Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 621
Filter
1.
Organ Transplantation ; (6): 225-2022.
Article in Chinese | WPRIM | ID: wpr-920853

ABSTRACT

Objective To analyze the distribution characteristics and drug resistance of pathogens in infected donors from organ donation after citizen's death. Methods Clinical data of 465 potential donors from organ donation after citizen's death were retrospectively analyzed. The airway secretion, urine and blood samples of all donors were cultured. The infection rate of the donors, the source and composition ratio of pathogens were summarized. The drug resistance of main Gram-negative and Gram-positive pathogens was analyzed. Results Among 465 donors, 330 cases were infected and the infection rate was 71.0%. Among the positive culture samples of all donors, lower respiratory tract samples accounted for 63.8%(292/458), 18.6%(85/458) for blood samples and 17.7%(81/458) for urine samples. A total of 512 pathogens were isolated, including 75.0%(384/512) of Gram-negative pathogens, 18.2%(93/512) of Gram-positive pathogens followed by 6.8%(35/512) of fungi. Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii were the most common Gram-negative pathogens. Klebsiella pneumoniae was sensitive to quinolones, compound preparations containing β-lactamase inhibitor (piperacillin-tazobactam, cefoperazone sodium-sulbactam sodium) and carbapenem antibiotics, whereas less sensitive to cephalosporins. Pseudomonas aeruginosa was sensitive to β-lactams, quinolones and aminoglycosides. Acinetobacter baumannii was sensitive to polymyxin, tigecycline and amikacin, whereas resistant to the other antibiotics. No Gram-positive pathogens was resistant to vancomycin, linezolid and teicoplanin. Staphylococcus aureus and coagulase-negative staphylococci were the most commonly isolated Gram-positive pathogens, which yielded resistance rates of 36% and 87% to oxacillin sodium, and were generally resistant to penicillin and erythromycin. The resistance rate of Enterococcus faecalis to quinolones and erythromycin exceeded 90%, and 55% for high-concentration gentamicin. Conclusions The infection rate of organ donors from organ donation after citizen's death is relatively high, and the main infection site is lung. Gram-negative pathogens are the most commonly isolated strains, and certain strains tend to exhibit multiple drug resistance.

2.
Article in Spanish | LILACS, BDNPAR | ID: biblio-1337804

ABSTRACT

La resistencia a los antimicrobianos (RAM), representa un grave problema por el uso indiscriminado de antimicrobianos de amplio espectro. En nuestro país, durante el primer cuatrimestre del año, se observó un aumento inusual en el número de aislamiento de gérmenes multirresistentes, sobre todo de bacilos gramnegativos, los cuales fueron remitidos al laboratorio de referencia con el objetivo de caracterizar los genes de resistencia a los carbapenemes. Estudio observacional y prospectivo de corte transversal en 456 aislamientos de bacilos gramnegativos provenientes de 11 centros colaboradores de la Red Nacional de Vigilancia de la RAM, remitidos al Laboratorio Central de Salud Pública entre enero y abril de 2021, para la detección molecular (reacción en cadena de la polimerasa múltiple) de los genes de resistencia enzimática bla OXA-51, bla OXA-23, bla OXA-24, bla OXA-48, bla OXA-58, bla NDM, bla KPC, bla IMP, bla VIM. Trescientos sesenta correspondieron a bacilos gramnegativos no fermentadores: 346 Acinetobacter baumannii y 14 Pseudomonas aeruginosa; 96 fueron miembros de Enterobacterales, siendo prevalente Klebsiella pneumoniae (81). Todos los aislamientos de Acinetobacter baumannii resultaron ser productores de carbapenemasas: OXA-23 (94%), NDM (4%), NMD+OXA-58 (2%); en Pseudomonas aeruginosa, 7 de los 14 aislamientos (50%) fueron portadores de metalobetalactamasa del genotipo NDM (100%). Los genotipos NDM (92%) y KPC (8%) fueron confirmados en Enterobacterales. La resistencia plasmídica a carbapenemes es endémica en nuestro país, siendo prevalentes los genotipos OXA-23 en Acinetobacter baumannii y NDM en Pseudomonas aeruginosa y Enterobacterales


Antimicrobial resistance (AMR) represents a serious problem due to the indiscriminate use of broad-spectrum antimicrobials. During the first quarter of the year, an unusual increase in the number of isolation multi-resistant germs, especially gram-negative bacilli was observed, specially of Gram-negative bacilli which were referred to the reference laboratory in order to characterize the carbapenems resistance genes. Observational and prospective cross-sectional study in 456 isolates of Gram-negative bacilli from 11 collaborating centers of the National AMR Surveillance Network, referred to the Central Public Health Laboratory (LCSP) between January and April 2021, for molecular detection (multiple polymerase chain reaction) targeting the enzymatic resistance genes: bla OXA-51, bla OXA-23, bla OXA-24, bla OXA-48, bla OXA-58, bla NDM, bla KPC, bla IMP, bla VIM. Of the 456 isolates studied, 360 corresponded to non-fermenting Gram-negative bacilli, of which 346 were confirmed as Acinetobacter baumannii and 14 Pseudomonas aeruginosa; 96 were Enterobacterales, being Klebsiella pneumoniae (81) the most prevalent. All isolates of Acinetobacter baumannii carried genes encoding carbapenemases, being the OXA-23 (94%) followed by NDM (4%) and NDM +OXA-58 (2%). In Pseudomonas aeruginosa strains, 7 of the 14 isolates (50%) were carriers of NDM metallobetalactamase (100%). No carbapenemase gene was detected in the remaining 7. In all Enterobacterales strains, the presence of carbapenemases of the NDM (92%) and KPC (8%) genotypes were confirmed. Plasmid resistance to carbapenems is endemic in our country, being the OXA-23 genotypes prevalent in Acinetobacter baumannii and NDM in Pseudomonas aeruginosa and Enterobacterales


