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Rev. Soc. Bras. Med. Trop ; 54: e02622020, 2021.
Article in English | ColecionaSUS, LILACS, ColecionaSUS, SES-SP | ID: biblio-1143877


Abstract INTRODUCTION: Carbapenemase-resistant enterobacteria that produce the bla NDM gene are found worldwide. However, this is the first report of blaNDM in Klebsiella aerogenes in Brazil. METHODS: The identification of bacterial species was performed using anautomated system and confirmed by biochemical tests, 16S rRNA gene sequencing, and detection of resistance genes. RESULTS: The clinical isolate showed minimum inhibitory concentration resistance to meropenem and polymyxin B at 8mg/L and 4mg/L, respectively. Only the blaNDM gene was detected. CONCLUSIONS: The current report of the blaNDM gene in isolated MDR enterobacteria indicates that this gene can spread silently in a hospital setting.

Enterobacter aerogenes/genetics , Bacterial Proteins , beta-Lactamases/genetics , Brazil , RNA, Ribosomal, 16S , Microbial Sensitivity Tests , Drug Resistance, Multiple, Bacterial/genetics , Enterobacteriaceae , Klebsiella pneumoniae/genetics , Anti-Bacterial Agents/pharmacology
Rev. Soc. Bras. Med. Trop ; 53: e20200064, 2020. tab, graf
Article in English | ColecionaSUS, LILACS, ColecionaSUS, SES-SP | ID: biblio-1136871


Abstract INTRODUCTION: Carbapenem-resistant Klebsiella pneumoniae infection lacks treatment options and is associated with prolonged hospital stays and high mortality rates. The production of carbapenemases is one of the most important factors responsible for this multi-resistance phenomenon. METHODS: In the present study, we analyzed the presence of genes encoding carbapenemases in K. pneumoniae isolates circulating in one of the public hospitals in the city of Aracaju, Sergipe, Brazil. We also determined the best combination of drugs that display in vitro antimicrobial synergy. First, 147 carbapenem-resistant K. pneumoniae isolates were validated for the presence of blaKPC, bla GES, bla NDM, bla SPM, bla IMP, bla VIM, and bla OXA-48 genes using multiplex polymerase chain reaction. Thereafter, using two isolates (97 and 102), the role of double and triple combinational drug therapy as a treatment option was analyzed. RESULTS: Seventy-four (50.3%) isolates were positive for bla NDM, eight (5.4%) for bla KPC, and one (1.2%) for both bla NDM and bla KPC. In the synergy tests, double combinations were better than triple combinations. Polymyxin B and amikacin for isolate 97 and polymyxin B coupled with meropenem for isolate 102 showed the best response. CONCLUSIONS: Clinicians in normal practice use multiple drugs to treat infections caused by multi-resistant microorganism; however, in most cases, the benefit of the combinations is unknown. In vitro synergistic tests, such as those described herein, are important as they might help select an appropriate multi-drug antibiotic therapy and a correct dosage, ultimately reducing toxicities and the development of antibiotic resistance.

Humans , Bacterial Proteins/genetics , beta-Lactamases/genetics , Klebsiella Infections/microbiology , Klebsiella pneumoniae/drug effects , Anti-Bacterial Agents/pharmacology , Brazil , DNA, Bacterial , Microbial Sensitivity Tests , Polymerase Chain Reaction , Prevalence , Drug Resistance, Multiple, Bacterial/genetics , Klebsiella pneumoniae/isolation & purification , Klebsiella pneumoniae/genetics
Rev. Soc. Bras. Med. Trop ; 53: e20190526, 2020. tab, graf
Article in English | ColecionaSUS, LILACS, ColecionaSUS, SES-SP | ID: biblio-1136834


Abstract INTRODUCTION: This study investigated the genetic environment of bla KPC-2 in Klebsiella pnemoniae multi-drug resistant clinical isolates. METHODS: Four carbapenemase gene isolates resistant to carbapenems, collected from infected patients from two hospitals in Brazil, were investigated using polymerase chain reaction and plasmid DNA sequencing. RESULTS: The bla KPC-2 gene was located between ISKpn6 and a resolvase tnpR in the non-Tn4401 element (NTEKPC-IId). It was detected on a plasmid belonging to the IncQ1 group. CONCLUSIONS To our knowledge, this is the first report of the presence of the bla KPC-2 gene in the NTEKPC-IId element carried by plasmid IncQ1 from infections in Brazil.

Humans , beta-Lactamases/genetics , Klebsiella Infections/microbiology , Klebsiella pneumoniae/genetics , Anti-Bacterial Agents/pharmacology , Plasmids/genetics , DNA, Bacterial/genetics , Microbial Sensitivity Tests , Polymerase Chain Reaction , Drug Resistance, Multiple, Bacterial , Klebsiella pneumoniae/isolation & purification , Klebsiella pneumoniae/enzymology
Rev. Soc. Bras. Med. Trop ; 53: e20200397, 2020. tab, graf
Article in English | ColecionaSUS, LILACS, ColecionaSUS, SES-SP | ID: biblio-1136816


