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Braz. j. biol ; 82: e237098, 2022. graf
Article in English | LILACS | ID: biblio-1153483


Abstract Endosymbiont bacteria can affect biological parameters and reduce the effectiveness of natural enemies in controlling the target insect. The objective of this work was to identify endosymbiont bacteria in Anaphes nitens (Girault, 1928) (Hymenoptera: Mymaridae), the main natural enemy used to manage Gonipterus platensis (Marelli, 1926) (Coleoptera: Curculionidae). Genomic DNA from six A. nitens populations was extracted and polymerase chain reactions (PCR) were performed with the primers to detect endosymbiont bacteria in this insect. The PCR products were amplified, sequenced, and compared with sequences deposited in the GenBank for the bacteria identification. All A. nitens populations had the bacterium Yersinia massiliensis (Enterobacteriales: Enterobacteriaceae). This bacterium was originally described as free-living, and it is associated with and composes part of the A. nitens microbiota. This is the first report of Y. massiliensis in an insect host.

Resumo As bactérias endossimbiontes podem afetar os parâmetros biológicos e reduzirem a eficácia de inimigos naturais no controle do inseto alvo. O objetivo deste trabalho foi identificar bactérias endossimbiontes em Anaphes nitens (Girault, 1928) (Hymenoptera: Mymaridae), o principal inimigo natural usado no manejo de Gonipterus platensis (Marelli, 1926) (Coleoptera: Curculionidae). O DNA genômico de seis populações de A. nitens foi extraído e as reações em cadeia da polimerase (PCR) realizadas com os primers para detectar bactérias endossimbiontes neste inseto. Os produtos de PCR foram amplificados, sequenciados e comparados com as sequências depositadas no GenBank para identificação das bactérias. Todas as populações de A. nitens tinham a bactéria Yersinia massiliensis (Enterobacteriales: Enterobacteriaceae). Esta bactéria foi originalmente descrita como de vida livre e está associada e compõe parte da microbiota de A. nitens. Este é o primeiro relato de Y. massiliensis em um hospedeiro.

Animals , Weevils , Hymenoptera/genetics , Yersinia/genetics , Enterobacteriaceae/genetics
Chinese Journal of Biotechnology ; (12): 1092-1106, 2021.
Article in Chinese | WPRIM | ID: wpr-878616


Antibiotic resistance is a major global concern and challenge in the 21st century. Enterobacteriaceae are one of the important pathogens of hospital-acquired infections. With the increasing use of antibiotics in clinical practice, a variety of drug-resistant Enterobacteriaceae, especially multidrug-resistant Enterobacteriaceae have emerged, posing an increasingly serious threat to human health. Bacteria can acquire antibiotic resistance by mutation or horizontal transfer of antibiotic resistance genes, and it is often possible to predict the corresponding resistance phenotype from known mechanism. However, recent findings suggest that genetic background and environmental factors could alter the expression of specific resistance genes and that a given genotype does not always generate the expected resistance phenotype. The genotype-phenotype segregation greatly hampers our ability to predict antibiotic resistance phenotype from a genetic perspective. In this review, we explore the genetic and environmental regulation of the expression of antibiotic resistance genes in a variety of Enterobacteriaceae, with the aim to provide scientific evidence for genetic prediction of antibiotic resistance phenotype and clinical guidance on drug use.

Anti-Bacterial Agents/pharmacology , Bacteria , Cross Infection , Drug Resistance, Microbial , Enterobacteriaceae/genetics , Humans
Chinese Journal of Biotechnology ; (12): 1081-1091, 2021.
Article in Chinese | WPRIM | ID: wpr-878615


The enterobacterial common antigen (ECA) is a polysaccharide composed of polysaccharide repeats that are located in the outer membrane of almost all Enterobacteriaceae bacteria and has diverse biological functions. ECA is synthesized by the synergistic action of multiple genes that are present in clusters on the genome of Enterobacteriaceae bacteria, forming the ECA antigen gene cluster, an important virulence factor that plays a role in host invasion and survival of Enterobacteriaceae in vivo. ECA also plays an important role in the maintenance of the bacterial outer membrane permeability barrier, flagella gene expression, swarming motility, and bile salts resistance. In addition, ECALPS, anchored in the core region of bacterial lipopolysaccharide, is an important surface antigen for bacteria, stimulating high levels of antibody production in the host and could be a target for vaccine research. This review summarizes ECA purification, genes involved in ECA biosynthesis, its immunological characteristics, biological functions and clinical applications.

Antigens, Bacterial/genetics , Enterobacteriaceae/genetics , Lipopolysaccharides , Polysaccharides
Rev. Soc. Bras. Med. Trop ; 54: e0724-2020, 2021. tab
Article in English | LILACS | ID: biblio-1155606


Abstract INTRODUCTION: Inadequate wastewater treatment and fecal contamination have a strong environmental impact on antimicrobial resistance (AMR). This study evaluated the profile of AMR enterobacteria and fecal contamination from four surface waters: Jiquiriça-Brejões River and Cabrito, Tororó, and Abaeté Lagoons. METHODS: We analyzed AMR β-lactamase genes using the polymerase chain reaction method and fecal contamination using Coliscan®. RESULTS: We found high levels of fecal contamination, β-lactamase producers, and AMR genes (blaOXA-48, blaSPM, and blaVIM) in all waterbodies. CONCLUSIONS: Poor sanitation evidenced by fecal contamination and human activities around these surface waters contributed to the distribution and increase in AMR enterobacteria.

