime,tobramycin and minocycline among different years (P<0.05). The resistant rate to imipenem and meropenem was lower than 2%. Among 546 strains of AmpC enzyme-producing E. cloacae,68 strains of ESBLs were detected,and detection rates were 5.77%,6.06%,8.70%,10.26%,13.79%,17.35%,18.75% during 2011-2017. CONCLUSIONS:AmpC enzyme-producing E. cloacae are mainly isolated from samples as wound secretion and midstream urine,and mainly come from ICU and neurosurgery department. The drug resistance of the bacteria is severe,and drug resistance of the bacteria to antibiotics as β-lactams and quinolones is increased significantly. The detection rate of ESBLs-producing strain increases year by year. The bacteria are sensitive to carbapenems antibiotics,which can be regarded as first choice. It is necessary to strengthen drug resistance and enzyme production monitoring of AmpC enzyme-producing E. cloacae,select antibiotics combined with results of drug sensitivity test so as to prevent or delay the rapid increase of its resistance rate.

Antimicrobial activity evaluation and comparison of methods of susceptibility for Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacter spp. isolates

Abstract The production of KPC (Klebsiella pneumoniae carbapenemase) is the major mechanism of resistance to carbapenem agents in enterobacterias. In this context, forty KPC-producing Enterobacter spp. clinical isolates were studied. It was evaluated the activity of antimicrobial agents: polymyxin B, tigecycline, ertapenem, imipenem and meropenem, and was performed a comparison of the methodologies used to determine the susceptibility: broth microdilution, Etest® (bioMérieux), Vitek 2® automated system (bioMérieux) and disc diffusion. It was calculated the minimum inhibitory concentration (MIC) for each antimicrobial and polymyxin B showed the lowest concentrations for broth microdilution. Errors also were calculated among the techniques, tigecycline and ertapenem were the antibiotics with the largest and the lower number of discrepancies, respectively. Moreover, Vitek 2® automated system was the method most similar compared to the broth microdilution. Therefore, is important to evaluate the performance of new methods in comparison to the reference method, broth microdilution.

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.