Abstract INTRODUCTION Antibiotic resistance in carbapenemase-producing Klebsiella pneumoniae is acquired and disseminated mainly by plasmids. Therefore, we aimed to investigate the occurrence of carbapenemase genes, analyze the genetic diversity by ERIC-PCR, and examine the most common plasmid incompatibility groups (Incs) in clinical isolates of K. pneumoniae from colonization and infection in patients from a hospital in Brazil. METHODS Twenty-seven isolates of carbapenem-resistant K. pneumoniae were selected and screened for the presence of carbapenemase genes and Incs by PCR, followed by amplicon sequencing. RESULTS The bla KPC and bla NDM genes were detected in 24 (88.8 %) and 16 (59.2 %) of the isolates, respectively. Thirteen isolates (48.1 %) were positive for both genes. The IncFIB (92.6 %) and IncQ (88.8 %) were the most frequent plasmids, followed by IncA/C, IncHI1B, and IncL/M, indicating that plasmid variability existed in these isolates. To our knowledge, this is the first report of IncHI1B in Brazil. We found eight isolates with clonal relationship distributed in different sectors of the hospital. CONCLUSIONS The accumulation of resistance determinants, the variability of plasmid Incs, and the clonal dissemination detected in K. pneumoniae isolates demonstrate their potential for infection, colonization, and the dissemination of different resistance genes and plasmids.

Humans , Klebsiella Infections , Klebsiella pneumoniae/genetics , Plasmids/genetics , Bacterial Proteins/genetics , beta-Lactamases/genetics , Brazil , Microbial Sensitivity Tests , Hospitals, Public , Anti-Bacterial Agents/pharmacology
Chinese Medical Journal ; (24): 2573-2585, 2020.
Article in English | WPRIM | ID: wpr-877863


BACKGROUND@#Carbapenemase-producing Klebsiella pneumoniae (CP-Kp) poses distinct clinical challenges due to extensively drug resistant (XDR) phenotype, and sequence type (ST) 11 is the most dominant blaKPC-2-bearing CP-Kp clone in China. The purpose of this current retrospective study was to explore the genetic factors associated with the success of XDR CP-Kp ST11 strains circulated in the intensive care unit (ICU) of a Chinese tertiary hospital.@*METHODS@#Six ST11 XDR CP-Kp strains were identified between May and December 2014 and validated by minimum inhibitory concentration examination, polymerase chain reaction, and pyrosequencing. The six ST11 XDR CP-Kp, as well as three multi-drug resistant (MDR) and four susceptible strains, were sequenced using single-molecule real-time method. Comprehensively structural and functional analysis based on comparative genomics was performed to identify genomic characteristics of the XDR ST11 CP-Kp strains.@*RESULTS@#We found that ST11 XDR blaKPC-2-bearing CP-Kp strains isolated from inpatients spread in the ICU of the hospital. Functionally, genes associated with information storage and processing of the ST11 XDR CP-Kp strains were more abundant than those of MDR and susceptible strains, especially genes correlative with mobile genetic elements (MGEs) such as transposons and prophages. Structurally, eleven large-scale genetic regions taken for the unique genome in these ST11 XDR CP-Kp strains were identified as MGEs including transposons, integrons, prophages, genomic islands, and integrative and conjugative elements. Three of them were located on plasmids and eight on chromosomes; five of them were with antimicrobial resistance genes and eight with adaptation associated genes. Notably, a new blaKPC-2-bearing ΔΔTn1721-blaKPC-2 transposon, probably transposed and truncated from ΔTn1721-blaKPC-2 by IS903D and ISKpn8, was identified in all six ST11 XDR CP-Kp strains.@*CONCLUSION@#Our findings suggested that together with clonal spread, MGEs identified uniquely in the ST11 XDR CP-Kp strains might contribute to their formidable adaptability, which facilitated their widespread dissemination in hospital.

Anti-Bacterial Agents , Bacterial Proteins , China , Electrophoresis, Gel, Pulsed-Field , Hospitals , Humans , Klebsiella Infections/drug therapy , Klebsiella pneumoniae/genetics , Microbial Sensitivity Tests , Multilocus Sequence Typing , Pharmaceutical Preparations , Retrospective Studies , beta-Lactamases/genetics
Rev. epidemiol. controle infecç ; 9(4): 281-286, out.-dez. 2019. ilus
Article in Portuguese | LILACS | ID: biblio-1152242


Justificativa e objetivos: Infecções Relacionadas à Assistência à Saúde (IRAS) causadas por bacilos Gram negativos multirresistentes (BGN-MDR) são consideradas um problema de saúde pública e um impacto nas taxas de mortalidade nas Unidades de Terapia Intensiva (UTI). O objetivo deste estudo foi verificar o perfil fenotípico de resistência à colistina e à tigeciclina, consideradas como último recurso terapêutico aos BGN-MDR. Métodos: Os dados foram coletados nas fichas de busca ativa do serviço de controle de infecções e prontuários médicos de pacientes internados em duas UTIs de um hospital público de Joinville, entre janeiro de 2016 e junho de 2017. Resultados: Ocorreram 256 IRAS por BGN, acometendo principalmente o gênero masculino (62%), com mediana de idade de 65 anos. Entre os BGN, 37% expressaram MDR; sendo as espécies mais frequentes: Klebsiella pneumoniae e (47%), Acinetobacter baumannii (23%) e Stenotrophomonas maltophilia (11%). A resistência de BGN-MDR à colistina e tigeciclina foi de 5% e de 12%, respectivamente; 5% dos isolados foram resistentes aos dois antibióticos. A taxa de óbito entre os pacientes com IRAS por BGN-MDR resistentes à colistina foi mais alta (60%) que aquelas à tigeciclina (45%). Conclusão: K. pneumoniae e A. baumannii produtores de carbapenemases, resistentes a colistina e tigeciclina prevaleceram entre os BGN-MDR, e estiveram associadas a maioria dos óbitos. Essas observações, junto com o alto uso de carbapenêmicos na terapia empírica, mostra a necessidade do uso racional de antimicrobianos.(AU)