Humans , Enterobacteriaceae/genetics , Anti-Infective Agents , Rural Population , Uganda , Feces
Braz. j. microbiol ; 49(4): 914-918, Oct.-Dec. 2018. tab
Article in English | LILACS | ID: biblio-974286


ABSTRACT The global emergence of carbapenemases led to the need of developing new methods for their rapid detection. The aim of this study was to evaluate the performance of the rapid tests for carbapenemase-producing and non-producing Enterobacteriaceae. Carbapenem non-susceptible Enterobacteriaceae from a surveillance study submitted to a multiplex real time PCR for carbapenemase detection were included in this study. The isolates were subjected to the rapid phenotypic tests Carba NP, Blue-Carba and Carbapenem Inactivation Method (CIM). A total of 83 carbapenemase-producing (43) and non-producing (40) isolates were included in the study. The sensitivity/specificity were 62.7%/97.5%, 95.3%/100%, and 74.4%/97.5% for Carba NP, Blue-Carba and CIM, respectively. Both Carba NP and Blue-Carba presented their final results after 75 min of incubation; the final results for CIM were obtained only after 8 h. Failure to detect OXA-370 carbapenemase was the main problem for Carba NP and CIM assays. As the Blue-Carba presented the highest sensitivity, it can be considered the best screening test. Conversely, CIM might be the easiest to perform, as it does not require special reagents. The early detection of carbapenemases aids to establish infection control measures and prevent carbapenemases to spread reducing the risk of healthcare associated infections and therapeutic failure.

Humans , Bacterial Proteins/analysis , beta-Lactamases/analysis , Enterobacteriaceae/enzymology , Enterobacteriaceae Infections/microbiology , Enzyme Assays/methods , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , beta-Lactamases/genetics , beta-Lactamases/metabolism , Brazil , Carbapenems/pharmacology , Polymerase Chain Reaction , Sensitivity and Specificity , Enterobacteriaceae/isolation & purification , Enterobacteriaceae/drug effects , Enterobacteriaceae/genetics , Enterobacteriaceae Infections/diagnosis , Anti-Bacterial Agents/pharmacology
Rev. chil. infectol ; 35(2): 147-154, abr. 2018. tab, graf
Article in Spanish | LILACS | ID: biblio-959424


Resumen Introducción: La resistencia de enterobacterias a quinolonas se ha difundido por el mundo, fenómeno presente también en Venezuela. El mecanismo de esta resistencia pudiera estar mediado por genes incluidos en el cromosoma bacteriano o transmitirse en el interior de plásmidos. Objetivo: Evaluar la resistencia a quino-lonas, codificada por genes qnr, presentes en cepas de enterobacterias, aisladas en el Hospital Universitario de Cumaná, Venezuela. Métodos: A las cepas obtenidas se les realizaron pruebas de susceptibilidad antimicrobiana a quinolonas, β-lactámicos y aminoglucósidos. La presencia del gen qnr se determinó por RPC. Las enterobacterias portadoras del gen qnr fueron sometidas al proceso de conjugación bacteriana para comprobar su capacidad de transferencia. A las transconjugantes obtenidas se les realizó pruebas de susceptibilidad antimicrobiana y RPC para comprobar la transferencia de los genes. Resultados: Se encontraron elevados porcentajes de resistencia antimicrobiana a quinolonas y betalactámicos. El 33,6% de las cepas eran portadoras del gen qnrB, y 0,9% del gen qnrA. Se obtuvieron 23 cepas transconjugantes; de éstas, 20 portaban el gen qnrB, no se observó la presencia de qnrA. Discusión: En conclusión, el elevado porcentaje de genes qnr encontrado en las enterobacterias aisladas, y comprobada la presencia de éstos en plásmidos transferibles, complica la aplicación de tratamientos basados en quinolonas y fluoroquinolonas, por lo que es recomendable el uso racional de estos antimicrobianos, y proponer la rotación de la terapia antimicrobiana, a fin de evitar la selección de cepas resistentes.

Background: Enterobacteria resistant to quinolones is increasing worldwide, including Venezuela. The mechanism for this resistance could be due to genes included in the chromosome or in transmissible plasmids. Aim: To evaluate the resistance to quinolones, coded by qnr genes present in enterobacteria species, isolated in the University Hospital of Cumana, Venezuela. Methods: Antimicrobial susceptibility tests to quinolones, beta-lactams and aminoglycosides were carried out to all the isolates. The presence of qnr genes were determined by PCR. The isolates carrying the qnr genes were used for bacterial conjugation tests to determine the presence of transferable plasmids. Antimicrobial susceptibility tests and PCR were carried out in the transconjugants to verify the transfer of the genes. Results: High levels of antimicrobial resistance to quinolones and beta-lactams were found among the isolates. We found that 33.6% of the isolates carry the qnrB gene and 0.9% qnr A gene. Of the 23 transconjugants, 20 showed to have qnrB gene, but none qnrA. Discussion: We concluded that the high frequency of qnr genes found in the enterobacteria isolates and their presence on transferable plasmids, complicate the use of quinolones for the treatment of bacterial infections, thus, a treatment plan should be designed with the rational use and the rotation of different types of antimicrobials, in order to avoid the selection of increasingly resistant strains.