Subject(s)
Pseudomonas Infections , Acinetobacter baumannii , Carbapenem-Resistant Enterobacteriaceae , Pseudomonas aeruginosa , Bacteria , Drug Resistance , Polymerase Chain Reaction , Genotype
3.
São José dos Campos; s.n; 20210000. 79 p. il, graf, tab.
Thesis in Portuguese | LILACS | ID: biblio-1358938

ABSTRACT

A terapia fotodinâmica antimicrobiana (TFDa) tem sido considerada uma alternativa para o tratamento de infecções cutâneas causadas por Acinetobacter baumannii. Entretanto, é necessária a busca por fotossensibilizadores ou compostos que potencializem seus efeitos. Os objetivos desse estudo foram testar uma nova Clorina e-6 (Fotoenticine FTC) como fotossensibilizador para TFDa sobre A. baumannii, e o Farnesol como potencializador dessa terapia. Além disso, os efeitos do FTC foram comparados ao Azul de Metileno (AM), um fotossensibilizador já aprovado para uso clínico. Para isso, foram empregados os seguintes métodos: 1) Teste de concentração inibitória mínima (CIM) para estabelecer a concentração do Farnesol a ser utilizada no estudo, 2) TFDa em culturas planctônicas com ou sem tratamento prévio com Farnesol, 3) Teste de permeabilidade da membrana celular de A. baumannii e análise por microscopia confocal para avaliar a internalização dos fotossensibilizadores, 4) TFDa em biofilmes para determinar a contagem de UFC/mL de A. baumannii e a viabilidade celular por fluorescência, 5) Ensaios in vivo para avaliar os efeitos da TFDa sobre lesões de queimadura infectadas por A. baumannii em Galleria mellonella. Como resultados, observou-se no teste de CIM que o Farnesol não teve efeito antimicrobiano sobre A. baumannii. A TFDa com AM e FTC reduziu, respectivamente, 4 e 2 log (UFC/mL) de A. baumannii em crescimento planctônico. Ambos os fotossensibilizadores foram capazes de penetrar nas células bacterianas, porém o Farnesol não aumentou a permeabilidade celular. A TFDa com AM reduziu 4 log (UFC/mL) de A. baumannii em biofilmes, já a TFDa com FTC não apresentou efeito sobre a contagem de UFC/mL. A aplicação da TFDa com FTC não teve efeito sobre as lesões de queimadura em G. mellonella, entretanto a TFDa com AM aumentou a sobrevida das larvas em 35%. Concluiu-se que a TFDa com FTC teve ação antimicrobiana apenas em culturas planctônicas de A. baumannii e a ação do Farnesol associada a TFDa foi cepa dependente. Dentro dos parâmetros testados nesse estudo, a atividade antimicrobiana da TFDa com FTC foi inferior ao AM nos ensaios in vitro e in vivo


Antimicrobial photodynamic therapy (aPDT) has been an alternative for the treatment of skin infections caused by Acinetobacter baumannii. However, it is necessary to search for photosensitizers or compounds that enhance their effects. The objectives of this study were to test a new Chlorine e-6 (Fotoenticine FTC) as a photosensitizer for aPDT on A. baumannii, and Farnesol as an enhancer for this therapy. In addition the effects of FTC were compared to Methylene Blue (MB), a photosensitizer already approved for clinical use. For this, the following methods were used: 1) Minimum inhibitory concentration test (MIC) to establish the concentration of Farnesol to be used in the study, 2) aPDT in planktonic cultures with or without previous treatment with Farnesol, 3) Permeability test of the cell membrane of A. baumannii and analysis by confocal microscopy to assess the internalization of photosensitizers, 4) aPDT in biofilms to determine the CFU/mL count of A. baumannii and cell viability by fluorescence, 5) In vivo assays to evaluate the effects of aPDT on burn injuries infected by A. baumannii in Galleria mellonella. As a result, it was observed in the MIC test that Farnesol had no antimicrobial effect on A. baumannii. aPDT with MB and FTC reduced, respectively, 4 and 2 log (CFU/mL) of A. baumannii in planktonic growth. Both photosensitizers were able to penetrate bacterial cells, however Farnesol did not increase cell permeability. aPDT with MB reduced 4 log (CFU/mL) of A. baumannii in biofilms, whereas aPDT with FTC had no effect on the CFU/mL count. The application of aPDT with FTC had no effect on burn injuries in G. mellonella, however aPDT with MB increased the larvae survival by 35%. It was concluded that aPDT with FTC had antimicrobial action only in planktonic cultures of A. baumannii and the action of Farnesol associated with PDT was a dependent strain. Within the parameters tested in this study, the antimicrobial activity of aPDT with FTC was lower than MB in in vitro and in vivo assays


Subject(s)
Photochemotherapy , Burns , Photosensitizing Agents , Acinetobacter baumannii
4.
Rev. epidemiol. controle infecç ; 11(1): 26-31, jan.-mar. 2021. ilus
Article in English | LILACS | ID: biblio-1362111

ABSTRACT

Background and Objectives: carbapenem resistance in Acinetobacter baumannii has reached extremely high levels worldwide, and class D OXA-type carbapenemases are the main associated mechanism. This study aimed to assess the phenotypic and molecular profile of clinical carbapenem-resistant A. baumannii (CRAb) isolates from a southern Brazilian border region. Methods: A. baumannii species was identified by the presence of the blaOXA-51 gene, and the susceptibility profile was determined by broth microdilution. The main carbapenemases were investigated by PCR and the molecular typing was performed by PFGE. Results: during the study, a total of 36 CRAb were recovered, of which 85.7% were from respiratory tract samples from ICU patients. High level resistance to were found in contrast to 100% of susceptibility for polymyxin B. The blaOXA-23 gene was present in 34 isolates and was the only one detected other than blaOXA-51. Molecular typing revealed the presence of four clonal strains, two of them endemic during the period of the study. Conclusion: to the best of our knowledge, our study brings the first data about resistance profile in Acinetobacter in the western border of southern Brazil and make aware of endemic clones of CRAb-producing-OXA-23 in this region of state, contributing for the construction of the national epidemiologic scenario of CRAb.(AU)