Background and objectives: Healthcare-associated Infections (HAIs) caused by multidrug-resistant Gram-negative bacilli (GNB-MDR) are considered a public health problem and have an impact on mortality rates in Intensive Care Units (ICU). The aim of this study was to verify the phenotypic profile of resistance to colistin and tigecycline, considered as the last antimicrobial choice to treat BGNMDR infections. Methods: Data were collected on the active search records of the infection control service and medical records of patients admitted to two ICUs at a public hospital in Joinville between January 2016 and June 2017. Results: There were 256 HAIs caused by GNB, mainly affecting males (62%), with a median age of 65 years. Among GNBs, 37% expressed MDR; the most frequent species were: Klebsiella pneumoniae (47%), Acinetobacter baumannii (23%) and Stenotrophomonas maltophilia (11%). The resistance of GNB-MDR to colistin and tigecycline was 5% and 12%, respectively; 5% of the isolates were resistant to both antibiotics. The death rate among patients with HAIs caused by colistin-resistant GNB-MDR was higher (60%) than those to tigecycline (45%). Conclusion: Carbapenemase-producing K. pneumoniae and A. baumannii, resistant to colistin and tigecycline, prevailed among GNB-MDRs, and were associated with most deaths. These observations, coupled with the high use of carbapenems in empirical therapy, show the need for rational use of antimicrobials.(AU)

Justificación y objetivos: Las Infección nosocomial (IHs) causadas por bacilos Gram negativos multirresistentes (BGN-MDR) se consideran un problema de salud pública y un impacto en las tasas de mortalidad en las Unidades de Terapia Intensiva (UTI). El objetivo de este estudio fue verificar el perfil fenotípico de resistencia a la colistina ya la tigeciclina, consideradas como último recurso terapéutico a los BGN-MDR. Métodos: Los datos fueron recolectados en las fichas de búsqueda activa del servicio de control de infecciones y prontuarios médicos de pacientes internados en dos UTIs de un hospital público de Joinville, entre enero de 2016 y junio de 2017. Resultados: Ocurrieron 256 IHs por BGN, que afectan principalmente al género masculino (62%), con mediana de edad de 65 años. Entre los BGN, el 37% expresó MDR; siendo las especies más frecuentes: Klebsiella pneumoniae (47%), Acinetobacter baumannii (23%) y Stenotrophomonas maltophilia (11%). La resistencia de BGN-MDR a la colistina y tigeciclina fue del 5% y del 12%, respectivamente; 5% de los aislados fueron resistentes a los dos antibióticos. La tasa de muerte entre los pacientes con IH causadas por los BGN-MDR resistentes la colistina fue más alta (60%) que aquellas a tigeciclina (45%). Conclusión: K. pneumoniae y A. baumannii productoras de carbapenemases, resistentes la colistina y la tigeciclina, fueron más frecuentes entre los BGN-MDR y su asociación estuvo presente en la mayoría de las muertes. Estas observaciones, junto con el alto uso de carbapenems en la terapia empírica, muestran la necesidad de un uso racional de los antimicrobianos.(AU)

Humans , Male , Female , Adolescent , Adult , Middle Aged , Aged , Young Adult , Colistin/pharmacology , Drug Resistance, Multiple, Bacterial , Tigecycline/pharmacology , Gram-Negative Bacteria/drug effects , Anti-Bacterial Agents/pharmacology , Phenotype , Cross Infection/drug therapy , Gram-Negative Bacterial Infections/drug therapy , Colistin/therapeutic use , Stenotrophomonas maltophilia/drug effects , Stenotrophomonas maltophilia/genetics , Acinetobacter baumannii/drug effects , Acinetobacter baumannii/genetics , Tigecycline/therapeutic use , Gram-Negative Bacteria/genetics , Hospitalization , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/genetics , Anti-Bacterial Agents/therapeutic use
Rev. chil. infectol ; 36(3): 304-311, jun. 2019. tab, graf
Article in Spanish | LILACS | ID: biblio-1013788