Plasmids , Quinolones/pharmacology , beta-Lactam Resistance/genetics , Drug Resistance, Bacterial/genetics , Enterobacteriaceae/genetics , Enterobacteriaceae Infections/genetics , Gram-Negative Bacteria/genetics , Anti-Bacterial Agents/pharmacology , Venezuela , beta-Lactamases/genetics , DNA, Bacterial/genetics , Microbial Sensitivity Tests , Polymerase Chain Reaction , Sequence Analysis, DNA , Escherichia coli Proteins , Enterobacteriaceae/isolation & purification , Enterobacteriaceae Infections/microbiology , Genes, Bacterial , Gram-Negative Bacteria/classification , Hospitals, University
Braz. j. microbiol ; 49(1): 16-17, Jan.-Mar. 2018.
Article in English | LILACS | ID: biblio-889216


ABSTRACT Kosakonia cowanii type strain 888-76T is a human pathogen which was originally isolated from blood as NIH group 42. In this study, we report the complete genome sequence of K. cowanii 888-76T. 888-76T has 1 chromosome and 2 plasmids with a total genome size of 4,857,567 bp and C+G 56.15%. This genome sequence will not only help us to understand the virulence features of K. cowanii 888-76T but also provide us the useful information for the study of evolution of Kosakonia genus.

Humans , Genome, Bacterial , Enterobacteriaceae/isolation & purification , Enterobacteriaceae/genetics , Enterobacteriaceae Infections/microbiology , Phylogeny , Plasmids/genetics , Base Composition , DNA, Bacterial/genetics , Molecular Sequence Data , Base Sequence , Enterobacteriaceae/classification
Mem. Inst. Oswaldo Cruz ; 113(10): e180192, 2018. tab, graf
Article in English | LILACS | ID: biblio-1040581


Raoultella planticola is an emerging zoonotic pathogen that is associated with rare but life-threatening cases of bacteremia, biliary tract infections, and urinary tract infections. Moreover, increasing antimicrobial resistance in the organism poses a potential threat to public health. In spite of its importance as a human pathogen, the genome of R. planticola remains largely unexplored and little is known about its virulence factors. Although lipopolysaccharides has been detected in R. planticola and implicated in the virulence in earlier studies, the genetic background is unknown. Here, we report the complete genome and comparative analysis of the multidrug-resistant clinical isolate R. planticola GODA. The complete genome sequence of R. planticola GODA was sequenced using single-molecule real-time DNA sequencing. Comparative genomic analysis reveals distinct capsular polysaccharide synthesis gene clusters in R. planticola GODA. In addition, we found bla TEM-57 and multiple transporters related to multidrug resistance. The availability of genomic data in open databases of this emerging zoonotic pathogen, in tandem with our comparative study, provides better understanding of R. planticola and the basis for future work.

Polysaccharides, Bacterial/biosynthesis , Genome, Bacterial/genetics , Enterobacteriaceae/genetics , Genes, Bacterial/genetics , Polysaccharides, Bacterial/genetics , Bacterial Capsules/genetics , Enterobacteriaceae/classification
Rev. Soc. Bras. Med. Trop ; 50(2): 173-178, Mar.-Apr. 2017. tab
Article in English | LILACS | ID: biblio-842833


Abstract INTRODUCTION: In this study, we used phenotypic methods to screen carbapenem-resistant Enterobacteriaceae (CREs) and evaluated their antimicrobial sensitivity profile. METHODS: One hundred and seventy-eight CREs were isolated at a university hospital in south Brazil in a one-year period. Samples were assessed using disk diffusion tests with inhibitors of β-lactamases such as phenylboronic acid (AFB), cloxacillin (CLOXA), and ethylenediaminetetraacetic acid (EDTA). Strains with differences in zone diameters ≥ 5mm for disks supplemented or not were considered producers of carbapenemases. RESULTS: Klebsiella pneumoniae was the most prevalent CRE, which appeared in 80.3% cases (n = 143). Among clinical materials, the rectal swab was responsible for 43.4% of the isolations (n = 62), followed by urine (18.9%; n = 27). Among the CREs identified in this study, the growth of 56.7% (n = 101) isolates, which were putative producers of Klebsiella pneumoniae carbapenemase (KPC), were inhibited by AFB, whereas 7.3% (n = 13) isolates were inhibited by both AFB and CLOXA and were considered as putative producers of plasmid-mediated AmpC; approximately 3.4% (n = 6) were inhibited by EDTA, which possibly produced metallo-β-lactamase. Lastly, 32.6% (n = 58) cases showed negative results for AFB, CLOXA, and EDTA sensitivity, and represented another class of β-lactamases and/or mechanism of resistance. CONCLUSIONS: Phenotypic screening of CREs is important for clinical laboratories that monitor outbreaks of resistant microbes. Phenotypic tests that use carbapenemase inhibitors and enhancers such as AFB, CLOXA, and EDTA are necessary since they are good screening methods for the detection of carbapenemases.

Humans , Carbapenems/pharmacology , beta-Lactam Resistance/genetics , Enterobacteriaceae/drug effects , Anti-Bacterial Agents/pharmacology , Phenotype , Microbial Sensitivity Tests , Enterobacteriaceae/classification , Enterobacteriaceae/enzymology , Enterobacteriaceae/genetics , Hospitals, University
Braz. j. microbiol ; 47(supl.1): 31-37, Oct.-Dec. 2016. tab
Article in English | LILACS | ID: biblio-839327


ABSTRACT During the last 30 years there has been a dissemination of plasmid-mediated β-lactamases in Enterobacteriaceae in Brazil. Extended spectrum β-lactamases (ESBL) are widely disseminated in the hospital setting and are detected in a lower frequency in the community setting. Cefotaximases are the most frequently detected ESBL type and Klebsiella pneumoniae is the predominant species among ESBL producers. Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae became widely disseminated in Brazil during the last decade and KPC production is currently the most frequent resistance mechanism (96.2%) in carbapenem resistant K. pneumoniae. To date KPC-2 is the only variant reported in Brazil. Polymyxin B resistance in KPC-2-producing K. pneumoniae has come to an alarming rate of 27.1% in 2015 in São Paulo, the largest city in Brazil. New Delhi metallo-β-lactamase was detected in Brazil in 2013, has been reported in different Brazilian states but are not widely disseminated. Antimicrobial resistance in Enterobacteriaceae in Brazil is a very serious problem that needs urgent actions which includes both more strict adherence to infection control measures and more judicious use of antimicrobials.