Justificativa e Objetivos: a resistência aos carbapenêmicos em Acinetobacter baumannii atingiu níveis extremamente altos em todo o mundo, e as carbapenemases do tipo OXA classe D são o principal mecanismo associado. O objetivo deste estudo foi avaliar o perfil fenotípico e molecular de isolados clínicos de A. baumannii resistentes aos carbapenêmicos (CRAb) de uma região de fronteira do sul do Brasil. Métodos: a espécie A. baumannii foi identificada através da presença do gene blaOXA-51, e o perfil de sensibilidade foi determinado por microdiluição em caldo. As principais carbapenemases foram investigadas por PCR, e a tipagem dos isolados de CRAb foi realizada por PFGE. Resultados: durante o período do estudo, 36 CRAb foram recuperados, dos quais 85,7% foram provenientes de amostras do trato respiratório de pacientes de UTI. Uma elevada resistência a aminoglicosídeos e fluoroquinolonas foi encontrada em contraste com 100% de sensibilidade a polimixina B. O gene blaOXA-23 foi encontrado em 34 isolados e foi o único detectado além do blaOXA-51. A tipagem molecular revelou a presença de quatro linhagens clonais, duas delas endêmicas ao longo do período do estudo. Conclusão: nosso estudo traz os primeiros dados sobre o perfil de resistência em Acinetobacter na fronteira oeste do sul do Brasil e alerta para a presença de clones endêmicos de CRAb produtores de OXA-23 nessa região, contribuindo para a construção do cenário epidemiológico nacional de CRAb.(AU)


Justificación y Objetivos: la resistencia a carbapenémicos en Acinetobacter baumannii ha alcanzado niveles extremadamente altos en todo el mundo y las carbapenemases OXA de clase D son el principal mecanismo asociado. El objetivo de este estudio fue evaluar el perfil fenotípico y molecular de los aislados clínicos de A. baumannii resistentes a carbapenémicos (CRAb) de una región fronteriza en el sur de Brasil. Métodos: la especie A. baumannii se identificó a través de la presencia del gen blaOXA-51 y el perfil de sensibilidad se determinó por microdilución en caldo. Las principales carbapenemasas fueron investigadas por PCR y la tipificación se hizo con PFGE. Resultados: durante el período de estudio, se recuperaron 36 CRAb, 85,7% de muestras del tracto respiratorio de pacientes de la UCI. Se encontró una alta resistencia a los aminoglucósidos y las fluoroquinolonas en contraste con 100% de sensibilidad a polimixina B. El gen blaOXA-23 se encontró en 34 aislamientos y fue el único detectado además de blaOXA-51. La tipificación molecular reveló la presencia de cuatro cepas clonales, dos de ellas endémicas durante el período de estudio. Conclusiones: hasta donde sabemos, nuestro estudio trae los primeros datos sobre el perfil de resistencia en Acinetobacter en la frontera oeste del sur de Brasil y reconoce los clones endémicos de CRAb productores de OXA.(AU)


Subject(s)
Acinetobacter Infections/epidemiology , Drug Resistance, Microbial , Carbapenem-Resistant Enterobacteriaceae , Carbapenems , Acinetobacter baumannii
5.
Rev. bras. anal. clin ; 53(1): 58-63, 20210330. graf, tab
Article in Portuguese | LILACS | ID: biblio-1291397

ABSTRACT

Objetivo: Avaliar a prevalência e o perfil de suscetibilidade aos antimicrobianos das cepas de Acinetobacter baumannii e Pseudomonas aeruginosa isoladas de amostras de lavado traqueal. Métodos: Trata-se de um estudo retrospectivo, transversal, descritivo, no qual foram coletados resultados de cultura de lavado traqueal de pacientes com PAV, internados em uma UTI adulta de um hospital público da cidade de Juiz de Fora, MG. Os dados foram coletados nos registros eletrônicos do Serviço de Controle de Infecção Hospitalar, referentes ao período de janeiro a dezembro de 2018. Resultados: Foram analisadas 469 amostras de lavado traqueal de pacientes adultos internados na UTI, sendo consideradas culturas positivas, aquelas com contagem de colônias ≥106UFC/ mL, totalizando 242 (51,52%) das amostras de lavado traqueal positivas, sendo que, destas, 230 foram monomicrobianas e 12 com dois micro-organismos. Foram isoladas 59 (24,89%) cepas de Acinetobacter baumannii e 45 (18,98%) cepas de Pseudomonas aeruginosa. De acordo com os critérios do CLSI 2018, 100% das cepas de A. baumannii se mostraram resistentes a meropenem, cefepime, ceftriaxona, ceftazidima e piperaci- lina-tazobactam. Conclusão: A. baumannii e Pseudomonas aeruginosa são agentes importantes de PAV, sendo que A. baumannii foi o patógeno mais comumente associado e apresentou multirresistência aos fármacos testados.


Objective: The objective of this study is to evaluate the prevalence and antimicrobial susceptibility profile of strains of A. baumannii and P. aeruginosa isolated from tracheal lavage. Methods: This is a retrospective, cross-sectional, descriptive study where tracheal lavage culture results were collected from patients with VAP admitted to an adult ICU at a public hospital in the city of Juiz de Fora. Data were collected through the records of the Hospital Infection Control Service for the period from January to December 2018. Results: 469 tracheal lavage samples from adult patients admitted to the ICU were analyzed. Positive cultures were considered if ≥106CFU / mL, totaling 242 (51.52%) of the tracheal lavage samples were positive; 55 (24.89%) strains of A. baumannii and 45 (18.98%) strains of P. aeruginosa were isolated. According to the CLSI 2018 criteria, A. Baumannii presented 100% of the strains resistant to meropenem, cefepime, ceftriaxone, ceftazidime and piperacillin-tazobactam. Conclusion: A. baumannii and P. aeruginosa are important agents of PAV. Furthermore, A. baumannii was the most commonly associated pathogen and presented multiresistance to the drugs tested, being considered as a public health issue.