Resumen Introducción: La expresión de β-lactamasas CTX-M pertenecientes a los grupos 1 y 9 en Klebsiella pneumoniae produce grados altos de resistencia a ceftazidima, y presentan una amplia distribución mundial. Objetivo: Identificar y caracterizar los genes blaCTX-M-Grupo1 y blaCTX-M-Grupo9 en aislados de K. pneumoniae resistentes a ceftazidima en un hospital de San José de Cúcuta, Colombia. Material y Método: Se diseñaron partidores para la identificación de K. pneumoniae y los genes blaCTX-M mediante reacción de polimerasa en cadena (RPC). Posteriormente se realizó el análisis de la relación genética de estos aislados por medio de la RPC basada en secuencias repetitivas (RPC-REP). Resultados: Treinta y ocho por ciento de los 24 aislados identificados por RPC como K. pneumoniae presentaron los genes blaCTX-M-3, blaCTX-M-15 y blaCTX-M-32 (Grupo CTX-M-1) y 42% los genes blaCTX-M14, blaCTX-M-24 y blaCTX-M-27 (Grupo CTX-M-9). El análisis filogenético agrupó los aislados de K. pneumoniae en cuatro clusters, mostrando correlación en los clusters I, II y IV, al comparar los perfiles genéticos con el tipo de muestra y grupo de genes. Discusión: Se encontró una frecuencia similar de los genes blaCTX-M-Grupo1 y blaCTX-M-Grupo 9 en aislados de K. pneumoniae resistentes a ceftazidima. La correlación entre la RPC-REP con los grupos de CTX-M y el tipo de muestra reveló la presencia de tres patrones clonales.

Background: The expression of CTX-M β-lactamases belonging to groups 1 and 9 in Klebsiella pneumoniae produces high levels of resistance to ceftazidime, and they have a wide distribution worldwide. Aim: To identify and characterize the blaCTX-M-Group1 and blaCTX-M-Group9 genes in K. pneumoniae isolates resistant to ceftazidime in a hospital in San José de Cúcuta, Colombia. Material and Methods: Primers were designed for the identification of K. pneumoniae and blaCTX-M genes by PCR. Subsequently, the genetic relationship of these isolates was analyzed by REP-PCR. Results: A 38% of the 24 isolates identified by PCR as K. pneumoniae showed blaCTX-M-3. blaCTX-M-15 y blaCTX-M-32 genes (Group CTX-M-1) and 42% blaCTX-M14. blaCTX-M-24 y blaCTX-M-27 genes (Group CTX-M-9). The phylogenetic analysis grouped the K. pneumoniae isolates into 4 clusters, showing correlation in clusters I, II and IV, when comparing the genetic profiles with the type of sample and group of genes. Discussion: We found a similar frequency of blaCTX-M-Group 1 and blaCTX-M-Group 9 genes in isolates of K. pneumoniae resistant to ceftazidime. The correlation between the REP-PCR with the CTX-M groups and the type of sample revealed the presence of three clonal patterns.

Humans , Bacterial Proteins/genetics , beta-Lactamases/genetics , Drug Resistance, Bacterial/genetics , Molecular Typing , Klebsiella pneumoniae/genetics , Phylogeny , Bacterial Proteins/isolation & purification , beta-Lactamases/isolation & purification , Ceftazidime , Polymerase Chain Reaction , Colombia , Klebsiella pneumoniae/isolation & purification , Anti-Bacterial Agents
Braz. j. med. biol. res ; 52(3): e8186, 2019. tab, graf
Article in English | LILACS | ID: biblio-989465


Klebsiella pneumoniae is one of the main pathogenic bacteria that causes nosocomial infections, such as pneumonia, urinary tract infection, and sepsis. Therefore, the rapid and accurate detection of K. pneumoniae is important for the timely treatment of infectious patients. This study aimed to establish a loop-mediated isothermal amplification (LAMP) method for the rapid and sensitive detection of K. pneumoniae-specific gene ureR_1 (Gene ID: 11847803). The ureR_1 gene was obtained through local and online BLAST, and the specific primers were designed for its detection. Positive reactions were observed on all 140 K. pneumoniae clinical isolates while all the 82 non-K. pneumoniae clinical isolates were negative. Plasmids with the specific gene and the mouse blood with K. pneumoniae were used for sensitivity analysis. The detection limit of the LAMP was 1 bacterium/reaction. The results showed that the LAMP targeted to ureR_1 is a fast, specific, sensitive, inexpensive, and suitable method for the detection of K. pneumoniae.

Nucleic Acid Amplification Techniques/methods , Genes, Bacterial , Klebsiella pneumoniae/genetics , Plasmids/isolation & purification , Plasmids/genetics , Temperature , Time Factors , Polymerase Chain Reaction/methods , Reproducibility of Results , Sequence Analysis, DNA , DNA Primers/isolation & purification , DNA Primers/genetics , Limit of Detection , Klebsiella pneumoniae/isolation & purification
Rev. Soc. Bras. Med. Trop ; 52: e20180352, 2019. tab
Article in English | LILACS | ID: biblio-1041560


Abstract INTRODUCTION: The emergence of New Delhi metallo-β-lactamase (NDM) is concernig because it reduces the antibiotic therapy options for bacterial infections. METHODS: Resistant and virulent genes from an isolate of Klebsiella pneumoniae derived from a patient with sepsis in a hospital in Recife-PE, Brazil, were investigated using PCR and DNA sequencing. RESULTS: bla NDM-1, aac(6')-Ib-cr and acrB resistance genes, and cps and mrkD virulence genes were detected. CONCLUSIONS To our knowledge, this is the first report on bla NDM-1 in Recife-PE. This detection alerts researchers to the need to control the spread of bla NDM-1 resistance gene by this bacterium in Brazil.