Humans , Drug Resistance, Bacterial , Enterobacteriaceae/drug effects , Enterobacteriaceae Infections/microbiology , Enterobacteriaceae Infections/epidemiology , Anti-Infective Agents/pharmacology , Plasmids/genetics , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , beta-Lactamases/genetics , beta-Lactamases/metabolism , Brazil/epidemiology , Polymyxins/therapeutic use , Polymyxins/pharmacology , beta-Lactams/therapeutic use , beta-Lactams/pharmacology , Enterobacteriaceae/enzymology , Enterobacteriaceae/genetics , Anti-Infective Agents/therapeutic use , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/pharmacology
Braz. j. microbiol ; 47(2): 444-451, Apr.-June 2016. tab
Article in English | LILACS | ID: lil-780833


Abstract Presence of extended spectrum beta-lactamases (ESBL) in bacteria is a growing health concern of global significance. The local, regional, national, and international epidemiological studies for extended spectrum beta-lactamases-producing Enterobacteriaceae and their encoding genes in foods are still incomplete. The objective of this study was to determine the occurrence of extended spectrum beta-lactamases-producing Enterobacteriaceae and the characteristics of their encoding genes from a total of 250 samples of various foods of animal-origin (100 raw chicken meat, 100 raw cow milk, and 50 raw cow milk cheese) sold in Turkey. Overall, 55 isolates were positive as extended spectrum beta-lactamases-producing Enterobacteriaceae. The most prevalent extended spectrum beta-lactamases-producing strain were identified as Escherichia coli (80%), followed by Enterobacter cloacae (9.1%), Citrobacter braakii (5.5%), Klebsiella pneumoniae (3.6%), and Citrobacter werkmanii (1.8%) by Vitek® MS. The simultaneous production of extended spectrum beta-lactamases and AmpC was detected in five isolates (9.1%) in E. coli (80%) and E. cloacae (20%). The frequency rates of blaTEM, blaCTX-M, and blaSHV were 96.4%, 53.7%, and 34.5%, respectively. The co-existence of bla -genes was observed in 82% of extended spectrum beta-lactamases producers with a distribution of blaTEM & blaCTX-M (52.7%), blaTEM & blaSHV (20%), blaTEM & blaCTX-M & blaSHV (12.7%), and blaSHV & blaCTX-M (1.8%). The most prevalent variant of blaCTX-M clusters was defined as blaCTX-M-1 (97.2%), followed by blaCTX-M-8 (2.8%). In summary, the analysed foods were found to be posing a health risk for Turkish consumers due to contamination by Enterobacteriaceae with a diversity of extended spectrum beta-lactamases encoding genes.

Bacterial Proteins/metabolism , beta-Lactamases/metabolism , Cheese/microbiology , Milk/microbiology , Enterobacteriaceae , Meat/microbiology , Bacterial Proteins/genetics , Turkey , beta-Lactamases/genetics , Cattle , Chickens , Drug Resistance, Multiple, Bacterial , Enterobacteriaceae/drug effects , Enterobacteriaceae/enzymology , Enterobacteriaceae/genetics , Food Microbiology , Anti-Bacterial Agents/pharmacology
Braz. j. microbiol ; 46(4): 1155-1159, Oct.-Dec. 2015. tab
Article in English | LILACS | ID: lil-769667


Abstract The antibiotic susceptibility profile was evaluated in 71 Enterobacteriaceae isolates obtained from outpatient urine cultures in July 2010 from two health institutions in Santa Fe, Argentina. The highest rates of antibiotic resistance were observed for ampicillin (AMP) (69%), trimethoprim/sulfamethoxazole (TMS) (33%), and ciprofloxacin (CIP) (25%). Meanwhile, 21% of the isolates were resistant to three or more tested antibiotics families. Thirty integron-containing bacteria (42.3%) were detected, and a strong association with TMS resistance was found. Third generation cephalosporin resistance was detected in only one Escherichia coli isolate, and it was characterized as a blaCMY-2 carrier. No plasmid-mediated quinolone resistance (PMQR) was found. Resistance to fluoroquinolone in the isolates was due to alterations in QRDR regions. Two mutations in GyrA (S83L, D87N) and one in ParC (S80I) were observed in all CIP-resistant E. coli. It was determined to be the main phylogenetic groups in E. coli isolates. Minimum Inhibitory Concentration (MIC) values against nalidixic acid (NAL), levofloxacin (LEV), and CIP were determined for 63 uropathogenic E. coli isolates as MIC50 of 4 μg/mL, 0.03125 μg/mL, and 0.03125 μg/mL, respectively, while the MIC90 values of the antibiotics were determined as 1024 μg/mL, 64 μg/mL, and 16 μg/mL, respectively. An association between the phylogenetic groups, A and B1 with fluoroquinolone resistance was observed. These results point to the importance of awareness of the potential risk associated with empirical treatment with both the families of antibiotics.