Subject(s)
Humans , Male , Female , Pneumonia , Pseudomonas aeruginosa , Respiration, Artificial , Acinetobacter Infections , Drug Resistance , Acinetobacter baumannii
6.
Article in Chinese | WPRIM | ID: wpr-912092

ABSTRACT

Nosocomial infections caused by gram-negative opportunistic pathogens, including Acinetobacter baumannii ( A. baumannii) and Klebsiella pneumoniae ( K. pneumoniae), pose a great challenge to health care management and human health. New treatment strategies are urgently needed to tackle with the spread of multi-drug resistant strains and the increase in bacterial virulence. Type Ⅵ secretion system (T6SS), a conservative secretory apparatus encoded in a variety of gram-negative bacteria, can inject effectors into other prokaryotic or eukaryotic cells in a contact-dependent manner to achieve antibacterial and anti-host properties. It is closely related to the environmental adaptability, competitiveness and colonization ability of bacteria in hosts. The T6SS gene cluster is composed of core genes, effector genes and associated genes, and the effectors encoded by it are highly diverse and play an important role in pathogen infection. This review summarized the advances in A. baumannii and K. pneumoniae T6SS in terms of competition, host colonization, interaction between conjugative plasmids and expression regulation, aiming to provide reference for future study on T6SS-related antimicrobial activity, virulence and resistance.

7.
Rev. Soc. Bras. Med. Trop ; 54: e20200087, 2021. tab, graf
Article in English | ColecionaSUS, LILACS, ColecionaSUS, SES-SP | ID: biblio-1136920

ABSTRACT

Abstract INTRODUCTION: In this study, we report a clonal dissemination of carbapenem resistant Acinetobacter baumannii isolates due to the acquisition of blaOXA-23 in a regional hospital located in Brazilian Amazon Region. METHODS: The isolates were identified by MALDI-TOF and the carbapenemase-encoding genes were detected by multiplex-PCR. The genetic similarity was investigated by pulsed-field gel electrophoresis (PFGE). RESULTS: Only 10 (55.6%) isolates harbored the gene bla OXA-23. PFGE analysis revealed that these isolates belong to a single clone. CONCLUSIONS: This dissemination strategy indicates the need for surveillance, adoption of control procedures defined in guidelines, and the careful administration of antimicrobials should be reinforced.


Subject(s)
Humans , Acinetobacter Infections/epidemiology , Acinetobacter baumannii/genetics , Bacterial Proteins/genetics , beta-Lactamases/genetics , Brazil/epidemiology , Drug Resistance , Microbial Sensitivity Tests , Electrophoresis, Gel, Pulsed-Field , Molecular Epidemiology , Hospitals , Anti-Bacterial Agents/pharmacology
8.
Braz. J. Pharm. Sci. (Online) ; 57: e19048, 2021. tab, graf
Article in English | LILACS | ID: biblio-1345460

ABSTRACT

Drug-resistant Acinetobacter baumannii is a frightening reality. The aim of this study is to examine the expression profiles of blaOXA-51 gene in carbapenemases producing A. baumannii treated with imipenem/sulbactam combination. Carbapenemases producing A. baumannii was identified among clinical isolates of A. baumannii obtained from patients at Shahid Rajaee hospital, Gachsaran, Iran, from January to June 2018. Synergism testing of imipenem/sulbactam on carbapenemases producing A. baumannii was carried out by broth microdilution method. Eventually, the expression of blaOXA-51 gene was carried out to investigate the inhibitory properties of imipenem/sulbactam combination against carbapenemases producing A. baumannii using quantitative real time RT-PCR. Among A. baumannii isolates, 24% were carbapenemases producing A. baumannii. Imipenem/sulbactam combination revealed synergistic and partial synergistic effect for all tested isolates (FIC= 0.313-0.75). Finally, imipenem/sulbactam combination displayed significant down-regulation of blaOXA-51 gene in carbapenemases producing A. baumannii. Imipenem synergizes with sulbactam against carbapenemases producing A. baumannii by targeting of the blaOXA-51 gene.


Subject(s)
Sulbactam/agonists , Imipenem/agonists , Acinetobacter baumannii/drug effects , Patients/classification , In Vitro Techniques/instrumentation , Pharmaceutical Preparations/analysis , Hospitals/classification , Methods
9.
Rev. Soc. Bras. Med. Trop ; 54: e05992020, 2021. tab
Article in English | LILACS | ID: biblio-1155526

ABSTRACT

Abstract INTRODUCTION: This study aimed to determine the role of genes encoding aminoglycoside-modifying enzymes (AMEs) and 16S rRNA methylase (ArmA) in Acinetobacter baumannii clinical isolates. METHODS: We collected 100 clinical isolates of A. baumannii and identified and confirmed them using microbiological tests and assessment of the OXA-51 gene. Antibiotic susceptibility testing was carried out using disk agar diffusion and micro-broth dilution methods. The presence of AME genes and ArmA was detected by PCR and multiplex PCR. RESULTS: The most and least effective antibiotics in this study were netilmicin and ciprofloxacin with 68% and 100% resistance rates, respectively. According to the minimum inhibitory concentration test, 94% of the isolates were resistant to gentamicin, tobramycin, and streptomycin, while the highest susceptibility (20%) was observed against netilmicin. The proportion of strains harboring the aminoglycoside resistance genes was as follows: APH(3′)-VIa (aphA6) (77%), ANT(2")-Ia (aadB) (73%), ANT(3")-Ia (aadA1) (33%), AAC(6′)-Ib (aacA4) (33%), ArmA (22%), and AAC(3)-IIa (aacC2) (19%). Among the 22 gene profiles detected in this study, the most prevalent profiles included APH(3′)-VIa + ANT(2")-Ia (39 isolates, 100% of which were kanamycin-resistant), and AAC(3)-IIa + AAC(6′)-Ib + ANT(3")-Ia + APH(3′)-VIa + ANT(2")-Ia (14 isolates, all of which were resistant to gentamicin, kanamycin, and streptomycin). CONCLUSIONS: High minimum inhibitory concentration of aminoglycosides in isolates with the simultaneous presence of AME- and ArmA-encoding genes indicated the importance of these genes in resistance to aminoglycosides. However, control of their spread could be effective in the treatment of infections caused by A. baumannii.