Humans , Female , Bacterial Proteins/genetics , Virulence/genetics , beta-Lactamases/genetics , Drug Resistance, Multiple, Bacterial/genetics , Klebsiella pneumoniae/genetics , Anti-Bacterial Agents/pharmacology , Microbial Sensitivity Tests , Polymerase Chain Reaction , Sequence Analysis, DNA , Sepsis/microbiology , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/enzymology
Rev. Soc. Bras. Med. Trop ; 52: e20190089B, 2019. tab, graf
Article in English | LILACS | ID: biblio-1041519


Abstract INTRODUCTION The relationships between phagocytosis, and mucoid phenotype, plasmid profile and virulence, and resistance genetic characteristics of Klebsiella pneumoniae clinical isolates were evaluated. METHODS Thirty isolates were used to determine the mucoid aspect. Four were selected for analysis of phagocytosis by alveolar macrophages. RESULTS Thirty percent of the samples presented the mucoid phenotype. The phagocytosis rate ranged from 21.5% to 43.43%. Phagocytosis was not correlated with the plasmid profile, but was apparently correlated with mucoid phenotype and antibiotic susceptibility. CONCLUSIONS: Several virulence factors act in parallel in K. pneumoniae to impair host defense.

Humans , Phagocytosis/genetics , Virulence/genetics , Drug Resistance, Microbial/genetics , Virulence Factors/genetics , Klebsiella pneumoniae/genetics , Anti-Bacterial Agents/pharmacology , Phagocytosis/physiology , Phenotype , Plasmids , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/pathogenicity
West Indian med. j ; 67(3): 226-228, July-Sept. 2018.
Article in English | LILACS | ID: biblio-1045848


ABSTRACT The main mechanism of quinolone resistance in Klebsiella (K) pneumoniae is caused by mutation of porin-related proteins and efflux pumps. This study aimed to investigate the prevalence of ciprofloxacin-resistant K pneumoniae in burns patients and to understand the role of the AcrAB multidrug efflux system on minimal inhibitory concentration (MIC) of ciprofloxacin. For this reason, 52 K pneumoniae samples were collected from burns patients and evaluated for the mechanism of ciprofloxacin resistance. The results demonstrated that 40 isolates of K pneumoniae were ciprofloxacin-resistant and 35 showed the mutation on gyrA locus. By inhibition of the efflux system, the MIC yield showed a significant decrease. Therefore, it could be concluded that the high rate of mutation on the gyrA locus in combination with quinolone resistance was responsible for ciprofloxacin resistance and by inhibition of AcrA, the resistance rate showed a significant decrease in K pneumoniae isolated from burns patients.

RESUMEN El principal mecanismo de resistencia a la quinolona en las Klebsiella (K) Pneumoniae tiene como causa la mutación de las porinas y las bombas de eflujo. Este estudio tuvo por objetivo investigar la prevalencia de las K pneumoniae resistentes a la ciprofloxacina en pacientes con quemaduras, así como entender el papel del sistema de eflujo multidroga AcrAB en la concentración inhibitoria mínima (CIM) de la ciprofloxacina. Por esta razón, se recogieron 52 muestras de K pneumoniae de pacientes con quemaduras, a fin de evaluar el mecanismo de resistencia a la ciprofloxacina. Los resultados mostraron que 40 aislados de K pneumoniae eran resistentes a la ciprofloxacina y 35 mostraron la mutación en el locus gyrA. Con la inhibición del sistema de eflujo, el rendimiento de CIM tuvo una disminución significativa. Por lo tanto, se pudo concluir que la alta tasa de mutación en el locus gyrA en combinación con la resistencia a la quinolona era responsable de la resistencia a la ciprofloxacina, y por la inhibición de AcrA, la tasa de resistencia mostró una disminución significativa en las K pneumoniae aisladas de los pacientes con quemaduras.

Humans , Male , Female , Burns/microbiology , Ciprofloxacin/pharmacology , Drug Resistance, Bacterial/genetics , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/genetics , Mutation/genetics , Microbial Sensitivity Tests
Braz. j. microbiol ; 49(supl.1): 93-100, 2018. tab, graf
Article in English | LILACS | ID: biblio-974332


Abstract Klebsiella pneumoniae is important human and animal pathogen that causes a wide spectrum of infections. In this study, isolates from cattle nasal swabs samples were identified by 16S rRNA, and to evaluate the antimicrobial susceptibility, virulence gene carrying levels, and multilocus sequence typing of K. pneumoniae isolates. 33 isolates of K. pneumoniae were isolated and identified in 213 nasal swabs samples, of which 12 were hypervirulent K. pneumoniae strains. Extended Spectrum Beta-Lactamases genes were found in 93.4% of the strains. Of which, TEM was the most prevalent (93.4%), followed by CTX-M and SHV were 57.6% and 39.4%, respectively. A main mutation pattern of quinoloneresistance-determining region, Thr83-Ieu and Asp87-Asn in gyrA and Ser87-Ile in parC, was detected in 33 K. pneumoniae isolates. All the isolates harbored at least two virulence factor genes, with ureA (97.0%) and wabG (91.0%) exhibiting high carriage rates in 33 K. pneumoniae isolates. MLST revealed 7 sequence types, of which 3 STs (2541, 2581 and 2844) were newly assigned. Using eBURST, ST2844 and ST2541 were assigned to new clonal complex 2844. Our study provides evidence and biological characteristics of K. pneumoniae isolates from cattle upper respiratory tract in Southwest China.