Humans , Anti-Bacterial Agents/pharmacology , Enterobacteriaceae Infections/microbiology , Enterobacteriaceae/drug effects , Enterobacteriaceae/isolation & purification , Quinolones/pharmacology , Urinary Tract Infections/microbiology , beta-Lactams/pharmacology , Argentina , Drug Resistance, Bacterial , Enterobacteriaceae/classification , Enterobacteriaceae/genetics , Genotype , Microbial Sensitivity Tests , Molecular Typing , Outpatients , Phylogeny , Plasmids/analysis
Rev. chil. infectol ; 32(5): 499-504, oct. 2015. tab
Article in Spanish | LILACS | ID: lil-771616


Quinolones are a family of synthetic broad-spectrum antimicrobial drugs whose target is the synthesis of DNA. They directly inhibit DNA replication by interacting with two enzymes; DNA gyrase and topoisomerase IV. They have been widely used for the treatment of several community and hospital acquired infections, in the food processing industry and in the agricultural field, making the increasing incidence of quinolone resistance a frequent problem associated with constant exposition to diverse microorganisms. Resistance may be achieved by three non-exclusive mechanisms; through chromosomic mutations in the Quinolone Resistance-Determining Regions of DNA gyrase and topoisomerase IV, by reducing the intracytoplasmic concentrations of quinolones actively or passively and by Plasmid-Mediated Quinolones-Resistance genes, [Qnr determinant genes of resistance to quinolones, variant gene of the aminoglycoside acetyltransferase (AAC(6')-Ib-c)] and encoding genes of efflux pumps (qepA and oqxAB)]. The future of quinolones is uncertain, however, meanwhile they continue to be used in an irrational way, increasing resistance to quinolones should remain as an area of primary priority for research.

Las quinolonas son un grupo de antimicrobianos sintéticos de amplio espectro, cuyo objetivo es la síntesis del ADN. Inhiben directamente su replicación al interactuar con dos enzimas; ADN girasa y topoisomerasa IV. Se han utilizado ampliamente para el tratamiento de infecciones intra y extra-hospitalarias, en el campo de la agricultura y en el procesamiento de alimentos, lo que hace que el incremento de resistencia a quinolonas sea un problema cada vez más frecuente, asociado a la constante exposición de diversos microorganismos. La resistencia puede alcanzarse mediante tres mecanismos no excluyentes entre sí; a través de mutaciones cromosómicas en genes codificantes que afectan las regiones determinantes de resistencia a quinolonas de ADN girasa y topoisomerasa IV, al reducir las concentraciones intracitoplásmicas de quinolonas de manera activa o pasiva y por genes de resistencia a quinolonas mediados por plásmidos [genes de resistencia a quinolonas determinates de qnr, gen variante de la aminoglucósido acetil transferasa (AAC(6’)-lb-cr) y genes codificadores de bombas de eflujo (qepAy oqxAB)]. El futuro de las quinolonas es incierto; sin embargo, mientras continúen empleándose para el manejo de infecciones en el ser humano, el incremento de resistencia a quinolonas debe permanecer como un área de importancia primaria para la investigación.

Humans , Anti-Bacterial Agents/pharmacology , Enterobacteriaceae/drug effects , Quinolones/pharmacology , Acetyltransferases/genetics , DNA Gyrase/genetics , DNA Topoisomerase IV/genetics , Drug Resistance, Bacterial/genetics , Enterobacteriaceae/enzymology , Enterobacteriaceae/genetics
Braz. j. med. biol. res ; 48(5): 415-419, 05/2015. graf
Article in English | LILACS | ID: lil-744377


Meningiomas are common, usually benign tumors, with a high postoperative recurrence rate. However, the genesis and development of these tumors remain controversial. We aimed to investigate the presence and implications of a mutated p53 protein and dopamine D2 receptor in a representative series of meningiomas and to correlate these findings with age, gender, tumor grade, and recurrence. Tumor tissue samples of 157 patients diagnosed with meningioma (37 males and 120 females, mean age 53.6±14.3 years) who underwent surgical resection between 2003 and 2012 at our institution were immunohistochemically evaluated for the presence of p53 protein and dopamine D2 receptor and were followed-up to analyze tumor recurrence or regrowth. Tumors were classified as grades I (n=141, 89.8%), II (n=13, 8.3%), or grade III (n=3, 1.9%). Dopamine D2 receptor and p53 protein expression were positive in 93.6% and 49.7% of the cases, respectively. Neither of the markers showed significant expression differences among different tumor grades or recurrence or regrowth statuses. Our findings highlight the potential role of p53 protein in meningioma development and/or progression. The high positivity of dopamine D2 receptor observed in this study warrants further investigation of the therapeutic potential of dopamine agonists in the evolution of meningiomas.

Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Cross Infection/epidemiology , Cross Infection/microbiology , Enterobacteriaceae Infections/epidemiology , Enterobacteriaceae Infections/microbiology , Academic Medical Centers , beta-Lactamases , Case-Control Studies , Cross-Sectional Studies , Enterobacteriaceae Infections/etiology , Enterobacteriaceae/genetics , Enterobacteriaceae/isolation & purification , Escherichia coli/isolation & purification , Feces/microbiology , Gastrointestinal Diseases , Klebsiella/isolation & purification , Long-Term Care , Prevalence , Pennsylvania/epidemiology , Residential Facilities , Risk Factors
Rev. Soc. Bras. Med. Trop ; 48(2): 162-169, mar-apr/2015. tab, graf
Article in English | LILACS | ID: lil-746224