Subject(s)
Acinetobacter baumannii/genetics , Bacterial Proteins , RNA, Ribosomal, 16S/genetics , Microbial Sensitivity Tests , Drug Resistance, Bacterial/genetics , Aminoglycosides/pharmacology , Methyltransferases , Anti-Bacterial Agents/pharmacology
10.
Infectio ; 24(1): 27-34, ene.-mar. 2020. tab, graf
Article in English | LILACS, COLNAL | ID: biblio-1090540

ABSTRACT

Abstract Objectives: Carbapenem resistantAcinetobacter baumannii is an important therapeutic and infection control challenge worldwide. In this study, we investigated the prevalence and distribution of molecular mechanisms of resistance among carbapenem resistant A. baumannii species at a tertiary care setting in South India. Materials and Methods: A total of 89 non-duplicate clinical isolates of carbapenem-resistantA. baumannii were collected from critical care units of St. John's Medical College Hospital, Bengaluru, India. Polymerase chain reaction (PCR) was performed to detect blaOXA type carbapenemase blaOXA-51-like, blaOXA-23-like, blaOXA-24-like and bla OXA-58-like, MBL genes blaNDM, blaIMP, and blaVIM genes. Molecular typing of carbapenem-resistant A. baumannii strains was performed by using Rep-PCR. Results: Eighty-seven of the isolates were found to carry the blaOXA-51 gene and 81 (91%) isolates were found to have blaOXA-51-like gene and blaOXA-23, gene. The bla OXA-24 like gene was detected in two isolates of which one also carried blaOXA-51 like and one isolate carried blaVIM coding gene. The prevalence of blaNDM, blaIMP, bla VIM genes was 12(13%),14 (16%) and 57(64%) respectively. Cluster analyses revealed a 90% similarity and were divided into 5 clusters. Most of the isolates containing carbapenemases coding genes grouped under cluster A, C and UC. Considerable heterogeneity was observed within UC cluster indicating circulation of multiple strains of A. baumannii within our institution. Conclusions: Carbapenemase coding blaOXA-23, blaOXA-24 and blaOXA-51 -like were more common than blaVIM and blaNDM. The presence of blaNDM with other genes coding for carbapenemases indicate the ability of the strains to acquire novel genes despite having its share of the blaOXA like carbapenemase.


Resumen Objetivos: El Acinetobacter baumannii resistente a Carbapenem es un reto importante en todo el mundo para su tratamiento y para el control de infecciones hospitalarias. Nosotros estudiamos la prevalencia y los mecanismos de resistencia en aislados de un centro de atención terciario, en el sur de la India Materiales y Métodos: Se estudiaron 89 aislados clínicos de A. baumannii recolectados en unidades de cuidado crítico del Hospital St. John's Medical College en Bengaluru, India. Se realizó amplificación por PCR (Reacción en Cadena de Polimerasa) y luego tipificación molecular con la técnica Rep-PCR (PCR de elementos repetitivos palindromicos) para detectar los genes de carbapenemasa blaOXA, blaOXA-51, blaOXA-23, blaOXA-24, blaOXA-58, MBL, blaNDM, blaIMP y blaVIM. Resultados: Se encontraron 87 aislados que llevaban el gen blaOXA-51 y de ellos en 81 (91%) se encontró blaOXA-51 y blaOXA-23. El blaOXA-24 se detectó en dos aislados de los cuales uno de ellos llevaba blaOXA-51 y otro blaVIM. Los genes blaNDM, blaIMP y blaVIM se encontraron en 12 (13%),14 (16%) y 57(64%) de los aislados, respectivamente. El análisis de agrupamiento reveló un 90% de similitud entre los aislados y que podían asignarse a 5 agrupamientos. La mayoría de aislados llevaban genes de carbapenemasas de los grupos A, C y UC. Se observó mucha heterogeneidad dentro del agrupamiento UC indicando que existe circulación de múltiples cepas de A. baumannii dentro de nuestra institución. Conclusiones: Las carbapenemasas que codifican para blaOXA-23, blaOXA-24 y blaOXA-51 son más comunes que blaVIM y blaNDM en nuestra institución. La presencia de NDM con otros genes codificando para carbapenemasas indica la capacidad que tienen este tipo de aislados para adquirir nuevos genes a pesar de contar con blaOXA.


Subject(s)
Humans , Carbapenems , Acinetobacter baumannii , Genetic Variation , Drug Resistance, Microbial , Cross Infection , India
11.
Article in English | WPRIM | ID: wpr-762459

ABSTRACT

BACKGROUND: The existing modified carbapenem inactivation methods (mCIMs) recommended by the CLSI for detecting carbapenemase production have not been applicable for Acinetobacter baumannii. We evaluated the influence of matrices used in mCIMs and CIMTris on the stability of the disks for detecting carbapenemase producers and suggested optimal mCIM conditions for detecting carbapenemase-producing A. baumannii. METHODS: Seventy-three A. baumannii isolates characterized for antimicrobial susceptibility and carbapenemase encoding genes were tested for carbapenemase production using mCIM and CIMTris. The influence of the matrices (Tryptic soy broth [TSB] and Tris-HCl) used in these methods on the stability of the meropenem (MEM) disk was also evaluated. The mCIM conditions were adjusted to enhance screening sensitivity and specificity for detecting carbapenemase-producing A. baumannii. RESULTS: The matrices had an impact on the stability of the MEM disk after the incubation period (two or four hrs). TSB nutrient broth is an appropriate matrix for mCIM compared with Tris-HCl pH 7.6, which leads to the loss of MEM activity in CIMTris. The sensitivity and the specificity of the optimal mCIM were both 100%. CONCLUSIONS: We established optimal mCIM conditions for simple, accurate, and reproducible detection of carbapenemase-producing A. baumannii.