Animals , Cattle , Bacterial Proteins/genetics , Klebsiella Infections/veterinary , Cattle Diseases/microbiology , Drug Resistance, Multiple, Bacterial , Virulence Factors/genetics , Klebsiella pneumoniae/isolation & purification , Klebsiella pneumoniae/drug effects , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/metabolism , Klebsiella Infections/microbiology , China , Virulence Factors/metabolism , Multilocus Sequence Typing , Klebsiella pneumoniae/genetics , Klebsiella pneumoniae/metabolism
Rev. chil. infectol ; 34(5): 476-484, oct. 2017. tab, graf
Article in Spanish | LILACS | ID: biblio-899745


Resumen En la actualidad, la diseminación de enterobacterias productoras de carbapenemasas se considera un grave problema en clínica debido al fracaso en el tratamiento de las infecciones que ellas producen. Entre las carbapenemasas, la enzima KPC se ha diseminado mundialmente y ha sido identificada en las principales especies de enterobacterias relacionadas con infecciones asociadas a la atención en salud, con claro predominio de Klebsiella pneumoniae a nivel mundial. El gen blaKPC es transportado, principalmente, por el transposón Tn4401, detectado en diversas especies de enterobacterias con distintos secuencio-tipo (ST) y diferente origen geográfico. Adicionalmente, se han descrito nuevas plataformas genéticas que se distinguen del Tn4401 original debido a inserciones y deleciones de otros genes. Los plásmidos que albergan el gen blaKPC pueden ser del tipo conjugativo y no conjugativo movilizable, y además contener otros determinantes genéticos de resistencia. Las cepas productoras de KPC pueden presentar diversos niveles de resistencia a los carbapenémicos, debido a la participación de mecanismos adicionales como diferente grado de expresión de porinas y bombas de expulsión asociados con la producción de β-lactamasas de espectro extendido y/o AmpC. Sin embargo, las carbapenemasas, con KPC como la enzima más frecuente, otorgan grados de resistencia más elevados.

The dissemination of carbapenemase-producing Enterobacteriaceae is currently considered a serious clinical problem due to the failure in the treatment of infections produced by them. Among the carbapenemases, the enzyme KPC has spread worldwide and has been identified in the main enterobacterial species related with healthcareassociated infections, although Klebsiella pneumoniae is the predominant specie. The blaKPC gene is transported, mainly by the transposon Tn4401, detected in various enterobacterial species of different sequence types (ST) and geographical origin. In addition, new genetic platforms that are distinguished, from Tn4401 because of insertions or deletions of other genes have been described. Plasmids containing the blaKPC gene can be conjugative and mobilizable non-conjugative plasmids, and can carry other genetic determinants of resistance. The KPC-producing strains may have different levels of resistance to carbapenems, due to the involvement of additional mechanisms such as different expression levels of porins and efflux pumps associated with the production of extended spectrum β-lactamases and/or AmpC. However, the carbapenemases, with KPC as the most common enzyme, provide higher levels of resistance.

Bacterial Proteins/biosynthesis , beta-Lactamases/biosynthesis , Klebsiella pneumoniae/enzymology , Bacterial Proteins/genetics , beta-Lactamases/genetics , Microbial Sensitivity Tests , Drug Resistance, Bacterial/genetics , Carbapenem-Resistant Enterobacteriaceae , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/genetics , Anti-Bacterial Agents/pharmacology
Braz. j. microbiol ; 48(3): 509-514, July-Sept. 2017. tab
Article in English | LILACS | ID: biblio-889143


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

Humans , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/metabolism , beta-Lactamases/metabolism , Enterobacteriaceae Infections/microbiology , Klebsiella Infections/microbiology , Klebsiella pneumoniae/drug effects , Microbial Sensitivity Tests/methods , Bacterial Proteins/genetics , beta-Lactamases/genetics , beta-Lactams/pharmacology , Drug Resistance, Bacterial , Enterobacter/drug effects , Enterobacter/genetics , Enterobacter/isolation & purification , Klebsiella pneumoniae/classification , Klebsiella pneumoniae/genetics , Klebsiella pneumoniae/isolation & purification , Polymyxin B/pharmacology
Braz. j. microbiol ; 48(3): 493-498, July-Sept. 2017. tab, graf
Article in English | LILACS | ID: biblio-889153


Abstract Carbapenems are considered last-line agents for the treatment of serious infections caused by Klebsiella pneumoniae, and this microorganism may exhibit resistance to β-lactam antibiotics due to different mechanisms of resistance. We evaluated 27 isolates of K. pneumoniae resistant to carbapenems recovered from inpatients at the University Hospital of Santa Maria-RS from July 2013 to August 2014. We carried out antimicrobial susceptibility, carbapenemase detection, testing for the presence of efflux pump by broth microdilution and loss of porin by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Genetic similarity was evaluated by ERIC-PCR. High levels of resistance were verified by the minimum inhibitory concentration for the antimicrobials tested. The blaKPC gene was present in 89% of the clinical isolates. Blue-Carba and combined disk with AFB tests showed 100% concordance, while the combined disk test with EDTA showed a high number of false-positives (48%) compared with the gold-standard genotypic test. Four isolates showed a phenotypic resistance profile consistent with the overexpression of the efflux pump, and all clinical isolates had lost one or both porins. The ERIC-PCR dendrogram demonstrated the presence of nine clusters. The main mechanism of resistance to carbapenems found in the assessed isolates was the presence of the blaKPC gene.