INTRODUCTION: Epidemiological data on the prevalence of extended-spectrum β-lactamases (ESBLs) are scarce in Brazil despite the fact that these data are essential for empirical treatment and control measures. The objective of this study was to evaluate the prevalence of different ESBLs by type and distribution in a tertiary hospital in southern Brazil. METHODS: We evaluated 1,827 enterobacterial isolates between August 2003 and March 2008 isolated from patients at a tertiary hospital. Samples were identified using a Vitek automated system and were confirmed by biochemical testing. The identified ESBL strains were characterized by phenotypic methods, polymerase chain reaction (PCR), and sequencing. Genetic similarities were evaluated by pulsed-field gel electrophoresis. RESULTS: It was 390 (21.3%) ESBL-producing strains, which expressed the ESBLs CTX-M (292), SHV (84), CTX and SHV (10), TEM (2), and PER (2). CONCLUSIONS: The prevalence of ESBL-expressing strains was high, especially in Klebsiella pneumoniae and Enterobacter spp. CTX-M was the predominant type of ESBL observed, and its genetic variability indicates a polyclonal distribution. .

Humans , Enterobacteriaceae/enzymology , beta-Lactamases/biosynthesis , Brazil , Bacterial Proteins/analysis , Bacterial Proteins/genetics , Electrophoresis, Gel, Pulsed-Field , Enterobacteriaceae/drug effects , Enterobacteriaceae/genetics , Enterobacteriaceae/isolation & purification , Genotype , Microbial Sensitivity Tests , Polymerase Chain Reaction , Tertiary Care Centers
Braz. j. infect. dis ; 19(2): 187-195, Mar-Apr/2015. tab
Article in English | LILACS | ID: lil-746522


In this study, 922 consecutive non-duplicate clinical isolates of Enterobacteriaceae obtained from hospitalized and non-hospitalized patients at Bejaia, Algeria were analyzed for AmpC-type β-lactamases production. The ampC genes and their genetic environment were characterized using polymerase chain reaction (PCR) and sequencing. Plasmid incompatibility groups were determined by using PCR-based replicon typing. Phylogenetic grouping and multilocus sequence typing were determined for molecular typing of the plasmid-mediated AmpC (pAmpC) isolates.Of the isolates, 15 (1.6%) were identified as AmpC producers including 14 CMY-4- producing isolates and one DHA-1-producing Klebsiella pneumoniae. All AmpC-producing isolates co-expressed the broad-spectrum TEM-1 β-lactamase and three of them co-produced CTX-M and/or SHV-12 ESBL. Phylogenetic grouping and virulence genotyping of the E. coli isolates revealed that most of them belonged to groups D and B1. Multilocus sequence typing analysis of K. pneumoniae isolates identified four different sequence types (STs) with two new sequences: ST1617 and ST1618. Plasmid replicon typing indicates that bla CMY-4 gene was located on broad host range A/C plasmid, while LVPK replicon was associated with bla DHA-1. All isolates carrying bla CMY-4 displayed the transposon-like structures ISEcp1/AISEcp1-blaCMY-blc-sugE. Our study showed that CMY-4 was the main pAmpC in the Enterobacteriaceae isolates inAlgeria.

Humans , Anti-Bacterial Agents/pharmacology , Cefoxitin/pharmacology , Enterobacteriaceae/drug effects , Enterobacteriaceae/genetics , Klebsiella pneumoniae/genetics , Algeria , beta-Lactam Resistance , Bacterial Proteins/genetics , DNA, Bacterial/genetics , Enterobacteriaceae/isolation & purification , Genotype , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/isolation & purification , Microbial Sensitivity Tests , Polymerase Chain Reaction , Sequence Analysis, DNA , beta-Lactamases/genetics
Rev. chil. infectol ; 31(6): 682-688, dic. 2014. graf, tab
Article in Spanish | LILACS | ID: lil-734761


Background: The emergence of carbapenemase mediated resistance in Enterobacteriaceae has a strong clinical impact. This study aimed to do a genotypic and phenotypic characterization of the enzymatic resistance to β-lactams in clinical Enterobacteriaceae isolates with decreased susceptibility to carbapenems in a university medical center in Santiago. Methods: During April-September 2010 at Hospital Clinico Universidad de Chile, 23 isolates of carbapenem non susceptible Enterobacteriaceae were collected. We used PCR for the detection of class A carbapenemases (SME, IMI, NMC, GES and KPC) and the modified Hodge with the boronic acid test to phenotypically assess the presence of serine-carbapenemases. To assess extended spectrum β-lactamases (ESBLs) the CLSI phenotypic tests were performed. Metallo-β-lactamases (MBL) and AmpC were assessed with commercial tablets. Results: 18/23 were Klebsiellapneumoniae and 5/23 strains were Enterobacter cloacae. All PCR to class A carbapenemases were negative. 3/23 strains (all E. cloacae), were positive to the Hodge modified test and 1/23, a K.pneumoniae, was positive to the boronic acid test. ESBLs were detected in 14/23 os the strains and AmpC in 5/23. No MBL was detected. Conclusion: No class A serine-carbapenemasa was detected. The decreased susceptibility to carbapenems is probably explained by the β-lactamase activity and due to porin loss.