Subject(s)
Acinetobacter baumannii , Acinetobacter , Hydrogen-Ion Concentration , Mass Screening , Methods , Sensitivity and Specificity
12.
Article in English | WPRIM | ID: wpr-762458

ABSTRACT

BACKGROUND: Mutations in the quinolone resistance-determining regions (QRDRs) of Acinetobacter baumannii DNA gyrase (gyrA) and topoisomerase IV (parC) are linked to fluoroquinolone (FQ) resistance. We developed a mismatched PCR-restriction fragment length polymorphism (RFLP) assay to detect mutations in the gyrA and parC QRDRs associated with FQ resistance in A. baumannii. METHODS: Based on the conserved sequences of A. baumannii gyrA and parC, two primer sets were designed for mismatched PCR-RFLP to detect mutations in gyrA (codons 83 and 87) and parC (codons 80 and 84) by introducing an artificial restriction enzyme cleavage site into the PCR products. This assay was evaluated using 58 A. baumannii strains and 37 other Acinetobacter strains that have been identified by RNA polymerase β-subunit gene sequence analysis.


Subject(s)
Acinetobacter baumannii , Acinetobacter , Conserved Sequence , DNA Gyrase , DNA Topoisomerase IV , DNA-Directed RNA Polymerases , Polymerase Chain Reaction , Sequence Analysis
13.
China Pharmacy ; (12): 2889-2894, 2020.
Article in Chinese | WPRIM | ID: wpr-837544

ABSTRACT

OBJECTIVE:To provide reference for clinical empirical treatme nt of non-fermentative Gram-negative bacilli (NFGNB)infection. METHODS :All kinds of clinical specimens were collected from Jan. 2010 to Dec. 2019 in a tertiary hospital from Hanzhong city of Shaanxi province ;the distribution and drug resistance of NFGNB were analyzed retrospectively. RESULTS : A total of 26 386 strains of pathogenic bacteria were detected in the hospital during 2010-2019,including 4 077 strains of NFGNB (15.45%),mainly from patients ≥60 years old (1 836 strains,45.05%). During the 10 years,the detection rate of NFGNB decreased from 20.14% in 2010 to 15.36% in 2019 (P<0.001). Acinetobacter baumannii (1 359 strains),Pseudomonas aeruginosa (1 269 strains),Stenotrophomonas maltophilia (447 strains) and Burkholderia cepacia (351 strains) were main pathogens. The detected NFGNB mainly came from hospitalized patients (4 001 strains),and most of them were found in ICU (17.05%),neurosurgery department (14.52%),respiratory department (12.41%),and respiratory tract (66.69%),secretion (7.80%)specimens. The detection rates of A. baumannii and P. aeruginosa in oncology department ,blood specimens and urine specimens showed an overall upward trend ,while the detection rates in ICU of the hospital showed a downward trend (P<0.05); the detection rate of P. aeruginosa in neurosurgery department showed an upward trend (P<0.05),and that of A. baumannii in respiratory department showed an upward trend (P<0.05). The resistance rate of A. baumannii to carbapenems increased from about 10% in 2010 to about 75% in 2019,and the guyh3201@163.com resistance rate to cephalosporins exceeded 78%. The resistance rates of P. aeruginosa to imipenem and me ropenem were lower than 35% and 30% respectively,and the trend of drug resistance did not change significantly (P>0.05);the resistance rates to 12 kinds of clinically commonly used antibiotics as piperacillin and aztreonam were lower than 40%. The resistance rate of S. maltophilia to compound sulfamethoxazole showed a decreasing trend (P<0.001),and the resistance rate to ceftazidime was high (54.70%-74.10%). The resistance rates of B. cepacia to compound sulfamethoxazole,meropenem and ceftazidime showed a downward trend (P<0.01),and were lower than 15% after 2014. CONCLUSIONS:Although the detection rate of NFGNB in our hospital showed a downward trend ,the multi-drug resistance and pan-drug resistance of A. baumannii are serious ,and the resistance rate to carbapenems is increased. Sensitive drugs such as cefoperazone/sulbactam,amikacin,levofloxacin and ceftazidime should be selected for NFGNB infection according to the results of drug sensitivity tests.

14.
Article in Chinese | WPRIM | ID: wpr-823929

ABSTRACT

Objective: To examine the effect of Rumex crispus (R. crispus) and Rumex sanguineus (R. sanguineus) plant extracts against isolates of Acinetobacter baumannii (A. baumannii) from wounds, including multidrug-resistant strains.Methods: Six prepared Rumex extracts were subjected to liquid chromatography-tandem mass spectrometry. Antimicrobial activity of extracts and pure compounds (catechin, quercetin, isoquercitrin, emodin, and gallic acid) was examined by a microtiter plate method, while for determination of compound binary combinations activity a checkerboard method was applied. Active fractions of extracts were detected by agar-overlay high-performance thin-layer chromatography-bioautography assay followed by liquid chromatography - diode array detection - mass spectrometry analysis. Results: A total of 28 compounds were detected in two extracts of R. crispus and 26 compounds in four different R. sanguineus extracts, with catechin as a dominant component. Anti-A. baumannii activity was confirmed for all six R. sanguineus and R. crispus extracts at the concentration range from 1 to 4 mg/mL. Neither examined single compounds nor their binary combinations exhibited an anti-A. baumannii activity (MIC>256 μg/mL). The bioautography showed that fractions with the most prominent anti-A. baumannii activity tended to contain more polar compounds, predominantly flavonol (quercetin and kaempherol) glycosides; but also fractions containing flavanone (eriodictyol) glycosides and anthraquinone (emodin) glycosides; and less polar eriodictyol aglycone. Conclusions: The results justify and elucidate the traditional application of R. sanguineus and R. crispus extracts for wound healing, indicating the necessity for their further examination in combat against multidrug-resistant A. baumannii isolates from wounds.