Humans , Anti-Bacterial Agents/pharmacology , Carbapenems/pharmacology , Klebsiella Infections/microbiology , Klebsiella pneumoniae/drug effects , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Drug Resistance, Bacterial , Klebsiella pneumoniae/genetics , Klebsiella pneumoniae/isolation & purification , Klebsiella pneumoniae/metabolism , Microbial Sensitivity Tests
Rev. Soc. Bras. Med. Trop ; 50(3): 321-328, May-June 2017. tab, graf
Article in English | LILACS | ID: biblio-896978


Abstract INTRODUCTION: Infections caused by β-lactamase-producing gram-negative bacteria, such as Klebsiella pneumoniae, are increasing globally with high morbidity and mortality. The aim of the current study was to determine antimicrobial susceptibility patterns and the prevalence of antibiotic resistance genes (β-lactamase and integron genes) using multiplex PCR. METHODS One-hundred K. pneumoniae isolates were collected from different clinical samples. Antibiotic susceptibility testing was performed with thirteen different antibiotics. Multiplex-PCR was used to detect β-lactamase (bla TEM, bla CTX-M, bla SHV , bla VEB, bla PER, bla GES, bla VIM, bla IMP, bla OXA, and bla KPC) and integron genes (int I, int II, and int III). RESULTS: The highest and lowest rate of resistance was exhibited against amikacin (93%) and imipenem (8%), respectively. The frequency of β-lactamase-positive K. pneumoniae was 37%, and the prevalence of the bla TEM, bla CTX-M, bla SHV , bla VEB, bla PER, bla GES, bla VIM, bla IMP, bla OXA, and bla KPC genes was 38%, 24%, 19%, 12%, 6%, 11%, 33%, 0%, 28%, and 23%, respectively. Of the 100 isolates, eight (8%) were positive for class I integrons; however, class II and III integrons were not detected in any of the strains. CONCLUSIONS: These results indicate co-carriage of a number of β-lactamase genes and antibiotic resistance integrons on the same plasmids harboring multi-drug resistance genes. It seems that these properties help to decrease treatment complications due to resistant bacterial infections by rapid detection, infection-control programs and prevention of transmission of drug resistance.

Humans , beta-Lactamases/genetics , Drug Resistance, Bacterial/genetics , Integrons/genetics , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/genetics , Klebsiella Infections/microbiology , DNA, Bacterial/genetics , Microbial Sensitivity Tests , Cross-Sectional Studies , Multiplex Polymerase Chain Reaction , Klebsiella pneumoniae/isolation & purification , Anti-Bacterial Agents/pharmacology
Rev. chil. infectol ; 33(5): 519-523, oct. 2016. ilus, graf, tab
Article in Spanish | LILACS | ID: biblio-844403


In order to study the clonal relationship and blaKPC gene detection in clinical isolates of Klebsiella pneumoniae resistant to carbapenems, we analyzed 22 clinical isolates of K. pneumoniae with resistance to imipenem and/ or meropenem, isolated in the laboratory of bacteriology at the University Hospital "Antonio Patricio de Alcalá" (HUAPA) from the Cumana city, Sucre state, Venezuela, for a period of five consecutive years. Susceptibility to different antimicrobials was determined, and the presence of carbapenemases was detected by modified Hodge method, phenyl boronic acid synergy and combination discs. blaKPC gene detection was conducted by polymerase chain reaction and the clonal relationship was determined by pulsed field electrophoresis. High rates of antimicrobial resistance were found, five strains were negative, at least one phenotypic method, and all carried the blaKPC gene. Clonal spread was observed only in the intensive care unit (ICU), while in other services, polyclonality was found. We concluded that blaKPC gene is present in K. pneumoniae strains resistant to carbapenems isolated in the HUAPA and clonal spread it was only in the ICU.

Con el objetivo de estudiar la relación clonal y detección del gen blaKPC en aislados clínicos de Klebsiella pneumoniae resistentes a carbapenémicos, se analizaron 22 cepas clínicas de K. pneumoniae con resistencia a imipenem y/o meropenem, aisladas en el laboratorio de bacteriología del Hospital Universitario "Antonio patricio de Alcalá" (HUAPA) de la ciudad de cumaná, Estado Sucre, Venezuela, durante un período de cinco años continuos. Se determinó la susceptibilidad a diversos antimicrobianos, y se detectó la presencia de carbapenemasas por los métodos de Hodge modificado, sinergia con ácido fenil borónico y combinación de discos. La detección del gen blaKPC se llevó a cabo mediante la técnica de reacción de polimerasa en cadena y la determinación de la relación clonal se realizó por electroforesis de campo pulsado. Se encontraron elevados porcentajes de resistencia antimicrobiana, cinco cepas resultaron negativas, al menos, a un método fenotípico y todas portaban el gen blaKPC. Se observó diseminación de clones únicamente en la Unidad de cuidados Intensivos (UCI), mientras que, en otros servicios, se halló policlonalidad. Se concluye que el gen blaKPC se encuentra presente en cepas de K. pneumoniae resistentes a carbapenémicos aisladas en el HUAPA y que hubo diseminación clonal sólo en UCI.