Introducción: La emergencia de resistencia a β-lactámicos por carbapenemasas en enterobacterias tiene gran importancia clínica. El objetivo de este estudio fue caracterizar genotípica y fenotípicamente la resistencia enzimática a β-lactámicos en enterobacterias con susceptibilidad disminuida a carbapenémicos, en cepas aisladas de pacientes de un hospital universitario de Santiago. Metodología: Durante abril-septiembre 2010, en el Hospital Clínico de la Universidad de Chile se recolectaron 23 aislados. Se detectaron serinocarbapenemasas clase A (SME, IMI, NMC, GES y KPC) mediante RPC. Se empleó el test de Hodge modificado y acido fenil-borónico (APB) para la detección fenotípica de serinocarbapenemasas. Se detectó la presencia de β-lactamasas de espectro extendido según CLSI y AmpC y MBL mediante tabletas comerciales. Resultados: 18 cepas (78,26%) correspondieron a Klebsiella pneumoniae y 5 cepas (21,74%) a Enterobacter cloacae. Todas las RPC para serinocarbapenemasas fueron negativas, en tanto, el test de Hodge fue positivo para 3/23 cepas, todas E. cloacae. Una cepa de K. pneumoniae fue positiva para APB. Se detectó BLEE en 14/23 cepas, AmpC en 5/23 cepas y no se detectó MBL. Conclusiones: En las cepas estudiadas no se detectaron serinocarbapenemasas clase A. Probablemente los mecanismos que explican la susceptibilidad disminuida a carbapenémicos, involucran resistencia enzimática, combinados con cambios en la permeabilidad de la membrana bacteriana.

Humans , Anti-Bacterial Agents/pharmacology , beta-Lactams , Bacterial Proteins/genetics , Carbapenems/pharmacology , Enterobacteriaceae/drug effects , beta-Lactamases/genetics , Chile , Enterobacteriaceae/enzymology , Enterobacteriaceae/genetics , Genotype , Hospitals, University , Microbial Sensitivity Tests , Phenotype
Rev. argent. microbiol ; 46(3): 210-217, oct. 2014. tab
Article in English | LILACS | ID: lil-734582


La resistencia a la combinación de ß-lactámico/inhibidor de ß-lactamasa en enterobacterias es un problema creciente que no ha sido estudiado intensamente en Argentina. En el presente trabajo, 54/843 enterobacterias recolectadas en un hospital universitario de la ciudad de Buenos Aires fueron resistentes a ampicilina-sulbactama, pero se mantuvieron sensibles a las cefalosporinas de segunda y tercera generación. Se analizaron los mecanismos enzimáticos presentes en los aislamientos que también fueron resistentes a amoxicilina-ácido clavulánico (AMC) (18/54). La secuenciación reveló dos variantes diferentes de blaTEM-1, donde blaTEM-1b es el alelo más frecuentemente detectado (10 Escherichia coli, 3 Klebsiella pneumoniae, 2 Proteus mirabilis y 1 Raoultella terrigena), seguidos por blaTEM-1a(1 K. pneumoniae). La resistencia a AMC parece estar asociada principalmente con la hiperproducción de TEM-1 (sobre todo en E. coli) o con la coexpresión con ß-lactamasas tipo OXA-2 y/o SHV (K. pneumoniae y P. mirabilis). Se describió una nueva variante de blaTEM(TEM-163) en un aislamiento de E. coli que presentó una CIM frente a AMC de 16/8 µg/ml. La enzima TEM-163 contiene dos sustituciones de aminoácidos respecto de TEM-1, Arg275Gln y His289Leu. Teniendo en cuenta la alta actividad específica observada y la baja IC50 para el ácido clavulánico, el patrón de resistencia de este aislamiento parece obedecer a la hiperproducción de la nueva variante de la ß-lactamasa de amplio espectro, en lugar de vincularse con un comportamiento similar al de una TEM resistente a inhibidores (IRT).

Resistance to ß-lactam/ß-lactamase inhibitors in enterobacteria is a growing problem that has not been intensively studied in Argentina. In the present work, 54/843 enterobacteria collected in a teaching hospital of Buenos Aires city were ampicillin-sulbactam-resistant isolates remaining susceptible to second-and third-generation cephalosporins. The enzymatic mechanisms present in the isolates, which were also amoxicillin-clavulanic acid (AMC)-resistant (18/54) were herein analyzed. Sequencing revealed two different variants of blaTEM-1, being blaTEM-1b the most frequently detected allelle (10 Escherichia coli, 3 Klebsiella pneumoniae, 2 Proteus mirabilis and 1 Raoultella terrigena) followed by blaTEM-1a(1 K. pneumoniae). Amoxicillin-clavulanate resistance seems to be mainly associated with TEM-1 overproduction (mostly in E. coli) or co-expressed with OXA-2-like and/or SHV ß-lactamases (K. pneumoniae and P. mirabilis). A new blaTEMvariant (TEM-163) was described in an E. coli strain having an AMC MIC value of 16/8 µg/ml. TEM-163 contains Arg275Gln and His289Leu amino acid substitutions. On the basis of the high specific activity and low IC50 for clavulanic acid observed, the resistance pattern seems to be due to overproduction of the new variant of broad spectrumß-lactamase rather than to an inhibitor-resistant TEM (IRT)-like behavior.