15.
Article in Chinese | WPRIM | ID: wpr-823131

ABSTRACT

Objective To investigate the distribution characteristics of ABA (Acinetobacter baumannii) and to analyze the influencing factors of the prognosis of elderly patients with COPD (chronic obstructive pulmonary disease) and lung infection in Shaanxi. Methods A retrospective single-center survey was conducted on 1 078 elderly patients with COPD admitted to our hospital from January 2015 to November 2019. According to the presence or absence of ABA infection, the patients were divided into infection group (n=63) and non-infection group (n=1 015). Through the electronic medical record system, the basic information of all patients was collected, including name, sex, age, case number, length of stay in ICU, index of auxiliary examination, combined diseases and prognosis. The prognostic outcomes of the two groups of patients were compared. Univariate analysis was performed on the baseline data of the two groups of the patients, and unconditional logistic multivariate regression analysis was used to further analyze the single factors with statistical difference, to explore the distribution and influencing factors of ABA in elderly COPD patients with pulmonary infection in Shaanxi. Results The mortality rate of the infected group was significantly higher than that of the non-infected group (χ2=8.670, P=0.003). Univariate analysis showed that there were significant differences in age, Apache II score, diabetes, PCT and ICU length of stay between the infected and non-infected groups (P<0.05), while there were no significant differences in sex, cerebrovascular disease, malnutrition, bed rest and tumor (P<0.05). In the infection group, 55 patients survived, 42 patients were discharged, 13 patients received extended hospitalization and 8 patients died. Of those who died, 5 were resistant to cefoperazone and all were resistant to carbapenems. Of those remaining hospitalized, 3 patients were resistant to cefoperazone sulbactam and 7 were resistant to carbapenems. Patients discharged from the hospital were more sensitive to carbapenems, minocycline and cefoperazone. According to multiple logistic regression analysis, apache II score (OR=3.480,95%CI 1.154-10.491), diabetes mellitus (OR=2.732,95%CI 1.297-5.753), high serum PCT (OR=6.334,95%CI 1.142-35.129) and ICU hospitalization (OR=3.773,95%CI 1.087-13.100) were independent risk factors influencing the prognosis of elderly patients with COPD in Shaanxi. Conclusion ABA Infection was correlated with age, Apache II score, diabetes Mellitus, PCT and length of stay in ICU, which could influence prognosis of elderly patients with COPD.

16.
Article in English | WPRIM | ID: wpr-821232

ABSTRACT

@#BACKGROUND: Acinetobacter baumannii (AB) bacteremia is an increasingly common and often fatal nosocomial infection. Identification of morbidity and mortality risk factors for AB bacteremia in emergency department (ED) patients may provide ways to improve the clinical outcomes of these patients. METHODS: The records for 51 patients with AB bacteremia and 51 patients without AB infection were collected and matched in a retrospective case-control study between 2013 and 2015 in a singlecenter ED. Risk factors were analyzed by Chi-square and multivariate logistic regression statistical models. RESULTS: A signifi cant risk factor for morbidity was the presence of a central venous catheter (CVC) (P<0.001). The mortality rate for the 51 patients with AB bacteremia was 68.6%. Risk factors for mortality were the presence of a CVC (P=0.021) and an ED stay longer than two weeks (P=0.015). CONCLUSION: AB infections lead to high morbidity and mortality. The presence of a CVC was associated with higher morbidity and mortality in patients with AB bacteremia. Avoiding CVC insertions may improve outcomes in ED patients with AB bacteremia.

17.
Article in Chinese | WPRIM | ID: wpr-818368

ABSTRACT

Objective Acinetobacter baumannii (A. baumannii) is a commonly infective bacterium in the hospital. This study aims to analyze its molecular epidemiological characteristics, detect the carrying rate of efflux pump and regulatory protein genes, and investigate the effects of tigecycline on the efflux pump and expression of regulatory protein genes. Methods A total of 183 A. baumannii strains were collected from inpatients of the affiliated hospital of Jiangsu University from May 2017 to March 2019. They were divided into an antimicrobial-resistant group (one or more antimicrobial-resistant strains, 139 strains) and a sensitive group (the drugs in the drug sensitivity test were all non-resistant strains, 44 strains). Repeated sequence PCR was used for homology analysis of the strains, and pulse-field gel electrophoresis (PFGE) was used as the gold standard for homology analysis to verify and compare some strains. PCR was used to detect the occurrence of drug resistance-related genes. Based on homology analysis, efflux pump carrying rate detection and antibiotics sensitivity test results, 6 clinical strains carrying all efflux pump genes but different resistance phenotypes were selected as experimental strains, including sensitive strains (SAB), the multidrug resistance strain (MDRAB) and the extensively drug-resistant strain (XDRAB). All strains were induced in vitro with the minimum inhibitory concentration (MIC) of tigecycline. The induced strains were categorized as induction group, and the same strains cultured in LB agar without tigecycline was used as a control group. MIC was used to analyze the tigecycline susceptibility, and RT-qPCR was used to detect the gene expression of efflux pumps, such as TetB, AbaQ and regulatory proteins (AdeS and BaeS), in drug-resistant strains. Results Homology analysis showed that there were 45 clonal groups in the detected clinical isolates, with no obvious outbreak of epidemic clonal groups. Efflux pumps and regulatory proteins were widely distributed in the clinical isolates, and the expression of AdeB, TetB, AbeS, AdeS in MDRAB and XDRAB is significantly higher than that insensitive group SAB. Continuous in vitro induction with tigecycline could increase the antimicrobial resistance of some clinical strains and even significantly increase the expression levels of efflux pumps and regulatory proteins. Conclusion A. baumannii is widely distributed in the clinic, and efflux pumps and regulatory proteins might play an important role in drug resistance process. The unreasonable use of tigecycline could enhance the tolerance of A. baumannii by up-regulating the expression of some bacterial efflux pumps.