Humans , beta-Lactamases/genetics , Klebsiella Infections/microbiology , Carbapenems/pharmacology , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/genetics , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Venezuela , DNA, Bacterial/genetics , Microbial Sensitivity Tests , Polymerase Chain Reaction , Electrophoresis, Gel, Pulsed-Field , Clone Cells
Rev. Soc. Bras. Med. Trop ; 49(4): 441-445, July-Aug. 2016. tab, graf
Article in English | LILACS | ID: lil-792801


Abstract: INTRODUCTION: Extended-spectrum beta-lactamases (ESBLs) are bacterial enzymes capable of hydrolyzing beta-lactams. The aim of this study was to describe the prevalence of TEM- and SHV-type ESBL-producing Klebsiella pneumoniae strains in Zahedan, Southeast Iran. METHODS: A total of 170 non-repetitive K. pneumoniae strains were collected from patients referred to three teaching hospitals of Zahedan. Antibiotic susceptibility testing was determined for 17 antibiotics using the Kirby-Bauer disc diffusion method. The frequency of ESBL-producing strains was calculated, and minimum inhibitory concentrations of ESBL-producing strains were determined for cefotaxime, ceftazidime, ceftriaxone, and cefpodoxime. The presence of bla TEM and bla SHV genes was tested in all ESBL-producing strains using polymerase chain reaction and DNA sequencing. RESULTS: Among the 170 K. pneumoniae clinical isolates, 55 (32.4%) were ESBL producers; 92.7% (n=51) and 72.7% (n=40) of the isolates carried the bla SHV and bla TEM genes, respectively, and 67.3% (n=37) carried both genes. The sequencing results showed that all bla TEM types were bla TEM-1, except for two isolates that were bla TEM-104. The bla SHV types were bla SHV-1, bla SHV-11, bla SHV-12, bla SHV-99, bla SHV-108, and bla SHV-110. CONCLUSIONS: The percentage of bla TEM and bla SHV among ESBL-producing K. pneumoniae isolates from Zahedan is relatively high, indicating the need for further surveillance and consideration in antibiotic use. To the best of our knowledge, this is the first report of TEM-104-, SHV-99-, SHV-108-, and SHV-110-type ESBLs among clinical isolates of K. pneumoniae from Iran, and TEM-1, SHV-1, SHV-11, and SHV-12 appear to be the dominant ESBLs in this region.

Humans , Bacterial Proteins/genetics , beta-Lactamases/biosynthesis , DNA, Bacterial/genetics , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/genetics , Anti-Bacterial Agents/pharmacology , Phenotype , Klebsiella Infections/microbiology , Sequence Analysis, DNA , Drug Resistance, Multiple, Bacterial/genetics , Disk Diffusion Antimicrobial Tests , Genes, Bacterial , Genotype , Iran
Braz. j. microbiol ; 46(3): 759-768, July-Sept. 2015. tab, ilus
Article in English | LILACS | ID: lil-755835


Klebsiella pneumoniae is an important cause of healthcare-associated infections worldwide. Selective pressure, the extensive use of antibiotics, and the conjugational transmission of antibiotic resistance genes across bacterial species and genera facilitate the emergence of multidrug-resistant (MDR) K. pneumoniae. Here, we examined the occurrence, phenotypes and genetic features of MDR K. pneumoniae isolated from patients in intensive care units (ICUs) at the First Affiliated Hospital of Xiamen University in Xiamen, China, from January to December 2011. Thirty-eight MDR K. pneumoniae strains were collected. These MDR K. pneumoniae isolates possessed at least seven antibiotic resistance determinants, which contribute to the high-level resistance of these bacteria to aminoglycosides, macrolides, quinolones and β-lactams. Among these isolates, 24 strains were extended-spectrum β-lactamase (ESBL) producers, 2 strains were AmpC producers, and 12 strains were both ESBL and AmpC producers. The 38 MDR isolates also contained class I (28/38) and class II integrons (10/38). All 28 class I-positive isolates contained aacC1, aacC4, orfX, orfX’ and aadA1 genes. β-lactam resistance was conferred through blaSHV (22/38), blaTEM (10/38), and blaCTX-M (7/38). The highly conserved blaKPC-2 (37/38) and blaOXA-23(1/38) alleles were responsible for carbapenem resistance, and a gyrAsite mutation (27/38) and the plasmid-mediated qnrB gene (13/38) were responsible for quinolone resistance. Repetitive-sequence-based PCR (REP-PCR) fingerprinting of these MDR strains revealed the presence of five groups and sixteen patterns. ...

Humans , Cross Infection/microbiology , Drug Resistance, Multiple, Bacterial/genetics , Klebsiella Infections/drug therapy , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/isolation & purification , Aminoglycosides/therapeutic use , Bacterial Proteins/genetics , China , Carbapenems/therapeutic use , DNA, Bacterial/genetics , Intensive Care Units , Klebsiella Infections/microbiology , Klebsiella pneumoniae/genetics , Microbial Sensitivity Tests , Plasmids/genetics , Quinolones/therapeutic use , beta-Lactam Resistance/genetics , beta-Lactamases/genetics