Humans , Amoxicillin-Potassium Clavulanate Combination/pharmacology , Drug Resistance, Bacterial/genetics , Enterobacteriaceae Infections/microbiology , Enterobacteriaceae/enzymology , beta-Lactamases/isolation & purification , Amino Acid Substitution , Argentina/epidemiology , Base Sequence , Cross Infection/epidemiology , Cross Infection/microbiology , Disk Diffusion Antimicrobial Tests , DNA, Bacterial/genetics , Enterobacteriaceae Infections/epidemiology , Enterobacteriaceae/drug effects , Enterobacteriaceae/genetics , Enterobacteriaceae/isolation & purification , Escherichia coli Proteins/genetics , Escherichia coli Proteins/isolation & purification , Escherichia coli Proteins/metabolism , Escherichia coli/drug effects , Escherichia coli/enzymology , Escherichia coli/genetics , Escherichia coli/isolation & purification , Genes, Bacterial , Hospitals, Teaching , Hospitals, Urban , Molecular Sequence Data , Sequence Homology, Nucleic Acid , Substrate Specificity , beta-Lactamases/genetics , beta-Lactamases/metabolism
Biomédica (Bogotá) ; 34(2): 180-197, abr.-jun. 2014. ilus, graf, tab
Article in Spanish | LILACS | ID: lil-712414


Introducción. La resistencia bacteriana es un problema de salud pública a nivel mundial que compromete seriamente la capacidad de tratar las infecciones. Objetivo. Describir el perfil de resistencia a los antimicrobianos marcadores en enterobacterias identificadas en hospitales colombianos. Materiales y métodos. Se hizo una revisión bibliográfica sistemática de las publicaciones indexadas en Medline, Embase y Lilacs, además de la búsqueda manual de todos los números de revistas colombianas reconocidas en el campo de la infectología y otros afines para identificar referencias no disponibles electrónicamente. Resultados. Se identificaron 43 estudios y reportes de vigilancia epidemiológica con información sobre la resistencia de las enterobacterias en hospitales, principalmente de Bogotá, Cali y Medellín. La tasa de resistencia en Escherchia coli oscila entre 3 y 11 %, 5 y 20 % y 0,2 a 0,8 % para piperacilina-tazobactam, cefalosporinas de tercera generación y carbapenémicos, respectivamente. En aislamientos de Klebsiella pneumoniae , la resistencia oscila entre 21,8 y 48,1 % frente a piperacilina-tazobactam, 20 y 35 % frente a cefalosporinas de amplio espectro y 3 y 8 % frente a carbapenémicos, con variaciones importantes por ciudades, niveles de atención y circunstancias clínicas. Conclusiones. La diseminación de la resistencia bacteriana en enterobacterias aisladas en hospitales colombianos es un problema creciente que requiere medidas prontas para cortar las cadenas de transmisión.

Introduction: Bacterial resistance is a public health problem worldwide that seriously compromises the possibility to treat infections. Objective: To identify levels of resistance to antibiotic markers in Enterobacteriaceae isolates from Colombian hospitals. Materials and methods: A systematic literature survey was done including articles indexed in Medline, Embase and LILACS. A manual search was made of Colombian scientific journals and other publications on infectious disease that were not available electronically. Results: In total, 43 observational studies and epidemiological reports were identified with information about resistance among Enterobacteriaceae isolates in Colombian hospitals, mainly from Bogotá, Cali and Medellín. The resistance rate of Escherichia coli ranges from 3 to 11%, 5 to 20% and from 0.2 to 0.8% for piperacillin-tazobactam, third generation cephalosporins and carbapenems, respectively. For Klebsiella pneumoniae resistance rates ranges from 21.8 to 48.1% to piperacillin-tazobactam, 20 to 35% to broad-spectrum cephalosporins and 3 to 8% to carbapenems, with significant variations by cities, levels of care and clinical settings. Conclusions: The spread of bacterial resistance in Enterobacteriaceae isolated in Colombian hospitals is a growing problem that calls for priority action to cut the chains of transmission.

Humans , Cross Infection/microbiology , Drug Resistance, Multiple, Bacterial , Enterobacteriaceae Infections/microbiology , Enterobacteriaceae/drug effects , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Colombia/epidemiology , Cross Infection/drug therapy , Cross Infection/epidemiology , Enterobacteriaceae Infections/drug therapy , Enterobacteriaceae Infections/epidemiology , Enterobacteriaceae/genetics , Enterobacteriaceae/isolation & purification , Hospital Departments/statistics & numerical data , Intensive Care Units/statistics & numerical data , Multicenter Studies as Topic , Observational Studies as Topic , Population Surveillance
Braz. j. microbiol ; 45(2): 603-611, Apr.-June 2014. ilus, tab
Article in English | LILACS | ID: lil-723124


Glucose dehydrogenase (GDH; EC 1.1. 5.2) is the member of quinoproteins group that use the redox cofactor pyrroloquinoline quinoine, calcium ions and glucose as substrate for its activity. In present study, Leclercia sp. QAU-66, isolated from rhizosphere of Vigna mungo, was characterized for phosphate solubilization and the role of GDH in plant growth promotion of Phaseolus vulgaris. The strain QAU-66 had ability to solubilize phosphorus and significantly (p < 0.05) promoted the shoot and root lengths of Phaseolus vulgaris. The structural determination of GDH protein was carried out using bioinformatics tools like Pfam, InterProScan, I-TASSER and COFACTOR. These tools predicted the structural based functional homology of pyrroloquinoline quinone domains in GDH. GDH of Leclercia sp. QAU-66 is one of the main factor that involved in plant growth promotion and provides a solid background for further research in plant growth promoting activities.

Enterobacteriaceae/enzymology , Enterobacteriaceae/physiology , Glucose 1-Dehydrogenase/genetics , Nerve Growth Factors , Phaseolus/growth & development , Phaseolus/microbiology , Cluster Analysis , Computational Biology , Cytosol/chemistry , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Enterobacteriaceae/genetics , Enterobacteriaceae/isolation & purification , Glucose 1-Dehydrogenase/chemistry , Models, Molecular , Molecular Sequence Data , Phylogeny , Protein Conformation , Protein Structure, Tertiary , Phosphorus/metabolism , Plant Roots/growth & development , Plant Shoots/growth & development , Quinones/analysis , Sequence Analysis, DNA , Sequence Homology