18.
China Pharmacy ; (12): 340-343, 2020.
Article in Chinese | WPRIM | ID: wpr-817341

ABSTRACT

OBJECTIVE:To provide reference for clinical treatment of Acinetobacter baumannii infection and rational use of antibiotics. METHODS :By retrospective analysis ,64 500 strains of bacteria were isolated from the inpatients of our hospital during Jan. 2015 to Dec. 2018. WHONET 5.6 software was used to analyze the detection rate ,specimen type ,departments of A. baumannii. The resistance of A. baumannii to 18 commonly used antibiotics in 4 years was analyzed by RxC table χ 2 test. RESULTS:A total of 2 072,2 040,2 017 and 2 143 strains of A. baumannii were isolated during 2015-2018,accounting for 12.85%,13.38%,13.60%,11.71% of positive specimens. The main specimen types of 8 272 strains of A. baumannii were sputum(4 368 strains,52.81%),pus(1 106 strains,13.37%),ascites(804 strains,9.72%). The main departments were burn department(1 605 strains,19.40%),hepatobiliary department (1 200 strains,14.51%),brain surgery department (977 strains, 11.81%). The drug resistance rate to 18 kinds of antibiotics showed a wave-like decreasing trend (P<0.001). In 2018,drug resistance rate to ampicillin and aztreonam was more than 80%,and that to ampicillin/sulbactam ,ceftazidime,levofloxacin, Compound sulfamethoxazole ,gentamicin,amikacin,tobramycin and tegacyclin was less than 50% ,among which the drug resistance rate to amikacin and tegacyclin were 14.7% and 0,respectively. CONCLUSIONS :There is no significant change in the number of isolates and detection rate of A. baumannii in our hospital between 2015 and 2018. The bacteria mainly cause respiratory tract infection. Amikacin or tegacyclin are recommended for treatment.

19.
Article in Korean | WPRIM | ID: wpr-816606

ABSTRACT

BACKGROUND: Acinetobacter baumannii infection is a significant health problem worldwide due to increased drug resistance. The limited antimicrobial alternatives for the treatment of severe infections by multidrug-resistant A. baumannii (MDRAB) make the search for other therapeutic options more urgent. Linalool, the major oil compound in Coriandrum sativum, was recently found to have high antibacterial activity against A. baumannii. The purpose of this study was to investigate the synergistic effect of linalool and colistin combinations against MDRAB and extensively drug-resistant A. baumannii (XDRAB).METHODS: A total of 51 strains of A. baumannii clinical isolates, consisting of 10 MDRAB and 41 XDRAB were tested. We determined the minimum inhibitory concentration (MIC) of linalool for the test strains using the broth microdilution method and searched for interactions using the time-kill assay.RESULTS: The time-kill assay showed that the linalool and colistin combination displayed a high rate of synergy (92.1%) (by synergy criteria 2), low rate of indifference (7.8%), and a high rate of bactericidal activity (74.5%) in the 51 clinical isolates of A. baumannii. The synergy rates for the linalool and colistin combination against MDRAB and XDRAB were 96% and 92.1%, respectively. No antagonism was observed for the linalool and colistin combination.CONCLUSION: The combination of linalool and colistin showed a high synergy rate, which may be beneficial for controlling MDRAB infections. Therefore, this combination is a good candidate for in vivo studies to assess its efficacy in the treatment of MDRAB infections.


Subject(s)
Acinetobacter baumannii , Acinetobacter , Colistin , Coriandrum , Drug Resistance , Methods , Microbial Sensitivity Tests
20.
Article in Korean | WPRIM | ID: wpr-816603

ABSTRACT

BACKGROUND: The emergence of multidrug-resistant Acinetobacter baumannii as a nosocomial pathogen is one of the major public health problems. The aim of this study was to evaluate the role of an efflux pump gene adeJ for the multidrug resistance of A. baumannii clinical isolates.METHODS: Two groups (MDRAB and SAB) of A. baumannii clinical isolates were studied. The SAB group consisted of strains that did not meet the criteria of MDRAB and were susceptible to more categories of antibiotics than MDRAB. Antimicrobial susceptibility results obtained by VITEKII system were used in data analysis and bacterial group allocation. We performed real-time reverse transcription PCR to determine relative expression of adeJ. We compared relative expression of adeJ in comparison groups by considering two viewpoints: i) MDRAB and SAB groups and ii) susceptible and non-susceptible groups for each antibiotic used in this study.RESULTS: The mean value of relative expression of adeJ of MDRAB and SAB groups was 1.4 and 0.92, respectively, and showed significant difference (P=0.002). The mean values of relative expression of adeJ of susceptible and non-susceptible groups to the antibiotics cefepime, ceftazidime, ciprofloxacin, imipenem, meropenem, tigecycline, piperacillin/tazobactam, ticarcillin/clavulanic acid, trimethoprim/sulfamethoxazole, piperacillin, and gentamicin showed statistically significant differences.CONCLUSION: The overexpression of adeIJK might contribute to the multi-drug resistance in A. baumannii clinical isolates. Further, the overexpression of adeIJK might be one of the factors contributing to the resistance to numerous antibiotics.


Subject(s)
Acinetobacter baumannii , Acinetobacter , Anti-Bacterial Agents , Ceftazidime , Ciprofloxacin , Drug Resistance, Multiple , Gentamicins , Imipenem , Piperacillin , Polymerase Chain Reaction , Public Health , Reverse Transcription , Statistics as Topic
SELECTION OF CITATIONS
SEARCH DETAIL